The Vacuum System

 The most important part of any accelerator is the vacuum system. You can find all kinds of neat ways to push along particles and it won't matter if they just smash into something else in a matter of a few nanometers.


The accelerator tube will be about 1 meter long, so a mean free path of 1 meter or more is needed. For this, a pressure of about  10⁻⁴ Torr is required. 

In order to achieve this level of vacuum, first a roughing pump bring the pressure down to about 15 millitorr :

This is a 2 stage Robinair Vacuum pump. These are normally used for servicing refrigerators and other cooling systems.

After the roughing pump brings the pressure down into the millitorr range, the diffusion pump gets turned on :

This pump uses jets of boiling oil to collide with remaining molecules and direct them to the roughing pump and out of the system.

Now, these pumps usually cost lots, but they were donations. The robinair from a refrigeration servicing company and the diffusion pump from a specialty vacuum company.

Next, hooking them up and getting a decent vacuum... (not as easy as it sounds)