The influence of rejection of a fraction of the single photoelectron peak in liquid scintillation counting

Li, Mo; Cassette, P.; Baldock, Clive

doi:10.1016/j.nima.2005.11.210

Cited by 9 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The comparison indicator I 2ij also addresses any pure βparticle emitting radionuclides but implements the full TDCR model described by Mo et al [26]. Unlike indicator I 1ij where parameters are fixed, some parameters L ij (called the free parameters) are implemented to deal optimally with the asymmetry changing issue (due to uneven wear of the photocathodes or a change of a photomultiplier tube.…”

Section: Definition Of the Key Comparison Indicator I 2i Jmentioning

confidence: 99%

“…Nelder Mead method was implemented by many NMIs to solve equation ( 7) [29,30]. The model for efficiency calculation in the framework of the TDCR measurement comes from [26] where:…”

Section: Definition Of the Key Comparison Indicator I 2i Jmentioning

confidence: 99%

“…• The convergence parameter ζ of the Nelder Mead minimization (discussed in section 5); • The non-detection fractions f A , f B , f C of single photon events, evaluated through the analysis of pulse height spectra for each photomultiplier tubes. If these values are low enough ( f < 1% resulting in a deep valley in the spectrum between the electronic noise and the single photoelectron peak), this fraction f has no significant impact on ε D (as discussed in [26]). • The Birks constant kB and its uncertainty u(kB) which were set by a procedure described in [6] to build a model maximizing the stability of the system.…”

Section: Definition Of the Key Comparison Indicator I 2i Jmentioning

confidence: 99%

See 2 more Smart Citations

The international reference system for pure beta-particle emitting radionuclides: an evaluation of the measurement uncertainties

et al. 2021

View full text Add to dashboard Cite

The international bureau of weights and measures (BIPM) is the centre for governments to act in common on matters relating to metrology, co-ordinating the world-wide measurement system and providing capabilities for international measurement comparisons on a shared-cost basis. The ionizing radiation department maintains and develops high-precision instrumentation to enable national metrology institutes to demonstrate the equivalence of primary standards of radioactivity. The scope of this service is expanding: the ‘extended international reference system (ESIR)’ project aims to provide a stable instrument capable of comparing standards of pure beta-emitting radionuclides, complementing existing instruments for gamma-emitters. In 2019, the members of the ESIR project devised a liquid scintillation system that is capable of producing very stable reference values over a long timescale, using a method inspired by the ‘triple-to-double coincidence ratio’ (TDCR) technique. This article sets out the approach that will be used for evaluating uncertainties in future comparison exercises using the ESIR. The method adopted was based on the guide to the expression of uncertainty in measurement published by the joint committee for guides in metrology. Particular care has been taken in choosing the evaluation method: the response of the TDCR instrument cannot be linearized, so a Monte-Carlo method was implemented and a technique to manage correlated input data was developed. A novel sampling technique was used for the input multi-variate distribution of coincident count rates; this approach may also be relevant to primary standards realized using the TDCR technique. Calculation have shown that standard uncertainties of the order of 0.1 % will be achievable for a typical radionuclide.

show abstract

Section: Definition Of the Key Comparison Indicator I 2i Jmentioning

confidence: 99%

“…Nelder Mead method was implemented by many NMIs to solve equation ( 7) [29,30]. The model for efficiency calculation in the framework of the TDCR measurement comes from [26] where:…”

Section: Definition Of the Key Comparison Indicator I 2i Jmentioning

confidence: 99%