Absorption and coincidence experiments on the radiations from the radioactive sodium, Na24

1938 ◽  
Vol 34 (3) ◽  
pp. 442-449 ◽  
Author(s):  
N. Feather ◽  
J. V. Dunworth
Keyword(s):  
Energy Spectrum ◽  
Continuous Spectrum ◽  
Ground State ◽  
Cascade Process ◽  
Γ Radiation ◽  
Upper Limit ◽  
Single Transition ◽  
Radioactive Sodium

The radiations from Na24 have been examined by the absorption and coincidence methods and evidence has been obtained for the conclusion that the energy spectrum of the β-particles is a simple continuous spectrum with an upper limit at 1·40 × 106 e.V., and that the emission of γ-radiation after the particle disintegration takes place almost always as a cascade process in which at least two quanta are involved, and very rarely by a single transition to the ground state.

scholarly journals The energy of disintegration of radio-phosphorous [P 30 ]

1935 ◽  
Vol 152 (877) ◽  
pp. 714-723 ◽  
Keyword(s):  
Excited State ◽  
Total Energy ◽  
Continuous Spectrum ◽  
Atomic Number ◽  
Particle Bombardment ◽  
Ground State ◽  
Radioactive Elements ◽  
Upper Limit ◽  
Association Meeting ◽  
The Difference

The exact masses of the nuclei are quantity of great interest depending directly on the forces of cohesion between the nuclear particles. Already much valuable information has been obtained about the lighter element both by mass-spectrographic methods and by the study of atomic dis-integrations. The discovery of the new radioactive elements has extended greatly the number of nuclei open to investigation, but since nearly all of these disintegrate by emitting either positrons or electrons forming a continuous spectrum we meet here the same difficulty in determining the total energy change in the disintegration as with the natural β-ray bodies. In this latter case Henderson* has proved the correcting of the suggestion of Ellis and Mott that the difference of energy of two nuclei, apart from γ-emission, is given by the upper limit of the β-ray spectrum. However, as was emphasized by Cockroft at the British Association Meeting at Norwich, in September, 1935, this is a point which needs verification in the region of low atomic number and particularly for positron disintegration. We have attempted to obtain some information on this point by investigating the disintegration of radio-phosphorus [P30] formed from aluminium by α-particle bombardment, The disintegration of radio phosphorus has already been investigated several times, but there is such a notable disagreement between the values given by different observers for the energy of the upper limit that we felt fresh experiments were needed, further, it is necessary to determine whether the upper limit corresponds to the formation of the ground state or of an excited state of the product nucleus.

scholarly journals Disintegration Constant and the Upper Limit of the Continuous -Spectrum

Nature ◽  
1935 ◽  
Vol 136 (3430) ◽  
pp. 142-142 ◽  
Author(s):  
G. J. SIZOO
Keyword(s):  
Continuous Spectrum ◽  
Upper Limit

Survey of data on primary cosmic-ray nuclei above 10 14 eV

1975 ◽  
Vol 277 (1270) ◽  
pp. 413-428 ◽  
Keyword(s):  
Energy Spectrum ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Radius Of Curvature ◽  
Galactic Centre ◽  
Spectral Exponent ◽  
Upper Limit ◽  
Low Energies ◽  
Continuous Range ◽  
Arrival Directions

Primary cosmic-ray particles, detected by means of the extensive cascades they generate in the atmosphere, have been observed over a continuous range of energies up to 1020 eV, and apparently somewhat higher. At energies such that the radius of curvature of their trajectories, if they are protons, as expected, is comparable to our distance from the galactic centre, the arrival directions of 84 observed particles are distributed randomly over the sky. The energy spectrum of the particles shows an anomaly near 1015 eV, where the flux is higher than expected by extrapolation of data near 1012 eV, and then falls very rapidly (spectral exponent y » 3.5 at energies just above 4 x 1015 eV). Above 1017 eV the flux falls off less rapidly, y being near 3.0 in the range 1018 to 3 x 1019 eV. Extrapolating the flux back to low energies from 1018 eV, where the particles are often assumed to be of extra-galactic origin, gives a flux higher than that actually observed at low energies. The best evidence on energies of the large showers indicates that these are above 1020 eV, which is greater than the upper limit to which metagalactic protons could survive interactions with microwave photons. There is evidence that many of the most energetic particles (near 1018 eV) are indeed protons, but this result is only preliminary.

The upper limit of energy in the β-ray spectrum of actinium B

1933 ◽  
Vol 29 (1) ◽  
pp. 156-160 ◽  
Author(s):  
B. W. Sargent
Keyword(s):  
Continuous Spectrum ◽  
Rapid Decay ◽  
End Point ◽  
Upper Limit ◽  
Magnetic Analysis ◽  
Thin Walled

Using a thin-walled electroscope, absorption curves in paper and aluminium were obtained for the β-rays of actinium (B + C) and actinium C″. From these curves the range of the β-rays of actinium B was found to be 0·08 ± ·02 gm./cm.2 The energy required for this range is 300,000 ± 50,000 volts, which must be the end-point of the continuous spectrum.On account of the overlapping of the β-ray spectra of actinium B and actinium C″ the range method can never yield an accurate value of the end-point of the former. Magnetic analysis appears to be the best means of finding this accurately, but the weakness and rapid decay of sources are formidable difficulties.

Detection of OH Maser Emission from Cornet Giacobini-Zinner

1985 ◽  
Vol 6 (2) ◽  
pp. 180-181 ◽  
Author(s):  
R. P. Norris ◽  
J. R. Forster ◽  
R. A. Duncan
Keyword(s):  
Production Rate ◽  
Radio Telescope ◽  
Ground State ◽  
Maser Emission ◽  
Upper Limit ◽  
Maser Radiation ◽  
Comet Halley

AbstractWe have detected OH maser radiation from the comet Giacobini-Zinner using the Parkes radio telescope. The emission was detected in two transitions of the ground state of OH, at an intensity consistent with the predicted OH molecular production rate. We also searched unsuccessfully for OH emission from comet Halley, from which we are able to place a significant upper limit on the intensity of OH emission.

EXCEPTIONAL STRUCTURES IN THE ODD-ODD NUCLEUS 250Md

2000 ◽  
Vol 09 (04) ◽  
pp. 309-317 ◽  
Author(s):  
P. C. SOOD ◽  
M. SAINATH ◽  
K. VENKATARAMANIAH
Keyword(s):  
Rare Earth ◽  
Energy Spectrum ◽  
Ground State ◽  
Low Energy ◽  
Α Decay ◽  
Decay Modes ◽  
Proton Interaction ◽  
Zero Range ◽  
Singlet Band ◽  
Rare Earth Nucleus

The low-energy two-quasiparticle bandhead energies for the odd-odd Z=101 nucleus 250 Md are evaluated using a zero range residual neutron-proton interaction. The 250Md ground state is seen to have the spin-parity Iπ=0- corresponding to the singlet band from the configuration {p : 7/2[514]⊗n:7/2[624]} in violation of the Gallagher-Moszkowski (GM) coupling rule. The situation here is shown to be almost identical to that for the rare-earth nucleus 166 Ho , which is the only well-established exception to the GM rule known so far. Analysis of the expected low energy spectrum, including the rotational levels, for 250 Md reveals the occurrence of an as-yet-unobserved long-lived high-spin Iπ = 7- isomeric state around (80±30) keV with dominant ε and α decay modes.

scholarly journals The upper limit of energy in the spectrum of radium E

1931 ◽  
Vol 131 (816) ◽  
pp. 90-99 ◽  
Keyword(s):  
Continuous Spectrum ◽  
Continuous Distribution ◽  
Absorption Curve ◽  
Heating Effect ◽  
End Point ◽  
Upper Limit ◽  
Ionisation Chamber ◽  
Magnetic Deflection

The disintegration of radium E has for some years attracted considerable attention. It is distinguished from the majority of β-ray bodies by the fact that there are no traces of peaks, due to homogeneous radiation, superimposed on the continuous spectrum of the disintegration electrons. It seems clearly established from the work of Ellis and Wooster, and of Meitner, on the heating effect of radium E, that the β-rays from this body are initially inhomogeneous when emitted from the nuclei. It is obviously of considerable interest to determine the velocity with which the fastest of the particles emerge from the nucleus; in other words the “ end point ” of the β-ray spectrum. The existence of such an upper limit in the case of radium E was first sug­gested by Gray, who observed an end point or kink in the β-ray absorption curve. Madgwick investigated the continuous distribution of the particles by means of an ionisation chamber and magnetic deflection, and found a fairly definite end point, such as Gurney║ had observed in the case of radium (B + C). Madgwick gave this end point as 5000 Hρ, corresponding to an upper limit of energy of 1,070,000 volts.

scholarly journals Renormalized spectrum of quasiparticle in limited number of states, strongly interacting with two-mode polarization phonons at T=0 K

2021 ◽  
Vol 24 (1) ◽  
pp. 13705
Author(s):  
M.V. Tkach ◽  
Ju.O. Seti ◽  
O.M. Voitsekhivska
Keyword(s):  
Energy Spectrum ◽  
Ground State ◽  
Green's Functions ◽  
Green’S Functions ◽  
Phonon Modes ◽  
Strongly Interacting ◽  
Renormalized Energy ◽  
Initial States ◽  
Analytical Expressions

Within unitary transformed Hamiltonian of Fröhlich type, using the Green's functions method, exact renormalized energy spectrum of quasiparticle strongly interacting with two-mode polarization phonons is obtained at T=0 K in a model of the system with limited number of its initial states. Exact analytical expressions for the average number of phonons in ground state and in all satellite states of the system are presented. Their dependences on a magnitude of interaction between quasiparticle and both phonon modes are analyzed.

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