本文關(guān)鍵詞： 摻釓液體閃爍體 光產(chǎn)額 衰減長(zhǎng)度 移波劑 密度泛函理論　出處：《西南科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：近年來(lái),中子和中微子探測(cè)已經(jīng)成為國(guó)際研究熱點(diǎn)。通過(guò)中微子探測(cè)獲得準(zhǔn)確可靠的中微子混合角θ13對(duì)于佐證電荷宇稱破壞定律和反物質(zhì)的存在具有重要的意義。目前對(duì)中子和中微子進(jìn)行探測(cè)的主要手段是采取閃爍探測(cè)器的方法。作為閃爍探測(cè)器的核心部件,同塑料閃爍體和晶體閃爍體相比,液體閃爍體由于其具有光產(chǎn)額高、光透過(guò)性好、易于制備大體積材料且形狀不受限制等優(yōu)點(diǎn),受到越來(lái)越多的關(guān)注和應(yīng)用。理想的液體閃爍體材料,應(yīng)該具備高的光產(chǎn)額、大的衰減長(zhǎng)度、快的熒光衰減時(shí)間、低的化學(xué)活性以及安全性好等特點(diǎn)。其中,溶劑作為液體閃爍體的主要組成部分,對(duì)液體閃爍體的各個(gè)性能都有很大的影響。目前,世界各地的許多國(guó)家都投入了巨大的財(cái)力致力于研究液體閃爍體溶劑的配方以提高液體閃爍體整體的性能。但是,對(duì)于單一的溶劑來(lái)說(shuō),總存在一定的缺陷和不足,比如光產(chǎn)額不高、光透過(guò)性不好、與盛裝液體閃爍體的有機(jī)玻璃(聚甲基丙烯酸甲酯)材料兼容性不好等。當(dāng)為解決這些問(wèn)題加入第二溶劑時(shí),又會(huì)有新的問(wèn)題出現(xiàn)。因此,如何制備出一種綜合性能良好的液體閃爍體成為了難點(diǎn)。另外,與液體閃爍體溶劑中的氫核相比,稀土金屬釓對(duì)于中子具有非常大的捕獲截面,因此常常把釓摻雜到液體閃爍體中去提高中微子的探測(cè)效率。本文首次采用偏三甲苯(Pseudocumene,PC)和線性烷基苯(Linear alkyl benzene,LAB)的混合溶劑作為液體閃爍體的基質(zhì),巧妙結(jié)合了兩種溶劑的優(yōu)缺點(diǎn)去實(shí)現(xiàn)液體閃爍體綜合性能的優(yōu)化。對(duì)混合溶劑的最佳配比進(jìn)行了探究,以光產(chǎn)額、衰減長(zhǎng)度和化學(xué)活性為參考依據(jù),發(fā)現(xiàn)20%PC-80%LAB的混合溶劑綜合性能較好。分別采用2,5-二苯基惡唑(2,5-Diphenyloxazole,PPO)和1,4-雙(2-甲基苯乙烯基)苯(1,4-bis(2-Methylstyryl)benzene,bis-MSB)作為第一閃爍體和移波劑。對(duì)最佳的液體閃爍體配方進(jìn)行了探究,并以之為研究對(duì)象進(jìn)行了光產(chǎn)額、衰減長(zhǎng)度、衰減時(shí)間以及和有機(jī)玻璃材料的兼容性測(cè)試。在這個(gè)工作的基礎(chǔ)上,本文采用直接溶解法和溶劑萃取法兩種方法對(duì)制備出的新型液體閃爍體進(jìn)行了釓的摻雜,并對(duì)兩種方法制備出的摻釓液體閃爍體進(jìn)行了性能的比較。光產(chǎn)額是液體閃爍體非常重要的一項(xiàng)性能,光產(chǎn)額越高,液體閃爍體探測(cè)的能量分辨率就越高。因此,為了進(jìn)一步地提高液體閃爍體的光產(chǎn)額,本文還設(shè)計(jì)合成了一種新型的移波劑,并與傳統(tǒng)的移波劑bis-MSB進(jìn)行了光學(xué)性能的比較,發(fā)現(xiàn)新型移波劑具有更高的光產(chǎn)額。為了深入研究移波劑發(fā)光過(guò)程中電荷的激發(fā)特性,本文還采用密度泛函理論對(duì)其進(jìn)行了理論計(jì)算,以紫外吸收和熒光發(fā)射為依據(jù),對(duì)適合的計(jì)算方法進(jìn)行了篩選,對(duì)前線分子軌道能量帶隙進(jìn)行了計(jì)算,利用Multiwfn 3.3.5的自然原子軌道法對(duì)新型移波劑和bis-MSB中甲氧基和甲基前線軌道的組分進(jìn)行了分析。
[Abstract]:In recent years. Neutron and neutrino detection has become an international research hotspot. Accurate and reliable neutrino mixing angle 胃 13 obtained by neutrino detection is of great significance to corroborate the law of charge parity destruction and the existence of antimatter. The main means of detecting neutrinos and neutrinos before detection is to use scintillation detectors as the core components of scintillation detectors. Compared with plastic scintillator and crystal scintillator, liquid scintillator has the advantages of high light yield, good light transmission, easy preparation of bulk materials and unlimited shape. The ideal liquid scintillator material should have the characteristics of high light yield, large attenuation length, fast fluorescence attenuation time, low chemical activity and good safety. As the main component of liquid scintillator, solvent has great influence on the properties of liquid scintillator. Many countries around the world have invested enormous financial resources to study the formulation of liquid scintillator solvents to improve the overall performance of liquid scintillators. However, for a single solvent. There are always some defects and deficiencies, such as light production is not high, light transmission is not good. Poor compatibility with organic glass (poly (methyl methacrylate)) containing liquid scintillators. New problems will arise when the second solvent is added to solve these problems. It is difficult to prepare a liquid scintillator with good comprehensive properties. In addition, the rare earth gadolinium has a very large neutron capture cross section compared with the hydrogen core in the liquid scintillator solvent. Therefore, gadolinium is often doped into liquid scintillators to improve the detection efficiency of neutrinos. In this paper, Pseudocumene is used for the first time. The mixture of PC- and linear alkyl benzene-lab) is used as the matrix of liquid scintillator. The advantages and disadvantages of the two solvents were skillfully combined to optimize the comprehensive properties of the liquid scintillator. The optimum ratio of the mixed solvents was investigated, based on the light yield, attenuation length and chemical activity. It was found that the mixed solvents of 20PC-80 lab had better comprehensive properties, and the PPOs and 1 of the mixed solvents were used respectively with 2PPO-5-Diphenyloxazoleine (2PPO-5-Diphenyloxazoleine). 4-Bis 2-Methylstyrylbenzene (2-Methylstyrylbenzene). Bis-MSBs were used as the first scintillator and wave-shifting agent. The optimum formulation of liquid scintillator was studied, and the optical yield and attenuation length were studied. The decay time and compatibility with plexiglass materials were tested. On the basis of this work, gadolinium doped new liquid scintillator was prepared by direct dissolution method and solvent extraction method. The properties of the gadolinium doped liquid scintillators prepared by the two methods were compared. The optical yield is one of the most important properties of liquid scintillators, and the higher the optical yield is, the higher the optical yield is. The higher the energy resolution of liquid scintillator detection, therefore, in order to further improve the optical yield of liquid scintillator, this paper also designed and synthesized a new wave-shifting agent. Compared with the conventional waveshifting agent bis-MSB, it is found that the new wave-shifting agent has higher optical yield. In order to study the charge excitation characteristics of the wave-shifting agent in the process of luminescence. In this paper, the density functional theory is used to calculate the energy band gap of the frontier molecular orbital. According to the ultraviolet absorption and fluorescence emission, the suitable calculation method is selected. The composition of methoxyl and methyl frontier orbitals in bis-MSB and a new type of wave-shifting agent were analyzed by using the natural atomic orbital method of Multiwfn 3.3.5.
【學(xué)位授予單位】：西南科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ422

【相似文獻(xiàn)】

相關(guān)期刊論文 前3條

1 馮宗游;液體閃爍體的一些實(shí)驗(yàn)結(jié)果——關(guān)于一些閃爍溶質(zhì)和溶劑的使用[J];核電子學(xué)與探測(cè)技術(shù);1982年02期

2 張惠選;張庚田;姚繼強(qiáng);;液體閃爍測(cè)量法測(cè)定土壤樣品中的鐳[J];鈾礦地質(zhì);1985年03期

3 松岡信明 ,寇榮春;利用液體閃爍測(cè)定法定量分析空氣中的~(222)Rn和~(220)Rn[J];國(guó)外醫(yī)學(xué)(放射醫(yī)學(xué)分冊(cè));1982年03期

相關(guān)會(huì)議論文 前10條

1 王祥馱;屈玉慧;;紅光液體閃爍體[A];全國(guó)第五屆核儀器及其應(yīng)用學(xué)術(shù)會(huì)議論文集[C];2005年

2 丁雅韻;張智勇;;大亞灣反應(yīng)堆中微子實(shí)驗(yàn)摻釓液體閃爍體的研制[A];中國(guó)化學(xué)會(huì)第26屆學(xué)術(shù)年會(huì)現(xiàn)代核化學(xué)與放射化學(xué)分會(huì)場(chǎng)論文集[C];2008年

3 張智勇;丁雅韻;李子杰;曹俊;張家文;;用于反應(yīng)堆中微子實(shí)驗(yàn)的摻釓液體閃爍體的研制[A];第十一屆全國(guó)活化分析學(xué)術(shù)會(huì)議論文摘要匯編[C];2006年

4 靳根明;宋明濤;鄔恩九;張伯彥;譚裕民;馮殿中;;載釓液體閃爍體的研究[A];第八屆全國(guó)核物理會(huì)議文摘集（下冊(cè)）[C];1991年

5 張智勇;丁雅韻;李子杰;曹俊;張家文;;用于反應(yīng)堆中微子實(shí)驗(yàn)的摻釓液體閃爍體的研制[A];首屆核化學(xué)與放射化學(xué)青年學(xué)術(shù)交流會(huì)論文摘要集[C];2006年

6 鄭普;陳淵;朱傳新;安力;牟云峰;郭海萍;;BC501液體閃爍體對(duì)n-γ及能量的分辨與其尺寸的關(guān)系[A];第四屆北京核學(xué)會(huì)核應(yīng)用技術(shù)學(xué)術(shù)交流會(huì)論文集[C];2006年

7 李娓酈;趙海泉;王祥馱;;穩(wěn)定高效的HND-LS型液體閃爍體[A];全國(guó)第五屆核儀器及其應(yīng)用學(xué)術(shù)會(huì)議論文集[C];2005年

8 鄭普;陳淵;朱傳新;;BC501A液體閃爍體中子伽馬分辨譜與能譜測(cè)量數(shù)字化[A];第十四屆全國(guó)核電子學(xué)與核探測(cè)技術(shù)學(xué)術(shù)年會(huì)論文集（上冊(cè)）[C];2008年

9 鄭普;陳淵;朱傳新;;BC501A液體閃爍體中子伽馬分辨譜與能譜測(cè)量數(shù)字化[A];第十四屆全國(guó)核電子學(xué)與核探測(cè)技術(shù)學(xué)術(shù)年會(huì)論文集（1）[C];2008年

10 朱傳新;陳淵;郭海萍;;BC-501A液體閃爍體γ探測(cè)效率[A];中國(guó)工程物理研究院科技年報(bào)（2003）[C];2003年

相關(guān)碩士學(xué)位論文 前5條

1 陳海濤;基于線性烷基苯的液體閃爍體在不銹鋼中的老化研究[D];南京航空航天大學(xué);2015年

2 王續(xù)琨;液體閃爍體衰減長(zhǎng)度測(cè)量裝置的研制與光產(chǎn)額測(cè)量[D];南華大學(xué);2016年

3 鄭占龍;一種新型摻釓液體閃爍體的制備與性能研究[D];西南科技大學(xué);2017年

4 席印印;液體閃爍體高能中子探測(cè)器研究[D];哈爾濱工程大學(xué);2013年

5 何莉蘋;低余暉液體閃爍體的制備與光學(xué)性能研究[D];中國(guó)工程物理研究院;2014年

，

本文編號(hào)：1453688