It is with regret that we announce the death of a long-standing employee of our institute - physics theorist Andrzej Senatorski - on 4 May 2022.

Andrzej Senatorski was born on 7 September 1934 in Lublin. He completed his studies in physics in 1955 at the University of Warsaw, at the age of only 21. He defended his doctoral thesis on spin waves in 1965, his supervisor being Professor Szczepan Szczeniowski. Initially, Mr Andrzej worked at the Warsaw University of Technology, and soon after his doctoral dissertation he joined our Institute (then the Nuclear Research Institute), although he continued to teach at the University until the 1970s. He spent a year - from March 1968 to February 1969 - as an intern in Brussels, in the department of Nobel Prize winner Ilia Prigogine, in the group of Radu Balescu. There he became interested in turbulence, especially plasma turbulence. From March 1969, he worked at Hoża, in the Department of Atomic Nucleus Theory, in the Laboratory of Plasma Physics. In this establishment (later renamed the Department of Theoretical Physics), he remained until his retirement, which he finally retired from at the end of 2013.

Mr Andrzej was a reliable colleague in times of need, always ready to help, warm and endowed with a discreet sense of humour. Because of his exceptional modesty and his tendency to remove himself into the shadows, he was sometimes a little underestimated. However, he understood physics deeply. He knew and "felt" plasma physics and the physics of non-linear phenomena very well. He was also very skilful with numerical methods. He published not very many papers, but they were of great value. His cooperation with Andrzej Skorupski and Erik Infeld was particularly fruitful. This resulted, among other things, in two articles in Physical Review Letters and two in Physical Review E.

He left a wife and four sons, from whom he lived to have grandchildren and great-grandchildren. He died surrounded by the love and care of his loved ones. He will remain forever in our memories.

Funeral ceremonies will commence on Friday, 13 May, at 10.30 a.m., with a Mass in the Church of St Andrew Bobola at 61 Rakowiecka Street; after which, at approximately 12 noon, Mr Andrzej will be buried in the Military Powązki cemetery (cemetery section A 15, row 3, grave 15).

Our deepest sympathies to his immediate family.

Directorate and Scientific Council

of the National Centre for Nuclear Research