1. A Proposal of Long Slit Spectrograph for WSO/UV Nanjing Institute of Astronomical Optics and Technology, National Astronomical Observatory of China, CAS National WSO/UV Implementation Committee of China 2006-June-28 Zhongwen Hu

2. Contents Team Members Introduction Requirements and assumption layout overview of NIAOT LSS Configurations and performance of LSS Cooperation Expected Quotation results of diffraction Gratings Cross check results of the optics design Schedule

3. NIAOT Introduction A unique research base in China, specialized in professional astronomical telescopes and instruments – 50 astronomical telescopes and instruments ; 30 exported to the USA, Spain, Japan and South Korea. Four main Laboratory –Mirror Technology –Astronomical Spectrum and High Resolution Imaging –Solar Instruments –New Technology Telescope

4. Team members introduction Prof. Yongtian Zhu, director Dr. Zhongwen Hu, Optics Dr. Yi Chen, FEA Ms. Jianing Wang, Electronics Mr. Lei Wang, Precision mechanics

5. Prof. Yongtian Zhu Vice Director of NIAOT Experience –the Coude Echelle Spectrograph for Chinese 2.16-meter astronomical Telescope – Spectrographs for LAMOST project –Proposed a novel two-mirror system for the soft X-ray projection lithograph

6. Soft X-ray beamline construction and calibration of a varied angle spherical grating monochromator (12-120nm) Echelle spectrograph (200-500nm) Polychromator ( 31channels) (UV-Visible). High precision measurements of grating groove density for VLS concave diffraction gratings (Uncertainty 1x10 -5 ). Especially small curvature radius gratings. Expression of groove density (N) and groove function (n) applicable for any gratings Dr. Zhongwen Hu

7. Soft x-ray beamline optics Movements in super high vaccum  3 Gratings could be exchanged  Gratings rotated to scan wavelength  Mirror rotated to compensate defocus First gas absorption spectrum with resolution 1000

8. NIAOT contribution to LSS Under direction of WIC working group of China NIAOT responsibilities –Participate system requirement definition –Design of LSS –Construction of prototype, flight model and test system –Complete instrument level test in China Some crosscheck of LSS test in Ukraine ? –Participate Integration with rest of WSO –Develop Calibration and data reduction methodology

9. THE ROWLAND MULTICHANNEL LONG SLIT SPECTROGRAPH FOR THE WSO/UV MISSION ----- R.E. Gershberg,et.al HIRDES Phase A Study -----Dr. Schwarz & Project Team Performance of the Long-Slit Spectrograph (LSS) ----V. Terebizh LSS References

10. New designs of LSS Possible layouts with various resolution-wavelength pattern  Optimized space and spectrum resolution with extended wavelength coverage  Expect better image quality for every point on slit

11. Use of special gratings Diffraction grating types  Classical gratings  VLS concave gratings  Holographic gratings of the first generation  Holographic gratings of the second generation

12. How to determine requirements of the LSS ? Interactive procedure between science mission requirements and technology capability and availability

13. Performance of the Long- Slit Spectrograph (LSS) Preliminary results V. Terebizh, April 2005 Distance of slit from optical axis 10  49.5 mm Entrance ： Width of slit Length of slit Rectangular: 1   82  m 75   6.2 mm Coating of surfacesAl + MgF 2 Far Ultraviolet (FUV) Near Ultraviolet (NUV) 1150  1775 Å 1750  3000 Å Refl. at 1150 Å ； 1, /3 surfaces at 1216 Å ； 1, /3 surfaces at 3000 Å ； 1, /3 surfaces 60 %, / 21 % 82 %, / 55 % 87 %, / 66 % LSS optical layout ： Modified Rowland-circle spectrograph with one reflection Dispersive element Curvature radii Light diameter Concave grating R 1 and R 2 ~ 1 m 110 mm Approximate size 1050 mm  350 mm Spectral resolution  : FUV NUV 2000  3000 1500  3000 Spectral resolution  for stars ~ 5000 Space resolution 0.40 ” Number of detectors 2  4 Requirements baseline of current NIAOT design

14. Optical configuration of LSS and Position Modified Rowland configuration LSS position in the instrument bay

15. A layout by R.E. Gershberg et.al (3 detectors and 6 gratings)

16. Overview of our layout Three possible layouts are considered: Layout 1a, Layout 1b, layout2 Each layout is shown with its resolution- wavelength pattern

17. 3 layouts of NIAOT design Layout 1aDetector 1Detector 2 Resolution500145050005800 Wavelength range( Å ) 1100-35001150-16552000-23702360-27102700 -3100 Layout 1bDetector 1Detector 2 Resolution500145025002000 Wavelength range( Å ) 1100-35001150-16551150-17751750-3050 Layout 2Detector 1Detector 2Detector 3 Resolution5002500200050005800 Wavelength range( Å ) 1100- 3500 1150- 1775 1750- 3050 2000- 2370 2360- 2710 2700 - 3100

18. Resolution-Wavelength pattern Layout 1a(5 gratings, 2 detctors)

19. Resolution-Wavelength pattern Layout 1b(4 gratings, 2 detctors)

20. Resolution-Wavelength pattern Layout 2(6 gratings, 3 detctors)

21. R.E. Gershberg’s proposal with 3 detectors and 6 gratings

22. Layout 1a ( 2 detectors and 5 gratings) Grating Detector

23. Configurations and performance Optical parameters Image quality Resolution achieved

24. Layout parameters for detector 1. R=500 Detector 1 Detector size (mm^2) Pixel size (um^2) 42.1x6.5 25x12 Grating No.1( Resolution 500) 10( Resolution 1450) Wavelength range( Å ) 1100 ~3500 1150-1655 Incident Angle(deg)4.176 6.625 Diffraction Angle(deg)-1.6363 0.814 Detector Tilt(deg)3.39 Incident Length(mm)897.737 Detector Position(mm)895.0517 Detector RadiusInfinite

25. Spot diagram on detector 1 with grating 1. Left is the images for different points on 6.2 mm slit within the related wavelength. Right is RMS spot radius which shows good space and spectrum resolution for varied slit positions.

26. Resolution test Slit width is 82 microns along spectrum direction space resolution 32 microns along the entrance slit. Gaussian distribution of image on slit with FWHM equals the slit width is assumed.

27. Layout parameters for detector 2 (1150 Å ~ 3050 Å, two gratings). R=2500 Detector 2 (alternative) Detector size (mm^2)Pixel size(um^2) 93.5 x6.525x12 Grating No.2 (Resolution 2500)3 (Resolution 2000) Wavelength range( Å ) 1150~17751750~3050 Incident Angle(deg)1210.725 Diffraction Angle(deg)0.1253-1.1456 Detector Tilt(deg)8.3755 Incident Length(mm)1035 Detector Position(mm)1022 Detector Radius(mm)1037.832

29. Layout parameters for detector 3 (2000 Å ~ 3500 Å, three gratings). R=5000 Detector 3 Detector size (mm^2) Pixel size (um^2) 76 x6.525x16 Grating No. 4 (R= 5000) 5 (R= 5800) 6 (R= 5800) Wavelength range( Å ) 2000~23702360~27102700 ~3100 Incident Angle(deg)21.48622.98223 Diffraction Angle(deg)8.53210.026710.0445 Detector Tilt(deg)0 Incident Length(mm)1035 Detector Position(mm) 953.471 Detector Radius(mm)902.776

31. Mechanical interface problem 1.Gratings enter into spaces of UV and VUV chamber --- Space resolution and detector pixel dimension 2.How many detectors mechanically available ---with or without folding mirrors? ---Interference with FC ?

32. International cooperation expected Detectors –The detector unit (with the High Voltage system) could be supplied by Britain? Electronics –Digital process unit provided by Germany? other

33. Detectors available? –Curved surface detector surface could be a flat plane –Rectangular pixel Square pixel degraded space resolution, two point sampling –Maximum available pixels –Mechanical dimensions

34. Possible vendors of gratings Jobin Yvon (France), Bruno Touzet Spectra-physics (U.S.), Doug Buerkle Carl Zeiss(Germany), Klaus Heidemann Shimadzu(Japan), Shinn Takada Grating has a diameter 115mm. Gratings could be one of the following type. a. spherical gratings fabrcated by aspheric optics b. asperical grating available

35. Grating parameters (Recording wavelength 310nm.) Grating No. 12 345 6 Tangential Radii 9001023.278 1026.626987.6782982.812 982.336 Sagital Radii895.9171001.634 1005.007990.4428994.145 994.602 Y of P1 - 53.4717 -217.144 -131.237178.386294.7175 387.576 Z of P1 - 897.115 -976.88 -1022.002-692.005-1043.679 -1043.92 Y of P20.1468244.804 92.7912974.360 5 2755.836 2577.349 Z of P2 - 895.451 -1042.999 -1060.278607.54-780.765 -827.065

36. Gratings, Reply from Jobin Yvon (France), –They can make our gratings on a custom substrate difficult for them to fabricate the toroidal substrate close to a sphere –They made their own calculations use the same layout parameters with modified recording wavelength

37. Comparison (110nm~350nm resolution 500) ---by Jobin Yvon NIAOT 310nm recording wavelength Jobin Yvon with a different wavelength

38. Grating 1 (resolution 500)

39. Grating 10 (resolution 1450)

40. Summary of NIAOT design (1)  The incident, the diffracted angles and the positions of detectors could be tuned to meet the space mechanically available for LSS  Very good image quality with extended wavelength range or increased resolution through points along the entrance slit.  Show the possibility to integrates some merits of several previous designs.

41. Summary of NIAOT design (2)  For resolution 500 on detector 1  Very good image quality is obtained across wavelength interval 1100 Å ~ 3500 Å through points on the slit.  No auxiliary reflecting mirror needed in principle. ─It depends on mechanical space available for LSS

42. Summary of NIAOT design (3) For resolution ~2500, detector 2 the wavelength range is covered by two gratings like Willem Wamsteker’s proposal, yet it has the image quality similar to that described in R.E. Gershberg’s four gratings mode or double gratings mode with resolution 1500. resolution ~5000 on detector 3

43. Notes Optical designs show improvements of the LSS performance. Yet it is not the finalized form considering the uncertainties in detectors and science mission requirements. System requirements concerning wavelength intervals and their resolution should be to optimized and balanced for newly claimed scientific mission

44. Schedule 2006.02-2007.03: Phase 0+A: Functional Requirements. Feasibility study. Initialization of procurement of component. 2006.12-2007.11: Phase B: Requirement specifications, Engineering environment set-up and preliminary design. 2007.11-2008.09: Phase C: Detailed design. 2008.09~2009.09: Phase D: Production of Flight Model. Ground qualification testing. 2009.09~2010.03: Assembling, Integration, and Verification, with the spacecraft. 2010.03~2010.09: Pre-launch testing 2010.10: Launch

45. Thank you !