[Esr-users] Hall C pressure drop - bye bye

[Paul Brindza]

Greetings


The intrepid Hall C Engineering Staff found and fixed the problem 
causing high pressure in the SHMS Hall C magnets.

The SHMS cool down system warm gas supply at 4 Atm. was left on after 
the HB magnet re-cool last week and the dipole cool down supply valve 
was not on the warm seat by several percent.

This caused a leak of warm, near 300 K helium into the dipole magnet and 
a lot of excess consumption at 4.5 K.

Both were corrected and the SHMS dipole pressure is now down to 1.52 
Atm. from 1.77 Atm previously and still dropping.

The Dipole helium supply JT is down to 32 % from a high of 60%.

It also appears that the dipole and Q2 and Q3 current leads zero current 
cooling flow rate may not be optimized.

We have increased the dipole current lead cooling flow rate and are 
observing for a potential further improvement in the helium consumption.

We'll let ya'l know how that part turns out in a few days when we have 
finished optimizing.


Cheers


Paul