F. FronteraOn behalf of

a large collaboration

Laue lens telescopes for unprecedented gamma-ray imaging

and sensitivity

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 gamma-ray 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 (BR-

247);– 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)

79.30 79.31 79.32100

102

104

106

108

1010

1012

1014

1016

1018

1020

1022

1024

1026

1028

1030

1032

1034

1036

1038

3800

2300

300

200

50

100

0

-50

-100

-150

-200

-250

-300

-350

-400

-450

-4500

I (

cps)

Omega (deg)

-2500

XRD

Deflection by 100 rad of a 200 m thick Si plate C

ou

nts

(arb

itra

ry u

nit

s)

PRL 90 (2003) 034801

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

ff

ssf dR

dE

61

2

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

Strain is more homogeneous than with the indentations and does not deteriorate the crystal

Si3N4 thickness

Amplitude deformation

(nm)

Osculating circle radius

(m)

100nm 0.7 10.3

200nm 1.5 5.2

400nm 3 2.6

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 kۥ For metrology for assembling and testing Laue lenses on the

ground (TAS-TO, INRIM, UNIFE); 200 kۥ For support frames for Laue lenses and stability problems and

accommodation study of Laue lenses (TAS-TO): 400 kۥ Lens prototype development (DTM): 500 kۥ 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€