- Post Doc position is available for the development of a high-efficiency serial protein crystallography method at room temperature by combining the ultrasonic acoustic levitation of single protein crystal and high-frame-rate pixel array detector at SLS and potentially at SwissFEL. See our recently published article, and the PSI news, "Experiment in a hovering droplet". For further information and application, see here.
- Ultrasonic acoustic levitation experiment at the macromolecular crystallography beamline was published at Scientific Reports, and featured at PSI news, "Experiment in a hovering droplet".
- New Vacuum Nanoelectronics homepage is open! Visit the page for the latest info on IVNC 2016, the 29th International Vacuum Nanoelectronics Conference, as well as the information on the Ken Shoulders, Capp Spindt, and Henry Gray and SEM pictures of nano emitters. IVNC 2016 will be held at the University of British Columbia in Vancouver, Canada, during 11-15 July.
- S. Tsujino reported (invited talk) at IVNC 2015, in Gaungzhou, China, the first demonstration of the emittance reduction to 0.1 micron/mm with a double-gate FEA .
ABOUTWe are developing metal field emitter array (FEA) cathode [1-14] as a potential upgrade option for the SwissFEL X-ray free electron laser  at Paul Scherrer Institute, which require a stringent cathode specs in current (200 pC in 10 ps) and normalized transverse emittance (0.4 mm-mrad). It should also be compatible with the high acceleration electric field in the order of 100 MV/m.
To realize a high brightness cathode that can out-perform the state-of-the-art cathode (such as photocathode), our strategy is to use field emitter arrays with the stacked double-gate structure [5-8] that can be compatible with the high acceleration electric field [9,10], combined with the high current ultra-fast laser-induced field emission [1-4,12].
High current and high beam brightness cathodes targeted by this group have the potential to improve the performance and stability of the SwissFEL X-ray free electron laser substantially. Such cathodes could also reduce the cost and the size of compact X-ray free electron lasers in the future significantly.
The double-gate FEAs with the demonstrated collimation capability will open up new electron beam applications including micro electron microscope, THz power amplifiers, ultra-compact mass spectrometers, X-ray sources, parallel e-beam lithography tools etc.
In collaboration with the University of Hamburg, we also conduct research directing to developing the brightest, next generation electron sources, for atomically resolving the structure-function correlation in biological systems – directly observe biology in action at atomic level.
References S. Tsujino, P. Beaud, E. Kirk, T. Vogel, H. Sehr, J. Gobrecht, and A. Wrulich, Ultrafast electron emission from metallic nanotip arrays induced by near infrared femtosecond laser pulses, Appl. Phys. Lett. 92, 193501 (2008).
 S. Tsujino, F. le Pimpec, J. Raabe, M. Buess, M. Dehler, E. Kirk, J. Gobrecht, and A. Wrulich, Static and optical field enhancement in metallic nanotips studied by two-photon photoemission microscopy and spectroscopy excited by picosecond laser pulses, Appl. Phys. Lett. 94, 093508 (2009).
 A. Mustonen, P. Beaud, E. Kirk, T. Feurer, and S. Tsujino, Five picocoulomb electron bunch generation by ultrafast laser-induced field emission from metallic nano-tip arrays, Appl. Phys. Lett. 99, 103504 (2011).
 A. Mustonen, P. Beaud, E. Kirk, T. Feurer, and S. Tsujino, Efficient light coupling for optically excited high-density metallic nanotip arrays, Scientific Reports, 2, 915 (2012).
 S. Tsujino, P. Helfenstein, E. Kirk, T. Vogel, C. Escher, and H.-W. Fink, Field-Emission Characteristics of Molded Molybdenum Nanotip Arrays With Stacked Collimation Gate Electrodes, IEEE Electron Device Letters, vol. 31, 1059 (2010).
 P. Helfenstein, E. Kirk, K. Jefimovs, T. Vogel, C. Escher, H.-W. Fink, and S. Tsujino, Highly collimated electron beams from double-gate field emitter arrays with large collimation gate apertures, Appl. Phys. Lett. 98, 061502 (2011).
 P. Helfenstein, K. Jefimovs, E. Kirk, C. Escher, H.-W. Fink, and S. Tsujino, Fabrication of metallic double-gate field emitter arrays and their electron beam collimation characteristics, J. Appl. Phys. 112, 093307 (2012).
 P. Helfenstein, V. A. Guzenko, H.-W. Fink, and S. Tsujino, _Electron beam collimation with a 40 000 tip metallic double-gate field emitter array and in-situ control of nanotip sharpness distribution, J. Appl. Phys. 113, 043306 (2013).
 S. Tsujino, M. Paraliev, E. Kirk, T. Vogel, F. Le Pimpec, C. Gough, S. Ivkovic, and H.-H. Braun, _Nanosecond pulsed field emission from single-gate metallic field emitter arrays fabricated by molding, J. Vac. Sci. Technol. B29, 02B117 (2011).
 S. Tsujino, M. Paraliev, E. Kirk, C. Gough, S. Ivkovic, and H.-H. Braun, Sub-nanosecond switching and acceleration to relativistic energies of field emission electron bunches from metallic nano-tips, Phys. Plasmas 18, 064502 (2011).
 S. Tsujino, M. Paraliev, E. Kirk, and H.-H. Braun, _Homogeneity improvement of field emission beam from metallic nano-tip arrays by noble-gas conditioning, Appl. Phys. Lett. 99, 073101 (2011).
 P. Helfenstein, A. Mustonen, T. Feurer, and S. Tsujino, _Collimated Field Emission Beams from Metal Double-Gate Nanotip Arrays Optically Excited via Surface Plasmon Resonance, Applied Physics Express, 6, 114301 (2013).
 S. Tsujino and M. Paraliev, _Picosecond electrical switching of single-gate metal nanotip parrays, J. Vac. Sci. Technol. B 32, 02B103 (2014).
 A. Mustonen, V. Guzenko, C. Spreu, T. Feurer, and S. Tsujino, High-density metallic nano-emitter arrays and their field emission characteristics, Nanotechnology 25, 085203 (2014).
 B. Patterson, R. Abela, H.-H. Braun, U. Flechsig, R. Ganter, Y. Kim, E. Kirk, A. Oppelt, M. Pedrozzi, S. Reiche, L. Rivkin, Th. Schmidt, B. Schmidt, V. N. Strocov, S. Tsujino, and A. F. Wrulich, Coherent science at the SwissFEL x-ray laser, New J. Physics, 12, 035012 (2010).
- PSI metallic field emitter arrays : Introduction and Nanotip fabrication
- Ultrafast near infrared laser-induced field emission
- Stacked double-gate field emitter arrays with large collimation gate apertures
- Picosecond electrical switching, high-accelration-compatibility, and relativistic acceleration
- Emittance of single-gate field emitter arrays
- In-situ uniformity control of field emission beam
Vacuum Nanoelectronics GroupChiwon Lee (wth Max-Planck Institute)
Jens Gobrecht, Prof. Dr.
Soichiro Tsujino, Dr. (Group Leader)
Collaborations (within PSI)V. Guzenko, Dr., P. Karvinen, Dr., and C. David, Dr., (LMN, Electron-beam lithography)
M. Paraliev, Dr. and G. Gough (GFA, HF and HV)
P. Beaud, Dr. (SYN-FEMTO, femtosecond spectroscopy)
M. Aiba, Dr. and M. Dehler, Dr. (GFA, FEA beam simulation)
H.-H. Braun, Dr. (Project leader accelerator, SwissFEL)
Collaborations externalT. Feurer, Prof. Dr. (University of Bern)
R. Bischofberger (Applied MicroSWISS GmbH)
R. J. D. Miller, Prof. Dr. (Max Plank Research Dept., Univ. Hamburg and Univ. Toronto)
FIRST lab., ETH Zürich
Former membersAnna Mustonen, Dr.
Patrick Helfenstein, Dr.
Prat Das Kanungo, Dr.
Youngjin Oh, Dr.
Eugenie Kirk, Dr.