1. WORK
08 01 江柔婷

2. What did I do?
Simple technique for determining the mean life of the cosmic ray mu meson
Muon physics
Measurement of the flux of sea-level cosmic ray
others

3. muon Two ways for a muon to disappear
Absorption of a stopped muon by scintillator nuclei is proportional to Z4
Measure with instrument v.s. the free space
μ- +p n+ ν μ

4. Just do it more!

5. Try it! Flux( muon) ~ Flux( cosmic ray) = 1 per min. per cm2
Scintillator area = 750 cm2 , # count per 60sec.,total count 750

6. Try it! Plateau: S1, S2 Threshold(s2, s3), befor coincidence,
# count : s3 (OK) ;
s2 (OVER)
S1 : 1000 v ,-100 mv
S2 : 1000 v ,-100 mv
S3 : 800 v ,-100 mv

7. Try it! PMT1 Discriminater Counter High Voltage Oscilloscope S1 S2 S3
Coincidence

8. Try it! Result (# count per 60 sec.): S1, S3 560.5 23.363
S1, S2, S - + - + - +

9. Delay check
Function
generator
Fan out x
oscilloscope

10. Delay check
Cable (color)
Model delay : 10ns

11. Perl
目標 : 實驗結果中挑選符合條件的值，再分類做圖，fitting得到關係式。
To be continued!