| 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 6-25 were replaced by lines 15-19 |
| - |
| - * On the Variox or Magnet VTI, open the needle valve more than |
| - usual in order to fill the pumping volume with some |
| - amount of liquid helium. Put a "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 |
| - (this takes some time, as the pressure decreases only slowly). |
| - Then regulate the valve at about 8 mbar. This value must not |
| - be obeyed exactly. In principle, the best needle valve setting |
| - is reached, when the 1 K pot temperature (not the VTI temperature!) |
| - is minimal. Hours might be spend to optimize the |
| - needle valve opening, a better idea is take somthing between 8 and |
| - 10 mbar as a good starting point, and optimize later, if necessary. |
| - It should be possible to achieve a 1 K pot temperature of |
| - about 2 K with the Variox and about 2.5 K with the MA09. |
| - However, when condensing the mixture, the 1 K pot temperature |
| - might increase to 3 to 4 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 27 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 30-34 were replaced by lines 24-30 |
| - RAISE). |
| - * Open valve 9 (while pressing on the 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. |
| + 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 37-47 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 49 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 55 |
| - |
| Lines 57-58 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 60 added 2 lines. |
| + |
| + [DIL1/igh.png] |
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