Thulium(III) oxide when irradiated in a nuclear reactor, thulium produces an isotope that emits x-rays. A button of this isotope is used to make a lightweight, portable x-ray machine for medical use. It is also used in lasers with surgical applications.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.