Subtask 1.2.d 241 Am radiative neutron cross section at the CERN Am radiative neutron cross section at the CERN n_TOF facility Subtask leader: CIEMAT Partners: CEA, CIEMAT, INFN, ITN, JRC Partners: CEA, CIEMAT, INFN, ITN, JRC D. Cano Ott – ANDES meeting in Paris, November 19 th
This activity was originally foreseen with the n_TOF Total Absorption Calorimeter (proposal CERN-INTC-2009-025 INTC-P-269). We have managed however to do an additional measurement with C 6 D 6 detectors at n TOF. however to do an additional measurement with C 6 D 6 detectors at n_TOF. M1.9 Measurements 241 Am radiative neutron cross section at the n_TOF facility Week 24 ( ahead of schedule ) facility. Week 24 ( ahead of schedule ) D.1.3 Final report on the 241 Am total and radiative neutron capture at IRMM and n TOF. Week 28 (according to schedule) a d _ O ee 8 (acco d g to sc edu e) D. Cano Ott – ANDES meeting in Paris, November 19 th
The 241 Am Sample The 241 Am sample measured at n_TOF during 2010 has been borrowed from GEEL. The sample (disk-shaped with 12.2 mm diameter) consists of 32.2 mg of 241 Am (~4 ith 12 2 di t ) i t f 32 2 f 241 A ( 4 GBq) oxide embedded in a 305 mg Al 2 O 3 matrix and encapsulated in a 0.5 mm thick aluminum canning. The known actinide impurities of the sample are 237 Np (2 1%) known actinide impurities of the sample are 237 Np (2.1%), 233,236,238 U (<0.01 %) and 239,240 Pu (<0.2%). A γ -ray spectrometry characterization and X-ray imaging have been performed at CERN been performed at CERN. D. Cano Ott – ANDES meeting in Paris, November 19 th
“Neutron capture cross section measurements of 238 U, 241 Am and 243 Am at n_TOF” CERN ‐ INTC ‐ 2009 ‐ 025/INTC ‐ P ‐ 269, Spokespersons: D. Cano ‐ Ott (CIEMAT) and F. Gunsing (CEA) Combined measurement with two experimental techniques - TAC and C 6 D 6 : 1. Reduction of systematic errors 2 2. Study of the complete range between thermal and 1 MeV (already achieved for 232 Th) Study of the complete range between thermal and 1 MeV (already achieved for Th) 3. Extension of the RRR thanks to high statistics of the TAC Total Absorption Calorimeter (TAC) C 6 D 6 detectors D. Cano Ott – ANDES meeting in Paris, November 19 th
The experimental setup with C 6 D 6 detectors Kapton window 75 m C6D6 Lead shielding 2 mm 2 mm 140mm 140mm 400 mm 500 mm Megas SiMon mm mm mm 54mm 54mm 61 m 54 m 52 m 200 mm Air gap Kapton window Kapton window 20 mm 20 mm 75 m Vacuum valve C6D6 C6D6 Aluminum tube Carbon Fiber tube Aluminium Tube Al window 100 m 100 m D. Cano Ott – ANDES meeting in Paris, November 19 th
The complete set of samples for the C 6 D 6 measurement Sample Purpose Diameter Mass (g) Thickness Composition (mm) (mm) 241 Am 241 Am measurement 12.2(1?) D Dummy b background k d Capsule with C l ith Al matrix Empty background Aluminum Canning g Empty Frame background Kapton (50 um) Nothing background Nothing at all Gold G ld reference cross f 12 20(5) 12.20(5) 0 1146 0.1146 0 050 0.050 197 A 197 Au section + fluence Gold reference cross 12.20(5) 0.5687 0.250 197 Au section + fluence Gold reference cross 45.00(5) 0.050 197 Au section + fluence Lead backgorund 12.20(5) 2.2888 2.0 nat Pb A total of 14·10 17 protons were allocated to the measurement from August 19 th till September 9 th (~3 weeks). D. Cano Ott – ANDES meeting in Paris, November 19 th
The experimental setup with the TAC 20 27 18 63 790 200 90 1580 893 3280 MGAS SiMon TAC Al (100 m ) Polypropylene Kapton (75 m ) (xx m ) 2 mm Pb shield 2 mm Pb shield 2 mm Pb shield 2 mm Pb shield 136 165 23 56 D. Cano Ott – ANDES meeting in Paris, November 19 th
The complete set of samples for the TAC measurement Sample Purpose Diameter (mm) Mass (g) Thickness Composition (mm) 241 Am 241 Am measurement 12.2(1?) D Dummy b background k d C Capsule with Al l ith Al matrix Empty Canning background Aluminum Empty Frame p y background g Kapton (50 um) p ( ) Nothing background Nothing at all Gold reference cross 12.20(5) 0.1146 0.050 197 Au section + fl fluence Gold reference cross 12.20(5) 0.5687 0.250 197 Au section + fluence Gold reference cross 45.00(5) 0.050 197 Au section + fluence L Lead d background b k d 12 20(5) 12.20(5) 2 2888 2.2888 2 0 2.0 nat Pb t Pb A total of 21·10 17 protons were allocated to the measurement from September 15 th till October 9 th (~3 weeks). ( ) D. Cano Ott – ANDES meeting in Paris, November 19 th
Experimental Results: 241 Am(n, γ ) with C 6 D 6 and the TAC A t Actual limit of l li it f the RRR in the evaluations D. Cano Ott – ANDES meeting in Paris, November 19 th
Summary and conclusions A combined 241 Am(n, γ ) measurement with the TAC and C 6 D 6 detectors has been performed succesfully at CERN. The Milestone 1 9 has been done ahead of schedule The Milestone 1.9 has been done ahead of schedule. The preliminary analysis shows that the data have very good statistics and very high quality. Excellent signal to noise ratio has been reached in both measurements. E ll t i l t i ti h b h d i b th t The C 6 D 6 measurement will presumably allow to extend the unresolved resonance region above the available data sets in EXFOR. The TAC+ C 6 D 6 data will allow a very careful resonance analysis in the resolved resonance region and “presumably” extend it to higher energies than currently available (if necessary). The analysis has been started in both cases The analysis has been started in both cases. The combination of the n_TOF results together with the IRMM ones (transmission + capture) will constitute world’s best data set for 241 Am. D. Cano Ott – ANDES meeting in Paris, November 19 th
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