# Presentation: 555518

## Before degassing RGA head

**Before degassing RGA head**

**After degassing RGA head**

_**RGA scans of test dewar**_
- December 23, 2005 (PR and SP)

- Ion Gauge readings :
- Vacuum (with RGA off) before degassing 6.0 E-7 Torr
- Vacuum (with RGA on) after degassing 6.9 E-7 Torr
- Vacuum (with RGA off) after degassing 6.2 E-7 Torr

- Test dewar pressures (dewar completely empty)
- Dec 22 at 09:00  7.7e-7 torr

## Dec 27, 2005  14:40

- 1-148 AMU’s range
- 20 points per AMU
- Scale factor and scan speed = 1
- Waited for RGA to stabilize for 20 minutes.
- Pressures
- Before turning on RGA  5.1 E-7
- After turning on RGA     6.0 E-7

- Test dewar  (P.R.)

- Test dewar pressures (dewar completely empty)
- Dec 26 at 15:08  4.9e-7 torr

## Dec 27, 2005 at 15:00   Pressure on ion gauge is 5.9 E-7

- Pressure from RGA program (hard to see above) 4.5 E-7
- Note different scale from previous graphs

- hydrogen

- water

- Nitrogen, carbon monoxide

- oxygen

- Carbon dioxide

- Turbo pump oil

## Dec 28, 2005  19:40

- Scan parameters are: 1-148 AMU’s range
-                 20 points per AMU Scale factor and scan speed = 1
- Waited for RGA to stabilize for 20 minutes.
- Pressures from ion gauge:
- Before turning on RGA  1.67E-6
- After turning on RGA     1.95E-6
- Pressure from RGA head is  :  2.2 E-6

- Test dewar  (P.R.)
- (dewar oppened, o ring groove scored, restarted pumping at 12:00)
- Less oxygen now ?

- Test dewar pressures (dewar completely empty, o-ring grove scored)
- Dec 28 at 13:20   4.1e-6
- Dec 28 at 19:15  1.67 e-6

## Dec 29,  2005 11:30 (PR,CK)

- Ion gauge pressure 9.5E-7 before RGA turn-on;  11.1E-7 after RGA turn on
- RGA derived total pressure is 1.4 E-6  - oxygen peak(at 32) is  2.54E-8

## Dec 29   2005  Test Dewar  12:30

- Ion gauge readings: RGA off = 9.6 E-7, RGA on=1.07 E-6
- RGA derived pressure 1.4 E-6 torr
- Partial pressures at (2/hydrogen = 4.00e-7)(18/water=9.89e-7)(32/oxygen=2.18e-8)

## Dec 30   2005  Test Dewar  10:30

- Ion gauge readings: RGA off = 6.7 E-7, RGA on=8.0E-7
- RGA derived pressure 9.8 E-7 torr
- Partial pressures at:
-  (2/hydrogen = 3.53e-7)(18/water=7.02e-7)(28/Nitrogen=1.14E-7)(32/oxygen=1.85e-8)

## Jan 2 2006   Test Dewar  10:55

- Ion gauge readings: RGA off = 3.58E-6, RGA on=3.9E-6
- RGA derived pressure 3.9E-6  torr
- Partial pressures at
-  (2/hydrogen = 1.23E-6)(18/water=3.18e-6)(28/Nitrogen=4.0E-7)((32/oxygen=2.54e-8)

- Test dewar was oppened at 11:00 of Dec 30
- Italian purity monitor (cleaned, baked for 2 hours at 150F by Walter Jaskierny) was put in.
- Pumping started at 12:30 of Dec 30
- Dec 30 at 13:30  pressure is 5.3e-5

## Jan 3 2006   Test Dewar  12:30

- Ion gauge readings: RGA off = 3.20E-6, RGA on=3.42E-6
- RGA derived pressure 2.6e-6  torr
- Partial pressures at
-  (2/hydrogen = 1.08e-6)(18/water=2.55e-6)(28/Nitrogen=3.80e-7)((32/oxygen=2.47e-8)

- With these settings each pass takes 5 minutes

## Same as previous page but ion gauge is turned off (for 30 minutes)

- Dec 30  13:30  5.3 e-5 torr
- Dec 31  06:30   7.92 e-6
- Jan  1 (2006) 11:30  4.37 e-6
- Jan 2 10:00  3.58 e-6  ;    Jan 3  07:30  3.09 e-6 ;  Jan 3 12:00 3.2 e-6 ;  Jan 4 12:00  2.5 e-6

***NOTE This is the only scan in this document until now taken with the ion gauge off !!!!***

- RGA derived pressure is 2.6 e-6

- Partial pressures at
-  (2/hydrogen = 4.80e-7)
- (18/water=2.53e-6)
- (28/Nitrogen=2.15e-7)
- ((32/oxygen=2.54e-8)

## Slide 11