Photoactivation of the 391.69 keV isomer state of ${}^{113m}\mathrm{In}$ by the ($\gamma ,2n$) reaction

Natural indium targets were exposed to high-energy bremsstrahlung radiation, from 9 MeV to 23 MeV. Using the measured $\gamma$ spectra, the yield ratio of ${}^{113m}\mathrm{In}$ and ${}^{115m}\mathrm{In}$ was determined. It was checked to what extent the measured values of the yield ratio can be reproduced using the existing experimental data of cross sections of relevant photonuclear reactions, as well as cross sections obtained by talys calculations. The measured reaction yield ratio was used to reconstruct the energy differential cross section of ${}^{115}\mathrm{In}(\gamma ,2n){}^{113m}\mathrm{In}$ using the unfolding procedure.

Figure 1

Geometry of experimental setup (not in scale).

Figure 2

Part of the $\gamma$-ray spectra collected after irradiation with 16 MeV and 22 MeV beams. The $\gamma$ lines of interested are labeled. Energy width of one channel is 0.2 keV.

Figure 3

Experimentally obtained relative yields $\frac{Y\left({}^{113m}\mathrm{In}\right)}{Y\left({}^{115m}\mathrm{In}\right)}$ for certain values of bremsstrahlung spectra end-point energy.

Figure 4

Spectra of photon flux on the indium disks for electrons energies between 18 MeV and 23 MeV incident on the tungsten radiator. The electron energy corresponds to the end-point energy of the respective photon-flux spectrum ($E_{\text{max}}$ in the Table 1.)

Figure 5

The above graph: talys 1.9 calculation of cross sections for ${}^{115}\mathrm{In}(\gamma ,{\gamma }^{\prime }){}^{115m}\mathrm{In}$ reaction obtained using the GLO (solid line) and BAL (dotted line) models for radiation strength function and six models for level density. Bottom graph: talys 1.9 calculation of cross sections for ${}^{113}\mathrm{In}(\gamma ,{\gamma }^{\prime }){}^{113m}\mathrm{In}$ reaction obtained using the GLO (thin solid line) and BAL (dotted line) models for radiation strength function and six models for level density; thick line: experimental data with spline interpolation [21].

Figure 6

Thin line: talys 1.9 calculation of cross sections for ${}^{115}\mathrm{In}(\gamma ,2n){}^{113m}\mathrm{In}$ reaction obtained using the GLO and BAL models for radiation strength function and six models for level density; thick line: experimental data from Ref. [5].

Figure 7

Comparison of calculated yields $Y\left({}^{113m}\mathrm{In}\right)/Y\left({}^{115m}\mathrm{In}\right)$ using talys 1.9 results with measured ones presented by thick solid line. The top band consisting of 36 values of the $Y\left({}^{113m}\mathrm{In}\right)/Y\left({}^{115m}\mathrm{In}\right)$ yield ratio was obtained with the GLO model, while the bottom band contains yield values calculated using the BAL model.

Figure 8

Comparison of calculated yield ratios $Y\left({}^{113m}\mathrm{In}\right)/Y\left({}^{115m}\mathrm{In}\right)$ using talys 1.9 results available and experimental data [5] with measured ones. Top band is obtained using GLO model while the bottom one is calculated using BAL model.

Figure 9

Comparison of calculated yield ratios $Y\left({}^{113m}\mathrm{In}\right)/Y\left({}^{115m}\mathrm{In}\right)$ using available experimental data for the ${}^{115}\mathrm{In}(\gamma ,{\gamma }^{\prime }){}^{115m}\mathrm{In}$ reaction [22] and ${}^{115}\mathrm{In}(\gamma ,2n){}^{113m}\mathrm{In}$ reaction [5] with measured ones. Results of calculations are connected by dashed line.

Figure 10

Unfolded results for the ${}^{115}\mathrm{In}(\gamma ,2n^{\prime }){}^{115m}\mathrm{In}$ cross section (line with a corridor of uncertainty) in comparison with default talys 1.9 function.