Ken Fowler, long-time leader of the LLNL fusion effort, and Don's colleagues Herb Berk and Dave Baldwin note "Don's leadership at Livermore helped solve the special theoretical features of mirror confinement that paved the way for the tandem mirror concept. His 1976 paper with Berk and Baldwin (PRL 19, 1831) showed why the non-linear behavior of mirrors unstable to cyclotron modes produced relaxation to a confined state consistent with observations. The theoretical group Pearlstein recruited has continued to make many contributions to tokamak research. With Ed Lee, Pearlstein also developed the theory of electron beam propagation in the Earth's atmosphere; and with Dick Bulmer he developed the widely-used CORSICA magnetics code."
Herb Berk also "fondly remembers many insightful hours arguing physics with Don." Dave Baldwin also notes "Don's companionship on bike rides and the golf course" and KenFowler especially remembers "the Fowler-Pearlstein tours of all 7 continents"
Don was born in Los Angeles in 1932 and moved to New York with his family when he was six years old. After graduation from City College of New York he attended the University of Pennsylvania where he received his Ph.D. in physics in 1958. He then accepted a research associate position at Florida State University. Soon thereafter he joined the fledgling privately-funded fusion program at General Atomics in San Diego, which had attracted some of the top scientists in the country. When General Atomics lost its private funding in the mid 1960s many of those scientists went elsewhere to join government-funded fusion efforts. Don joined the fusion group at LLNL in 1967 where he spent the rest of his official career. Though he officially retired from LLNL in1996, Don continued his research, publishing scientific papers over the next two decades.
A lengthy list of Don's publications can be found at: https://www.researchgate.net/scientific-contributions/64908225_L_D_Pearlstein
Condolences and Memories can be sent to the family via Don's son Neil at: email@example.com