P. Cara

A Stepped Approach from IFMIF/EVEDA Toward IFMIF

Abstract In this paper we analyze from the technical point of view the possibility of developing the IFMIF facility (International Fusion Materials Irradiation Facility) in a stepped approach from the prototypes, presently under testing in the framework of the IFMIF/EVEDA Project (IFMIF Engineering Validation and Engineering Design Activities), but with the capability to fulfill the DEMO (Demonstration reactors) needs in a first step and the fusion power plant needs in a second step. The paper is focused on the so-called DONES (DEMO Oriented Neutron Source) alternative. It is built using one of the 40 MeV IFMIF accelerators, together with a strong simplification of some of the other systems and subsystems, driven by the lower power to be handled in the DONES facility, by transferring the PIE (post-irradiation experiment) analysis to other external facilities, by reducing the remote handling activities foreseen in the facility, and by reducing the type of irradiation experiments to be performed simultaneously. A preliminary neutronic evaluation of the achievable radiation map and on the requirements for the transfer of the irradiated modules to the external facility is also presented.

International Fusion Materials Irradiation Facility injector acceptance tests at CEA/Saclay: 140 mA/100 keV deuteron beam characterizationa)

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.

Operation and commissioning of IFMIF (International Fusion Materials Irradiation Facility) LIPAc injector

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.

Installation and first operation of the International Fusion Materials Irradiation Facility injector at the Rokkasho site

The International Fusion Materials Irradiation Facility (IFMIF) linear IFMIF prototype accelerator injector dedicated to high intensity deuteron beam production has been designed, built, and tested at CEA/Saclay between 2008 and 2012. After the completion of the acceptance tests at Saclay, the injector has been fully sent to Japan. The re-assembly of the injector has been performed between March and May 2014. Then after the check-out phase, the production of the first proton beam occurred in November 2014. Hydrogen and deuteron beam commissioning is now in progress after having proceeded with the final tests on the entire injector equipment including high power diagnostics. This article reports the different phases of the injector installation pointing out the safety and security needs, as well as the first beam production results in Japan and chopper tests. Detailed operation and commissioning results (with H(+) and D(+) 100 keV beams) are reported in a second article.

Analysis of Maximum Voltage Transient of JT-60SA Toroidal Field Coils in Case of Fast Discharge

The voltage transient appearing across and inside the toroidal field (TF) coils of JT-60SA in case of fast voltage variation, such as a safety discharge operated by the quench protection circuit (QPC), can be significantly high. In fact, the voltage distribution between coils and inside the winding can be not uniform during fast transient, being influenced by the presence of parasitic capacitances. A simplified electrical model of the TF coils has been developed to investigate this aspect. Its robustness has been proved by means of parametric sensitivity analysis, and the impact of the included simplifications has been evaluated. The obtained model has been used in conjunction with an electrical model of the TF circuit elements, including a simplified model of the QPC able to reproduce the voltage appearing across its terminals as observed during experimental operation of the QPC prototype. The worst case in terms of transient voltage applied to the winding has been identified, corresponding to a fault to ground occurring just after QPC operation. It has been verified that the resulting voltage is largely inside the coil insulation capability defined by performed insulation voltage tests.