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In this work we present an overview of ion cyclotron emission (ICE) signals observed on ASDEX Upgrade (AUG) with a B-dot probe array [1]. The array was recently augmented with an 8 channel digitizer (up to 250 MHz sampling rate) that makes it possible to measure a phase from up to 8 (out of 12) probes. This diagnostic upgrade allows to measure the field-aligned (∼toroidal) propagation direction and the mode number for ICE. The high-frequency Alfvén eigenmode is a commonly observed instability in NBI-heated plasmas on AUG. The frequency of this mode is typically around half the on-axis cyclotron frequency of the driving fast ion species. The mode characteristics measured with the improved ICE diagnostic are consistent with the shear-polarized (or global) Alfvén eigenmode: the mode propagates toroidally in the counter-current, counter-injection direction with a high (>20) mode number. Core ICE is also commonly observed in NBI-heated discharges on AUG. These signal spectra match the on-axis cyclotron frequency (and higher harmonics) of the driving fast ion species and the excitation mechanism is consistent with the magnetoacoustic cyclotron instability (MCI). The recent toroidal phase measurements show that we are dealing with a nearly perpendicularly (to the background magnetic field) propagating wave, in line with the MCI picture. [ABSTRACT FROM AUTHOR]

Laboratory experiment is an attractive method of exploring the plasma physics that may occur in solar and astrophysical shocks. An experiment enables repeated and detailed measurements of a plasma as the input conditions are adjusted. To form a scaled experiment of an astrophysical shock a plasma physics model of the shock is required, and the important dimensionless parameters identified and reproduced in the laboratory. A laboratory simulation of a young supernova remnant is described. The experiment uses the interaction of two millimetre-sized counter-streaming laser-produced plasmas placed in a strong transverse magnetic field to achieve this scaling. The collision-free dynamics of the two plasmas and their interaction are studied with and without the magnetic field through spatially and temporally resolved optical measurements. Laboratory astroplasma physics experiments using high-energy, high-power laser technology enables us to reproduce in the laboratory the conditions of temperature and pressure that are met in extreme stellar environments. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Laboratory astro-plasma physics experiments are being designed to advance both our astrophysics and plasma physics knowledge. With current laser technology, target design and diagnostics, it is now possible to reproduce and measure the conditions of temperature and pressure usually met in extreme stellar environments. Coupled with scaled plasma physics it is possible to simulate certain aspects of astrophysical phenomena in the laser laboratory. The focus is on experiments designed to address key aspects of the plasma physics occurring in supernova remnants. In this approach ideal magneto-hydrodynamics is applied to the supernova remnant and then scaled. Matching dimensionless parameters in a laboratory experiment enables the simulation of complex astro-plasma systems offering the advantage of repeated, detailed measurements and the flexibility to alter the input conditions. Work at York has centered on developing a collisionless plasma experiment. The experiment involves a magnetic field, and two laser-exploded plasmas to make possible a laboratory study of the interaction between a supernova remnant and the interstellar medium. These experiments and the analysis are discussed. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]