The tenth LIPAc Technical Meeting 10 (LTM10) was held in Rokkasho (Japan) from November 14th until 17th, where the current status of the design, manufacturing, installation and commissioning of the LIPAc accelerator’s components were discussed. More than 30 experts from laboratories in Europe, including CIEMAT (Madrid, Spain), CEA (Saclay, France) INFN (Legnaro, Italy); and Japan, including QST (Rokkasho, Japan) and KEK (on behalf of QST) attended the meeting, which was coordinated by the LIPAc Project Team and QST. In addition, videoconferencing was available to allow remote participation of EU colleagues who could not attend in person.
Detailed discussions were held to reach common agreement on the key technical issues that have arisen, and progress was reported on many aspects of the project. The following gives an overview of the progress made in key areas:
Full commencement of phase “B” commissioning was announced, and the LEBT (Low Energy Beam Transport) was removed to allow final positioning of the RFQ. During the last campaign of Injector commissioning, a current of 112 mA with acceptable emittance in CW operation was achieved. While this falls short of the goal, this represents an excellent improvement. Further adjustments must be made to the accelerator column, followed by 24/7 beam extraction, to achieve the target parameters.
The bead pull measurements were successfully completed, and the final measured frequency was equal to 174.089 MHz. When scaled to the normal operating temperature of 20 °C and considering the effects of vacuum and beam loading, this is equivalent to 175.014 MHz. Following LEBT removal, the RFQ super modules were placed in their final position, and aligned within a tolerance of 50 µm. The RFQ was pumped down and the correct vacuum conditions for the three super-modules were achieved. The RFQ can now be baked-out before final assembly can proceed. Control cubicles and junction boxes were installed and are now being configured.
RF System and Coaxial lines:
Tangible progress was made since LTM09, which was held in April 2016. RF module 02 for the SRF LINAc was tested and sent to Saclay for Sathori test stand. After use in Saclay, it will be sent to Rokkasho for installation in Rokkasho. RF module 03 will be sent to Rokkasho on 30th of November 2016, together with the SRF LINAc coaxial lines, while RF module 04 is now in the final stages of preparation at Indra’s facilities, and is expected to be ready for shipment to Rokkasho in January 2017. The installation of the RF cooling system onsite is almost complete. The RFQ coaxial lines have been installed in preliminary position. Final positioning will be made after the connection is made to the RFQ.
MEBT and D-Plate:
Most of the installation and commissioning activities of the MEBT and D-plate were performed in parallel during pre-commissioning last summer 2016. Preparation for the next installation campaign already started with the objective to reach the LIPAc phase B configuration (Injector-RFQ-MEBT-Dplate and LPBD) next year. The displacement of the MEBT to its final position is planned beginning of 2017. Once it is validated by an alignment survey, it will be followed by displacement and alignment of the Dplate. Then the ancillaries (cabling, piping, compressed air and vacuum) will be installed on both equipment and tested. The integration of LCD into CCS will conclude this campaign; at least for these two accelerator components, driving to their check out and commissioning.
SRF Linac and Cleanroom:
All the main components of the cryomodule are expected at CEA (Saclay, France) by the end of March 2017 and ready for shipment to Rokkasho by the end of April 2016. It was agreed that the assembly of the cryomodule will be performed at Rokkasho in dedicated clean room which will be available in Rokkasho by the end October 2017.
The Sathori test stand is prepared and awaiting commissioning of the power supplies and RF modules. CEA expect to start testing the cavities at the beginning of 2017
Most of the components for the cryoplant have been delivered to Rokkasho. The final components, including the helium buffer tank and the control cubicles, will be delivered during December 2016. The installation activities started during November, with the first major components being installed in their final locations and the commencement of piping works. Civil work associated with the cryoplant is also progressing with the construction of the foundations for the Nitrogen and Helium storage tanks.
The HEBT manufacturing drawings have been completed and many components, such as the water cooling system, and associated pipe, fittings and valves; have been manufactured or procured and delivered to Rokkasho. 4 out of 5 HEBT support frames have been manufactured at CIEMAT, and manufacturing of the first quadrupole is complete. For the beam dump, the inner cone of the first prototype has been manufactured, and a second prototype is being manufactured. The acceptance tests for the beam dump shield are expected to proceed at CIEMAT in December 2016. The main steel shielding and mobile shielding manufacture is now in an advanced state, and final acceptance tests are expected in February 2017. The cooling system design continues, but manufacture will need to be accelerated to match with the current schedule.
Phase B commissioning is approaching, and as such, the dedicated control configuration is required for the control system. An additional 42 signals are required, a test bench for the timing system has been prepared, and the program for data creation is being prepared. Local control system integration for phase B will include the RFQ, RF/LLRF, MEBT and D-plate. The Central Control System upgrade contract is expected to start in January 2017. Moreover the need for a beam simulation study to optimize the configuration of beam was recognized as being urgent. Data event recording tool must be implemented, and the operational screens in the control room are being prepared according to the needs of the different subsystems.
The next meeting LTM11 will be held between April and May 2017, with the location yet to be decided.
After a shutdown period of more than five months long, along which a thorough maintenance campaign on the injector took place, 90keV proton beam, with more than 100mA current, was extracted again this week, in preparation for the last injector commissioning campaign that will span over 5 weeks until November 4th.
From October 3rd until November 4th the last campaign of the accelerator commissioning will take place. This time will be used to fine tune the source before the RFQ is finally assembled attached to it by the end of November. To assure the optimal condition of the injector for this important stage, a thorough maintenance campaign has been performed along the summer, with more than 70 interventions including vacuum system, PPS and control system upgrade, recalibration of high voltage power supplies, RF equipment and the complete cleanup and reassembly of the injector column.
In parallel, during this period, installation activities have progressed steadily. In the vault, the RFQ finalized the assembly of the four super modules and completed the bead pull measurement tests satisfactorily, in preparation for the last piping and cabling works. In addition, a task force from CIEMAT has been working on MEBT (bunchers, quadrupole magnets) and D-Plate (which hosts most of the beam instrumentation) to finalize the mechanical installation, pressure and vacuum tests and signal cabling. Regarding the RF system, all eight chains for the RFQ and two for the bunchers have been installed commissioning will start soon. Currently, coaxial transmission lines are under the final stage of installation.
On Thursday 21 April, a celebration took place as major accelerator components had been transported by F4E to the Rokkasho Fusion Centre allowing the start of second phase in the commissioning of LIPAc. This is another major milestone on road of success for the IFMIF/EVEDA Project. Already in 2013, the engineering design activities were successfully accomplished on schedule. By 2015, the Target and Test facility validation activities were fully completed, with the exception of the on-going corrosion/erosion tests in the lithium loop constructed in Brasimone by ENEA. This facility is now providing important results to quantify the corrosion/erosion rates of fusion reactor steel grades in contact with a high speed flow of liquid lithium.
The LIPAc is under installation and commissioning in Rokkasho. Its key systems are designed and manufactured mainly by CEA, CIEMAT and INFN integrating also some important components contributed by SCK-CEN (see Figure above for a breakdown of the contributions). The LIPAc is designated to operate in unprecedented beam conditions at the cutting edge of present days’ accelerators technologies. During the previous meeting of Broader Approach Steering Committee (BASC-17), hosted on 11 December 2015 by RFX, an extension of the LIPAc validation period until December 2019 was approved. The deuteron source (Injector) developed by CEA has demonstrated that the beam characteristics are achievable in a parameter field never reached before (100 kA and 140 mA deuteron beam). An operational point with protons to be used as beam input to the ensuing accelerator stage, the Radio Frequency Quadrupole (RFQ) developed by INFN, has been determined. Additional commissioning of the Injector towards the mandated operation mode in Continuous Wave, i.e. 100% duty cycle of the beam, will take place during 2016 interleaved with the preparation activities for beam commissioning with the RFQ. The RFQ now under installation at Rokkasho is the longest one ever constructed. Today 6 out of 8 RF power chains developed by CIEMAT are already installed, which are to deliver 200 kW each to operate the RFQ. The last two chains are to arrive before the summer.
The celebration of the success of the Injector commissioning and the start of installation of the RFQ and the RF power generator for the Linear IFMIF Prototype Accelerator enjoyed utmost interest among European and Japanese partners. The celebration received the participation of representation from the European Delegation in Japan and the Embassies of all the six European countries that have been involved in the IFMIF/EVEDA project. Among the European guests were the Ambassador of Spain to Japan, Gonzalo de Benito; the Director of Nuclear Energy, Safety and ITER of the DG Energy in the European Commission, Massimo Garribba; the Chairman of the Governing Board of F4E, Joaquin Sanchez; the Chairman of CEA, Daniel Verwaerde, the member of the Executive Board of INFN, Eugenio Nappi; the Directors of INFN Legnaro, Giovanni Fiorentini, and of INFN Torino, Amedeo Staiano; Angel Ibarra from CIEMAT. Among the Japanese guests were the Governor of Aomori Prefecture, Shingo Mimura; the President of QST, Toshio Hirano; the President of JAEA (to which the Japanese Fusion programme belong to until 31 March 2016), Toshio Kodama; the Deputy Director General of Research and Development Bureau at MEXT; Shuichiro Itakura.
The 9th LIPAc Technical Meeting (LTM09) was held at the IFERC Site in Rokkasho, Japan, from 19th to 22nd April 2016. More than 40 experts from different involved institutes, including CEA (Saclay, France), INFN (Legnaro, Italy), QST (Rokkasho, Japan), CIEMAT (Madrid, Spain), F4E (Garching, Germany) and the IFMIF/EVEDA Project Team; attended the meeting. In addition, Japanese experts from KEK and J-PARC attended on behalf of QST.
Many satellite meetings were held, with devoted discussions on most of the accelerator systems, including the MEBT (Medium Energy Beam Transport), HEBT (High Energy Beam Transport) and the Beam Dump; the control systems, including vacuum system integration and its overall process management, the control room configuration; the different phases of LIPAc commissioning, including integrated operation scenarios and beam dynamics issues; and the cryomodule assembly.
During the LTM, much detailed technical information was presented, highlighting the significant progress that has been made for the manufacture and installation of various components since the previous LTM08 held in Garching (Germany) on 24-26 November 2015.
The main outcomes presented during the meeting are listed below:
Over the last 6 months injector operations have been very intense: 3 measurements campaigns were carried out as well as curative and major preventive maintenance. The deuteron beam commissioning performed in December 2015 gave promising results, the emittance met specifications at 20 % and 50 % duty cycle for currents of 110 mA at the level of the beam stop. In March 2016, the measurement campaign with a proton beam, which is a scaled version by a factor of 0.5 in intensity and energy, but with the same perveance as a deuteron beam, enabled to find a good working point at 10 % duty cycle. The last measurement campaign was very effective thanks to the careful maintenance performed and to Tracewin simulations which made it possible to determine the most interesting sets of machine parameters giving the best beam characteristic
RF power systems
Remarkable progress was made for the RF system, with the delivery and installation inside RF power supply area of the Accelerator Building of all of the HVPSs and the first three RF Modules for the RFQ. The main cable trays, panel boards and grounding systems have also been installed, and the transformers and the HV breakers on the electrical platform are complete.
The four RF modules for the SRF LINAc have been manufactured, and the first unit has been partially tested and will soon be ready for shipment. It will be shipped to CEA Saclay for integration on the Sathori Test Stand.
The RFQ super module installation was successfully completed according to the schedule presented at LTM08 (Garching, Germany). The bead pull measurements will commence on 25/04/16 and will be completed by the end of July after 3 campaigns of measurement. The RFQ will then be relocated to its final position immediately afterwards.
The RFQ cooling skid and accessories are at Rokkasho and the water cooling skid requires some adjustment before its final installation/site commissioning.
The MEBT arrived in Rokkasho in March 2016, and was temporarily positioned inside the Accelerator Vault by the end of March. The electrical cubicles and other electrical equipment are expected to arrive in the middle of July, while the cooling skid, piping and associated accessories are currently being manufactured
The D-plate was installed inside the Accelerator Vault in a temporary position, in April 2016.
While licensing activities for the complete cryomodule continue, the formal approval of the cavity design by KHK was obtained representing a great success for those involved.
Manufacturing contracts for all critical components have now been placed, and the tender process for a number of non-critical-path items has also been launched. Agreement has nearly been reached on the definition of the requirements for the clean room to be constructed at Rokkasho, and the tendering process for the clean room’s construction is expected to start by June.
The main cryogenic system components, including He compressors, oil removal system and cold box, have been manufactured and delivered to Rokkasho.
The requirements for the licensing of the cryoplant have been clarified. The cryoplant distribution piping and equipment are currently being designed.
The HEBT water cooling skid, which will cool the magnet of the MEBT and HEBT, arrived in Rokkasho in January 2016. It was positioned inside the Accelerator HEX room and the piping is expected to start after the final positioning of the MEBT, which will intervene after the final positioning and back out of the RFQ.
A number of manufacturing contracts for the HEBT are ongoing, including the construction of the quadrupole and dipole. The design of the beam chambers is complete and the technical specifications have been prepared. The remaining components, i.e., power supply, supports, magnets coil system, vacuum pumps and associated equipment; have also been designed and are being procured.
Design for manufacture continues for both the Beam Dump low alloy steel shielding and mobile shielding, with manufacturing expected to start for both at the end of May 2016. Final assembly and acceptance tests are expected to commence in September. Manufacturing is progressing well for the Beam Dump cartridge.
The dedicated Control Systems and LIPAc Operation satellite meeting was fruitful. It was identified that the integration of the different LCS into the CCS is on the critical path and mitigation actions should be considered. It was agreed also the need to tackle the various operational issues e.g. setup of the vacuum systems, identifying the thresholds for the MPS and setup of common operating procedures. An operating procedure for phase B, including a start-up procedure needs to be prepared urgently and missing operations with possible proposed configurations must be identified.
The meeting was successful in spite the overlapping of Broader Approach Steering Committee half-yearly meeting (BASC) and LIPAc ceremony. The main actors who have done all the technical work could also attend LIPAc ceremony and finally to the pleasant banquet that took place in the Kizan restaurant in Misawa, together with all ceremony participants for the celebration of success of the Injector commissioning and the start of installation of the RFQ and RF power generation for the LIPAc.
See you at the next LTM10 at the end of November 2016, again in Rokkasho (Japan)
We are proud to announce that on February 22nd 2016 the RFQ supermodules boxes were received at Rokkasho BA site. The three supermodules were delivered separately by INFN, already preassembled and aligned in INFN Legnaro (Italian National Institute of Nuclear Physics). The RFQ, a 10 m long structure composed by 18 modules flanged together will be the longest and will accelerate the highest intensity beam in the world (D+ particle from 0.1 MeV to 5 MeV at 125 mA in CW).
All the supermodule packages have been stored in the vault area waiting to start installation shortly, as it has been scheduled to start from March 31st. All the IFMIF community wants to thanks all INFN personel involved in the design, fabrication, assembly and testing of such high technology subsystem.
Last week additional components delivered from CIEMAT were also received in Rokkasho, the spanish institute on energy and environmental sciences, including the HEBT cooling skid, the third RF module (after the already installed two first modules) and some ancillary components from the MEBT.
During this first half of year 2016 most components for next LIPAc Commissioning phase B are expected to be delivered to Rokkasho and to be installed, including the whole RFQ system, MEBT, diagnostics and D-Plate, RF Power system for RFQ and Bunchers, cooling system and the associated local control systems for all the above.