Preparation of Drop-Deposited Sources in 4π Absorbers for Total Decay Energy Spectrometry.

Total decay energy spectrometry (Q spectrometry) with cryogenic detectors is a promising technique for analysis of α-emitting actinides. However, this technique is very sensitive to the quality of the source preparation due to the absorption of the nuclear recoil energy in the source material. Drop deposition of the radioactive solution without care produces spectra with unpredictable peak shapes. In order to keep the simplicity of the drop deposition technique, we study the deposition of solution on latex nanoparticles or in nanoporous gold (NPAu) to improve the source quality. 4π absorbers were fabricated and tested using these two techniques. The absorbers contained a mixture of Pu isotopes. From the best Q spectrum, the composition of Pu isotopes and other actinides was measured and it is in very good agreement with the reference values given by alpha and mass spectrometry. [ABSTRACT FROM AUTHOR]