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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.

A Radio Frequency Quadrupole (RFQ) is an essential part of linear accelerator (LINAC). It is situated at the very beginning of the accelerator and has three important functions: focusing, bunching and acceleration. The RFQ prepares the beam before its injection into the strong acceleration cavities and so it impacts the behaviour of the beam in the whole accelerator. Hence, it must be designed as reliable and efficient as possible. At the present time, the simulation of the electromagnetic fields and beam dynamics are carried out with some approximations in order to obtain a reasonable computation time. However, faster and more accurate solvers would first allow us to better understand the RFQ technology for high beam currents and second would potentially allow us to perform some numerical optimization. Our main objective is to develop a fast and accurate solver for the electromagnetic fields and for the beam dynamics. Our laboratory is specialized in fast methods for the electromagnetic fields simulation of antennas. Our solvers are based on the Method of Moments (MoM) in the frequency domain. This method could be applied as well for the electromagnetic fields simulation in accelerating cavities. One of the main advantages of the MoM in comparison to finite elements is that it requires only unknowns on the surface of the cavity. For high beam current, it would be very convenient to be able to calculate simultaneously the equations of motion and the Maxwell’s equations since the fields scattered due to the space charge can be as strong as the source fields. Such a simulation is so-called a self-consistent simulation.

Ac­cel­er­a­tor Driv­en Sys­tems (ADS) are promis­ing tools for the ef­fi­cient trans­mu­ta­tion of nu­cle­ar waste prod­ucts in ded­i­cat­ed in­dus­tri­al in­stal­la­tions, called trans­muters. The Myrrha pro­ject at Mol, Bel­gium, placed it­self on the path to­wards these ap­pli­ca­tions with a mul­ti­pur­pose and ver­sa­tile sys­tem based on a liq­uid PbBi (LBE) cooled fast re­ac­tor (80 MWth) which may be op­er­at­ed in both crit­i­cal and sub­crit­i­cal modes. In the lat­ter case the core is fed by spal­la­tion neu­trons ob­tained from a 600 MeV pro­ton beam hit­ting the LBE coolant/tar­get. The ac­cel­er­a­tor pro­vid­ing this beam is a high in­ten­si­ty CW su­per­con­duct­ing linac which is laid out for the high­est achiev­able re­li­a­bil­i­ty. The com­bi­na­tion of a par­al­lel re­dun­dant and of a fault tol­er­ant scheme should allow ob­tain­ing an MTBF value in ex­cess of 250 hours that is re­quired for op­ti­mal in­tegri­ty and suc­cess­ful op­er­a­tion of the ADS. Myrrha is ex­pect­ed to be op­er­a­tional in 2023. The forth­com­ing 4-year pe­ri­od is fully ded­i­cat­ed to R&D ac­tiv­i­ties, and in the field of the ac­cel­er­a­tor they are strong­ly fo­cused on the re­li­a­bil­i­ty as­pects and on the prop­er shap­ing of the beam trip spec­trum.