A symmetric multi-rod tunable microwave cavity for a microwave cavity dark matter axion search.

The microwave cavity technique is currently the most sensitive way of looking for dark matter axions in the 0.1 GHz-10 GHz range, corresponding to masses of 0.41 µeV-41 µeV.

Boutique neutrons advance Ar/Ar geochronology.

We designed and tested a compact deuteron-deuteron fusion neutron generator for application to Ar/Ar geochronology. The nearly monoenergetic neutrons produced for sample irradiation are anticipated to provide several advantages compared with conventional fission spectrum neutrons: Reduction of collateral nuclear reactions increases age accuracy and precision. Irradiation parameters within the neutron generator are more controllable compared with fission reactors.

Characterization of the HAYSTAC axion dark matter search cavity using microwave measurement and simulation techniques.

Many searches for axion cold dark matter rely on the use of tunable electromagnetic resonators. Current detectors operate at or near microwave frequencies and use cylindrical cavities with cylindrical tuning rods. The cavity performance strongly impacts the signal power of the detector, which is expected to be very small even under optimal conditions.

Beam-induced back-streaming electron suppression analysis for an accelerator type neutron generator designed for Ar/Ar geochronology.

A facility based on a next-generation, high-flux D-D neutron generator has been commissioned and it is now operational at the University of California, Berkeley. The current generator designed for Ar/Ar dating of geological materials produces nearly monoenergetic 2.45MeV neutrons at outputs of 10n/s.

Experimental searches for galactic halo axions.

A very light axion would be copiously produced during the Big Bang as a zero-temperature Bose gas, and it would possess vanishingly small couplings to matter and radiation. It thus represents an ideal cold dark matter candidate. Galactic halo axions may be detected by their resonant conversion to microwave photons in a high-Q cavity permeated by a strong magnetic field.