Gama spektrometer na osnovi scintilacijskega pretvornika

LIKAR, MARKO (author), Jankovec, Marko (mentor)

Običajno nas pri meritvah sevanja zanima ne samo aktivnost, ampak tudi energija nekega neznanega ionizirajočega sevanja. Zato sem se namenil izdelati instrument, ki bo lahko meril poleg jakosti tudi energijski spekter γ žarkov. Na koncu, ko je bil instrument skupaj s programom na mikrokrmilniku končan, sem lahko opravil še meritve nihanja visoke napetosti, doseg instrumenta od najnižje možne energije pa do najvišje, ki jo lahko še merimo, ločljivost pri določenih energijah in linearnost izmerjenega energijskega spektra. Izkazalo se je, da instrument ponuja kljub nekaj ubranim bližnjicam dobro ločljivost. Pri merjenju izotopa K-40, s sevalno energijo γ sevanja 1460 keV, ima instrument 5.3 % ločljivost. Kar je primerljivo z drugimi merilniki, ki so na voljo te čase na tržišču. Žal pa zaradi zmanjšanja porabe visokonapetostnega dela ima za skoraj 3.6 % slabšo linearnost, ki na vgrajenem prikazovalniku ni opazna. Za natančnejše meritve na računalniku pa je nelinearnost prevelika.

• Language: Slovenian
• Keywords: Gama spektrometer, scintilator, fotopomnoževalka, tiskano vezje
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2014
• PID: 20.500.12556/RUL-30040
• Publication date in RUL: 13.11.2014

Secondary language

• Language: English
• Title: Gamma spectrometer based on a scintillation converter

Abstract

Generally when measuring radiation we are interested not only in intensity but in energy of unknown ionising radiation too. For this purpose I committed myself to built such instrument that will be capable of measuring intensity and energy spectrum of γ radiation. At the end when the instrument was finished together with the program on microcontroller, we were able to measure fluctuation of high voltage supply, energy range of the instrument, linearity and resolution at specified energy. Despite of some shortcuts taken, the measured resolution at 1460 keV from K-40 radioactive element was 5.3 %. Which is very good and comparable to other such instrument nowadays on the market. But on the other hand because of lowering the power consumption of high voltage supply, the linearity is very poor, measured 3.6 %. Which is not visible on the built in LCD, but for more precise measurements on computer it is too high.

• Keywords: Gamma spectrometer, scintillator, photomultiplier tube, printed circuit