The nuclear alinement of promethium isotopes and the decay scheme of 149 Pm

1960 ◽  
Vol 259 (1298) ◽  
pp. 377-385 ◽  
Keyword(s):  
Excited State ◽  
Low Temperature ◽  
Decay Scheme ◽  
Maximum Energy ◽  
Angular Distributions ◽  
Ionic State

Nuclear alinement of the isotopes 149 Pm and 151 Pm has been obtained in the ethyl sulphate and double nitrate lattices by the low-temperature alinement method. The anisotropic γ -ray angular distributions were used to detect this alinement. The results suggest that in the double-nitrate lattice the lowest ionic state of Pm 3+ is a singlet and that alinement arises through a ‘pseudo-quadrupole’ mechanism. Beta and γ -spectroscopy measurementsshow that the 285 keV γ -ray in the decay of 149 Pm is associated with a weak (1.8 ± 0.3 %) β -group of maximum energy 0.77 ± 0.05 MeV. The alinement measurements are consistent with this 285 keV γ -ray being principally M 1 with the spin of the excited state being 5/2 or 9/2.

YIELDS AND ANGULAR DISTRIBUTIONS OF FAST PHOTOPROTONS

1963 ◽  
Vol 41 (6) ◽  
pp. 871-880 ◽  
Author(s):  
O. M. Mracek Mitchell ◽  
K. G. McNeill
Keyword(s):  
Maximum Energy ◽  
Angular Distributions ◽  
Bremsstrahlung Spectrum

Measurements are described on the angular distributions of fast photoprotons (Ep > 8 Mev) ejected from 16 elements of [Formula: see text] by a bremsstrahlung spectrum of 22-Mev maximum energy. Some shell features are observed which, together with results of other authors, are discussed in terms of the Wilkinson model of photodisintegration.

Visible photodissociation of the CO2 dimer cation: fast and slow dissociation dynamics in the excited state

2019 ◽  
Vol 21 (6) ◽  
pp. 3083-3091 ◽  
Author(s):  
Yuji Nakashima ◽  
Kenichi Okutsu ◽  
Keita Fujimoto ◽  
Yuri Ito ◽  
Manabu Kanno ◽  
...  
Keyword(s):  
Excited State ◽  
Angular Distributions ◽  
Ion Imaging ◽  
Imaging Experiment ◽  
Dissociation Dynamics ◽  
Slow Dissociation ◽  
532 Nm

Velocity and angular distributions of photofragment CO2+ ions produced from mass-selected (CO2)2+ at 532 nm excitation were observed in an ion imaging experiment.

Synthesis And Luminescence Of RhIII(phpy)2(S∪E) Complexes With phpy– = Deprotonated 2-Phenylpyridine And S∪E– = Diethyldithiocarbamate, 2-Pyridinethiolate And 2-Quinolinethiolate

2005 ◽  
Vol 60 (3) ◽  
pp. 359-362 ◽  
Author(s):  
Valeri Pawlowski ◽  
Horst Kunkely ◽  
Arnd Vogler
Keyword(s):  
Excited State ◽  
Low Temperature ◽  
Ambient Conditions

Complexes of the general composition RhIII(phpy)2(S∪E) with phpy− = 2-(2-pyridyl)phenyl and S∪E− = diethyldithiocarbamate, 2-pyridinethiolate and 2-quinolinethiolate were prepared and characterized. The complexes with S∪E− = diethyldithiocarbamate and 2-pyridinethiolate show a low-temperature luminescence which originates from a phpy ππ∗ intraligand triplet. For the complex with S∪E− = 2-quinolinethiolate (or thiooxinate) the lowest-energy excited state is of the quinolinethiolate intraligand type. This complex displays a fluorescence as well as a phosphorescence under ambient conditions

Observation of multi-channel non-adiabatic dynamics in aniline derivatives using time-resolved photoelectron imaging

2016 ◽  
Vol 194 ◽  
pp. 185-208 ◽  
Author(s):  
Magdalena M. Zawadzki ◽  
Marco Candelaresi ◽  
Lisa Saalbach ◽  
Stuart W. Crane ◽  
Martin J. Paterson ◽  
...  
Keyword(s):  
Excited State ◽  
Angular Distributions ◽  
Relaxation Dynamics ◽  
Photoelectron Imaging ◽  
Time Resolved ◽  
Valence States ◽  
Ultimate Fate ◽  
Site Selective ◽  
Photoelectron Angular Distributions ◽  
Electronic Character

We present results from a recent time-resolved photoelectron imaging (TRPEI) study investigating the non-adiabatic relaxation dynamics of N,N-dimethylaniline (N,N-DMA) and 3,5-dimethylaniline (3,5-DMA) following excitation at 240 nm. Analysis of the experimental data is supported by ab initio coupled-cluster calculations evaluating excited state energies and the evolution of several excited state physical properties as a function of N–H/N–CH3 bond extension – a critical reaction coordinate. The use of site-selective methylation brings considerable new insight to the existing body of literature concerning photochemical dynamics in the related system aniline at similar excitation wavelengths. The present work also builds on our own previous investigations in the same species at 250 nm. The TRPEI method provides highly differential energy- and angle-resolved data and, in particular, the temporal evolution of the photoelectron angular distributions afforded by the imaging approach offers much of the new dynamical information. In particular, we see no clear evidence of the second excited 2ππ* state non-adiabatically coupling to the lower-lying S1(ππ*) state or the mixed Rydberg/valence S2(3s/πσ*) state. This, in turn, potentially raises some unresolved questions about the overall nature of the dynamics operating in these systems, especially in regard to the 2ππ* state's ultimate fate. More generally, the findings for the aromatic systems N,N-DMA and 3,5-DMA, taken along with our recent TRPEI results for several aliphatic amine species, highlight interesting questions about the nature of electronic character evolution in mixed Rydberg-valence states as a function of certain key bond extensions and the extent of system conjugation. We begin exploring these ideas computationally for a systematically varied series of tertiary amines.

scholarly journals The transmutation of magnesium, aluminium and silicon by deuterons

1948 ◽  
Vol 194 (1036) ◽  
pp. 131-145 ◽  
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Excited States ◽  
Satisfactory Agreement ◽  
Compound Nucleus ◽  
Maximum Energy ◽  
Nuclear Mass ◽  
Proton Group ◽  
Q Values ◽  
Induced Radioactivity

A study has been made of the protons emitted by magnesium, aluminium and silicon targets when bombarded by deuterons of energy between 700 and 1000 keV. The Q values of these (d, p) reactions have been accurately determined. Observations of the induced radioactivity in the targets and comparisons with the Q values in analogous nuclei permit tentative assignments to the isotopes responsible. The Q values and assignments are: 24Mg (d, p) 2SMg 26Mg (d, p) 26Mg* 2®Mg (d, p) 27Mg 27A1 (d, p ) 28A1 28Si (d, p)2»Si “ Si (d, p)«Si Q = 5 03 MeV Q = 4-45 MeV (to excited state) Q = 4 05 MeV Q = 5-46 MeV = 4-46 MeVl = 3-98 MeV 1 (to excited states) = 3-31 MeV j Q = 6-16 MeV .= 4-87 MeV) .. .. , . , . = 3-75 MeV j The yield of the proton group attributed to 26 Mg (d, p ) 26 Mg* shows a resonance at 955 kV bombarding voltage, as does also the yield of radioactive 26 A1 formed in the reaction 26 Mg (d, n) 26 A1. This indicates a resonance level in the compound nucleus 27A1 at an excitation energy of 17 MeV. The maximum energy of the β+ rays from 26 A1 was measured as 2-8 MeV. The Q values listed above lead to a set of nuclear mass values, but these mass values are not always in satisfactory agreement with the published Q values for certain other reactions.

Beta decay of 187W

1970 ◽  
Vol 48 (9) ◽  
pp. 1040-1054 ◽  
Author(s):  
A. W. Herman ◽  
E. A. Heighway ◽  
J. D. MacArthur
Keyword(s):  
Excited State ◽  
Beta Decay ◽  
Decay Scheme ◽  
Decay Energy ◽  
Beta Transition ◽  
Point Energy ◽  
Absolute Intensities ◽  
Gamma Coincidence ◽  
First Excited State ◽  
Coincidence Measurements

Coincidence studies have established in the decay scheme of,187W the existence of transitions of energy 7, 36, 77, 455, 589, and 639 keV with intensities of 3.0 ± 0.5%, 0.50 ± 0.06%, 0.31 ± 0.07%, 0.05 ± 0.02%, 0.14 ± 0.04%, and 0.05 ± 0.02% respectively as well as yielding the absolute intensities of the well-known transitions in 187Re. In addition the beta–gamma coincidence measurements have shown that (1) a first-forbidden unique transition feeds the first-excited state of 187Re, (2) there is at most a very weak beta transition to the level at 512 keV, (3) there is no inner beta group of about 300 keV end-point energy and intensity 8% as indicated by several earlier investigations, and (4) the decay energy of 187W to 187Re is 1311 ± 2 keV. The relevance of these observations to the structure of 187Re is discussed.

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