Research of luminophores afterglow under influence of pulsed X-ray radiation of nanosecond duration

The work describes an investigation of afterglow of various luminophores under influence of pulsed X-ray radiation of nanosecond duration. As a source of radiation a pulsed X-ray "Yasen 01" apparatus is applied. Maximum impulse current of an X-ray tube is 300 A. Maximum electron energy is 120 keV. Half-height pulse duration of an X-ray burst is about 30 ns. A pulse repetition rate is up to 4 kHz. Two types of X-ray luminophores based on gadolinium oxysulfide Gd 2 O 2 S:Tb and cesium iodide CsI:Tl have been investigated. The novelty of the work is use of a fast-acting solid-state semiconductor photomultiplier. It allows recording changes of luminophores luminosity in the nanosecond time range. The photomultiplier is characterized by having two discreet outputs for measuring quickly and slowly time-changing light flows. Presence of two signal outputs allows recording changes of luminophores luminosity both during fast nanosecond excitation and during long-time afterglow. Obtained data about the nature of afterglow of investigated luminophores makes it possible to select the best one for use in conjunction with a pulsed X-ray apparatus with a high pulse repetition rate. © Published under licence by IOP Publishing Ltd

X-ray sources of nanosecond pulses based on semiconductor opening switch for CT

This study describes the development of prototype CT scanners with 2 different pulsed X-ray sources. X-ray sources used in this work have a semiconductor opening switch. It is used to generate high voltage pulses and provides pulse repetition frequency up to 5 kHz. The work uses two pulsed X-ray sources, which have different peak voltages and pulse energies. Tomographic sections and 3D images for test objects are obtained, the advantages of pulsed X-ray sources compared to continuous sources are discussed. © 2020 American Institute of Physics Inc.. All rights reserved.he research is supported by the Russian Science Foundation (RSF), grant № 18-79-00020

4-kW multi-phase battery powered power supply

A method was developed for building the powerful battery power supplies. Using the method, the battery power supply with a 4 kW max power and up to 93% efficiency was developed to supply the "Yasen" X-ray apparatus. Two 60 Acenterdoth series-connected starter lead-acid batteries were used as a primary power supply. A DC output voltage of the source is stable over the entire power range and equals to 310 V. The power supply is based on a 5-phase HF-inverter. There is no difficulty in designing such power supplies with different power outputs. It can be done by the increasing or the decreasing number of phases (of inverter channels). This approach is not limited by the increased number of the inverter channels. The maximum output power will be determined by the battery characteristics only. The power supply is mounted on a mobile trolley, to increase the mobility of the entire set of equipment. The unit dimensions are 410•320•440, the weight is about 40 kg. The unit is forced air-cooled. A power operating mode is short and periodic

Use of diagnostic nanosecond X-ray pulse apparatuses

Objective. The study the specific features of using diagnostic nanosecond X-ray pulse apparatuses versus X-ray diagnostic apparatuses using direct current X-ray tubes.Material and methods. Dosimetric tests of ARDP-01 and Yasen-01 X-ray pulse apparatuses versus RUM20 and Siemens Axiom Iconos R200 apparatuses using direct current X-ray tubes were carried out.Results. The tests established that the patient radiation dose by a Yasen-01 apparatus is 2.5–3 times lower than that by a Siemens Axiom Iconos R200 apparatus. The radiation dose by an ARDP-01 apparatus was 10–20 times lower than that by a RUM20 apparatus when using film radiation detectors.Conclusion. The performed investigations demonstrate a manifold reduction in the lower X-ray radiation with the use of nanosecond X-ray pulse apparatuses as compared to the continuous radiation. Without changing the characteristics of a radiation detector, the dose can be further reduced by increasing the amplitude and decreasing the duration of the pulse of X-ray tube current, and raising the pulse ratio