Laser Driven Target at MIT

1
Laser Driven Target at MIT
Chris Crawford, Ben Clasie, Jason
Seely,Dipangkar Dutta, Haiyan Gao

• Introduction
• Optical pumping
• Spincell optimization
• Components of the LDT
• Atomic Fraction Results
• Preliminary Polarization
• Future Work

2
Overview

• Atomic Beam Source
• Well established technology
• Can create pure spin states
• 8 x 1016 atoms/s
• 84 atomic fraction
• 80 polarization

• Laser Driven Target
• Compact design
• Active pumpinghigher flux
• 2 x 1018 atoms/s
• 60 atomic fraction
• 50 polarization

3
Optical Pumping
At spin temperature equilibrium, the population
of each spin state n(mF) is controlled by the
Boltzmann equation.
4
Spincell Optimization

• Developed a code to simulate recombination and
  depolarization
• One must minimize the Surface Area / Volume
  ratio, and the length of the transport tube
  Dimensions 2 diameter spherical spincell with 5
  cm neck

5
Target Chamber
6
Polarimeter
7
Sextupole Magnet
8
QMA Detector
9
Dissociator Trials
10
Atomic Fraction
11
Preliminary Polarization
Laser transmission
Laser transmission
QMA mass 1 signal
QMA mass 1 signal

• polarization 20 ( helicity) and 23 (-
  helicity)
• polarization preserving mirrors only 87 efficient

12
Future Work

• Redo polarization tests with correct mirrors.
• Fine-tune operational parameters.
• Investigate the quality of the spincell coating.
• Investigate performance of sextupole filter.
• Run tests with deuterium.
• Redesign target for operation at BLAST.