Experimental Programmes and Applications at GSI/FAIR.

Nuclear Physics Technology Showcase Event:

STFC Knowledge Exchange Workshop 26th September 2013

Paddy Regan Radioactivity Group, NPL &

Dept. of Physics, University of Surrey

Outline • The FAIR Project

– NUclear STructure, Astrophysics & Reactions = NUSTAR • R3B (nuclear reactions) • HiSPEC / DESPEC (nuclear spectroscopy) • ILIMA (Nuclear Masses)

• Instrumentation Developments associated with DESPEC@FAIR

– AGATA – gamma rays ‘in beam’ following reactions. – FATIMA / DESPEC Array – gamma rays from decay. – DTAS – total gamma-ray energy following decay – calorimeter. – AIDA (charge particle measurements / ASICs ) – charged particles from decay – R3B – charged particles ‘in beam’

• Applications using nuclear data and measurements ? – Nuclear decay data / level schemes – Standards for medicine / nuclear waste evaluations.

• e.g., 227Th → 223Ra →219Rn →215Po →211Pb→ 211Bi. • Development of ‘time stamped’, digital coincidence experimentation.

– New radiation ‘hard’ detections systems (diamond) – Pn values in fission fragments (reactor control) – Identification / characterisation of nuclear fuel waste. – Position-sensitive (gamma) detection (waste / reactor core imaging) – Blues skies…new nuclear Isomeric states, nuclear batteries ?

FRIB GSI/FAIR RIKEN

TRIUMF NSCL

GANIL ISOLDE

Existing major dedicated facilities

Future major facilities

HRIBF

Radioactive Ion Beam Facilities Worldwide

Experimental Radioactive Ion Beam Facilities

Plus additional some stable beam facilities (Legnaro, Argonne, New Delhi, Canberra, Bucharest.....U. Birmingham ?

The Current and Future

KORIA

fragmentation/fission

~1GeV/u

fragment separator

350m

Facility for Antiproton and Ion Research (FAIR) NUSTAR: SuperFRS and experiments on three (energy) branches…. > 800 collaborators

Low-energy branch / DESPEC

Towards HISPEC @ FAIR

Picture from 5. Apr 2013 (http://www.fair-center.de)

Gamma Spectroscopy: HISPEC / DESPEC

HISPEC- AGATA @ FAIR

While waiting for FAIR - HISPEC: PreSPEC @ GSI

FRS Particle identification: TPC tracking detectors ToF measurement Energy-loss measurement

LYCCA Outgoing particle tracking and identification: Z identification via E-ΔE Mass identification via E-ToF

Gamma-ray detection 2011: 105 HPGe detectors (Euroball) BaF Scintillators (HECTOR) 2012: HPGe array using pulse- shape analysis and γ-ray tracking techniques (AGATA) BaF&LaBr scintillators (HECTOR+)

In-beam ejectile γ-spectroscopy

the generic challenge at RIBs

Challenges • Incoming particle selection and identification: here FRS @ GSI • v/c ≈ 0.5: large Doppler-shift of γ-radiation • High accuracy in α and θ → granular detectors • Outgoing particle identification: LYCCA • Detection of γ-radiation: AGATA

incoming particle (Z, A, v)

target nucleus

reaction optical axis

Doppler shifted γ-radiation

θ Outgoing particle (Z’, A’, v’)

α

LYCCA Lund-York-Cologne CAlorimeter

• 17 silicon DSSSD detectors for tracking and energy loss • 144 CsI scintillators for particle energy • 3 fast plastic scintillators for time of flight and tracking

UK ‘leaders’ – Mike Bentley (York) ; Annika Lohstroh (Surrey)

PreSPEC-AGATA in 2012

RIB from FRS

HECTOR+

AGATA LYCCA

Set-up: AGATA collaboration

GSI γ-group

Annika Lohstroh (Surrey)

R3B =

Reactions with Relativistic Radioactive

Beams

Courtesy M. Chartier

•DEcay SPECstroscopy

within NuSTAR

includes:

* AIDA (tagging, for HI, α, p, e-) * FATIMA (LaBr3 ‘fast-timing’ array) * DTAS (Total decay calorimeter)

* BELEN (β--delayed neut. detector)

Stopped RISING array

(105 germanium detectors)

Used in 16 PAC approved

experiments at GSI

from 2006-2011.

Now EURICA@RIBF-RIKEN

The Principle of the Active Stopper Focal plane implantation detector sensitive to electron emission

The waiting time between particle implantation and β-particle (or i.c. electron) emission is a measure of the decay half-life. Gamma rays emitted following these decays are detected by the RISING array.

e-

Si Strips

194Os fed by 3 separate β- decaying states in 194Re.

AIDA: introduction Advanced Implantation Detector Array (AIDA) UK collaboration: University of Edinburgh, University of Liverpool, STFC Daresbury Laboratory & STFC Rutherford Appleton Laboratory

• SuperFRS • Exotic nuclei ~ 50 – 200MeV/u • Implant – decay correlations • Multi-GeV implantation events • Subsequent low-energy decays • Tag events for gamma and neutron detector arrays

Detector: multi-plane Si DSSD array wafer thickness 1mm 8cm x 8cm (128x128 strips) or 24cm x 8cm (384x128 strips) Instrumentation: ASIC low noise (<12keV FWHM), low threshold (0.25% FSR) 20GeV FSR plus ( 20MeV FSR or 1GeV FSR) fast overload recovery (~µs) spectroscopy performance time-stamping

AIDA: status • Systems integrated prototypes available - prototype tests in progress • Production planned Q3/2010

Mezzanine: 4x 16 channel ASICs Cu cover EMI/RFI/light screen cooling

FEE: 4x 16-bit ADC MUX readout (not visible) 8x octal 50MSPS 14-bit ADCs Xilinx Virtex 5 FPGA PowerPC 40x CPU core – Linux OS

Gbit ethernet, clock, JTAG ports Power

FEE width: 8cm Prototype – air cooling Production – recirculating coolant

8cm x 8cm AIDA Enclosure

DSSSD - instrumentation via Kapton PCB - minimal package size - minimal material budget - lifetime maximisation - performance impact Package size 10cm x 10cm Snout length 568mm

Tests with AIDA Production Hardware: 20MeV range

• Realistic input loading CD ~ 60pF, IL ~ 60nA • Expectation ~12keV FWHM

Decay Heat

• Nuclear reactors produce >1000 different species of radionuclide (fission fragments, their daughter decays and activation products/minor actinides) etc.

• Energy released from decay of these nuclides is mostly as beta-particles (i.e., electrons) and gamma rays.

• In normal operation approx 8% of the energy generated in a thermal fission reactor comes from decay heat.

• What happens (heat wise) when a reactor is switched off or there is a LOCA (e.g., Fukushima) ?

Possible high efficiency design of a TAS for DESPEC?

‘new’ CeBr3 detectors?

‘old’ NaI(Tl) detectors

FATIMA for DESPEC

• FATIMA = FAst TIMing Array = A high efficiency, gamma-ray detection array for precision measurements of nuclear structure in the most exotic and rare nuclei.

• Specs.

– Good energy resolution. – Good detection efficiency – Excellent timing qualities (~100 picoseconds).

• Can use to measure lifetimes of excited nuclear states; provide

precision tests of shell model theories of nuclear structure. • Array is UK contribution to the DESPEC (Decay Spectroscopy)

Project within NUSTAR;

• Part of ~ £8M STFC NUSTAR project grant (runs to 2015).

Brighton / Surrey groups have purchased (purchase co-ordinator Chris Townsley) 31 1.5” x 2” LaBr3 detectors from St Gobain. Delivered to Surrey/Brighton Dec 2012. Mounted into designed holders with Hamamatsu PMTs Jan 2013. 8 for used in FATIMA @ EXILL (shipped to ILL Feb. 2013) 21 used in EURICA @ RIKEN to be sent to RIKEN ~Feb 2013.

137Cs source gives (initial) test energy resolution of ~3.5% at 662 keV. Note presence of internal radioactivity in detector. PMT HV range ~1300 V

1436 keV EC (2+→ 0+ in 138Ba) 789 keV + β-

In 138Ce

Ba x-rays from 137Cs & EC from 138La decay

138La, T1/2=1.02x1011 years A.A.Sonzogni, NDS 98 (2003) 515

5+ 138La

1435.8 138Ba82

2+

0+

ec (66%)

0+

2+

138Ce80 788.7

β- (34%)

‘Useful’ applications?

Why does nuclear data and high quality gamma / charged

particle measurement matter….

What can you do with it?

238U

232Th

40K Can check the assumption of ‘secular equilibrium’: Identify decays from specific isotopes in each decay chain. Get accurate value for NORM Ac.

Decay chain of 235U (Actinium) Series includes 227Th →223Ra & daughters

223Ra decay standardisation.

By, Sean Collins, Andrew Pearce, John Keightley (Radioactivity Group, NPL)

(one reason) why this is important….

Summary • FAIR project going ahead, starts ~2018

– STFC-funded science to measure (accurately) gamma rays; heavy-ions; protons; heavy-ions; alpha particles; neutrons (fast and slow) & their positions and times.

• Pre-FAIR NuSTAR experiments already going on or completed at

– GSI • RISING + active stopper • PreSPEC (with AGATA) including LYCCA • R3B – development of the Si tracker – radiation hard and lots of channels… • ILIMA (precision mass measurements using rings)

– RIKEN • EURICA with FATIMA for decay gamma-ray spectrometry, nuclear characterisation. • AIDA for ‘exotic’ charged-particle decay measurements • DTAS for decay heat / Total Absorption Gamma Spectrometry (TAGS).

• In addition to ‘nuclear physics’ interest, such experiments are ‘USEFUL’….Why?

– Development of radiation detection systems for ‘difficult’ environments, e.g., • LYCCA – radiation ‘hard’ diamond detectors • Novel ‘basic ‘gamma spectrometry with new detectors (e.g. LaBr3 / CeBr3) • What radioisotopes are present and how much ? • Importance of measurements for public confidence in nuclear waste / medical

isotope use etc.

– Nuclear data (and analysis techniques) used in development and innovation in new (and/or more accurate) radioactive standards for therapeutic or labelling.

235U decay chain …

α-particle energies (correlated with decay γ rays) using the RISING active Stopper following 238U fragmentation. Submitted to Phys. Rev. C, Sept., 2013