[Esr-users] HMS Dipole cool down

[Paul Brindza]

Greetings

The HMS dipole cool down is proceeding slowly at about 7 grams/sec. and 
we are at 193 K.
At the current rate we may be able to start filling Monday and finish by 
Wednesday.
This is not optimal given the large amount of work remaining to get HMS 
D ready for the start of Physics.

The Dipole has to be powered up after the long warm period.
Permanent NMR field measurement systems have to be installed, wired and 
made to work.
These NMR's have to be measured throughout the entire HMS D range o - 
3000 amps.
A temporary field measurement device has to be installed in the aperture 
of the HMS D and this required opening up the HMS vacuum system.
Cross calibrations between permanent and center mount fields performed.
Everything reversed in time to run in December.

meanwhile new HMS wire chambers have to be installed, made to work and 
them cosmic calibration data taken.

In short every day counts so we have to speed up whatever we can.

Lets start with the cool down of the HMS Dipole.
We usually cool down from 300 to 80 K in 3 days.
This requires 10 grams per second warm helium thru the coll down heat 
exchanger.
With more Helium gas now, we can be ready to do a slow Helium fill by 
late Friday night or early Saturday morning.
The HMS Dipole could be full and ready to power test by Monday morning.
The HMS D has never quenched and does not require any training.
Much of the running will be at low power in any case.

That is our request.

Sincerely

Paul Brindza

On 10/18/2017 11:13 AM, Qiuli Sun wrote:
> Howdy,
>
> We are ramping HB up to 3200 A after lunch today to do field measurement today. We also plan to ramp SHMS Dipole up to 3400 A today or tomorrow afternoon.
>
> Quench is not expected. Fast dump is not planned.
>
> Thanks a lot for the attention.
>
> Eric
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