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Status of the n_TOF experiment

Status of the n_TOF experiment. E.Chiaveri ( EN-STI-EET ) On behalf of n_TOF collaboration. ITEMS. Experimental campaign July – November 2011 EAR2 (experimental Area 2) follow up Tentative planning for 2012 Summary. Proton status.

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Status of the n_TOF experiment

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  1. Status of the n_TOF experiment E.Chiaveri (EN-STI-EET) On behalf of n_TOF collaboration INTC Meeting

  2. ITEMS INTC Meeting • Experimental campaign July – November 2011 • EAR2 (experimental Area 2) follow up • Tentative planning for 2012 • Summary

  3. Proton status INTC Meeting Thanks to the earlierstart and to the higherintensity/pulse n_TOFreaches for the first time itsintensityrequest/year

  4. Measurements performed between July and November 2011 • Reference measurements of the high energy (n,a) cross section of 10B with a CVD diamond detector for the prospect of future applications, CERN-INTC-2010-061 ; INTC-I-125 • Measurement of the neutron capture cross-section of 236U, CERN-INTC-2010-065 ; INTC-M-017 • The role of Fe and Ni for s-process nucleosynthesis in the early Universe and for innovative nuclear technologies ,CERN-INTC-2006-012 ; INTC-P-208. • Neutron capture cross section measurements of 238U, 241Am and 243Am at n_TOF, CERN-INTC-2009-025 ; INTC-P-269. • Measurement of the fission cross-section of 240Pu and 242Pu at CERN's n_TOF facility, CERN-INTC-2010-042 ; INTC-P-280. • Irradiation of FBG optical sensors in the n_TOF dump, CERN-INTC-2011-031; INTC-I-135. • MicroMegas performance test for (n,a) measurements at n_TOF: S33(n,a) cross section. CERN-INTC-2010-023 ; INTC-I-092 • Angular distributions in the neutron-induced fission of actinides, CERN-INTC-2010-038 ; INTC-P-209-ADD-1 INTC Meeting

  5. C. Weiss et al. (U. Wien), Reference measurements of the high energy (n,a) cross section of 10B with a CVD diamond detector for the prospect of future applications, CERN-INTC-2010-061 pCVDdeveloped and usedfor 1st time!! - Verywellshieldedfromg-flash - Preliminary Pulse ShapeAnalysis - Preliminary data analysis Detector (4 pads) box with Sample inside Preamplifiers Neutrons • Preamplifiers n_TOF γ –background?! Improvement 2012: Thinner Diamond (Less background) Under vacuum (Better discrimination) INTC Meeting

  6. N. Colonna et al., (INFN-Bari), Measurement of the neutron capture cross-section of 236U, CERN-INTC-2010-065 ; INTC-M-017 • 236U3O8 sample • 338 mg of 236U • 99.85% Enriched • U6 Dimensions: 10 x 0.25 mm • Al Canning dimensions: 15 x 0.75 mm • Composition: 0.05% U5 99.85 U6 0.10% U8 INTC Meeting

  7. N. Colonna et al., (INFN-Bari), Measurement of the neutron capture cross-section of 236U, CERN-INTC-2010-065 ; INTC-M-017 [Measurement with C6D6] Full range in one shot! Optimal signal to background ratio!! INTC Meeting

  8. N. Colonna et al., (INFN-Bari), Measurement of the neutron capture cross-section of 236U, CERN-INTC-2010-065 ; INTC-M-017 [Measurement with the TAC] Empty RRR limit in ENDF INTC Meeting

  9. D. Cano-Ott (CIEMAT, Madrid) and F. Gunsing (CEA, Saclay) et al., Neutron capture cross section measurements of 238U, 241Am and 243Am at n_TOF, CERN-INTC-2009-025 ; INTC-P-269. • Wide sample, with perfect alignment it covers ~97% of the beam (53.90 x 30.30 mm) [NOT SEALED!!!] • 6.125 ± 0.002 g • Isotopic analysis done in 1984: <1 ppm233U, <1ppm 234U, ~11ppm 235U, <1ppm 236U • ‘Bonbon’ casing with ~60 microns of Al, ~75 microns Kapton Nominal values: TOF~8E12 ppp / EAST~3e12ppp Original 238U mass~600 mg Final mass of 238U~6g : Counting rates up to 3-4 counts/microsecond Since the TAC can hold only up to 1 counts/microsecond: TOF intensity reduced to 0.5-0.9e12 ppp 238U TOF EAST Nominal EASTTOF INTC Meeting

  10. D. Cano-Ott (CIEMAT, Madrid) and F. Gunsing (CEA, Saclay) et al., Neutron capture cross section measurements of 238U, 241Am and 243Am at n_TOF, CERN-INTC-2009-025 ; INTC-P-269. Second Resonance 238U Dummy Empty First Resonance Third Resonance INTC Meeting

  11. R. Palomo, J.M. Quesada and C. Guerrero , Use of FBG sensors as temperature-based Beam Profile Monitors • Optical Fibers with Bragg Gratings (100% transmission except for the selected l) are used for measuring temperature changes, deformations and recently dose induced by protons. • Neutron interactions may induce measurable effects in Fiber Bragg Gratings (already observed in protons beams) by means of (among others): • Nucleus recoils inducing changes in temperature • Material damage • Nuclear reactions that would change the composition of the fiber (thus the transmitted l) Experimental results for two FBG under the proton beam exposure with polyimide coating (coated) and embedded in a fiber composite material (embedded). Black line shows the ambient temperature wavelength shifts in the reference FBG (off beam). PARASITIC MEASUREMENT NEAR THE N_TOF BEAM DUMP: • FBG in vacuum: sensitive to sudden and continuous changes in temperature and material damage • Fibers in air sensitive to material damage. • If effects are NOT observed: • green light for the use of fibers in high neutron field environments. • If effects ARE observed: • possibility to use FBG as neutron dosimeters, neutron profilers, etc. INTC Meeting

  12. M. Calviani, (CERN), E. Berthoumieux (CEA, Saclay) et al., Measurement of the fission cross-section of 240Pu and 242Pu at CERN's n_TOF facility, CERN-INTC-2010-042 ; INTC-P-280. • 240,242Pu(n,f) with MGAS (A: Tsinganis) 235U ENDF/B-VII 240Pu ENDF/B-VII 242Pu (1.2MBq) 240Pu (27.3MBq) INTC Meeting

  13. J. Praena (U. Sevilla) and I. Porras (U. Granada) et al, MicroMegas performance test for (n,a) measurements at n_TOF: 33S(n,a) cross section. CERN-INTC-2010-023 ; INTC-I-092 [SCHEDULLED FOR 9-21 NOVEMBER 2011] Sample characterization at CNA: Surface density and homogeneity determined at CNA (Seville) via RBS using protons and alphas. Sample preparation at CERN: The solution has been found by reacting S while being evaporated with a thin Cu layer deposited onto a thin Kapton foil, to form a stable compound Cu2S, which is strongly adherent to the substrate. MGAS set-up (back-to-back samples to study ang. distr.) Empty 10B33S(x2 thin)33S(x2 thick) INTC Meeting

  14. L. Tassan-Got (IN2P3, Orsay) et al., Angular distributions in the neutron-induced fission of actinides, CERN-INTC-2010-038 ; INTC-P-209-ADD-1 [SCHEDULLED 9-21 NOVEMBER] Startsfromsuccesful n_TOF-Ph1 meas. with PPAC (237Np & 209Bi up t 1 GeVamongothers) Limitedang. acceptanceSignficantcorrectionsduetouncertainang.distributions • n_TOF Ph-2 set-up: • Samplestilted 45degrees wrt. neutronbeam • 10 PPAC detectorswith 9 targets in between (235U, 238U, 237Np, 6x232Th) • Segmentedcathodestostudytheang. distributions of FF, in additiontosn,f(En). INTC Meeting

  15. Detector tests to prepare forthcoming years INTC Meeting • Proton telescope to measure (n,p) (n,d) reaction up to 1 GeV (Dubna, Kyushu) • Detector behavior with respect to the gamma-flash: 1GeV -> TOF~90 ns, 500 MeV -> TOF~200 ns • Detector timing performance • Silicon strip for (n,p) (n,a) of astrophysics interest (University of Edinburgh) • Detector behavior in the vicinity of the neutron beam • Combination of high granularity detectors with TOF measurements • Test of BGO and CVD Diamond detector • Investigation of the response to high energy photons If these tests are successful -> INTC proposal

  16. Overview of the n_TOF spallation target area EAR2 (@20 m from pit, above ground) To be built ISR Technical gallery (@10 m from pit) Existing hole n_TOF target pit INTC Meeting

  17. EAR-2 Experiments follow-up INTC Meeting Final Conceptual Design Document will be presented and discussed to Collaboration Board (Dec 2011) February 2012 will be presented to INTC End of February will be presented to Research Board for the final approval

  18. N_TOF measurements plan 2012 INTC Meeting

  19. Summary • 2011 experimental campaign • According to scheduled program • EAR-2 (Experimental Area 2) • Final Conceptual Design Document on progress • Planning for experimental campaign 2012 • 88Sr Clarification letter • 235U Fission Tagging of Proposal • 93Zr Proposal INTC Meeting

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