Re: 2 points to remember

[Richard Jones <richard.t.jones@uconn.edu>]

Members of the GlueX photon beam working group,

Our next biweekly meeting is coming up this Thursday morning at 9:30am 
EST.  We now have updated drawings for the tagger hall to review, space 
considerations in the region of the tagger vacuum exit window for 
installation and removal of the thin window protection plate during 
servicing of the hodoscopes, updates on the tagger background rates from 
Sascha, two issues raised by Jim (see below), and plans for the April 
run at CHESS.  I will put together an agenda page on the wiki tomorrow, 
to which anyone can add items that they would like to see raised.

Richard Jones


Jim Stewart wrote:
> Hello Richard
>
> I would like to add 2 items to the list we should think about.
>
>
> The active collimator will be mounted on a table which is movable with 
> 2 stepping motors. The stepping motors can put out a lot of noise as 
> they are typically driven with square wave pulses. When we check the 
> active collimator next we need to try to run a stepping motor in the 
> area to see if we have to deal with RF pickup. There are stepping 
> motor controllers which use AC to control the steps not a square wave 
> but these are not standard.
>
>
> Micheal Tiefenback was looking at the spot size on the beam dump and 
> noticed a significant spread in the final energy caused by synchrotron 
> radiation. We should look to see how many photons we get from 
> synchrotron radiation and where they go.
>
> cheers
> jim