09-08-2016: Difference between revisions
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=Study forward detector gamma flash = | |||
==with Pb curtains== | |||
{| border="1" | |||
| Run # ||D90 n Rate (Counts/pulse)|| Configuration | |||
|- | |||
|5302 || || 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''DU''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Installed 3rd collimator wall, D30 has one 1/16" thick lead curtain [[File:Rate2nC_5302.png|40px]][[File:Run5302_ToF_Histograms.png|40px]] | |||
|- | |||
|5303 || || 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is DU , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Installed 3rd collimator wall, D30 has '''NO''' lead curtain [[File:Rate2nC_5303.png|40px]][[File:Run5303_ToF_Histograms.png|40px]] | |||
|- | |||
|} | |||
==Shielding & Beam dump impact on gamma flash== | |||
{| border="1" | |||
| Run # ||D90 n Rate (Counts/pulse)|| Configuration | |||
|- | |||
|5300 || || 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to '''0.2563 cm''', Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is Empty , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,[[File:Rate2nC_5300.png|40px]][[File:Run5300_ToF_Histograms.png|40px]] | |||
|- | |||
|5301 || || 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to '0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is Empty , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand, '''Installed 3rd collimator wall''', removed line of site between D30 and cell wall collimator [[File:Rate2nC_5301.png|40px]][[File:Run5301_ToF_Histograms.png|40px]] | |||
|- | |||
|5305 || || 11.1 MeV , 2 ns pulse width , 300 mA , '''90 Hz''' , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''EMPTY''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,'''Removed 3rd collimator wall''', D30 has NO thick lead curtain, [[File:Rate2nC_5305.png|40px]][[File:Run5305_ToF_Histograms.png|40px]] | |||
|- | |||
|5306 || || 11.1 MeV , 2 ns pulse width , 300 mA , '''200 Hz''' , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, [[File:Rate2nC_5306.png|40px]][[File:Run5306_ToF_Histograms.png|40px]] | |||
|- | |||
|5307 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, [[File:Rate2nC_5307.png|40px]][[File:Run5307_ToF_Histograms.png|40px]] | |||
|- | |||
|5308 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''~0.5 mm x 7 cm x 4 mm Thorium''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, [[File:Rate2nC_5308.png|40px]][[File:Run5308_ToF_Histograms.png|40px]] | |||
|- | |||
|5312 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''EMPTY''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, Install 16" deep x24" wide x 14" high ALuminium photon''' beam dump'''. Beam upstream side of dump is 37" from wall[[File:Rate2nC_5312.png|40px]][[File:Run5312_ToF_Histograms.png|40px]] | |||
|- | |||
|5313 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace aluminium dump with a half lead brick ''' centered on 2" wide beam''' left right[[File:Rate2nC_5313.png|40px]][[File:Run5313_ToF_Histograms.png|40px]] | |||
|- | |||
|5314 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace aluminium dump with a half lead brick '''centered 4" from beam''' center [[File:Rate2nC_5314.png|40px]][[File:Run5314_ToF_Histograms.png|40px]] | |||
|- | |||
|5315 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace aluminium dump with a half lead brick '''centered 2" from beam''' center [[File:Rate2nC_5315.png|40px]][[File:Run5315_ToF_Histograms.png|40px]] | |||
|- | |||
|5316 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5316.png|40px]][[File:Run5316_ToF_Histograms.png|40px]] | |||
|- | |||
|} | |||
== Tuning impact on gamma flash== | |||
We set up a veto to create a signal that represented the second peak of the gamma flash in D270 & others. A veto pulse was created for the LED to prevent it from outputing a logic high during the first 20 ns after the beam pulse. | |||
{| border="1" | |||
| Run # ||D90 n Rate (Counts/pulse)|| Configuration | |||
|- | |||
|5309 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''EMPTY''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, '''Veto OUT'''[[File:Rate2nC_5309.png|40px]][[File:Run5309_ToF_Histograms.png|40px]] | |||
|- | |||
|5310 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, '''Veto IN'''[[File:Rate2nC_5310.png|40px]][[File:Run5310_ToF_Histograms.png|40px]] | |||
|- | |||
|} | |||
=Thorium plate rates.= | |||
{| border="1" | |||
| Run # ||D90 n Rate (Counts/pulse)|| Configuration | |||
|- | |||
|5316 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''EMPTY''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5316.png|40px]][[File:Run5316_ToF_Histograms.png|40px]] | |||
|- | |||
|5317 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is '''Thorium plate''' orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5317.png|40px]][[File:Run5317_ToF_Histograms.png|40px]] | |||
|- | |||
|5318 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open '''to 8 mm slit''', Cell side collimator '''OPEN to 7.5 cm''' , radiator 3/4" IN , Target is Thorium plate orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5318.png|40px]][[File:Run5318_ToF_Histograms.png|40px]] | |||
|- | |||
|5319 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator '''1.5" IN''' , Target is Thorium plate orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5319.png|40px]][[File:Run5319_ToF_Histograms.png|40px]] | |||
|- | |||
|5320 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is '''EMPTY''' , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5320.png|40px]][[File:Run5320_ToF_Histograms.png|40px]] | |||
|- | |||
|5321 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is '''Thorium plate''' orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5321.png|40px]][[File:Run5321_ToF_Histograms.png|40px]] Target in minus target out -> [[File:TargetInMinusOut(runs5321and5320).png|60px]] | |||
|- | |||
|5322 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is '''Empty''' orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right [[File:Rate2nC_5322.png|40px]][[File:Run5322_ToF_Histograms.png|40px]] | |||
|- | |||
|5323 || || 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is '''Empty''' orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right, 1" Al brick on end to have 4" of Al at exit of tunnel of love [[File:Rate2nC_5323.png|40px]][[File:Run5323_ToF_Histograms.png|40px]] | |||
|} | |||
=End of Run summary= | |||
#The back wall was a source of photons that can be reduced best with blinders | |||
#The ToF spectrum needs better separation between gamma flash and neutrons, Move detectors back? | |||
#The tunnel of love reduced the photon singles rate by about 10% for D120 & D150 (compare runs 5300 & 5301). | |||
#Opening the collimator slit fully caused gamma flash to appear close to the neutron ToF | |||
#Neutron singles rate in D225 was within the desired rate of 2e-3 n/pulse for a thorium plate target at 90 degrees to the beam | |||
#D30's rate decreases by a factor of three for every inch of lead shielding added to the front | |||
#pair spectrometer magnet has little impact on detector background | |||
#beam tuning may increase photon flash. | |||
#determine collimator size to produce photon cone that is contained within the photon dump (blinders) | |||
#cleanup collimator inside wall separating accelerator room and experimental cell | |||
=No target run= | |||
=Determine how many fissions per pulse.= | |||
=run 1 mg HEU to see (probably miserable) rates= | |||
=Exploratory measurements with 47% HEU.= | |||
= CFD studies= | |||
=P.S. sweep magnet in/out= | |||
= Long run on Thorium= | |||
= Long run on 1 mg HEU= | |||
=Pictures= | |||
[[Pictures(09-09-2016)]] | |||
[[2nCor_44#Run_Plan]] | [[2nCor_44#Run_Plan]] | ||
Latest revision as of 20:58, 27 September 2016
Study forward detector gamma flash
with Pb curtains
| Run # | D90 n Rate (Counts/pulse) | Configuration |
| 5302 | 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is DU , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Installed 3rd collimator wall, D30 has one 1/16" thick lead curtain  File:Run5302 ToF Histograms.png
| |
| 5303 | 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is DU , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Installed 3rd collimator wall, D30 has NO lead curtain  File:Run5303 ToF Histograms.png
|
Shielding & Beam dump impact on gamma flash
| Run # | D90 n Rate (Counts/pulse) | Configuration |
| 5300 | 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is Empty , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand, File:Run5300 ToF Histograms.png
| |
| 5301 | 11.1 MeV , 2 ns pulse width , 450 mA , 200 Hz , Accelerator side collimator open to '0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is Empty , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand, Installed 3rd collimator wall, removed line of site between D30 and cell wall collimator  File:Run5301 ToF Histograms.png
| |
| 5305 | 11.1 MeV , 2 ns pulse width , 300 mA , 90 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain,  
| |
| 5306 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain,  
| |
| 5307 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain,  
| |
| 5308 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is ~0.5 mm x 7 cm x 4 mm Thorium , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain,  
| |
| 5312 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, Install 16" deep x24" wide x 14" high ALuminium photon beam dump. Beam upstream side of dump is 37" from wall 
| |
| 5313 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace aluminium dump with a half lead brick centered on 2" wide beam left right 
| |
| 5314 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace aluminium dump with a half lead brick centered 4" from beam center  
| |
| 5315 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace aluminium dump with a half lead brick centered 2" from beam center  
| |
| 5316 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right  
|
Tuning impact on gamma flash
We set up a veto to create a signal that represented the second peak of the gamma flash in D270 & others. A veto pulse was created for the LED to prevent it from outputing a logic high during the first 20 ns after the beam pulse.
| Run # | D90 n Rate (Counts/pulse) | Configuration |
| 5309 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, Veto OUTFile:Rate2nC 5309.pngFile:Run5309 ToF Histograms.png | |
| 5310 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, Veto INFile:Rate2nC 5310.pngFile:Run5310 ToF Histograms.png |
Thorium plate rates.
| Run # | D90 n Rate (Counts/pulse) | Configuration |
| 5316 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right
| |
| 5317 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator open to 0.2563 cm, Cell side collimator OPEN to 2 cm , radiator 3/4" IN , Target is Thorium plate orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right  
| |
| 5318 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 3/4" IN , Target is Thorium plate orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right  
| |
| 5319 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is Thorium plate orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right  
| |
| 5320 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is EMPTY , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right  
| |
| 5321 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is Thorium plate orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right   Target in minus target out -> .png){kind=small}
| |
| 5322 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is Empty orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right  
| |
| 5323 | 11.1 MeV , 2 ns pulse width , 300 mA , 200 Hz , Accelerator side collimator wide open to 8 mm slit, Cell side collimator OPEN to 7.5 cm , radiator 1.5" IN , Target is Empty orthogonal to beam (90) , D30 HV changed -1550V, All other detectors at -1700 V, removed pair spectrometer magnet, poly, and stand,Removed 3rd collimator wall, D30 has NO thick lead curtain, replace half lead brick with battle ship steel 17" high 24" deep and 4" beam left right, 1" Al brick on end to have 4" of Al at exit of tunnel of love  
|
End of Run summary
- The back wall was a source of photons that can be reduced best with blinders
- The ToF spectrum needs better separation between gamma flash and neutrons, Move detectors back?
- The tunnel of love reduced the photon singles rate by about 10% for D120 & D150 (compare runs 5300 & 5301).
- Opening the collimator slit fully caused gamma flash to appear close to the neutron ToF
- Neutron singles rate in D225 was within the desired rate of 2e-3 n/pulse for a thorium plate target at 90 degrees to the beam
- D30's rate decreases by a factor of three for every inch of lead shielding added to the front
- pair spectrometer magnet has little impact on detector background
- beam tuning may increase photon flash.
- determine collimator size to produce photon cone that is contained within the photon dump (blinders)
- cleanup collimator inside wall separating accelerator room and experimental cell