Calibration of the efficiency of a Si(Li) photon spectrometer in the energy region 5 to 125 keV

Measurements of M and L X-ray energies and relative intensities emanating from 241Am source

Energies and relative Intensities of 13 X-ray transitions in the M X-ray spectrum (per 100 disintegrations of ²⁴¹Am) viz. M₄N₁, Mξ_1,2, M₃N₁, Mα, Mβ, Mγ, M₂N₁, M₃O_4,5+M₃P₁, M₃Q₁, M₁N₃, M₂N₄+M₁N₃, M₂O₁ and M₁O_2,3 lines along with L₁-L₃ have been measured in addition to the 21L X-ray lines viz. Lℓ, Lt, Ls, Lα₂, Lα₁, Lη, Lβ₆, Lβ_2,15, Lβ₄, Lβ_5,7, Lβ₁, Lβ₃, Lβ_9,10, Lγ₅, Lγ₁, Lγ_2,8, Lγ_3,6, Lγ_4,4, Lγ₁₃ including two new lines at 19.63 and 23.17keV, have been measured. Since the M and L X-ray lines of ₉₃Np in the decay of ²⁴¹Am source are frequently used for energy and efficiency calibration of the Si(Li)/HpGe detectors, the present measurements have been undertaken with an objective to update the data since there are either no concrete data available (even in the Table of Radioactive Isotopes and Table of Radionuclides) or there exist inconsistencies/disparities in the data available in the earlier publications. We confirm the existence of L₁-L₃ X-ray transition (falling in the region of M X-ray energy range) and Lt, Ls and Lβ_9,10 (forbidden transitions as per selection rules). However, the origin of the two new L X-ray lines at 19.63 and 23.17keV, both with intensities of 0.05±0.01%, could not be ascertained.

Determination of absolute photon emission intensities of (210)Pb

Photon emission intensities of (210)Pb have been determined using sources prepared from a standard solution, whose activity was measured by liquid scintillation counting. The absolute γ-ray and X-ray emission intensity was measured by conventional γ-ray spectrometry. Complementary measurements of the L X-ray spectrum were performed using a cryogenic detector, characterized by very high energy resolution and constant detection efficiency. As a result, precise emission intensities of the individual X-ray lines were obtained taking into account the presence of satellite lines.

Decay data evaluation project (DDEP): updated evaluations of the 233Th and 241Am decay characteristics

The results of new decay data evaluations are presented for (233)Th (beta(-)) decay to nuclear levels in (233)Pa and (241)Am (alpha) decay to nuclear levels in (237)Np. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2009.