Lena/Aug 2016

August 2016

08/15/2016

NURI paper

Talked to Dima about the NURI magnetometer network paper. His comments:

• The device section describes a solution without a problem. Add to the introducion:
  • need for the accurate timing
  • need to correlate signals from the different sensors
  • magnetometer has to be portable

Mx magnetometer sensitivity

Talked to Thad about a possibility to have a synchronously pumped scalar Mx magnetometer in the fMCG project. The advantages would be:

• not having to cancel the field
• no calibration
• no 1/f electronic noise

Disadvantages:

• spin-exchange relaxation
• no vector sensitivity

Calculations for an Mx magnetometer built with a paraffin-coated 1cm3 cell show that it should be possible to get around 3 fT/sqrtHz per 1cm of the probe length.

• Download the Mathematica notebook - File:ScalarMagnetometerParaffinCells.zip

Alkali vapor cells sources

Asked around to find who could make some paraffin-coated cells for us. Dima's sources:

• Misha Balabas ($500-$700 per cell)
• Antonie Weis (sells 20x20mm cells that they no longer use)
• Wenhao's group (can make cells or fill cells)
• Precision Glass Blowing (had poor T1)

Asked Vitaliy Shutov from Frequency Standards Lab in FIAN, Troitsk. They have a setup that produces the cells in small (~10) batches. The cells are baked and sealed under vacuum and don't have stems. Cells can be filled with any gas mixture, but they don't make coating. The cells come in two sizes

• 8x15mm
• 5x3.5mm

Velichansky's group also has a stash of paraffin-coated 20x20mm cells.