LAUE – A gamma-ray lens project Science Requirements

Preliminary Spericification Review meeting- April 2010

F. Frontera

LAUE – A gamma-ray lens projectLAUE – A gamma-ray lens project

Science RequirementsScience Requirements


Main contributors

• Vito Carassiti, INFN, Sezione di Ferrara

• Federico Evangelisti, INFN, Sezione di Ferrara

• Filippo Frontera, UNIFE

• Cristiano Guidorzi, UNIFE

• Gianluca Loffredo, UNIFE

• Stefano Squerzanti, INFN, Sezione di Ferrara

• Enrico Virgilli, UNIFE


Organization of the presentation

Importance of the hard X-/soft gamma-ray astronomy

Goals of the Laue project;

Project science requirements: Source;

Beamline;

Final collimator

Crystals

Petal frame

Assembling crystals in the petal

Focal plane detector system

GSE


FACILITY LAYOUT (I)

The facility will be installed in the Ferrara LARIX tunnel

The main parts needed for the assembly (see next slide) are the following :

– Source (Betatron) generating the beam at the needed energy– Beam line consisting of a vacuum tube reducing the beam

adsorption and the scattering– Collimator adjusting the beam dimension to the crystal size– Lens robotized assembly set up; due to the high geometrical

precision required , the lens will be fixed on the assembly frame and won’t move during the assembly operations

– Detector giving the crystal orientation at the focal length


FACILITY LAYOUT (II)

LEAD SHIELD

SOURCE (BETATRON)

BEAM LINE (VACUUM TUBE)

COLLIMATOR

LENS ASSEMBLY ZONE

DETECTOR

TUNNEL


BETATRON MOTION SYSTEM (I)

The beam irradiates the crystals one by one . The lens is fixed and the betatron needs the followings motions (see figure of the next slide) covering a lens sector of 600x600 mm^2 surface :

– Translation along Y axis – Translation along Z axis – rotation around Y axis – rotation around Z axis

The exit beam is collimated by a calibrated hole made on a lead 50 mm thick plate

Close to the betatron a fixed lead 150 mm shield is needed against the emitted radiation ; the opposite side of the tunnel needs a 65mm lead sliding door


BETATRON MOTION SYSTEM (II)

BETATRON

Z AXIS

DETECTOR

Y AXIS

X AXIS(BEAM AXIS)


BEAMLINE

The beam line is a cylindrical volume in which the photons move from the source to the lens

The cylindrical volume is given by stainless steel tubes ( 20 m total length) 600 mm in diameter

Each tube is 3 m length and equipped with a vacuum pumping system ; the vacuum required is 1 mbar on the whole beam line

A bellow each 3 tubes allows the alignment and compensate the variation in length of the line

Two windows at both the end of the beam line withstand the load given by the atmospheric pressure . The material budget is reduced using carbon fiber (1-2 mm thickness)


COLLIMATOR MOTION SYSTEM (I)

The collimator allows the control of the beam dimension : the beam irradiates the crystals of the lens one by one , covering an area as big as the crystal or less . The following motions are needed (see the figure of the next slide):

– Translation along Y axis – Translation along Z axis – Rotation around Y axis – Rotation around Z axis– Rotation around X axis

The beam dimension control is given by crossing slats adapting the hole dimension to the crystal/lens requirements


COLLIMATOR MOTION SYSTEM (II)

BETATRON

Z AXIS

DETECTOR

Y AXIS

X AXIS(BEAM AXIS)

COLLIMATING HOLE


DETECTOR MOTION SYSTEM (I)

The detector (see next slide) needs the following motions :– Translation along Y axis – Translation along Z axis– Translation along X axis – Rotation around Y axis – Rotation around Z axis– Rotation around X axis

The X translation moves the detector from the focus to the lens

The Y, Z translations and X, Y, Z rotations determinate the average plane of the crystals


DETECTOR MOTION SYSTEM (II)

BETATRON

Z AXIS

DETECTOR

Y AXIS

X AXIS(BEAM AXIS)

DETECTOR


Key goals of future γ-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 AGNs spectra;– 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;


Final Goal

Development of a new generation of gamma-ray telescopes with:– sensitivity up to two-three orders of magnitude

better than INTEGRAL at the same energies. – a much better (≤ arcmin) imaging capability

A Gamma Ray Imager


Importance of a Gamma Ray Imager

The importance of a Gamma Ray Imager is mentioned:

– 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.”


Activity already done on Laue lens development in Europe

ESA ITT assigned to Alenia-Thales Italia for Laue lens crystal developments.

CESR Institute, Toulouse (PI, P. Von Ballmoos): Laue lens technology development for annihilation and nuclear line studies.

UNIFE with HAXTEL ASI contract: development of lens assembling technology for low (<15 m) focal lengths. Prototype successfully developed and tested (Frontera et al. 2008).

Crystal tests for Laue lenses (N. Barriere, now at UCB) Development of focal plane imaging detectors for Laue lenses

(IASF Bologna, Rome, Milan and Palermo). Monte Carlo studies of polarimeters in the focus of Laue lenses

(University of Coimbra (R. Silva) in collaboration with IASFBO). Proposed GRI by a Large International Collaboration to the 1st

ESA call within the “Cosmic Vision 2015-2025” plan in June 2007.


First lens prototype image

Difference between measured image and Monte Carlo image in the case of a perfect assembling of the crystals in the lens


Prospects for Laue lenses Possible addition of a second satellite hosting a Laue

lens fro nuclear lines (700-800 keV) in formation flying with a Japanese satellite with a Compton telescope aboard (PI T. Takahashi).

Test of a 70-300 keV Laue lens aboard a balloon Results of the feasibility study presented at the national workshop

on Long Duration Balloons (Rome, June 2008, Frontera et al. 2008).

Submission of a broad band (1-600 keV) telescope (ML, Laue lenses) proposal at the 2° issue of ESA Calls for “Cosmic Vision” program.

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LAUE

DTM

PROJECT OFFICE

1000 DTM

SVILUPPO CRISTALL

I

2000 IMEM

PROGET. e SVILUPPO PETALO

3000TAS-MI

TEST PETALO

4000UNI-FE

STUDIO ASSEMBL.

LENTE

5000TAS-TO

Management / PA

1100 DTM

Science Requirement

s

1200 UNIV-FE

System engineering & technical

support

1300 TAS-MI

Cristalli a mosaico

2100 IMEM

Cristalli corrugati

2200 LSS-

UNIFE

Produzione tessere

2300 IMEM

Metodo di assembl. e

allineamento

3100 DTM

Sviluppo attrezzatura e realizzazione

prototipo

3200 DTM

Test ingegnerisitici

petalo

3300 TAS-MI

MGSE

4100 UNI-FE

EGSE realizzazione

4200 TAS-MI

EGSE: defin./accet.

e realizzazione

rivelatore

4300 IASF-BO

Test scientifico

petalo

4400 UNI-FE

Progetto e analisi

5100TAS-TO

Metrologia

5200TAS

Documents

LAUE – A gamma-ray lens project Science Requirements