光電(dian)倍增管（PMT）是(shi)一種高靈敏度(du)和(he)超快時間響(xiang)應光探測器。典型(xing)的光電(dian)倍增管，如圖所示在真(zhen)空管，包括(kuo)光電(dian)發射陰極(ji)（光電(dian)陰極(ji)）和(he)聚焦電(dian)極(ji)、電(dian)子倍增，電(dian)子收集極(ji)（陽極(ji)）裝置。

　　光(guang)(guang)電(dian)倍(bei)增管在(zai)可以(yi)檢測(ce)紫外(wai)、可見光(guang)(guang)和近(jin)紅外(wai)線光(guang)(guang)電(dian)探(tan)測(ce)器的輻(fu)射能(neng)量的高靈敏度(du)和低(di)噪聲。光(guang)(guang)電(dian)倍(bei)增管和快速響應，低(di)背景、大面積陰極等。

　　根據光(guang)(guang)電(dian)(dian)(dian)效應(ying)，二次(ci)電(dian)(dian)(dian)子(zi)發射和電(dian)(dian)(dian)子(zi)光(guang)(guang)學的(de)(de)原理，透明(ming)真(zhen)空內(nei)殼配備特殊(shu)電(dian)(dian)(dian)極的(de)(de)裝置。光(guang)(guang)電(dian)(dian)(dian)陰極的(de)(de)作用下(xia)光(guang)(guang)子(zi)發射電(dian)(dian)(dian)子(zi)，這些電(dian)(dian)(dian)子(zi)被外部電(dian)(dian)(dian)場(chang)或(huo)磁(ci)場(chang)加速、聚(ju)焦在(zai)(zai)電(dian)(dian)(dian)線桿上的(de)(de)**次(ci)。影響(xiang)時間極電(dian)(dian)(dian)子(zi)可以(yi)讓時間來釋放更(geng)多的(de)(de)電(dian)(dian)(dian)子(zi)，它們是集中(zhong)在(zai)(zai)第二。所(suo)以(yi)，一般在(zai)(zai)超過(guo)十次(ci)乘(cheng)法、放大可以(yi)達到108 ~ 1010。*后，在(zai)(zai)高壓陽極收集的(de)(de)光(guang)(guang)電(dian)(dian)(dian)流放大。直接(jie)成(cheng)正比的(de)(de)輸出電(dian)(dian)(dian)流和光(guang)(guang)子(zi)數。整個過(guo)程(cheng)大約10到8秒。

圖1為光電(dian)(dian)倍(bei)(bei)增(zeng)(zeng)管(guan)(guan)原(yuan)理圖，它由光電(dian)(dian)陰極(ji)(ji)(ji)(ji)(ji)(ji)。若干倍(bei)(bei)增(zeng)(zeng)極(ji)(ji)(ji)(ji)(ji)(ji)和(he)陽(yang)極(ji)(ji)(ji)(ji)(ji)(ji)三部分組成(cheng)。光電(dian)(dian)陰極(ji)(ji)(ji)(ji)(ji)(ji)由銻艷材料制成(cheng)倍(bei)(bei)增(zeng)(zeng)極(ji)(ji)(ji)(ji)(ji)(ji)是在(zai)(zai)鎳(nie)或銅(tong)的(de)村底上涂上銻銫材料而形成(cheng)的(de)，倍(bei)(bei)增(zeng)(zeng)極(ji)(ji)(ji)(ji)(ji)(ji)數為10~30級，陽(yang)極(ji)(ji)(ji)(ji)(ji)(ji)所收(shou)集電(dian)(dian)子在(zai)(zai)外(wai)電(dian)(dian)路形成(cheng)電(dian)(dian)流輸(shu)出。光電(dian)(dian)倍(bei)(bei)增(zeng)(zeng)管(guan)(guan)在(zai)(zai)各個倍(bei)(bei)增(zeng)(zeng)極(ji)(ji)(ji)(ji)(ji)(ji)和(he)陽(yang)極(ji)(ji)(ji)(ji)(ji)(ji)均加上電(dian)(dian)壓，陰極(ji)(ji)(ji)(ji)(ji)(ji)K電(dian)(dian)位min，倍(bei)(bei)增(zeng)(zeng)極(ji)(ji)(ji)(ji)(ji)(ji)D1 ，D2 的(de)、D3.。的(de)電(dian)(dian)位依次升高，陽(yang)極(ji)(ji)(ji)(ji)(ji)(ji)A電(dian)(dian)位max。

圖1

　射在陰極(ji)(ji)上(shang)的(de)(de)(de)(de)光(guang)激發(fa)出光(guang)電(dian)子(zi)(zi)(zi)(zi)(zi)，由于倍(bei)(bei)增(zeng)極(ji)(ji)D電(dian)位存在高于陰極(ji)(ji)電(dian)位，因此這些光(guang)電(dian)子(zi)(zi)(zi)(zi)(zi)被進行加速(su)(su)，并轟擊(ji)倍(bei)(bei)增(zeng)極(ji)(ji)D，倍(bei)(bei)增(zeng)極(ji)(ji)D受到一(yi)(yi)定能(neng)量的(de)(de)(de)(de)電(dian)子(zi)(zi)(zi)(zi)(zi)轟擊(ji)后(hou)，能(neng)放出更多的(de)(de)(de)(de)電(dian)子(zi)(zi)(zi)(zi)(zi)（稱為(wei)(wei)二二次(ci)(ci)(ci)(ci)電(dian)子(zi)(zi)(zi)(zi)(zi)）。由于每(mei)個倍(bei)(bei)增(zeng)極(ji)(ji)設計成(cheng)能(neng)充分接受前一(yi)(yi)極(ji)(ji)的(de)(de)(de)(de)二次(ci)(ci)(ci)(ci)電(dian)子(zi)(zi)(zi)(zi)(zi)的(de)(de)(de)(de)幾何形狀和在各個倍(bei)(bei)增(zeng)極(ji)(ji)D.+1和倍(bei)(bei)增(zeng)極(ji)(ji)D.之間都存在正電(dian)壓(ya)，每(mei)一(yi)(yi)次(ci)(ci)(ci)(ci)轟擊(ji)都會(hui)產(chan)生(sheng)更多的(de)(de)(de)(de)二次(ci)(ci)(ci)(ci)電(dian)子(zi)(zi)(zi)(zi)(zi)。 設第一(yi)(yi)倍(bei)(bei)增(zeng)極(ji)(ji)有。個二次(ci)(ci)(ci)(ci)電(dian)子(zi)(zi)(zi)(zi)(zi)發(fa)出，這o個電(dian)子(zi)(zi)(zi)(zi)(zi)經(jing)過(guo)n次(ci)(ci)(ci)(ci)加速(su)(su)和轟擊(ji)加速(su)(su)后(hou)，產(chan)生(sheng)的(de)(de)(de)(de)電(dian)子(zi)(zi)(zi)(zi)(zi)數(shu)為(wei)(wei)o。構成(cheng)倍(bei)(bei)增(zeng)極(ji)(ji)的(de)(de)(de)(de)材料的(de)(de)(de)(de)a=3~6，設o=4，當n= 20時，則放大倍(bei)(bei)數(shu)為(wei)(wei)4，可見光(guang)電(dian)信增(zeng)管的(de)(de)(de)(de)放大倍(bei)(bei)數(shu)是很高的(de)(de)(de)(de)。

　光電倍增管的組成
　　光電(dian)(dian)(dian)(dian)(dian)倍(bei)增管(guan)由(you)入(ru)(ru)射(she)窗(chuang)、光電(dian)(dian)(dian)(dian)(dian)陰極(ji)、電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)光學輸入(ru)(ru)系(xi)統(tong)(tong)、倍(bei)增系(xi)統(tong)(tong)、陽(yang)(yang)極(ji)等部分(fen)組成(cheng)。它(ta)的(de)工作原理是建立在光電(dian)(dian)(dian)(dian)(dian)效應、二次(ci)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)發射(she)和電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)光學的(de)理論(lun)基礎上。它(ta)的(de)工作過程是光子(zi)(zi)(zi)(zi)入(ru)(ru)射(she)到光陰極(ji)上產生光電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)，光電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)通過電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)光學系(xi)統(tong)(tong)（聚(ju)焦系(xi)統(tong)(tong)），進(jin)入(ru)(ru)倍(bei)增系(xi)統(tong)(tong)，電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)得(de)到倍(bei)增，通過陽(yang)(yang)極(ji)把電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)收(shou)集起來，形成(cheng)陽(yang)(yang)極(ji)電(dian)(dian)(dian)(dian)(dian)流或電(dian)(dian)(dian)(dian)(dian)壓輸出。光電(dian)(dian)(dian)(dian)(dian)倍(bei)增管(guan)典(dian)型結構如(ru)圖2所示。

圖2

　光(guang)電(dian)(dian)倍(bei)增(zeng)管通(tong)(tong)常(chang)(chang)分為端(duan)(duan)窗(chuang)式（Head-on）和(he)側窗(chuang)式（ Side-on ）兩大類型，如圖3所示。端(duan)(duan)窗(chuang)式光(guang)電(dian)(dian)倍(bei)增(zeng)管是(shi)(shi)通(tong)(tong)過管殼頂部接(jie)受入射光(guang)，其對(dui)應的陰極結(jie)構(gou)形式通(tong)(tong)常(chang)(chang)為透(tou)(tou)射式（半透(tou)(tou)明）光(guang)陰極，在石(shi)油測井(jing)中通(tong)(tong)常(chang)(chang)使用這種類型光(guang)電(dian)(dian)倍(bei)增(zeng)管。側窗(chuang)式光(guang)電(dian)(dian)倍(bei)增(zeng)管是(shi)(shi)通(tong)(tong)過管殼側面接(jie)受入射光(guang)，其對(dui)應的陰極結(jie)構(gou)形式通(tong)(tong)常(chang)(chang)是(shi)(shi)反射式（不透(tou)(tou)明）光(guang)陰極。

圖3

（來源：網(wang)站，版權歸原(yuan)作(zuo)者）