NSCL Directory Profile

Hendrik Schatz Professor Experimental Nuclear Astrophysics   PhD, Physics, University of Heidelberg 1997 Joined NSCL in December 1999 Phone (517) 333-6397 Fax (517) 353-5967 Office W211   schatz at nsclmsuedu Professional homepage

Our group’s interdisciplinary research program is at the intersection of nuclear physics and astrophysics. The goal is to understand the nuclear processes that occur naturally in our universe. Nuclear reactions created, and still create, the chemical elements our world is made of. Nuclear reactions make the sun and all the stars shine, and nuclear reactions power some of the greatest fireworks in our universe - stellar explosions like supernovae, novae, and X-ray bursts. Our research is tied in closely with the Joint Institute for Nuclear Astrophysics (JINA), offering unique opportunities for interdisciplinary research, such as targeted schools and workshops, opportunities for student and postdoc exchange with other institutions in the US and worldwide, interaction with visitors, and a JINA club for students and postdocs.

Our main interest is the role that very unstable radioactive nuclei play in astrophysics. Despite their very short lifetimes - many decay within 10-100 milliseconds - they can shape the nature of the observed stellar explosions. They are also intermediate steps for the synthesis of the elements. Elements like silver, gold or uranium found today on Earth are the decay products of exotic isotopes probably produced in supernova explosions. Very unstable nuclei therefore determine the composition of the entire universe. Another site where unstable nuclei exist in large quantities are the crusts of neutron stars. Neutron stars are typically a bit more massive than our sun, yet their radius is only that of a small city (6 miles) and they rotate so rapidly that a neutron star day can last less than a second. Neutron stars represent the most compact state of matter - a tablespoon full of neutron star matter weighs 500 million tons. At such extreme densities, the decay of isotopes that are extremely unstable on Earth is blocked. These isotopes therefore form layers in the neutron star crust and need to be understood to explain observations.

Our group is mainly concerned with recreating the unstable isotopes made in stellar explosions and neutron stars in the laboratory. Little is known so far about these nuclei because of the extreme difficulty of producing them. This has hampered the explanation of many recent observations of X-ray burst and nova explosions, and is one of the issues that prevents us from answering the question of the origin of the heavy elements in nature. At NSCL we are now able to produce many of the important unstable isotopes and study their often surprising properties for the first time. We are involved in a variety of experiments ranging from mass measurements and decay studies to the use of reactions.

Consequently, we use a range of devices such as the neutron detector NERO, NSCL Beta Counting System, the SeGA γ-array, and the S800 spectrometer and work together with other groups at NSCL and elsewhere. The new NSCL low energy facility expected to be operational in 2009-2010 will also offer unique new opportunities for nuclear astrophysics experiments. At the same time, we are also involved in theoretical astrophysics calculations. Some of the calculations are done in our group, and others with collaborations through JINA.