E-Print Archive

There are 4594 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
Repeated Type III Burst Groups Associated with a B-Class Flare and a Narrow-Width CME
Separating the effects of earthside and far side solar events. A case study.
Deciphering The Slow-rise Precursor of a Major Coronal Mass Ejection
Three-dimensional Turbulent Reconnection within Solar Flare Current Sheet
Sequential Remote Brightenings and Co-spatial Fast Downflows during Two Successive Flares
A Model for Confined Solar Eruptions Including External Reconnection
The eruption of a magnetic flux rope observed by Solar Orbiter and Parker Solar Probe
Comprehensive radiative MHD simulations of eruptive flares above collisional polarity inversion lines
An Anisotropic Density Turbulence Model from the Sun to 1 au Derived From Radio Observations
Comparison of damping models for kink oscillations of coronal loops
On the three-dimensional relation between the coronal dimming, erupting filament and CME. Case study of the 28 October 2021 X1.0 event
Polarisation of decayless kink oscillations of solar coronal loops
CME Propagation Through the Heliosphere: Status and Future of Observations and Model Development
30-min Decayless Kink Oscillations in a Very Long Bundle of Solar Coronal Plasma Loops
The Role of High-Frequency Transverse Oscillations in Coronal Heating
ARTop: an open-source tool for measuring Active Region Topology at the solar photosphere
Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE
New cases of super-flares on slowly rotating solar-type stars and large amplitude super-flares in G- and M-type main-sequence stars
Constraints on the variable nature of the slow solar wind with the Wide-Field Imager on board the Parker Solar Probe
Prediction of short stellar activity cycles using derived and established empirical relations between activity and rotation periods

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