Difference between revisions of "Niowave 11-2015"

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(Created page with "The energy deposited by electrons scattered into a 3.48 diameter stainless steel beam pipe (1.65 mm thick) from a PbBi target as a function of a uniform Solenoidal magnetic fiel…")
 
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With SS windows
 
With SS windows
 
  Positrons->Draw("sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)","evt.BeamPosMomZ>0 && evt.BeamPosPosZ>-500 && sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)<97.4/2");
 
  Positrons->Draw("sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)","evt.BeamPosMomZ>0 && evt.BeamPosPosZ>-500 && sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)<97.4/2");
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 +
Positron Collection rates with '''60 cm''' long Solenoid
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 +
{| border="1"
 +
| [[File:PositronEventWithSolenoid_09-16-15A.png|200px]]  ||[[File:PositronEventWith0.3Solenoid_09-16-15A.png|200px]] 
 +
|-
 +
| When the solenoid is 1.5 Tesla, a 10 MeV electron produces a 6.5 MeV photon that pair produces a 4.4 MeV positron and a 1 MeV electron  || Same Event but this time the solenoid is 0.3 Tesla and the positron hits the beam pipe, annihilates and makes two 511 keV photons
 +
|+ Sample Positron Production Events
 +
|}
 +
 +
{| border="1"
 +
| [[File:PositronEventWithSolenoid_09-16-15B.png|200px]]  ||[[File:PositronEventWith0.3Solenoid_09-16-15B.png|200px]] 
 +
|-
 +
| When the solenoid is set to 1.5 Tesla, a 10 MeV electron produces three photons less than 1 MeV in the target, two of them compton scatter in the beam pipe || The same event but this time the electron produces only 1 photon than ionizes in the target
 +
|+ Sample Brem event producing no positrons
 +
|}
 +
 +
 +
With SS windows
 +
Positrons->Draw("sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)","evt.BeamPosMomZ>0 && evt.BeamPosPosZ>-500 && sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)<97.4/2");
 +
 +
 +
{| border="1"
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{| border="1"
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| B-field (Tesla) || || 34.8 mm diameter pipe || 47.5 || 60.2 || 72.9 || 97.4
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|-
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| 0.0  || 0.35 || 1,2,4,4,5 || 2,3,4,4,6 || 4,4,6,7,9 || 6,8,9,10,11 || 16,14,15,16,17
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|-
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| 0.1  ||  ||225,236,250,246,249=241<math> \pm</math> 10 || 282,282,293,294,306=291<math> \pm</math> 10 || 373,366,370,364,373=369<math> \pm</math> 4 || 451,437,440,438,451=443<math> \pm</math> 7 || 602,584,563,558,570=575<math> \pm</math> 18
 +
|-
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|  0.3    ||  0.35 || 626,619,596,619,611 =614<math> \pm</math> 11|| 720,726,706,730,717=720<math> \pm</math> 9|| 871,864,840,841,834 =850<math> \pm</math> 16|| 987,968,939,943,952 =958<math> \pm</math> 20|| 1118,1106,1069,1067,1080=1088<math> \pm</math> 23
 +
|-
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| 0.6  ||  ||929,935,949,969,961=949<math> \pm</math> 17 ||1022,1031,1046,1059,1052 =1042<math> \pm</math> 15 || 1120,1130,1152,1154,1146 =1140<math> \pm</math> 15|| 1168,1184,1210,1221,1206 =1198<math> \pm</math> 21|| 1212, 1218,1240,1254,1242=1233<math> \pm</math> 18
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|-
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|  1.0  || 0.35 ||1117,1085,1083,1061,1085=1086<math> \pm</math> 20 || 1188,1154,1140,1111,1134=1145<math> \pm</math> 28||1225,1190,1178,1149,1172 =1183<math> \pm</math> 28||1243.1208,1195,1164,1184=1199<math> \pm</math> 30|| 1252,1219,1206,1178,1200=1211<math> \pm</math> 27
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|-
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|  1.5  || 0.22 ||
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|-
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|  2.0  || 0.10 ||1198,1210,1215,1223,1176=1204<math> \pm</math> 18 || 1216,1227,1235,1241,1196 =1223<math> \pm</math> 18|| 1237,1243,1252,1257,1214=1241<math> \pm</math> 17|| 1249,1252,1262,1266,1225 =1251<math> \pm</math> 16|| 1257,1262,1270,1276,1234=1260<math> \pm</math> 16
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|-
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|  4.0  || 0.002 ||
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|+
 +
|}
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 +
 +
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{| border="1"
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| [[File:PositronRates-vs-SolenoidField_10-1-15.png |200px]] 
 +
|+ Positron Rates -vs- Solenoid Field for 2mm thick PbBi target and several Beam pipe diameters
 +
|}

Revision as of 20:53, 12 April 2016

The energy deposited by electrons scattered into a 3.48 diameter stainless steel beam pipe (1.65 mm thick) from a PbBi target as a function of a uniform Solenoidal magnetic field.


B-field (Tesla) Hot Spot ([math]MeV/e^-[/math])
0.0 0.35
0.3 0.35
1.0 0.35
1.5 0.22
2.0 0.10
4.0 0.002


To convert this deposited energy per incident electron on the target to a heat load in the pipe you need to divide by the area of the pipe.

A histogram is filled with 1 cm bins along the Z axis. The surface area becomes [math]1 cm \times 2 \pi 3.48/2 = 10.933 cm^2[/math]. The beam pipe diameter assumed is 3.48 cm.

When filling the histogram binned 1 cm in Z, you should weight it by the amount of depositred energy divided by the circumference of the pipe and divided by the number of incident electrons on the target (5 million). The energy units are converted to keV by multiplying the numberator by 100 or in this case dividing by 5000 instead of 5 million.


TH1F *T00N=new TH1F("T00N","T00N",100,-1000.5,-0.5)
Electrons->Draw("evt.EoutPosZ>>T00N","evt.DepE/10.088/5000")


To convert From Mev/ e- to kW/cm^2 assuming a current of 1mA (10^-3 C/s) you

[math]\left( \frac{\mbox{MeV}}{\mbox{cm}^2 \mbox{e}^-}\right) \times \left( \frac{ \mbox{e}^-}{1.6 \times 10^{-19}\mbox{C}} \right ) \times \left( \frac{1 \times 10^{-3} \mbox{C}}{\mbox{s}} \right ) \times \left( \frac{1.6 \times 10^{-13}\mbox{W} \cdot \mbox{ s}}{\mbox{MeV} }\right )[/math]

[math]\left( \frac{\mbox{keV}}{\mbox{cm}^2 \mbox{e}^-}\right) = \left( \frac{\mbox{W} }{\mbox{cm}^2 } \right )[/math]



BeamPipeDepEmev-vs-B.png BeamPipeDepPower-vs-B.png BeamPipeDepPower-vs-lowB.png
Energy deposited (MeV) along a 1 m long beam pipe of stainless steel 1.65 mm thick.

With SS windows

Positrons->Draw("sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)","evt.BeamPosMomZ>0 && evt.BeamPosPosZ>-500 && sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)<97.4/2");

Positron Collection rates with 60 cm long Solenoid

PositronEventWithSolenoid 09-16-15A.png PositronEventWith0.3Solenoid 09-16-15A.png
When the solenoid is 1.5 Tesla, a 10 MeV electron produces a 6.5 MeV photon that pair produces a 4.4 MeV positron and a 1 MeV electron Same Event but this time the solenoid is 0.3 Tesla and the positron hits the beam pipe, annihilates and makes two 511 keV photons
Sample Positron Production Events
PositronEventWithSolenoid 09-16-15B.png PositronEventWith0.3Solenoid 09-16-15B.png
When the solenoid is set to 1.5 Tesla, a 10 MeV electron produces three photons less than 1 MeV in the target, two of them compton scatter in the beam pipe The same event but this time the electron produces only 1 photon than ionizes in the target
Sample Brem event producing no positrons


With SS windows

Positrons->Draw("sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)","evt.BeamPosMomZ>0 && evt.BeamPosPosZ>-500 && sqrt(evt.BeamPosPosX*evt.BeamPosPosX+evt.BeamPosPosY*evt.BeamPosPosY)<97.4/2");


B-field (Tesla) 34.8 mm diameter pipe 47.5 60.2 72.9 97.4
0.0 0.35 1,2,4,4,5 2,3,4,4,6 4,4,6,7,9 6,8,9,10,11 16,14,15,16,17
0.1 225,236,250,246,249=241[math] \pm[/math] 10 282,282,293,294,306=291[math] \pm[/math] 10 373,366,370,364,373=369[math] \pm[/math] 4 451,437,440,438,451=443[math] \pm[/math] 7 602,584,563,558,570=575[math] \pm[/math] 18
0.3 0.35 626,619,596,619,611 =614[math] \pm[/math] 11 720,726,706,730,717=720[math] \pm[/math] 9 871,864,840,841,834 =850[math] \pm[/math] 16 987,968,939,943,952 =958[math] \pm[/math] 20 1118,1106,1069,1067,1080=1088[math] \pm[/math] 23
0.6 929,935,949,969,961=949[math] \pm[/math] 17 1022,1031,1046,1059,1052 =1042[math] \pm[/math] 15 1120,1130,1152,1154,1146 =1140[math] \pm[/math] 15 1168,1184,1210,1221,1206 =1198[math] \pm[/math] 21 1212, 1218,1240,1254,1242=1233[math] \pm[/math] 18
1.0 0.35 1117,1085,1083,1061,1085=1086[math] \pm[/math] 20 1188,1154,1140,1111,1134=1145[math] \pm[/math] 28 1225,1190,1178,1149,1172 =1183[math] \pm[/math] 28 1243.1208,1195,1164,1184=1199[math] \pm[/math] 30 1252,1219,1206,1178,1200=1211[math] \pm[/math] 27
1.5 0.22
2.0 0.10 1198,1210,1215,1223,1176=1204[math] \pm[/math] 18 1216,1227,1235,1241,1196 =1223[math] \pm[/math] 18 1237,1243,1252,1257,1214=1241[math] \pm[/math] 17 1249,1252,1262,1266,1225 =1251[math] \pm[/math] 16 1257,1262,1270,1276,1234=1260[math] \pm[/math] 16
4.0 0.002


PositronRates-vs-SolenoidField 10-1-15.png
Positron Rates -vs- Solenoid Field for 2mm thick PbBi target and several Beam pipe diameters