1. Solid‐State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109
2. Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom and Diagnostic Radiology and Radiation Protection, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom
3. Department of Physics, University of Virginia, Charlottesville, Virginia 22908