Vacuum tube characteristics in relation to the selection of coincident pulses from cosmic ray counters
✍ Scribed by Lewis Fussell Jr.; Thomas H. Johnson
- Publisher
- Elsevier Science
- Year
- 1934
- Tongue
- English
- Weight
- 317 KB
- Volume
- 217
- Category
- Article
- ISSN
- 0016-0032
No coin nor oath required. For personal study only.
✦ Synopsis
Many investigations of cosmic ray phe-FOUNDATION nomena depend upon the counting of CO-Commu~ca~on No. S6. incident discharges of two or more Geiger-Mueller counters. Although several devices have been suggested for selecting and recording coincidences, the most convenient is undoubtedly a vacuum tube circuit. The first circuit of this type, used by Bothe and Kolhorster 1 for recording coincident discharges of two counters, made use of a vacuum tube with two grids, one counter being connected to each grid. Other circuits for recording coincident pulses have also been suggested, but the most satisfactory is without doubt that proposed by Rossi 2 and incorporated into the circuit described by Johnson and Street. 3 This is represented in its essential form in Fig. . Each of the several counters, of which there may be any arbitrary number, is connected directly or through other stages of amplification to the control grids of a corresponding number of vacuum tubes, so that negative pulses from the counters raise the internal impedances of the tubes from low to high values. The plates of the several tubes are connected in parallel through the resistance R to the supply voltage, V, and the change in the potential of the point A constitutes the output pulse to the recording circuit. If this pulse is large enough to overcome a certain negative bias on the grid of the first tube of this circuit a count is recorded, whereas a smaller output pulse has no effect. The condition for faithful recording of coincidences is that the smallest output pulse resulting