He6-CRES

A collaboration working on using microwaves for precision beta-decay spectra measurements.
Main goal: sensitive searches for chirality-flipping interactions in ⁶He and ¹⁹Ne.

He6-CRES Collaboration Members

RF setup

Radioactivity (⁶He or ¹⁹Ne) is injected via the turbo pump (top). The `⁶He monitor' is a high-stability scintillator detector, read by SiPMs, used to normalize spectra taken at different magnetic fields. The radioactivity inside the magnetic field produces microwaves (approx. 20 GHz) read via low-noise amplifiers (RF Amps), kept at approx. 5K.

Event tracking

RF-Amp signals are digitized at approx. 2 GHz and time slices of approx. 50 microsec are processed for FFTs. Sparse spectrograms are made taking points that show power above background. Points are grouped into tracks, and tracks into events. The initial frequency of an event, ω, yields the beta energy (E = q B c²/ω).

Experimental setup

He-CRES Setup Video

Heather Harrington, Winston DeGraw, Drew Byron and Kris Knutsen near the He6-CRES apparatus. The radioactivity comes from the production room via the pipe barely visible on the top of the photo. It then gets compressed into the decay cell by a turbo pump.		Closer view of decay cell: the three trap coils are used to produce a magnetic field of approx. a part per thousand of the main field, yielding a magnetic trap for betas.
Heather Harrington busy aligning the NMR probe for mapping the superconducting solenoid (blue) magnetic field.		Top right: Winston DeGraw and Savannah Hightower testing the SiPMs setup for the `⁶He monitor'. Bottom left: Close-up on the SiPM readout board.