Plutonium absorption spectra

The spectra of both plutonium compounds have strong absorption bands at 3400 cm-1 and 1600 cm-1 that are interpreted as due to C-H and C=C stretching frequencies. The IR spectrum of has a... 

Plutonium(IV) polymer has been examined by infrared spectroscopy (26). One of the prominent features in the infrared spectrum of the polymer is an intense band in the OH stretching region at 3400 cm 1. Upon deuteration, this band shifts to 2400 cm 1. However, it could not be positively assigned to OH vibrations in the polymer due to absorption of water by the KBr pellet. In view of the broad band observed in this same region for I, it now seems likely that the bands observed previously for Pu(IV) polymer are actually due to OH in the polymer. Indeed, we have observed a similar shift in the sharp absorption of U(0H)2S0ir upon deuteration (28). This absorption shifts from 3500 cm 1 to 2600 cm 1. 

Absorption Spectra, of Aqueous Ions. The absorption spectra of Pu(III) [22541-70-4], Pu(IV) [22541-44-2], Pu(V) [22541-69-1], and Pu(VI) [22541-41-9] in mineral acids, ie, HC104 and HN03, have been measured (78—81). The Pu(VII) [39611-88-61] spectrum, which can be measured only in strong alkali hydroxide solution, also has been reported (82). As for rare-earth ion spectra, the spectra of plutonium ions exhibit sharp lines, but have larger extinction coefficients than those of most lanthanide ions (see Lanthanides). The visible spectra in dilute acid solution are shown in Figure 4 and the spectrum of Pu(VII) in base is shown in Figure 5. The spectra of ions of plutonium have been interpreted in relation to all of the ions of the 5f elements (83). 

The spectra of both plutonium compounds have strong absorption bands at 3400 cm and 1600 cm that are interpreted as due to C-H and C=C stretching frequencies. The IR spectrum of C2H l2 has a broad complex absorption from 2800-4000 cm and a sharp, strong band at 1128 cm . Absorption in the 3000 cm region is normally associated with CH stretching vibrations.( ) The normal CH2 stretch is found at higher frequencies in C=CH2 and CsCH groupings. 

Figure 1. Absorption spectra of plutonium(III). (1) Pu(III) in IM HCIO (2) the PuCIq ion in 85% succinonitrile-15% acetonitrile. This solution was prepared by dissolving PuClg in the solvent saturated with (C2Hg) NCl and containing a small amount of anhydrous HCl. The PuCIq spectrum was corrected for 2.0% Pu(IV) (as PuCIq ) which appears to constitute a slight overcorrection, and because of this the fine structure in the 670-870 mix region may not be exactly correct for PuCl/ ...

The UV-VIS spectrum of [Np02(Ll)] complex contains absorption band at 977 nm that is considered as evidence of Np(V) presence and indication of the change in the coordination sphere of Np atom in solution. Isoamethyrin LI also forms plutonyl complex [Pu02(Ll)], when treated with acidic solution of plutonyl(VI) chloride. Taking into account that Pu is reduced more readily than Np, authors made the conclusion about pentavalent state of plutonium that is supported by the absence of Pu(Vl) absorption peak near 830 nm. The similar changes in the spectra of L2-L5 with the addition of neptunyl or plutonyl are observed. By this means, the formation of Np(V) and Pu(V) complexes with... 

On the other hand, if the excited state is strongly localized, i.e. if the electron stays during the emission process on the same atom with the same spin, a resonance line can be emitted. The existence of an exciton-type state could be taken into consideration to explain the presence of the resonance lines but, except for thorium, the ratio of Mjy and My R line intensities is different from the ratio of the corresponding absorption line heights. In particular, the Mjy R line is absent in the spectrum of plutonium. As a consequence, the emission spectra cannot be interpreted suitably by ex-citonic transitions. 

An analytical mockup of the experimental system was made and the GEM c e (Monte Carlo) was used to calculate Ms for a scries of plutonium-polystyrene cubes. Calculations were made using two simulated beams whose spectra arc assumed to bracket the experimental beam spectrum. The peak of the spectra for C and D are at 1.8 and 2.2 MeV, respectively. The code, inserts source neutrons perpendicular to the front face of the cube and tracks a neutron until it is lost by leakage or absorption. All neutron progeny are similarly treated. The results are also shown in Fig. 1. 

Neutron balance and miscellaneous details. Details of the neutron economy of a reactor fueled with plutonium are given in Table 14-7. Parasitic captures in Pu are relatively high y is 1.84, compared with a, v oi 2.9. The neutron spectrum is relatively soft almost 60% of all fissions are caused by thermal neutrons and, as a result, absorptions in lithium are high. 

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