Experimental Methods and Setup
A custom run plan was created to test simulated dose per pulse results. This run plan began with an attempt to show reproducibility. To find how reproducible the OSLs are, a single OSL is placed in the center of the beam spot of the 25b accelerator at the IAC. The IAC engineers set up the centered laser for experimental use, and using a glass plate placed at 50cm, to be used as a backing plate, OSLs were exposed to a differing number of pulses under the same beam characteristics. These characteristics are as follows:
- Beam energy: 8 Mev
- Pulse width: 500ns
- Peak current: 50mA.
Shot # Number of Pulses Number of OSLs Dose (Rad) (0,0) Dose/pulse (Rad) (0,0) Al Brick with W Converter Expected Dose/pulse (Rad) 1 6 1 768.10344 128.017 Out 2 6 1 795.26442 132.544 Out 3 6 16 - Off Center Out - 4 6 17 592.89645 98.816075 Out 5 6 1 1435.75504 239.292 Out 6 2 1 468.28238 234.141 Out 7 4 1 842.87814 210.719 Out 8 5 1 1062.99342 212.598 Out 9 3 1 646.63748 215.545 Out 10 6 17 796.48564 199.12141 Out 11 51948 17 531.9275 .01023961461 In 12 52106 17 541.85896 .01039916631 In 13 6 1
Through this run plan, dose per pulse measurements are taken. As the OSLs have a maximum operating point at 1500 Rad, it was decided to keep the dose in the middle of the operating range. With the listed beam characteristics, six unattenuated pulses is the maximum possible to subject the OSLs to without saturating the OSLs.
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- The point of the electrons was to find dose/pulse information on-axis of the accelerator to help find total dose for quartz. This information was then used to irradiate some quartz and ABS plastic samples to a known dose, to allow for rad hard tests. Along with structural integrity tests in the plastic. (transparency in quartz).
Once the initial singles and arrays of OSLs had been dosed by the electron beam, a one inch thick Aluminum brick was placed at the end of the beam pipe. Further down the beam line, a sweeping magnet was inserted to redirected all charged particles away from the next set of OSLs. Using the aluminum brick as a converter and beam stop, a photon beam was formed.