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Andrew G. Weisenberger - One of the best experts on this subject based on the ideXlab platform.

  • Readout electronics for multianode Photomultiplier Tubes with pad matrix anode layout
    2003 IEEE Nuclear Science Symposium. Conference Record (IEEE Cat. No.03CH37515), 2003
    Co-Authors: Vladimir Popov, S. Majewski, Andrew G. Weisenberger
    Abstract:

    We have developed economical readout concept for multianode Photomultiplier Tubes which have a matrix type pad anode layout. This style of anode layout is used in many position sensitive Photomultiplier Tubes such as R5900-M64 and recently available flat panel H8500 PMT from Hamamatsu Photonics, as well as the Burle PLANACO/spl trade/ 85011 PSPMT. All these PMTs have a matrix of 8/spl times/8 anode pads requiring signal readout from 64 outputs. The number of readout channels quickly increases in systems utilizing many of these PMTs. In order to reduce the number of active channels to be read we have employed a two-dimensional decoupling resistive matrix circuit. A decoupling resistive matrix was designed to convert the 2-D area readout into a projective two single coordinate readout, and, thereby, to simplify readout electronics. In the case of PMT array, the circuit permits ganging together signals from several of the Photomultipliers in the same way as done in the cross-wire Photomultiplier tube anode layout. We tested this readout concept in several compact gamma cameras designed and built at Jefferson Lab. The largest size array consists of 3/spl times/4 (12 total) of H8500 Photomultiplier Tubes with 768 individual anode pad outputs, which were decoupled into 32x+24y (56 total) readout channels, a reduction by factor - 14.

  • Investigation into the use of position sensitive Photomultiplier Tubes for beta radiography
    Proceedings of 1994 IEEE Nuclear Science Symposium - NSS'94, 1
    Co-Authors: Andrew G. Weisenberger, S. Majewski, S. Mehrotra, Vladimir Popov, Margaret S. Saha
    Abstract:

    Various radioisotopes such as P/sup 32/ and C/sup 14/ are used as radiolabels for autoradiography in biological and gene research. We have investigated the possibility of using two types of Photomultiplier Tubes coupled to plastic and crystal scintillators to detect and quantify the beta emissions of P/sup 32/ and C/sup 14/ in amounts typical for autoradiography of dot-blot bioassays in the microtiter and other formats. The Hamamatsu R4760 (with 16 individual channels) and R2486 (a position sensitive PMT with 16/spl times/16 cross-wire anodes) were the two multichannel Photomultiplier Tubes tested. The levels of beta radiation typically found in autoradiographic experiments are shown to be detectable using plastic and crystal scintillators coupled to these Photomultiplier Tubes. >

S. Majewski - One of the best experts on this subject based on the ideXlab platform.

  • Readout electronics for multianode Photomultiplier Tubes with pad matrix anode layout
    2003 IEEE Nuclear Science Symposium. Conference Record (IEEE Cat. No.03CH37515), 2003
    Co-Authors: Vladimir Popov, S. Majewski, Andrew G. Weisenberger
    Abstract:

    We have developed economical readout concept for multianode Photomultiplier Tubes which have a matrix type pad anode layout. This style of anode layout is used in many position sensitive Photomultiplier Tubes such as R5900-M64 and recently available flat panel H8500 PMT from Hamamatsu Photonics, as well as the Burle PLANACO/spl trade/ 85011 PSPMT. All these PMTs have a matrix of 8/spl times/8 anode pads requiring signal readout from 64 outputs. The number of readout channels quickly increases in systems utilizing many of these PMTs. In order to reduce the number of active channels to be read we have employed a two-dimensional decoupling resistive matrix circuit. A decoupling resistive matrix was designed to convert the 2-D area readout into a projective two single coordinate readout, and, thereby, to simplify readout electronics. In the case of PMT array, the circuit permits ganging together signals from several of the Photomultipliers in the same way as done in the cross-wire Photomultiplier tube anode layout. We tested this readout concept in several compact gamma cameras designed and built at Jefferson Lab. The largest size array consists of 3/spl times/4 (12 total) of H8500 Photomultiplier Tubes with 768 individual anode pad outputs, which were decoupled into 32x+24y (56 total) readout channels, a reduction by factor - 14.

  • Application of small inexpensive side-on (side-window) Photomultiplier Tubes for scintillating fiber readout
    IEEE Transactions on Nuclear Science, 1992
    Co-Authors: A.g. Weisenberger, B. Kross, S. Majewski, R. Wojcik, C. Zorn
    Abstract:

    Small inexpensive side-on Photomultiplier Tubes (PMTs) with excellent characteristics were tested for scintillating fiber readout. The location of the photocathode and nonuniform response of the Photomultiplier poses problems in fiber or light guide readout. To overcome these problems the authors have devised and tested a fiber to PMT coupling technique which partially collimates the cone of light exciting a fiber by using small spherical lenses which are used in fiber-optics communication applications. An improvement was obtained with the focusing technique as opposed to using the fibers alone. The results of the measurements and the properties of the side-on PMT are discussed.

  • Investigation into the use of position sensitive Photomultiplier Tubes for beta radiography
    Proceedings of 1994 IEEE Nuclear Science Symposium - NSS'94, 1
    Co-Authors: Andrew G. Weisenberger, S. Majewski, S. Mehrotra, Vladimir Popov, Margaret S. Saha
    Abstract:

    Various radioisotopes such as P/sup 32/ and C/sup 14/ are used as radiolabels for autoradiography in biological and gene research. We have investigated the possibility of using two types of Photomultiplier Tubes coupled to plastic and crystal scintillators to detect and quantify the beta emissions of P/sup 32/ and C/sup 14/ in amounts typical for autoradiography of dot-blot bioassays in the microtiter and other formats. The Hamamatsu R4760 (with 16 individual channels) and R2486 (a position sensitive PMT with 16/spl times/16 cross-wire anodes) were the two multichannel Photomultiplier Tubes tested. The levels of beta radiation typically found in autoradiographic experiments are shown to be detectable using plastic and crystal scintillators coupled to these Photomultiplier Tubes. >

Elly Nedivi - One of the best experts on this subject based on the ideXlab platform.

  • spectral resolved multifocal multiphoton microscopy with multianode Photomultiplier Tubes
    Optics Express, 2014
    Co-Authors: Jae Won Cha, Dimitrios S Tzeranis, Jaichandar Subramanian, Ioannis V Yannas, Elly Nedivi
    Abstract:

    Multiphoton excitation fluorescence microscopy is the preferred method for in vivo deep tissue imaging. Many biological applications demand both high imaging speed and the ability to resolve multiple fluorophores. One of the successful methods to improve imaging speed in a highly turbid specimen is multifocal multiphoton microscopy (MMM) based on use of multi-anode Photomultiplier Tubes (MAPMT). This approach improves imaging speed by using multiple foci for parallelized excitation without sacrificing signal to noise ratio (SNR) due to the scattering of emission photons. In this work, we demonstrate that the MAPMT based MMM can be extended with spectral resolved imaging capability. Instead of generating multiple excitation foci in a 2D grid pattern, a linear array of foci is generated. This leaves one axis of the 2D MAPMT available for spectral dispersion and detection. The spectral-resolved MMM can detect several emission signals simultaneously with high imaging speed optimized for high-throughput, high-contents applications. The new procedure is illustrated using imaging data from the kidney, peripheral nerve regeneration and dendritic morphological data from the brain.

  • multifocal multiphoton microscopy based on multianode Photomultiplier Tubes
    Optics Express, 2007
    Co-Authors: Ki Hean Kim, Christof Buehler, Karsten Bahlmann, Timothy Ragan, Weichung Allen Lee, Elly Nedivi, Erica L Heffer, Sergio Fantini
    Abstract:

    Multifocal multiphoton microscopy (MMM) enhances imaging speed by parallelization. It is not well understood why the imaging depth of MMM is significantly shorter than conventional single-focus multiphoton microscopy (SMM). In this report, we show that the need for spatially resolved detectors in MMM results in a system that is more sensitive to the scattering of emission photons with reduced imaging depth. For imaging depths down to twice the scattering mean free path length of emission photons (2xl (s) (em)), the emission point spread function (PSF(em)) is found to consist of a narrow, diffraction limited distribution from ballistic emission photons and a broad, relatively low amplitude distribution from scattered photons. Since the scattered photon distribution is approximately 100 times wider than that of the unscattered photons at 2xl (s) (em), image contrast and depth are degraded without compromising resolution. To overcome the imaging depth limitation of MMM, we present a new design that replaces CCD cameras with multi-anode Photomultiplier Tubes (MAPMTs) allowing more efficient collection of scattered emission photons. We demonstrate that MAPMT-based MMM has imaging depth comparable to SMM with equivalent sensitivity by imaging tissue phantoms, ex vivo human skin specimens based on endogenous fluorophores, and green fluorescent protein (GFP) expressing neurons in mouse brain slices.

Y Onel - One of the best experts on this subject based on the ideXlab platform.

  • characterization of Photomultiplier Tubes in a novel secondary ionization mode for secondary emission ionization calorimetry
    arXiv: Instrumentation and Detectors, 2016
    Co-Authors: E Tiras, Kamuran Dilsiz, Hasan Ogul, D Southwick, B Bilki, J Nachtman, Y Onel
    Abstract:

    Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes have been characterized for use in Secondary Emission Ionization Calorimetry study, that is a novel techique to measure the electromagnetic shower particles in extreme radiation environment. There are different SE modes used in the tests, developed from conventional PMT mode. Here, the technical design of secondary emission modules and characterization measurements of both SE modes and the PMT mode are reported.

  • afterpulse timing and rate investigation of three different hamamatsu Photomultiplier Tubes
    Journal of Instrumentation, 2008
    Co-Authors: U Akgun, A S Ayan, G Aydin, F Duru, J Olson, Y Onel
    Abstract:

    We present the results of the tests performed on 90 Photomultiplier Tubes (PMT) to characterize their afterpulses. Three different types of H amamatsu PMTs (R7525, R6427, and R1398) were studied for their afterpulse rates and timings at different incident light intensities and gain values, at the University of Iowa PMT test station. Afterpulse rates show slight increase with the PMT gain, but there is almost no dependence on incident light intensity. Three specific time delays are determined for the afterpulses, and their indivi dual rate contributions are characterized. The results from manufacturer's independent tests on R7525 PMTs are reported, as well. The possible effects of these afterpulses on the future hadron c ollider experiments are also discussed.

R W Hollander - One of the best experts on this subject based on the ideXlab platform.

  • quantum efficiencies of several vuv sensitive Photomultiplier Tubes
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1993
    Co-Authors: P Dorenbos, J T M De Haas, R Visser, C W E Van Eijk, R W Hollander
    Abstract:

    Abstract The quantum efficiencies (QEs) of several VUV sensitive photon detectors were determined and compared with each other. We tested the following Photomultiplier Tubes (PMTs): five Philips XP2020Qs, one Hamamatsu R2059, and one Thorn EMI 9426. We also tested a Na-salicylate coated glass window combined with a Philips XP2020 PMT. At wavelengths smaller than 230 nm, the QEs of both the Thorn EMI and Philips PMTs appear significantly better than the QE of the Hamamatsu PMT. Furthermore, at these wavelengths, the QE of the XP2020Q PMTs was found to be much higher than advertised in the manufacturers catalogues.

  • absolute light yield measurements on baf sub 2 crystals and the quantum efficiency of several Photomultiplier Tubes
    Nuclear Science Symposium and Medical Imaging Conference, 1992
    Co-Authors: P Dorenbos, J T M De Haas, R Visser, C W E Van Eijk, R W Hollander
    Abstract:

    The quantum efficiency curves of five Philips XP2020Q Photomultiplier Tubes (PMTs), one Hamamatsu R2059 PMT, and a Na-salicylate coated glass window are determined using a calibrated Thorn EMI 9426 PMT as a reference. The QE of XP2020Q PMTs at wavelengths smaller than 230 nm appears much better than the values specified by the manufacturer. Consequently, the often reported photon yield of 2000 photons/MeV for the fast component of the scintillation pulses from pure BaF/sub 2/ crystals determined with this tube is overestimated. The authors' results, obtained by means of calibrated equipment and using 662-keV gamma -rays, yield a value of 1400 photons/MeV. >