No abstract

The high throughput X-ray Spectroscopy Mission XMM is a "Cornerstone" project of the ESA Horizon 2000 Science Programme. The optical heart of this satellite consists in 3 Mirror Assemblies (MA). Each MA includes a Mirror Module (MM) containing 58 X-ray optical quality Mirror Shells (MS) and an X-ray baffle (XRB) which reduces straylight. Two of the three MAs are equipped with a Reflection Grating Assembly (RGA) for spectral analysis. Tests are performed in the CSL FOCALX facility. The goal of the presented tests is to evaluate the X-ray effective area of a MM. These tests are accomplished in a vertical configuration. An X-ray pencil beam is used for X-ray reflectivity measurements at Al, Au, Cu and Mo lines between 1.5 and 13 keV. A partial illumination collimated X-ray beam with a C continuous spectrum allows to measure the effective area of the MM over a 1 .5 -9 keV range. This paper gives a short description of the tested specimens, and presents the test configuration in CSL Focal X facility. The paper focuses on a complete and original way to work out experimentally effective areas of an X-ray telescope. Analysis of the achieved results is carried out.

The X-ray Multi-Minor Mission is one of the four "Cornerstone" projects in the ESA Long-Term Program for Space Science. Presently, five XMM Minor Modules (MM) (including one Qualification Model) have been tested in the FOCALX facility of CSL. The MMs are illuminated by a vertical EUV (58.4 nm) collimated beam allowing to get the optical performance in an effective flight configuration. To fully analyse the MM characteristics, reflectivity measurements are performed in X-ray thanks to a pencil beam. The reflectivity measurements of single shell are performed at Al, Au, Cu, Mo lines between 1 .5and 1 3 keV. This information is used to evaluate the effective area in X-rays. Wing scattering measurements are performed and show a good correlation with the Power Spectral Density measured with a PROMAP microscope interferometer during minor shell manufacturing. This paper deals first with the presentation and comparison of the results achieved on the five MMs. In a second step the results of complementary tests, performed to cross check the data and to get a better understanding of the MM behaviour, are discussed.

In the frame of the X-ray Multi Mirror Mission (XMM), the second European Space Agency (ESA) cornerstone project, in total five Flight Models of the Mirror Module have been built. The Mirror Modules are the optical heart of the satellite. Each Mirror Module contains 58 X-ray optical quality Mirror Shells which have been produced and integrated by Media Lano. Each of these Mirror Modules has been tested in the Centre Spatial de Liege (CSL) FOCAL-X facility. The goal of these tests was to measure the optical performance of the Mirror Modules under simulated launch and in-orbit configurations, and to perform some calibration on the Mirror Modules. To achieve these goals, a full EUV (58.4 nm) collimated beam is used to assess the optical characteristic in a representative flight configuration. The X-ray performance is controlled by means of an X-ray pencil beam and an X-ray collimator. The pencil beam is used for the determination of the Mirror Shell position, wing scattering and X-ray reflectivity measurements, the later one for the effective area measurement over 1 .5 to 8 keV energy range. This paper mainly deals with the latest results achieved on the Flight Model 4 Mirror Assembly and the fifth Flight Mirror Module. The first one is integrated on the spacecraft, the second has been built to serve as an additional spare flight MM of the highest quality and to further develop the mirror module production and measurement process. After the presentation of these test results, the lessons learnt from the manufacturing and the testing of the mirrors will be presented.

In the frame of the XMM project, several test campaigns are accomplished to qualify the optical elements of the mission. The tests described in this paper are performed on a XMM Flight Model Mirror Module (FM MM) added with a Reflection Grating Assembly (RGA). The Mirror Module contains 58 X-ray optical quality shells, an X-ray baffle (XRB) to reduce the straylight. This complete XMM Flight Model Mirror Assembly (MA) is tested in a vertical configuration at CSL, in a full aperture or partial EUV collimated beam illumination, and with an X-ray pencil beam. One of the advantages of the EUV collimated beam is to verify the correct position of the RGA when integrated in flight configuration on the Mirror Module structure. This is not possible in X-ray with a fmite source distance. The partial EUV illumination is performed to verify the correct integration of the RGA grating stacks. The pencil beam allows to make an accurate metrology of the XRB position, and to verify the positions of the 0, 1 and 2 diffraction order foci.In this paper, the tested module is first exposed, and the approach to qualify the instrument is described. The analysis of the results achieved over the different test configurations is presented. The impact of the environmental tests on the Reflection Grating Box is also diagnosed.