Showing papers in "Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment in 2009"

Particle flow calorimetry and the PandoraPFA algorithm

Abstract: The Particle Flow (PFlow) approach to calorimetry promises to deliver unprecedented jet energy resolution for experiments at future high energy colliders such as the proposed International Linear Collider (ILC). This paper describes the PandoraPFA particle flow algorithm which is then used to perform the first systematic study of the potential of high granularity PFlow calorimetry. For simulated events in the ILD detector concept, a jet energy resolution of σ E / E ≲ 3.8 % is achieved for 40–400 GeV jets. This result, which demonstrates that high granularity PFlow calorimetry can meet the challenging ILC jet energy resolution goals, does not depend strongly on the details of the Monte Carlo modelling of hadronic showers. The PandoraPFA algorithm is also used to investigate the general features of a collider detector optimised for high granularity PFlow calorimetry. Finally, a first study of the potential of high granularity PFlow calorimetry at a multi-TeV lepton collider, such as CLIC, is presented.

The Borexino detector at the Laboratori Nazionali del Gran Sasso

Abstract: Borexino, a large volume detector for low energy neutrino spectroscopy, is currently running underground at the Laboratori Nazionali del Gran Sasso, Italy. The main goal of the experiment is the real-time measurement of sub-MeV solar neutrinos, and particularly of the monoenergetic (862 keV) 7 Be electron capture neutrinos, via neutrino–electron scattering in an ultra-pure liquid scintillator. This paper is mostly devoted to the description of the detector structure, the photomultipliers, the electronics, and the trigger and calibration systems. The real performance of the detector, which always meets, and sometimes exceeds, design expectations, is also shown. Some important aspects of the Borexino project, i.e. the fluid handling plants, the purification techniques and the filling procedures, are not covered in this paper and are, or will be, published elsewhere (see Introduction and Bibliography).

Rietveld analysis software for J-PARC

Abstract: A new analysis software suite, Z-Code, is under development for powder diffraction data analyses in the Materials and Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). This software suite comprises data processing, data analyses, graphical user interface and visualization software. As a part of Z-Code, a Rietveld analysis program for neutron (TOF and angle dispersive) and X-ray data, Z-Rietveld, has been developed. Here we report the basic traits and some significant features of Z-Rietveld.

The IceCube data acquisition system: Signal capture, digitization, and timestamping

Abstract: IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs). detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved. (c) 2009 Elsevier B.V. All rights reserved.

Structural Materials Science end-station at the Kurchatov Synchrotron Radiation Source: Recent instrumentation upgrades and experimental results

Abstract: The Structural Materials Science end-station installed at the Kurchatov Synchrotron Radiation Source has been operating in the user mode since 2004. The facility is primarily devoted to combined structural studies of functional materials with the use of three basic synchrotron hard X-ray techniques, viz., powder X-ray diffraction (XRD), X-ray absorption spectroscopy (XANES and EXAFS) and small-angle X-ray scattering (SAXS). In the present paper, a brief description of the facility and recent developments of its instrumentation are given. Improved research capabilities of the facility are demonstrated with examples of recent experimental results.

A concise review on THGEM detectors

Abstract: We briefly review the concept and properties of the THick Gaseous Electron Multiplier (THGEM); it is a robust, high-gain gaseous electron multiplier, manufactured economically by standard printed-circuit drilling and etching technology. Its operation and structure resemble that of gaseous electron multiplier's (GEM's) but with 5–20-fold expanded dimensions. The millimeter-scale hole-size results in good electron transport and in large avalanche-multiplication factors, e.g. reaching 10 7 in double-THGEM cascaded single-photoelectron detectors. The multiplier's material, parameters and shape can be application-tailored; it can operate practically in any counting gas, including noble gases, over a pressure range spanning from 1 mbar to several bars; its operation at cryogenic (LAr) conditions was recently demonstrated. The high gain, sub-millimeter spatial resolution, high counting-rate capability, good timing properties and the possibility of industrial production capability of large-area robust detectors, pave ways towards a broad spectrum of potential applications; some are discussed here in brief.

PILATUS: A single photon counting pixel detector for X-ray applications

Abstract: The hybrid pixel technology combines silicon sensors with CMOS-processing chips by a 2D micro bump-bonding interconnection technology developed at Paul Scherrer Institute [C. Broennimann, E.F. Eikenberry, B. Henrich, R. Horisberger, G. Huelsen, E. Pohl, B. Schmitt, C. Schulze-Briese, M. Suzuki, T. Tomizaki, H. Toyokawa, A. Wagner. J. Synchrotron Rad. 13 (2005) 120 [1] ; T. Rohe, C. Broennimann, F. Glaus, J. Gobrecht, S. Heising, M. Horisberger, R. Horisberger, H.C. Kaestl, J. Lehmann, S. Streuli, Nucl. Instr. and Meth. Phys. Res. A 565 (2006) 303 [2] ]. PILATUS hybrid pixel detectors like other instruments [X. Llopart, M. Campell, R. Dinapoli, D. San Segundo, E. Pernigotti. IEEE Trans. Nucl. Sci. 49 (2002) 2279 [3] ; N. Boudet, J.-F. Berar, L. Blanquart, P. Breugon, B. Caillot, J.-C. Clemens, I. Koudobine, P. Delpierre, C. Mouget, R. Potheau, I. Valin, Nucl. Instr. and Meth. Phys. Res. A 510 (2003) 41 [4] ] are operating in the so-called “single photon counting mode”: Every X-ray quantum is directly converted into an electrical signal and counted by the detector system. Several prototype detectors in various geometries were produced, tested and established at different synchrotron beamlines worldwide. We explain the technology and present some recent highlights from various fields of applications.

Photoelectron spectroscopy under ambient pressure and temperature conditions

Abstract: We describe the development and applications of novel instrumentation for photoemission spectroscopy of solid or liquid surfaces in the presence of gases under ambient conditions of pressure and temperature. The new instrument overcomes the strong scattering of electrons in gases by the use of an aperture close to the surface followed by a differentially-pumped electrostatic lens system. In addition to the scattering problem, experiments in the presence of condensed water or other liquids require the development of special sample holders to provide localized cooling. We discuss the first two generations of Ambient Pressure PhotoEmission Spectroscopy (APPES) instruments developed at synchrotron light sources (ALS in Berkeley and BESSY in Berlin), with special focus on the Berkeley instruments. Applications to environmental science and catalytic chemical research are illustrated in two examples.

Vacuum ultraviolet beamline at the Swiss Light Source for chemical dynamics studies

Abstract: A bend-magnet vacuum ultraviolet (VUV) beamline, intended for chemical dynamics studies, was constructed and brought into operation at the Swiss Light Source (SLS) of the Paul Scherrer Institut. The beamline delivers synchrotron radiation in the 5–30 eV photon energy range with a photon flux of 10 11 photons/s at 10 eV and 10 12 photons/s at 20 eV with a resolving power of 2500. The resolving power increases to 10 4 at the cost of photon flux. An in-house designed rare gas filter is used to suppress higher harmonic radiation by a factor of >10 4 , yielding purely monochromatic light in the energy range of 5–21.6 eV. The filter is compact, easy to align, requires a total pumping power of less than 645 l/s and consumes only 3 normal l/h of filter gas. It is located at the end of the beamline, right in front of the experimental endstation. It is usually operated at a higher pressure than the endstation, which offers the additional benefit of protecting the beamline vacuum from sample contamination.

The high kinetic energy photoelectron spectroscopy facility at BESSY progress and first results

Abstract: Photoelectron spectroscopy at high kinetic energy is a research field that receives an increasing interest due to the possibility of studying bulk properties of materials and deeply buried interfaces. Recently the high kinetic energy electron (HIKE) spectroscopy facility at BESSY in Berlin has become operative at the bending magnet beamline KMC-1. The first results show very good performance. Electron spectra have been recorded using X-ray energies from 2 keV up to 12 keV. Using back-scattering conditions in the crystal monochromator, very high-resolution has been achieved for photon energies around 2, 6 and 8 keV. In the latter case, spectra with a resolving power from the monochromator of >= 80 000 have been achieved and it has been possible to perform electron spectroscopy with resolving power of >= 60 000, yielding a total instrument resolution of about 150 meV as determined directly from spectra. This paper describes the facility and reports some of the first results. (C) 2009 Elsevier B.V. All rights reserved.

Surface sensitivity of X-ray photoelectron spectroscopy☆

Abstract: We give an overview of four terms (the inelastic mean free path (IMFP), the effective attenuation length (EAL), the mean escape depth (MED), and the information depth (ID)) that are frequently used (and sometimes misused) in statements on the surface sensitivity of X-ray photoelectron spectroscopy. We give definitions of each term and show how each term is intended for different applications. Misunderstanding of these terms often arises when the complicating effects of elastic scattering of the signal electrons are overlooked. As a result, numerical values of the IMFP, EAL, and MED for a given material and electron energy will generally be different. Values of the EAL, MED, and ID will also depend on the elastic-scattering properties of the sample and the experimental configuration. We give information on sources of data for IMFPs, EALs, and MEDs, and present simple analytical expressions from which EALs, MEDs, and IDs can be determined.

Hard X-ray photoemission spectroscopy

Abstract: Except in the very early stage of the development of X-ray photoemission spectroscopy (XPS) by Kai Siegbahn and his coworkers, the excitation sources for XPS studies have predominantly been the Al Kα and Mg Kα emission lines. The advent of synchrotron radiation sources opened up the possibility of tuning the excitation photon energy with much higher throughputs for photoemission spectroscopy, however the excitation energy range was limited to the vacuum ultra violet and soft X-ray regions. Over the past 5–6 years, bulk-sensitive hard X-ray photoemission spectroscopy using high-brilliance high-flux X-rays from third generation synchrotron radiation facilities has been developed. This article reviews the history of HXPES covering the period from Kai Siegbahn and his coworkers’ pioneering works to the present, and describes the fundamental aspects, instrumentation, applications to solid state physics, applied physics, materials science, and industrial applications of HXPES. Finally, several challenging new developments which have been conducted at SPring-8 by collaborations among several groups are introduced.

China Spallation Neutron Source: Design, R&D, and outlook

Abstract: The China Spallation Neutron Source (CSNS) is an accelerator based multidiscipline user facility planned to be constructed in Dongguan, Guangdong, China. The CSNS complex consists of an negative hydrogen linear accelerator, a rapid cycling proton synchrotron accelerating the beam to 1.6 GeV energy, a solid tungsten target station, and instruments for spallation neutron applications. The facility operates at 25 Hz repetition rate with an initial design beam power of 120 kW and is upgradeable to 500 kW. The primary challenge is to build a robust and reliable user's facility with upgrade potential at a fraction of "world standard" cost. We report the status, design, R&D, and upgrade outlook including applications using spallation neutron, muon, fast neutron, and proton, as well as related programs including medical therapy and accelerator-driven sub-critical reactor (ADS) programs for nuclear waste transmutation. (C) 2008 Elsevier B.V. All rights reserved.

The MiniBooNE Detector

Abstract: The MiniBooNE neutrino detector was designed and built to look for ν μ → ν e oscillations in the ( sin 2 2 θ , Δ m 2 ) parameter space region where the LSND experiment reported a signal. The MiniBooNE experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBooNE detector.

Liquid microjet for photoelectron spectroscopy

Abstract: Photoelectron spectroscopy from highly volatile liquids, especially from water and aqueous solutions, has recently become possible due to the development of the vacuum liquid microjet in combination of high-brilliance synchrotron radiation The present status of this rapidly growing field is reported here, with an emphasize on the method's sensitivity for detecting local electronic structure, and for monitoring ultrafast dynamical processes in aqueous solution exploiting core-level resonant excitation

Resonant laser power build-up in ALPS—A ''light shining through a wall'' experiment

Abstract: The ALPS Collaboration runs a “light shining through a wall” (LSW) experiment to search for photon oscillations into “weakly interacting sub-eV particles” (WISPs) inside of a superconducting HERA dipole magnet at the site of DESY. In this paper we report on the first successful integration of a large-scale optical resonant cavity to boost the available power for WISP production in this type of experiments. The key elements are a frequency tunable narrow line-width continuous wave laser acting as the primary light source and an electronic feed-back control loop to stabilize the power build-up. We describe and characterize our apparatus and demonstrate the data analysis procedures on the basis of a brief exemplary run.

Eu2+-doped Ba2CsI5, a new high-performance scintillator

Abstract: The crystal growth and scintillation properties of Ba 2 CsI 5 :Eu 2+ are reported. Crystals were produced by the vertical Bridgman technique in a sealed quartz ampoule. Ba 2 CsI 5 :Eu 2+ presents excellent scintillation properties. An estimated light yield of 97,000±5,000 photons per MeV (ph/MeV) of absorbed gamma-ray energy was measured. An energy resolution (FWHM over peak position) of 3.8±0.3% was observed for the 662 keV full absorption peak. Pulsed X-ray luminescence measurements show a relatively complex time response with four exponential decay components of 48,383, 1500 and 9900 ns with a contribution to the total light output of 1%, 26%, 68% and 25%, respectively. Under X-ray and UV excitation, the emission corresponds to a broadband centered at 2.85 eV. First principles calculations show strong localization of the excited state on the Eu site. Ba 2 CsI 5 :Eu 2+ has a density of about 5 g/cm 3 . These first reported scintillation properties make Ba 2 CsI 5 :Eu 2+ a very high-performance scintillator.

Testbeam studies of production modules of the ATLAS tile calorimeter

Abstract: We report test beam studies of 11% of the production ATLAS Tile Calorimeter modules. The modules were equipped with production front-end electronics and all the calibration systems planned for the final detector. The studies used muon, electron and hadron beams ranging in energy from 3 to 350 GeV. Two independent studies showed that the light yield of the calorimeter was View the MathML source, exceeding the design goal by 40%. Electron beams provided a calibration of the modules at the electromagnetic energy scale. Over 200 calorimeter cells the variation of the response was 2.4%. The linearity with energy was also measured. Muon beams provided an intercalibration of the response of all calorimeter cells. The response to muons entering in the ATLAS projective geometry showed an RMS variation of 2.5% for 91 measurements over a range of rapidities and modules. The mean response to hadrons of fixed energy had an RMS variation of 1.4% for the modules and projective angles studied. The response to hadrons normalized to incident beam energy showed an 8% increase between 10 and 350 GeV, fully consistent with expectations for a noncompensating calorimeter. The measured energy resolution for hadrons of View the MathML source was also consistent with expectations. Other auxiliary studies were made of saturation recovery of the readout system, the time resolution of the calorimeter and the performance of the trigger signals from the calorimeter.

IBARAKI materials design diffractometer (iMATERIA)—Versatile neutron diffractometer at J-PARC

Abstract: Ibaraki prefecture, the local government of the area for J-PARC site, was decided to build a versatile neutron diffractometer (IBARAKI Materials Design Diffractometer, iMATERIA) to promote an industrial application for neutron beam in J-PARC. iMATERIA is planned to be a high throughput diffractometer so that materials engineers and scientists can use it like the chemical analytical instruments in their materials development process. It covers in d range 0.18

Design and construction of the Mini-Calorimeter of the AGILE satellite

Abstract: AGILE is a small space mission of the Italian Space Agency (ASI) devoted to gamma-ray and hard-X astrophysics, successfully launched on April 23, 2007. The AGILE Payload is composed of three instruments: a gamma-ray imager based on a tungsten-silicon tracker (ST), for observations in the gamma ray energy range 30 MeV–50 GeV, a Silicon based X-ray detector, SuperAGILE (SA), for imaging in the range 18–60 keV and a CsI(Tl) Mini-Calorimeter (MCAL) that detects gamma rays or charged particles energy loss in the range 300 keV–100 MeV. MCAL is composed of 30 CsI(Tl) scintillator bars with photodiode readout at both ends, arranged in two orthogonal layers. MCAL can work both as a slave of the ST and as an independent gamma-ray detector for transients and gamma-ray bursts detection. In this paper a detailed description of MCAL is presented together with its performance.

HEXITEC ASIC—a pixellated readout chip for CZT detectors

Abstract: HEXITEC is a collaborative project with the aim of developing a new range of detectors for high-energy X-ray imaging. High-energy X-ray imaging has major advantages over current lower energy imaging for the life and physical sciences, including improved phase-contrast images on larger, higher density samples and with lower accumulated doses. However, at these energies conventional silicon-based devices cannot be used, hence, the requirement for a new range of high Z-detector materials. Underpinning the HEXITEC programme are the development of a pixellated Cadmium Zinc Telluride (CZT) detectors and a pixellated readout ASIC which will be bump-bonded to the detector. The HEXITEC ASIC is required to have low noise (20 electrons rms) and tolerate detector leakage currents. A prototype 20×20 pixel ASIC has been developed and manufactured on a standard 0.35 μm CMOS process.

Photon and neutron interrogation techniques for chemical explosives detection in air cargo: A critical review

Abstract: Scanning cargo transported via aircraft (“air cargo”) for explosive threats is a problem that presently lacks a comprehensive technical solution. While chemical explosives detection in the baggage-scanning domain has a rich history that sheds light on potential solutions, air cargo differs in several important ways, and thus one cannot look to the present array of technologies. Some contemporary solutions, such as trace analysis, are not readily applied to cargo because of sampling challenges while the larger geometry of air cargo makes others less effective. This review article examines an array of interrogation techniques using photons and neutrons as incident particles. We first present a summary of the signatures and observables chemical explosives provide and review how they have been exploited in baggage scanning. Following this review is a description of the challenges posed by the air-cargo application space. After considering sources of photons and neutrons, we describe methods focused on transmission imaging, sub-surface examination, and elemental characterization. It is our goal to expand the understanding of each method's technical promise while largely deferring questions that revolve around footprint, safety, and conduct of operations. Our overarching intent is that a comprehensive understanding of potential techniques will foster the development of a comprehensive solution.

Simultaneous soft X-ray transmission and emission microscopy

Abstract: Novel low-energy X-ray fluorescence (LEXRF) system based on a multiple Si drift detector (SDD) configuration has been developed and implemented in the European TwinMic X-ray microspectroscopy station operating at the Italian synchrotron radiation facility ELETTRA. The setup, hosting up to eight large-area SDDs with specially adapted readout electronics, has demonstrated excellent performance for elemental analysis in the 280–2200 eV photon energy range, which covers the K and L edges of light elements, starting from C. The great advantage is the simultaneous acquisition of LEXRF, absorption and phase contrast maps, providing complementary information on elemental composition and morphology of specimen at submicrometer length scales.

High-pressure xenon gas electroluminescent TPC for 0-ν ββ-decay search

Abstract: A high-pressure xenon gas TPC can provide both event topology information and optimized energy resolution for the detection of ββ decay in 136Xe. The result of optimization indicates that, at the 136Xe Q-value of 2480 keV, an energy resolution of δE/E<5×10−3 FWHM may be realizable, even at the 1000 kg scale. Signal detection by electroluminescence appears essential to realize this performance. A specific method for generation and detection of the electroluminescent signal and particle tracking in high-pressure xenon gas is advanced. Strengths and weaknesses of high-pressure xenon gas TPC detectors are evaluated and compared to detectors based on liquid xenon.

Response of the CALICE Si-W Electromagnetic Calorimeter Physics Prototype to Electrons

Abstract: A prototype silicon–tungsten electromagnetic calorimeter (ECAL) for an international linear collider (ILC) detector was installed and tested during summer and autumn 2006 at CERN. The detector had 6480 silicon pads of dimension 1 × 1 cm 2 . Data were collected with electron beams in the energy range 6–45 GeV. The analysis described in this paper focuses on electromagnetic shower reconstruction and characterises the ECAL response to electrons in terms of energy resolution and linearity. The detector is linear to within approximately the 1% level and has a relative energy resolution of ( 16.53 ± 0.14 ( stat ) ± 0.4 ( syst ) ) / E ( GeV ) ⊕ ( 1.07 ± 0.07 ( stat ) ± 0.1 ( syst ) ) ( % ) . The spatial uniformity and the time stability of the ECAL are also addressed.

Total characterization of neutron detectors with a 252Cf source and a new light output determination

Abstract: A full characterization of neutron detector properties was achieved by means of a 252 Cf source with timing of fission events. The input neutron energies were separated with the time-of-flight technique. The pulse height, the pulse shape and the time-of-flight spectra were measured in coincidence mode as three-dimensional distributions. On the basis of these data, the following characteristics were determined for each detector: response function, light output versus proton (neutron) energy, energy resolution function for neutron energies from 1 to 7 MeV, time shift correction, and finally the detector efficiency from threshold up to 12 MeV. The experimental results were compared with Monte-Carlo simulations. Two new analytical dependencies are suggested for the light output calculation for electrons and protons.

The n_TOF Total Absorption Calorimeter for neutron capture measurements at CERN

Abstract: The n_TOF Collaboration has built and commissioned a high-performance detector for ( n , γ ) measurements called the Total Absorption Calorimeter (TAC). The TAC was especially designed for measuring neutron capture cross-sections of low-mass and/or radioactive samples with the accuracy required for nuclear technology and stellar nucleosynthesis. We present a detailed description of the TAC and discuss its overall performance in terms of energy and time resolution, background discrimination, detection efficiency and neutron sensitivity.

Development of ZnO:Ga as an ultra-fast scintillator

Abstract: We report on several methods for synthesizing the ultra-fast scintillator ZnO(Ga), and measurements of the resulting products. This material has characteristics that make it an excellent alpha detector for tagging the time and direction of individual neutrons produced by t-d and d-d neutron generators (associated particle imaging). The intensity and decay time are strongly dependent on the method used for dopant incorporation. We compare samples made by diffusion of Ga metal to samples made by solid state reaction between ZnO and Ga2O3 followed by reduction in hydrogen. The latter is much more successful and has a pure, strong near-band-edge fluorescence and an ultra-fast decay time of the x-ray-excited luminescence. The luminescence increases dramatically as the temperature is reduced to 10K. We also present results of an alternate low-temperature synthesis that produces luminescent particles with a more uniform size distribution. We examine possible mechanisms for the bright near-band-edge scintillation and favor the explanation that it is due to the recombination of Ga3+ donor electrons with ionization holes trapped on H+ ion acceptors.

Radiation-induced point- and cluster-related defects with strong impact on damage properties of silicon detectors

Abstract: This work focuses on the investigation of radiation-induced defects responsible for the degradation of silicon detector performance. Comparative studies of the defects induced by irradiation with 60 Co-γ rays, 6 and 15 MeV electrons, 23 GeV protons and reactor neutrons revealed the existence of point defects and cluster-related centers having a strong impact on damage properties of Si diodes. The detailed relation between the “microscopic” reasons as based on defect analysis and their “macroscopic” consequences for detector performance is presented. In particular, it is shown that the changes in the Si device properties (depletion voltage and leakage current) after exposure to high levels of 60 Co-γ doses can be completely understood by the microscopically investigated formation of two point defects, a deep acceptor and a shallow donor, both depending strongly on the oxygen concentration in the silicon bulk. Specific for hadron irradiation are the annealing effects which decrease (increase) the originally observed damage effects as seen by the changes of the depletion voltage and these effects are known as “beneficial” and “reverse” annealing, respectively. A group of three cluster-related defects, revealed as deep hole traps, proved to be responsible specifically for the reverse annealing. Their formation is not affected by the oxygen content or silicon growth procedure suggesting that they are complexes of multi-vacancies located inside extended disordered regions.

Digital discrimination of neutrons and gamma-rays in liquid scintillators using wavelets

Abstract: A novel algorithm for the digital discrimination of neutrons and gamma-rays in a mixed radiation field is presented. Most of the pulse shape discrimination methods in scintillation detection systems use time-domain features of the signal (e.g. charge comparison method or constant-time discrimination). However, there are no frequency-domain discrimination methods up to date in the literature. Our method employs the wavelet transform to extract frequency-domain features for discrimination. Compared to the pulse gradient analysis (PGA) algorithm, it provides an improvement in reducing the overlap area between neutron and gamma events and also in increasing the Figure of Merit (FoM). Another advantage of this method consists in the removal of the dependency of the discrimination method on timing features. Since the light output in the scintillation process is very noisy, this kind of dependency may degrade the performance of the algorithm.