Transcript *************DST

世界の地上太陽光学望遠鏡とDST
飛騨天文台
上野
From 花岡さん資料
この資料中で紹介する地上太陽望遠鏡
1) Sac Peak DST (1969 -- )
2) VTT (1989 -- ) & GREGOR (201X --)
3) SST (2002 -- )
4) BBSO: NST (1969, 2008 -- )
5) Hida DST (1979 -- )
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
入射窓径７６ｃｍ
焦点面太陽径５１ｃｍ
67m
250トンの全光学系を水
銀で浮かせるタイプの
ベアリングで支えている
41.5m
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Solar Adaptive Optics Project
Since the late 1990s the National Solar
Observatory has been advancing the ShackHartmann technique. We divide the solar
image into subapertures then deform a
flexible mirror so each subaperture matches
one reference subaperture. In 1998 we
applied a low-order AO system to the Dunn
Solar Telescope, thus allowing it to operate
near its diffraction limit under moderately
good atmospheric conditions. This
technology now is applied at several solar
telescopes around the world.
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for imaging
A unique instrument at the focus of the Dunn Solar
Telescope is the Universal Birefringent Filter, or
UBF. (Lyot type filter with rotating crystal elements
using quarter waveplates and linear polarizers to
tune.)
It can be tuned to look at any particular visible
color in the Sun's spectrum. A picture can then be
taken of that region of the sun. This allows scientists
to observe different altitudes and temperatures on
the sun, as each chemical element emits or absorbs
its own color of light.
In order to record images or spectra, an
electronic camera called a CCD is often
used. The pictures are read by a computer
and stored either on disk or magnetic tape
for later analysis.
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for imaging
IBIS: Interferometric Bidimensional Spectrometer
The Interferometric Bidimensional Spectrometer (IBIS) is a Solar Research Instrument
on the DST.
（ファブリペローフィルタによる2次元フィルタ分光）
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
HSG: the Horizontal Spectrograph
The Horizontal Spectrograph (HSG) is a high spectral
and spatial resolution instrument. The spectrograph
consists of a rectangular slit, of fixed width,
a collimator lens, plane grating, camera lenses, and
CCD detectors.
Component Description
Grating:
316 lines/mm reflection type by Bausch and Loumb
206mm x 128 mm ruled area
Blazed at 63.4333 degrees (63 degrees, 26 minutes)
Blaze wavelength - all
Resolution 472,596 (2/3 of theoretical) at 5000 A,
11th order, resolving power 7mA
Slit:
Adjustable
Scale at slit = 7.5arcsec/mm, Maximum FOV = 170 x 170 arcsec
1 arcsec = 133.3 microns
Collimating Lens: 3 meter focal length for f36 setup, 1.5 meter focal length for f72
Camera Lenses: 3 meter focal length singlets or 1.5 meter focal length singlets
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
4種類の分光偏光装置
Advanced Stokes Polarimeter (ASP) : This uses a
horizontally-mounted spectrograph to study complex
magnetic fields, such as are common in sunspots. The
ASP can also be used with the UBF to produce
simultaneous, coordinated data sets.
Cf. Elmore et al. 1992 SPIE, 1746, 22E
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
The Diffraction-Limited Spectro-Polarimeter (DLSP) built in collaboration with the HAO
and operated at the NSO Dunn Solar Telescope is an innovative and contempo grating
polarimeter specifically designed to meet the high requirements pursued in solar
spectropolarimetry. With the excellent imaging properties of the instrument and the
efficient performance of the high-order adaptive optics system we achieve a spatial
resolution of 0.4 arcsec on a regular basis.
The spectrograph is in an autocollimated configuration (Littrow mount) with an off-axis
parabola (P). The dispersive element is a 79 grooves/mm Echelle grating (G) working in
high order (36th order). The aperture slit (S) has a width of 12 micron. The detector
(CCD) is a high speed, backside illuminated split-frame transfer sensor (652 x 494 pixel)
manufactured by PixelVision.
The DLSP uses two ferro-electric liquid crystals upfront right after the exit port to
modulate the light beam. A polarizing beam splitter (PBS) right in front of the detector
acts as an analyzer.
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
The DLSP has two operation modes coined high- and low-resolution mode. In high
resolution the diffraction limit of the DST @630.2 nm is critically sampled with 0.09
arcsec/pixel covering 59 arcsec along the slit. In low resolution the spatial sampling is 0.25
arcsec/pixel allowing for a larger FOV of 163 arcsec.
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
FIRS: the Facility IR Spectropolarimeter
The Facility Infrared Spectrapolarimeter for the Dunn Solar Telescope is an advanced imaging
spectropolarimeter developed by the Institute for Astronomy - University of Hawai'i (P.I. Haosheng
Lin) and the National Solar Observatory. This instrument provides simultaneous spectral coverage at
visible and infrared wavelengths through the use of a unique dual-armed spectrograph design. The
geometry of the spectrograph has been specially designed to capture the Fe I 6302 Å and 15648 Å
lines with maximum efficiency. In addition, the spectrograph operates in a multiple slit mode. By using
narrow band filters, the spectra from four consecutive slit positions can be imaged at once on the
same detector. This feature greatly reduces the time necessary to scan across a large area on the sun,
making it an ideal instrument for the study of quickly developing active regions.
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
SPINOR: Spectro-Polarimeter for Infrared and Optical Regions
SPINOR is an instrument developed for the NSO by HAO.
Polarization Optics
All the optical mounts built for the Advanced Stokes Polarimeter are used for SPINOR as well. Every
ASP optical element is replaced by a new achromatic one.
Entrance Window Calibration Polarizer
The entrance window calibration polarizer is an array of 13 VersaLight wafers. The wafer diameter is
approximately 150mm (with a flat on one side aligned to the polarization direction). The mechanical
mount developed for DST calibration that fits over the entrance window of the telescope has been
modified to accept these achromatic Versalight polarizers.
Calibration Linear Polarizer
The calibration linear polarizer is VersaLight selected for good performance over a 50mm aperture
and AR coated for 450nm to 1600nm. The location of the calibration Linear polarizer is the stage
closest to the exit port of the telescope in the Calibration Modulation Unit.
Calibration Retarder
The calibration retarder is a 50mm diameter bi-crystalline achromat of the design shown in the plot,
but with thicknesses scaled for quarter wave retardance between 450nm to 1600nm and AR coated
for the same range. The location of the calibration retarder is the stage just above the calibration
linear polarizer in the Calibration Modulation Unit where the light beam is f/72.
Sacramento Peak, National Solar Observatory
Richard B. Dunn Solar Telescope (DST)
Instruments for spectroscopy
SPINOR: Spectro-Polarimeter for Infrared and Optical Regions
Polarization Modulator
The polarization modulator is a 50mm diameter bi-crystalline achromat with thicknesses scaled
for 0.35 wave retardance from 450nm to 1600nm and AR coated for the same range. The location of
the polarization modulator is just after the fast mirror near the exit of the Calibration Modulation Unit
where the beam is f/36. This retarder design includes positive and negative birefringent crystals has a
low variation of retardance vs. angle. It is likely that the temperature will need to be monitored as
there is a small variation of retardance vs temperaturethat diminishes with wavelength.
Polarizing Beam Splitter
The polarizing beam splitter uses a VersiLight beam splitting cube, is 16.5mm per side and is the same
design as that developed for the ASP. As with the ASP, the image of the slit is split into two beams
separated vertically. Each beam is polarized at 45º to the orientation of the rulings on the grating. The
polarizing beam splitter is just behind the entrance slit of the Horizontal spectrograph.
Gratings
Since SPINOR operates over a much wider wavelength range compared to ASP, different grating
choices are appropriate. Depending upon the spectral line of interest and spectral resolution desired
different gratings might be selected. Higher blaze angle gives higher spectral resolution for the same
spatial sample size. Since SPINOR will operate with AO, its design should tend towards higher spatial
resolution than the ASP, but since it is a research instrument and cannot be optimized for a single line,
not as high as DLSP. These spectrograph issues lead to a spectrograph using a 40 mm slit and
1000mm camera lens.The Infrared Triplet is of special interest for SPINOR as the three lines are
inaccessible to ASP both due to the calibration optics and the performance of the 316 line/mm grating
at these wavelengths. Four possible SPINOR gratings have good performance for near infrared lines.
Teide Observatory, Tenerife
Vacuum Tower Telescope (VTT)
38m
It is operated under the leadership of the
KIS (60%) in cooperation with AIP (20%) and
MPS (20%). It is a classical solar telescope:
two celeostat morrors feed the sunlight into
the telescope. It has a 70 cm diameter
primary mirror and a focal length of 46 m.
Thanks to an adaptive optics system, in
operation since spring 2000, it is able to
resolve details down to 0.2 arcsec.
Teide Observatory, Tenerife
Vacuum Tower Telescope (VTT)
- Diameter of primary mirrorl: 70 cm
- Focal length: 45.640 m
- Aperture ratio f/D: 65.7
- Resolving power at 543.4 nm: 0.196"
- Image scale in primary focu: 4.59"/mm
Teide Observatory, Tenerife
Vacuum Tower Telescope (VTT)
An adaptive-optics system
Is permanently installed and available to all instruments; this leads to a substantial
improvement of the image quality. On good days, this provides a spatial resolution of
about 0.2 arcsec at 500 nm for short exposures, and of some 0.5 arcsec for exposures as
long as 10 seconds.
- 35 actuators, 50mm
illuminated pupil diameter,
100mm total diameter
- Minimum radius of curvature
(maximum voltage (±400V)
applied to all actuators): ca ±
20m
- First resonance frequency:
900 Hz
Teide Observatory, Tenerife
Vacuum Tower Telescope (VTT)
Instruments for Imaging
TESOS/VIP is a 2D spectrometer based on three Fabry-Pérot interferometers with a
telecentric design and a spectral resolution of 250,000. It covers the visible part of the
spectrum and can be operated in intensity mode, to record Stokes-I line profiles of 2D
images, and in polarization mode, to measure the full polarization state of the light
along line profiles (I, Q, U, and V).
HELLRIDE (HELioseismic Large Region Interferometric Device) is a Fabry-Pérot
spectrometer that can scan 16 different solar lines, with 20 wavelength steps each, at a
cadence of 60 seconds, in a field-of-view as large as 100×100 arcsec2. This instrument
is outstanding as it provides unique data to study atmospheric waves, and will help to
understand how the chromosphere is heated by shock waves.
Teide Observatory, Tenerife
Vacuum Tower Telescope (VTT)
Instruments for Spectroscopy
Echelle spectrograph; a grating spectrograph with a predisperser, which allows to
measure up to three different spectral bands at a spectral resolution of about 1 million.
A reliable interaction with the telescope and the AO-Tip-Tilt system ensures that maps
of solar regions-of-interest can be scanned.
Data acquisition is performed with up to three of the following CCDs: PCO 1, PCO 2, &
Sensicam (more details on CCDs below). On the slit (focal plane of telescope), the
image scale is 4.49 arcsec/mm. The image scale in the focal pane of the spectrograph is
8.98 arcsec/mm.
TIP-II (Tenerife Infrared Polarimeter) is a near-infrared spectropolarimeter which is
used together with the Echelle spectrograph to measure the Stokes profiles of near
infrared spectral lines (1.0-1.8 μm) with high spectral and spatial resolution. The solar
surface can be scanned using a scanning unit
LARS (Absolute Reference Spectrograph) introduces a laser-frequency reference comb
into the spectral images through a fibre optics system. Line positions can,
consequently, be measured on an absolute wavelength scale.
Teide Observatory, Tenerife
GREGOR (under preparing)
GREGOR is the new 1.5 m solar telescope
currently assembled on Tenerife, Spain, by the
German consortium of the KiepenheuerInstitut für Sonnenphysik, the Leibniz Institute
for Astrophysics Potsdam, the Institut für
Astrophysik Göttingen, the Max-Planck-Institut
für Sonnensystemforschung and other
international partners.
Teide Observatory, Tenerife
GREGOR (under preparing)
The telescope is designed for high-precision
measurements of the magnetic field and the
gas motion in the solar photosphere and
chromosphere with a resolution of 70 km on
the Sun, and for high resolution stellar
spectroscopy.
The new Gregory type telescope with open
telescope structure, alt-azimuth mount,
complete retractable dome, adaptive optics
and a pool of well established and new
developed post focus instruments will replace
the 45 cm Gregory Coudé telescope at the
Teide Observatory on Tenerife which will be
retired after 40 years of service.
Teide Observatory, Tenerife
GREGOR (under preparing)
- 1500mm free aperture
- Gregory configuration with additional tertiary mirror (M3)
- light weighted optics
- integrated adaptive optics
- Image de-rotatornominal field of view 150" (max. 300")
- effective focal length: 55.6m (F/38)
- low instrumental polarisation
- polarisation and calibration unit in symmetric beam
- wavelength range from 350nm to several µm
- night time observations possible
- mirrors made from silicon carbide (Cesic)
- primary mirror (D=1,5m) active thermally controlled
- M2 (D=0.43m) and M3 (D=0,36m) passive cooled
Teide Observatory, Tenerife
GREGOR (under preparing)
Hochauflösendes, zweidimensionales Spektro-Polarimeter
（高分解能2次元フィルタ偏光分光観測装置）
Als eines der ersten wissenschaftlichen Instrumente wird ein
Spektrometer mit zwei Fabry-Perot-Interferometern (FPI) im
kollimierten Strahlengang zur Verfügung stehen. Für
Polarisationsmessungen kann ein Full-Stokes-Polarimter in den
Strahlengang eingefügt werden.
CCD Kameras mit 1376 x 1040 Pixeln aufgenommen.
Bei der gewählten Auflösung ergibt dies ein maximales
Bildfeld von 52 Bogensekunden x 40 Bogensekunden.
Die Kameras werden mit 12 Bit digitalisiert.
Der spektraler Bereich reicht von 530 nm bis 960 nm,
die spektrale Auflösung ist etwa 250 000.
52秒角×40秒角
カメラ：12ビット
530nmのから960 nmのスペクトル範囲
スペクトル分解能：250 000
最大視野時フレームレート：毎秒約10フレーム
Teide Observatory, Tenerife
GREGOR (under preparing)
Nacht-Spektrograph（ＵＶ・可視2波長同時分光観測装置）
Als eines der wenigen Sonnenteleskope kann GREGOR auch regelmäßig für
Nachtbeobachtungen eingesetzt werden. Dazu wird es mit einem fiberoptischen
Doppelspektrographen ausgestattet. Die spektrale Auflösung beträgt etwa 100
000. Mit diesem Spektrographen sollen sonnenähnliche Sterne parallel im
visuellen und blauem Spektralbereich beobachtet werden. Der Betrieb soll
möglichst vollständig robotisch erfolgen.
Teide Observatory, Tenerife
GREGOR (under preparing)
POLIS （可視・近紫外の２波長同時分光偏光観測装置）
Mit einem Nachbau des Polarimetric Littrow Spectrometer (POLIS) Instrumentes
am VTT können gleichzeitige, polarimetrische Beobachtungen bei zwei
bestimmten Wellenlängenbereich des sichtbaren und nahen ultravioletten
Spektrums gemacht werden. Die spektrale Auflösung beträgt etwa 250 000. Die
Installation des Instruments wird nach der Inbetriebnahme des Teleskops
erfolgen.
Teide Observatory, Tenerife
GREGOR (under preparing)
Infrarot Spaltspektrograph
Für Beobachtungen im Wellenlängenbereich von etwa 1µm bis 1.8µm wird das
GREGOR Teleskop mit einem Spaltspektrographen ausgestattet. Mit einer
Kamera mit 1020 x 1024 Pixeln erhält man ein Bildfeld von etwa 136
Bogensekunden x 137 Bogensekunden. Die spektrale Auflösung beträgt zwischen
380 000 bis etwa 570 000. Mit einem Polarimeter hinter dem Eintrittsspalt
können die verschiedenen Polarisationszustände des Sonnenlichtes gemessen
werden.
Für die Zukunft ist geplant, den
Spektrographen auch für parallele
Beobachtungen im optischen
Wellenlängenbereich zu erweitern.
赤外線スリット分光装置の立体概略図
黄色の５階にある光学ベンチ（青色）に
偏光モジュレータと入射スリット。
スリットを通った太陽光は４階（グレー）の
スペクトルカメラミラーによって捕らえ、
回折格子上にコリメートさせる。
Roque de los Muchachos Observatory, La Palma
Swedish Solar Telescope (SST)
The Swedish 1-m Solar Telescope (SST) is a
refracting solar telescope at Roque de los
Muchachos Observatory, La Palma in the Canary
Islands. It is run by the Institute for Solar
Physics of the Royal Swedish Academy of
Sciences. The primary element is a single fused
silica lens, making it the second largest optical
refracting telescope in use in the world. The
110-cm lens has a clear aperturediameter of
98 cm. The SST is most often used as
a Schupmann telescope, thereby correcting
the chromatic aberrations of the singlet
primary.
The SST is a vacuum telescope, meaning that it
is evacuated internally to avoid disruption of the
image from air inside. This is a particular
problem with solar telescopes because of the
heating from the large amounts of light
collected being passed on to any air causing
image degradation. As of 2005 it has produced
the highest resolution images on the Sun of any
Roque de los Muchachos Observatory, La Palma
Swedish Solar Telescope (SST)
Currently, the SST is operating with an adaptive
optics system with a 37-actuatordeformable
mirror from AOPTIX, although upgrades are
underway.
Roque de los Muchachos Observatory, La Palma
Swedish Solar Telescope (SST)
A. Details of the box holding the field
mirror and field lens.
B. The Schupman corrector with one
lens and one mirror.
C. The re-imaging optics, located on
the optical table and consisting of a
tip-tilt mirror, an adaptive mirror
and a re-imaging lens.
Roque de los Muchachos Observatory, La Palma
Swedish Solar Telescope (SST)
Instruments
The SST has two modes of operation.
One mode is a spectrograph mode, using the TRI-Port Polarimetric EchelleLittrow (TRIPPEL) spectrograph with a resolution of R = 230 000 (corresponding to
1.3 km/s at the solar surface). TRIPPEL is a Littrow spectrograph using a 79
grooves/mm echelle grating with a blaze angle of 63.43 degrees.
Roque de los Muchachos Observatory, La Palma
Swedish Solar Telescope (SST)
Instruments
The other mode is an imaging mode, where imaging is split up in a red and a blue
beam by a dichroic beamsplitter. The red beam has a tunable filter called CRisp
Imaging SpectroPolarimeter (CRISP) which operates from 510 to 860 nm and is able
to measure polarization by using liquid crystal modulation combined with a polarizing
beamsplitter. The total system uses three 1k × 1k Sarnoff CCDs, two are used for
direct observations and the third is used in aiding the MOMFBD image reconstruction
method. The blue beam is a setup with a total of 4 MegaPlus II es4020 cameras.
Big Bear Solar Observatory
* Built by the California Institute of Technology in 1969.
* In 1997, transferred to the New Jersey Institute of Technology (NJIT).
* The surface of Big Bear Lake is about 2,055 meters (6,742 ft) abovesea level.
* The main observatory building is in the open waters of the lake.
The original main solar telescopes:
a 65 cm (26 in) vacuum reflector
Its Main purpose was studies of sunspots
on the solar surface.
Big Bear Solar Observatory
The New Solar Telescope (NST)
-In early 2007, The New Solar Telescope (NST) was began building.
- December 2008, first engineering light at the Nasmyth focus
- January 2009, solar observations began.
- The telescope is set on an equatorial mount.
- 1.6 m (63 in) clear aperture open frame, off-axis Gregorian telescope.
- new ventilated dome
Big Bear Solar Observatory
The New Solar Telescope (NST)
-In early 2007, The New Solar Telescope (NST) was began building.
- December 2008, first engineering light at the Nasmyth focus
- January 2009, solar observations began.
- The telescope is set on an equatorial mount.
- 1.6 m (63 in) clear aperture open frame, off-axis Gregorian telescope.
- new ventilated dome
Big Bear Solar Observatory
The New Solar Telescope (NST)
- f/2.4 primary mirror (M1)
- 83.2m effective focal length (f/52 at Gregorian focus)
- Telescope optics (PM,SM) made of Zerodur (ドイツ・ショット社が開発した低膨張率光学ガラス).
- Plate scale 2.48 arcsec/mm
- Diffraction limited resolution of 0.06" at 500nm and 0.2" at 1,565nm (with AO)
- Computer controlled pointing and tracking
- Real-time systems for maintaining telescope alignment
- Temperature monitoring at many points on the telescope
- Active optics & Adaptive optics
- Gregory-Coudé focus => 2 arcmin FOV
Wavelength range from 0.39-1.6μm with AO
- Nasmyth focus
=> All wavelengths > 0.39μm also
at with tip/tilt but without AO
Big Bear Solar Observatory
The New Solar Telescope (NST)
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for imaging
開発中のものも含め、現在以下の4種類の焦点面装置がある
・BFIs
・VIS
・IRIM
・NIRIS
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for imaging
光球撮像用
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for imaging
彩層観測用
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for imaging
光球の赤外磁場偏光観測
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for imaging
IRIMの後継機：視野拡大、スループット増大、彩層ラインも
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for Spectroscopy（いずれも開発中）
Fast Imaging Solar Spectrograph (FISS)
collaborative work between Seoul National University (SNU) and
Korean Astronomy and Space Science Institute (KASI)
Concept of two-mirrored field scanner.
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for Spectroscopy （いずれも開発中）
Fast Imaging Solar Spectrograph (FISS)
As of now, FISS is undergoing lab tests at KASI. Alignment test on a horizontal optical
table was successful. The FWHM at the focal plane was 2.5 pixels and this can be
regarded as moderate sampling. Still imaging test using coelostat is ongoing. Finally, it
should undergo the same procedure on a vertical optical table, which is the same
environment at the Coudé lab of NST. →現在既にＮＳＴに設置して観測を開始している
が、空間分解能の点で本来の性能が出ていないようで、要調整。（１１月のＳｏｌａｒ－Ｃ会
議で本件についての講演の予定あり。）
Big Bear Solar Observatory
The New Solar Telescope (NST)
Instruments for Spectroscopy （いずれも開発中）
低温赤外対応多波長スペクトログラフ
Hida Observatory
Domeless Solar Telescope (DST)
１次焦点面
クーデ鏡ユニット
1次焦点面ユニット
ＰＧ部
ＰＧセンサ
コーン・ダイアフラム
ターレット
垂直分光器
Gバンドの撮像
を行なう場合は、
ここにダイクロ
イックミラーを
置く
（１）１９７９年～１９９６年：
撮像データは写真フィルムに記録。
（２）１９９５年 ～２０００年：
PULNiX製アナログビデオカメラの
画像を、レーザービデオディスク
メディアに記録。
（３）２００１年～現在：
デジタルCCDカメラ KODAK MegaPlux4.2iにて直接デジタル画像とし
て記録。
垂直分光器焦点面におけるHαリオフィルタによるフィルタグラフ観測データ例
垂直分光器
垂直分光器を用いた偏光分光観測による
光球マグネトグラフのデータ例
現VMGC
現ircam2PC
現ircamPC
現dstraid
垂直分光器を用いたCa II K線スペクトロヘリオグラフ
観測による彩層ジェットの観測例
(Morita et al. 2010)
水平分光器
水平分光器
水平分光器を用いた３波長同期スペクトロヘリオグラフの観測例
分光器・回折格子の性能について (ツェルニー・ターナー型)
太陽像の焦点面
スペクトルの焦点面
回折格子
(グレーティング)
コリメータ鏡
カメラ鏡
グレーティング（回折格子）の基本公式
ｄ
A
α
B
C
β
光の波が強め合う入反射角度の関係式：
ｍλ ＝ ＡＢ＋ＢＣ
＝ ｄ（sinα＋sinβ） ・・・(1)
ここで、ｍ：干渉の次数（整数）
波長分散
ｄβ/ｄλ ＝ １／（ｄβ/ｄλ）＝ ｍ / ｄcosβ ・・・(2)
波長分解能
λ/Δλ ＝ Ｎｍ/1.22 ・・・(3)
ここで、Ｎ；有効な溝の全本数
（なぜなら、 Δβ ＝ 1.22λ／Ｄ ＝ 1.22λ／Ｎｄcosβ
Ｄ；反射光の口径
かつ、
Δβ ＝（ｍ/ｄcosβ）Δλ ）
Nｄ
D
β
ドームレス太陽望遠鏡 垂直分光器を用いた場合の例
回折格子の溝の密度
：632本/mm
観測する波長と入反射角（例）：6302.5Å、
α=54.29°、β=51.38° (必ずαーβ=2.907°)
観測するスペクトルの次数（例）：４
(1)式左辺 mλ＝４×6302.5＝25210
(1)式右辺
ｄ（sinα＋sinβ）＝107/632×(sin(54.29°)+sin(51.38°)＝25210
ここで、(2)式より
分散：
dβ/dλ = m / d cosβ = 4 /(107/632) cos(51.38°)
= 4.05×10-4 [rad/Å] = 5.689 [mm/Å]
また、
有効口径内の溝の全本数：N = (632本/mm×400 mm)
なので、(3)式より、
波長分解能：λ/Δλ ＝ Ｎｍ/1.22
＝ 632×400 × 4 / 1.22 ＝ 828852
よって、Δλ＝ λ／828852 ＝ 6302.5 Å／828852
＝ 0.00760 Å
ドームレス太陽望遠鏡 水平分光器6番ポートを用いた場合の例
回折格子の溝の密度
：1201本/mm
観測する波長と入反射角
：7773Å、
β=32.98°、α=22.90° (必ずβーα=10.08° for port-6)
観測するスペクトルの次数：1
(1)式左辺
mλ＝１×7773＝7773
(1)式右辺
ｄ（sinα＋sinβ）＝107/1201×(sin(22.90°)+sin(32.98°) ～ 7773
ここで、(2)式より
分散：
dβ/dλ = m / d cosβ = １ /(107/1201) cos(32.98°)
= 1.432×10-4 [rad/Å] = 1.430 [mm/Å] = 0.699 [Å/mm]
（焦点距離9.985mとして）
また、有効口径内の溝の全本数：N = (1201本/mm×160 mm÷cosα) なので(3)式より
波長分解能：λ/Δλ ＝ Ｎｍ
＝(1201×160/cos(22.90°))× 1 ＝ 208601
よって、Δλ＝ λ／208601 ＝ 7773 Å／208601 ～ 0.0372 Å
ここまで