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)

-1

2

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