![]() Use of these molds means that no further “hand polishing” must be performed on each individual mirror, drastically cutting down the effort and expense needed to produce the mirror sets. Lindsay Glesener, explains the FOXSI approach: “Rather than just building a bigger or improved mirror, this new focusing technology is an entirely transformative way of measuring X-rays from the Sun.” FOXSI’s mirrors are produced at NASA’s Marshall Space Flight Center using a “fast replication” process that involves electroforming nickel onto carefully shaped and polished molds. The heart of FOXSI’s technology is its reflecting mirrors that are specially designed for solar observations. To accomplish this task, FOXSI features several novel, cutting-edge technologies. These young researchers took advantage of a rare opportunity to build, test, and fly a NASA experiment, participated in all aspects of the preparation and flight, and are now the lead scientists analyzing the results. The FOXSI-3 team includes postdoctoral researchers, graduate students, and undergraduate students. The challenge for FOXSI was to take this technology and adapt it for observing the Sun, which produces a wider range of brightnesses and more complex, intricate sources than any other astronomical object. However, it is possible to reflect X-rays using a mirror with a small angle of incidence and a perfect shape this method is used by NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) mission as well as several instruments that operate at lower energies. Therefore, past missions had to use indirect methods to image high-energy X-ray sources in the sky. Traditional reflecting or refractive telescopes do not work for X-rays because the rays tend to simply pass through or absorb in the medium. The Focusing Optics X-ray Solar Imager, or FOXSI, is a sounding rocket experiment that takes a novel approach to this challenge. To observe this faint emission in the tumultuous context of a solar flare is a demanding requirement for any X-ray technology. For this reason, solar astrophysicists are searching for faint X-rays emanating from the hidden sites from which these events originate to understand the keys to energy release in the corona. Understanding the origins of these events is therefore of the utmost importance. When Earth-directed, these ejections can cause geomagnetic storms with the potential to threaten spacecraft, astronauts, and power grids. Solar flares are often associated with coronal mass ejections, in which huge volumes of plasma are kicked out of the corona and sent off into interplanetary space. Yet the part of this emission that most intrigues solar astrophysicists is the faintest X-ray flux, which can reveal how solar flares are triggered, how they transfer energy, and how they accelerate particles up to extraordinarily high energies. During solar flares, which temporarily heat up the corona locally to many tens of millions of degrees, a multitude of X-rays are radiated into space. ![]() The Sun gives off abundant X-rays from its fiery, multimillion-degree corona (the outermost layer of the solar atmosphere) and poses particular challenges for X-ray imaging. To deal with these challenges, a sounding rocket experiment team has developed an array of new technologies that can reveal how the Sun emits high-energy radiation, plasma, and particles. The Sun presents some unique challenges to researchers attempting to unravel its high-energy behavior. X-rays from the Sun help us probe the highest-energy phenomena that occur in our solar system, including solar storms and their origins. ![]() The FOXSI X-ray mirror (left) and an X-ray image of the Sun captured by the Photon Energy Imager in soft X-rays (PhoEnIX), one of FOXSI-3’s new cameras (right).
0 Comments
Leave a Reply. |