本文選題：便攜式輻射探測(cè)器　切入點(diǎn)：靈敏度　出處：《華中科技大學(xué)》2013年碩士論文　論文類型：學(xué)位論文

【摘要】：近年來，隨著核科學(xué)與技術(shù)的飛速發(fā)展，核輻射安全越來越受到人們的關(guān)注。便攜式輻射探測(cè)器因具有攜帶方便、操作簡(jiǎn)單、實(shí)時(shí)有效、可定性定量分析等優(yōu)點(diǎn)，成為保障個(gè)人與環(huán)境安全的重要儀器。但對(duì)于不同的核應(yīng)用領(lǐng)域，其對(duì)應(yīng)的放射源種類和強(qiáng)度也各不相同，這就要求輻射探測(cè)器具有寬的劑量率量程和寬的能量范圍，以及足以區(qū)分核素種類的能量分辨率。低劑量率的探測(cè)需要高靈敏度，采用傳統(tǒng)探測(cè)器和模擬電子學(xué)系統(tǒng)難以同時(shí)保證量程范圍，若要獲得脈沖的能量信息，量程將進(jìn)一步縮小。此外，要獲得高的靈敏度，即需要大尺寸閃爍晶體，受限于PMT的體積和工作電壓，便攜性差，新型固態(tài)光電器件SiPM具有替換PMT的潛力，但其動(dòng)態(tài)范圍不足限制了可探測(cè)的能量范圍。 本文研究新型探測(cè)器技術(shù)和數(shù)據(jù)獲得系統(tǒng)，研制了一種高靈敏、高分辨、寬范圍的便攜式輻射探測(cè)器。在探測(cè)器設(shè)計(jì)上，采用SiPM作為光電器件提高便攜性，利用YSO/SiPM作為低能高率量程探測(cè)器，BGO/SiPM作為高能低量程探測(cè)器，實(shí)現(xiàn)了寬劑量率量程探測(cè)。通過組合探測(cè)器技術(shù)解決了SiPM的動(dòng)態(tài)范圍不足的問題，實(shí)現(xiàn)了寬能量范圍的探測(cè)，并分別實(shí)現(xiàn)在低能段和高能段獲得理想的能量分辨率。在數(shù)據(jù)獲得系統(tǒng)方面，評(píng)估了MVT全數(shù)字?jǐn)?shù)據(jù)獲取系統(tǒng)在能量分辨率，，衰減時(shí)間常數(shù)，堆疊恢復(fù)等方面的應(yīng)用。最后實(shí)現(xiàn)了寬能量范圍的探測(cè)器和高靈敏寬量程的劑量率儀樣機(jī)。 通過第三方校準(zhǔn)，基于YSO/SiPM的高量程探測(cè)器的靈敏度為299cps/μSv/h，劑量率量程為5μSv/h-100μSv/h，實(shí)驗(yàn)測(cè)試結(jié)果顯示劑量率上限接近1mSv/h�；贐GO/SiPM的高靈敏探測(cè)器靈敏度為662cps/μSv/h，劑量率量程為5μSv/h-100μSv/h，實(shí)驗(yàn)測(cè)試結(jié)果顯示劑量率下限可達(dá)0.01μSv/h。在寬能譜評(píng)估中，低能探測(cè)器在59.5keV處得到35%的能量分辨率，能量范圍可從59.5keV到中能，高能探測(cè)器在511Kev處得到24%的能量分辨率，可探測(cè)511keV以上的高能射線。結(jié)果表明本文提出的方法可以實(shí)現(xiàn)高靈敏、高分辨、寬范圍的便攜式輻射探測(cè)器。
[Abstract]:In recent years, with the rapid development of nuclear science and technology, people pay more and more attention to the safety of nuclear radiation. It has become an important instrument for personal and environmental safety. However, for different nuclear applications, the corresponding types and intensities of radioactive sources are different, which requires a wide range of dose rate and a wide range of energy for radiation detectors. And enough energy resolution to distinguish nuclides. The detection of low dose rate requires high sensitivity. It is difficult for conventional detectors and analog electronic systems to ensure the range at the same time. If the energy information of the pulse is to be obtained, The measurement range will be further reduced. In addition, to obtain high sensitivity, large scintillation crystals are required, limited by the volume and working voltage of the PMT, and low portability. The new solid-state optoelectronic device SiPM has the potential to replace the PMT. But its dynamic range is not enough to limit the detectable energy range. In this paper, the new detector technology and data acquisition system are studied, and a portable radiation detector with high sensitivity, high resolution and wide range is developed. In the design of the detector, SiPM is used as an optoelectronic device to improve the portability. Using YSO/SiPM as low energy and high rate range detector, BGO / SiPM is used as high energy low range detector to realize wide dose rate range detection. The problem of insufficient dynamic range of SiPM is solved by combined detector technology, and the detection of wide energy range is realized. In the aspect of data acquisition system, the energy resolution and attenuation time constant of MVT digital data acquisition system are evaluated. Finally, the detector with wide energy range and the dosimeter prototype with high sensitivity and wide range are realized. Through third-party calibration, The sensitivity of high range detector based on YSO/SiPM is 299 cps/ 渭 Sv / h, and the range of dose rate is 5 渭 Sv/h-100 渭 Sv / h. The experimental results show that the upper limit of dose rate is close to 1 mSv / h. The sensitivity of high sensitive detector based on BGO/SiPM is 662 CPS / 渭 Sv / h, and the range of dose rate is 5 渭 Sv/h-100 渭 Sv / h. The experimental results show that the dose rate is 5 渭 Sv / h. The lower limit of the rate can be up to 0.01 渭 Sv / h. The low energy detector has an energy resolution of 35% at 59.5 Kev, and the energy range from 59.5 Kev to moderate energy. The high energy detector can obtain 24% energy resolution at 511 Kev. The results show that the proposed method can be used to realize portable radiation detectors with high sensitivity, high resolution and wide range.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：R318.6

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本文編號(hào)：1573125