Identification Detector Research Articles

Simultaneous counting of two subsets of leukocytes using fluorescent silica nanoparticles in a sheathless microchip flow cytometer

A portable flow cytometer has been recognized as an important tool for many clinical applications such as HIV/AIDS screening in developing countries and regions with limited medical facilities and resources. Conventional flow cytometers typically require multiple detectors for simultaneous identification of multiple subsets of immune cell. To minimize the number of detectors toward portable flow cytometry or to analyze multi-parametric cellular information with minimum number of detectors in conventional flow cytometers, we propose a versatile multiplexed cell-counting method using functional silica nanoparticles (SiNPs). FITC-doped SiNPs, which are 100 times brighter than the FITC molecules itself, were used as new intensity-based fluorescent dye complexes to simultaneously measure two subsets of leukocytes using a single detector. CD45(+)CD4(+) cells tagged with these FITC-doped SiNPs were 50 times brighter than CD45(+)CD4(-) cells tagged only with FITC. To make the overall system compact, a disposable microchip flow cytometer that does not require sheath flow was developed. Combining these dye-doped SiNPs based detection schemes and the sheathless microchip flow cytometer scheme, we successfully identified and counted two subsets of leukocytes simultaneously (R(2) = 0.876). These approaches can be the building blocks for a truly portable and disposable flow cytometer for various clinical cytometry applications.

The Pixel Hybrid Photon Detector of the LHCb RICH

The LHCb experiment at the CERN Large Hadron Collider employs two Ring Imaging Cherenkov (RICH) detectors for particle identification. The first covers the charged particle momentum range 1 - 60 GeV/c using aerogel and C 4 F 10 radiators and the second covers up to 100 GeV/c using CF 4 . Cherenkov light will be detected using a novel type of position sensitive device: the pixel Hybrid Photon Detector (HPD). In the pixel HPD, photoelectrons are produced in a multialkali photocathode, accelerated and focused by an electrostatic field, and then detected by a pixelated silicon detector which is bump-bonded onto a 40 MHz read-out chip. This paper reports on the development of the LHCb RICH detectors and the performance of the HPDs.

Measurements of Cherenkov Photons with Silicon Photomultipliers

A novel photon detector, the Silicon Photomultiplier (SiPM), has been tested in proximity focusing Ring Imaging Cherenkov (RICH) counters that were exposed to cosmic-ray particles in Ljubljana, and a 2 GeV electron beam at the KEK research facility. This type of RICH detector is a candidate for the particle identification detector upgrade of the BELLE detector at the KEK B-factory, for which the use of SiPMs, microchannel plate photomultiplier tubes or hybrid avalanche photodetectors, rather than traditional Photomultiplier Tubes (PMTs) is essential due to the presence of high magnetic fields. In both experiments, SiPMs are found to compare favourably with PMTs, with higher photon detection rates per unit area. Through the use of hemispherical and truncated pyramid light guides to concentrate photons onto the active surface area, the light yield increases significantly. An estimate of the contribution to dark noise from false coincidences between SiPMs in an array is also presented.

Performance of the LHCb RICH photo-detectors and readout in a system test using charged particles from a 25 ns-structured beam

The LHCb experiment at the CERN Large Hadron Collider (LHC) utilises two Ring Imaging CHerenkov (RICH) detectors for particle identification. To verify that the RICH assembly will perform as expected prior to installation, an array of 48 production Hybrid Photon Detectors and their readout have been tested under realistic running conditions in a 25 ns-structured charged particle beam provided by the SPS facility at CERN. This system test is an important milestone in the overall commissioning of the LHCb detector and demonstrates that all aspects meet the stringent physics requirements of the LHCb experiment.

HADRON PHYSICS WITH THE CRYSTAL BALL AT MAMI

The physics program of the Crystal Ball spectrometer at MAMI-C began in early 2007. Experiments utilize the upgraded electron accelerator that provides high intensity beams of circularly and linearly polarized real photons with maximum energy of 1.5 GeV. The highly segmented nearly 4π acceptance detection system consists of the Crystal Ball, particle identification detector and versatile endcap TAPS. A wide range of physics topics is under study including the production and decay of η, ω, and η' mesons, the investigation of coherent meson photoproduction on nuclei, measurements of polarization and double polarization observables in meson photoproduction on proton and neutron. The current status of the experiment and some preliminary results are reported.

Development of a Wearable Motion Detector for Telemonitoring and Real-Time Identification of Physical Activity

Characteristics of physical activity are indicative of one's mobility level, latent chronic diseases, and aging process. Current research has been oriented to provide quantitative assessment of physical activity with ambulatory monitoring approaches. This study presents the design of a portable microprocessor-based accelerometry measuring device to implement real-time physical activity identification. An algorithm was developed to process real-time tri-axial acceleration signals produced by human movement to identify targeted still postures, postural transitions, and dynamic movements. Fall detection was also featured in this algorithm to meet the increasing needs of elderly care in free-living environments. High identification accuracy was obtained in performance evaluation. This device is technically viable for telemonitoring and real-time identification of physical activity, while providing sufficient information to evaluate a person's activity of daily living and her/his status of physical mobility. Limitations regarding real-time processing and implementation of the system for telemonitoring in the home environment were also observed.

Yields of β-Hydroxynitrates and Dihydroxynitrates in Aerosol Formed from OH Radical-Initiated Reactions of Linear Alkenes in the Presence of NOx

Yields of beta-hydroxynitrates and dihydroxynitrates in aerosol formed from OH radical-initiated reactions of linear C(8)-C(17) 1-alkenes and C(14)-C(17) internal alkenes in the presence of NO(x) were measured using a thermal desorption particle beam mass spectrometer coupled to a high-performance liquid chromatograph (HPLC) with UV-vis detector for identification and quantification. For 1-alkenes, total yields of beta-hydroxynitrates normalized for OH radical addition to the CC double bond increased with carbon number, primarily because of enhanced gas-to-particle partitioning, to a plateau of 0.140 +/- 0.009 in the C(14)-C(17) range, with 1-hydroxy/2-hydroxy isomer fractions of 0.7:0.3. When combined with yields measured by O'Brien et al. ( O'Brien , J. M. , Czuba , E. , Hastie , D. R. , Francisco , J. S. , and Shepson , P. S. J. Phys. Chem. A 1998 , 102 , 8903 ) for reactions of smaller alkenes, the results for both 1-alkenes and internal alkenes indicate that the branching ratios for the formation of beta-hydroxynitrates from the reactions of NO with beta-hydroxyperoxy radicals (averaged over both isomers) increase from 0.009 for C(2) up to 0.13-0.15 for C(14) and larger and are approximately half the values determined by Arey et al. ( Arey , J. , Aschmann , S. M. , Kwok , E. S. C. , and Atkinson , R. J. Phys. Chem. A 2001 , 105 , 1020 ) for the corresponding alkyl peroxy radicals. The range of branching ratios may be higher for individual isomers, but this could not be determined. It is estimated that for 1-alkenes, approximately 60-70% of OH radical addition occurred at the terminal carbon atom. Average yields of dihydroxynitrates normalized for OH radical addition were 0.039 +/- 0.006 and 0.006 +/- 0.002 for 1-alkenes and internal alkenes, with differences reflecting enhanced decomposition of beta-hydroxyalkoxy radicals formed from internal alkenes. The addition of NH(3) reduced yields significantly, apparently by altering hydrogen bonding between hydroxy and peroxy groups in hydroxyperoxy radical-NO complexes, whereas adding H(2)O had no obvious effect.

The ALICE HMPID detector ready for collisions at the LHC

ALICE has been specifically optimized to study heavy-ion collisions at the LHC, up to a charged particle density of 8000 per unit of rapidity in central heavy-ion collisions at s NN = 5.5 TeV . The High Momentum Particle Identification Detector (HMPID) has a proximity focusing geometry with a liquid C 6F 14 Cherenkov radiator coupled to Multi-Wire Pad Chambers (MWPC) equipped with CsI photocathodes, over a total active area of 11 m 2 . It has been designed to identify charged pions and kaons in the range 1 ⩽ p ⩽ 3 Gev / c and protons in the range 2 ⩽ p ⩽ 5 Gev / c . The as-built detector and all relevant subsystems (gas, liquid C 6F 14, cooling and control) are described. Installation issues and first commissioning results are also presented.

Gas Cherenkov detectors for high momentum charged particle identification in the ALICE experiment at LHC

Protons identification up to 10 GeV / c and more is a challenge. We present here an exhaustive study of the possibilities offered by a combination of a gaseous radiator having low index of refraction (C 5F 12) with the proven concept of large area CsI photocathodes, instrumenting either a multiwire chamber or a GEM detector. We present two geometries. One of them is proximity-focusing, nevertheless allows identification in a large momentum range. The second one deals with a focusing geometry with a spherical mirror. Simulations of the performance of both types are presented.

Status of the Fast Focusing DIRC (fDIRC)

We have built and successfully tested a novel particle identification detector concept, the Fast Focusing DIRC (fDIRC). The prototype's concept is based on the BaBar DIRC with several important improvements: (a) much faster pixelated photon detectors based on Burle MCP-PMTs and Hamamatsu MaPMTs, (b) a focusing mirror allowing a smaller photon detector, reducing the sensitivity to backgrounds in future applications, (c) electronics capable of measuring the single photon resolution to better than σ≈100–200 ps. The fDIRC is the first RICH detector to successfully correct the chromatic error by timing.

Development of a RICH detector for electron identification in CBM

The Compressed Baryonic Matter (CBM) experiment at the future FAIR accelerator at Darmstadt, Germany, will investigate baryonic matter at highest net-baryon densities but moderate temperatures by colliding nuclei at beam energies from 8 to 45 AGeV. One of the key observables are low-mass vector mesons and charmonium decaying into lepton pairs. For electron identification a RICH detector is foreseen. In this contribution detector simulations, feasibility studies and first steps in the detector development are discussed.

Pattern recognition techniques of charged hadron identification with HMPID at LHC

The High Momentum Particle Identification Detector (HMPID), already installed in the ALICE setup at LHC, is ready to identify charged hadrons with momentum up to 5 GeV/ c. It consists of seven modules of a RICH detector with a CsI photocathode. The HMPID will operate to identify charged hadrons both in Pb–Pb collisions and in p–p collisions. The strategy to identify charged hadrons will differ according to the colliding system. In the case of central Pb–Pb collisions, the identification of Cherenkov photons requires efficient pattern recognition algorithm (based on a modified Hough transform, that maps the pad coordinate space directly to the Cherenkov angle parameter space). In the first p–p collisions, instead, where the tracking has to be optimized (or even missing, as sometimes in the cosmic runs), a first reconstruction step based on a new algorithm (Hidden Track Algorithm—HTA) will be used. The tracking parameters are not used in the pattern recognition, at the end an estimate of the track direction as well as the mean 〈 θ C 〉 will be performed. The HTA will be here described and preliminary results on its performances will be presented.

The combination approach of SVM and ECOC for powerful identification and classification of transcription factor.

BackgroundTranscription factors (TFs) are core functional proteins which play important roles in gene expression control, and they are key factors for gene regulation network construction. Traditionally, they were identified and classified through experimental approaches. In order to save time and reduce costs, many computational methods have been developed to identify TFs from new proteins and to classify the resulted TFs. Though these methods have facilitated screening of TFs to some extent, low accuracy is still a common problem. With the fast growing number of new proteins, more precise algorithms for identifying TFs from new proteins and classifying the consequent TFs are in a high demand.ResultsThe support vector machine (SVM) algorithm was utilized to construct an automatic detector for TF identification, where protein domains and functional sites were employed as feature vectors. Error-correcting output coding (ECOC) algorithm, which was originated from information and communication engineering fields, was introduced to combine with support vector machine (SVM) methodology for TF classification. The overall success rates of identification and classification achieved 88.22% and 97.83% respectively. Finally, a web site was constructed to let users access our tools (see Availability and requirements section for URL).ConclusionThe SVM method was a valid and stable means for TFs identification with protein domains and functional sites as feature vectors. Error-correcting output coding (ECOC) algorithm is a powerful method for multi-class classification problem. When combined with SVM method, it can remarkably increase the accuracy of TF classification using protein domains and functional sites as feature vectors. In addition, our work implied that ECOC algorithm may succeed in a broad range of applications in biological data mining.

LaCl3(Ce) and LaBr3(Ce) gamma-ray spectra with various plutonium isotopic and uranium enrichment standards

This report assesses the utility of lanthanum-halide detectors for isotope identification and total mass measurements for uranium and plutonium isotopes. Comparisons to similar measurements with NaI detectors are made.

Absolute momentum calibration of the HARP TPC

In the HARP experiment the large-angle spectrometer is using a cylindrical TPC as main tracking and particle identification detector. The momentum scale of reconstructed tracks in the TPC is the most important systematic error for the majority of kinematic bins used for the HARP measurements of the double-differential production cross-section of charged pions in proton interactions on nuclear targets at large angle. The HARP TPC operated with a number of hardware shortfalls and operational mistakes. Thus it was important to control and characterize its momentum calibration. While it was not possible to enter a direct particle beam into the sensitive volume of the TPC to calibrate the detector, a set of physical processes and detector properties were exploited to achieve a precise calibration of the apparatus. In the following we recall the main issues concerning the momentum measurement in the HARP TPC, and describe the cross-checks made to validate the momentum scale. As a conclusion, this analysis demonstrates that the measurement of momentum is correct within the published precision of 3%.

The first version buffered large analog bandwidth (BLAB1) ASIC for high luminosity collider and extensive radio neutrino detectors

Future detectors for high luminosity particle identification and ultra high energy neutrino observation would benefit from a digitizer capable of recording sensor signals with high analog bandwidth and large record depth, in a cost-effective, compact and low-power way. A first version of the buffered large analog bandwidth (BLAB1) ASIC has been designed based upon the lessons learned from the development of the large analog bandwidth recorder and digitizer with Ordered Readout (LABRADOR) ASIC. While this LABRADOR ASIC has been very successful and forms the basis of a generation of new, large-scale radio neutrino detectors, its limited sampling depth is a major drawback. A prototype has been designed and fabricated with 64 k deep sampling at multi-GSa/s operation. We present test results and directions for future evolution of this sampling technique.

The LHCb RICH photon detector system

The LHCb experiment at the CERN Large Hadron Collider will employ two Ring Imaging Cherenkov (RICH) detectors for particle identification. The Cherenkov photons will be detected by planes of photon detectors covering a total active surface area of 2.1 m 2. The detector chosen for this task is the pixel hybrid photon detector (HPD). This combines silicon pixel sensors, integrated electronics and high-density interconnects together with vacuum-tube technology to produce an efficient, low-noise detector sensitive to single photons. For the complete photon detector system of the LHCb RICH, 484 such HPDs are required and these have been fully integrated into detector modules. Specific aspects of this integration within the RICH system are described together with the steps taken to ensure the efficiency and reliability of the detector in the harsh environment of LHCb.

The High Momentum Particle Identification Detector in ALICE at LHC

The ALICE High Momentum Particle Identification Detector (HMPID) is a proximity focusing ring imaging Cherenkov (RICH) for the hadron discrimination at high transverse momenta ( 1 < p t < 3 GeV/c for π and k, 1 < p t < 5 GeV/c for p). This paper focus on the HMPID particle identification (PID) capabilities in the expected charged particle occupancy dN ch / d η = 6000 , simulated in central Pb-Pb ALICE events.

ENERGY DISPERSIVE SPECTROMETRY OF COMMON ROCK FORMING MINERALS: by Kenneth p. Severin; Kluwer Academic Publishers (2004), 225 p., spiral bound hardback; $169. ISBN 978-1-4020-2840-3.

Book Review| November 01, 2007 ENERGY DISPERSIVE SPECTROMETRY OF COMMON ROCK FORMING MINERALS: by Kenneth p. Severin; Kluwer Academic Publishers (2004), 225 p., spiral bound hardback; $169. ISBN 978-1-4020-2840-3. John Fournelle John Fournelle Cameron Electron Microprobe Lab, Dept. of Geology and Geophysics, University of Wisconsin, 1215 West Dayton Street, Madison, WI 53706, U.S.A. Search for other works by this author on: GSW Google Scholar American Mineralogist (2007) 92 (11-12): 2006. https://doi.org/10.2138/am.2007.504 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation John Fournelle; ENERGY DISPERSIVE SPECTROMETRY OF COMMON ROCK FORMING MINERALS: by Kenneth p. Severin; Kluwer Academic Publishers (2004), 225 p., spiral bound hardback; $169. ISBN 978-1-4020-2840-3.. American Mineralogist 2007;; 92 (11-12): 2006. doi: https://doi.org/10.2138/am.2007.504 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search This book is a useful addition to reference works kept in geological SEM and EPMA labs that routinely use EDS detectors for phase identification. It provides a welcome update to the SEM Petrology Atlas (Welton, AAPG, 1984), which documented both SEM images and EDS spectra of 60 minerals that are mainly those in sedimentary rocks. Welton’s spectra were acquired with Be window detectors of gold-coated specimens. Severin, like many of us who run SEM or electron probe labs, bounces around between various projects and can have a hard time recalling the details of spectra analyzed last month, much less last... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Scalar top study: Detector optimization

A vertex detector concept of the linear collider flavour identification (LCFI) collaboration, which studies pixel detectors for heavy quark flavour identification, has been implemented in simulations for c-quark tagging in scalar top studies. The production and decay of scalar top quarks (stops) is particularly interesting for the development of the vertex detector as only two c-quarks and missing energy (from undetected neutralinos) are produced for light stops. Previous studies investigated the vertex detector design in scenarios with large mass differences between stop and neutralino, corresponding to large visible energy in the detector. In this study we investigate the tagging performance dependence on the vertex detector design in a scenario with small visible energy for the international linear collider (ILC).