Fishing for info's (manuals, kinetic enhancement possibilities) on ebay'd Oxford CU10

[Arrow]

Hi Ryan

check follow points before starting up the system:

- check al least if enough oil is in the vacuum pump (or replace it because of the age)

- check the tube for vacuum leaks. often old O rings are dead and give leaks. With leaks, the laser does not work.
you need to close the gas inlet, open the valves of the gas flow, and to power up the vacuum pump.
when the system was on air for a long time, let the pump run forat least 3-4 hours.
check the vacuum on the gauge. after swithing off the pump, the pressure should rise up maximum 1-2 mbar / hour
when the pressure rises faster, then the system has a leak, most time the O-rings on tube end and on the brewster windows are old and hard
to see the gas flow use figure 8.1 in chapter 8 of the manual

- check the thyratron tank and clean it out when you can see any dirt into the oli or on the bottom or on the HV components
when necessary, pump the oil out of the tank. a old fuel pump from a car is perfect for that job
clean the tank and all components, and be very patient when tighten the connections of the big (blue) condensators,
let the oil go through a sieve when necessary, or better, replace it as soon as you see as the laser works
use gloves when handling the oil

HV safety
- the Oxford lasers haves a dump switch to discharge the capacitors after switching off of the HV. But it is alway a very good practice
to check the voltage on the capacitors with a HV probe and to short it with an additional labor cable.
There are 3 points to check
- at HV supply in the PSU
- in the thyratron tank
- peaking capacitors at the tube end
In case there is a bad connection, the dump switch must NOT BE ABLE TO DISCHARGE ALL OF THEM !!! Keep this alway in mind.

After this few points, you can go to the normal start procedure described in the manual.

Andi

[robotarmy]

Hi Ryan

check follow points before starting up the system:

- check al least if enough oil is in the vacuum pump (or replace it because of the age)

- check the tube for vacuum leaks. often old O rings are dead and give leaks. With leaks, the laser does not work.
you need to close the gas inlet, open the valves of the gas flow, and to power up the vacuum pump.
when the system was on air for a long time, let the pump run forat least 3-4 hours.
check the vacuum on the gauge. after swithing off the pump, the pressure should rise up maximum 1-2 mbar / hour
when the pressure rises faster, then the system has a leak, most time the O-rings on tube end and on the brewster windows are old and hard
to see the gas flow use figure 8.1 in chapter 8 of the manual

- check the thyratron tank and clean it out when you can see any dirt into the oli or on the bottom or on the HV components
when necessary, pump the oil out of the tank. a old fuel pump from a car is perfect for that job
clean the tank and all components, and be very patient when tighten the connections of the big (blue) condensators,
let the oil go through a sieve when necessary, or better, replace it as soon as you see as the laser works
use gloves when handling the oil

HV safety
- the Oxford lasers haves a dump switch to discharge the capacitors after switching off of the HV. But it is alway a very good practice
to check the voltage on the capacitors with a HV probe and to short it with an additional labor cable.
There are 3 points to check
- at HV supply in the PSU
- in the thyratron tank
- peaking capacitors at the tube end
In case there is a bad connection, the dump switch must NOT BE ABLE TO DISCHARGE ALL OF THEM !!! Keep this alway in mind.

After this few points, you can go to the normal start procedure described in the manual.

Andi

Excellent! Thank you so much for the tips. This pretty much lines up with what I've read, except for the bit about checking the quality of the oil in the tank. Do you know how to get into the tank? Is it just a matter of cracking the screws off the heatsink plate with the bnc's and HT stuff bolted to it?

I think the main problem I'm going to run into with these is the fact that the manuals I have don't line up with the lasers I have... Getting onto Oxford lasers on monday to sort this out...

[Arrow]

Oil absorbs moisture so it is a good idea to change the oil every 3-4 years.
sometime a component in the tank failed and polluted the oil and also without this, over time the tanks go a bit contaminated.
So clean it when it looks not clean.
Making a lot of pictures during dismantling helps to refit :-)

the tank position depends on laser, can be in head or in psu, ask Oxford for the correcte manual. I owned CU25 and still ACL45
but both are different in construction to the CU10

Andi

[robotarmy]

Update:

Good bits: Pumpdown went great, still holds a vacuum, and the HV side of life seems good!
Bad bits: Forked up the neon plumbing and leaked a whole friggin' bottle overnight. Bollocks.

[robotarmy]

It works!!

[mixedgas]

Welcome to a very exclusive club!

Got a grating? I love that pair of colors!

Steve