ALBERT

Description: MTRAP (Magnetic Transition Region Probe) will reveal the fine-scale physical processes in the Sun's magnetic transition region, the complex layer from the upper photosphere to the upper chromosphere/lower transition region. In the magnetic transition region plasma forces and magnetic forces are of comparable strength, which results in complex interplay of the two, which interplay governs the coupling of the convectively-driven deeper layers to the magnetically-driven upper transition region and inner corona. The fine-scale magnetic structure, processes, and events in the magnetic transition region are key to the genesis of the Sun's entire hot, dynamic outer atmosphere and to the initiation of large eruptive events. MTRAP will be a single spacecraft in Sun-synchronous Earth orbit. Because MTRAP will probe and measure the 3-D structure and dynamics of the magnetic field and plasma in the chromosphere and transition region with unprecedented resolution, the required telescope size and telemetry rates dictate that MTRAP be in Earth orbit, not in deep space. The observations will feature visible and infrared maps of vector magnetic and velocity fields in the magnetic transition region and photosphere. These will have large field of view (greater than 100,000 km), high resolution (greater than 100 km), and high sensitivity (greater than 30 G in transverse field). These observations of the lower atmosphere will be complemented by UV maps of the structure, velocity, and magnetic field (including the full vector field if technically feasible) higher up, in the upper chromosphere and lower transition region. MTRAP will also have an EUV imaging spectrograph observing coronal structure and dynamics in the same field of view with comparable resolution. Specific phenomena to be analyzed include spicules, bright points, jets, the base of plumes, and the triggering of eruptive flares and coronal mass ejections. Additional information is included in the original extended abstract.

Description: A major focus of solar physics is the measurement of the temporal and spatial variability of solar magnetic fields from the photosphere into the lower corona, together with the study of how their behavior produces the dynamic phenomena in this region such as flares and Coronal Mass Injection (CMEs). Considerable success has been achieved in the characterization of the full vector field in the photosphere, where P, the ratio of the gas pressure to the magnetic pressure, is greater than or equal to 1. At higher levels in the atmosphere where beta is less than 1, the magnetic field (through the Lorentz force) controls the structure and dynamics of the solar atmosphere, and rapid changes in structure with release of energy become possible. However, observations of the field at these higher levels have proven to be difficult, placing a serious limitation on our understanding of the physical processes occurring there. This poster will discuss the Solar Ultraviolet Magnetograph Investigation (SUMI), a hardware development study for an instrument capable of measuring the polarization in ultraviolet lines of C IV and Mg II formed in the transition region and upper chromosphere. We are currently developing optical technologies necessary to build an instrument that will achieve a major advance in performance over that of earlier attempts (e.g., SMM/UVSP). Initially configured as a sounding rocket payload, such a UV magnetograph would allow us to make exploratory measurements extending the observation of solar magnetic fields into new and dynamic regimes. This work is supported by NASA through the SEC Program in Solar Physics and the program for Technology Development for Explorer Missions and Sofia.

Description: The next generation of solar missions will reveal and measure fine-scale solar magnetic fields and their effects in the solar atmosphere at heights, small scales, sensitivities, and fields of view well beyond the reach of Solar-B. The necessity for, and potential of, such observations for understanding solar magnetic fields, their generation in and below the photosphere, and their control of the solar atmosphere and heliosphere, were the focus of a science definition workshop, 'High-Resolution Solar Magnetography from Space: Beyond Solar-B,' held in Huntsville Alabama in April 2001. Forty internationally prominent scientists active in solar research involving fine-scale solar magnetism participated in this Workshop and reached consensus that the key science objective to be pursued beyond Solar-B is a physical understanding of the fine-scale magnetic structure and activity in the magnetic transition region, defined as the region between the photosphere and corona where neither the plasma nor the magnetic field strongly dominates the other. The observational objective requires high cadence (less than 10s) vector magnetic field maps, and spatially resolved spectra from the IR, visible, vacuum UV, to the EUV at high resolution (less than 50km) over a large FOV (approximately 140,000 km). A polarimetric resolution of one part in ten thousand is required to measure transverse magnetic fields of less than 30G. The latest SEC Roadmap includes a mission identified as MTRAP to meet these requirements. Enabling technology development requirements include large, lightweight, reflecting optics, large format sensors (16K x 16K pixels) with high QE at 150 nm, and extendable spacecraft structures. The Science Organizing Committee of the Beyond Solar-B Workshop recommends that: (1) Science and Technology Definition Teams should be established in FY04 to finalize the science requirements and to define technology development efforts needed to ensure the practicality of MTRAP's observational goals; (2) The necessary technology development funding should be included in Code S budgets for FY06 and beyond to prepare MTRAP for a new start no later than the nominal end of the Solar-B mission, around 2010.

Description: Solar physics has been successful in characterizing the full vector magnetic field in the photosphere, where the ratio of gas pressure to magnetic pressure (Beta) is 〉1. However, at higher levels in the atmosphere, where Beta 〈〈1 and flares and CMEs are believed to be triggered, observations are difficult, severely limiting the understanding of these processes. In response to this situation, we are developing SUMI (the Solar Ultraviolet Magnetograph Investigation) a unique instrument designed to measure the circular and linear polarization of upper chromospheric Mg II lines (280 nm) and circular polarization of transition region C IV lines (155 nm). To date the telescope mirrors have been built, tested and coated with dielectric stacks designed to reflect only the wavelengths of interest. We have also developed a unique UV polarimeter and completed the design of a high-resolution spectrograph that uses dual toroidal varied- line-space (TVLS) gratings. Incorporating measurements of those components developed so far, the revised estimate of the system throughput exceeds our original estimate by more than an order of magnitude. A sounding rocket flight is anticipated in 2006. Our objectives and progress are detailed in this presentation.

Description: The Solar-B mission is a joint enterprise between Japan, the United States of America and the United Kingdom. The collaboration is led by ISAS, the Japanese Institute for Space and Astronautical Science (ISAS), NASA and PPARC (Particle Physics and Astrophysics Research Council) play supporting roles in the development of the scientific objectives and provision of the scientific instruments. The mission's primary objective is to conduct a systems study of the solar atmosphere through the acquisition of coordinated measurements of the photosphere, the transition region/low corona and the upper corona using three instruments: an optical telescope, an extreme ultraviolet imaging spectrometer and a soft x-ray telescope. Drs. Saku Tsuneta (NAOJ) and Alan Title (LMSAL) lead the optical imaging team. The optical telescope is a 50-cm aperture, diffraction limited, Gregorian. The focal plane package will record high resolution images, Dopplergrams, and vector magnetic fields on spatial scales dominated by elemental photospheric flux tubes, and over a field of view large enough to contain small active regions. Drs. Tetsuya Watanabe, Len Culhane (MSSL) and George Doschek (NRL) led the EUV imaging and spectroscopy team. The EUV telescope has a 15-cm primary mirror feeding a toroidal grating. The optics have multiplayer coatings which select two wavebands between 180-204 A and 250-290 A. Drs. Kiyoto Shibasaki (NAOJ) and Leon Golub (SAO) lead the X-ray imaging team. The x-ray telescope will provide full disk, soft x-ray images with twice the spatial resolution of the Yohkoh SXT and enhanced sensitivity to longer (〉40 A) wavelengths. The launch of Solar-B, into a sun-synchronous orbit, is scheduled for August 2004. Solar-B is the second mission in the Sun-Earth Connection, Solar-Terrestrial Probe Program which is managed by the Goddard Space Flight Center. The Science Directorate of the Marshall Space Flight Center manages the Solar-B Project for the ST Probe Project Office. This paper discusses the objectives, specifications, and design of the scientific instruments as presented at the Preliminary Design Review held at MSFC in May 2000.

Description: An earlier analysis preformed and published will be revisited and applied to SECCHI's observations. Using coronal models and imaging-rendering techniques we will investigate several important facts regarding the solar stereographic mission. A synthesized image will be presented formed from integrating the emission from the volume elements along the line-of-sight path through a three-dimensional volume. We used analysis of pairs of these synthesized images with various angular perspectives to investigate the effect of angular separation on mission objectives. The resulting images and analysis provide guidelines for developing a stereographic mission analysis program.

Description: The next several years are an exciting time in the exploration of the solar system. NASA and its international partners have a veritable armada of spaceships heading out to the far reaches of the solar system. We'll send the first spacecraft beyond our solar system into interstellar space. We'll launch our first mission to Pluto and the Kuiper Belt and just our second to Mercury (the first in 30 years). We'll continue our intensive exploration of Mars and begin our detailed study of Saturn and its moons. We'll visit asteroids and comets and bring home pieces of the Sun and a comet. This is truly an unprecedented period of exploration and discovery! To facilitate access to information and to provide the thematic context for these missions NASA s Solar System Exploration Program and Solar System Exploration Education Forum have developed several products.

Description: Traditional magnetographs measure the solar magnetic field at the visible "surface" of the Sun, the photosphere. The Solar Ultraviolet Magnetograph Investigation (SUMI) is a design study for an instrument to measure the solar magnetic field higher in the atmosphere, in the upper chromosphere and in the transition region at the base of the corona. The magnetic pressure at these levels is much stronger than the gas pressure (in contrast to the situation at the photosphere), and so the field is much more dynamic. Observations in this region will significantly improve our understanding of the physical processes driving flares and heating in the Sun's upper atmosphere. The instrument will incorporate new technologies to achieve the polarization efficiencies required to isolate the magnetic lines (Civ at 155nm and MgII at 280nm) to be observed in the UV. We describe the scientific goals, the SUMI baseline design and the optical components that are being developed for a sounding rocket program.

Description: The commonly used minimum mass power law representation of the pre-solar nebula is reanalyzed using a new cumulative-mass-model. This model predicts a smoother surface density approximation compared with methods based on direct computation of surface density. The density is quantified using two independent analytical formulations. First, a best-fit transcendental function is applied directly to the basic planetary data. Next a solution to the time-dependent disk evolution equation is parametrically adapted to the solar nebula data. The latter model is shown to be a good approximation to the finite-size early Solar Nebula, and by extension to other extra solar protoplanetary disks.