Linac Run Plan April 2018, Dr. McNulty

Beam Line info

0 degree line

Aluminum window = 0.5mm thick. Radius = 23.813mm

Air gap between Aluminum window and glass slide = 45mm

Glass slide Thickness = 1mm

Run Plan

To find operating point

- Will use 15 OSLs from reproducibility study to make sure that dose is within acceptable range

Experiment

85 Nanodot OSLs for use (dose not include OSLs from reproducibility study)

- upper limit of OSLs is 15Gy, want to be around 7.5Gy with multiple pulses

Machine: 25b Linac

Beam Energy: 8 MeV

Rep Rate: Max (150Hz)

Will talk to engineers about double pulsing and guaranteeing number of pulses and update.

Shot #	Start Time	End Time	Number of Pulses	Number of OSLs	Distance to end of beampipe	Beam Current	Aluminum Brick
1	7:00am	7:05am	2	1	1m	5 mA	Out
2	7:10am	7:15am	2	1	1m	10 mA	Out
3	7:20am	7:25am	2	1	1m	25 mA	Out
4	7:30am	7:35am	2	1	1m	50 mA	Out
5	7:40am	7:45am	2	1	1m	25 mA	Out
6	7:50am	7:55am	2	1	1m	25 mA	Out
7	8:00am	8:05am	2	16	1m	25 mA	In
8	8:10am	8:15am	2	16	1m	25 mA	In
9	8:20am	8:25am	2	16	1m	25 mA	Out
10	8:30am	8:35am	2	16	1m	25 mA	Out
11	8:40am	8:45am	2	16	1m	25 mA	Out

Absorbed Dose Information

100mA, 100ns pulse width, 25cm from beam pipe

Assuming [math]100\frac{mA}{pulse}[/math] and a pulse width of [math]100ns[/math]

Then [math]100\frac{mA}{pulse}=100\frac{mC}{s*pulse}=0.1\frac{C}{s*pulse}[/math]

[math]0.1\frac{C}{s*pulse}(100ns)=10*10^{-9}\frac{C}{pulse}[/math]

[math]10*10^{-9}\frac{C}{pulse}*\frac{1\ e-}{1.602*10^{-19}}=6.2422*10^{10}\frac{e-}{pulse}[/math]

Using a distance of 25cm for all simulations following.

OSL

[math]\frac{1}{1000}[/math] of a pulse. ~62mil e- simulated, ~62bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]4.46596*10^{6} MeV[/math]

OSL geometry: 0.501cm diameter cylinder of 0.03cm thickness with beam incident on flat face.

OSL Crystal density[math]=3.9698\frac{g}{cm^{3}}[/math]

Mass of a single OSL crystal: [math](\pi(0.2505)^{2}*(0.03))*(3.9698)=0.0234777g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]4.46596*10^{9} MeV[/math]

Converting to Joules for dose calculation: [math]4.46596*10^{9} MeV=7.15525*10^{-4}J[/math]

Average dose per pulse [math]\frac{7.15525*10^{-4}J}{0.0234777*10^{-3}\ Kg}=30.4768\ Gy=3047.68\ rad[/math]

Quartz

[math]\frac{1}{1000}[/math] of a pulse. ~62mil e- simulated, ~62bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]4.71875*10^{8} MeV[/math]

Quartz Geometry: 1 inch cylinder with electrons incident upon the base of the cylinder.

Quartz density[math]=2.32\frac{g}{cm^{3}}[/math]

Mass of Quartz used in simulation: [math](\pi(1.27)^{2}*(2.54))*(2.32)=29.8593g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]4.71875*10^{11} MeV[/math]

Converting to Joules for dose calculation: [math]4.71875*10^{11} MeV=0.0756027J[/math]

Average dose per pulse [math]\frac{0.0756027\ J}{29.8593*10^{-3}\ Kg}=2.53196\ Gy=253.196\ rad[/math]

25mA, 100ns pulse width, 25cm from beam pipe

Cut current by a factor of 4. 100mA->25mA

Assuming [math]25\frac{mA}{pulse}[/math] and a pulse width of [math]100ns[/math]

Then [math]25\frac{mA}{pulse}=25\frac{mC}{s*pulse}=0.025\frac{C}{s*pulse}[/math]

[math]0.025\frac{C}{s*pulse}(100ns)=2.5*10^{-9}\frac{C}{pulse}[/math]

[math]2.5*10^{-9}\frac{C}{pulse}*\frac{1\ e-}{1.602*10^{-19}}=1.56055*10^{10}\frac{e-}{pulse}[/math]

Using a distance of 25cm for all simulations following.

OSL

[math]\frac{1}{1000}[/math] of a pulse. ~15mil e- simulated, ~15bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]1.11636*10^{6} MeV[/math]

OSL geometry: 0.501cm diameter cylinder of 0.03cm thickness with beam incident on flat face.

OSL Crystal density[math]=3.9698\frac{g}{cm^{3}}[/math]

Mass of a single OSL crystal: [math](\pi(0.2505)^{2}*(0.03))*(3.9698)=0.0234777g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]1.11636*10^{9} MeV[/math]

Converting to Joules for dose calculation: [math]1.11636*10^{9} MeV=1.78841*10^{-4}J[/math]

Average dose per pulse [math]\frac{1.78841*10^{-4}J}{0.0234777*10^{-3}\ Kg}=7.61748\ Gy=761.748\ rad[/math]

Quartz

[math]\frac{1}{1000}[/math] of a pulse. ~15mil e- simulated, ~15bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]9.82027*10^{7} MeV[/math]

Quartz Geometry: 1 inch diameter, 0.5 inch tall cylinder with electrons incident upon the base of the cylinder.

Quartz density[math]=2.32\frac{g}{cm^{3}}[/math]

Mass of Quartz used in simulation: [math](\pi(1.27)^{2}*(1.27))*(2.32)=14.9296g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]9.82027*10^{10} MeV[/math]

Converting to Joules for dose calculation: [math]9.82027*10^{10} MeV=0.0157321J[/math]

Average dose per pulse [math]\frac{0.0157321\ J}{14.9296*10^{-3}\ Kg}=1.05375\ Gy=105.375\ rad[/math]

25mA, 100ns pulse width, 50cm from beam pipe

Changed distance from end of beam pipe from 25cm to 50cm.

Cut current by a factor of 4. 100mA->25mA

Assuming [math]25\frac{mA}{pulse}[/math] and a pulse width of [math]100ns[/math]

Then [math]25\frac{mA}{pulse}=25\frac{mC}{s*pulse}=0.025\frac{C}{s*pulse}[/math]

[math]0.025\frac{C}{s*pulse}(100ns)=2.5*10^{-9}\frac{C}{pulse}[/math]

[math]2.5*10^{-9}\frac{C}{pulse}*\frac{1\ e-}{1.602*10^{-19}}=1.56055*10^{10}\frac{e-}{pulse}[/math]

OSL

[math]\frac{1}{1000}[/math] of a pulse. ~15mil e- simulated, ~15bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]9.29701*10^{5} MeV[/math]

OSL geometry: 0.501cm diameter cylinder of 0.03cm thickness with beam incident on flat face.

OSL Crystal density[math]=3.9698\frac{g}{cm^{3}}[/math]

Mass of a single OSL crystal: [math](\pi(0.2505)^{2}*(0.03))*(3.9698)=0.0234777g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]9.29701*10^{8} MeV[/math]

Converting to Joules for dose calculation: [math]9.29701*10^{8} MeV=1.48938*10^{-4}J[/math]

Average dose per pulse: [math]\frac{1.48938*10^{-4}J}{0.0234777*10^{-3}\ Kg}=6.34381\ Gy=634.381\ rad[/math]

Quartz

[math]\frac{1}{1000}[/math] of a pulse. ~15mil e- simulated, ~15bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]9.21601*10^{7} MeV[/math]

Quartz Geometry: 1 inch diameter, 0.5 inch tall cylinder with electrons incident upon the base of the cylinder.

Quartz density[math]=2.32\frac{g}{cm^{3}}[/math]

Mass of Quartz used in simulation: [math](\pi(1.27)^{2}*(1.27))*(2.32)=14.9296g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]9.21601*10^{10} MeV[/math]

Converting to Joules for dose calculation: [math]9.21601*10^{10} MeV=0.0147657J[/math]

Average dose per pulse [math]\frac{0.0147657\ J}{14.9296*10^{-3}\ Kg}=0.98902\ Gy=98.902\ rad[/math]

25mA, 100ns pulse width, 50cm from beam pipe, tungsten target with aluminum beamstop

Added .254cm of Tungsten and 2.286cm of Aluminum to be used as converter and beam stop.

Assuming [math]25\frac{mA}{pulse}[/math] and a pulse width of [math]100ns[/math]

Then [math]25\frac{mA}{pulse}=25\frac{mC}{s*pulse}=0.025\frac{C}{s*pulse}[/math]

[math]0.025\frac{C}{s*pulse}(100ns)=2.5*10^{-9}\frac{C}{pulse}[/math]

[math]2.5*10^{-9}\frac{C}{pulse}*\frac{1\ e-}{1.602*10^{-19}}=1.56055*10^{10}\frac{e-}{pulse}[/math]

OSL (8MeV)

[math]\frac{1}{1000}[/math] of a pulse. ~15mil e- simulated, ~15bil e- per pulse. With beam parameters given above.

Deposited Energy: [math]19.1759 MeV[/math]

OSL geometry: 0.501cm diameter cylinder of 0.03cm thickness with beam incident on flat face.

OSL Crystal density[math]=3.9698\frac{g}{cm^{3}}[/math]

Mass of a single OSL crystal: [math](\pi(0.2505)^{2}*(0.03))*(3.9698)=0.0234777g[/math]

Scaling deposited energy by 1000 to account for only shooting a 1000th of a pulse, the deposited energy becomes [math]9.29701*10^{8} MeV[/math]

Converting to Joules for dose calculation: [math]19.1759*10^{3} MeV=3.0723177*10^{-9}J[/math]

Average dose per pulse: [math]\frac{3.0723177*10^{-9}J}{0.0234777*10^{-3}\ Kg}=0.000130861\ Gy=0.0130861\ rad[/math]

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Thesis