Mass measurements and evaluation around A = 22

Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer TRIGA-TRAP

“…In order to take all connections into account, which usually over-determine the masses, the AME is based on a least-squares fit to the experimental data, described by a set of linear equations. Details about this treatment can be found in [6], and especially concerning Penning trap measurements in [25,26]. Even though several results reported here agree with values from the mass tables as well as with recent measurements from mass spectrometry, and all the carbon to carbon cross-checks are compatible with a null difference, the fact that some of the TRIGA-TRAP data deviate significantly (see Fig.…”

Experimental study ofβ-delayed proton decay ofAl23for nucleosynthesis in novae

“…Uncertainties from the calibration dominate in the region where no background reduction was made, whereas in the background-subtracted region the fitting error impacts the uncertainty. As the masses of the proton and of 22 Na are known to high precision [31,32], their contributions to the uncertainties in the emitted-proton energies are negligible (though still included in the calculations). The energies of the excited states in 23 Mg are E ex (…”

“…, where S p ( 23 Mg) = 7580.9(7) keV [31][32][33]. We calculated the relative intensities of the proton groups by normalizing the fitted peak areas to the observed number of 451 keV γ-rays.…”

“…We will discuss in more detail the state at E * = 7787 keV because it makes the largest contribution to the astrophysical reaction rate and because, to our knowledge, this is only the second case in the literature in which both proton and γ-ray branches have been measured from the same state simultaneously; the other case known is a state is in 32 Cl [36]. These situations are rare because of the exponential dependence of the barrier penetration probability on the proton energy: for larger E p most states decay by proton emission, while at lower energies proton emission is so much hindered that γ-ray emission predominates.…”

Absolute determination of theNa22(p,γ)Sallaska1, Wrede2, Garcı́a3 et al. 2011Phys. Rev. C255340View full textAdd to dashboardCite

“…First, we extracted the resonance energy from the observed gamma-ray energy, along with the excitation energy of the daughter level [45] and Qvalue (7580.53 ± 0.79 keV, using the newly measured masses of 23 Mg [46] and 22 Na [47]). From a thick-target 27 Al(p, γ) measurement at E p = 406 keV, the spectrum was calibrated using transitions energies 5088.05 and 7357.84 keV and each first-escape peak from the corresponding gamma rays.…”