Research and development of a compact discharge-driven D–D fusion neutron source for explosive detection Kiyoshi Yoshikawa a, * , Kai Masuda a , Teruhisa Takamatsu a , Seiji Shiroya b , Tsuyoshi Misawa b , Eiki Hotta c , Masami Ohnishi d , Kunihito Yamauchi c , Hodaka Osawa d , Yoshiyuki Takahashi b a Institute of Advanced Energy, Kyoto University, Uji, Kyoto, Japan b Research Reactor Institute, Kyoto University, Kumatori, Osaka, Japan c Department of Energy Sciences, Tokyo Institute of Technology, Yokohama, Japan d Department of Electrical Engineering and Computer Science, Kansai University, Suita, Osaka, Japan Available online 7 April 2007 Abstract Current results are described on the research and development of the advanced humanitarian landmine detection system by using a compact discharge-type fusion neutron source called IECF (Inertial-Electrostatic Confinement fusion) devices. With a 50 mm-thick water-jacketed IEC device (IEC20C) of a 200 mm inner diameter, it can produce 10 7 neutrons/s stably in CW mode for 80 kV and 80 mA. Ample 10.8 MeV c-rays produced through (n, c) reaction with nitrogen atoms in the melamine (C 3 H 6 N 6 ) powder (explosive sim- ulant) are clearly measured by a BGO-NaI-combined scintillation sensor with distinct difference in cases with and without melamine. This proves feasibility of the identification of the buried landmines. Ó 2007 Elsevier B.V. All rights reserved. PACS: 52.58.Qv Keywords: IECF (inertial-electrostatic confinement fusion); Compact neutron/proton source; Explosive detection; Positron emitter isotope production; BNCT 1. Introduction An IECF (inertial-electrostatic confinement fusion) device is an extremely compact, and simple device as is shown in Fig. 1, running by electrical discharge on D–D or D–T or D– 3 He fuel gases. It basically consists of a hol- low cathode at the center of a spherical vacuum chamber serving as the anode and filled with a fuel gas. A glow dis- charge takes place between the anode and cathode as is seen in Fig. 1, thereby, producing ions that are accelerated toward the cathode, and many of them penetrating the hollow cathode wire undergo fusion reactions through beam–beam collisions, or beam-background gas collisions (Fig. 2). Actually, by this very simple device, D–D neutrons, and D– 3 He protons both in excess of 10 8 n/s in CW mode at University of Wisconsin, Madison [1,2], and 6.8 · 10 9 D–D neutrons/s in pulsed mode at Tokyo Institute of Technology [3] were achieved. This concept was first proposed in 1950s aiming at the future fusion power plant, which is basically a beam–beam colliding fusion device with an extremely compact and sim- ple configuration. Working with Fransworth, an inventor of the US Television, at ITT laboratories, Hirsch obtained record neutron output of approximately 10 8 D–D neu- trons/s, and 10 10 D–T neutrons/s, respectively, in 1967 from a gridded IECF device driven by six ion guns [4]. 0168-583X/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2007.04.026 * Corresponding author. Tel.: +81 774 38 3440; fax: +81 774 38 3449. E-mail address: kiyoshi@iae.kyoto-u.ac.jp (K. Yoshikawa). www.elsevier.com/locate/nimb Nuclear Instruments and Methods in Physics Research B 261 (2007) 299–302 NIM B Beam Interactions with Materials & Atoms