The Number of Lines in a Series as a Function of Electron Pressure.
Abstract
In an intense discharge the higher lines of a series merge into a continuous spectrum at a value of the effective quantum number nm which depends upon the electron con centration N. A previous paper by the author gives values of the electron concentra tion for the caesium discharge for a wide range of vapor pressures and current densities. The number of lines in the D and F series have been determined for this range of condi tions. The maximum quantum number for the red component of the D series and for the F series is given by the equation log Ne = 23.06  7.5 log flm. This relation agrees well with theoretical results for hydrogenic spectra and has been applied to stellar spectra. For mainsequence Ao stars the electron pressure in at mospheres is 0.4 X ~ at the Balmer limit; 0.7 X io4 at the Paschen limit, and i.8 X ~~4 at 4340 A. The star a Cygni has a pressure of about ` X ~ At. at the Balmer limit, while for white dwarfs the pressure exceeds 102 At
 Publication:

The Astrophysical Journal
 Pub Date:
 October 1939
 DOI:
 10.1086/144117
 Bibcode:
 1939ApJ....90..429M