Difference between revisions of "Discussion of e+/e- tertiary beams in Hall D"
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(→Running conditions of 2-photon experiment in Hall B) |
(→Running conditions of 2-photon experiment in Hall B) |
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==Running conditions of 2-photon experiment in Hall B== | ==Running conditions of 2-photon experiment in Hall B== | ||
* based on numbers in [http://zeus.phys.uconn.edu/halld/tertiary_beams/HDPWG_RPBennett.pdf this talk by Robert Bennett] | * based on numbers in [http://zeus.phys.uconn.edu/halld/tertiary_beams/HDPWG_RPBennett.pdf this talk by Robert Bennett] | ||
| − | *: beam energy: 5.5 GeV | + | *: primary beam energy: 5.5 GeV |
*: max beam current: 120 nA | *: max beam current: 120 nA | ||
*: radiator thickness: 0.009 radiation lengths | *: radiator thickness: 0.009 radiation lengths | ||
*: max power in photon beam: 5.9 W | *: max power in photon beam: 5.9 W | ||
| + | |||
| + | For comparison, here are the maximum design numbers for polarized running with GlueX. Note that these rates are a bit higher than the standard high-luminosity running conditions, but these are the upper limits that we simulated when we designed the collimator cave shielding and beam line instrumentation. | ||
| + | *: primary beam energy: 12 GeV | ||
| + | *: max beam current: 3 μA | ||
| + | *: radiator thickness: 0.0001 radiation lengths | ||
| + | *: max power in photon beam: 4.8 W | ||
| + | |||
| + | Imagine just taking the running conditions from the TPE experiment in Hall B and replicate them in Hall D, sticking as close as possible to the GlueX photon beam configuration. | ||
| + | *: primary beam energy: 12 GeV | ||
| + | *: max beam current: 3 μA | ||
| + | *: radiator thickness: 0.00025 radiation lengths (50 micron diamond) | ||
| + | *: max power in photon beam: 12 W | ||
| + | |||
| + | This is only a factor 2.5 higher absorbed dose in the collimator cave than expected for high-luminosity running in GlueX. A more conservative configuration with the same photon beam power would be the following. | ||
| + | *: primary beam energy: 12 GeV | ||
| + | *: max beam current: 300 nA | ||
| + | *: radiator thickness: 0.0025 radiation lengths (500 micron diamond) | ||
| + | *: max power in photon beam: 12 W | ||
| + | |||
| + | Another idea to think about: | ||
| + | *: O(m/E) precollimation of photon beam at exit from tagger hall would give factor 2.7 reduction in beam power, also harden the spectrum. | ||
| + | *: 1m/E collimator @ 30m (radiator - tagger hall exit) has diameter 2.6mm which is feasible in terms of alignment and beam focal spot size. Under these conditions, the following would apply. | ||
| + | *: primary beam energy: 12 GeV | ||
| + | *: max beam current: 300 nA | ||
| + | *: radiator thickness: 0.0025 radiation lengths (500 micron diamond) | ||
| + | *: max power in photon beam: 4.5 W | ||
Revision as of 13:27, 31 October 2012
Running conditions of 2-photon experiment in Hall B
- based on numbers in this talk by Robert Bennett
- primary beam energy: 5.5 GeV
- max beam current: 120 nA
- radiator thickness: 0.009 radiation lengths
- max power in photon beam: 5.9 W
For comparison, here are the maximum design numbers for polarized running with GlueX. Note that these rates are a bit higher than the standard high-luminosity running conditions, but these are the upper limits that we simulated when we designed the collimator cave shielding and beam line instrumentation.
- primary beam energy: 12 GeV
- max beam current: 3 μA
- radiator thickness: 0.0001 radiation lengths
- max power in photon beam: 4.8 W
Imagine just taking the running conditions from the TPE experiment in Hall B and replicate them in Hall D, sticking as close as possible to the GlueX photon beam configuration.
- primary beam energy: 12 GeV
- max beam current: 3 μA
- radiator thickness: 0.00025 radiation lengths (50 micron diamond)
- max power in photon beam: 12 W
This is only a factor 2.5 higher absorbed dose in the collimator cave than expected for high-luminosity running in GlueX. A more conservative configuration with the same photon beam power would be the following.
- primary beam energy: 12 GeV
- max beam current: 300 nA
- radiator thickness: 0.0025 radiation lengths (500 micron diamond)
- max power in photon beam: 12 W
Another idea to think about:
- O(m/E) precollimation of photon beam at exit from tagger hall would give factor 2.7 reduction in beam power, also harden the spectrum.
- 1m/E collimator @ 30m (radiator - tagger hall exit) has diameter 2.6mm which is feasible in terms of alignment and beam focal spot size. Under these conditions, the following would apply.
- primary beam energy: 12 GeV
- max beam current: 300 nA
- radiator thickness: 0.0025 radiation lengths (500 micron diamond)
- max power in photon beam: 4.5 W
