Re: Tagger and Hall D Machine protection requirements

[Elton Smith <elton@jlab.org>]

HI Kelly,

I am copying this message to Arne and the Hall D tagger group for
additional comments. My assumption is that most of the requirements will
be similar to Hall B photon operation.

For the Fast Shutdown system (what does the D stand for?), our main
requirement is that we do not want to spill the electron beam into the
experimental Hall D. For this we plan to have a permanent magnet in the
photon line, but of course want to shutdown the beam in the event the
tagger magnet accidentally trips. Therefore, FSD inputs would include:
o beam current monitor not to exceed value for Hall D
o beam transport magnets to the radiator
o tagger magnet (tied somehow to the electron beam energy?)
o burn-through collimator upstream of radiator to make sure the beam does
not steer off course
o low-current monitor in the photon line to detect any accidental
electron beam

> 1.) Will the diamond radiator have a "position" or "motion" FSD?
I assume position
> 2.) Will the tagger have a "Beam Offset Monitor" similar to Hall B's?
If this is in the electron beam dump, yes that is very useful to monitor
the deflected electron beam.

See attached GlueX-doc-32 for reference.

On Thu, 31 May 2007, Kelly Mahoney wrote:

> Will, Elton,
> I am consolidating requirements for the Tagger and Hall D fast shutdown
> system.  Could you please help me in gathering FSD inputs needed from
> the Physics side?
>
> I also have a few specific questions:
> 1.) Will the diamond radiator have a "position" or "motion" FSD?
> 2.) Will the tagger have a "Beam Offset Monitor" similar to Hall B's?
>
> Write or call if you have questions or need clarification.
>
> Thanks,
>
> Kelly
>

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