---+ !!!!!!!Warning, this is for the analog system !!!!!!!!!!!!

For a new Bolometer Wedge we want to perform a Network Analysis and take BoloIV curves (among other things)
This procedure consists of preparing the SQUID's.

the script /home/daquser/scripts/daily_setup_script.sh which will create a directory named after the current date, and make links to important directories. It is a good idea to work in this directory.

Step 1. Heating Bolometer Wedge above T_c.
Do this before Locking Squids and taking Network Analysis. We want to keep the Simon Chase Fridge ultra head at 0.7K. We do this by heating the Ultra pump to about 12K, at which point the pressure in the ultra head maintains a 3He boiling point of 0.7K.

  • step 1. Turn off the 3He ultra switch
  • step 2. Wait 2 minutes for the switch to open
  • step 3. Heat the 3He ultra pump with 5V (don't want the current to be too large)
  • step 4. Warm the pump to 12-14K. Do not overshoot!
  • step 5. Reduce 3He ultra pump voltage to maintain quiessent current (around 1V)
  • step 6. Close 3He ultra switch.
Step 2. Lock SQUID's.
The SQUID controller boards need to be powered up. You can do this by running ReadoutUI9u, selecting any channel, then quit the program. Start the Daemons to allow communication with the Osc/Demod board. Do this by running /etc/init.d/fMUX restart Do not run the Daemons with ReadoutUI9u running. It will not work.

Open ReadoutGUI
  • select the board address (currently e8)
  • select the squid address (check the cables plugged into the osc/demod board)
  • enable the first stage amplifier
You can then take V-Phi's of the SQUID's. Choose the best current bias and flux bias for the SQUID.

Step 3. Bolometer Network Analysis
Finds the frequencies at which to bais the bolometers. (will fill in details Jan '08)

Step 4. Bias the bolometers. You can change the various bolometer parameters using ./scripts/set_oscdemod_paramters.py [arg1] [arg2] [arg3] Where arg1 is the parameter to change, arg2 is the value to change it to and arg3 is the hex address of the bolometer. Example ./scripts/set_oscdemod_parameters -ca 0 e1:rb will set the carrier amplitude of the bolometer at the address e1:rb to zero. we may have a script to do the bolometer wedge biasing

Step 5. Check the health of the SQUIDS
You will want to check that the SQUIDS are still ok after biasing the wedge. Use either

  • ./scripts/flag_fluxJumps.py This will display the DC values of the SQUID and flag any high values. Any high value (>100) indicates that the SQUID has jumped up a magnetic flux quanta (high point on the IV curve). This will decrease the dynamic range of the SQUID. You can fix this using ./scripts/zeroandrelock_fluxJumps.py (may only work at APEX) or you can manually zero and relock the SQUIDS using the ReadoutGUI.
  • ./scripts/flag_fluxJumps_demodRails.py This will read the AC values of the SQUIDS. Any high values >7000 | <7000 indicates that the bolometer has railed. You will need to renull the bolometer?
Step 6. Bring the Bolometers below Tc
  • Step 1. Turn off the current to the 3HeUltra pump.
  • Step 2. Close the 3HeUltra pump switch. This can be done in parallel with turning off the pump current.
Step 7. Check the health of the SQUIDS and bolometers.
You can check the health of the bolometers by running ./scripts/summarize_squid_rms.py to display the rms values for all the SQUIDS or ./scripts/getrms.py [arg] where arg is the SQUID address. Any high rms value will indicate that the bolometer has 'latched' - gone superconducting. The current flowing through the bolometer will cause the SQUID to freak out. You can shut the SQUID off using ./scripts/unlock_and_disable_squids.py [arg] where arg is the SQUID address. *NOTE*- This will lose all the information from the seven bolometers readout by that SQUID. You can also bring all the SQUIDS in the wedge above Tc via Step 1. and re bias the bolometers.

Step 8. Take Boloiv data for the bolometers.

  • This step is outlined in James' lab note book. Will update wiki in Jan '08.
-- JamesKennedy - 11 Oct 2007

This topic: BolometerTesting > WebHome > BoloPrep Topic revision: r3 - 2011-09-23 - KevinBandura
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