Gamma and X radiation absorption characteristics of specially selected types of concrete

Medical institutions with linear accelerators, cyclotrons as installations for particles acceleration, nuclear facilities as nuclear power stations and nuclear research reactors using concrete in building construction. In cost-benefit analysis the question is what are the radiation characteristics of different types of concrete, which could be used to protect against gamma and X rays. In this paper, computer code XCOM was used for the calculation of the total mass attenuation coefficients, which is an important factor for determination of the photon attenuation, as well as during research and testing of radiation protection properties for concrete with components of different type materials. Thereby, the basic absorption radiation characteristics of ordinary and barite concretes, as well as specially selected type of concrete with magnetite and steel and concrete UHPC with barite and nanosilica as specific material composition, were considered. The results of this research point to the conclusion that before the concrete production of certain mechanical properties is approached, it is reasonable to apply the appropriate methodology with the numerical calculation of the basic absorption characteristic of the concrete for protection against gamma and X radiation.SynerCrete’18 International Conference on Interdisciplinary Approaches for Cement-based Materials and Structural Concrete; October 24-26, r 2018, Funchal, Madeira Island, Portuga

Development of RADFET detector for personal dosimeter system for European astronauts

Radiation environment in space is very complex, with varying contributions from photons, electrons, protons, and heavy ions. There is a need to measure radiation dose received by the astronauts onboard International Space Station (ISS), and the European Space Agency (ESA) has been supporting a collaborative research project aimed at development of a personal dosimeter for European astronauts at ISS. The development of the personal dosimeter system is in the final phase, with the launch expected in the second half of 2015. The system is called “European Crew Personal Active Dosimeter (EuCPAD)” and consists of a base unit and several mobile units. Base unit is stationery and houses system electronics, Tissue Equivalent Proportional Counter (TEPC), and charging slots for mobile units. Mobile units are worn by the astronauts during their daily activities and consist of four dosimetric modules: thin silicon diode, thick silicon diode, Direct Ion Storage (DIS) dosimeter, and Radiation Sensing Field Effect Transistor (RADFET). We describe the EuCPAD system and our efforts in development of the RADFET module for the EuCPAD mobile unit.Third International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2015, June8-12, 2015, Budva, Montenegr

Sensitivity of standard and stacked RADFET dosimeters

Radiation Sensing Field Effect Transistors (RADFETs), also known as MOSFET dosimeters, are discrete p-channel MOSFETs with the gate oxide engineered for increased radiation sensitivity. RADFETs are small, require very little or no power during operation, read-out is simple and non-destructive, and their electronic signal is suitable for integration with the electronics systems. For these reasons RADFETs have found applications in quality assurance of radiotherapy, dose monitoring in high energy physics laboratories, accidental personal dosimetry, and space. Lower dose applications, such as e.g. occupational personal dosimetry and radiology, are currently out of reach owing to inherent sensitivity limits of the standard RADFET technology. Tyndall National Institute has been involved in RADFET research and development, fabrication, and commercialisation for several decades and has acquired significant experience in the technology and applications. This paper presents Tyndall recent efforts in RADFET manufacturing and characterisation for different applications and discusses possible approaches towards increased sensitivity of the technology, including standard and stacked RADFETs.Fourth International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2016, May 23-27, 2016, Niš, Serbi

Validation Method for Pesticide Residue after Gamma Irradiation

Pesticide residues include the remaining substances or mixtures, metabolites and impurities in food which are considered to be toxicological significance. The goal of this work was validation method for the determination of residue by UPLC PDA and GC MS techniques. Special scope has been chlorpyrifos from apple after oil and emulsion formulation Radar EW and Radar EC treatment. In order to fully respond to this task, it has been induced the degradation products of active component -chlorpyrifos from these formulations. The degradation products chlorpyrifosoxon, 3,5,6-trichloro-2-pyridinol (TCP) and o,o -diethyl thiophosphate (DTPA) received after gamma radiation samples in a permanent for 66 hours with 2,5 KGray from Co-60 source. Gamma radiation is the closest degradation to natural conditions, followed degradation path, based on the chemical and microbiological processes. Four different extraction procedures have been used: liquid-liquid extraction (Dutch procedure), solid phase extraction with HLB cartridge, multiwall carbon nano tubes and Quechers extraction. The recovery for these clean up methods has been in range 75-94%. The validation parameters for UPLC PDA has been: LOD 0,06 ppm, LOQ 0,18 ppm. The linearity was confirmed by correlation coefficient, R=0.998 for UPLC. The parameter for GC MS has been on ppm level also. The correlation coefficient for GC MS is 0.999. The result on apple samples showed that for pesticide residue quantifications is more adequate GC MS technique that is characterized by highest recovery, the lowest standard deviation and better LOQ.Fourth International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2016, May 23-27, 2016, Niš, Serbi

Experimental characterization and monte carlo simulation of the dosimetric parameters of the mosfet structure in the fields of ionizing radiation.

Rezultati naučnih istraživanja pokazuju da jonizujuće zračenje može dovesti do funkcionalnog ili trajnog oštećenja poluprovodničkih naprava različitog tipa u ekstremnim radnim uslovima (u okruženju nuklearnog reaktora, akceleratorske instalacije, nuklearne eksplozije ili prilikom testiranja naprava za eksploataciju u kosmosu). Cilj ovog rada je primena specifične metodologije kojom se preciznije prati uticaj jonizujućeg zračenja na karakteristike MOSFET komponente. Specifičnost metodologije se ogleda u tome da pored toga što se određuje zavisnost promene napona praga od eksperimentalno određene apsorbovane doze u MOSFET-u koji se nalazi u polju jonizujućeg zračenja, uvode se i Monte Karlo proračuni veličina od kojih zavise dozimetrijski parametri MOSFET strukture i sagledava se njihova veza sa rezultatima eksperimenta. Jedan od predmeta istraživanja u disertaciji obuhvata eksperimentalni rad na proučavanju izabranih parametara MOSFET komponente kojima se može sprovoditi dozimetrija u poljima jonizujućih zračenja. Eksperimenti su obuhvatili određivanje zavisnosti napona praga VT i promene napona praga ΔVT od ukupne apsorbovane doze zračenja za slučajeve različitih poluprovodničkih, strukturnih i konstrukcionih karakteristika izabranih komercijalnih MOSFET komponenti, što se postiže promenama u debljini oksida gejta, u dopiranosti poluprovodničke osnove, u različitoj vrsti poluprovodničkog materijala, u prisustvu slojeva za pasivizaciju, u dužini i širini kanala između sorsa i drejna, u naponu napajanja gejta u toku zračenja...The results of scientific research show that ionizing radiation can lead to functional or permanent damage of semiconductive devices of various types in extreme operating conditions (in the environment of a nuclear reactor, accelerator installation, nuclear explosion, or when testing the devices for exploitation in the cosmos). The aim of this study is to establish a specific methodology for more accurate monitoring of the impact of ionizing radiation on the characteristics of the MOSFET component. The specificity of this methodology is reflected in the fact that besides the determination of the dependence of the change in the threshold voltage of the experimentally determined absorbed dose in the MOSFET, which is located in the field of ionizing radiation, there is also the introduction of the Monte Carlo size calculations which the dosimetric parameters of MOSFET structure depend on and the examination of their connection with the results of the experiment. One of the objects of research in the thesis includes experimental work on studying the selected parameters of the MOSFET component in the fields of ionizing radiation. The experiments included the determination of the dependence of the threshold voltage VT and the changes in the threshold voltage ΔVT on the total absorbed dose of radiation for various semiconductor, structural and constructional characteristics, of selected MOSFET components which is achieved by changing the thickness of the gate oxide, the level of doping the semiconductor base, by using a different type of semiconductor material, the presence of passivation layers, the length and width of the channel between the source and the drain, the voltage of the power supply for the gate during the radiation..

Method of analyzing the behavior of a refrigeration device under variable loads

Postupak analize ponašanja rashladnog uređaja pri promenljivim opterećenjima se sastoji iz sledećih faza: faza (1), matematička simulacija rada uređaja u celini i komponenti uređaja; faza (1.1), razmatranje karakteristika pojedinih komponenti uređaja za određene radne uslove; faza (1.2), dobijanje radnih karakteristika uređaja u celini i faza (2), eksperimentalna analiza ponašanja uređaja pri promenljivim opterećenjima. OsnovMethod of analyzing the behavior of a refrigeration device under variable loads consists of step (1) of mathematical simulation of device operation process as a whole and device components; step (1.1) of consideration of the characteristics of individual components of the device for certain operating conditions; step (1.2) to obtaining the operating features of the device and step (2) of experimental analysis of device behavior under variable loads. The novelty of the invention is implementation of steps (1, 1.1,1.2).Broj prijave: P-2020/1458Podaci o nosiocu prava: INSTITUT ZA NUKLEARNE NAUKE „VINČA“ – INSTITUT OD NACIONALNOG ZNAČAJA ZA REPUBLIKU SRBIJU, UNIVERZITETA U BEOGRADU (CENTAR ZA SINTEZU, PROCESIRANJE I KARAKTERIZACIJU MATERIJALA ZA PRIMENU U EKSTREMNIM USLOVIMA-CEXTREME LAB), Mike Petrovića Alasa 12-14, 11351 Beograd-Vinča, RSPriznati datum podnošenja prijave: 01.12.2020

Analysis of frequency selective measurements in the vicinity of software radio transmitter

Uskopojasno merenje nivoa elektromagnetskog polja je jedna od opšteprihvaćenih metoda za procenu izloženosti stanovništva nejonizujućim zračenjima. Ova metoda je naročito potrebna kada na nekoj lokaciji od interesa sa aspekta zaštite od nejonizujućih zračenja postoji više izvora nejonizujućeg zračenja (često u bliskom frekventnom opsegu), i kada je potrebno razdvojiti njihov uticaj na stanovništvo. Da bi se merenja izvršila kvalitetno, potrebno je poznavanje relevantnih karakteristika merne opreme kao i što bolje poznavanje izvora nejonizujućeg zračenja čije elektromagnetsko polje merimo. U ovom radu će biti dat primer uskopojasnog merenja nejonizujćeg zračenja, uz analizu njegove ponovljivosti, gde je kao merni instument korišćen analizator spektra sa odgovarajućom antenom, a kao izvor stanica softverskog radija u predajnom režimu.Frequency selective narrowband measurement of electromagnetic field level is one of the generally accepted methods for estimating exposure to nonionizing radiation. This method is especially needed when there are several sources of nonionizing radiation on measuring site (often very close in frequnecy) and it is necessary to separate their influence on population. In order to perform good quality measurments, it is needed to know all the relevant facts about measuring equipment and also as many details as possible about the source of nonionizing radiation whose electromagnetic field is measured. In this paper we will give an example and analysis of frequency selective narrowband measurement of nonionizing radiation in which handheld spectrum analyzer is used as a measuring device and a software radio transmitter as a source.XXVII Simpozijum Društva za zaštitu od zračenja Srbije i Crne Gore, Tara, 12-14. oktobar 2011

Relative humidity regulation procedure in the cooling device coolong chamber

Postupak regulacije relativne vlažnosti u rashladnoj komori rashladnog uređaja uvodi higrostat (4) i ventilator (5) u rashladnu komoru rashladnog uređaja, da bi se suvišna vlaga od svežih namirnica i kaliranja rashlađenih proizvoda odstranila iz komore. Kada se napuni komora rashladnog uređaja, u komori poraste i temperatura i relativna vlažnost. Higrostatom (4) se kontroliše relativna vlažnost i podesi na željenu vrednost. Kada se relativna vlažnost poveća higrostat (4) šalje impuls ventilatoru (5) koji povećanjem brzine strujanja smanjuje temperaturu u komori i vraća relativnu vlažnost na željenu vrednost.The method of regulating the relative humidity in the refrigeration chamber of the refrigeration unit introduces a hygrostat (4) and a fan (5) into the refrigeration chamber of the refrigeration unit, in order to remove excess moisture from fresh food and refrigerated products shrinkage. When the cooling chamber is filled, the temperature and relative humidity in the chamber increase. The relative humidity is controlled by the hygrostat (4) and set to the desired value. When the relative humidity increases, the hygrostat (4) sends an impulse to the fan (5), which reduces the temperature in the chamber by increasing the flow rate and returns the relative humidity to the desired value.Broj prijave: P-2020/0817Podaci o nosiocu prava: INSTITUT ZA NUKLEARNE NAUKE „VINČA“ – INSTITUT OD NACIONALNOG ZNAČAJA ZA REPUBLIKU SRBIJU, UNIVERZITETA U BEOGRADU (CENTAR ZA SINTEZU, PROCESIRANJE I KARAKTERIZACIJU MATERIJALA ZA PRIMENU U EKSTREMNIM USLOVIMA-CEXTREME LAB), Mike Petrovića Alasa 12-14, 11351 Beograd-Vinča, RSPriznati datum podnošenja prijave: 22.07.2020

The method for optimizing refrigeration compressor by simulating the operation of compressor electric motor and compressor valves as part of the aggregate units operation

Postupak optimizacije rada rashladnih kompresora pomoću simulacije rada elektromotora kompresora i ventila kompresora u sklopu rada agregatiranih jedinica, se sastoji iz tri faze:matematička simulacija rada kompresora, uticaj ugrađenog elektromotora kompresora na rad kompresora i uticaj geometrijskih karakteristika ventila na rad kompresora. Novina pronalaska je u primeni druge i treće faze postupka. Iz postupka proističe da je neophodno ventile konstruktivno prilagođavati odgovarajućim elektromotorima tj. režimima rada rashladnih agregata.The method for optimizing the operation of refrigeration compressors by simulating the operation of electric compressor motor and compressor valves within the operation of aggregate units, consists of three phases: mathematical simulation of compressor operation, the influence of the built-in electric motor of the compressor on the operation of the compressor and the influence of the geometric characteristics of the valve on the operation of the compressor. The novelty of the invention is implementation of the second and third phases of the method. It is necessary to constructively adopt the valves to correspond to the electric motor, ie. operating modes of refrigeration units.Broj prijave: P-2020/1457Podaci o nosiocu prava: INSTITUT ZA NUKLEARNE NAUKE „VINČA“ – INSTITUT OD NACIONALNOG ZNAČAJA ZA REPUBLIKU SRBIJU, UNIVERZITETA U BEOGRADU (CENTAR ZA SINTEZU, PROCESIRANJE I KARAKTERIZACIJU MATERIJALA ZA PRIMENU U EKSTREMNIM USLOVIMA-CEXTREME LAB), Mike Petrovića Alasa 12-14, 11351 Beograd-Vinča, RSPriznati datum podnošenja prijave: 01.12.2020

An improved RADFET-based module with an extended dose range of 1 kGy TID based on COTS parts

An improved RADFET based module dosemeter has been developed by Varadis (a spin out company of Tyndall National Institute in Cork, Ireland) with serial number RM-VT01-A. The module is based on commercially available, commercial-off-the-shelf (COTS) parts and represents an updated version of its predecessor RM-VT01 with an upper dose limit of 10Gy (1 kRad) also based on COTS parts. The RM-VT01-A module was tested to a total dose of 1kGy (100 kRad) in Co60 field at Vinča Institute of Nuclear Sciences, Belgrade, Serbia. The improved module circuit was specifically designed to address the challenge of withstanding 1 kGy (100 kRad) received dose. The primary goal of this poster is to present the improvements in the circuit design and working principle. For this purpose, eleven modules were tested, 8 powered and 3 unpowered during irradiation. The module electronics accommodates both irradiation “sense” and readout “single-current-point” mode, outputting the RADFET threshold voltage (VT) as a dosimetric information, directly proportional to the absorbed dose. The output voltage of the module was measured with a simple benchtop voltmeter to demonstrate module operation simplicity and easy system integrability. The experimental data results showed excellent agreement with the dosimetry system used at the Vinca irradiation facility, and calibration data of the VT01 RadFET part.ELICSIR Project Symposium; January 25-27, 2023, Niš, Serbi