On the Brightness, Emittance, and Coherence of Field Emission Beam
Soichiro Tsujino (Paul Scherrer Institut)
IVNC 2021 Tutorial, July 5, 2021, virtual/Lyon, France,
The highly brilliant electron beam produced by field emitters is one of the critical ingredients for the development of high resolution electron microscopes achieving atomic resolution[1–4]. The high current, high current density, and high beam brightness of electron beams orignating from field emission tip sources have been also intensely studied in the past for several applications including high frequency vacuum tubes[5,6], accelerators[7–9], time-resolved electron diffraction[10,11], coherent imaging[12,13], to name a few. In this tutorial, after a brief overview of the development of the atomic-resolution electron microscopes[1–3,19], we will introduce key concepts for beam applications such as the brightness, the transverse emittance, and the transverse coherence length of field emitters[2–4,14–17,19] and review recent measurements on the transverse emittance9 and the transverse coherence length[11,18]. Finally, the importance of the coherence within the source and the transverse structure of the wave function of field emission electrons on the propagation and the spot size of field emission beam will be discussed[12–15,20].
 Crewe, A. V., Issacson, M., and Johnson, D. (1967) Rev. Sci. Instrum 40, 241.
 Krivanek, O. K. et al. (2008) in Advances in Imaging and Electron Physics (Hawkes, P., Ed.) 153, 121–160, Elsevier Inc.
 Krivanek, O. K., et al. (2011) in Scanning Transmission Electron Microscopy (PennycookS., and Nellist, P. Eds. ) 1–41, Springer, New York, NY.
 Kruit, P. (2016) inTransmission Electron Microscopy (Carter, C. B., andWilliams, D. B. Eds.), 2–14, Springer
International Publishing, Switzerland.
 Booske, H. (2008) Phys. Plasmas15, 055502.
 Whaley, D. R., et al. (2009) IEEE Transactions on Electron Devices,IEEE Trans. ED56, 896–905.
 Brau, C. A. (1997) Nucl. Instr. Meth. A393, 426–429.
 Ganter, et al. (2006) Proceedings of FEL 2006, BESSY, Berlin, Germany THCAU04.
 Tsujino, S., Das Kanungo, P., Monshipouri, M., Lee, C., and Miller, R. J. D. (2016) Nat Commun 7, 13976.
 Miller, R. J. D. (2014) Ann. Rev. Chem. 65, 583—604.9
 Lee, C., Tsujino, S. and Miller, R. J. D. (2018) Appl. Phys. Lett.113, 013505.
 Latychevskaia, T. (2017) Ultramicroscopy175, 121–129.
 Krecinic, K., and Ernstorfer, R. (2021) Phys. Rev. Appl.15, 064031.
 Pozzi, G. (1987) Optik77, 69–73.
 Mandel L., and Wolf, E, (1995) Optical Coherence and Quantum Optics 1st ed., Cambdige University Press, Cambrige.
 Reiser, M. (2008) Theory, Design of Charged Particle Beams, WILEY-VCH Verlag GmbH Co.KGaA, Weinheim.
 Thompson A. R., et al. (2017) in Interferometry and Syhnthesis in Radio Astronomy 3rd ed.,767–780,
Astronomy and Astrophysics Library, Springer International Publishing, Switzerland.
 Cho, B., Ichimura, T., Shimizu, R., and Oshima, C. (2004) Phys. Rev. Lett.92,246103.
 Williams, D., and Carter, C. B. (2009) in Transmission Electron MIcroscopyA Textbook for Materials Science,
73–89, Springer Science+Business Media LLC.
 Tsujino, S. (2018) J. Appl. Phys.124, 044304.