On shift: Bill Franklin, Yuan Xiao
CCR worked to tune beam during the morning. After encountering trouble
getting good lifetime and halo (exacerbated by problems keeping the halo
monitors on), we decided to turn the holding field on. However, the water
flow interlock to turn on the longitudinal field still could not be
satisfied due to air bubbles in the cooling water supply. An access to
the BLAST pit was made to measure the water temperature in this device and
verify its stability. Ultimately, a decision that is was safe to override
the flow interlock (there is still a temperature interlock) and run the
holding field at full strength was made by the Mechanical Group.
With the holding field at full strength, ops was able to produce 80 mA
with 20 minute lifetime and low halo pretty quickly. We have been
taking data since about 14:30 with unpolarized hydrogen at 0.05 sccm. Some
of these runs have no wire chamber data as they were tripping repeatedly.
Lowering voltages on a couple of the sense wires seemed to help. The plan
is to take 2-3 more runs, then raise the target flow to 0.1 sccm and
take 4-5 more runs with the warm cell. Cooling of the target cell will
commence this evening in preparation for ion polarimeter runs tomorrow.
-- ********************************************************************** Wilbur A. Franklin * Phone: 617-253-9518 Bates Linear Accelerator Center * FAX: 617-253-9599 P.O. Box 846 * Email: wafrankl@mit.edu Middleton, MA 01949 * **********************************************************************
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