DayStar Filters 0.3Å Quantum Helium D3 Solar Filter (Research Grade)

Article number: HED.3PE
Availability: Order Now!
Delivery time: Special Order
  • Study Solar Flare Dynamics!
  • View Sunspots and Supergranulation Detail.
  • Engineered for Professional Research Use.
  • Electronic Doppler Tuning Control.
  • 5875.61A Helium D3 Solar Filter.

Daystar Quantum Helium D3 Line 0.3Å PE

DayStar is proud to offer the only Helium D3 Solar Filter available on the market today. Due to our recent advancements in technology which allow more precise tuning of a DayStar filter, we are finally able to capture the Helium emission line. The Daystar Quantum Helium D3 Line 0.3Å PE is only available in PE grade due to the high precision in CWL  accuracy required to isolate the D3 line. It has a maximum bandwidth of 0.3Å at f/30.

Discovered in the visual spectrum at 5875.61Å nearby Sodium D1 and D2 lines by Pierre Janssen in 1868 during a solar eclipse, Helium is the second most abundant element in the Universe.

Studies of the Helium lines are typically involved in research of solar flares. Contours of emission and absorption lines in flares are studied in Helium D3 at 5875.6 Å. Also, two of the most attractive spectral windows for spectropolarimetric investigations of the physical properties of the plasma structures in the solar chromosphere and corona are the ones provided by the spectral lines of the He I 10830 Å and D3 multiplets, whose polarization signals are sensitive to the Hanle and Zeeman effects.

The 10830 Å line offers significant information, but is only applicable from high altitude and space‐borne viewing platforms due to the interference of terrestrial Oxygen lines. The line is also in the infrared, where the quantum efficiency of most Silicon‐based CCD cameras is very low due to the proximity of the Silicon bandgap. Special IR wavelength imaging sensors are required for such an application.

Alternatively, the He D3 line offers value in terrestrial applications. Isolation and identification of the line is a challenge due to the narrow width of its absorption line and proximity to other lines. Very narrow FWHM and precise tuning is critical for proper isolation.

Research studies in D3 in the past have focused on flare research and comparisons of correspondence of absorption in D3 with Magnetic Lines. Those studies used ‘overlapograms’, as He D3 filters have not been available before today.

Features visible in D3 are:

  • Sunspot Detail
  • SuperGranulation
  • Plague
  • Emission in Flare Footprints
  • Absorption following Magnetic Lines
  • Small prominences.

Quantum PE Grade Series

Our Quantum PE grade series is designed for professional research studies and applications in which precision homogeneity and onband transmitance values across the substrate surface are required. These filters require additional quality control steps and additional fabrication and testing time.

Our precision Quantum housing incorporates ALL of the desired features for today’s professional solar astronomer.

Daystar Filters is pleased to offer new, high resolution spectrographic scanning services for all our Quantum PE clients. Our new, specially engineered spectroscopic testing equipment provides high resolution mapping of all new DayStar Filters we manufacture.

PE grade filters are manufactured and qualified to a spectral uniformity in CWL (Central Wavelength) accuracy of ± 0.05 ångström*. Our high resolution etalon mapping equipment offers qualification certified accurate by independent testing with etalon transmission sample sizes of 5mm, 2mm or 1mm sample sizes with certification printouts available on new PE filter purchases.

*The mean peak wavelength of all 12 mm. dia. areas shall be within ± 0.05 ångström of the full aperture wavelength measurement.


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