[Halld-tagger] Diamonds for fall

[Richard Jones]

Hovanes,

Currently mounted in the goniometer, we still have one 50 micron diamond
untouched. Plus we have the 17 micron diamond which we are testing now
during this run, which I believe to be perhaps our best option for running
in the fall. The one that is untouched is named JD70-105. Its rocking
curves when measured before it ever saw e- beam was virtually identical to
the original rocking curve widths for JD70-100, the one that has now
degraded after running in GlueX pretty much continuously from December 2016
- present.

For the future, we have 4 more 50um diamonds that we need to remove from
their defective mounts and remount using a refined gluing technique. This
remount will be done this summer, in preparation for anticipated beam time
at CLS next fall. I think it would also be useful to have JD70-100 removed
from the goniometer and delivered to UConn so that we can take it to CLS
and measure the radiation damage effects. This will be a great help in
projecting the supply of radiators that we will need, moving into the
high-luminosity era.

On Fri, Apr 20, 2018 at 4:01 PM, Hovanes Egiyan <hovanes at jlab.org> wrote:

> Hi Richard,
>
> You probably were following the change of shape of the coherent edge of
> JD70-100
> diamond over this run. Now it is on the second spot (in reality there were
> really four spots,
> two for 0/90 and two 45/135), and the edge It is getting shallow again. Do
> we have more 50um diamonds
> that are measured and are good? As I remember, the results from your last
> run were not so good.
> Do you have plans to get more measured for coming fall?
>
> Cheers,
>     Hovanes.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/halld-tagger/attachments/20180420/0172d8c4/attachment.html>