LB January Flux Simulations - Revision history

Brenleyt: /* 1.5 cm Diam beam */

2018-02-26T17:06:09Z

1.5 cm Diam beam

2018-02-26T16:49:26Z

1.5 cm Diam beam

2018-02-26T16:48:59Z

1.5 cm Diam beam

2018-02-26T16:40:29Z

1.5 cm Diam beam

2018-02-26T16:39:13Z

1.5 cm Diam beam

2018-01-25T19:23:46Z

2018-01-25T19:23:16Z

2018-01-25T18:28:43Z

2018-01-25T18:20:11Z

2018-01-25T18:19:18Z

@@ Line 59: / Line 59: @@
 For a 1.5cm diameter beam I was able to find a place on the nickel foil that had half as much flux as the selenium. Below is a plot of the selenium flux with both fine bins and coarse bins
+[[File:LB SeleniumFlux G4Sim 1.5cmBeam FullViewFineBins Jan2018.png|200px]]
 [[File:LB SeFluxPlot FullView 1.5cmBeam Jan2018.png|200px]]

@@ Line 54: / Line 54: @@
 ==1.5 cm Diam beam==
 Below is a more finely binned histogram so a better flux profile can be seen:
 [[File:LB NickelFlux G4Sim 1.5cmBeam FullViewFineBins Jan2018.png|200px]]
-For a 1.5cm diameter beam I was able to find a place on the nickel foil that had half as much flux as the selenium. Below is a plot of the selenium flux
+For a 1.5cm diameter beam I was able to find a place on the nickel foil that had half as much flux as the selenium. Below is a plot of the selenium flux with both fine bins and coarse bins
 [[File:LB SeFluxPlot FullView 1.5cmBeam Jan2018.png|200px]]

← Older revision		Revision as of 16:48, 26 February 2018
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	==1.5 cm Diam beam==		==1.5 cm Diam beam==
		+	Below is a more finely binned histogram so a better flux profile can be seen:
		+	[[File:LB NickelFlux G4Sim 1.5cmBeam FullViewFineBins Jan2018.png\|200px]]
		+
	For a 1.5cm diameter beam I was able to find a place on the nickel foil that had half as much flux as the selenium. Below is a plot of the selenium flux		For a 1.5cm diameter beam I was able to find a place on the nickel foil that had half as much flux as the selenium. Below is a plot of the selenium flux

← Older revision		Revision as of 16:40, 26 February 2018
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	[[File:LB NickelFlux G4Sim 1.5cmBeam FullView Jan2018.png\|200px]]		[[File:LB NickelFlux G4Sim 1.5cmBeam FullView Jan2018.png\|200px]]
		+
		+	From here we can see that the flux is half from the center at the bottom of the foil and from <math>\pm</math>10-15mm in the x position

← Older revision		Revision as of 16:39, 26 February 2018
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	<math> \frac{10309}{19207} = 0.54 </math>		<math> \frac{10309}{19207} = 0.54 </math>
		+
		+	We can also simply look at the nickel foil flux and find a region where the flux would be half as much. Below is a plot of the nickel foil
		+
		+	[[File:LB NickelFlux G4Sim 1.5cmBeam FullView Jan2018.png\|200px]]

@@ Line 1: / Line 1: @@
 Simulations were run using geant4 to try and see if the ratio of the flux between the nickel foil and the inner selenium pellet would explain why the ratios of the rates are not correct. A general particle source was used to fire electrons in a beam at a titanium beam window, which then proceeds to an aluminum/tungsten radiator. After that the particles will encounter a nickel foil followed by an aluminum sheet and finally a selenium pellet that is -0.75cm off of the beam axis (to try and replicate the location of the foil relative to the selenium pellet). The run.mac file is shown below
@@ Line 32: / Line 33: @@
 [[File:LB JanFluxSim SideView.png|200px]]
 [[File:LB JanFluxSim RotatedView.png|200px]]
 ==2.5 cm diam electron beam==

@@ Line 33: / Line 33: @@
 [[File:LB JanFluxSim RotatedView.png|200px]]
 Below are the flux plots as a function of position for the nickel foil and the selenium pellet using a 2.5cm beam diameter.
@@ Line 48: / Line 49: @@
 It could be feasible that with a 2.5cm diameter beam that if the pellet were centered at 1.5cm off beam axis in the x direction, then the flux would be half.
+==1.5 cm Diam beam==
 For a 1.5cm diameter beam I was able to find a place on the nickel foil that had half as much flux as the selenium. Below is a plot of the selenium flux

@@ Line 38: / Line 38: @@
 [[File:LB SeFlux G4Sim FullView Jan2018.png|200px]]
-Now try moving the target around until there is an area that has twice as much flux as the selenium pellet.
+Now try moving the target around until there is an area that has half as much flux as the selenium pellet.
-[[File:LB NickelFlux G4Sim Jan2018.png|200px]]
+[[File:LB NickelFlux G4Sim Zoom 2.5cmBeam Jan2018.png|200px]]
 [[File:LB SeFlux G4Sim Jan2018.png|200px]]
-We can see here that the selenium pellet has 13620 counts in it, while the selected region of the nickel foil has 26980 counts. Taking the ratio gives 0.50.
+We can see here that the selenium pellet has 13620 counts in it, while the selected region of the nickel foil has 6805 counts. Taking the ratio gives 0.50.
-If we are looking for a bin that is the size of the target that has twice the amount of counts, then that was not found with this beam diameter, so I will try smaller diameter beams as well.
+It could be feasible that with a 2.5cm diameter beam that if the pellet were centered at 1.5cm off beam axis in the x direction, then the flux would be half.

@@ Line 5: / Line 5: @@
 /gps/position 0 0 -5 m
-/gps/pos/type Plane
+/gps/pos/type Beam
 /gps/pos/shape Circle
-/gps/pos/radius 0.5 cm
+/gps/pos/radius 0.75 cm
 /tracking/verbose 2
@@ Line 17: / Line 17: @@
 /gps/verbose 2
-/gps/pos/sigma_r 0.5 cm
+/gps/pos/sigma_r 0.75 cm
 /gps/energy 32 MeV
-/run/beamOn 50000
+/run/beamOn 1000000
 The dimensions of the pieces of interest are:

← Older revision		Revision as of 18:19, 25 January 2018
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	Note that this position on the nickel foil is still at the bottom of the Aluminum cylinder, similar to where the selenium would actually be due to the fact that there was not much ash in the cylinder to raise its position in y. It would seem that if the selenium pellet were centered off the x axis by 5mm, then it would be feasible that the flux through the selenium pellet would be half.		Note that this position on the nickel foil is still at the bottom of the Aluminum cylinder, similar to where the selenium would actually be due to the fact that there was not much ash in the cylinder to raise its position in y. It would seem that if the selenium pellet were centered off the x axis by 5mm, then it would be feasible that the flux through the selenium pellet would be half.
		+
		+	The ratio of the number of photons through the selenium and the number of photons through the small area of the nickel is
		+
		+	<math> \frac{10309}{19207} = 0.54 </math>