網(wǎng)站地圖聯(lián)系我們English中國(guó)科學(xué)院
您現(xiàn)在的位置:首頁(yè) > 科學(xué)傳播 > 科普?qǐng)@地 > 粒子天體物理 > 宇宙射線研究的發(fā)展 > 宇宙線和伽瑪射線實(shí)驗(yàn)
空間實(shí)驗(yàn)
2010-11-15 |文章來(lái)源: | 瀏覽次數(shù):  |

對(duì)宇宙間最高能粒子進(jìn)行探測(cè)是一項(xiàng)技術(shù)挑戰(zhàn)。把儀器設(shè)備安置在高空氣球和衛(wèi)星上帶上天空進(jìn)行的天體物理觀測(cè)實(shí)驗(yàn)更加困難。如果是為了探測(cè)來(lái)自恒星和星系的X射線或γ射線輻射,這項(xiàng)技術(shù)就有很大的意義。地球大氣是這些種輻射的強(qiáng)吸收物,氣球或衛(wèi)星能使觀測(cè)在大氣以上進(jìn)行。另一方面,如果打算用這種辦法捕捉超高能宇宙射線,就必須有極大的耐心。能量高于1019eV的宇宙射線粒子,平均每年在1平方公里的面積上只落下一顆。換成空間觀測(cè),利用面積為1平方米的典型衛(wèi)星探測(cè)器攔截的話,等待100萬(wàn)年才有可能探測(cè)到1顆這類宇宙射線的粒子!

  • ACE [Advanced Composition Explorer] Mission mainly for solar particles; launched in August 1997.

  • AGILE [Astro-rivelatore Gamma a Immagini LEggero] X-ray/gamma ray mission to be launched in October 2006.

  • AMS [Alpha Magnetic Spectrometer] Detector to be flown on the International Space Station

利用強(qiáng)磁場(chǎng)和精密探測(cè)器來(lái)探測(cè)宇宙空間的反物質(zhì)和暗物質(zhì),探索和研究宇宙物理學(xué)、基本粒子物理學(xué)和宇宙演化學(xué)的一些重大和疑難問(wèn)題的阿爾法(α)磁譜儀(Alpha Magneitic Spectrom-eter,簡(jiǎn)稱AMS)的研制工作正在進(jìn)行。AMS是人類送入宇宙空間的第一個(gè)大型磁譜儀,這是美籍華裔物理學(xué)家丁肇中教授提出并領(lǐng)導(dǎo)的大型國(guó)際合作科學(xué)研究項(xiàng)目,由美國(guó)和中國(guó)等10多個(gè)國(guó)家和地區(qū)的37個(gè)科研機(jī)構(gòu)參加科研工作。

AMS由一個(gè)直徑約1.2米、高0.8米、重量約為1.85噸的圓環(huán)形永磁體產(chǎn)生均勻的平行磁場(chǎng),磁束密度約為0.15特斯拉。圓環(huán)內(nèi)安裝6層硅微調(diào)探測(cè)器,用來(lái)記錄帶電宇宙射線粒子的運(yùn)動(dòng)軌跡。一個(gè)帶正電荷的粒子在穿過(guò)磁場(chǎng)時(shí),其運(yùn)動(dòng)方向?qū)⑴c帶負(fù)電的相反。根據(jù)每層記錄下來(lái)的帶電粒子穿過(guò)的軌跡,可以推算出粒子的偏轉(zhuǎn)方向及帶電荷的大小。帶電荷量愈大,在穿過(guò)每層硅微調(diào)探測(cè)器時(shí)能量損失愈快。具有較大動(dòng)量的粒子在穿過(guò)探測(cè)器時(shí)偏轉(zhuǎn)的角度較小,從而可以估計(jì)出粒子的質(zhì)量。磁譜儀的上、下兩層還裝有閃爍體,當(dāng)粒子穿過(guò)時(shí)會(huì)發(fā)出亮點(diǎn),其亮度與粒子穿過(guò)時(shí)的能量成正比。通過(guò)上、下兩層光點(diǎn)亮度及穿過(guò)瞬間的比較,可以得出粒子能量的損失大小以及粒子穿過(guò)所需的時(shí)間。反物質(zhì)、暗物質(zhì)在磁場(chǎng)中運(yùn)動(dòng)時(shí)會(huì)表現(xiàn)出不同的特點(diǎn),因而可以探測(cè)出來(lái)。1998年6月AMS搭載美國(guó)"發(fā)現(xiàn)號(hào)"航天飛機(jī)成功地進(jìn)行了首次飛行,進(jìn)行了約10天的試驗(yàn)性探測(cè),取得了許多重大物理成果。計(jì)劃于2008年升空進(jìn)入由美、俄、西歐、日本和加拿大等國(guó)聯(lián)合研究的“國(guó)際空間站”進(jìn)行長(zhǎng)達(dá)3―5年的數(shù)據(jù)采集工作。(左圖為“發(fā)現(xiàn)號(hào)”航天飛機(jī)上的AMS)

中國(guó)在這項(xiàng)重要的研究和應(yīng)用中也作出了重要的貢獻(xiàn)。高能所等單位承擔(dān)大型永磁體系統(tǒng)的設(shè)計(jì)、研制、測(cè)試和空間環(huán)境模擬實(shí)驗(yàn)。(右圖為AMS01永磁體系統(tǒng)在北京進(jìn)行震動(dòng)實(shí)驗(yàn))

AMS二期工程中高能所參加了最重的子探測(cè)器--電磁量能器AMS-02的研制。AMS-02設(shè)計(jì)載荷要求最高、最苛刻,高能所研制的初樣成功通過(guò)了空間環(huán)境模擬試驗(yàn),達(dá)到了美國(guó)NASA的技術(shù)要求,并依據(jù)所建立的有限元模型對(duì)AMS-02作了減重,對(duì)飛行件設(shè)計(jì)方案作了相應(yīng)的修正。AMS-02飛行件主體總裝和空間環(huán)境模擬試驗(yàn)于2004年完成,通過(guò)了NASA專家的嚴(yán)格審查。中國(guó)在研制過(guò)程中掌握了數(shù)項(xiàng)國(guó)內(nèi)以往沒(méi)有成熟經(jīng)驗(yàn)的先進(jìn)試驗(yàn)技術(shù)及模擬計(jì)算修正技術(shù),獲得了很高的國(guó)際顯示度。

  • ASCA [Advanced Satellite for Cosmology and Astrophysics] (X-ray mission but with some cosmic-ray relevant results, see also here). Observations ended July 14, 2000.

  • BeppoSAX [Satellite per Astronomia X] (operational May 1996 - April 2002)

  • Chandra X-ray satellite

  • CGRO [Compton Gamma Ray Observatory] (mission terminated) with the four experiments:

    • BATSE [Burst And Transient Source Experiment]

    • OSSE [Oriented Scintillation Spectrometer Experiment]

    • Comptel [imaging Compton telescope] (also here)

    • EGRET [Energetic Gamma Ray Experiment Telescope]

  • Geotail (measures the Earth's magnetotail)

  • GLAST [Gamma ray Large Area Space Telescope] (to be launched in Oct. 2007, see also NASA page)

  • GRANAT gamma-ray satellite with several experiments (SIGMA, WATCH and others) was turned off November 27, 1998

    • SIGMA [Système d'Imagerie Gamma à Masque Aléatoire]

  • HETE [High-Energy Transient Experiment] (launch failed on 4 Nov. 1996) has a follow-up:
    HETE-2 (launched October 9, 2000).

  • IMP-8 (Interplanetary Monitoring Platform)

  • INTEGRAL [INTErnational Gamma-Ray Astrophysics Laboratory] (launched October 17, 2002)

  • NINA [New Instrument for Nuclear Analysis], a mission for low energy cosmic rays.

  • PAMELA (magnet spectrometer, launched June 15, 2006). See also here.

  • Polar (examines the Earth's magnetosphere and ionosphere)

  • Rosat X-ray satellite (ended February 12, 1999)

  • RXTE [Rossi X-ray Timing Explorer]

  • SAMPEX [Solar Anomalous Magnetospheric Particle Explorer]

  • Spectrum-X-Gamma satellite is a future mission (see also here and here)

  • Suzaku X-ray satellite (Astro-E2 mission, see also this NASA page)

  • SWIFT (gamma ray burst mission, launched November 20, 2004)

  • Ulysses (explores interplanetary space at high solar latitudes)

  • Voyager (two spacecrafts heading towards interstellar space)

  • WIND (explores solar wind and plasma processes near the earth as well as gamma-ray bursts)

  • XMM-Newton [X-ray Multi-mirror Mission] (see also pages at GSFC)

Some missions/experiments proposed or under development:

  • ACCESS [Advanced Cosmic ray Composition Experiment for the Space Station] (see also pages at U. of Maryland)

  • AGILE [Astro-rivelatore Gamma a Immagini LEggero] (a light-weight gamma-ray imager, see also here)

  • Andromeda (a coded-aperture gamma-ray telescope)

  • BLAST [Burst Locations with an Arc Second Telescope]

  • EUSO [Extreme Universe Space Observatory ] (see also under fluorescence experiments)

  • MEGA [Medium Energy Gamma-ray Astronomy]

  • OWL [Orbiting Wide-angle Light-collectors] (see also under fluorescence experiments)

For a comprehensive list of high-energy astrophysics missions see here. For a list of gamma-ray missions see also this page.


中國(guó)科學(xué)院高能物理研究所    備案序號(hào):京ICP備05002790號(hào)
地址:北京市918信箱    郵編:100049    電話:86-10-88235008    Email: ihep@ihep.ac.cn