On the Liberation of Ions by Electron Bombardment

Abstract

EDITOR 1269 and minus 1 kev. Assuming the A\ (p,y) resonance to lie at 993.3 kev we then found the F(p,y) resonance at 873.1 kev and the Li 7 (p,n)Be 7 threshold at 1880 kev agreeing with Herb, Snowden, and Sala's values to well within our voltage ripple. This scale then puts the T 3 (£,»)He 3 threshold at 1019"i + * kev, giving a Q value of -763.7 kev, where the mass factor used was 0.749s.Assuming zero-neutrino mass and a beta-ray end point of 18.3 kev this threshold measurement gives the n-H mass difference as 782 ± 1.5 kev. The 18.3-kev end point which gives the T 3 -He 3 mass difference has been measured in this laboratory by Graves and Meyer 3 and by McKibben and Shurig. 4 This value is in agreement with other recent results. 6 The neutron-proton mass difference determined here is roughly 18 kev lower than that given by Bell and Elliott 6 and that reported by Jenkins. 7 The systematic errors, aside from the absolute energy scale, which one would expect in our experiment are all such as to raise the threshold of T 3 (£,w)He 3 and therefore the neutron-hydrogen mass difference.T HE beta-spectrum of I 131 has recently been studied in this laboratory 1 with a view toward determining its possible complexity. In connection with this study a number of internal conversion lines were found and were assigned as K, L and M lines of four gamma-ray energies. Metzger and Deutsch 2 also have recently made a study of the I 131 radiations. Their report did not include a gamma-ray of 163 kev energy

Electrical discharges in high vacuum

“…VAN DE GRAAFF and his collaborators as well as other authors have made many measurements to determine A and B [1], [21, [3], [4] and [5]. The results of all these measurements contradict the above theory namely AB always proved to be much smaller than 1.…”

Electrical phenomena at the surface of electrically stressed metal cathodes. I. Electroluminescence and breakdown phenomena with medium gap spacings (2-8 mm)

“…Maskrey and Dugdale (1966) suggested that impurity charging could occur by positive ions emitted at the anode following electron bombardment by beams emitted at the cathode. This seems unlikely in the present case in view of the small size of cathode impurity and the small value of the coefficient of positive ion production under electron impact (10-6 at 50 kV in a moderately clean oil pumped system, (Filosofo and Rostagni 1949)). In addition breakdowns were frequently observed from k-spot regions which were not favourably placed to receive positive ions, e.g.…”

The Electrical Breakdown of Small Gaps in Vacuum

“…This effect has bee11 met by Bennett (1931), Anderson (19:3,5), and Heard and Lauer (1952). 3Ieasurements in recent years (Trump ancl Van de Graaff 1947;Filosofa and Rostagni 1949;Webster et ab. 1952) on the coefficients involved in process (d) have indicated that they are not large enough to account for breakdolvn.…”