Experiment Procedures Checklists
This page will describe the test procedures for using the vacuum chamber, commonly referred to as the LSL (LUNAR Sumulation Laboratory).
Background
Kapton and other polyimide films have been both widely used and well studied in the astronomy field. It has been employed on many spaceflight vehicles and exhibits excellent performance under these extreme conditions. However, the LUNAR Program is attempting to use the film as a revolutionary radio antenna array. This requires the film to be coated with silver dipoles and exposed for many months in a harsh environment. As this new variable is added, we must ascertain whether the film will continue to perform as well on the Moon. Initial testing suggests there is little resultant change.
The purpose of this test is to monitor what effects, if any, lunar conditions may have on the film. The specific variables we will reproduce are large temperature variations (-150ËšC to 100ËšC), exposing the film to UV light similar to the intensity emitted by the Sun, and placing the film under vacuum. We will closely monitor and document film temperature during the test.
The test will last for approximately one month. The chamber will cycle from one temperature extreme to another every 24 hours, i.e., two days will simulate one month in real time. In this process, the UV lamp will be turned on during the hot cycle and off during the cold cycle. Vacuum conditions will be maintained throughout the entire test.
Read This Page Before Working with LSL
Procedure Guidelines
* In case of an immediate emergency, CLOSE THE GATE VALVE AND TURN THE
ROUGH PUMP OFF. This will isolate the chamber from the inlet lines and prevent
chamber contamination.
Never do the following at any point
* Turn on the chamber roughing valve under vacuum
* Open the cryo roughing valve under vacuum
* Open the cryopump regen valve at any point
* Be aware of WHERE YOU ARE in the procedure at ALL times.
* Read through these procedures completely first and follow them carefully.
* Remember to record the time and your initials at each step as you go.
* When you have completed a data sheet, immediately place it in the binder.
* You must fill 2 dewars before you relieve the person who is monitoring the chamber.
Carefully read the above guidelines and understand the importance of not contaminating the chamber.
Test Name: ______________________________________________________________
Test Abbreviation: __________
Date: _______________
Day Number: ________
Primary Operator: ____________
LSL Cryopump Regen Procedures
NOTE: Only complete the regen procedure if the cryopump has been turned off.
| Operation
Number |
Operation | Time | Operator |
| 1 | Close the Gate Valve | ||
| 2 | Check the LN2 system with these steps:
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| 3 | Verify that the GN2 backfill pressure regulator is about 5 psi (circular dial midway above the rough pump). | ||
4 |
At the control console verify the following switch status: Master Switch – ON Roughing Pump – OFF LN2 Cold Trap – OFF Chamber Roughing Valve – OFF Cryopump Roughing Valve – OFF Gate Valve – OFF Cryopump Regeneration – OFF Heater Enable – OFF GN2 Backfill Valve – OFF Make sure the blue rough pump exhaust valve is open (vertical). |
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| 5 | Start the rough pump by turning on the Roughing Pump valve. Make sure the oil level is at least filled halfway in the window. | ||
| 6 | Monitor the roughing line pressure. When the roughing line is at 1 Torr or below, turn on the LN2 Cold Trap valve. Monitor the temperature inside the door of the main console until it stabilizes at -300ËšF. | ||
| 7 | Monitor the roughing line pressure. When:
AND
OPEN the Cryopump Roughing Line valve. Adjust GN2 backfill if necessary. |
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| 8 | When the cryo pressure is less than 10 Torr (1E2), open the Cryopump Regen Valve. |
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| 9 | After about one hour, close the Cryopump Regen Valve. | ||
| 10 | When the pressure of the cryopump is below 80 mTorr (8.0E-1), close the Cryo Roughing Valve. | ||
11 |
Wait 30 seconds, then measure the rate of rise of the cryopump. The rate of rise should be less than 20 mTorr / 5 min (2E-2). If not, open the Cryo Roughing Valve until the pressure reads 80 mTorr. Open the Cryopump Regen Valve and wait longer. Go back to step 9 and repeat as necessary. |
Pressure: |
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| 12 | When the rise rate is less than 20 mTorr/min, open the Cryo Roughing Valve. | ||
| 13 | When the cryo pressure is less than 45 mTorr (4.5E-2), close the Cryo Roughing valve. | ||
| 14 | Turn on the cryopump system.
Turn off Roughing Pump valve and the LN2 Cold Trap valve. |
Test Name: _______________________________
Test Abbreviation: ___________
Date: ___________
Day Number: ____
Primary Operator: __________
Pre-Pump and Pumpdown Procedures
Pre-Pump
| Operation
Number |
Operation | Time | Operator |
| 1 | Ensure the Cryopump is operating by checking that:
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| 2 | Verify all components are bolted in place, the door is latched, and all vacuum ports are sealed. | ||
| 3 | Make sure the chamber is at atmospheric pressure (7E2). Open the manual purge valve on the side of the chamber by turning the knob to the left. | ||
| 4 | Set the GN2 backfill regulator to about 5 psi. | ||
| 5 | Turn on the chamber backfill valve for a one hour purge. | ||
| 6 | After one hour, close the manual purge valve on the side of the chamber by turning the knob to the right. Close the backfill valve. |
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| 7 | Open the manual Cold Plate Valve (located on the top of the chamber above the rough pump). Counterclockwise is open. | ||
| 8 | Make sure you have 4 full dewars and open the blue exhaust valve (vertical). | ||
| 9 | Set backfill regulator to 15 psi. | ||
| 10 | Set heater GN2 regulator to 0 psi. | ||
| 11 | At the control console, verify the switch status:
Roughing Pump – OFF LN2 Cold Trap – OFF Chamber Roughing Valve – OFF Cryopump Roughing Valve – OFF Cryopump system – ON Gate Valve – OFF Cryopump Regeneration – OFF GN2 Backfill Valve – OFF Solenoid Power Status Switches (x4) – Disabled Table and Shroud controller – OFF |
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| 12 | Verify that the blue rough pump exhaust valve is open (vertical). | ||
| 13 | Get a blank Betty data sheet and fill out the top section and start taking data every 15 minutes. | ||
| 14 | If you are UNABLE to complete any items or if equipment malfunctions you will need to end the test in the following manner | ||
| 15 | Verify the manifold and liquid nitrogen valves are open. Switch on the Cold Plate on Betty Control Panel 2 console. You should hear hissing and LN2 line should begin to frost. |
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| 16 | Switch on the Rough Pump valve. |
Pumpdown
| Operation Number | Operation | Time | Operator |
| 1 | After a few seconds the roughing line pressure should reach 1 Torr. When it does, switch on Cold Trap valve. Check the oil level in the rough pump. It should be in the middle of the sight glass. | ||
| 2 | Monitor the gauge inside the main console to make sure the temperature reaches the set point: -300ËšF. | ||
| 4 | When the cold plate temperature reaches 0ËšC and the rough line pressure is below 50 millitorr (5.0E-2), switch open the chamber rough valve. | ||
| 5 | Monitor chamber pressure and cold plate temperature. When the chamber pressure is 45 millitorr (4.5E-2) or below and the cold plate temperature is -80ËšC or below, crossover. Relatively quickly and in this order:
SHUT DOWN IF THIS DOES NOT HAPPEN.
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| 6 | Chamber pressure should be in the minus four range. When it reads (0.0E-0) turn on the ION gauge 1. Turn on the RGA. Begin temperature cycling. |
Test Abbreviation: ___________
Date: __________
Day Number: _____
Primary Operator: ______________
Room Temperature to Cold
| Step | Task | Time |
| 1 | Turn on the heater near the coils. Flip the table select valve to liquid. |
|
| 2 | On the table controller override: Flip the gas switch to off. Flip the liquid switch to auto. |
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| 3 | Flip the table controller switch to on. | |
| 4 | Flip the auto switch next to the digital display. Set the temperature to -150Ëš C on the digital display. |
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| 5 | Enable the table liquid valve on the solenoid power console. The light should turn on. Listen for hissing. If the light does not turn on or you are concerned that the valve was not enable, disable liquid valve and listen for the interlock “clunking”. Enable the liquid valve again and listen for hissing. Turn on heater. |
|
| 6 | Watch to make sure temperature starts dropping on the digital display. | |
| 7 | Begin taking data sets every 15 minutes. |
Test Abbreviation: ___________
Date: ____________
Day Number: _______
Primary Operator: ______________
Cold to Hot
| Step | Task | Time |
| 1 | 15 minutes before you are ready to go hot, preheat the gas heater by flipping the heater valve on (blue light on control panel). Disable the liquid valve on the solenoid power console. |
|
| 2 | Flip the table select switch to gas. | |
| 3 | On the table controller override: Switch the liquid valve to off. Switch the gas valve to auto.
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| 4 | Set the temperature to 100Ëš C on the digital display. | |
| 5 | Switch the heater to on (blue light will turn on). | |
| 6 | Set the GN2 heater regulator to 50 psi. | |
| 7 | Enable the gas valve on the solenoid power console. The table gas light should turn on. If it does not or you are concerned the valve was not enabled, disable the gas valve and listen for the interlock “clunking”. Enable the gas valve and listen for hissing. |
|
| 8 | Watch to make sure the temperature begins to rise.
Turn off heater. |
|
| 9 | Begin taking data sets every 15 minutes. |
Test Abbreviation: ____________
Date: ___________
Day Number: _______
Primary Operator: ______________
Hot to Cold
| Step | Task | Time |
| 1 | Flip the heater switch with the blue light to off. | |
| 2 | Set the GN2 heater regulator to 0 psi. | |
| 3 | Disable the gas switch on the solenoid power console. | |
| 4 | Flip on the liquid switch on the table select valve. | |
| 5 | On the table controller override: Flip the gas switch to off. Flip the liquid switch to auto. |
|
| 6 | Flip the switch next to the digital display to auto. Set the temperature to -150Ëš C on the digital display. |
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| 7 | Watch to make sure the temperature begins to drop. Turn on heater. |
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| 8 | Begin taking data sets every 20 minutes. |
Test Abbreviation: __________
Date: __________
Day Number: ______
Primary Operator: ___________
Shut Down Procedures
| Step | Task | Initials |
| 1 | Take a data set and note that you are shutting down | |
| 2 | Turn RGA off by closing program (saves automatically) and unplug the:
|
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| 3 | Wait 15 minutes | |
| 4 | Shut off the ion gauge | |
| 5 | Close the gate valve | |
| 6 | Switch on the backfill valve and backfill to 550 torr (5.5E2) | |
| 7 | Switch off backfill valve | |
| 8 | Close the LN2 cold plate on Betty Control Panel 2 | |
| 9 | Close the cold plate manual valve | |
| 10 | Close the:
Turn heater off. |
|
| 11 | Shut off flukes |
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