Recent results of measurements of the 14N(n,p)14C, 35Cl(n,p)35S, 36Cl(n,p)36S, and 36Cl(n,α)33P reaction cross sections

What we do and do not know about the s-process in AGB stars

“…These 14 N nuclei act as a strong neutron poison during the s-process because of the relatively high cross section of the 14 N(n,p) 14 C reaction. The last measurement of this reaction gave 2.04 ± 0.16 mbarn at 24.5 keV [ 11] confirming previous calculations [ 12] and measurements [ 13]. In conclusion, the s-process is completely inhibited in models that include rotation [ 9].…”

Measurement of the parity-violating triton emission asymmetry in the reactionLi6(n,α)<

“…For the averaged values we took into account the directions reversal of the real P -odd effect due to the reversal of the guiding magnetic field. In the first experiment [28] the field direction was reversed every 30 min., in the last experiment [29] every 4 min.…”

“…Such influences were checked many times using electronic test signals as described in Refs. [24,28,29]. For instance, a small effect was caused by switching the radio-frequency of the adiabatic spin-flipper on and off.…”

“…In a second measurement, we aligned the guiding magnetic field horizontally and perpendicular to the neutron beam [28], in order to check for a contribution of left-right asymmetry because of a vertical inclination of the chamber. For the best alignment of the chamber relative to the beam in terms of intensity, we obtained the asymmetry a LR = (4.9 ± 1.9)×10 −7 .…”

“…All results in this section are given normalised to the constant component of the detector signal in the main experiment and to the solid angle and neutron polarisation, in order to make them directly comparable with the asymmetry in the main experiment. The result obtained at PNPI in Gatchina was a 0-test = (2.0 ± 1.7) ×10 −8 [28]. The zero-test carried out at the PF1B neutron beam at the ILL was performed with a neutron polarisation of more than 94% and yielded [30]: Figure 7 corresponds to results of the "0"-test experiment opposite directions of the guiding magnetic field.…”