40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  PSL  Not logged in ELOG logo
Entry  Thu Nov 12 18:01:10 2009, Frank, Things to Buy, RefCav, heaters for the other two chambers 
    Reply  Thu Nov 12 20:56:38 2009, rana, Things to Buy, RefCav, heaters for the other two chambers 
       Reply  Fri Nov 13 10:56:32 2009, Frank, Things to Buy, RefCav, heaters for the other two chambers 
          Reply  Fri Nov 13 12:46:35 2009, rana, Misc, RefCav, heaters for the other two chambers 
             Reply  Tue Nov 17 12:01:54 2009, Frank, Misc, RefCav, heaters for the other two chambers 
Message ID: 10     Entry time: Fri Nov 13 10:56:32 2009     In reply to: 9     Reply to this: 12
Author: Frank 
Type: Things to Buy 
Category: RefCav 
Subject: heaters for the other two chambers 

Quote:

I think its important to think of a good solution, since we may want to retrofit some other chambers.

For the electronics to drive the heater, let's make sure not to use the power supply solution that is in use now in LIGO and at the 40m. We should make sure to make the design such that the residual temperature noise from the heater is below what we expect for coating thermal noise, assuming we use Fused Silica spacer of 1m length.

This should be quite easy in principle, especially with the radiative shields on the inside.

 

 What is a "good" solution for you? A custom-made heater fitting the whole thing like the ones at the sites? They are expensive and it will take several weeks/month  to get them. The only advantage i see is that you can remove them from the chamber but do we need this feature? The other heaters are standard parts and you just stick them to the chamber, so you have a good thermal contact to it. As we only have two of the "other" chambers with a different layout for the small CF flanges i think this is good enough for our tests. For a new super-cavity chamber we can choose a different design. I think it does not make a big difference in stability. The design of the insulation is more important..

Yeah, i'm currently thinking off designing a first prototype for such a low-noise driver. As i think we will use the DAQ for temp controll thats the only part we need (and the power supply for the supply, but we have one of those). The current heaters i want to use have enough heating power when used with up to 24V, which is a good value as easy to buy. The noise can be easy as low as a couple of 10nV/sqrt(Hz) with standard parts..

ELOG V3.1.3-