Abstract

Theoretical computations are given for the radiation and electrical characteristics of the cesium discharge for pressure and power input above the range of present experimental technique. For a given pressure and temperature the electron concentration is given by Saha’s equation, the resistivity depends on the temperature and electron concentration and for sufficiently high pressures the power input is not much greater than the total power radiated by the vapor. The power radiated is evaluated from values of the emissivity times the radiant flux of a blackbody at the vapor temperature. Graphical integration gives the total radiant and luminous flux. An optimum luminous efficiency of about 180 lumens per watt is estimated for a fairly wide range of conditions centering around tube diameter 1 cm, pressure 176 mm, and temperature 6000°K. This requires a current of about 300 amperes and a gradient of 22 volts per cm. The brightness temperature is 5400°K and the color temperature roughly 3700°K. At 760 mm the brightness and color are nearly those of a blackbody. Values for various conditions are tabulated.

© 1939 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Basic Principles in Illumination Calculations*

Parry Moon
J. Opt. Soc. Am. 29(3) 108-116 (1939)

The Limiting Sensitivity of the Alternating-Current Method of Photo-Cell-Current Amplification

E. A. Johnson, W. H. Mock, and R. E. Hopkins
J. Opt. Soc. Am. 29(12) 506-511 (1939)

Standardization of the Luminous Transmission Scale Used in the Specification of Railroad Signal Glasses

Kasson S. Gibson and Geraldine Walker Haupt
J. Opt. Soc. Am. 29(5) 188-200 (1939)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (4)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (2)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (9)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription