[Hallb-engineering] [New Logentry] Torus OOPS Review

[kashy at jlab.org]

Logentry Text:
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In positive polarity the force on OOPS B1 of coil B went to 1431lbs, almost to the controlled rampdown limit of 1450 lbs. This was with the Torus at full positive current and the Solenoid at full positive current.  We decided to lower the current to 85% of max and continue the run and to investigate if there is a possible adjustment of OOPS that can lower the max load on OOPS B1. When we went to full reverse (negative current) field on the Torus with the Solenoid at full positive current the load cell E3 went up to 1412 lbs and its limit is 1500lbs. 

The 8 load cells with moderate to high loads are B1, C1, E3, E4 and F3, F4. 

I reviewed the loads on all 8 load cells with the Solenoid at full positive current and the Torus at full current both positive and negative current.

To reduce the peak loads on OOPS I suggest we make adjustments on two OOPS and if need back off on the opposing ones to assure we have gap for warmup.
This will allow confident running of the Torus to full field for the spring running.

I suggest the following adjustments:
Increase B2 load cell by 300 lbs while at 0 current:-> this should lower B1 to about 1150lbs and make B2 300lbs at full + current
                                                          it should also:-> make B2 600lbs and B1 0lbs at full - current
Increase E4 load cell by 150lbs while at 0 current:-> this should make E3 about 1250 lbs and E4 about 750 at full - current
                                                         it should also:-> make E4 about 1200lbs and E3 0lbs at full + current. 

To make adjustments will require; at minimum moving out some sectors of DC and a risk assessment and job plan should be done prior to proceeding. I would feel comfortable with increasting the B1 load cell trip value to 1500lbs which would give us some margin and we could delay the adjustment until a later time if the loads continue to change. 

Another consideration is that this analysis does not have the solenoid at - current and I don't know how that will effect the Torus OOPS loads.



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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3507673
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