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Kai Vetter

4171 Etcheverry Hall
Additional Affiliation: 

Director, Institute for Resilience Communities
Head, Applied Physics Program
Nuclear Science Division
Berkeley, CA 94720
Mailstop 50C



1995 PhD, Physics, J. W. Goethe-University, Frankfurt (Nuclear Physics)
1990 M.S., Physics, J. W. Goethe-University, Frankfurt (Nuclear Physics)
1987 B.S., Physics, Technical University, Darmstadt (Physics)

Teaching and Research: 

Professor Vetter teaches the core NE104 course, “Radiation Detection and Nuclear Instrumentation Laboratory” which combines lectures and laboratory work to teach the basic concepts, implementations, and operations in radiation detection. In addition, he teaches NE107, “Introduction to Imaging”, an introduction to medical imaging physics and systems, including X-ray radiography and Computed Tomography (CT), radionuclide imaging (planar imaging as well as Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET)), and Magnetic Resonance Imaging (MRI). Examples of advanced concepts that are being discussed are the recently developed phase-contrast X-ray imaging and hyper-polarization MRI. Professor Vetter also teaches the graduate level course NE204, “Advanced Concepts in Radiation Detection”. This course combines lectures and experiments, focusing on advanced concepts in radiation detection ranging from basic and advanced digital filters for signal processing in semiconductor and scintillator detectors to radiation imaging.

Areas of Interest: 

Professor Vetter’s research interests range from fundamental physics to biomedical imaging and homeland security. He is authored and co-authored over 150 peer-reviewed publications. He is also heads the Applied Nuclear Physics program at Lawrence Berkeley National Laboratory. This program entails almost all aspects of radiation detection including the detector fabrication, readout, integration and signal processing.

In addition to his research and teaching activities, Professor Vetter heads the recently established Institute for Resilient Communities. This institute is dedicated to providing tools that enhance resilience in communities locally and globally. The goal is to minimize the impact associated with sudden or long-term changes induced by human actions or nature. To achieve this goal, it combines science, technology, education, and outreach and involves academic and educational institutions as well as communities in an international, multi-disciplinary, and multi-cultural context.

The Institute for Resilient Communities provides a framework for research, education, and community involvement to minimize the physical and psychological impact of future disruptive events and developments. It provides a forum for dialogue among researchers, educators, decision makers, and communities locally and globally.

As an example, the 2011 events at the Fukushima Daiichi Nuclear Power Plant in Japan highlighted the unmet need to enhance resilience to radiological and nuclear accidents. The incident and associated large releases of radioactive materials had and continue to have an enormous societal and economic impact on Japan and globally. Although no casualties and health effects have been and likely will be attributable directly to radiation, these events have manifold and substantial impact on local communities and have provoked ongoing anxiety and concerns around the world.

Current Research Focus: 

The Applied Nuclear Physics Program pursues a large range of projects related to radiation detection as well as applied and fundamental physics:

  • Development and demonstration of new and/or improved gamma-ray (and neutron) imaging concepts for applications ranging from Homeland Security and Nuclear Non-Proliferation to Biomedical Imaging.
  • Specifically, detection and imaging schemes are being developed from the micrometer to the meter scale. High-resolution CCDs are being developed with micrometer resolution to measure details of radiation scattering induced charged particles, large-scale (e.g. 1 squaremeter) scintillator based gamma-ray imager are being employed to demonstrate new capabilities in the detection and identification of materials in large standoff distances. 
  • Mapping and characterization of radiation backgrounds in our environment
  • Environmental monitoring of radioactivity in our environment; Fukushima measurements; Transport and dispersion of radioactive materials in our environment.
  • Development of the Nuclear Street View, the presentation of nuclear radiation fields in our environment in 3D, combined with 3D objects in our environment.
  • 3D Volumetric Imaging and Scene-Data Fusion; Fusion of 3D radiation and object information based on spectroscopic gamma-ray imaging and visual and laser-mapping imaging.
  • Development and demonstration of real-time ion-cancer beam verification based on prompt gamma-ray imaging.
  • Development and demonstration of new and improved concepts in Ge detector technologies to provide unprecedented capabilities in observing rare decays or rare interactions. One of the objectives is the reduction in electronic noise for kg-scale detectors to levels significantly below 100 eV. 
  • Search for neutrino-less double-beta decay in Ge-76 to obtain better understanding on fundamental properties of neutrinos to answer fundamental questions such as: Is the neutrino its own anti-neutrino or what is the mass of neutrinos? 
  • Detection of Coherent Nuclear Neutrino Scattering, a predicted Standard Model process, that could potentially enable the detection of neutrinos from nuclear power reactors.
  • Basic nuclear physics experiments and associated instrumentation to better understand the basic structure of nuclei.
  • Characterization and enhancement of current semiconductor fabrication processes.
  • Development of strip-based CCD sensors for ultra-high resolution fast readout.
  • Pulse-shape analysis in segmented semiconductor detectors for improved event reconstruction.
Honors and Awards: 

2015    Presidential Citation, American Nuclear Society; Citation recognizes leadership in enhancing Community Resilience

2012    Presidential Citation, American Nuclear Society; Citation recognizes leadership in communications after Fukushima

2006    Edward Teller Fellowship Award, Lawrence Livermore National Laboratory

1997    Outstanding Performance Award, Lawrence Berkeley National Laboratory

1995    Fellowship, Deutsche Forschungsgemeinschaft

1990    Graduated Summa Cum Laude (University of Frankfurt)

Professional Activities: 

2011 Co-Chair, Program Committee, Symposium of Radiation Measurements and Applications, Berkeley, CA
2010 Workshop on Germanium-Based Detectors and Technologies, Berkeley, CA
2009-present Technical Support Advanced Technology Demonstration program for DHS/DNDO, Washington D.C.
2008-2009 Chair, Northern California Section of American Nuclear Society
2008 -present Co-Organizer, Advanced Summer School in Radiation Detection and Measurements, Berkeley, Tokyo, Munich
2007-2008 Chair-elect, Northern California Section of American Nuclear Society
2007 Organizer, Workshop for Detectors and Detector Configuration for the Majorana Experiment, Seattle, WA
2005-2011 Member, Technical Council for Majorana
2004-2011 Member, Gretina Advisory Committee
2004 Chair, session for SPECT imaging, DOE Workshop on Future of Gamma-Ray Imaging in Medical Sciences
2003-2011 Member, Gretina Technical Review Committee for DOE
2003-2008 Member, Majorana Executive Committee
2003-2004 Member, Gretina Steering Committee
2002 Member, National Gamma-Ray Tracking Coordination Committee
2001 Co-organizer, Workshop on Digital Signal Processing for Nuclear Physics Applications
2000 Chair, GRETA Working Group on Signal Processing and Gamma-Ray Tracking
2000-present Reviewer for IEEE Transactions in Nuclear Science
2000-present Reviewer for DOE Small Business Innovation Research Grant
1999-present Reviewer for Nuclear Instrumentation and Methods in Physics Research
1998-2006 Reviewer for Physical Review Letters and Physical Review C


Selected Publications: 
  • R. Cooper, M. Amman, K. Vetter, “A prototype high purity germanium detector for high resolution gamma-ray spectroscopy at high count rates”, Nucl. Instr. Meth. A 795 (2015) 167
  • T. Aucott, M. Bandstra, V. Negut, J. Curtis, D. Chivers, K. Vetter,” Effects of Detector Efficiency and Energy Resolution on Gamma-Ray Background Rejection in Mobile Spectroscopy and Imaging Systems”, Nucl. Instr. Meth. A, 789 (2015) 128
  • Q. Looker, M. Amman, K. Vetter, “Inter-Electrode Charge Collection in High-Purity Germanium Detectors with Amorphous Semiconductor Contacts”, accepted, Nucl. Instr. Meth. A 781 (2015) 20
  • Q. Looker, M. Amman, K. Vetter,” Leakage current in high-purity germanium detectors with amorphous semiconductor contacts”, Nucl. Instr. Meth. A, 777 (2015) 138
  • A. Haefner, D. Gunter, B. Plimley, R. Pavlovsky, K. Vetter,” Gamma-ray Momentum Reconstruction from Compton Electron Trajectories by Filtered Back-projection”, Appl. Phys. Lett. 105, 184101 (2014)
  • T. Aucott , M. Bandstra, V. Negut, J. Curtis, K. Vetter “Effects of Background on Gamma-Ray Detection for Mobile Spectroscopy and Imaging Systems", IEEE Transactions in Nuclear Science, Volume 61.2 (2014), 985
  • K. Vetter, D. Chivers, B. Plimley, A. Coffer, T, Aucott, Q. Looker,” First demonstration of electron-tracking based Compton imaging in solid-state detectors”, Nucl. Instr. Meth. A 652 (2011) 599
  • B. Plimley, D. Chivers, A. Coffer, T. Aucott, W. Wanga, K. Vetter, ”Reconstruction of electron trajectories in high-resolution Si devices for advanced Compton imaging”, Nucl. Instr. Meth. A 652 (2011)  
  • D. Chivers, A. Coffer B. Plimley, K. Vetter, “Impact of Measuring Electron Tracks in High-Resolution Scientific Charge-Coupled Devices within Compton Imaging Systems”, Nucl. Instr. Meth. A 654 (2011) 244
  • L. Mihailescu, K. Vetter, D. Chivers, “Standoff 3D Gamma-Ray Imaging”, IEEE Trans. Nucl. Sci. 56, 2 (2009) 479
  • D.B. Campbell, K. Vetter, R. Henning, K.T. Lesko, Y.D. Chan, A.W. Poon, M. Perry, D.Husley, A.R. Smith, “Evaluation of radioactive background rejection in 76Ge neutrino-less double-beta decay experiments using a highly segmented HPGe detector”, Nucl. Instr. Meth. A, 587 (2008) 60
  • K. Vetter, “Recent Developments in the Fabrication and Operation of Germanium Detectors”, Annual Review in Nuclear and Particle Physics, 57 (2007) 326
  • K. Vetter, M. Burks, C. Cork, M. Cunningham, D. Chivers, E. Hull, T. Krings, H. Manini, L. Mihailescu, K. Nelson, D. Protic, J. Valentine and D. Wright, “High-sensitivity Compton imaging with position-sensitive Si and Ge detectors”, Nucl. Instr. Meth. A 579 (2007) 363
  • L. Mihailescu, K. Vetter, M. Burks, E. Hull, W. Craig, “SPEIR: a Compton camera”, Nucl. Instr. Meth. A 570 (2007) 89
  • T. Niedermayr, K. Vetter, L. Mihailescu, G. J. Schmid, D. Beckedahl, J. Blair, J. Kammeraad, “Gamma-ray imaging with a coaxial HPGe detector”, Nucl. Instr. Meth. A 553 (2005) 501
  • K. Vetter, M. Burks, L. Mihailescu, “Gamma-ray imaging with position-sensitive HPGe detectors”, Nucl. Inst. Meth. A 525 (2004) 322
  • I.Y.Lee, M.A.Deleplanque, K.Vetter, “Developments in large gamma-ray detector arrays”, Rep. Prog. Phys. 66, 1095 (2003)
  • K. Vetter, “Gamma-Ray Tracking: New Opportunities for Nuclear Physics”, Feature article in Nuclear Physics News, Vol. 12, No.2, 2002
  • K.Vetter , “Gamma-ray tracking: Utilizing new concepts in the detection of gamma-radiation”, Eur.Phys.J. A 15, 265 (2002)
  • C. L. Hartmann Siantar, K. Vetter, G. L. DeNardo, S. J. DeNardo, “Treatment planning for molecular targeted radionuclide therapy”, Cancer Biotherapy and Radiopharmaceuticals 17(3) (2002)
  • K.Vetter, “GRETA: The proof-of-principle for gamma-ray tracking”, Nucl.Phys. A682, 286c (2001)
  • G.J.Schmid, D.A.Beckedahl, J.E.Kammeraad, K.P.Ziock, J.J.Blair, K.Vetter, A.Kuhn, “Gamma-ray Compton Camera Imaging with a Segmented HPGe Detector”, Nucl. Instr. Meth. A459, 565 (2001)
  • K.Vetter, “GRETA: The proof-of-principle of gamma-ray tracking”, Nucl.Phys. A682, 286c (2001)
  • K.Vetter, A.Kuhn, M.A.Deleplanque, I.Y.Lee, F.S.Stephens, R.M.Clark, M.Cromaz, R.M.Diamond, P.Fallon, G.J.Lane, A.O.Macchiavelli, C.E.Svensson, “Performance of the GRETA Prototype Detector”, Nucl. Instr. Meth. A452, 105 (2000)