122399752
The ALICE instrument and the measured cosmic ray elemental abundances
Abstract A Large Isotopic Composition Experiment (ALICE) is a balloon-borne spectrometer which can determine the elemental and isotopic composition of galactic cosmic rays with energies near 1 GeV/nucleon. ALICE was flown from Prince Albert, Canada in August 1987, and remained at float altitude (120000 feet) for 14.7 hours. In this paper, we describe the experimental methods and analysis which will be used for subsequent isotopic analysis. We obtained very precise charge resolution over the entire designed range: 0.10 and 0.16 charge units at neon and iron, respectively. Results on the galactic cosmic ray abundances and absolute fluxes of the elements from neon through nickel are reported.
122146103
An isotope experiment using Cherenkov range technique
Abstract The ALICE balloon experiment utilizes the Cherenkov-range technique to determine the isotopic composition of the cosmic radiation in the elemental range magnesium through iron. The instrument operates in the energy range 350 MeV/nucleon to 800 MeV/nucleon. Particle charge and energy are determined from scintillation and Cherenkov radiation emissions within light diffusion chambers. Trajectories of incoming particles are determined by means of large area gas drift chambers. The stopping range of the particles is measured in a cellulose nitrate range stack. This paper reports details of the experimental technique and results of the balloon flight.
5109815
On non-linear partial differential equations with an infinite-dimensional conditional symmetry
Abstract The invariance of non-linear partial differential equations under a certain infinite-dimensional Lie algebra A N ( z ) in N spatial dimensions is studied. The special case A 1 ( 2 ) was introduced in [J. Stat. Phys. 75 (1994) 1023] and contains the Schrodinger Lie algebra sch 1 as a Lie subalgebra. It is shown that there is no second-order equation which is invariant under the massless realizations of A N ( z ) . However, a large class of strongly non-linear partial differential equations is found which are conditionally invariant with respect to the massless realization of A N ( z ) such that the well-known Monge–Ampere equation is the required additional condition. New exact solutions are found for some representatives of this class.
1673322
Local scale invariance, conformal invariance and dynamical scaling
Building on an analogy with conformal invariance, local scale transformations consistent with dynamical scaling are constructed. Two types of local scale invariance are found which act as dynamical space-time symmetries of certain non-local free field theories. Physical applications include uniaxial Lifshitz points and ageing in simple ferromagnets.
1672606
The kinetic spherical model in a magnetic field
The long-time kinetics of the spherical model in an external magnetic field and below the equilibrium critical temperature is studied. The solution of the associated stochastic Langevin equation is reduced exactly to a single non-linear Volterra equation. For a sufficiently small external field, the kinetics of the magnetization reversal transition from the metastable to the ground state is compared to the ageing behaviour of coarsening systems quenched into the low-temperature phase. For an oscillating magnetic field and below the critical temperature, we find evidence for the absence of the frequency-dependent dynamic phase transition, which was observed previously to occur in Ising-like systems.