A New Spin on Photoemission Spectroscopy Page: 49 of 259
This thesis or dissertation is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
Figure 2.1. Schematic of Hertz's famous experiment demonstrating the photoelectric effect.
Large inductors (a,e) powered by a battery (b) drive spark gaps (d,f). When switch (c) is
open, primary spark at (d) was found to influence the possibility of spark at (f). Influence
of primary spark could be shielded with a metal plate (p). Figure adapted from ref. 31.
most influential contributions was performed by Philipp Lenard, who began his career as
an assistant to Hertz. Lenard began to investigate the velocity distribution of the photo-
electrons, although at the time they were not understood to be electrons, but were referred
to as cathode rays. He wondered if adsorbed gases on the cathode had an influence on his
measurements, and he began doing his photoemission experiments in vacuum tubes, such
as shown in Figure 2.2(a). With such an apparatus, he performed many experiments on the
effect of external electric and magnetic fields on the cathode rays, and used retarding poten-
tials at the anodes to study their velocity distributions. He came to three key conclusions
in 1902 which had no immediate explanation.33 First he noted that the number of cathode
rays depended on the light intensity. Second, he found that cathode ray velocity did not,
however, depend on the light intensity. Finally, he found that the velocity was dependent
on the light frequency. Lenard later received the 1905 Nobel prize for his work with cathode
rays, which he described as "negatively charged quanta of electricity". It is interesting to
Here’s what’s next.
This document can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Thesis Or Dissertation.
Jozwiak, Chris. A New Spin on Photoemission Spectroscopy, thesis or dissertation, December 1, 2008; United States. (https://digital.library.unt.edu/ark:/67531/metadc1014237/m1/49/?rotate=90: accessed May 26, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.