Beamed neutron emission driven by laser accelerated light ions

Abstract

Highly anisotropic, beam-like neutron emission with peak flux of the order of 10 9 n/sr was obtained from light nuclei reactions in a pitcher-catcher scenario, by employing MeV ions driven by a subpetawatt laser. The spatial profile of the neutron beam, fully captured for the first time by employing a CR39 nuclear track detector, shows a FWHM divergence angle of~ 70 , with a peak flux nearly an order of magnitude higher than the isotropic component elsewhere. The observed beamed flux of neutrons is highly favourable for a wide range of applications, and indeed for further transport and moderation to thermal energies. A systematic study employing various combinations of pitchercatcher materials indicates the dominant reactions being d(p, n+p) 1 H and d(d,n) 3 He. Albeit insufficient cross-section data are available for modelling, the observed anisotropy in the neutrons' spatial and spectral profiles is most likely related to the directionality and high energy of the projectile ions.

Proton probing of laser-driven EM pulses travelling in helical coils

“…Although the two latter properties are advantageous in plasma radiography applications [2][3][4][5][6] , these are generally undesirable in view of many other potential applications [7,8] . Therefore controlling and optimising the laser driven ion beam parameters has been one of the intensively studied research topic over the past decade [8][9][10][11][12][13] .…”

Dynamic control of laser driven proton beams by exploiting self-generated, ultrashort electromagnetic pulses

“…In order to maintain a suitably high ion flux over the distances required for applications, such as radiobiology 3 , warm dense matter creation 4 , neutron source development 5 , some means of constraining the beam divergence is needed. The manipulation of laser generated proton beams presents specific challenges due to the high bunch charge and short pulse nature of the beams.…”

Experimental demonstration of a compact epithermal neutron source based on a high power laser

“…The input flux of fast neutrons can be significantly enhanced by increasing the energy and number of incident ions on the catcher. Order of magnitude higher fast neutron fluxes than produced in the current experiment have been already reported [2][3][4], and, in principle, can be further improved upon by taking advantage of ongoing developments in laser-driven ion acceleration [23][24][25]. A credible source of fast neutrons can also be obtained by deploying MeV electron jets from laser-driven exploding foils [5].…”

“…There has been over the last decades a sustained interest in laser-driven neutron sources, which are capable of producing sub-ns bursts of fast (MeV energies) neutrons with high brightness [1][2][3][4][5]. Although fast neutrons are useful for many applications, such as imaging [6] and material testing for fusion reactor vessels [7], the arena of neutron science and applications mainly requires slow neutrons (with energies ranging from sub-meV to keV) which are provided at reactor [8] and accelerator [9] based facilities by moderating fast neutrons.…”