Thu·Dec 25, 2014Thursday·December 25, 2014

1. 01*

   Seaborg's Plutonium?

   Eric B. Norman🇺🇸 · Keenan J. Thomas🇺🇸 · Kristina E. Telhami

   Passive x-ray and gamma-ray analysis was performed on UC Berkeley's EH&S Sample S338. The object was found to contain Pu-239 and no other radioactive isotopes. The mass of Pu-239 contained in this object was determined to be 2.0 +- 0.3 micrograms. These observations are consistent with the identification of this object being the 2.77-microgram plutonium oxide sample described by Glenn Seaborg and his collaborators as the first sample of Pu-239 that was large enough to be weighed.

   nucl-exphysics.ins-det1 citation
2. 02*

   Role of p-induced population of medium mass(A $\sim$ 150) neutron rich nuclei

   D. Banerjee🇨🇭 · A. Saha🇺🇸 · T. Bhattacharjee🇮🇳 · R. Guin🇮🇳 · S. K. Das🇮🇳 · P. Das🇮🇳 · Deepak Pandit🇮🇳 · A. Mukherjee · A. Chowdhury · Soumik Bhattacharya🇮🇳 · S. Das Gupta🇨🇦 · S. Bhattacharyya🇮🇳 · P. Mukhopadhyay · S. R. Banerjee🇮🇳

   Excitation functions were measured by stacked-foil activation technique for the ${}^{150}$Nd(p, xpyn) reaction using 97.65 enriched ${}^{150}$Nd target. Measurement up to $\sim$50 above barrier and down to 18 below the barrier was performed using proton beam energy (E${}_p$) of 7 - 15 MeV from VECC Cyclotron. The yield of suitable $\gamma$ rays emitted following the decay of relevant evaporation residues was determined using a 50 High Purity Germanium (HPGe) detector.(p,n) cross section was found to follow the expected trend with a maximum value of 63.7(4.9)mb at E${}_p$ $\sim$ 8.6 MeV. (p,2n) cross section gradually increased with E${}_p$ and had maximum contribution to the total reaction cross section after E${}_p$ $\sim$ 9.0 MeV. (p, p${}^{\prime }$n) reaction channel also showed a reasonable yield with a threshold of E${}_p$ $\sim$ 12.0 MeV. The experimental data were corroborated with statistical model calculations using different codes, viz., CASCADE, ALICE/91 and EMPIRE3.1. All the calculations using a suitable set of global parameters could reproduce the excitation function fairly well in the present energy range.

   nucl-exPRC(2015)·12 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.