Improvement of the phase regulation between two amplifiers feeding the inputs of the 3dB combiner in the ASDEX-Upgrade ICRH system

The present ICRF system at ASDEX Upgrade uses 3dB combiners to forward the combined power of a generator pair to a single line. Optimal output performance is achieved when the voltages at the two input lines of a combiner are equal in amplitude and the phase in quadrature. If this requirement is not met, a large amount of power is lost in the dummy loads of the combiner. To minimize losses, it is paramount to reach this phase relationship in a fast and stable way. The current phase regulation system is based on analog phase locked loops circuits. The main limitation of this system is the response time: several tens of milliseconds are needed to achieve a stable state. In order to get rid of the response time limitation of the current system, a new system is proposed based on a multi-channel direct digital synthesis device which is steered by a microcontroller and a software-based controller. The proposed system has been developed and successfully tested on a test-bench. The results show a remarkable improvement in the reduction of the response times. Other significant advantages provided by the new system include greater flexibility for frequency and phase settings, lower cost and a noticeable size reduction of the system

Bunch Measurements with BPM at Low Energy Hadron Accelerators

International audienceBeam Position Monitors (BPM) are one of the key diagnostics use in LINACs, BPMs should ensure a continuous monitoring of the beam position and energy. BPMs also give an indication of the beam transverse shape. For electron LINACs, beam longitudinal length is measured with BPMs. However, in hadron LINACs, it is performed with intrusive modules (wire scanners, beam shape monitors) This document relates the measurement of beam longitudinal length with BPMs. It is divided in two parts: first, a theoretical model of the BPM operation and the formulas driving the measurement of beam longitudinal length from BPM output signals. Second, an experimental study run at MYRRHA LINAC facility and showing good agreement between estimated values of beam longitudinal length from Tracewin simulations and BPM measurements

Cancer and mosquitoes – An unsuspected close connection

International audienceCancer is a major public health issue and represents a significant burden in countries with different levels of economic wealth. In parallel, mosquito-borne infectious diseases represent a growing problem causing significant morbidity and mortality worldwide. Acknowledging that these two concerns are both globally distributed, it is essential to investigate whether they have a reciprocal connection that can fuel their respective burdens. Unfortunately, very few studies have examined the link between these two threats.This review provides an overview of the possible links between mosquitoes, mosquito-borne infectious diseases and cancer. We first focus on the impact of mosquitoes on carcinogenesis in humans including the transmission of oncogenic pathogens through mosquitoes, the immune reactions following mosquito bites, the presence of non-oncogenic mosquito-borne pathogens, and the direct transmission of cancer cells. The second part of this review deals with the direct or indirect consequences of cancer in humans on mosquito behaviour. Thirdly, we discuss the potential impacts that natural cancers in mosquitoes can have on their life history traits and therefore on their vector capacity. Finally, we discuss the most promising research avenues on this topic and the integrative public health strategies that could be envisioned in this context

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

MTCA.4-Based LLRF System Prototype Status for MYRRHA

International audienceWithin the framework of MINERVA, the first Phase of MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) project, IN2P3 labs are in charge of the development of several accelerator elements. Among those, a fully equipped Spoke cryomodule prototype was constructed. It integrates two superconducting single spoke cavities operating at 2K, the RF power couplers and the associated cold tuning systems. On the control side, a MTCA.4-based Low Level RadioFrequency (LLRF) system prototype has been implemented by IJCLab including FPGA specific firmware, a new µRTM frequency downconverter module from the company IOxOS Technologies and EPICS developments in collaboration with the SCK•CEN. The status of the LLRF system will be shown as well as its preliminary tests results

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

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