Treatment of background in γ-γ fast-timing measurements

E. R. Gamba, A. M. Bruce, M. Rudigier

Research output: Contribution to journalArticle

Abstract

Background characterisation in γ-γ fast-timing measurements is of essential importance when lifetimes of the order of tens of picoseconds are being measured. In this work, the nature, composition and behaviour of the timing background is extensively discussed and an adaptation of the background subtraction method used in E γ -E γ -E γ cubes to the case of E γ -E γ -ΔT cubes, is presented. This is applied to 252 Cf fission data, showing very low peak-to-background ratios (less than 0.5), collected using a hybrid array made of 51 HPGe detectors from Gammasphere and 25 LaBr 3 (Ce) scintillators. Two different procedures are suggested: the “Interpolation” approach and the “Three Samples” approach. Both were used to measure the lifetime of the 2 + state in 110 Ru, and gave τ = 483(38) ps and τ = 445(34) ps, respectively, both within one standard deviation of the literature value of τ l = 462(29) ps. The 2 + state in 114 Pd was also measured using the three samples approach and the lifetime obtained was τ = 104(12) ps, consistent with the literature lifetime of τ l = 118(20) ps.

Original languageEnglish
Pages (from-to)93-103
Number of pages11
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Volume928
DOIs
Publication statusPublished - 14 Mar 2019

Fingerprint

Phosphors
Interpolation
time measurement
Detectors
life (durability)
Chemical analysis
subtraction
scintillation counters
interpolation
fission
standard deviation
detectors

Keywords

  • Background correction
  • Centroid shift method
  • Fast-timing
  • GCD method
  • Lifetime measurements
  • γ-γ coincidences

Cite this

@article{28b0caf121c6414aabd1e107446c4994,
title = "Treatment of background in γ-γ fast-timing measurements",
abstract = "Background characterisation in γ-γ fast-timing measurements is of essential importance when lifetimes of the order of tens of picoseconds are being measured. In this work, the nature, composition and behaviour of the timing background is extensively discussed and an adaptation of the background subtraction method used in E γ -E γ -E γ cubes to the case of E γ -E γ -ΔT cubes, is presented. This is applied to 252 Cf fission data, showing very low peak-to-background ratios (less than 0.5), collected using a hybrid array made of 51 HPGe detectors from Gammasphere and 25 LaBr 3 (Ce) scintillators. Two different procedures are suggested: the “Interpolation” approach and the “Three Samples” approach. Both were used to measure the lifetime of the 2 + state in 110 Ru, and gave τ = 483(38) ps and τ = 445(34) ps, respectively, both within one standard deviation of the literature value of τ l = 462(29) ps. The 2 + state in 114 Pd was also measured using the three samples approach and the lifetime obtained was τ = 104(12) ps, consistent with the literature lifetime of τ l = 118(20) ps.",
keywords = "Background correction, Centroid shift method, Fast-timing, GCD method, Lifetime measurements, γ-γ coincidences",
author = "Gamba, {E. R.} and Bruce, {A. M.} and M. Rudigier",
year = "2019",
month = "3",
day = "14",
doi = "10.1016/j.nima.2019.03.028",
language = "English",
volume = "928",
pages = "93--103",
journal = "Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment",
issn = "0168-9002",

}

TY - JOUR

T1 - Treatment of background in γ-γ fast-timing measurements

AU - Gamba, E. R.

AU - Bruce, A. M.

AU - Rudigier, M.

PY - 2019/3/14

Y1 - 2019/3/14

N2 - Background characterisation in γ-γ fast-timing measurements is of essential importance when lifetimes of the order of tens of picoseconds are being measured. In this work, the nature, composition and behaviour of the timing background is extensively discussed and an adaptation of the background subtraction method used in E γ -E γ -E γ cubes to the case of E γ -E γ -ΔT cubes, is presented. This is applied to 252 Cf fission data, showing very low peak-to-background ratios (less than 0.5), collected using a hybrid array made of 51 HPGe detectors from Gammasphere and 25 LaBr 3 (Ce) scintillators. Two different procedures are suggested: the “Interpolation” approach and the “Three Samples” approach. Both were used to measure the lifetime of the 2 + state in 110 Ru, and gave τ = 483(38) ps and τ = 445(34) ps, respectively, both within one standard deviation of the literature value of τ l = 462(29) ps. The 2 + state in 114 Pd was also measured using the three samples approach and the lifetime obtained was τ = 104(12) ps, consistent with the literature lifetime of τ l = 118(20) ps.

AB - Background characterisation in γ-γ fast-timing measurements is of essential importance when lifetimes of the order of tens of picoseconds are being measured. In this work, the nature, composition and behaviour of the timing background is extensively discussed and an adaptation of the background subtraction method used in E γ -E γ -E γ cubes to the case of E γ -E γ -ΔT cubes, is presented. This is applied to 252 Cf fission data, showing very low peak-to-background ratios (less than 0.5), collected using a hybrid array made of 51 HPGe detectors from Gammasphere and 25 LaBr 3 (Ce) scintillators. Two different procedures are suggested: the “Interpolation” approach and the “Three Samples” approach. Both were used to measure the lifetime of the 2 + state in 110 Ru, and gave τ = 483(38) ps and τ = 445(34) ps, respectively, both within one standard deviation of the literature value of τ l = 462(29) ps. The 2 + state in 114 Pd was also measured using the three samples approach and the lifetime obtained was τ = 104(12) ps, consistent with the literature lifetime of τ l = 118(20) ps.

KW - Background correction

KW - Centroid shift method

KW - Fast-timing

KW - GCD method

KW - Lifetime measurements

KW - γ-γ coincidences

U2 - 10.1016/j.nima.2019.03.028

DO - 10.1016/j.nima.2019.03.028

M3 - Article

AN - SCOPUS:85063110525

VL - 928

SP - 93

EP - 103

JO - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

JF - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

SN - 0168-9002

ER -