For the first time the emission of neutron bursts in the process of high-voltage discharge in air was observed. Experiments were carried out at an average electric field strength of ∼1 MV·m(-1) and ...discharge current of ∼10 kA. Two independent methods (CR-39 track detectors and plastic scintillation detectors) registered neutrons within the range from thermal energies up to energies above 10 MeV and with an average flux density of ≳10(6) cm(-2) per shot inside the discharge zone. Neutron generation occurs at the initial phase of the discharge and correlates with x-ray generation. The data obtained allow us to assume that during the discharge fast neutrons are mainly produced.
The possibility of neutron generation by irradiating deuterated crystalline structures with an electron beam with an energy of 20–40 keV was studied. As targets, the deuterated crystalline structures ...of palladium and textured CVD diamond were used. Measurements of neutron emission are presented, which were carried out by three independent methods—scintillation detectors, counters based on He-3, and track detectors CR-39.The average neutron flux during irradiation was estimated as 1–10 s
in 4
sr.
At the ion accelerator HELIS at the LPI, the neutron yield is investigated from a deuteron-deuteron (DD) reaction in a deuterated Pd target, during an irradiation of its surface by a 20 keV deuterium ...(D) ion beam. The measurements of the neutron flux in the D beam direction are performed in dependence on the target angleβwith respect to the D beam axis using a multichannel detector based onHe3counters. A significant anisotropy in the neutron yield is observed, and it was higher by a factor of 2 atβ=0compared to that atβ=±30° . The possible reasons for the anisotropy, including D ion channeling, are discussed. The orientation effect of increasing the relative probability of the DD reaction in Pd due to channeling was investigated by computer simulations using the bcm-2.0 code. The numerically obtained 20 keV D trajectories allow calculating the flux density of channeled D in dependence on the penetration depth and angle of incidence. The enhanced D flux density between crystal planes at a zero incident angle with respect to (200) Pd planes allows a qualitative explanation of the increase of the neutron yield in the DD reaction.
At the HELIS ion accelerator, the dependence of the yield of DD nuclear-reaction products (neutrons and protons) on the angle of rotation of a Ti and CVD diamond (diamond obtained by chemical vapor ...deposition) target relative to the axis of the D+ ion beam at energies of
E
≤ 35 keV is studied. Neutron detection is carried out by two independent methods: proportional counters filled with
3
He and a scintillation detector with a stilbene crystal. Protons are detected using a diamond detector. The detectors are located on the side and behind the target. The CVD-diamond target has a polycrystalline structure and texture with the (100) grain orientation. The crystal structure of the titanium target is homogeneous and isotropic. The measurements show the dependence of the neutron flux recorded by the detectors located on the side and behind the target on the orientation of the target made of textured CVD diamond in the deuterium ion beam at energies of 25 and 30 keV. The proton yield from the CVD diamond target shows a dependence on the target-rotation angle at an energy of 25 keV. For the Ti target, no such effects are observed. The orientational dependence in the yield of neutrons and protons from textured diamond is explained by the effect of channeling deuterium ions in its structure.
A spectrometer allowing recording nuclear reaction products characteristic of boron—proton radiotherapy technologies is developed. A hardware-software system of the spectrometer allows identifying ...alpha particles and other light products of nuclear reactions in the energy range of 0.5 MeV—10 MeV is presented. The spectrometer was tested at the Prometeus proton accelerator of the Physico-Technical Center (PTC) LPI (Protvino) and the HELIS installation of the LPI (Moscow). The spectrometer applicability to the study of the
p
+
11
B → 3α nuclear reaction at protons energies used in proton therapy is shown.
The results of studies of the interaction of ion beams and X-ray quanta with deuterated crystal structures at the HELIS facility (LPI) are presented. Results on research of DD-reactions in deuterated ...crystal structures at deuteron energies 10 - 25 keV show significant enhancement effect. It is shown that the effect of the beams of ions Ne+ and H+ at energies in the range of 10 - 25 keV and a beam of X-radiation of 20 - 30 keV for deuterated target leads to stimulation of DD-reaction. For the target of CVD-diamond it is showed that the orientation of the sample with respect to the deuteron beam affects the neutron yield. Targets (deuterated CVD diamond, palladium, zirconium and titanium) were irradiated with both ion beams and X-ray quanta using an X-ray tube with an energy of up to 30 keV. Analysis of X-ray fluorescence spectra from deuterated targets of CVD diamond and palladium revealed "additional" peaks that are not identified by any of the characteristic radiation lines. Their appearance cannot be connected with any known element, as well as with diffraction processes.
—
A neutron detection system at the HELIS setup created by the Lebedev Physical Institute is based on proportional counters. Systems for shaping, discriminating, reading, digitizing, and processing ...signals from 36 SNM18 proportional neutron counters are. The location of the counters in all directions around the analyzed target made it possible to perform a set of experiments to study the angular dependences of neutron yields in the DD reaction in deuterated crystal structures at deuteron energies of 10–25 keV, as well as to stimulate the DD reaction with ion beams.
Measurements of emission from nuclear reaction products (neutrons and protons) have been carried out appearing in the deuterated structures of textured CVD diamond, palladium, titanium, and zirconium ...under irradiation with a beam of X rays using independent methods (neutron detector based on He-3 counters, Si surface-barrier semiconductor detectors and CR-39 track detector). The possibility of enhancement of both DD reaction and multi-particle deuterium fusion by the beam of X rays with energy ranging 20–30 keV in solid deuterated targets has been established. Analysis of X-ray fluorescence spectra of the target bombarded by beams of ions has revealed “additional” peaks, the occurrence of which cannot be related to any of the known elements, and requires separate study.
The interaction between a deuterium ion (D
+
) beam and deuterium-enriched Pd and Ti targets are studied using the HELIS ion accelerator (Lebedev Physical Institute). The neutron yield is determined ...from the DD reaction in the deuterated Pd target whose surface is irradiated with a D
+
-ion beam with an energy of 20 keV. The neutron flux is measured in the D
+
-ion-beam direction as a function of the angle β of target rotation relative to the beam axis using a multichannel detector based on
3
He counters. Significant anisotropy (orientation effect) of the neutron yield is observed; it is two times higher at β
=
0° than at β
=
±30°. The orientation effect can be associated with channeling and the so-called flux-peaking effect. It is studied by computer simulations using the BCM-2.0 code. The enhanced density of the D
+
flux between the (200) planes of a Pd crystal (where implanted D is located) at zero angle of incidence with respect to these planes makes it possible to qualitatively explain the observed orientation effect. No effect is observed in a homogeneous target of deuterated titanium.
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