At line 2 added 9 lines. |
+ It is highly recommended to use the automatic condensing scripts in SEA. |
+ Click on "sorbpump", when "readyforpump", make sure that the IVC is connected |
+ to a running turbo pump, and the valve and the IVC space is open. |
+ |
+ The automatic script is doing a sligthly different condensing procedure than |
+ described below. |
+ |
+ * If not yet done, the IVC has to be pumped. Do not do that before the sorb T |
+ is at 4K. |
Lines 6-24 were replaced by lines 15-19 |
- |
- * On the Variox or Magnet VTI, open the needle valve more than |
- normally in order to fill the pumping volume with some |
- amount of liquid helium. Put "flow" of 20 mbar until the |
- 1 K pot temperature is stable below 3 K. Then close |
- the needle valve until a "flow" of about 10 mbar is reached |
- (the pressure decreases only slowly). Then regulate the |
- valve at about 10 mbar. This value must not be obeyed exactly, |
- the idea behind the needle valve settings is the following: |
- ** A lower flow is better for consumption (a "flow" of more |
- than 10 mbar increase substatnitally the He consumption, but |
- during the process of condensing it might be o.k.). |
- ** The flow should be high enough to hold the 1 K pot temperature |
- low (over long term: about 2 K with the Variox and about 2.5 K |
- with the MA09). During the condensing phase, the 1 K pot temperature |
- might increate to 3.5 K for a short time, when pushing the |
- mixture quickly. |
- |
- * Open the 3 valves in the pumping line and the 2 valves in |
+ * Cool the VTI ("1 K pot" thermometer) to a temperature below 3 K. With the |
+ Variox 2 K may be reached, with MA09 about 2.5 K. |
+ Open the needle valve to get a pressure at the 65 m3 |
+ pump of about 12 mbar. |
+ * Open the valves in the pumping line and in |
Line 26 was replaced by line 21 |
- * Open the green valve marked "out" below the dump. The dump is the |
+ * Open the green valves marked "out" and "in" on the dump. The dump is the |
Lines 28-31 were replaced by lines 23-30 |
- * Open valve 9 (while pressing on the black valve button, press |
- RAISE). |
- * The reading on G2 is proportional to the amout of mixture in the |
- dump. It should read something around 660 mbar. |
+ * Switch on the 3He pump (while pressing on the 3He button, press |
+ RAISE). |
+ * Make sure that the heater on the mixing chamber is off and that |
+ the setpoint is zero. Switch off the still heater also. |
+ * Open valve 9 (while pressing on the valve button, press |
+ RAISE). |
+ * The reading on G2 is proportional to the amount of mixture in the |
+ dump. It should read something around 660(DIL1) or 400(DIL2) mbar. |
Lines 34-44 were replaced by lines 33-48 |
- * Open a little valve 12A (4.0 % to start). |
- * While the pressure reading on G1 should always be below about 400 mbar, |
- Valve 12A can bae opened gradually, and opened completely, when the |
- reading on G2 drops below 350 mbar. |
- |
- * After some time (about 30 min when using the Variox) the pressure on |
- G1 falls below 150 mbar, and it is time to pump out the dump: close |
- valve 9, and open valve 14 for a short time (close it when P1 raises |
- above 50 mbar). As soon as the pressure on P1 drops down, you might open |
- and close valve 14 again, but make sure that the pressure on G1 does |
- not increase above 350 mbar. |
+ * Open valve 13A |
+ * Open V12A a little (4 %) to allow the mixture pass the trap slowly. |
+ * When the pressure reading on G1 stabilizes or decreases, open valve 12A |
+ completely. |
+ * During condensation, the 1 K pot temperature might raise to more than 3 K, |
+ especially when the pressure on G1 is high. Adjusting the needle valve |
+ is only necessary, when this temperature get too high and prevents |
+ the condensation to progress. |
+ * After some time (depends on the temperature of the mix. chamber) |
+ the mixing chamber should reach about 1 K, and then |
+ the pressure on G1 stabilizes at a low value. |
+ Now you may start to pump out the dump: close valve 9, |
+ and open valve 14 for a short time |
+ (close it when P1 raises above 50 mbar). |
+ As soon as the pressure on P1 drops down, you might open |
+ and close valve 14 again. Do that several times. |
Line 46 was replaced by line 50 |
- raise above 50 mbar. Leave the valve open until the P1 drops below 0.1. |
+ raise above 50 mbar. Leave the valve open until P1 drops below 1. |
Removed line 52 |
- |
Lines 54-55 were replaced by lines 57-58 |
- the flow on the condenser line might falls below 100 (black display below |
- the valve panel). |
+ the flow on the condenser line might fall below 100 (black display below |
+ the valve panel, on DIL1 only). |
At line 57 added 2 lines. |
+ |
+ [DIL1/igh.png] |