PePPO 03132012

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Accelerator Configuration

Accelerator Settings
beam energy 6.8 MeV
Beam type: Electron
I_average: 0.3 nA
I_peak: 0.05[math] \mu[/math] A 0.006 duty factor
pulse width: 10 [math]\mu[/math]s (it seems on 200 [math] \mu[/math]s is possible?)
Rate: 60 Hz
PEPPO Spectrometer: 151.3 A

Set HV to Detectors

Signal channel HV dac HV (V)
Detectors #1 A1 2.4 960
Detectors #2 A2 3.0 1200

How to turn HV On


Scope Pictures

CH1: Beam Sync CH2: A1 CH3: A2

Target Pictures
No Target 1 03132012 AnnhCountScopePic.png 2 03132012 AnnhCountScopePic.png
Chromox Target 3 03132012 AnnhCountScopePic.png 4 03132012 AnnhCountScopePic.png

Annihilation Counter Runs

Signal Definitions for Trigger logic
SYNC:=60 Hz sync pulse 200 micro seconds long
Det1:= Annihilation Counter #1 (HV1)
Det2:=Annihilation Counter #2 (HV2)



Run# run mode Run length (sec) Beam Target Trig Logic VME discriminator Threshold (mV) HV1 (setting/V) HV2 (setting/V) Deadtime
2902 sample 0 e[math]^-[/math] Chromox (Det1 OR Det2) 50 2.4/960 3/1200 93.1818% [math]\pm[/math] 10.3874%
2903 sample 203 e[math]^-[/math] Empty (Det1 OR Det2) 50 2.4/960 3/1200 84.9788% [math]\pm[/math]0.106622%
2904 sample 452 e[math]^-[/math] Empty Det1 AND Det2 50 2.4/960 3/1200 12.2563% [math]\pm[/math] 2.32772%
2905 sample 556 e[math]^-[/math] Chromox Det1 AND Det2 50 2.4/960 3/1200 3.16901% [math]\pm[/math] 4.2301% Peppo-032302012-r2905-A1.png Peppo-032302012-r2905-A2.png
2908 sample 150 off out (Det1 or Det2) 50 2.4/960 3/1200 74.0667% [math]\pm[/math] 0.157206%
2909 sample 1118 off out (Det1 AND Det2) 50 2.4/960 3/1200 3.57143% [math]\pm[/math]26.9725%


data analysis

Negative Energy ?

This run 2902, Int_Ch14 histogram. Why there is negative?

Peppo-032302012-r2902-int14-negative.png

Pulses

run 2905

1st 100 puleses

PePPO-03132012-pulses-2905-1to100.png

pulse that only partially read-in:

PePPO-03132012-pulses-2905-1-pulse-cut-off.png

PePPO-03132012-pulses-2905-9th-pulse-cut-off.png

first 10 pulses, some pulses that only partially read-in:

PePPO-03132012-pulses-2905-10-pulse-cut-off.png 


looks like some pulses are only partially read-in. We need to delay signal more?

One possible cut may to determine if the signal is increasing within the first 100 - 300 $Iterations.  This would be like creating a leading edge discriminator in software.




T->Draw("CH14:Iteration$","Iteration$<300 & CH14<100","L",10,1)

looks like it just won't draw. I need to know the to way exclude that event does not satisfy "Iteration$<300 & CH14<100" requirement.

PePPO-03132012-pulses-selection-try-1.png




Why CH14 histogram is all positive, but int_14 histogram has negatives?

PePPO-03132012-pulses-2905-CH14-Hist.png

PePPO-03132012-pulses-2905-int 14-Hist.png

TF Analysis

Using the following ROOT programs

Media:03212012_T.C.txt

Media:03212012_T.h.txt


Run# run mode Run length (sec) Beam Target Trig Logic VME discriminator Threshold (mV) HV1 (setting/V) HV2 (setting/V) Deadtime
2902 sample 0 e[math]^-[/math] Chromox (Det1 OR Det2) 50 2.4/960 3/1200 93.1818% [math]\pm[/math] 10.3874%
2903 sample 203 e[math]^-[/math] Empty (Det1 OR Det2) 50 2.4/960 3/1200 84.9788% [math]\pm[/math]0.106622%
2904 sample 452 e[math]^-[/math] Empty Det1 AND Det2 50 2.4/960 3/1200 12.2563% [math]\pm[/math] 2.32772% 03212012 Ch14r2904.png
2905 sample 556 e[math]^-[/math] Chromox Det1 AND Det2 50 2.4/960 3/1200 3.16901% [math]\pm[/math] 4.2301% 03212012 Ch14r2905.png
2908 sample 150 off out (Det1 or Det2) 50 2.4/960 3/1200 74.0667% [math]\pm[/math] 0.157206%
2909 sample 1118 off out (Det1 AND Det2) 50 2.4/960 3/1200 3.57143% [math]\pm[/math]26.9725%

Run 2904 and 2905 coincidence overlay (NOT Deadtime corrected)

03212012 Coinc2904-5.png

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