Implementation of the Implementation of the concept: AGATA/GRETA - - PowerPoint PPT Presentation

Implementation of the Implementation of the concept: AGATA/GRETA concept: AGATA/GRETA

• Specs
• Configurations of 4π Arrays
• Monte Carlo simulations
• The detectors
• Status

Requirements for a Gamma Tracking Array Requirements for a Gamma Tracking Array

efficiency, energy resolution, dynamic range, angular resolution, timing, counting rate, modularity, angular coverage, inner space Quantity Target Value Specified for

50 % 25 % 10 % 60 - 70 % 40 - 50 % better than 1° 3 MHz 300 kHz > 34 cm Photo-peak efficiency (εph) Eγ = 1 MeV, Mγ = 1, β < 0.5 Eγ = 1 MeV, Mγ =30, β < 0.5 Eγ =10 MeV, Mγ = 1 Peak-to-total ratio (P/T) Eγ = 1 MeV, Mγ = 1 Eγ = 1 MeV, Mγ = 30 Angular resolution (Δθγ) for ΔE/E < 1% at large β Maximum event rates Mγ = 1 Mγ = 30 Inner diameter for ancillary detectors

Building a Geodesic Ball (1) Building a Geodesic Ball (1)

Start with a platonic solid e.g. an icosahedron On its faces, draw a regular pattern of triangles grouped as hexagons and pentagons. E.g. with 110 hexagons and (always) 12 pentagons Project the faces

• n the enclosing

sphere; flatten the hexagons.

Building a Geodesic Ball (2) Building a Geodesic Ball (2)

Space for encapsulation and canning obtained cutting the

• crystals. In the example, 3

crystals form a triple cluster Add encapsulation and part of the cryostats for realistic MC simulations Al capsules 0.4 mm spacing 0.8 mm thick Al canning 2.0 mm spacing 1.0 mm thick A radial projection of the spherical tiling generates the shapes of the detectors. Ball with 180 hexagons.

Building a Geodesic Ball (3) Building a Geodesic Ball (3)

Geodesic Tiling of Sphere Geodesic Tiling of Sphere

using 60 using 60– –240 hexagons and 12 pentagons 240 hexagons and 12 pentagons

60 80 110 120 150 180 200 240

GRETA vs. AGATA GRETA vs. AGATA

120 hexagonal crystals 2 shapes 30 quadruple-clusters all equal Inner radius (Ge) 18.5 cm Amount of germanium 237 kg Solid angle coverage 81 % 4320 segments Efficiency: 41% (Mγ=1) 25% (Mγ=30) Peak/Total: 57% (Mγ=1) 47% (Mγ=30)

Ge crystals size: Length 90 mm Diameter 80 mm

180 hexagonal crystals 3 shapes 60 triple-clusters all equal Inner radius (Ge) 23.5 cm Amount of germanium 362 kg Solid angle coverage 82 % 6480 segments Efficiency: 43% (Mγ=1) 28% (Mγ=30) Peak/Total: 58% (Mγ=1) 49% (Mγ=30)

Expected Performance Expected Performance

Response function Absolute efficiency value includes the effects of the tracking algorithms! Values calculated for a source at rest.

Effect of ancillary devices Effect of ancillary devices

Absolute photopeak efficiency (tracking included) Peak-to-total ratio (response function) Ancillary devices have an impact comparable to the case of conventional arrays (tracking is “robust”!) Ancillary devices have an impact comparable to the case of conventional arrays (tracking is “robust”!)

The AGATA Demonstrator The AGATA Demonstrator

Objective of the final R&D phase 2003 Objective of the final R&D phase 2003-

• 2008

2008

5 asymmetric triple-clusters 36-fold segmented crystals 555 digital-channels

• Eff. 3 – 8 % @ Mγ = 1
• Eff. 2 – 4 % @ Mγ = 30

Full EDAQ with on line PSA and γ-ray tracking In beam Commissioning First installation site: LNL

Main issue is Doppler correction capability → coupling to beam and recoil tracking devices

AGATA Demonstrator + PRISMA AGATA Demonstrator + PRISMA

• E. Fioretto

INFN - LNL

• E. Fioretto

INFN - LNL 195 MeV 195 MeV 36

36S +

S + 208

208Pb,

Pb, θ θlab

lab = 80

= 80o

• E (

E (a.u a.u.) .) Δ ΔE ( E (a.u a.u.) .)

Z=16 Z=16 Z=28 Z=28

X Y X position X position Y position Y position

Δ ΔE/E < 2% E/E < 2% Z/ Z/Δ ΔZ ~ 60 for Z=20 Z ~ 60 for Z=20 Δ Δt t < 500 < 500 ps ps Δ ΔX = 1 mm X = 1 mm Δ ΔY = 2 mm Y = 2 mm Δ Δt t ~ 350 ~ 350 ps ps, , Δ ΔX = 1 mm X = 1 mm Δ ΔY = 1 mm Y = 1 mm

First installation site for the Demonstrator: the PRISMA spectrometer at LNL

AGATA Demonstrator

MCP

Quadrupole Dipole MWPPAC Ion Chamber

From CLARA to AGATA From CLARA to AGATA

March 2008 April 2010

Some pictures Some pictures

Some pictures Some pictures

Effect of the recoil velocity Effect of the recoil velocity

β=20% The comparison between spectra

• btained knowing or not knowing

the event-by-event velocity vector shows that additional information will be essential to fully exploit the concept of tracking β (%) 5 20 50 δs(cm) 1.5 0.5 0.3

σdir(degrees)

2 0.6 0.3 Δβ (%) 2.4 0.7 0.3

Uncertainty on the recoil direction (degrees)

Effect of the recoil velocity Effect of the recoil velocity

90Zr recoils with E~350 MeV (with 10% dispersion) assumed.

β from reconstructed trajectory length and TOF. Direction from start detector. AGATA Demonstrator + PRISMA

Agata Geant4 code + PRISMA simulation

Doppler correction capabilities Doppler correction capabilities

With the Demonstrator it will be possible to increase the detection efficiency of a factor 2 with respect to CLARA, while keeping a good quality of the spectra (essential point for the physics campaign). AGATA Demonstrator + PRISMA AGATA Demonstrator + PRISMA

Performance Performance

Photopeak efficiency P/T Ratio

1 MeV photons, point source at rest. Tracking is performed.

~14cm: Possible target-detector distance for the Demonstrator on PRISMA

Effect of the recoil velocity Effect of the recoil velocity

Peak FWHM Photopeak efficiency

1 MeV photons, Mγ = 1. Tracking is performed.

Typical values for reaction products at PRISMA

2010 LNL 5TC 2012 GSI/FRS ≥8TC 2014 GANIL/SPIRAL2 ~15TC

AGATA D.+PRISMA

AGATA D. + VAMOS + EXOGAM

AGATA D. @ FRS

Total Eff. > 10%

AGATA Demonstrator/1 AGATA Demonstrator/1π π Experimental Program Experimental Program

Total Eff. > 20% Total Eff. ~6%

GRETINA GRETINA

Cost 17 M$ (full project including man-power and contingency) 30 36-fold segmented detectors 10 triple-clusters Start construction 2007 Start operation 2010

AGATA/GRETINA Prototypes 1 AGATA/GRETINA Prototypes 1

Tapered regular hexagonal shape Taper angle 10º Diameter (back) 80 mm Length 90 mm Weight 1.5 kg Outer electrode 36-fold segmented Al encapsulation 0.7 mm (side walls)

Courtesy Canberra-Eurisys

Encapsulation of crystal in a permanent vacuum is essential for highly segmented Ge detectors

Pulse Shape Simulations

• Th. Kröll, A. Görgen

A.Wiens et al. NIMA 618 (2010) 223 E.Farnea et al. NIMA 621 (2010)331

Segmentation of the AGATA detector Segmentation of the AGATA detector

Implementation in GEANT4

AGATA/GRETINA Prototypes 2 AGATA/GRETINA Prototypes 2

Courtesy I-Yang Lee, LBNL Courtesy J.Eberth, IKP Cologne

The GRETINA Module (Prototype I) The GRETINA Module (Prototype I)

3 Ge crystals 111 channels

Asymmetric AGATA Triple Cryostat Asymmetric AGATA Triple Cryostat

Challenges:

• mechanical precision
• heat development, LN2 consumption
• microphonics
• noise, high frequencies
• integration of 111 high resolution

spectroscopy channels

• cold FET technology for all signals

The first GRETINA Quadruple Cluster The first GRETINA Quadruple Cluster

B-type A-type

Structure of Electronics and DAQ Structure of Electronics and DAQ

TRACKING Control, Storage… EVENT BUILDER PSA FARM Core + 36 seg.

GL Trigger Clock 100 MHz T-Stamp

Other detectors

Fast 1st Level Trigger

interface to GTS, merge time-stamped data into event builder, prompt local trigger from digitisers

Detector Level

Other Detectors GTS DIGITIZER PREAMPL. ATCA Carrier GTS

Global Level

DAQ-NARVAL RUN- & SLOW-Control

HIGH THROUGHTPUT PRE- PROCESSING CARRIER / MEZZANINES

Other detectors Digital preamplifier concept

100MB/s/ detector

200MB/s/ segment

Data rates in Full Data rates in Full-

• AGATA

AGATA

(300 kHz of M (300 kHz of Mγ

γ = 30

= 30 50 kHz singles) 50 kHz singles)

100 B/ev 5 MB/s 200 MB/s 1.5 ··· 7.5 kB/ev ~ 100 MB/s

36+1 7.5 kB/event

380 MB/s ~ 200 B/segment ~ 10 MB/s 100 Ms/s 14 bits

Pulse Shape Analysis Event Builder γ-ray Tracking HL-Trigger, Storage On Line Analysis

< 100 MB/s

SEGMENT GLOBAL Energy & Classification

5*n max. 900 MB/s

save 600 ns of

pulse rise time

E, t, x, y, z,...

DETECTOR

LL-Trigger Suppression / Compression ADC

Local Process.

+

• GL-Trigger

GL-Trigger to reduce event rate to whatever value PSA will be able to manage 20 μs/event

AGATA hybrid charge sensitive preamplifiers AGATA hybrid charge sensitive preamplifiers

F.Zocca, A.Pullia, G.Pascovici INFN-Milano, GANIL, IKP-Köln

ADC overflow voltage level

Saturated

• utput without

pulsed-reset Ideal non-saturated

• utput without

pulsed-reset Preamplifier output with continuous-reset (50μs decay time constant) Output with pulsed-reset

An ADC overflow condition would saturate the system for a long while A pulsed-reset mechanism allows a fast recovery of the output quiescent value, so minimizing the system dead time

Mixed reset technique: continuous + pulsed Mixed reset technique: continuous + pulsed

F.Zocca, A.Pullia, G.Pascovici INFN-Milano, GANIL, IKP-Köln

( )

O

E V V k T b T b E + − − + =

2 1 1 2 2 1

E = energy of the large signal T = reset time

contribution of the tail due to previous events

Time Time-

• Over

Over-

• Threshold (TOT) technique

Threshold (TOT) technique

V1 , V2 = pre-pulse and post-pulse baselines b1 , b2 , k1 , E0 = fitting parameters

second-order time-energy relation

• ffset term

Within ADC range standard “pulse-height mode” spectroscopy Beyond ADC range new “reset mode” spectroscopy F.Zocca, A.Pullia, G.Pascovici

Source test Source test 241

241Am+Be

Am+Be

“reset” mode “pulse-height” mode

Energy Resolution (fwhm) in pulse-height mode Resolution (fwhm) in reset mode 4.440 MeV (12C) 104 keV 2.34 % 104 keV 2.34 % ~5.6 MeV 10.5 keV 0.14 % 18.8 keV 0.34 % ~6.1 MeV 15.1 keV 0.17 % 17.1 keV 0.28 % 7.6312 MeV (Fe) 11 keV 0.14 % 7.6456 MeV (Fe) 11 keV 0.14 % 18.8 keV (29.4 keV for the double- peak) 0.25 % (0.38 % for the double- peak) 8.9984 MeV (Ni) 15 keV 0.17 % 18.9 keV 0.21 %

F.Zocca, A.Pullia, G.Pascovici

The AGATA Digitiser The AGATA Digitiser

• 1 module per AGATA crystal (3 per AGATA

triple cluster)

• Analogue and Digital Inspection lines
• Digital CFD decupled output for General

purpose trigger (e.g. Fast trigger complementary detectors conventional electronics )

• Local histogramming capability

Excellent Performance: SNR average value 75.45 dB. ENOB average value 12.24 bits IPHC Strasbourg, The University of Liverpool, STFC-Daresbury

ATCA Pre ATCA Pre-

• Processing Electronics

Processing Electronics

ATCA -Carrier

SEGMENT mezzanine (also Core mezzanine) 6 channels GTS mezzanine

The Pre-Processing is the first level that can interact with the Global Trigger through the GTS mezzannine. It receives, and send to the Digitizer, the Global clock synchronizing the system.

Preprocessing Electronics Preprocessing Electronics

1 crystal needs : 2 ATCA carriers, 1 TCLK, 1 GTS, 7 segment mezzanines

Analogue Analogue vs vs Digital Electronics Digital Electronics

Detector (Germanium) Detector (Germanium) Shaping Amplifier Shaping Amplifier CFD CFD DAQ E t FADC FADC MWD DCFD Filters DAQ E t ADC ADC TDC TDC PSA Tracking E t x,y,z E t

Standard Arrays AGATA

Segment Detector Array Detector (Germanium) Detector (Germanium)

Digital processing of signals Digital processing of signals

Actual filter is trapezoidal

Performance comparable to best analog electronics. Higher count rate capabilities ∝ Q ∝ Eγ

Moving Window

Energy

Moving Window Deconvolution (MWD) A.Georgiev and W. Gast, IEEE Trans. Nucl. Sci., 40(1993)770 V.T.Jordanov and G.F.Knoll, Nucl.Instr.Meth., A353(1994)261

Trigger and timing

Slope Condition Counting (SSC) Normalized Step Response (NSR) W.Gast et al, IEEE Trans.Nucl.Sci., 48(2001)2380

Signal processing at high counting rates Signal processing at high counting rates

1 ms, 100 Ms/s

Preamplifier signal SCC MWD (width 5 μs)

@ 40 kHz 28 events 5 pileups

possibility of adaptive shaping

GTS tree + Digital Trigger GTS tree + Digital Trigger

Max capacity of 2 levels: 9 GTS 6 triple clusters + 2 ancillaries (AGAVA)

To the trigger A ternary tree for collecting the trigger requests, and distributing back the validations/rejections to GTS leaves

PCIe eval. board with a Virtex4 FX100 Partly in firmware (partitions, sumbuses) Partly in software running on the PPC Implemented by Luciano Berti (LNL) Present version: 48 inputs in 2 partitions Each partition has 4 multiplicity thresholds The two partitions can be in coincidence Typically: P1 with the Ge crystals P2 with the ancillary Trig1 P1 >=1 & P2 = 1 Trig2 P1 >=2

AGATA DAQ: NARVAL AGATA DAQ: NARVAL

Advanced Data Flow system developed in ADA

Root GUI for analysis NARVAL Producer

Front End Electronics

NARVAL Producer

Front End Electronics

Pre Processing Pre Processing Pulse Shape Analysis Pulse Shape Analysis Event Building Event Building Tracking Tracking Consumer Consumer

AGATA Crystal AGATA Crystal NARVAL Producer

Complementary detectors

NARVAL Producer

Complementary detectors

RUN GUI

The Commissioning runs The Commissioning runs

• Week 12: 30Si@70MeV+12C fusion-evaporation,

AGATA only

– Solved issues with software and detector positioning

• Week 27: 56Fe@220MeV+197Au Coulomb

excitation, AGATA+DANTE

– Optimisation of the signal basis

• Week 43: 32S@130MeV+110Pd fusion-evaporation

– First in-beam test with AGAVA – High-multiplicity events

• Weeks 46 and 49: 58Ni@235MeV +96Zr

multinucleon transfer, AGATA+PRISMA

– Optimisation of the software and DAQ setup

First in First in-

• beam test at LNL

beam test at LNL

• During week 12 (March 16-22) the full system

was tested with an in-beam test using the

30Si(70MeV)+12C reaction

• The system included:

– PSA and tracking performed in real time (online) – Triggerless mode

Off Off-

• line analysis

line analysis

RED 1785 1790 1795 1800 1805 1810 5 10 15 20 25 30 35 40 GREEN 1795 1800 1805 1810 1815 1820 5 10 15 20 25 30 35 40 BLUE 1808 1813 1818 1823 1828 1833 5 10 15 20 25 30 35 40

swap

Relative positioning from the Doppler shifts of segments spectra

Non Non-

• segmented detector

segmented detector

1823 keV ?? DET

AGATA AGATA

DET SEG

17.7 keV

AGATA AGATA

DET SEG MGS

14.6 keV

AGATA AGATA

DET SEG MGS JASS

12.5 keV

Off Off-

• line analysis

line analysis

40K

1823 keV

40K

2333 keV

Optimize:

positions PSA (+basis) tracking

1 year

1 month RED

• nline

Second in Second in-

• beam test at LNL

beam test at LNL

• 56Fe at 220 MeV 197Au

– (Similar to the 56Fe on 208Pb performed in 2001 with MARS)

• Scattered ions detected in the MCP DANTE, taken with

the AGATA electronics (AGAVA not yet ready)

• Ge-Dante coincidence selected by the AGATA

real-time digital trigger

• Analysis of ATC1 done in real time in the Narval farm
• Analysis of DANTE done off-line after the test as the
• nline processing programs were not ready
• Preliminary results (obtained in just one week) looked

very promising

• Improvement of the preliminary results with partial

data sets (linear part of DANTE only) and optimized signal basis

Position of interactions in Dante 547 keV (197Au) 847 keV ( 56Fe) Dante+PSA 4.6 keV Original ~30 keV

Structure of the Doppler shift for the 847 keV peak as a function of the position in Dante 56Fe 197Au

220 MeV

Dante+PSA 2.6 keV Original ~10 keV

Optimized result: 3.2 keV Optimized result: 3.2 keV

Third in Third in-

• beam test at LNL

beam test at LNL

• 32S at 135 MeV 110Pd fusion-evaporation
• Coincidence between two AGATA triple clusters, an

array of five LaBr3 detectors and a Si-strip detector acquired through the AGAVA interface

• Preliminary results (obtained in just one week) look

very promising

AGATA AGATA – – high multiplicity events high multiplicity events

Projection of γγ matrix Most intense channel:

138Sm

AGATA AGATA – – high multiplicity events high multiplicity events

138Sm ground-state band (sum of gates)

neutrons protons

Neutron drip-line Proton drip-line

Spectroscopy and lifetimes in the new region of deformation n-rich A~60, N~40 nuclei

n-rich nuclei

Lifetimes in neutron-rich Ca isotopes N=50 shell gap: lifetime, and excited states Quenching of the N=82 shell gap in n-rich nuclei

More than 20 LoI:

Highly Excited Collective Modes. Proton-rich mirror nuclei. Superdeformed states in A~40 proton-rich region. Order-Chaos transition in warm rotating nuclei. etc...

Evolution of collectivity and Dynamical Symmetries in the rare earths Mix-symmetry states Lifetimes in the region

• f the island of inversion

Physics program: Physics program: evolution of magic evolution of magic numbers and numbers and collectivity collectivity in n in n-

• rich

rich nuclei, but not only... nuclei, but not only...

Performed experiments Performed experiments (so far)

(so far)

• Coulomb Excitation of the Presumably Super-Deformed Band in 42Ca

(A.Maj, F.Azaiez, P.Napiórkowski)

• Neutron-rich nuclei in the vicinity of 208Pb (Zs.Podolyák)
• Inelastic scattering as a tool to search for highly excited states up

to the region of the Giant Quadrupole Resonance (R.Nicolini)

• Lifetime measurement in neutron-rich Ni, Cu and Zn isotopes

(E.Sahin, M.Doncel, A.Görgen)

• Lifetime measurements of the neutron-rich Cr isotopes

(J.J.Valiente-Dobón)

• Order-to-chaos transition in warm rotating 174W nuclei (V.Vandone)
• Lifetime measurement of the 6.792MeV state in 15O (R.Menegazzo)