本文選題：大亞灣中微子探測器 + 惰性中微子�。� 參考：《山東大學》2016年博士論文

【摘要】：中微子物理作為粒子物理、天體物理和宇宙學的交叉前沿學科,是當今理論及實驗研究的熱點。在粒子物理標準模型中,中微子是自旋為1/2的Dirac粒子,不帶電,只參與弱相互作用,最初被認為是沒有質量的。但是,近幾十年來一系列實驗乙證實,中微子有很小的質量,并且其質量本征態(tài)與弱相互作用的味道本征態(tài)不簡并,因此在傳播過程中可以在不同的味道之間轉化,發(fā)生中微子振蕩。在標準三代中微子振蕩模型中,中微子的每個味道本征態(tài)(ve,vμ,vτ)都可以寫成三個質量本征態(tài)(v1,v2,v3)的線性疊加。參數化后,三代中微子的振蕩模型就可以通過三個混合角θ12、θ1a、θ23,兩個獨立的質量平方差△m212、Δm322和一個CP相角δCP來描述。在精確測量中微子振蕩參數的過程中,LSND實驗由于設計時兩個質量平方差還未知,并且當時有暗物質模型假設存在質量大于1 eV的中微子,因此LSND將物理目標定為測量較大的質量平方差,并最終觀測到了振蕩現(xiàn)象。然而,現(xiàn)在我們已經知道兩個質量平方差分別為△m212～10-5 eV2、|△m312|10-3 eV2,所以LSND觀測到的振蕩現(xiàn)象超出了標準三代中微子模型,這一異常首次引起了人們對質量約為1 eV的中微子的注意。之后出現(xiàn)的一系列實驗異常,包括為了驗證LSND結果設計的MiniBooNE加速器實驗異常,還有不同類型的反應堆中微子異常、Gallium異常,甚至宇宙學數據分析顯示的異常跡象,都不能通過標準三代中微子振蕩模型解釋。由于加速器上的Zo衰變實驗已經證明只存在三種參與弱作用的輕中微子,所以只能假設存在一種甚至多種不直接參與弱作用、但是可以通過中微子振蕩與三代“活躍”中微子混合的“惰性中微子”。惰性中微子的引入無論從理論還是從實驗的角度看,都是非常自然的處理方法,但是考慮到也有一些實驗并沒有觀測到可能存在惰性中微子振蕩的跡象,因此目前我們還不能確定惰性中微子是否存在。綜合一系列實驗的全局擬合結果顯示,如果存在惰性中微子,那么惰性中微子與活躍中微子之間的質量平方差可能在1 eV2量級。顯然,僅有一兩個統(tǒng)計量不是很高的實驗表明存在惰性中微子,是不足以讓人信服的。我們需要有一系列不依賴于模型、使用不同原理或探測手段的實驗來提供確鑿的證據。這就使得利用大亞灣的實驗裝置進行惰性中微子的研究成為一種可能。大亞灣實驗的主要物理目標是測量三個混合角中最后一個未知的混合角θ13至sin22θ130.01的精度。大亞灣實驗于2012年3月首次以5.2σ公布了θ13不為零的結果,給出sin22θ913=0.092±0.016(stat.)+0.005(syst.),被美國權威學術雜志《科學》評選為當年的十大科學突破,并在2015年獲得“基礎物理學突破獎”。大亞灣實驗完成之后,如果各種實驗裝置到時候就那么廢棄,未免太過可惜。因此我們提議：結合當前惰性中微子研究的熱點,在大亞灣停止取數后,利用大亞灣實驗的探測器和反應堆,升級建造一個短基線(100 m)中微子振蕩實驗,以探測△m412～1 eV.的惰性中微子為主要物理目標,同時可以開展關于反應堆中微子能譜的精確測量、以及探測器技術應用相關的研究。本論文就是圍繞這個提議展開,探討了利用大亞灣中微子探測器進行惰性中微子實驗的可行性。為了得到實驗的靈敏度,我們采取了一些假設,構造了χ2函數,討論了尺寸效應和探測器位置布局對靈敏度的影響。研究發(fā)現(xiàn)：利用大亞灣中微子探測器進行惰性中微子研究的提議在10-2eV2(?)△m412(?)1 eV2的參數空間靈敏度較高,而在△m412(?)1 eV2的參數空間,由于大亞灣反應堆為商業(yè)用反應堆,堆芯尺寸太大,因此提升測量靈敏度的可能性有限。如果我們側重于探索Δm412～1eV2區(qū)域,那么推薦非對稱的探測器布局,其中近點探測器與相近反應堆之間的距離最好小于30 m,探測器之間的距離最好在m的量級；如果我們側重于探索△m412～several×0.1 eV2區(qū)域,則推薦對稱的探測器布局,以減少反應堆之間的干涉、避免可能的人為因素導致的對某些Δm412值探索能力的喪失。為了估算探測器移到地表時的宇宙線繆子通量及相應的本底水平,我們開發(fā)了一套Geant4模擬程序,并模仿大亞灣實驗與其它一些實驗的設計,構造了一個中心探測器外有水池、鉛和混凝土屏蔽材料的探測器模型。通過研究發(fā)現(xiàn),在這種探測器設計方案下,繆子反符合探測器和中心探測器液閃區(qū)域中的宇宙線繆子事例率分別高達約15 kHz和2 kHz。通過取20μs的繆子反符合時間窗口,并對模擬數據添加要求從快信號前20μs到慢信號后20μs的時間范圍內沒有大于0.7 MeV信號的多重度挑選條件,我們估計出了繆子引起的關聯(lián)本底事例率約為0.2 Hz的保守結果。這里的0.2 Hz關聯(lián)本底,與大亞灣實驗中繆子引起的關聯(lián)本底主要來自9Li/8He和快中子不同,主要是來自于未被反符合掉的子事例。參考大亞灣實驗的經驗,我們知道想要模擬得到足夠統(tǒng)計量的9Li/8He和快中子本底不可行,因此只好利用其產額對繆子能量的power law依賴關系,估算了這兩類本底大小的量級,分別為O(10-3)Hz和0(10-2)Hz。使用模擬給出的11 Hz繆子致快信號事例率,加上大亞灣設計報告給出的50 Hz放射性本底事例率,近似作為總的快信號事例率,同時使用模擬給出的3 Hz繆子致慢信號事例率近似作為總的慢信號事例率,我們計算給出非常保守的0.04 Hz偶然符合本底事例率。關于對宇宙線中子本底的額外討論,我們發(fā)現(xiàn)選取的“水池-鉛-混凝土”的屏蔽層結構具有非常強的中子屏蔽能力,導致宇宙線中子引起的本底事例率不會超過0.001 Hz�？傊�,以探測器位于大亞灣兩個反應堆中點時IBD事例率約為0.6Hz為例,這樣的本底水平完全有可能使實驗的信噪比好于1。綜合靈敏度和本底水平的研究結果,本文最后我們基于大亞灣核電站反應堆附近的實際情況,選取了兩個可能擺放探測器的位置,然后通過研究靈敏度隨一些參數的變化趨勢,提出了利用大亞灣中微子探測器進行惰性中微子實驗的需求。發(fā)現(xiàn)以大亞灣反應堆和探測器的現(xiàn)有條件,只要能使bin-to-bin誤差σdb(?)(1)％,本底事例率Rbkg(?)(10)Hz,就可能在10-2 eV2(?)△m412(?)3eV2參數空間具有較強的排除能力。Bin-to-bin誤差σdb(?)(1)％這一需求根據以往的實驗經驗,應該比較容易滿足。本底事例率Rbkg(?)(10)Hz的需求,通過研究“閃爍體-聚乙烯-鐵”屏蔽層設計方案下的本底水平,發(fā)現(xiàn)即便不使用很厚的屏蔽材料也可以滿足。因此我們認為,利用大亞灣中微子探測器進行惰性中微子實驗的提議,在探測10-2 eV2(?)△m412(?)3 eV2的參數空間時具有可行性。
[Abstract]:Neutrino physics, a cross frontier subject in particle physics, astrophysics and cosmology, is a hot spot in theoretical and experimental research. In the standard model of particle physics, neutrino is a Dirac particle with a spin of 1/2, which is not charged, only participates in weak interaction and is initially considered to have no mass. However, a series of experimental B in recent decades has been considered. It is proved that the neutrino has a small mass, and its mass eigenstate and the taste eigenstate of the weak interaction are not simple. Therefore, the neutrino oscillation can be converted between different flavors during the propagation process. In the standard three generation neutrino oscillation model, each flavor eigenstate (VE, V, V tau) of the neutrino can be written as three substances. The linear superposition of the eigenstate (V1, V2, V3). After the parameterization, the oscillation model of the three generation neutrino can be described by three mixed angles, theta 12, theta 1a, theta 23, two independent mass squared Delta m212, Delta m322 and a CP angle Delta CP. In the process of accurate measurement of the neutrino oscillation parameters, the LSND experiment is due to two mass squared differences in the design. Unknown, and at that time there was a dark matter model that assumed a neutrino with a mass greater than 1 eV, so LSND set the physical target as a measured mass squared difference, and finally observed the oscillation. However, now we have known that two mass squared differences are Delta m212 to 10-5 eV2, Delta m312|10-3 eV2, so LSND observed vibration. The phenomenon is beyond the standard three generation neutrino model, which first caused attention to the neutrinos with a mass of about 1 eV. A series of experimental anomalies followed, including the MiniBooNE accelerator experimental anomalies designed to verify the LSND results, and the different types of counter Reactor Neutrino anomalies, Gallium anomalies, and even the universe. The abnormal signs in the analysis of the data analysis can not be explained by the standard three generation neutrino oscillation model. Since the Zo decay experiment on the accelerator has proved that only three light neutrinos involved in the weak action have been proved, it can only assume that there is one or more non direct participation in the weak action, but it can pass the neutrino oscillation and the three generation. The introduction of inert neutrinos in the mixture of neutrinos. The introduction of inert neutrinos, both theoretically and experimentally, is a very natural treatment. However, there are some experiments that have not observed signs that the inert neutrino oscillations are likely to exist, so we are not yet able to determine whether inert neutrinos are available. The global fitting results of a series of experiments show that the mass squared difference between inert neutrinos and active neutrinos may be in the order of 1 eV2 if there are inert neutrinos. Obviously, only one or two statistics are not very high, and the existence of inert neutrinos is not sufficient to convince people. We need to have a line. It is not dependent on the model to provide solid evidence using experiments with different principles or detection methods. This makes it possible to use the experimental device in Dayawan to study inert neutrinos. The main physical object of the Dayawan experiment is to measure the last unknown mixture angle of the mixed angle of three mixed angles, theta 13 to sin22 theta 130.01. Degree. In March 2012, the Dayawan experiment published the results of theta 13 not zero for the first time with 5.2 sigma, giving sin22 theta 913=0.092 + 0.016 (stat.) +0.005 (syst.), being selected as the ten major scientific breakthrough by the American authoritative academic magazine "Science >" and winning the "basic physics burst Award" in 2015. After the experiment was completed, if various experiments were completed. It is a pity that the device is so abandoned, so we propose that, with the current hot spot of inert neutrino research, after stopping in Dayawan, we use the detector and reactor in the Dayawan experiment to upgrade the construction of a short baseline (100 m) neutrino oscillation experiment to detect the inert neutrinos of delta M412 to 1 eV. as the main object. In this paper, the feasibility of the inert neutrino experiment using the Dayawan neutrino detector is discussed around this proposal. In order to obtain the sensitivity of the experiment, we have taken some assumptions. The x 2 function is constructed, and the effect of the size effect and the location of the detector on the sensitivity is discussed. It is found that the proposal of the inert neutrino study using the Dayawan neutrino detector is more sensitive in the parameter space of the 10-2eV2 (?) Delta M412 (?) 1 eV2, and the parameter space of the delta M412 (?) 1 eV2, because the Dayawan reactor is commercial In the reactor, the core size is too large, so the possibility of improving the sensitivity of the measurement is limited. If we focus on the exploration of the delta M412 ~ 1eV2 region, then the asymmetric detector layout is recommended, in which the distance between the near point detector and the similar reactor is best less than 30 m, and the distance between the detectors is best at the order of M; if we side Rather than exploring the delta M412 ~ several x 0.1 eV2 region, a symmetrical detector layout is recommended to reduce interference between the reactors and avoid the loss of potential exploration capabilities for some Delta M412 values caused by possible human factors. In order to estimate the cosmic ray Muse flux and the corresponding background levels when the detector moves to the surface, a set of Gean is developed. The T4 simulation program, and imitates the design of the Dayawan experiment and other experiments, constructs a detector model of a pool, lead and concrete shielding materials outside the central detector. Through the study, it is found that the cosmic ray Samuel case rate in the Muse counter conforming detector and the central detector's liquid flash area under the design of this detector is found. Do not get up to about 15 kHz and 2 kHz. by taking a 20 mu s Muse counter coincidence time window, and adding a multi severe selection condition that requires no more than 0.7 MeV signals in the time range of the analog data from 20 mu before the fast signal to the slow signal 20 mu s, and we estimate the conservative result of the incidence of the underlying case rate of about 0.2 Hz caused by the muse. The background of the 0.2 Hz Association, which is mainly derived from the 9Li/8He and fast neutrons in the Dayawan experiment, mainly comes from the sub cases that have not been inverse conformed. Referring to the experience of the Dayawan experiment, we know that the 9Li/8He and the fast neutron background are not feasible to simulate sufficient statistics, so we have to use their production. For the power law dependence of the Muse energy, the magnitude of these two kinds of background sizes are estimated, respectively, the rate of fast signal cases caused by 11 Hz Muse by simulation of O (10-3) Hz and 0 (10-2) Hz., plus the rate of 50 Hz radioactive background events given in the Dayawan design report, approximately as the total fast signal case rate, and using the 3 Hz given by the simulation. The rate of the slow signal case rate of the Muse is approximated as the total slow signal case rate. We calculate a very conservative 0.04 Hz coincidence case rate. With regard to the extra discussion of the neutron background of the cosmic ray, we find that the selected "pool lead concrete" shielding structure has a very strong neutron shielding ability, which leads to the cosmic ray. The bottom case rate will not exceed 0.001 Hz., and the IBD incident rate is about 0.6Hz when the detector is located at the middle point of the two reactor in Dayawan. This background level can make the experimental signal-to-noise ratio better than the 1. comprehensive sensitivity and the background level. Finally, we are based on the reactor of the Dayawan nuclear power plant. In the vicinity of the actual situation, the location of two possible detectors is selected, and then the demand of the inert neutrino experiment using the Dayawan neutrino detector is proposed by studying the variation trend of the sensitivity with some parameters. It is found that the existing conditions of the Dayawan reactor and the detector can make the bin-to-bin error DB (?) (?) (?) (?) (1). %, the background case rate is Rbkg (?) (?) (10) Hz, it is possible to have a strong exclusion.Bin-to-bin error of.Bin-to-bin error dB (?) (1)% (?) (1)% in the 10-2 eV2 (?) Delta M412 (?) 3eV2 parameter space. According to the previous experimental experience, it should be easier to meet the requirement of the background case rate Rbkg (?) (?) (10) Hz, by studying the design of "scintillation PE iron" shielding layer The background level under the scheme is found to be satisfied even without the use of very thick shielding materials. Therefore, we think that the proposal of using the Dayawan neutrino detector for inert neutrino experiments is feasible in detecting the parameter space of 10-2 eV2 (?) Delta M412 (?) 3 eV2.
【學位授予單位】：山東大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：O572.321

【相似文獻】

相關期刊論文 前10條

1 P·KennedyMcEwen;邊原;;焦面探測器陣列的信號處理器[J];應用光學;1988年01期

2 楊鵬翎;馮國斌;王群書;王振寶;程建平;;中紅外高能激光光斑探測器[J];中國激光;2009年08期

3 徐愛強;;光學探測器陣列對目標方位角的判定[J];應用光學;1984年04期

4 陳剛,溫志渝,梁玉前,蔣子平,黃儉,熊宇虹;采用曲線擬合消除探測器陣列非線性對吸收光譜的影響[J];光譜學與光譜分析;2005年03期

5 大舟;激光束診斷用新型探測器—原子層熱電堆[J];光機電信息;1995年03期

6 陳剛,溫志渝,吳英,楊桂榮,溫中泉,黃尚廉;光電探測器陣列光敏元寬度對譜線峰值位置影響的研究[J];光子學報;2002年03期

7 王云萍;;探測器陣列法測量激光光斑參數關鍵技術分析[J];激光雜志;2007年04期

8 譚毅;;多元相控聚焦探測器的方向特性[J];物理實驗;2011年06期

9 段曉峰;黃永清;王琦;黃輝;任曉敏;溫凱;;具有多波長處理功能的單片集成光探測器陣列[J];中國激光;2009年09期

10 劉鵬;;同步輻射探測器的應用與發(fā)展[J];物理;2007年08期

相關會議論文 前10條

1 鄒鴻;陳鴻飛;鄒積清;施偉紅;張錄;寧寶俊;田大宇;;硅條帶探測器陣列在空間粒子探測中的應用[A];中國空間科學學會空間探測專業(yè)委員會第十八次學術會議論文集（下冊）[C];2005年

2 李齊林;鄧小武;陳立新;黃曉延;;2-D半導體探測器陣列方向性響應的研究[A];中華醫(yī)學會放射腫瘤治療學分會六屆二次暨中國抗癌協(xié)會腫瘤放療專業(yè)委員會二屆二次學術會議論文集[C];2009年

3 馬攀;戴建榮;Jie She;;探測器陣列大野測量時散射體積缺損對測量準確性的影響[A];2007第六屆全國放射腫瘤學學術年會論文集[C];2007年

4 張行坤;;數字化X線設備CR和DR的成像原理[A];中華醫(yī)學會醫(yī)學工程學分會第八次學術年會暨《醫(yī)療設備信息》創(chuàng)刊20周年慶祝會論文集[C];2006年

5 吳廣國;黃勇;賈彬;曹學蕾;孟祥承;王煥玉;李秀芝;梁琨;楊茹;韓德俊;;硅漂移探測器的制作工藝及特性研究[A];第十四屆全國核電子學與核探測技術學術年會論文集（上冊）[C];2008年

6 吳廣國;黃勇;賈彬;曹學蕾;孟祥承;王煥玉;李秀芝;梁琨;楊茹;韓德俊;;硅漂移探測器的制作工藝及特性研究[A];第十四屆全國核電子學與核探測技術學術年會論文集（1）[C];2008年

7 徐子森;;多層螺旋CT技術新進展[A];山東醫(yī)學會醫(yī)療器械專業(yè)委員會第八次學術年會論文集[C];2000年

8 L．Bagby;M．Johnson;R．Lipton;顧維新;;硅條探測器及其讀出芯片SVX飽和的研究[A];第8屆全國核電子學與核探測技術學術年會論文集（一）[C];1996年

9 向思樺;陳四海;潘峰;黃磊;賴建軍;柯才軍;易新建;;柔性仿生復眼成像系統(tǒng)探測機理模擬研究[A];2004全國圖像傳感器技術學術交流會議論文集[C];2004年

10 常勁帆;王錚;李秋菊;張研;;LHAASO地面粒子探測器陣列前端電子學初步設計[A];第十五屆全國核電子學與核探測技術學術年會論文集[C];2010年

相關重要報紙文章 前1條

1 實習生 姜靖;探索在量子領域前沿[N];科技日報;2007年

相關博士學位論文 前8條

1 石銘;延伸波長InGaAs探測器的表面與界面研究[D];中國科學院研究生院(上海技術物理研究所);2015年

2 黃星;短波紅外InGaAs探測器輻照特性研究[D];中國科學院研究生院(上海技術物理研究所);2015年

3 陳泉佑;利用大亞灣中微子探測器進行惰性中微子實驗的可行性研究[D];山東大學;2016年

4 王凡;仿視網膜分布探測器設計及成像特性研究[D];北京理工大學;2015年

5 楊賀潤;Micromegas探測器的性能研究[D];蘭州大學;2010年

6 楊波;可見拓展的短波紅外InGaAs探測器研究[D];中國科學院研究生院（上海技術物理研究所）;2014年

7 王自昱;微機電系統(tǒng)中的聲學推進器和探測器[D];武漢大學;2011年

8 郝新軍;LHAASO水切倫科夫探測器原型陣列讀出電子學研究[D];中國科學技術大學;2011年

相關碩士學位論文 前10條

1 王鑫;工業(yè)CT探測器光電流信號放大及轉換特性研究[D];重慶大學;2011年

2 齊國濤;Si-PIN X射線探測器性能研究[D];河北師范大學;2012年

3 劉海;LiTaO_3探測器的二維結構分析[D];長春理工大學;2007年

4 范生強;BST鐵電薄膜紅外探測器陣列的制備工藝及其電學性能[D];湖北大學;2011年

5 郝博濤;大氣激光通信系統(tǒng)探測器陣列分集接收技術研究[D];長春理工大學;2013年

6 倉黎黎;基于384×288探測器的非制冷紅外圖像處理技術研究[D];南京理工大學;2009年

7 丁勇;軌道振動和探測器傾斜對錐束CT的影響[D];東北大學;2008年

8 劉飛;光通信系統(tǒng)中波長選擇性波導探測器的研究[D];北京郵電大學;2013年

9 馬霄云;氟化鋇探測器的設計組裝和性能測試[D];蘭州大學;2007年

10 王釋偉;新型PIN硅半導體探測器的輻射損傷研究[D];蘭州大學;2006年

，

本文編號：1918626