1. T2K Run8 MUMON Summary

2. troubles, setting changes
proton beam bunch width increased
from run : timing offset adjusted
frequent timing error
run : timing fix applied
timing module replacement, delay changed by 15ns
from run : timing offset adjusted
IC attenuator 0dB  6dB
from Run710098
EMTs installed
ver.2, 3 : from Run71
ver.4 : from run74

3. history plots Run70,72,73,74 Run71 BSD files BSD is not reprocessed
use updated one instead of BSD

4. profile center X stable within 2 cm Si & IC are consistent
anti-correlation w/ proton beam position

5. profile center Y stable within 3 cm Si & IC are consistent
anti-correlation w/ proton beam position

6. SSEM – Si correlation w/ angle corr.

7. profile width X 2~3 cm fluctuation Si & IC are consistent
correlated w/ proton beam width

8. profile width Y 2~3 cm fluctuation Si & IC are consistent
correlated w/ proton beam width

9. Si/CT history Horn PS current correction works very well
w/ Horn PS correction
Horn PS current correction works very well
slightly decreasing after the correction ?

10. IC/CT history Horn PS current correction works very well
w/ Horn PS correction
calibration run
(IC is 25cm displaced)
attenuator
0dB  6dB
Horn PS current correction works very well
slightly increasing after the correction ?

11. Si/IC history
IC attenuator
0dB  6dB
Si / IC is gradually decreasing

12. investigation of Si yield decrease

13. run by run mean value history
use run>= ( IC attenuator setting change )
same vertical scales (2% full range)

14. run by run mean value history
use run>= ( IC attenuator setting change )
linear decrease  can be a radiation damage
degradation rate ~ 1% / 5x1020 POT

15. bunch by bunch yield 1st bunch yield is decreasing faster
1st bunch 2nd bunch
3rd bunch 4th bunch
5th bunch 6th bunch
7th bunch 8th bunch
1st bunch yield is decreasing faster
suggesting increase of tail (slow) component
IC 8th bunch is saturating
as beam power increase

16. proton beam bunch width
bunch width affects Si/CT or Si/IC
checked CT pulse width
50% of peak
FWHM
10% of peak
rise time
decay time

17. proton beam bunch width
drastic change on Nov.24 (run071058)
variation after run71 is not monotonically
cannot be a main reason of
Si yield decrease

18. waveform comparison selected runs which have similar CT5 pulse width
1st bunch waveform normalized by CT5 1st bunch ppp
averaged waveform (~1300shots), timing adjusted
Run
date
power
CT5
FWHM
rise time
710229
Dec. 16
430 kW
94.8 ns
66.0 ns
720053
Jan. 17
440 kW
96.4 ns
66.5 ns
730034
Mar. 13
96.2 ns
65.7 ns
740035
Apr. 9
450 kW
95.2 ns
65.1 ns

19. CT5 waveform
run710229
run720053
run730034
run740035

20. IC center ch waveform
run710229
run720053
run730034
run740035

21. Si center ch waveform
run710229
run720053
run730034
run740035
pulse height of Si signal is gradually decreasing

22. backup