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

Highest single pulse simulated parameters are 25mA with 100ns pulse width.

Absorbed Dose Information

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

May 31st 2018 - 25b 0 degree port