The Myrrha linear accelerator

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

Simulation of a radio frequency quadrupole with the Method of Moments

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

Control System Developments for the MYRRHA Linac

International audienceThe goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100 MWth Accelerator Driven System by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV linear accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. The control system of the future MYRRHA linac will have an essential role to play in this extreme reliability scenario. On the one hand the intrinsic reliability of the entire control system must be ensured. On the other hand control system will have to take up very high level duties of complex decision taking. This paper summarizes the ongoing developments for the concept design of such a control system. The related experimental activities performed and planned around the MYRRHA injector platform (ECR ion source + LEBT + RFQ) will also be described

WEBEXPIR: Windowless Target Electron Beam Experimental Irradiation

International audienceThe WEBEXPIR (Windowless target Electron Beam EXPerimental IRradiation) programme was set up as part of the MYRRHA/XT-ADS R&D efforts on the spallation target design, in order to answer different questions concerning the interaction of a proton beam with a liquid lead-bismuth eutectic (LBE) free surface. An experiment was conceived at the IBA TT-1000 Rhodotron, a 7-MeV electron accelerator which produces beam currents of up to 100 mA. Due to the small penetration depth of the 7-MeV electron beam and the high beam currents available, the TT-1000 allows to imitate the high power deposition at the MYRRHA/XT-ADS LBE free surface

Minerva (MYRRHA Phase 1) RFQ Beam Commissioning

International audienceThe MYRRHA project aims at coupling a 600 MeV proton accelerator to a subcritical fission core operating at a thermal power of 60 MW. The nominal proton beam for this ADS has an intensity of 4 mA and is delivered in a quasi-CW mode. Phase 1 of the project will realize a 100 MeV, 4 mA superconducting linac with the mission of ensuring the ADS requirements in terms of reliability and fault tolerance. As part of the reliability optimization program the integrated prototyping of the MINERVA injector is ongoing. The front-end of the injector is composed of an ECR proton source, a 2.6 m long LEBT (low energy beam transport line) and a four-rod RFQ accelerating the beam to 1.5 MeV. The present contribution focuses on the current beam tests on the RFQ, including beam matching, RF conditioning, assessment of the cavities’ performances and accelerated beam characterisation

Integrated Prototyping in View of the 100 MeV Linac for Myrrha Phase 1

International audienceThe MYRRHA project borne by SCK•CEN, the Belgian Nuclear Research Centre, aims at realizing a pre-industrial Accelerator Driven System (ADS) for exploring the transmutation of long lived nuclear waste. The linac for this ADS will be a High Power Proton Accelerator delivering 2.4 MW CW beam at 600 MeV. It has to satisfy stringent requirements for reliability and availability: a beam-MTBF of 250h is targeted. The reliability goal is pursued through a phased approach. During Phase 1, expected till 2024, the MYRRHA linac up to 100 MeV will be constructed. It will allow to evaluate the reliability potential of the 600 MeV linac. It will also feed a Proton Target Facility in which radioisotopes of interest will be collected through an ISOL system. This contribution will focus on the transition to integrated prototyping, which will emphasize (i) a test platform consisting of the initial section of the normal conducting injector (5.9 MeV), (ii) the realization of a complete cryomodule for the superconducting linac and of its cryogenic valve box. The cryomodule will house two 352 MHz single spoke cavities operated at 2K

MYRRHA-MINERVA Injector Status and Commissioning

International audienceThe MYRRHA project at SCK•CEN, Belgium, aims at coupling a 600 MeV proton accelerator to a subcritical fission core operating at a thermal power of 60 MW. The nominal proton beam for this ADS has an intensity of 4 mA and is delivered in a quasi-CW mode. MYRRHA’s linac is designed to be fault tolerant thanks to redundancy implemented in parallel at low energy and serially in the superconducting linac. Phase 1 of the project, named MINERVA, will realise a 100 MeV, 4 mA superconducting linac with the mission of demonstrating the ADS requirements in terms of reliability and of fault tolerance. As part of the reliability optimisation program the integrated prototyping of the MINERVA injector is ongoing at SCK•CEN in Louvain-la-Neuve, Belgium. The injector test stand aims at testing sequentially all the elements composing the front-end of the injector. This contribution will highlight the beam dynamics choices in MINERVA’s injector and their impact on ongoing commissioning activities

The MYRRHA Project

The main objective of MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) at SCK•CEN, the Belgian Nuclear Research Centre, is to demonstrate the large scale feasibility of nuclear waste transmutation using an Accelerator Driven System (ADS). It is based on a high power cw operated 600 MeV proton Linac with an average beam power of 2.4 MW. Due to the coupling of the accelerator with a fast reactor, a major concern is reliability and availability of the accelerator. Only 10 beam trips longer than 3 s are allowed per 3-month operation cycle, resulting in an overall required Mean Time Between Failure (MTBF) of at least 250 hours. The MYRRHA Linac consists of a room temperature 17 MeV Injector based on CH-cavities and the superconducting main Linac using different RF structures as Single Spokes, Double-Spokes and elliptical cavities. In 2017 it has been decided to stage the project and to start with the construction of a 100 MeV Linac (Injector and Single Spoke section) including a 400 kW proton target station. This facility will be operational in 2026 aiming to evaluate the reliability potential of the 600 MeV Linac. The FrontEnd consisting of an ECR source, LEBT and 1.5 MeV RFQ is already operational while the first 7 CH-cavities are under construction. The presentation gives an overview about the MYRRHA Project, its challenges and the status of construction and testingThe main objective of the MYRRHA project at SCK•CEN, the Belgian Nuclear Research Centre, is to demonstrate the feasibility of nuclear waste transmutation using an Accelerator Driven System (ADS). It is based on a High Power CW operated 600 MeV proton Linac with an average beam power of 2.4 MW. Due to the coupling of the accelerator with a subcritical reactor, a major concern is reliability and availability of the accelerator. The MYRRHA Linac consists of a room temperature 17 MeV Injector based on CH-cavities and the superconducting main Linac using different RF structures as Single Spokes, Double-Spokes and elliptical cavities. In 2017, it has been decided to stage the project and to start with the construction of a 100 MeV Linac (Injector and Single Spoke section) including a 400 kW proton target station. This facility (MINERVA) will be operational in 2026 aiming to evaluate the reliability potential of the 600 MeV Linac. The Front-End consisting of an ECR source, LEBT and 1.5 MeV RFQ is already operational while the first 7 CH-cavities are under construction. The presentation gives an overview about the MYRRHA Project, its challenges and the status of construction and testing

The MYRRHA project

International audienceThe main objective of MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) at SCK•CEN, the Belgian Nuclear Research Centre, is to demonstrate the large scale feasibility of nuclear waste transmutation using an Accelerator Driven System (ADS). It is based on a high power cw operated 600 MeV proton Linac with an average beam power of 2.4 MW. Due to the coupling of the accelerator with a fast reactor, a major concern is reliability and availability of the accelerator. Only 10 beam trips longer than 3 s are allowed per 3-month operation cycle, resulting in an overall required Mean Time Between Failure (MTBF) of at least 250 hours. The MYRRHA Linac consists of a room temperature 17 MeV Injector based on CH-cavities and the superconducting main Linac using different RF structures as Single Spokes, Double-Spokes and elliptical cavities. In 2017 it has been decided to stage the project and to start with the construction of a 100 MeV Linac (Injector and Single Spoke section) including a 400 kW proton target station. This facility will be operational in 2026 aiming to evaluate the reliability potential of the 600 MeV Linac. The Front-End consisting of an ECR source, LEBT and 1.5 MeV RFQ is already operational while the first 7 CH-cavities are under construction. The presentation gives an overview about the MYRRHA Project, its challenges and the status of construction and testing

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