Interactions of relativistic 36Ar and 40Ar nuclei in hydrogen: Isotopic production cross sections

Abstract

The interactions of 36 Ar projectile nuclei with energies of 361, 546, and 765 MeV/nucleon and 40 Ar nuclei with 352 MeV/nucleon, have been studied in a liquid-hydrogen target as part of a program to study interactions of relevance to the problem of cosmic-ray propagation in the interstellar medium. We have measured the cross sections for the production of isotopic fragments of the projectile nuclei in these interactions. The variations of these cross sections with mass, charge, and energy, are examined for insights into any systematic features of this type of fragmentation reaction that might aid predictions of other, unmeasured cross sections. These cross sections are also compared with the values derived from the most commonly used prediction techniques. It is suggested that these techniques could be improved by taking account of the systematic features identified here.

Current status and desired precision of the isotopic production cross sections relevant to astrophysics of cosmic rays: Li, Be, B, C, and N

“…At the end of the 1980s, several CR and particle physicists gathered in the so-called "Transport Collaboration" [46], proposing a dedicated program focused on, but not restricted to, data from Z < 26 beams. A significant effort was made by Bill Webber and his colleagues, who measured a number of isotopic production cross sections using secondary ion beams on liquid hydrogen, carbon, and methylene CH 2 targets (and using a CH 2 -C subtraction technique) in the energy range ∼400-800 MeV/n [47][48][49][50][51][52][53][54][55][56][57][58][59]. The cross sections measured by the members of the Transport Collaboration and assembled from the literature along with the existing at that time semiempirical codes (WNEW and YIELDX [52,60,61]) were made available to the community through a dedicated web-site.…”

A Bayesian-neural-network prediction for fragment production in proton induced spallation reaction *

“…The Markov chain Monte Carlo (MCMC) methods are applied to optimize the model control parameters and obtain the predictive distribution. As one of the MCMC methods, the hybrid Monte Carlo (HMC) algorithm was first introduced by Neal [34] to deal with the model parameters and Gibbs sampling for hyperparameters. The HMC is a form of the metropolis algorithm, where the candidate states are found via dynamical simulation.…”

The importance of Fe fragmentation for LiBeB analyses

“…On the one hand, a wealth of nuclear data was provided by the Transport Collaboration et al (1990), who studied isotopic production cross sections through direct reactions, that is by measuring secondaries produced by ion beams (mostly Z < 26) colliding liquid hydrogen or carbon and methylene CH 2 targets (and using a CH 2 − C subtraction technique). This technique was notably used by Bill Webber and his colleagues, in the energy range ∼400-800 MeV/n (Webber & Brautigam 1982;Ferrando et al 1988;Webber et al 1990dWebber et al ,b,c,a, 1998cKnott et al 1996;Chen et al 1997a,b;Knott et al 1997). On the other hand, Michel and Leya's group (Michel et al 1989(Michel et al , 1995(Michel et al , 1997Dittrich et al 1990a;Bodemann et al 1993;Sudbrock et al 1996;Leya et al 1998Leya et al , 2005Leya et al , 2006Ammon et al 2008) as well as Sisterson's group (Sisterson et al 1992(Sisterson et al , 1994(Sisterson et al , 1997(Sisterson et al , 2000Sisterson & Caffee 1998;Kim et al 2002;Sisterson & Vincent 2006) relied on indirect reactions, where a target of heavy elements is irradiated by a high-energy proton beam.…”