Spectroscopic analysis of α-particle emission from 241Am and 226Ra sources

Abstract

This paper investigates the energy spectra of α-particles emitted by radioactive sources ²⁴¹Am and ²²⁶Ra using a multichannel analyzer. Calibration of the detection system was performed with the primary peak of ²⁴¹Am at 5486 keV, yielding a sensitivity of S = 0.4631 mV/keV. The energy dependence on channel number was established, ensuring accurate energy characterization of the measured spectra. The effect of air pressure on α-particle spectra was analyzed by varying the pressure from vacuum to 500 hPa and 1000 hPa. Results demonstrated a systematic shift of the main peak position towards lower channels due to energy losses in the air, accompanied by peak broadening. For ²⁴¹Am, the primary peak shifted from approximately channel 2500 in vacuum to channels 2200 and 2000 at 500 hPa and 1000 hPa, respectively. The peak broadening increased linearly with energy loss, described by the relationship q = 0.073 ⋅ ΔE + 24.2 keV, where the constant 24.2 keV represents the intrinsic resolution of the detector. Comparative analysis of ²⁴¹Am and ²²⁶Ra spectra revealed the simpler structure of ²⁴¹Am, characterized by a single primary peak, versus the more complex, multi-component spectrum of ²²⁶Ra, which reflects contributions from daughter nuclides. Despite this complexity, the detector successfully captured the overall profile of ²²⁶Ra. These findings confirm the high precision of the detection system in measuring α-particle spectra under varying experimental conditions and highlight its potential for further studies of α-radiation interactions and the development of advanced detector technologies.