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The European Spallation Source will be driven by a 5 MW linear accelerator, producing 2.86 ms long proton beam pulses with a peak current of 62.5 mA at 14 Hz. Following the source commissioning in 2018 and 2019, the RFQ was successfully conditioned and subsequently commissioned with beam in 2021. In this paper, we will present results of studies on beam matching to the RFQ, both for low and high current beam modes, and will compare these results to model predictions., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

RFQ at ESS has been successfully gone through RF conditioning, RF re-conditioning and low duty cycle beam commissioning. RFQ fulfills required functions and overall performance is satisfactory. RF conditioning, three RF re-conditionings after LEBT intervention and beam commissioning will be reported and RFQ performance during these periods will be described. RFQ performance in a large extent is reflected by dynamics and interactions between RF, cavity and beam. Thanks to advanced hardware capabilities and intelligent software intelligence, observation of those dynamics and interactions are done in detailed level. Analysis of those dynamics and interaction will be introduced. Some techniques to deal with challenges resulted from those dynamics and interactions will also be discussed., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

A new injector called NEWGAIN will be added to the SPIRAL2 Linear Accelerator (LINAC), in parallel with the existing one. It will be mainly composed of an ion source and a Radio Frequency Quadrupole (RFQ) connected to the superconductive LINAC of SPIRAL2. The new RFQ will accelerate at 88.05 MHz particles with charge-over-mass ratio (Q/A) between 1/3 and 1/7, from 10 keV/u up to 590 keV/u. It consists of a 4-vane resonant cavity with a total length of 7 m. It is a CW machine that has to show stable operation, provide the request availability, have the minimum losses in order to provide the highest current to the superconductive LINAC and show the best quality/cost ratio. This paper will present the preliminary RF design and the thermomechanical study for this RFQ., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Radio Frequency Quadrupole (RFQ) of the European Spallation Source (ESS), operates at 352.21 MHz with an RF pulse length of 3.2 ms and repetition rate of 14 Hz. The RFQ focuses, bunches and accelerates the 62.5 mA proton beam from 75 keV up to 3.6 MeV. In an effort to study and compare the results from 3D electromagnetic codes, different models of the RFQ were simulated with CST Studio suite. This paper presents the selection of optimal parameters for simulation of the RFQ cavity voltage and comparison of the results with the RFQ design code Toutatis., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The 352.21 MHz Radio Frequency Quadrupole (RFQ) for the European Spallation Source ERIC (ESS) has been delivered by the end of 2019 by CEA/IRFU. The RFQ is designed to accelerate a 70 mA proton beam from 75 keV up to 3.62 MeV. It consists of a 4-vane resonant cavity with a total length of 4.6 m. Two coaxial power loop couplers feed the RFQ with the 1.4 MW of RF power required for beam operation. This paper first presents the main systems required for the RFQ conditioning. Then it summarizes the main steps and results of this high power RF conditioning completed at ESS from June 9 to July 29, 2021 in order to achieve the nominal field for a pulse length of 3.2ms at the repetition rate of 14Hz., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and will deliver 10 low-beta cryomodules as In-Kind Contribution to the PIP-II project, with cavities supplied by LASA-INFN and power couplers and tuning systems supplied by Fermilab. This paper presents the CEA scope of work that includes the design, manufacturing, assembly and tests of the cryomodules and the upgrade of the existing infrastructures to the PIP-II requirements., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The European Spallation Source, currently under construction in Lund Sweden, will be a spallation neutron source driven by a superconducting proton linac with a design power of 5 MW. The linac features a high peak current of 62.5 mA and long pulse length of 2.86 ms with a repetition rate of 14 Hz. The normal conducting part of the linac has been undergoing beam commissioning in multiple steps, and the main focus of the beam commissioning has been on bringing systems into operation, including auxiliary ones. In 2022, beam was transported to the end of the first tank of the five-tank drift tube linac. This paper provides a summary of the beam commissioning activities at ESS and the current status of the linac., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

Eight of the medium and high beta cryomodules deliv-ered to ESS by CEA are tested at CEA before delivery; the two medium and high beta prototypes and the three first of each type of the series. The goal of these tests is to validate the assembly and the performances on few cryomodules before the next cryomodules of the series are delivered to ESS. This paper summarizes the general results obtained during the tests at 2 K and at high RF power, Pmax = 1.1 MW. The cavities reach the ESS re-quirements, E_{acc} = 16.7 MV/m (Medium beta) and 19.9 MV/m (High beta) with an efficient compensation of the Lorentz detuning by the piezo tuner over the full RF pulse length of 3.6 ms at 14 Hz. After the successful tests at CEA, the first cryomodules have been shipped to ESS where the final acceptance test are performed., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Radio Frequency Quadrupole (RFQ) was conditioned at the European Spallation Source during spring 2021. We used part of the conditioning time to estimate the accelerating potential within the RFQ analyzing the x-rays bremsstrahlung radiation emitted by the electrons released and accelerated in the RFQ. The results of these measurements are in good agreement with the theoretical prediction., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The construction of the ESS accelerator is in full swing. Many key components have been delivered from our in-kind partners and installation, testing and commissioning is making remarkable progress. The first machine section to be commissioned with beam is the Normal Conducting Linac (NCL). When completed, a 14 Hz, 2.86 ms proton beam up to 62.5 mA will be transported from the Ion Source, through the Low Energy Beam Transport (LEBT) line, the Radiofrequency Quadrupole (RFQ), the Medium Energy Beam Transport (MEBT) line and the five Drift Tube Linac (DTL) tanks up to 90 MeV where it will be injected in the first superconducting module of the machine. This paper will highlight recent progress across the NCL, present briefly the first commissioning results and discuss the upcoming phases as well as challenges in delivering a machine capable of meeting the requirements for a next generation spallation neutron facility., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

For the development of efficient superconducting cavi-ties, field emission is an important parasitic phenomena to monitor. A diagnostic system composed of Geiger-Mueller (G-M) probes, NaI(Tl) scintillators are placed in the cryomodule test stand. Collected data is analysed and confronted to particle tracking simulation and electro magnetic shower code. With such systematic analysis we aim to identify the most probable field emission location and hence help to improve clean procedures during as-sembly and operation., Proceedings of the 20th International Conference on RF Superconductivity, SRF2021, East Lansing, MI, USA

CEA in Kind contribution to the ESS superconducting LINAC includes 30 elliptical medium and high-beta cryomodules. CEA is in charge of the production of all the components (except the cavities delivered by LASA and STFC) as well as the assembly of the cryomodules and a few cryogenic and RF tests. The power couplers operating at a maximum power of 1.1MW on a 3.6ms pulse at 14Hz are conditioned at high RF power on a dedicated stand. The assembly of the cryomodules is performed at CEA by a private Company under the supervision of CEA. This paper presents the status of the cryomodules production and the infrastructure dedicated to this project at CEA Saclay., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The 352 MHz Radio Frequency Quadrupole (RFQ) for the European Spallation Source ERIC (ESS) has been delivered by the end of 2019. It has been provided by CEA, IRFU, Saclay/France. It consists of five sections with a total length of 4.6 m and accelerates the 70 mA proton beam from 75 keV up to 3.6 MeV. It will be fed with 900 kW peak power through two coaxial loop couplers. The installation process (alignment, vacuum test), as well as the tuning process based on bead-pull measurements, is presented in this paper., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The IFMIF accelerator aims to provide an accelerator-based D-Li neutron source to produce high intensity high energy neutron flux to test samples as possible candidate materials to a full lifetime of fusion energy reactors. A prototype of the low energy part of the accelerator (LIPAc) is under construction at Rokkasho Fusion Institute in Japan. It includes one cryomodule containing 8 half-wave resonators (HWR) operating at 175 MHz and eight focusing solenoids. The talk will cover the progress of developments in the IFMIF/EVEDA cryomodule: the qualification of 8 cavities, the RF conditioning results of 8 high-power couplers, the manufacturing and test of the 8 superconducting solenoids and the equivalent operational equivalent tests performed at Saclay. The assembling status of the cryomodule at Rokkasho site will also be presented., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany

The prototype IFMIF-EVEDA cryomodule encloses eight superconducting 175 MHz β=0.09 Half-Wave Resonators (HWR). They are designed together with the power coupler to accelerate a high intensity deuteron beam (125 mA) from to 5 to 9 MeV. Two cavity packages, complete with tuning system and power couplers, have been tested in a dedicated horizontal test cryostat - SaTHoRI (Satellite de Tests HOrizontal des Résonateurs IFMIF). The successful operational equivalent tests and tuning of the SRF accelerating units is reported., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany

CEA Saclay is in charge of the cavity prototypes that is designing, manufacturing, testing and integrating them into demonstrator cryomodules. We have manufactured 6 medium beta and 5 high beta cavities. As part of these activities we are interested in field emission as one of the limiting factors for cavity performances. We are currently collecting data from cavities operated in vertical cryostat and inside cryomodules. Analysis are carried out by means of particle tracking simulation and comparison with radiation dose monitor and scintillators., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany

The SPIRAL2 RFQ was recently successfully commissioned at nominal voltage of 114 kV, corresponding to 1.65 Kilpatrick factor. The paper describes limitations of the RFQ main subsystems, cavity conditioning difficulties, as well as changes implemented in the LLRF and automatic procedures to simplify turn on and operation of the whole system., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

Three normal conducting rebunchers will be installed at the Medium Energy Beam Transport (MEBT) of the SARAF-LINAC phase II [saraf]. The MEBT line is designed to follow a 1.3 MeV/u RFQ, is about 5 m long, and contains three 176 MHz rebunchers providing a field integral of 10⁵ kV. CEA is in charge of the design and fabrication of the Cu plated stainless steel, 3-gap rebuncher. The high power tests and RF conditioning have been successfully performed at the CEA Saclay on the first cavity. A solid state power amplifier, which has been developed by SNRC and has been used for the RF tests. The cavity has shown a good performance according to calculations, regarding the dissipated power, peak temperatures and coupling factor. RF conditioning was started with a duty cycle of 1\% and increased gradually until continuous wave (CW), which is the nominal working mode in SARAF-LINAC., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

SNRC and CEA collaborate to the upgrade of the SARAF accelerator to 5 mA CW 40 MeV deuteron and proton beams (Phase 2). CEA is in charge of the design, construction and commissioning of the MEBT line and the superconducting linac (SARAF-LINAC Project). The prototypes of the 176 MHz NC rebuncher, SC cavities, RF coupler and SC solenoid-Package have been tested recently. Meanwhile, the cryomodules technical specifications have been written and called for tender. This paper presents the status of the SARAF-LINAC Project at April 2019., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

CEA is committed to delivering a Medium Energy Beam Transfer line and a Super Conducting Linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons from 1.3MeV to 35MeV or deuterons from 2.6 MeV to 40.1MeV. The SCL consists in 4 cryomodules separated by warm section housing beam diagnostics. The two first identical cryomodules hosts respectively 6 and 7 half-wave resonator (HWR) low beta (0.091) cavities 176MHz. In order to test the cavity with its tuner and coupler and validate some design consideration, the Equipped Cavity Test Stand (ECTS) has been designed and will be presented., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

CEA is committed to delivering a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons to 35 MeV or deuterons to 40 MeV. The SCL consists in 4 cryomodules. The first two cryomodules host 6 7 half-wave resonator (HWR) low beta cavities (β = 0.09) at 176 MHz, and the last two crymodules host 7 HWR medium beta cavities (β = 0.18). The low beta prototype was qualified, the medium beta is being qualified. The results of the RF tests will be presented in this poster., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The 352 MHz Radio Frequency Quadrupole (RFQ) for the European Spallation Source ERIC (ESS) will be de-livered during 2019. It is provided by CEA, IRFU, Sac-lay/France. It consists of five sections with a total length of 4.6 m and accelerates the proton beam from 75 keV up to 3.6 MeV. It will be feed with 1.6 MW peak power through two coaxial loop couplers. This paper will present the manufacturing status of the five sections and the qualification test of the RF power couplers., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

CEA is in charge of the 30 elliptical medium and high-beta cryomodules to be installed in the ESS tunnel in Lund, Sweden. Before launching the assembly of the series cryomodules, CEA developed a medium-beta cryomodule technology demonstrator in a collaboration with IPNO, LASA and ESS. This paper briefly presents the cryomodule assembly and summarizes the main results of the high RF power tests performed in 2018 in a dedicated test stand in CEA Saclay. The main ESS requirements were reached: E_{acc} = 16.7 MV/m in cavities, Pforward = 1.1 MW in power couplers, RF pulses length = 3.6 ms at 14 Hz. The piezo tuners efficiently compensated the Lorentz forces detuning and could stabilize the accelerating field better than 1% over the full length of the expected ESS 2.86 ms beam pulse without any LLRF regulation system. Following this successful validation CEA started the assembly of the first ESS medium-beta series cryomodule, Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

A new type of Beam Loss Monitor (BLM) system is being developed for use in the European Spallation Source (ESS) linac, primarily aiming to cover the low energy part (proton energies between 3-100 MeV). In this region of the linac, typical BLM detectors based on charged particle detection (i.e. Ionization Cham-bers) are not appropriate because the expected particle fields will be dominated by neutrons and photons. Another issue is the photon background due to the RF cavities, which is mainly due to field emission from the electrons from the cavity walls, resulting in brems-strahlung photons. The idea for the ESS neutron sensi-tive BLM system (ESS nBLM) is to use Micromegas detectors specially designed to be sensitive to fast neutrons and insensitive to low energy photons (X and gammas). In addition, the detectors must be insensitive to thermal neutrons, because those neutrons may not be directly correlated to beam losses. The appropriate configuration of the Micromegas operating conditions will allow excellent timing, intrinsic photon back-ground suppression and individual neutron counting, extending thus the dynamic range to very low particle fluxes., Proceedings of the 61\textsuperscript{st} ICFA ABDW on High-Intensity and High-Brightness Hadron Beams, HB2018, Daejeon, Korea

The RF power coupler system for the RFQ of the ESS LINAC will feed 1.6 MW peak power through two coaxial loop couplers for a 352.21 MHz operation at the expected duty cycle. A specific test stand has been designed to condition the power couplers, and test the different auxiliary components in the nominal conditions of the RFQ. The power couplers were successfully assembled, installed and instrumented on the test cavity. This paper presents the general layout of the test stand, the installation and preparation of the power couplers for their conditioning at high RF power up to the ESS nominal conditions., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The 352 MHz Radio Frequency Quadrupole (RFQ) for the European Spallation Source ERIC (ESS) will be delivered during 2018. After delivery, installation and tuning of the cavity, the high power RF conditioning will be performed. At this point all the different systems that are needed to condition and operate the RFQ have to be in place and operational. This paper will give an overview of the system analysis that has been performed for the RFQ. The RFQ requirements for the RF system, including the RF distribution system (RFDS), the Low Level RF (LLRF) and the local RF protection system (RFLPS) will be presented. In addition, the paper covers the system integration of the structure in the ESS control and vacuum systems as well as the outcome of a machine protection analysis., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

Two ESS elliptical cavities cryomodule prototypes are being developed and will be tested at CEA Saclay before starting the series production. This paper presents the preliminary test results of the first medium beta cavities cryomodule demonstrator M-ECCTD. The measurements of the cryogenic performances at 80 K and 2 K of the different cryomodule components and circuits are given. The first RF test results performed at low power are also reported., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

For the first time, in April 2016, the SILHI source produced a proton beam for IPHI RFQ. Due to several technical difficulties on the RFQ water cooling skid, a short RF power pulse (100 μs at the beginning until few hundred microseconds) is injected into the RFQ accelerates the high intensity proton beam up to 3 MeV. The repetition rate is tuned between 1 and 5 Hz. Under these conditions, the beam power after the RFQ is lower than 100 W. At the end of 2017, the 352 MHz RFQ conditioning has been completed (with the same duty cycle) and the proton beam has been accelerated. The increase of the beam power is expected to continue in 2018 in order to reach several kilowatts by the end of the year. In addition, two Ionization beam Profile Monitors (IPM) developed for ESS have been tested on the deviated beam line with a very low duty cycle. The IPHI facility should demonstrate the possibility to produce neutrons with a flexible compact accelerator in the framework of the SONATE project. This paper presents the status of the IPHI project in April 2018., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The SaTHoRI test stand (Satellite de Tests Horizontal des Résonateurs IFMIF) aims to characterize a jacketed and fully dressed cavity with its coupler and tuner. A dedicated test cryostat has been manufactured and is connected to an existing horizontal test cryostat which provides the cryogenic coolant. A RF source ' provided by the IFMIF collaboration, one of the four RF sources which will be used for the cryomodule at Rokkasho ' has been installed and commissioned at CEA. This paper describes the test stand and presents the first results., Proceedings of the 18th Int. Conf. on RF Superconductivity, SRF2017, Lanzhou, China

CEA Saclay in collaboration with IPN Orsay is in charge of the ESS elliptical cavities cryomodule design, prototyping and series production. Two cryomodule prototypes are being developed and will be tested at CEA Saclay before starting the series production. The main cryomodule design features are first reminded. We present the cavities and couplers test results and the achieved assembly sequences of the first medium beta cavities cryomodule demonstrator M-ECCTD. The progress on the preparation of the CEA cryomodule test station is given. The procurement status and development plan of the second high beta demonstrator H-ECCTD are also reported. Finally we give the components procurement progress and the assembly strategy of the 30 series cry-omodules to be integrated at CEA before delivery to ESS at Lund., Proceedings of the 18th Int. Conf. on RF Superconductivity, SRF2017, Lanzhou, China

The IFMIF accelerator aims to provide an accelerator-based D-Li neutron source to produce high intensity high energy neutron flux to test samples as possible candidate materials to a full lifetime of fusion energy reactors. A prototype of the low energy part of the accelerator is under construction at Rokkasho in Japan. It includes one cryomodule containing 8 half-wave resonators (HWR) operating at 175 MHz and eight focusing solenoids. This paper presents the status of the IFMIF SRF Linac., Proceedings of the 18th Int. Conf. on RF Superconductivity, SRF2017, Lanzhou, China

The IFMIF accelerator aims to provide an accelerator-based D-Li neutron source to produce high intensity high energy neutron flux to test samples as possible candidate materials to a full lifetime of fusion energy reactors. A prototype of the low energy part of the accelerator is under construction at Rokkasho in Japan. It includes one cryomodule containing 8 half-wave resonators (HWR) operating at 175 MHz .The first manufactured HWR has passed low power tests at 4.2K in vertical cryostat succesfully and exceeds the specifications. It has also been tested in the dedicated horizontal Sathori cryostat equiped with its cold tuning system. The serial production and qualification tests of the 8 cavities which will eventually equip the cryomodule are carried out in parallel. In this paper, we focus on the HWR preparation and test results and give a status of the manufacturing activities., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

This article presents the preparation work performed by CEA for the assembly of the IFMIF Cryomodule. Before the shipping of the components to Japan many tests and trial assemblies has been realized on the CEA site of Saclay, France. The cryomodule, which is part of the Linear IFMIF Prototype Accelerator (LIPAc) under construction at Rokkasho in Japan, will be assembled there under the responsibility of F4E (Fusion for Energy) with CEA assistance. To fulfill the assembly of the cavity string, a cleanroom will be built at Rokkasho under the responsibility of QST., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The SPIRAL2 RFQ is designed to accelerate light and heavy ions with A/Q from 1 to 3 at 0.73 MeV/A. The nominal beam intensities are up to 5 mA CW for both proton and deuteron beams and up to 1 mA CW for heavier ions. The four-vane cavity is made with 5 1-meter long sections mechanically assembled, it works at 88 MHz and is powered up to 180 kW CW to achieve the nominal vane voltage of 113.7 kV for A/Q = 3 ions. This paper describes the RF conditioning of the RFQ at GANIL with the setting of its RF systems and cooling system used to tune the cavity resonance frequency., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

This paper gives the fabrication status of the IFMIF cryomodule. This cryomodule will be part of the Linear IFMIF Prototype Accelerator (LIPAc) whose construction is ongoing at Rokkasho, Japan. It is a full scale of one of the IFMIF accelerator, from the injector to the first cryomodule. The cryomodule contains all the necessary equipment to transport and accelerate a 125 mA deuteron beam from an input energy of 5 MeV up to the output energy of 9 MeV. It consists of a horizontal vacuum tank of around 6 m long, 3 m high and 2.0 m wide, which includes 8 superconducting HWRs for beam acceleration, working at 175 MHz and at 4.45 K, 8 Power Couplers to provide RF power to cavities up to 70 kW CW in LIPAc case and 200 kW CW in IFMIF case, and 8 Solenoid Packages as focusing elements., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The first ESS prototype cryomodule with medium beta cavities named M-ECCTD is being assembled at CEA Saclay. The Q curves of the 4 cavities mounted inside the cryomodule are presented, and the four power couplers have been conditioned at high power before their assembly onto the cavity string. Completion of the M-ECCTD assembly outside clean room is in progress as well as the finalization of the RF power test stand preparation. RF power tests of the M-ECCTD will be performed during summer 2017. CEA is preparing the production of the ESS medium and high beta cryomodules of the series before the test of the M-ECCTD and the contracts for the procurement of the most critical components have already been signed, Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The European Spallation Source (ESS) will deliver first protons on target by mid 2019. Civil construction of the accelerator tunnel has made good progress and will allow starting installation of the normal conducting frond end (NCFE) by end of 2017. To achieve these milestones the design of all major beam line components have been completed and the construction of the subsystems begun. We report on the advancement of the subsystems and the commissioning progress of the microwave discharge Proton Source (PS-ESS)., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

The ESS Radio-Frequency Quadrupole (RFQ) is a 4-vane resonant cavity designed at the frequency of 352.21 MHz frequency. It must accelerate and bunch a 70 mA proton beams from 75 keV to 3.62 Mev of energy with a 4% duty cycle. The current 3D design evolved and is currently divided in 5 segments for a total length of 4.54 m. This paper presents a complete radiofrequency (RF) analysis using the ANSYS Multiphysics 3D RF simulating code HFSS and a RFQ 4-wire transmission line model (TLM). It describes the integrated cooling strategy based on a coupling between the RF power losses and the thermo-mechanical physics in order to allow a proper RFQ tuning once under operation., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

The ESS Radio-Frequency Quadrupole (RFQ) is a 4-vanes resonant cavity designed at the frequency of 352.21 MHz. It must accelerate and bunch a 70mA proton beams from 75keV to 3.62MeV with a 4% duty cycle. The RFQ design has already been done, and documented in other papers. This one will present the global status of the RFQ, with technical solutions cho-sen for the main components (for fabrication and op-eration) and the present status of the RFQ fabrication., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

Vane RFQs are particularly well suited to high intensity proton acceleration, since they offer minimal RF power losses and best accelerating field accuracy. Cea-Irfu is involved in several developments of 4 vane RFQs namely IPHI, Spiral2, Linac4 and ESS. This paper gives an overview of the design flow and tools developed at Irfu in order to design, tune, condition and commission RFQs. SPIRAL2 RFQ will be mainly used to illustrate this design flow. This CW RFQ requires 180 kW to achieve the nominal accelerating voltage. It can accelerate a 5 mA proton or deuteron beam (A/Q=1 and 2) or a 1 mA ion beam with up to A/Q=3 at 0.75 MeV/A. Conditioning and commissioning of this RFQ are actually in progress., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

During the fabrication of an RFQ, deviation from the perfect geometry will occur during assembling, brazing and machining the different parts. These geometrical defects will impact the theoretical inter-vane voltage, given by the beam dynamics, by altering the quadrupolar component as well as adding dipolar terms in the voltage function. Tuners can correct partially the effect of the manufacturing. The study summarizes the effects of the voltage errors on the beam quality in the case of the ESS RFQ with a harmonic analysis of the voltage function. We discuss the acceptable level of voltage errors and associated mechanical tolerances., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

In the frame of the European Spallation Source (ESS) project, a linear accelerator composed of a superconducting section is being developed. This accelerator owns two kinds of cavities called “medium beta cavity” (β=0.67) and “high beta cavity” (β= 0.86). These cavities are equipped with RF power couplers whose main characteristics are: fundamental frequency: 704.42MHz, peak RF power: 1.1MW, repetition rate: 14Hz, RF pulse width>3.1ms. These couplers are common to the two cavities. The CEA Saclay is responsible for the design, the manufacture, the preparation and the conditioning of the couplers used for the Elliptical Cavities Cryomodule Technological Demonstrators (ECCTD). This work is performed in collaboration with ESS and the IPNO. This paper describes the coupler architecture, its different components, the main characteristics and the specific features of its elements (RF performance, dissipated power, cooling, coupler box test for the conditioning). The status of the manufacture of each coupler part is also presented., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada

All SPIRAL2 cryomodules (twelve with one quarter wave resonator (QWR) at β=0.07 and seven with two QWRs at β=0.12) have been produced and qualified, and are now in installation phase on the LINAC at GANIL. After a general introduction on the LINAC, we will first remember and compare the different design choices taken for the two families of cryomodules. We will then present a summary of the techniques used for the preparation and integration of the cavities in the cryomodules, and compare the achieved performances with design parameters. At last, we describe the status of the LINAC installation as of end of August 2015., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada