New data could boost production of cancer-fighting radioactive isotope

<p><strong>Background:</strong> The ¹⁷⁶Yb⁢(𝑛,𝛾)⁢¹⁷⁷Yb→¹⁷⁷Lu reaction is of interest in nuclear medicine as it is the preferred production route for 177Lu. This radioisotope has seen a very fast growth of usage in nuclear medicine in recent years due to its outstanding properties. New data on this reaction could provide useful information for production at new facilities.</p><p><strong>Purpose:</strong> We aim to resolve resonances in the ¹⁷⁶Yb⁢(𝑛,𝛾)⁢¹⁷⁷Yb reaction for the first time. Previous capture measurement provided data at thermal point and encompassed integral measurements in the range from 3 keV to 1 MeV, where three time-of-flight measurements are available, but with low resolution to resolve the resonances. Transmission measurements from the 1970s resolved and analyzed some resonances.</p><p><strong>Method:</strong> We measure the neutron capture cross section of ¹⁷⁶Yb⁢(𝑛,𝛾)⁢¹⁷⁷Yb by means of the time-of-flight technique at the Experimental Area 1 of the n_TOF facility at CERN using an enriched ¹⁷⁶Yb₂⁢O₃ sample and an array of four C₆⁢D₆ liquid scintillation detectors.</p><p><strong>Results:</strong> We have resolved 164 resonances up to 21 keV, including 96 new ones. We also provide new capture experimental data from 90 eV to 3 keV, and we extend the resolved resonance region up to 21 keV. In addition, resonance decay widths, Γ_𝛾 and Γ_𝑛, are provided for all resonances together with resonance energies.</p><p><strong>Conclusions:</strong> The ¹⁷⁶Yb⁢(𝑛,𝛾)⁢¹⁷⁷Yb reaction has been measured, providing resonance parameters for the first time from a few eV to 21 keV. The analysis of the resonances has been carried out and compared with previous works and existing libraries, revealing discrepancies due to the new information on Γ_𝛾 parameters. Our results are consistent with the Γ_𝑛 parameters obtained in transmission measurements.</p>