ABSTRACT
The Linear IFMIF (International Fusion Materials Irradiation Facility) Prototype Accelerator (LIPAc) is aiming at demonstrating the low energy section of a 40 MeV/125 mA IFMIF deuteron accelerator up to 9 MeV with a full beam current in cw operation. For such a high-power beam, the LIPAc injector is required to produce a 100 keV D+ beam with 140 mA and match it for injection into the Radio Frequency Quadrupole (RFQ) accelerator. The injector is designed by CEA-Saclay based on the high intensity light ion source (SILHI). In 2019, the commissioning of the RFQ to demonstrate the D+ beam acceleration at a low duty cycle (0.1%) was conducted. A nominal beam current of 125 mA D+ beam was accelerated up to 5 MeV through the RFQ successfully. The LIPAc injector fully satisfied the requirements for RFQ beam commissioning at the pulse mode.
ABSTRACT
The Banc d'Etude et de Tests des Sources d'Ions (BETSI) test bench was built in 2009 for the Spiral2 project. Year after year, upgrades were done on the low energy beam line in order to have a complete injector equipped with 2 solenoids and vacuum chambers with multiple viewports for various kinds of beam-diagnostics. BETSI was designed for a 50 kV high voltage, and all the sources that were installed on the platform were also designed for that voltage. As the advanced light ion source extraction system ions source family is getting larger, the design is made for higher extraction voltages. As the common extraction voltage is 100 kV, the BETSI platform was upgraded to this voltage value. The control-command was upgraded, and at this voltage, a great care on the electromagnetic protections was taken in order to protect the equipment when spark occurs. This paper describes the choice of the upgrade, its installation, and some performances already obtained with a permanent magnet ion source equipped with a large accelerating tube.
ABSTRACT
The SEPAGE diagnostic will detect charged particles (electrons, protons, and ions) accelerated in the interaction of the PETAL (PETawatt Aquitaine Laser) laser with its targets on the LMJ (Laser MegaJoule)-PETAL laser facility. SEPAGE will be equipped with a proton-radiography front detector and two Thomson parabolas (TP), corresponding to different ranges of the particle energy spectra: Above 0.1 MeV for electrons and protons in the low-energy channel, with a separation capability between protons and 12C6+ up to 20 MeV proton energy and above 8 MeV for the high-energy channel, with a separation capability between protons and 12C6+ up to 200 MeV proton kinetic energy. This paper presents the calibration of the SEPAGE's low-energy channel TP at the Tandem facility of Orsay (France) with proton beams between 3 and 22 MeV and carbon-ion beams from 5.8 to 84 MeV. The magnetic and electric fields' integrals were determined with an accuracy of 10-3 by combining the deflections measured at different energies with different target thicknesses and materials, providing different in-target energy losses of the beam particles and hence different detected energies for given beam energies.
ABSTRACT
The objective of linear IFMIF prototype accelerator is to demonstrate 125 mA/CW deuterium ion beam acceleration up to 9 MeV. The injector has been developed in CEA Saclay and already demonstrated 140 mA/100 keV deuterium beam [R. Gobin et al., Rev. Sci. Instrum. 85, 02A918 (2014)]. The injector was disassembled and delivered to the International Fusion Energy Research Center in Rokkasho, Japan. After reassembling the injector, commissioning has started in 2014. Up to now, 100 keV/120 mA/CW hydrogen and 100 keV/90 mA/CW deuterium ion beams have been produced stably from a 10 mm diameter extraction aperture with a low beam emittance of 0.21 π mm mrad (rms, normalized). Neutron production by D-D reaction up to 2.4 × 10(9) n/s has been observed in the deuterium operation.
ABSTRACT
To avoid saturation, beam current transformers must be shielded from solenoid, quad, and RFQ high stray fields. Good understanding of field distribution, shielding materials, and techniques is required. Space availability imposes compact shields along the beam pipe. This paper describes compact effective concatenated magnetic shields for IFMIF-EVEDA LIPAc LEBT and MEBT and for FAIR Proton Linac injector. They protect the ACCT Current Transformers beyond 37 mT radial external fields. Measurements made at Saclay on the SILHI source are presented.
ABSTRACT
In the framework of the ITER broader approach, the International Fusion Materials Irradiation Facility (IFMIF) deuteron accelerator (2 × 125 mA at 40 MeV) is an irradiation tool dedicated to high neutron flux production for future nuclear plant material studies. During the validation phase, the Linear IFMIF Prototype Accelerator (LIPAc) machine will be tested on the Rokkasho site in Japan. This demonstrator aims to produce 125 mA/9 MeV deuteron beam. Involved in the LIPAc project for several years, specialists from CEA/Saclay designed the injector based on a SILHI type ECR source operating at 2.45 GHz and a 2 solenoid low energy beam line to produce such high intensity beam. The whole injector, equipped with its dedicated diagnostics, has been then installed and tested on the Saclay site. Before shipment from Europe to Japan, acceptance tests have been performed in November 2012 with 100 keV deuteron beam and intensity as high as 140 mA in continuous and pulsed mode. In this paper, the emittance measurements done for different duty cycles and different beam intensities will be presented as well as beam species fraction analysis. Then the reinstallation in Japan and commissioning plan on site will be reported.
ABSTRACT
During the past two years, a new ECR 2.45 GHz type ion source has been developed especially dedicated to intense light ion injector project like IPHI (Injecteur Proton Haute Intensité), IFMIF (International Fusion Materials Irradiation Facility), to reduce beam emittance at RFQ entrance by shortening the length of the LEBT. This new ALISES concept (Advanced Light Ion Source Extraction System) is based on the use of an additional LEBT short length solenoid very close to the extraction aperture. The fringe field of this new solenoid produces the needed magnetic field to create the ECR resonance in the plasma chamber. Such geometry allows first putting the solenoid at ground potential, while saving space in front of the extraction to move the first LEBT solenoid closer and focus earlier the intense extracted beam. During the commissioning of the source in 2011-2012, ALISES has produced about 20 mA extracted from a 6 mm diameter plasma extraction hole at 23 kV. But the magnetic configuration combined to the new extraction system geometry led to important Penning discharge conditions in the accelerator column. Lots of them have been eliminated by inserting glass pieces between electrodes to modify equipotential lines with unfavorable ExB vacuum zones where particles were produced and trapped. To study Penning discharge location, several 3D calculations have been performed with OPERA-3D/TOSCA code to simulate the possible production and trapping of electrons in the extraction system. The results obtained on different sources already built have shown very good agreement with sparks location observed experimentally on electrodes. The simulations results as well as experimental measurements are presented and solutions to prevent possible Penning discharge in future source geometries are established.
ABSTRACT
One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.
ABSTRACT
The production of rare radioactive ion beam (RIB) far from the valley of stability is one of the final purposes of the Spiral2 facility in Caen. The RIB will be produced by impinging a deuteron beam onto a carbon sample to produce a high neutron flux, which will interact with a uranium target. The primary deuteron beam is produced by an ion source based on ECR plasma generation. The deuteron source and the low energy beam transport (LEBT) has been assembled and tested at CEA Saclay. Diagnostics from other laboratories were implemented on the LEBT in order to characterize the deuteron beam produced and compare it to the initial simulations. The ion source has been based on a SILHI-type source, which has demonstrated good performances in pulsed and continuous mode, and also a very good reliability on long term operation. The 5 mA of deuteron beam required at the RFQ entrance is extracted from the plasma source at the energy of 40 kV. After a brief description of the experimental set-up, this article reports on the first beam characterization experiments.
ABSTRACT
In the framework of the IFMIF-EVEDA project (International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities), CEA∕IRFU is in charge of the design, construction, and characterization of the 140 mA continuous deuteron injector, including the source and the low energy beam line. The electron cyclotron resonance ion source which operates at 2.45 GHz is associated with a 4-electrode extraction system in order to minimize beam divergence at the source exit. Krypton gas injection is foreseen in the 2-solenoid low energy beam line. Such Kr injection will allow reaching a high level of space charge compensation in order to improve the beam matching at the radio frequency quadrupole (RFQ) entrance. The injector construction is now completed on the Saclay site and the first plasma and beam production has been produced in May 2011. This installation will be tested with proton and deuteron beams either in pulsed or continuous mode at Saclay before shipping to Japan. In this paper, after a brief description of the installation, the preliminary results obtained with hydrogen gas injection into the plasma chamber will be reported.
ABSTRACT
By the 90s, the CEA has undertaken to develop the production of intense light ion beams from unconfined ECR plasma. Today, three sources for IPHI, SPIRAL2, and IFMIF projects (respectively, 100 mA of H(+), 8 mA of D(+), and 140 mA of D(+)) are installed at CEA∕Saclay. In order to improve performances and decrease dimensions of these sources, it is necessary to better understand the mechanisms involved in the production and extraction of particles. As a consequence, theoretical and experimental studies are being carried out. We present a theoretical study based on SOLMAXP, a home-made particle-in-cell code. The aim is to investigate the possibility of reducing the plasma chamber size without loss of beam characteristics. This code has been validated by beam intensity measurements on a permanent magnet based source, producing a proton beam of 30 mA at 40 kV on the test bench BETSI. In order to reduce experimentally the dimensions of plasma chamber, a new source, named ALISES with variable plasma chamber volume, is under assembly.
ABSTRACT
In the framework of the IFMIF-EVEDA phase (International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities), the CEA-Saclay is in charged of the design and realization of the 140 mA cw deuteron source. The IFMIF EVEDA demonstrator will be installed in Japan in the next six years and will have to accelerate the deuteron beam up to 9 MeV. CEA will build the source and the low energy beam line (LEBT) and will test the cw high intensity deuteron production at Saclay. The SILHI source is an electron cyclotron resonance (ECR) source, operating at 2.45 GHz. In 2001, it produced more than 130 mA of deuteron beam in pulsed mode to minimize neutron production. Such a result pushes to develop a new ECR source based on the SILHI design and equipped with a specific extraction system. Several options of the accelerator column will be implemented in order to improve the reliability and the efficiency of the source. The IFMIF source and LEBT design will be reported.
ABSTRACT
In the framework of several International HPPA projects (such as IFMIF, IPHI, and Spiral2) the CEA handles the design and the developments of several electron cyclotron resonance (ECR) ion sources. For the IFMIF EVEDA demonstrator, a 140 mA cw extracted deuteron beam will be required for high yield of neutron production. For radioactive ion production in the Spiral2 project, several milliamperes of deuterons will be delivered with a permanent magnet source. The optimization of the beam quality at the entrance of the radio frequency quadropole (RFQ) accelerator system triggered the need of a new test bench for ion source optimization and beam qualification. The BETSI ion source test bench will operate up to 50 kV and ignite cw or pulsed hydrogen plasma with a 2.45 GHz magnetron. Great care has already been taken to design electrostatic optics of the extraction system to minimize the emittance growth. Plasma diagnostics will be inserted in the source chamber and several beam diagnostics (emittance and current measurements, beam species analysis) will also be implemented on the low energy beam line transport (LEBT). These diagnostics allow the simultaneous analysis of the beam quality with the plasma parameters of the source. Regional funding request will also be needed to improve the LEBT for space charge compensation measurements. The design of the present and upgraded test bench will be reported as well as the first extracted beam analysis.
ABSTRACT
Based on the experience of the SILHI electron cyclotron resonance (ECR) ion source for the IPHI accelerator, which produces routinely 100-120 mA H(+) beam, the CEA-Saclay is in charge of the design and realization of the 140 mA cw deuteron source for the IFMIF project (International Fusion Materials Irradiation Facility). IFMIF is an accelerator-based neutron irradiation facility consisting of two accelerators of 125 mA D(+) beam at 40 MeV that hit in parallel a lithium target. IFMIF utilizes the deuteron-lithium (d-Li) neutron, producing a reaction to simulate the 14 MeV neutron environment in deuterium-tritium (D-T) fusion reactors. In the framework of the IFMIF EVEDA phase (Engineering Validation and Engineering Design Activities), we are studying a cw ECR ion source with a new extraction system to allow high current extraction while keeping a low divergence as well as a small emittance. Starting from SILHI five-electrode system with H(+) ions, the extracted beam characteristics as well as electric field conditions are compared with the cases of four- and three-electrode extraction systems. Experimental results made on the SILHI source with H(+) ions are briefly discussed. Extensive experimental results on the new source test bench BETSI are expected as soon as the design and fabrication of a dedicated extraction system with a new set of electrodes will be finished.
