First Determination of the Ionization Potential of Americium and Curium

Abstract

By multistep resonance ionization with lasers, followed by mass spectrometry, the first ionization potential of neutral atoms can be measured with quantities of only about one nanogram. The ionization potentials of americium (5.9736(3) eV) and of curium (5.9914(2) eV) were thus determined for the first time. The figure on the right shows a plot of the number of ions N versus the total photon energy Etot of three laser beams, which are essential for the experiment. The arrow points to the ionization threshold.

Chapter 18. Scandium, yttrium, the lanthanides and the actinides

“…The first determination of the ionization potentials of americium and curium has been reported; they are 5.9736 and 5.9914 eV respectively. 226 ),] have also been reported.,,, In the gas phase, UCl, is tetrahedral with U-Cl2.51 (electron diffraction); the visible and near-IR spectra of UOCI, in melts have been reported.233b Fast atom bombardment of uranyl salts in involatile organic matrices produces a series of clusters [(U02)x0,,] with x ranging to above Thermal decomposition of UO2(NO,),*6H,O does not give the anhydrous nitrate, hydroxynitrates being formed., 35 Several uranium tellurides, such as CsUTe,, CsTiUTe, and CsCuUTe,, with one-and two-dimensional structures, have been synthesized from the reaction of a Cs,Te, flux with the metals. 236 Several interesting reports concerning uranyl complexing have appeared this year.…”

Americium

“…Corresponding to the absolute term value (48767 cm À1 ) of the ground state, the ionization potential of Am(I) is 6.0 eV (Carlson et al, 1970). As noted above Deissenberger et al (1995) refined the ionization potential to 5.9738(2) eV.…”

“…Trautmann and colleagues (Trautmann, 1994;Deissenberger et al, 1995) experimentally determined the first ionization potential of americium to be 5.9738…”

A review on the mass spectrometric studies of americium: Present status and future perspective

“…RIMS was used to determine the first ionization energy of Am as 5.9736(3) eV (Deissenberger et al, ). Due to the high sensitivity of RIMS (that arises from selective excitation and ionization), about 0.4 ng of 243 Am was sufficient for these measurements.…”