Laue lens telescopes for
unprecedented gamma-ray imaging
and sensitivity
F. Frontera
On behalf of
a large collaboration
AHEAD Meeting,
Rome, 10 Feb 2009
Participants to the proposal
–
–
–
–
–
–
–
–
–
Dipartimento Fisica – Ferrara
INAF/IASF-Bologna
CNR, IMEM, Parma
INRIM (ex G. Ferraris e G. Colonnetti)- Turin
DTM Technologies, Modena
Thales-Alenia Space Italia, Turin
Thales-Alenia Space Italia, Milan
Institute Laue Langevin (ILL), Grenoble (TBD)
University of Coimbra, Portugal (R. M. Curado da
Silva)
– Active Space, Coimbra, Portugal
Main goals achievable with deep gammaray observations (>70/100 keV)
•
Study of matter under extreme conditions:
–
–
–
–
–
–
•
Physics in the presence of super-strong magnetic fields
(magnetars);
Precise role of the Inverse Compton in cosmic sources (e.g.,
AGN, GRBs);
Precise role of non-thermal mechanisms in extended objects (e.g.,
Galaxy Clusters);
Origin and distribution of high energy cut-offs in the spectra of
AGNs;
Origin of Cosmic X-ray diffuse background (CXB). Synthesis
models require a spectral roll-over with EF = 100-400 keV of the
contributing source population, that is still unidentified.
Determination of the antimatter production processes and its origin
from the detection of annihilation lines.
Study of the violent Universe:
–
Origin and emission mechanisms in cosmic explosions (e.g. SNIa)
from the detection and study of nuclear lines;
Requirements
• Development of a new generation of gamma-ray
telescopes with
– sensitivity two-three orders of magnitude better than
INTEGRAL at the same energies.
– ≤ 1 arcmin imaging capability
A Gamma Ray Imager
Recognized importance of a Gamma Ray
Imager
• The need of a Gamma Ray Imager is recognized
– In the ESA Cosmic Vision 2015-2025 Document (BR247);
– In the “Astronet Infrastructure Roadmap” document
(p.37), that completes the Document “A science vision for
a European Astronomy” prepared by the ASTRONET
Team: “Further development of existing and new technologies
should be encouraged in these areas in order to fully address the
challenges set out in the Science Vision. One such area is imaging
and spectroscopy in the very difficult 0.1-10 MeV photon energy
range.”
Main ongoing development activity in
Europe
•
•
•
•
•
ESA: ITT assigned to Alenia-Thales Italia for Laue
lens crystal development.
CESR Institute, Toulouse (PI, P. Von Ballmoos) with
CNES contracts also to industry for lens development.
Physics Dept, University of Ferrara (PI, F. Frontera),
with ASI support until 2007 for lens development.
IASF Bologna, Rome, Milan and Palermo for
development of focal plane imaging detectors for
Laue lenses.
University of Coimbra, Portugal (PI R. Silva) in
collaboration with IASF Bologna for Monte Carlo
studies of optimized polarimeters in the focus of Laue
lenses.
Other ongoing development activity:
•
UNI Ferrara/LSS (Lab for Sensors and
Semiconductors): development
techniques for broad energy band
crystal production (ondulated crystals).
•
CNR/IMEM- Parma: techniques
development for production of new
mosaic crystals.
Studies for gamma-ray missions with
Laue lenses
•
GRI proposal submitted to ESA (1° call Cosmic
Vision)
Possible addition of a second satellite hosting
Laue lenses, in flight formation with a Japanese
satellite with a Compton telescope aboard
(Proposer: T. Takahashi).
•
–
–
•
First meeting in Marseille (July 2008).
The next meeting is scheduled on 9-10 March 2009 in
Japan.
Test of a 70-300 keV Laue lens in a balloon
experiment
–
Results of the feasibility study presented at the national
workshop on Long Duration Balloons (Rome, June
2008).
Some results at the University of
Ferrara
First lens prototype
• Mosaic crystals of Cu[111]
• Tile size: 15x15x2 mm3
• Mosaic spread: 3/4 arcmin
• Lens support: carbon fiber
First prototype measured image
Difference between measured image and Monte Carlo image in the case
of a perfect assembling of the crystals in the lens
Bending by indentations (LSS)
1038
1036
-4500
1034
-2500
1032
1028
-450
-400
-350
1026
-300
24
10
-250
1022
-200
1020
-150
18
10
-100
1016
-50
Counts (arbitrary
I (cps) units)
1030
14
10
XRD
0
1012
50
1010
100
108
200
106
300
104
Deflection by 100 rad of a
10
10
200 m thick Si plate
PRL 90 (2003) 034801
2300
2
3800
0
79.30
79.31
79.32
Omega (deg)
Bending by tensile strips-LSS
Deposition of tensile layers on a substrate is a
method to bend a sample
Silicon sample
Deposition at high temperature
Cooling at room temperature
 Es  d
f 

 1   6 R f d f
2
s
Internal stress is generated
according to Stoney’s equation
NIM B 234 (2005) 40
Crystalline undulator-LSS
Layout of an undulator
L=0.5 mm
Si3N4 thickness
Amplitude
deformation
(nm)
Osculating
circle radius
(m)
100nm
0.7
10.3
200nm
1.5
5.2
400nm
3
2.6
Strain is more homogeneous than with the
indentations and does not deteriorate the crystal
Bending by anistropy-induced
effects in silicon-LSS
• A primary external
deformation results in
a secondary
anisotropy-driven
deformation and in
turn in broadening of
the rocking curve
Main goal of the present proposal
• General Goal: Development of a technology for the industrial
production of Laue lens telescopes with focal lengths up to 100
m for soft gamma-ray astronomy.
• This development requires the following:
– development of technologies for the production in reasonable
times, that are compatible with the realization of space mission,
of a large amount of proper crystals (mosaic, or something like)
needed for the lens;
– Development, at industrial level, of an integrated technology for
the accurate assembling, in reasonable times, of the crystal tiles
in lens petals;
– Development of a proper technology for the assembling of the
lens petals to build the lens;
– Realization of a lens prototype;
– Development of a suitable equipment for the test of the lens
prototype.
Roughly expected costs
• For science goal identification vs. Laue lens properties and
Monte Carlo Laue lens optimization study: 150 k€
• For crystal development activity (IMEM,LSS,ILL): 600 k€
• For development of high focal length Laue lens assembling
technology (DTM, TAS-MI): 700 k€
• For metrology for assembling and testing Laue lenses on the
ground (TAS-TO, INRIM, UNIFE); 200 k€
• For support frames for Laue lenses and stability problems and
accommodation study of Laue lenses (TAS-TO): 400 k€
• Lens prototype development (DTM): 500 k€
• For development of apparatus for Laue lens testing (UNIFE):
800 k€
• Development of a suitable focal plane detector for the lens
testing: 150 k€.
• TOTAL (TBV): 3.5 M€