356,647 research outputs found
Extended range X-ray telescope
An X-ray telescope system is described which is comprised of a tubular mount having a collecting region remote from the one axial end. A soft X-ray/XUV subsystem associated with the collecting region directs only relatively soft, near on-axis X-rays/XUV radiation incident on a first portion of the collecting region into a first detector sensitive to relatively soft X-rays/XUV radiation. A hard X-ray subsystem associated with the collecting region directs only relatively hard near on-axis X-rays incident on a second portion of the collecting region into a second detector sensitive to relatively hard X-rays
X-rays from Supernova Remnants
A summary of X-ray observations of supernova remnants is presented including
the explosion fragment A of the Vela SNR, Tycho, N132D, RX J0852-4622, the Crab
Nebula and the 'bulls eye', and SN 1987A, high-lighting the progress made with
Chandra and XMM-Newton and touching upon the questions which arise from these
observations and which might inspire future research.Comment: 13 pages, 18 figures. To appear in the Proceedings of the 270.
WE-Heraeus Seminar on Neutron Stars, Pulsars and Supernova Remnants, Jan.
21-25, 2002, Physikzentrum Bad Honnef, eds W. Becker, H. Lesch & J. Truemper.
Proceedings are available as MPE-Report 27
Looking Back: Unneeded X-rays
From the discovery of x-rays in 1896 to the present, Dr. Mazur explores the history of risk management of radiation exposure from x-rays and nuclear fallout
X-rays from Hot Subdwarfs
Thanks to the high sensitivity of the instruments on board the XMM-Newton and
Chandra satellites, it has become possible to explore the properties of the
X-ray emission from hot subdwarfs. The small but growing sample of hot
subdwarfs detected in X-rays includes binary systems, in which the X-rays
result from wind accretion onto a compact companion (white dwarf or neutron
star), as well as isolated sdO stars in which X-rays are probably due to shock
instabilities in the wind. X-ray observations of these low mass stars provide
information which can be useful also for our understanding of the winds of more
luminous and massive early-type stars and can lead to the discovery of
particularly interesting binary systems.Comment: Review paper to be published in Advances in Space Research (special
issue on "X-ray emission from hot stars and their winds"
X-ray source uses interchangeable target anodes to vary X-ray wavelength
Compact laboratory X ray tube generates X rays of various wavelengths by using interchangeable target anodes. The wavelength of the X rays depends on the metal from which the anode is made
Solar X-ray spectrum reproduced in vacuum
Desired low energy X rays are produced by modifying commercial ion tubes and combining them with standard power supplies and control circuitry. These X rays have less deviation from the solar X ray spectrum in energy and intensity
Photonic band gap and x-ray optics in warm dense matter
Photonic band gaps for the soft x-rays, formed in the periodic structures of
solids or dense plasmas, are theoretically investigated. Optical manipulation
mechanisms for the soft x-rays, which are based on these band gaps, are
computationally demonstrated. The reflection and amplification of the soft
x-rays, and the compression and stretching of chirped soft x-ray pulses are
discussed. A scheme for lasing with atoms with two energy levels, utilizing the
band gap, is also studied.Comment: 3 figures, will be published on Po
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