1 / 22

Measurement of β - delayed neutrons around the third r-process peak

S410 EXPERIMENT GSI – SEPTEMBER 2011. Measurement of β - delayed neutrons around the third r-process peak. ROGER CABALLERO FOLCH, FRS User meeting 2011 - GSI , 28 th November 2011. Introduction. Setup. Analysis. Future goals. Contents. Introduction and astrophysics motivation.

minty
Download Presentation

Measurement of β - delayed neutrons around the third r-process peak

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. S410 EXPERIMENT GSI – SEPTEMBER 2011 Measurement of β-delayed neutrons around the third r-process peak ROGER CABALLERO FOLCH, FRS User meeting 2011 - GSI, 28thNovember 2011

  2. Introduction Setup Analysis Future goals Contents Introduction and astrophysics motivation Setup: FRS – SIMBA – BELEN Current analysis status and its outlook Summary and future goals 1/14

  3. Introduction Setup Analysis Future goals Introduction Experiment S410: Beta-decay measurements of new isotopes near the third r-process peak (N~126) • Performed at GSI in September 2011 with a week of beam time • Shared setup with S323 experiment The measurements settings were centered on two isotopes: 215Tl, 211Hg. We have preliminarily identified the following nuclei: 211-217Tl 207-214Hg 205-210Au 199,202Ir 203,206Pt 2/14

  4. DF3 + QRPA Introduction Setup Analysis Future goals Introduction Motivation Nuclear structure knowledge:  beta decay studies of these nuclei Half lives (T1/2) Beta delayed neutron emission probabilities (Pn) provide information about their decay mechanism and nuclear structure in this mass region Astrophysics (r-process): nucleosynthesis aspects of the heavy mass elements. The new values for T1/2 and Pn, will provide valuable information for the test of theoretical models. (I.Borzov, et al. 2003) + FRDM + QRPA (P.Moeller, et al. 2003) Exp. T. Kurtukian et al. “Ignorance”-Curve Phys. Lett. B (Submitted) 3/14

  5. t1/2 exists identified Introduction Setup Analysis Future goals Introduction State of the art Centered N=126 Area of interest Pn (%) QRPA Bn= 2-3 MeV 4/14

  6. Introduction Setup Analysis Future goals Introduction Setup Fragment separator spectrometer (FRS). Beam characteristics. 1.6 g/cm2 Be target 2x109ions/spill intensity SIMBA + BELEN Bρ settings for: 215Tl, 211Hg and as references 216Po, 205Bi, 135Sb Spill length ~1s with a period around 4s 5/14 Separation in flight Bρ – ΔE – Bρ

  7. Introduction Setup Analysis Future goals Setup Experimental hall (S4) configuration and settings SIMBA & BELEN SCI ITAG MUSIC TPC DEGRADER SLITS 6/14

  8. Introduction Setup Analysis Future goals Setup Implantation detector: SIMBA (Silicon Implantation Detector and Beta Absorber) Multilayer silicon detector Allows to measure both ion implants and β-decays. Decay events can be correlated in time with the detection of neutrons. SIMBA detector XY FRONT A B C REAR Tracking layers XY (60 segm.) 60x60 mm2 (0.3mm thick) 2 SSSD (7 segm.) 60x40 mm2 (1mm thick) 2 SSSD (7 segm.) 60x40 mm2 (1mm thick) 3 DSSD (implantation area, 60x40 segm.): 60x40 mm2 (0.7mm thick) Front view 7/14

  9. Introduction Setup Analysis Future goals Setup Neutron detector: BELEN (Beta Delayed Neutron Detector) - Neutron detector designedby UPC GRETER researchgroup (Barcelona) - The detection of theneutron is based on thedetection of products of the reaction of the neutron with 3He counters: 3He + n 3H + 1H + 765 keV - 30 3He counters: Polyethylene moderator n n Proportional 3He counter Ion beam Silicon β decay detector n 8/14

  10. Introduction Setup Analysis Future goals Setup Neutron detector: BELEN (Beta Delayed Neutron Detector) BELEN-30 neutron detector · 10 with 10 atm pressure · 20 with 20 atm pressure Neutron shielding SIMBA inside the matrix BEAMLINE 8/14

  11. Introduction Setup Analysis Future goals Analysis Setup Analysisprocedure (Preliminary plots / ongoing) SCI21-SCI41  ToF TPC21-22 – TPC41-42  Positioncalibration MUSIC 41-42-43  Energy Losscalibration Tracking detectors calibrations & particle ID Particle ID check via 205Bi isomers,216Po α-decays FRS setting 215Tl SIMBA calibration implantationpatterns Po Bi Analysis of halflives and Pn Pb PRELIMINARY Tl Digital data acquisitionsystemfeatures Hg Au 215Tl Pt A/Q 9/14

  12. Introduction Setup Analysis Future goals Analysis Analysisprocedure (Preliminary plots / ongoing) SCI21-SCI41  ToF TPC21-22 – TPC41-42  Positioncalibration MUSIC 41-42-43  Energy Losscalibration Tracking detectors calibrations & particle ID Particle ID check via 205Bi isomers,216Po α-decays FRS setting 211Hg SIMBA calibration implantationpatterns Po Analysis of halflives and Pn Bi PRELIMINARY Pb Digital data acquisitionsystemfeatures Tl Hg Au 211Hg Pt Ir A/Q 9/14

  13. Introduction Setup Analysis Future goals Analysis Analysisprocedure (Preliminary plots / ongoing) 205Bi setting has been used as Z identification reference via isomer gamma rays and 216Po setting as A/Q checking in the region of interest. Tracking detectors calibrations & particle ID Particle ID check via 205Bi isomers,216Po α-decays SIMBA calibration implantationpatterns Z Analysis of halflives and Pn Digital data acquisitionsystemfeatures 205Bi Counts A/Q keV 10/14

  14. Introduction Setup Analysis Future goals Analysis Analysisprocedure (Preliminary plots / ongoing) Tracking detectors calibrations & particle ID - SIMBA calibrations are being performed with a 137Cs source - β-decay curves will provide half lives values Noise Particle ID check via 205Bi isomers,216Po α-decays Counts Implantation Implants SIMBA calibration implantationpatterns keV Beta disintegrations Beta decay Analysis of halflives and Pn Digital data acquisitionsystemfeatures Energy deposited (ch) Ch 11/14

  15. Introduction Setup Analysis Future goals Analysis Analysisprocedure (Preliminary plots / ongoing) • Time correlation between neutron and beta decay • -252Cf for BELEN efficiency and can be checked with 135Sb Tracking detectors calibrations & particle ID Counts Particle ID check via 205Bi isomers,216Po α-decays SIMBA calibration implantationpatterns Analysis of halflives and Pn Digital data acquisitionsystemfeatures Neutron signal Noise Pulser Energy (ch) 12/14

  16. Introduction Setup Analysis Future goals Analysis Analysisprocedure (Preliminary plots / ongoing) • DDAS • Triggerless digital data acquisition • systemused for thefirst time in this • type of experiments at GSI. • Itallows to eliminatethedead time • of conventionalacquisitionsystems • thanks to thedouble memory digital • cards whichallow to acquire data • and reading of previouslytaken data at thesame time. • Advantages: • Increasetheefficiencybyabout 8% (from 27 to 35%) • Flexibility for large time correlation (fundamental to obtaincorrelationswith all neutron and to changethe gates offline) • Allows to correctsome experimental effects, e.g. To reduceneutronbackgroundfromuncorrelated neutrons. Tracking detectors calibrations & particle ID Particle ID check via 205Bi isomers,216Po α-decays SIMBA calibration implantationpatterns Analysis of halflives and Pn Digital data acquisitionsystemfeatures 13/14

  17. Introduction Setup Analysis Future goals Futuregoals Analysis Outlook • ImprovedID-Plot via final calibrations of frs detectors • Determineimplantation rates for eachidentifiedisotope • Determineimplant-betacorrelations and neutron-betacorrelations • Implementananalysismethod for derivinghalf-lifes and for determiningbeta-delayedneutronemissionprobabilities. • In collaborationwiththeoreticians, studytheimpact of theseresults on nuclear models, as well as on r-processnucleosynthesiscalculations. • Futuregoals • Upgrade of detector: up to 90 counters (detection efficiency ~70%): collaboration with Dubna • Combine with AIDA implantation detector (first separate tests in August 2011): talk Robert Page (Tue, 10:10) • Optimizedetectionsystem (BELEN) and itsacquisition (DDAS) for future experiments withmoreexoticbeams (FAIR). • Prepare for first experiments closer to ther-processpath @FAIR/DESPEC (>2018) • Measure Pxn 14/14

  18. The end! Thanks to collaborators: Institut de Física Corpuscular de València (IFIC) UniversitatPolitècnica de Catalunya (UPC) HelmholtzzentrumfürSchwerionenforschung GmbH (GSI) NSCL, Michigan State University (MSU-USA) CIEMAT (Madrid) Universidade de Santigo de Compostela (USC) Department of Physics, University of Surrey (UK) CFNUL Universidade de Lisboa (Portugal) School of Physics & Astronomy, U. Edinburgh (UK) Department of Physics, University of Liverpool (UK) STFC, Daresbury Laboratory (UK) LaboratoriNazionalidiLegnaro, INFN (Italy) Flerov Laboratory, JINR, Dubna (Russia) CENBG, Université Bordeaux (France)

  19. Introduction Setup Analysis status Data analysis Outlook & future Introduction State of the art Focus of present proposal r-path Effect of half-lives “Ignorance”-Curve The Astr. Jour., 579 (2002), H. Schatz et al. Proc. CGS-13 (2009), G. Martinez-Pinedo 4/16

  20. DF3 + QRPA Introduction Setup Analysis Future goals Introduction State of the art FRDM + QRPA Pn T1/2 K.-L. Kratz, (private communication) K.-L. Kratz, (private communication) Effect of half-lives + FRDM + QRPA (P.Moeller, et al. 2003) (I.Borzov, et al. 2003) Exp. T. Kurtukian et al. Phys. Lett. B (Submitted) r-processpath The Astr. Jour., 579 (2002), H. Schatz et al. Proc. CGS-13 (2009), G. Martinez-Pinedo 4/14

  21. Introduction Setup Setup Analysis status Analysis status Data analysis Outlook & future Particle identification The method is based in Time of Flight (ToF) measurement according to the energy loss (ΔE) in the (MUSIC) ionisation chambers and the B fields (Bρ) set. Z Counts 205Bi setting has been used as Z identification reference via isomer gamma rays and 216Po setting as A/Q checking in the region of interest. 205Bi keV A/Q 9/16

More Related