Experimental Programmes and Applications at GSI/FAIR.

Transcription

1 Experimental Programmes and Applications at GSI/FAIR. Nuclear Physics Technology Showcase Event: STFC Knowledge Exchange Workshop 26 th September 2013 Paddy Regan Radioactivity Group, NPL & Dept. of Physics, University of Surrey

2 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., 227 Th 223 Ra 219 Rn 215 Po 211 Pb 211 Bi. Development of time stamped, digital coincidence experimentation. New radiation hard detections systems (diamond) P n 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?

3

4 The Current and Future Experimental Radioactive Ion Beam Facilities RIKEN TRIUMF NSCL FRIB HRIBF GANIL GSI/FAIR ISOLDE KORIA Future major facilities Existing major dedicated facilities Radioactive Ion Beam Facilities Worldwide Plus additional some stable beam facilities (Legnaro, Argonne, New Delhi, Canberra, Bucharest...U. Birmingham?

5 Facility for Antiproton and Ion Research (FAIR) NUSTAR: SuperFRS and experiments on three (energy) branches. > 800 collaborators ~1GeV/u 350m fragmentation/fission fragment separator Low-energy branch / DESPEC

6 Towards FAIR Gamma Spectroscopy: HISPEC / DESPEC Picture from 5. Apr 2013 (

7 HISPEC- FAIR

8 While waiting for FAIR - HISPEC: GSI Gamma-ray detection 2011: 105 HPGe detectors (Euroball) BaF Scintillators (HECTOR) 2012: HPGe array using pulseshape analysis and γ-ray tracking techniques (AGATA) BaF&LaBr scintillators (HECTOR+) 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

9 In-beam ejectile γ- spectroscopy the generic challenge at RIBs incoming particle (Z, A, v) θ Doppler shifted γ-radiation Outgoing particle (Z, A, v ) optical axis reaction α target nucleus Challenges Incoming particle selection and identification: here 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

10 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)

11 PreSPEC-AGATA in 2012 RIB from FRS AGATA LYCCA HECTOR+ Set-up: AGATA collaboration GSI γ-group

12 Annika Lohstroh (Surrey)

13 R 3 B = Reactions with Relativistic Radioactive Beams

14 Courtesy M. Chartier

15

16

17 DEcay SPECstroscopy within NuSTAR includes: * AIDA (tagging, for HI, α, p, e - ) * FATIMA (LaBr 3 fast-timing array) * DTAS (Total decay calorimeter) * BELEN (β - -delayed neut. detector)

18

19 Stopped RISING array (105 germanium detectors) Used in 16 PAC approved experiments at GSI from Now

20 The Principle of the Active Stopper Focal plane implantation detector sensitive to electron emission e - Si Strips 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.

21 194 Os fed by 3 separate β - decaying states in 194 Re.

22 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 ~ MeV/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

23 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 FEE width: 8cm Prototype air cooling Production recirculating coolant Gbit ethernet, clock, JTAG ports Power

24 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

25 Tests with AIDA Production Hardware: 20MeV range Realistic input loading C D ~ 60pF, I L ~ 60nA Expectation ~12keV FWHM

26 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)?

27

28 Possible high efficiency design of a TAS for DESPEC? old NaI(Tl) detectors new CeBr3 detectors?

29 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).

30

31

32

33 Brighton / Surrey groups have purchased (purchase co-ordinator Chris Townsley) x 2 LaBr 3 detectors from St Gobain. Delivered to Surrey/Brighton Dec Mounted into designed holders with Hamamatsu PMTs Jan for used in EXILL (shipped to ILL Feb. 2013) 21 used in RIKEN to be sent to RIKEN ~Feb 2013.

34 Ba x-rays from 137 Cs & EC from 138 La decay 137 Cs source gives (initial) test energy resolution of ~3.5% at 662 kev. Note presence of internal radioactivity in detector. PMT HV range ~1300 V 789 kev + β - In 138 Ce 1436 kev EC ( in 138 Ba)

35 2 + ec (66%) La β - (34%) 138 La, T 1/2 =1.02x10 11 years A.A.Sonzogni, NDS 98 (2003) Ba Ce 80

36

37 Useful applications? Why does nuclear data and high quality gamma / charged particle measurement matter. What can you do with it?

38 238 U 232 Th 40 K Can check the assumption of secular equilibrium : Identify decays from specific isotopes in each decay chain. Get accurate value for NORM Ac.

39

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

41

42

43 223 Ra decay standardisation. By, Sean Collins, Andrew Pearce, John Keightley (Radioactivity Group, NPL)

44 (one reason) why this is important.

45 Summary FAIR project going ahead, starts ~2018 STFC-funded science to measure (accurately) gamma rays; heavy-ions; protons; heavyions; 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. LaBr 3 / CeBr 3 ) 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.

46 235 U decay chain α-particle energies (correlated with decay γ rays) using the RISING active Stopper following 238 U fragmentation. Submitted to Phys. Rev. C, Sept., 2013