PRINCEPS: Towards the automation of simultaneous gamma ray and internal conversion electron analysis
LIV.DAT student Adrian Montes Plaza has recently had a paper published about the code he has developed to facilitate the analysis of conversion electron spectra. Results obtained for 190Pb using this code were presented in the Mazurian Lakes Conference on Physics which was held last year in Piaski, Poland.
Transitions from excited states in atomic nuclei predominantly proceed via gamma ray or conversion electron emission, depending on their electromagnetic character and multipolarity. One of the best fingerprints for shape coexistence in nuclei is the measurement of conversion electrons. In order to extract electron intensities or internal conversion coefficients (ICCs), the measured electron spectra needs to be deconvoluted into the different components.
PRINCEPS (PRogram for INternal Conversion Electron and Photon Spectroscopy) has been developed in order to analyse and deconvolute internal conversion electron energy spectra measured simultaneously with gamma rays. The code calculates the expected conversion electron spectrum based on the gamma ray information, i.e. energy, multipolarity and intensity for every transition. It also accounts for user-defined resolution and efficiency parameters. The determination of the ICCs is performed by employing the well-known BrIcc conversion coefficient calculator. However, PRINCEPS allows the user to include measured conversion coefficients via mixed multipolarities. In particular, it can handle E0 transitions based on the provided electron intensity.
The performance of PRINCEPS is demonstrated with a standard 133Ba calibration source and with experimental in-beam data from the isotope 190-Tl, for which three conversion coefficients have been reported above the 9- isomeric state.
'Towards the automation of simultaneous γ-ray and internal conversion electron analysis', A.M. Plaza, et al., Proceedings XXXVII Mazurian Lakes Conference on Physics Probing Fundamental Properties of Matter with Rare Isotopes, Vol. 17 (2024), article 3-A11
The full published paper in Acta Physica Polonica B can be found here.
*Image:
CC-BY 4.0. (Colour on-line) γ-ray and electron energy spectrum measured with a 133Ba source employing the SAGE spectrometer. The calculated spectrum obtained with PRINCEPS is overlaid with the measured one. The most prominent transitions are colour-coded, while the calculated total energy spectrum is in black. Transition energies in 133Cs are labelled, whereas K-, L-, and M-components have been marked with lines. In the residuals, K-component 3σ energy widths are colour-shaded. A 3σ grey band is also shown according to the residuals uncertainty average.