Hall D Design Report version 3
Chapter 4: Photon Beamline and Tagger
contributors:
Richard Jones
Dan Sober
Jim Kellie
Ken Livingston
Franz Klein
Curtis Meyer
This page is the workspace for the development of chapter 4 for version 3
of the Hall D design report. All new figures for the report will be posted
below For revisions and additions to the body of the text, it is more
convenient to use a word processor format that everyone can access, and
then use color to indicate the places that have been added or revised.
We will experiment with LaTeX to see if it will be easy to use to use
with color and the web.
- chapter4v2.ps.gz
- the full text and figures for chapter 4 from Hall D Design Report v2 (9/1999)
- chapter4v3-0.ps.gz
- zeroth draft of v3 chapter 4, showing major changes from version 2 (9/2000)
- chapter4v3-1.ps.gz
- first draft of v3 chapter 4, showing changes from draft 0 (10/2000)
- chapter4v3-2.ps.gz
- second draft of v3 chapter 4, uploaded to central Hall D web site for DRv3
(10/24/2000)
Latest update: chapter4.ps.gz
updated
Open issues:
[DS] October 6, 2000
Q1.
Question (for coh.brems. experts especially): Is 0.5% channel width
acceptable for the fixed array? It would not be a great change in scope
to ~double the number of counters, and as part of a more general
experimental facility I think 0.25% or 0.3% (giving RMS <0.1%) would
satisfy nearly anyone's needs while 0.5% (60 MeV) might be marginal.
Edit history: (latest first)
[JK] October 10, 2000
-
Figs 4.4 and 4.16 show the tagger bending in opposite directions. Could
fig 4.4 be changed?
- 10/17/2000 - done - DS,RTJ
-
Fig 4.4 also shows two beam dump magnets for the main
beam exiting the tagger, but I think the text says there will be no such
magnets.
-
Could you please delete ' with De Beers ' from the text.
Apparently, De Beers do not wish to be mentioned by name in an American
based document at the moment so I suppose we should respect their wishes.
-
You score out CB at one point but then refer to it later. I suggest
we just use the words coherent bremsstrahlung. ... more fixes of
this sort ...
-
There are really two references for the Mainz tagger. One on the
magnet and the other on the focal plane, which are
- Anthony et al., Nucl. Instr. and Meth. A301
(1991) 230-240.
- S.J. Hall et al., Nucl. Instr. and Meth. A 368 (1996) 689-708.
The reference on diamond crystals is still waiting on a high resolution
topograph of the Mainz diamond which should be measured in November. Could
you refer to this as a private communication to myself?
[FK] October 9, 2000
-
Here is the first draft of a paragraph on polarimetry.
I tried to find out which method to monitor the beam polarization may be
the best one. I haven't done the calculations for a hadronic process yet
(like SCHC of rho^0). For both types of polarimeter (triplet and pair)
I made some geant simulation and QED based calculations. The proposed
setup is similar to the polarimeter we've designed for Hall-B except
higher resolution for the mustrip detectors. Unfortunately, a similar
detector cannot be used in a triplet polarimeter because the signal output
for soft electrons showed too much fluctuations. The triplet polarimeter
would have the advantage that it could stay in the beam because the
detector devices would be 1-2 cm apart from the photon beam.
[DS] October 6, 2000
-
Next-to-last sentence of 4.4.2, "energy resolution better than 5%"
should be "0.5%". (but see question above).
-
Tables 4.4, 4.5 and 4.6: They all still have the 1.0-Tesla values; new
versions are attached. Note the label reversal "along FP" and "perp. to
ray" in the column labels of 4.5.
-
It just occurred to me that the beam sizes at the dump (Sec. 4.4.5) are
probably those calculated for the 1.0-Tesla design. I will re-calculate
and let you know if there is an appreciable change. [RTJ note: I
received corrected values 10/9/2000]