Latest revision as of 07:38, 22 January 2013

NEW

Renewed and improved noise thermometer.
The wiring for four Double-Channel-Squids is installed.
Two more stainless steel Coax-Cables are installed with their own port at room-temperature. The are numbered #5 and #6. Up to now they end at the mixing chamber and are connected to each other.
Two semi-rigid coax-cables were installed, too.
Filter-boxes I, II and VI were improved by adding a second coil at the input (cryo-end) of the filter circuit. The coils were manufactured by Würth Electronik, Part No. 744221, 2000 $\mu$ H; 600mA; 0.42 ${\Omega }$

07.09.2012 : Degauss FPD, see log-book at page 234.
Testing new noise thermometer ... and it worked!!!!
18.09.2012 : NEW RECORD! Due to the new filter-box design we reached a new record! The crabon thermometer mounted on the mixing chamber reached the highest resistance so far: R_MC,CT5=14.1k ${\Omega }$ . Referred to the old Bayreuth-Calibration this is about 9 mK, corresponding to a our new calibration table (see log book p.139) this is about ~6 mK. Nevertheless even this temperature seems to be too high since the RuOx-thermometer already shows a temperature below 5.9mK (lowest limit of its calibration) at ~11k ${\Omega }$ of the crabon thermometer. It is also remarkable that we reached this high resistance while we used the LR-700 multiplexer. Prior to this using the multiplexer always showed up ugly disturbance of the read out resistance values.
New read-out setup of the FPD! See log-book for further details. We successfully managed to see all five fix-points!
We improved Pt NMR PLM-4 Setup. We also customized the variable PLM-4 gain. The original value of Gain 50 is now an amplification of a factor a 3!!

30.08.2012: FIRST DAY - CLOSING, CLEANING & PRE-COOLING
- Closing cryostat and dewar. Cleaning/pumping lines.
- Exchange gas p_VC~3mbar.
- 17:57 : Pre-cooling with 50l LN.

31.10.2012: - RAMP MAGNET
- 15:38 : Magnet armed and dangerous I_M=40A, T_RuOx~70mK

Disconnect RuOx from BOX VI:X2! Connect to BOX I: X7 since using BOX VI seems to cause parasitic heating based on coupling 4.5kHz frequency into the cryostat.
Build up / create a kind of switch-box to improve handling the different persistent current switches!
Renew FFT-Software and computer for a better and faster Noise-thermometer read-out :)

@@ Line 13: / Line 13: @@
 * 07.09.2012 : Degauss FPD, see log-book at page 234.
-* Testing new noise thermometer ...
+* Testing new '''noise thermometer''' ... and it worked!!!!
 * 18.09.2012 : '''NEW RECORD!''' Due to the new filter-box design we reached a new record! The crabon thermometer mounted on the mixing chamber reached the highest resistance so far: '''R<sub>MC,CT5</sub>=14.1k{{O}}'''. Referred to the old Bayreuth-Calibration this is about 9 mK, corresponding to a our new calibration table (see log book p.139) this is about ~6 mK. Nevertheless even this temperature seems to be too high since the RuOx-thermometer already shows a temperature below 5.9mK (lowest limit of its calibration) at ~11k{{O}} of the crabon thermometer. It is also remarkable that we reached this high resistance while we used the LR-700 multiplexer. Prior to this using the multiplexer always showed up ugly disturbance of the read out resistance values.
-* New read-out setup of the FPD! See log-book for further details. We successfully managed to see all five fix-points!
+* New read-out setup of the '''FPD'''! See log-book for further details. We successfully managed to see all five fix-points!
+* We improved Pt '''NMR PLM-4 Setup'''. We also customized the variable PLM-4 gain. The original value of Gain 50 is now an amplification of a factor a 3!!