On the use of the South-American neutron monitors

Cosmic ray scientific community deserves special attention to the Chacaltaya site for its over 5 km altitude. In this site, a neutron monitor of the IGY type operated from 1960 to 1969, and the one of the NM-64 type since 1966 (16.31◦ S, 291.85◦E, height: about 5200 m a.s.l.). We discuss the relevance of such kind of detector when it is integrated with the other South-American neutron monitors: a) LARC (62.20◦S, 301.04◦E, height: 40 m a.s.l., King George Island, Antarctica; operating since 1991); b) LOS CERRILLOS (33.45◦S, 289.40◦E, height: 570 m a.s.l., Santiago, Chile; to be installed in the near future); c) HUANCAYO (12.03◦S, 284.67◦E, height: 3400 m a.s.l., Huancayo, Peru; hoping to recover its acquired data)

Italia/Chile Collaboration for LARC

An Antarctic Laboratory for Cosmic Rays (LARC) has been opened on the King George Island (Fildes Bay - Ardley Cove) during January 1991. The cosmicray detector is a standard 6-NM-64 type. The present status of the LARC project and relevant scientific goals for Solar-Terrestrial Physics are briefly outlined

Cosmic-ray transparency for a medium-latitude observatory

The access of cosmic-ray particles to a medium-latitude observatory is analysed fromresults coming fromthe numerical solution of the charged-particle motion in the geomagnetic field. Evaluations are performed mainly for the Lomnick´yˇSt´ıt neutron monitor location (LS: 2634 m a.s.l., geographic coordinates 49.20◦ N, 20.22◦ E), but some results for the Antarctic Laboratory for Cosmic Rays (LARC: 40 ma.s.l, 62.20◦ S and 301.04◦ E) are also given. Particular attention is paid to the variability of the magnetospheric screening appearing when the external magnetic field is added to the internal one

Gevrey local solvability in locally integrable structures

We consider a locally integrable real-analytic structure, and we investigate the local solvability in the category of Gevrey functions and ultradistributions of the complex d' naturally induced by the de Rham complex. We prove that the so-called condition Y(q) on the signature of the Levi form, for local solvability of d' u=f, is still necessary even if we take f in the classes of Gevrey functions and look for solutions u in the corresponding spaces of ultradistributions.Comment: 12 page

MASS MEASUREMENT UNCERTAINTY FOR PLUTONIUM ALIQUOTS ASSAYED BY CONTROLLED-POTENTIAL COULOMETRY

Minimizing plutonium measurement uncertainty is essential to nuclear material control and international safeguards. In 2005, the International Organization for Standardization (ISO) published ISO 12183 'Controlled-potential coulometric assay of plutonium', 2nd edition. ISO 12183:2005 recommends a target of {+-}0.01% for the mass of original sample in the aliquot because it is a critical assay variable. Mass measurements in radiological containment were evaluated and uncertainties estimated. The uncertainty estimate for the mass measurement also includes uncertainty in correcting for buoyancy effects from air acting as a fluid and from decreased pressure of heated air from the specific heat of the plutonium isotopes