Zhanshan Wang Institute of Precision Optical Engineering (IPOE) School of Physics Science and Engineering Tongji University, Shanghai , China Soft X-ray and X-ray multilayers for Chinese Telescopes

Outline Soft X-ray Polarimetry with LAMP Multilayers for LAMP X-ray Timing and Polarization(XTP) project Depth-graded multilayers for XTP Summary and outlook

There were nearly no any experience in China on making grazing incidence X-ray telescopes In the late 1970’s Chinese Academy of Sciences launched a X-ray telescope project and in the early 1980’s, it was cancelled. In 2004, the plan for exploring Moon was started. In 2007, a EUV telescope worked on the Moon was planned. On Dec. 2, 2013, the EUV telescope was launched and now is in the orbit.

A EUV telescope on the moon 30.4nm imaging of magnetosphere 58.4nm light from ionsphere for He-II, for He-I

Soft X-ray Polarimetry with LAMP E Lightweight Asymmetry and Magnetism Probe (LAMP) LAMP is in the framework of a small satellite unpolarized polarized

Science with LAMP Pulsars –To measure the geometry of B-field –To constrain the equation of state –Be able to identify “bare quark stars” Relativistic jets in Blazars –To measure the B-field in the X-ray jet Black hole binaries and active galactic nuclei –To measure the disk inclination and help constrain BH spin Soft X-ray Polarimetry with LAMP

Multilayers for LAMP 40° 50 ° Total collection area : 1300cm 2 Using multilayer mirrors working at ~250 eV

Multilayers for LAMP

The incident angle is different at different positions of the surface At central field, the incident angle is in the range from 40 to 50 degrees

Multilayers for LAMP Cr/C multilayer N=120 D= nm Rs=23%~26%~31% at  = nm

Multilayers for LAMP Magnetron Sputtering 125mm  450mm Target size

Multilayers for LAMP Cr/C multilayers ， D=2.3nm Multilayers for LAMP, D= nm period is larger than that at normal incident The multilayers were made for LAMP and are waiting for polarization measurements

X-ray Timing and Polarization(XTP) project The X-ray Timing and Polarization (XTP) mission, proposed by IHEP, is currently being developed in China to explore some main physical problems by observing the Black Holes and other compact objects.

X-ray Timing and Polarization(XTP) project Segmented and highly nested conical approximation to a Wolter I geometry E=2-30 keV, f=4m It is very important to increase sensitivity in this energy band

Depth-graded multilayers for XTP Design of depth-graded multilayers Key parameters E max =30 keV f =4m Bilayer thickness = 2.5 nm 2dsin  = Bragg Law:

Depth-graded multilayers for XTP Design of depth-graded multilayers Starting structures Merit functions Optimized algorithms Keys of design Merit functions: R s (j): reflectivity of each photon energy point R 0 : reflectivity target value

Optimized algorithms a) Using more sophisticated new solution generation mechanism How to determine the new multilayer structure b) Annealing schedule in an optimized layer-thickness range How to optimize: which way SA is a global optimization algorithm However, slow convergence and long calculation time Some modifications The good results can be obtained in short time 1 simulated annealing algorithm Depth-graded multilayers for XTP Design of depth-graded multilayers

3 Local optimized algorithms Optimized algorithms Design results: starting structures Short time, sometimes good results 2 Random search method Thickness of each layer: random change Some good results: long time Depth-graded multilayers for XTP Design of depth-graded multilayers

1 Power law progression of bilayer thicknesses 2 Multilayer stacks with a varieties of periods Starting structures Depth-graded multilayers for XTP Design of depth-graded multilayers

Focal length4 m Outer Diameter170 mm Inner Diameter 60 mm Mirror length20 cm Mirror thickness0.2 mm Number of nested shells62 Table. Design parameters of XTP Energy range: 2-30 keV Depth-graded multilayers for XTP Design of depth-graded multilayers

Number of groupsGrazing incident angles 2 groups 0.20°, 0.30° 4 groups 0.15°, 0.20°, 0.25°, 0.30° 6 groups 0.15°, 0.18°, 0.21°, 0.24°, 0.27°, 0.30° 8 groups 0.15°, 0.17°, 0.19°, 0.21°, 0.23°, 0.25°, 0.27°, 0.30° 10 groups 0.15°, 0.16°, 0.17°, 0.18°, 0.20°, 0.22°, 0.24°, 0.26°, 0.28°, 0.30° 12 groups 0.15°, 0.16°, 0.17°, 0.18°, 0.19°, 0.20°, 0.21°, 0.22°, 0.24°, 0.26°, 0.28°, 0.30° 14 groups 0.15°, 0.16°, 0.17°, 0.18°, 0.19°, 0.20°, 0.21°, 0.22°, 0.23°, 0.24°, 0.25°, 0.26°, 0.28°, 0.30° 16 groups0.15°, 0.16°, 0.17°, 0.18°, 0.19°, 0.20°, 0.21°, 0.22°, 0.23°, 0.24°, 0.25°, 0.26°, 0.27°, 0.28°, 0.29°, 0.30° Depth-graded multilayers for XTP Design of depth-graded multilayers

Depth-graded multilayers for XTP Design of depth-graded multilayers

Depth-graded multilayers for XTP Design of depth-graded multilayers

Magnetron Sputtering systems Fabrication of supermirrors Depth-graded multilayers for XTP

X-ray Timing and Polarization(XTP) project There are mainly two ways to build highly segmented nested optics The main process for making depth-graded multilayers is different between NuSTAR and Astro-H The depth-graded multilayers used in NuSTAR were deposited on slumped glass shells The depth-graded multilayers used in Astro-H were deposited on cylindrical glass mandrels

X-ray Timing and Polarization(XTP) project New Magnetron Sputtering Coater Deposition on slumped glass shells on cylindrical glass mandrels

D1 X-ray diffractometer made by Bede Company X-ray reflectometer in SR XE － 100 atomic force microscope Depth-graded multilayers for XTP

Comparison of different designs Depth-graded multilayers for XTP

Correction of the deposition rate Depth-graded multilayers for XTP

Schematic of replication of a multilayer

Depth-graded multilayers for XTP The reflectivity of a multilayer before replication The reflectivity of a multilayer after replication

Depth-graded multilayers for XTP Primary results about performance of depth-graded multilayers with power law progression of bilayer thicknesses Thickness distribution Grazing angle =0.3degrees W/Si multilayer

Depth-graded multilayers for XTP Thickness distribution Grazing angle =0.35degrees W/Si multilayer Primary results about performance of depth-graded multilayers with power law progression of bilayer thicknesses

Depth-graded multilayers for XTP Thickness distribution Grazing angle =0.4degrees W/Si multilayer Primary results about performance of depth-graded multilayers with power law progression of bilayer thicknesses

Summary and outlook The LAMP and XTP multilayer mirrors have been designed and primarily fabricated. The primary experimental results were obtained Improving the performance of mirrors and making prototype of a telescope for XTP Improving the performance of mirrors and making prototype for LAMP

IPOE multilayer group, Tongji University, China BSRF Soft X-ray Group,China (M.Q.Cui, L.J.Sun, J. Zhu) NSRL Spectral Radiation Standard and Metrology (H.J.Zhou) Acknowledgements Natural Science Foundation of China National 863 High Technology Program Strategic Priority Research Program on Space Science, the Chinese Academy of Sciences