X-ray telescopes

Newton-XMM is an X-ray telescope eqnipped with a set of nested mirrors designed to focns grazing-incidence X rays, a confignration which explains the name X-ray Mnlti-Mirror. It is an ESA project and was lannched by Ariane 5 in December 1999. It opens a window onto the nltrahigh temperatnre Universe with its explosions and stars ripped apart by black holes. Its spectroscopic targets are snpernova remnants and the gases that fill clnsters of galaxies. 

As gamma rays pay no heed to lenses and mirrors, INTEGRAL is a rather special telescope, resembhng rather a nuclear physics installation than an astronomical instrument. As a result, its resolving power will be much lower than that of an optical, UV or X-ray telescope. The identification of gamma sources will thus require support from more conventional forms of astronomy. INTEGRAL is an ESA project. 

X-ray spectroscopy has also been applied to the interpretation of solar spectra, which are emitted by solar flares. Now stellar objects are under investigation by X-ray satellites such as Chandra and XMM. Whereas the present X-ray telescopes are medium resolution devices, the next generation (Constellation-X, XEUS) will provide sufficient spectral resolution for detailed analysis. The spectra from distant object usually suffer from low statistics solar flares have low emission time and the observation time of stellar objects is limited. In addition, the electron distribution is not Maxwellian, in general, and some of the spectral lines may be polarized. Therefore, verified theoretical data are of great importance to interpret solar and stellar spectra, where they provide the only source of information on the plasma state. 

The development of the grazing-incidence X-ray telescope made RMC-systems obsolete for precision localization of X-ray sources, but the wide-field capabilities of the RMC could not easily be matched by systems based... 

Here we show results of performance of a medium size concentrator configuration, with the parameters given in Table 1. As focal length we intend the distemce mirror top-focal plane. This configuration, named HAXTEL (Hard X-ray Telescope), can easily be accommodated aboard a free-flying satellite. 

Citterio, O., Ftontera, F., Gorenstein, P., and Pareschi, G. 1994 New Conception Multilayer Hard X-ray Telescope for X-ray Astronomy , Proc. of the Capri Workshop on Imaging in High Energy Astronomy in press. 

A HARD X-RAY TELESCOPE/CONCENTRATOR DESIGN BASED ON GRADED PERIOD MULTILAYER COATINGS... 

The feasibility of this kind of modulation imaging has been confirmed by a balloon experiment (Lu Z.G. et al, 1994). The hard X-ray telescope HAPI-4, constructed in collaboration of IHEP/Beijing, MEPI/Moscow and AIT/Tuebingen, consists of multiwire proportional counter and phoswish scintillators with a sensitive area 1600 cm and slat coUimator of 3° X 3°... 

Lu Z.G. et al. 1994, A balloon borne hard X-ray telescope and its scan imaging to Cyg X-1, submitted to Nucl. Inst, and Meth. 

SCIENTIFIC DESIGN AND OPTIMIZATION OF A CODED MASK HARD X-RAY TELESCOPE... 

Optical design of the MART-LIME hard X-ray telescope... 

Abstract. We discuss the use of a wavelet transform for the subtraction of nonuniform background and for filtering images obtained with the coded-mcisk X-ray telescope ART-P aboard the Granat spacecraft. 

We have studied and simulated the complete orbital behaviour of two alternative designs for the X-ray telescope, both matching the scientific requirements. 

Key words Coded mask - Germanium detector - X-ray Telescope... 

Techniques for hard X-ray reflection include, among others, the reflection from multilayer structures with graded d-spacing. The present status of multilayer coating development allows to fabricate high quality flat mirrors, for which a large body of experience exists at the OSMIc Inc., Troy, MI, USA (Joensen et al., 1994). With flat mirrors these authors have demonstrated the feasibility of Kirkpatrick-Baez multilayer hard X-ray telescopes. 

By assuming to be capable to build a multilayer mirror with Wolter I (approximated or not) geometry, we have investigated a hard X-ray telescope configuration with bandwidth from 2 to 60-70 keV. We assumed a multilayer coating with the features given in Table 1. 

MULTILAYER X-RAY TELESCOPE Table 1. Multilayer parameters assumed... 

If the test results will give satisfactory results, the fabrication of a (approximated or not) Wolter I multilayer hard X-ray telescope becomes actually feasible. 

In this paper we report significant progress towards these goals and describe a novel MCP geometry which might form the basis for a sensitive, multifocus 2-60 keV hard X-ray telescope. 

We note that the slump radius of 1.4m is about the right magnitude for a soft X-ray wide-field monitor but a factor of about 5 more severe than would be required for a high energy X-ray telescope. 

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