Engineering topics

Amy Winebarger

Publications and source records attributed to Amy Winebarger.

46 records · Page 3

NASA NTRSDate not supplied

The Third Flight of the Marshall Grazing Incidence X-Ray Spectrometer (MaGIXS-3)

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is the first X-ray slitless imaging spectrograph sounding rocket instrument designed to observe spectrally dispersed soft X-ray images of the solar corona over a wide field-of-view. During the first flight of MaGIXS (MaGIXS-1), occurred on 30 July 2021, several emission lines from coronal structures including X-ray bright points were observed. Further, MaGIXS-1 analysis also demonstrated the successful inversion of overlappograms using robust unfolding algorithms. Given the demonstrated success of MaGIXS-1, the second flight of the instrument with a simplified optical design, MaGIXS-2, is scheduled for 2024 to observe high temperature diagnostic emission lines. Results from MaGIXS-1 discovered dominant missing emission lines near 15A, arising from relatively cool plasma that peaks around 2 MK. This wavelength region hosts several closely spaced satellite lines of Fe XVII, Fe XVI and Fe XV ions, which are expected to be enhanced at lower temperatures and are currently unmodeled in the CHIANTI atomic database. This wavelength region offers one of the most unique diagnostics to measure electron temperature, as well as signatures of equilibrium state of the plasma in active regions, which has not been studied so far. The goal of MaGIXS-3 mission is the to determine coronal heating parameters, such as the spatial and temporal properties of coronal heating events, by measuring discriminating observations, such as electron temperature, effective temperature, density, abundance, and departures from thermal equilibrium of the plasma, by observing the Sun in the SXR wavelength range. To meet this goal, the MaGIXS instrument will be upgraded with a new X-ray telescope mirror that will provide higher spatial and spectral resolution and throughput, allowing for spectral lines to be observed at the relevant spatial and temporal scales. In addition, MaGIXS-3 will also carry The Resolving Inversion Context X-ray Spectrometer (TRICXS), a high dispersion Bragg crystal spectrometer to spectrally resolve the lines near 14.9 to 15.9A, critical to unlock the full diagnostic potential of this wavelength range. Here we will present the preliminary concept design of MaGIXS-3 and discuss the potential observations.

X-ray Imaging↗

NASA NTRSDate not supplied

Demonstration of Chromospheric Magnetic Mapping with CLASP2.1

Probing the magnetic nature of the Sun’s chromosphere requires measurement of the polarization profiles of relevant magnetically sensitive spectral lines, many of which are in the ultraviolet spectrum, necessitating observations above the absorbing terrestrial atmosphere. The CLASP series of sounding rocket missions were designed to develop and test a technique for observing the Sun in ultraviolet light, and for quantifying the polarization of that light. By demonstrating successful measurement and interpretation of the polarization in hydrogen Lyman-alpha and the Mg II h and k spectral lines, these missions are crucial steps towards routine quantitative characterization of the local thermal and magnetic conditions in the solar chromosphere. In the most recent observations, CLASP2.1, the spectrograph slit was scanned across an active region plage to acquire a two-dimensional map of Stokes V/I, to demonstrate the ability of UV spectropolarimetry to yield chromospheric magnetic fields over a large area. The technique yields a set of simultaneous line-of-sight magnetograms at multiple heights within the plage atmosphere. By combining the CLASP2.1 measurements with magnetograms from Hinode/SOT or SDO/HMI, a wide range of atmospheric heights are mapped, from the photosphere to the upper chromosphere.

David E McKenzie↗

NASA NTRSDate not supplied

An Overview of MaGIXS-2: The second flight of the Marshall Grazing Incidence X-ray Spectrometer

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a sounding rocket mission that completed a successful flight from the White Sands Missile Range on July 30, 2021. MaGIXS captured spatially resolved soft X-ray spectra from portions of two solar active regions during its roughly 5-minute flight. The instrument was originally designed as a grazing incidence slit spectrograph but flew in a slit-less configuration that produced overlapping spectroheliograms. For the second flight, MaGIXS-2, the instrument has been reconfigured to a more simplified optical layout that reuses the Wolter-I telescope and blazed varied-line space reflective grating. The field stop at the telescope focal plane and the finite conjugate spectrometer mirror pair have been removed – the telescope now directly feeds the grating. Additionally, an identical but new 2k x 1k CCD camera has been built for this flight. The MaGIXS-2 data product will again be overlapping spectroheliograms of at least one solar active region, but with improved resolution, a larger field of view and increased effective area. Here we present the updated instrument layout, the expected performance, the integration and calibration approach, and proposed future improvements, including the implementation of additional complimentary spectral diagnostics.

Imaging Spectrometer↗

NASA NTRSDate not supplied

Probing the Sun with Imaging Spectrographs

EUV and X-ray images of the Sun have revolutionized our understanding of our closest star. With them, we can probe the structure of the solar atmosphere and see how they evolve as a function of space and time. However, image data cannot be used to determine line-of-sight velocities, abundances, or densities. This information is required to calculate the energy budget of eruptive events, provide boundary conditions for global solar models, and explore fundamental processes occurring in the solar atmosphere. For those diagnostics, we require spectroscopy. Because the structures on the Sun are extended sources, most modern-day spectrometers observe the Sun through long narrow slits. Two-dimensional, spectrally pure solar images with velocity, abundance, and density information are built up by stepping the slit over regions of interest. This method implies that two-dimensional information is highly limited by cadence and the temporal evolution and spatial structure of these parameters can never be truly separated. Both spatial and spectral information can be obtained in a single snapshot with slitless spectrometers, which were often used in the 1950-1970s, but were abandoned due to the difficulty of unfolding the overlapping spatial and spectral information. Thanks to advances in computer processing speeds and machine learning algorithms, there have been several techniques developed to complete the spatial/spectral unfolding, unlocking the full capability of slitless spectrometers for solar observations. The goal of this talk is to give an overview of the capability of such instruments and demonstrate their usefulness in the next decade of solar observatories and beyond.

Amy Winebarger↗

NASA NTRSDate not supplied

Study of Coronal Heating in Solar Active Regions Using Wide-Field Imaging Spectroscopy: Hinode EIS Slot Observations

Understanding the frequency of heating events that keep the coronal plasma at several million Kelvin above the photospheric temperature of~ 6000K, is one of the most important problems in solar astrophysics. Spectroscopic observations of the Sun in the extreme ultraviolet (EUV) indicate that the coronal plasma reaches temperatures from 1 to 5 MK in active regions. It is also established that temperature in active regions can vary strongly with time and, moreover, contain sub-regions that evolve and develop separately. Tracking the spatio-temporal evolution of temperature requires continuous observation of the entire active region via imaging and spectroscopy. Traditional slit imaging spectroscopy probes plasma heating in solar active regions through observations of diagnostic emission lines and the resulting data are spectrally pure. Here, imaging is performed through rastering process, which severely limits co-temporal observations and often can be slow to miss events that evolve at other portions of the active region. In contrast, wide-field imaging spectroscopy offer simultaneous coverage of a large field of view as well as obtain spectral information in the same direction. This data suffers from spatial-spectral confusion, and are called spectroheliograms. Using the state-of-the-art inversion techniques that are developed recently, now spectroheliogram data can be unfolded to yield spectrally pure maps of large fields over long duration of observations. We use wide slit data, usually referred as ‘slot’, from the EUV Imaging Spectrometer (EIS) onboard Hinode satellite, focusing on active region observations. Here, we present our study of coronal heating in an active region using a long duration Hinode EIS slot observation.

Active region heating↗

NASA NTRSDate not supplied

Alternate Inversion Paradigm for Spectroheliogram Data

Over the past five years, new methods to reconstruct spectrally pure maps of the Sun from spectroheliogram data have emerged, essentially unlocking this long-abandoned method of obtaining both spatial and spectral information over a large field of view simultaneously. The original inversion method determined the plasma’s emission measure distribution as a function of temperature at every spatial location in the field of view. To complete this inversion, a response matrix had to be created mapping the emission measure in different (temperature, space) bins to detector, requiring assumptions on the thermal and ionization equilibrium and abundance state of the plasma. We have since derived a new method of the inversion that does not require these atomic assumptions to be made. Instead, we use only the different locations of spectral lines from the same ion species and the possible ratios of those single-species spectral lines, removing the need for a priori knowledge on the state of the emitting plasma. In this presentation, we demonstrate this method using observed data from the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) and simulated data from the EUV CME and Coronal Connectivity Observatory (ECCCO) investigation.

Amy Winebarger↗

NASA NTRSDate not supplied

Active Region Simulation with EBTEL

Active regions (ARs) are areas in the sun’s upper atmosphere that are bright in the extreme ultraviolet (EUV) and X-ray spectrum. Coronal loops are one key feature of an AR. They can be described as arcs of plasma resulting from loop-shaped magnetic fields on the sun. The average temperature of these loops is over one million kelvin, which is significantly hotter than the sun’s surface. The mechanism for the heat transfer of these high temperatures remains unknown and is referred to as the coronal heating problem. One leading hypothesis regarding this mystery is that small, impulsive heating events called nanoflares are a major contributor. Here, we explore the contribution of nanoflares in the heating of AR plasma. We utilize the Enthalpy-Based Thermal Evolution of Loops (EBTEL) program to simulate NOAA 12846, as observed on July 25, 2021. We then use that simulation to analyze how the frequency of nanoflare heating events affects the EUV and X-ray observations in existing instruments, including SDO’s AIA and Hinode’s XRT. We also predict how this AR would appear in recently developed X-ray instruments, such as NASA’s MaGIXS.

Active region↗

NASA NTRSDate not supplied

Using Multiplicative Algebraic Reconstruction Techniques (MART) to Derive Instrument Requirements for Computed Tomography Imaging Spectrographs

Computed Tomography Imaging Spectrographs (CTISs), which are generally slitless or large-aperture spectrographs that observe a wide, dispersed field of view in multiple dispersion angles or diffraction orders, provide a unique opportunity to capture spectral information over an extended source, such as the Sun, but require software reconstruction techniques to be fully utilized. A useful data product that can be recovered from CTIS observations is intensity maps of solar features in single spectral lines. These intensity maps can then be used to determine temperature, density, abundance, and equilibrium properties of the emitting plasma. We apply the multiplicative algebraic reconstruction technique (MART) to example data from a variety of CTIS configurations to determine the capability and limitations of the method to return spectrally-pure maps. By completing this study, we aim to establish a path to derive requirements for CTIS instruments that rely on reconstruction techniques to meet their science objectives.

Amy Winebarger↗

NASA NTRSDate not supplied

The Next Generation Marshall Grazing Incidence X-Ray Spectrometer (MaGIXS) Sounding Rocket Experiments

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a sounding rocket experiment that carries an X-ray slitless imaging spectrograph to observe spectrally dispersed soft X-ray (SXR) images of the solar corona over a wide field-of-view. The first flight of MaGIXS occurred on 30 July 2021, during which several emission lines from coronal structures including X-ray bright points were observed. Analysis of MaGIXS-1 data demonstrated the application of new inversion techniques and opened a new arena of inverting complex spectroheliogram data, which has spatial-spectral information overlapped. The second flight of MaGIXS, with a simplified optical design, is scheduled for 2024. The goal of MaGIXS-2 is to observe high temperature diagnostic emission lines within an active region core. MaGIXS-1 discovered dominant missing emission lines near 15Å wavelength region, which hosts several closely spaced satellite lines of Fe XVII, Fe XVI, and Fe XV ions, arising from relatively cool plasma that peaks near 2MK. These lines are expected to be enhanced at lower temperatures and offers one of the most unique diagnostics to measure electron temperature, as well as signatures of equilibrium state of the plasma in active regions, which has not been studied so far. The science goal of the third sounding rocket flight of MaGIXS is to determine coronal heating parameters, such as the spatial and temporal properties of coronal heating events, by measuring discriminating observations, such as electron temperature, effective temperature, density, abundance, and departures from thermal equilibrium of the plasma, by observing the Sun in the SXR wavelength range. For this, the MaGIXS instrument will be upgraded with a new X-ray telescope mirror that will provide higher spatial and spectral resolution and throughput, allowing for spectral lines to be observed at the relevant spatial and temporal scales. In addition, MaGIXS-3 will also carry The Resolving Inversion Context X-ray Spectrometer (TRICXS), a high dispersion Bragg crystal spectrometer to spectrally resolve the lines near 15Å, critical to unlock the full diagnostic potential of this wavelength range. Here we will present the preliminary concept design of MaGIXS-3 and discuss the potential observations.

X-ray Imaging↗

NASA NTRSDate not supplied

Critical Developments Made Through the Sounding Rocket Program

Scientists have flown scientific instruments on sub-orbital rockets since the years following World War II when excess rocket motors were made available. Much of our knowledge of heliophysics and astrophysics that now seem well accepted and commonplace have been discovered through the sounding rocket program. The program has also been key in both developing technologies and training scientists and engineers, which have allowed for instruments to be developed for long-term operations satellites. In this talk, I will review critical developments that emerged from the sounding rocket program that have had a lasting impact on our fields.

Amy Winebarger↗