He3 Target Test Items

From Hall A Wiki
Jump to: navigation, search

Target Holding Field

  • Field survey: field strengh, gradient
  • Field rotation glitch check

Cell Characterization


  • Filling density
  • Broadening of Alkali absorption
  • N2 density: filling density, pressure curve

Wall Thickness

  • Laser interference measurement: wall and window

Cell Volume/Geometry

  • Caliper method
  • Archimedes' method

Optical Pumping System

Laser Optics

  • Laser power measurement
  • Laser spectrum measurement/Absorption adjustment
  • Calibrations of optics orientations, e.g. λ/4 plates
  • Laser polarization measurement
  • Optics alignment [1]
  • Power consumption at laser connectors (if there is any)


  • RTD calibration
  • Condition optimization: oven temperature as a function of gas flow and heater power



  • Q-curve measurement of all pickup coils to prevent resonance
  • Minimize pickup coil background with maximum RF power
  • Linearity check of amplifiers: preamplifier, lock-in amplifier
  • Flux calibration: pickup coil survey and flux calculation
  • He3 NMRs: frequency and field sweeps (including NMRs during EPR calibration)
  • AFP loss measurement
  • Internal temperature measurement in pumping chamber using NMR
  • NMR cross calibration: frequency vs. field, different locations
  • Water NMR calibration: field sweep (frequency sweep as well if possible)


  • Characterization of feedback system: proportional and integration gains
  • D2 light detection optimization [2]
  • EPR calibration: absolute polarization measurement
  • Cross check with water calibrated NMRs
  • D1 light EPR measurement (if using narrow-band laser)

MISC Studies

  • Spin up time
  • Relaxation time: room temperature, high temperature
  • Optimization of pumping condition: laser power, oven temperature
  • Polarization gradient across cell