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Computational nanotechnology
1-2017
ISSN 2313-223X
7.3. EXAMINATION AND ASSESSMENT OF ELECTROPHYSICAL AND RADIOMETRIC CHARACTERISTICS OF THE Si (Li) PIN-PHOTODETECTING
PLASTICSCINTILLATION SYSTEM
Muminov Ramizulla Abdullaevich, Academician Uzbekistan Academy of sciences. Institute of Physics and Technology, Scientific and Production Association «Physics-Sun» of the Academy of Sciences of the Republic of Uzbekistan
Radzhapov Sаli Ashirovich, doctor of sciences, Institute of Physics and Technology, Scientific and Production Association «Physics-Sun» of the Academy of Sciences of the Republic of Uzbekistan
Radzhapov Begjan Sаlievich, PhD student, Institute of Physics and Technology, Scientific and Production Association «Physics-Sun» of the Academy of Sciences of the Republic of Uzbekistan, e-mail: [email protected]
Abstract: In article questions of development of manufacturing techniques Si(Li) p-i-n of photodetectors are considered, and also electrophysical and radiometric characteristics of system scintillator - Si(Li) p-i-n the photodetector for registration x-ray and scale of beams of small intensity are investigated.
Index terms: semiconductor detector, photo detector, scintillator, gamma radiation, X-ray radiation.
ИССЛЕДОВАНИЕ И ОЦЕНКА ЭЛЕКТРОФИЗИЧЕСКИХ И РАДИОМЕТРИЧЕСКИХ ХАРАКТЕРИСТИК SI(LI)P-I-N ФОТОДЕТЕКТОР-ПЛАСТМАССОВЫЙ СЦИНТИЛЛЯТОР
Муминов Рамизулла Абдуллаевич, академик АНРУз, Физико-Технический Институт Научно-производственного объединения «Физика-Солнце» Академии наук Республики Узбекистан
Раджапов Сали Аширович, д-р физ.-мат. наук, Физико-Технический Институт Научно-производственного объединения «Физика-Солнце» Академии наук Республики Узбекистан
Раджапов Бегжан Солиевич, аспирант, Физико-Технический Институт Научно-производственного объединения «Физика-Солнце» Академии наук Республики Узбекистан, e-mail: [email protected]
Аннотация: В статье рассмотрены вопросы разработки технологии изготовления Si(Li) p-i-n фотодетекторов, а также исследованы электрофизические и радиометрические характеристики системы сцинтиллятор - Si(Li) p-i-n фотодетектор для регистрации рентгеновских и гамма лучей малой интенсивности.
Ключевые слова: полупроводниковый детектор, фотодетектор, сцинтиллятор, гамма излучение, рентгеновское излучение.
It was recently found that widely used type of scintillators - PMT - have disadvantages. These disadvantages include small dynamic range of linearity, high voltage power supply, significant size and weight, low efficiency for small intense low-energy radiation. Scintillator - photodetector, in turn, has a dynamic range of linearity, running from 10 keV to 10 MeV gamma radiation, is of small size and weight and low electrical power.
The present work is aimed at examining electrophysical and radiometric characteristics of the electrical system of the scintillator -Si (Li) p-i-n photodetector. Si (Li) pin photodetectors were made of p-type silicon (p = 1-5 kOm.sm) with a long lifetime of minority carriers, developed by zone melting method using a special siliconion technology [1]. Lithium was diffused on the silicon plate of rectangular or round shape with depth of 30 mkm at a temperature of T = 420 ° C. Drift of lithium ions was carried out at a temperature of T = (80 -f 90) ° C and a voltage of U = 100 V, followed by a leveling off at T = 60 ° C and the voltage U = 30 V [2]. After completing the compensation of the silicon, the whole crystal with the dimensions of the sensitive area 20x15x0,3 mm was subjected to chemical engineering process in order to ensure minimum thickness of the "dead" layers of input and output windows and reverse leakage current to minimize noise detector. Then, Si (Li) p-i-n structure was placed in a housing wherein contact with Al (1000A°) and
Au (~ 200A°) was applied using vacuum deposition technique, and then such structure was connected with a plastic scintillator with dimensions 20x20x10mm using a lubricant with optimized optical parameters.
I-нА Е.кэВ
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EXAMINATION AND ASSESSMENT OF ELECTROPHYSICAL AND RADIOMETRIC CHARACTERISTICS OF THE Si (Li) PIN-PHOTODETECTING PLASTICSCINTILLATION SYSTEM
Muminov R. A., Radzhapov S. A., Radzhapov B. S.
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Figure 1. Scintillator - Si (Li) p-i-n photodetector ectrophysical characteristics (a), sectional structure (b ). 1 - Al foil d = 50 mm, 2 - the general body of SC-Si (Li), 3 - plastic scintillator, 4 - special optical grease, 5 - Si (Li)-p-i-n detector and radiometric characteristics (v).
Created systems of scintillator - Si (Li) p-i-n photodetector at a temperature T = 25 °C and operating voltage U = arr (18-30) have the dark current I = 25-40 nA, capacitance C = 280 pF, noise E w = 8 - 12 keV, the energy resolution of 137Cs with energy E у = 662 keV prepared (8-10)%.
Thus, the study of the electrical and radiometric characteristics of the scintillator - Si (Li) p-i-n photodetectors demonstrates that the developed detectors are suitable for dosimetry and
spectrometry of low-energy charged particles.
Список литературы:
1. Asimov SA, Mo'minov RA, SH Shamirzaev AJ Yafasov Silicon-lithium detectors of nuclear
radiation. -Tashkent.: Fan, 1981.-257s.
2. S.A. Radzhapov. A Versatile Spectrometer Based on a Large-Volume Si (Li) pin Structure / /
Instruments and Experimental Techiques. - New York, 2007, Vol. 50, No. 4, pp. 452-454.
