<div class="gmail_quote">---------- Forwarded message ----------<br>From: "Joseph Grames" <<a href="mailto:grames@jlab.org">grames@jlab.org</a>><br>Date: Dec 11, 2013 9:48 AM<br>Subject: Re: Injector question<br>
To: "Alexandre Camsonne" <<a href="mailto:camsonne@jlab.org">camsonne@jlab.org</a>><br>Cc: "Matt Poelker" <<a href="mailto:poelker@jlab.org">poelker@jlab.org</a>>, "Riad Suleiman" <<a href="mailto:suleiman@jlab.org">suleiman@jlab.org</a>><br>
<br type="attribution">Hi Alexandre,<br>
<br>
Do you have some idea of the radiation you desire? For example, x-rays of what energy? How much of a dose? Nearly all of our dumps are shielded, so it may be possible but details would help, e.g. how big are crystals, how much does is needed, is there a maximum dose you worry about, etc. Perhaps it's possible to do a beam test where we "load" a crystal at a dump, purposely dose it for X, then remove. Then there is no permanent reconfiguration of shielding or calibration of BLM's, etc.<br>
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Yes, John has done some really great things lately finding ways to easily reduce the rep rate of the laser, while maintaining good average laser power and beam quality. This is not at all like the BFM where beam was chopped and as a result average current and bunch quality suffered. Rather, the new method relies on dividing a top frequency by factors of 2. So, e.g., one can start with 998MHz, to provide 499, 249.5, 124.75, 62.375, 31.1875, and lowest attempted, 15.59375 MHz, which starts to become an issue with the fiber amplifier we presently use.<br>
<br>
What's your idea/need?<br>
<br>
Joe<br>
<br>
----- Original Message -----<br>
From: "Alexandre Camsonne" <<a href="mailto:camsonne@jlab.org">camsonne@jlab.org</a>><br>
To: "Matt Poelker" <<a href="mailto:poelker@jlab.org">poelker@jlab.org</a>>, "Riad Suleiman" <<a href="mailto:suleiman@jlab.org">suleiman@jlab.org</a>>, "Joe Grames" <<a href="mailto:grames@jlab.org">grames@jlab.org</a>><br>
Sent: Wednesday, December 11, 2013 9:38:49 AM<br>
Subject: Injector question<br>
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Hello,<br>
<br>
I have two questions about the injector.<br>
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We are looking at curing of calorimeter blocks so we would need to irradiate a few blocks and try to recover them using different light wavelength.<br>
Do you think there would be any possibility to put one block in the injector dump from time to time if you are doing injector tests ? Would have to check with radcon about radiation but if we could get onsite irradiated blocks that would be very useful for our tests.<br>
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Also there was some mentioned of the possibility of changing the beam structure more easily with the new laser, I think John mentioned that at a meeting at some point. Will that still be a possibility ? What frequency would be available ? 250 MHz 125 MHz, lower ?<br>
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Thank you,<br>
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Alexandre<br>
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