Etude de la dynamique des faisceaux dans l'accélérateur primaire d'EURISOL et de ses cavités supraconductrices de type "triple spoke"

EURISOL sera la source de prochaine génération pour la production de faisceaux intenses d ions exotiques. Son complexe accélérateurs se compose d un linac primaire, des ensembles cibles et sources et d un linac de post-accélération qui fournit les ions radioactifs aux différentes aires expérimentales. L étude menée dans ce mémoire concerne l accélérateur primaire : un linac RF supraconducteur capable d accélérer plusieurs types d ions (D + , 3 He2+ et H ) jusqu à une puissance maximale de 4 MW. Des simulations de la dynamique des faisceaux ont démontré qu il était très favorable de baser l accélération dans la partie de moyenne énergie (0.2 < beta < 0.4) sur des cavités de type triple spoke fonctionnant à 352 MHz. La conception électromagnétique de la cavité proposée a conduit, grâce à une géométrie originale, à des valeurs de champs maximaux de surface de 33 MV/m pour le champ électrique et de 72 mT pour l induction magnétique à un gradient accélérateur ambitieux de 8 MV/m. Le transport des faisceaux dans la structure proposée initialement pour le linac primaire d EURISOL a ensuite été simulé. Une solution alternative et périodique pour la partie de basse énergie est également proposée. Celle-ci conduit à réduire considérablement l augmentation des valeurs de l émittance et des paramètres de halo.EURISOL will be the next generation source of intense radioactive ion beams. Its accelerator complex consists of a driver linac, a set of targets and sources and a post-accelerator linac which aims at supplying different experimental areas with the exotic ions. The presented study deals with the driver accelerator: a superconducting RF linac capable of accelerating different ion kinds (D + , 3 He2+ and H ) up to a maxi- mal power of 4 MW. First beam dynamics studies pointed out a very good acceleration efficiency when triple spoke cavities working at a frequency of 352 MHz are used in the medium energy part (0.2 < beta < 0.4). Thanks to a novel geometry, the electromagnetic design of the proposed cavity leads to 33 MV/m and 72 mT for the peak electric field and magnetic induction respectively at an ambitious accelerating field of 8 MV/m. The beam transport was then simulated and optimized in the original layout and calculations were also performed considering an alternative, periodic solution, for the low energy part. The all-periodic linac keeps the beam qualities better by strongly reducing the emittance growth and the halo formation.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Investigation of different layouts for the EURISOL driver

This technical note describes, first, the main parameters of the driver optimised for the protons and, in a second part, shows optimised layouts which include the additional features

Status of and Plans for the Beam Dynamics Program DYNAC

International audienceA short introduction to the linac beam dynamics code DYNAC will be given. Recently implemented features, such as a Graphical User Interface (GUI), will be presented and benchmarking of the Radio Frequency Quadrupole (RFQ) model will be discussed. Additional planned features to DYNAC and the GUI will be touched upon

ESS Linac Beam Physics Design Update

The European Spallation Source, ESS, uses a linear accelerator to bombard the tungsten target with the high intensity protons beam for producing intense beams of neutrons. The nominal average beam power of the linac is 5~MW with a peak beam power at target of 125~MW. This paper focuses on the beam dynamics design of the ESS linac and the diagnostics elements used for the tuning of the lattice and matching between sections

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

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