While the supply of accelerator physicists in the United States has grown modestly over the last decade, it hasn’t been able to catch up with demand fueled by industry interest in medical particle accelerators and growing collaborations at the national labs.

About 15 PhDs in accelerator physics are granted by US universities each year. That’s up from around 12 per year, a rate that held relatively steady from 1985 to 2005. But accelerator physicists often come to the field without a specialized degree. For people like Yunhai Cai of the US Department of Energy's SLAC National Accelerator Laboratory, this has been a blessing and a curse. A blessing because high demand meant Cai found a ready job after his post doctoral studies, even though his expertise was in particle theory and he had never worked on accelerators. A curse because now, despite the growth, his field is still in need of more experts.

“Eleven of DOE’s seventeen national laboratories use large particle accelerators as one of their primary scientific instruments,” says Eric Colby, senior technical advisor for the Office of High Energy Physics at DOE. That means plenty of job opportunities for those coming out of special training programs or eager to transfer from another field. “These are major projects that will require hundreds of accelerator physicists and engineers to successfully complete.”

Transition mettle

Cai, now a senior staff scientist at SLAC and head of the Free-Electron Laser and Beam Physics Department, is one of many scientists recruited from other fields. The transition is intensive, and Cai considers himself fortunate that his academic background taught him the mathematical principles behind his first job.

Notwithstanding, “the most valuable help was the trust of many leaders in the field of accelerators,” Cai says. “They offered me a position knowing I had no experience in the field.”

Training specialists from other fields is a common and successful practice, says Lia Merminga, associate lab director for accelerators at SLAC. A planned upgrade to SLAC's Linac Coherent Light Source is creating a high demand for specialized accelerator experts, such as cryogenics engineers and superconducting radio frequency (SRF) physicists and engineers.

“Instead of hiring trained cryogenics engineers who are in short supply, we hire mechanical engineers and train them in cryogenics either by providing for hands-on experience or with coursework,” Merminga says.

New funds catalyze university research

The National Science Foundation has recently provided a boost to university research, which could help produce more accelerator scientists. In 2014 NSF launched their Accelerator Science program, distributing a total of $18.8 million in research funds, divided among approximately 30 awards in 2014 and 2015. The grants seed and support fundamental accelerator science at universities independent of government projects. Additionally, the program aims to entice students to accelerator science by challenging recipients to develop potentially disruptive technologies and ideas that could lead to breakthrough discoveries, as well as by supporting student travel to major accelerator science conferences.

“We are looking for high-risk, transformational ideas cross-cutting with other academic disciplines, with the goal of attracting the best students and postdocs,” says Vyacheslav Lukin, accelerator science program director at NSF. “Such students tend to gravitate toward the truly challenging problems with potential for novel solutions.”

Significantly, the NSF program recognizes accelerator science as a distinct field, which many institutions have been slow to do.

“There are few universities offering disciplines in the field of accelerators,” Cai says. “Most importantly, many people think it is [only] an engineering field.” Similar concerns were raised in responses to a 2015 Request for Information posted by DOE on the issue of too few accelerator physicists. Multiple respondents pointed out that many research awards don’t include work with accelerators.

Others believe solutions lie in outreach. SLAC has instituted programs to introduce undergraduates to research opportunities in accelerator science and plans to extend partnerships and internships to more schools and industries. Some respondents have pushed even further, supporting K-12 outreach as well.

Colby says that DOE will be implementing some of the suggestions over the next few years to strengthen its decades-long tradition of sponsoring accelerator science that supports its mission.