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A Determination of the Cloud Expansion Method of the Direction of Emissions of B-Rays Produced by X-Rays


Loughridge, Donald Holt (1927) A Determination of the Cloud Expansion Method of the Direction of Emissions of B-Rays Produced by X-Rays. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/NWNK-J316.


Cloud expansion photographs of the photoelectrons produced in hydrogen, air, and argon by means of the Kα radiation of Mo show that the most probable direction of emission is the same for all three gases, and forms an angle of about 70° with the x-ray beam. These angles have been measured by means of a stereoscopic comparator specially built for the purpose. The total number of tracks measured is 443. Distribution curves plotted with number of tracks starting at a given angle with the x-ray beam against the angle show a narrower peak for hydrogen than for the argon. This qualitatively supports the view that the distribution is due to secondary scattering by the electrons in the atoms thru which the photo-electron passes and that the initial direction of emission may be constant for a definite wave length and depend only on the radiation.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Physics
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Millikan, Robert Andrews
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1927
Record Number:CaltechETD:etd-06242004-102853
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2709
Deposited By: Imported from ETD-db
Deposited On:24 Jun 2004
Last Modified:03 Oct 2019 23:20

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PDF (Loughridge_dh_1927.pdf) - Final Version
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