Tom Kirchner's Personal Homepage

Tom Kirchner's Personal Homepage

Dr. Tom Kirchner
Professor of Physics
Graduate Program Director
Department of Physics and Astronomy
York University
4700 Keele Street
Toronto, Ontario, M3J 1P3
Tel: (416) 736-2100 ext 33695
Fax: (416) 736-5516
tomk [at]

Teaching (2019/20)

PHYS 4011/5050 : Atomic and Molecular Physics

Previously, I also taught PHYS 1410 , PHYS 3010 , PHYS 4010 , PHYS 5000 , PHYS 6204 , and PHYS 6208 at York. You can find some info and lecture notes by clicking on the links above.


My research is concerned with the question of how atomic and molecular few-body systems respond to perturbations exerted on them by impinging particles and external fields. Such collision or laser field induced quantum dynamics have implications for a variety of topics and applications ranging from plasma diagnostics to radiation biology. What is more, they constitute a problem of fundamental importance: How do the building blocks of matter interact and evolve in space and time? The better this question is answered the more is learned about a further issue that receives considerable attention: Can few-body quantum dynamics be manipulated purposefully and controlled actively? I have participated in a number of projects and activities to shed light on these issues by theoretical analysis and computations. The theoretical approaches used include density functional theory to deal with the many-electron problem, and both nonperturbative and perturbative quantum methods to describe the dynamics of the systems.

In the last few years we have been working on methods to describe ionization and fragmentation of multi-center molecules. Applications are concerned with, e.g., ion-induced fragmentation of water, which is a relevant process in the radiation damage of biological tissue.

Selected papers on ion-molecule collisions

  1. H. J. Lüdde, M. Horbatsch, and T. Kirchner, Electron capture and ionization cross-section calculations for proton collisions with methane and the DNA and RNA nucleobases, Eur. Phys. J. D 73, 249 (2019)
  2. H. J. Lüdde, M. Horbatsch, and T. Kirchner, Proton-impact-induced electron emission from biologically relevant molecules studied with a screened independent atom model, J. Phys. B 52, 195203 (2019)
  3. H. J. Lüdde, M. Horbatsch, and T. Kirchner, A screened independent atom model for the description of ion collisions from atomic and molecular clusters, Eur. Phys. J. B 91, 99 (2018)
  4. H. J. Lüdde, A. Achenbach, T. Kalkbrenner, H.-C. Jankowiak, and T. Kirchner, An independent-atom-model description of ion-molecule collisions including geometric screening corrections, Eur. Phys. J. D 70, 82 (2016)
  5. H. Luna, W. Wolff, E. C. Montenegro, A. C. Tavares, H. J. Lüdde, G. Schenk, M. Horbatsch, and T. Kirchner, Ionization and electron-capture cross sections for single- and multiple-electron removal from H2O by Li3+ impact, Phys. Rev. A 93 052705 (2016)
  6. T. Kirchner, M. Murakami, M. Horbatsch, and H. J. Lüdde, Ion collisions with water molecules: a time-dependent density functional theory approach, in: Advances in Quantum Chemistry, Vol. 65: Theory of Heavy Ion Collision Physics in Hadron Therapy, ed. by Dz. Belkic, (Elsevier, Amsterdam 2013)
  7. M. Murakami, T. Kirchner, M. Horbatsch, and H. J. Lüdde, Quantum-mechanical calculation of multiple electron removal and fragmentation cross sections in He+-H2O collisions, Phys. Rev. A 86, 022719 (2012)
  8. M. Murakami, T. Kirchner, M. Horbatsch, and H. J. Lüdde, Fragmentation of water molecules by proton impact: the role of multiple electron processes, Phys. Rev. A 85, 052713 (2012)
  9. M. Murakami, T. Kirchner, M. Horbatsch, and H. J. Lüdde, Single and multiple electron removal processes in proton-water vapor collisions, Phys. Rev. A 85, 052704 (2012)

Full list of my publications

Vita (last update: October 2019)

To York's Physics and Astronomy department homepage