thank you TerraMex very much, all your questions are very important to me to design this finned pipe.
here are the answers:
1, from my experience, i do back your opion, though the heat convection speed in the heatpipe is 100,000 times than the plane pipe(in theory), but the most important things to this finned pipe is how to emit the heat more quick and more efficient. because this finned pipe is total made of copper, the heat convection speed is very quick compared with the tranditonal heatsink, whether the Al heatsink, or copper embeded. but your theory still have a problem, i think maybe you compare this finned pipe with coolermaster or other producer's heatpipe. their heatpipe is tumbled in the heatsink, but my pinned pipe is a whole one, thus there is no boundary layer to hold up the heat transfer, and this is the most difference.
2, it never won't be small. you can check the P4 chip die, can my finned pipe's inside dimension (d)cover it? and what's more, the above characters are all changable if needed, including the fin length, fin thickness, fin width, and the space between the fin line, and the pipe diameter.
3, i won't embed any copper in it,even to say welded, because all these technology will have a very big problem, the heat resistance. so why not choose a solid copper stick, and fish out the unwanted copper, only leave enough copper base and copper wall? and let it be a finished heatsink.
4, in the first, i did think that use a fan blowing on it, but the result is your saying:only the upper fins will get a decent amout of air through them. The lower ones will probably get a minimum if any.
5,so, i'm going to have a lateral fans, and if possible i want to make a air cover, and let the fan blows it from the side.
6, you said Zalman :They do work, but they're not that good. I agree with you, many my friends said the flower is a stunt, the fin is inserted, and too long and too thin.
thank you again, and hope your futhure advice. :P