CryoNIRSP Performance Summary Sept. 20, 2014
CryoNIRSP Wavelength and
Angular Resolution
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1000 2000 3000 4000 5000 6000 7000
Sp
ati
al R
eso
luti
on
[arc
sec]
Wavelength [nm]
C DL V
VBI
VISP DLNIRSP
CryoNIRSP
VTF
CryoNIRSP Overview
• Standalone instrument: no AO or beam sharing,
integrated context imaging and spectropolarimetry
• Diffraction limited at long-wavelengths without AO
• Big FOV
• Broad wavelength range
• “Coronal Instrument”
– Reflective optics, Optimized scattered light control
– Core and wing PSF calibration
– Wide dynamic range photometry
• Flux sensitivity allows full-aperture stellar polarization
calibration
CryoNIRSP Modes
• Science operations modes (imaging and
spectroscopy)
– Solar Disk
– Off-limb corona
– Near-limb corona
• Calibration modes
– Geometry registration (context, spectral, beamsplitter)
– Wavelength
– Polarimetric crosstalk
– Photometric/scattered light
CryoNIRSP Optical Summary:
A cryogenic instrument
Table 4.6. Representative CryoNIRSP
Optical Specifications
CryoNIRSP
Grating (primary) Echelle: 32 line/mm
Grating size 408 154 mm
Relay, focal ratio 18
Coll/Cam. Focal Ratio 18/8
Plate scale 0.16 mm/arcsec
Slit Width, multi-slits 52/175µm
Pixel scale (at 1 μm) 165 mÅ
Pixel scale (arcsec) 0.12“ (18μm pix) Design/Diffraction
limited FOV 240/90”
Hawaii-2RG FOV 240" Cold blocking filter
BW 1%
System QE 5% Max spectral
resolution at 4μm 100000
CryoNIRSP FOV
4’ slit
3’ scan
90s
CryoNIRSP Single Slit Data Sample: Si IX 3.93μm
3.94μm
3.92μm
240 arcsec = 0.25 R☺
I+P
I-P
ATST and CryoNIRSP will
measure B>5G at this resolution
in about 1hr
Kuhn, IAS, 2008
Si IX: v, B Sensitivity Estimates
• Estimate Si IX 3.9μm line measurements 1arcsec, 1min
• At edge of field, r = 0.25R from limb
– S =102 phot/s/pix(1μS) x (n=40) x (9pix=1”) x (60s) = 2x106 phot
– B ≈ S k=10-3
– σv = 60km/s x k = 60 m/s
– σB = 60 x 0.24 = 15G
• Near limb
– S =103 phot/s/pix (10μS) x (n=40) x (9pix=1”) x (60s) = 2x107 phot
– B ≈ S k=3x10-4
– σv = 60km/s x k = 20 m/s
– σB = 60 x 0.24 = 5G
• 3x4’ region, 1” samples, 5G max. sensitivity, 3hr (1hr w/
triple slit)
Exposed CryoNIRSP 77K
Cold Optics
Spectrograph
Context
Imager
Helium closed-cycle coolers
Mechanism feed-thrus
Warm coude
optics
CN Wavelengths and benchmark
coronal magnetic sensitivity
Wavelength (μm) Line
0.53 FeXIV
0.637 FeX
0.789 FeXI
1.075 FeXIII
1.083 HeI
1.25 S IX
1.43 Si X
2.218 FeIX
2.326 CO
2.58 SiX
3.028 MgVIII
3.93 Si IX
4.651 CO
Sky and Corona at 0.1R
Temperature sensitivity from 3000K to 3MK
(2R)
DKIST and CryoNIRSP: emergent
science frontiers
• The molecular photosphere
– Ambipolar dynamics in sunspots
• Observing the heliosphere from the ground
– A dusty plasma, “inner source”
• Our dark energy problem
– Seeing coronal magnetism
– Permitted + Forbidden line Hanle Vector coronal
magnetometry
• Night-time solar physics
– Imaging magnetism in other stellar atmospheres
and learning from solar magnetism
– Circumstellar science (imbedded stars…)