An Improved Method for Antihydrogen Spectroscopy

Wednesday, April 4, 2018

Berkeley physicists Joel Fajans and Jonathan Wurtele, along with their students and postdocs, have spent over a decade working on antihydrogen physics as part of the ALPHA Collaboration at CERN. A new article featured in Nature last December recognized the significance of the quest for precision antihydrogen spectroscopy (Characterization of the 1S–2S transition in antihydrogen, Ahmadi et al.).  

The major focus of the Berkeley group has been to invent and develop new plasma physics techniques for synthesizing antihydrogen.  

A recent paper in Physical Review Letters, part of the thesis work of grad student Celeste Carruth, reports an improved method for controlling plasma density and temperature. This method enabled a factor-of-ten increase in trapping rates. These increased trapping rates in turn allowed for reduced statistical and systematic errors that had previously limited ALPHA measurements.

The future is very promising! Improvements to the infrastructure for antiproton generation at CERN will provide on-demand antiprotons after the upcoming two-year CERN accelerator shutdown.

Graduate student Eric Hunter’s very successful plasma cavity cooling experiments may result in further improvements in antihydrogen synthesis. This work, interesting in its own right as a study of coupled nonlinear oscillators, appeared in AIP Physics of Plasmas (Low magnetic field cooling of lepton plasmas via cyclotron-cavity resonance, E. Hunter et al.).

The research has benefited greatly from nearly two-dozen undergraduate students who spent a summer working on the ALPHA project at CERN and who worked here on the related plasma physics. 

Pictured above, at CERN: 
Professor Jonathan Wurtele, undergraduate students Helia Kamal, Nate Belmore, Carlos Sierra, Stefania Balasiu, Cheyenne Nelson, graduate student Celeste Carruth, and Professor Joel Fajans.

The research of Fajans and  Wurtele is supported by the NSF-DOE Partnership in Plasma Science.