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.

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.

A DETERMINATION OF THE HALF LIVES OF SOME MAGNETIC DIPOLE γ-RAY TRANSITIONS

1953 ◽  
Vol 31 (3) ◽  
pp. 377-392 ◽  
Author(s):  
R. L. Graham ◽  
R. E. Bell
Keyword(s):  
Magnetic Dipole ◽  
Energy Relation ◽  
Single Source ◽  
Coincidence Method ◽  
Coincidence Circuit ◽  
Coincidence Counting ◽  
Conversion Coefficients ◽  
Γ Ray ◽  
End To End

A number of magnetic dipole γ-ray transitions have been studied using a coincidence circuit of short resolving time (2τ0 = 2 × 10−9 sec), a two lens single β-ray spectrometer, a pair of lens spectrometers placed end to end with coincidence counting of the focused radiations from a single source, and a scintillation spectrometer. Lifetimes have been measured using the delayed coincidence method and where feasible conversion coefficients and K/L ratios obtained. Comparison is made with theoretical estimates of the lifetime–energy relation for M1 γ-ray transitions.The new results are as follows:[Formula: see text]

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 12 C(γ, 3α) reaction energy levels of 8 Be and 12 C

1955 ◽  
Vol 228 (1174) ◽  
pp. 376-396 ◽  
Keyword(s):  
Ground State ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Angular Distributions ◽  
Reaction Energy ◽  
Reaction Proceeds ◽  
Γ Ray ◽  
Relationship Of ◽  
The Relationship ◽  
Α Particles

The mechanism of the 12 C(γ, 3α) reaction, for γ-ray energies, E γ , up to about 40 MeV, has been determined from a study of over 2500 stars in nuclear emulsions. The study includes investigation of the angular distributions and correlations of the α-particles. The reaction is initiated mainly by electric-dipole and electric-quadrupole γ-ray interaction, the former being unexpectedly strong when E γ < 20 MeV. For E γ < 25 MeV the reaction proceeds mainly by transitions to the ground-state of 8 Be (spin J = 0), and to 2⋅95 ± 0⋅10 MeV ( J = 2) and 4⋅0 ± 0⋅1 MeV ( J = 2 or 4) levels of 8 Be. Transitions to levels near 6, 10 and 15 MeV (all J = 0, 2 or 4) become predominant when 25 MeV ≤ E γ <26 MeV. For E γ ≥ 26 MeV, most transitions lead to 16⋅8 ± 0⋅2 MeV ( J = 2) and 17⋅6 ± 0⋅2 MeV ( J = 2, possibly 0) levels, and possibly to a further 16⋅4 ± 0⋅2 MeV ( J = 0 or 2) level, levels which have not been detected in other reactions. The reaction mechanism is interpreted in terms of competing modes of decay of a compound nucleus, demonstrating the strong influence of the isotopic spins ( T ) of the levels of 12 C and 8 Be involved. For example, the 2 + levels of 12 C involved when 16 MeV ≤ E γ <20 MeV are (unexpectedly) found to have T = 1, and the 16⋅8 and 17⋅6 MeV levels of 8 Be are also found to have T = 1. The relationship of the 12 C (γ, 3α) reaction to other 12 C photodisintegration reactions (including some new reactions established during the present experiments) is discussed.

Decay of 143Eu

1974 ◽  
Vol 52 (10) ◽  
pp. 847-853 ◽  
Author(s):  
G. Kennedy ◽  
S. C. Gujrathi ◽  
P. F. Hinrichsen
Keyword(s):  
Ground State ◽  
Coupling Model ◽  
Intermediate Coupling ◽  
Ground State Spin ◽  
Reaction Data ◽  
Intermediate Coupling Model ◽  
Γ Rays ◽  
Γ Ray ◽  
State Spin ◽  
Good Agreement

A high resolution study of γ-ray transitions in 143Sm following the β+ decay of 143Eu has been made using Ge(Li) detectors. Fifty-seven γ rays are assigned to the decay of 143Eu, and the ground state spin of 143Eu is established as 5/2+. Spin and parity assignments are made on the basis of γ-ray branching, deduced log ft values, and by comparison with previous (p,d) reaction data. Good agreement between experiment and predictions of the intermediate coupling model suggests that this model adequately accounts for the low lying levels of 143Sm.

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.

scholarly journals The absolute intensities and internal conversion coefficients of the y-rays of radium B and radium C

1930 ◽  
Vol 129 (809) ◽  
pp. 180-207 ◽  
Keyword(s):  
Electronic Structure ◽  
Internal Conversion ◽  
Photoelectric Absorption ◽  
Homogeneous Groups ◽  
Absolute Intensities ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Γ Rays ◽  
Γ Ray ◽  
Parent Atom

It is well known that with many radioactive bodies the departure of the disintegration particle is followed by the emission of γ-rays. In addition to γ-rays of frequencies v 1 , v 2 , ..., it is observed that there is an electronic emission consisting of several homogeneous groups whose energies can be written The energies of these groups are identical with those that would be produced by photoelectric absorption in the parent atom of the γ-rays emitted from the nucleus, and this phenomenon is frequently described as the internal conversion of γ-rays. By this is meant that in every case when the nucleus emits energy E this occurs in the form of radiation of frequency E/ h , but that this does not always escape as such from the atom. In a fraction a of the cases the radiation is absorbed in the electronic structure and gives rise to a photoelectron, in the remaining fraction (1 — α) the γ-ray is emitted clear of the atom. The quantity a is termed the coefficient of internal conversion. Smekal* and others have pointed out that there is no need and even no justification to consider the γ-ray ever to be emitted in the case of those atoms which give photoelectrons. All that can be truly inferred from the experimental facts is that the atom as a whole is capable of emitting energy E, and this it may do either in the form of a quantum of radiation hv = E, or in the form of an electron of energy E — K, or E — L, etc., followed by the appropriate excited K-, L-, X-radiations. The greater portion of this energy E is certainly resident in the nucleus, so that this second standpoint implies some type of what may be termed collision interaction between the nucleus and the electronic structure of the atom.

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.

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