External alignment with XRay Telescope XRT and EUV

External alignment with X-Ray Telescope (XRT) and EUV Imaging Spectrometer (EIS) Y. Katsukawa (NAOJ) and SOT team SOT 17 @ NAOJ 1 Apr 17 -22, 2006

Satellite coordinate definition 5. 　UFSS-SA 6. 　UFSS-SB 11. 　OBU 3. 　XRT 9. 　IRU-B 1 UFSS OTA 7. 　NSAS 1. 　OTA 1 UFSS EIS 4. 　EIS OTA x: N-S y: E-W 2. 　FPP 8. 　STT z: Slit wrt Solar-N 10. 　IRU-B 2 Z z 13. 　BUS-Y y X z 12. 　BUS+X Y Apr 17 -22, 2006 X x SOT 17 @ NAOJ Z Y 2

Alignment requirements The pointing axis of SOT represents the pointing axis of Solar-B; alignment of each instrument is performed so that its pointing axis to be coincide with that of the SOT. Apr 17 -22, 2006 SOT 17 @ NAOJ 3

Alignment cubes OTA alignment cube n n Alignment cubes (cube mirrors) are attached to all the telescopes. Normal direction of the mirror surfaces represent the pointing direction of each telescope in the space-craft level test. The cubes are usually measured by a theodolite. Offset angles of pointing direction was measured with respect to the alignment cubes in the instrument level tests. Pointing direction wrt the cubes Apr 17 -22, 2006 Theodolite measurement x (“) y (“) z (“) OTA 14 45 -73 XRT 764 -546 EIS -152 -419 SOT 17 @ NAOJ 4

SOT pointing measurement Flat mirror Tiltmeter n Z X Alignment cube n Theodolite n 2 ndary Field Stop The field-of-view of SOT (OTA) is defined by the 2 ndary field stop (2 FS) located at the Gregorian focus. The FOV of 2 FS is slightly larger than FPP NFI CCD. The pointing axis of OTA is defined by the ray passing through the center of 2 FS and the center of the entrance pupil. The interferometer was aligned to the FOV center defined by 2 FS in the WFE measurements. Tilt of the reference flat mirror provides the pointing direction of OTA. Interferometer Apr 17 -22, 2006 SOT 17 @ NAOJ 5

OTA – FPP alignment check on S/C n Z X FPP Optical Bench CCD n 2 ndary field stop A beam splitter was inserted between OTA and FPP. The theodolite was aligned to 2 FS of OTA, and provides a beam into FPP. The crosshair of theodolite was well located at the center of CCD (better than 4” on the Sun). collimator lens unit Beam splitter reimaging lens theodolite Apr 17 -22, 2006 SOT 17 @ NAOJ 6

Telescope alignment n FPP template XRT template n FPP template n Each telescope is mounted to the optical bench unit (OBU) by three mounting legs. Tilt of the telescopes was aligned to OTA by adjusting lengths of the mounting legs. When the adjustment, we used a telescope template which represents mechanical I/F of each telescope. Finally alignment was confirmed by the actual telescopes. EIS template Apr 17 -22, 2006 SOT 17 @ NAOJ 7

Alignment cube measurements n We have measured the telescope alignment cubes in the integration, before and after the S/C vibration test. Alignment cube (arcsec) FPP XRT EIS UFSS -SA x y z Pointing error wrt OTA x y z Integration 2005. 6. 27 1019 -1437 1151 Pre-Vibration 2005. 9. 14 1016 -1459 1146 Post-Vibration 2005. 11. 21 1009 -1463 1148 Re-integration 2006. 2. 15 1011 -1440 1161 Integration 2005. 7. 19 -765 593 -66 -15 2 7 Pre-Vibration 2005. 9. 14 -796 597 -46 6 27 Post-Vibration 2005. 11. 21 -761 590 -47 -11 -1 26 Integration 2005. 7. 14 138 422 -62 -28 -42 11 Pre-Vibration 2005. 9. 14 124 412 -72 -42 -52 1 Post-Vibration 2005. 11. 21 132 421 -65 -34 -43 8 Pre-Vibration 2005. 9. 14 276 88 89 -21 4 -591 Post-Vibration 2005. 11. 21 285 91 71 -12 7 -609 Apr 17 -22, 2006 SOT 17 @ NAOJ 8

Summary n n n The measurement accuracy (repeatability) is better than 20” in the spacecraft-level measurements. We have measured pointing alignment among SOT, XRT, EIS, and the sun-sensor several times, and the offsets are less than 1 arcmin for all the telescopes. The final alignment measurement will be carried out before delivery to Uchinoura. Apr 17 -22, 2006 SOT 17 @ NAOJ 9