“The SIMBOL-X optics”, Bologna, 14 May 2007 SIMBOL-X SIMBOL-X OPTICS SIMBOL-X OPTICS Giovanni...

“The SIMBOL-X optics”, Bologna, 14 May 2007

SIMBOL-X SIMBOL-X OPTICSSIMBOL-X OPTICS

Giovanni PareschiINAF - Osservatorio Astronomico di Brera

Lower Spider

Upper Spider

Case

Shell


SIMBOL-X

Poster presentation related to the SX optics implementation

• Basso et al., “The relation between the weight and the quality image in a X-ray telescope, with a particular regard to Simbol-X”

• Vernani, et al., “Feasibility study for the manufacturing of the multilayer x-ray optics for Simbol-X”

• Cotroneo et al, “Simbol-X mirror module design scientific optimization”

• Basso et al, “The problem of the calibration of SIMBOL-X X-ray telescope”

• Spiga et al., “ The scattering caused by microrougnhess in the Simbol-X multilayer coated optics”

• Romaine, et al, ”Multilayer coated hard X-ray mirrors based on Ni electroformed mirror shells”


SIMBOL-X

OUTLINEOUTLINE

• Designing of the Simbol-X optics

• The technology for the optics fabrication

• Remarks on the calibration issue


SIMBOL-X

Top-level scientific requirementsTop-level scientific requirementsEnergy band: ~0.5 – ≥ 80 keV

Field of view (at 30 keV): ≥ 12’ (diameter)

On-axis effective area:

≥ 100 cm2 at 0.5 keV≥ 1000 cm2 at 2 keV≥ 600 cm2 at 8 keV≥ 300 cm2 at 30 keV≥ 100 cm2 at 70 keV≥ 50 cm2 at 80 keV (goal)

Detectors background< 210-4 cts s-1cm-2keV-1 HED< 310-4 cts s-1cm-2keV-1 LED

On-axis sensitivity ≤ 10-14c.g.s.(~0.5 µCrab), 10-40 keV band, 3 1Ms,

Line sensitivity at 68 keV < 3 10-7 ph cm-2 s-1 (3 1Ms)

Angular resolution≤ 20”(HPD), E < 30 keV≤ 40”(HPD) @ E = 60 keV (goal)

Spectral resolutionE/E = 40-50 at 6-10 keVE/E = 50 at 68 keV (goal)

Absolute timing accuracy 100 µs (50 µs goal)

Absolute pointing reconstruction ~ 3 (radius, 90%) (2” goal)

Mission duration3 years including commissioning and calibrations (2 years of scientific program) + provision for a possible 2 year extension

Total number of pointings> 1000 (first 3 years, nominal mission) 500 (during the possible 2 year mission extension)


SIMBOL-X

SX Flux Sensitivity


SIMBOL-X

Advantages of focusing optics versus Advantages of focusing optics versus direct-view detectorsdirect-view detectors

ETA

BnF

eff

int

min2

ETA

BnF

eff

HEWr

***5.0

**

int

min

Moreover: much better imaging capabilities!B =background flux, Tint = integration time, E = integration bandwidth

rHEW = FL * HEW [rad]

HEW = Half Energy Width = circle where 50 % of focused photons is contained


SIMBOL-X

Angular resolution for past & future Hard Angular resolution for past & future Hard X-ray ExperimentsX-ray Experiments

ExperimentExperiment YearYear ““Imaging” Imaging” techniquetechnique

Angular Angular resolutionresolution

SAX-PDS 1996 Rocking collimator

> 3600 arcsec(collimator pitch)

INTEGRAL-IBIS 2002 Coded mask 720 arcsec(mask pitch)

HEFT (baloon) 2005 Multilayer optics > 90 arcsec HEW

NEXT 2013? Multilayer Optics

90-60 arcsecHEW

SIMBOL-X 2013? Multilayer Optics

15-20 arcsecHEW


SIMBOL-X

IMAGING (I)IMAGING (I)

Osservazione XMM dello stesso campo tra 0.1 e 10 keV


SIMBOL-X

IMAGING (II)IMAGING (II)

1’

50” HPD; eq. 2Crab

30”HPDEq.2Crab

15”HPDEq.0.2Crab

10’

10’

10’


SIMBOL-X

The focusing problem in the hard X-ray The focusing problem in the hard X-ray region (> 10 keV)region (> 10 keV)

Ecrit

but

Wolter I geometry

F = focal length R = reflectivity

L = mirror height = incidence angle

Aeff F2 x c2 x R2

At photon energies > 10 keV the cut-off angles for total reflection are very small also for heavy metals

the geometrical areas with usual focal the geometrical areas with usual focal lengths (> 10 m) are in general lengths (> 10 m) are in general negligiblenegligible


SIMBOL-X

0.6 o

Focal Length Vs. Diameters for SIMBOL-X Focal Length Vs. Diameters for SIMBOL-X and other X-ray telescopes and other X-ray telescopes

Multilayers

Aeff F2 x c2 x R2

Ecrit

The Formatio

n Flight architecture offers th

e

The Formatio

n Flight architecture offers the

opportunity to im

plement long FL telescopes!

opportunity to

implement lo

ng FL telescopes!


SIMBOL-XDesign ConstraintsDesign Constraints

• FOCAL LENGTH: ≥ 19 m (due to formation flight parameters)

• DETECTOR SIZE: 7 +/1 cm (Size of the LED wafer + lateral ditering)

• NUMBER OF MIRROR SHELLS: ≤ 100

• MAXIMUM DIAMETER: 70 cm (i.e. as XMM)

• MINIMUM DIAMETER: ≥ 25 cm (to allow the multilayer deposition “post facto”)

• MASS TO AREA RATIO: a reliable number in line with angular resolution of at least 20 arcsec HEW

• MASS: not larger than 480 (TBD) including structure


SIMBOL-X

SIMBOL-X Baseline DesignSIMBOL-X Baseline Design

Baseline

detector size


SIMBOL-X

Optics designOptics design

Focal length : 20 mShell diameters : 30 to 70 cmShell thickness : 0.2 to 0.6 mm Number of shells : 100

• Heritage from XMM–Newton : nickel shells obtained by electroforming replication method; low mass obtained via a reduced thickness of shells

• Coating : multi-layer Pt/C needed for requirement on large FOV and on sensitivity up to > 80 keV

N.B. I: The optics module will have both sides covered with thermal blankets

N.B. II: a proton diverter will be implemented


SIMBOL-X

Mirror shell production by Ni electroforming Mirror shell production by Ni electroforming replicationreplication

BeppoSAX

Jet-X/Swift

XMM-Newton

ESA credits


SIMBOL-X

Existing Coating FacilitiesExisting Coating Facilities at INAF- at INAF-OAB & Media Lario Techn.OAB & Media Lario Techn.


SIMBOL-X

HPD = 15 arcsecYear: 1994 HPD = 15 arcsec

Year: 1999

Thin JET-X shell : 25 arcsec

Thickness Vs. Diameter trend for Ni-Thickness Vs. Diameter trend for Ni-replicated opticsreplicated optics


SIMBOL-X

Wall thickness/diameter trade-offWall thickness/diameter trade-off

z

kHHEW

1

A

B

XMM f=7.5m

JetX 1shell f=3.5m

S

M/Acol

computed rescaling to the correct focal length (20m)

HEW

M/Acol

12” 25”

z

d

tHEW

Mass including structure ≈480 kg

Radial force for a thin shell. Exponent ‘z’=3

R

w

F

3

3

tE

RFwHEW

tE

rMHEW 0

Edge moment for a thin shell. Exponent ‘z’=1

Thicknesses ~ 2 times less than XMM


SIMBOL-X

Lower Spider

Upper Spider

Case

ShellSection of the ring

The use of stiffening rings for handling The use of stiffening rings for handling and integration of thin mirror shellsand integration of thin mirror shells


SIMBOL-X

Temporary spider must give stiffness to the upper side of the entire set of shells and must be removed after gluing of all the shells on the upper spider.

Gluing of first set of DGC. Temporary IS can be used to apply control devises

Removing of stiffening rings

Positioning of second shell and gluing of second set of DGC

Repeated for N shell

ISDGC

. . . . .

Gluing of N shells on the upper spider and removing all DGC

Removing temporary IS

Temporary spiderDouble grooves clips (DGC)

Internal shaft (IS)

Integration procedureIntegration procedure


SIMBOL-X

Deposition of the multilayer film onto the internal surface of a replicated mirror shell (development activity carried out so far in collaboration with the Harvard-Smithsonian CfA) particularly well suited for Simbol-X, since based on large diameter optics

Pt

C

Multilayer deposition systemMultilayer deposition system


SIMBOL-X

Multilayer coated Ni mirror shells Multilayer coated Ni mirror shells tested at Pantertested at Panter

CREDITS: Panter/MPE


SIMBOL-X

The long focal length calibration issueThe long focal length calibration issue

Possible Simbol-X position in the Panter facility for calibrations

*Simbol-X position

Fraction of the measured EA in double reflection for different lengths of the X-ray facility (as source-detector distance) for Simbol-X. The PANTER facility case corresponds approximately to the red line case.


SIMBOL-X

Test of very long focal length optics (20 - 30 m) Test of very long focal length optics (20 - 30 m) in pencil beam setup with more than 1 shellin pencil beam setup with more than 1 shell

Horizontal rotation correction

Lateral correction

FM

WM

Comparators used to monitor the optic position during the optic spinning

Vertical tilt correction

Axial spin

Scheme of the manipulator: the possible movements/adjustments of the optical module are indicated


SIMBOL-X

Programmatic pointsProgrammatic points

• By the end of the Phase a is planned to develope and calibrate a couple of multi-shell prototypes, caled down of a factor 2 wrt Simbol-X (Focal Length = 10 m, max diameter = 35 cm)

• It is planned the development of a diamond-turning facility for the madrel fabrication

• In Phase B a fully representative demonstrator will be developed and calibrated

Date post:	19-Jan-2016
Category:	Documents
Upload:	katherine-josephine-lang
View:	224 times
Download:	7 times

“The SIMBOL-X optics”, Bologna, 14 May 2007 SIMBOL-X SIMBOL-X OPTICS SIMBOL-X OPTICS Giovanni...

Documents