Laser - plasma generation of ultra-short intense neutron pulse

Oct 13, 2020, 6:35 PM
1h
Online

Online

Poster report Section 6. Plasma physics and thermonuclear fusion. Poster session 6

Speaker

Konstantin Platonov (Peter the Great St.Petersburg Polytechnic University)

Description

Laser - plasma generation of ultra-short intense neutron pulse

$^1$Andreev А.А., $^2$Komarov V.А, $^3$Platonov К.Yu.

$^1$Saint-Petersburg State University, 199034 UniversitetskayaEmb. 7-9, St. Petersburg, Russia
$^2$FGUP scientific research institute of Complex Tests of Optiko-electronic Devices 188540, Leningrad region, Sosnovy Bor
$^3$Peter the Great St. Petersburg Polytechnic University,
195251 Polytechnicheskaya st. 29, St. Petersburg, Russia

Acceleration of Deytron nuclear in thin (micron size) laser targets (polyethylene C$_2$D$_4$) to a МэВ energy and the subsequent interaction with the secondary targets from D$_2$O, LiF, Be of 1 mm thickness was considered. It is shown, that at the energy of laser pulse of 250 J, duration 10 ps, diameter of the laser spot 5 microns and intensity 1.3x10$^{20}$ W/cm$^2$ in a secondary target there is the generation of ultrashort (<30 ps) neutron pulse containing from 4x10$^9$ (for LiF secondary target) to 10$^{10}$ neutrons (Be target) with characteristic energy about 10 MeV. Pulse intensity of a neutron flux from a surface of a secondary target reaches 10$^{20}$ neutrons/cm$^2$s, that exceeds the intensity of neutron flux of the reactors making in a continuous regime ~10$^{15}$ neutrons/cm$^2$s. Angular distribution of neutrons has a maximum in laser pulse direction and semi-width about ±60$^o$ from this direction is calculated. At 10 Hz repetition rate of a laser pulse, the realization quasi-stationary neutrons source with average intensity about 10$^{12}$ neutrons/cm$^2$s is possible. In laser-plasma neutron source a laser pulse with less (~ 100 fs) duration and upper (up 1 kHz) repetition frequency may be used. Peak intensity of a neutron flux thus will decrease on 2 order, however average intensity will remain constant. Despite of smaller average intensity and essentially smaller total number of neutrons, some potential application of laser-plasma super-short neutron pulses can be interesting for neutron spectroscopy of ultrafast (tens ps) physical, chemical and biological processes, which cannot be realized by means of traditional neutron sources.

Primary authors

Konstantin Platonov (Peter the Great St.Petersburg Polytechnic University) Prof. Alekcandr Andreev (Saint-Petersburg State University) Dr Vladimir Komarov (FGUP scientific research institute of Complex Tests of Optiko-electronic Devices)

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