Terbium-161

Terbium-161 (Tb-161) is an intriguing isotope with significant potential in various scientific and industrial fields.

What is Terbium-161?

Terbium-161 is a radioactive isotope of terbium with a half-life of about 6.89 days. It decays via beta decay to stable dysprosium-161 (Dy-161), emitting gamma radiation in the process. The primary gamma photons produced include energies around 48 keV, making Tb-161 a valuable source of gamma rays for specific applications.

How is Terbium-161 Produced?

Tb-161 is not found naturally and is typically produced through neutron irradiation of gadolinium-160 (Gd-160) in a nuclear reactor. The production process involves:

  1. Neutron Irradiation: Gd-160 + n → Tb-161 + γ
  2. Separation and Purification: After irradiation, Tb-161 is chemically separated and purified from other by-products for use in various applications.

Industrial Applications of Terbium-161

Tb-161 has several critical industrial applications due to its gamma radiation and relatively short half-life:

  1. Medical Radiotherapy: Tb-161 is being researched for use in targeted radiotherapy, particularly in treatments for certain cancers. Its beta emission and gamma rays make it suitable for delivering localized radiation doses.
  2. Research and Development: Tb-161 is used in scientific research to study various processes involving radioactive decay and gamma emission.

Terbium-161 in Gamma Spectroscopy

Gamma spectroscopy involves analyzing the energy and intensity of gamma rays emitted by radioactive substances. Tb-161 serves as a reliable source for gamma spectroscopy due to its distinct gamma emission at 48 keV.

In my recent experiment, I received 250 Bq of Tb-161 from an unknown source at the University of unknownland on July 11, and it arrived on July 24. I conducted a gamma spectrum analysis using my Multi-Channel Analyzer (MCA). By focusing on the peak at 48 keV, I measured 37,453 counts in 3,402 seconds, resulting in 11 Bq in the Region of Interest (ROI). Since this peak represents 17% of the total gamma emission, the total activity was calculated as 17%/11 Bq64 Bq.
The theoretical activity of Tb-161 on July 24, calculated based on its half-life, is approximately 67.57 Bq, showing that my experimental results are consistent with expected decay.