Subtask 1.2.d 241 Am radiative neutron cross section at the CERN Am - - PowerPoint PPT Presentation

Subtask 1.2.d

241Am 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 19th

This activity was

• riginally

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 C6D6 detectors at n TOF. however to do an additional measurement with C6D6 detectors at n_TOF. M1.9 Measurements 241Am 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 241Am 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 19th

The 241Am Sample

The 241Am sample measured at n_TOF during 2010 has been borrowed from GEEL. The sample (disk-shaped ith 12 2 di t ) i t f 32 2 f 241A ( 4 with 12.2 mm diameter) consists of 32.2 mg of 241Am (~4 GBq) oxide embedded in a 305 mg Al2O3 matrix and encapsulated in a 0.5 mm thick aluminum canning. The known actinide impurities of the sample are 237Np (2 1%) known actinide impurities of the sample are 237Np (2.1%),

233,236,238U (<0.01 %) and 239,240Pu (<0.2%). A γ-ray

spectrometry characterization and X-ray imaging have been performed at CERN

• D. Cano Ott – ANDES meeting in Paris, November 19th

been performed at CERN.

“Neutron capture cross section measurements of 238U, 241Am and 243Am 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 C6D6: 1. Reduction of systematic errors 2 Study of the complete range between thermal and 1 MeV (already achieved for 232Th) 2. 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) C6D6 detectors

• D. Cano Ott – ANDES meeting in Paris, November 19th

The experimental setup with C6D6 detectors

140mm

Kapton window 75 m C6D6 Lead shielding 2 mm SiMon

Megas 54mm 140mm 400 mm 500 mm mm mm mm

2 mm Air gap

54mm 200 mm 54 m

Kapton window

61 m 52 m

Al window 100 m 20 mm C6D6 C6D6

20 mm

Kapton window 75 m Carbon Fiber tube Aluminium Tube

Vacuum valve

Aluminum tube 100 m

• D. Cano Ott – ANDES meeting in Paris, November 19th

The complete set of samples for the C6D6 measurement

Sample Purpose Diameter (mm) Mass (g) Thickness (mm) Composition

241Am

measurement 12.2(1?)

241Am

D b k d C l ith Dummy background Capsule with Al matrix Empty Canning background Aluminum g Empty Frame background Kapton (50 um) Nothing background Nothing at all G ld f 12 20(5) 0 1146 0 050

197A

Gold reference cross section + fluence 12.20(5) 0.1146 0.050

197Au

Gold reference cross section + fluence 12.20(5) 0.5687 0.250

197Au

Gold reference cross section + fluence 45.00(5) 0.050

197Au

Lead backgorund 12.20(5) 2.2888 2.0

natPb

A total of 14·1017 protons were allocated to the measurement from August 19th till September 9th (~3 weeks).

• D. Cano Ott – ANDES meeting in Paris, November 19th

The experimental setup with the TAC

790 20 63 200 90 18 1580 893 3280 27

MGAS SiMon TAC

Al (100 m ) Polypropylene (xx m ) Kapton (75 m )

2 mm Pb shield 2 mm Pb shield 2 mm Pb shield 2 mm Pb shield 136 23 165

• D. Cano Ott – ANDES meeting in Paris, November 19th

56

The complete set of samples for the TAC measurement

Sample Purpose Diameter (mm) Mass (g) Thickness (mm) Composition

241Am

measurement 12.2(1?)

241Am

D b k d C l ith Al Dummy background Capsule with Al matrix Empty Canning background Aluminum Empty Frame background Kapton (50 um) p y g p ( ) Nothing background Nothing at all Gold reference cross section + fl 12.20(5) 0.1146 0.050

197Au

fluence Gold reference cross section + fluence 12.20(5) 0.5687 0.250

197Au

Gold reference cross section + fluence 45.00(5) 0.050

197Au

L d b k d 12 20(5) 2 2888 2 0

tPb

Lead background 12.20(5) 2.2888 2.0

natPb

A total of 21·1017 protons were allocated to the measurement from September 15th till October 9th (~3 weeks).

• D. Cano Ott – ANDES meeting in Paris, November 19th

( )

Experimental Results: 241Am(n,γ) with C6D6 and the TAC

A t l li it f Actual limit of the RRR in the evaluations

• D. Cano Ott – ANDES meeting in Paris, November 19th

Summary and conclusions

A combined

241Am(n,γ) measurement with the TAC and C6D6 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. E ll t i l t i ti h b h d i b th t Excellent signal to noise ratio has been reached in both measurements. The C6D6 measurement will presumably allow to extend the unresolved resonance region above the available data sets in EXFOR. The TAC+ C6D6 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 241Am.

• D. Cano Ott – ANDES meeting in Paris, November 19th