Distinguished senior scientist emeritus Arthur Poskanzer spent the majority of his career working at the Lawrence Berkeley National Laboratory, or Berkeley Lab, where he developed some of his great achievements in nuclear physics. He died June 30, two days after his 90th birthday.

Poskanzer was constantly thinking. During hikes in the woods or at home, sitting in his chair and propping his feet up on the ottoman, Poskanzer sought out his scientific notions through moments of silence, according to Lucille Poskanzer, his wife of 67 years. Once he thought of something, he would whip out the little voice recorder he stored in his pocket and start speaking.

“He would do that in the middle of the night,” Lucille Poskanzer said. “I would wake up and there he was, talking into his recorder. I thought he was dreaming, but he wasn’t dreaming, he was having ideas.”

Arthur Poskanzer had a “linear” train of thought, according to Lucille Poskanzer. His thoughts, when left uninterrupted, would lead to the beginnings of multiple ventures through which he gained notoriety among the nuclear sciences community.

A pioneer in particle physics and nuclear chemistry, Arthur Poskanzer won multiple awards for his leadership in these fields, including the Glenn T. Seaborg Award for Nuclear Chemistry from the American Chemical Society and the Tom W. Bonner Prize for experimental nuclear physics from the American Physical Society, according to an SFGate article.

Arthur Poskanzer was the first scientific director of the Bevalac accelerator and co-developed the Plastic Ball, a detector that aided in discovering the collective flow of nuclear matter and remains an essential tool in studying it, according to the Berkeley Lab website.

At the Relativistic Heavy Ion Collider program, or RHIC, at Brookhaven National Laboratory, Arthur Poskanzer co-founded the Solenoid Tracker at Relativistic Heavy Ion Collider, or STAR collaboration. In addition, Arthur Poskanzer was a leading organizer of the heavy-ion program at the European Council for Nuclear Research, or CERN, an atomic physics laboratory, the American Physical Society added.

“He held himself to a very high standard and he held the people about him to a very high standard,” said Peter Jacobs, a senior scientist at Berkeley Lab and former colleague of Arthur Poskanzer. “He was driven by the challenge of debating with nature.”

While he retired in 2002, Arthur Poskanzer continued to return to Berkeley Lab for more than a decade in pursuit of his passion for science and mentoring young scientists with his concept of retirement being Wednesdays off, Jacobs noted.

Arthur Poskanzer died from pulmonary fibrosis, which had affected him starting about the time of his retirement, according to the SFGate article. He is survived by Lucille Poskanzer, their three children and four grandchildren.

“I was absolutely astonished by the number of emails that I got after he died and all the tributes that came in with memories of people’s interactions with him,” Lucille Poskanzer said. “You never can assess how many people a person has influenced in their life. And he influenced a lot of people.”