Gamma and X-Radiation in the Decay ofAm241

Abstract

takes into consideration the energy dependent effect of the detection efficiency and the effect of the constant "window width" of the scintillation spectrometer, the present data indicates that the 138-kev 7 ray is considerably stronger, and the 77-kev x-ray much weaker than measured by Jensen et al 7 This is consistent with the recent work by Schardt et al*The dotted curve in fig. 3 represents the summing spectrum obtained with the sample in the phosphor. The As K x-rays arising from K capture were cut off by the use of a thin Al absorber. Peaks are noticed at 405, 281, 138, and 98 kev. This infers the following:(1) The highest excited energy level involved is at 405 kev since no sum peak appears above this energy. (It is assumed here that no meta-stable states are present. DeBenedetti and McGowan 9 found no delayed coincidences in the 10~~6-to 10~3-sec range.) Thus, any two 7 rays whose energies add up to more than 405 kev cannot be in cascade.(2) The strong sum peak at 405 kev shows that the 138-and the 269-kev transitions are in cascade.(3) Since no indication of summing is noticed at 346 kev, the 77-kev 7 ray appears not to be in cascade with the 269-kev 7 ray as suggested by Jensen et al., 7 whereas on the basis of the present investigation, there 8 A. W. Schardt and J. P. Welker, Phys. Rev. 93, 916 (1954).The decay scheme of Am 241 is discussed in terms of new information on the conversion electrons, gamma rays, and L series x-rays accompanying its alpha decay. The photons were measured with a scintillation spectrometer and a bent crystal spectrometer and the conversion electron spectrum was determined with a double focusing beta-ray spectrometer.

Electron Capture and Alpha Decay ofNp235

“…From a correlation of data available on relative abundances of L x-rays in the region of Z~92, 17 it is found that L a x-rays arise predominantly from the filling of Lin shell vacancies, while L$ and L y x-rays are produced from the filling of a combination of L-shell vacancies. As first noted by James et at., 2 the relative L x-ray intensities associated with the L capture of Np 235 indicate a large fraction of Xm-shell vacancies.…”

Theoretical study on K , L , and M X-ray transition energies and rates of neptunium and its ions

“…Taking the Kα 2 for example, the transition energy is 97068.18 eV compared with the experimental result 97069±3 eV of Barreau et al [22] For the transition rates of these lines, the results presented are smaller than the other ones, which may due to including the Breit interaction and QED effects in the calculations. In order to compare with the measured spectra, [24] our transition rates of K X-rays are convoluted into a Gaussian line shape of broadening 600 eV and plotted in Fig. 1.…”

“…[10][11][12][13][14][15][16][17][18][19][20][21] Barreau et al [22] and Ahmad et al [23] measured energies, natural widths and intensities of Np K X-rays, respectively. Jaffe et al [24] and Day [25] analyzed the L X-rays of Np following the decay of 241 Am for the first time. Weksler et al [26] measured transition energies of L lines associated with α-decay of 241 Am with a high-resolution Si (Li) spectrometer.…”

Decay ofCe144

“…Because in the work of Jaffe et al 1 the Li and Ln conversion electrons from this gamma ray were not…”

“…1 discuss the unusual properties of the 59.6-kev state in Np 237 , which is populated by more than 99% of the Am 241 disintegrations. They measured the total conversion coefficient of the 59.6-kev gamma ray to be 0.92, and concluded that the radiation is electric dipole.…”