Direct evaluation of high neutron density environment using (n,2n) reaction induced by laser-driven neutron source

Single shot radiography by a bright source of laser-driven thermal neutrons and x-rays

“…In this letter, we show the development of LDNS generating high yield of fast neutrons (10 10 ) within a short bunch duration (∼1 ns) from a fingertip-size source (∼1 cm 3 ). The peak neutron density reaches 10 19 n s −1 cm −3 , which is higher than those of stellar environments seen in Red Giant Stars 14,25) in Universe. Furthermore, the source generates bright x-rays simultaneously with neutrons.…”

“…37) In the present experiment, the density of the thermal neutrons is evaluated to be ∼10 4 cm −2 per a pulse on the sample, corresponding to ∼10 10 neutrons in 4π at the source. Nowadays, a single laser shot of several LDNSs 4,[11][12][13][14] can achieve the yields of approximately 10 10 for fast neutrons, indicating that the present scheme of radiography is applicable to these LDNSs.…”

“…The ToF detector was calibrated with (n, 2n) nuclear reactions. 14) The neutron energy spectrum shows a broad spread having the maximum energy of up to 20 MeV [see Fig. 2(b)].…”

Non-destructive inspection of water or high-pressure hydrogen gas in metal pipes by the flash of neutrons and x rays generated by laser

“…6 Neutrons have already been applied in wide areas of research because of their charge neutrality and high transmittance to most substance. Laser-driven neutron sources (LDNSs) [6][7][8][9][10][11][12][13][14][15][16][17][18] are compact sources realized by high-power lasers. LDNSs based on laser-ion acceleration include two targets.…”

“…19 With moderators such as high density polyethylene located near the second target, the fast neutrons are decelerated to epithermal, 13 thermal, 14 and cold 15 regions to adapt for the study of various science and engineering applications. LDNSs have been studied [6][7][8][9][10][11][12][13][14][15][16][17][18] for their following features: (i) each neutron pulse has a short time duration (∼ns), (ii) neutrons could be generated from a compact space smaller than 1 cm 3 , and (iii) it is possible to produce different types of radiations including x rays 20 at the same laser shot. Because of the former two features, LDNSs could be used for neutron radiography with short time and high spatial resolution.…”