Helmut Paul

Helmut Paul ( * November 4, 1929 in Vienna) is an Austrian nuclear and atomic physics. As a full professor of experimental physics, he taught at the University of Linz from 1971 to 1996. Since then he has been a professor emeritus. He was rector of the University of 1974 until 1977.

Life

Helmut Paul was born in 1929 as the only child of Hans and Paul Ilona (nee Just) in Vienna. Both parents came from a bourgeois milieu. The father worked in accounting and finance department of Siemens, the mother was at first a private and later interpreter at the U.S. Embassy in Vienna.

Helmut Paul was a very good student, and early on it became clear that he was mathematically gifted. The high school years, partly in Berlin and partly in Gmunden were concluded in Vienna with the Matura in 1947. Paul started in the fall of 1947, the study of physics and mathematics at the University of Vienna. His mathematics teachers were the world-famous mathematician Johann Radon and Edmund Hlawka; to radon and his family were also friendly relations. His physics teacher in Vienna included Hans Thirring, Felix Ehrenhaft and later the nuclear physicist Berta Karlik.

The academic year 1950/51 Paul spent a scholarship from the U.S. State Department at the Graduate School of Purdue University in Lafayette, United States. Paul wrote a Master's Thesis on the response probability of Geiger counters for gamma radiation and could this academic year with the degree of Master of Science to complete. The supervisor of this thesis, Professor Rolf M. Steffen, Paul stated that he would like to look after him as doctoral students.

Already in the spring of 1952, Paul was back at Purdue University, this time for the doctoral ( Ph.D.), he in December 1954 with a dissertation completed over the weakening of gamma-gamma angular correlation in the radioactive decay of the atomic nucleus of a hafnium isotope by the time-varying fields in liquid solutions, in function of the temperature. After returning to Vienna Paul received a half-day position at the Institute for Radium Research of the Academy of Sciences, led by Professor Karlik. This assignment was also personally Helmut Paul of great importance. He learned the secretary of Professor Karlik, Mary Elizabeth Mathis, know and love. In December 1956, Helmut Paul and Elizabeth Mathis engaged, the wedding took place in June 1957. The marriage produced three children.

By October 1957 Helmut Paul took up a scholarship position of the Ford Foundation at CERN in Geneva, which had been given him by Berta Karlik. At CERN, was the first particle accelerator, the synchrocyclotron, just gone into operation, and Paul was able to participate in the first experiment, which was carried out with this apparatus. It was the search for the rare decay of the charged pion into an electron and a neutrino; the decay was detected with a probability of 0.012% relative to the normal decay into muon and neutrino.

After the two very fruitful years in Geneva, Paul went a third time after Purdue, this time as a Visiting Professor in representation of Professor Steffen. There he studied a beta-gamma angular correlation. Meanwhile, a new research center in Seibersdorf in Austria was built in Vienna, in which closer colleagues from the Radium Institute ( Rupert Patzelt ) or the 2nd Physics Institute at the University of Vienna (Peter Weinzierl ) were employed; Weinzierl offered him a position in Seibersdorf, and Paul accepted. Paul worked from October 1960 to March 1971 in Seibersdorf center, interrupted by a fourth stay in America, this time at the Brookhaven National Laboratory on Long Iceland ( l965/66 ).

In Seibersdorf Paul had a magnetic intermediate image beta spectrometer available. So he measured the shapes of beta spectra. But above all, he examined the spectrometer itself, in order to show that the measured forms are not caused by error of the instrument. A substantial part of his work was a project to measure the angular correlation in the beta decay of the neutron, a difficult project that lasted for years and was finally ended when Paul was no longer in Seibersdorf.

At Brookhaven, Paul was trying to demonstrate a possible parity mixing in an excited state of the radioactive atomic nucleus of a hafnium isotope, which would manifest itself in a small circular polarization of the emitted gamma radiation. The result was negative: There was no circular polarization found. Incidentally, Paul published a summary paper on the shapes of beta spectra, which he had begun in Seibersdorf.

1970 Paul received a call to the young University of Social and Economic Sciences (from 1975: Johannes Kepler University ) Linz for the newly established full professor for experimental physics. Paul had the chance to participate in the planning for the establishment of the newly constructed building physics before taking up his professorship. Since there had been no experimental teaching pulpit, had everything (teaching, workshop, electronics, etc. ) to be rebuilt.

On April 1, 1971, he took up his professorship. Soon a particle accelerator for 700 keV protons was purchased (later also a tandem accelerator), and in collaboration with O. Benka, D. Semrad, A. Kropf and other atomic physics experiments were made. To make known internationally Linzer group were held at Paul's initiative workshops, initially three on ionization of inner atomic shells by light ions. A table with J. Muhr and O. Bolik created by Paul of the cross sections for K-shell ionization by light ions is available on the internet.

After Paul's interest had turned to the stopping power of charged particles in matter ( Stopping Power ), he initiated again three international workshops on this subject with which D. Semrad, P. Bauer, R. Gols and other employees had long been employed extensively.

In July 1995, took place in Linz, the " Sixteenth International Conference on Atomic Collisions in Solids" instead, with Paul as Chairman; D. Semrad, P. Bauer, O. Benka served as editors of the conference proceedings.

The years in Linz had a very successful time for Paul. In addition to teaching and research also Paul's leadership qualities were appreciated and in demand. Paul's balanced and confidence -inspiring personality was yours to the fact that in 1972 Senator Paul was. In 1973 he was elected Dean of the Faculty of science and technology, and in 1974 he was elected rector of the university - for three years, until 1977, In 1985 he was again elected for two years as dean. .

Following his retirement in 1996, Paul's interest focused on medical physical issues. He was co-author on several reports of the International Commission on Radiation Units and Measurements ( ICRU ) and a report by the International Atomic Energy Agency. Paul received and receives even after his retirement in 1996 invited lectures at medical conferences abroad, particularly in the USA (most recently 2012), but also to Brazil ( 2011).

1990 Paul has begun to build up a collection of all published brake loss data for light ions, with numerous graphs and post them on websites. In the meantime, he has expanded the collection to all positive ions, and he keeps it at latest standards it is important for him to compare these data with various theories statistically to as the quality of the data ( and theories ) judge. His private interests include extensive travel, participation in a church choir and working on a family genealogy.

Works (selection)

• List of publications since 2000 - jku.at