Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex I: Pulsed Spallation Neutron Source

Abstract

Abstract:At the Japan Proton Accelerator Research Complex (J-PARC), a pulsed spallation neutron source provides neutrons with high intensity and narrow pulse width pulse to promote researches on a variety of science in the Materials and Life Science Experimental Facility (MLF). It was designed to be driven by a proton beam with an energy of 3 GeV, a power of 1 MW at a repetition rate of 25 Hz, that is world's highest power level. It is still on the way towards the goal to accomplish the operation with a 1 MW proton beam. In this review, distinctive features of the target-moderator-reflector system of the pulsed spallation neutron source are presented.

High stereographic resolution texture and residual stress evaluation using time-of-flight neutron diffraction

“…TAKUMI (Moriai et al, 2006;Harjo et al, 2011) is an engineering materials TOF neutron diffractometer at the Materials and Life Science Experimental Facility (MLF), J-PARC (Takada et al, 2017;Nakajima et al, 2017;Sakasai et al, 2017), dedicated to in situ microstructure and stress evaluation during hot (or warm or cryogenic) deformation and ex situ microstructure and residual stress measurements of large engineering components ( Fig. 2a).…”

“…The pulsed proton beam involved in this study was operated at 25 Hz (25 pulses per second) with a proton beam power of around 200 kW, and 4.3 Â 10 13 neutrons were obtained at each proton pulse through the spallation reaction of mercury nuclei after collision between the proton beam and the mercury target vessel (Takada et al, 2017). Consequently, the neutron flux at the sample scattering center of TAKUMI was about 9.6 Â 10 6 n cm À2 s À1 in the high-intensity experimental mode.…”

Materials and Life Science with Quantum Beams at the Japan Proton Accelerator Research Complex

“…The book has been separated into four review articles, as published in the journal Quantum Beam Science [8][9][10][11]. Central to all J-PARC experimental divisions is the landmark accelerator complex (Figure 1), composed of a linear accelerator (LINAC) feeding H − ions by stripping them to protons into the Rapid Cycle Synchrotron.…”

“…The four sections are divided into descriptions of the Pulsed Spallation Neutron Source [8], the Neutron Scattering Instruments [9], the Neutron Devices and Computational and Sample Environments [10], and the Muon Facility [11]. The four sections are divided into descriptions of the Pulsed Spallation Neutron Source [8], the Neutron Scattering Instruments [9], the Neutron Devices and Computational and Sample Environments [10], and the Muon Facility [11].…”

“…The core of the neutron beam lines is the pulsed spallation source reviewed in the article by Takada et al [8]. The target is the device where the accelerated proton beam hits heavy atoms, and spallation takes place by excitation of the nuclei and subsequent evaporation of neutrons.…”