C 7 LYC for Neutrons Partha Chowdhury University of Massachusetts - - PowerPoint PPT Presentation

▶
c 7 lyc for neutrons
SMART_READER_LITE
LIVE PREVIEW

C 7 LYC for Neutrons Partha Chowdhury University of Massachusetts - - PowerPoint PPT Presentation

Jul 04, 2023 410 likes •637 views

C 7 LYC for Neutrons Partha Chowdhury University of Massachusetts Lowell Work supported by U.S. Department of Energy Learning with Purpose Learning with Purpose Overview Unique dual n- g scintillator Cs 2 LiYCl 6 (CLYC) n- g

slide-1
SLIDE 1

Learning with Purpose Learning with Purpose

C7LYC for Neutrons

Partha Chowdhury University of Massachusetts Lowell

Work supported by U.S. Department of Energy

slide-2
SLIDE 2

Learning with Purpose

  • Unique dual n-g scintillator Cs2LiYCl6 (CLYC)
  • n-g discrimination and spectroscopic properties
  • Fast neutron spectroscopy with 7Li-enriched C7LYC
  • Benchmark science capabilities with C7LYC array
  • Larger crystal sizes and efficiency measurements
  • Auxiliary scintillator for FRIB science?

Overview

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-3
SLIDE 3

Learning with Purpose

novel scintillator for fast neutron spectroscopy

En = 1 MeV Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-4
SLIDE 4

Learning with Purpose

  • Gamma response better than NaI
  • Excellent n-g pulse-shape discrimination
  • ~10% neutron pulse height resolution
  • No ToF needed, increased geometrical efficiency
  • Explore fast neutron spectroscopy potential
  • Eliminated 6Li(n,a) peak via 7Li-enriched C7LYC
  • Built a 16-element array of 1” x 1” C7LYC

(largest crystals available at the time)

  • Elastic/inelastic neutron scattering at Los Alamos
  • Beta-delayed neutron spectroscopy at CARIBU
  • Efficiency and low energy measurements at UML

C7LYC for nuclear science

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-5
SLIDE 5

Learning with Purpose

56Fe(n,n’) at LANSCE

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-6
SLIDE 6

Learning with Purpose Learning with Purpose

En > 0.9 MeV En > 0.0 MeV

100 keV slices on incident neutron energy

56Fe(n,n’) at LANSCE

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-7
SLIDE 7

Learning with Purpose Learning with Purpose

100 keV slices on incident neutron energy

En > 1.9 MeV En > 1.0 MeV

56Fe(n,n’) at LANSCE

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-8
SLIDE 8

Learning with Purpose Learning with Purpose

100 keV slices on incident neutron energy

En > 2.9 MeV En > 2.0 MeV

56Fe(n,n’) at LANSCE

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-9
SLIDE 9

Learning with Purpose Learning with Purpose

100 keV slices on incident neutron energy

En > 3.9 MeV En > 3.0 MeV

56Fe(n,n’) at LANSCE

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-10
SLIDE 10

Learning with Purpose

MCNPX efficiency “estimates”

1”

Large uncertainty in Monte Carlo simulations

35Cl(n,p) cross-section measurements lacking

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-11
SLIDE 11

Learning with Purpose

35Cl(n,p) cross-sections ENDF/B-VII.1 (2011) ENDF/B-VII.0 (2006)

LANL-led experiment (Jan 2018) to measure 35Cl(n,p) cross-sections

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-12
SLIDE 12

Learning with Purpose

relative cross-section estimates

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

Ramirez et al, PRC 95,064605 (2017)

Elastic Inelastic (21+) ~60 mb/sr at minimum ~60 mb/sr average

slide-13
SLIDE 13

Learning with Purpose

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

relative cross-sections (expt 1)

present data (50-keV slice with arbitrary normalization) compared with simulations/database for elastic angular distribution cross-sections)

slide-14
SLIDE 14

Learning with Purpose

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

relative cross-sections (expt 2)

present data (50-keV slice with arbitrary normalization) compared with simulations/database for elastic angular distribution cross-sections)

slide-15
SLIDE 15

Learning with Purpose

b-delayed neutron trials at CARIBU

Gamma background in CARIBU hall PRESENT FUTURE

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

(CLYC results inconclusive, to be repeated in new low-background CARIBU hall)

slide-16
SLIDE 16

Learning with Purpose

the first 3” x 3” C7LYC

Active volume Array X 1.7

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-17
SLIDE 17

Learning with Purpose

the first 3” x 3” C7LYC

3” x 3” C7LYC 1” x 1” C7LYC 3” x 3” C7LYC (blue) 3” x 3” NaI (red) C7LYC Efficiency 98% of NaI C7LYC FWHM 5.8% NaI FWHM 7.8%

137Cs

661 keV

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-18
SLIDE 18

Learning with Purpose

C7LYC tests at UMass Lowell

✦Directly measure C7LYC efficiency at accelerator ✦Mono-energetic neutrons via 7Li(p,n)7Be ✦Neutron production rate via 7Be assay (52-day half-life) ✦One 7Be per neutron, 10% b-decay branch, 479-keV g-ray

1” x 1 3”x 3”

In-situ lithium target evaporator

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-19
SLIDE 19

Learning with Purpose

C7LYC tests at UML

7Li(p,n)7Be (g.s) 7Li(p,n)7Be*

Neutron gated spectrum

3”x 3”

DE = 429 keV

Neutron energy (keV)

En = 2 MeV En = 1.5 MeV En = 1 MeV En = 0.5 MeV En = 0.25 MeV

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-20
SLIDE 20

Learning with Purpose

  • Benchmark C7LYC for fast neutron spectroscopy
  • LANL (n,n’) experiments very promising
  • Measure efficiency and low energy response at UML
  • Explore (d,n) spectroscopy at UML
  • Explore PSD + TOF for low energy neutrons
  • 35Cl(n,p) cross-section measurements (LANL lead)
  • Detailed simulations with measured cross-sections
  • Beta-delayed neutron experiments at new CARIBU hall
  • Optimize n-gamma coincidence capabilities with array
  • Test as auxiliary detector with large gamma arrays

status and outlook

Chowdhury FRIB Decay Station Workshop Jan 25, 2018

slide-21
SLIDE 21

Learning with Purpose

UMass Lowell

Tristan Brown, Emery Doucet, Kim Lister, Gemma Wilson, Chris Morse, Andrew Rogers, Nathan D’Olympia, Alan Mitchell, Emily Jackson

Los Alamos

Matt Devlin, Jaime Gomez, Shea Mosby, Ron Nelson Supported by U.S. Department of Energy NNSA-SSAP Grant DE-NA0002932 and Office of Science Grant DE-FG02-94ER40848

THANK YOU!

Collaborators

Chowdhury FRIB Decay Station Workshop Jan 25, 2018