Table 7.
Stability of ihe radiation intensity, expressed as photomultiplier signal average (V), determined for a copper (Cu), silver (Ag), and iron (Fe) hollow cathode operated in helium at 10 Torr and a current of 200, 100, and 200 mA. The measurements were taken at time intervals of 100 s after a preburn of 10 min.
| V | |||
|---|---|---|---|
| Time, s | Cu | Ag | Fe |
| 0 | 8.43 | 8.13 | 6.00 |
| 100 | 8.43 | 8.15 | 6.05 |
| 200 | 8.33 | 8.15 | 5.97 |
| 300 | 8.20 | 8.17 | 6.00 |
| 400 | 8.17 | 8.20 | 5.95 |
| 500 | 8.23 | 8.20 | 5.90 |
| 600 | 8.19 | 8.20 | 5.95 |
| 700 | 8.09 | 8.19 | 5.87 |
| 800 | 8.07 | 8.17 | 5.85 |
| 900 |
8.10 |
8.27 |
5.85 |
| Aver | 8.22 | 8.18 | 5.94 |
| σ | 0.13 | 0.04 | 0.07 |
| % σ | 1.6 | 0.5 | 1.2 |