DoE National Labs employ Physicists

The Department of Energy National Laboratories are powerhouses of science and technology whose researchers support scientists and engineers from academia, government, and industry with access to specialized equipment, world-class research facilities, and skilled technical staff. They like to hire physicists at every level, including student interns and recent B.S. degree recipients and M.S. and Ph.D. physicists. Each lab has a different focus, so spend a few minutes finding out what kind of science happens there.  Some are centered around highly specialized equipment (e.g. the linear accelerator at SLAC) while others have an enormous range of research (e.g. the NIST, the National Institute of Standards and Technology).  They are located all over the country and many faculty members have associations with particular labs - ask the professors, post docs and grad students if they know about particular labs! Ask them which students got jobs there and ask them to put you in touch.

Some positions require U.S. citizenship or permanent residence, but not all do. International students should check the listings for each position and not assume that they are not qualified.  DoE labs tend to be less restrictive than DoD (Department of Defense) labs in this regard. 

BNL Brookhaven National Lab:
LANL (Los Alamos National Lab):
LBNL (Lawrence Berkeley National Lab):
LLNL (Lawrence Livermore National Lab):
NASA (National Aeronautics and Space Administration):
NIST (National Institute of Standards and Technology):
NOAA (National Oceanic and Atmospherics Administration):;
ONRL (Oak Ridge National Lab):
PNNL (Pacific Northwest National Lab):
SLAC (Stanford Linear Accelerator Center):
Every lab lists things differently and some digging is needed to find relevant positions, but the keywords physics, operation, operator, assistant, associate help to find relevant listings.  Job categories to look for:  Assistant/Associate/Intern if you have a BS or are looking for an internship, but generally you look at jobs have to read down to see if they want a BS or higher degree.  You can find quite a few in an hour of searching - here are some examples from a quick search of a few selected labs by Heidi Schellman in August 2020:
Operations Assistant* —  (ANL) — these are really cool - you run a major experiment worth about $500M; don’t push the wrong button. 
Software Engineering Associate - requires good programing skills
Post Bachelor Research Associate - (PNNL) - recent graduates!
Post College Appointee - (LLNL) - recent graduates!
Engineering Technologist 1 - (LANL) 
Science Associate - (BNL)
Tour Guide - (SLAC)
*Tip from Prof Schellman: Those machine operator jobs are the best.  They hire recent grads, work them hard running complicated machinery and then they go on to other things.  Like Prof. Bonnie Flemming (Yale) and Prof. Linda Spentzouris (IIT) who both started out as machine operators and came back to academia after several years.  Prof. Mary James got her PhD while working full time at SLAC as an accelerator physicist and engineer, so she was likely the boss of the machine operators.