Absolute efficiency of a two-stage microchannel plate for electrons in the 30 - 900 eV energy range

2021 ◽  
Author(s):  
Alice Apponi ◽  
Francesco Pandolfi ◽  
Ilaria Rago ◽  
Gianluca Cavoto ◽  
Carlo Mariani ◽  
...  
Keyword(s):  
Pulse Shape ◽  
Time Window ◽  
Detection Efficiency ◽  
Pulse Height ◽  
Microchannel Plate ◽  
Electron Gun ◽  
Two Stage ◽  
Shape Distribution ◽  
Custom Made ◽  
Absolute Efficiency

Abstract We report on an apparatus able to measure the absolute detection efficiency of a detector for electrons in the 30 - 900 eV range. In particular, we discuss the characterisation of a two-stage chevron microchannel plate (MCP). The measurements have been performed in the LASEC laboratory at Roma Tre University, whit a custom-made electron gun. The very good stability of the beam current in the fA range, together with the picoammeter nominal resolution of 0.01 fA, allowed the measurement of the MCP absolute efficiency ε. We found an ε = (0.489±0.003) with no evident energy dependence. We fully characterised the MCP pulse shape distribution, which is quasi-Gaussian with a well visible peak above the noise level. We measured a 68% variation of the average pulse height between 30 and 500 eV. Furthermore, with a deeper analysis of the pulse shape, and in particular of the correlation between pulse height, area and width, we found a method to discriminate single- and multi- electron events occurring within a 10 ns time window.

Effect of energy filtering on micro-diffraction in the SEM

1994 ◽  
Vol 52 ◽  
pp. 604-605
Author(s):  
James F. Mancuso ◽  
Leo A. Fama ◽  
William B. Maxwell ◽  
Jerry L. Lehman ◽  
Hasso Weiland ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Ccd Camera ◽  
High Gain ◽  
Microchannel Plate ◽  
Electrostatic Energy ◽  
Energy Filtering ◽  
Electron Channelling ◽  
Low Energy Electrons ◽  
Low Sensitivity ◽  
Angular Field Of View

Micro-diffraction based crystallography is essential to the design and development of many classes of ‘crafted materials’. Although the scanning electron microscope can provide crystallographic information with high spatial resolution, its current utility is severely limited by the low sensitivity of existing diffraction techniques (ref: Dingley). Previously, Joy showed that energy filtering increased contrast and pattern visibility in electron channelling. This present paper discribes the effect of energy filtering on EBSP sensitivity and backscattered SEM imaging.The EBSP detector consisted of an electron energy filter, a microchannel plate detector, a phosphor screen, optical coupler, and a slow scan CCD camera. The electrostatic energy filter used in this experiment was constructed as a cone with 5 coaxial electrodes. The angular field-of-view of the filter was approximately 38°. The microchannel plate, which was the initial sensing component, had high gain and had 50% to 80% detection efficiency for the low energy electrons that passed through the retarding field filter.

High detection efficiency neutron sensitive microchannel plate

2013 ◽  
Vol 8 (01) ◽  
pp. P01015-P01015 ◽  
Author(s):  
J Pan ◽  
Y Yang ◽  
Y Tian ◽  
M Zeng ◽  
T Deng ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Microchannel Plate ◽  
High Detection ◽  
High Detection Efficiency

Lexical and sentential priming in competition: Implications for two-stage theories of lexical access

2001 ◽  
Vol 22 (2) ◽  
pp. 191-215 ◽  
Author(s):  
ARTURO E. HERNANDEZ ◽  
CHRISTINE FENNEMA-NOTESTINE ◽  
CARE UDELL ◽  
ELIZABETH BATES
Keyword(s):  
Lexical Access ◽  
Time Window ◽  
Early Stage ◽  
Time Windows ◽  
Unrelated Word ◽  
Two Stage ◽  
Sentential Context ◽  
Lexical Priming ◽  
Priming Word ◽  
Stage Theories

This article presents a new method that can compare lexical priming (word–word) and sentential priming (sentence–word) directly within a single paradigm. We show that it can be used to address modular theories of word comprehension, which propose that the effects of sentence context occur after lexical access has taken place. Although lexical priming and sentential priming each occur very quickly in time, there should be a brief time window in which the former is present but the latter is absent. Lexical and sentential priming of unambiguous words were evaluated together, in competing and converging combinations, using time windows designed to detect an early stage where lexical priming is observed but sentential priming is not. Related and unrelated word pairs were presented visually, in rapid succession, within auditory sentence contexts that were either compatible or incompatible with the target (the second word in each pair). In lexical decision, the additive effects of lexical priming and sentential priming were present under all temporal conditions, although the latter was always substantially larger. In cross-modal naming, sentential priming was present in all temporal conditions; lexical priming was more fragile, interacting with timing and sentential congruence. No evidence was found for a stage in which lexical priming is present but sentential priming is absent – a finding that is difficult to reconcile with two-stage models of lexical versus sentential priming. We conclude that sentential context operates very early in the process of word recognition, and that it can interact with lexical priming at the earliest time window.

scholarly journals Model and Algorithm of Two-Stage Distribution Location Routing with Hard Time Window for City Cold-Chain Logistics

2020 ◽  
Vol 10 (7) ◽  
pp. 2564
Author(s):  
Liying Yan ◽  
Manel Grifoll ◽  
Pengjun Zheng
Keyword(s):  
Time Window ◽  
Hybrid Genetic Algorithm ◽  
Distribution Networks ◽  
Cold Chain ◽  
Two Stage ◽  
Logistics Network ◽  
Stage Distribution ◽  
Hard Time ◽  
Location Routing ◽  
Logistics Enterprises

Taking cold-chain logistics as the research background and combining with the overall optimisation of logistics distribution networks, we develop two-stage distribution location-routing model with the minimum total cost as the objective function and varying vehicle capacity in different delivery stages. A hybrid genetic algorithm is designed based on coupling and collaboration of the two-stage routing and transfer stations. The validity and feasibility of the model and algorithm are verified by conducting a randomly generated test. The optimal solutions for different objective functions of two-stage distribution location-routing are compared and analysed. Results turn out that for different distribution objectives, different distribution schemes should be employed. Finally, we compare the two-stage distribution location-routing to single-stage vehicle routing problems. It is found that a two-stage distribution location-routing system is feasible and effective for the cold-chain logistics network, and can decrease distribution cost for cold-chain logistics enterprises.

Quantum detection efficiency of spherical microchannel plate in extreme ultraviolet

2011 ◽  
Vol 19 (11) ◽  
pp. 2596-2602
Author(s):  
尼启良 NI Qi-liang ◽  
韩素立 HAN Su-li ◽  
陈斌 CHEN Bin ◽  
王海峰 WANG Hai-feng
Keyword(s):  
Extreme Ultraviolet ◽  
Detection Efficiency ◽  
Microchannel Plate ◽  
Quantum Detection

scholarly journals TV scanning applied for two dimensional photon counting imaging

1986 ◽  
Vol 118 ◽  
pp. 71-74
Author(s):  
Sueo Miyaki ◽  
Syuzo Isobe ◽  
Nobuo Shinchara
Keyword(s):  
Photon Counting ◽  
Microchannel Plate ◽  
Two Dimensional ◽  
Test Results ◽  
Two Stage ◽  
Astronomical Observations

A system with an electronomulitplier of two-stage microchannel plate and a vidicon TV camera is developed for two dimensional photon-counting imaging and is applied for astronomical observations at the Nasmyth focus of the 75cm alt-az telescope of the Sundai Observatory at Kita-Karuizawa (SOK). Some test results are shown here.

Interaction of 14.0 MeV-Neutrons with 12C in Stilbene

1971 ◽  
Vol 26 (2) ◽  
pp. 317-319 ◽  
Author(s):  
H.-U. Fabian
Keyword(s):  
Cross Sections ◽  
Pulse Shape ◽  
Charged Particles ◽  
Pulse Height ◽  
Pulse Height Spectrum ◽  
Pulse Spectrum ◽  
Heavy Charged Particles ◽  
The Cross

AbstractThe pulse height spectrum of all heavy charged particles induced by 14.0 MeV neutrons in a 1" × 1" stilbene scintilla­ tor was measured using a pulse shape discriminator and the associated particle technique. The proton pulse spectrum was subtracted and the remaining alpha-pulse distribution is shown in a diagram. The sum of the cross sections for the reactions 12C (n, n') 3 α and 12C (n, α)9 Be was determined to be σc= (260±20) mb.

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