E-Print Archive

There are 4507 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Future Possibilities for Doppler and Magnetic Field Measurements in the Extended Solar Atmosphere View all abstracts by submitter

G. Allen Gary   Submitted: 2008-07-08 08:44

For the first time, a vacuum ultraviolet telescope can be built to observe magnetic fields, plasma flows, and heating events in the Sun's atmosphere. These observations can provide key data for space weather models. The vacuum ultraviolet (VUV) region allows remote sensing of the upper levels of the solar atmosphere where the magnetic field dominates the physics. A VUV Fabry-Perot interferometer (FPI) will allow us to observe the magnetic field, flows, and heating events in the mid-transition region (between the chromosphere and corona). Observations of this region are needed to directly probe the magnetic structure and activity at the base of the corona where the magnetic field is approximately force-free, i.e., where gas pressures are very small. This is a key element in developing accurate models of the Sun's dynamics for space weather. The specific region of interest is the 100 km thick transition region, between the chromosphere and the much hotter corona, which strongly emits at 155 nm from triply ionized carbon (CIV) at 100,000 K. This is best observed by an imaging interferometer that combines the best attributes of a spectrograph and an imager. We present the latest results from the NASA Marshall Space Flight Center (MSFC) FPI. The major elements of thetunable CIV VUV FP interferometer are the 35mm MgF2 etalon plates with a plate finesse of F>25 at 155 nm, the pi-dielectric coatings, a Hansen mechanical mount in a pressurize canister, and the piezoelectric control system. The control system for the etalon is a capacitance-stabilized Hovemere Ltd. standard system. The special Cascade Optical Corporation reflectance coatings are 25 pi-multilayers of high-low refractive layers paired in phase. This CIV interferometer, when flown above Earth's atmosphere, will obtain narrow-passband images, magnetograms, and Dopplergrams of the transition region in the CIV 155 nm line at a rapid cadence. We recently measured the MSFC VUV FPI using the University of Toronto's fluoride excimer laser as a proxy for CIV 155 nm. The test demonstrated the first tunable interferometer with the passband required for a VUV filter magnetograph. The measured values have a full-width half-maximum (FWHM) passband of 10 pm, a free-spectral range (FSR) of 61pm, and a transmittance of 58% at 157 nm. The resulting VUV interferometer finesse is 5.9. With this success, we are developing an instrument suitable for a flight on an orbiting solar observatory. A description of the interferometer for this mission is described.

Authors: G. Allen Gary (CSPAR), John M. Davis (MSFC), and Edward A. West (MSFC)
Projects: None

Publication Status: Submitted to Journal of Advances in Space Research (Elservier 2008)
Last Modified: 2008-09-23 20:57
Go to main E-Print page  Forced oscillations of coronal loops driven by EIT waves  Helical motion of magnetic flux tubes in the solar atmosphere  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
The role and contribution of magnetic fields, characterized via their magnetic flux, to the statistical structuring of the solar atmosphere
Do periods of decayless kink oscillations of solar coronal loops depend on noise?
Automatic detection technique for solar filament oscillations in GONG data
Probing the Density Fine Structuring of the Solar Corona with Comet Lovejoy
Confined plasma transition from the solar atmosphere to the interplanetary medium
Extracting the Heliographic Coordinates of Coronal Rays using Images from WISPR/Parker Solar Probe
Two-spacecraft detection of short-period decayless kink oscillations of solar coronal loops
Genesis and Coronal-jet-generating Eruption of a Solar Minifilament Captured by IRIS Slit-raster Spectra
First detection of transverse vertical oscillation during the expansion of coronal loops
A New Position Calibration Method for MUSER Images
Sigmoid Formation Through Slippage of A Single J-shaped Coronal Loop
MHD Simulation of Homologous Eruptions from Solar Active Region 10930 Caused by Sunspot Rotation
Dropouts of Fully Stripped Ions in the Solar Wind: A Diagnostic for Wave Heating versus Reconnection
Plasma heating and nanoflare caused by slow-mode wave in a coronal loop
The Lyman-α Emission in a C1.4 Solar Flare Observed by the Extreme Ultraviolet Imager aboard Solar Orbiter
Imaging and Spectroscopic Observations of the Dynamic Processes in Limb Solar Flares
Evolution of the critical torus instability height and CME likelihood in solar active regions
A Magnetogram-matching Method for Energizing Magnetic Flux Ropes Toward Eruption
A 2D Model for Coronal Bright Points: Association with Spicules, UV bursts, Surges and EUV Coronal Jets
The relativistic solar particle event on 28 October 2021: Evidence of particle acceleration within and escape from the solar corona

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey

© 2000-2020 Solar Physics Group - Montana State University