Validation of the Series Power Couplers of the LIPAc SRF Linac

International audienceIn 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

LIPAc RF power system: design and main practical implementation issues

The Linear IFMIF (International Fusion Materials Irradiation Facility) Prototype Accelerator (LIPAc) is a 9 MeV, 125 mA, continuous wave (CW) deuteron accelerator aimed to validate the technology for the IFMIF accelerators. The construction of LIPAc, which is currently the most powerful deuteron accelerator in the world, has been carried out under the Broader Approach (BA) Agreement between EU and Japan, and it is located at Rokkasho (Japan). CIEMAT is one of the five European Institutions that has participated in the design, manufacturing and commissioning/operation of the main accelerator components, among them, the Radio Frequency Power System (RFPS).The RFPS contains all the equipment necessary to generate the required RF power to feed the LIPAc cavities. These cavities demand eighteen RF power chains at 175 MHz being distributed as follows: eight 200 kW tetrode-based chains for the Radiofrequency Quadrupole (RFQ), two 16 kW solid-state chains for the re-buncher cavities, and eight 105 kW tetrode-based chains for the Superconducting RF Linac Half-Wave Resonators.The design of the RFPS main components is presented in this paper, including the tetrode-based chains, the Solid-State Power Amplifier (SSPA) for the re-buncher cavities, the High Voltage Power Supplies (HVPSs) for the final amplifiers anodes and the RF water cooling system. Additionally, the main difficulties encountered during the first months of the RFPS commissioning and operation will be described, together with the applied improvements

Integration of 175 MHz LIPAc RF system and RFQ Linac for Beam Commissioning

The eight-chain RF system and radio frequency quadrupole (RFQ) linac were successfully integrated at the facility of the Linear IFMIF Prototype Accelerator (LIPAc). We achieved an unprecedented high current deuteron beam up to55 mA in pulse operation (300 μs, 1 Hz). The keys of the success were (1) understanding reflected power from RFQ to RF system, (2) tuning each RF chain individually, (3) intensive RF conditioning for holding the stable RF power in the RFQ, and (4) optimizing the beam loading compensation control. Interestingly, the reflection at the breakdown in RF conditioning was higher than an estimation and reached up to 600 kW so far. In order to avoid damage on tetrodes by the high reflection, the impedance of each circulator was accurately adjusted

Progress Report on LIPAC

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-LINAC1

Commissioning Status of Linear IFMIF Prototype Accelerator (LIPAc)

International audienceThe 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

Progress Report on LIPAC

International audienceInternational 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

RFQ Commissioning of Linear IFMIF Prototype Accelerator (LIPAc)

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 5MeV-125mA-0.1% duty cycle with D+ will be done

Functional Overview of the RF Power System for the LIPAc RFQ

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

Overview of the Validation Activities of IFMIF/EVEDA: LIPAc, the Linear IFMIF Prototype Accelerator and LiFus6, the Lithium Corrosion Induced Facility

In this report, the latest results of the validation activities of the IFMIF/EVEDA project under the Broader Approach agreement are overviewed. For the Linear IFMIF Prototype Accelerator (LIPAc) to demonstrate the 9MeV/125mA D+ beam acceleration, the beam qualification study of the injector was completed with the emittance of 0.16 pi mm mrad smaller than required 0.3 pi mm mrad, and the maximum vane voltage in the RFQ cavity was achieved at 143kV exceeding the required 132kV. These components and other subsystems of LIPAc are ready to inject the beam to RFQ to provide the 5MeV D+ beam. The Superconducting RF linac necessary for the 9MeV D+ beam is close to the end of manufacturing phase to start its final assembly in Rokkasho. For the liquid lithium loop activities, 4,000 hours lithium corrosion test of the Reduced Activation Ferritic/Martensitic steels using the LiFus6 were completed and verified that the corrosion rate can be kept under control and well below the requirement of 1 micro-m/y, after achieving a good purity of lithium, < 30ppm N