Download Gamma-400 on spacecraft “Navigator”

Gamma-400 mission
Approved by ROSCOSMOS
originally devoted to the study of:
gamma rays (0.03 – 3 TeV)
& high-energy electrons and positrons.
G400 provides an excellent opportunity to configure the apparatus for accomplishing
physics tasks beyond the current generation of space missions.
availability for a revision of the project without altering the original objectives
The Italian collaboration is concentrating on:
•
•
Study of the p and He spectra up to the “knee” region (1014 – 1015 eV)
Extension of the gamma capability in the 50 – 300 MeV region
Gamma-400
“Hunting for Cosmic Accelerators”
Various teams including PAMELA, AGILE, FERMI-GLAST
Gamma-400 instrument installed on
the ‘Navigator’ spacecraft
• The characteristics of the satellite:
• scientific payload 2600 kg,
• power budget 2 kW,
• expected lifetime >5 years
Gamma-400
Gamma-400 on spacecraft “Navigator”
Initial orbit parameters
Inclination 51.8°
Perigee 500 km
Apogee 300000 km
Gamma-400
Russian conceptual scheme of the apparatus
Converter/Tracker
(W+Si)
Imaging Calor.
(CC1)
Homogeneous
Calorimeter
(BGO)
(CC2)
Gamma-400 main parameters
Gamma-ray energy range
0.03 -3 TeV
Calorimeter
90 х 90 cm2
~ 25 Xo
Angular resolution
(Eγ ≥ 100 GeV)
~ 0.01
Energy resolution
(Eγ ≥ 10 GeV)
~ 1%
Proton rejection
106
Telemetry downlink
100 GB/day
Power consumption
2000 W
Max. dimensions
2x2x3 m3
Scientific payload mass
2600 kg
Gamma-400- original project
Russian original physics tasks:
•
Study of physical processes in the astrophysical processes emitting
•
-radiation in the range ~ 3 GeV – 3 TeV (galactic sources at ~ TeV, PWN, TeV blazars…)
•
Measurement of energy spectra of galactic and extra-galactic diffuse gamma radiation.
Search for spectral anomalies.
•
Study of the electron + positron spectra up to ~ 3 TeV (Dark Matter search)
•
Key requirements:
•
angular resolution @100GeV ~ 0.01° ,
•
energy resolution ≥ 10 GeV ~ 1% (Fermi-LAT (0.05O , ~10%))
• G-400 is focused on the detection of the
three main components of cosmic radiation:
gamma-rays
• 1.
from 30 MeV up to TeV energies,
with substantial improvements concerning
– the angular resolution,
– the broad-band sensitivity,
– And continuous exposure of sources without Earth occultations;
electrons/positrons up to TeV energy
range and beyond, with much improved sensitivity
• 2.
compared with current space, balloon-borne, and ground
measurements;
proton/nuclei
cosmic-rays up to the "knee", with
• 3. spectrum and composition of
unprecedented detail up to 1 PeV/nucleon.
•
•
G-400 has substantial differences towards gamma-ray astrophysics missions (AGILE and
Fermi), cosmic-ray instruments (PAMELA, AMS, CALET) and balloon-borne instruments.
G-400 unique properties:
– G-400 will be a "dual" instrument capable of measuring both photons
and particles based on a state-of-the-art imaging Silicon Tracker and a
very deep Calorimeter with 25-30 X0 and large acceptance;
– extended gamma-ray sensitivity in the range 30 MeV – 1 TeV, improving
the current sensitivity near 100 MeV by a factor 5-10, and source
exposure at 10-100 GeV by a factor of 5-6 for extended pointings;
– much improved angular resolution at gamma-ray energies (~2o at 100
MeV, ~0.1o above 10 GeV) for a very large field of view (2.5 sr);
– pointing strategy with no Earth occultations, very large exposure per
unit time for extended monitoring (months) of individual sources;
– efficient leptonic (e- + e+) detection with optimal lepton/nuclei
discrimination and spectral determination in the poorly studied range 110 TeV;
– deep calorimetry for proton/nuclei detection and spectroscopy up to
knee energies near 1 PeV/nucleon.
Scientific goals
• The Cosmic Accelerator Hunter !
– Facing the problem of cosmic acceleration of protons/nuclei and
electrons
– determining with high accuracy the spectrum of cosmic
electron/positrons in the energy range 1-10 TeV, that currently shows
non trivial spectral features with the possible existence of different
components of different origins and cutoffs.
– characterization of the CR propagation in our Galaxy
– Precision study of15hadronic cosmic-rays from protons to iron for
energies up to 10 cross-check with ground-based measurements.
• Dark matter improved searches
– resolving the Galactic Center region and Galactic plane
– low-/high-energy determination of the gamma-ray “bubble” emanating
from the Galactic plane.
– precision Study of the diffuse Galactic and extragalactic gamma-ray
backgrounds.
• High-resolution mapping and space-resolved spectral studies of
relevant Supernova Remnants
– problem of the CR origin and their propagation. Large sensitivity to
neutral pion emission below 3-400 MeV.
• Ideal detector for transients:
– uninterrupted (no Earth occultations) and large-exposure monitoring of
extragalactic and Galactic sources.
– gamma-ray transients such as Crab Nebula flares, micro-quasar gammaray outbursts, extragalactic black holes in Active Galactic Nuclei, GammaRay Bursts.
Gamma-400 Basic ideas for an improved apparatus
Two years of R&D
(projct of the new instrument, simulations, prototypes)
1. Maintain the Russian original targets :
• achieving significantly better angular and energy resolution for high energy ( 100 GeV)
gamma rays than Fermi-LAT,
• High quality measurement of the electrons flux at high energies.
2. Configure the upper part of the apparatus to:
1. detect gamma-ray sources in the largely unexplored energy range down to 30 – 300
MeV. In this range small cross section for pair production and inability of AGILE and
Fermi-LAT to reach a large effective area below a few hundreds of MeV.
3. Develop an isotropic, homogeneous and deep imaging calorimeter with
1. excellent energy resolution and rejection power,
2. Capability to measure cosmic-ray protons and nuclei entering from the sides,
3. Total GF for nuclei exceeding 1 m2sr
4. enabling the measurement of proton and nuclei fluxes up to (and above) 1
PeV/nucleon, thus allowing to near the “knee” at least for protons and He.
Gamma-400
Gamma-400
Upper Charge Detector
Low-energy gamma-ray
Tracker (Thin W – Si or
Si only, ~ 15-25 planes)
High-energy gamma-ray
Tracker (Segmented W
Converter + Si µstrip planes)
Deep ( 25 X0)
homogeneous
Calorimeter (BGO). Side
charge detectors not shown
apparatus versions used in one of the preliminary simulations.
G-400 Silicon Tracker configurations with Tungsten preliminary study
Estimated effective area Aeff with overall photon efficiency ε = 1/3
(reliable but conservative estimate)
Config.
towers
tower
structure
distance
between
planes (cm) /
total H (cm)
total
L (cm)
Ageom
(cm2)
A_eff (cm2) @
100 MeV ε =
1/3
Ns = strip tot.
number
Nc = readout
channel tot.
number
total power
(W)
V03R01
2x2
(9.1 cm) x 5
2.5 – 3.0
55 – 66
91.0
8,280
2760
661,818
330,909
330
V03R02
3x3
(9.1 cm) x 4
2.5 – 3.0
55 – 66
109.2
11,924
3974
1,191,272
595,636
595
V03R03
3x3
(9.1 cm) x 5
2.5 – 3.0
55 – 66
136.5
18,632
6210
1,489,092
744,546
744
• 20 planes with W converter and 2 planes of Si detectors (X- and Y- planes) total 22
planes (last 2 planes without W converter)
• 0.035 X0 per plane
• 121 μm Si strips, alternate analog readout
• ~1.0 mWatt/readout channel (AMS VA-hdr chips: 0.7 mW/ch)
• homogeneous tracker
• below 1 GeV, very high (aim to be the best) Aeff
• excellent spatial resolution using optimized pitch and analog readout
G-400 Silicon Tracker configurations with Tungsten
GEANT4 simulation
G-400 V03R00:
• Tracker: 20 layers with W (0.03X0) +
double-sided Si μstrip detectors.
• Total depth: ~0.7 X0
• Pitch=100 μm, total height ~115 cm
Angular resolution:
115 cm
PSF 68%. Assuming digital readout. Single track linear fit
(HE), single track (LE worst) or double track with energy
from simulation (LE best)
G-400 Silicon Tracker configurations with Tungsten
shorter to increase geometrical factor
G-400 V03R02:
• Tracker: 20 layers with W (0.035 X0) + 44
single-sided Si μstrip detectors.
• Total depth: ~0.7 X0
• Pitch=121 μm, total height ~60 cm
Currently upgrading the simulation.
60 cm
Ottimizzazione del calorimetro
Massimizzazione del fattore
geometrico, utilizzando
anche le 4 facce laterali
Necessario un calorimetro il
piu` possibile omogeneo e
isotropo
Confronto tra materiali (1)
• Massa 1400Kg
• Due geometrie:
–Cubo
–Parallelepipedo di profondita` 1.5

Volume sensibile
perfettamente omogeneo
Confronto tra materiali (2)
• Massa 1400Kg
• Due geometrie:
–Cubo
–Parallelepipedo di profondita` 1.5

Blocchi cubici 222 cm2 con
spaziatura 0.3 cm
L’ottaedro troncato
permette una
tassellazione uniforme
cubica dello spazio
Minimizzando le zone morte e` possibile distanziare maggiormente
i cristalli, aumentando il fattore geometrico a parita` di peso
Expected flux of nuclei @knee
•Fit of low-energy
direct
measurements
•Rigiditydependent knee
Expected nuclei counts
(present proposed configuration)
Expected nuclei counts
(maximum calorimeter capability)
Expected flux of
electrons + positrons
Expected counts
(maximum calorimeter capability)
Expected counts
(present proposed configuration)
Individual proton and helium anisotropy
sensitivity
A+
(max)
A(min)
Science
GF (m2sr)
(calorimeter)
Past
missions
Planned
missions
From
CREAM
nuclei
0.21
~161 days
(6  LDB)
??
??
ATIC
nuclei
electrons
0.25
~35 days
---
---
ECAL
electrons
nuclei
0.23
---
LDB
??
FERMI
electrons
1.6* (@300 GeV)
0.6* (@800 GeV)
265 days
??
---
AMS-02
electrons
0.095
---
10 years
2011
CALET
electrons
nuclei
0.12
---
5 years
2013
CREST
electrons
0.3 (@ 3TeV)
>10 (>20TeV)
---
LDB
2011
PEBS-1
electrons
0.6
---
LDB
2014
* Effective GF for electron selection including efficiency
Gamma-400
Trieste activity: focused on the study and design of the Gamma-ray tracker.
Trieste will also collaborate with Firenze (Calorimeter) and
Pisa-Siena (Charge Detectors) on photo- detectors (SiPMs) for the BGO crystals
(FACTOR and TWICE) and large dynamic range
front-end electronics for the silicon pad detectors (CASIS and CASIS2).
Activity 2012:
1) Study and optimization (with MC simulations) of the Tracker structure, taking into
account the scientific objectives of the experiment, and the power and mass
budgets.
2. Realization and test of a tracker pre-prototype (using available detectors and ASICs)
for initial mechanical, assembling and interconnection studies.
This activity comprises (a.o.): study and evaluation of: the optimal W thickness, the
total number of conversion/detection planes, the necessary spatial resolution on the
track impact point, the characteristics of the microstrip detectors (strip pitch, read-out
method, AC-coupling with either polysilicon or punch-through bias, minimization of the
non-sensitive edge areas, etc.), the characteristics of the front-end electronics wrt the
Requested performance and the available power, the characteristics of the DAQ, etc…
Gamma-400
Activity 2013:
1) Realization of a small-area Tracker prototype (but with full number of planes), on the basis
of the results obtained in the first year, with silicon detectors optimized for Gamma-400
(R&D run on 6”) with FBK. Prototyping run of optimized front-end ASICs with a specialized
industry.
2. Test of the small-area Tracker prototype on a particle beam. Comparison of the
experimental performance with those expected by MC simulations.
Gamma-400: partecipanti e richieste 2012
Missioni estere
10 k€ (Riunioni
collaboratori russi)
Missioni interne
5 k€ (Riunioni e contatti tra le sezioni della
collaborazione, contatti con le industrie)
Materiale di consumo
50 k€ (fogli di tungsteno, materiali
meccanica, circuiti stampati, assemblaggi
e bonding)
65 k€
Totale
Andrea Vacchi (Dir. Ric.) R.N.
Valter Bonvicini (I Ric.) R.L.
Mirko Boezio (I Ric.)
Emiliano Mocchiutti (Ric. Art. 23)
Anna Gregorio (R.U.)
Ritabrata Sarkar (Borsista Post. Doc. INFN)
0.3
0.5
0.4
0.2
0.4
0.3
Totale Ricercatori
6 ( 2.1 FTE)
Servizio Elettronica e Rivelatori
Servizio Officina Meccanica
Servizio Alte Tecnologie
4 m.u.
4 m.u.
4 m.u.
e
contatti
con
i
Preventivo di spesa (Sezione di Firenze)
FTE (Sezione di Firenze)
Pisa-Siena
Concluding: G400 observational tasks
• High precision measurements of the position of the sources
• energy spectrum and possible time fluctuation of high energy
gamma’s in the 0.01GeV-3TeV energy range.
• Extension of gamma’s measurements towards the 50-300MeV region.
• Precision measurement of electron+positron spectrum to > 3 TeV.
• Measurement of the energy spectrum of:
– protons beyond 2 PeV.
– helium beyond 1 PeV/nucleon.
• Measurement of the individual flux of nuclei up to actinides and of
the energy spectra of the most abundant ones.