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V. Peskov

Publications and source records attributed to V. Peskov.

At least 37 records · Page 2Linked to original sources

Performance of wire-type Rn detectors operated with gas gain in ambient air in view of its possible application to early earthquake predictions

We describe a detector of alpha particles based on wire type counters (single-wire and multiwire) operating in ambient air at high gas gains (100-1000). The main advantages of these detectors are: low cost, robustness and ability to operate in humid air. The minimum detectable activity achieved with the multiwire detector for an integration time of 1 min is 140 Bq per m3, which is comparable to that featured by commercial devices. Owing to such features the detector is suited for massive application, for example for continuous monitoring of Rn or Po contaminations or, as discussed in the paper, its use in a network of Rn counters in areas affected by earth-quakes in order to verify, on a solid statistical basis, the envisaged correlation between the sudden Rn appearance and a forthcoming earthquake.

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Advances in the Development of Micropattern Gaseous Detectors with Resistive Electrodes

We describe the most recent efforts made by various groups in implementing resistive electrodes in micropattern gaseous detectors with the aim to combine in the same design the best features of RPCs (for the example, their robustness and spark protection property) with the high granularity and thus the good position resolution offered by microelectronic technology. In the stream of this activity, we have recently developed two novel detectors with resistive electrodes: one was based on resistive micromeshes and the second one is a MSGC with resistive electrodes. We have demonstrated that the resistive meshes are a convenient construction element for various designs of spark protective detectors: RPCs type, GEM type and MICROMEGAS type. These new detectors enable to considerably enhance the RPC and micropattern detectors applications since they feature not only a high position resolution but also a relatively good energy resolution (25-30 persent FWHM at 6 keV) and, if necessary, they can operate in cascaded mode allowing the achievement of a high overall gas gain. The main conclusion from these studies is that the implementation of resistive electrodes in micropattern detectors makes them fully spark protected; on this basis we consider this direction very promising.

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On the physics and technology of gaseous particle detectors

Despite an already long and fruitful history, gaseous elementary-particle detectors remain today an important mainstay of high-energy and nuclear physics experiments and of radiation detection in general. In here we briefly describe some of the gaseous detector's main technologies and applications, along with some unsolved gas-discharge physics aspects of practical relevance.

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First Tests of Gaseous Detectors Made of a Resistive Mesh

We describe here various detectors designs: GEM type, MICROMEGAStype, PPACtype as well as cascaded detectors made of a resistive mesh manufactured from a resistive Kapton foil, (20 microns thick, resistivity a few MOhm per square) by a laser drilling technique. As in any other micropattern detectors the maximum achievable gas gain of these detectors is restricted by the Raether limit, however, the resistive mesh makes them and the front end electronics fully spark protected. This approach could be an alternative or complimentary to the ongoing efforts in developing MICROMEGAS and GEMs with resistive anode readout plates and can be especially beneficial in the case of micropattern detectors combined with a micropixel-type integrated front end electronics

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Gain limits of a Thick GEM in high-purity Ne, Ar and Xe

The dependence of the avalanche charge gain in Thick Gas Electron Multipliers (THGEM) on the purity of Ne, Ar and Xe filling gases was investigated. The gain, measured with alpha-particles in standard conditions (atmospheric pressure, room temperature), was found to considerably drop in gases purified by non-evaporable getters. On the other hand, small N2 admixtures to noble gases resulted in high reachable gains. The results are of general relevance in the operation of gas-avalanche detectors in noble gases, particularly that of two-phase cryogenic detectors for rare events.

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Research on discharges in micropattern and small gap gaseous detectors

This report summarizes the present knowledge on discharges in micropattern and small gap gaseous detectors and the physical mechanisms involved. These include the space-charge (Raether's) limit, rate-induced breakdown, cathode excitation effect and electron emission from the cathodes in the form of jets, inter-GEM breakdown in multistep configurations and finally surface streamers.

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Towards THGEM UV-photon detectors for RICH: on single-photon detection efficiency in Ne/CH4 and Ne/CF4

The article deals with the detection efficiency of UV-photon detectors consisting of Thick Gas Electron Multipliers (THGEM) coated with CsI photocathode, operated in atmospheric Ne/CH4 and Ne/CF4 mixtures. We report on the photoelectron extraction efficiency from the photocathode into these gas mixtures, and on the photoelectron collection efficiency into the THGEM holes. Full collection efficiency was reached in all gases investigated, in some cases at relatively low multiplication. High total detector gains for UV photons, in excess of 10^5, were reached at relatively low operation voltages with a single THGEM element. We discuss the photon detection efficiency in the context of possible application to RICH.

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Progress in the development of a S RETGEM-based detector for an early forest fire warning system

In this paper we present a prototype of a Strip Resistive Thick GEM photosensitive gaseous detector filled with Ne and ethylferrocene vapours at a total pressure of 1 atm for an early forest fire detection system. Tests show that it is one hundred times more sensitive than the best commercial ultraviolet flame detectors and therefore, it is able to reliably detect a flame of 1.5x1.5x1.5 m3 at a distance of about 1km. An additional and unique feature of this detector is its imaging capability, which in combination with other techniques, may significantly reduce false fire alarms when operating in an automatic mode. Preliminary results conducted with air filled photosensitive gaseous detectors are also presented. The approach main advantages include both the simplicity of manufacturing and affordability of construction materials such as plastics and glues specifically reducing detector production cost. The sensitivity of these air filled detectors at certain conditions may be as high as those filled with Ne and EF. Long term test results of such sealed detectors indicate a significant progress in this direction. We believe that our detectors utilized in addition to other flame and smoke sensors will exceptionally increase the sensitivity of forest fire detection systems. Our future efforts will be focused on attempts to commercialize such detectors utilizing our aforementioned findings.

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Advances in Micro-Pattern Gaseous Detectors and their Applications

In the last decade, several new imaging gaseous detectors, called micro-pattern gaseous detectors, have been conceived and rapidly developed. In this paper, the most popular designs of these detectors and their applications to high energy physics and astrophysics experiments will be described. The main focus of this review will however be on the ongoing activities on practical applications of micro-pattern detectors to medicine and industry

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THGEM operation in Ne and Ne/CH4

The operation of Thick Gaseous Electron Multipliers (THGEM) in Ne and Ne/CH4 mixtures, features high multiplication factors at relatively low operation potentials, in both single- and double-THGEM configurations. We present some systematic data measured with UV-photons and soft x-rays, in various Ne mixtures. It includes gain dependence on hole diameter and gas purity, photoelectron extraction efficiency from CsI photocathodes into the gas, long-term gain stability and pulse rise-time. Position resolution of a 100x100 mm^2 X-rays imaging detector is presented. Possible applications are discussed.

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GEMs with Double Layred Micropattern Electrodes and their Applications

We have developed and tested several new designs of GEM detectors with micropattern electrodes manufactured by microelectronic technology. In one design, the inner layer of the detector electrode consists of thin metallic strips and the outer layer is made of a resistive grid manufactured by a screen printing technology. In other designs, the electrodes were made of metallic strips fed by HV via micro-resistors manufactured by a screen printing technology. Due to these features, the new detectors have several important advantages over conventional GEMs or ordinary thick GEMs. For example, the resistive grid (in the first design) and the screen printed resistors (in other designs) limited the current in case of discharges, making these detectors intrinsically spark-protected. We will here describe our tests with the photosensitive versions of these detectors (coated with CsI layers) and the efforts of implementing them in several applications. In particular, we will focus on our activity towards the ALICE RICH detector upgrade and on tests of simplified prototypes of cryogenic dark matter detectors.

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Photosensitive Strip RETHGEM

An innovative photosensitive gaseous detector, consisting of a GEM like amplification structure with double layered electrodes (instead of commonly used metallic ones) coated with a CsI reflective photocathode, is described. In one of our latest designs, the inner electrode consists of a metallic grid and the outer one is made of resistive strips; the latter are manufactured by a screen printing technology on the top of the metallic strips grid The inner metallic grid is used for 2D position measurements whereas the resistive layer provides an efficient spark protected operation at high gains - close to the breakdown limit. Detectors with active areas of 10cm x10cm and 10cm x20cm were tested under various conditions including the operation in photosensitive gas mixtures containing ethylferrocene or TMAE vapors. The new technique could have many applications requiring robust and reliable large area detectors for UV visualization, as for example, in Cherenkov imaging devices.

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Progress in Developing Hybrid RPCs: GEM-like Detectors with Resistive Electrodes

We have recently developed an innovative detector of photons and charged particles: a GEM-like gaseous amplification structure with resistive electrodes instead of commonly used metallic ones. This novel detector combines the best property of GEMs- the capability to operate in a cascaded mode and in poorly quenched gases - and of RPC: the protection against sparks. In this paper will shortly review our latest achievements in this direction, however the main focus will be given on a new advanced design that allows to build large area detectors manufactured by a screen printing technology. The proposed detector, depending on the applications, can operate either in a GEM mode (electron multiplications through holes only) or as a hybrid RPC with simultaneous amplifications in the drift region and in the holes. The possible applications of this new detector will be discussed.

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Study of GEM-like detectors with resistive electrodes for RICH applications

We have developed prototypes of GEM-like detectors with resistive electrodes to be used as RICH photodetectors equipped with CsI photocathodes. The main advantages of these detectors are their intrinsic spark protection and possibility to operate at high gain (~10E5) in many gases including poorly quenched ones, allowing for the adoption of windowless configurations in which the radiator gas is also used in the chamber. Results of systematic studies of the resistive GEMs combined with CsI photocathodes are presented: its quantum efficiency, rate characteristics, long-term stability, etc. On the basis of the obtained results, we believe that the new detector will be a promising candidate for upgrading the ALICE RICH detector

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Development of New Hole-Type Avalanche Detectors and the First Results of their Applications

We have developed a new detector of photons and charged particles- a hole-type structure with electrodes made of a double layered resistive material: a thin low resistive layer coated with a layer having a much higher resistivity. One of the unique features of this detector is its capability to operate at high gas gains (up to 10E4) in air or in gas mixtures with air. They can also operate in a cascaded mode or be combined with other detectors, for example with GEM. This opens new avenues in their applications. Several prototypes of these devices based on new detectors and oriented on practical applications were developed and successfully tested: a detector of soft X-rays and alpha particles, a flame sensor, a detector of dangerous gases. All of these detectors could operate stably even in humid air and/or in dusty conditions. The main advantages of these detectors are their simplicity, low cost and high sensitivity. For example, due to the avalanche multiplication, the detectors of flames and dangerous gases have a sensitivity of 10-100 times higher than commercial devices. We therefore believe that new detectors will have a great future.

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Detector of alpha particles and x-rays operating in ambient air in pulse counting mode or/and with gas amplification

Ionization chambers working in ambient air in current detection mode are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and cetera. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification. . To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of 1. The second type alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10E4). A detailed comparison between these two detectors is given as well as comparison with the commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible applications of these new detectors is alpha particle background monitors which, due to their low cost can find wide application not only in houses, but in public areas: airports, railway station and so on.

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A New Supersensitive Flame Detector and its Use for Early Forest Fire Detection

A new flame detector, three orders of magnitude more powerful than the existing ones, is presented. This detector needs to be mass-produced for its use in order to be incorporated in an early forest fire detection system. A project able to implement its use to overcome the forest fire emergency is described.

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Developments and the preliminary tests of Resistive GEMs manufactured by a screen printing technology

We report promising initial results obtained with new resistive-electrode GEM (RETGEM) detectors manufactured, for the first time, using screen printing technology. These new detectors allow one to reach gas gains nearly as high as with ordinary GEM-like detectors with metallic electrodes; however, due to the high resistivity of its electrodes the RETGEM, in contrast to ordinary hole-type detectors, has the advantage of being fully spark protected. We discovered that RETGEMs can operate stably and at high gains in noble gases and in other badly quenched gases, such as mixtures of noble gases with air and in pure air; therefore, a wide range of practical applications, including dosimetry and detection of dangerous gases, is foreseeable. To promote a better understanding of RETGEM technology some comparative studies were completed with metallic-electrode thick GEMs. A primary benefit of these new RETGEMs is that the screen printing technology is easily accessible to many research laboratories. This accessibility encourages the possibility to manufacture these GEM-like detectors with the electrode resistivity easily optimized for particular experimental or practical applications.

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