3 He cell production at NIST M. Jon Dadras

Outline Basics of a 3 He cells Basics of a 3 He cells Blowing/Baking Blowing/Baking Filling Filling Uses Uses Our new station at SNS Our new station at SNS

Blowing, Baking, & Distilling GE180 glass (no boron) GE180 glass (no boron) Tubing is baked along with cell for sterilization Tubing is baked along with cell for sterilization How cool is the oven? How cool is the oven?

Baking after Distillation

Putting the metals in the cell

Measuring K vs Rb ratio

Final Cut

Schematic of Filling Station

Optical Set-up

Helmholtz Coils

NMR-FID NMR Use a solenoid for holding field Send RF pulse Pick-up coil is same as RF coil Results: K-cell, 400 hrs, ratio = 45, w. K Laser, P = 75%

How is 3 He Polarized Circularly polarized light impinges on an alkali- metal (Rb) resonant with gs  1 st exc. transition Circularly polarized light impinges on an alkali- metal (Rb) resonant with gs  1 st exc. transition Light spin-polarizes the electrons Light spin-polarizes the electrons Spin-exchange occurs through binary collisions Spin-exchange occurs through binary collisions Meaning there’s a spin-spin interaction between the nucleus of the noble gas ( 3 He) and the spin-polarized electron Meaning there’s a spin-spin interaction between the nucleus of the noble gas ( 3 He) and the spin-polarized electron Courtesy of 3

How to Perform the Measurement Empty cell transmission Empty cell transmission Filled cell P=0, T=e -σnd Filled cell P=0, T=e -σnd Finally we use AFP-NMR to monitor the 3 He polarization Finally we use AFP-NMR to monitor the 3 He polarization What is AFP-NMR? What is AFP-NMR? n + 3 He  p + 3 H