Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Hans Volker Klapdor-Kleingrothaus (also known as H.V. Klapdor) was born on January 25, 1942 in Reinbek and is a German physicist who works in nuclear physics, particle physics and astrophysics. Klapdor-Kleingrothaus studied physics at the University of Hamburg and received his PhD (Dr. rer. nat.) in 1969 with a thesis on gamma-ray spectroscopy at a particle accelerator. From 1969 until 2007 he worked at the Max Planck Institute for Nuclear Physics in Heidelberg, originally studying heavy ion reactions.