Energy non-linearity study of a high-resolution metallic magnetic calorimeter.

Low temperature detectors (LTDs) are high energy resolution energy dispersive spectrometers. Therefore, they are suitable for accurate measurements of X-ray or gamma-ray transition energies. However, the energy response of LTDs is non-linear. Therefore, it is required to correct the non-linearity to provide precise and accurate measurement. In this work, we present the study of the non-linearity of an LTD based on metallic magnetic sensors having an energy resolution below around 50 eV up to energies of 200 keV. The non-linearity was measured using a mix of radionuclides, 241Am, 152Eu, 210Pb, 129I and 139Ce, emitting X-rays and gamma-rays below 200 keV. The pulse energies and the energy spectra were obtained from different types of signal processing to evaluate their impact on the non-linearity. In addition, pulses were recorded with different preamplifier gains to identify possible non-linearity arising from the electronics and the DAQ. Finally the measured non-linearities were compared with the calculated non-linearity form the thermodynamic quantities of the MMC. • Energy non-linearity measurement of a low temperature detector using radionuclides. • Study of the non-linearity of an MMC under different recording conditions. • Influence on the non-linearity of different signal processing methods. • Comparison between experimental and calculated non-linearities. [ABSTRACT FROM AUTHOR]