First results of the new n_tof spallation target commissioning

Transcription

1 new First results of the new 1 and the Collaboration 1 Irfu/SPhN CEA Saclay, France WONDER2009, Cadarache, 29 sept.-2 oct

2 Outline new 1 2 new 3 4 2

3 time line Commissioning May TARC experiment Feasibility New Target construcmon Commissioning CERN/LHC/ Add May Concept by C.Rubbia 1997 CERN/ET/Int. Note Phase I Isotopes Capture: 25 Fission: 11 Papers: 21 Proc.: 51 Doc: 150 Problem InvesMgaMon Phase II Upgrades: Borated H2O Second Line Class A 2010 Proposal submifed Aug ConstrucCon started new

4 new Source: CERN-SC RP-TN experiment was forced to stop in 2004 due to significant increase of activity in the filters 4

5 : Target removal Target visual inspection & photography, RC-camera Dose rate measurements of target Measurement of hole at the beam impact location Analysis of lead Samples taken FLUKA simulations of the target, as well as detailed maps for pit and pool new Target surface inspection using a dedicated custom-built (and developed) laser system Extensive study of the target corrosion mechanism 2 external reviews verified the concept of the new target Water cooled lead target Improved cooling New cooling system 5

6 new new Optimized for a better cooling two different circuit for cooling and moderation reduced size Additional aluminum windows 6

7 Cooling station and ventilation layout Target cooling Ventilation station new Monitoring of O 2 content, ph and conductivity in the water O 2 removal (O 2 level 80 ppb) resin filter to stop spallation products constant flow rate at 5 m 3 /h Primary target area is continuously flushed: Filter 7 Be (not efficient for noble gas) Flow rate: m 3 /h Release dose to the public must not exceed 1µSv/yearly run 7

8 Expected neutron fluence new Effect of additional aluminum windows need to be well characterized during 8

9 new The shape and intensity of the neutron fluence at has been characterized by means of five different measurements (25 May -10 Aug. 2009): Reaction Shape Intensity PTB 235 U(n,f) Yes Yes µmegas 235 U(n,f) & 10 B(n,α) Yes SiMon 6 Li(n,t) Yes (E n kev) TAC 197 Au(n,γ) No Yes (@4.9eV) Activation 197 Au(n,γ) 198 Au(β) No Yes (@4.9eV) Beam profile has been determined thanks to: a MediPix with 6 Li and (CH 2 ) n converters (June 2009) a XY-µMeGas with a 10 B deposit (July 2009) Resolution function is being determined by studying 56 Fe(n,γ) resonances with C6D6 detectors (10 Aug Sept. 2009) 9

10 new All measurements agree within 10% and show a flux decrease of 16% in average 10

11 new The shape of the neutron flux is similar to the past (official) but shows deeper structure above 10 kev 11

12 analysis Comparison XY-µMeGas data vs simulation for the new target from thermal up to 1 MeV Projection of a cut around the mean value of the 2D distribution ± 2.5 mm in simulated data ± 2.8 mm for XY-µMeGas data (5*0.566 mm) new 12 Experimental Simulated

13 Beam profile results (low energy) Thermal to 1eV 1eV to 1keV new 13 A vertical tilt of the 2 nd collimator by 2 mm upstream give good agreement

14 Beam profile results (high energy) 1 kev to 100 kev 100 kev to 1 MeV new 14 Disagreement at high energy could be related to a collimator shift effect?

15 Summary new had to stop in 2004 due to a raise of activity in the cooling station A new target has been installed in 2008 forced water flow and bigger beam spot to avoid overheating oxygen removal to avoid target oxidation. New target started end of may: neutron flux shape presents more structure than in the past neutron flux is presently 16% lower than before, probably due to a bad collimator alignment. neutron beam profile measurement also indicate an alignment problem. resolution function is not yet analyzed but due to the additional aluminum window, the resolution is expected to be slightly worse than before. 15

16 Perspectives new Moderator upgrades Aim: reduce the 1 H(n,γ[2.2 MeV]) 2 H contribution Separate circuit for the moderator Demineralized light water Borated water (1.28% highly enriched 10 B) Same flux above 1 ev 10x reduction of 2.2 MeV γ System already in the engineering phase and will be ready for the 2010 run Class-A lab Convert the experimental area to Class-A = No restriction on radioactive samples Foreseen for 2010/ nd experimental area Flight-path length : 20 m 90 o respect to p-beam direction expected neutron flux enhancement: 20 drastic reduction of the γ flash Technical study for next spring 16

17 The Collaboration U. Abbondanno, G. Aerts, H. Álvarez, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulos, L. Audouin, G. Badurek, P. Baumann, F. Bečvář,, F. Calviño, D. Cano-Ott, R. Capote, C. Carrapiço, A. Carrillo de Albornoz, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Cortes, A. Couture, J. Cox, M. Dahlfors, S. David, I. Dillman, R. Dolfini, C. Domingo-Pardo, W. Dridi, I. Duran, C. Eleftheriadis, Appendix The Collaboration M. Embid-Segura, L. Ferrant, A. Ferrari, R. Ferreira-Marques, H. Frais-Koelbl, K. Fujii, W. Furman, I. Goncalves, E. Gonzalez-Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, C. Guerrero, F. Gunsing, B. Haas, R. Haight, M. Heil, A. Herrera-Martinez, M. Igashira, S. Isaev, E. Jericha, F. Käppeler, Y. Kadi, D. Karadimos, D. Karamanis, M. Kerveno, V. Ketlerov, P. Koehler, V. Konovalov, E. Kossionides, M. Krtička, C. Lampoudis, H. Leeb, A. Lindote, I. Lopes, M. Lozano, S. Lukic, J. Marganiec, L. Marques, S. Marrone, P. Mastinu, C. Massimi, A. Mengoni, P.M. Milazzo, C. Moreau, M. Mosconi, F. Neves, H. Oberhummer, S. O Brien, M. Oshima, J. Pancin, C. Papachristodoulou, C. Papadopoulos, C. Paradela, N. Patronis, A. Pavlik, P. Pavlopoulos, L. Perrot, M.T. Pigni, R. Plag, A. Plompen, A. Plukis, A. Poch, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, M. Rosetti, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, L. Sarchiapone, I. Savvidis, C. Stephan, G. Tagliente, J.L. Tain, L. Tassan-Got, L. Tavora, R. Terlizzi, G. Vannini, P. Vaz, A. Ventura, D. Villamarin, M.C. Vincente, V. Vlachoudis, R. Vlastou, F. Voss, S. Walter, H. Wendler, M. Wiescher, K. Wisshak 17