R. Eykens

TL;DR: In this paper, the n(238U)/n(235U) isotope ratio of the NBL CRM 112a standard has been re-measured in a collaborative effort by several geochemistry laboratories and the Institute for Reference Materials and Measurements.

TL;DR: In this article, the authors measured the lifetime of the Neutron by counting decay protons stored in a Penning trap whose magnetic axis coincided with a neutron-beam axis.

TL;DR: A measurement of the neutron lifetime by the absolute counting of in-beam neutrons and their decay protons and the systematic uncertainty is dominated by neutron counting, in particular, the mass of the deposit and the cross section.

TL;DR: In this article, a double spike reference material IRMM-3636 was prepared gravimetrically using highly enriched U-233 and U-236 isotope material and the n((235)U)/n(U-238) ratio was adjusted to about 1:1 and certified with an extended relative uncertainty of 0016% (coverage factor k = 2).

TL;DR: This is the most precise measurement of the neutron lifetime to date using an in-beam method and is dominated by uncertainties in the mass of the 6 LiF deposit and the 6Li(n,t) cross section.