Hi!
I put a file to the files section diffusion pump. This is an invention what I accomplished on the last week.
The main problem was with my DP, its pumping speed was low 220l/sec. Not enough to operate the ion source and the ebeam gun in the same time(IBAD). I put photos from the modification I have made, in my photo album.
The bulged part was turned on the lathe from two solid pieces. Than TIG welded from the inside into the old pump. The nozzle tower is the same. On the outside I soldered a soft copper pipe 8mm diam, for the cooling. The original 750W heating changed to 1500W. I use Apiezon AP201 oil now. But only for try, later I am going to change to Santovac 5
I put 250ccm from the AP201 into, than it was vacuumised for two hours. Than I turned on the cooling and heating, and with closed plate valve vacuumise for another 5 hours, because of outgassing.Then shut down.
Next day I turned on, and vacuumised for 4 hours, but now with opened plate valve.
The base pressure was easily achieved 2x10-5 Torr. After this I opened the needle valve and let Argon into the chamber. In the same time I checked the vacuum gauge. The differet was obvious. Opening the valve same amount as before the pressure was lower. It could tolerate higher gas load than before.
I can't measure the pumping speed, but this is now enough to operate the ion source too.
