2,895 research outputs found
Thermal Equilibration of 176-Lu via K-Mixing
In astrophysical environments, the long-lived (\T_1/2 = 37.6 Gy) ground state
of 176-Lu can communicate with a short-lived (T_1/2 = 3.664 h) isomeric level
through thermal excitations. Thus, the lifetime of 176-Lu in an astrophysical
environment can be quite different than in the laboratory. We examine the
possibility that the rate of equilibration can be enhanced via K-mixing of two
levels near E_x = 725 keV and estimate the relevant gamma-decay rates. We use
this result to illustrate the effect of K-mixing on the effective stellar
half-life. We also present a network calculation that includes the
equilibrating transitions allowed by K-mixing. Even a small amount of K-mixing
will ensure that 176-Lu reaches at least a quasi-equilibrium during an
s-process triggered by the 22-Ne neutron source.Comment: 9 pages, 6 figure
Multi-frequency fine resolution imaging radar instrumentation and data acquisition
Development of a dual polarized L-band radar imaging system to be used in conjunction with the present dual polarized X-band radar is described. The technique used called for heterodyning the transmitted frequency from X-band to L-band and again heterodyning the received L-band signals back to X-band for amplification, detection, and recording
Direct measurement of the 14N(p,g)15O S-factor
We have measured the 14N(p,g)15O excitation function for energies in the
range E_p = 155--524 keV. Fits of these data using R-matrix theory yield a
value for the S-factor at zero energy of 1.64(17) keV b, which is significantly
smaller than the result of a previous direct measurement. The corresponding
reduction in the stellar reaction rate for 14N(p,g)15O has a number of
interesting consequences, including an impact on estimates for the age of the
Galaxy derived from globular clusters.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let
Constraining ^(26)Al+p resonances using ^(26)Al(^3He,d)^(27)Si
The ^(26)Al(^3He,d)^(27)Si reaction was measured from 0°≤θ_(c.m.)≤35° at E(^3He)=20 MeV using a quadrupole-dipole-dipole-dipole magnetic spectrometer. States in ^(27)Si were observed above the background at 7652 and 7741 keV and upper limits were set for the state at 7592 keV. Implications for the ^(26)Al(p,γ)^(27)Si stellar reaction rate are discussed
Experimental evidence of a natural parity state in Mg and its impact to the production of neutrons for the s process
We have studied natural parity states in Mg via the
Ne(Li,d)Mg reaction. Our method significantly improves the
energy resolution of previous experiments and, as a result, we report the
observation of a natural parity state in Mg. Possible spin-parity
assignments are suggested on the basis of published -ray decay
experiments. The stellar rate of the Ne(,)Mg
reaction is reduced and may give rise to an increase in the production of
s-process neutrons via the Ne(,n)Mg reaction.Comment: Published in PR
The Experiences of Women with a Diagnosis of Borderline Personality Disorder (BPD) Using Sensory Modulation Approaches in an Inpatient Mental Health Rehabilitation Setting
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