[sevisehda]

Its not actuallya a vacuum inside the heatpipe since there is the vapor of whatever coolant your using. It would take some math and trial and error but it should be possible to create a heatpipe. You'd have to do the math to figure out the details howevere the principle would be quite simple. Add a quantity of alcohol(or any coolant) to your heatpipe. Leave a small hole at the top of the pipe to allow air/vapors to escape. Now heat the base of the pipe to much higher than the normal operating temp. This will cause the coolant to boil off and should push most of the air out of the heatpipe. Now quickly seal the pipe and allow it to cool. As the heatpipe and vapors cool the pressure inside the pipe will drop.

Although it would take experimentation to get it just right it should work pretty well.