Prof. Chrystian Droste passed away

We are saddened to announce the death of our mentor and colleague.
His passing is a tremendous loss. We will forever remember him and remain grateful for his knowledge, support, and commitment.

Mr. Chrystian (as he was called by his students and collaborators) was an outstanding scholar and an excellent teacher. His lectures—calm, precise, and clear—will always remain for us an unrivaled model of excellence in teaching nuclear physics. From the very beginning of the operation of the Warsaw Cyclotron, Professor Droste was involved in the research conducted at HIL. For us—his academic grandchildren—he will remain a master and a model of scientific rigor and diligence.

Professor Chrystian Droste was a man of exceptional nobility—remarkably sensitive and caring toward all those under his supervision: colleagues, doctoral students, and students. He was a person of extraordinary modesty, always placing the needs of his students and collaborators above his own achievements and recognition.

I had the honor of working with him for the past 60 years, during which I came to appreciate what an outstanding scientist he truly was. He taught us how to prepare and conduct experiments with great thoroughness, even when they were highly complex. He paid particular attention to the reliability of conclusions drawn and to their deep theoretical understanding. His lectures and seminars were exemplary models of such presentations. Even today, some people still use notes from his talks. Under his guidance, we mastered several very demanding experimental techniques, including:

• measurements of internal conversion coefficients of electrons,
• measurements of angular distributions and correlations of gamma radiation, as well as the determination of its polarization (still considered pioneering work—these publications continue to be cited, now around 200 times), and
• methods for measuring picosecond lifetimes of nuclear states—the Recoil Distance Method (RDM) and the Doppler Shift Attenuation Method (DSAM).

In the 1960s, at the Niels Bohr Institute, he participated in the first Coulomb excitation experiments in the world. He developed a style of scientific work that later encouraged  his students to advance the technique of Coulomb excitation using heavy-ion beams and to establish, at the Heavy Ion Laboratory of the University of Warsaw, one of today’s leading research groups in this field.

The team he led conducted groundbreaking research on chirality in atomic nuclei. Our 2006 paper is still frequently cited as the first experimental evidence of this phenomenon, which had been theoretically predicted in 1997.

In close collaboration with distinguished theorists, he interpreted our experimental results within innovative models: the coupling of a nucleon to a quadrupole collective core, and a collective core coupled to two nucleons. He also conducted extensive experimental and theoretical studies of the susceptibility of atomic nuclei to triaxial quadrupole deformations.

Julian Srebrny