Structure and Evolution of the Universe: Micro Arc-Second Imaging in X-Ray Spectrum

1. MAXIM Periscope Module Science Liaison H. John Wood (Read by Jennifer Bracken) 25 April 2003

2. Structure and Evolution of the Universe • In order to study the structure and evolution of the universe – micro arc-second imaging will be required • X-ray imaging can pierce the dusty centers of galaxies in order to study some of the most energetic events in creation • What can you see with micro arc-second imaging in the x-ray region of the spectrum? • accretion disks of black holes • stellar coronae and interacting binaries • Cataclysmic variables and X-ray binaries • Distant Active Galactic Nuclei

3. Two globular clusters These globular clusters both have giant black holes at their centers

4. The Event Horizon can be Imaged by MAXIM

5. Purpose of the Study • An optics – oriented study • Are the mirrors impossible to make? • Are actuators available to move the mirrors by nm steps over microns of range? • Can the thermal and structural environment be benign enough to maintain mirror figure and stability? • Is internal metrology needed – if so how to implement? • What would the alignment procedures be? • Trade study on the mirror sizes and the impact on the number and sizes of the spacecrafts • What are the cost, mass and power inputs?

6. The Collecting Area of Chandra for 1/10 The Cost • Chandra has 0.5 arc sec resolution and its mirrors cost $400M • This study has shown that it is possible to build a microarcsec imaging telescope with the same collecting area as the current Chandra for 1/10 its cost • The study has also shown how the engineering can be done to allow X-ray imaging and spectroscopy in formation flying • The nature of the detector allows imaging over a large range of energies simultaneously

7. Full MAXIM Design Overview • Configuration at L2 • Hub and 25 free-flyers form an “objective” over a one-kilometer diameter area • 4-mirror grazing-incidence periscopes in each spacecraft reflect x-rays to a detector ship 20,000 km away • Alignment of the optical beams and phasing of them on the detector allows formation of an image • Collecting area is 1000 square centimeters – the entrance aperture is 18.25 by 0.489 cm for each periscope • Thus, each of the 25 free flyers will have 4 periscopes and the hub will have 12 periscopes for a total of 112 periscopes

8. Full MAXIM Design Overview con’t • Optical design • 4-mirror grazing-incidence periscope design simulates the properties of a thin lens: optical tolerances are relaxed in comparison to a typical two-mirror X-ray design • In the periscope, each flat mirror is used at 1 degree angle of incidence • Mirrors are known by their numbers in sequence they are hit by X-rays (#1 entrance, #2, #3 and #4 exit) • Flat mirrors are 30 x 20 x 5 cm with the optical reflection on the 30 x 20 face (gold coat) • Graze direction is in the 30 cm direction and requires figure quality of lambda/300 (633nm) • Orthogonal direction only requires lambda/10 • Beam steering with roll and pitch of the exit mirror (#4) • Optical path length phasing by motion of a daughter bench carrying mirrors #2 and #3 relative to the main optical bench which hold #1 and #4 with its actuators

9. Side View of a Periscope Module Mirrors in lilac; bench in fuchsia; daughter bench in orange with its actuator in gold

10. A Dual-Periscope Module Note the entrance slots right with one shutter open & one closed

11. Up Next • The Systems Engineering Report will be presented by Deborah Amato