Neutrons are powerful tools for investigating the structure and properties of materials used in science and technology. Recently, laser-driven neutron sources (LDNS) have attracted the attention of different communities, from science to industry, in a variety of applications, including radiography, spectroscopy, security, and medicine. However, the laser-driven ion acceleration mechanism for neutron generation and for establishing the scaling law on the neutron yield is essential to improve the feasibility of LDNS. In this paper, we report the mechanism that accelerates ions with spectra suitable for neutron generation. We show that the neutron yield increases with the fourth power of the laser intensity, resulting in the neutron generation of 3×1011 in 4π at a maximum, with 1.1×1019 W cm−2, 900 J, 1.5 ps lasers. By installing a “hand-size” moderator, which is specially designed for the LDNS, it is demonstrated that the efficient generation of epithermal (0.1–100 eV) neutrons enables the single-shot analysis of composite materials by neutron resonance transmission analysis (NRTA). We achieve the energy resolution of 2.3% for 5.19-eV neutrons 1.8 m downstream of the LDNS. This leads to the analysis of elements and isotopes within sub-μs times and allows for high-speed nondestructive inspection.
|Journal||Physical Review X|
|Publication status||Published - 31 Jan 2023|
Bibliographical noteFunding Information:
This work was funded by Grant-in-Aid for Scientific Research (No. 25420911, No. 26246043, and No. 22H02007) of MEXT, A-STEP (AS2721002c), and PRESTO (JPMJPR15PD) commissioned by JST. The authors thank the technical support staff of ILE for their assistance with the laser operation, target fabrication, and plasma diagnostics. This work was supported by the Collaboration Research Program of ILE, Osaka University. The collaboration of the J. A. E. A. was supported by the subsidy of the MEXT for nuclear security promotion. A. Y. deeply appreciates useful suggestions from Professor Kiyanagi of Nagoya University and Professors Kamiyama and Sato of Hokkaido University on the estimation of the neutron generation and moderation, Dr. M. Kanasaki and Professor K. Oda of Kobe University on the evaluation of neutron yield, and Professor I. Murata of Osaka University on the detector calibration using his Am-Be neutron source. A. Y. gratefully appreciates suggestions from the committee on “Laser-driven Neutron Source” commissioned by the Laser Society of Japan. A. Y. also appreciates fruitful discussions with the members of a consultancy meeting on “Advances in Laser-driven Neutron and X-ray Sources” commissioned by IAEA.
© 2023 authors. Published by the American Physical Society.
ASJC Scopus subject areas
- Physics and Astronomy(all)