1. Department of Chemical Engineering, Stanford University, Stanford, California 94305 and Department of Engineering Sciences, Division of Solid State Electronics, Uppsala University, 75121 Uppsala, Sweden
2. ION-TOF GmbH, Heisenbergstraße 15, 48149 Münster, Germany
3. Department of Chemical Engineering, Stanford University, Stanford, California 94305
4. Department of Electrical Engineering, Stanford University, Stanford, California 94305
5. Department of Material Science and Engineering, Stanford University, Stanford, California 94305