Barcelona, 21 de maig de 2010

1. Delayedneutronemission afterβ-decay of exoticnuclei Barcelona, 21 de maig de 2010

2. Introduction Detector IGISOL system Efficiency252Cf Analysis Contents Introduction: Research objectives Detector IGISOL system (Ion Guide Isotope Separator On-Line) Efficiency calculation  Cf-252 calibration Data analysis 2/20

3. Introduction Introduction Detector IGISOL system Efficiency252Cf Analysis Research objectives: “Nuclear data for physics and nuclear engineering” • Neutron emission after beta decay Exotic nuclei? BETA 3/20

4. Introduction Introduction Detector IGISOL system Efficiency252Cf Analysis Research objectives • Neutron emission from beta decay 4/20

5. Introduction Introduction Detector IGISOL system Efficiency252Cf Analysis Research objectives • Example of exotic nuclei to study neutron BETA 5/20

6. Introduction Introduction Detector IGISOL system Efficiency252Cf Analysis Research objectives • Example of exotic nuclei to study neutron BETA 6/20

7. Introduction Introduction Detector IGISOL system Efficiency252Cf Analysis Research objectives Physics knowledge: Study different aspects of the decay of these nuclei and hence provide very complete information about their decay mechanism and structure. Applications: Some of them are close to the path of the astrophysical r process, the determination of the full beta strength could help to improve theoretical models used for the calculation of beta decay properties (region A~90) Nuclear reactor safety. (Decay heat, fission reaction control) International projects collaboration: Development and testing instrumentation for the FAIR facility (DESPEC collaboration) 7/20

8. Introduction Detector Introduction Detector IGISOL system Efficiency252Cf Analysis Detector structure 8/20

9. Detector Introduction Detector IGISOL system Efficiency252Cf Analysis Reaction • Mechanisms of detecting neutrons are based on indirect methods 3He + n → 3H + 1H + 765 keV Polyethylene moderator n n ions Proportional counter n 9/20

10. Detector Introduction Detector IGISOL system Efficiency252Cf Analysis Electronic chain for data acquisition and signal processing Software implementat: GASIFIC  Fitxers binaris 10/20

11. Detector IGISOL system Introduction Detector IGISOL system Efficiency252Cf Analysis Nuclei production Ion Guide Isotope Separator On-Line: • Study of short-lived (T1/2>1us): • The nuclei of interest have to be produced and immediately used for the experiments • Separation of the nuclei of interest from other contaminants • Very pure ion beam is achieved • Other Traps for radioactive ions: ISOLTRAP at CERN, Geneva, Switzerland SHIPTRAP at GSI, Darmstadt, Germany LEBIT at MSU, East Lansing, Michigan, USA TITAN at TRIUMF, Vancouver, Canada CPT at ANL, Argonne, Illinois, USA TRIGA-TRAP at Univ. of Mainz, Germany 11/20

12. IGISOL system Introduction Detector IGISOL system Efficiency252Cf Analysis IGISOL layout 1- Ion guide 2- k130 cyclotron beamline 3- beam dump 4- acceleration chamber 5- dipole magnet (mass separation “A”) 6- switchyard 7- RFQ cooler 8- tandem penning trap 9- miniquadrupole deflector 10- electrostatic deflector and beamline to upper floor 11- experimental setups 12/20

13. Sistema IGISOL system Introduction Detector Efficiency252Cf Analysis Ion guide • Basic idea: To slow down and thermalize initially energetic recoil ions from nuclear reactions in gas. Tipically Helium. • Ions are transported by a gas flow out of the gas cell and injected to the high vacuum section for further acceleration and mass separation. 13/20

14. Sistema IGISOL system Introduction Detector Efficiency252Cf Analysis JYFL trap • Possibility of producingisobaricallypurified ion beams • Applying successive dipole and quadripole rf fields which lead to mass-selective cooling and centering according to: B/wc=m(A)/q • JYFLTRAP is an ion trap system for cooling, bunching and isobaric purification of radioactive ion beams produced at IGISOL • Main applications are mass and Q-value measurements of exotic nuclei and preparation isobarically or even isomerically pure beams for decay spectroscopy experiments 14/20

15. Sistema IGISOL system Introduction Detector Efficiency252Cf Analysis Photos &Pictures 15/20

16. IGISOL system Efficiency252Cf Introduction Detector IGISOL system Efficiency252Cf Analysis Detector experimental efficiency • -Spontaneous fission source Cf-252 • Uncertainty 15% aprox! 136I (1313keV) 138Cs (1435keV) 140La (1596keV) • Fission products to analyze gamma peaks: 16/20

17. Efficiency252Cf Introduction Detector IGISOL system Efficiency252Cf Analysis • Gamma detector calibration Energy calibration : Am-241, Cs-137 & Co-60 mixt source Efficiency calibration: Eu-152 source • 59,5keV • 661,5keV • 1173 y 1332,5keV • 1460keV (K-40) • 122keV, 344,3keV, 411keV, 778,9keV, 867,4keV, 964keV, 1112keV,1408keV Uncertainty obtained: 7,5% 17/20

18. Efficiency252Cf Introduction Detector IGISOL system Experiment Analysis Cf-252 Activity • Cf-252 spectrum Zoom Spectrum area with interesting peaks: 1313keV, 1435keV & 1506keV 18/20

19. Efficiency252Cf Analysis Introduction Detector IGISOL system Efficiency252Cf Analysis Single measures GENIE (MCA/PC data transfer + peak analysis) Wireshark as data package capture  LLC Protocol [@dest + @source + lengt + aa aa 03 + ctrl + data + + nºpack + ctrl + lengt + ctrl 0 +lengt + real data] (See excel file) PalmTop Cheaper system according uses ATOMKI group (Hungary) Free licence software 19/20

20. Analysis Introduction Detector IGISOL system Efficiency252Cf Analysis Data analysis ROOT: Cern development, multifunctional software, programable GASIFIC implemented and developed by IFIC (UV) in C++ using ROOT libraries: - Binary file adquisition - Generate user root files to analyze - Modify correlation time between beta & neutron emittion OTHER: Go4 (GSI) 19/20

21. Links of interest http://www.baeturia.com/neutronassos/ https://www.jyu.fi/fysiikka/en/research/accelerator/ S’ha acabat!... ???