Fig. 1.
Energy spectra of the electron beams used in the experiment.
Fig. 2.
Irradiation setup scheme.
Fig. 3.
Energy spectra of the 1.13 mm thick disc irradiated by 15.6 MeV electrons, measured 70 h and 136 h after irradiation.
Fig. 4.
The most characteristic lines confirming the presence of 99Mo after background extraction.
Table 1.
Calculated activities (Geant4 simulations and experimental data) of 99Mo in targets after irradiations by 12.6 MeV electrons
| Target thickness (mm) | Time of irradiation (min) | f (Hz) | Measured A (kBq) | Simulated A (kBq) |
|---|---|---|---|---|
| 0.12 | 88 | 71.70 | 13 ± 4 | 17 ± 0.3 |
| 0.33 | 74 | 85.27 | 63 ± 8 | 60 ± 0.5 |
| 1.13 | 16 | 94.38 | 70 ± 7 | 64 ± 0.5 |
Table 2.
Calculated activities (Geant4 simulations and experimental data) of 99Mo in targets after irradiations by 15.6 MeV electrons
| Target thickness (mm) | Time of irradiation (min) | f (Hz) | Measured A (kBq) | Simulated A (kBq) |
|---|---|---|---|---|
| 0.12 | 62 | 35.33 | 36 ± 4 | 38 ± 0.9 |
| 0.33 | 52 | 59.79 | 152 ± 10 | 165 ± 1.6 |
| 1.13 | 224 | 6.46 | 653 ± 36 | 630 ± 3.4 |
Fig. 5.
Measured and expected activity of the molybdenum targets irradiated with the beam of an energy 12.6 MeV.
Fig. 6.
Measured and expected activity of the molybdenum targets irradiated with the beam of an energy 15.6 MeV.
Table 3.
Geant4 simulation results of (e−, n) and (γ, n) reaction analysis for 12.6 MeV electrons
| Target thickness (mm) | Total nuclei of 99Mo produced per electron impinging on the target | Nuclei 99Mo produced through the (e−, n) reaction per electron impinging on the target | Ratio (e−, n)/total 99Mo |
|---|---|---|---|
| 0.12 | (3.5 ± 0.08)·10−9 | (2.5 ± 0.03)·10−9 | 0.74 |
| 0.33 | (1.35 ± 0.01)·10−8 | (0.70 ± 0.05)·10−8 | 0.51 |
| 1.13 | (6.85 ± 0.02)·10−8 | (1.70 ± 0.01)·10−8 | 0.25 |
Table 4.
Geant4 simulation results of (e−, n) and (γ, n) reaction analysis for 15.6 MeV electrons
| Target thickness (mm) | Total nuclei of 99Mo produced per electron impinging on the target | Nuclei 99Mo produced through the (e−, n) reaction per electron impinging on the target | Ratio (e−, n)/total 99Mo |
|---|---|---|---|
| 0.12 | (5.0 ± 0.1)·10−9 | (1.3 ± 0.01)·10−8 | 0.72 |
| 0.33 | (3.6 ± 0.04)·10−8 | (3.55 ± 0.01)·10−8 | 0.50 |
| 1.13 | (3.57 ± 0.02)·10−7 | (1.075 ± 0.002)·10−7 | 0.26 |