Stanislav Šafrata may be considered without exaggeration to be the founding father of cryogenics and low-temperature physics in the former Czechoslovakia. He was born on 9 September 1925 in Osturňa. Later, he attended a grammar school in Bratislava, Slovakia, and a Higher Industrial School in Prague. In 1949, he graduated from the Faculty of Natural Sciences of Charles University in Prague, where he completed his additional scientific training in physics three years later. The scope of his scientific expertise and activities was always very broad as evidenced by a monography co-authored with V. Petržílek: Electricity and Magnetism, published in 1953.
Stanislav Šafrata may be considered without exaggeration to be the founding father of cryogenics and low-temperature physics in the former Czechoslovakia. He was born on 9 September 1925 in Osturňa. Later, he attended a grammar school in Bratislava, Slovakia, and a Higher Industrial School in Prague. In 1949, he graduated from the Faculty of Natural Sciences of Charles University in Prague, where he completed his additional scientific training in physics three years later. The scope of his scientific expertise and activities was always very broad as evidenced by a monography co-authored with V. Petržílek: Electricity and Magnetism, published in 1953.
S. Šafrata was the founder and, for many years, the head of the Low-Temperature Physics Department, the first centre for low temperature physics in the former Czechoslovakia. The main goal of the Low-Temperature Physics Department, which was founded in 1955 as part of the Institute of Nuclear Research in Řež, involved the preparation of polarised targets for the then promising study of nuclear reactions; this Department would also conduct experiments with oriented cores and studied superconductive materials. S. Šafrata has achieved widespread recognition primarily for his works on electron scattering on oriented holmium cores; the study of magnetic properties of cerium magnesium nitrate, where a part of magnetic cerium atoms was replaced with a non-magnetic lanthanum and the resulting substance was processed using the adiabatic demagnetisation method to achieve a record-low temperature of 0,67 mK (these studies laid the foundations of a globally recognized temperature scale up to 2 mK); or the detection of forbidden nuclear magnetic resonance transitions using the highly sensitive squid methodology.
For such experiments, cryogenic technology and procedures were needed, which cannot dispense with liquid helium. To this end, in collaboration with P. L. Kapica and the Ferox Děčín state enterprise, he developed a helium liquefier, which was installed and commissioned at the Low-Temperature Physics Department on 13 April 1960. The cooperation between Ferox Děčín and the Low-Temperature Physics Department inspired a series of commercial products, such as helium liquefiers, Dewar vessels and cryostats. Together, they developed a multi-layer insulation and applied it to the manufacture of liquid nitrogen and liquid helium vessels; their cooperation also involved the development of a cryocauter used in medicine for the removal of specific types of tumours.
As the head of the Low-Temperature Physics Department, S. Šafrata initiated the founding of other centres of low-temperature physics, primarily in Brno, the Czech Republic, and Košice, Slovakia. As a complementary training in the field of low-temperature physics, he would organize summer schools. In 1979, as part of a reorganisation scheme, the Low-Temperature Physics Department was transitioned to the Institute of Physics (FZU) of the Czechoslovak Academy of Sciences. S. Šafrata also significantly contributed to establishing the department of low-temperature physics (KFNT) at the Faculty of Mathematics and Physics of Charles University (the KFNT officially started to operate on 1. 9. 1981 as a joint workplace of the Faculty of Mathematics and Physics of Charles University and the FZU) and, subsequently, became the head of the department, performing the role for the next decade.
S. Šafrata was an internationally recognized expert, promoting Czech science and technology among foreign organisations. Throughout his life, he would take part in a number of internships abroad e.g. at Standford University (J. Whitley, W. A. Little), at the Institute of Physical Problems in Moscow (P. L. Kapica) or at Oxford University (N. Kurti) and he would apply the lessons learned to the day-to-day operation of the department in Řež. He was a founding member of the International Cryogenic Engineering Committee (ICEC) and was a chairman of the A1 International Institute of Refrigeration (IIR) committee, which, during its 23rd International Refrigeration Congress IIR, awarded him a Medal for Merits – one of the highest awards of this intergovernmental organisation, which was established in Paris in 1908 and which brings together the representatives of 62 states. He was one of the founding members of the organisational committee of the Cryogenics conference, which meets every other year and which, in the 40 years of its existence, has become a recognized international platform for low-temperature physics and technology.
S. Šafrata was an active member of the C5 low-temperatures physics commission at the International Union of Pure and Applied Physics (IUPAP). He was a long-term member of the editorial committees of two physical journals – Cryogenics and the Journal of Low-Temperature Physics (JLTP). He actively cooperated with the Joint Institute of Nuclear Research (SUJV) in Dubna, Russia, and for this cooperation he, and his colleagues Finger and Janout received a State Prize. In 1996, as a token of international appreciation of his merits, Prague, the capital of his homeland, was chosen to host the LT 21 global low-temperature physics conference bringing together as many as 1500 participants. S. Šafrata presided over the meeting together with a German physicist F. Pobell.
S. Šafrata died on 24 January 2020. He was 94.
By: prof. RNDr. Ladislav Skrbek, DrSc.