A comparison of the experimental cross sections of the (n, γ) reaction for several nuclei (103Rh, 127I, 181Ta, 197Au) with the compound nucleus model calculations has been made. In the formula used for the probability of gamma-ray emission from the compound nucleus, the presence of the well-known giant resonance was accounted for, as well as the presence of the "pigmy resonance" appearing at the energy Eγ ≈ 6 MeV. The agreement with the experimental values is better in this case than when the "pigmy resonance" is neglected. The same conclusions can be obtained from the calculations of the shape of the spectrum of neutron capture and from the Γγ/D ratio.

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Pure deuterium plasma discharge from plasma focus breeds 1.01 MeV tritons via the D(d,p)T fusion branch, which has the same cross section as the D(d,n)3He (En=2.45 MeV) fusion branch. Tritons are trapped in and collide with the background deuterium plasma, producing 14.1 MeV neutrons via the D(t,n)4He reaction. The paper presents published in preliminary form as well as unpublished experimental data and theoretical studies of the neutron yield ratio R=Yn(14.1 MeV)/Yn(2.45 MeV). The experimental data were obtained from 1 MJ Frascati plasma focus operated at W=490 kJ with pure deuterium plasma (in the early 1980s). Neutrons were monitored using the nuclear activation method and nuclear emulsions. The present theoretical analysis of the experimental data is based on an exact adaptation of the binary encounter theory developed by Gryzinski. It is found that the experimentally defined value 1⋅10−3<R<3⋅10−3 can be explained theoretically only if one considers that tritium burnup occurs in the plasma domains of very high density (n≳1021 cm−3), high temperature (kT≳1 keV), and short trapping time (t0≤20 ns). These domains are known as efficient traps of MeV ions but are not the main source of D(d,n)3He fusion.

Abstract. In the early 90's, it was discovered that a Plasma Focus (PF) system self-creates a plasma-tarp in which high energy-threshold nuclear-reactions occur at high reaction rates. Short life radioisotopes (SLR)s such as *F "F, 'b, r40, '% have been genaatd (lo6 -10' per pulse} with a PF-machine using 7 kJ energy storage to produce &e plasmas jY radioactivity from the SLRs is measured with rugged, Geiger counters inserted into the PF-chamber, zmd a sp&fic SLR is identified by its half-life. The PF chamba wore discharge) is Sued with a mixture of gases that constitutes the latter plasma-target -beam system, e.g., the elements required to produce specific SLRs through nuclear mactions. In this paper, arguments are presented showing that a modest sized PF-machine, using a 50 -75 kJ fast capacitor-hank, when operated at pulse f@rencies of l-10 Hz can produce 2 10' SLRs/pulse. This paper reports the results of testing a PF as a e breeder of SLRs with dual applications for: (i) Secondary Radioactive Nuclear Beams ion-sources (2 < 35), and (ii) as a breeder of radioisotopes for biomedicine (Z I 10) and/or PET imaging.