Comments : 6 Comments »
Categories : Physics
Last week I was in Geneva doing a talk at LIFT 2012, which I will post when it goes online. As part of the conference I was invited to tour CERN and the Large Hardron Collider. Despite a hungover 7AM wakeup I managed to make the train to CERN. What an amazing experience!!
A cutaway showing how the beam line section are connected. The beam line tubes contract several centimeters as they are cooled with liquid helium, so bellows and sliding joins are used:
This is the main testing facility for beam line tubes:
This is a cavity resonator used in the Large Electron Positron Collider – the predecessor to the LHC:
Here we see the control room for the Large Hadron Collider. SO COOL.
James Bridle , who spoke at LIFT, wrote a nice post on our CERN visit.
Comments : 11 Comments »
Categories : Electron Gun, polywell, Sydney Experiment
I have Swiss TV journalist Yves Gerber in the lab today. I will try the electron gun again while he is here.
Previously in the comments, Olivier suggested the vacuum pressure is too high. Indeed, at 1.66 millitorr the pressure was higher than I wanted.
My first goal today is to check the empty vacuum chamber with blank flanges. A best case scenario.
With the initial pump down I only got down to ~3 millitorr… about the same as last time. I used the stethoscope to listen for a leak but did not hear one.
I tried tightening the flanges one last time, and suddenly the pressure started dropping again. I forget how much torque these conflat flanges need to fully seal.
Now I am seeing pressure in the range of 0.098 millitorr and dropping. Much better!
So now let’s install the electron gun, and see what we get.
With the electron gun components in the chamber I am able to get down to 0.27 millitorr… not bad!
But when I turn on the electron gun… still no beam.