1. 6/2/2015 Solar-B XRT XRT-1 A High Resolution Grazing Incidence Telescope for the Solar-B Observatory Solar-B XRT Presenter: Leon Golub Smithsonian Astrophysical Observatory

2. 6/2/2015 Solar-B XRT XRT-2 XRT Team U-Side Leon Golub U.S.-P.I. Jay Bookbinder P.M. Peter Cheimets P.E. Ed DeLuca P.S. Alana Sette Mark Weber J-Side Kiyoto Shibasaki P.I. Taro Sakao Secretariat Ryouhei Kano Secretariat … and many others in US and Japan.

3. 6/2/2015 Solar-B XRT XRT-3 Talk Overview The Solar B Mission The X-Ray Telescope on Solar B –Science Requirements –Instrument Design Sample Observing Plans –XRT “firsts”

4. 6/2/2015 Solar-B XRT XRT-4 Solar B Spacecraft Mass: 875 kg Power: 1000W Telemetry: 4Mbps Data Recorder: 8Gbit Attitude: Solar pointed Stability: 0.3 arcsec per 1s Launch: Summer 2006 Orbit: Polar, Sun-Sync, 600km

5. 6/2/2015 Solar-B XRT XRT-5 Solar-B XRT Flight Design Front Door and Hinge Assembly Electrical Box Ascent Vents 2 places Graphite Tube Assembly CCD Camera and Radiator

6. 6/2/2015 Solar-B XRT XRT-6 XRT Instrumentation X-Ray Telescope –Mirror inner diameter: 35 cm –Focal Length 2700 cm –Geometric Area 5 cm 2 Shutter/Analysis Filters –τ exp 1ms to 10s –9 X-ray, 1 WL filter Camera –2Kx2K back-illuminated CCD –1 arcsec pixels (13.5μm)

7. 6/2/2015 Solar-B XRT XRT-7 Focal Plane Filter Wheels Open Thin Be Ti/Poly Thick Al Thick Be Med Be Open Med Al White Light Al/Poly Al/Mesh C/Poly

8. 6/2/2015 Solar-B XRT XRT-8 XRT Exposure Times Focal Plane Intensities for XRT Passbands

9. 6/2/2015 Solar-B XRT XRT-9 XRT Science Goals 1.Coronal Mass Ejections 2.Coronal Heating 3.Reconnection and Jets 4.Flare Energetics 5.Photospheric-Coronal Coupling

10. 6/2/2015 Solar-B XRT XRT-10 XRT Science Goals 1 Coronal Mass Ejections –How are they triggered? High time resolution –What is their relation to the magnetic structures? High spatial resolution –What is the relation between large scale instabilities and the dynamics of small structures? Large FOV Broad temperature coverage

11. 6/2/2015 Solar-B XRT XRT-11 CME Movie

12. 6/2/2015 Solar-B XRT XRT-12 XRT Science Goals 2 Coronal Heating –How do coronal structures brighten? High time resolution –What are the wave contributions? High Spatial Resolution –Do loop-loop interactions cause heating? Large FOV Broad temperature coverage

13. 6/2/2015 Solar-B XRT XRT-13 Coronal Heating: Sample Observation What needs to be explained: Outflows Motions along field Separatrices and QSLs Intermingled hot and cool plasma

14. 6/2/2015 Solar-B XRT XRT-14 XRT Science Goals 3 Reconnection and Jets –Where and how does reconnection occur? Is it related to slow CMEs? High time resolution Large FOV –What are the relations to the local magnetic field? High spatial resolution Broad temperature coverage Coordinated observing with EIS/SOT

15. 6/2/2015 Solar-B XRT XRT-15 Slow CME-associated Flare Events

16. 6/2/2015 Solar-B XRT XRT-16 XRT Science Goals 4 Flare Energetics –Where and how do flares occur? High time resolution –What are the relations to the local magnetic field? High spatial resolution Large FOV Broad temperature coverage High temperature response Large dynamic range

17. 6/2/2015 Solar-B XRT XRT-17 Flare Energetics - Example

18. 6/2/2015 Solar-B XRT XRT-18 SXT Science Goals 5 Photospheric-Coronal Coupling –Can a direct connection between coronal and photospheric events be established? High time resolution High spatial resolution –How is energy transferred to the corona? Large FOV –Does the photosphere determine coronal fine structure? Broad temperature coverage Coordinated observing with SOT-FPP/EIS

19. 6/2/2015 Solar-B XRT XRT-19 Example: Rotating Spot The time has come to move beyond “loops” and “isolated mini-atmospheres”! Courtesy A. Title

20. 6/2/2015 Solar-B XRT XRT-20 The XRT “Firsts” 1.Unprecedented combination of spatial resolution, field of view and image cadence. 2.Broadest temperature coverage of any coronal imager to date. 3.High data rate for observing rapid changes in topology and temperature structure. 4.Extremely large dynamic range to detect entire corona, from coronal holes to X-flares. 5.Flare buffer, large onboard storage and high downlink rate provide unique observing capability. New XRT Instrumental Capabilities:

21. 6/2/2015 Solar-B XRT XRT-21 Anticipated XRT Science “Firsts” Flares & Coronal Mass Ejections. How are they triggered, and what is their relation to the numerous small eruptions of active region loops? What is the relationship between large-scale instabilities and the dynamics of the small-scale magnetic field? XRT will determine the topology, physical parameters (T, ne) and interrelatedness of the regions integral to flare/CME formation. Coronal heating mechanisms. How do coronal loops brighten? TRACE has observed loop oscillations associated with flares (Nakariakov et al. 1999). Are other wave motions visible? Are they correlated with heating? Do loops heat from their footpoints upward, or from a thin heating thread outward? Do loop-loop interactions contribute to the heating? XRT will exhibit the evolution and activity of both active and quiet inner coronal structures on MHD (seconds) to surface B diffusion (days) timescales.

22. 6/2/2015 Solar-B XRT XRT-22 Anticipated XRT Science “Firsts” Solar flare energetics. Solar-B will observe many flare event. The XRT can test the reconnection hypothesis that has emerged from the Yohkoh data analysis. XRT will greatly extend the sample of observed flares in intensity, spatial and temporal resolution, allowing stringent tests of flare theories. Reconnection & Coronal Dynamics. Yohkoh observations of giant arches, jets, kinked and twisted flux tubes, and microflares imply that reconnection plays a significant role in coronal dynamics. With higher spatial resolution and with improved temperature response, the XRT will help clarify the role of reconnection in the corona. XRT will determine importance of flows, B-field–plasma interactions, relevance of null points, reconnection sites and separatrix (or QSL) surfaces. Photosphere/corona coupling. Can a direct connection be established between events in the photosphere and a coronal response? To what extent is coronal fine structure determined at the photosphere?

23. 6/2/2015 Solar-B XRT XRT-23 Typical XRT Observing Plan Assumptions : X-ray data compress to 3 bits/pixel White light data compress to 5 bits/pixel Filter move and settle time 1.2 s per step Shutter prep time 0.2 s Parallel shift @ 10krows/s read time 512kpixels/s => 3.075 s to read 768x768 FOV Exposure times: 1s for filters 1 & 2; 3s for filter 3 Data Rate:53 kB/s Compressed data

24. 6/2/2015 Solar-B XRT XRT-24 Sample XRT Program Emerging Flux Program Understand the interaction of emerging magnetic flux into the existing coronal magnetic field. Implementation: Follow an AR as it crosses disk center (~1 week) Use 768x768 FOV (13'x13') Use 3 filters to obtain basic temperature coverage Run at a 60-sec. cadence to follow coronal structures Take WL images every 45 min for context & alignment

25. 6/2/2015 Solar-B XRT XRT-25 Use of On-Board Storage Typical observing program requires >6 downlinks per day.

26. 6/2/2015 Solar-B XRT XRT-26 End Presentation

27. 6/2/2015 Solar-B XRT XRT-27 Instrument Requirements

28. 6/2/2015 Solar-B XRT XRT-28 Analysis Filter Set

29. 6/2/2015 Solar-B XRT XRT-29 XRT Exposure Times Focal Plane Intensities for XRT Passbands

30. 6/2/2015 Solar-B XRT XRT-30 Diagnostics via Focal Plane Analysis Filters and Filter Ratios Throughput vs. T for C, Al, and Ti Filter ratios vs. T for some representative focal plane filter pairs.

31. 6/2/2015 Solar-B XRT XRT-31 XRT DEM Widget Interface No. knots is no. bands - 1 Initial guess: Flat (unit) DEM No errors included In this example!

32. 6/2/2015 Solar-B XRT XRT-32 “Real” AR DEM 4 filters7 filters Solid line: Input DEM Dashed lines: Best-fit Model DEMs 100×

33. 6/2/2015 Solar-B XRT XRT-33 Entrance Filter Design PROTECTIVE COVER ATTACHMENT POINTS CAPTIVE SCREW ATTACHMET FILTER FRAME BACK SURFACE FRONT SURFACE LIGHT SUPRESSION RIB

34. 6/2/2015 Solar-B XRT XRT-34 XUV Filter Design Aluminum-Nickel MeshAluminum-Polyimide Beryllium-Nickel Mesh Titanium-Polyimide

35. 6/2/2015 Solar-B XRT XRT-35 Rear Assembly Overview FOCUS MECHANISM FILTER WHEEL AND SHUTTER ASSEMBLY CAMERA FOCUS INTERFACE REAR ADAPTER FLANGE GRAPHITE TUBE

36. 6/2/2015 Solar-B XRT XRT-36 Artist’s Conception The Real Thing Solar-B

37. 6/2/2015 Solar-B XRT XRT-37 Spot Size for Various Focus Positions