The Mini-Calorimeter detector The Mini-Calorimeter detector for the AGILE missionfor the AGILE mission

C. Labantia, A. Arganb, A. Bulgarellia, G. di Coccoa, M. Gallic, F. Gianottia, M. Marisaldia, A. Mauria, E. Rossia, M. Tavanid, A. Tracia, M. Trifoglioa

aIASF/CNR Sezione di Bologna, Italy bIASF/CNR Sezione di Milano, Italy cENEA Bologna, Italy dIASF/CNR Sezione di Roma, Italy

AGILEAstrorivelatore Gamma ad Immagini LEggero(Light Gamma-ray Imager for Astrophysics)

AGILE is a small mission of the Italian Space Agency (ASI), the involved institute are:

IASF-CNR INAF, Milano Univ. di Trieste and INFN CIFSIASF-CNR INAF, Roma IASF-CNR INAF, Bologna Univ. Roma 2 and

INFNUniv. Roma 1 and INFN ENEA Roma ENEA Bologna

Homepage: http://agile.mi.iasf.cnr.it/

The AGILE Mission combines, for the first time in high-energy astrophysics a wide field-of-view instrument sensitive in the 30 MeV - 50 GeV band, with a 10-40 keV X-ray monitor.

It will explore a wide variety of celestial phenomena including active galactic nuclei (AGNs), gamma-ray bursts (GRBs), diffuse emission, pulsars, and other Galactic sources.

Mass: 190 kg (120 kg payload)

Power 135 W (46 W payload)

Launch: Autumn 2005

Orbit: Equatorial at ~ 560 km

Mission lifetime: 3 years minimun

Courtesy of AST Courtesy of AST

AGILE Integrated PayloadAGILE Integrated Payload

P/L Shell

P/L Detector

Anticoincidence

Super Agile (10 – 40 keV)

Silicon Tracker

Minicalorimeter(.3 – 200 MeV)

P/L Data Handling Unit

P/L Power Supply Unit

Star Sensors Units

GPS Units

SystemHarness & Heaters

GRID(30 MeV – 50 GeV)

Instrument PerformanceInstrument PerformanceAGILE-GRIDEn. range ~ 30 MeV- 50 GeV

Aeff (400 MeV, 0º) ~570 cm2FOV ~ 3 srPSF (400 MeV, 0º) ~1.22ºSource Loc. Acc. ~ 5' - 20'E/E ~ 1Deadtime < 200 sec

Super--AGILEEn. range ~ 10- 40 keV

Aeff (13.1 keV, 0º) ~ 80 cm2 FOV ~ 0.8 srPSF (pixel size) ~ 6'Source Loc. Acc. ~ 1' - 3'E < 4 keVDeadtime ~ 5 sec

MinicalorimeterEn. range ~ 0.3- 200 MeV E ~ 1 MeV

Aeff (1- 10 MeV, 0º) ~500 cm2 Deadtime ~ 5 sec

MCAL on AGILEMCAL on AGILE

TASK

• In the GRID operation mode, supply energy and position informations on the particles detected by the Tracker.

• In the BURST operation mode supply time and energy informations of impulsive gamma events.

• Continuolsly supply the background behaviour via ratemeters in variuos energy ranges

ARCHITECTURE

• MCAL is made of 30 CsI(Tl) scintillator bars.• The bars are arranged in two layer of 15 elements orthogonal to each other• Each bar is optically coupled to 2 Photodiodes (PD).• The signals of each bar are feed to the GRID and BURST chain where they are analysed

at the same time

MCAL assemblyMCAL assembly

MCAL Bar detectorsMCAL Bar detectors• CsI(Tl) scintillator 375 23 15 mm

• 2 custom PIN PD for each bar (Si active area 256 mm2, 130 pF, Il 1.5 nA @ 20 °C)

• The scintillation light collected by one PD depends from the interaction position x and theenergy deposited EI E*exp(-x)

in the range 0.0020.045 cm-1 depending from surface treatment and wrapping• Weighting the signals A end B from the two PD of one bar the energy and position can be

evaluatedx ln (A/B) E sqrt(A*B)

Bar surface treatmentBar surface treatment

10

14

18

22

26

0 4 8 12 16 20

Distance from PDs (cm)

Lig

ht

ou

tpu

t (e

-/k

eV

)

Wide side: grinded,Narrow side: polished,Att. coeff. = 0.025 cm-1

Wide side: grinded,Narrow side: grinded,Att. coeff = 0.039 cm-1.

Wide side: polished,Narrow side: grinded,Att. coeff. = 0,0107 cm-1.

Wide side: polished,Narrow side: polished,Att. coeff. = 0.002 cm-1.

Flight bar designFlight bar design

The bars with PD glued, wrapping etc. are hoisted in a carbon fibre structure to give modularity and strenght.

Two prototype bars have been tested in the MCAL temperature ranges (operative, non-operative etc).

Plane of the signals from PDsPlane of the signals from PDs

1 cm from PD A 18.75 cm from PD A 36.5 cm from PD A

Test with a collimated 22Na source (511 and 1275 keV)

0 32 64 96

1

14

30.50

4000

8000

12000

dist. from PD

counts

ch. U. A.

Energy and position evaluationEnergy and position evaluation

0100

200300

1

14

30.5

0

500

1000

1500

ch (A.U.)

counts

dist. from PD

0100

200300

400500

1

18.7

36.5

0

500

1000

1500

ch

counts

dist. fromPD

Collimated 22Na spectra collected by one PD for different source positions.

Energy reconstruction

Position reconstruction

Light output vs Temp.Light output vs Temp.PD A

5.0

10.0

15.0

20.0

25.0

0 10 20 30 40

dist from PD [cm]

e-/k

eV

40

30

20

10

0

-10

-20

PD B

5.0

10.0

15.0

20.0

25.0

0.0 10.0 20.0 30.0 40.0

dist from PD [cm]

e-/k

eV

Light output near the PD vs T

20.0

22.0

24.0

-20 -10 0 10 20 30 40

Temp °C

e-/k

eV

PD A

PD B

1275 keV peak % resolution FWHM @

5.0

10.0

15.0

0 10 20 30 40dist from PD A [cm]

%

1275 keV peak channel

220.0

240.0

260.0

280.0

0 10 20 30 40

dist from PD A [cm]

E in

ch

40

30

20

10

0

-10

-20

Energy and position resolutionEnergy and position resolutionPosition reconstruction @ 1275 keV

0.0

32.0

64.0

96.0

128.0

0 10 20 30 40

dist from PD A [cm]

pos

in c

h

Error (1 ) in position reconstruction with Na-22, all Energies

1

2

3

4

0 5 10 15 20 25 30 35 40

dist from PD A [cm]

cm

All parameters evaluated with pre-amps shoving ~ 850 e- rm noise at room Temp.

MCAL operative modesMCAL operative modes

Energy resolution FWHM ~ 10 % @ 1 MeV~0.7% @ 100 MeV

Position resolution (1 ) ~20 mm @ 1 MeV~2 mm @ 100 MeV

Time resolution (Burst) ~2 s

Energy Range GRID: 1 – 500 MeVBURST: 0.25 – 250 MeV

Event time of analysis GRID: ~60 sBURST: ~10 s/bar

1) GRID: MCAL is ‘slave’ of the Tracker. On command all the PD signals are stretched, AD converted and sent to the Data Handling.

Operative range for each bar is 1 500 MeV.

MCAL can start a GRID event if it detects more than 50 MeV on the whole system.

The FEE can handle an event rate up to 1300 Hz.

2) BURST: MCAL indipendently detects events in the range 250 keV e 250 MeV.

The AD converted data are processed in the Data Handling for transient event search. The FEE can handle an event rate up to 500 kHz.

MCAL FEE deals, at the same time, the processing of the two modes as well as thegeneration of House_Keeping data, Telecommands implementation etc.

MCAL FEEMCAL FEE• Overall power consumption: 5 W• PD’ s charge preamplifiers: ~ 850 e- rms• GRID, BURST, HK & TC functions contained in two boards with the same footprint of the bar assembly

Simplified Engeneering Model of MCAL DFEE

Each board includes the analogue chains for 15 bars. The circuits for GRID operations up to A/D conversion are contained in one board, the BURST operations are all developed in the other board.

MCAL Test EquipmentMCAL Test Equipment

A dedicated Test Equipment has been realized for SEM MCAL test

The system is based on a VME bus with a board for each MCAL I/F (GRID, BURST, HK-TC)

… … Bridge

BUrst

GRID

HK

TC

MCAL SEM8 bars

DFEESEM

VME Crate

Host ComputerScience Console

Optical cable

Test with particlesTest with particlesMCAL SEM (with early prototype bar detectors) has been tested both in laboratory and, togheter with a prototype Tracker and AC, with particle beam (CERN T-9 and T-11)

1 2

3 4

5

6

7

8

P4 P3 P2 P1

18 mm variable

Strip 384

Strip 1

Beam

Lato A

Lato B

Lat

o A

Lat

o B

Tracker

Set-up misure CERN

MCAL

Test with particlesTest with particles

Energy lost by of 2 GeV/c impinging on MCAL with various angle Difference between the position of

interaction of impinging on one MCAL bar evaluated with the PD data and with the projection of the position evaluated in the Tracker.

ConclusionsConclusions

AGILE will be launched at the end of 2005

The prototype studies on MCAL detector and electronics have demonstated the validity of the choosen design