Status of the 241Am(n,f) measurement @ EAR2 · EAR2 Large Collimator Ø 6 cm Detectors: Micromegas...

Status of the 241Am(n,f) measurement @ EAR2

Z. Eleme1, N. Patronis1, A. Stamatopoulos2, A. Tsinganis3, M. Kokkoris2, V. Michalopoulou2,3, M. Diakaki2,4, R. Vlastou2, L. Tassan-Got3, N.

Colonna5, J. Heyse6, M. Barbagallo3, M. Mastromarco3, D. Macina3, E. Chiaveri3 and the n_TOF Collaboration7

1 UoI, 2 NTUA, 3 CERN, 4 CEA-Cadarache, 5 INFN-Bari, 6 JRC-Geel, 7 www.cern.ch/ntof

n_TOF Collaboration Meeting

November 27th-28th, 2018, Granada

Zinovia Eleme Zinovia.Eleme@cern.ch University of Ioannina

Introduction

1

Motivation

● 241Am is present in high-level nuclear waste● Important for different waste transmutation and recycling scenarios● 241Am(n,f) reaction is included in the NEA High Priority Request List● Present experimental uncertainties do not meet the requirements set by sensitivity

studies of advanced nuclear systems

Experimental Details

● EAR2● Large Collimator Ø 6 cm● Detectors: Micromegas● Gas: Mixture of Ar:CH

4:isoC

4H

10 (88:10:2) @ 1 bar

● Target Samples → 6 x 241Am && Neutron flux monitor samples → 2 x 235U && 2 x 238U

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

Experimental Set-Up

3

Sample Characteristics

241Am 235U 238U

Areal Density (ug/cm2) 4-5 9-10 73-78

Diameter (cm) 6 6 6

No. of samples 6 2 2

Total mass (mg) 0.765 0.559 4.28

Total Activity (MBq) 99.6 0.91e-4 0.53e-4

Average Activity per sample (MBq) 16.6 0.455e-4 0.265e-4

238U235U

241Am

MGAS

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

Experimental Set-Up

4

Improvement over previous fission experiments with μMGAS due to the MGAS due to the new pre-amps from INFN-Bari

Single Channel PCBs No crosstalk

&&

Shielded in Al boxesReduction of noise

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

Neutron Beam

Experimental Set-Up

4

Improvement over previous fission experiments with μMGAS due to the MGAS due to the new pre-amps from INFN-Bari

Single Channel PCBs No crosstalk

&&

Shielded in Al boxesReduction of noise

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

Neutron Beam

γ- flash Τreatment and Signal Reconstructionreatment and Signal Reconstruction

5

● Average g-flash subtraction for each detector →Thanks to A. Stamatopoulos!!

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

Quality Check of Data with 40% of Statistics

6

γ -flash residuals

alpha activity

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

7n_TOF Collaboration Meeting

November 27th-28th, 2018, Granada

Counting Spectra

9n_TOF Collaboration Meeting

November 27th-28th, 2018, Granada

235U Detectors

241Am Detectors238U Detectors

Counting Spectra close to MeV region

10n_TOF Collaboration Meeting

November 27th-28th, 2018, Granada

Consistent up to

a few MeV

Next Steps ..

11n_TOF Collaboration Meeting

November 27th-28th, 2018, Granada

● Check the 100% of statistics● Finalise PSA Parameters● Amplitude Cut Correction with Simulations● Mass Correction due to Impurities of the Targets

Thank you

Backup Slides

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada

n_TOF Collaboration MeetingNovember 27th-28th, 2018, Granada