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XRT On-orbit Performance. R. Kano (NAOJ) & Japan-US XRT Team. Contents. Optical Performance (Telescope Temperature) Mechanics CCD Performance Effect of Radiation Environment Unexpected Things The temperature in the front part of XRT. The motion of one of the filter wheel (FW1).
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XRT On-orbit Performance R. Kano (NAOJ) & Japan-US XRT Team Hinode Workshop in China
Contents • Optical Performance • (Telescope Temperature) • Mechanics • CCD Performance • Effect of Radiation Environment • Unexpected Things • The temperature in the front part of XRT. • The motion of one of the filter wheel (FW1). • The change of the XRT response. Hinode Workshop in China
Optical Performance: PSF • From the observation of a Mercury transit, FWHM = 1.0 ± 0.12 arcsec(Weber et al. 2007, PASJ). • This is statistically consistent with the pre-launch measurement.FWHM 〜 0.8 arcsec. Mercury Hinode Workshop in China
Optical Performance: Scattered Lights • Eclipse observations suggest the scattered lights, which have not yet parameterized. • For the analysis of faint objects, especially in a coronal hole and above the limb, we have to pay a great attention to the scattered lights. Non-occulted data “Al/Mesh” “Ti/Poly” Occulted data Hinode Workshop in China Kano et al. 2008
Mechanism • XRT has 2 filter wheels, 2 shutters, and 1 focusing motor. • Except for 1 filter wheel (FW1), all mechanism works well. • Latter I will talk about FW1. Hinode Workshop in China
XRT Camera Temperature カメラエレキ(XRT-E)温度 (カメラ搭載)プリアンプ温度 (11月以降のスパイクは技術試験による影響で既知の事象) CCDベークアウト OPヒーターON (2007/06/18) カメラON CCDヒーターOFF Goal: -43℃ (水色) ヒーター制御用のCCD温度センサー(-60℃では誤差大) CCDが軌道上で最も高温となるケース (ベークアウト時を除く) CCD温度 (CCD冷却用)放熱板温度 Hinode Workshop in China
Dark Current • 黒い実線が打上げ前データ。 • 青プロットが軌道上の通常観測時。 • 赤プロットは軌道上でのBake-outの際に 測定したもの。 • (緑線は64secで1DNとなるレート) 軌道上高温ケース 図: 暗電流値の軌道上および地上試験での測定結果 通常の露光時間(~10sec以下)では無視できるほど小さい! Hinode Workshop in China
solar disk solar disk 2007/02/09 20:32:32 2007/02/09 21:12:44 Pseudo signals by high-energy- particle events. DC-offset level for 8”x8” images Effects of High Energy Particles Histogram of XRT counts (a) Out of SAA (b) Inside of SAA Hinode Workshop in China
< 10 pixel= < 0.04% 10 ~ 30 pixel = 0.04~0.12% 30 ~ 100 pixel = 0.12~0.41% 100 ~ 300 pixel = 0.41~1.22% 300 ~ 1000 pixel = 1.22~4.07% 1000 ~ 3000 pixel = 4.07~12.2% > 3000 pixel = > 12.2% SAAではCCD画質が悪化HLZではそれほどでもない HLZ SAA HLZ Hinode Workshop in China
Temperature Diagnostics Hinode Workshop in China Narukage et al. 2007
Unexpected Things Hinode Workshop in China
There are some unexpected things. • The temperature in the front part of XRT. • Higher than our expectation, but no serious problem for XRT operations and observations. • FW1 accidentally stopped in November, 2006. • But it returned to normal operations since May 10th, 2007. • The change of the XRT response. • We have the data to calibrate the XRT response. • XRT team will deriver the database of the XRT response through SSWDB in near future. Hinode Workshop in China