本文選題：宇宙線 + 冪律譜�。� 參考：《河北師范大學》2012年碩士論文

【摘要】：宇宙線被物理學家喻為神秘的天外來客，它是來自地球之外的高能微觀粒子。自1912年發(fā)現(xiàn)宇宙線至今已有一百年時間，在這期間人們對宇宙線進行了連續(xù)不斷的實驗探測和理論研究。但是到目前為止，關于宇宙線粒子的幾個根本性問題我們?nèi)匀粺o法得到清晰完美的答案，例如宇宙線的起源、加速和傳播等問題。宇宙線問題成為現(xiàn)代物理學中最重要也是最基本的問題之一。 本論文主要討論造成宇宙線能譜異常的原因，并利用GALPROP對兩種解釋模型中的次級粒子預期值進行比較。我們首先簡述宇宙線物理的有關知識，然后對數(shù)值求解銀河系宇宙線傳播的程序包GALPROP進行詳細介紹，繼而在此基礎之上對近幾年宇宙線能譜異常的問題進行討論。關于宇宙線能譜的觀測，，在氣球?qū)嶒濩REAM之前的觀測結果中，宇宙線的標準能譜是單一冪律譜。然而最新的CREAM實驗觀測表明，從質(zhì)子到鐵的元素能譜在～200GeV/核子能段出現(xiàn)了異常的變硬，明顯不同于一般的單一冪律譜。接著衛(wèi)星實驗PAMELA公布的最新數(shù)據(jù)顯示，質(zhì)子和氦核的能譜在剛度為～200GV的地方也出現(xiàn)了拐折，而且和ATIC、CREAM的結果是自洽的，且不同于單一冪律譜。有關這一反�，F(xiàn)象的理論討論很多，本文重點討論其中的兩種：一種理論認為，這種能譜異常變硬是由宇宙線粒子注入到星際空間時非線性加速機制造成的；另一種理論則認為，能譜的拐折是臨近的單一源能譜和背景能譜疊加造成的。另外，我們要重點比較這一異常現(xiàn)象對于反質(zhì)子、正電子、伽瑪射線的預言在這兩種模型中的不同。 我們利用GALPROP的宇宙線擴散+對流模型對CREMA和PAMELA能譜進行了很好的解釋，接著我們對質(zhì)子和氦核產(chǎn)生的反質(zhì)子，以及伽瑪射線進行了計算，發(fā)現(xiàn)能譜的異常確實造成了反質(zhì)子和伽瑪射線的預言在兩種模型中不同。另外我們還計算了正電子能譜，經(jīng)過比較，兩者也存在相應的差異。
[Abstract]:Cosmic ray is regarded by physicists as a mysterious alien. It is a high-energy microparticle from outside the earth. It has been a hundred years since the discovery of cosmic rays in 1912. During this period, continuous experimental exploration and theoretical study of cosmic rays have been carried out. But so far, we can not get a clear and perfect answer to several fundamental questions about cosmic ray particles, such as the origin, acceleration and propagation of cosmic rays. Cosmic ray problem has become one of the most important and basic problems in modern physics. This paper mainly discusses the causes of cosmic ray energy spectrum anomalies and compares the expected values of secondary particles in the two interpretation models by GALPROP. We first introduce briefly the knowledge of cosmic ray physics, then introduce in detail the program package GALPROP for numerical solution of cosmic ray propagation in the Milky way, and then discuss the problem of cosmic ray energy spectrum anomaly in recent years. With regard to the observation of cosmic ray energy spectrum, the standard energy spectrum of cosmic ray is a single power law spectrum in the observation results before the balloon experiment CREAM. However, the latest CREAM observations show that the energy spectra from proton to iron show abnormal hardening at the energy level of 200GeV / nucleon, which is obviously different from the general single power law spectrum. Then the latest data released by satellite experiment PAMELA show that the energy spectrum of proton and helium nucleus also turns at the stiffness of 200GV, and it is self-consistent with the result of ATIC-CREAM and is different from the single power law spectrum. There are many theoretical discussions about this anomalous phenomenon, two of which are mainly discussed in this paper: one theory is that the abnormal hardening of the energy spectrum is caused by the nonlinear acceleration mechanism when cosmic ray particles are injected into interstellar space; The other theory holds that the energy spectrum turn is caused by the superposition of the adjacent single source energy spectrum and the background energy spectrum. In addition, we will focus on the comparison of the predictions of this anomaly for antiprotons, positron and gamma rays in these two models. We use GALPROP's cosmic ray diffusion convection model to explain the CREMA and PAMELA spectra, and then we calculate the antiprotons produced by protons and helium nuclei, as well as gamma rays. It is found that the anomalous energy spectrum does cause the antiproton and gamma ray predictions to differ between the two models. In addition, we also calculated the positron energy spectrum, and after comparison, there is a corresponding difference between the two.
【學位授予單位】：河北師范大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：P172.4

【參考文獻】

相關期刊論文 前2條

1 祝鳳榮;王瑞光;唐云秋;盧紅;陳松戰(zhàn);程寧;馮朝陽;郭義慶;石峰;王云岡;汪越;譚有恒;張慧敏;張吉龍;張毅;;羊八井太陽中子望遠鏡和中子監(jiān)測器對2005年1月20日GLE事件的探測(英文)[J];高能物理與核物理;2007年04期

2 胡紅波;;銀河宇宙線起源、加速和傳播問題的一些研究進展[J];現(xiàn)代物理知識;2011年04期

相關碩士學位論文 前1條

1 劉茂元;利用羊八井ARGO實驗研究宇宙線大尺度各向異性[D];河北師范大學;2009年

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