Searching online

Seeking information online is heartbreaking. Typing "franck-hertz" in Google produces over 40000 hits. A random perusal shows that most of them are "lab-manuals" posted by teachers, presumably for their own students. Few if any of those are satisfactory.

For example, it is easy to check that – at least with mercury – the experiment works regardless of the sign of the potential between the accelerating grid and the anode. This was pointed out in the literature more than 20 years ago (see McMahon 1983 below) and clearly implies that the traditional explanation of the experiment is deeply flawed. Nevertheless I am not aware of any single case where the students are encouraged to actually verify the influence of the sign of the imposed grid-anode bias.

Evidently, the vast majority of physics instructors are either unaware of such problems or unwilling to question the prevalent explanation. A comprehensive revision of the textbook interpretation is obviously long overdue and the present site aims to help.

Fortunately, there is a way to obtain the "serious" references among fewer items of the usual “textbook” variety. Google Scholar produces significantly fewer hits which include several of the items listed below.



* Standard Franck-Hertz Experiment

1) Melissinos A C 1966 Experiments in Modern Physics (New York: McGraw-Hill) pp. 8-17

2) Franck J and Hertz G 1914 Verh. Deutsche Phys. Ges. 16, 457

3) Franck J and Hertz G 1925 Nobel lectures

    F-H nobel 1925.pdf

4) Genoglio R J 1973 Am. J. Phys. 41, 288 : Average energy of electrons in a Franck-Hertz tube.

    Genoglio 1973.pdf

  1. 5)Huebner J S 1976 Am. J. Phys. 44, 302-303 : Comment on the Franck-Hertz experiment.

    Huebner 1976.pdf

  1. 6)Buhr W, Klein W and Pressler S 1983 Am. J. Phys. 51, 810-814 : Electron impact excitation and uv emission in the Franck-Hertz experiment.

    Buhr 1983.pdf

  1. 7)McMahon D R A 1983 Am. J. Phys. 51, 1086 : Elastic collision effects in the Franck-Hertz experiment.

    McMahon 1983.pdf

  1. 8)Fletcher J 1985 J. Phys. D: Appl. Phys. 18, 221-227: Non-equilibrium in low-pressure rare gas discharges.

    Fletcher 1985.pdf

9) Hanne G F 1988 Am. J. Phys. 56, 696-700 : What really happens in the Franck-Hertz experiment

    with mercury?

    Hanne 1988.pdf

10) Robson R E, Li B and White R D 2000 J. Phys B: At. Mol. Opt. Phys. 33, 507-520 :

      Spatially periodic structures in electron swarms and the Franck-Hertz experiment.

      Robson-Li-White 2000.pdf

11) Li B, White R D and Robson R E 2002 J. Phys. D: Appl. Phys. 35, 2914-2924 : Spatially periodic structures

      in electron swarms : ionization, NDC effects and multi-term analysis.

      Li-White-Robson 2002.pdf

12) Siegeneger F and Winkler R 2002 Eur. Phys. J. AP 19, 211-212: On the kinetics of electron trapping

      in the Franck-Hertz experiment.

      Sigeneger 2002.pdf

13) Siegeneger F, Winkler R and Robson R E 2003 Contrib. Plasma Phys. 43, 178-197 : What really

      happens  with the electron gas in the famous Franck experiment?

      Sigeneger 2003.pdf

14) Rapior G, Sengstock K and Baev V 2006 : Am. J. Phys. 74, 423-428 : New features of the Franck-Hertz experiment.

      Rapior 2006.pdf

15) Nicoletopoulos P and Robson R E 2008 Phys. Rev. Lett. 100, 124502: Periodic electron structures in gases:

      A fluid model of the "window" phenomenon.

      Fluid model 2008.pdf


   * Extended Franck-Hertz Experiment

1) Harnwell G P and Livingood J J 1933 Exper. Atomic Phys. (New York: Academic) pp. 317-318

2) Melissinos A C 1966 Experiments in Modern Physics (New York: McGraw-Hill) pp. 8-17

3) Mohler F L, Foote P D and Meggers W F 1920 J. Opt. Soc. Am. 4, 364 -370 : Resonance

    potentials and low-voltage arcs for metals of the second group of the periodic table.

    Mohler 1920.pdf

4) Einsporn E 1921 Z. Phys.  5, 208-219 : Über die Anregungs- und Ionisierungsspannungen des


    Einsporn 1921.pdf

5) Eldridge J A 1922 Phys. Rev. 20, 456-475 : The energy losses accompanying ionization

    and resonance in mercury vapor.

    Eldridge 1922.pdf

6) Minkowski R 1923 Z. Phys. 18, 258-262 : Über die freie Weglänge langsammer Electronen in

    Hg- und Cd- Dampf.

    Minkowski 1923.pdf

7) Martin A D and Quinn P J 1984 Am. J. Phys. 52, 1114-1116 : Electron spectroscopy using

     a Franck-Hertz tube.

     Martin 1984.pdf

8) Liu F H 1987 Am. J. Phys. 55, 366-369 : Franck-Hertz experiment with higher excitation

    level measurements.

    Liu 1987.pdf

9) Nicoletopoulos P 2002 Eur. J. Phys. 23, 533-548 : Critical potentials of mercury with a

    Franck-Hertz tube.

    Critical potentials 2002.pdf

10) Nicoletopoulos P 2004 Eur. J. Phys. 25, 373-383 : The '0.4 eV' shape resonance of mercury

      in a Franck-Hertz tube.

      Shape resonance 2004.pdf

11) Nicoletopoulos P 2008 Phys. Rev. E 78, 026403: Double-layer formation in the extended  Franck-Hertz experiment.

      Double layer 2008.pdf


Up-to-date literature on the Franck-Hertz experiment