Download - High Energy Measurements for Solar, Heliospheric, Magnetospheric, and Atmospheric Physics
High Energy Measurements for Solar, Heliospheric, Magnetospheric, and
Atmospheric Physics
R. P. Lin
J. Sample, A. Shih, S. Christe, S. Krucker, I. Hannah
Physics Department & Space Sciences Laboratory
University of California, Berkeley
& D. Smith (UCSC), R. Millan (Dartmouth)
Apollo 15 Subsatellite
FAST
(Fast Auroral SnapshoT)
• Science Package Electric Field Instruments Particle Instruments Electronics• Mission Operations• Science Operations Launched on 21 Aug 1996Mission Presently Operating
RHESSI
(Ramaty High Energy Solar Spectroscopic Imager)• Project Management• Spacecraft Bus• Science Package Imager Spectrometer Electronics• Mission Operations• Science Operations• Ground Data Systems Launched February 5, 2002Mission presently operating
Cosmic Hot interstellar Plasma Spectrometer (CHIPS)
THEMIS Integration and Test• Currently ongoing at the UCB Space Sciences Laboratory• 5 identical spacecraft & instrument suites
RHESSI TGFs: LightcurvesDurations from 200 us to 3.5 ms; consistent with BATSE, shorter than most TLEs.
RHESSI TGFs: SpectrumSummed spectrum of 289 TGFs
Spectra tend to be similar fromevent to event, but slightly morevariation than chance
Models are relativistic runawaybreakdown simulation byJ. Dwyer.
Unabsorbed bremsstrahlungmust be steeper than Earound 1 MeV; spectrum seen requires > 50 g/cm ofintervening air (Dwyer & Smith 2005, in press)
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Jan 17 2004, 12:46:50.970 Longest and brightest RHESSI TGF Northern Chad (Sahara). No storms here, but plenty of storms in January at the conjugate point. If every TGF has a conjugate flash, the first Sahara event we see should be faint, not bright! Unless.....
We got lucky and caught the e- beam directly with the spacecraft!Currently looking for conjugate storms & sferics.
Multiple Scintillators for Terrestrial, Cosmic, Solar, and Magnetospheric
Events (MSTCSM)
John Sample and Albert Y. Shih
Science objectives of MSTCSM
• MSTCSM can provide improved and completely new observations of events ranging from those of terrestrial or magnetospheric origins to those of solar or cosmic origins
• MSTCSM observes 20 keV to 16 MeV photons and 600 keV to 6 MeV electrons with excellent time resolution
• For terrestrial gamma-ray flashes (TGFs), MSTCSM is more sensitive than RHESSI and can obtain better timing information and structure
• For microbursts in the magnetosphere, MSTCSM can determine the spectrum of the relevant particles for the first time and improve the pitch angle determination by SAMPEX
• For solar flares, MSTCSM has an order of magnitude better time resolution than RHESSI and more effective area (~ 8 times more at X-ray energies, and ~ 2–3 times more at gamma-ray energies)
• For cosmic sources such as gamma-ray bursts and magnetars, MSTCSM can look for time structure better than other instruments
Instrument design for MSTCSM
• Spacecraft in a sun-synchronous polar low-Earth orbit
• Fixed pointing towards the Earth and the Sun, but minimal requirements on accuracy
• Two lanthanum bromide (LaBr) scintillators and four plastic scintillators, each 1-cm thick
• Two sizes of plastic scintillators for dynamic range
• Orientation of scintillators is depicted for two points of view
• One set of scintillators is shadowed from the Sun for deadtime and pileup considerations
To Sun
To Earth
40 cm
20 cm
2 cm
20 cm
2 cmTo Sun
To Earth
LaBr plastic
Technical details for MSTCSM• Analysis chain similar to RHESSI
• Each scintillator event recorded separately with time and energy
• Fast and slow shaping channels
• Timing: < 0.05 microseconds
• At very high count rates, individual events are not retained, but spectra are produced from the fast channel
• Onboard generation of lightcurves for automatic and/or manual selection of data periods to keep
• ~ 3 GB of data produced per day• 8 GB solid state recorder• 4 Mbit/s downlink• ~ 0.1 m2 of solar panels with
battery to provide ~ 10 W power• < 0.1 m3 total volume
Component Mass
LaBr scintillators 4.25 kg x 2
Plastic scintillators 0.85 kg x 2
PMTs 0.2 kg x 6
IDPU and electronics 2 kg
Housing 3 kg
Total 16.4 kg
Spectral Components
511 keV- positron annihilation
Neutron-capture2.2 MeV power law - electron bremsstrahlung
De-excitation lines -narrow
broad
total model
Germanium Array in Low Earth Orbit (GALEO)
Solar Hard X-ray Focusing Optics S. Christe, S. Krucker, B. Ramsay (MSFC)
• Flare/CME Coronal Acceleration Region
• Micro-Nano Flares
• Electron beams
• Type III radio bursts.
• Type I Bursts
• Quiet Sun
• Axions
Science - Quiet Sun/Nanoflares
THEMISTHEMISTHEMIS
Hannah et al, 2007
Optic - 1 m focal length
Some Pictures
Detectors : Pixelated Si