An a. c. operated mass spectrograph of the Mattauch type.
A mass spectrograph for chemical analysis of solid samples has been developed. The Mattauch arrangement of a 31° 50′ electric deflection followed by a 90° deflection in a magnetic field was used in order to obtain a large mass range in focus on one plate. The accelerating and deflecting voltages, and the current for the electromagnet were obtained from stabilized rectifier circuits connected to the 60‐cycle a.c. supply. The electromagnet with 100 milliamperes gave a field of 18,800 gauss across a ⅛″ gap. During the introduction of the plate or insertion of new electrodes a gate valve was closed to isolate the spectrograph from the pumping system. In this way different samples could be examined rapidly. The ion source was energized by a compact Tesla transformer wound on Lucite cylinders. One exposure covered a mass range from any mass M to a mass 10M.
Ion Sources for Mass Spectroscopy
Three spectroscopic methods of exciting spectra have been examined as possible sources of positive rays. The vacuum vibrator, a mechanically interrupted low potential spark, has been found to give positive ions although the source is not constant. The discharge of a large condenser charged to 60 kilovolts between metal electrodes, has been found unsatisfactory as a source of positive ions. A high frequency alternating spark coupled inductively to a primary oscillating spark circuit, is a strong convenient source. The ions may be accelerated to form a beam, and, with the Thomson parabola method of analysis, it has been found that multiply charged ions of the electrode elements are formed in all cases tried.
Wellenlängen der Vakuumfunkenspektren von Kohlenstoff, Stickstoff und Sauerstoff im extremen Ultraviolett
ZusammenfassungDie folgenden Wellenlängentabellen repräsentieren die kurzwelligen Vakuumfunkenspektren der Elemente C, N und O. Sie umfassen insgesamt etwa 1200 Linien von 104 bis 1923 Å und sind im Gebiet 115 bis 550 Å mit vergrößerten Spektrogrammen illustriert.