Difference between revisions of "PePPO 02222012"

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https://cebaf.jlab.org/atlis/task/12074
 
https://cebaf.jlab.org/atlis/task/12074
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 +
= JLab Wiki =
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https://positron.jlab.org/wiki/index.php/02222012_AnnihCntr_TestPlan
  
 
=Accelerator Configuration=
 
=Accelerator Configuration=
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* If I have 80% dead time, I should multiply my counts by 1/(1-80%)=5.
 
* If I have 80% dead time, I should multiply my counts by 1/(1-80%)=5.
  
 +
 +
Erica's dead time calculation:
 +
Dead time = L1A/L1
 +
 +
Erica Said
 +
L1 or Level 1 is the incoming trigger. In this case is the detector signal (or the AND, when there is a coincidende, of the 2 detector signals) used as a start.
 +
The L1A or Level 1 Accept is the signal coming from the VME CPU that tells to the rest of the electronics that it can read and accept trigger, because it is not busy processing the previous data.
 +
 +
My understand is: L1 is incoming triggers. L1A are those L1 that is accepeted (or executed).
 +
 +
So, L1A/L1 should be the live time.
 +
 +
<math>\frac{\left . \frac{L1A}{L1}\right |_{Beam on}}{\left .\frac{L1A}{L1} \right  |_{Beam off}} = \frac{0.03}{0.17} = \frac{1}{6} \Rightarrow </math> mutiply the beam on data by a factor of 6 and leave the beam off data alone
  
 
{| border="1"  |cellpadding="20" cellspacing="0  
 
{| border="1"  |cellpadding="20" cellspacing="0  
 
|-
 
|-
−
| Run#|| run mode||Beam ||Target ||Run Duration || VME discriminator Threshold (mV) || Det1 connected to || Spectrum
+
| Run#|| run mode||Beam ||Target ||Run Duration|| L1A  ||    L1    || Dead time (L1A/L1) ||Connected to || Spectrum || 511 Rate (Hz)
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|-
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| 2734||  sample || on ||  In  || 130 s      ||613861|| 20688978 || 0.0296709195 || FADC Chan#14 || [[Image:2734_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr.png | 300 px]] [[Image:2734_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr_511_Zoom.png | 300 px]] || 165.4
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|-
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| 2735||  sample || on ||  In  || 69 s        ||318135|| 11173904 || 0.0284712487 || FADC Chan#14 || [[Image:2735_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr.png | 300 px]] [[Image:2735_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr_511_Zoom.png | 300 px]] || 149.1
 
|-
 
|-
−
| 2737||  sample || off ||  Out || 466 s        ||       20      || FADC Chan#14 ||[[Image:PEPPo_22Feb2012_Anni_Det_Test_Det1_spetrum_dead_time_Corrected.png | 300 px]]  
+
| 2736||  sample || on ||  In || 73 s        ||423650|| 3961157  || 0.106951075  || FADC Chan#14 || [[Image:2736_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr.png | 300 px]] [[Image:2736_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr_511_Zoom.png | 300 px]] || 70.19
 
|-
 
|-
 +
| 2737||  sample || off||  Out  || 466 s      ||525684|| 3115913  || 0.16870946  || FADC Chan#14 || [[Image:2737_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr.png | 300 px]]        ||
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|}
  
−
|}
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[[Image:Over_Lay_PEPPo_22Feb2012_Anni_spetrum_dead_time_Corr.png | 300 px]]

Latest revision as of 04:48, 8 March 2012

Below is a beam test plan for the PePPO annihilation counters.

ATLIS task #

https://cebaf.jlab.org/atlis/task/12074

JLab Wiki

https://positron.jlab.org/wiki/index.php/02222012_AnnihCntr_TestPlan

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
Rate: 60 Hz
PEPPO Spectrometer: 151.3 A

Observe Beam spot on ITV5D03A

Record an image of the beam spot size seen by the ChroMox viewscreen.

PEPPo 22Feb2012 Anni Det Test Beam onChroMox Tar.png


https://cebaf.jlab.org/elog/entry/1666618

Turn on Annihilation Counters

Step 1: Bring up MEDM slow controls screen (skip if PEPPO screen is already up)

Skip this step if MEDM is already available on your screen

Otherwise

ssh username@opsmdaq1

type the following command to start the MEDM screen 

opsmenu

a screen appears with one button called "OPS Menu"

a submenu appears when you click on that button.

Select the "EDM" menu.

The Monticello GUI will appear

click on the Injector screen (left button") and select "PePPO overview" from the menu

Look for a menu item with the title associated with the annihilation counters


Step2: Set HV to Detectors

Set the value of the HV dac listed in the table below (0-5) which corresponds to the desired HV for Detector #1 or #2.


For example: If you set HV dac value to 2.4 for detector #1 then its HV will be set to 960 which should bring the 511 peak into range for the FADC.


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


There is on/off button for HV PS on the control menu. After setting the above HV dac values, you need to turn it on, then you will notice the display column change with a read back value.

Set FADC threshold

Login to the IOC for the FADC (on 11/7/2011 the command "telnet iocmdaq1" worked)

When logged in to the ROC for the FADC you use the function below to set the FADC threshold 

faSetThreshold(FA_SLOT,fADC_Threshold,0xffff);

On Aug of 2011 the following values worked

fADC_Theshold = 200

FA_SLOT=?


reminder
the processing mode function has the following syntax


faSetProcMode(FA_SLOT,1,280,250,3,6,1,0);

Setup CODA run configuration

If CODA is running select the run configuration

"Annih_Sample"

If CODA isn't running


go to the CODA Runcontrol GUI and check that the configuration is using "FADC"

if coda isn't running try use the information below to start it

Start CODA

Take Data

Log book entry

https://cebaf.jlab.org/elog/entry/1666585

https://cebaf.jlab.org/elog/entry/1666627

Target in

Check that the ChroMox target is in by observing a beam spot


Then start the DAQ and run for 15 minutes

Run# run mode Beam Target Trig at Run Duration VME discriminator Threshold (mV) HV1 (setting/V) HV2 (setting/V) PL (setting/ns) PTW (setting/ns) Det1 connected to Det2 connected to Spectrum 511 / Beam Current
2734 sample on In det1 130 s 20 2.4/960 3/1200 280/1120 250/1000 FADC Chan#14 Not connected 300 px 4.9 /0.3 nA = 16.33 Hz/nA 2734PEPPo 22Feb2012 Anni Det Test Det1 Tar In 511.png
2735 sample on In det1 69 s 20 2.4/960 3/1200 280/1120 250/1000 FADC Chan#14 Not connected PEPPo 22Feb2012 Anni Det Test Det1 Tar In.png 4.246 /0.3 nA = 14.15 Hz/nA 2735PEPPo 22Feb2012 Anni Det Test Det1 Tar In 511.png
2736 sample on In det1 73 s 50 2.4/960 3/1200 280/1120 250/1000 FADC Chan#14 Not connected 2636PEPPo 22Feb2012 Anni Det Test Det1 Tar In.png 7.507 / 0.3 nA = 25.023 Hz/nA 2736PEPPo 22Feb2012 Anni Det Test Det1 Tar In 511.png


http://opweb.acc.jlab.org/CSUEApps/elog/entry/1666627


We took data for the annihilation counter detectors with their own configuratio n and no fadc trheshold, but Threshold in the VME discriminator of 20mV. The detector N.1 is plugged in: fadc channel CH 14 TDC channel CH 9

/data/annihilation/

We have 2 differnt runs, one with the beam in the target of the annilitation cr oss insertet and one with no beam in the beam line.

Target out

Watch the ChroMox viewer as you move it out of position, so there is no longer a target in place.

Start a CODA run for 15 minutes


Run# run mode Beam Target Trig at Run Duration VME discriminator Threshold (mV) HV1 (setting/V) HV2 (setting/V) PL (setting/ns) PTW (setting/ns) Det1 connected to Det2 connected to pulses
2737 sample off Out det1 466 s 20 2.4/960 3/1200 280/1120 250/1000 FADC Chan#14 Not connected PEPPo 22Feb2012 Anni Det Test Det1 100k pulses.png PEPPo 22Feb2012 Anni Det Test Det1 pulse big.png PEPPo 22Feb2012 Anni Det Test Det1 pulse small.png

Data Analysis

Overlay of runs.

PEPPo 22Feb2012 Anni Count OverLay 1.png

August Det #1 measurements with a source suggest a calibration of Aug 2011 Annihilation Counter Measurements.

510.998910 keV/39652.6 integrated channel


PEPPo 22Feb2012 Anni Count OverLay Norm EnCal.png


PEPPo 22Feb2012 Anni Count OverLay Norm EnCal Log.png

PEPPo 22Feb2012 Anni Count OverLay Norm EnCal Log Zoom.png


Just plot either run 2734 or 2735 and label with the threshold value of 20 mV

Replace run 2736 label with threshold 50 mV label

Replace run 2737 label with 20 mV Background label.

Replace titles with a Date of the experiment. Label axes "MeV and Hz"

set number size 0.4 and letter sizes 0.6

PEPPo 22Feb2012 Anni Count OverLay Norm EnCal Log Zoom 2.png

Dead time correction

  • Find dead time.

Scaler:__________|-|__|-|__|-|__|-|__|-|___ 5 pulses

FADC scaler: ____________|-|_____________ 1 pulse

(5-1)/5=80% dead time.

  • If I have 80% dead time, I should multiply my counts by 1/(1-80%)=5.


Erica's dead time calculation: 

Dead time = L1A/L1

Erica Said
L1 or Level 1 is the incoming trigger. In this case is the detector signal (or the AND, when there is a coincidende, of the 2 detector signals) used as a start.
The L1A or Level 1 Accept is the signal coming from the VME CPU that tells to the rest of the electronics that it can read and accept trigger, because it is not busy processing the previous data.

My understand is: L1 is incoming triggers. L1A are those L1 that is accepeted (or executed).

So, L1A/L1 should be the live time.

[math]\frac{\left . \frac{L1A}{L1}\right |_{Beam on}}{\left .\frac{L1A}{L1} \right |_{Beam off}} = \frac{0.03}{0.17} = \frac{1}{6} \Rightarrow [/math] mutiply the beam on data by a factor of 6 and leave the beam off data alone

Run# run mode Beam Target Run Duration L1A L1 Dead time (L1A/L1) Connected to Spectrum 511 Rate (Hz)
2734 sample on In 130 s 613861 20688978 0.0296709195 FADC Chan#14 2734 PEPPo 22Feb2012 Anni spetrum dead time Corr.png 2734 PEPPo 22Feb2012 Anni spetrum dead time Corr 511 Zoom.png 165.4
2735 sample on In 69 s 318135 11173904 0.0284712487 FADC Chan#14 2735 PEPPo 22Feb2012 Anni spetrum dead time Corr.png 2735 PEPPo 22Feb2012 Anni spetrum dead time Corr 511 Zoom.png 149.1
2736 sample on In 73 s 423650 3961157 0.106951075 FADC Chan#14 2736 PEPPo 22Feb2012 Anni spetrum dead time Corr.png 2736 PEPPo 22Feb2012 Anni spetrum dead time Corr 511 Zoom.png 70.19
2737 sample off Out 466 s 525684 3115913 0.16870946 FADC Chan#14 2737 PEPPo 22Feb2012 Anni spetrum dead time Corr.png


Over Lay PEPPo 22Feb2012 Anni spetrum dead time Corr.png

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