Bug #1030
Updated by Julie Roche 2 months ago
He4 hypothesis
A "toy" model by D. Mack: https://logbooks.jlab.org/entry/4300261
Some estimation from super-elastic: https://logbooks.jlab.org/entry/4302727 and
https://logbooks.jlab.org/entry/4303408
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At 40 psia, Loop3 LH2 yields do not depend on fan frequency (neither do the LD2 rate): https://logbooks.jlab.org/entry/4303345.
Loop 3 produces 5% more yield at 30 psia than at 25 psia( https://logbooks.jlab.org/entry/4296639 and https://logbooks.jlab.org/entry/4296687) and then 5% more from 30 to 35 psia (https://logbooks.jlab.org/entry/4300169) and then 5% more from 35 to 40 psia https://logbooks.jlab.org/entry/4300169.
Loop 3 gives us more yields than Loop 2 at 11 uA for 58 and 42 Hz: https://logbooks.jlab.org/entry/4294810
No beam current dependence for Loop2 and Loop3 at 58 Hz: https://logbooks.jlab.org/entry/4295103. This feature is also seen in the target boiling data we took back in Sept 2023: https://redmine.jlab.org/issues/845#change-2067
Loop 2 - The issue is not an effect of the controller - https://logbooks.jlab.org/entry/4294867
Loop 2 - The issue subsides some when the fan is reversed, but running the fan reversed is unsustainable https://logbooks.jlab.org/entry/4292236
Loop2 yield decreases when fan speed increases https://logbooks.jlab.org/entry/4289172.
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Comparison to DIS simulation: with the most ad-hoc tuning of Loop3 (42Hz, 30 psi)we get 80% of expected DIS rates on LH2 (97% on LD2, Loop 1, 50Hz, 25 psi). https://logbooks.jlab.org/entry/4297882
and here is a comparison between LH2 and LD2
https://logbooks.jlab.org/entry/4298838
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Loop2 target cell wall:
data were taken during vaporization https://logbooks.jlab.org/entry/4293900
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There might be a constant ztarget shape difference between LH2 and LD2 throughout the NPS data taking: https://logbooks.jlab.org/entry/4293600.