FURTHER MEASUREMENTS ON THE γ RAYS PRODUCED BY NEUTRON CAPTURE IN BERYLLIUM AND CARBON

1953 ◽  
Vol 31 (1) ◽  
pp. 49-54 ◽  
Author(s):  
G. A. Bartholomew ◽  
B. B. Kinsey
Keyword(s):  
Excited State ◽  
Ground State ◽  
Neutron Capture ◽  
First Excited State ◽  
Γ Rays ◽  
Γ Ray

New measurements have been made of the neutron capture radiation from beryllium and carbon using a more sensitive pair spectrometer. From beryllium, γ rays with energies of 6.81 and 3.41 ± 0.06 Mev. were detected. The former is the ground state γ ray previously reported. The 3.41 Mev. γ ray, which has an intensity of about 0.25 photon per capture, seems to be due to the excitation of the first excited state in Be10. From carbon, in addition to the 4.95 Mev. ground state γ ray previously reported, a γ ray was found with an energy of 3.68 ± 0.05 Mev. and with an intensity of about 0.3 photon per capture. No γ rays were observed which could be associated with the excitation of the level at 3.9 Mev. in C13.

THE NEUTRON CAPTURE 7-RAYS FROM POTASSIUM

1953 ◽  
Vol 31 (6) ◽  
pp. 927-931 ◽  
Author(s):  
G. A. Bartholomew ◽  
B. B. Kinsey
Keyword(s):  
Excited State ◽  
Potassium Carbonate ◽  
Ground State ◽  
Neutron Capture ◽  
State Transition ◽  
Ground State Transition ◽  
Γ Rays ◽  
Γ Ray

The capture γ-rays from potassium have been re-examined with greater resolution than was used in previous experiments. The upper end of the spectrum has been carefully studied both with a sample of natural potassium carbonate and with another in which the potassium was enriched in K40. From a comparison of the spectra two γ-rays with energies of 9.39 ± 0.06 and 8.45 ± 0.02 Mev. are assigned to capture by that isotope. The strong γ-ray at 7.757 ± 0.008 Mev. previously ascribed to the ground state transition in K40 is now found to represent a transition to a low-lying excited state in that nucleus.

scholarly journals Copper and sulphur depth profile in patina layers using NRA and RBS

2019 ◽  
Vol 11 ◽  
Author(s):  
G. Kalliabakos ◽  
S. Kossionides ◽  
P. Misailides ◽  
C. T. Papadopoulos ◽  
R. Vlastou
Keyword(s):  
Excited State ◽  
Cross Sections ◽  
Ground State ◽  
Depth Distribution ◽  
Nuclear Reaction Analysis ◽  
Beam Direction ◽  
The Third ◽  
First Excited State ◽  
Γ Ray

A combination of nuclear reaction analysis (NRA) and Rutherford backscattering spectroscopy (RBS) were utilized in order to obtain information on the depth distribution of sulphur and copper in artificially produced and natural patina layers. The copper profiling was performed by using the reaction 63Cu(p,p'y)6 3Cu and detecting the 1327 keV γ-ray deexciting the third excited state to the ground state of 6 3Cu produced. For the determination of sulfur the 2230 keV γ-ray was used, deexciting the first excited state to the ground state of 32S formed through the reaction 3 2S(p,p'y)3 2S, which exhibits three sharp resonances at projectile energies 3.094, 3.195 and 3.379 MeV. The relevant cross-sections were measured in the energy range between 3.0 and 3.7 MeV in steps of 20 keV at 125° to the incident proton beam direction. Supporting information on the depth distribution of oxygen and the other elements of the patina samples was obtained by p-RBS (Ep = 1.5 MeV; θ = 160°).

scholarly journals Determination of Sulfur and Copper Profile with nuclear reactions

2019 ◽  
Vol 10 ◽  
pp. 1
Author(s):  
S. Kossionides ◽  
G. Kaliambakos ◽  
R. Vlastou ◽  
C. T. Papadopoulos
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Ground State ◽  
Nuclear Reactions ◽  
Nuclear Reaction Analysis ◽  
The Third ◽  
First Excited State ◽  
Γ Ray ◽  
Resonant Reaction

The concentration and depth profile of Cu and S in patinna samples have been determined by using Nuclear Reaction Analysis (NRA) and Rutherford Backscattering Spectroscopy (RBS). For the NRA the differential cross section was mesaured for the 1327 keV 7-ray deexciting the third excited state to the ground state of 6 3Cu through the reaction 63Cu(p,p'7), as well as, for the 2230 keV γ-ray deexciting the first excited state to the ground state through the resonant reaction 32S(p,p'7). The mesaurements of both excitation functions were performed in the energy range 3.0 - 3.7 MeV in 20 keV steps and at an angle of 125°.

NEUTRON CAPTURE GAMMA RAYS FROM FLUORINE, MAGNESIUM, GALLIUM, BROMINE, AND HAFNIUM

1957 ◽  
Vol 35 (12) ◽  
pp. 1361-1379 ◽  
Author(s):  
P. J. Campion ◽  
G. A. Bartholomew
Keyword(s):  
Energy Range ◽  
Gamma Rays ◽  
Ground State ◽  
Neutron Capture ◽  
State Transition ◽  
High Energy ◽  
The Other ◽  
Ground State Transition ◽  
Γ Rays ◽  
Γ Ray

The neutron capture γ-ray spectra of fluorine, magnesium, gallium, bromine, and hafnium have been studied in the energy range above 3 Mev. In fluorine four γ-rays and in magnesium 12 γ-rays have been detected in addition to those previously observed. Most of these new radiations can be assigned to the known level schemes of the product nuclei. The spectrum obtained for each of the other elements is complex with only a few of the high energy γ-rays resolved, and in each case the γ-ray of highest energy is very weak and difficult to distinguish from the background. The most energetic gallium γ-ray at 7.73 ± 0.02 Mev. may be emitted in the direct ground state transition in Ga70 while the 7.879 ± 0.013 Mev. γ-ray from bromine probably corresponds to the ground state transition in Br80. In hafnium none of the observed γ-rays can be identified with a ground state transition in any of the isotopes.

Excitation Energy of the Fourth Excited State in 18F

1972 ◽  
Vol 50 (14) ◽  
pp. 1682-1684 ◽  
Author(s):  
I. Berka ◽  
C. Rolfs ◽  
R. E. Azuma
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Coincidence Measurement ◽  
Resonant States ◽  
Mean Lifetime ◽  
First Excited State ◽  
Γ Rays ◽  
The Mean ◽  
Γ Ray

The excitation energy of the Jπ = 5+, fourth excited state in 18F has been determined to be Ex = 1119.0 ± 0.6 keV from a measurement of the energy of the γ-ray transition to the 937 keV, first excited state. This new excitation energy removes the discrepancies in the excitation energy of resonant states based on γ-ray decay schemes involving this state. The mean lifetime has been determined to be τ(1119) = 218 ± 8 ns by a delayed coincidence measurement between the γ rays populating and deexciting this state.

THE DECAY OF Au193 AND LEVEL SCHEME OF Pt193

1957 ◽  
Vol 35 (5) ◽  
pp. 672-692 ◽  
Author(s):  
G. T. Ewan
Keyword(s):  
Excited State ◽  
Electron Capture ◽  
Level Scheme ◽  
Half Life ◽  
Internal Conversion ◽  
Upper Limit ◽  
First Excited State ◽  
Γ Rays ◽  
Γ Ray ◽  
Conversion Spectrum

Au193 has been produced as the daughter of Hg193 formed by the reaction Au197(p, 5n)Hg193 in the McGill synchrocyclotron. The internal conversion spectrum and unconverted γ-ray spectrum have been examined using β-ray spectrometers, Nal spectrometers, and coincidence techniques. Au193 decays by electron capture to Pt193 with a half-life of 17.5 ± 0.2 hr. An upper limit of 0.08% per disintegration has been placed on the probability of emission of positrons in this decay. Twenty-eight γ-rays, all below 500 kev., have been observed associated with the decay of Au193. The first excited state of Pt193 has been shown to be at 12.7 kev. and the lifetime of this state measured as (2.2 ± 0.8) × 10−9sec. A level scheme is proposed for Pt193.

GAMMA-RAY STUDIES USING DEUTERIUM-LOADED PHOTOGRAPHIC PLATES

1950 ◽  
Vol 28a (5) ◽  
pp. 475-487 ◽  
Author(s):  
C. H. Millar ◽  
A. G. W. Cameron ◽  
M. Glicksman
Keyword(s):  
Ground State ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Excited Level ◽  
Cooling Water ◽  
Β Decay ◽  
Nuclear Emulsions ◽  
Γ Rays ◽  
Γ Ray

Deuterium-loaded nuclear emulsions have been used to study the γ-rays of neutron capture in sodium, chlorine, and cadmium, and the γ-rays following the β-decay of N16. Proton tracks caused by the photodisintegration of deuterium were measured, and from these the γ-ray energies were calculated. Several lines have been observed in the γ-ray spectra of neutron capture. The known energy of the 6.124 Mev. γ-ray following the decay of N16 (produced in the cooling water of the Chalk River pile) was used to calibrate the plates. A higher energy γ-ray from the decay of N16 was tentatively identified as corresponding to a transition from the 6.897 Mev. excited level of O16 to the ground state and was found to have one-seventh the intensity of the 6.124 Mev. γ-ray.

THE DISINTEGRATION OF Tm170

1952 ◽  
Vol 30 (5) ◽  
pp. 459-475 ◽  
Author(s):  
R. L. Graham ◽  
J. L. Wolfson ◽  
R. E. Bell
Keyword(s):  
Excited State ◽  
Ground State ◽  
Electric Quadrupole ◽  
Maximum Energy ◽  
Single Source ◽  
Coincidence Counting ◽  
Upper Limits ◽  
Conversion Coefficients ◽  
Γ Rays ◽  
Γ Ray

The radiations from the decay of Tm170 (127 day) have been studied by means of a lens type β-ray spectrometer, a scintillation spectrometer, short resolving time (2τ0 = 2 × 10−9 sec.) coincidence counting techniques, and a pair of lens type β-ray spectrometers placed end to end with coincidence counting of the focused radiations from a single source. A disintegration scheme is proposed which is consistent with the experimental results. Decay is found to be by negative β-ray emission; the spectrum consists of two components, one of maximum energy 968 ± 4 kev. (76%) proceeding to the ground state of Yb170 and one of maximum energy 884 ± 4 kev. (24%) to an excited state in Yb170 followed by emission of a γ ray or conversion electron to the ground state. The γ-ray transition in Yb170 is found to have an energy of 84.1 ± 0.1 kev., a half-life of (1.57 ± 0.05) × 10−9 sec, and conversion coefficients aK = 1.60 ± 0.15, aL = 4.1 ± 0.5, aM = 1.2 ± 0.2 which show that it is electric quadrupole in character. Upper limits are given for decay by K capture, 0.3%, or positive β-ray emission, 0.01%, and also for the occurrence of other γ rays.

A meta-analysis and review examining a possible role for oxidative stress and singlet oxygen in diverse diseases

2017 ◽  
Vol 474 (16) ◽  
pp. 2713-2731 ◽  
Author(s):  
Athinoula L. Petrou ◽  
Athina Terzidaki
Keyword(s):  
Oxidative Stress ◽  
Excited State ◽  
Singlet Oxygen ◽  
Ground State ◽  
Meta Analysis ◽  
Common Mechanism ◽  
High Electron ◽  
A Value ◽  
First Excited State

From kinetic data (k, T) we calculated the thermodynamic parameters for various processes (nucleation, elongation, fibrillization, etc.) of proteinaceous diseases that are related to the β-amyloid protein (Alzheimer's), to tau protein (Alzheimer's, Pick's), to α-synuclein (Parkinson's), prion, amylin (type II diabetes), and to α-crystallin (cataract). Our calculations led to ΔG≠ values that vary in the range 92.8–127 kJ mol−1 at 310 K. A value of ∼10–30 kJ mol−1 is the activation energy for the diffusion of reactants, depending on the reaction and the medium. The energy needed for the excitation of O2 from the ground to the first excited state (1Δg, singlet oxygen) is equal to 92 kJ mol−1. So, the ΔG≠ is equal to the energy needed for the excitation of ground state oxygen to the singlet oxygen (1Δg first excited) state. The similarity of the ΔG≠ values is an indication that a common mechanism in the above disorders may be taking place. We attribute this common mechanism to the (same) role of the oxidative stress and specifically of singlet oxygen, (1Δg), to the above-mentioned processes: excitation of ground state oxygen to the singlet oxygen, 1Δg, state (92 kJ mol−1), and reaction of the empty π* orbital with high electron density regions of biomolecules (∼10–30 kJ mol−1 for their diffusion). The ΔG≠ for cases of heat-induced cell killing (cancer) lie also in the above range at 310 K. The present paper is a review and meta-analysis of literature data referring to neurodegenerative and other disorders.

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