中国科学技术大学：《正电子物理》课程教学讲稿（正电子在材料科学中的应用）06 正电子技术及其发展（正电子技术的发展）

三、正电子技术的发展 口数字化 口大型综合化 口平台化

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໻ൟ ࣪ৄᑇ

1探测技术数字化 ●数字示波器 ●数据采集卡

1.᥶⌟ᡔᴃ᭄ᄫ࣪ ᭄ᄫ⼎⊶఼ ᭄᥂䞛䲚व

用数字示波器做采集卡 Digital measurement of positron lifetime K.Rytsola,J.Nissila,J.Kokkonen,A.Laakso,R.Aavikko,K.Saarinen Laboratory of Phrysies,Heisinki Universiry of Technology.P.O.Box 1100.FIN-02015 HUT.Espoo.Finland Applied Surface Science 194 (2002)260-263 e e

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Dynode Dynode Anode Start d Stop Anode [ Delay Pulse combiner Input Oscilloscope Ethernet Pc Trigger Disc Coinc Disc Fig.1.Schematic diagram of a 'first generation'digital positron lifetime spectrometer. e

Detector: Plastic 30 X 20mm3 cylindrial scintillators Philips XP2020 PMT Digital oscilloscope Tektronix TDS 3052,5GS/s,500MHz) Pulses at 200 ps intervals,leading into about 100 samples per pulse

Detector: Plastic φ30h20mm3 cylindrial scintillators Philips XP2020 PMT Digital oscilloscope Tektronix TDS 3052, 5GS/s, 500MHz) Pulses at 200 ps intervals, leading into about 100 samples per pulse.

2.0x105 250 1.5 200 1.0 150 100 0.5 50 0.0 0 2040 60 80 100 0 20 40 60 80 100 TIME (ns) TIME(ns) Fg.()A typical itid iftim vent captured by the sils.About 15sampes areolcted ithn the rise tme of the pulse. Thetimng noation isextracted from theitied pulses by oseation with a mode pue,the res of which is given n(b). The positron lifetme is then calculated as a timeifference between the peak postions

Time resolution Electronics time resolution:33ps Total time resolution:203ps,for 50%Co windows Counts:15/s

Time resolution Electronics time resolution:33ps Total time resolution: 203ps, for 50%Co windows Counts: 15/s

10 m 10 bulk Si Bulk Si ● as measured 109 source corrections 218ps and background subtracted 10 10 008 TuTTT 10 D 毛 DpD直DoID 10 -1 0 2 3 4 TIME (ns)

Bulk Si 218ps

A new positron lifetime spectrometer using a fast digital oscilloscope and BaF2 scintillators H.Saito.*,Y.Nagashima2,T.Kurihara,T.Hyodo Institute of Physics,Graduate School of Arts and Sciences,University of Tokyo,3-8-1 Komaba Meguro-ku,Tokyo,153-8902 Japan Institute of Materials Structure Science,High Energy Accelerator Research Organization(KEK).1-1.O-ho,Tsukuba-shi,Ibaragi. 305-0801 Japan Nuclear Instruments and Methods in Physics Research A 487(2002)612-617 e

Detector system Hamamatsu H3378(R2083Q)+BaF2, oneΦ28×20，twoΦ28×10 ■ Digital oscillocsope:LeCroy Wavepro 960 4GS/s,2GHZ,4channels in

Detector system Hamamatsu H3378(R2083Q)+BaF2, one φ28h20, two φ28h10 Digital oscillocsope: LeCroy Wavepro 960 4GS/s, 2GHz, 4channels in.