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An overview of the recent operations and the main results of cesium injection in the Source for the Production of Ions of Deuterium Extracted from Rf plasma (SPIDER) negative ion source are described in this contribution. In experiments without cesium injection, all SPIDER plants were tested to verify the basic expectations on the operational parameters (e.g., electron cooling effectiveness of magnetic filter field) and to determine its operational region. For beam properties, it was shown that the current density varies across the beam in the vertical direction. In preliminary cesium experiments, the expected increase of negative ion current and simultaneous decrease of co-extracted electrons were found, along with the influence of the control parameters (polarization of the plasma electrodes, magnetic filter field) on the SPIDER beam uniformity in the horizontal and vertical directions. It was shown that non-Gaussian tails can be identified in the angular distribution on the plane perpendicular to the beam propagation direction. Stray particles, nonhomogeneous beam and large divergence might result in unexpected heat and particle loads over ITER neutral beam injector (NBI) accelerator grids; it is the goal of SPIDER to assess and possibly to identify suitable methods for controlling these beam features. A major shutdown, planned for late 2021, to solve the issues identified during the operation and to carry out scheduled modifications, is outlined. Such improvements are expected to allow SPIDER to pursue the ITER requirements in terms of negative ion current, electron-to-ion ratio, and beam duration.

Two different low energy proton (LEP) test methods, one with quasi-monoenergetic and the other with very wide proton beam energy spectra, have been studied. The two test methodologies have been applied to devices that were suggested from prior heavy-ion tests to be sensitive to proton direct ionization (PDI). The advantages and disadvantages of the two test methods are discussed. The test method using quasi-monoenergetic beams requires device preparation and high energy resolution beams, but delivers results that can be interpreted directly and can be used in various soft error rate (SER) calculation methods. The other method, using a heavily degraded high energy proton beam, requires little to no device preparation but more efforts on the beam characterization, and is confined to a specific SER method. While both methods deliver comparable estimates on the SER, the relatively complex determination of the beam characteristics in the degraded beam method makes it less straightforward to use. This work furthers presents a method to extract PDI sensitive volume parameters from degraded high energy proton beam cross-section data. This method extends the use of a previously published method to the degraded high energy beam LEP testing method. peerReviewed

Re-irradiation with X-rays and particle beams can be used to treat localized recurrence of unresectable head and neck cancer after initial irradiation therapy. However, re-irradiation therapy increases the risk of severe and late sequelae by 4-to 8-fold. It can also result in fatal outcomes, such as rupture of the carotid artery and cerebral necrosis or abscess. A 41-year-old woman was diagnosed with squamous cell carcinoma of the external auditory canal. The patient was initially treated with X-ray irradiation. However, the patient underwent re-irradiation with heavy particle beams and neutron rays for a recurrent tumor. The patient developed necrosis of the skull base involving the facial skin and temporal bone 2 months after the last session of re-irradiation therapy. The tissue in the parapharyngeal and masticatory regions also became completely necrotic, resulting in extensive exposure of the brain parenchyma. Although the patient underwent conservative and surgical treatment, necrosis of the tissue progressed, and a large part of the brain was exposed. Approximately 2.5 years later, although the brain is still exposed, the patient is alive without disease. Although the tumor had subsided and long-term survival was achieved, our patient developed serious osteoradionecrosis of the skull base with extensive brain exposure. For patients who are not candidates for surgery, re-irradiation alone is an option, albeit with poor prospects. This approach should be discussed with the patient while balancing the potential survival gain against the burden of treatment and the risk of complications.

The correct quantification of the dose released in charged particle therapy treatments requires the knowledge of the double differential fragmentation cross section of particles composing both the beam and the target. The FragmentatiOn Of Target (FOOT) experiment aims at measuring these cross sections for ions of interest for charged particle therapy applications. This article describes the performance of the time-of-flight (TOF)-wall detector of the experiment. The detector is composed of two layers of 44 cm $\times 2$ cm $\times 3$ mm plastic scintillator bars (20 for each layer), arranged orthogonally and read-out by silicon photomultipliers. The detector is designed to identify the charge of fragments ranging from protons to oxygen ions, with a maximum energy of 700 MeV/u, by measuring the energy released in the scintillators and the TOF with respect to a start counter. In this study, the detector was scanned with carbon ions of energy between 115 and 400 MeV/u and with a 60-MeV proton beam. The measurements show an energy resolution ( $\sigma _{E}/\mu _{E}$ ) between 6% and 4% and a contribution of the detector to the TOF system time resolution between 25 and 20 ps (standard deviation) for carbon ions and between 100 and 80 ps for protons.

Trabajo de fin de Grado. Grado en Física. Curso académico 2021-2022., [ES]En las últimas décadas se han producido numerosos avances orientados a la consecución de nuevos esquemas de aceleración que permitan obtener energías superiores a las que se consiguen en los aceleradores de partículas convencionales, así como conse guir que los nuevos esquemas tengan unas dimensiones más compactas y un coste de producción menor que dichos montajes clásicos. Entre todos los esquemas propuestos, el más prometedor fue aquel en el que se proponía utilizar pulsos láser para excitar ondas en un plasma, las cuales darían lugar a campos electromagnéticos capaces de acelerar partículas hasta energías del orden de GeV. Esta idea dio lugar al desarrollo del LWFA (Laser Wakefield Accelerator). La idea de emplear un plasma como medio acelerador dio lugar a otros esquemas, entre los cuales destaca la utilización de haces de partículas, en vez de pulsos láser, para excitar el campo acelerador en el plasma. Este método dio lugar al llamado PWFA (Plasma Wakefield Accelerator). A lo largo de los sucesivos capítulos que conforman este Trabajo de Fin de Grado se explicarán las características de funcionamiento del LWFA y PWFA, así como de los nuevos aceleradores híbridos formados por ambos esquemas y se hará una puesta al día de los avances en dichos aceleradores., [EN]In recent decades, there have been numerous advances aimed at achieving new acceleration schemes that allow to obtain higher energies than those achieved in conventional particle accelerators, as well as making the new schemes more compact in size and much cheaper than the classical set-ups. Among all the proposed schemes, the most promising was the one that proposed to use laser pulses to excite waves in a plasma, which would generate electromagnetic fields capable of accelerating particles up to energies of the order of GeV. This idea gave rise to the development of the LWFA (Laser Wakefield Accelerator). The idea of using a plasma as the accelerator medium gave rise to other schemes, among them it stands out the use of particle beams, instead of laser pulses, to excite the accelerator field in the plasma. This method gave rise to the so-called PWFA (Plasma Wakefield Accele rator). Throughout the successive chapters that make up this work, the operating characteristics of the LWFA and PWFA, as well as the new hybrid accelerators formed by both schemes, will be explained and an update on the progress of these accelerators will be provided

The very limited availability of fast neutron facilities, particularly in Europe, for testing of microelectronics has motivated the construction of ChipIr, a new beamline at the ISIS neutron and muon source in the UK. ChipIr has been designed for Single Event Effect testing at the device-level, board-level and system-level which requires a beam of uniform intensity over a selectable area in the order of hundreds of ${\text{cm}}^{2}$ cm 2 . Measurements of the beam uniformity are presented in this paper. A memory chip of interest for space applications, based on SRAMs and developed by ESA for monitoring of radiation fields, has been used for a comparative characterization of the beam. Consistent results have been found, giving confidence on the intensity and shape of the fast neutron spectrum of ChipIr.

Mini-EUSO is a telescope launched on board the International Space Station in 2019 and currently located in the Russian section of the station. Main scientific objectives of the mission are the search for nuclearites and Strange Quark Matter, the study of atmospheric phenomena such as Transient Luminous Events, meteors and meteoroids, the observation of sea bioluminescence and of artificial satellites and man-made space debris. It is also capable of observing Extensive Air Showers generated by Ultra-High Energy Cosmic Rays with an energy above 1021 eV and detect artificial showers generated with lasers from the ground. Mini-EUSO can map the night-time Earth in the UV range (290 - 430 nm), with a spatial resolution of about 6.3 km and a temporal resolution of 2.5 μs, observing our planet through a nadir-facing UV-transparent window in the Russian Zvezda module. The instrument, launched on 2019/08/22 from the Baikonur cosmodrome, is based on an optical system employing two Fresnel lenses and a focal surface composed of 36 Multi-Anode Photomultiplier tubes, 64 channels each, for a total of 2304 channels with single photon counting sensitivity and an overall field of view of 44◦. Mini-EUSO also contains two ancillary cameras to complement measurements in the near infrared and visible ranges. In this paper we describe the detector and present the various phenomena observed in the first year of operation., PoS: Proceedings of Science, 395, ISSN:1824-8039, Proceedings of 37th International Cosmic Ray Conference

Single-photon sources have a variety of applications. One of these is quantum radiometry, which is reported on in this paper in the form of an overview, specifically of the current state of the art in the application of deterministic single photon sources to the calibration of single photon detectors. To optimize single-photon sources for this purpose, extensive research is currently carried out at the European National Metrology Institutes (NMIs), in collaboration with partners from universities. Single-photon sources of different types are currently under investigation, including sources based on defect centres in (nano-)diamonds, on molecules and on semiconductor quantum dots. We will present, summarise, and compare the current results obtained at European NMIs for single-photon sources in terms of photon flux, single-photon purity, and spectral power distribution as well as the results of single-photon detector calibrations carried out with this type of light sources.

Intensity-modulated radiotherapy (IMRT) is one of the most popular techniques for cancer treatment. However, existing IMRT planning methods can only generate one solution at a time and, consequently, medical physicists should perform the planning process many times to obtain diverse solutions to meet the requirement of a clinical case. Meanwhile, multiobjective evolutionary algorithms (MOEAs) have not been fully exploited in IMRT planning since they are ineffective in optimizing the large number of discrete variables of IMRT. To bridge the gap, this article formulates IMRT planning into a large-scale combinatorial many-objective optimization problem and proposes a coevolutionary algorithm to solve it. In contrast to the existing MOEAs handling high-dimensional search spaces via variable grouping or dimensionality reduction, the proposed algorithm evolves one population with fine encoding for local exploitation and evolves another population with rough encoding for global exploration. Moreover, the convergence speed is further accelerated by two customized local search strategies. The experimental results verify that the proposed algorithm outperforms state-of-the-art MOEAs and IMRT planning methods on a variety of clinical cases.

The Divertor Tokamak Test facility (DTT) will be a new experimental facility located at Frascati, Rome, Italy, whose main goal will be to have a better understanding on hot plasma interactions with plasma-facing components (PFCs) and aid in the development of ITER and successively DEMO. The improved conceptual design of the beamline for the DTT neutral beam heating (NBH) system is here overviewed, with a particular focus on the technical solutions adopted to fulfill the requirements and maximize beamline performances. The proposed system features a beamline providing deuterium neutrals (D⁰) with an energy of 510 keV and an injected power of 10 MW. Various design options have been considered, and a comprehensive set of simulations has been carried out using several physics and engineering codes to drive the choice of the most suitable design options and optimize them, aiming at finding a good compromise among different design requirements.

International audience; Dark Count Rate (DCR) in Single-Photon Avalanche Diodes (SPAD) in Complementary Metal-Oxide Semiconductor technology is characterized and analyzed with a comprehensive simulation methodology. Based on a series of measurements of SPAD with various architectures, on an extended range of voltages and temperatures, the DCR measurements are correlated to the spatial localization of traps within the device and their parameters. To this aim, process and electrical simulations using Technology Computer-Aided Design (TCAD) tools are combined with an in-house McIntyre solver to compute the breakdown probability (Pt). The traps are accounted for using thermal SRH carrier generation-recombination mechanism which is coupled with the position-dependent breakdown probability. This rigorous methodology makes it possible to directly compare with DCR measurements, since only generated carriers with a non-negligible breakdown probability are considered

The availability of reliable analytical models is essential to the optimal design of energy harvesters and for the prediction of the system behavior. In this paper, we consider a low-input nonlinear system based on a flexible buckled beam forced in a bistable configuration. The harvester has been demonstrated to generate power in the excess of $400~\mu \text{W}$ with the optimal resistive load of 15 $\text{k}\Omega $ and a monotonic input with root-mean-square accelerations of 13.35 m/s2. The power generated is suitable for powering low-power measurement systems or sensor nodes. This paper focuses on a methodology for the modeling of the mechanical dynamical behavior of the device subject to a periodic impulsive signal. A measurement protocol for the evaluation of system’s hidden quantities, the beam’s restoring force, and the beam’s displacement between its stable states is introduced. A second-order behavioral model with a nonlinear term representing the beam’s restoring force has been used. In order to model the nonlinearity, two different potential energy functions have been compared by fitting the models to the experimental data with different constrains, through a performance index evaluating the fitting error.

The far-field patterns of atoms diffracted from a classical light field, or from a quantum one in a photon-number state are identical. On the other hand, diffraction from a field in a coherent state, which shares many properties with classical light, displays a completely different behavior. We show that in contrast to the diffraction patterns, the interference signal of an atom interferometer with light-pulse beam splitters and mirrors in intense coherent states does approach the limit of classical fields. However, low photon numbers reveal the granular structure of light, leading to a reduced visibility since Welcher-Weg (which-way) information is encoded into the field. We discuss this effect for a single photon-number state as well as a superposition of two such states., Comment: 9 pages, 3 figures

Quantum theory is the foundation of modern physics. Some of its basic principles, such as Born's rule, however, are based on postulates which require experimental testing. Any deviation from Born's rule would result in higher-order interference and can thus be tested in an experiment. Here, we report on such a test with a quantum light source based on a color center in hexagonal boron nitride (hBN) coupled to a microcavity. Our room temperature photon source features a narrow linewidth, high efficiency, high purity, and on-demand single-photon generation. With the single-photon source we can increase the interferometric sensitivity of our three-path interferometer compared to conventional laser-based light sources by fully suppressing the detector nonlinearity. We thereby obtain a tight bound on the third-order interference term of $3.96(523)\times 10^{-4}$. We also measure an interference visibility of 98.58% for our single-photons emitted from hBN at room temperature, which provides a promising route for using the hBN platform as light source for phase-encoding schemes in quantum key distribution.

New journal of physics 23(3), 031101 (2021). doi:10.1088/1367-2630/abcc62, Plasma-based accelerators use the strong electromagnetic fields that can be supported by plasmas to accelerate charged particles to high energies. Accelerating field structures in plasma can be generated by powerful laser pulses or charged particle beams. This research field has recently transitioned from involving a few small-scale efforts to the development of national and international networks of scientists supported by substantial investment in large-scale research infrastructure. In this New Journal of Physics 2020 Plasma Accelerator Roadmap, perspectives from experts in this field provide a summary overview of the field and insights into the research needs and developments for an international audience of scientists, including graduate students and researchers entering the field., Published by IOP, [London]

International audience; Design, development, manufacturing, and test activities of the RF power system (RFPS) for Linear IFMIF Prototype Accelerator (LIPAc) were completed in Europe. Installation and commissioning activities were carried out at the International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) site in Rokkasho, Japan. Challenging IFMIF requirements led to a number of innovations during design and development. Commissioning required a major effort on calibration and fine setting and led to development of new functionalities. The RFPS was validated under full power and 125-mA deuteron beam loading conditions, in the radio frequency quadrupole (RFQ), demonstrating good performance. This article is an overview about how technical challenges impacted the prototype RFPS design and its functional evolution during commissioning, cavity conditioning, and beam operation of the RFQ.

The main purpose of the Divertor Tokamak Test (DTT) facility is to study alternative solutions to mitigate the issue of power exhaust under integrated physics and technical conditions relevant for an International Thermonuclear Experimental Reactor (ITER) and a DEMOnstration Power Plant (DEMO). DTT will be equipped with a 510-keV, 40-A neutral beam injector (NBI) based on negative deuterium ion particles, designed to yield about 10 MW of neutral power to the DTT tokamak. The strongly triangular shape of the beam and the ITER-like multifocusing strategy required a different approach than more conventional solutions in designing the electrostatic plates in order to guarantee the desired beam deflection. This article describes the performance optimization process carried out for the injector of the DTT NBI system. In particular, a new electrostatic design concept for the accelerator grids has been implemented, the hyperlens grids (HGs): additional grids with a lens-like profile, imparting to each separate beamlet the necessary exit deflection without shape deformation.

Neutrons with energies between 0.1-10 MeV can significantly impact the Soft Error Rate (SER) in SRAMs manufactured in scaled technologies, with respect to high-energy neutrons. Their contribution is evaluated in accelerator, ground level and avionic (12 km of altitude) environments. Experimental cross sections were measured with monoenergetic neutrons from 144 keV to 17 MeV, and results benchmarked with Monte Carlo simulations. It was found that even 144 keV neutrons can induce upsets due to elastic scattering. Moreover, neutrons in the 0.1-10 MeV energy range can induce more than 60% of the overall upset rate in accelerator applications, while their contribution can exceed 18% in avionics. The SER due to neutrons below 3 MeV, whose contribution has always been considered negligible, is found to be up to 44% of the total upsets in accelerator environments. These results have strong Radiation Hardness Assurance (RHA) implications for those environments with high fluxes of neutrons in the 0.1-10 MeV energy range. peerReviewed

The Neutral Beam Test Facility (NBTF) was built at Consorzio RFX (Padova, Italy) to carry out dedicated experiments with the specific purpose of pursuing the requirements of ITER neutral beam injectors. The SPIDER experiment, which is part of the NBTF program, is devoted to the study and optimization of the ion source of the ITER injectors. The present contribution describes the operation of a fixed triple Langmuir probe, which has been recently installed in SPIDER for the investigation of the source plasma. Indeed, this diagnostic is able to measure the time evolution of the main plasma features for the entire duration of the plasma discharge, allowing the correlation between plasma properties, such as density, electron temperature and plasma potential, and source parameters, i.e. filter field intensity, RF power and bias voltages. Furthermore, the capability of the triple probe arrangement of measuring the instantaneous plasma density and electron temperature (also at high frequency) has been exploited to investigate a modulation of plasma parameters, which emerged while operating SPIDER either with multiple generators or with a single generator at low power and with high filter field. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.

It has long been known that the ellipse normally used to model the phase space extension of a beam in linear dynamics may be represented by a complex number which can be interpreted similar to a complex impedance in electrical circuits, so that classical electrical methods might be used for the design of such beam transport lines. However, this method has never been fully developed, and only the transport transformation of single particular elements, like drift spaces or quadrupoles, has been presented in the past. In this article, we complete the complex formalism of linear beam dynamics by obtaining a general differential equation and solving it, to show that the general transformation of a linear beam line is a complex Moebius transformation. This result opens the possibility of studying the effect of the beam line on complete regions of the complex plane and not only on a single point. Taking advantage of this capability of the formalism, we also obtain an important result in the theory of the transport through a periodic line, proving that the invariant points of the transformation are only a special case of a more general structure of the solution, which are the invariant circles of the one-period transformation. Among other advantages, this provides a new description of the betatron functions beating in case of a mismatched injection in a circular accelerator This work was supported in part by the Ministerio de Asuntos Economicos y Transformacion Digital (MINECO) under Grant DPI2017-82373-R and in part by Universidad del Pais Vasco/Euskal Herriko Univertsitatea (UPV/EHU) under Grant GIU18/196

International audience; On the vertex detector of the International Linear Collider, a large number of hits are generated by the charged particles coming from the beam background. These charged particles produce large angles of incidence and generate elongated clusters. The CMOS pixel sensor (CPS) which would contain on-chip artificial neural networks could tag and remove these clusters to reduce the data flow of the detector system. The clustering procedure is the first step of data preprocessing. The conventional clustering algorithm is not suitable for on-chip integration since it requires sequential and iterative processing. In this article, a 2-D real-time clustering algorithm is proposed. The clustering algorithm is tested by 4500 frames of pixel values (12 bit/pixel) from MIMOSA-18. The clustering algorithm is implemented using Very High-Speed Integrated Circuit Hardware Description Language (VHDL), synthesized for different windows, multiplexers, and analog-to-digital converter (ADC) resolution. Power consumption and the occupied surface of the clustering implementation are presented. This implementation provides a possibility to integrate the clustering procedure into a CPS.

International audience; At the CERN LHC experiments, several gaseous detector technologies are operated in gas recirculation mode to lower operational costs and gas emissions. In the next years, Micro Pattern Gaseous Detector (MPGD) technologies will be largely implemented in the LHC experiments, with dedicated gas systems, and they will experience a significantly increased background radiation rate, especially in the HL-LHC phase. It is therefore fundamental to study MPGD operated with LHC gas systems, especially under gas recirculation, to be able to guarantee their safe long-term operation. In this context, the performance of Gas Electron Multiplier (GEM) detectors operated in gas recirculating systems have been studied at the CERN Gamma Irradiation Facility (GIF++), which provides an intense gamma irradiation along with a Muon beam from the SPS accelerator. Triple-GEM detectors performance has been studied in relation to operation stability during long-term high rate irradiation, as well as in terms of Muon detection efficiency with different gamma background rates. Both tests were realized with various gas mixtures and gas system conditions. A complete overview of the results obtained at the GIF++is presented, showing the successful operation of Triple-GEM detectors during long-term high-rate irradiation and good Muon detection efficiency in HL-like background radiation.

The fabrication of integrated quantum dot (QD)-optical microcavity systems is a requisite step for the realization of a wide range of nanophotonic experiments (and applications) that exploit the ability of QDs to emit nonclassical light, e.g., single photons. Thanks to their ∼20-nm positioning accuracy and to their proven potential for single-photon operation, the QDs obtained by spatially selective hydrogen irradiation of dilute-nitride semiconductors —such as Ga(AsN) and Ga(PN)—are uniquely suited for integration with photonic nanodevices. In the present work, we demonstrate the ability to deterministically integrate single, site-controlled Ga(AsN)/Ga(AsN):H QDs within a photonic crystal (PhC) cavity. The properties of the fabricated QD-PhC cavity systems are then probed by photon correlation—providing clear evidence of single-photon emission—and time-resolved microphotoluminescence spectroscopy. Detailed information on the dynamics of our integrated nanodevices can be inferred by comparing these experiments to the solutions of a rate-equations system, developed by taking into account all the main processes leading to the capture, relaxation, and recombination of carriers in and out of the QD. This allows us to follow the evolution of the relevant recombination rates in our system for varying energy detuning, \(\Delta\)E, between the QD and the PhC cavity. When the QD exciton transition is nearly resonant with the cavity mode, a large (>tenfold) enhancement of the spontaneous emission rate is observed, in substantial agreement with Jaynes-Cummings (JC) theory. For intermediate detunings ( \(\Delta\)E ∼ 1.5–3.5 meV), on the other hand, the observed enhancement is significantly larger than that predicted by JC theory, due to the important role played by acoustic phonons in mediating the QD-PhC cavity coupling in a solid-state environment. Apart from its fundamental interest, the observation of such phonon-mediated, broadband enhancement of light-matter interaction significantly relaxes the requirements for the realization of a large variety of cavity QED-based experiments and applications. These include many photonic devices for which the use of site-controlled Ga(AsN)/Ga(AsN):H QDs would be inherently advantageous, such as those based on the coupling between more than one QD and a single cavity mode (e.g., few-QD nanolasers and QD solids).

In this work, we have investigated the crystalline-size dependence of optical absorption and photoluminescence emission of CH3NH3PbI3 films, which is necessary to identify the potential practical applications of the gadgets based on perovskite films. This study was carried out at low temperatures to minimize the extra complexity induced by thermal effects. The purpose was to clarify the origin of the dual emission peak previously reported in the literature. We found that the grain size is responsible for the appearance or disappearance of this dual emission on CH3NH3PbI3 at low temperatures, whereas we have inferred that the thickness of the perovskite layer is a much more important factor than the size of the grains in the location of the energy of the band gap. Moreover, the increase in the grain size allows slowing down the phase transition. Additionally, we evidence a decrease in the effective Rydberg energy of the exciton in several samples, from 23–25 meV at 7 K to 12–13 meV at 165 K, by fitting to Elliott–Toyozawa theory. We have extracted other important physical parameters of perovskites from the photoluminescence-data deconvolution, such as the band gap, exciton–phonon interaction, and exciton binding energy. A new phase transition at 45.5 K was determined by the temperature dependence of full width at half-maximum and the integrated intensity of the photoluminescence, and it was confirmed by the radiative lifetime obtained from the time-resolved photoluminescence emission by means of time-correlated single-photon counting at different temperatures, excitation fluencies, and emission energies.

Engineers usually test multiple printed circuit boards (PCBs) and integrated circuits (ICs) in the neutron beam to improve the error statistics. The attenuation of an atmospheric-like neutron spectrum by materials commonly used in PCBs is evaluated experimentally and with simulations of the neutron transport. Measurements were performed during neutron irradiation experiments of multiple boards using a beam monitor to correlate simulations with experimental results.

Heating and current drive (H&CD) systems are being investigated for a demonstration fusion power plant DEMO to deliver net electricity for the grid around 2050. Compared to ITER, which has to show the generation of 500-MW thermal power, the target of DEMO is the successful production of 300 to 500 MW electrical power to the grid and to aim for a self-sufficient tritium fuel cycle. Three H&CD systems are under development for DEMO in Europe, the electron cyclotron (EC) system, the neutral beam injection (NBI) system, and the ion cyclotron system. Based on present studies for plasma ramp-up, ramp-down, and flat top phases, to be further validated in more detailed simulations, the assumed total launched power needed from the H&CD system in DEMO is in the range of 50-100 MW, to be provided for plasma heating and control. This paper describes the design and Research and Development status of selected H&CD systems, considered for their deployment in the EU DEMO. It was always considered that different H&CD configurations and design variants will have an impact on the performances for the whole fusion plant. It shall be noted that the basis for the H&CD integrated design and system development is the actual version of the European fusion electricity roadmap. The project also elaborates on H&CD efficiency improvements which will reduce the recirculating power fraction in the future fusion power plants. Different studies under investigation will be discussed such as for NBI the photoneutralization and for EC novel concepts for gyrotron multistage-depressed collector.

Semiconductor quantum dots (QDs) have recently emerged as a leading platform to generate highly indistinguishable photons efficiently, and this work addresses the timely question of how good these solid-state sources can ultimately be. We establish the crucial role of lattice relaxation in these systems in giving rise to trade-offs between indistinguishability and efficiency. We analyse the two source architectures most commonly employed: a QD embedded in a waveguide and a QD coupled to an optical cavity. For waveguides, we demonstrate that the broadband Purcell effect results in a simple inverse relationship, in which indistinguishability and efficiency cannot be simultaneously increased. For cavities, the frequency selectivity of the Purcell enhancement results in a more subtle trade-off, in which indistinguishability and efficiency can be increased simultaneously, although not arbitrarily, which limits a source with near-unity indistinguishability (>99%) to an efficiency of approximately 96% for realistic parameters. The efficiency and indistinguishability of single-photon emission by a quantum dot optically coupled to a microcavity and to a waveguide are theoretically investigated. Owing to unavoidable phonon sideband, they can never reach 100% simultaneously.

Artificial satellites employed as trusted nodes can increase the distance between two parties to establish quantum key distribution (QKD), unlike fiber based communication lines that are limited up to a few hundred kilometers. This report summarises our progress on a ground receiver for satellite QKD and its tracking receiving system (TRS). The authors demonstrate the operation of the TRS in practice and achieve standard tracking error of 1.4/Ltrad observing four satellites over 80% of the time they were available. The optical signal, which was the sunlight reflected of low Earth orbit satellites, was attenuated to a single photon level and was detected effectively using avalanche single photon detectors. The authors have thus proved that the developed system is capable of stable reception of quantum signal from a satellite. © Published under licence by IOP Publishing Ltd. This work is supported by Russian Science Foundation (grant No. 17-71-20146).

Энерго- и масс-анализ используется в решении многих задач. В последнее время в качестве фиксирующих спектры устройств все чаще используются спектрографы. Целью данной работы является рассмотрение фокусирующих свойств магнитных полей особого класса, которые смогут использоваться для создания эффективного энергоанализатора, сконструированного на базе неоднородных магнитных полей и осуществляющего спектрографический режим работы. В ходе работы было рассмотрено движение пучков заряженных частиц в неоднородных магнитных полях, задаваемых как однородные по Л. Эйлеру функции. Были построены траектории движения частиц в таких полях в зависимости от оптимального режима запуска пучка частиц. Для всех конфигураций полей были найдены основные характеристики, определяющие их свойства, в том числе размер пятна каждого моноэнергетичного пучка, разрешение по энергии и дисперсия. Все рассмотренные конфигурации позволяют реализовать спектрографический режим, что демонстрируют многочисленные моделирования движения частиц (электронов) и траекторные потоки, представленные в данной работе., Energy and mass analysis is used to solve different tasks. Nowadays spectrographs have been increasingly applied as spectrum recording devices. The aim of this work is to consider the focusing properties of magnetic fields of a special class that can be used to create an effective energy analyzer designed on inhomogeneous magnetic fields and performing a spectrographic mode of operation. It is investigated the motion of charged particle beams in inhomogeneous magnetic fields, defined as homogeneous in Euler’s sense functions. The trajectories of particle motion in such fields were counted and the optimal modes were defined. For all field configurations, the main characteristics that determine their properties were found, including the spot size of each monoenergetic beam, energy resolution and energy dispersion. All the considered configurations allow us to implement a spectrographic mode, which is demonstrated by numerous simulations of the movement of particles (electrons) and trajectory flows presented in this work.

International audience; The pion resonance in the nuclear reaction cross section is seen to have a direct impact on the single-event effect (SEE) cross section of modern electronic devices. This was experimentally observed for single-event upsets and single-event latchup. Rectangular parallelepiped (RPP) models built to fit proton data confirm the existence of the pion SEE cross-section resonance. The impact on current radiation hardness assurance (RHA) soft error rate (SER) predictions is, however, minimal for the accelerator environment since this is dominated by high neutron fluxes. The resonance is not seen to have a major impact on the high-energy hadron equivalence approximation established for testing in mixed-field facilities.

Turkish Accelerator Center (TAC) Proton Accelerator Facility (PAF) is a project proposal that aims to build a megawatt (MW) power proton accelerator in Turkey. The proton source of this project was chosen as a microwave discharge ion source due to its long life time, its high current, and its lower maintenance requirements when compared with other ion source types. A microwave discharge ion source test stand was built to gain experience for TAC PAF and for similar projects requiring high beam current in Turkey. A magnetron with 2.45-GHz frequency, 50-Hz repetition rate, and 150-W fixed power was used to create the hydrogen plasma. Two different electrode systems were experimented: the first design consists of 2-mm radius plasma electrode that extracts beam currents up to 0.75 mA and the second design consists of 4-mm radius plasma electrode that extracts beam currents up to 5.2 mA.

Induced photon correlations are directly demonstrated by exploring two coupled nonlinear processes in an integrated device. Using orthogonally polarized modes within an integrated microring cavity, phase matching of two different nonlinear four-wave mixing processes is achieved simultaneously, wherein both processes share one target frequency mode, while their other frequency modes differ. The overlap of these modes leads to the coupling of both nonlinear processes, producing photon correlations. The nature of this process is confirmed by means of time- and power-dependent photon correlation measurements. These findings are relevant to the fundamental understanding of spontaneous parametric effects as well as single-photon-induced processes, and their effect on optical quantum state generation and control. © 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

International audience; With the aim to build a real-time controlled time-of-flight Compton camera for an improved ion-range dose delivery control on hadrontherapy, as defined by the CLaRyS collaboration project, a programming data acquisition and slow control back-end electronics is necessary. This paper presents the FPGA based firmware architecture, embedded software and associated tools for the back-end electronics of CLaRyS, that is able to provide multiple 3 Gb/s optical links for data acquisition, trigger distribution and slow control over its detectors. Performance of the system based on simulations and analysis of the results acquired during the characterization of a beam hodoscope will be presented. Experiments were performed with the 65 MeV proton beam of the medical cyclotron at the Mediterranean Protontherapy Institute, in Nice.

International audience; A collimated gamma camera consisting of a multi-parallel slit collimator and an absorber has been proposed to be coupled with a beam hodoscope for ion-range verification during hadrontherapy by means of Prompt Gamma (PG) detection. The beam hodoscope associated to this gamma camera provides information on the incident ion position and arrival time to improve the PG image reconstruction and time-of-fight measurement. The data acquisition (DAQ) system of this detection system has been designed to meet the specifications: 1 µs trigger delay, timing resolution < 1 ns, 100 kHz trigger rate and a few 108 bits/s final data rate. It consists of 8 frond-end (FE) readout boards of two types: 2 boards for the hodoscope and 6 boards for the absorber. These FE boards have the same basic structure, consisting of a FPGA, an optical transceiver and a multi-channel analog readout module. The main difference between the two types of FE boards is that the former incorporates two 32-channel readout ASICs, and the latter employs 8-channel DRS4 (Domino Ring Sampling) mezzanines (3 for each board). In addition the system also includes a data-communication module, mainly composed of a data transmission control board called AMC40 which has a 1-Gbit/s Ethernet link for PC connection and 36 available 3 Gbit/s optical links to FE readout boards. On the other hand, we have developed the firmware of every FE board FPGA to realize several multi-phase clock time-to-digital (TDC) convertors: one for the system synchronization and the others for particle’s arrival time tagging. For the 2 hodoscope FE boards, FPGA firmware implementation includes an adjustable-depth measured-data buffer, an histogram-based fast time-of-flight estimation, coincidence-event searching and data zero-suppression. Our designed DAQ system has recently been tested successfully with a reduced-size collimated camera configuration coupled with the beam hodoscope in the Mediterranean proton therapy Institute in Nice (France).

This paper discusses the properties of electron beams formed in plasma wakefield accelerators through ionization injection. In particular, the potential for generating a beam composed of co-located multi-colour beamlets is demonstrated in the case where the ionization is initiated by the evolving charge field of the drive beam itself. The physics of the processes of ionization and injection are explored through OSIRIS simulations. Experimental evidence showing similar features are presented from the data obtained in the E217 experiment at the FACET facility of the SLAC National Laboratory. This article is part of the Theo Murphy meeting issue ‘Directions in particle beam-driven plasma wakefield acceleration’.

International audience; The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5 MW, 2 GeV superconducting proton linac. Among other beam instrumentation systems, this high intensity linac requires a Beam Loss Monitoring (BLM) system. An important function of the BLM system is to protect the linac from beam-induced damage by detecting unacceptably high beam loss and promptly inhibiting beam production. In addition to protection functionality, the system is expected to provide the means to monitor the beam losses during all modes of operation with the aim to avoid excessive machine activation. This paper focuses on the FPGA implementation of the real-time data processing in the nBLM system and presents preliminary result of a prototype system installed at LINAC4 at CERN.

International audience; Superconducting coplanar-waveguide resonators that can operate in strong magnetic fields are important tools for a variety of high-frequency superconducting devices. Magnetic fields degrade resonator performance by creating Abrikosov vortices that cause resistive losses and frequency fluctuations or suppress the superconductivity entirely. To mitigate these effects, we investigate lithographically defined artificial defects in resonators fabricated from Nb-TiN superconducting films. We show that by controlling the vor-tex dynamics, the quality factor of resonators in perpendicular magnetic fields can be greatly enhanced. Coupled with the restriction of the device geometry to enhance the superconductors critical field, we demonstrate stable resonances that retain quality factors 10 5 at the single-photon power level in perpendicular magnetic fields up to B ⊥ 20 mT and parallel magnetic fields up to B 6 T. We demonstrate the effectiveness of this technique for hybrid systems by integrating an In-Sb nanowire into a field-resilient superconducting resonator and use it to perform fast charge readout of a gate-defined double quantum dot at B = 1 T.

Myocardial perfusion imaging (MIP) with single photon emission computer tomography is one of the most accurate procedures for the detection of coronary artery disease. Tissue attenuation artifacts are a significant limitation of MIP, especially in obese patients. CT-based attenuation correction (AC) is widely used to undermine these artifacts. The objective of this study was to evaluate the influence of an adipose tissue equivalent in the total myocardial counts after AC in SPECT/CT imaging. To accomplish this a Heart Thorax Phantom was filled with 99mTcO 4 -(simulating the uptake of 99mTc-Tetrofosmin in the cardiac walls and liver) for SPECT/CT imaging using an additional layer of 100% lipid fat and a torso phantom. The acquired data was reconstructed with Filtered Back Projection (FBP), iterative algorithms without AC (IRNC) and iterative algorithms with AC (IRAC) for posterior evaluation of total cardiac wall counts (Anterior, Inferior, Lateral and Septal). There was a significant reduction in total mean counts of the lateral and septal walls, with the addition of a layer of fat and the torso phantom, when FBP and IRNC reconstructions were applied (p ≤0,05) which may have been caused by tissue attenuation artifacts. The addition of a layer of fat and of the torso phantom, directly increased the total mean counts of the septal, lateral and inferior walls, when IRAC reconstruction was used (p ≤0,05) suggesting a benefit in the use of AC in larger body habitus. In conclusion the adipose tissue equivalent directly influenced the total myocardium counts when AC methods were applied, and further research is advised.

Well-controlled yet practical systems that give access to interference effects are critical for established and new functionalities in ultrafast signal processing, quantum photonics, optical coherence characterization, etc. Optical fiber systems constitute a central platform for such technologies. However, harnessing optical interference in a versatile and stable manner remains technologically costly and challenging. Here, degrees of freedom native to optical fibers, i.e., polarization and frequency, are used to demonstrate an easily deployable technique for the retrieval and stabilization of the relative phase in fiber interferometric systems. The scheme gives access (without intricate device isolation) to

Superconducting coplanar-waveguide resonators that can operate in strong magnetic fields are important tools for a variety of high-frequency superconducting devices. Magnetic fields degrade resonator performance by creating Abrikosov vortices that cause resistive losses and frequency fluctuations or suppress the superconductivity entirely. To mitigate these effects, we investigate lithographically defined artificial defects in resonators fabricated from Nb-Ti-N superconducting films. We show that by controlling the vortex dynamics, the quality factor of resonators in perpendicular magnetic fields can be greatly enhanced. Coupled with the restriction of the device geometry to enhance the superconductors critical field, we demonstrate stable resonances that retain quality factors ?105 at the single-photon power level in perpendicular magnetic fields up to Bƒ? ?20mT and parallel magnetic fields up to Bƒ ?6T. We demonstrate the effectiveness of this technique for hybrid systems by integrating an In-Sb nanowire into a field-resilient superconducting resonator and use it to perform fast charge readout of a gate-defined double quantum dot at B=1T.

In this paper, a measurement methodology for the characterization of the mechanical and electrical behavior of a nonlinear vibrational harvester is discussed and demonstrated on a real case study. The harvester, here considered, takes advantage of a flexible beam in a snap-through-buckling configuration and a novel magnetic repulsion mechanism to compensate for the asymmetric behavior of the device, in the vertical direction, due to the effect of the proof mass load. A measurement protocol aimed at the device performance estimation in terms of the minimum acceleration, the number of switching events, the output voltage, the generated power, and the mechanical-to-electrical conversion efficiency of the system is discussed. The advantages of the proposed compensation strategy are highlighted by evaluating the device’s performances in the range of frequency 0.5–12 Hz for different tilts applied to the device and compared to the performance of the same device without the repulsion mechanism. The harvester is capable of scavenging energy in the range 0.5–5 Hz with acceptable efficiency; it can, however, be exploited up to 12 Hz with an acceptable loss of efficiency. A power of about $412~\mu \text{W}$ with a root-mean-square acceleration of 10.22 m/s2 at 5 Hz and an efficiency of about 23.5% has been measured for the harvester, with the repulsive mechanism, operated in the vertical position. The power generated is suitable for powering wireless devices.

We demonstrate the strong coupling between a single electron spin in silicon and a single photon in a superconducting microwave cavity. Using the same cavity we perform rapid high-fidelity single-shot readout of two-electron spin states.

openaire: EC/H2020/633053/EU//EUROfusion Heating and current drive systems such as high energy Neutral Beam Injection (NBI) are being considered for pulsed EU DEMO (“DEMO1”) pre-conceptual design. Their aim is to provide auxiliary power, not only during flat-top, but also during transient phases (i.e. plasma current ramp-up and ramp-down). In this work, NBI fast particle power loads on DEMO1 first wall, due to shine-through and orbit losses, are calculated for the diverted plasma ramp-up phase. Numerical simulations are performed using BBNBI and ASCOT Monte Carlo codes. The simulations have been done using a complete 3D wall geometry, and implementing the latest DEMO NBI design, which foresees NBI at 800 keV particle energy. Location and power density of NBI-related power loads at different ramp-up time steps are evaluated and compared with the maximum tolerable heat flux taken from ITER case. Since NBI shine-through losses (dominant during low density phases) depend mainly on the beam energy, plasma density and volume, DEMO has a more favourable situation than ITER, enlarging NBI operational window. Using ITER criteria, DEMO NBI at full energy and power could be switched on during ramp-up at ~ 1.3 × 1019 m-3. This increases the appeal of neutral beam injectors as auxiliary power systems for DEMO.

Agradecimentos: The ALICE Collaboration would like to thank all its engineers and technicians for their invaluable contributions to the construction of the experiment and the CERN accelerator teams for the outstanding performance of the LHC complex. The ALICE Collaboration gratefully acknowledges the resources and support provided by all Grid centres and the Worldwide LHC Computing Grid (WLCG) collaboration. The ALICE Collaboration acknowledges the following funding agencies for their support in building and running the ALICE detector: A. I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation (ANSL), State Committee of Science and World Federation of Scientists (WFS), Armenia; Austrian Academy of Sciences, Austrian Science Fund {FWF}: [M 2467-N36] and Nationalstiftung für Forschung, Technologie und Entwicklung, Austria; Ministry of Communications and High Technologies, National Nuclear Research Center, Azerbaijan; CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO (CNPq), Universidade Federal do Rio Grande do Sul (UFRGS), FINEP - FINANCIADORA DE ESTUDOS E PROJETOS (Finep) and FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO (FAPESP), Brazil; Ministry of Science & Technology of China (MSTC), National Natural Science Foundation of China (NSFC) and Ministry of Education of China (MOEC) , China; Croatian Science Foundation and Ministry of Science and Education, Croatia; Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear (CEADEN), Cubaenergía, Cuba; Ministry of Education, Youth and Sports of the Czech Republic, Czech Republic; The Danish Council for Independent Research | Natural Sciences, the Carlsberg Foundation and Danish National Research Foundation (DNRF), Denmark; Helsinki Institute of Physics (HIP), Finland; Commissariat à l’Energie Atomique (CEA), Institut National de Physique Nucléaire et de Physique des Particules (IN2P3) and Centre National de la Recherche Scientifique (CNRS) and Rlégion des Pays de la Loire, France; Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF) and GSI Helmholtzzentrum für Schwerionenforschung GmbH, Germany; General Secretariat for Research and Technology, Ministry of Education, Research and Religions, Greece; National Research, Development and Innovation Office, Hungary; Department of Atomic Energy Government of India (DAE), Department of Science and Technology, Government of India (DST), University Grants Commission, Government of India (UGC) and Council of Scientific and Industrial Research (CSIR), India; Indonesian Institute of Science, Indonesia; Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi and Istituto Nazionale di Fisica Nucleare (INFN), Italy; Institute for Innovative Science and Technology , Nagasaki Institute of Applied Science (IIST), Japan Society for the Promotion of Science (JSPS) KAKENHI and Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan; Consejo Nacional de Ciencia (CONACYT) y Tecnología, through Fondo de Cooperación Internacional en Ciencia y Tecnología (FONCICYT) and Dirección General de Asuntos del Personal Academico (DGAPA), Mexico; Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands; The Research Council of Norway, Norway; Commission on Science and Technology for Sustainable Development in the South (COMSATS), Pakistan; Pontificia Universidad Católica del Perú, Peru; Ministry of Science and Higher Education and National Science Centre, Poland; Korea Institute of Science and Technology Information and National Research Foundation of Korea (NRF), Republic of Korea; Ministry of Education and Scientific Research, Institute of Atomic Physics and Ministry of Research and Innovation and Institute of Atomic Physics, Romania; Joint Institute for Nuclear Research (JINR), Ministry of Education and Science of the Russian Federation, National Research Centre Kurchatov Institute, Russian Science Foundation and Russian Foundation for Basic Research, Russia; Ministry of Education, Science, Research and Sport of the Slovak Republic, Slovakia; National Research Foundation of South Africa, South Africa; Swedish Research Council (VR) and Knut & Alice Wallenberg Foundation (KAW), Sweden; European Organization for Nuclear Research, Switzerland; National Science and Technology Development Agency (NSDTA), Suranaree University of Technology (SUT) and Office of the Higher Education Commission under NRU project of Thailand, Thailand; Turkish Atomic Energy Agency (TAEK), Turkey; National Academy of Sciences of Ukraine, Ukraine; Science and Technology Facilities Council (STFC), United Kingdom; National Science Foundation of the United States of America (NSF) and United States Department of Energy, Office of Nuclear Physics (DOE NP), United States of America Abstract: The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to evaluate the geometrical alignment and the corresponding correction of the absolute energy scale, to obtain the nonlinearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at root s = 13 TeV. After applying all corrections, the achieved mass resolutions for pi(0) and eta mesons for p(T) gt; 1.7 GeV/c are sigma(pi 0)(m) = 4.56 +/- 0.03 MeV/c(2) and sigma(eta)(m) = 15.3 +/- 1.0 MeV/c(2), respectively CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP FINANCIADORA DE ESTUDOS E PROJETOS - FINEP Aberto

The possibility to locally incorporate/remove hydrogen atoms in/from dilute-nitride semiconductors is demonstrated. This method can be applied to the fabrication of site-controlled single-photon emitters but also to the optimization/fabrication of photonic devices, via refractive-index engineering. ? OSA 2019 ? 2019 The Author(s)

We demonstrate the strong coupling between a single electron spin in silicon and a single photon in a superconducting microwave cavity. Using the same cavity we perform rapid high-fidelity single-shot readout of two-electron spin states.

Currently a positron emission tomography (PET) based on novel, cutting-edge technology is developed by the Jagiellonian-PET (J-PET) collaboration. In this contribution, the principle of plastic scintillator based detector system, J-PET and the investigation of its feasibility for proton beam therapy range monitoring will be presented. Results of Monte Carlo simulation studies aiming at the characterization of secondary radiation induced by a proton beam in a PMMA phantom and detected by the J-PET scanner will be shown. Accounting for detector acceptance and PET-gamma detection efficiency in the plastics the diagnostic J-PET scanner can acquire 1.7×10−5 PET-gammas per primary proton. The J-PET detector configurations and signal acquisition during and after the therapy is discussed.

International audience; This article reports on the development of thin diamond detectors and their characterization for their application in temporal profile measurements of subnanosecond ion bunches. Two types of diamonds were used: a 20 μm thin polycrystalline chemical vapor deposited (CVD) diamond and a membrane with a thickness of (5 ± 1) μm etched out of a single crystal (sc) CVD diamond. The combination of a small detector electrode and an impedance matched signal outlet leads to excellent time response properties with a signal pulse resolution (FWHM) of τ = (113 ± 11) ps. Such a fast diamond detector is a perfect device for the time of flight measurements of MeV ions with bunch durations in the subnanosecond regime. The scCVD diamond membrane detector was successfully implemented within the framework of the laser ion generation handling and transport project, in which ion beams are accelerated via a laser-driven source and shaped with conventional accelerator technology. The detector was used to measure subnanosecond proton bunches with an intensity of 10⁸ protons per bunch.

Dose delivery verification in proton beam radiotherapy is used to ensure the delivery of the dose to the correct location. A positron emission tomography (PET) scanner can be used to detect the secondary radiation during the treatment, so-called in-beam PET. This is a challenging application for PET due to the low counts and limited angular coverage. We propose a maximum a posteriori (MAP) reconstruction with median root prior (MRP) for the reconstruction of in-beam PET data. The proposed method was compared against MAP with total variation (TV) prior and maximum likelihood expectation maximization (MLEM), which have previously been used for this application. The effects of different ring configurations and time-of-flight information were tested with simulations of a geometrical phantom and a realistic patient treatment plan. The results indicate that both MAP methods produced sharper edges than MLEM, allowing more accurate edge localization in the reconstructed images. Even for the partial ring configurations, no elongation was observed with MAP methods. MAP-MRP successfully reduced the noise, whereas MAP-TV resulted in checkerboard artifacts. MAP-MRP was also more stable against the selection of the reconstruction parameters. In conclusion, MAP-MRP offers a simple and robust alternative for the reconstruction of in-beam PET data.