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.
The key technological stages of assembly of silicone tracking modules with silicon strip sensors for use in the wide-aperture silicon tracking system of the BM@N experiment are considered. Methods ...for finding the optimal parameters for the ultrasonic linear automatic welding of aluminum microcables with a silicon sensor are described. The methodology and results of intermediate QA testing during the assembly of the silicone tracking module are presented. The method of mounting unpackaged microcircuits on a board is described. The results of the preproduction assembly of silicone tracking modules are presented.
—
A module with a double-sided microstrip silicon sensor is the basic element of the silicon tracking system (STS) for the BM@N experiment. The signal-to-noise ratio is the main parameter of the ...tracking system for a high-energy physics experiment, which is determined by the complex influence of the parameters of the detector and the front-end electronics. An analytical model of various noise sources is presented, and parameters determining the efficiency of charge collection from the detector are discussed. The noise has been measured for several module configurations differing in the sensor size and the length of the signal cable connecting the sensor strips to the input circuits of the front-end electronics. Results of measurements of the signal from a
106
Ru β-source are presented. It is shown that the signal-to-noise ratio for STS modules is at least 18.
—
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.
The silicon tracking system of the BM@N experiment consists of four stations based on double-sided microstrip silicon sensors. The sensors make it possible to obtain a spatial resolution for tracks ...of secondary charged particles up to 17 μm. Two ASIC boards, the input channels of which are connected to the strips with ultralight (0.23% X
0
) aluminum flex cables, are used to readout and process signals from both sides of the sensor. Such an assembly is called a module. Silicon sensors are mounted on lightweight carbon-fiber support trusses in a way that the dead zones at the edges are overlapped due to the tiled layout. The frontend electronics are housed in metal containers with a heat sink system located at the rare ends of the carbon-fiber support truss. A set of modules attached to the carbon-fiber support truss with two containers with readout electronics at the ends is called a supermodule. The accuracy of the sensor positioning in the station plane plays a crucial role in limiting the degrees of freedom of the parameters determined by the software during the final alignment of the tracking system elements. A special device that allows mounting sensors on a carbon fiber truss with an accuracy of up to 15 µm on a 1200 mm base is developed to assemble supermodules. The results of testing the device are given.
The paper discusses some issues of existing norms and requirements to educational and professional activities. The required soft (non-technical), general professional and professional skills are ...prescribed by educational standards, job descriptions are regulated by professional standards. Higher education programs must provide quality professional skills. A mandatory assessment and monitoring of professional skills should become a powerful motivator for employees’ long-life learning and selfeducation. A criterion for assessing the quality of education is a graduate who works in the specialty and qualitatively fulfils the job responsibilities. The reference to the statistics in educational and budgeting spheres is used to raise the problem of practical compliance of educational standards and professional job functions. Educationalstandardsshouldspecifythejobsappropriateforthegraduate.The control over competence formation must ensure the qualitative qualification. The conclusion is made that an employer does not finds it beneficial to retrain a certified specialist. A graduate of higher educational institution should be able to immediately fulfill the duties stated in his job description. In all stages of their higher education program, students should learn by doing to enhance skills by action learning, which must be ensured by the educational institution. In this regard, internship curriculum should be constantly monitored and regularly updated. There is an urgent need for educators to take up part-time jobs with relevant non-educational organizations or to receive regular refresher training. As for engaging outside professionals from non-educational organizations, it could be considered only as exception. It is proposed to develop a separate educational standard for the training of lecturers of higher education, as teachers must master the methodology of teaching students. A standard to guide professional activities of lecturers should also be worked out and recommended for practical application. This standard should be an extension of the educational standard. The potential and viability of this study is proved by the draft educational standards that put educational skills in compliance with professional standards (job descriptions).The growing number of publications on harmonizing educational and professional standards is also an evidence of its topicality.
Electronic structure of the Cs/n-GaN nano-interface has been studied in situ via synchrotron-based photoelectron spectroscopy by excitation in the energy range of 70–400 eV. The GaN sample was grown ...by an original method of epitaxy of low-defect unstressed nanoscaled films on AlGaN/SiC/Si substrate. Changes in the surface state spectra and in the Ga 3d, Cs 4d, Cs 5p, N 1s core level spectra have been revealed under different cesium coverages. The intrinsic surface states for the clean GaN surface at binding energies of ∼5.0 eV and ∼7.0 eV are attenuated during Cs adsorption. Simultaneously three Cs induced surface states are found to arise. Drastic changes in the surface state spectrum were ascertained and shown to be originated from the local interacting Ga dangling bonds and adsorbed Cs atoms initiating the electron redistribution effect with formation of the semiconductor-like Cs/n-GaN interface.
•Ultrathin Cs/n-GaN/Si(111) interface is formed.•Electronic structure of interface is studied by synchrotron PES.•The Ga 3d, Cs 4d, Cs 5p, N 1s core level spectra changes under Cs adsorption.•Suppressing of intrinsic surface state of GaN is found during Cs adsorption.•Three surface states induced by Cs adsorption are found in valence band region.
Display omitted
•Acetone catalytic conversion in hydrocarbon medium was studied by isotope labeling.•Under studied conditions C3-C5 olefins formed from hexane contain H from acetone.•Obtained results ...can be explained by acetone addition to carbocations as an enol.
In this research the isotope labeling experiments were used to study the reaction pathways of acetone conversion in hydrocarbon medium in the presence Y and ZSM-5 zeolites. Acetone is a model for ketones, which are a considerable fraction of bio-oil. The analysis of the isotope distribution in the conversion products was carried out by 1H NMR and GC/MS methods; it was shown that the deuterium labels introduced with acetone are distributed mainly in C3-C4 olefins, as well as pentenes and 2-methylpentane. The results obtained correspond with the previously proposed assumption that the catalytic cracking of ketones, capable to transform into enols, in a hydrocarbon medium starts with a nucleophilic attack of the protonated ketone on hydrocarbon intermediates. Additionally, the H/D exchange between deuterated compounds and cracking intermediates or zeolite has been established.
The electronic structure of a pure tungsten surface oxidized at an oxygen pressure of 1 Torr and a temperature of 1000 K has been in situ studied by photoelectron spectroscopy in ultrahigh vacuum. ...Photoemission spectra from the valence band and O 1
s
, O 2
s
, and W 4
f
core levels at synchrotron excitation in the photon energy range of 80–600 eV have been analyzed. A semiconductor tungsten oxide film is found to form, which contains different oxides of tungsten with the oxidation state from 6+ to 4+. Oxides of tungsten with the oxidation state of 6+ are mainly formed on the surface; their fraction gradually decreases while moving away from the surface, while the amount of oxides of tungsten with the oxidation state of 4+ increases.
PDF
