Registration Of Charged Particles Research Articles

Test experiment to determine the time distribution of the background between MMF accelerator pulses on the RADEX channel

The authors offer works using the MMF INR RAS neutron channel to study the cluster structures in light nuclei, in particular, 𝛼-4n-𝛼 and 8Be-4n in the highly excited state 12Be*. This needs the registration of charged particles from the 12Be* 𝛽-decay during its formation in the 𝑛+13C reaction in the intervals between cascade neutron pulses. The paper presents the first results of an experiment on measuring the spectra and time distributions of gamma-quanta and neutrons using a proton beam of 50 Hz and a duration of 0.3 𝜇s.

Method and unit for dynamic control of conversion characteristics of spectrometric paths for multichannel charged particle registration systems

A method and unit for dynamic control of conversion characteristics of spectrometric paths of multichannel charged particle registration systems based on specialized microchip with a large degree of integration similar to IDE1140 in structure is proposed. The conversion characteristics are controlled during operation of the device by auto-adjusting the offset and gain of the scaling amplifier. The proposed method allows to use the entire dynamic range of the analog-to-digital converter and adjust the temperature drift for each channel at the hardware level during operation of the device.

THE MECHANISM OF ANOMALY OF CHARGED PARTICLES BEFORE THE EARTHQUAKE

Some mechanisms are considered in the form of analysis of the propagation and origin of charged particles involved in acting forces in energy transfer processes that lead to a highly deformed seismically active state and create the necessary conditions for the occurrence of an earthquake. The results of monitoring the registration of charged particles of radioactive radiation of the earth’s crust for the purpose of earthquake forecasting are analyzed. During monitoring, responses to the origin of an event - an earthquake-are observed in the behavior of charged particles, which are located on remote parts of the earth’s crust relative to the place where charged particles are registered. In this case, wide horizons of the earth’s crust are involved, where tectonic disturbances are developed, covering not only the deep layers of the earth’s crust, but also the sections that appear in the upper parts. These tectonic disturbances can be considered as through-current channels that facilitate the transfer of energy from great depths. On the earth’s surface, the behavior of charged particles should be considered within the framework of the action of geomagnetic and atmospheric electricity fields. These fields at the earth’s surface are a carrier field that provides a special transfer of not only energy and matter. Thus, the propagation of charged particle flows over considerable distances from the epicenter of earthquakes can be caused by the carrier fields of deep change processes.

Spatial resolution of triple-GEM detectors

Gas Electron Multiplier (GEM) based detectors are widely used in numerous collider experiments and, in particular, at the Budker Institute of Nuclear Physics (BINP). In order to determine the best possible spatial resolution, the simulation of charged particle registration process is accomplished. The simulation shows that spatial resolution is definitely less than 20 μ m for applied operation configurations. The simulation of electron transport through single GEM and through GEM-cascade shows that an electron cluster is compressed by GEM holes and an effective transverse diffusion is reduced by approximately 15% as maximum. The experimental part of the work is devoted to the operability tests of the designed detector with orthogonal strips readout with a pitch of 250 μ m and the measurements of its characteristics including the dependence of gain on GEM-voltage, the registration efficiency and the spatial resolution. Spatial resolution of the studied detector is measured as 31 . 5 ± 0 . 9 ( s t a t . ) − 7 . 5 + 6 . 9 ( s y s t . ) μ m .

Improvement of Makrofol® De 7-2 polycarbonate optical properties by thermal annealing for the registration of alpha particles

Translucent Makrofol® DE 7-2 polycarbonate samples are thermally-annealed at 200°C for different durations in the air. UV–Vis spectra of the thermally-annealed Makrofol® DE 7-2 were measured. The results reveal that the light absorbance by thermally-annealed Makrofol® DE 7-2 is significantly minimized which enhances the visualization of the charged particle track registered on it. Both direct and indirect band gaps show pronounced stability over all thermal annealing durations; the same behavior was observed to Urbach’s energy and the number of carbon atoms per cluster where no reasonable alteration was observed. The thermally-annealed Makrofol® DE 7-2 was irradiated with 3MeV alpha particles and etched for different durations in 75% 6N KOH+25% C2H5OH at 50°C. Alpha particle track diameter is found to be linearly correlated with the etching time up to 3h before the Bragg peak. The chemical etching efficiency of alpha particle tracks ranges from 0.22 to 0.26. The current new findings indicate the possibility to improve the optical properties of translucent Makrofol® DE 7-2 by a thermal annealing for its utilization in charged particle registration.

Influence of external and internal conditions of detector sample treatment on the particle registration sensitivity of Solid State Nuclear Track Detectors of type CR-39

The sensitivity of charged particle registration with SSNTD is the most important parameter to decide about the applicability of those detectors in research, technology and environmental dosimetry. The sensitivity is strongly influenced by the treatment of detector samples before, during and after the exposure and the final evaluation process by chemical etching. Whereas changes in detection properties by external environmental influences are generally considered, the dependences on the etching conditions are ignored. Commonly the sensitivity is assumed to compensate variations in the etching conditions for track revealing. In the present work the validity of this hypothesis will be checked. In the frame of the existing database the sensitivity is not really independent on variations in etching temperatures and should be corrected for differences in the activation energies for stimulation of the bulk and track etching process. Differences in the concentration dependence may be of minor importance. Furthermore, the registration sensitivity depends on environmental conditions before, during and after the irradiation with particles under investigation. Such external parameters are the air pressure, the sample temperature and modification of bulk material by out-gassing in vacuum and exposure to γ-rays. However, the available database is insufficient and inaccurate to draw final conclusions on the detection properties of SSNTD under various external and internal conditions.

Microanode image porous dielectric detector

Porous dielectric detectors (PDDs) can expand the methods of image registration of charged particles, neutrons, and x rays to a great extent; however they are not sufficiently studied yet. Recently it was revealed that multiwire and microstrip PDDs operate stably in dc mode. This paper presents a new two-dimensional microanode image PDD (MAIPDD). Also, preliminary results of investigation of MAIPDD for 5.9 keV x rays and two types of microstrip PDDs are presented.

Fast neutron dose response of a commercial polycarbonate

A commercial polycarbonate produced in Brazil is being studied to be used as neutron detector material using Solid State Nuclear Track Detection (SSNTD) method replacing the well-known detector materials Makrofol and CR-39. This technique is based on the damage (tracks) registration of charged particles produced by the interaction of neutrons with carbon and oxygen atoms of some dielectric materials. The IPEN dosimeter prototype is composed by 30 × 10 × 1.5 mm 3 polycarbonate piece inserted between two Polymethyl Methacralate (PMMA) plates 2 mm thick. The prototypes were irradiated placed on an ISO slab phantom using an isotropic 241AmBe source at LN/LNMRI (Neutrons Laboratory of the National Laboratory of Ionizing Radiation Metrology). To study the dose response groups of five prototypes were irradiated with Hp(10) from 0.5 to 20 mSv with normal incidence and to investigate the angular incidence effect with Hp(10) = 5 mSv with incidence angles of 15°, 45°, 60°, 75°, 85° and 90°. The detectors were revealed by chemical etching with the solution PEW-40 during 3 h. The track density of the detector surface was determined by the average of track counting of five fields ( 20 × 0.1 mm 2). The track response to equivalent dose Hp(10) showed a good agreement with linear fit in the studied interval. The track density strongly decreases for incidence angles higher than 45°.

Multilayer semiconductor spectrometer for studying light neutron-rich nuclei

A two-arm semiconductor spectrometer for registration of charged particles (p, d, t, 3,4He) and their correlations from stopped negative pion absorption reaction is described. The spectrometer is used for search and spectroscopy of light neutron-rich nuclei produced in two- and three-body reactions. The spectrometer consists of two telescopes of 16 Si-detectors in each arm with a sensitive surface of 8 cm 2. The total sensitive thickness of the telescope (43 mm of Si) provides stopping power for protons up to 100 MeV. The design of the spectrometer makes it possible to use a radioactive target 14C. A technique of determining the spectrometric characteristics of the setup is presented. It is shown that energy resolution (FWHM) of the spectrometer in inclusive measurements is of about 500 keV and missing-mass resolution in correlations is of about 1 MeV.

Measurements of high-energy neutron and proton fluxes on-board “Mir-Spectr” orbital complex

The measurements of high-energy neutron (with energies∼ 30–300 MeV) and proton (with energies ∼ 1–200 MeV) fluxes are being conducted on-board “Mir-Spectr” orbital complex. Neutrons are detected by the undirected (FOV ∼ 4π sr) scintillator spectrometer, consisting of 4 identical CsI(Tl) detector units (the effective area for neutrons ∼ 30 cm 2). The gamma-quanta, which can be also detected by this instrument, are separated from neutrons by the analysis of the scintillator output pulse shape. To exclude registration of charged particles an anticoincidence plastic scintillator shield is realized in each detector unit. The proton fluxes are measured by the telescope based on 3 semiconductor detectors with small geometry factor (∼1 cm 2×sr). As the first result of the experiment the upper limit of the integral flux of local and albedo neutrons in the equatorial region (L<1.1) was estimated. The results of this measurements can be useful for the radiation security. Also, the neutrons of solar flares can be detected in this experiment.

High Energy Charged Particle Registration in CR-39 Polycarbonated Detector

Track etch rate characteristics of CR-39 plastic detector exposed to 28Si ions of 670 MeV energy have been investigated. Experimental results were obtained in terms of frequency distribution of the track diameter, track density and bulk etching rate. A dependence of the mean track diameter on energy was found. The application of the radiation effect of heavy ions on CR-39 in the field of radiation detection and dosimetry are discussed. Results indicated that it is possible to produce etchable tracks of 28Si in this energy range in CR-39. We also report the etching characteristics of these tracks in the CR-39 detector.

High energy charged particle registration in CR-39 polycarbonate detector

Track etch rate characteristics of CR-39 plastic detector exposed to 28 Si ions of 670 MeV energy have been investigated. Experimental results were obtained in terms of frequency distribution of the track diameter, track density and bulk etching rate. A dependence of the mean track diameter on energy was found. The application of the radiation effect of heavy ions on CR-39 in the field of radiation detection and dosimetry are discussed. Results indicated that it is possible to produce etchable tracks of 28 Si in this energy range in CR-39. We also report the etching characteristics of these tracks in the CR-39 detector.

Light charged particle registration characteristics of CR-39 plastic track detectors

Abstract CR-39 plastic sheets have been tested for their response to protons, deuterons, and alpha particles. The enlargement of the latent damage trail has been studied (a) under varying experimental conditions, and (b) as a function of energy, restricted energy loss, and Z2 crr/β2 of the light charged particles. The critical angles of etching of CR-39 and its response curves have been obtained. Scanning-Electron-Microscopy (SEM) has been employed for studying the profiles of the etched channels.

Critical rate of energy loss for registration of charged particles in cellulose nitrate

Cellulose nitrate films LR-115 type II (Kodak-Pathé) have been exposed, at right angles, to alpha-particle beams in the energy range 2.5–5.5 MeV. From measurements of both through-etched track diameter and through-etched track density, a critical rate of energy loss for track registration of (0.85 ± 0.05) MeV cm 2 mg −1 has been derived, which corresponds to a critical alpha-particle energy of (4.6 ± 0.4) MeV. These results are compatible with those obtained by other authors whenever similar etching conditions have been used. The concepts of a threshold rate of energy loss and a threshold energy for etched-track formation are introduced, and their values are obtained from the experiment as being (0.80 ± 0.05) MeV cm 2 mg −1 and (5.1 ± 0.4) MeV, respectively. In addition, the present work provides a suitable set of useful reference data for further applications of such plastic nuclear track detector in problems concerned with the detection of low-energy alpha particles.

The restricted energy loss criterion for registration of charged particles in plastics

It was found that the restricted energy loss rate of charged particles can be used as a convenient criterion to predict the formation or non-formation of etchable tracks in plastics. The criterion allows sensitivity assignments, in absolute units, to each of the polymeric detectors. An experimentally determined parameter indicates that only electron energy transfer collisions of about 1.0 keV and less are important in track formation. The criterion is consistent with the known experimental observations of charged particle registration in plastics. It is proposed that latent (etchable) tracks are formed when the energy density (dose) in the immediate vicinity of the particle trajectory exceeds a critical value that is characteristic of the particular detecting material and the specific etching conditions.

The Effect of Oxygen and Humidity on Charged Particle Registration in Organic Foils

The number and diameter of microscopically visible alpha-particle tracks which can be etched in the surface of sensitive plastic foils such as cellulose triacetate are increased by the presence of oxygen. Pre- or posttreatment of foils with water or humid air increases the etching speed but not the foils' sensitivity. Treatment of foils with diluted H202 increases the sensitivity slightly, but the etching speed considerably. Some parameters of the oxygen/humidity effect are described; its possible consequences for the interpretation of the latent track formation process and its practical applications are discussed briefly.

The registration of charged particles in solids: An alternative to autoradiography in the life sciences

The registration of charged particles in solids: An alternative to autoradiography in the life sciences

Registration of charged particles emerging in gas of a spark chamber with large gap between the electrodes

Registration of charged particles emerging in gas of a spark chamber with large gap between the electrodes

Photographic Plates for Use in Nuclear Physics

The registration of charged particles by the photographic emulsion is considered from the standpoint of their space rate of energy loss on passage through matter. On the basis of the highest-energy particles that can be recorded as recognizable tracks, an energy-loss value of 0.013 Mev per centimeter of air path is taken as an approximate threshold sensitivity value of the best present-day nuclear-particle emulsions. This energy-loss value corresponds to alpha-particles of energy g400 Mev, deuterons of 100 Mev, protons of 50 Mev, and electrons of 20 kev. Some evidence is cited to show that these limiting energy values are in accord with experience.Range-energy curves for alpha-particles, protons, deuterons, and mesons in high silver halide concentration emulsions are given, based on constant stopping-power values of the emulsion. A relative stopping-power value of 1800 is used for alpha-particles, and a value of 2000 is used for protons, deuterons, and mesons.Data on the composition, physical characteristics, and sensitivity, and also recommended uses of some of the commercially available nuclear-particle emulsions are presented.A theoretical calculation of the stopping power of the photographic emulsion relative to that of air is given. Curves of stopping power versus energy for alpha-particles and protons in a high silver halide content emulsion are calculated and compared with published experimental values.Grain density and its variation in the recorded tracks of nuclear particles in the photographic emulsion are discussed. It is pointed out that the grain density for low-energy particles approaches a maximum value determined by the grain population of the unexposed emulsion. A qualitative discussion is given to show why grain spacing varies with particles of differing ionizing power.Finally, the mechanism of latent-image formation is considered from the standpoint of ion-pair production in the grain. Using the energy-loss value of 0.013 Mev per centimeter as a threshold limit and a value of 7.6 ev for the energy required to produce an ion pair in silver bromide, it is shown that about 150 ion pairs must be produced in a single grain to form the latent image.