IDEE, The Electron Spectrometer for the Taranis Mission

J.-A. Sauvaud1, P. Devoto, A. Fedorov1, G. Orttner1,

O. Chasselat1, K. Wong1, L. Prech2, Z. Nemecek2,

1 IRAP/CNRS-U. of Toulouse

2 Charles University, Prague

Chibis international workshop, Tarusa, 13-15 february 2013

IDEE conception

3 objectives:

-Pitch-angle Distribution of Radiation Belt Electrons (wave particle interactions)

-Lightning-induced Electron Precipitation (LEP)

-Relativistic Runaway Electrons (RRE)

W= 3.5 eV/e--hole pair

The spectrometers uses semi-conductors as particle detectors

DEMETER and TARANIS

WAVE PARTICLE INTERACTIONS

1. Cyclotron resonance

ELECTRON FLUXES AT 650 KM ALTITUDE (200 keV)

Electron interaction with VLF

NWC

‘Cyclotron’ induced structures

Sauvaud et al., 2008

Effect of VLF transmitter 19.8 kHz

Note the large difference of slopes in the inner belt as compared to the ‘cyclotron slope’

Electrons Protons

Drift resonance: ULF-particle INTERACTIONS

LIGHTENING ELECTRON PRECIPITATION / VLF-ELECTRON INTERACTION

2 s

Voss et al, Nature, 1984.

Lightning induced electron precipitation (DEMETER - above Europe: weak energy, critical time resolution of electron data )

DEMETER

Distribution of lightnings, winter 2008-2009

ELECTRONS

Terrestrial gamma flashes energy spectrum

RHESSI10 msec

Parent electrons:dJ/dE=2.2 10-3 exp(-E/7.2)

TGF

Υ spectrum

Computed TGF Electrons

Lehtinen et al., 2010; Carlson et al., 2011

Carlson et al., 2011

SAMPEX electron bursts possibly related to TGF

Lehtinen et al.

DEMETERRRE

Part

/(cm

2.s.

sr.k

eV)

Electron fluxes

Expected TGF electrons

The electrons that escape to satellie altitude are most likely secondary electrons produced by TGF

Can a detector like IDP

(DEMETER) do that?

Relativistic Runaway Electrons (RRE) Not enough Geometrical Factor

Lightning-induced Electron Precipitation (LEP)Time resolution not adequate

Pitch-angle Distribution of Radiation Belt Electrons No angular channels

The resulting IDEE sensor for TARANIS

IDEE

2 detector planes: Si + CdTe (coincidence for direction), large section of CdTe for RRE

ADDING SEPARATION INTO THE COLLIMATOR = angular separation of low energy electrons

Objectif - Runaway Relativistic Electrons

Possible RRE spectrum (Red)

Where we can distinguish a RRE spectrum from the bkg electrons.

(After DEMETER data)

Runaway Relativistic Electrons

Possible RRE spectrum (Red)Detection of RRE8 horizontal bands, 8 CdTe cells in eachthickness 6mm to stop electrons up to 4 Mev

IDEE-TARANIS

IDEE

CdTe

CdTe

Response to RRE event

Geant-4 simulation20 counts/event

Measurable signalfor CdTe only

Response to associated Gamma rays

Geant-4 simulation

when gamma onlyare received, the measured signal isvery weak.

Gammas will notdisturbed electronmeasurements.

STATUS OF THE EXPERIMENT

Sensor head design: performed

Electronic design: performed. ASIC developedDPU: performed (Charles university)

Modes: defined

Burst trigger: ready

Thermal study: made

EQM: made