Laser Setup for Testing Silicon Microstrip Detectors Kharlamov, P. I.; Shitenkov, M. O.; Dementev, D. V. ...
Instruments and experimental techniques (New York),
06/2022, Letnik:
65, Številka:
3
Journal Article
Recenzirano
A setup for conducting channel-by-channel testing and calibration of microstrip silicon detectors using collimated laser pulses is described. A feature of this setup is the use of an infrared laser ...diode to simulate a signal from the passage of a charged particle through the detector substance. A system of lenses makes it possible to obtain a transverse beam size of up to 5 μm, which, in combination with the use of a precision stepper motor, allows testing of each detector channel in an automatic mode. The operation of the system on modules of the BM@N silicon track system is demonstrated.
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Various materials were tested for use in the elements of the cooling system for the readout electronics of the BM@N silicon tracking detector. The thermal design was performed using the ANSYS ...software package and the thermal conductivities of various adhesives and carbon-fiber composites were experimentally measured. The results were used to select materials for cooling fins. Thermal tests of the prototypes of front-end-board boxes have been carried out, during which various thermal interfaces were also tested.
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A silicon tracking system is one of the main parts of the BM@N experiment. It is based on double-sided microstrip silicon detectors with front-end electronics controlled by data flows. The ...performance of the front-end electronics, as well as of the timing and data-acquisition systems, has been verified by carrying out beam tests at the LINAK-200 linear electron accelerator with an electron energy as high as 200 MeV. The tests demonstrated the reliable operation of the prototype system for data acquisition and readout.
The goal of this study was to characterize the electroencephalographic (EEG) and behavioral properties of young adult rats during extended video-EEG monitoring following photothrombotic brain ...infarction. Two-month-old male Sprague–Dawley rats underwent photothrombotic brain infarction of the left sensorimotor cortex with the photosensitive dye rose bengal (
n=10) or were used as controls (
n=9). Qualitative and quantitative EEG analysis was performed on digital video-EEG records obtained during 6 months of recording. The main finding of this study was that 5/10 (50%) lesioned animals developed focal epileptic seizures ipsilateral to the cortical infarct characterized by rhythmic spike-wave discharges with or without behavioral change. Epileptic animals demonstrated increased delta, theta, and low beta-range power ipsilateral to the infarct that reliably distinguished them from lesioned nonepileptic and control animals. Lesioned animals (epileptic and nonepileptic) also demonstrated a distinct pattern of focal rhythmic theta activity before or after generalized high beta-range discharges. Electrical and behavioral characteristics common to both lesioned and control animals included: (1) focal rhythmic theta activity in either hemisphere; (2) focal low beta-range discharges in either hemisphere; (3) generalized high beta-range discharges; (4) absence seizures; (5) generalized pseudoperiodic spike discharges associated with mild multifocal body jerks; (6) tonic-clonic seizures (one naı̈ve control; one lesioned animal). Cresyl violet staining of lesioned animals’ brains showed consistent infarcts of the sensorimotor cortex extending to the subcortical white matter. These results provide an expanded electrobehavioral description of young adult rats following photothrombotic brain infarction and augment further investigation into the molecular, cellular, and network alterations that contribute to the establishment of post-stroke epilepsy.
For the first time, a phenomenon of high-velocity outbursts ejected from the surface of liquid tungsten microparticles in a flow of argon-air plasma under atmospheric pressure was observed. As ...tungsten particles sized 50 to 200 μm moved in a plasma flow, stratified radiating spheres up to 9 mm in diameter formed around such particles. The spheres were sources of high-velocity outbursts whose ejection direction coincided with the direction of the plasma flow. The velocity of the anomalous outbursts amounted to 3-20 km s. In the outburst images, the distribution of glow intensity along outburst tracks exhibited a wavy decaying behavior with a wavelength of 5-15 mm. Possible physical factors that could be the cause of the phenomenon are discussed.
The results obtained by estimating the contribution of 8Be and 9B nuclei to the coherent dissociation of
10
C,
10
B, and
12
C relativistic nuclei in nuclear track emulsions (“white” stars) are ...presented. The selection of white stars accompanied by 9B leads to a distinct peak appearing in the distribution of the excitation energy of 2α2
p
ensembles and having a maximum at 4.1 ± 0.3 MeV. A 8Be nucleus manifests itself in the coherent-dissociation reaction
10
B →
2
He + H with a probability of (25 ± 5)%, (14 ± 3)% of it being due to 9B decays. The ratio of the branching fractions of the
9
B +
n
and
9
Be +
p
mirror channels is estimated at 6 ± 1. An analysis of the relativistic dissociation of
12
C nuclei in a nuclear track emulsion revealed nine 3α events corresponding to the Hoyle state.
Abstract A study of the inelastic scattering of neutrons with an energy of MeV on the nuclei of oxygen, phosphorus, and sulfur was performed at the TANGRA facility at JINR (Dubna). The experiment ...aimed to refine existing data and obtain new data on the yields and angular distributions of γ -quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron method. Two types of detector systems were used to register γ -quanta. The γ -ray yields were measured using a high-purity germanium (HPGe) detector. The angular distributions of γ -rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi Ge O (BGO) located around the sample. The performed experiments measured the yields of two transitions for the reaction of tagged neutrons with O, nine transitions for the reaction with P, and nine transitions for the reaction with S for the first time. The angular anisotropy of the γ -radiation accompanying the inelastic scattering of neutrons with an energy of MeV on P nuclei was also measured for the first time.
In the present paper, we report on the results of an experimental study of heat- and mass-transfer processes in a Plazer 30-PL-W plasma-jet facility used for arc-plasma wire spraying. Using an ...original optical diagnostic system, we have studied melting behavior of the metal wire, break up and atomization of liquid metal. For the first time, experimental data on the in-flight velocity and temperature of spray particles in arc-plasma wire spraying were obtained. In spite of moderate particle velocities (about 50 m/s), the obtained steel coatings proved to have a low porosity of 1.5%. While studying the spraying process of tungsten wire, we observed the occurrence of anomalous high-velocity (over 4000 m/s) outbursts ejected from the surface of liquid metal droplets. The nature of such outbursts calls for further study.
Recent findings related with the unstable nuclei 8Be and 9B in the coherent dissociation of relativistic nuclei 10C, 10B and 12C in nuclear track emulsion (“white”stars) are highlighted. Selection of ...the 10C “white”stars accompanied by 8Be (9B) leads to appearance of the distinct peak with a maximum at 4.1 ± 0.3 MeV in the excitation energy distribution of 2α2p ensembles. The 8Beg.s. nucleus is manifested in the coherent dissociation 10B → 2He + H with a probability of 25 ± 5 % including 13 ± 3 % of 9B decays. A probability ratio of the mirror channels 9B + n and 9Be + p is estimated to be 10 ± 1. Reanalysis of relativistic 12C dissociation in lead enriched emulsion revealed 9 3α-events corresponding to the Hoyle state.
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