Development of a Compact High Intensity Ion Source for Light Ions at CEA-Saclay

International audienceDuring the past 5 years, a R&D program has been launched to improve the beam quality of ECR 2.45 GHz high intensity light ion sources for high power accelerators. The main goal was to minimize the divergence and emittance growth of intense beams due to the space charge as early as possible on the low energy transfer line for a better injection in the second stage of acceleration (RFQ). This has been achieved by reducing the length of the extraction system, to be able to put the first solenoid as close as possible to the extraction aperture. This was performed with the ALISES concept (Advanced Light Ion Source Extraction System). Encouraging results have been obtained in 2012 but with limitations due to Penning discharges in the accelerating column. Taking advantages of ALISES geometry, intensive studies and simulations have been undertaken to eliminate the discharge phenomena. An Innovative and compact source geometry has been found and the source has been fabricated. This new prototype and its performances will be described, as well as magnetic field configuration studies and its influence on the extracted beam

Beam Diagnostics of the LIPAC Injector With a Focus on the Algorithm Developed for Emittance Data Analysis of High Background Including Species Fraction Calculation

International audienceTo prove the feasibility of the IFMIF accelerators concept, the EVEDA phase will commission in Japan the LIPAC accelerator, which will deliver a 125 mA/9 MeV CW deuteron beam. LEDA already managed 100 mA in CW at 6.7 MeV in 2000. The different subsystems of LIPAC have been designed and constructed mainly by European labs with the injector developed by CEA-Saclay. This injector must deliver a 140 mA/100 keV CW deuteron beam at 99% D⁺ ratio, which is produced by a 2.45 GHz ECR ion source. The low energy beam transport line is based on a dual solenoid focusing system to transport the beam and to match it into the RFQ. The normalized RMS target emittance at the RFQ entrance is targeted to be within 0.25π mm·mrad. This article describes the diagnostics installed in the LEBT to measure beam parameters such as intensity, profile, emittance, species fraction and degree of space charge compensation. The article also focuses on the algorithm developed to analyze emittance data of high background from an Allison scanner. Species fractions (D⁺, D2+, D3+) using mass separation technique were also calculated with the Allison scanner installed between the two solenoids in a first stage

High Intensity Beam Production at CEA/Saclay For The IPHI Project

International audienceCEA/Saclay is involved in high power proton accelerators for long years. This activity started in the 90's, with the development of the SILHI source which routinely produces tens mA of proton beam. Several industrial difficulties led to a very long IPHI RFQ construction process. The 352 MHz RFQ conditioning is presently in progress. Before the completion of the conditioning in CW mode, tests with pulsed proton beam have been decided. As a consequence, the SILHI source recently produced very short H⁺ beam pulses in order to allow the first IPHI beam acceleration. Such very short pulses, in the range of few hundred microseconds, allowed analyzing the beam loading of the RFQ cavity as well as conditioning the middle energy diagnostic. This article will focus on the source parameters and beam characteristics in the low energy beam line leading to the best RFQ transmission

Source and LEBT Beam Preparation for IFMIF-EVEDA RFQ

International audienceThe commissioning phase of the IFMIF-EVEDA RFQ requires a complete beam characterization with simula-tions and measurements of the beam input from the IFMIF-EVEDA ion source and LEBT, in order to reach the RFQ input beam parameters. In this article, the simula-tions results of the complex source-LEBT with the corre-sponding set of measurements and their impact on the commissioning plan will be reported

Tocilizumab versus anakinra in COVID-19: results from propensity score matching

International audienceBackground Tocilizumab and anakinra are anti-interleukin drugs to treat severe coronavirus disease 2019 (COVID-19) refractory to corticosteroids. However, no studies compared the efficacy of tocilizumab versus anakinra to guide the choice of the therapy in clinical practice. We aimed to compare the outcomes of COVID-19 patients treated with tocilizumab or anakinra. Methods Our retrospective study was conducted in three French university hospitals between February 2021 and February 2022 and included all the consecutive hospitalized patients with a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection assessed by RT-PCR who were treated with tocilizumab or anakinra. A propensity score matching was performed to minimize confounding effects due to the non-random allocation. Results Among 235 patients (mean age, 72 years; 60.9% of male patients), the 28-day mortality (29.4% vs. 31.2%, p = 0.76), the in-hospital mortality (31.7% vs. 33.0%, p = 0.83), the high-flow oxygen requirement (17.5% vs. 18.3%, p = 0.86), the intensive care unit admission rate (30.8% vs. 22.2%, p = 0.30), and the mechanical ventilation rate (15.4% vs. 11.1%, p = 0.50) were similar in patients receiving tocilizumab and those receiving anakinra. After propensity score matching, the 28-day mortality (29.1% vs. 30.4%, p = 1) and the rate of high-flow oxygen requirement (10.1% vs. 21.5%, p = 0.081) did not differ between patients receiving tocilizumab or anakinra. Secondary infection rates were similar between the tocilizumab and anakinra groups (6.3% vs. 9.2%, p = 0.44). Conclusion Our study showed comparable efficacy and safety profiles of tocilizumab and anakinra to treat severe COVID-19

Intermediate Commissioning Results of the Required 140 mA/100 keV CW D⁺ ECR Injector of LIPAc, IFMIF's Prototype

International audienceThe LIPAc accelerator aims to operate in Rokkasho Fusion Institute a 125 mA/CW deuteron beam at 9 MeV to validate the concept of IFMIF's accelerators that will operate in CW 125 mA at 40 MeV. The 2.45 GHz ECR injector developed by CEA-Saclay is designed to deliver 140 mA/100 keV CW D⁺ beam with 99% D⁺ fraction ratio. Its LEBT relies on a dual solenoid focusing system to transport and match the beam into the RFQ. The normalized RMS emittance at the RFQ injection cone is required to be within 0.25π mm·mrad to allow 96% transmission through the 9.81 m long RFQ. An equal perveance H⁺ beam of half current and half energy as nominal with D⁺ is used to avoid activation during commissioning. The injector commissioning at Rokkasho is divided into three phases to characterize the emittance between the two solenoids of the LEBT (A1) and just downstream the RFQ injection cone (A2) and the extraction system of the source (A3). Phase A1 has been achieved and phase A2 continues in 2016 in order to reach the required beam parameters and to match the beam into the RFQ. This paper reports the commissioning results of phase A1 and the intermediate ones of phase A2 for H⁺ and D⁺ beams

Beam Commissioning of the IFMIF EVEDA Very High Power RFQ

IFMIF, the International Fusion Materials Irradiation Facility, is an accelerator-based neutron source that will use Li(d, xn) reactions to generate a flux of neutrons with a broad peak at 14 MeV equivalent to the conditions of the Deuterium-Tritium reactions in a fusion power plant. IFMIF is conceived for fusion materials testing. The IFMIF prototype linear accelerator (LIPAc) is jointly developed by Europe and Japan within the IFMIF EVEDA project: it is composed of an ion source, a LEBT, an RFQ, a MEBT and a SC linac, with a final energy of 9 MeV. The 4-vane Radio Frequency Quadrupole (RFQ), developed by INFN in Italy, will accelerate a 130 mA deuteron beam from 0.1 to 5 MeV in continuous wave, for a beam power of 650 kW. The 9.8 m long 175 MHz cavity is composed of 18 x 0.54 m long modules flanged together and aligned within 0.3 mm tolerance. The RFQ was completed, delivered and assembled at the Rokkasho site and is presently under extended RF tests. The second phase of beam commissioning (up to 2.5 MeV/u) was scheduled to start at the end of 2017. Several unexpected issues and incidents significantly delayed the original program, which is however proceeding step by step toward the full achievement of its goals.9th International Particle Accelerator COnference - IPAC201

Beam Commissioning of the IFMIF EVEDA Very High Power RFQ

International audienceIFMIF, the International Fusion Materials Irradiation Facility, is an accelerator-based neutron source that will use Li(d, xn) reactions to generate a flux of neutrons with a broad peak at 14 MeV equivalent to the conditions of the Deuterium-Tritium reactions in a fusion power plant. IFMIF is conceived for fusion materials testing. The IFMIF prototype linear accelerator (LIPAc) is jointly developed by Europe and Japan within the IFMIF EVEDA project: it is composed of an ion source, a LEBT, an RFQ, a MEBT and a SC linac, with a final energy of 9 MeV. The 4-vane Radio Frequency Quadrupole (RFQ), developed by INFN in Italy, will accelerate a 130 mA deuteron beam from 0.1 to 5 MeV in continuous wave, for a beam power of 650 kW. The 9.8 m long 175 MHz cavity is composed of 18 x 0.54 m long modules flanged together and aligned within 0.3 mm tolerance. The RFQ was completed, delivered and assembled at the Rokkasho site and is presently under extended RF tests. The second phase of beam commissioning (up to 2.5 MeV/u) was scheduled to start at the end of 2017. Several unexpected issues and incidents significantly delayed the original program, which is however proceeding step by step toward the full achievement of its goals

Development of calorimetry methodology for beam current measurement of the Linear IFMIF Prototype Accelerator (LIPAc)

The goal of LIPAc (Linear IFMIF Prototype Accelerator) is to achieve a 125 mA, 9 MeV, CW (continuous wave, i.e. 100% duty cycle) deuteron beam with an average beam power of 1.125 MW. In the beam current mea- surement, it is considered that calorimetric measurement is advantageous for high current and CW operations since it is not subject to secondary electrons, etc. In calorimetric measurements, it is necessary to measure the temperature rise of the cooling water as accurately as possible. We applied this method to LIPAc proton beams at the Beam Stop unit. In order to check the reliability, we inserted a heater in the cooling loop as a heat source and obtained correlation between the applied and measured power, which was found to be 1.0. Moreover, using this heater, accuracy of this measurement with respect to the flow rate of the cooling water was investigated. Due to heat transfer and the fluctuations of water temperature, etc., there is a range of flow rates in which the measurement error can be minimized with our calorimetric measurement system