Excitation-Curves for Fluorine and Lithium

Observations on the alpha-particles emitted by lithium and the gamma-rays emitted by lithium and fluorine when bombarded with protons of energies up to 1000 kv have been improved by the use of a corona-free, 10,000-megohm voltmeter-resistor for voltage-measurements. By this means the accuracy of our measurements has been brought to two percent on an absolute scale and about one percent on a relative scale. Oscillograph-studies of voltage-fluctuations have shown that up to 1000 kv the voltage is constant to \ifmmode\pm\else\textpm\fi{}1.4 percent "peak-ripple." For the distribution-curve for voltage versus time the "half-maximum" width is about one percent at 1000 kv. Results thus far obtained for the gamma-ray resonances are as follows: There is an indication of a weak multiplet structure in fluorine in the region between 500 and 700 kv with a broad but fairly prominent "resonance" at 650 to 700 kv. The existence of a resonance in lithium at 850 kv was not confirmed.