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Electron ionization time-of-flight mass spectrometry (EI-TOF-MS) has been widely used in the fields of chemical, environmental, food, medical and pharmaceutical, etc. Coupling gas chromatography (GC) with EI-TOF-MS yields promising qualitative and quantitative results, and the performance is closely related to with the ion guide devices. A good ion guide device for EI ion source can generate a narrow beam of low-energy ions, resulting in high ion transition efficiency. In this study, an ion transition system for EI ion source with radio frequency quadrupole (RFQ) as the collisional focusing ion guide was developed. The ions in the RFQ could be cooled by collisions with buffer gas molecules and focused to near the axis by a RF field. To determine the parameters of the RFQ, including rod length, rod radius, field radius, RFQ exit orifice diameter, RF frequency, RF amplitude, and other transmission electrode voltages, vacuum design theory, RF quadrupole field theory and SIMION software simulations were applied. The performance of a GC-EI-TOFMS instrument was significantly improved using RFQ as collisional focusing ion guide, and the evaluation results showed that the mass resolution was up to 6500 FWHM (m/z 502), the limit of detection (LOD) was 1 pg of OFN (S/N > 30:1), the mass range was 15–968 amu, the mass accuracy was below 0.01 amu, and the relative standard deviation (RSD) was below 1.5% within one week. This study provided an example to build an ion transition system for mass spectrometry, which had important theoretical and practical significance in design and development of new mass spectrometric instrument.

The ISOL facility ALTO, located at Orsay in France, provides stable ion beams from a 15 MV Tandem accelerator and neutron-rich radioactive ion beams (RIB) from the interaction of a γ -flux induced by a 50 MeV 10 μA electron beam in a uranium carbide target. A magnetic dipole mass separator and a resonance ionization laser ion source allow to select the ions of interest. New setups are under preparation to extend the fundamental properties measured at ALTO of ground and excited states of exotic nuclei. For example, high-precision mass measurements for an accurate determination of the nuclear binding energy. To perform these measurements two devices will be hosted at ALTO: a radio frequency quadrupole to cool and bunch (RFQCB) the continuous radioactive beam and the double Penning trap mass spectrometer MLLTRAP, commissioned off-line at the Maier-Leibnitz Laboratory (MLL) in Garching, Germany. The unique production mechanism using photo-fission at the ALTO facility allows for mass measurements in a neutron rich area of nuclides of major interest around 132 Sn with less isobaric contamination than using proton drivers. In this context, we plan to measure neutron-rich silver isotopes (Z = 47, A > 121) to explore the possible weakening of the shell gap for Z

The N = 126 factory currently under construction at Argonne National Laboratory’s ATLAS facility will make use of multi-nucleon transfer reactions to produce nuclei around the N = 126 shell closure that are of interest for the study of the rapid neutron capture process and are not available in sufficient quantities using common particle-fragmentation, target-fragmentation, or fission production techniques. As part of this facility, a radio frequency quadrupole (RFQ) buncher will cool and accumulate the beam, converting a high-emittance, continuous beam into a low-emittance bunched beam suitable for trapping. Here, the construction of the RFQ cooler-buncher, based on the design used at the National Superconducting Cyclotron Laboratory’s BECOLA and EBIT cooler-bunchers, will be discussed. This design features injection optics optimized to maximize acceptance, separated cooling and bunching regions, and a simplified RFQ electrode construction.

In order to facilitate the widespread use of neutrons in industrial applications, it is important to provide a compact, semi-ready-made neutron source that a company and a factory can easily install. We are therefore developing a compact neutron source system utilizing a downsized proton accelerator as an entry level model for industrial use and materials development, which consists of a proton source, a four-vane radio frequency quadrupole linear accelerator (RFQ) and a lithium target for neutron production by the Li ( p,n ) 3 7 Be 4 7 reaction. An RFQ is suitable to accelerate protons in the low energy region because it accepts DC beams extracted from the proton source and accelerates effectively to the design energy with bunching and focusing using the electric fields. Furthermore, it is possible to design the RFQ with a higher frequency than conventionally used owing to technological advances in high power solid-state RF amplifiers. We investigated the specifications for 500 MHz and 650 MHz through beam trajectory and electromagnetic simulations and fabricated a 2.5 MeV prototype of the 500 MHz type with a 2.45 GHz ECR proton source.

Selective laser photodetachment of anions is a novel technique for isobar suppression in Accelerator Mass Spectrometry (AMS). Ion-laser interaction times on the order of ms required for near-complete isobar suppression are achieved by retarding the ions in a gas-filled radio frequency quadrupole cooler. Inside this RFQ, the cooled anion beam is overlapped collinearly with an intense cw-laser beam. Within the Ion Laser InterAction Mass Spectrometry (ILIAMS) project at the University of Vienna, a dedicated injector beamline has been coupled to the VERA-AMS facility to explore and develop this method. In this work, experimental investigations on ion beam transmission, stability and elemental selectivity of the new setup are presented. A 532 nm laser at 10 W transmitted power provides suppression factors larger than ten orders of magnitude for S− and MgO− under AMS conditions with simultaneous beam transmission for the ions of interest of up to 80%. The excellent ion identification capabilities of the subsequent AMS system also facilitate the study of destruction and formation of molecular anions inside the ion cooler. These kinetic and chemical reactions with the buffer gas provide additional elemental selectivity in certain cases, whereas others constitute a source of background.

A 325 MHz, 3.0 MeV Radio Frequency Quadrupole (RFQ) is being developed for 1 GeV proton accelerator for proposed Indian Spallation Neutron Source (ISNS) facility at Raja Ramanna Centre for Advanced Technology, Indore. RFQ will be a normal conducting four vane resonating structure made of Oxygen Free Electronic (OFE) copper. During high power operation of RFQ, Radio Frequency (RF) field induced heating results in temperature rise, thermal deformations and shift in resonant frequency from designed values. Therefore thermal stability of RFQ is one of the important design issues. Various RF–thermal–structural coupled multiphysics analysis methodologies for thermal management of RFQ have been attempted in past and reported in literature. However, these efforts are primarily limited to 2D simulations for a thin slice of RFQ cross section and do not addresses for longitudinal temperature rise of cooling water, distribution of frequency tuners, vane tip modulations and vane cut back at the inlet and exit of RFQ structure. This paper proposes a finite element method (FEM) based multiphysics analysis methodology for numerical simulation of RFQ structure. The methodology consists of a complete 3D-RF-fluid–thermal–structural–RF coupled analysis for predicting temperature rise, thermal deformations and frequency shift of RFQ structure due to RF heating. All analysis (electromagnetic, fluid, thermal and structural) and their coupling are carried out using a single code namely ANSYS Mechanical. The simulated results from proposed methodology are compared with published work and a maximum error of less than 7% is obtained. The numerical comparison of described methodology with other multiphysics analysis methodologies (such as importing 2D field maps and using heat transfer coefficient from empirical relations) has been carried out. The described methodology is paving the way for the design and development of ISNS RFQ structure.

An 8-MeV linear proton medical accelerator designed with a high RF duty operation is being developed at Ibaraki Neutron Medical Research Center for iBNCT (Ibaraki - Boron Neutron Capture Therapy). The reliability and stability of the cooling water control system has become one of the most important issues in realizing the medical application of the accelerator, which is designed considering high performance and low costs. However the previous cooling water control system with a commercial PID (Proportional–Integral–Differential) controller could not meet the operation requirements of the medical accelerator. Therefore, a new intelligent cooling water controller is successfully developed by application of Fast Feed-forward for Future (FFF). The detailed design of the intelligent cooling water control system and its great efficacy in improving accelerator operation is described in this paper. The stability of the cooling water temperature is improved greatly from the previous ± 0 . 30 ° C to the current ± 0 . 03 ° C. Moreover, the response time of cooling water control is decreased dramatically from the previous 5 min to approximately 20 s. Precise operation and an excellent auto-tuning of the RFQ (Radio Frequency Quadrupole LINAC) cavity are realized by using this stable and intelligent water control system. The beam transmittance is also improved slightly after a fine scan experiment with different settings of RF devices under stable acceleration operation. Finally, the RF startup time is also reduced by using this intelligent cooling water control system. Now the iBNCT accelerator operation is greatly improved with a very high reliability and stability. The accelerator will be operated as a practical medical therapy in late 2019. The technology developed in this intelligent cooling water control system will be very useful for the development of similar accelerators with high performance and low cost.

The thermal stability of the radio frequency quadrupole (RFQ) is an important concern during commissioning. The cooling water takes away the power dissipated on the RFQ internal surface to maintain the thermal stability and limit the structural deformation. In this paper, the thermal-fluid coupled analysis of the RFQ is described and 3D temperature distribution of the RFQ cavity structure is given. The method of adjusting the water temperature is determined through analysis. The heat transfer coefficient for the cooling channels and the outlet water temperature about the water cooling system are obtained. A comparison of the results in simulation and experiment is presented. The cooling system can meet the requirements of RFQ operating.

The proposed Compact Intense Fast NEutron Facility (CIFNEF) will have a wide range of applications, including the investigation of the exotic structure of neutron-rich nuclei, data for the nuclear fission , and the simulation of the neutron field in a star. To satisfy aims of producing high-intensity fast neutrons and forward neutrons with very low environmental background, the CIFNEF linac should have the capacity of accelerating continuous wave (CW) deuteron (D + ), hydrogen ( H 2 + ) and lithium (7Li 3 + ) beams to 2.5 MeV/u with maximum beam currents of 10 mA, 5 mA and 10 uA, respectively. Based on the above requirements, we proposed a novel compact linac using a combination of RFQ and DTL structures. The dynamics of RFQ and DTL are completed to meet all requirements and start-to-end simulation results show that the three ion species can be accelerated to the final energy with transmission efficiency above 99% as well as good beam quality with lower emittance growth. In addition, we performed error sensitivity analysis and combined error study to evaluate the error tolerance limits of the obtained design.

A 162.5 MHz, 7.2 MeV Radio Frequency Quadruples (RFQ) is being designed for the injector of a heavy ion medical machine, which is promoted by the Institute of Modern Physics (IMP), Chinese Academy of Science (CAS). The proposed RFQ will adopt the conventional 4-rod structure, which is most commonly used for the heavy ion linac at low energy section. RF design was based on a new fast-bunching beam dynamics design. Comparing with the conventional beam dynamics design, this design strategy makes the structure more compact and need less power consumption. To meet the requirements of beam dynamics, various methods were used to optimize the electric field distribution. The electric field fluctuation under 3.5% and the dipole field ratio under 3% were obtained simultaneously. Water temperature rise and cavity thermal deformation were also simulated based on the special water-cooling system design. Under the setting of the cooling parameters, the temperature rise of cooling water was kept below 2 °C in theory. Considering the possible frequency shift during assembling and operation, the tuning range of the movable plungers is 500 kHz to compensate frequency shift.

A design principle with robust considerations has been applied to design a new alternating phase focused (APF) drift tube linear accelerator (linac) for particle beam therapy. By assuming a sinusoidal synchronous phase formula and a linearly increasing electrode voltage scheme, the structure of the APF linac is automatically optimized with a cost function including robustness using the nonlinear correlated stacking optimization method (CSM). The design procedure includes the radio frequency quadrupole (RFQ) to drift tube linac (DTL) matching, and an end-to-end simulation of the APF acceleration beam dynamics. Moreover, the stability of the solution obtained is analyzed with respect to various independent errors as well as a number of joint errors. The designed APF DTL linac together with an already established RFQ is planned to replace the existing Alvarez-type permanent magnet focused DTL linac aiming at easier manufacturing and cost reduction.

For a high-current Radio Frequency Quadrupole (RFQ) accelerator, space charge will strongly affect the stability of beams, which brings challenges and difficulties to the beam dynamics design. For an in-depth study of this space charge effect, a project has been proposed by Peking University and the Institute of Modern Physics of the Chinese Academy of Sciences. This project requires a 162.5 MHz RFQ to accelerate a 100-mA continuous-wave (CW) proton beam to 3 MeV. The beam dynamics design of this RFQ is based on the four-section procedure with improved radial focusing strength along the RFQ. We have investigated the relationship between limiting current and beam transmission to analyze the reasons for emittance growth and beam loss. We have also carried out an irradiation experiment based on this beam dynamics design to study the irradiation damage of the electrode surface, as this can be one main reason for reduced transmission or unstable operation that most existing high-current RFQs encounter after long-time operation. The results show that low-energy beam losses need to be kept as low as possible to prolong the life of the RFQ electrodes. The final simulated transmission efficiency reached 99.8%, as confirmed by the code toutatis .

This paper describes the physical design of a 7 MeV proton linac injector for a synchrotron-based proton-therapy system, sponsored by the Chinese government under the support of the National Key Research and Development Program. The proton linac injector consists of an electron cyclotron resonance proton source, a low-energy beam transport section, a radio-frequency quadrupole (RFQ) accelerator, and an Alvarez-type drift tube linac (DTL). The peak current of the proton beam at the exit of the DTL accelerator is required to exceed 12 mA, with a normalized emittance of ⩽ 1 . 2 π mm mrad (90% particles), a repetition rate of 0.5 Hz, and a beam pulse width of 40–100 μ s . For the beam current whose momentum spread falls within ± 0.3%, the intensity must exceed 8 mA. The design of the linac injector is optimized in the principle of adopting sophisticated domestic technologies and cost control. Only one tetrode-based RF power amplifier is required after minimizing the total peak-power consumption of the RFQ and DTL accelerator, which is 378 kW. The idea of the RF power lines feeding two cavities with one amplifier is presented. To facilitate the manufacture of permanent-magnet quadrupoles and reduce the cost, the focusing strength at the end of the RFQ accelerator is optimized. Consequently, the focusing strength of all permanent-magnet quadrupoles is the same, and the DTL accelerator can be directly connected to match the RFQ accelerator without a medium-energy beam transport section between them. After construction, the 7 MeV proton linac injector is hoped to be the first homemade linac injector for a synchrotron-based proton-therapy facility in China.

Quadrupolar Asymmetry (QA), which has been a rampant problem for rod-type Radio Frequency Quadrupole (RFQ) Linacs, arises due to the geometry of resonant structure. A systematic parametric simulation study has been performed to unravel their effect on Figure of Merit (FoM) quantities namely Quality Factor (Q), Shunt Impedance ( R sh ) and Quadrupolar Asymmetry (QA). A novel stem and cavity shape is proposed, which caters to the profile of electromagnetic fields of the resonant structure. A design methodology is formulated, which demonstrates that Quadrupolar Asymmetry can be annihilated, and a symmetric electric field can be produced in all four quadrants of rod-type RFQ accelerator.

The combination of in-flight separation with a gas-filled stopping cell has opened a new field for experiments with exotic nuclei. For instance, at the SHIP/SHIPTRAP facility at GSI in Darmstadt high-precision mass measurements of rare nuclei have been successfully performed. In order to extend the reach of SHIPTRAP to exotic nuclei that are produced together with high rates of unwanted reaction products, a novel compact radio frequency quadrupole (RFQ) system has been developed. It implements ion cooling, identification and separation according to mass numbers and bunching capabilities. The system has a total length of one meter only and consists of an RFQ cooler, an RFQ mass filter and an RFQ buncher. A mass resolving power (FWHM) of 240 at a transmission efficiency of 90% has been achieved. The suppression of contaminants from neighboring masses by more than four orders of magnitude has been demonstrated at rates exceeding 1 0 6 ions/s. A longitudinal emittance of 0.45 eV μ s has been achieved with the RFQ buncher, which will enable improved time-of-flight mass spectrometry downstream of the device. With this triple RFQ system the measurement of e.g. N = Z nuclides in the region up to tin will become possible at SHIPTRAP. The technology is also well suited for other rare-isotope facilities with experimental setups behind a stopping cell, such as the fragment separator FRS with the FRS Ion Catcher at GSI.

The Extreme Light Infrastructure – Nuclear Physics (ELI-NP) laboratory in Bucharest, Romania, will host an IGISOL-type facility which will study exotic neutron-rich ion beams produced via photo-fission in actinide targets placed at the center of a cryogenic gas cell. Using a complex radio frequency quadrupole for radioactive ion beam formation, a powerful multiple-reflection time-of-flight mass spectrometer for selecting the refractory isotopes of interest, and several measurement stations, this facility will be an exciting new tool for nuclear scientists. The two mechanisms of ion transport inside the gas cell, namely drift by electric fields and drag by supersonic gas jets, are studied. A program to test the individual components of the stopping cell is discussed.

This paper describes the physical design of a radio-frequency quadrupole (RFQ) accelerator for a compact accelerator-driven neutron source . The 325-MHz RFQ accelerates a 30-mA deuteron beam from 50 keV to 2 MeV, which is directly matched to the drift-tube linac (DTL) without a separate beam matching section. The objective of this design is to obtain a short RFQ with a tolerable transmission and power consumption. Using a modified four-section procedure, the inter-vane voltage is ramped with RFQ longitudinal position to obtain the required short length, and the focusing strength is varied to suppress beam loss. The RFQ has a length of 193.2 cm, with a peak power consumption of 186 kW, and a beam transmission of 94.1%.

The radio frequency structure design of the radio frequency quadrupole (RFQ) for the front end of China Material Irradiation Facility (CMIF), which is an accelerator based neutron irradiation facility for fusion reactor material qualification, has been completed. The RFQ is specified to accelerate 10 mA continuous deuteron beams from the energies of 20 keV/u to 1.5 MeV/u within the vane length of 5250 mm. The working frequency of the RFQ is selected to 162.5 MHz and the inter-vane voltage is set to 65 kV. Four-vane cavity type is selected and the cavity structure is designed drawing on the experience of China Initiative Accelerator Driven System (CIADS) Injector II RFQ. In order to reduce the azimuthal asymmetry of the field caused from errors in fabrication and assembly, a frequency separation between the working mode and its nearest dipole mode is reached to 17.66 MHz by utilizing 20 pairs of π -mode stabilizing loops (PISLs) distributed along the longitudinal direction with equal intervals. For the purpose of tuning, 100 slug tuners were introduced to compensate the errors caused by machining and assembly. In order to obtain a homogeneous electrical field distribution along cavity, vane cutbacks are introduced and output endplate is modified. Multi-physics study of the cavity with radio frequency power and water cooling is performed to obtain the water temperature tuning coefficients. Through comparing to the worldwide CW RFQs, it is indicated that the power density of the designed structure is moderate for operation under continuous wave (CW) mode.

The resonant frequency stability of the radio frequency quadrupole (RFQ) is an important concern during commissioning. The power dissipated on the RFQ internal surface will heat the cavity and lead to a temperature rise and a structural deformation, especially in the continuous wave (CW) RFQs, which will cause the resonant frequency shifts. It is important to simulate the temperature rise, the deformation and the frequency shift of the RFQ cavity. The cooling water takes away the power to maintain the frequency stability. Meanwhile, the RFQ resonant frequency can be tuned by adjusting the water temperature. In this paper, a detailed three-dimensional multi-physics analysis of the Low Energy Accelerator Facility (LEAF) RFQ will be presented and a commissioning frequency tuning strategy will be studied.

The Korea Heavy Ion Medical Accelerator (KHIMA) project has been developed for cancer therapy. The injector system consists of a low energy beam transport (LEBT) line, a radio-frequency quadrupole, a drift tube linac with two tanks, and a medium energy beam transport (MEBT) line with a charge stripper section. The injector system transports and accelerates the 12 C 4 + beam that is produced from electron cyclotron resonance ion source up to 7 MeV/u, respectively. The 12 C 6 + beam, which is transformed by a charge stripper from the 12 C 4 + beam, is injected into a synchrotron and accelerated up to 430 MeV/u. The lattice for the injector system was designed to optimize the beam parameters and to meet beam requirements for the synchrotron. We performed start-to-end simulations from the LEBT line to the MEBT line to confirm that the required design goals of the beam and injector system were met. Our simulation results indicate that our design achieves the required performance and a good transmission efficiency of 90%. We present the lattice design and beam dynamics for the injector system in the KHIMA project.

The Ion Laser InterAction Setup (ILIAS) project at the University of Vienna aims at the exploration of negative ion beam filtering by selective laser photodetachment for applications in accelerator mass spectrometry (AMS). A gas-filled radio frequency quadrupole (RFQ) is used to decelerate and cool negative atomic and molecular ion beams with intensities of up to several hundred nA, and overlap them collinearly with a continuous wave (cw) laser beam. Ion-laser interaction times ranging from 500 μs to several ms allow for highly efficient, selective photodetachment depletion of disturbing ion species within these beams. The elemental selectivity of this technique is based on the differences in electron affinities, and therefore does not depend on relative differences in atomic numbers. It may therefore provide sufficient isobar suppression for new trace isotopes, which are not accessible with existing AMS techniques. The ILIAS RFQ cooler was characterized at a purpose-built test bench with respect to ion beam transmission, ion cooling capabilities and ion residence times as a function of injected ion current to assess its suitability for future AMS use. A 63 Cu − test beam of 600 nA was photodetached with more than 99.999% efficiency with a 532 nm laser at 10.8 W power. At the same time, ions of interest having electron affinities higher than the photon energy passed the cooler unaffected. Total ion losses were thus found to be below 50% of the sputter source output. Finally, first photodetachment experiments in connection with 26 Al detection demonstrated selective isobar suppression of MgO − vs. AlO − by more than 4 orders of magnitude. Currently, the RFQ cooler is moved to a new injector beamline at the Vienna Environmental Research Accelerator (VERA) for first applications of this novel technique at a state-of-the-art AMS facility.

An 81.25 MHz continuous wave (CW) radio frequency quadrupole (RFQ) accelerator has been designed for the Low Energy Accelerator Facility (LEAF) at the Institute of Modern Physics (IMP) of the Chinese Academy of Science (CAS). In the CW operating mode, the proposed RFQ design adopted the conventional four-vane structure. The main design goals are providing high shunt impendence with low power losses. In the electromagnetic (EM) design, the π-mode stabilizing loops (PISLs) were optimized to produce a good mode separation. The tuners were also designed and optimized to tune the frequency and field flatness of the operating mode. The vane undercuts were optimized to provide a flat field along the RFQ cavity. Additionally, a full length model with modulations was set up for the final EM simulations. Following the EM design, thermal analysis of the structure was carried out. In this paper, detailed EM design and thermal simulations of the LEAF-RFQ will be presented and discussed. Structure error analysis was also studied.

Along many low energy beam transport (LEBT) systems transverse hadron beam matching to a subsequent radio frequency quadrupole (RFQ) is performed by magnetic quadrupole multiplets. Large apertures combined with short distances between the quadrupoles lead to overlap of individual singlet fields and significantly impact on the effective beam optics. Systematic measurements of beam transmission through an RFQ have been done and compared to beam dynamics simulations. For the latter, simplified hard-edge quadrupole fields were replaced by measured field data. It turned out that the hard-edge model is not sufficiently accurate to achieve acceptable agreement between calculated and measured beam properties.

A four-vane type Radio Frequency Quadrupole (RFQ) is very sensitive to geometrical errors since these may result into mixing of unwanted modes with the desired operating mode. This perturbs the voltage profile of the RFQ, which may deteriorate the beam dynamics, and increase the emittance growth and beam loss. In order to tune the RFQ for a desired voltage profile, a computer program based on transmission line model of RFQ is typically used. Although the theory of tuning program and its experimental validation has been discussed in earlier publications (Palmieri et al., 2010; Sanyasirao, 2014), here we discuss a methodology to perform the tuning of an RFQ in a simulation environment. This approach enables us to do an in-depth analysis of the tuning process, which is illustrated by performing the studies for an example case of the RFQ for the proposed Indian Facility for Spallation Research (IFSR), using the 3D Electro-Magnetic (EM) code CST-MWS. In these simulations, modelling of the vane-tip modulations of the RFQ has been performed in the code CST-MWS, for which a new procedure, using a macro, has been developed, which is presented here. We study perturbation in the voltage profile for two specific situations — first, due to vane-tip modulations, and second, due to misalignment errors. We correct the effect due to each of these perturbations in the simulation environment, using the tuning algorithm, and verify it using the 3D EM code. It has been shown in the paper that the same tuning algorithm with suitable modification can be used also for tuning of the end-cells of RFQ.

In the medium energy beam transport (MEBT) line of KHIMA project, a high precision beam phase probe monitor is required for a precise tuning of RF phase and amplitude of Radio Frequency Quadrupole (RFQ) accelerator and IH-DTL linac. It is also used for measuring a kinetic energy of ion beam by time-of-flight (TOF) method using two phase probes. The capacitive beam phase probe has been developed. The electromagnetic design of the high precision phase probe was performed to satisfy the phase resolution of 1° (@200 MHz). It was confirmed by the test result using a wire test bench. The measured phase accuracy of the fabricated phase probe is 1.19 ps. The pre-amplifier electronics with the 0.125 ∼ 1.61 GHz broad-band was designed and fabricated for amplifying the signal strength. The results of RF frequency and beam energy measurement using a proton beam from the cyclotron in KIRAMS is presented.

Bhabha Atomic Research Centre, Trombay is developing LEHIPA (Low Energy High Intensity Proton Accelerator) as pre-injector for 1 GeV proton accelerator for proposed ADSS (Accelerator Driven Sub-critical reactor System). LEHIPA is 20 MeV, 30 mA room temperature accelerator and consists of RFQ (Radio Frequency Quadrupole) and DTL (Drift Tube Linac) as major accelerating structures. The RF (Radio Frequency) design of DT (Drift Tube) of DTL aimed at maximizing the shunt impedance; this demands the size (transverse) of DTs to be minimal. The width of the DT is governed by the β of the particle and trade-off between transit time factor and effective accelerating voltage in the DT gap. The availability of limited volume in DTs for housing magnetic quadrupole has motivated the use of permanent magnets for generating the quadrupole field, as they have high magnetic energy density when compared to conventional electromagnets. With usage of permanent magnets, joule heating is eliminated, this helps in limiting the heat load. DTL has copious microwave heat with heat flux as large as 10 W/cm2 at certain locations. The beam dynamics requires uniformity of integral magnetic field gradient of PMQ (Permanent Magnet Quadrupole) to be better than ± 0.5% with nominal value of 2.05 T. Further the drift tubes which houses these PMQs have microwave heat generation on outer surface which ranges from 5 kW to 8 kW depending on the size of the DT. This heat is required to be removed, not doing so would result in resonant frequency detuning in DTL cavity and enhanced temperature would deteriorate the strength of permanent magnets of the PMQ, thereby compromising their focal length. The drift tube has hydraulic circuit for microwave heat removal. This paper describes the magnetic design of the PMQ using Sm2Co17 rare earth permanent magnets. Paper discusses the magnetic design for optimizing integral magnetic field gradient (integral Gdl) uniformity. A novel magnetic field tuning technique is used for tuning the integral magnetic field gradient to required value. Comprehensive magnetic tuning and characterization scheme is presented which relates the measured magnetic moment of the permanent magnets, un-tuned integral Gdl and pole length to the required integral Gdl. Based on this scheme thirty six PMQ embedded drift tubes have been developed. Paper also details the results of characterization of twenty PMQs which forms part of 10 MeV to 15 MeV DTL. The scheme used for tuning integral magnetic field gradient is universal and can be implemented in similar permanent magnets quadrupoles and other permanent magnet based systems.

This work describes the design and realization of a radio frequency (RF) system with a single klystron to power two conjunct independent cavities, namely, an RF quadrupole (RFQ) and a drift tube linac (DTL). In contrast with a two-klystron scheme, an RF system that adopts a single-klystron scheme for two accelerating cavities exhibits simpler configuration, smaller occupation area, and lower cost. However, the low intrinsic flexibility of the single-klystron scheme needs to be compensated by independent adjustment of RF field phases and amplitudes inside the two cavities. A proposed RF system design based on the single-klystron scheme includes a 4.77 dB power divider, an adjustable power attenuator, and a phase shifter. The power attenuator and phase shifter are set in different branches of the RF power transmission line. This design is used to power an RFQ and a downstream DTL in the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. During commissioning, the amplitudes inside the RFQ and DTL and the relative phase difference between them can be adjusted independently. The 13 MeV proton beam commissioning result verifies the design parameters and effectiveness of the single-klystron-based RF system. A proton beam energy of 12.92 MeV and a beam peak current of 41.2 mA at the exit of DTL were achieved, and the beam transmission from the entrance of RFQ to the exit of DTL reached 88.6%.

Transverse projected emittances of injected beams are strictly limited for synchrotrons with multi-loop injection. Horizontal and vertical emittances easily grow up when beam phase spaces in the x x ′ and y y ′ planes are coupled. Coupling in beam motion can be induced by tilted quadrupoles and solenoids. Various formalisms have been investigated to describe the beam coupling, which include the matrix and Hamiltonian formalism. In the matrix formalism, the transverse beam motion is parametrized by 4 × 4 beam matrices and the transfer matrices of the elements. Several methods or theories are used to obtain the decoupling matrix, including the equations solving, eigensystem analysis, geometrical method, Courant–Snyder theory and Hamiltonian perturbation theory. We propose an approach to obtain the decoupling matrix based on linear symplectic transformation theory. By adopting several consecutive tilted quadrupoles, the philosophy, as well as the numerical code for solving the decoupling and matching problem, are developed and checked for the general case. The transversely-coupled beam due to a 45 ∘ -rotated radio frequency quadrupole (RFQ) can be decoupled in the downstream drift tube linac with only five tilted fixed-gradient permanent-magnet quadrupoles (PMQs), which is suggested to be the minimal number of PMQs for decoupling and matching. The transverse emittance growth is verified to be suppressed below 5% by multi-particle simulation. The error study shows that the transmission rate can reach 98% with a probability of 99%.

In 4-rod RFQ accelerators, typically there is a non-zero on-axis longitudinal electric field component between the electrodes and the end-plates at both the beam entrance and exit. The longitudinal end-field component is caused by the violation of the quadrupole potential symmetry due to an uneven charging of the electrode overhang ends. This is a direct consequence of the design inherent geometric asymmetry of the conventional 4-rod structure. Because the unwanted end-fields will change the nominal beam properties e.g. energy, emittance and transmission, they can cause problems for the beam matching, especially to the downstream accelerating structures. In this paper, a novel method is being proposed to even out the potentials on all four electrode ends to ± | U vane ∕ 2 | , like in the case of 4-vane RFQs. Benefitting from this new method, a full compensation of the longitudinal component of the end-fields in the studied 4-rod RFQ model has been achieved.

The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

The RAON accelerator of Rare Isotope Science Project (RISP) has been developed to accelerate heavy ion beams generated by superconducting electron cyclotron resonance ion source (ECR-IS). The beams produced by the ECR-IS are transported through Low Energy Beam Transport (LEBT) section to Radio Frequency Quadrupole (RFQ), Medium Energy Beam Transport (MEBT) section, and low energy superconducting linac (SCL1). Prior to the construction of the RAON accelerator, the components of the LEBT section, the RFQ, the MEBT section, and the part of the SCL1 need to put to the test with the beams generated by the ECR-IS. For that reason, a test facility is under development and will be installed within a few year. Also, in order to build the test facility more efficiently within its restrictive space requirements, we designed the lattice of the test facility newly and then, with this newly designed lattice, in order to demonstrate that the test facility performs well, the start-to-end beam simulation needs to be carried out. In this paper, we will describe the new lattice design of the test facility and the result of the start-to-end beam simulation for the test facility. In addition to the simulation for the single charge state beam, the transportation and acceleration of the three charge state beams will be also examined in the test facility.

s To match the beam from the Radio Frequency Quadrupole (RFQ) accelerator to the Superconducting Half-wave Resonator (HWR) Linac, two room temperature (RT) double-gap Quarter-wave Resonator (QWR) bunchers are designed to be located in the Medium Energy Beam Transport Line (MEBT) for the C-ADS Injector II at IMP. Both cavities work at 162.5 MHz, with β=0.067 and a beam aperture diameter of 40 mm. The effective voltage of these two cavities needs to reach 135 kV in Continuous Wave (CW) mode. In this paper, the RF design and thermal analysis of the cavities will be presented, along with the tuners and coupler consideration. The measured frequencies, Rsh/Q0, Q0 and voltage of the cavities agree well with the simulation result. Details of the RF test results including the full power tests of the cavities will be shown.

Radio-frequency quadrupole (RFQ) technology incorporated into the low energy ion beam line of an accelerator system can greatly broaden the range of applications and facilitate unique experimental capabilities. However, ten’s of keV kinetic energy negative ion beams with large emittances and energy spreads must first be decelerated down to 36 Cl − ion beam with 8 eV full-width half maximum Gaussian energy spread and 35 mrad angular divergence can be efficiently decelerated and then cooled in He gas, with a maximum pressure of 7 mTorr, to 2 eV within 450 mm in the RFQs. Vacuum transmissions were 100%. Ion energy distributions at initial RFQ capture are shown to be much larger than the average value expected from the deceleration potential and this appears to be a general result arising from kinetic energy gain in the RFQ field. In these simulations, a potential for deceleration to 25 eV resulted in a 30 eV average energy distribution with a small fraction of ions >70 eV.

Typical accelerator mass spectrometry (AMS) ion sources readily produce useable currents of a wide variety of negative ions, including exotic species, and the sensitivity and dynamic range of AMS can be used for relatively unambiguous ion identification at low count rates. Difficulty producing negative ion currents with high fluxes (ex. when electron binding energies are small) and unambiguous identification of reaction products can be obstacles to negative ion-gas reaction studies. Thus, an AMS setup can be considered to be suitable for certain ion-gas reaction studies. Presented here are preliminary studies on interactions of SrF3−, YF3−, ZrF3−, YF4− and ZrF5− with NO2 gas at

Currently analysis of 36Cl by accelerator mass spectrometry (AMS) requires large facilities for separation of the isobar 36S. Previously, it has been shown possible to suppress S− by >6 orders of magnitude at low energies in a prototype radio-frequency quadrupole (RFQ) instrument by ion reactions in NO2 gas in the injection line of an AMS system. Reaction products for the negative ions S−, SO− and Cl− with NO2, and S− with N2O, have been surveyed in order to understand isobar attenuation plateaus and the losses of analyte ions. Ion energies were at eV levels, but had a large initial energy spread of at least several eV. Under these conditions, the aggregate total S− and SO− cross sections in NO2 were estimated to be 6.6 × 10−15 cm2 and 7.1 × 10−15 cm2 respectively and the major reaction channel observed was electron transfer producing NO2−. Other reaction products observed for S− were SO−, SO2−, NS−, and NSO2−. On the other hand, S−, SO− and NS− were found to be largely unreactive with N2O despite the existence of some highly exothermic reaction channels. When Cl− was injected into NO2, reaction products such as ClO− and NO2− were observed only at low levels suggesting that larger Cl− transmissions should be possible with some RFQ design modifications. The ClO− reaction product had only a small attenuation under the experimental conditions, despite having near resonant electron affinity with NO2.

Laser photodetachment is the process when the extra electron of a negative ion is removed by means of laser radiation. This can happen only if the photon energy is larger than the electron affinity of the ion. The process can be used in mass spectrometry to selectively suppress unwanted isobars, provided that the electron affinity of the unwanted isobar is lower than that of the isobar under investigation. At the Ion Laser InterAction Setup (ILIAS) at the University of Vienna laser photodetachment of negative atomic and molecular ions is studied and its applicability for selective isobar suppression in accelerator mass spectrometry (AMS) is evaluated. The setup provides mass separated beams of negative ions with energies up to 30 keV. Negative ions are produced in a Middleton type cesium sputter ion source, mass selected and overlapped with a strong continuous wave laser beam. In order to extend the interaction time of ions and laser, the ion beam is decelerated to thermal energies in a gas-filled radio frequency quadrupole cooler. For an appropriate choice of the photon energy, unwanted isobars are neutralized while the isobar of interest is unaffected and remains negatively charged. A description of the ILIAS setup and results from the commissioning phase of the RFQ cooler are presented. Up to 8% ion beam transmission could be achieved after a recent redesign of the extraction system. Furthermore first results of photodetachment experiments of 63Cu− within the RFQ cooler are presented.

The design of a radio frequency quadrupole, an important section of all ion accelerators, and the calculation of its beam dynamics properties can be achieved using the existing computational tools. These programs, originally designed in 1980s, show effects of aging in their user interfaces and in their output. The authors believe there is room for improvement in both design techniques using a graphical approach and in the amount of analytical calculations before going into CPU burning finite element analysis techniques. Additionally an emphasis on the graphical method of controlling the evolution of the relevant parameters using the drag-to-change paradigm is bound to be beneficial to the designer. A computer code, named DEMIRCI, has been written in C++ to demonstrate these ideas. This tool has been used in the design of Turkish Atomic Energy Authority (TAEK)'s 1.5 MeV proton beamline at Saraykoy Nuclear Research and Training Center (SANAEM). DEMIRCI starts with a simple analytical model, calculates the RFQ behavior and produces 3D design files that can be fed to a milling machine. The paper discusses the experience gained during design process of SANAEM Project Prometheus (SPP) RFQ and underlines some of DEMIRCI's capabilities., Comment: 7 pages, 9 figures

For the Front End Test Stand (FETS) linear accelerator project at the Rutherford Appleton Laboratory in the UK, a 4 m, 4 vanes Radio Frequency Quadrupole (RFQ) with a resonant frequency of 324 MHz has been designed. The RF power feeding the RFQ gives rise to the temperature increase in the RFQ, which in turn, results in shifting the resonant frequency of the RFQ. The frequency shift and the stability in the RFQ frequency can be maintained based on the reflected power or signal phase information. We have, however, investigated restoration of the RFQ nominal frequency based on the RF signal phases driving a stepper motor. The concept and the system set-up and electronics are described in detail. Results of the measurements indicating the full restoration of the RFQ nominal frequency based on the RF signal phases and stepper motor are presented. Moreover, measured sensitivity of tuner with respect to its position is given.

An effective potential to describe ion motion in radio frequency (rf) quadrupole fields is developed. It is based on the Mathieu equation instead of the standard averaging technique. An effective Hamiltonian series equation which is the extension of the classical effective potential approach allows determining the frequencies more accurately than in the case of the classical approach to the derivation of the effective potential; the latter uses only the first member of a Taylor series. Because the quadrupole potential is quadratic, time averaging of all the harmonics of the oscillation frequencies is possible and in this work all harmonics are considered using a strict mathematical background. The method can be applied to quadrupole operation at any value of the Mathieu parameters (a, q). With this method the ion motion in a quadrupole field is described by an effective quadratic potential and inside the stability zones this is a simple harmonic oscillator. It is shown that for a linear radio frequency (rf) quadrupole, with rf-only operation in the first stability region, the effective potential well depth, D, increases continuously with q and is given by the well-known relation D = q V 0 / 4 where V0 is the amplitude of the rf voltage, pole to ground; however, here its validity is proved for q values up to the stability boundary at q = 0.9080. The potential well size (i.e., the acceptable range of initial coordinates) is separated from the potential well depth (i.e., the acceptable range of initial kinetic energies). The theory also allows calculating the acceptable range of initial coordinates, and it is shown that these decrease with increasing q as ≈ r 0 1 − q / q * (where q* = 0.9080 is the high q boundary of the first stability zone, and r0 is the radius of the gap between electrodes) while the acceptable range of initial kinetic energies is still controlled by the potential well depth calculated as D = q V 0 / 4 . Preliminary numerical experiments and an alternate approach show the validity of the results.

Just as 2013 marks the centenary of the birth of mass spectrometry through the publication of Thomson’s classic book ‘Rays of Positive Electricity and Their Application to Chemical Analyses’, it is also exactly six decades since Paul and Steinwedel filed their first German patent ‘Verfahren zur Trennung bzw. Zum getrennten Nachweis von Ionen verschiedener spezifischer Ladung’ (‘Method for separating or separately detecting ions of different specific charges’) on 24th December, 1953. This patent described the quadrupole mass filter (QMF) and the three-dimensional quadrupole ion trap (3D-QIT), both of which operate by confining ions mass-selectively through the application of radio frequency quadrupolar potentials to appropriate electrode structures. In the ensuing 60 years since the initial description of these devices the impact of quadrupole technology upon mass spectrometry as a whole has been truly remarkable, especially when combined with chromatographic separation methods and/or other types of mass analysers. This retrospective article will aim to trace the principal milestones in the evolution of transmission quadrupoles (the QMF, quadrupole beam guides, and triple quadrupole tandem instruments) and of trapping quadrupoles (the 3D-QIT and, the more recent, linear quadrupole ion trap (LQIT)), both as stand-alone instruments and in various hybrid configurations. Recent research advances into quadrupole technology itself will be discussed; an account of ion trapping in the Kingdon trap and the Orbitrap™ mass spectrometer is included in the Supplementary Information for comparison.

This work introduces the Necsa Radio Frequency Quadrupole (RFQ) accelerator facility and its work concerning fast neutron radiography (FNR). Necsa operates a 4-5 MeV, up to 50 mA deuteron RFQ. The previous deuterium gas target station has been modified to enable producing a white neutron beam employing a solid B4C target. Furthermore, the high energy beam transport (HEBT) section is under adjustment to achieve a longer flight-path and a better focus. This work presents an overview of the facility, the modifications made, and introduces past and ongoing neutron radiography investigations.

The cross sections of 63Cu(d,p)64Cu and natCu(d,x)65Zn were determined for deuteron beam energy range of 2.77–5.62 MeV at the SARAF Phase I variable energy LINAC. Thin copper foils were irradiated by a deuteron beam followed up by measurement of the produced activation at the Soreq NRC low-background γ-counting system. The results are consistent with data in the literature, but are of better accuracy. The data are important for assessment of the activation of components of Radio Frequency Quadrupole injectors and Medium Energy Beam Transport beam dumps in modern deuteron LINACs.

A continuous-wave (CW) heavy ion radio frequency quadrupole (RFQ) accelerator was developed for the Low Energy Accelerator Facility (LEAF) at IMP. The RFQ accelerator is the most effective accelerator for accelerating the low energy high intensity beam, but there are challenges achieving the stable CW operation. This paper presents the development of the LEAF RFQ based on the stable CW operation. In the beam dynamics design, a multi-harmonic buncher is utilized to reduce the longitudinal emittance and the constant-voltage design is applied for low RF power loss. In the radio frequency (RF) design, the constant-voltage four-vane RFQ is selected to reduce the power dissipation. The π -mode stabilizing loop (PISL) is employed to reduce the admixture of the dipole field. In order to ensure the stability of the cavity structure, the multi-physics of the cavity are analysed. The resonant frequency sensitivities of the cooling water temperature are studied to tune the cavity frequency during operation. Through low power test and tuning, the resonance frequency and field distributions are optimized. The beam commissioning ( 4He 1 + , 14N 2 + and 86Kr 13 + ) and some radiation experiments have been performed. The entire processes of the LEAF RFQ development, such as, beam dynamics design, RF design, multi-physics analysis, low power test, high power conditioning, beam commissioning and some radiation experiments, will be detailed presented in this paper. The results of testing and commissioning indicate that the development of the LEAF RFQ has succeeded. And the design scheme for RFQ with stable CW operation in this work can be applied to other future CW RFQs.

Confinement of single ions in a novel radio-frequency (RF) quadrupole ion trap with spherical shape is investigated. An optimization of this spherical ion trap (SIT) is carried out in order to suppress its nonlinearity substantially by eliminating the electric octupole moment. Hence, a trapping potential and consequently an electric field very similar to the ideal quadrupole ion trap (QIT) are obtained. Afterwards, three stability regions for the optimized SIT are numerically computed. The regions coincide well with those reported in the literature for the ideal QIT. The reason is attributed to the zero electric octupole moment of our proposed trap. The simple geometry of our optimized SIT and relative ease of fabrication along with its increased trapping volume in comparison with the conventional hyperbolic quadrupole ion trap, make it an appropriate choice for miniaturization.

3 MeV H beam from the Radio Frequency Quadrupole (RFQ) will be accelerated to 80 MeV in the CSNS (China Spallation Neutron Source) linear accelerator (Linac). The wire scanner is used to measure the transverse beam profile and the emittance, and the carbon or tungsten wire is considered to use. Thermal analysis of the wire scanners in the Linac is presented in this paper. The maximum temperature (T,) of the wire decreases as the beam energy increases, and we also calculate the influence of all possible parameters on T-m. T-m, of carbon wire is significantly lower than tungsten wire if both the beam parameters and wire geometric parameters are set to the same, which can be attributed to its higher heat capacity and radiant emissivity. In addition, we present the results of sublimation rate of the wire, which show that tungsten wire has a much lower evaporation rate than carbon wire in the same temperature, which can be attributed to the different vapor pressures of the two materials. To limit the thermionic emission, the maximum beam frequency approximately has an exponential relationship with beam rms size at a certain beam pulse width. (C) 2014 Elsevier B.V. All rights reserved.

The coupled RFQ–SFRFQ (CRS) cavity designed in Peking University is a new type linac that coupled radio frequency quadrupole (RFQ) and separated function radio frequency quadrupole (SFRFQ) structure into a single cavity. An upgraded helium injector for the CRS cavity consisting of a 2.45 GHz permanent magnet electron cyclotron resonance (ECR) ion source and a 1.16 m low energy beam transport (LEBT) has been constructed and tested. The beam conditions of the injector were carefully optimized to satisfy the requirements of the CRS linac, the corresponding control system and a two-dimension scanner code CRSv1.0 were developed for optimizing the beam transmission from LEBT section to the entrance of the CRS cavity. The beam transmission efficiency has reached to approximately 87.5% as well as the optimized operating parameters were obtained by means of the scanner code.

Radio Frequency Quadrupole (RFQ) accelerators often need to face the challenges of space charge effects from high beam currents. This study investigated how to reach an efficient beam dynamics design for a 325 MHz, 3 MeV, 70–100 mA proton RFQ with not only high beam transmission and short structure length but also high beam quality simultaneously. To avoid emittance transfer which can lead to beam instabilities, a so-called e l e t (ratio of the longitudinal and transverse emittances) = 1.0 design guideline is being proposed. In this paper, the application of this design guideline integrated with the “New Four-Section Procedure” and the corresponding design results are presented.

A new Continuous Wave (CW) Radio Frequency Quadrupole (RFQ) for the ATLAS (Argonne Tandem Linac Accelerator System) Intensity Upgrade was developed, built and tested at Argonne National Laboratory. We present here a characterization of the RFQ output beam in the longitudinal phase space, as well as a measurement of the transverse beam halo. Measurement results are compared to simulations performed using the beam dynamics code TRACK.

3rd International Meeting of the Union for Compact Accelerator-driven Neutron Sources, UCANS III, 31 July–3 August 2012, Bilbao, Spain & the 4th International Meeting of the Union for Compact Accelerator-driven Neutron Sources, UCANS IV, 23-27 September 2013, Sapporo, Hokkaido, Japa. 10 pags., 9 figs.; 1 tab. Codes: ibsimu, gpt, nigun, mad, tracewin, toutatis and rfqsim., The ESS-Bilbao (ESSB) light ion linear accelerator is conceived as a multi-purpose machine that will serve as a driving force for the construction of the European Spallation Source (ESS). The first part of the ESSB injector comprises a proton source of the Electron Cyclotron Resonance (ECR) kind. The low energy beam is transported along a two solenoid Low Energy Transport System (LEBT) that will couple the ion source to the 352.2 MHz Radio Frequency Quadrupole (RFQ). This RFQ –based on a modular design where the vane sections are held in place by bolts, and the welds only serve to make the structure vacuum tight, aims to accelerate a 75 mA beam from 45 keV up to 3 MeV, while keeping the beam both transversely and longitudinally focused together with minimum emittance growth. Once the RF timing structure is set to the beam, it is conveniently matched through the Medium Energy Beam Transport (MEBT) to the Drift Tube Linac (DTL), which will take this 3 MeV beam up to the required energy by the designed Be rotating target (50 MeV). © 2014 The Authors

The upgrade to the ISOLDE facility, HIE-ISOLDE, will include an upgrade to the RFQCB (radio frequency quadrupole cooler and buncher), the focus of which will be fixing the problems of alignment with the current machine, improving the integrity of the vacuum system, stabilizing the internal gas pressure, and the changes associated with a new position. The beam passage inside the RFQCB has been simulated with an independent code to highlight the importance of the internal gas pressure, to motivate design changes in the new RFQCB and to explain ways to improve the performance of the current machine. The suspected misalignment of ISCOOL has been quantified, and, using a simulation of ions passing through the external injection electrodes, the effect of the misalignment on machine acceptance has been detailed. Plans for the future RFQCB test stand and HIE-ISOLDE installation have been outlined.