220 likes | 426 Views
No, not the LHC. High-Energy Particle Accelerator. By: Nicolas Scozzaro. Introduction. What particles does the sun accelerate, and how? What are the principles of detecting particles accelerated by the sun, especially x-rays and gamma- rays?. Flares Coronal mass ejections (CME’s)
E N D
No, not the LHC High-Energy Particle Accelerator By: Nicolas Scozzaro
Introduction • What particles does the sun accelerate, and how? • What are the principles of detecting particles accelerated by the sun, especially x-rays and gamma-rays?
Flares Coronal mass ejections (CME’s) (Lin, 2000) Two acceleration Processes:
Solar flares and CME’s can occur together • Or they can occur individually
Release 1032 – 1033 ergs over the course of 100-1000 seconds Conversion? 1 erg = 100 nanojoules (1*10-7 J) => 1025 – 1026 J 1 J = eV => 6.24*1043 – 1044eV For comparison, total world energy use for 2008 was about 5*1020 J Flares
Electrons • Most gain 10’s of keV from acceleration • Some gain up to 100’s of MeV • Ions (H, He, heavier elements) • Most gain a few MeV • Some gain up to 10’s of GeV • HOW? • Magnetic reconnection What do flares Accelerate?
Huge bubbles of gas threaded with magnetic field lines On average ~ 1012kg Ejection velocities: 20 – 3200 km/s Angular spread ~ 100 degrees Can drive a shock wave, dangerous to astronauts, sensitive instruments, etc. http://solarscience.msfc.nasa.gov/images/c2_1mth.mpg Coronal Mass Ejection
http://www.youtube.com/watch?v=ilhrR2jQSqM&feature=related How do we study the sun? Balloons Sounding Rockets Satellites
Rotating grids How are solar high-energy ray telescopes built?
Collimators How are solar high-energy ray telescopes built?
Uniformly redundant array (URA) mask How are solar high-energy ray telescopes built?
MoirÈ Pattern Techniques
Germanium detectors Why germanium? Conducts better than silicon when cooled to cryogenic temperatures
R. P. Lin, “Particle acceleration in solar flares and coronal mass ejections,” IAU Symposium, 195, 15 (2000). Temmer,M., Veronig,A.M., Kontar,E.P., Krucker,S., Vrsnak,B. 2010, The Astrophysical Journal, 712, 1410-1420Combined STEREO/RHESSI study of CME acceleration and particle acceleration in solar flares Shao,C., & Huang, G. 2009, The Astrophysical Journal, 694, L162-L165Hard-Soft-Hard Flare Spectra and Their Energy Dependence in Spectral Evolution of a Solar Hard X-Ray Flare Shih,A.Y. 2009, PhD Thesis, Disseration, University of California, BerkeleyGamma-ray observations of solar-flare ion acceleration Krucker,S., Hurford,G.J., MacKinnon,A.L., Shih,A.Y., and Lin,R.P. 2008, The Astrophysical Journal, 678, L63-L66Coronal gamma-ray bremsstrahlung from solar flare-accelerated electrons Wikipedia Nasa website References