Lena/Sep 2016: Difference between revisions

Jump to navigation Jump to search

Lena/Sep 2016 (view source)

Revision as of 20:35, 8 September 2016

1,106 bytes removed ,  8 September 2016
→‎Fundamental noise limit estimates
* [[File:2016.09.01 Group Meeting.pdf|Zack's notes]]
* Thad suggested that we should have a logarithmic amplifier (so the signal is large enough for the ADC), and a PID loop at sub-Hz frequency to get rid of the DC fields around the sensor array.
 
=== Fundamental noise limit estimates ===
 
Finished the Mathematica models of the Mx in coated cell, SERF with buffer gas and SERF with OTS coating + 30 Torr Ne magnetometers. The models estimate the best achievable performance of each magnetometer in perfect circumstances (taking into account probe and pump de-pumping). Each magnetometer has a cubic cell of 1x1x1 cm. The magnetometers rank by sensitivity (from best to worst):
 
# SERF + OTS coating + 30 Torr N2 (0.1 fT/sqrtHz)
# SERF + 300 Torr N2 (0.5 fT/sqrtHz)
# Synchronously pumped magnetometer with a paraffin coated cell (1.5 fT/sqrtHz)
 
Mx magnetometers sensitivity is limited because they have lower alkali vapor concentration (can't heat coating above 60°C), and radiation trapping (no N2 in the cells). The SERF with OTS coating has narrower zero-field resonance line, so the probe can be detuned much closer than in the magnetometers with buffer gas. They also run at lower temperatures and so they have larger T1 due to decreased self-spin destruction collisions rate.
 
 
Download here: [[File:Magnetometers fundamental limit 1cm3.zip]]
 
== 09/01/2016 ==
Retrieved from "https://wiki.physics.wisc.edu/zhivun/index.php/Special:MobileDiff/192"

Navigation menu