Status on 25 Mg(n, γ ) and neutron flux in 2012 Bologna, 27 November 2013

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Status on 25 Mg(n, γ ) and neutron flux in 2012 Bologna, 27 November 2013. C. Massimi. 2012 Flux Detectors & data Flux and its uncertainty Mg(n, γ ) RSA, examples MACS, preliminary Conclusions. Outline. 2012 Flux – Available data. Capture collimator (1.8 cm). Fission - PowerPoint PPT Presentation

Transcript of Status on 25 Mg(n, γ ) and neutron flux in 2012 Bologna, 27 November 2013

  • Status on 25Mg(n,) andneutron flux in 2012

    Bologna, 27 November 2013C. Massimi

  • Outline2012 FluxDetectors & dataFlux and its uncertainty

    Mg(n,)RSA, examples MACS, preliminary

    Conclusions

  • 2012 Flux Available dataCapture collimator (1.8 cm)Fission collimator (8 cm)

    ExperimentRUNSTotal protonsUsable protonsDST available ?238U(n,)13499-138362.4410181.53101892,93Zr(n,)13866-143023.1510182.46101887Sr(n,)14325-145772.001018-235U Fiss.Tag. 14579-153884.2810183.61101859Ni(n,)15569-157031.510181.261018TOTAL1.3410198.861018

    ExperimentTotal protonsUsed protonsFission angular distribution2.010181.721018

  • 2012 Flux Available dataCapture collimator (1.8 cm)Fission collimator (8 cm)

    ExperimentSiMonMicroMegas10BMicroMegas235UPTB238U(n,)92,93Zr(n,)87Sr(n,)235U Fiss.Tag.59Ni(n,)

    ExperimentPPAC 235UFission angular distribution

  • 2012 Flux SiMon dataDST version 11, an improved routine exists but not used yetAmplitude Spectrum Silicon 1TOF > 104 ns No -flashn+6Li + 3H

  • 2012 Flux SiMon dataDST version 11, an improved routine exists but not used yetAmplitude Spectrum Silicon 2TOF > 104 ns No -flashn+6Li + 3H

  • 2012 Flux SiMon dataDST version 11, an improved routine exists but not used yetAmplitude Spectrum Silicon 3TOF > 104 ns No -flashn+6Li + 3H

  • 2012 Flux SiMon dataDST version 11, an improved routine exists but not used yetAmplitude Spectrum Silicon 4TOF > 104 ns No -flashn+6Li + 3H

  • 2012 Flux SiMon dataTOF spectrum, gate on 3H peakSilicon 1260 keV87 kev 35 kev ~ 0.5 eV

  • 2012 Flux SiMon dataTOF spectrum, gate on 3H peakSilicon 2 0.5 - 2 eV

  • 2012 Flux SiMon dataTOF spectrum, gate on 3H peakSilicon 3 ~ 0.5 eV

  • 2012 Flux SiMon dataTOF spectrum, gate on 3H peakSilicon 4 ~ 0.5 eV

  • 2012 Flux SiMon dataRejection of radiofrequency(?) signals in coincidence--- No conditions--- 1 signal--- No coincidences (30 ns)

  • 2012 Flux SiMon dataRejection of radiofrequency(?) Energy depositionSolutionElectronic noise not present in parasitic bunches

  • 2012 Flux SiMon dataBeam stability Ratio of beam monitors

  • 2012 Flux SiMon dataBeam stability Ratio of beam monitorsprotons / pkupR.M.S. ~ 4,3 %R.M.S. ~ 5,4 %--- Dedicated beam--- Parasitic beam

  • 2012 Flux SiMon dataDetector stability Ratios of Sili counts Vs Conditions:Amplitude 3H peakTOF thermal region

    RatioAverageBefore rej.R.M.S. Before rej.SILI 1 / PROT1.8210-1310%SILI 2 / PROT1.4310-1315%SILI 3 / PROT1.3210-136%SILI 4 / PROT1.6810-1311%

    AverageAfter rej.R.M.S. After rej.1.8510-133.2%1.4710-135.3%1.3310-133.6%1.6910-134.1%

  • 2012 Flux SiMon dataDetector stability Ratios of Sili counts Vs Conditions:Amplitude 3H peakTOF thermal region

    RatioAverageBefore rej.R.M.S. Before rej.SILI 1 / SILI 21.2912.0%SILI 1 / SILI 3 1.394.5%SILI 1 / SILI 41.094.2%SILI 2 / SILI 31.098.0%SILI 2 / SILI 40.868.5%SILI 3 / SILI 40.784.3%

    AverageAfter rej.R.M.S. After rej.1.276.0%1.394.5%1.274.1%1.105.1%0.865.6%0.784.2%

  • 2012 Flux SiMon dataSiMon Counts normalized to protons

  • 2012 Flux SiMon dataSiMon Counts normalized to pkup

  • 2012 Flux SiMon dataSiMon Counts normalized to protons

  • 2012 Flux SiMon dataUncertainty due to counting statistic87 kev 35 kev 6 kev En< 0.5 eV

  • 2012 Flux SiMon dataLFLUX=182.35 mLCAPT=184.21 mFrom flux to capture

  • 2012 Flux SiMon dataComparison with previous yearsDifference at thermal> 10%

    Average difference 10%

  • 2012 Flux SiMon dataComparison with previous years12 45 s1 MeV 90 keVDifferenceat high energy ?260 keV

  • SiMon data not enoughEn > few keV SiMon efficiency not well known simulation or experimental ratio (2011 data)?

  • SiMon Vs PPAC data2012 PPAC data from Esther Leal Cidoncha

  • SiMon Vs PPAC dataMatching region PPAC SIMON3 25 keV3% systematic uncertainty depending on the matching region

  • SiMon Vs PPAC data

  • SiMon + PPAC data--- Evaluated 2011--- This work 2012SiMonPPACFlux from0.03 eV < En< 1 MeV

  • SiMon + PPAC data--- Evaluated 2011--- This work 20123% systematic uncertainty depending on the matching regionSame shape

  • Flux 2011 2012 --- Evaluated 2011--- This work 2012ATTENTION to normalization197Au56FeReal situation

  • Flux 2011 2012 Real situation

  • New 25Mg(n,) measurement why ? Because of the limitations in 2003 measurementSample MgO, powder sampleTransmission experiment on natMg sample

    n_TOF facility Phase-I: Water as neutron moderator

    Measurement Few data collectedPhysical Review C 85 (2012) 044615

  • New 25Mg(n,) measurement why ? Because of the limitations in 2003 measurement did we improve?Sample MgO, powder sampleTransmission experiment on natMg sample

    n_TOF facility Phase-I: Water as neutron moderator

    Measurement Few data collectedYes a lotMetal sampleTransmission experiment on enriched 25Mg sample

    Yes Borated water

    NOAgain few data collected

  • 25Mg(n,) first resonanceRecall: 2003 capture data normalized to this resonance

  • 25Mg(n,) first resonanceRecall: 2003 capture data normalized to this resonance=1.730.03 eV

  • 25Mg(n,) first resonanceRecall: 2003 capture data normalized to this resonance=1.730.03 eV

    =1.50.5 eV

  • 25Mg(n,) first resonanceRecall: 2003 capture data normalized to this resonance=1.730.03 eV

    =1.50.5 eV

    =1.280.03 eV

  • 25Mg(n,) up to 100 keVClean up resonances list

  • 25Mg(n,) up to 100 keVCheck with transmission data from GELINA

  • 25Mg(n,) up to 300 keV RSA ongoing

  • 25Mg(n,) up to 100 keVCheck with transmission data from GELINA

  • 25Mg(n,) - MACSMaxwellian-averaged capture cross section~ 10 - 20% lower than previously reported

  • 25Mg(n,) - MACSMaxwellian-averaged capture cross section~ 10 - 20% lower than previously reported

  • Conclusions2012 flux, obtained from the combination of SiMon and PPAC data, available:uncertainty due to counting statistic < 4%systematic uncertainty ~ 3% for En > 30 keV

    25Mg(n,) measurement at n_TOFRSA, check with transmission dataMACS 20% lower than previously reported important astrophysical implicationUncertainty reduced

  • Cristian MassimiDipartimento di Fisica e [email protected]

    www.unibo.it

  • Neutron SensitivityPreliminary study: N,BICRON ~ 10-4

  • Silicon 2 - stabilityNi campaign

  • Silicon 2 - stability

  • Silicon 2 - stability

  • Flux 2010 2011 2012

  • Flux 2011 2012

  • Flux 2011 2012

  • Mg sampleOLD sample (powder)New sample (metallic)Enrichment 95.75%24Mg ~ 3%,26Mg ~ 1.2%Enrichment 97.86 %24Mg ~ 1.83 %26Mg ~ 0.31 %INFN paid ~ $13 500

    PropertyValueMass MgO3.19 gDiameter22 mmThickness2.3 mmAreal density1.234x10-2 at/b

    PropertyValueMass Mg3.94 gDiameter20 mmThickness7 mmAreal density3.00x 10-2 at/b

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