1. FFT analysis Goal : Energy calibration ( systematic error estimation)
problem
study
Ni Ka1 lower energy tail
Excess between Ni Ka and Kb
Excess between Ti Ka and Kb
Systematic mean shift in self trigger (after gain correction)
Systematic mean shift in E549 trigger
Odd-even effect
Integral / differential non-linearity
To reduce background noise(1,2,3)
FOUT cut
REF scaler (pile-up event cut)
Flash ADC
Fit method (1,2,3,4,5)
Response function
Lower tail component
Upper tail component (pile-up)
Energy calibration for short period (shift-by-shift)
data set grouping using pedestal stability
Cu contamination
Wilkinson ADC (6)
FFT analysis
Rebin = 8

2. FFT of comparator-type ADC spectrum (for all region, Nbin=4096)
Almost no “16” component
Rebin=8
All region 2
FFT 4 8
PH ADC (self) [ch]
All region
FFT
Simulated ADC spectrum (with similar statistics)
No odd-even effect.

3. FFT of comparator-type ADC spectrum (for all region, Nbin=512 Rebin=8)
PH ADC (self) [ch]
FFT
Simulated ADC spectrum
The (odd-even) effect could be
negligible with “Rebin=8”.

4. FFT of comparator-type ADC spectrum (for flat region)
SDD#1, Self triggered events,
E570 2nd cycle all data (Run# (154run))
FFT
FFT
PH ADC (self) [ch]
512 bin
Select flat region

5. No “16” component Odd-Even effect Flat region
2 (=512/256)
256
192 4 8
160
128 64
Flat region
: 3000ch ~ 3256ch (total 256 bin)
No “16” component

6. Check all SDD’s spectra (SDD#1-8)
For SDD#1 - 8
Self triggered events
E570 2nd cycle all data (Run# (154run))
Select flat region (NBIN=512, 3000<ch<3512)
Statistics  Normalized

7. SDD #1-4
SDD1
SDD2
SDD3
SDD4

8. SDD #5-8
SDD5
SDD6
SDD7
SDD8

9. Rebin = 2

10. Rebin=2, SDD #1-4

11. Rebin=2, SDD #5-8

12. Rebin = 4

13. Rebin=4, SDD #1-4

14. Rebin=4, SDD #5-8

15. Rebin = 8

16. Rebin=8, SDD #1-4

17. Rebin=8, SDD #5-8

18. For Wilkinson-type ADC

19. FFT of Wilkinson-type ADC spectrum (for all region, Nbin=4096)
(NOT low 3bits inverting)
SDD#1, Self triggered events,
E570 2nd cycle all data (Run# (154run))
2 (=512/256)
Odd-Even effect
FFT 4
No “8” component

20. FFT of Wilkinson-type ADC spectrum (for flat region)
blue : Raw spectra
Black : low 3bits inverting
SDD#1, Self triggered events,
E570 2nd cycle Run# (3run) … about 7hours
FFT
No “8” component
512 bin
Select flat region

21. Rebin = 2, 4 (w/ low 3bits inverting)
The (odd-even) effect could be
negligible with “Rebin=4”.