本文選題：高海拔宇宙線觀測(cè)站 + 空氣簇射芯探測(cè)器　； 參考：《湖南大學(xué)》2016年碩士論文

【摘要】：宇宙線的探測(cè)和研究是人們揭開(kāi)宇宙空間神秘面紗的重要手段,尋找宇宙線起源是當(dāng)前宇宙線物理的核心問(wèn)題。為此,我國(guó)物理學(xué)家提出了多種探測(cè)手段聯(lián)合觀測(cè)的高海拔宇宙線觀測(cè)站(Large High Altitude Air Shower Observatory, LHAASO)計(jì)劃,計(jì)劃中的空氣簇射芯探測(cè)器陣列(SCDA)的主要目的是精確測(cè)量宇宙線大氣簇射軸芯區(qū)的高能電磁成份。在此背景下,本文開(kāi)展了對(duì)SCDA讀出電子學(xué)電荷測(cè)量方案的預(yù)研設(shè)計(jì)。SCDA讀出電子學(xué)系統(tǒng)的主要任務(wù)是精確測(cè)量光電倍增管(PMT)輸出的電荷量。為實(shí)現(xiàn)高精度、大動(dòng)態(tài)范圍電荷量的測(cè)量,本設(shè)計(jì)采用了基于電流積分法的電荷測(cè)量方案,并結(jié)合電子學(xué)設(shè)計(jì)指標(biāo)對(duì)該方案進(jìn)行優(yōu)化設(shè)計(jì)研究,對(duì)其中的電流積分電路、濾波成形方案等部分進(jìn)行理論分析、Pspice仿真驗(yàn)證。另外由于SCDA的分散式排布方式,讀出電子學(xué)需通過(guò)同軸電纜與探測(cè)器連接。為防止信號(hào)的反射,本設(shè)計(jì)在電子學(xué)前端與電荷積分放大器的虛地點(diǎn)之間接入等效的50歐姆電阻以實(shí)現(xiàn)終端阻抗匹配,并提出了適用于大動(dòng)態(tài)范圍電荷測(cè)量電路的并聯(lián)分流形式的阻抗匹配方案�；陔姾蓽y(cè)量方案的研究,本文從模擬電路設(shè)計(jì)、電子學(xué)PCB版圖設(shè)計(jì)以及FPGA固件設(shè)計(jì)這幾方面詳細(xì)介紹了讀出電子學(xué)原理樣機(jī)的研制。并在實(shí)驗(yàn)室搭建了模擬實(shí)際工程的測(cè)試系統(tǒng)對(duì)電荷測(cè)量電路進(jìn)行電荷測(cè)量范圍、測(cè)量精度、積分非線性等參數(shù)的測(cè)試,測(cè)試結(jié)果表明本電荷測(cè)量電路系統(tǒng)能實(shí)現(xiàn)在6.2pC～8118 pC電荷測(cè)量范圍下電荷測(cè)量精度達(dá)到1.12%,其滿量程積分非線性為0.234%,滿足電子學(xué)設(shè)計(jì)指標(biāo)要求。另外,由于采用并聯(lián)分流的“虛地”阻抗匹配方案,讀出電子學(xué)系統(tǒng)可以通過(guò)簡(jiǎn)單的調(diào)節(jié)并聯(lián)電阻比值實(shí)現(xiàn)不同電荷量的測(cè)量。文中也對(duì)此進(jìn)行了測(cè)試,測(cè)試結(jié)果表明本電路系統(tǒng)在不同的電荷量輸入情況下具有很好的適用性。
[Abstract]:The detection and study of cosmic rays is an important means for people to uncover the mystery of cosmic space. Finding the origin of cosmic rays is the core problem of cosmic ray physics at present. For this reason, physicists in our country have put forward the large High Altitude Air Shower Observatory, LHAASO) program of the high altitude cosmic ray observation station, which is observed jointly by a variety of exploration methods. The main purpose of the planned air shower core detector array (SCDAA) is to accurately measure the high energy electromagnetic composition in the cosmic ray atmosphere shower core. In this context, the main task of the SCDA readout electronics system is to accurately measure the charge output of the photomultiplier tube. In order to measure charge in high precision and large dynamic range, a charge measurement scheme based on current integration method is used in this design. The optimization design of the scheme is carried out in combination with the electronic design index, and the current integral circuit is designed. The filter shaping scheme is analyzed theoretically and verified by PSpice simulation. In addition, due to the distributed arrangement of SCDA, readout electronics must be connected to the detector via coaxial cable. In order to prevent the reflection of the signal, the design connects the equivalent 50 ohms resistance between the electronic front end and the virtual location of the charge integral amplifier to achieve the terminal impedance matching. A parallel shunt impedance matching scheme is proposed for charge measurement circuits in large dynamic range. Based on the research of charge measurement scheme, this paper introduces the design of readout electronics principle prototype in detail from the aspects of analog circuit design, electronic PCB layout design and FPGA firmware design. At the same time, a testing system is set up in the laboratory to test the parameters of charge measurement circuit, such as the range of charge measurement, the accuracy of measurement, the integral nonlinearity, etc. The test results show that the charge measurement circuit system can realize the accuracy of charge measurement in the range of 6.2pC~8118 PC charge measurement, and its full range integral nonlinearity is 0.234, which meets the requirements of electronic design. In addition, because of the parallel shunt "virtual earth" impedance matching scheme, the readout electronic system can simply adjust the ratio of parallel resistance to realize the measurement of different charge quantities. The test results show that the circuit system has good applicability under different charge input conditions.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：TH75
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本文編號(hào)：1986490