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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

For several years, CEA has been involved in the development of superconducting linac for fusion related project, with the goal to develop an high flux neutrons source to test and qualify specific materials to be used in fusion power plants. In the framework of the ITER Broder Approch, a prototype cryomodule is under construction in Japan for the IFMIF/EVEDA phase(Engineering Validation and Engineering Design Activities) and the construction of the Accelerator Prototype (LIPAc) at Rokkasho, fully representative of the IFMIF low energy (9 MeV) accelerator (125 mA of D⁺beam in continuous wave). Meanwhile, the design studies of a plant called DONES (Demo Oriented NEutron Source, derived from IFMIF) started, with a superconducting linac made of 5 cryomodules. These one are based on the same principles as the one developed for IFMIF/EVEDA, but taking into account the lessons learnt from the prototype. This paper will present the similarities but also the differences between the cryomodules for IFMIF/EVEDA and DONES., Proceedings of the 20th International Conference on RF Superconductivity, SRF2021, East Lansing, MI, USA

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 is responsible of the 650 MHz low-beta section made of 9 cryomodules, with the design of the cryostat (i.e the cryomodule without the cavities, the power couplers and the frequency tuning systems) and the manufacturing of its components, the assembly and tests of the pre-production cryomodule and the 9 series ones. This paper will present the design of the 650 MHz low-beta cryomodule., Proceedings of the 20th International Conference on RF Superconductivity, SRF2021, East Lansing, MI, USA

The prototype High Beta 650 MHz cryomodule (pHB650 CM) has been designed by an integrated design team, consisting of Fermilab (USA), CEA (France), STFC UKRI (UK), and RRCAT (India). The manufacturing and assembly of this prototype cryomodule is being done at Fermilab, whereas the production cryomodules will be manufactured and assembled by STFC-UKRI. As the first PIP-II cryomodule for which standardization was applied, the design, manufacturing and assembly of this cryomodule led to significant lessons being learnt and experiences gathered. These were incorporated into the design of the pre-production Single Spoke Resonator Type 2 cryomodule (ppSSR2 CM) and the pre-production Low Beta 650 MHz cryomodule (ppLB650 CM). This paper presents the pHB650 CM lessons learned and experiences gathered from the design to the lower coldmass assembly and how this cryomodule has a positive impact on all the next Proton Improvement Plan-II (PIP-II) cryomodules due to the standardization set up among SSR and 650 cryomodules., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

Construction and validation of the Linear IFMIF Prototype Accelerator (LIPAc) have been conducted under the framework of the IFMIF/EVEDA project. The LIPAc consists, in its final configuration, of a 100 keV injector and the world longest 5 MeV RFQ accelerator, followed by a MEBT with high space charged and beam loaded re-buncher cavities, an HWR-SRF linac, HEBT with a Diagnostic Plate, ending in a Beam Dump (BD) designed to stop the world highest deuteron current of 125 mA CW at 9 MeV. The beam commissioning at a low duty cycle of ~0.1 % led to a successful RFQ acceleration of 125 mA and 5 MeV beam in 2019. The following beam commissioning phase was initiated in July 2021 with a temporary transport line replacing the SRF linac. The major goals of this phase are to validate the RFQ, MEBT and BD performances up to CW and to characterize the beam properties in preparation to the final configuration with the SRF linac. This paper will present progresses made in this phase so far, such as a low-current and low-duty beam commissioning completed in Dec. 2021, CW operation campaign of the injector towards the nominal beam current, and RF conditioning of the RFQ towards CW., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

The Proton Improvement Plan II (PIP-II) is the first U.S. accelerator project that will have significant contributions from international partners. The prototype High Beta 650 MHz cryomodule (pHB650 CM) is designed by an integrated design team, consisting of Fermilab (USA), CEA (France), UKRI-STFC (UK), and RRCAT (India). The manufacturing assembly of this prototype cryomodule will be done at Fermilab, whereas the production cryomodules will be manufactured and/or assembled by UKRI-STFC, RRCAT, or Fermilab. Similar to the prototype Single Spoke Resonator 1 cryomodule (pSSR1 CM), this cryomodule is based on a strong-back at room temperature supporting the coldmass. The pSSR1 CM led to significant lessons being learnt on the design, procurement, and assembly processes. These lessons were incorporated into the design and processes for the pHB650 CM. Amongst many challenges faced, the main challenges of the pHB650 CM design were to make the cryomodule compatible to overseas transportation and to design components that can be procured in USA, Europe, and India., Proceedings of the 20th International Conference on RF Superconductivity, SRF2021, East Lansing, MI, USA

The IFMIF-DONES (DEMO-Oriented Neutron Early Source) facility has passed the preliminary design phase and the detailed design phase is very much advanced. Next step will be the preparation phase for the construction of the facility. The DONES facility aims at developing a database of fusion-like radiation effects on materials to be used in future fusion reactors up to damage levels expected in the EU DEMO. It will be based on an intense neutron source created by an accelerated deuteron beam (125 mA CW, 40 MeV) impinging on a liquid lithium curtain. The DONES Accelerator Systems (AS) will be responsible of delivering this 5 MW D⁺ beam with very high availability. The beam acceleration will be performed by several stages: an ion source and LEBT, an RFQ, a MEBT, an SRF Linac and a HEBT transporting and delivering an optimized profile down to the target. A high power RF system and several ancillaries will ensure the equipment is properly operated. This contribution will report the present status of the AS design, the main challenges faced, the R programme to overcome them, and the prospects for the construction and commissioning of the DONES accelerator in Granada (Spain)., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

核融合エネルギー分野における日本と欧州による共同事業の一つとして始まった強力中性子源である国際核融合材料照射施設（IFMIF）の工学実証・工学設計活動(EVEDA) では、IFMIFの工学設計・主要機器の製作・試験が実施されている。この活動の一環として、原型加速器(LIPAc)の建設がQST六ヶ所核融合研究所で進行中である。LIPAｃを構成するコンポーネントの一つである超伝導高周波加速器(SRF)は、125 mAの重陽子ビームを5 MeVから9 MeVまで加速する設計となっている。SRFクライオモジュールの組立ては当初欧州で行われる予定だったが、輸送による機器損傷のリスクを避けるため、六ヶ所で組立てられることになった。そこで、クライオモジュールの組立てに必要な作業環境の整備がQSTの責任のもと行われ、2019年3月からF4Eの責任のもと組立作業が始まり、2019年度内の完了を目標としている。環境整備として、クライオモジュール組立てに必要なクリーンルーム(ISO 14644-1 class 5)の導入、またスロー排気システムや高純度ガス設備等の構築を行った。本発表では環境整備作業や各設備の詳細、組立作業の現状及び今後の予定について報告する。, 第16回日本加速器学会年会

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

International audience; The prototype IFMIF cryomodule encloses eight superconducting 175 MHz beta 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. One prototype HWR and the 8 cavities to be hosted in the cryomodule have been manufactured, prepared and tested. The paper describes the phases of the cavities development, including fabrication, processing, and RF resonant frequency management. We focus on the results of the RF tests which have been performed for all bare and jacketed HWRs in a vertical cryostat.

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

In the framework of the IFMIF/EVEDA project, the cryomodule of the Linear IFMIF Prototype Accelerator (LIPAc) will be assembled then tested at Rokkasho in 2019. Eight Series Power Couplers (PC) operating at 175 MHz were manufactured under a CEA contract, in order to equip this Cryomodule. They were all successfully RF conditioned up to 100 kW CW in TW and SW configurations. All the high RF power tests were performed under CIEMAT responsibility in BTESA Company premises, according to the CEA requirements. In order to fix difficulties encountered during the fab process, manufacturing and quality control have been analyzed in depth. Thanks to the corrective actions implemented, every PC reached the performances targeted for qualification. This paper will give details about this manufacturing phase and provide an overview of the obtained RF test results., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

International audience; The goal of the IFMIF-DONES (International Fusion Materials Irradiation Facility-DEMO Oriented Neutron Source) project is to build an irradiation facility that will provide a sufficient neutron flux to study and characterize structure materials foreseen for future fusion power plant. In order to accelerate the required 125mA/40 MeV continuous deuteron beam from 5 MeV to 40 MeV, a superconducting radio-frequency (SRF) linac, housed in five cryomodules, is proposed. The design is based on two beta families (β=0.11 and β=0.17) of half-wave resonators (HWR) at 175MHz. The transverse focusing is achieved using one solenoid coil per focusing period. This paper presents the extensive multiparticle beam dynamics simulations that have been performed to adapt the beam along the SRF-linac in such a high space charge regime. As one of the constraints of the IFMIF linac is a low level of beam losses, specific optimizations have been done to minimize the beam occupancy in the line (halo). A Monte Carlo error analysis has also been carried out to study the effects of misalignments or field imperfections (static errors) and also vibrations or power supplies ripple (dynamic errors). The results of these errors studies are presented and discussed.

The staged installation and commissioning of LIPAc is ongoing at Rokkasho Fusion Institute of QST, Japan for validating the low energy section of the IFMIF deuteron accelerator up to 9 MeV. The LIPAc Superconducting Radio Frequency accelerator (SRF) cryomodule is assembled under the responsibility of the EU Home Team, and the assembly work recently started at Rokkasho in March 2019. To fulfil the cleanliness requirements for the assembly process, QST took the responsibility to prepare the infrastructure of a cleanroom and associated devices. In this present paper, the details of the preparation work for the cryomodule assembly made by QST will be presented., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany

International Fusion Materials Irradiation Facility (IFMIF) is the neutron source for simulating fusion reactor environment using two 40 MeV/125 mA CW D+ beams. LIPAc facility is under construction in Rokkasho for validating 9 MeV/125 mA CW linac technology as a prototype of the IFMIF accelerator. Commissioning of 5 MeV CW RFQ is underway after the completion of installation of RFQ, MEBT, diagnostic plate. low power beam dump, RF power system and their auxiliaries. As the first step, high power RF conditioning is planned to complete in early 2018 and beam commissioning will start with stepwise approach at the same time. The status of LIPAc construction for preparing 9 MeV acceleration and results of RFQ beam commissioning are presented., 29th Linear Accelerator Conference-LINAC18

International audience; The IFMIF project aiming at material tests for a future fusion DEMO reactor is under the EVEDA phase in the BA Agreement of fusion program between Japan and EU. As the accelerator activity, the installation and commissioning of the Linear IFMIF Prototype Accelerator (LIPAc) is at the second stage of demonstration of the feasibility of the low energy section of an IFMIF deuteron accelerator up to 9 MeV with a beam current of 125 mA, CW. The installation of injector, RFQ, MEBT, D-Plate and LPBD for LIPAc with 8 coaxial high-power transmission lines and RF power system was just done in 2017 at Rokkasho, Japan. After that, the RF conditioning of RFQ for beam commissioning is underway. The beam commissioning of RFQ with H⁺/D⁺ and the acceleration demonstration up to 5 MeV-125 mA-0.1% duty cycle with D⁺ will be done.

The DONES (DEMO oriented neutron source) project is aimed at constructing a DEMO of IFMIF to provide sufficient material damage [1]. In the SRF-Linac of this project, losses can cause harmful material activation and must be maintained much less than 1W/m. It's a challenge to keep losses at such a low level with high beam power and high space charge. This paper presents two designs of the DONES SRF-Linac, one with 4 cryomodules and another with 5 cryomodules. The design details to reduce the losses and the multi-particle simulation results will be shown. The errors studies for these results will also be discussed., 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 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 from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40.1 MeV. The SCL consists in 4 cryomodules separated by warm diagnostics housing beam diagnostics. The first two identical cryomodules host 6 half-wave resonator (HWR) low beta cavities (β = 0.091), 176 MHz. The last two identical cryomodules are equipped with 7 HWR high-beta cavities (β = 0.181), 176 MHz. The beam is focused through superconducting solenoids located between cavities housing steering coils. A Beam Position Monitor is placed upstream each solenoid. A diagnostic box containing a beam profiler and a vacuum pump will be placed at the end of each cryomodule. The cryomodules and the warm sections are being designed. These studies will be presented in this poster., 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

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 superconducting linac (SARAF-LINAC Project). This paper presents to the accelerator community the status at March 2017 of the SARAF-LINAC Project., 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

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 superconducting linac (SARAF-LINAC Project). This paper presents to the accelerator community the status at August 2016 of the SARAF-LINAC Project., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

The International Fusion Materials Irradiation Facility (IFMIF) aims to provide an accelerator-based, D-Li neutron source to produce high energy neutrons at sufficient intensity and irradiation volume for DEMO materials qualification. Part of the Broader Approach (BA) agreement between Japan and EURATOM, the goal of the IFMIF/EVEDA project is to work on the engineering design of IFMIF and to validate the main technological challenges which, among a wide diversity of hardware includes the LIPAC (Linear IFMIF Prototype Accelerator), a 125 mA CW deuteron accelerator up to 9 MeV mainly designed and manufactured in Europe. The aim of this paper is to address the engineering issues of the MEBT and SRF linac related to assembly and Integration at LIPAc facility, focusing in the seismic analysis of the beamlines to ensure the robustness of the equipment and the alignment activities with the cutting edge technology performed in Europe before sending the components to Rokkasho. These activities are essential before starting the installation process of the MEBT in the first half of 2016, and to initiate the assembly and integration of the SRF Linac cryomodule in the next phase., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

The IFMIF aims to provide an accelerator-based, D-Li neutron source to produce high energy neutrons at sufficient intensity. Part of the BA agreement (Japan-EURATOM), the goal of the IFMIF/EVEDA project is to work on the engineering design of IFMIF and to validate the main technological challenges which includes a 125mA CW D⁺ accelerator up to 9 MeV mainly designed and manufactured in Europe. The components are in an advanced stage of manufacturing. The first components which allow the production of a 140 mA-100 keV deuteron beam have been delivered, installed and under commissioning at Rokkasho. The second phase (100 keV to 5 MeV) will end by March 2017. The third phase (short pulse) and forth phase (cw) will be the integrated commissioning of the LIPAc up to 9 MeV. The duration of the project has been recently extended up to end 2019 to allow the commissioning and operation of the whole accelerator (1MW). The aim of this paper is to give an overview of the LIPAc, currently under commissioning in Japan, to outline the engineering design and the development of the key components, as well as the expected outcomes of the engineering work, associated with the experimental program., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power CW accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV, a Linear IFMIF Prototype Accelerator (LIPAc) is presently under construction for the first phase of the project. Eight power couplers are needed for the cryomodule of LIPAc. After the validation of the two prototypes, the manufacturing of the Series Power Couplers was lunched. This paper will report the status of the manufacturing progress. It will also describe the acceptance tests in addition to the criteria adopted for these critical RF power units. The manufacturing imperfections and some finishing techniques used for the different parts will be also presented and discussed., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

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 from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40.1 MeV. The SCL consists 4 cryomodules equipped with warm diagnostics. The first two identical cryomodules host 6 half-wave resonator (HWR) low beta cavities (β = 0.091), 176 MHz. As the last two identical welcome 7 HWR high-beta cavities (β = 0.181), 176 MHz. The beam is focused through the superconducting solenoids located between cavities housing steering coils. A Beam Position Monitor is placed upstream each solenoid. A diagnostic box containing a beam profiler, a bunch length monitor and a vacuum pump will be inserted between 2 consecutive cryomodules. The HWR cavities, the solenoid package and the cryomodules are being designed. These studies will be presented in this poster., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada

The IFMIF LIPAc cryomodule houses eight half-wave resonators and eight solenoids which will be assembled on a support frame in clean room. Due to the short lattice defined by beam dynamics constraints, there is not much room between two elements for the operators’ hands to connect them. In order to test, optimize and validate the clean room assembly procedures and the associated tools, a test bench, consisting of a frame, a little bigger than one eight of the final support has been manufactured. In order to start the tests before the delivery of the actual key components of the cryomodule, a dummy cavity, solenoid and coupler were manufactured and will be used to perform tests outside and inside the clean room to validate the assembly procedure and the tools. The mock-up will then be used to train the operators for the assembly of the whole string., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada

The IFMIF accelerator aims to provide an accelerator-based D-Li neutron source to produce high intensity high energy neutron flux for testing of candidate materials for use in fusion energy reactors. The first phase of the project, called EVEDA (Engineering Validation and Engineering Design Activities) aims at validating the technical options by constructing an accelerator prototype, called LIPAc (Linear IFMIF Prototype Accelerator) whose construction has begun. 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 output energy of 9 MeV. It consists of a horizontal vacuum tank approximately 6 m long, 3 m high and 2.0 m wide, and includes 8 superconducting HWRs working at 175 MHz and at 4.45 K for beam acceleration. 8 Power Couplers provide RF power to the cavities up to 70 kW CW in the LIPAc case and 200 kW CW in the IFMIF case, with 8 Solenoid Packages acting as focusing elements. This paper gives an overview of the progress, achievements and status of the IFMIF SRF LINAC., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

This paper provides an overview of the final design and fabrication status of the IFMIF cryomodule, including the design issues, and deals with the strategies implemented in order to mitigate the main technical and logistical risks identified. The seismic constraints as well as licensing requirements, transportation issue and assembly process are also addressed. The IFMIF cryomodule presented here will be part of the LIPAc project (Linear IFMIF Prototype Accelerator). It is a full scale prototype of one of the IFMIF accelerators, from the injector to the first cryomodule, aiming at validating the technical options for the future accelerator-based D-Li neutron source to produce high intensity high energy neutron flux for testing of candidate materials for use in fusion energy reactors. The cryomodule contains all the equipment to transport and accelerate a 125 mA deuteron beam from an input energy of 5 MeV up to 9 MeV. It consists of a horizontal cryostat of about 6 m long, 3 m high and 2 m wide, which includes 8 superconducting HWRs for beam acceleration working at 175 MHz and at 4.5 K, 8 power couplers to provide RF power to cavities, and 8 Solenoid Packages as focusing elements., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada

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. The first phase of the project aims at validating the technical options for the construction of an accelerator prototype, called LIPAc (Linear IFMIF Prototype Accelerator). A cryomodule hosting 8 Half Wave Resonators (HWR) at 175 MHz will provide the acceleration from 5 to 9 MeV. We report on the progress of the HWR manufacturing. A pre-series cavity will be used to assess and optimize the tuning procedure of the HWR, as well as the processing steps and related tooling. A new horizontal test cryostat (SATHORI) is also being set up at Saclay in the existing SRF test area. The SATHORI is dedicated to the IFMIF HWR performance check, fully equipped with its power coupler and cold tuning system. A 30kW-RF power will be available for these tests., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada

Protecting superconducting cavities from the surrounding static magnetic field is considered as a key point to reach very good cavity performances. This can be achieved by both limiting the causes of magnetic flux around the cavity in the cryomodule, and enclosing cavities and/or cryomodules into magnetic shields. We will present the effort made at CEA into this direction: shield design, shield material characterization, at room and cryogenic temperature, and search and attenuation of the magnetic background present in the cryomodule during the cavities superconducting transition. This last point will be especially studied for the IFMIF project where the cryomodule houses the focusing magnets. Aspects of the cold magnetic shields for ESS will also be discussed., Proceedings of the 17th International Conference on RF Superconductivity, SRF2015, Whistler, BC, Canada

This article reports on the long-term frequency stabilty characterisation of a new type of cryogenic sapphire oscillator using an autonomous pulse-tube cryocooler as its cold source. This new design enables a relative frequency stability of better than 4.5e-15 over one day of integration. This represents to our knowledge the best long-term frequency stability ever obtained with a signal source based on a macroscopic resonator., Comment: 9 pages, 5 figures

International audience

The IFMIF project aiming at material tests for a future fusion DEMO reactor is under the EVEDA phase in the BA Agreement of fusion program between Japan and EU. As the accelerator activity, the installation and commissioning of the Linear IFMIF Prototype Accelerator (LIPAc) is at the second stage of demonstration of the feasibility of the low energy section of an IFMIF deuteron accelerator up to 9 MeV with a beam current of 125 mA, CW. The installation of injector, RFQ, MEBT, D-Plate and LPBD for LIPAc with 8 coaxial high-power transmission lines and RF power system was just done in 2017 at Rokkasho, Japan. After that, the RF conditioning of RFQ for beam commissioning is underway. The beam commissioning of RFQ with H⁺/D⁺ and the acceleration demonstration up to 5 MeV-125 mA-0.1% duty cycle with D⁺ will be done., Proceedings of the 61\textsuperscript{st} ICFA ABDW on High-Intensity and High-Brightness Hadron Beams, HB2018, Daejeon, Korea

The goal of the IFMIF-DONES (International Fusion Materials Irradiation Facility-DEMO Oriented Neutron Source) project is to build an irradiation facility that will provide a sufficient neutron flux to study and characterize structure materials foreseen for future fusion power plant. In order to accelerate the required 125mA/40 MeV continuous deuteron beam from 5 MeV to 40 MeV, a superconducting radio-frequency (SRF) linac, housed in five cryomodules, is proposed. The design is based on two beta families (β=0.11 and β=0.17) of half-wave resonators (HWR) at 175MHz. The transverse focusing is achieved using one solenoid coil per focusing period. This paper presents the extensive multiparticle beam dynamics simulations that have been performed to adapt the beam along the SRF-linac in such a high space charge regime. As one of the constraints of the IFMIF linac is a low level of beam losses, specific optimizations have been done to minimize the beam occupancy in the line (halo). A Monte Carlo error analysis has also been carried out to study the effects of misalignments or field imperfections (static errors) and also vibrations or power supplies ripple (dynamic errors). The results of these errors studies are presented and discussed., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The prototype IFMIF cryomodule encloses eight superconducting 175 MHz beta 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. One prototype HWR and the 8 cavities to be hosted in the cryomodule have been manufactured, prepared and tested. The paper describes the phases of the cavities development, including fabrication, processing, and RF resonant frequency management. We focus on the results of the RF tests which have been performed for all bare and jacketed HWRs in a vertical cryostat., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany