1. Focal Plane Instrumentation at Big Bear Solar Observatory
Wenda Cao
Big Bear Solar Observatory
New Jersey Institute of Technology

2. Why ?
How are magnetic fields generated and how are they destroyed?
What role do magnetic fields play in the organization of plasma structures and the impulsive releases of energy?
What are the mechanisms responsible for solar variability (that ultimately affects the Earth)?
NST
NST
NST
An angular resolution of 0.1 arcsec or better to resolve the pressure scale height and the photon mean free path
A high photon flux at the critical spatial resolution for precise magnetic and velocity field measurements
Access to a broad set of diagnostics, VIR to IR
NST
Why ?
2 Nov 2007

3. What ?
An angular resolution of 0.1 arcsec or better to resolve the pressure scale height and the photon mean free path
A high photon flux at the critical spatial resolution for precise magnetic and velocity field measurements
Access to a broad set of diagnostics, VIR to IR
Adaptive Optics: diffraction limited image;
InfraRed Imaging Magnetograph (IRIM): infrared high precision polarimetry and spectrometry;
Visible Imaging Magnetograph (VIM): visible spectrometry and polarimetry;
Real-time Speckle Image Processor: high resolution dynamics monitor;
What ?
2 Nov 2007

4. Where ?
Adaptive Optics
2 Nov 2007

5. Adaptive Optics System
Tutelary to Obtain High Spatial Resolution
2 Nov 2007

6. Principle of Adaptive Optics
How ?
Principle of Adaptive Optics
2 Nov 2007

7. Scientific Results Adaptive Optics 2 Nov 2007 System Feature
Corrected modes 35
Subapertures 76
Actuators 97
Bandwidth (closed-loop)
120 Hz
Residual wave front error
1.9 rad2 (AO off)
Mean squared wave front error
0.58 rad2 (AO on)
Wavelength range for WFS
Broadband visible
Intensity contrast (lock point)
~ 550 nm
Light fraction (WFS)
~ 5 %
Adaptive Optics
2 Nov 2007

8. InfraRed Imaging Magnetograph
Infrared Imaging Magnetograph -- IRIM
2 Nov 2007

9. Infrared Imaging Magnetograph – IRIM
How ?
Wavelength Range: 1 ~ 1.6 m ( Fe I m and Fe I m )
Field of View: ~ 80” × 80”
Four Operation Modes:
► Polarimetry: Stokes I, Q, U, V
► Spectrometry: spectral line profile
► Dopplergram: a few selected spectral points
► Photometry: narrow (~0.1Å), medium(~2.5Å), broad(~50Å)
High Spatial Resolution: close to diffraction limit
High Temporal Resolution: < 1 min
Moderate Spectral Resolution: λ/δλ~ 105
High Throughput: > 35 % for polarized light
High Zeeman Sensitivity: V / I ~ 10-4 λ X Y
Infrared Imaging Magnetograph – IRIM
2 Nov 2007

10. Infrared Imaging Magnetograph – IRIM
How?
IRIM = Fabry-Perot + Birefringent Lyot Filter + Interference Filter
Infrared Imaging Magnetograph – IRIM
2 Nov 2007

11. Observation I – IRIM Polarimetry
IRIM and MDI:
Observation I – IRIM Polarimetry
2 Nov 2007

12. Visible Imaging Magnetograph
Visible Imaging Magnetograph -- VIM
2 Nov 2007

13. How ?
Wavelength Range: 400 ~ 700 nm ( G-band, Fe I nm and H nm)
Field of View: ~ 80” × 80”
Four Operation Modes:
► Polarimetry: Stokes I, Q, U, V
► Spectrometry: spectral line profile
► Dopplergram: a few selected spectral points
► Photometry: narrow (~0.08Å)
High Spatial Resolution
High Temporal Resolution: < 1 min
Moderate Spectral Resolution: λ/δλ~ 105
High Throughput: > 65 % λ X Y
VIM
2 Nov 2007

14. Observation II – IRIM Photometry
2 Nov 2007

15. The future of BBSO focal plane instrument
Next …
Adaptive Optics:
AO-76 transfer to NST
NST high order AO system
MCAO
Infrared Imaging Magnetograph:
Upgrade to NST
Dual Infrared Fabry-Perot System
Visible Imaging Magnetograph:
Real-time Speckle Processor:
Phase Diversity Processor
The future of BBSO focal plane instrument
2 Nov 2007