Nikita Bernier wrote:

Nikita Bernier wrote: Thursday, April 05, 2012, 16:31 Target boat contains 6 BeO pellets : Sample,   Mass (g),   Thickness (mm),   Density (g/cm3) 1   1.2842,    5.406,        1.4647 2   1.2619,    5.150,        1.5108 3   1.2886,    5.316,        1.4946 4   1.2858,    5.310,        1.4931 5   1.3382,    5.520,        1.4948 6   1.3916,    5.650,        1.5187   Samples are made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 1:0.1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets. Pellets are loaded on a target boat coated/sintered with TaC. The target boat is wrapped with a Ta foil that is 0.002 inches thick. **** Sintering is postponed until the situation with the ventilation in the lab06 is cleared. ****    Tuesday, May 22, 2012, 16:44 Target chamber is currently being pumped down. Leak check will be done tomorrow by turning on the cooling water for the heat shield.

 Wednesday, May 23, 2012, 17:38

TGHT was stepped up to about 55A before the auto ramping was initiated.  The vacuum limit parameter was set for good vac at <4.0 e-5 Torr and bad vac at >5.0 e0-5 Torr. 

The pressure is coming close to the trip limit (8.5 e-5 Torr) (see attachment 1: strip tool over the past 5 hours).  Changed the vacuum limit parameter:  good vac =3.0e-5 Torr, bad vac= 4.0e-5 Torr. 

 Saturday, May 26, 2012, 10:44

TGHT is auto ramping up smoothly as the pressure is regulating between 1e-5 to 4 e-5 torr.  (See attachment 2, past 21 hr)

Sunday, May 27, 2012, 12:25  

There could be a power bump  early this morning at 06:30hr, and tripped off the TGHT power supply (see attachment #3).  The computer in the cold lab was found to be off expectedly, so the alarm handler running on that computer was also shut off (*Need a UPS on this computer!)  

Called the ISAC Ops, and  nothing about any power bump around that time was noticed.  

Turned on TGHT p/s and set TGHT at 318A, local at 315A/4.58V.  TGHT has been running for about 10 mins.  Currently vac at 4.2e-7 Torr.  

Sunday, May 27, 2012, 12:35

Initiating TGHT auto ramping... 

 Monday, May 28, 2012, 00:20

TGHT has reached to 600A and will remain at that current for the rest of the night.  The target oven temperature will be measured tomorrow.

See attachment#4 for the striptool over the past 10hr.

 Monday, May 28, 2012, 10:56

TGHT stayed at 600A for about 12 hours.  Pressure gradually came down to 7.6e-7 Torr. (See attachment #5). 

At TGHT=600A, The target boat temperature was measured at 1400C (with the pyrometer), and the Ta-heat shield (1-layer) was at 1050C. [Note: These temperature measurements are very closed to the measurements with an empty LP target (with not heat shield), TGHT @ 600A = 1360C].

Monday, May 28, 2012, 11:04

Due to the water leak from the Evap2 chiller, the system has to be shut off for inspection. 

TGHT was tapped down to 0A.  The target was cooled down for about 20min before the chiller was turned off.

Will continue with the process after the problem is solved...