Picture of boy being examining by doctor at a tuberculosis sanatorium

Understanding our future through Open Access research about our past...

Strathprints makes available scholarly Open Access content by researchers in the Centre for the Social History of Health & Healthcare (CSHHH), based within the School of Humanities, and considered Scotland's leading centre for the history of health and medicine.

Research at CSHHH explores the modern world since 1800 in locations as diverse as the UK, Asia, Africa, North America, and Europe. Areas of specialism include contraception and sexuality; family health and medical services; occupational health and medicine; disability; the history of psychiatry; conflict and warfare; and, drugs, pharmaceuticals and intoxicants.

Explore the Open Access research of the Centre for the Social History of Health and Healthcare. Or explore all of Strathclyde's Open Access research...

Image: Heart of England NHS Foundation Trust. Wellcome Collection - CC-BY.

Scaled experiment to investigate auroral kilometric radiation mechanisms in the presence of background electrons

McConville, S. L. and Ronald, K. and Speirs, D. C. and Gillespie, K. M. and Phelps, A. D R and Cross, A. W. and Bingham, R. and Robertson, C. W. and Whyte, C. G. and He, W. and King, M. and Bryson, R. and Vorgul, I. and Cairns, R. A. and Kellett, B. J. (2014) Scaled experiment to investigate auroral kilometric radiation mechanisms in the presence of background electrons. Journal of Physics: Conference Series, 511 (1). ISSN 1742-6588

[img] PDF (AAM-SandraMcConville)
AAM_SandraMcConville.pdf
Accepted Author Manuscript

Download (178kB)

Abstract

Auroral Kilometric Radiation (AKR) emissions occur at frequencies ∼300kHz polarised in the X-mode with efficiencies ∼1-2% [1,2] in the auroral density cavity in the polar regions of the Earth's magnetosphere, a region of low density plasma ∼3200km above the Earth's surface, where electrons are accelerated down towards the Earth whilst undergoing magnetic compression. As a result of this magnetic compression the electrons acquire a horseshoe distribution function in velocity space. Previous theoretical studies have predicted that this distribution is capable of driving the cyclotron maser instability. To test this theory a scaled laboratory experiment was constructed to replicate this phenomenon in a controlled environment, [3-5] whilst 2D and 3D simulations are also being conducted to predict the experimental radiation power and mode, [6-9]. The experiment operates in the microwave frequency regime and incorporates a region of increasing magnetic field as found at the Earth's pole using magnet solenoids to encase the cylindrical interaction waveguide through which an initially rectilinear electron beam (12A) was accelerated by a 75keV pulse. Experimental results showed evidence of the formation of the horseshoe distribution function. The radiation was produced in the near cut-off TE01 mode, comparable with X-mode characteristics, at 4.42GHz. Peak microwave output power was measured ∼35kW and peak efficiency of emission ∼2%, [3]. A Penning trap was constructed and inserted into the interaction waveguide to enable generation of a background plasma which would lead to closer comparisons with the magnetospheric conditions. Initial design and measurements are presented showing the principle features of the new geometry.