Ongoing developments of the DIAMANT ancillary detector ...particle discrimination with DSP Method:...

Ongoing developments of the DIAMANT ancillary Ongoing developments of the DIAMANT ancillary detector array for use with EXOGAM-2 and AGATAdetector array for use with EXOGAM-2 and AGATA

B.M. Nyakó et al. (ATOMKI + U.D) NEDA Workshop, 3-5 Nov. 2010, IFIC, Valencia, Spain.

B.M. Nyakó et al.: (ATOMKI, GANIL, Univ. Napoli)B.M. Nyakó et al.: (ATOMKI, GANIL, Univ. Napoli)

Layout of talk:Layout of talk:

1.1. TheThe DIAMANTDIAMANT history history (technicalities; recall: N=Z '09, Legnaro)(technicalities; recall: N=Z '09, Legnaro)

2. 2. Former “mechanical“ developments Former “mechanical“ developments (Chamber, cabling, etc.)(Chamber, cabling, etc.)

3.3. Ongoing detector developments Ongoing detector developments (CsI+APD; FP7: SPIRAL2-PP)(CsI+APD; FP7: SPIRAL2-PP)

4.4. Ongoing developments of digital electronics Ongoing developments of digital electronics (Options vs. 5.)(Options vs. 5.)

5.5. Financial, personnel Financial, personnel (open)(open) questions questions

6.6. SummarySummary

1.1. The The DIAMANT DIAMANT history:history:

DIAMANT is an ~ 4DIAMANT is an ~ 4π, high-granularity π, high-granularity light charged-particle light charged-particle ancillary ancillary detector array for large detector array for large ?? -ray spectrometers (EB, EXOGAM, AGAT-ray spectrometers (EB, EXOGAM, AGATA)A)

TheThe collaboration:collaboration:

Past:Past: CENBG CENBG [J.N. Scheurer [J.N. Scheurer (retired '09)(retired '09) et al.] et al.] ++ (original geometry +)(original geometry +)

Present:Present: ATOMKI + Univ. of Debrecen ATOMKI + Univ. of Debrecen [B.M. Nyakó*) et al.] [B.M. Nyakó*) et al.] (VXI, new geometry, maintenance)(VXI, new geometry, maintenance)

Univ. of Napoli Univ. of Napoli [G. La Rana et al.] [G. La Rana et al.] ++ (fin(financial contribution +)ancial contribution +)

Future:Future: IFICIFIC [A. Gadea et al.]; [A. Gadea et al.]; GANIL (host/help)GANIL (host/help)

*) Contact person; *) Contact person; [email protected]@atomki.hu

B.M. Nyakó et al. (ATOMKI + U.D) NEDA Workshop, 3-5 Nov. 2010, Valencia, Spain.

DIAMANT technicalities: DIAMANT technicalities: CsI(Tl) scint.CsI(Tl) scint. has an intrinsic Particle Discrimination capabilityhas an intrinsic Particle Discrimination capability

Tapered CsI detectors assembled on the Flexi-Board

Rectangle: for FW-Wall Tapered: for Flexi-Board

Efficiency: [% of 4π]

geometrical: ≈ 90

det. protons: ≈ 70

det. alphas: ≈ 50

Quad-CsI-s

Folded-up Flexi-Board on service stand

d(CsI) = 3 mm: Eproton ≤ 25 MeV

Ealpha ≤ 100 MeV

PIN photodiode readout

The CsI detectors

DIAMANT technicalities (cntd):DIAMANT technicalities (cntd):PD is based on Ballist. Def. method, realized by PD is based on Ballist. Def. method, realized by VXI electronics,VXI electronics, measures: E, PID, TIME measures: E, PID, TIME

The Signals from the Part. Discr. Card

Gating on 1D (Time, PID) or 2D spectra (PID-vs-Time, PID-vs-E, Time-vs-E) enables:

- rejection of random events - selection/rejection of reaction channels - enhancement of gammas with special conditions

The Octal Part. Discr. Card in VXI standard

α particles

ProtonsDeuterons

γ Rays (CsI)

γ Rays (PIN-diode)

Example 2D spectrum of a CsI crystal

DIAMANT has been used in many EXOGAM + N-Wall experimentsDIAMANT has been used in many EXOGAM + N-Wall experiments

Successful use of exp. setup including DIAMANT as veto-detector:

Results from exp. E451a: Search for T=0 pairing and a new coupling scheme in 92Pd and 88Ru by Bo Cederwall et al.,

has been accepted by Nature (2010)for publication:

B. Cederwall et al., New spin-alignedpairing phase in atomic nuclei inferredfrom the structure of 92/46Pd46

DIAMANT wrt. EXOGAM + N-WallDIAMANT wrt. EXOGAM + N-Wall

Plans for Plans for furtherfurther improvements improvements (PF2I)(PF2I)

Known Problems – Future Improvements:

A. Troublesome installation of CsI detectors in DIAMANT chamber

B. CsI calibration, Target loading vs. efficiency, Vacuum feed-through

C. Maintenance of the DIAMANT VXI cards is not obvious

D. Limitations due to γ-absorption for Eγ < 200 keV; CsI(Tl), PAs, cables

E. Test the applicability of Avalanche PDs for CsI-s in DIAMANT

F. The CsI electronics has to be compatible with next-generation DAQ systems

G. (Position sensitive setups?)

How to enhance the performance of DIAMANT to match it with that of furture How to enhance the performance of DIAMANT to match it with that of furture gamma-detector arrays gamma-detector arrays EXOGAM-2 & AGATAEXOGAM-2 & AGATA intended for nuclear structure intended for nuclear structure

studies with high intensity stable and radioactive beams of SPIRAL-2 ?studies with high intensity stable and radioactive beams of SPIRAL-2 ?

B.M. Nyakó (ATOMKI) EXOGAM WS-07 24-26 April, 2007. GANIL, Caen

2.2. “Mechanical” developments: “Mechanical” developments: (ad PF2I.a-b)(ad PF2I.a-b)

The NEW chamber of DIAMANT (used in the '09 experiments)The NEW chamber of DIAMANT (used in the '09 experiments)

The overall vacuum perfomance was excellent (pThe overall vacuum perfomance was excellent (pHe-4He-4 < 10 < 10-9-9 bar); Tested at ATOMKI bar); Tested at ATOMKI

Identical flanges(AlMgSi Alloy)

Metal-metal gluing: 3MTM Scotch WeldTM (DP190 gray) Epoxy adhesive)

Glued PCB vacuum feedthroughs

2a)2a) Re-design of the mechanics for the DIAMANT chamber Re-design of the mechanics for the DIAMANT chamber (Aluminum where possible) (Aluminum where possible) Shape is kept, flanges are standardized (still glued --> grounding OK)Shape is kept, flanges are standardized (still glued --> grounding OK)

2b) 2b) Improved Improved reproducible/stable reproducible/stable installation of the FlexiBoard usinginstallation of the FlexiBoard using positioning holes positioning holes

Use of new beam collimation Use of new beam collimation prevents the FlexiBoard etc. being hit by the beam prevents the FlexiBoard etc. being hit by the beam to avoid dirt inside (Important for new setup with APD-s)to avoid dirt inside (Important for new setup with APD-s)

Upstream view of the collimator

Downstream view of the FlexiBoard X-section with adjusting/positioning legs

2c)2c) Glued PCB feed-throughs: solution adapted from Glued PCB feed-throughs: solution adapted from AFRODITE (TLABS, SA)AFRODITE (TLABS, SA)

Very good vacuum is ensuredVery good vacuum is ensured

2d)2d) T&B high-density connectors are replaced by SCSI-2 connectors (except one)T&B high-density connectors are replaced by SCSI-2 connectors (except one)

To ensure better shielding/grounding of ribbon (output) signal cablesTo ensure better shielding/grounding of ribbon (output) signal cables

SCSI-2 and high-density T&B connectors SCSI-2 and high-density T&B connectors Glued PCB vacuum feed-throughsGlued PCB vacuum feed-throughs

2e)2e) Replacement of the T&B high-density connectors of the 2nd-stage PreAmps with Replacement of the T&B high-density connectors of the 2nd-stage PreAmps with SCSI-2 connectors is in progress SCSI-2 connectors is in progress

3.3. Ongoing detector developmentsOngoing detector developments: : (ad. PF2I a & e)(ad. PF2I a & e)Feasibility studies of using Avalanche PD-s with DIAMANT CsI detectorsFeasibility studies of using Avalanche PD-s with DIAMANT CsI detectors

a)a) Basic measurements with APD-s Basic measurements with APD-s

b) b) Designing low-power consumption PA for APD-sDesigning low-power consumption PA for APD-s

c)c) Systematics of noise vs shaping time measurements Systematics of noise vs shaping time measurements for DIAMANT CsIfor DIAMANT CsI

d)d) Comparison of noise for PIN-photodiode and APD Comparison of noise for PIN-photodiode and APD (w. standard electronics)(w. standard electronics)

e)e) Comparison of PID-vs-Energy spectra obtained with PIN-photodiode Comparison of PID-vs-Energy spectra obtained with PIN-photodiode and APD with DIAMANT Part. Discr. electronicsand APD with DIAMANT Part. Discr. electronics

Motivation: Motivation: Improve the performance of DIAMANT as for particle discrimination Improve the performance of DIAMANT as for particle discrimination

with r. to low-energy separation limit;with r. to low-energy separation limit;

Lower the gamma-ray absorption (reduce material)Lower the gamma-ray absorption (reduce material)

Solution: Solution: Use of high-gain Avalache-PhotoDiodes instead of pin-PDsUse of high-gain Avalache-PhotoDiodes instead of pin-PDs

Status:Status: Feasibility studies of using APD-s instead of pin-PDs started within Feasibility studies of using APD-s instead of pin-PDs started within the the EXOGAM-2 section of the SPIRAL2-PP FP7 projectEXOGAM-2 section of the SPIRAL2-PP FP7 project

Properties of short wavelength type APD-s:

Advantages:

good spectral respons for CsI lighthigh quantum efficiency

low dark current at Vbd

(Vopt

~ 350V)gain ~ 50 (T=20 C)

Disadvantages:

Needs higher Voltage PS (opt. ~350 V)

Gain is temperature dependent --> stabilisation

Hamamatsu S8664-10-10

3a)3a) Basic measurements with APD-s Basic measurements with APD-s ((Gábor Kalinka)Gábor Kalinka)

Aim: Aim: Learn main features of APD-s to help designing a dedicated PreAmp for CsILearn main features of APD-s to help designing a dedicated PreAmp for CsI

Determine the Direct Current Multiplication of the APD vs. Rev. Bias.Determine the Direct Current Multiplication of the APD vs. Rev. Bias.

Rev Current vs Rev BiasRev Current vs Rev Bias Rev Curr. - Gen. Curr. vs Rev OverBiasRev Curr. - Gen. Curr. vs Rev OverBias

IIdd ( (DiffusionCurrent)DiffusionCurrent)

IIgg (Generation Current) (Generation Current) ~ 2.5~ 2.5··(U-102V(U-102V))1.41.4

3a)3a) Basic measurements with APD-s Basic measurements with APD-s (cntd(cntd))

DirectCurrentMult. = [IDirectCurrentMult. = [Icyancyan(U) – I(U) – Iblueblue((U)]/ IU)]/ Icyancyan (U=0)(U=0)

Rev. Current measured using DC LED illuminationRev. Current measured using DC LED illumination

Direct Current MultiplicationDirect Current Multiplication

Direct Current MultiplicationDirect Current Multiplication

With illumination With illumination (Cyan)

Without illumination Without illumination (Blue)

Conclusions: Conclusions: APD-s reverse current could have different contribution to the noise APD-s reverse current could have different contribution to the noise vs. shaping time --> Test it experimentally !vs. shaping time --> Test it experimentally !

Conclusions: Conclusions: CsI(Tl) + APD can be used for low-energy CsI(Tl) + APD can be used for low-energy γγ-spectroscopy as well as -spectroscopy as well as for charged-particle spectroscopy and discrimination for charged-particle spectroscopy and discrimination

3a)3a) Basic measurements with APD-s Basic measurements with APD-s (cntd(cntd))

Aim: Aim: Test performance of CsI(Tl) + APD with gamma and alpha sources Test performance of CsI(Tl) + APD with gamma and alpha sources

137137Cs gamma-ray sourceCs gamma-ray source

DIAMANT-CsI + APD, DIAMANT-CsI + APD, 241241Am sourceAm source

Pulser, Pulser, 241241Am (5.48 MeVAm (5.48 MeV 5.5%

18%

36%

2.5%

3b)3b) Designing a low-consumption PreAmp for APD-sDesigning a low-consumption PreAmp for APD-s

Aim: Aim: Design a low power consumption small size PA (in-vacuum) for APD-s, Design a low power consumption small size PA (in-vacuum) for APD-s, make prototype, determine optimal parameters, test performancemake prototype, determine optimal parameters, test performance

Circuitry of the new PACircuitry of the new PA

Results: Results: Prototype made, tested, used in testing of APD-s & PIN-PD-sPrototype made, tested, used in testing of APD-s & PIN-PD-s

Preliminary tests for determining optimal parameters for Particle Discr.Preliminary tests for determining optimal parameters for Particle Discr.

János Gál

3c)3c) Systematics of noise vs shaping time measurements for DIAMANT CsISystematics of noise vs shaping time measurements for DIAMANT CsI

Aim: Aim: Determine optimal parameters for FPGA programs to be applied for Determine optimal parameters for FPGA programs to be applied for particle discrimination with DSPparticle discrimination with DSP

Method: Method: Measure FWHM for alpha source lines and a precision pulser for Measure FWHM for alpha source lines and a precision pulser for different shaping times and Udifferent shaping times and UAPDAPD-s and compare it with data-s and compare it with dataobtained with PIN PD-s obtained with PIN PD-s

AMR33 Alpha sourceAMR33 Alpha source

Precision PulserPrecision Pulser

Tau = 0.4 usTau = 0.4 us





Tau = 12.8 usTau = 12.8 us

Method: Method: Measure FWHM for alpha source lines and a precision pulser for Measure FWHM for alpha source lines and a precision pulser for different shaping timesdifferent shaping times

3c)3c) Systematics of noise vs shaping time (cntd)Systematics of noise vs shaping time (cntd)

U=410V; Tau = 12.8 usU=410V; Tau = 12.8 us

U=350V; Tau = 12.8 usU=350V; Tau = 12.8 us

5.1475.147 5.4825.482 5.798 MeV5.798 MeV

PulserPulser

Method: Method: Measure FWHM for alpha source lines and a precision pulser for Measure FWHM for alpha source lines and a precision pulser for different Udifferent UAPDAPD-s then evaluate by precise calibration -s then evaluate by precise calibration


3c)3c) Systematics of noise vs shaping time (cntd) Results:Systematics of noise vs shaping time (cntd) Results:


Conclusions:Conclusions: Optimal shaping time and UOptimal shaping time and UAPDAPD can be determined to obtain the can be determined to obtain the

smallest electric noise smallest electric noise To be compromised with optimal values for Ball. DeficitTo be compromised with optimal values for Ball. Deficit

3d)3d) Ballistic Deficit – vs - Ballistic Deficit – vs - ττsh sh for PIN-photodiode and APD for Efor PIN-photodiode and APD for Eα α =5.147MeV (AMR33) =5.147MeV (AMR33)

Conclusions: Conclusions: Avalanche-PD and PIN-photodiode gives similar BD Avalanche-PD and PIN-photodiode gives similar BD --> former part. Discr. Method based on BD can be applied --> former part. Discr. Method based on BD can be applied

in DSP solution in DSP solution

3e)3e) Comparison of PID-vs-Energy spectra for DIAMANT CsI detectors using Comparison of PID-vs-Energy spectra for DIAMANT CsI detectors using

PIN-photodiode and Avalanche PD with an AMR33 alpha source: PIN-photodiode and Avalanche PD with an AMR33 alpha source:

DIAMANT electronics: 1st+2nd stage PreAmp with a Part. Discr. Unit (DIAMANT electronics: 1st+2nd stage PreAmp with a Part. Discr. Unit (ττintint= 14 = 14 μμs)s)

Energy [arb. Unit] Energy [arb. Unit] Energy [arb. Unit] Energy [arb. Unit] Energy [arb. unit]Energy [arb. unit]

PIN-photodiode (U=50V)PIN-photodiode (U=50V) Avalanche PhotodiodeAvalanche Photodiode

1st+2nd PreAmp 1st+2nd PreAmp 1st+2nd PreAmp 1st+2nd PreAmp 1st PreAmp Only1st PreAmp Only

Gain: x8 Gain: x8 Gain: x1 Gain: x1 Gain: x8 Gain: x8

Par

ticle

ID

(ar

b.

uni

t)P

artic

le I

D (

arb

. u

nit) U=350 V

U=370 V U=410 V

U=390 V

U=350 V

U=370 V U=410 V

U=390 V

Conclusions: Conclusions: - Avalanche-PD should give much better part. separation than PIN-PD-s;- Avalanche-PD should give much better part. separation than PIN-PD-s;- FWHM- FWHMPIDPID improves with U improves with UAPDAPD (qualitative) (qualitative)

4.4. Ongoing developments of digital electronics Ongoing developments of digital electronics (Options vs. 5.)(Options vs. 5.)Feasibility studies of using ATOMKI-developed DSP unit (to be done!)Feasibility studies of using ATOMKI-developed DSP unit (to be done!)

aa)) DSP for new APD-based CsI detectors can be realised usingDSP for new APD-based CsI detectors can be realised using ATOMKI-s LIR cards (Virtex4 based system)ATOMKI-s LIR cards (Virtex4 based system)

b) b) Use EXOGAM's DSP electronics and develop softwareUse EXOGAM's DSP electronics and develop software

The block-scheme of The block-scheme of ATOMKI's ATOMKI's DSP unitDSP unit

First reults with LaBr3:Ce detectors (PARIS): energy and coinc spectraFirst reults with LaBr3:Ce detectors (PARIS): energy and coinc spectra

5.5. Financial, personnel Financial, personnel (open)(open) questions questions

a)a) DIAMANT group applied for Hung. Res. Fund: under processDIAMANT group applied for Hung. Res. Fund: under process(requested support for EXOGAM2+DIAMANT related investments: (requested support for EXOGAM2+DIAMANT related investments: ~ 250 kEUR) ~ 250 kEUR)

b) b) Students involved in DSP development works Students involved in DSP development works (PhD + 2 undergraduates)(PhD + 2 undergraduates)

c)c) Planned works: simulations for DIAMANT+ AGATA (students)Planned works: simulations for DIAMANT+ AGATA (students)

Summary of Ongoing and Future Developments of Summary of Ongoing and Future Developments of DIAMANT for EXOGAM2/AGATADIAMANT for EXOGAM2/AGATA

Ongoing developments:Mechanical improvements of the DIAMANT chamber:

good vacuum, new cabling for better grounding/shielding (practically done)

Prototype PreAmp. dedicated to CsI+APD detectors has been developed Tested its performance for optimizing its parameters with DSP electronics

Future developments:Use of Digital Signal Processing to replace the present VXI electronics

(Still Needs financing!)for compatibility with EXOGAM-2 and AGATA

Options:

Use the 4-channel module developed in ATOMKI (EXOGAM-2 FP7)

Use the modules under development for EXOGAM2 (AGATA)

Tasks:Develop dedicated Xilinx programs at ATOMKI for CsI+APD detector signals for either type of DSP electronics (ATOMKI or EXOGAM2)

Participants of the presented developments:

János Gál, Gyula Hegyesi, Gábor Kalinka, József Molnár, Barna Nyakó,Zsolt Dombrádi (FP7), János Timár, Iván Valastyán

Institute of Nuclear Research, (ATOMKI), Debrecen, Hungary

Katalin Juhász Faculty of Informatics, University of Debrecen, Debrecen, Hungary

G. La RanaDipartimento di Fisica, Universita di Napoli and INFN, Napoli, Italy

Thanks for help to the local GANIL staff:Gilles de France, Jean Ropert

and

J.N. Scheurer (CENBG, CRNS-IN2P3-Université de Bordeaux I, Gradignan Cedex, France)

Ongoing developments of the DIAMANT ancillary detector ...particle discrimination with DSP Method:...

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