[Tpe] quartz beam monitors

[David Kashy]

Brian etal,

Nominally the center of the vacuum box in height is the center of the 
beam, but if you need 1-2mm or better you should have this verified. 
Yesterday while discussing the alignment plans with the survey team I 
found that they are aligning the PS magnet steel. I do not think the 
vacuum box is perfectly centered in the magnet. Thus the inside edges of 
the vacuum box will not be the same horizontal distance from the beam. 
This will effect the distribution of the particles left and right... 
would it be better to have the box centered?

They do know that they have to center the photon blocker on the beam. 
The lepton blocker is not adjustable since it was designed to be a close 
fit to the inside of the box. Thus it will match the offset of the 
vacuum box. I've asked that the survey group check the vacuum box 
alignment relative to the magnet so we have an idea about the size of 
the potential problem.

I see no problem with you mounting your luminosity monitors to the 
lepton blocker frame on the upstream edge. Just work with Doug and Joe 
to get it done.

Dave



On 11/17/2010 4:25 PM, Brian A Raue wrote:
> Hi Dave,
>     I have, until now, dropped the ball on mounting for the quartz 
> beam luminosity monitor detectors.  These go on each side of the beam 
> a look at the low energy waste (<0.5 GeV) part of the lepton beams.
>     A good place to put these at the front edge of the PS vacuum box.  
> I think we should be able to put them on the lip of the lepton beam 
> blocker about 6" from beam center.  They need to be centered 
> vertically so we probably need a couple of small blocks attached to 
> the blocker box with their top sides 0.5 cm from the beam center (the 
> quartz crystals are 1 cm high).
>     If it is okay to put them there, I design and make the blocks.  I 
> just need to know the distance from the floor of the blocker box to 
> beam height.
>
> Brian