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In the present study, the optical constants of niobium carbide (NbC) in soft x-ray wavelength region of 6–15 nm have been determined using angle dependent x-ray reflectivity measurements. Experimentally measured optical constants (δ and β) are compared with tabulated values of Henke et al. The δ values are found 5–30% lower than the bulk value whereas deviation in beta values is around 5–38%. To the best of our knowledge, the present study gives the first reported experimental values of optical constants for niobium carbide in 6–15 nm wavelength range. The knowledge of experimentally measured optical constants of NbC will help in practical calculation of optical devices. [ABSTRACT FROM AUTHOR]

In this paper the detailed structure of the transport beam line design is proposed, quadrupoles and deflectors specifications in order to transport the beam from the optic adaptation point in the SPIRAL2 production building up to the adaptation point in the DESIR hall. All optical elements, in beam line, are electrostatic and so, settings are independent of the ratio q/m of the particle. The calculations are done by COSY INFINITY computer code in first order of approximation and without fringe field effects. The beam emittances at the starting point (adaptation point in the SPIRAL2 production building) in horizontal and vertical planes are 80p mm mrad. The beam line is designed in such a way that the beam sizes, in both planes, at the end (adaptation point in the DESIR hall) are kept the same as they are at the starting point; the horizontal and vertical displacements from the optic axis at starting and ending points are the same, ±6 mm. In such case the efficiency of transport of the beam is high. [Projekat Ministarstva nauke Republike Srbije, br. OI-171018]

Production costs and energy efficiency are the main priorities for the photovoltaic (PV) industry (COP21 conclusions). To lower costs and increase efficiency, we are proposing to reduce the number of processing steps involved in the manufacture of N-type Passivated Rear Totally Diffused (PERT) silicon solar cells. Replacing the conventional thermal diffusion doping steps by ion implantation followed by thermal annealing allows reducing the number of steps from 7 to 3 while maintaining similar efficiency. This alternative approach was investigated in the present work. Beamline and plasma immersion ion implantation (BLII and PIII) methods were used to insert n-(phosphorus) and p-type (boron) dopants into the Si substrate. With higher throughput and lower costs, PIII is a better candidate for the photovoltaic industry, compared to BL. However, the optimization of the plasma conditions is demanding and more complex than the beamline approach. Subsequent annealing was performed on selected samples to activate the dopants on both sides of the solar cell. Two annealing methods were investigated: soak and spike thermal annealing. Best performing solar cells, showing a PV efficiency of about 20%, was obtained using spike annealing with adapted ion implantation conditions. [ABSTRACT FROM AUTHOR]

Proton radiography is used for advanced hydrotesting as a new type radiography technology due to its powerful penetration capability and high detection efficiency. A new proton radiography terminal will be developed to radiograph static samples at the Institute of Modern Physics of Chinese Academy of Science. The proton beam with the maximum energy of 2.6 GeV will be produced by Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring. The proton radiography terminal consists of the matching magnetic lens and the Zumbro lens system. In this paper, the design scheme and all optic parameters of this beam terminal for 2.6 GeV proton energy are presented by simulating the beam optics using WINAGILE code. My-BOC code is used to test the particle tracking of proton radiography beam line. Geant4 and G4beamline codes are used for simulating the proton radiography system. The results show that the transmission efficiency of proton without target is 100%, and the effect of secondary particles can be neglected. To test this proton radiography system, the proton images for an aluminum plate sample with two rectangular orifices and a step brass plate sample are respectively simulated using Geant4 code. The results show that the best spatial resolution is about 36 μm, and the differences of the thickness are not >10%. [ABSTRACT FROM PUBLISHER]

Abstract: A long-standing challenge in the design of a Heavy Ion Fusion power plant is that the ion beams entering the target chamber, which number of order a hundred, all need to be routed from one or two multi-beam accelerators through a set of transport lines. The beams are divided into groups, each of which has a unique arrival time and may have a unique kinetic energy. It is also necessary to arrange for each beam to enter the target chamber from a prescribed location on the periphery of that chamber. Furthermore, it has generally been assumed that additional constraints must be obeyed: that the path lengths of the beams in a group must be equal, and that any delay of “main-pulse” beams relative to “foot-pulse” beams must be provided by the insertion of large delay-arcs in the main beam transport lines. Here we introduce the notion of applying “differential acceleration” to individual beams or sets of beams at strategic stages of the transport lines. That is, by accelerating some beams “sooner” and others “later,” it is possible to simplify the beam line configuration in a number of cases. For example, the time delay between the foot and main pulses can be generated without resorting to large arcs in the main-pulse beam lines. It is also possible to use differential acceleration to effect the simultaneous arrival on target of a set of beams (e.g., for the foot-pulse) without requiring that their path lengths be precisely equal. We illustrate the technique for two model configurations, one corresponding to a typical indirect-drive scenario requiring distinct foot and main energies, and the other to an ion-driven fast-ignition scenario wherein the foot and main beams share a common energy. [Copyright &y& Elsevier]

Abstract: Experiments with strangeness of −3 are now being planned at the J-PARC hadron experimental facility (HD-hall) to study ΩN interaction and structure of Ω baryons. In order to perform experiments, two new beam lines are to be constructed in the HD-hall, which will provide charged secondary beams with higher momentum than those of existing beam lines. In this paper, planned experimental programs on physics at J-PARC as well as current designs of the new beam lines are introduced. [Copyright &y& Elsevier]

Abstract: Two experiments to search for (E19) and bound states (E27) have been carried out so far at K1.8 beam line of J-PARC Hadron Facility. No peak structure was observed in the E19 first run at 1.92 GeV/c. Three experiments, spectroscopy of a neutron-rich hypernucleus, 6 Λ H (E10), γ-ray spectroscopy of 19 Λ F and 4 Λ He (E13) at K1.8 and another search for bound system (E15) at K1.8BR, are scheduled by summer 2013. Experiments on Λ hypernuclei will be carried out at a newly constructed K1.1 beam line with SKS, while physics will be conducted at K1.8 beam line after 2014. Future plan of Hadron Hall extension under consideration is briefly reported. [Copyright &y& Elsevier]

Abstract: This work demonstrates that the sequence of a Ge co-implant with a B2H6 PLAD in the source/drain is very critical in order to improve advanced PMOS performance. Locating the Ge co-implant after the B2H6 PLAD resulted in higher total retained B dose and less implant damage. PMOS performance was significantly improved compared to B2H6 PLAD without the Ge co-implant or Ge co-implant before B2H6 PLAD. The Ge implant energy was optimized to locate the Ge peak around the B deposition layer/Si substrate interface for a better knocking effect and less implant damage. With the optimized Ge implant conditions the source/drain contact resistance and sheet resistance were significantly reduced, while the junction leakage current was not degraded. As a result, PMOS I ds improved by 12%, transconductance KL improved by 14%, and I OFF variation improved by 33% without significant change in mean I OFF. This process helps overcome technical challenges of B2H6 PLAD, providing a path for continued scaling of PMOS junction depth with improved device performance. [Copyright &y& Elsevier]

The superconducting magnet system for the J-PARC neutrino beam line for the T2K experiment has been served for the beam operation without serious disturbance since April 2009. Present most concern of the system is the operational current limit of superconducting corrector magnets for beam steering due to systematic quenches at lower currents. Operational experience of the magnet system and examples of troubleshoot including countermeasures against the corrector magnet quenches are presented. [ABSTRACT FROM AUTHOR]

Following success of a prototype R&D, construction of a superconducting magnet system for J-PARC neutrino beam line has been carried out since 2005. A new conceptual beam line with the superconducting combined function magnets demonstrated the successful beam transport to the neutrino production target. [ABSTRACT FROM AUTHOR]

Abstract: Neutron guides are widely used to transport the neutrons from the moderator to the sample. Due to the constructive features of the ring corridor of the fast pulsed reactor IBR-2, the minimal distance between the moderator and the guide entrance is around 6m. The main goal of the paper is to optimize the neutron optical system between the moderator and the entrance of the new neutron guides. Using Monte Carlo simulations we calculate the possible best gain of the neutron flux density at the guide exit. After the described optimization process, the optimal system is obtained. The recommendations for construction of the new beam line are provided too. Similar technique and the proposed system could be easily adapted for another similar beam line at the neutron sources. [Copyright &y& Elsevier]

A superconducting magnet system for the J-PARC neutrino beam line has been under construction since 2004. The system consists of 14 doublet cryostats; each contains 2 combined function magnets (SCFM). The SCFM uses two single layer left/right asymmetric coils that produce a dipole field of 2.6 T and quadrupole of 19 T/m. The SCFMs had been developed by 2004, mass-produced since 2005, and completed by summer 2008. The system is being installed since Feb. 2008 till the end of 2008. The paper summarizes the system overview including cryogenics and safety peripheries. The paper also reports the production and installation status. [ABSTRACT FROM AUTHOR]

Abstract: In the modified SX-700 monochromator installed at beam line I411, the focusing before the exit slit is achieved by a plane elliptical mirror. Like in the original SX-700 design, the resolution is mainly limited by the slope errors of the focusing mirror. A simple method to improve the resolution is to replace the focusing mirror by one with smaller slope errors. The effects of replacing the refocusing mirror by similar but more accurate in shape are studied both by carrying out ray tracing simulations and by analytical approach. Also the effect of replacing the grating was studied. [Copyright &y& Elsevier]

The heat load on superconducting magnets induced by beam loss is a major subject to be solved for stable operation of the 50 GeV-0.75 MW J-PARC neutrino beam line. Heat load for a 10 W/point beam loss in an actual coil was calculated using the MARS code which simulates the actual magnet. Calculated heat load was up to 20 kJ/m³ /pulse. Instantaneous heating of 0-40 kJ/m³/pulse was induced in Rutherford type cable in an experiment, and the thermal characteristic measured using SHe. The cable specimen for an experimental verification used the same structure as the superconducting cable for the magnet in the test. It was found that a heat pulse of 20 kJ/m⊃3 caused an instantaneous temperature rise of 0.25 K in the experiment and will not induce a quench according to the quench simulation calculation. [ABSTRACT FROM AUTHOR]

A neutrino oscillation experiment using the J-PARC 50 GeV 0.75 MW proton beam is planned as a successor to the K2K project currently being operated at KEK. A superconducting magnet system is required for the arc section of the primary proton beam line to be within the space available at the site. A system with 28 combined function magnets is proposed to simplify the system and optimize the cost. The required fields for the magnets are 2.6 T dipole and 19 T/m quadrupole. The magnets are also required to have a large aperture, 173.4 mm diameter, to accommodate the large beam emittance. The magnets will be protected by cold diodes and cooled by forced flow supercritical helium produced by a 4.5 K, 2∼2.5 kW refrigerator. This paper reports the system overview and the design status. [ABSTRACT FROM AUTHOR]

In this paper the role of distributed and parallel computing in beam physics is discussed. The natural parallel and distributed structures of beam physics problems allow the use of parallel and distributed computer systems. But the usual approaches based on traditional numerical methods demand using the resources of supercomputers. This leads to the impossibility of using such multiprocessing systems as computational clusters. In this paper some examples of beam physics problems are discussed from the computational point of view using clustered systems. [Copyright &y& Elsevier]

In this paper some problems of beam-lines optimization are discussed. The suggested approach makes available flexible and convenient tools both for the investigation of beam-line properties and for the synthesis of such systems using computer codes. This approach was developed as a natural result of the solution of practical problems from beam physics. [Copyright &y& Elsevier]

A beam line for electrons with energies in the range of 1–45 GeV, low contamination of hadrons and muons and high intensity up to 106 per accelerator spill at 27 GeV was setup at U70 accelerator in Protvino, Russia. A beam tagging system based on drift chambers with 160 μm resolution was able to measure relative electron beam momentum precisely. The resolution σp/p was 0.13% at 45 GeV where multiple scattering is negligible. This test beam setup provided a possibility to study properties of lead tungstate crystals (PbWO4) for the BTeV experiment at Fermilab. [Copyright &y& Elsevier]