STEREO/IMPACT/SIT

SIT HVPS In-flight

Turn-on Procedure

Date: 06/06/09

Unit: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date:
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

PURPOSE

This document specifies the procedure for turning on and ramping up the
SIT high voltage power supply in flight.

**Assumption:** This procedure assumes that the instrument will be
powered on continuously for 5 consecutive days.

**I. Perform an aliveness test before sending commands for the turn-on
procedure.**

Verify SIT table checksums available in housekeeping data on SIT GSE:

  ----------------------- ----------------------- -----------------------
  **Description**         **Expected Value**      **Actual Value**

  SIT FM1 tab cksm        52A82E (4/28/06)        

  SIT FM2 tab cksm        46E9B7 (4/28/06)        
  ----------------------- ----------------------- -----------------------

Verify the following singles rates on SIT GSE match expected values
(cts/min):

+-----------------------+---------------+------------+-----------------+
| **Description**       | **Expected    | **Actual   | **Comments**    |
|                       | Value**       | Value**    |                 |
+-----------------------+---------------+------------+-----------------+
| SRT                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| STP                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| VS                    | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| SSD                   | \>600         |            |                 |
+-----------------------+---------------+------------+-----------------+
| VSE                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| Matrix Rates (ApId    | All 0         |            |                 |
| 605)                  |               |            |                 |
+-----------------------+---------------+------------+-----------------+
| Beacon Rates (ApId    | All 0         |            |                 |
| 619)                  |               |            |                 |
+-----------------------+---------------+------------+-----------------+
| Pulse Height Events   | All 0         |            |                 |
|                       |               |            |                 |
| (ApId 606-617)        |               |            |                 |
+-----------------------+---------------+------------+-----------------+

Verify the following status information has been returned on SIT GSE and
matches expected values:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  SW Ver             0602                                     

  SW error           0 = (no error)                           

  HV Step            00                                       

  Toferror           0 = error events                         

  HV Status          0 = off                                  

  Eonly              0 = ET coincidence                       
                     required                                 

  Junk (Events)      0 = junk events                          
                     ignored                                  

  LIMHI              500                                      

  calib gain         9 - 11                                   

  calib offset       -14 to --65, should                      
                     settle at --15 but                       
                     may take as much as                      
                     an hour (don't wait                      
                     for it!).                                

  calib error        0x08, should settle                      
                     to 0x00                                  
  ------------------ --------------------- ------------------ --------------

Verify the following status information has been returned on SIT GSE and
matches expected values:

  ----------------- ----------------- ----------------- -----------------
  **Description**   **Expected        **Actual Values** **Comments**
                    Values**                            

  HV                -79.6                               

  Tof T             25-35 C                             

  Foil T            20-25 C                             

  SSD T             20-25 C                             

  +3.3 V monitor    3.3 V                               

  +2.5 V monitor    2.5 V                               

  +5 V monitor      5 V                                 

  +6 V monitor      6 V                                 
  ----------------- ----------------- ----------------- -----------------

**II. Command sequence for HVPS turn on**

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 1
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Commands:

**immed 1**

**hvenable 1**

**CAUTION: the following is a hazardous command. Check carefully before
sending**

**hvramp 40**

> After 2-3 minutes, verify the HV setting and count rates:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            40                                       

  HV                 985 - 1045                               

  HV Status          1 = on                                   

  SRT                0                                        

  STP                0                                        

  VS                 0                                        

  SSD                \>600                                    

  VSE                0                                        
  ------------------ --------------------- ------------------ --------------

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp 80**

> After 2-3 minutes, verify the HV setting and count rates:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            80                                       

  HV                 2063 - 2156                              

  HV Status          1 = on                                   

  SRT                0-10                                     

  STP                0-10                                     

  VS                 0-10                                     

  SSD                \>600                                    

  VSE                0-10                                     
  ------------------ --------------------- ------------------ --------------

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp 90**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            90                                       

  HV                 2345 - 2422                              

  HV Status          1 = on                                   

  SRT                \>10                                     

  STP                \>10                                     

  VS                 \>0                                      

  SSD                \>600                                    

  VSE                \>0                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 2
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp a0**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            A0                                       

  HV                 2610 - 2704                              

  HV Status          1 = on                                   

  SRT                \>10                                     

  STP                \>10                                     

  VS                 \>0                                      

  SSD                \>600                                    

  VSE                \>0                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 3
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp a8**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            A8                                       

  HV                 2760 - 2853                              

  HV Status          1 = on                                   

  SRT                \>100                                    

  STP                \>100                                    

  VS                 \>1                                      

  SSD                \>600                                    

  VSE                \>1                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day
4\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp b0**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            B0                                       

  HV                 2843 - 2986                              

  HV Status          1 = on                                   

  SRT                \>100                                    

  STP                \>100                                    

  VS                 \>1                                      

  SSD                \>600                                    

  VSE                \>1                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 5
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully before
sending**

**hvramp b8**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            B8                                       

  HV                 2976 - 3109                              

  HV Status          1 = on                                   

  SRT                \>100                                    

  STP                \>100                                    

  VS                 \>1                                      

  SSD                \>600                                    

  VSE                \>1                                      
  ------------------ --------------------- ------------------ --------------

\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

Notes:

\(1\) range of expected HV values based on range between fm1 and fm2
hot/cold cases observed during thermal vac, ± 30 V allowance for 2
channel jitter in ADC

\(2\) range of expected count rates in detectors variable due to
diferent levels of activity observed in IP space. Figure below shows
COUNTS/SECOND for Wind/STEP for comparable count rates during first
portion of 2006

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