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Sample records for resolution emitter readout

  1. Scintillator avalanche photoconductor with high resolution emitter readout for low dose x-ray imaging: lag.

    PubMed

    Lia, Dan; Zhao, Wei; Nanba, Masakazu; Egami, Norifomi

    2009-09-01

    A new concept of indirect conversion flat-panel imager with avalanche gain and field emitter array (FEA) readout is being investigated. It is referred to as scintillator avalanche photoconductor with high resolution emitter readout (SAPHIRE). The present work investigates the temporal performance, i.e., lag, of SAPHIRE. Since the temporal performance of the x-ray detection materials, i.e., the structured scintillator and avalanche amorphous selenium (a-Se) photoconductor, has been studied previously, the investigation is focused on lag due to the FEA readout method. The principle of FEA readout is similar to that of scanning electron beam readout used in camera tubes, where the dominant source of lag is the energy spread of electrons. Since the principles of emission and beam focusing methods for FEA are different from thermionic emission used in camera tubes, its electron beam energy spread and hence lag is expected to be different. In the present work, the energy spread of the electrons emitted from a FEA was investigated theoretically by analyzing different contributing factors due to the FEA design and operations: The inherent energy spread of field emission, the FEA driving pulse delay, and the angular distribution of emitted electrons. The electron energy spread determined the beam acceptance characteristic curve of the photoconductive target, i.e., the accepted beam current (I(a)) as a function of target potential (V(t)), from which lag could be calculated numerically. Lag calculation was performed using FEA parameters of two prototype HARP-FEA image sensors, and the results were compared with experimental measurements. Strategies for reducing lag in SAPHIRE were proposed and analyzed. The theoretical analysis shows that the dominant factor for lag is the angular distribution of electrons emitted from the FEA. The first frame lags for two prototype sensors with 4 and 25 microm HARP layer thicknesses were 62.1% and 9.1%, respectively. A lag clearance

  2. SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) for low dose x-ray imaging: Spatial resolution.

    PubMed

    Li, Dan; Zhao, Wei

    2008-07-01

    An indirect flat panel imager (FPI) with programmable avalanche gain and field emitter array (FEA) readout is being investigated for low-dose and high resolution x-ray imaging. It is made by optically coupling a structured x-ray scintillator, e.g., thallium (Tl) doped cesium iodide (CsI), to an amorphous selenium (a-Se) avalanche photoconductor called high-gain avalanche rushing amorphous photoconductor (HARP). The charge image created by the scintillator/HARP (SHARP) combination is read out by the electron beams emitted from the FEA. The proposed detector is called scintillator avalanche photoconductor with high resolution emitter readout (SAPHIRE). The programmable avalanche gain of HARP can improve the low dose performance of indirect FPI while the FEA can be made with pixel sizes down to 50 μm. Because of the avalanche gain, a high resolution type of CsI (Tl), which has not been widely used in indirect FPI due to its lower light output, can be used to improve the high spatial frequency performance. The purpose of the present article is to investigate the factors affecting the spatial resolution of SAPHIRE. Since the resolution performance of the SHARP combination has been well studied, the focus of the present work is on the inherent resolution of the FEA readout method. The lateral spread of the electron beam emitted from a 50 μm×50 μm pixel FEA was investigated with two different electron-optical designs: mesh-electrode-only and electrostatic focusing. Our results showed that electrostatic focusing can limit the lateral spread of electron beams to within the pixel size of down to 50 μm. Since electrostatic focusing is essentially independent of signal intensity, it will provide excellent spatial uniformity. © 2008 American Association of Physicists in Medicine.

  3. SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) for low dose x-ray imaging: Spatial resolution

    PubMed Central

    Li, Dan; Zhao, Wei

    2008-01-01

    An indirect flat panel imager (FPI) with programmable avalanche gain and field emitter array (FEA) readout is being investigated for low-dose and high resolution x-ray imaging. It is made by optically coupling a structured x-ray scintillator, e.g., thallium (Tl) doped cesium iodide (CsI), to an amorphous selenium (a-Se) avalanche photoconductor called high-gain avalanche rushing amorphous photoconductor (HARP). The charge image created by the scintillator∕HARP (SHARP) combination is read out by the electron beams emitted from the FEA. The proposed detector is called scintillator avalanche photoconductor with high resolution emitter readout (SAPHIRE). The programmable avalanche gain of HARP can improve the low dose performance of indirect FPI while the FEA can be made with pixel sizes down to 50 μm. Because of the avalanche gain, a high resolution type of CsI (Tl), which has not been widely used in indirect FPI due to its lower light output, can be used to improve the high spatial frequency performance. The purpose of the present article is to investigate the factors affecting the spatial resolution of SAPHIRE. Since the resolution performance of the SHARP combination has been well studied, the focus of the present work is on the inherent resolution of the FEA readout method. The lateral spread of the electron beam emitted from a 50 μm×50 μm pixel FEA was investigated with two different electron-optical designs: mesh-electrode-only and electrostatic focusing. Our results showed that electrostatic focusing can limit the lateral spread of electron beams to within the pixel size of down to 50 μm. Since electrostatic focusing is essentially independent of signal intensity, it will provide excellent spatial uniformity. PMID:18697540

  4. SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) for low dose x-ray imaging: spatial resolution.

    PubMed

    Li, Dan; Zhao, Wei

    2008-07-01

    An indirect flat panel imager (FPI) with programmable avalanche gain and field emitter array (FEA) readout is being investigated for low-dose and high resolution x-ray imaging. It is made by optically coupling a structured x-ray scintillator, e.g., thallium (Tl) doped cesium iodide (CsI), to an amorphous selenium (a-Se) avalanche photoconductor called high-gain avalanche rushing amorphous photoconductor (HARP). The charge image created by the scintillator/HARP (SHARP) combination is read out by the electron beams emitted from the FEA. The proposed detector is called scintillator avalanche photoconductor with high resolution emitter readout (SAPHIRE). The programmable avalanche gain of HARP can improve the low dose performance of indirect FPI while the FEA can be made with pixel sizes down to 50 microm. Because of the avalanche gain, a high resolution type of CsI (Tl), which has not been widely used in indirect FPI due to its lower light output, can be used to improve the high spatial frequency performance. The purpose of the present article is to investigate the factors affecting the spatial resolution of SAPHIRE. Since the resolution performance of the SHARP combination has been well studied, the focus of the present work is on the inherent resolution of the FEA readout method. The lateral spread of the electron beam emitted from a 50 microm x 50 microm pixel FEA was investigated with two different electron-optical designs: mesh-electrode-only and electrostatic focusing. Our results showed that electrostatic focusing can limit the lateral spread of electron beams to within the pixel size of down to 50 microm. Since electrostatic focusing is essentially independent of signal intensity, it will provide excellent spatial uniformity.

  5. SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) for low dose x-ray imaging: Spatial resolution

    SciTech Connect

    Li Dan; Zhao Wei

    2008-07-15

    An indirect flat panel imager (FPI) with programmable avalanche gain and field emitter array (FEA) readout is being investigated for low-dose and high resolution x-ray imaging. It is made by optically coupling a structured x-ray scintillator, e.g., thallium (Tl) doped cesium iodide (CsI), to an amorphous selenium (a-Se) avalanche photoconductor called high-gain avalanche rushing amorphous photoconductor (HARP). The charge image created by the scintillator/HARP (SHARP) combination is read out by the electron beams emitted from the FEA. The proposed detector is called scintillator avalanche photoconductor with high resolution emitter readout (SAPHIRE). The programmable avalanche gain of HARP can improve the low dose performance of indirect FPI while the FEA can be made with pixel sizes down to 50 {mu}m. Because of the avalanche gain, a high resolution type of CsI (Tl), which has not been widely used in indirect FPI due to its lower light output, can be used to improve the high spatial frequency performance. The purpose of the present article is to investigate the factors affecting the spatial resolution of SAPHIRE. Since the resolution performance of the SHARP combination has been well studied, the focus of the present work is on the inherent resolution of the FEA readout method. The lateral spread of the electron beam emitted from a 50 {mu}mx50 {mu}m pixel FEA was investigated with two different electron-optical designs: mesh-electrode-only and electrostatic focusing. Our results showed that electrostatic focusing can limit the lateral spread of electron beams to within the pixel size of down to 50 {mu}m. Since electrostatic focusing is essentially independent of signal intensity, it will provide excellent spatial uniformity.

  6. Investigation of spatial resolution and temporal performance of SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) with integrated electrostatic focusing

    NASA Astrophysics Data System (ADS)

    Scaduto, David A.; Lubinsky, Anthony R.; Rowlands, John A.; Kenmotsu, Hidenori; Nishimoto, Norihito; Nishino, Takeshi; Tanioka, Kenkichi; Zhao, Wei

    2014-03-01

    We have previously proposed SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout), a novel detector concept with potentially superior spatial resolution and low-dose performance compared with existing flat-panel imagers. The detector comprises a scintillator that is optically coupled to an amorphous selenium photoconductor operated with avalanche gain, known as high-gain avalanche rushing photoconductor (HARP). High resolution electron beam readout is achieved using a field emitter array (FEA). This combination of avalanche gain, allowing for very low-dose imaging, and electron emitter readout, providing high spatial resolution, offers potentially superior image quality compared with existing flat-panel imagers, with specific applications to fluoroscopy and breast imaging. Through the present collaboration, a prototype HARP sensor with integrated electrostatic focusing and nano- Spindt FEA readout technology has been fabricated. The integrated electron-optic focusing approach is more suitable for fabricating large-area detectors. We investigate the dependence of spatial resolution on sensor structure and operating conditions, and compare the performance of electrostatic focusing with previous technologies. Our results show a clear dependence of spatial resolution on electrostatic focusing potential, with performance approaching that of the previous design with external mesh-electrode. Further, temporal performance (lag) of the detector is evaluated and the results show that the integrated electrostatic focusing design exhibits comparable or better performance compared with the mesh-electrode design. This study represents the first technical evaluation and characterization of the SAPHIRE concept with integrated electrostatic focusing.

  7. SAPHIRE: A New Flat-Panel Digital Mammography Detector With Avalanche Photoconductor and High-Resolution Field Emitter Readout

    DTIC Science & Technology

    2006-06-01

    CsI), and form a charge image that is read out by a high-resolution field emitter array (FEA). We call the proposed detector SAPHIRE ( Scintillator ...CsI), and form a charge image that is read out by a high-resolution field emitter array (FEA). We call the proposed detector SAPHIRE ( Scintillator ... detector with avalanche gain: Fundamental feasibility investigation for SHARP-AMFPI ( Scintillator HARP Active Matrix Flat Panel Imager)”, Med. Phys

  8. An indirect flat-panel detector with avalanche gain for low dose x-ray imaging: SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout)

    NASA Astrophysics Data System (ADS)

    Zhao, Wei; Li, Dan; Rowlands, J. A.; Egami, N.; Takiguchi, Y.; Nanba, M.; Honda, Y.; Ohkawa, Y.; Kubota, M.; Tanioka, K.; Suzuki, K.; Kawai, T.

    2008-03-01

    An indirect flat-imager with programmable avalanche gain and field emitter array (FEA) readout is being investigated for low-dose x-ray imaging with high resolution. It is made by optically coupling a structured x-ray scintillator CsI (Tl) to an amorphous selenium (a-Se) avalanche photoconductor called HARP (high-gain avalanche rushing photoconductor). The charge image created by HARP is read out by electron beams generated by the FEA. The proposed detector is called SAPHIRE (Scintillator Avalanche Photoconductor with HIgh Resolution Emitter readout). The avalanche gain of HARP depends on both a-Se thickness and applied electric field E Se. At E Se of > 80 V/μm, the avalanche gain can enhance the signal at low dose (e.g. fluoroscopy) and make the detector x-ray quantum noise limited down to a single x-ray photon. At high exposure (e.g. radiography), the avalanche gain can be turned off by decreasing E Se to < 70 V/μm. In this paper the imaging characteristics of the FEA readout method, including the spatial resolution and noise, were investigated experimentally using a prototype optical HARP-FEA image sensor. The potential x-ray imaging performance of SAPHIRE, especially the aspect of programmable gain to ensure wide dynamic range and x-ray quantum noise limited performance at the lowest exposure in fluoroscopy, was investigated.

  9. Study of the spatial resolution for binary readout detectors

    NASA Astrophysics Data System (ADS)

    Yonamine, R.; Maerschalk, T.; Lentdecker, G. De

    2016-07-01

    Often the binary readout is proposed for high granularity detectors to reduce the generated data volume to be readout at the price of a somewhat reduced spatial resolution compared to an analogue readout. We have been studying single hit resolutions obtained with a binary readout using simulations as well as analytical approaches. In this note we show that the detector geometry could be optimized to offer an equivalent spatial resolution than with an analogue readout.

  10. O-space with high resolution readouts outperforms radial imaging.

    PubMed

    Wang, Haifeng; Tam, Leo; Kopanoglu, Emre; Peters, Dana C; Constable, R Todd; Galiana, Gigi

    2017-04-01

    While O-Space imaging is well known to accelerate image acquisition beyond traditional Cartesian sampling, its advantages compared to undersampled radial imaging, the linear trajectory most akin to O-Space imaging, have not been detailed. In addition, previous studies have focused on ultrafast imaging with very high acceleration factors and relatively low resolution. The purpose of this work is to directly compare O-Space and radial imaging in their potential to deliver highly undersampled images of high resolution and minimal artifacts, as needed for diagnostic applications. We report that the greatest advantages to O-Space imaging are observed with extended data acquisition readouts. A sampling strategy that uses high resolution readouts is presented and applied to compare the potential of radial and O-Space sequences to generate high resolution images at high undersampling factors. Simulations and phantom studies were performed to investigate whether use of extended readout windows in O-Space imaging would increase k-space sampling and improve image quality, compared to radial imaging. Experimental O-Space images acquired with high resolution readouts show fewer artifacts and greater sharpness than radial imaging with equivalent scan parameters. Radial images taken with longer readouts show stronger undersampling artifacts, which can cause small or subtle image features to disappear. These features are preserved in a comparable O-Space image. High resolution O-Space imaging yields highly undersampled images of high resolution and minimal artifacts. The additional nonlinear gradient field improves image quality beyond conventional radial imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. High resolution scintillation detector with semiconductor readout

    DOEpatents

    Levin, Craig S.; Hoffman, Edward J.

    2000-01-01

    A novel high resolution scintillation detector array for use in radiation imaging such as high resolution Positron Emission Tomography (PET) which comprises one or more parallelepiped crystals with at least one long surface of each crystal being in intimate contact with a semiconductor photodetector such that photons generated within each crystal by gamma radiation passing therethrough is detected by the photodetector paired therewith.

  12. HIGH RESOLUTION EMITTANCE MEASUREMENTS AT SNS FRONT END

    SciTech Connect

    Aleksandrov, Alexander V; Zhukov, Alexander P

    2013-01-01

    The Spallation Neutron Source (SNS) linac accelerates an H- beam from 2.5MeV up to 1GeV. Recently the emittance scanner in the MEBT (2.5 MeV) was upgraded. In addition to the slit - harp measurement, we now can use a slit installed on the same actuator as the harp. In combination with a faraday cup located downstream in DTL part of the linac, it represents a classical slit-slit emittance measurement device. While a slit slit scan takes much longer, it is immune to harp related problems such as wire cross talk, and thus looks promising for accurate halo measurements. Time resolution of the new device seems to be sufficient to estimate the amount of beam in the chopper gap (the scanner is downstream of the chopper), and probably to measure its emittance. This paper describes the initial measurements with the new device and some model validation data.

  13. A high resolution delay line readout for microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. S. W.; Lampton, M. L.; Raffanti, R.

    1989-01-01

    Investigations are reported of delay line configurations used to encode photon event locations in microchannel plate (MCP) detectors. Several delay line schemes of planar and multilayer structure are discussed. The importance of the delay line substrate material is examined, and it is shown that the raw signals from delay lines are narrow (about 3-4 ns FWHM). The factors determining the delay line resolution are evaluated, and it is demonstrated that these are in agreement with measurements. Resolutions of about 18-micron FWHM have been achieved. Measurements of the linearity of the delay line readout show that event centroid locations deviate from perfect linearity by less than 50 microns, even with the very simple anode fabrication methods employed. The image stability has also been evaluated and it is shown that image shifts are less than one resolution element over a period of two months.

  14. A high resolution delay line readout for microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. S. W.; Lampton, M. L.; Raffanti, R.

    1989-01-01

    Investigations are reported of delay line configurations used to encode photon event locations in microchannel plate (MCP) detectors. Several delay line schemes of planar and multilayer structure are discussed. The importance of the delay line substrate material is examined, and it is shown that the raw signals from delay lines are narrow (about 3-4 ns FWHM). The factors determining the delay line resolution are evaluated, and it is demonstrated that these are in agreement with measurements. Resolutions of about 18-micron FWHM have been achieved. Measurements of the linearity of the delay line readout show that event centroid locations deviate from perfect linearity by less than 50 microns, even with the very simple anode fabrication methods employed. The image stability has also been evaluated and it is shown that image shifts are less than one resolution element over a period of two months.

  15. Readout architecture for sub-nanosecond resolution TDC

    NASA Astrophysics Data System (ADS)

    Marteau, J.; Carlus, B.; Gardien, S.; Girerd, C.; Ianigro, J.-C.; Montorio, J.-L.; Gibert, D.; Nicollin, F.

    2012-04-01

    The DIAPHANE project is pluri-disciplinary collaboration between particle physicists and geophysicists to perform the tomography of large geological structure mainly devoted to the study of active volcanoes. The detector used for this tomography, hereafter referred to as telescope, uses a standard, robust, cost-effective and well-known technology based on solid plastic scintillator readout by photomultiplier(s) (either multichannel pixelized PM or silicon PM). The electronics system is built on the concept of autonomous, triggerless, smart sensor directly connected on a standard fast Ethernet network. First radiographies have been performed on the Mont-Terri underground laboratory (St-Ursanne, Switzerland) and on the active volcano of La Soufrière (Guadeloupe, Lesser Antilles, France). We present an upgrade of the readout architecture allowing to embed a sub-nanosecond resolution TDC within the existing programmable logic to help in the background rejection (rear flux, random coincidences) and to improve the detection purity and the radiography quality. First results obtained are also presented and briefly discussed.

  16. High-Resolution Mammography Detector Employing Optical Switching Readout

    NASA Astrophysics Data System (ADS)

    Irisawa, Kaku; Kaneko, Yasuhisa; Yamane, Katsutoshi; Sendai, Tomonari; Hosoi, Yuichi

    Conceiving a new detector structure, FUJIFILM Corporation has successfully put its invention of an X-ray detector employing "Optical Switching" into practical use. Since Optical Switching Technology allows an electrode structure to be easily designed, both high resolution of pixel pitch and low electrical noise readout have been achieved, which have consequently realized the world's smallest pixel size of 50×50 μm2 from a Direct-conversion FPD system as well as high DQE. The digital mammography system equipped with this detector enables to acquire high definition images while maintaining granularity. Its outstanding feature is to be able to acquire high-precision images of microcalcifications which is an important index in breast examination.

  17. Development of large area, pico-second resolution photo-detectors and associated readout electronics

    SciTech Connect

    Grabas, H.; Oberla, E.; Attenkoffer, K.; Bogdan, M.; Frisch, H. J.; Genat, J. F.; May, E. N.; Varner, G. S.; Wetstein, M.

    2011-07-01

    The Large Area Pico-second Photo-detectors described in this contribution incorporate a photo-cathode and a borosilicate glass capillary Micro-Channel Plate (MCP) pair functionalized by atomic layer deposition (ALD) of separate resistive and electron secondary emitters materials. They may be used for biomedical imaging purposes, a remarkable opportunity to apply technologies developed in HEP having the potential to make major advances in the medical world, in particular for Positron Emission Tomography (PET). If daisy-chained and coupled to fast transmission lines read at both ends, they could be implemented in very large dimensions. Initial testing with matched pairs of small glass capillary test has demonstrated gains of the order of 105 to 106. Compared to other fast imaging devices, these photo-detectors are expected to provide timing resolutions in the 10-100 ps range, and two-dimension position in the sub-millimeter range. A 6-channel readout ASIC has been designed in 130 nm CMOS technology and tested. As a result, fast analog sampling up to 17 GS/s has been obtained, the intrinsic analog bandwidth being presently under evaluation. The digitization in parallel of several cells in two microseconds allows getting off-chip digital data read at a maximum rate of 40 MHz. Digital Signal Processing of the sampled waveforms is expected achieving the timing and space resolutions obtained with digital oscilloscopes. (authors)

  18. Digital Signal Processors for Cryogenic High-Resolution X-Ray Detector Readout

    SciTech Connect

    Friedrich, S; Drury, O; Bechstein, S; Henning, W; Momayezi, M

    2003-01-01

    The authors are developing fast digital signal processors (DSPs) to read out superconducting high-resolution X-ray detectors with on-line pulse processing. For superconducting tunnel junction (STJ) detector read-out, the DSPs offer on-line filtering, rise time discrimination and pile-up rejection. Compared to analog pulse processing, DSP readout somewhat degrades the detector resolution, but improves the spectral purity of the detector response. They discuss DSP performance with the 9-channel STJ array for synchrotron-based high-resolution X-ray spectroscopy.

  19. Image readout device with electronically variable spatial resolution

    NASA Astrophysics Data System (ADS)

    Benz, H. A.

    1981-07-01

    An invention relating to the use of a standing acoustic wave charge storage device as an image readout device is described. A frequency f sub 1 was applied to the storage transfer device to create a traveling electric field in the device in one direction along a straight line. A second frequency f sub 2 was applied to the charge transfer device to create a traveling electric field opposite to the first traveling electric field. A standing wave was created. When an image was focused on the charge transfer device, light was stored in the wells of the standing wave. When the frequency f sub 2 is removed from the device, the standing wave tends to break up and the charges stored move to an electrode connected to an output terminal and to a utilization device where the received charges represent the image on the surface of the charge transfer device along a projection of said straight line.

  20. Development of a multiplexed readout with high position resolution for positron emission tomography

    NASA Astrophysics Data System (ADS)

    Lee, Sangwon; Choi, Yong; Kang, Jihoon; Jung, Jin Ho

    2017-04-01

    Detector signals for positron emission tomography (PET) are commonly multiplexed to reduce the number of digital processing channels so that the system can remain cost effective while also maintaining imaging performance. In this work, a multiplexed readout combining Anger position estimation algorithm and position decoder circuit (PDC) was developed to reduce the number of readout channels by a factor of 24, 96-to-4. The data acquisition module consisted of a TDC (50 ps resolution), 4-channel ADCs (12 bit, 105 MHz sampling rate), 2 GB SDRAM and USB3.0. The performance of the multiplexed readout was assessed with a high-resolution PET detector block composed of 2×3 detector modules, each consisting of an 8×8 array of 1.52×1.52×6 mm3 LYSO, a 4×4 array of 3×3 mm2 silicon photomultiplier (SiPM) and 13.4×13.4 mm2 light guide with 0.7 mm thickness. The acquired flood histogram showed that all 384 crystals could be resolved. The average energy resolution at 511 keV was 13.7±1.6% full-width-at-half-maximum (FWHM) and the peak-to-valley ratios of the flood histogram on the horizontal and vertical lines were 18.8±0.8 and 22.8±1.3, respectively. The coincidence resolving time of a pair of detector blocks was 6.2 ns FWHM. The reconstructed phantom image showed that rods down to a diameter of 1.6 mm could be resolved. The results of this study indicate that the multiplexed readout would be useful in developing a PET with a spatial resolution less than the pixel size of the photosensor, such as a SiPM array.

  1. Development of a low-noise readout ASIC for Silicon Drift Detectors in high energy resolution X-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Atkin, E.; Levin, V.; Malankin, E.; Shumikhin, V.

    2017-03-01

    ASIC with a low-noise readout channel for Silicon Drift Detectors in high energy resolution X-ray spectrometry was designed and prototyped in the AMS 350 nm CMOS process via Europractice as a miniASIC. For the analog readout channel tests there was used the detector module SDD-10-130-PTW LTplus-ic (PNDetector GmbH). The measured energy resolution of this module with the designed readout channel: 200 eV (FWHM) at 55Fe, -16 °C, 1 kcps and a peaking time of 8 μs.

  2. Digitial readout for microwave kinetic inductance detectors and applications in high time resolution astronomy

    NASA Astrophysics Data System (ADS)

    Strader, Matthew James

    This dissertation spans two topics relating to optical to near-infrared astronomical cameras built around Microwave Kinetic Inductance Detectors (MKIDs). The first topic is the development of a digital readout system for 10- to 30-kilopixel arrays of MKIDs. MKIDs are superconducting detectors that can detect individual photons with a wide range of wavelengths with high time resolution (SI{2}{micro s}) and low energy resolution. The advantage of MKIDs over other low temperature detectors with similar capabilities is that it is relatively straightforward to multiplex MKIDs into large arrays. All the complexity of readout is in room temperature electronics. This work discusses the implementation and programming of these electronics. The second part of this work demonstrates the capabilities of the prototype optical and near-infrared MKID instrument with observations of pulsars. Detecting optical pulsations in these objects require high time resolution and low noise. The discovery of a correlation between the brightness of optical pulses from the Crab pulsar and the time of arrival of coincident giant radio pulses is presented. The search for optical pulses from a millisecond pulsar J0337+1715 is discussed along with a new upper limit on the brightness of its optical pulses.

  3. Feasibility study of an avalanche photodiode readout for a high resolution PET with nsec time resolution

    SciTech Connect

    Schmelz, C.; Ziegler, S.; Bradbury, S.M.; Holl, I.; Lorenz, E.; Renker, D.

    1995-08-01

    A feasibility study for a high resolution positron emission tomograph, based on 9.5 x 4 x 4 mm{sup 3} LSO crystals viewed by 3 mm diameter avalanche photodiodes, has been carried out. Using a Na{sup 22} source the authors determined a spatial resolution of 2.3 {+-} 0.1 mm, an energy resolution around 15 % and a time resolution of 2.6 nsec. Possible configurations for larger scale tests and a tomograph are given.

  4. Mining maximal approximate numerical frequent patterns from uncertain data and application for emitter entity resolution

    NASA Astrophysics Data System (ADS)

    Xu, Xin

    2017-06-01

    Numerous fuzzy pattern mining methods have been proposed to address the uncertainty and incompleteness of quantitative data. Traditional fuzzy pattern mining methods generally have to transform the original quantitative values into either crystal items or fuzzy regions first, which is hard to apply without comprehensive domain knowledge. In addition, existing numerical pattern mining methods generally suffer high computational cost. Inspired by the above problems, we put forward an efficient maximal approximate numerical frequent pattern mining (MANFPM) method without fuzzy item or region specification. Experimental results have validated its scalability and effectiveness for application in emitter entity resolution.

  5. Response function of super-resolution readout of an optical disc studied by coupled electromagnetic-thermal simulation

    NASA Astrophysics Data System (ADS)

    Sano, Haruyuki; Shima, Takayuki; Kuwahara, Masashi; Fujita, Yoshiya; Uchiyama, Munehisa; Aono, Yoshiyuki

    2016-09-01

    To fully understand the properties of the readout signal in the super-resolution state, we implemented a multi-physics simulation of the propagation of electromagnetic waves and heat conduction in an optical disc that incorporates an InSb active layer. Response functions were obtained by calculating the light intensity reflected from a single small-pit structure. It was found that a typical response function in the super-resolution state has an asymmetric double-peak structure with high-spatial-frequency components. The complex profile of the response function indicated that the position of protrusions in the readout signal does not exactly correspond to that of the refractive index profile of the pit arrangement. We demonstrated that the measured readout signals also exhibit this particular characteristic and are roughly reproduced by the signals estimated from the response functions.

  6. High-density channel model and detection method for signal readout from super-resolution near-field structure discs

    NASA Astrophysics Data System (ADS)

    Hosogai, Shota; Ansai, Tsutomu; Yoshinari, Takehisa; Tanabe, Takaya

    2016-09-01

    Although a readout method using the super-resolution near-field structure (super-RENS) effect can overcome diffraction limits, readout characteristics for greatly surpassed high-density conditions do not become clear, because a high-density channel function having a differential response property is superimposed on a normal readout function. We propose a high-density channel model to indicate the properties of the super-RENS effect directly. This model can be expressed as a differential response function using the finite impulse response (FIR) filter model. It expresses the super-RENS readout process, which is divided on the basis of recording densities such as high and normal Blu-ray Disc™ densities. We estimated the properties of super-RENS readout signals by comparison between theoretical expressions and experiments. Results show that good signal quality require readout signals having sharp peaks and smaller offsets. We also evaluated the channel model by adding an adaptive FIR filter and a Viterbi decoder by simulations. Results show that the super-RENS disc can achieve a fourfold higher recording density if the signal-to-noise ratio (S/N) is improved to 6 dB in the case of partial response (PR) (1 + D + D 2).

  7. Lutetium oxyorthosilicate block detector readout by avalanche photodiode arrays for high resolution animal PET.

    PubMed

    Pichler, B J; Swann, B K; Rochelle, J; Nutt, R E; Cherry, S R; Siegel, S B

    2004-09-21

    Avalanche photodiodes (APDs) have proven to be useful as light detectors for high resolution positron emission tomography (PET). Their compactness makes these devices excellent candidates for replacing bulky photomultiplier tubes (PMTs) in PET systems where space limitations are an issue. The readout of densely packed, 10 x 10 lutetium oxyorthosilicate (LSO) block detectors (crystal size 2.0 x 2.0 x 12 mm3) with custom-built monolithic 3 x 3 APD arrays was investigated. The APDs had a 5 x 5 mm2 active surface and were arranged on a 6.25 mm pitch. The dead space on the edges of the array was 1.25 mm. The APDs were operated at a bias voltage of approximately 380 V for a gain of 100 and a dark current of 10 nA per APD. The standard deviation in gain between the APDs in the array ranged from 1.8 to 6.5% as the gain was varied from 50 to 108. A fast, low-noise, multi-channel charge sensitive preamplifier application-specific integrated circuit (ASIC) was developed for the APD readout. The amplifier had a rise time of 8 ns, a noise floor of 515 e- rms and a 9 e- pF(-1) noise slope. An acquired flood image showed that all 100 crystals from the block detector could be resolved. Timing measurements with single-channel LSO-APD detectors, as well as with the array, against a plastic scintillator and PMT assembly showed a time resolution of 1.2 ns and 2.5 ns, respectively. The energy resolution measured with a single 4.0 x 4.0 x 10 mm3 LSO crystal, wrapped in four-layer polytetrafluoroethylene (PTFE) tape and coupled with optical grease on a single APD of the array, yielded 15% (full width at half maximum, FWHM) at 511 keV. Stability tests over 9 months of operation showed that the APD arrays do not degrade appreciably. These results demonstrate the ability to decode densely packed LSO scintillation blocks with compact APD arrays. The good timing and energy resolution makes these detectors suitable for high resolution PET.

  8. Decoupling absorption and emission processes in super-resolution localization of emitters in a plasmonic hotspot

    NASA Astrophysics Data System (ADS)

    Mack, David L.; Cortés, Emiliano; Giannini, Vincenzo; Török, Peter; Roschuk, Tyler; Maier, Stefan A.

    2017-02-01

    The absorption process of an emitter close to a plasmonic antenna is enhanced due to strong local electromagnetic (EM) fields. The emission, if resonant with the plasmonic system, re-radiates to the far-field by coupling with the antenna via plasmonic states, whose presence increases the local density of states. Far-field collection of the emission of single molecules close to plasmonic antennas, therefore, provides mixed information of both the local EM field strength and the local density of states. Moreover, super-resolution localizations from these emission-coupled events do not report the real position of the molecules. Here we propose using a fluorescent molecule with a large Stokes shift in order to spectrally decouple the emission from the plasmonic system, leaving the absorption strongly resonant with the antenna's enhanced EM fields. We demonstrate that this technique provides an effective way of mapping the EM field or the local density of states with nanometre spatial resolution.

  9. Decoupling absorption and emission processes in super-resolution localization of emitters in a plasmonic hotspot

    PubMed Central

    Mack, David L.; Cortés, Emiliano; Giannini, Vincenzo; Török, Peter; Roschuk, Tyler; Maier, Stefan A.

    2017-01-01

    The absorption process of an emitter close to a plasmonic antenna is enhanced due to strong local electromagnetic (EM) fields. The emission, if resonant with the plasmonic system, re-radiates to the far-field by coupling with the antenna via plasmonic states, whose presence increases the local density of states. Far-field collection of the emission of single molecules close to plasmonic antennas, therefore, provides mixed information of both the local EM field strength and the local density of states. Moreover, super-resolution localizations from these emission-coupled events do not report the real position of the molecules. Here we propose using a fluorescent molecule with a large Stokes shift in order to spectrally decouple the emission from the plasmonic system, leaving the absorption strongly resonant with the antenna's enhanced EM fields. We demonstrate that this technique provides an effective way of mapping the EM field or the local density of states with nanometre spatial resolution. PMID:28211479

  10. Time-Optimized High-Resolution Readout-Segmented Diffusion Tensor Imaging

    PubMed Central

    Reishofer, Gernot; Koschutnig, Karl; Langkammer, Christian; Porter, David; Jehna, Margit; Enzinger, Christian; Keeling, Stephen; Ebner, Franz

    2013-01-01

    Readout-segmented echo planar imaging with 2D navigator-based reacquisition is an uprising technique enabling the sampling of high-resolution diffusion images with reduced susceptibility artifacts. However, low signal from the small voxels and long scan times hamper the clinical applicability. Therefore, we introduce a regularization algorithm based on total variation that is applied directly on the entire diffusion tensor. The spatially varying regularization parameter is determined automatically dependent on spatial variations in signal-to-noise ratio thus, avoiding over- or under-regularization. Information about the noise distribution in the diffusion tensor is extracted from the diffusion weighted images by means of complex independent component analysis. Moreover, the combination of those features enables processing of the diffusion data absolutely user independent. Tractography from in vivo data and from a software phantom demonstrate the advantage of the spatially varying regularization compared to un-regularized data with respect to parameters relevant for fiber-tracking such as Mean Fiber Length, Track Count, Volume and Voxel Count. Specifically, for in vivo data findings suggest that tractography results from the regularized diffusion tensor based on one measurement (16 min) generates results comparable to the un-regularized data with three averages (48 min). This significant reduction in scan time renders high resolution (1×1×2.5 mm3) diffusion tensor imaging of the entire brain applicable in a clinical context. PMID:24019951

  11. High-spatial-resolution MWPC for medical imaging with positron emitters

    SciTech Connect

    Del Guerra, A.; Perez-Mendez, V.; Schwartz, G.; Sleaford, B.

    1982-03-01

    The performance of a 15 x 15 cm/sup 2/ MultiWire Proportional Chamber (MWPC) with lead glass tube converter is presented. A standard Argon-Methane (70-30) gas mixture has been used at various pressures between 1.0 and 2.0 atm. For 511 keV ..gamma..-rays incident almost perpendicular onto a 1.0 cm thick lead glass tube converter, a detection efficiency of 4.5%, a time resolution of 130 ns (FWHM) and a spatial resolution of 1.3 mm (FWHM) has been obtained at 2 atm. Fast delay lines, capacitively coupled to the cathodes, standard integrated amplifiers and comparator electronics have been adopted for the position read-out. The use of fast delay lines (specific delay 8 ns/cm) ensures a high rate capability. A multiplanar positron camera is proposed, made of six MWPC modules arranged to form the lateral surface of a hexagonal prism. Each module (50 x 50 cm/sup 2/) will have a 2 cm thick converter on both sides of the chamber and will be operating at 2 atm. The expected performance is presented and compared with that of a recent multi-ring BGO camera, and is shown to be superior in spatial resolution and comparable in event rate at a considerably lower cost.

  12. A simple readout method for MWPCs with high-rate and sub-millimetre resolution

    NASA Astrophysics Data System (ADS)

    Fonte, P.

    1994-09-01

    In this work we describe the experimental tests of a new approach to the fast digital readout of MWPCs: electronic subdivision of the cathode strips increases the readout granularity, while a special coding method allows one to extract the address information from a small number of analogue channels with very simple electronics. The principle is demonstrated to be correct and a quite satisfactory performance is observed. This method may help to create economically the large and fast readout systems necessary for high-luminosity colliders and synchrotron radiation research. Also space-borne applications may profit from reduced weight and power requirements.

  13. Study and simulation of the read-out electronics design for a high-resolution plastic scintillating fiber based hodoscope

    NASA Astrophysics Data System (ADS)

    Blasco, José María; Sanchis, E.; Granero, D.; Martín, J. D.; González, V.; Sanchis-Sánchez, E.

    2015-06-01

    This work presents the study and simulation of a high-resolution charged particle detection device for beam positioning, monitoring and calibration, together with its read-out proposal. To provide the precise positional information of the beam, the detection system has been based on Plastic Scintillating Fibers (PSF), while the read-out on a Silicon-PhotoDiode (Si-PD) array. To carry out the study, a PSF prototype with one detection plane has been experimentally tested with a β particle source. Besides, Monte Carlo simulations of the complete system have also been conducted. Both simulations and experimental tests give consistency to the results obtained. The work presented in this article show the usefulness of this proposal for high-precision charged particle positioning, achieving resolutions up to 100 μm.

  14. A high-resolution multi-slit phase space measurement technique for low-emittance beams

    SciTech Connect

    Thangaraj, J. C. T.; Piot, P.

    2012-12-21

    Precise measurement of transverse phase space of a high-brightness electron beamis of fundamental importance in modern accelerators and free-electron lasers. Often, the transverse phase space of a high-brightness, space-charge-dominated electron beam is measured using a multi-slit method. In this method, a transverse mask (slit/pepperpot) samples the beaminto a set of beamlets, which are then analyzed on to a screen downstream. The resolution in this method is limited by the type of screen used which is typically around 20 {mu}m for a high-sensitivity Yttrium Aluminum Garnet screen. Accurate measurement of sub-micron transverse emittance using this method would require a long drift space between the multi-slit mask and observation screen. In this paper, we explore a variation of the technique that incorporates quadrupole magnets between the multi-slit mask and the screen. It is shown that this arrangement can improve the resolution of the transverse-phase-space measurement with in a short footprint.

  15. Time resolution of time-of-flight detector based on multiple scintillation counters readout by SiPMs

    NASA Astrophysics Data System (ADS)

    Cattaneo, P. W.; De Gerone, M.; Gatti, F.; Nishimura, M.; Ootani, W.; Rossella, M.; Shirabe, S.; Uchiyama, Y.

    2016-08-01

    A new timing detector measuring ∼ 50 MeV / c positrons is under development for the MEG II experiment, aiming at a time resolution σt ∼ 30 ps. The resolution is expected to be achieved by measuring each positron time with multiple counters made of plastic scintillator readout by silicon photomultipliers (SiPMs). The purpose of this work is to demonstrate the time resolution for ∼ 50 MeV / c positrons using prototype counters. Counters with dimensions of 90 × 40 × 5mm3 readout by six SiPMs (three on each 40 × 5mm2 plane) were built with SiPMs from Hamamatsu Photonics and AdvanSiD and tested in a positron beam at the DAΦNE Beam Test Facility. The time resolution was found to improve nearly as the square root of the number of counter hits. A time resolution σt = 26.2 ± 1.3 ps was obtained with eight counters with Hamamatsu SiPMs. These results suggest that the design resolution is achievable in the MEG II experiment.

  16. Toward Large FOV High-Resolution X-Ray Imaging Spectrometer: Microwave Multiplexed Readout of 32 TES Microcalorimeters

    NASA Technical Reports Server (NTRS)

    Yoon, Wonsik; Adams, Joseph S.; Bandler, Simon R.; Chervenak, James A.; Datesman, Aaron M.; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; Miniussi, Antoine R.; hide

    2017-01-01

    We performed a small-scale demonstration at GSFC of high-resolution x-ray TES microcalorimeters read out using a microwave SQUID multiplexer. This work is part of our effort to develop detector and readout technologies for future space based x-ray instruments such as the microcalorimeter spectrometer envisaged for Lynx, a large mission concept under development for the Astro 2020 Decadal Survey. In this paper we describe our experiment, including details of a recently designed, microwave-optimized low-temperature setup that is thermally anchored to the 50 mK stage of our laboratory ADR. Using a ROACH2 FPGA at room temperature, we simultaneously read out 32 pixels of a GSFC-built detector array via a NIST-built multiplexer chip with Nb coplanar waveguide resonators coupled to RF SQUIDs. The resonators are spaced 6 MHz apart (at approx. 5.9 GHz) and have quality factors of approximately 15,000. Using flux-ramp modulation frequencies of 160 kHz we have achieved spectral resolutions of 3 eV FWHM on each pixel at 6 keV. We will present the measured system-level noise and maximum slew rates, and briefly describe the implications for future detector and readout design.

  17. Test beam studies of the light yield, time and coordinate resolutions of scintillator strips with WLS fibers and SiPM readout

    DOE PAGES

    Denisov, Dmitri; Evdokimov, Valery; Lukic, Strahinja; ...

    2016-12-24

    Prototype scintilator+WLS strips with SiPM readout for large muon detection systems were tested in the muon beam of the Fermilab Test Beam Facility. Furthermore, light yield of up to 137 photoelectrons per muon per strip has been observed, as well as time resolution of 330 ps and position resolution along the strip of 5.4 cm.

  18. Test beam studies of the light yield, time and coordinate resolutions of scintillator strips with WLS fibers and SiPM readout

    NASA Astrophysics Data System (ADS)

    Denisov, Dmitri; Evdokimov, Valery; Lukić, Strahinja; Ujić, Predrag

    2017-03-01

    Prototype scintilator+WLS strips with SiPM readout for large muon detection systems were tested in the muon beam of the Fermilab Test Beam Facility. Light yield of up to 137 photoelectrons per muon per strip has been observed , as well as time resolution of 330 ps and position resolution along the strip of 5.4 cm.

  19. Comparison of Detector Intrinsic Spatial Resolution Characteristics for Sensor on the Entrance Surface and Conventional Readout Designs

    PubMed Central

    Miyaoka, Robert S.; Li, Xiaoli; Lockhart, Cate; Lewellen, Tom K.

    2011-01-01

    We report on a high resolution, monolithic crystal PET detector design concept that provides depth of interaction (DOI) positioning within the crystal. Our design utilizes a novel sensor on the entrance surface (SES) approach combined with a maximum likelihood positioning algorithm. We compare the intrinsic spatial resolution characteristics (i.e., X, Y and Z) using our SES design versus conventional placement of the photo-sensors on the rear surface of the crystal. The sensors can be any two-dimensional array of solid state readout devices (e.g., silicon photomultipliers (SiPM) or avalanche photodiodes (APD)). SiPMs are a new type of solid-state photodetector with Geiger mode operation that can provide signal gain similar to a photomltipiler tube (PMT). Utilizing a multi-step simulation process, we determined the intrinsic spatial resolution characteristics for a variety of detector configurations. The SES design was evaluated via simulation for three different two-dimensional array sizes: 8×8 with 5.8×5.8 mm2 pads; 12×12 with 3.8×3.8mm2 pads; and 16×16 with 2.8×2.8 mm2 pads. To reduce the number of signal channels row-column summing readout was used for the 12×12 and 16×16 channel array devices. The crystal was modeled as a 15 mm monolithic slab of a lutetium-based scintillator with the large area surface varying from 48.8×48.8 mm2 up to 49.6×49.6 mm2 depending upon the dimensions of the two-dimensional photo-sensor array. The intrinsic spatial resolution for the 8×8 array is 0.88 mm FWHM in X and Y, and 1.83 mm FWHM in Z (i.e., DOI). Comparing the results versus using a conventional design with the photo-sensors on the backside of the crystal, an average improvement of ~24% in X and Y and 20% in Z is achieved. The X, Y intrinsic spatial resolution improved to 0.67 mm and 0.64 mm FWHM for the 12×12 and 16×16 arrays using row-column readout. Using the 12×12 and 16×16 arrays also led to a slight improvement in the DOI positioning accuracy. PMID

  20. Comparison of Detector Intrinsic Spatial Resolution Characteristics for Sensor on the Entrance Surface and Conventional Readout Designs.

    PubMed

    Miyaoka, Robert S; Li, Xiaoli; Lockhart, Cate; Lewellen, Tom K

    2010-01-01

    We report on a high resolution, monolithic crystal PET detector design concept that provides depth of interaction (DOI) positioning within the crystal. Our design utilizes a novel sensor on the entrance surface (SES) approach combined with a maximum likelihood positioning algorithm. We compare the intrinsic spatial resolution characteristics (i.e., X, Y and Z) using our SES design versus conventional placement of the photo-sensors on the rear surface of the crystal. The sensors can be any two-dimensional array of solid state readout devices (e.g., silicon photomultipliers (SiPM) or avalanche photodiodes (APD)). SiPMs are a new type of solid-state photodetector with Geiger mode operation that can provide signal gain similar to a photomltipiler tube (PMT). Utilizing a multi-step simulation process, we determined the intrinsic spatial resolution characteristics for a variety of detector configurations. The SES design was evaluated via simulation for three different two-dimensional array sizes: 8×8 with 5.8×5.8 mm(2) pads; 12×12 with 3.8×3.8mm(2) pads; and 16×16 with 2.8×2.8 mm(2) pads. To reduce the number of signal channels row-column summing readout was used for the 12×12 and 16×16 channel array devices. The crystal was modeled as a 15 mm monolithic slab of a lutetium-based scintillator with the large area surface varying from 48.8×48.8 mm(2) up to 49.6×49.6 mm(2) depending upon the dimensions of the two-dimensional photo-sensor array. The intrinsic spatial resolution for the 8×8 array is 0.88 mm FWHM in X and Y, and 1.83 mm FWHM in Z (i.e., DOI). Comparing the results versus using a conventional design with the photo-sensors on the backside of the crystal, an average improvement of ~24% in X and Y and 20% in Z is achieved. The X, Y intrinsic spatial resolution improved to 0.67 mm and 0.64 mm FWHM for the 12×12 and 16×16 arrays using row-column readout. Using the 12×12 and 16×16 arrays also led to a slight improvement in the DOI positioning accuracy.

  1. A New Flat-Panel Digital Mammography Detector with Avalanche Photoconductor and High-Resolution Field Emitter Readout

    DTIC Science & Technology

    2005-06-01

    electric field Ese as opposed to the fixed high conversion gain of HgI 2 or PbI2. One of 4 the practical problems of having a fixed high gain is that the...Nylen, K. Shah, L. Melekhov and H. Hermon, "Comparison of PbI2 and HgI 2 for direct detection active matrix x-ray image sensors", J. Appl. Phys. 91...a-Se and HgI 2", Appl. Phys. Lett. 80, 1664-1666 (2002) 23 14 N. Matsuura, Wei Zhao, Z. Huang and J. A. Rowlands, "Digital radiology using active

  2. Development and characterization of high-resolution neutron pixel detectors based on Timepix read-out chips

    NASA Astrophysics Data System (ADS)

    Krejci, F.; Zemlicka, J.; Jakubek, J.; Dudak, J.; Vavrik, D.; Köster, U.; Atkins, D.; Kaestner, A.; Soltes, J.; Viererbl, L.; Vacik, J.; Tomandl, I.

    2016-12-01

    Using a suitable isotope such as 6Li and 10B semiconductor hybrid pixel detectors can be successfully adapted for position sensitive detection of thermal and cold neutrons via conversion into energetic light ions. The adapted devices then typically provides spatial resolution at the level comparable to the pixel pitch (55 μm) and sensitive area of about few cm2. In this contribution, we describe further progress in neutron imaging performance based on the development of a large-area hybrid pixel detector providing practically continuous neutron sensitive area of 71 × 57 mm2. The measurements characterising the detector performance at the cold neutron imaging instrument ICON at PSI and high-flux imaging beam-line Neutrograph at ILL are presented. At both facilities, high-resolution high-contrast neutron radiography with the newly developed detector has been successfully applied for objects which imaging were previously difficult with hybrid pixel technology (such as various composite materials, objects of cultural heritage etc.). Further, a significant improvement in the spatial resolution of neutron radiography with hybrid semiconductor pixel detector based on the fast read-out Timepix-based detector is presented. The system is equipped with a thin planar 6LiF convertor operated effectively in the event-by-event mode enabling position sensitive detection with spatial resolution better than 10 μm.

  3. A silicon pixel readout ASIC with 100 ps time resolution for the NA62 experiment

    NASA Astrophysics Data System (ADS)

    Dellacasa, G.; Garbolino, S.; Marchetto, F.; Martoiu, S.; Mazza, G.; Rivetti, A.; Wheadon, R.

    2011-01-01

    The silicon tracker of the NA62 experiment requires the measurement of the particles arrival time with a resolution better than 200 ps rms and a spatial resolution of 300 μm. A time measurement technique based on a Time to Amplitude Converter has been implemented in an ASIC in order to prove the possibility to integrate a TDC with resolution better than 200 ps in a pixel cell. Time-walk problem has been addressed with the use of the Constant Fraction Discriminator technique. The ASIC has been designed in a CMOS 0.13 μm technology with single event upset protection of the digital logic.

  4. Investigation of high resolution compact gamma camera module based on a continuous scintillation crystal using a novel charge division readout method

    NASA Astrophysics Data System (ADS)

    Dai, Qiu-Sheng; Zhao, Cui-Lan; Zhang, Hua-Lin; Qi, Yu-Jin

    2010-08-01

    The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel sub-tractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99mTc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image shrinkage problem associated with the conventional resistive readout can be effectively overcome by the novel subtractive resistive readout with an appropriate fraction subtraction factor. The response output area (ROA) of the camera shown in the flood image was improved up to 34%, and an intrinsic spatial resolution better than 2 mm of detector was achieved. In conclusion, the utilization of a continuous scintillation crystal and a flat-panel PSPMT equipped with a novel subtractive resistive readout is a feasible approach for developing a high performance and lower cost compact gamma camera.

  5. Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph

    NASA Astrophysics Data System (ADS)

    Moskal, P.; Rundel, O.; Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Giergiel, K.; Gorgol, M.; Jasińska, B.; Kamińska, D.; Kapłon, Ł.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz; Pałka, M.; Raczyński, L.; Rudy, Z.; Sharma, N. G.; Słomski, A.; Silarski, M.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.; Witkowski, P.; Zieliński, M.; Zoń, N.

    2016-03-01

    Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the 2× 5 configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the 2× 5 matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of ≈ 0.170 ns for 15 cm axial field-of-view (AFOV) and ≈ 0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.

  6. Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph.

    PubMed

    Moskal, P; Rundel, O; Alfs, D; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Giergiel, K; Gorgol, M; Jasińska, B; Kamińska, D; Kapłon, Ł; Korcyl, G; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Niedźwiecki, Sz; Pałka, M; Raczyński, L; Rudy, Z; Sharma, N G; Słomski, A; Silarski, M; Strzelecki, A; Wieczorek, A; Wiślicki, W; Witkowski, P; Zieliński, M; Zoń, N

    2016-03-07

    Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the [Formula: see text] configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the [Formula: see text] matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of [Formula: see text]0.170 ns for 15 cm axial field-of-view (AFOV) and [Formula: see text]0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.

  7. High-resolution Y-axis readout for delay-line microchannel anodes

    NASA Technical Reports Server (NTRS)

    Raffanti, R.; Lampton, M.

    1993-01-01

    We have devised a method to obtain a high-resolution Y-axis event position determination from microchannel plate delay-line detectors. The method is based on the double-delay-line wedge-wedge charge partition principle of Lampton et al. (1990), where the X axis is read out by a pair of side-by-side delay lines and the Y-axis coordinate is determined by comparing the charges on the two parallel delay lines. However, our new method abandons the common field return path of the two delay lines, and splits them into two adjacent but independent transformer coupled timing circuits having no common ground connection except via the charge-measurement amplifiers. Thus we eliminate the large electrostatic capacitance of the delay lines from the input of the charge-measuring system. Over its limited working field, the spatial resolution in the Y coordinate can easily equal the resolution provided in the X coordinate by the delay line. Applications to extreme and FUV photon-counting spectroscopy are envisioned.

  8. MuTRiG: a mixed signal Silicon Photomultiplier readout ASIC with high timing resolution and gigabit data link

    NASA Astrophysics Data System (ADS)

    Chen, H.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Shen, W.; Stankova, V.; Schultz-Coulon, H. C.

    2017-01-01

    MuTRiG is a mixed signal Silicon Photomultiplier readout ASIC designed in UMC 180 nm CMOS technology for precise timing and high event rate applications in high energy physics experiments and medical imaging. It is dedicated to the readout of the scintillating fiber detector and the scintillating tile detector of the Mu3e experiment. The MuTRiG chip extends the excellent timing performance of the STiCv3 chip with a fast digital readout for high rate applications. The high timing performance of the fully differential SiPM readout channels and 50 ps time binning TDCs are complemented by an upgraded digital readout logic and a 1.28 Gbps LVDS serial data link. The design of the chip and the characterization results of the analog front-end, TDC and the LVDS data link are presented.

  9. FERMI: a digital Front End and Readout MIcrosystem for high resolution calorimetry

    NASA Astrophysics Data System (ADS)

    Alexanian, H.; Appelquist, G.; Bailly, P.; Benetta, R.; Berglund, S.; Bezamat, J.; Blouzon, F.; Bohm, C.; Breveglieri, L.; Brigati, S.; Cattaneo, P. W.; Dadda, L.; David, J.; Engström, M.; Genat, J. F.; Givoletti, M.; Goggi, V. G.; Gong, S.; Grieco, G. M.; Hansen, M.; Hentzell, H.; Holmberg, T.; Höglund, I.; Inkinen, S. J.; Kerek, A.; Landi, C.; Ledortz, O.; Lippi, M.; Lofstedt, B.; Lund-Jensen, B.; Maloberti, F.; Mutz, S.; Nayman, P.; Piuri, V.; Polesello, G.; Sami, M.; Savoy-Navarro, A.; Schwemling, P.; Stefanelli, R.; Sundblad, R.; Svensson, C.; Torelli, G.; Vanuxem, J. P.; Yamdagni, N.; Yuan, J.; Ödmark, A.; Fermi Collaboration

    1995-02-01

    We present a digital solution for the front-end electronics of high resolution calorimeters at future colliders. It is based on analogue signal compression, high speed {A}/{D} converters, a fully programmable pipeline and a digital signal processing (DSP) chain with local intelligence and system supervision. This digital solution is aimed at providing maximal front-end processing power by performing waveform analysis using DSP methods. For the system integration of the multichannel device a multi-chip, silicon-on-silicon multi-chip module (MCM) has been adopted. This solution allows a high level of integration of complex analogue and digital functions, with excellent flexibility in mixing technologies for the different functional blocks. This type of multichip integration provides a high degree of reliability and programmability at both the function and the system level, with the additional possibility of customising the microsystem to detector-specific requirements. For enhanced reliability in high radiation environments, fault tolerance strategies, i.e. redundancy, reconfigurability, majority voting and coding for error detection and correction, are integrated into the design.

  10. The TDCpix Readout ASIC: A 75 ps Resolution Timing Front-End for the Gigatrackerof theNA62 Experiment

    NASA Astrophysics Data System (ADS)

    Rinella, G. Aglieri; Fiorini, M.; Jarron, P.; Kaplon, J.; Kluge, A.; Martin, E.; Morel, M.; Noy, M.; Perktold, L.; Poltorak, K.

    NA62 is an experiment under development at the CERN Super Proton Synchrotron, aiming at measuring ultra rare kaon decays. The Gigatracker (GTK) detector shall combine on-beam tracking of individual particles with a time resolution of 150 ps rms. The peak flow of particles crossing the detector modules reaches 1.27 MHz/mm2 fora total rateof about 0.75 GHz.Ahybrid siliconpixel detectoris beingdevelopedto meet these requirements. The pixel chip for the Gigatracker (TDCpix) is under design. The TDCpix chip will feature 1800 square pixels of 300×300 μm2 arranged in a matrix of 45 rows × 40 columns. Bump-bonded to a silicon pixel sensor it shall perform time stamping of particle hits with a timing accuracybetter than 200 ps rms and a detection efficiencyabove 99%. The chosen architecture provides full separation of the sensitive analog amplifiers of the pixel matrix from the noisy digital circuits of the TDCs and of the readout blocks. Discriminated hit signals from each pixel are transmitted to the end of column region. An array ofTime to Digital Converters (TDC) is implemented at the bottom of the pixel array. The TDCs are based on time tagging the events with the fine time codes generated by Delay Locked Loops (DLL) and have a nominal time bin of ˜100 ps. Time stamps and time-over-threshold are recorded for each discriminated hit and the correction of the discriminator's time-walk is performed off-detector. Data are continuously transmitted on four 2.4 Gb/s serial output links. Adescription of the on-going design of the final TDCpix is given in this paper. Design choices and some technical implementation details are presented. Aprototype ASIC including thekeycomponents of this architecture has been manufactured. The achievement of specification figures such as a time resolution of the processing chain of 75 ps rms as well as charged particle time stampingwitha resolutionbetterthan200psrmswere demonstratedexperimentally.Asummaryoftheseresultsisalso presented in

  11. High-resolution colorimetric assay for rapid visual readout of phosphatase activity based on gold/silver core/shell nanorod.

    PubMed

    Gao, Zhuangqiang; Deng, Kaichao; Wang, Xu-Dong; Miró, Manuel; Tang, Dianping

    2014-10-22

    Nanostructure-based visual assay has been developed for determination of enzymatic activity, but most involve in poor visible color resolution and are not suitable for routine utilization. Herein, we designed a high-resolution colorimetric protocol based on gold/silver core/shell nanorod for visual readout of alkaline phosphatase (ALP) activity by using bare-eyes. The method relied on enzymatic reaction-assisted silver deposition on gold nanorod to generate significant color change, which was strongly dependent on ALP activity. Upon target ALP introduction into the substrate, the ascorbic acid 2-phosphate was hydrolyzed to form ascorbic acid, and then, the generated ascorbic acid reduced silver ion to metal silver and coated on the gold nanorod, thereby resulting in the blue shift of longitudinal localized surface plasmon resonance peak of gold nanorod accompanying a perceptible color change from red to orange to yellow to green to cyan to blue and to violet. Under optimal conditions, the designed method exhibited the wide linear range 5-100 mU mL(-1) ALP with a detection limit of 3.3 mU mL(-1). Moreover, it could be used for the semiquantitative detection of ALP from 20 to 500 mU mL(-1) by using the bare-eyes. The coefficients of variation for intra- and interassay were below 3.5% and 6.2%, respectively. Finally, this method was validated for the analysis of real-life serum samples, giving results matched well with those from the 4-nitrophenyl phosphate disodium salt hexahydrate (pNPP)-based standard method. In addition, the system could even be utilized in the enzyme-linked immunosorbent assay (ELISA) to detect IgG at picomol concentration. With the merits of simplification, low cost, user-friendliness, and sensitive readout, the gold nanorod-based colorimetric assay has the potential to be utilized by the public and opens a new horizon for bioassays.

  12. Selective Emitters

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L. (Inventor)

    1992-01-01

    This invention relates to a small particle selective emitter for converting thermal energy into narrow band radiation with high efficiency. The small particle selective emitter is used in combination with a photovoltaic array to provide a thermal to electrical energy conversion device. An energy conversion apparatus of this type is called a thermo-photovoltaic device. In the first embodiment, small diameter particles of a rare earth oxide are suspended in an inert gas enclosed between concentric cylinders. The rare earth oxides are used because they have the desired property of large emittance in a narrow wavelength band and small emittance outside the band. However, it should be emphasized that it is the smallness of the particles that enhances the radiation property. The small particle selective emitter is surrounded by a photovoltaic array. In an alternate embodiment, the small particle gas mixture is circulated through a thermal energy source. This thermal energy source can be a nuclear reactor, solar receiver, or combustor of a fossil fuel.

  13. Selective emitters

    NASA Astrophysics Data System (ADS)

    Chubb, Donald L.

    1992-01-01

    This invention relates to a small particle selective emitter for converting thermal energy into narrow band radiation with high efficiency. The small particle selective emitter is used in combination with a photovoltaic array to provide a thermal to electrical energy conversion device. An energy conversion apparatus of this type is called a thermo-photovoltaic device. In the first embodiment, small diameter particles of a rare earth oxide are suspended in an inert gas enclosed between concentric cylinders. The rare earth oxides are used because they have the desired property of large emittance in a narrow wavelength band and small emittance outside the band. However, it should be emphasized that it is the smallness of the particles that enhances the radiation property. The small particle selective emitter is surrounded by a photovoltaic array. In an alternate embodiment, the small particle gas mixture is circulated through a thermal energy source. This thermal energy source can be a nuclear reactor, solar receiver, or combustor of a fossil fuel.

  14. High-resolution imaging X-ray detector. [using microchannel plates and electronic readout for spaceborne telescope

    NASA Technical Reports Server (NTRS)

    Kellogg, E.; Henry, P.; Murray, S.; Van Speybroeck, L.; Bjorkholm, P.

    1976-01-01

    The paper describes an X-ray detector using microchannel plates as a photocathode surface and imaging photoelectron multiplier, and a crossed wire grid as a two-dimensional position-sensitive detector. The position resolution is 10 microns. The crossed wire grid consists of 100-micron-diam wires on 200-micron centers. Position sensing is accomplished by electronic interpolation to 1/20 of the wire spacing. The quantum efficiency of the microchannel plates varies from 29% at 0.28 keV to 5% at 3 keV. This detector will provide second-of-arc X-ray imaging in the focal plane of the 342.9-cm focal length grazing-incidence telescope being prepared for the HEAO-B observatory. By addition of suitable photocathodes, it can be used for single-photon imaging light detection in the UV, visible, and near-IR-ranges. In all cases, it gives a very low dark counting rate, allows timing of individual events to 1 microsec or less, and can handle counting rates up to 10,000 per sec.

  15. High-resolution imaging X-ray detector. [using microchannel plates and electronic readout for spaceborne telescope

    NASA Technical Reports Server (NTRS)

    Kellogg, E.; Henry, P.; Murray, S.; Van Speybroeck, L.; Bjorkholm, P.

    1976-01-01

    The paper describes an X-ray detector using microchannel plates as a photocathode surface and imaging photoelectron multiplier, and a crossed wire grid as a two-dimensional position-sensitive detector. The position resolution is 10 microns. The crossed wire grid consists of 100-micron-diam wires on 200-micron centers. Position sensing is accomplished by electronic interpolation to 1/20 of the wire spacing. The quantum efficiency of the microchannel plates varies from 29% at 0.28 keV to 5% at 3 keV. This detector will provide second-of-arc X-ray imaging in the focal plane of the 342.9-cm focal length grazing-incidence telescope being prepared for the HEAO-B observatory. By addition of suitable photocathodes, it can be used for single-photon imaging light detection in the UV, visible, and near-IR-ranges. In all cases, it gives a very low dark counting rate, allows timing of individual events to 1 microsec or less, and can handle counting rates up to 10,000 per sec.

  16. CAD-II: the second version current-mode readout ASIC for high-resolution timing measurements

    NASA Astrophysics Data System (ADS)

    Yuan, Z. X.; Deng, Z.; Wang, Y.; Liu, Y. N.

    2016-07-01

    This paper presents the second version of a fully current-mode front-end ASIC, CAD (Current Amplifier and Discriminator), for MRPC detectors for TOF applications. Several upgrades have been made in this new version, including: 1). Using differential input stages with input impedance down to 30 Ω and LVDS compatible outputs; 2). Much higher current gain and bandwidth of 4.5 A/A and 380 MHz 3). Fabricated in 0.18 μ m CMOS process instead of 0.35 μ m CMOS technology used in CAD-I. The detailed design of the ASIC will be described as well as the measurement results. The single-ended input impedance could be as low as 32 Ω and the power consumption was measured to be 15 mW per channel. Input referred RMS noise current was about 0.56 μ A. The threshold could be set as low as 4.5 μ A referred to input, corresponding to 9 fC for the typical MRPC detector signal with 2 ns width. Sub-10 ps resolution has been measured for input signal above 200 μ A.

  17. Matrix effects on the triplet state of the OLED emitter Ir(4,6-dFppy)2(pic) (FIrpic): investigations by high-resolution optical spectroscopy.

    PubMed

    Rausch, Andreas F; Thompson, Mark E; Yersin, Hartmut

    2009-03-02

    The sky-blue emitting compound Ir(4,6-dFppy)(2)(pic) (iridium(III)bis[2-(4',6'-difluorophenyl)pyridinato-N,C(2')]-picolinate), commonly referred to as FIrpic and representing a well-known emitter material for organic light emitting diodes (OLEDs), has been investigated in detail by optical spectroscopy. Studies at temperatures from T = 1.5 K to T = 300 K were carried out in CH(2)Cl(2) and tetrahydrofuran (THF). In CH(2)Cl(2), two discrete sites were observed at cryogenic temperatures and studied by site-selective, high-resolution spectroscopy. The investigations reveal that the molecules located at the two sites exhibit distinctly different photophysical properties. For example, the three substates I, II, and III of the emitting triplet state T(1) of the low-energy site A show a distinctly larger zero-field splitting (ZFS) and exhibit shorter individual decay times than observed for the high-energy site B. The vibrational satellite structures in the emission spectra of the substates I(A) and I(B) exhibit clear differences in the ranges of metal-ligand (M-L) vibrations. For the compound studied in a polycrystalline THF host, giving only strongly inhomogeneously broadened spectra, the ZFS parameters and substate decay times vary in a similar range as observed for the two discrete sites in the CH(2)Cl(2) matrix. Thus, the amount of ZFS, the emission decay times, and also the intensities of the M-L vibrational satellites are affected by the matrix cage, that is, the host environment of the emitting complex. These properties are discussed with respect to variations of spin-orbit coupling routes. In particular, changes of d-orbital admixtures, that is, differences of the metal-to-ligand charge transfer (MLCT) character in the emitting triplet, play an important role. The matrix effects are expected to be also of importance for FIrpic and other Ir(III) compounds when applied as emitters in amorphous OLED matrixes.

  18. Brownian Emitters

    NASA Astrophysics Data System (ADS)

    Tsekov, Roumen

    2016-06-01

    A Brownian harmonic oscillator, which dissipates energy either by friction or via emission of electromagnetic radiation, is considered. This Brownian emitter is driven by the surrounding thermo-quantum fluctuations, which are theoretically described by the fluctuation-dissipation theorem. It is shown how the Abraham-Lorentz force leads to dependence of the half-width on the peak frequency of the oscillator amplitude spectral density. It is found that for the case of a charged particle moving in vacuum at zero temperature, its root-mean-square velocity fluctuation is a universal constant, equal to roughly 1/18 of the speed of light. The relevant Fokker-Planck and Smoluchowski equations are also derived.

  19. A pixel unit-cell targeting 16 ns resolution and radiation hardness in a column read-out particle vertex detector

    SciTech Connect

    Wright, M.; Millaud, J.; Nygren, D.

    1992-10-01

    A pixel unit cell (PUC) circuit architecture, optimized for a column read out architecture, is reported. Each PUC contains an integrator, active filter, comparator, and optional analog store. The time-over-threshold (TOT) discriminator allows an all-digital interface to the array periphery readout while passing an analog measure of collected charge. Use of (existing) radiation hard processes, to build a detector bump-bonded to a pixel readout array, is targeted. Here, emphasis is on a qualitative explanation of how the unique circuit implementation benefits operation for Super Collider (SSC) detector application.

  20. Asymmetrical field emitter

    DOEpatents

    Fleming, James G.; Smith, Bradley K.

    1995-01-01

    Providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure.

  1. Asymmetrical field emitter

    DOEpatents

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  2. Emittance Theory for Thin Film Selective Emitter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Lowe, Roland A.; Good, Brian S.

    1994-01-01

    Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

  3. Super-resolution high sensitivity AC Magnetic Field Imaging with NV Centers in Diamond

    NASA Astrophysics Data System (ADS)

    Bauch, Erik; Jaskula, Jean-Christophe; Trifonov, Alexei; Walsworth, Ronald

    2015-05-01

    The Nitrogen-Vacancy center in diamond (NV center), a defect consisting of a nitrogen atom next to a missing atom, has been successfully applied to sense magnetic field, electric field, temperature and can also be used as fluorescence marker and single photon emitter. We will present super-resolution imaging of NV centers and simultaneous sensing of AC magnetic fields with high sensitivity. To demonstrate the applicability of super-resolution magnetic field imaging, we resolve several NV centers with an optical resolution smaller than 20 nm and probe locally the gradient of a externally applied magnetic field. Additionally, we demonstrate the detection of magnetic field signals from 1H protons with subdiffraction image resolution. We will also show that our super-resolution magnetometer will benefit from a new readout method based on a spin-to-charge mapping that we have developed to increase the readout contrast.

  4. BESIII ETOF upgrade readout electronics commissioning

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Zhuang; Dai, Hong-Liang; Wu, Zhi; Heng, Yue-Kun; Zhang, Jie; Cao, Ping; Ji, Xiao-Lu; Li, Cheng; Sun, Wei-Jia; Wang, Si-Yu; Wang, Yun

    2017-01-01

    It is proposed to upgrade the endcap time-of-flight (ETOF) of the Beijing Spectrometer III (BESIII) with a multi-gap resistive plate chamber (MRPC), aiming at an overall time resolution of about 80 ps. After completing the entire readout electronics system, some experiments, such as heat radiation, radiation hardness and large-current beam tests, have been carried out to confirm the reliability and stability of the readout electronics. An on-detector test of the readout electronics has also been performed with the beam at the BEPCII E3 line. The test results indicate that the readout electronics system fulfills its design requirements. Supported by Chinese Academy of Sciences (1G201331231172010)

  5. Emittance Theory for Cylindrical Fiber Selective Emitter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.

    1998-01-01

    A fibrous rare earth selective emitter is approximated as an infinitely long cylinder. The spectral emittance, epsilon(lambda), is obtained by solving the radiative transfer equations with appropriate boundary conditions and uniform temperature. For optical depths, Kappa(R) = alpha(lambda)R, where alpha(lambda) is the extinction coefficient and R is the cylinder radius, greater than 1 the spectral emittance is nearly at its maximum value. There is an optimum cylinder radius, R(opt), for maximum emitter efficiency, eta(E). Values for R(opt) are strongly dependent on the number of emission bands of the material. The optimum radius decreases slowly with increasing emitter temperature, while the maximum efficiency and useful radiated power increase rapidly with increasing temperature.

  6. Floating emitter solar cell

    NASA Technical Reports Server (NTRS)

    Chih, Sah (Inventor); Cheng, Li-Jen (Inventor)

    1987-01-01

    A front surface contact floating emitter solar cell transistor is provided in a semiconductor body (n-type), in which floating emitter sections (p-type) are diffused or implanted in the front surface. Between the emitter sections, a further section is diffused or implanted in the front surface, but isolated from the floating emitter sections, for use either as a base contact to the n-type semiconductor body, in which case the section is doped n+, or as a collector for the adjacent emitter sections.

  7. A microstrip detector with delay line readout

    SciTech Connect

    Barbosa, A.F. , BP 220, 38043 Grenoble CNPq Riekel, C.; Wattecamps, P. , BP 220, 38043 Grenoble )

    1992-01-01

    Principal limitations of position sensitive gasfilled detectors for x-ray synchrotron radiation applications are the counting rate and the positional resolution. Improvements in both areas are expected with microstrip technology. First results of a linear position sensitive microstrip detector with delay line readout are shown, and the possibility to achieve two-dimensional localization is evaluated.

  8. Photonically Engineered Incandescent Emitter

    DOEpatents

    Gee, James M.; Lin, Shawn-Yu; Fleming, James G.; Moreno, James B.

    2005-03-22

    A photonically engineered incandescence is disclosed. The emitter materials and photonic crystal structure can be chosen to modify or suppress thermal radiation above a cutoff wavelength, causing the emitter to selectively emit in the visible and near-infrared portions of the spectrum. An efficient incandescent lamp is enabled thereby. A method for fabricating a three-dimensional photonic crystal of a structural material, suitable for the incandescent emitter, is also disclosed.

  9. Photonically engineered incandescent emitter

    DOEpatents

    Gee, James M.; Lin, Shawn-Yu; Fleming, James G.; Moreno, James B.

    2003-08-26

    A photonically engineered incandescence is disclosed. The emitter materials and photonic crystal structure can be chosen to modify or suppress thermal radiation above a cutoff wavelength, causing the emitter to selectively emit in the visible and near-infrared portions of the spectrum. An efficient incandescent lamp is enabled thereby. A method for fabricating a three-dimensional photonic crystal of a structural material, suitable for the incandescent emitter, is also disclosed.

  10. Demountable readout technologies for optical image intensifiers

    NASA Astrophysics Data System (ADS)

    Lapington, J. S.; Howorth, J. R.; Milnes, J. S.

    2007-04-01

    We describe a generic microchannel plate intensifier design for use with a variety of demountable readout devices manufactured using standard multi-layer PCB techniques. We present results obtained using a 50 Ω multi-element design optimized for high speed operation and a four electrode multi-layer device developed from the wedge and strip anode with enhanced image resolution. The benefits of this intensifier design are discussed and a project to develop a detector system for bio-medical applications using a demountable readout device with integrated multi-channel ASIC-based electronics is announced.

  11. Electronic readout systems for microchannel plates

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1985-01-01

    The modes of operation of position-sensitive electronic readout systems which use high-gain microchannel plate (MCP) electron multipliers are described, and their performance characteristics, along with those of the MCP, are compared. Among the structures presented are the wedge-and-strip, Codacon, and multilayer coincidence-anode MAMA (Multimode Microchannel Array) arrays. Spatial resolution of 25 x 25 sq microns (coincidence anode arrays) is achieved with an array format of 256 x 1024 pixels. On the basis of the performance data it is concluded that the readout systems using only conducting electrodes offer the best performance characteristics.

  12. A PET detector module with monolithic crystal, single end readout, SiPM array and high depth-of-interaction resolution

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Zhou, R.; Yang, C.

    2016-08-01

    Depth of interaction (DOI) technology can improve the spatial resolution of nuclear medicine imaging system which uses scintillation detectors such as Positron Emission Tomography (PET). In this paper, a prototype detector module with DOI capability is established to make complementary characteristic tests on an existing method and to improve the experimental performance using the same method. We investigate the gamma incident surface and incident angle effects on the positioning method with our model in simulations and evaluate its 3-D positioning results in experiment. It shows that the positioning results are highly affected by the gamma incident surface and incident angle. The 137Cs energy resolution is 12.1% and the DOI resolution is estimated at 2.26 mm in average by our detector in experiment.

  13. Test-beam results of a silicon pixel detector with Time-over-Threshold read-out having ultra-precise time resolution

    NASA Astrophysics Data System (ADS)

    Aglieri Rinella, G.; Cortina Gil, E.; Fiorini, M.; Kaplon, J.; Kluge, A.; Marchetto, F.; Albarran, M. E. Martin; Morel, M.; Noy, M.; Perktold, L.; Tiuraniem, S.; Velghe, B.

    2015-12-01

    A time-tagging hybrid silicon pixel detector developed for beam tracking in the NA62 experiment has been tested in a dedicated test-beam at CERN with 10 GeV/c hadrons. Measurements include time resolution, detection efficiency and charge sharing between pixels, as well as effects due to bias voltage variations. A time resolution of less than 150 ps has been measured with a 200 μm thick silicon sensor, using an on-pixel amplifier-discriminator and an end-of-column DLL-based time-to-digital converter.

  14. Diamond fiber field emitters

    DOEpatents

    Blanchet-Fincher, Graciela B.; Coates, Don M.; Devlin, David J.; Eaton, David F.; Silzars, Aris K.; Valone, Steven M.

    1996-01-01

    A field emission electron emitter comprising an electrode formed of at least one diamond, diamond-like carbon or glassy carbon composite fiber, said composite fiber having a non-diamond core and a diamond, diamond-like carbon or glassy carbon coating on said non-diamond core, and electronic devices employing such a field emission electron emitter.

  15. Pulsed hybrid field emitter

    DOEpatents

    Sampayan, S.E.

    1998-03-03

    A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays. 11 figs.

  16. Pulsed hybrid field emitter

    DOEpatents

    Sampayan, Stephen E.

    1998-01-01

    A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays.

  17. The DIORAMA Neutron Emitter

    SciTech Connect

    Terry, James Russell

    2016-05-05

    Emission of neutrons in a given event is modeled by the DioramaEmitterNeutron object, a subclass of the abstract DioramaEmitterModule object. The GenerateEmission method of this object is the entry point for generation of a neutron population for a given event. Shown in table 1, this method requires a number of parameters to be defined in the event definition.

  18. DIAMOND SECONDARY EMITTER

    SciTech Connect

    BEN-ZVI, I.; RAO, T.; BURRILL, A.; CHANG, X.; GRIMES, J.; RANK, J.; SEGALOV, Z.; SMEDLEY, J.

    2005-10-09

    We present the design and experimental progress on the diamond secondary emitter as an electron source for high average power injectors. The design criteria for average currents up to 1 A and charge up to 20 nC are established. Secondary Electron Yield (SEY) exceeding 200 in transmission mode and 50 in emission mode have been measured. Preliminary results on the design and fabrication of the self contained capsule with primary electron source and secondary electron emitter will also be presented.

  19. Design and performance of the new cathode readout proportional chambers in LASS

    SciTech Connect

    Aiken, G.; Aston, D.; Dunwoodie, W.

    1980-10-01

    The design and construction of a new proportional chamber system for the LASS spectrometer are discussed. This system consists of planar and cylindrical chambers employing anode wire and cathode strip readout techniques. The good timing characteristics of anode readout combine with the excellent spatial resolution of cathode readout to provide powerful and compact detectors. Preliminary resolution data are presented along with operating characteristics of the various devices.

  20. VCSELs for interferometric readout of MEMS sensors

    NASA Astrophysics Data System (ADS)

    Serkland, Darwin K.; Geib, Kent M.; Peake, Gregory M.; Keeler, Gordon A.; Shaw, Michael J.; Baker, Michael S.; Okandan, Murat

    2016-03-01

    We report on the development of single-frequency VCSELs (vertical-cavity surface-emitting lasers) for sensing the position of a moving MEMS (micro-electro-mechanical system) object with resolution much less than 1nm. Position measurement is the basis of many different types of MEMS sensors, including accelerometers, gyroscopes, and pressure sensors. Typically, by switching from a traditional capacitive electronic readout to an interferometric optical readout, the resolution can be improved by an order of magnitude with a corresponding improvement in MEMS sensor performance. Because the VCSEL wavelength determines the scale of the position measurement, laser wavelength (frequency) stability is desirable. This paper discusses the impact of VCSEL amplitude and frequency noise on the position measurement.

  1. XAMPS Detectors Readout ASIC for LCLS

    SciTech Connect

    Dragone, A; Pratte, J.F.; Rehak, P.; Carini, G.A.; Herbst, R.; O'Connor, P.; Siddons, D.P.; /BNL, NSLS

    2008-12-18

    An ASIC for the readout of signals from X-ray Active Matrix Pixel Sensor (XAMPS) detectors to be used at the Linac Coherent Light Source (LCLS) is presented. The X-ray Pump Probe (XPP) instrument, for which the ASIC has been designed, requires a large input dynamic range on the order of 104 photons at 8 keV with a resolution of half a photon FWHM. Due to the size of the pixel and the length of the readout line, large input capacitance is expected, leading to stringent requirement on the noise optimization. Furthermore, the large number of pixels needed for a good position resolution and the fixed LCLS beam period impose limitations on the time available for the single pixel readout. Considering the periodic nature of the LCLS beam, the ASIC developed for this application is a time-variant system providing low-noise charge integration, filtering and correlated double sampling. In order to cope with the large input dynamic range a charge pump scheme implementing a zero-balance measurement method has been introduced. It provides an on chip 3-bit coarse digital conversion of the integrated charge. The residual charge is sampled using correlated double sampling into analog memory and measured with the required resolution. The first 64 channel prototype of the ASIC has been fabricated in TSMC CMOS 0.25 {micro}m technology. In this paper, the ASIC architecture and performances are presented.

  2. Microwave multiplex readout for superconducting sensors

    NASA Astrophysics Data System (ADS)

    Ferri, E.; Becker, D.; Bennett, D.; Faverzani, M.; Fowler, J.; Gard, J.; Giachero, A.; Hays-Wehle, J.; Hilton, G.; Maino, M.; Mates, J.; Puiu, A.; Nucciotti, A.; Reintsema, C.; Schmidt, D.; Swetz, D.; Ullom, J.; Vale, L.

    2016-07-01

    The absolute neutrino mass scale is still an outstanding challenge in both particle physics and cosmology. The calorimetric measurement of the energy released in a nuclear beta decay is a powerful tool to determine the effective electron-neutrino mass. In the last years, the progress on low temperature detector technologies has allowed to design large scale experiments aiming at pushing down the sensitivity on the neutrino mass below 1 eV. Even with outstanding performances in both energy ( eV on keV) and time resolution ( 1 μs) on the single channel, a large number of detectors working in parallel is required to reach a sub-eV sensitivity. Microwave frequency domain readout is the best available technique to readout large array of low temperature detectors, such as Transition Edge Sensors (TESs) or Microwave Kinetic Inductance Detectors (MKIDs). In this way a multiplex factor of the order of thousands can be reached, limited only by the bandwidth of the available commercial fast digitizers. This microwave multiplexing system will be used to readout the HOLMES detectors, an array of 1000 microcalorimeters based on TES sensors in which the 163Ho will be implanted. HOLMES is a new experiment for measuring the electron neutrino mass by means of the electron capture (EC) decay of 163Ho. We present here the microwave frequency multiplex which will be used in the HOLMES experiment and the microwave frequency multiplex used to readout the MKID detectors developed in Milan as well.

  3. Sensor readout detector circuit

    DOEpatents

    Chu, Dahlon D.; Thelen, Jr., Donald C.

    1998-01-01

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems.

  4. Sensor readout detector circuit

    DOEpatents

    Chu, D.D.; Thelen, D.C. Jr.

    1998-08-11

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems. 6 figs.

  5. Nanoelectrospray Emitter Arrays Providing Inter-Emitter Electric Field Uniformity

    PubMed Central

    Kelly, Ryan T.; Page, Jason S.; Marginean, Ioan; Tang, Keqi; Smith, Richard D.

    2008-01-01

    Arrays of electrospray ionization (ESI) emitters have been reported previously as a means of enhancing ionization efficiency or signal intensity. A key challenge when working with multiple, closely spaced ESI emitters is overcoming the deleterious effects caused by electrical interference among neighboring emitters. Individual emitters can experience different electric fields depending on their relative position in the array, such that it becomes difficult to operate all of the emitters optimally for a given applied potential. In this work, we have developed multi-nanoESI emitters arranged with a circular pattern, which enable the constituent emitters to experience a uniform electric field. The performance of the circular emitter array was compared to a single emitter and to a previously developed linear emitter array, which verified that improved electric field uniformity was achieved with the circular arrangement. The circular arrays were also interfaced with a mass spectrometer via a matching multi-capillary inlet, and the results were compared with those obtained using a single emitter. By minimizing inter-emitter electric field inhomogeneities, much larger arrays having closer emitter spacing should be feasible. PMID:18553942

  6. Electrochemical formation of field emitters

    DOEpatents

    Bernhardt, Anthony F.

    1999-01-01

    Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area.

  7. Readout for a large area neutron sensitive microchannel plate detector

    NASA Astrophysics Data System (ADS)

    Wang, Yiming; Yang, Yigang; Wang, Xuewu; Li, Yuanjing

    2015-06-01

    A neutron sensitive microchannel plate (MCP) detector was developed for neutron imaging on the beamline of a compact pulsed hadron source (CPHS). The detector was set up with a Wedge-and-Strip Anode (WSA) and a delay line anode readout to compare the spatial resolution and throughput with these two anodes. Tests show that the WSA readout is suitable for small area imaging with a spatial resolution of 200 μm with low energy X-rays in a 50 mm diameter MCP-WSA assembly. However, the spatial resolution deteriorated to 2 mm in a 106 mm diameter MCP-WSA assembly because the noise caused by the parasitic capacitance is 10 times larger in the larger assembly than in the 50 mm diameter assembly. A 120 mm by 120 mm delay line anode was then used for the 106 mm MCP readout. The spatial resolution was evaluated for various voltages applied to the MCP V-stack, various readout voltages and various distances between the MCP V-stack rear face and the delay line. The delay line readout had resolutions of 65.6 μm in the x direction and 63.7 μm in the y direction and the throughput was greater than 600 kcps. The MCP was then used to acquire a neutron image of an USAF1951 Gd-mask.

  8. Cancer from internal emitters

    SciTech Connect

    Boecker, B.B.; Griffith, W.C. Jr.

    1995-10-01

    Irradiation from internal emitters, or internally deposited radionuclides, is an important component of radiation exposures encountered in the workplace, home, or general environment. Long-term studies of human populations exposed to various internal emitters by different routes of exposure are producing critical information for the protection of workers and members of the general public. The purpose of this report is to examine recent developments and discuss their potential importance for understanding lifetime cancer risks from internal emitters. The major populations of persons being studied for lifetime health effects from internally deposited radionuclides are well known: Lung cancer in underground miners who inhaled Rn progeny, liver cancer from persons injected with the Th-containing radiographic contrast medium Thorotrast, bone cancer from occupational or medical intakes of {sup 226}Ra or medical injections of {sup 224}Ra, and thyroid cancer from exposures to iodine radionuclides in the environment or for medical purposes.

  9. RFI emitter location techniques

    NASA Technical Reports Server (NTRS)

    Rao, B. L. J.

    1973-01-01

    The possibility is discussed of using Doppler techniques for determining the location of ground based emitters causing radio frequency interference with low orbiting satellites. An error analysis indicates that it is possible to find the emitter location within an error range of 2 n.mi. The parameters which determine the required satellite receiver characteristic are discussed briefly along with the non-real time signal processing which may by used in obtaining the Doppler curve. Finally, the required characteristics of the satellite antenna are analyzed.

  10. Study of spacecraft direct readout meteorological systems

    NASA Technical Reports Server (NTRS)

    Bartlett, R.; Elam, W.; Hoedemaker, R.

    1973-01-01

    Characteristics are defined of the next generation direct readout meteorological satellite system with particular application to Tiros N. Both space and ground systems are included. The recommended space system is composed of four geosynchronous satellites and two low altitude satellites in sun-synchronous orbit. The goesynchronous satellites transmit to direct readout ground stations via a shared S-band link, relayed FOFAX satellite cloud cover pictures (visible and infrared) and weather charts (WEFAX). Basic sensor data is transmitted to regional Data Utilization Stations via the same S-band link. Basic sensor data consists of 0.5 n.m. sub-point resolution data in the 0.55 - 0.7 micron spectral region, and 4.0 n.m. resolution data in the 10.5 - 12.6 micron spectral region. The two low altitude satellites in sun-synchronous orbit provide data to direct readout ground stations via a 137 MHz link, a 400 Mhz link, and an S-band link.

  11. Medipix2 parallel readout system

    NASA Astrophysics Data System (ADS)

    Fanti, V.; Marzeddu, R.; Randaccio, P.

    2003-08-01

    A fast parallel readout system based on a PCI board has been developed in the framework of the Medipix collaboration. The readout electronics consists of two boards: the motherboard directly interfacing the Medipix2 chip, and the PCI board with digital I/O ports 32 bits wide. The device driver and readout software have been developed at low level in Assembler to allow fast data transfer and image reconstruction. The parallel readout permits a transfer rate up to 64 Mbytes/s. http://medipix.web.cern ch/MEDIPIX/

  12. Design of a ballistic fluxon qubit readout

    NASA Astrophysics Data System (ADS)

    Herr Kidiyarova-Shevchenko, Anna; Fedorov, Arkady; Shnirman, Alexander; Il'ichev, Evgeny; Schön, Gerd

    2007-11-01

    A detailed design is given for a flux qubit readout using ballistic fluxons. In this scheme, fluxons propagate through an underdamped Josephson transmission line (JTL) coupled to the qubit, whose state affects the fluxon propagation time. For strong qubit-JTL coupling, and far from the symmetry point, a qubit can be measured with fidelity greater than 99% and measurement time of 4 ns. The readout circuit requires additional rapid single flux quantum (RSFQ) interface circuitry to launch and receive the delayed flux solitons. The parameters of this driver and receiver have been optimized to produce low fluxon speed at launch and impedance matching at the receiver. The delayed solitons are compared to a reference line using a detector with time resolution of better than 16 ps. Both the JTL and RSFQ interface were designed for the Nb 30 A cm-2 process developed at VTT, Finland, with postdeposition of the Al qubit at IPHT, Germany.

  13. Effect of Temperature Gradient on Thick Film Selective Emitter Emittance

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Good, Brian S.; Clark, Eric B.; Chen, Zheng

    1997-01-01

    A temperature gradient across a thick (greater than or equal to .1 mm) film selective emitter will produce a significant reduction in the spectral emittance from the no temperature gradient case. Thick film selective emitters of rare earth doped host materials such as yttrium-aluminum-garnet (YAG) are examples where temperature gradient effects are important. In this paper a model is developed for the spectral emittance assuming a linear temperature gradient across the film. Results of the model indicate that temperature gradients will result in reductions the order of 20% or more in the spectral emittance.

  14. SNO+ Readout Electronics Upgrades

    NASA Astrophysics Data System (ADS)

    Bonventre, Richard; Shokair, Timothy; Knapik, Robert

    2012-03-01

    The SNO+ experiment is designed to explore several topics in neutrino physics including neutrinoless double beta decay, reactor antineutrinos, and low energy solar neutrinos. SNO+ uses the existing Sudbury Neutrino Observatory (SNO) detector, with the heavy water target replaced with liquid scintillator. The new target requires an upgrade to the command and control electronics to handle the higher rates expected with scintillation light as compared to Cherenkov light. The readout electronics have been upgraded to autonomously push data to a central data acquisition computer over ethernet from each of the 19 front end crates. The autonomous readout is achieved with a field programmable gate array (FPGA) with an embedded processor. Inside the FPGA fabric a state machine is configured to pull data across the VME-like bus of each crate. A small C program, making use of the open source Light Weight IP (LWIP) libraries, is run directly on the hardware (with no operating system) to push the data via TCP/IP. The hybrid combination of `high-level' C code and a `low-level' VHDL state machine is a cost effective and flexible solution for reading out individual front end crates.

  15. Automatic readout micrometer

    DOEpatents

    Lauritzen, Ted

    1982-01-01

    A measuring system is disclosed for surveying and very accurately positioning objects with respect to a reference line. A principal use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse or fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

  16. Automatic readout micrometer

    DOEpatents

    Lauritzen, T.

    A measuring system is described for surveying and very accurately positioning objects with respect to a reference line. A principle use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse of fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

  17. Reappraisal of solid selective emitters

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.

    1990-01-01

    New rare earth oxide emitters show greater efficiency than previous emitters. As a result, based on a simple model the efficiency of these emitters was calculated. Results indicate that the emission band of the selective emitter must be at relatively low energy (less than or equal to .52 eV) to obtain maximum efficiency at moderate emitter temperatures (less than or equal to 1500 K). Thus low bandgap energy PV materials are required to obtain an efficient thermophotovoltaic (TPV) system. Of the 4 specific rare earths (Nd, Ho, Er, Yb) studied Ho has the largest efficiency at moderate temperatures (72 percent at 1500 K). A comparison was made between a selective emitter TPV system and a TPV system that uses a thermal emitter plus a band pass filter to make the thermal emitter behave like a selective emitter. Results of the comparison indicate that only for very optimistic filter and thermal emitter properties will the filter TPV system have a greater efficiency than the selective emitter system.

  18. Rare Earth Garnet Selective Emitter

    NASA Technical Reports Server (NTRS)

    Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

    1994-01-01

    Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approx. = 0.75, sup 4)|(sub 15/2) - (sup 4)|(sub 13/2),for Er-YAG and epsilon(sub lambda) approx. = 0.65, (sup 5)|(sub 7) - (sup 5)|(sub 8) for Ho-YAG) at 1500 K. In addition, low out-of-band spectral emittance, epsilon(sub lambda) less than 0.2, suggest these materials would be excellent candidates for high efficiency selective emitters in thermophotovoltaic (TPV) systems operating at moderate temperatures (1200-1500 K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. Selective emitters in the near IR are of special interest for thermophotovoltaic (TPV) energy conversion. The most promising solid selective emitters for use in a TPV system are rare earth oxides. Early spectral emittance work on rare earth oxides showed strong emission bands in the infrared (0.9 - 3 microns). However, the emittance outside the emission band was also significant and the efficiency of these emitters was low. Recent improvements in efficiency have been made with emitters fabricated from fine (5 - 10 microns) rare earth oxide fibers similar to the Welsbach mantle used in gas lanterns. However, the rare earth garnet emitters are more rugged than the mantle type emitters. A thin film selective emitter on a low emissivity substrate such as gold, platinum etc., is rugged and easily adapted to a wide variety of thermal sources. The garnet structure and its many subgroups have been successfully used as hosts for rare earth ions, introduced as substitutional

  19. ALMA deep field in SSA22: Blindly detected CO emitters and [C II] emitter candidates

    NASA Astrophysics Data System (ADS)

    Hayatsu, Natsuki H.; Matsuda, Yuichi; Umehata, Hideki; Yoshida, Naoki; Smail, Ian; Swinbank, A. Mark; Ivison, Rob; Kohno, Kotaro; Tamura, Yoichi; Kubo, Mariko; Iono, Daisuke; Hatsukade, Bunyo; Nakanishi, Kouichiro; Kawabe, Ryohei; Nagao, Tohru; Inoue, Akio K.; Takeuchi, Tsutomu T.; Lee, Minju; Ao, Yiping; Fujimoto, Seiji; Izumi, Takuma; Yamaguchi, Yuki; Ikarashi, Soh; Yamada, Toru

    2017-06-01

    We report the identification of four millimeter line-emitting galaxies with the Atacama Large Milli/submillimeter Array (ALMA) in SSA22 Field (ADF22). We analyze the ALMA 1.1-mm survey data, with an effective survey area of 5 arcmin2, frequency ranges of 253.1-256.8 and 269.1-272.8 GHz, angular resolution of 0{^''.}7 and rms noise of 0.8 mJy beam-1 at 36 km s-1 velocity resolution. We detect four line-emitter candidates with significance levels above 6σ. We identify one of the four sources as a CO(9-8) emitter at z = 3.1 in a member of the proto-cluster known in this field. Another line emitter with an optical counterpart is likely a CO(4-3) emitter at z = 0.7. The other two sources without any millimeter continuum or optical/near-infrared counterpart are likely to be [C II] emitter candidates at z = 6.0 and 6.5. The equivalent widths of the [C II] candidates are consistent with those of confirmed high-redshift [C II] emitters and candidates, and are a factor of 10 times larger than that of the CO(9-8) emitter detected in this search. The [C II] luminosity of the candidates are 4-7 × 108 L⊙. The star formation rates (SFRs) of these sources are estimated to be 10-20 M⊙ yr-1 if we adopt an empirical [C II] luminosity-SFR relation. One of them has a relatively low S/N ratio, but shows features characteristic of emission lines. Assuming that at least one of the two candidates is a [C II] emitter, we derive a lower limit of [C II]-based star formation rate density (SFRD) at z ∼ 6. The resulting value of >10-2 M⊙ yr-1 Mpc-3 is consistent with the dust-uncorrected UV-based SFRD. Future millimeter/submillimeter surveys can be used to detect a number of high-redshift line emitters, with which to study the star formation history in the early universe.

  20. Compensated digital readout family

    NASA Technical Reports Server (NTRS)

    Ludwig, David E.; Skow, Michael

    1991-01-01

    ISC has completed test on an IC which has 32 channels of amplifiers, low pass anti-aliasing filters, 13-bit analog-to-digital (A/D) converters with non-uniformity correction per channel and a digital multiplexer. The single slope class of A/D conversion is described, as are the unique variations required for incorporation of this technique for use with on-focal plane detector readout electronics. This paper describes the architecture used to implement the digital on-focal plane signal processing functions. Results from measured data on a test IC are presented for a circuit containing these functions operating at a sensor frame rate of 1000 hertz.

  1. Rare earth garnet selective emitter

    NASA Technical Reports Server (NTRS)

    Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

    1994-01-01

    Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approximately equal to 0.74, ((4)l(sub 15/2)) - ( (4)l(sub13/2)), for Er-YAG and epsilon(sub lambda) approximately equal to 0.65, ((5)l(sub 7))-((5)l(sub 8)) for Ho-YAG) at excellent candidates for high efficiency selective emitters in the thermophotovoltaics (TPV) systems operating at moderate temperatures (1200-1500K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. This paper presents normal spectral emittance, epsilon(sub lambda), measurements of holmium (Ho), and erbium (Er) doped YAG thin film selective emitters at 1500 K, and compares those results with the theoretical spectral emittance.

  2. Compact confocal readout system for three-dimensional memories using a laser-feedback semiconductor laser.

    PubMed

    Nakano, Masaharu; Kawata, Yoshimasa

    2003-08-01

    We present a compact confocal readout system for three-dimensional optical memories that uses the thresholding property of a semiconductor laser for feedback light. The system has higher axial resolution than a conventional confocal system with a pinhole. We demonstrate readout results for data recorded in two recording layers with the developed system.

  3. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    DOEpatents

    Wang, Daojing; Yang, Peidong; Kim, Woong; Fan, Rong

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  4. Amorphous-diamond electron emitter

    DOEpatents

    Falabella, Steven

    2001-01-01

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  5. Electrochemical formation of field emitters

    DOEpatents

    Bernhardt, A.F.

    1999-03-16

    Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays is disclosed. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area. 12 figs.

  6. Readout method for stored information

    NASA Technical Reports Server (NTRS)

    Lewicki, G. W.

    1976-01-01

    Readout technique increases density of stored information for projection onto facsimile reproduction. Data stored on line structures is scanned at 90 deg. angle over area larger than recorded format to ensure complete recovery of information.

  7. Development of arrayed microcolumns and field emitters

    NASA Astrophysics Data System (ADS)

    Kim, Ho Seob; Bok Lee, Young; Choi, Sung Woong; Kim, Hyung Woo; Kim, Dae-Wook; Ahn, Seung Joon; Oh, Tae Sik; Song, Yoon-Ho; Chon Park, Byong; Jong Lim, Sun

    2017-06-01

    Electron beam devices have been widely used for inspection or lithography processes. The multibeam technology based on arrayed microcolumns has been developed to overcome the low throughput issue. However, the multicolumn system has some drawbacks such as complexity, electron optics, and electron source. The first drawback is the difficulty in multicolumn assembly. In particular, the alignment process of a source lens and a tip requires sophisticated techniques. The second drawback is that the e-beam characteristics of microcolumns constituting the multicolumn differ from column to column. To solve the first drawback, a sub-5-nm-resolution probe beam optic design with a simple structure and a two-dimensional carbon nanotube (2D-CNT) electron emitter instead of the widely used tungsten field emitter tip have been studied.

  8. READOUT ELECTRONICS FOR A HIGH-RATE CSC DETECTOR

    SciTech Connect

    OCONNOR,P.; GRATCHEV,V.; KANDASAMY,A.; POLYCHRONAKOS,V.; TCHERNIATINE,V.; PARSONS,J.; SIPPACH,W.

    1999-09-25

    A readout system for a high-rate muon Cathode Strip Chamber (CSC) is described. The system, planned for use in the forward region of the ATLAS muon spectrometer, uses two custom CMOS integrated circuits to achieve good position resolution at a flux of up to 2,500 tracks/cm{sup 2}/s.

  9. Tuneable superradiant thermal emitter assembly

    NASA Astrophysics Data System (ADS)

    Mallawaarachchi, Sudaraka; Premaratne, Malin; Gunapala, Sarath D.; Maini, Philip K.

    2017-04-01

    Superradiance is a signature effect in quantum photonics that explains the collective enhancement of emission power by a factor of N2 when N emitters are placed in subwavelength proximity. Although the effect is inherently transient, successful attempts have been made to sustain it in the steady-state regime. Until recently, the effects of superradiance were not considered to be applicable to thermal emitters due to their intrinsic incoherent nature. Novel nanophotonic thermal emitters display favorable coherent characteristics that enable them to obey principles of superradiance. However, published analytical work on conventional superradiant thermal emitter assemblies shows an anomalous power scaling of 1 /N , and therefore increasing the number of thermal emitters leads to a degeneration of power at resonance. This phenomenon immediately renders the effect of thermal superradiance futile since it cannot outperform noncoupled emitters in the steady-state regime. We propose an alternative assembly of thermal emitters with specific features that improves the power scaling while maintaining the effects of superradiance. In essence, we show that our emitter assembly achieves superior power delivery over conventional noncoupled emitter systems at resonance. Additionally, this assembly has the ability to be tuned to operate at specific resonant frequencies, which is a vital requirement for applications such as photothermal cancer therapy.

  10. The PAUCam readout electronics system

    NASA Astrophysics Data System (ADS)

    Jiménez, Jorge; Illa, José M.; Cardiel-Sas, Laia; de Vicente, Juan; Castilla, Javier; Casas, Ricard

    2016-08-01

    The PAUCam is an optical camera with a wide field of view of 1 deg x 1 deg and up to 46 narrow and broad band filters. The camera is already installed on the William Herschel Telescope (WHT) in the Canary Islands, Spain and successfully commissioned during the first period of 2015. The paper presents the main results from the readout electronics commissioning tests and include an overview of the whole readout electronics system, its configuration and current performance.

  11. FXR LIA Optimization - Time-resolved OTR Emittance Measurement

    SciTech Connect

    Jacob, J; Ong, M; Wargo, P; LeSage, G

    2005-07-21

    The Flash X-Ray Radiography (FXR) facility at Lawrence Livermore National Laboratory utilizes a high current, long pulse linear induction accelerator to produce high doses of x-ray radiation. Accurate characterization of the transverse beam emittance is required in order to facilitate accelerator modeling and tuning efforts and, ultimately, to optimize the final focus spot size, yielding higher resolution radiographs. In addition to conventional magnet scan, pepper-pot, and multiple screen techniques, optical transition radiation (OTR) has been proven as a useful emittance measurement diagnostic and is particularly well suited to the FXR accelerator. We shall discuss the time-resolved emittance characterization of an induction linac electron beam using OTR, and we will present our experimental apparatus and analysis software. We shall also develop the theoretical background of beam emittance and transition radiation.

  12. Semiconductor detectors with proximity signal readout

    SciTech Connect

    Asztalos, Stephen J.

    2014-01-30

    Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need.

  13. Fiber and Crystals Dual Readout Calorimeters

    NASA Astrophysics Data System (ADS)

    Cascella, Michele; Franchino, Silvia; Lee, Sehwook

    The RD52 (DREAM) collaboration is performing R&D on dual readout calorimetry techniques with the aim of improving hadronic energy resolution for future high energy physics experiments. The simultaneous detection of Cherenkov and scintillation light enables us to measure the electromagnetic fraction of hadron shower event-by-event. As a result, we could eliminate the main uctuation which prevented from achieving precision energy measurement for hadrons. We have tested the performance of the lead and copper fiber prototypes calorimeters with various energies of electromagnetic particles and hadrons. During the beam test, we investigated the energy resolutions for electrons and pions as well as the identification of those particles in a longitudinally unsegmented calorimeter. Measurements were also performed on pure and doped PbWO4 crystals, as well as BGO and BSO, with the aim of realizing a crystal based dual readout detector. We will describe our results, focusing on the more promising properties of homogeneous media for the technique. Guidelines for additional developments on crystals will be also given. Finally we discuss the construction techniques that we have used to assemble our prototypes and give an overview of the ones that could be industrialized for the construction of a full hermetic calorimeter.

  14. Fiber and crystals dual readout calorimeters

    NASA Astrophysics Data System (ADS)

    Cascella, Michele; Franchino, Silvia; Lee, Sehwook

    2016-11-01

    The RD52 (DREAM) collaboration is performing R&D on dual readout calorimetry techniques with the aim of improving hadronic energy resolution for future high energy physics experiments. The simultaneous detection of Cherenkov and scintillation light enables us to measure the electromagnetic fraction of hadron shower event-by-event. As a result, we could eliminate the main fluctuation which prevented from achieving precision energy measurement for hadrons. We have tested the performance of the lead and copper fiber prototypes calorimeters with various energies of electromagnetic particles and hadrons. During the beam test, we investigated the energy resolutions for electrons and pions as well as the identification of those particles in a longitudinally unsegmented calorimeter. Measurements were also performed on pure and doped PbWO4 crystals, as well as BGO and BSO, with the aim of realizing a crystal based dual readout detector. We will describe our results, focusing on the more promising properties of homogeneous media for the technique. Guidelines for additional developments on crystals will be also given. Finally we discuss the construction techniques that we have used to assemble our prototypes and give an overview of the ones that could be industrialized for the construction of a full hermetic calorimeter.

  15. Pooled CRISPR screening with single-cell transcriptome readout.

    PubMed

    Datlinger, Paul; Rendeiro, André F; Schmidl, Christian; Krausgruber, Thomas; Traxler, Peter; Klughammer, Johanna; Schuster, Linda C; Kuchler, Amelie; Alpar, Donat; Bock, Christoph

    2017-03-01

    CRISPR-based genetic screens are accelerating biological discovery, but current methods have inherent limitations. Widely used pooled screens are restricted to simple readouts including cell proliferation and sortable marker proteins. Arrayed screens allow for comprehensive molecular readouts such as transcriptome profiling, but at much lower throughput. Here we combine pooled CRISPR screening with single-cell RNA sequencing into a broadly applicable workflow, directly linking guide RNA expression to transcriptome responses in thousands of individual cells. Our method for CRISPR droplet sequencing (CROP-seq) enables pooled CRISPR screens with single-cell transcriptome resolution, which will facilitate high-throughput functional dissection of complex regulatory mechanisms and heterogeneous cell populations.

  16. A time projection chamber with GEM-based readout

    NASA Astrophysics Data System (ADS)

    Attié, David; Behnke, Ties; Bellerive, Alain; Bezshyyko, Oleg; Bhattacharya, Deb Sankar; Bhattacharya, Purba; Bhattacharya, Sudeb; Caiazza, Stefano; Colas, Paul; Lentdecker, Gilles De; Dehmelt, Klaus; Desch, Klaus; Diener, Ralf; Dixit, Madhu; Fleck, Ivor; Fujii, Keisuke; Fusayasu, Takahiro; Ganjour, Serguei; Gao, Yuanning; Gros, Philippe; Hayman, Peter; Hedberg, Vincent; Ikematsu, Katsumasa; Jönsson, Leif; Kaminski, Jochen; Kato, Yukihiro; Kawada, Shin-ichi; Killenberg, Martin; Kleinwort, Claus; Kobayashi, Makoto; Krylov, Vladyslav; Li, Bo; Li, Yulan; Lundberg, Björn; Lupberger, Michael; Majumdar, Nayana; Matsuda, Takeshi; Mehdiyev, Rashid; Mjörnmark, Ulf; Müller, Felix; Münnich, Astrid; Mukhopadhyay, Supratik; Ogawa, Tomohisa; Oskarsson, Anders; Österman, Lennart; Peterson, Daniel; Riallot, Marc; Rosemann, Christoph; Roth, Stefan; Schade, Peter; Schäfer, Oliver; Settles, Ronald Dean; Shirazi, Amir Noori; Smirnova, Oxana; Sugiyama, Akira; Takahashi, Tohru; Tian, Junping; Timmermans, Jan; Titov, Maksym; Tsionou, Dimitra; Vauth, Annika; Wang, Wenxin; Watanabe, Takashi; Werthenbach, Ulrich; Yang, Yifan; Yang, Zhenwei; Yonamine, Ryo; Zenker, Klaus; Zhang, Fan

    2017-06-01

    For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1 T solenoidal field and read out with three independent Gas Electron Multiplier (GEM) based readout modules, are reported. The TPC was exposed to a 6 GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.

  17. Fully digital readout of segmented solid state detectors

    NASA Astrophysics Data System (ADS)

    Blumenhagen, K. H.; Badura, E.; Bräuning, H.; Hoffmann, J.; Koch, K.; Kurz, N.; Märtin, R.; Minami, S.; Ott, W.; Spillmann, U.; Stöhlker, Th; Weber, G.; Weber, M.

    2013-09-01

    In this work, the digital readout of semiconductor detectors in combination with digital filters was investigated. Both non-segmented high-purity germanium and segmented planar lithium-drifted silicon detectors were used. In each case, photons from a stationary americium (241Am) gamma source were detected. The resulting preamplifier output pulses were digitized at a fixed sampling frequency and stored entirely. Digital filters were applied to the stored waveforms to extract time and energy information. The performance of different digital filters was compared. The optimum energy resolution obtained was comparable with the value resulting from an analogue readout system based on standard nuclear instrumentation module and versatile module Europe bus electronics.

  18. Readout technologies for directional WIMP Dark Matter detection

    NASA Astrophysics Data System (ADS)

    Battat, J. B. R.; Irastorza, I. G.; Aleksandrov, A.; Asada, T.; Baracchini, E.; Billard, J.; Bosson, G.; Bourrion, O.; Bouvier, J.; Buonaura, A.; Burdge, K.; Cebrián, S.; Colas, P.; Consiglio, L.; Dafni, T.; D'Ambrosio, N.; Deaconu, C.; De Lellis, G.; Descombes, T.; Di Crescenzo, A.; Di Marco, N.; Druitt, G.; Eggleston, R.; Ferrer-Ribas, E.; Fusayasu, T.; Galán, J.; Galati, G.; García, J. A.; Garza, J. G.; Gentile, V.; Garcia-Sciveres, M.; Giomataris, Y.; Guerrero, N.; Guillaudin, O.; Guler, A. M.; Harton, J.; Hashimoto, T.; Hedges, M. T.; Iguaz, F. J.; Ikeda, T.; Jaegle, I.; Kadyk, J. A.; Katsuragawa, T.; Komura, S.; Kubo, H.; Kuge, K.; Lamblin, J.; Lauria, A.; Lee, E. R.; Lewis, P.; Leyton, M.; Loomba, D.; Lopez, J. P.; Luzón, G.; Mayet, F.; Mirallas, H.; Miuchi, K.; Mizumoto, T.; Mizumura, Y.; Monacelli, P.; Monroe, J.; Montesi, M. C.; Naka, T.; Nakamura, K.; Nishimura, H.; Ochi, A.; Papevangelou, T.; Parker, J. D.; Phan, N. S.; Pupilli, F.; Richer, J. P.; Riffard, Q.; Rosa, G.; Santos, D.; Sawano, T.; Sekiya, H.; Seong, I. S.; Snowden-Ifft, D. P.; Spooner, N. J. C.; Sugiyama, A.; Taishaku, R.; Takada, A.; Takeda, A.; Tanaka, M.; Tanimori, T.; Thorpe, T. N.; Tioukov, V.; Tomita, H.; Umemoto, A.; Vahsen, S. E.; Yamaguchi, Y.; Yoshimoto, M.; Zayas, E.

    2016-11-01

    The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies.

  19. EMITTANCE COMPENSATION FOR MAGNETIZED BEAMS

    SciTech Connect

    KEWISCH,J.; CHANG, X.

    2007-06-25

    Emittance compensation is a well established technique for minimizing the emittance of an electron beam from a RF photo-cathode gun. Longitudinal slices of a bunch have a small emittance, but due to the longitudinal charge distribution of the bunch and time dependent RF fields they are not focused in the same way, so that the direction of their phase ellipses diverges in phase space and the projected emittance is much larger. Emittance compensation reverses the divergence. At the location where the slopes of the phase ellipses coincide the beam is accelerated, so that the space charge forces are reduced. A recipe for emittance compensation is given in. For magnetized beams (where the angular momentum is non-zero) such emittance compensation is not sufficient because variations in the slice radius lead to variations in the angular speed and therefore to an increase of emittance in the rotating game. We describe a method and tools for a compensation that includes the beam magnetization.

  20. Thin-Film Selective Emitter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Lowe, Roland A.

    1993-01-01

    Direct conversion of thermal energy into electrical energy using a photovoltaic cell is called thermophotovoltaic energy conversion. One way to make this an efficient process is to have the thermal energy source be an efficient selective emitter of radiation. The emission must be near the band-gap energy of the photovoltaic cell. One possible method to achieve an efficient selective emitter is the use of a thin film of rare-earth oxides. The determination of the efficiency of such an emitter requires analysis of the spectral emittance of the thin film including scattering and reflectance at the vacuum-film and film-substrate interfaces. Emitter efficiencies (power emitted in emission band/total emitted power) in the range 0.35-0.7 are predicted. There is an optimum optical depth to obtain maximum efficiency. High emitter efficiencies are attained only for low (less than 0.05) substrate emittance values, both with and without scattering. The low substrate emittance required for high efficiency limits the choice of substrate materials to highly reflective metals or high-transmission materials such as sapphire.

  1. Nanostructure-Induced Distortion in Single-Emitter Microscopy.

    PubMed

    Lim, Kangmook; Ropp, Chad; Barik, Sabyasachi; Fourkas, John; Shapiro, Benjamin; Waks, Edo

    2016-09-14

    Single-emitter microscopy has emerged as a promising method of imaging nanostructures with nanoscale resolution. This technique uses the centroid position of an emitter's far-field radiation pattern to infer its position to a precision that is far below the diffraction limit. However, nanostructures composed of high-dielectric materials such as noble metals can distort the far-field radiation pattern. Previous work has shown that these distortions can significantly degrade the imaging of the local density of states in metallic nanowires using polarization-resolved imaging. But unlike nanowires, nanoparticles do not have a well-defined axis of symmetry, which makes polarization-resolved imaging difficult to apply. Nanoparticles also exhibit a more complex range of distortions, because in addition to introducing a high dielectric surface, they also act as efficient scatterers. Thus, the distortion effects of nanoparticles in single-emitter microscopy remains poorly understood. Here we demonstrate that metallic nanoparticles can significantly distort the accuracy of single-emitter imaging at distances exceeding 300 nm. We use a single quantum dot to probe both the magnitude and the direction of the metallic nanoparticle-induced imaging distortion and show that the diffraction spot of the quantum dot can shift by more than 35 nm. The centroid position of the emitter generally shifts away from the nanoparticle position, which is in contradiction to the conventional wisdom that the nanoparticle is a scattering object that will pull in the diffraction spot of the emitter toward its center. These results suggest that dielectric distortion of the emission pattern dominates over scattering. We also show that by monitoring the distortion of the quantum dot diffraction spot we can obtain high-resolution spatial images of the nanoparticle, providing a new method for performing highly precise, subdiffraction spatial imaging. These results provide a better understanding of the

  2. Nanostructure-Induced Distortion in Single-Emitter Microscopy

    NASA Astrophysics Data System (ADS)

    Lim, Kangmook; Ropp, Chad; Barik, Sabyasachi; Fourkas, John; Shapiro, Benjamin; Waks, Edo

    2016-09-01

    Single-emitter microscopy has emerged as a promising method of imaging nanostructures with nanoscale resolution. This technique uses the centroid position of an emitters far-field radiation pattern to infer its position to a precision that is far below the diffraction limit. However, nanostructures composed of high-dielectric materials such as noble metals can distort the far-field radiation pattern. Nanoparticles also exhibit a more complex range of distortions, because in addition to introducing a high dielectric surface, they also act as efficient scatterers. Thus, the distortion effects of nanoparticles in single-emitter microscopy remains poorly understood. Here we demonstrate that metallic nanoparticles can significantly distort the accuracy of single-emitter imaging at distances exceeding 300 nm. We use a single quantum dot to probe both the magnitude and the direction of the metallic nanoparticle-induced imaging distortion and show that the diffraction spot of the quantum dot can shift by more than 35 nm. The centroid position of the emitter generally shifts away from the nanoparticle position, in contradiction to the conventional wisdom that the nanoparticle is a scattering object that will pull in the diffraction spot of the emitter towards its center. These results suggest that dielectric distortion of the emission pattern dominates over scattering. We also show that by monitoring the distortion of the quantum dot diffraction spot we can obtain high-resolution spatial images of the nanoparticle, providing a new method for performing highly precise, sub-diffraction spatial imaging. These results provide a better understanding of the complex near-field coupling between emitters and nanostructures, and open up new opportunities to perform super-resolution microscopy with higher accuracy.

  3. Emittance compensation in split photoinjectors

    NASA Astrophysics Data System (ADS)

    Floettmann, Klaus

    2017-01-01

    The compensation of correlated emittance contributions is of primary importance to optimize the performance of high brightness photoinjectors. While only extended numerical simulations can capture the complex beam dynamics of space-charge-dominated beams in sufficient detail to optimize a specific injector layout, simplified models are required to gain a deeper understanding of the involved dynamics, to guide the optimization procedure, and to interpret experimental results. In this paper, a slice envelope model for the emittance compensation process in a split photoinjector is presented. The emittance term is included in the analytical solution of the beam envelope in a drift, which is essential to take the emittance contribution due to a beam size mismatch into account. The appearance of two emittance minima in the drift is explained, and the matching into the booster cavity is discussed. A comparison with simulation results points out effects which are not treated in the envelope model, such as overfocusing and field nonlinearities.

  4. READOUT SYSTEM FOR ARRAYS OF FRISCH-RING CDZNTE DETECTORS.

    SciTech Connect

    CUI, Y.; BOLOTNIKOV, A.E.; CAMARDA, G.S.; DE GERONIMO, G.; O'CONNOR, P.; JAMES, R.B.; KARGAR, A.; HARRISON, M.J.; MCGREGOR, D.S.

    2006-10-29

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution for identifying isotopes, <1% FWHM at 662 keV, and good efficiency for detecting gamma rays. We will fabricate and test at Brookhaven National Laboratory an integrated module of a 64-element array of 6 x 6 x 12 mm{sup 3} Frisch-ring detectors, coupled with a readout electronics system. It supports 64 readout channels, and includes front-end electronics, signal processing circuit, USB interface and high-voltage power supply. The data-acquisition software is used to process the data stream, which includes amplitude and timing information for each detected event. This paper describes the design and assembly of the detector modules, readout electronics, and a conceptual prototype system. Some test results are also reported.

  5. The NA62 liquid Krypton calorimeter's new readout system

    NASA Astrophysics Data System (ADS)

    Ceccucci, A.; Fantechi, R.; Farthouat, P.; Lamanna, G.; Rouet, J.; Ryjov, V.; Venditti, S.

    2014-01-01

    The NA62 experiment [1] at CERN SPS (Super Proton Synchrotron) accelerator aims at studying Kaon decays with high precision. The high resolution Liquid Krypton (LKr) calorimeter, built for the NA48 [2] experiment, is a crucial part of the experiment photon-veto system; to cope with the new requirements, the back-end electronics of the LKr had to be completely renewed. Due to the huge number of the calorimeter readout channels ( ~ 14 K) and the maintenance requirement over 10 years of the experiment lifetime, the decision to sub-contract the development and production to industry was taken in 2011. This paper presents the primary test results of the Calorimeter REAdout Module (CREAM) [3] prototype delivered by the manufacturer in March 2013. All essential features, analog performance, data processing and readout, are covered.

  6. A compact light readout system for longitudinally segmented shashlik calorimeters

    NASA Astrophysics Data System (ADS)

    Berra, A.; Brizzolari, C.; Cecchini, S.; Cindolo, F.; Jollet, C.; Longhin, A.; Ludovici, L.; Mandrioli, G.; Mauri, N.; Meregaglia, A.; Paoloni, A.; Pasqualini, L.; Patrizii, L.; Pozzato, M.; Pupilli, F.; Prest, M.; Sirri, G.; Terranova, F.; Vallazza, E.; Votano, L.

    2016-09-01

    The longitudinal segmentation of shashlik calorimeters is challenged by dead zones and non-uniformities introduced by the light collection and readout system. This limitation can be overcome by direct fiber-photosensor coupling, avoiding routing and bundling of the wavelength shifter fibers and embedding ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present the first experimental test of this readout scheme performed at the CERN PS-T9 beamline in 2015 with negative particles in the 1-5 GeV energy range. In this paper, we demonstrate that the scheme does not compromise the energy resolution and linearity compared with standard light collection and readout systems. In addition, we study the performance of the calorimeter for partially contained charged hadrons to assess the e / π separation capability and the response of the photosensors to direct ionization.

  7. Sub-10ps monolithic and low-power photodetector readout

    SciTech Connect

    Varner, Gary S.; Ruckman, Larry L.

    2009-02-20

    Recent advances in photon detectors have resulted in high-density imaging arrays that offer many performance and cost advantages. In particular, the excellent transit time spread of certain devices show promise to provide tangible benefits in applications such as Positron Emission Tomography (PET). Meanwhile, high-density, high-performance readout techniques have not kept on pace for exploiting these developments. Photodetector readout for next generation high event rate particle identification and time-resolved PET requires a highly-integrated, low-power, and cost-effective readout technique. We propose fast waveform sampling as a method that meets these criteria and demonstrate that sub-10ps resolution can be obtained for an existing device.

  8. Highly directional thermal emitter

    DOEpatents

    Ribaudo, Troy; Shaner, Eric A; Davids, Paul; Peters, David W

    2015-03-24

    A highly directional thermal emitter device comprises a two-dimensional periodic array of heavily doped semiconductor structures on a surface of a substrate. The array provides a highly directional thermal emission at a peak wavelength between 3 and 15 microns when the array is heated. For example, highly doped silicon (HDSi) with a plasma frequency in the mid-wave infrared was used to fabricate nearly perfect absorbing two-dimensional gratings structures that function as highly directional thermal radiators. The absorption and emission characteristics of the HDSi devices possessed a high degree of angular dependence for infrared absorption in the 10-12 micron range, while maintaining high reflectivity of solar radiation (.about.64%) at large incidence angles.

  9. Anatomical details of the brainstem and cranial nerves visualized by high resolution readout-segmented multi-shot echo-planar diffusion-weighted images using unidirectional MPG at 3T.

    PubMed

    Naganawa, Shinji; Yamazaki, Masahiro; Kawai, Hisashi; Sone, Michihiko; Nakashima, Tsutomu; Isoda, Haruo

    2011-01-01

    We compared diffusion-weighted imaging (DWI) with readout-segmented multi-shot echo-planar imaging (rs-EPI) and single-shot EPI, both using unidirectional motion-probing gradient, in 10 patients for visualization of the anatomical structures in the brainstem. DWI by rs-EPI was significantly better than DWI by single-shot EPI for visualizing the medial longitudinal fasciculus, lateral lemniscus, corticospinal tract, and seventh/eighth cranial nerves and offered significantly less distortion of the brainstem.

  10. Towards graphane field emitters.

    PubMed

    Ding, Shuyi; Cole, Matthew T; Li, Chi; Zhou, Yanhuai; Collins, Clare M; Kang, Moon H; Parmee, Richard J; Lei, Wei; Zhang, Xiaobing; Dai, Qing; Milne, William I; Wang, Baoping

    2015-12-10

    We report on the improved field emission performance of graphene foam (GF) following transient exposure to hydrogen plasma. The enhanced field emission mechanism associated with hydrogenation has been investigated using Fourier transform infrared spectroscopy, plasma spectrophotometry, Raman spectroscopy, and scanning electron microscopy. The observed enhanced electron emissionhas been attributed to an increase in the areal density of lattice defects and the formation of a partially hydrogenated, graphane-like material. The treated GF emitter demonstrated a much reduced macroscopic turn-on field (2.5 V μm(-1)), with an increased maximum current density from 0.21 mA cm(-2) (pristine) to 8.27 mA cm(-2) (treated). The treated GFs vertically orientated protrusions, after plasma etching, effectively increased the local electric field resulting in a 2.2-fold reduction in the turn-on electric field. The observed enhancement is further attributed to hydrogenation and the subsequent formation of a partially hydrogenated structured 2D material, which advantageously shifts the emitter work function. Alongside augmentation of the nominal crystallite size of the graphitic superstructure, surface bound species are believed to play a key role in the enhanced emission. The hydrogen plasma treatment was also noted to increase the emission spatial uniformity, with an approximate four times reduction in the per unit area variation in emission current density. Our findings suggest that plasma treatments, and particularly hydrogen and hydrogen-containing precursors, may provide an efficient, simple, and low cost means of realizing enhanced nanocarbon-based field emission devices via the engineered degradation of the nascent lattice, and adjustment of the surface work function.

  11. Towards graphane field emitters

    PubMed Central

    Ding, Shuyi; Li, Chi; Zhou, Yanhuai; Collins, Clare M.; Kang, Moon H.; Parmee, Richard J.; Zhang, Xiaobing; Milne, William I.; Wang, Baoping

    2015-01-01

    We report on the improved field emission performance of graphene foam (GF) following transient exposure to hydrogen plasma. The enhanced field emission mechanism associated with hydrogenation has been investigated using Fourier transform infrared spectroscopy, plasma spectrophotometry, Raman spectroscopy, and scanning electron microscopy. The observed enhanced electron emissionhas been attributed to an increase in the areal density of lattice defects and the formation of a partially hydrogenated, graphane-like material. The treated GF emitter demonstrated a much reduced macroscopic turn-on field (2.5 V μm–1), with an increased maximum current density from 0.21 mA cm–2 (pristine) to 8.27 mA cm–2 (treated). The treated GFs vertically orientated protrusions, after plasma etching, effectively increased the local electric field resulting in a 2.2-fold reduction in the turn-on electric field. The observed enhancement is further attributed to hydrogenation and the subsequent formation of a partially hydrogenated structured 2D material, which advantageously shifts the emitter work function. Alongside augmentation of the nominal crystallite size of the graphitic superstructure, surface bound species are believed to play a key role in the enhanced emission. The hydrogen plasma treatment was also noted to increase the emission spatial uniformity, with an approximate four times reduction in the per unit area variation in emission current density. Our findings suggest that plasma treatments, and particularly hydrogen and hydrogen-containing precursors, may provide an efficient, simple, and low cost means of realizing enhanced nanocarbon-based field emission devices via the engineered degradation of the nascent lattice, and adjustment of the surface work function. PMID:28066543

  12. GBT based readout in the CBM experiment

    NASA Astrophysics Data System (ADS)

    Lehnert, J.; Byszuk, A. P.; Emschermann, D.; Kasinski, K.; Müller, W. F. J.; Schmidt, C. J.; Szczygiel, R.; Zabolotny, W. M.

    2017-02-01

    The CBM experiment at FAIR will use GBTX and Versatile Link based readout systems for several of its subdetectors. The paper describes the GBT based readout concept in CBM, emphasizing the common features among systems. Particular choices and features of the readout are motivated mainly by the requirements in the readout of the silicon tracking system (STS). Common developments like a common CBM readout board are presented. The prototype board provides full GBT functionality for all systems, can be interfaced to various prototype readout chains and be refined for later detector specific versions.

  13. Focal plane infrared readout circuit

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor)

    2002-01-01

    An infrared imager, such as a spectrometer, includes multiple infrared photodetectors and readout circuits for reading out signals from the photodetectors. Each readout circuit includes a buffered direct injection input circuit including a differential amplifier with active feedback provided through an injection transistor. The differential amplifier includes a pair of input transistors, a pair of cascode transistors and a current mirror load. Photocurrent from a photodetector can be injected onto an integration capacitor in the readout circuit with high injection efficiency at high speed. A high speed, low noise, wide dynamic range linear infrared multiplexer array for reading out infrared detectors with large capacitances can be achieved even when short exposure times are used. The effect of image lag can be reduced.

  14. Thermopile detector radiation hard readout

    NASA Astrophysics Data System (ADS)

    Gaalema, Stephen; Van Duyne, Stephen; Gates, James L.; Foote, Marc C.

    2010-08-01

    The NASA Jupiter Europa Orbiter (JEO) conceptual payload contains a thermal instrument with six different spectral bands ranging from 8μm to 100μm. The thermal instrument is based on multiple linear arrays of thermopile detectors that are intrinsically radiation hard; however, the thermopile CMOS readout needs to be hardened to tolerate the radiation sources of the JEO mission. Black Forest Engineering is developing a thermopile readout to tolerate the JEO mission radiation sources. The thermal instrument and ROIC process/design techniques are described to meet the JEO mission requirements.

  15. Linear readout of object manifolds

    NASA Astrophysics Data System (ADS)

    Chung, SueYeon; Lee, Daniel D.; Sompolinsky, Haim

    2016-06-01

    Objects are represented in sensory systems by continuous manifolds due to sensitivity of neuronal responses to changes in physical features such as location, orientation, and intensity. What makes certain sensory representations better suited for invariant decoding of objects by downstream networks? We present a theory that characterizes the ability of a linear readout network, the perceptron, to classify objects from variable neural responses. We show how the readout perceptron capacity depends on the dimensionality, size, and shape of the object manifolds in its input neural representation.

  16. Resonance Frequency Readout Circuit for a 900 MHz SAW Device.

    PubMed

    Liu, Heng; Zhang, Chun; Weng, Zhaoyang; Guo, Yanshu; Wang, Zhihua

    2017-09-15

    A monolithic resonance frequency readout circuit with high resolution and short measurement time is presented for a 900 MHz RF surface acoustic wave (SAW) sensor. The readout circuit is composed of a fractional-N phase-locked loop (PLL) as the stimulus source to the SAW device and a phase-based resonance frequency detecting circuit using successive approximation (SAR). A new resonance frequency searching strategy has been proposed based on the fact that the SAW device phase-frequency response crosses zero monotonically around the resonance frequency. A dedicated instant phase difference detecting circuit is adopted to facilitate the fast SAR operation for resonance frequency searching. The readout circuit has been implemented in 180 nm CMOS technology with a core area of 3.24 mm². In the experiment, it works with a 900 MHz SAW resonator with a quality factor of Q = 130. Experimental results show that the readout circuit consumes 7 mW power from 1.6 V supply. The frequency resolution is 733 Hz, and the relative accuracy is 0.82 ppm, and it takes 0.48 ms to complete one measurement. Compared to the previous results in the literature, this work has achieved the shortest measurement time with a trade-off between measurement accuracy and measurement time.

  17. Polycrystalline Mercuric Iodide Films on CMOS Readout Arrays

    PubMed Central

    Hartsough, Neal E.; Iwanczyk, Jan S.; Nygard, Einar; Malakhov, Nail; Barber, William C.; Gandhi, Thulasidharan

    2009-01-01

    We have created high-resolution x-ray imaging devices using polycrystalline mercuric iodide (HgI2) films grown directly onto CMOS readout chips using a thermal vapor transport process. Images from prototype 400×400 pixel HgI2-coated CMOS readout chips are presented, where the pixel grid is 30 μm × 30 μm. The devices exhibited sensitivity of 6.2 μC/Rcm2 with corresponding dark current of ∼2.7 nA/cm2, and a 80 μm FWHM planar image response to a 50 μm slit aperture. X-ray CT images demonstrate a point spread function sufficient to obtain a 50 μm spatial resolution in reconstructed CT images at a substantially reduced dose compared to phosphor-coated readouts. The use of CMOS technology allows for small pixels (30 μm), fast readout speeds (8 fps for a 3200×3200 pixel array), and future design flexibility due to the use of well-developed fabrication processes. PMID:20161098

  18. Resonance Frequency Readout Circuit for a 900 MHz SAW Device

    PubMed Central

    Liu, Heng; Zhang, Chun; Weng, Zhaoyang; Guo, Yanshu; Wang, Zhihua

    2017-01-01

    A monolithic resonance frequency readout circuit with high resolution and short measurement time is presented for a 900 MHz RF surface acoustic wave (SAW) sensor. The readout circuit is composed of a fractional-N phase-locked loop (PLL) as the stimulus source to the SAW device and a phase-based resonance frequency detecting circuit using successive approximation (SAR). A new resonance frequency searching strategy has been proposed based on the fact that the SAW device phase-frequency response crosses zero monotonically around the resonance frequency. A dedicated instant phase difference detecting circuit is adopted to facilitate the fast SAR operation for resonance frequency searching. The readout circuit has been implemented in 180 nm CMOS technology with a core area of 3.24 mm2. In the experiment, it works with a 900 MHz SAW resonator with a quality factor of Q = 130. Experimental results show that the readout circuit consumes 7 mW power from 1.6 V supply. The frequency resolution is 733 Hz, and the relative accuracy is 0.82 ppm, and it takes 0.48 ms to complete one measurement. Compared to the previous results in the literature, this work has achieved the shortest measurement time with a trade-off between measurement accuracy and measurement time. PMID:28914799

  19. Diamondoid monolayers as electron emitters

    DOEpatents

    Yang, Wanli; Fabbri, Jason D.; Melosh, Nicholas A.; Hussain, Zahid; Shen, Zhi-Xun

    2013-10-29

    Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

  20. Diamondoid monolayers as electron emitters

    DOEpatents

    Yang, Wanli [El Cerrito, CA; Fabbri, Jason D [San Francisco, CA; Melosh, Nicholas A [Menlo Park, CA; Hussain, Zahid [Orinda, CA; Shen, Zhi-Xun [Stanford, CA

    2012-04-10

    Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

  1. Demonstration of Time Domain Multiplexed Readout for Magnetically Coupled Calorimeters

    NASA Technical Reports Server (NTRS)

    Porst, J.-P.; Adams, J. S.; Balvin, M.; Bandler, S.; Beyer, J.; Busch, S. E.; Drung, D.; Seidel, G. M.; Smith, S. J.; Stevenson, T. R.

    2012-01-01

    Magnetically coupled calorimeters (MCC) have extremely high potential for x-ray applications due to the inherent high energy resolution capability and being non-dissipative. Although very high energy-resolution has been demonstrated, until now there has been no demonstration of multiplexed read-out. We report on the first realization of a time domain multiplexed (TDM) read-out. While this has many similarities with TDM of transition-edge-sensors (TES), for MGGs the energy resolution is limited by the SQUID read-out noise and requires the well established scheme to be altered in order to minimize degradation due to noise aliasing effects. In cur approach, each pixel is read out by a single first stage SQUID (SQ1) that is operated in open loop. The outputs of the SQ1 s are low-pass filtered with an array of low cross-talk inductors, then fed into a single-stage SQUID TD multiplexer. The multiplexer is addressed from room temperature and read out through a single amplifier channel. We present results achieved with a new detector platform. Noise performance is presented and compared to expectations. We have demonstrated multiplexed X-ray spectroscopy at 5.9keV with delta_FWHM=10eV. In an optimized setup, we show it is possible to multiplex 32 detectors without significantly degrading the Intrinsic detector resolution.

  2. Operational characteristics of Wedge and Strip image readout systems

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Lampton, M.; Bixler, J.; Bowyer, S.; Malina, R. F.

    1986-01-01

    Application of the Wedge and Strip readout system in microchannel plate detectors for the Extreme Ultraviolet Explorer and FAUST space astronomy programs is discussed. Anode designs with high resolution (greater than 600 x 600 pixels) in imaging and spectroscopy applications have been developed. Extension of these designs to larger formats (100 mm) with higher resolution (3000 x 3000 pixels) are considered. It is shown that the resolution and imaging are highly stable, and that the flat field performance is essentially limited by photon statistics. Very high speed event response has also been achieved with output pulses having durations of less than 10 nanoseconds.

  3. Visible Spectrum Incandescent Selective Emitter

    SciTech Connect

    Sonsight Inc.

    2004-04-30

    The purpose of the work performed was to demonstrate the feasibility of a novel bi-layer selective emitter. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected part of the radiation spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature. The major research objectives involved answering the following questions: (1) What maximum VIS/NIR radiant power and emissivity ratios can be attained at 2650 K? (2) What is the observed emitter body life and how does its performance vary with time? (3) What are the design tradeoffs for a dual heating approach in which both an internally mounted heating coil and electrical resistance self-heating are used? (4) What are the quantitative improvements to be had from utilizing a bi-layer emitter body with a low emissivity inner layer and a partially transmissive outer layer? Two approaches to obtaining selective emissivity were investigated. The first was to utilize large optical scattering within an emitter material with a spectral optical absorption that is much greater within the visible spectrum than that within the NIR. With this approach, an optically thick emitter can radiate almost as if optically thin because essentially, scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. The performance of thin emitters was also investigated (for optically thin emitters, spectral emissivity is proportional to spectral absorptivity). These emitters were fabricated from thin mono-layer emitter rods as well as from bi-layer rods with a thin emitter layer mounted on a substrate core. With an initially estimated energy efficiency of almost three times that of standard incandescent bulbs, a number of energy, economic and environmental benefits such as less energy use and cost, reduced CO{sub 2} emissions, and no mercury contamination

  4. Thermal emittance and response time of a cesium antimonide photocathode

    NASA Astrophysics Data System (ADS)

    Cultrera, Luca; Bazarov, Ivan; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Merluzzi, Richard; Nichols, Matthew

    2011-10-01

    Measurements of the intrinsic emittance and response time of a Cs3Sb photocathode are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. Photoemission response time is evaluated using a RF deflecting cavity synchronized to a picosecond laser pulse train. We find that Cs3Sb has both small mean transverse energy, 160 ± 10 meV at 532 nm laser wavelength, and a prompt response time (below the resolution of our measurement) making it a suitable material for high brightness electron photoinjectors.

  5. Fast Low-Cost Multiple Sensor Readout System

    DOEpatents

    Carter-Lewis, David; Krennich, Frank; Le Bohec, Stephane; Petry, Dirk; Sleege, Gary

    2004-04-06

    A low resolution data acquisition system is presented. The data acquisition system has a plurality of readout modules serially connected to a controller. Each readout module has a FPGA in communication with analog to digital (A/D) converters, which are connected to sensors. The A/D converter has eight bit or lower resolution. The FPGA detects when a command is addressed to it and commands the A/D converters to convert analog sensor data into digital data. The digital data is sent on a high speed serial communication bus to the controller. A graphical display is used in one embodiment to indicate if a sensor reading is outside of a predetermined range.

  6. A cylindrical SPECT camera with de-centralized readout scheme

    NASA Astrophysics Data System (ADS)

    Habte, F.; Stenström, P.; Rillbert, A.; Bousselham, A.; Bohm, C.; Larsson, S. A.

    2001-09-01

    An optimized brain single photon emission computed tomograph (SPECT) camera is being designed at Stockholm University and Karolinska Hospital. The design goal is to achieve high sensitivity, high-count rate and high spatial resolution. The sensitivity is achieved by using a cylindrical crystal, which gives a closed geometry with large solid angles. A de-centralized readout scheme where only a local environment around the light excitation is readout supports high-count rates. The high resolution is achieved by using an optimized crystal configuration. A 12 mm crystal plus 12 mm light guide combination gave an intrinsic spatial resolution better than 3.5 mm (140 keV) in a prototype system. Simulations show that a modified configuration can improve this value. A cylindrical configuration with a rotating collimator significantly simplifies the mechanical design of the gantry. The data acquisition and control system uses early digitization and subsequent digital signal processing to extract timing and amplitude information, and monitors the position of the collimator. The readout system consists of 12 or more modules each based on programmable logic and a digital signal processor. The modules send data to a PC file server-reconstruction engine via a Firewire (IEEE-1394) network.

  7. A Triple-GEM Detector with Pixel Readout for High-Rate Beam Tracking in COMPASS

    NASA Astrophysics Data System (ADS)

    Nagel, T.; Austregesilo, A.; Haas, F.; Ketzer, B.; Konorov, I.; Krämer, M.; Mann, A.; Paul, S.

    2008-06-01

    For its physics program with a high-intensity hadron beam of 2 · 107 particles/s, the COMPASS experiment at CERN requires tracking of charged particles scattered by very small angles with respect to the incident beam direction. While good resolution in time and space is mandatory, the challenge is imposed by the high beam intensity, requiring radiation-hard detectors which add very little material to the beam path in order to minimise secondary interactions. To this end, a set of triple-GEM detectors with pixel readout in the beam region and 2-D strip readout in the periphery is currently being built. The pixel size has been chosen to be 1×1 mm2, which constitutes a compromise between the spatial resolution achievable and the number of readout channels. Surrounding the pixel area, a 2-D strip readout with a pitch of 400 μm has been realised on the same printed circuit foil. In total an active area of 10 × 10 cm2 is covered using 2048 readout channels. Analogue readout by the APV25 ASIC has been chosen in order to profit from amplitude measurements which help to improve the spatial resolution by clustering neighbouring hit strips or pixels. A detector prototype has been tested successfully in the 5 · 107 particles/s COMPASS muon beam, as well as in a focused hadron beam. The design of the detector and first results concerning its performance as a beam tracker will be presented.

  8. Thermionic converter emitter support arrangement

    DOEpatents

    Allen, Daniel T.

    1990-01-01

    A support is provided for use in a therminonic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end (34) is supported by a spring structure (44) that includes a pair of Belleville springs, and the spring structure is supported by a support structure (42) fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element (74) at the front end, a larger metal main support (76) at the rear end that is attached to the housing, and with a ceramic layer (80) between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer (120) captured between the Belleville springs.

  9. Thermionic converter emitter support arrangement

    DOEpatents

    Allen, Daniel T.

    1990-01-01

    A support is provided for use in a thermionic converter to support an end an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially at its temperatures changes. The emitter end (34) is supported by a spring structure (44) that includes a pair of Belleville springs, and the spring structure is supported by a support structure (42) fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element (74) at the front end, a larger metal main support (76) at the rear end that is attached to the housng, and with a ceramic layer (80) between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer (120) captured between the Belleville springs.

  10. A custom readout electronics for the BESIII CGEM detector

    NASA Astrophysics Data System (ADS)

    Da Rocha Rolo, M.; Alexeev, M.; Amoroso, A.; Baldini Ferroli, R.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bugalho, R.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Carassiti, V.; Cerioni, S.; Chai, J. Y.; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Di Francesco, A.; Dong, J.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Garzia, I.; Gatta, M.; Greco, M.; Lavezzi, L.; Leng, C. Y.; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Marciniewski, P.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Varela, J.; Verma, S.; Wheadon, R.; Yan, L.

    2017-07-01

    For the upgrade of the inner tracker of the BESIII spectrometer, planned for 2018, a lightweight tracker based on an innovative Cylindrical Gas Electron Multiplier (CGEM) detector is now under development. The analogue readout of the CGEM enables the use of a charge centroid algorithm to improve the spatial resolution to better than 130 μm while loosening the pitch strip to 650 μm, which allows to reduce the total number of channels to about 10 000. The channels are readout by 160 dedicated integrated 64-channel front-end ASICs, providing a time and charge measurement and featuring a fully-digital output. The energy measurement is extracted either from the time-over-threshold (ToT) or the 10-bit digitisation of the peak amplitude of the signal. The time of the event is generated by quad-buffered low-power TDCs, allowing for rates in excess of 60 kHz per channel. The TDCs are based on analogue interpolation techniques and produce a time stamp (or two, if working in ToT mode) of the event with a time resolution better than 50 ps. The front-end noise, based on a CSA and a two-stage complex conjugated pole shapers, dominate the channel intrinsic time jitter, which is less than 5 ns r.m.s. The time information of the hit can be used to reconstruct the track path, operating the detector as a small TPC and hence improving the position resolution when the distribution of the cloud, due to large incident angle or magnetic field, is very broad. Event data is collected by an off-detector motherboard, where each GEM-ROC readout card handles 4 ASIC carrier FEBs (512 channels). Configuration upload and data readout between the off-detector electronics and the VME-based data collector cards are managed by bi-directional fibre optical links. This paper covers the design of a custom front-end electronics for the readout of the new inner tracker of the BESIII experiment, addressing the relevant design aspects of the detector electronics and the front-end ASIC for the CGEM readout

  11. Combustion powered thermophotovoltaic emitter system

    SciTech Connect

    McHenry, R.S.

    1995-07-01

    The US Naval Academy (USNA) has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the high temperature requirements necessary for high system efficiency. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design.

  12. Emitter location errors in electronic recognition system

    NASA Astrophysics Data System (ADS)

    Matuszewski, Jan; Dikta, Anna

    2017-04-01

    The paper describes some of the problems associated with emitter location calculations. This aspect is the most important part of the series of tasks in the electronic recognition systems. The basic tasks include: detection of emission of electromagnetic signals, tracking (determining the direction of emitter sources), signal analysis in order to classify different emitter types and the identification of the sources of emission of the same type. The paper presents a brief description of the main methods of emitter localization and the basic mathematical formulae for calculating their location. The errors' estimation has been made to determine the emitter location for three different methods and different scenarios of emitters and direction finding (DF) sensors deployment in the electromagnetic environment. The emitter has been established using a special computer program. On the basis of extensive numerical calculations, the evaluation of precise emitter location in the recognition systems for different configuration alignment of bearing devices and emitter was conducted. The calculations which have been made based on the simulated data for different methods of location are presented in the figures and respective tables. The obtained results demonstrate that calculation of the precise emitter location depends on: the number of DF sensors, the distances between emitter and DF sensors, their mutual location in the reconnaissance area and bearing errors. The precise emitter location varies depending on the number of obtained bearings. The higher the number of bearings, the better the accuracy of calculated emitter location in spite of relatively high bearing errors for each DF sensor.

  13. Position Sensitive Proximity Charge Sensing Readout of HPGe Detectors

    NASA Astrophysics Data System (ADS)

    Priest, Anders Peterson

    Electrode segmentation is a necessity to achieve position sensitivity in semicon- ductor radiation detectors. Traditional segmentation requires decreasing electrode sizes while increasing channel numbers to achieve very fine position resolution. These electrodes can be complicated to fabricate, and many electrodes with individual electronic channels are required to instrument large detector areas. To simplify the fabrication process, we have moved the readout electrodes onto a printed circuit board that is positioned above the ionization type detection material. In this scheme, charge from radiation interactions will be shared amongst several electrodes, allowing for position interpolation. Because events can be reconstructed in between electrodes, fewer electrodes are needed to instrument large detector areas. The proximity charge sensing method of readout promises to simplify detector fabrication while maintaining the position resolution that is required by fields such as homeland security, astrophysics, environmental remediation, nuclear physics, and medical imaging. We performed scanning measurements on a proof of principle detector that we fabricated at Lawrence Berkeley National Laboratory (LBNL). These measurements showed that position resolution much finer than the strip pitch was achievable using the proximity charge readout method. We performed analytic calculations and Monte Carlo modeling to optimize the readout electrode geometry for a larger detector to test the limits of this technology. We achieved an average position resolution of 288 microm with eight proximity electrodes at a 5 mm pitch and 1 mm strip width, set 100 microm away from the detector surface by a Kapton spacer. To achieve this resolution using standard technologies, 300 microm pitch strips are necessary, and would require 100 channels to instrument the same area. Through our optimization calculations, we found that there is a trade-off between position resolution and energy resolution

  14. An analysis of side readouts of monolithic scintillation crystals

    NASA Astrophysics Data System (ADS)

    Li, Xin; Furenlid, Lars R.

    2016-10-01

    We have explored a method of using the side surfaces of a thin monolithic scintillation crystal for reading out scintillation photons. A Monte-Carlo simulation was carried out for an LYSO crystal of 50:8mmx50:8mmx3mm with 5 silicon photomultipliers attached on each of the four side surfaces. With 511 keV gamma-rays, X-Y spatial resolution of 2:10mm was predicted with an energy resolution of 9:0%. We also explored adding optical barriers to improve the X-Y spatial resolution, and an X-Y spatial resolution of 786um was predicted with an energy resolution of 9:2%. Multiple layers can be stacked together and readout channels can be combined. Depth-of- interaction information (DOI) can be directly read out. This method provides an attractive detector module design for positron emission tomography (PET).

  15. Optimal CCD readout by digital correlated double sampling

    NASA Astrophysics Data System (ADS)

    Alessandri, C.; Abusleme, A.; Guzman, D.; Passalacqua, I.; Alvarez-Fontecilla, E.; Guarini, M.

    2016-01-01

    Digital correlated double sampling (DCDS), a readout technique for charge-coupled devices (CCD), is gaining popularity in astronomical applications. By using an oversampling ADC and a digital filter, a DCDS system can achieve a better performance than traditional analogue readout techniques at the expense of a more complex system analysis. Several attempts to analyse and optimize a DCDS system have been reported, but most of the work presented in the literature has been experimental. Some approximate analytical tools have been presented for independent parameters of the system, but the overall performance and trade-offs have not been yet modelled. Furthermore, there is disagreement among experimental results that cannot be explained by the analytical tools available. In this work, a theoretical analysis of a generic DCDS readout system is presented, including key aspects such as the signal conditioning stage, the ADC resolution, the sampling frequency and the digital filter implementation. By using a time-domain noise model, the effect of the digital filter is properly modelled as a discrete-time process, thus avoiding the imprecision of continuous-time approximations that have been used so far. As a result, an accurate, closed-form expression for the signal-to-noise ratio at the output of the readout system is reached. This expression can be easily optimized in order to meet a set of specifications for a given CCD, thus providing a systematic design methodology for an optimal readout system. Simulated results are presented to validate the theory, obtained with both time- and frequency-domain noise generation models for completeness.

  16. Shielding in ungated field emitter arrays

    SciTech Connect

    Harris, J. R.; Jensen, K. L.; Shiffler, D. A.; Petillo, J. J.

    2015-05-18

    Cathodes consisting of arrays of high aspect ratio field emitters are of great interest as sources of electron beams for vacuum electronic devices. The desire for high currents and current densities drives the cathode designer towards a denser array, but for ungated emitters, denser arrays also lead to increased shielding, in which the field enhancement factor β of each emitter is reduced due to the presence of the other emitters in the array. To facilitate the study of these arrays, we have developed a method for modeling high aspect ratio emitters using tapered dipole line charges. This method can be used to investigate proximity effects from similar emitters an arbitrary distance away and is much less computationally demanding than competing simulation approaches. Here, we introduce this method and use it to study shielding as a function of array geometry. Emitters with aspect ratios of 10{sup 2}–10{sup 4} are modeled, and the shielding-induced reduction in β is considered as a function of tip-to-tip spacing for emitter pairs and for large arrays with triangular and square unit cells. Shielding is found to be negligible when the emitter spacing is greater than the emitter height for the two-emitter array, or about 2.5 times the emitter height in the large arrays, in agreement with previously published results. Because the onset of shielding occurs at virtually the same emitter spacing in the square and triangular arrays, the triangular array is preferred for its higher emitter density at a given emitter spacing. The primary contribution to shielding in large arrays is found to come from emitters within a distance of three times the unit cell spacing for both square and triangular arrays.

  17. Ultra Low Emittance Light Sources

    SciTech Connect

    Bengtsson,J.

    2008-06-23

    This paper outlines the special issues for reaching sub-nm emittance in a storage ring. Effects of damping wigglers, intra-beam scattering and lifetime issues, dynamic aperture optimization, control of optics, and their interrelations are covered in some detail. The unique choices for the NSLS-II are given as one example.

  18. Nanosecond monolithic CMOS readout cell

    DOEpatents

    Souchkov, Vitali V.

    2004-08-24

    A pulse shaper is implemented in monolithic CMOS with a delay unit formed of a unity gain buffer. The shaper is formed of a difference amplifier having one input connected directly to an input signal and a second input connected to a delayed input signal through the buffer. An elementary cell is based on the pulse shaper and a timing circuit which gates the output of an integrator connected to the pulse shaper output. A detector readout system is formed of a plurality of elementary cells, each connected to a pixel of a pixel array, or to a microstrip of a plurality of microstrips, or to a detector segment.

  19. A data readout approach for physics experiments

    NASA Astrophysics Data System (ADS)

    Huang, Xi-Ru; Cao, Ping; Gao, Li-Wei; Zheng, Jia-Jun

    2015-07-01

    With increasing physical event rates and the number of electronic channels, traditional readout schemes meet the challenge of improving readout speed caused by the limited bandwidth of the crate backplane. In this paper, a high-speed data readout method based on the Ethernet is presented to make each readout module capable of transmitting data to the DAQ. Features of explicitly parallel data transmitting and distributed network architecture give the readout system the advantage of adapting varying requirements of particle physics experiments. Furthermore, to guarantee the readout performance and flexibility, a standalone embedded CPU system is utilized for network protocol stack processing. To receive the customized data format and protocol from front-end electronics, a field programmable gate array (FPGA) is used for logic reconfiguration. To optimize the interface and to improve the data throughput between CPU and FPGA, a sophisticated method based on SRAM is presented in this paper. For the purpose of evaluating this high-speed readout method, a simplified readout module is designed and implemented. Test results show that this module can support up to 70 Mbps data throughput from the readout module to DAQ. Supported by National Natural Science Foundation of China (11005107) and Independent Projects of State Key Laboratory of Particle Detection and Electronics (201301)

  20. Magnetic field emission gun with zirconiated emitter.

    PubMed

    Troyon, M

    1989-03-01

    A magnetic-field-superimposed field emission gun with low aberrations and equipped with a zirconiated tungsten emitter has been developed for applications where very stable high probe currents are required. It has been tested on a conventional electron microscope at 10 kV and on an electron beam testing system at 1 kV. Probe current i = 250 nA in a probe size d = 0.4 micron is obtained at 10 kV; at 1 kV the resolution is 0.1 micron with i = 5 nA, and 0.4 micron with i = 30 nA. For these probe currents, the spatial broadening effect due to electron-electron interactions in the beam is the preponderant factor limiting the probe size.

  1. Development of TORCH readout electronics for customised MCPs

    NASA Astrophysics Data System (ADS)

    Gao, R.; Brook, N.; Castillo García, L.; Cussans, D.; Fohl, K.; Forty, R.; Frei, C.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; Van Dijk, M.

    2016-04-01

    The TORCH detector is being developed for low-momentum particle identification, combining time-of-flight and Cherenkov techniques to achieve charged particle pi/K/p separation up to 10 GeV/c over a flight distance of 10m. This requires a timing resolution of 70 ps for single photons. Based on an existing scalable design, production and testing of a TORCH readout system has been undertaken over the past year, and a novel customized Micro Channel Plate (MCP) photomultiplier device with 128-channels has been instrumented. This paper will report on the development of the readout system which is being used to measure time-of-flight in a test-beam, and its performance. We will also discuss the communication and data alignment between the TORCH system and the TimePix3 telescope in order to provide track reconstruction.

  2. Towards a new generation of pixel detector readout chips

    NASA Astrophysics Data System (ADS)

    Campbell, M.; Alozy, J.; Ballabriga, R.; Frojdh, E.; Heijne, E.; Llopart, X.; Poikela, T.; Tlustos, L.; Valerio, P.; Wong, W.

    2016-01-01

    The Medipix3 Collaboration has broken new ground in spectroscopic X-ray imaging and in single particle detection and tracking. This paper will review briefly the performance and limitations of the present generation of pixel detector readout chips developed by the Collaboration. Through Silicon Via technology has the potential to provide a significant improvement in the tile-ability and more flexibility in the choice of readout architecture. This has been explored in the context of 3 projects with CEA-LETI using Medipix3 and Timepix3 wafers. The next generation of chips will aim to provide improved spectroscopic imaging performance at rates compatible with human CT. It will also aim to provide full spectroscopic images with unprecedented energy and spatial resolution. Some of the opportunities and challenges posed by moving to a more dense CMOS process will be discussed.

  3. Sensor Development and Readout Prototyping for the STAR Pixel Detector

    SciTech Connect

    Greiner, L.; Anderssen, E.; Matis, H.S.; Ritter, H.G.; Stezelberger, T.; Szelezniak, M.; Sun, X.; Vu, C.; Wieman, H.

    2009-01-14

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) is designing a new vertex detector. The purpose of this upgrade detector is to provide high resolution pointing to allow for the direct topological reconstruction of heavy flavor decays such as the D{sup 0} by finding vertices displaced from the collision vertex by greater than 60 microns. We are using Monolithic Active Pixel Sensor (MAPS) as the sensor technology and have a coupled sensor development and readout system plan that leads to a final detector with a <200 {micro}s integration time, 400 M pixels and a coverage of -1 < {eta} < 1. We present our coupled sensor and readout development plan and the status of the prototyping work that has been accomplished.

  4. Revealing single emitter spectral dynamics from intensity correlations in an ensemble fluorescence spectrum.

    PubMed

    Brokmann, Xavier; Marshall, Lisa; Bawendi, Moungi

    2009-03-16

    We show that the single emitter linewidth underlying a broadened ensemble emission spectrum can be extracted from correlations among the stochastic intensity fluctuations in the ensemble spectrum. Spectral correlations can be observed at high temporal and spectral resolutions with a cross-correlated pair of avalanche photodiodes placed at the outputs of a scanning Michelson interferometer. As illustrated with simulations in conjunction with Fluorescence Correlation Spectroscopy, our approach overcomes ensemble and temporal inhomogeneous broadening to provide single emitter linewidths, even for emitters under weak, continuous, broadband excitation. (c) 2009 Optical Society of America

  5. Automatic emittance measurement at the ATF

    SciTech Connect

    Wang, X.J.; Malone, R.; Batchelor, K.; Ben-Zvi, I.

    1993-07-01

    An automatic emittance measurement system to characterize the transverse emittance of the electron beam produced by the BNL photocathode electron gun is described. The system utilize a VAX workstation and a Spiricon beam analyzer. A operator window (created through the Vista control software package) controls the emittance measurement system and the graphic presentation of the results. Quadrupole variation method is used for the ATF automatic emittance measurement system. A simple emittance formula was derived to study the performance of the quadrupole variation method, and compared with the ATF experimental data is also presented.

  6. An ac bridge readout for bolometric detectors

    NASA Technical Reports Server (NTRS)

    Rieke, F. M.; Lange, A. E.; Beeman, J. W.; Haller, E. E.

    1989-01-01

    The authors have developed a bolometer readout circuit which greatly improves the low-frequency stability of bolometric detectors. The circuit uses an ac bias voltage and two matched bolometers and allows stable dc bolometer operation for integration times greater than 10 s. In astronomical applications the readout allows for qualitatively different observation modes (e.g. staring or slow-drift scanning) which are particularly well suited for space observations and for the use of arrays. In many applications the readout can increase sensitivity. The authors present noise spectra for 4He temperature bolometers with no excess noise at frequencies greater than 0.1 Hz. The measured optical responsivity of a bolometer operated with the present readout is the same as that of a bolometer operated with a conventional readout.

  7. Carbon nanotubes as field emitter.

    PubMed

    Zou, Rujia; Hu, Junqing; Song, Yuelin; Wang, Na; Chen, Huihui; Chen, Haihua; Wu, Jianghong; Sun, Yangang; Chen, Zhigang

    2010-12-01

    Carbon nanotubes (CNTs) have recently emerged as a promising material of electron field emitters. They exhibit extraordinary field emission properties because of their high electrical conductivity, high aspect ratio "needle like" shape for optimum geometrical field enhancement, and remarkable thermal stability. In this Review, we emphasize the estimation and influencing factors of CNTs' emission properties, and discuss in detail the emission properties of macroscopic CNT cathodes, especially fabricated by transplant methods, and describe recent progress on understanding of CNT field emitters and analyze issues related to applications of CNT based cold cathodes in field emission display (FED). We foresee that CNT-FED will take an important place in display technologies in the near future.

  8. Metal halide perovskite light emitters

    PubMed Central

    Kim, Young-Hoon; Cho, Himchan; Lee, Tae-Woo

    2016-01-01

    Twenty years after layer-type metal halide perovskites were successfully developed, 3D metal halide perovskites (shortly, perovskites) were recently rediscovered and are attracting multidisciplinary interest from physicists, chemists, and material engineers. Perovskites have a crystal structure composed of five atoms per unit cell (ABX3) with cation A positioned at a corner, metal cation B at the center, and halide anion X at the center of six planes and unique optoelectronic properties determined by the crystal structure. Because of very narrow spectra (full width at half-maximum ≤20 nm), which are insensitive to the crystallite/grain/particle dimension and wide wavelength range (400 nm ≤ λ ≤ 780 nm), perovskites are expected to be promising high-color purity light emitters that overcome inherent problems of conventional organic and inorganic quantum dot emitters. Within the last 2 y, perovskites have already demonstrated their great potential in light-emitting diodes by showing high electroluminescence efficiency comparable to those of organic and quantum dot light-emitting diodes. This article reviews the progress of perovskite emitters in two directions of bulk perovskite polycrystalline films and perovskite nanoparticles, describes current challenges, and suggests future research directions for researchers to encourage them to collaborate and to make a synergetic effect in this rapidly emerging multidisciplinary field. PMID:27679844

  9. Alpha particle emitters in medicine

    SciTech Connect

    Fisher, D.R.

    1989-09-01

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ({sup 211}At) and natural bismuth-212 ({sup 212}Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ({sup 223}Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs.

  10. Active pixel sensor array with multiresolution readout

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R. (Inventor); Kemeny, Sabrina E. (Inventor); Pain, Bedabrata (Inventor)

    1999-01-01

    An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node. There is also a readout circuit, part of which can be disposed at the bottom of each column of cells and be common to all the cells in the column. The imaging device can also include an electronic shutter formed on the substrate adjacent the photogate, and/or a storage section to allow for simultaneous integration. In addition, the imaging device can include a multiresolution imaging circuit to provide images of varying resolution. The multiresolution circuit could also be employed in an array where the photosensitive portion of each pixel cell is a photodiode. This latter embodiment could further be modified to facilitate low light imaging.

  11. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Technical Reports Server (NTRS)

    Henderson, S.W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Wollack, E. J.

    2016-01-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies-imaged in intensity and polarization at few arcminute-scale resolution-will enable precision cosmological constraints and also awide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the AdvancedACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the AdvancedACTPol cryogenic detector arrays.

  12. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Technical Reports Server (NTRS)

    Henderson, S.W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Wollack, E. J.

    2016-01-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies-imaged in intensity and polarization at few arcminute-scale resolution-will enable precision cosmological constraints and also awide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the AdvancedACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the AdvancedACTPol cryogenic detector arrays.

  13. Readout electronics for LGAD sensors

    NASA Astrophysics Data System (ADS)

    Alonso, O.; Franch, N.; Canals, J.; Palacio, F.; López, M.; Vilà, A.; Diéguez, A.; Carulla, M.; Flores, D.; Hidalgo, S.; Merlos, A.; Pellegrini, G.; Quirion, D.

    2017-02-01

    In this paper, an ASIC fabricated in 180 nm CMOS technology from AMS with the very front-end electronics used to readout LGAD sensors is presented as well as its experimental results. The front-end has the typical architecture for Si-strip readout, i.e., preamplification stage with a Charge Sensitive Amplifier (CSA) followed by a CR-RC shaper. Both amplifiers are based on a folded cascode structure with a PMOS input transistor and the shaper only uses passive elements for the feedback stage. The CSA has programmable gain and a configurable input stage in order to adapt to the different input capacitance of the LGAD sensors (pixelated, short and long strips) and to the different input signal (depending on the gain of the LGAD). The fabricated prototype has an area of 0.865 mm × 0.965 mm and includes the biasing circuit for the CSA and the shaper, 4 analog channels (CSA+shaper) and programmable charge injection circuits included for testing purposes. Noise and power analysis performed during simulation fixed the size of the input transistor to W/L = 860 μm/0.2 μm. The shaping time is fixed by design at 1 us and, in this ASIC version, the feedback elements of the shaper are passive, which means that the area of the shaper can be reduced using active elements in future versions. Finally, the different gains of the CSA have been selected to maintain an ENC below 400 electrons for a detector capacitor of 20 pF, with a power consumption of 150 μ W per channel.

  14. Transverse Emittance Reduction with Tapered Foil

    SciTech Connect

    Jiao, Yi; Chao, Alex; Cai, Yunhai; /SLAC

    2011-12-09

    The idea of reducing transverse emittance with tapered energy-loss foil is proposed by J.M. Peterson in 1980s and recently by B. Carlsten. In this paper, we present the physical model of tapered energy-loss foil and analyze the emittance reduction using the concept of eigen emittance. The study shows that, to reduce transverse emittance, one should collimate at least 4% of particles which has either much low energy or large transverse divergence. The multiple coulomb scattering is not trivial, leading to a limited emittance reduction ratio. Small transverse emittances are of essential importance for the accelerator facilities generating free electron lasers, especially in hard X-ray region. The idea of reducing transverse emittance with tapered energy-loss foil is recently proposed by B. Carlsten [1], and can be traced back to J.M. Peterson's work in 1980s [2]. Peterson illustrated that a transverse energy gradient can be produced with a tapered energy-loss foil which in turn leads to transverse emittance reduction, and also analyzed the emittance growth from the associated multiple coulomb scattering. However, what Peterson proposed was rather a conceptual than a practical design. In this paper, we build a more complete physical model of the tapered foil based on Ref. [2], including the analysis of the transverse emittance reduction using the concept of eigen emittance and confirming the results by various numerical simulations. The eigen emittance equals to the projected emittance when there is no cross correlation in beam's second order moments matrix [3]. To calculate the eigen emittances, it requires only to know the beam distribution at the foil exit. Thus, the analysis of emittance reduction and the optics design of the subsequent beam line section can be separated. In addition, we can combine the effects of multiple coulomb scattering and transverse energy gradient together in the beam matrix and analyze their net effect. We find that,when applied to an

  15. Optical readout of uncooled thermal detectors

    NASA Astrophysics Data System (ADS)

    Datskos, Panos G.; Rajic, Slobodan; Senesac, Larry R.; Earl, Dennis D.; Evans, Boyd M., III; Corbeil, James L.; Datskou, Irene

    2000-12-01

    We investigated microposition sensing of micro-electro- mechanical systems (MEMS) that is based on optical readout techniques. We determined the parameters that affect or limit the performance of optical readout techniques especially as they apply to detection of infrared radiation. Such microposition sensing schemes are very important as readout mechanisms for large arrays of microstructures which are required for imaging. In addition, we explored the performance of uncooled micromechanical IR sensors using Fresnel zone plates (FZP). This type of diffractive feature diffracts along the optical axis and not perpendicular to that axis. We found that temperature fluctuation noise and background fluctuation noise, are currently the limits to the performance of uncooled micromechanical IR detectors. The noise at the output of the optical readout includes amplified noise from the micromechanical structures and noise added by the optical readout itself. However, the added noise is negligible compared to the amplified temperature fluctuation noise inherent in the microstructures. In this context an optical readout is nearly an ideal, noiseless readout method.

  16. Study of MWPCs with interpolating pad readout for high multiplicity charged particle detection

    SciTech Connect

    Debbe, R.; Fischer, J.; Lissauer, D.; Ludlam, T.W.; Makowiecki, D.; O'Brien, E.; Radeka, V.; Rescia, S.; Rogers, L.C.; Smith, G.C.; Stephani, D.; Yu, B. ); Greene, S.V.; Hemmick, T.K.; Mitchell, J.T.; Shivakumar, B. ); Mathieson, E. )

    1990-10-01

    Two types of MWPC with interpolating cathode pad'' readout for two dimensional position sensitive detection have been studied. One type uses rectangular pads and resistive charge division. A detector with an active area of 26 cm {times} 16 cm, over 1000 readout channels has been built. With readout spacing of 1 cm, a position resolution of {approximately}70{mu}m (rms) for 5.4 keV x-rays and a differential non-linearity of {plus minus}6% have been achieved. Another type of detector uses chevron'' shaped pads for geometrical charge division. Position resolution {approximately}50{mu}m (rms) for 5.4 keV x-rays has been observed in a test detector and results of an investigation to reduce differential non-linearity are reported. 11 refs., 6 figs.

  17. Readout techniques for photon-counting microchannel image systems

    NASA Technical Reports Server (NTRS)

    Lampton, Michael

    1988-01-01

    A comparative evaluation is made of such readout methods for the microchannel plates that are commonly used in EUV, FUV, and X-ray low light level image systems as the (1) phosphor-video, (2) phosphor and binary-mask encoder, (3) direct discrete-position encoder, (4) direct analog amplitude position-encoder systems, and (5) delay-line encoders. Relative advantages and limitations are discussed in the context of low light level space-based astronomy applications. The delay-line technique offers great promise for high-resolution applications where oversampling is mandatory, as in spectroscopy.

  18. New readout system for submicron tracks with nuclear emulsion

    NASA Astrophysics Data System (ADS)

    Katsuragawa, T.; Umemoto, A.; Yoshimoto, M.; Naka, T.; Asada, T.

    2017-04-01

    In this paper, we summarize a newly developed automatic readout system, composed of a microscope with an optics stage, to analyze charged particle tracks of less than 1 μm recorded in a fine-grained nuclear emulsion. This system's optics have the high spatial resolution, epi-illumination, and xenon-mercury lamp necessary to achieve sufficient contrast and brightness for small silver grains up to about 40 nm in diameter. Methods of shape recognition and focus point acquisition were developed that enabled the system to identify submicron tracks corresponding to nuclei on the order of 10-100 keV.

  19. Beam Loss and Longitudinal Emittance Growth in SIS

    NASA Astrophysics Data System (ADS)

    Kirk, M.; Hofmann, I.; Boine-Frankenheim, O.; Spiller, P.; Hülsmann, P.; Franchetti, G.; Damerau, H.; König, H. Günter; Klingbeil, H.; Kumm, M.; Moritz, P.; Schütt, P.; Redelbach, A.

    2005-06-01

    Beam losses of several percent occur regularly in SIS. The onset occurs during the RF capture of the beam. Previous studies have revealed that the losses can come from the RF bucket at the start of acceleration being over filled due to the longitudinal bucket acceptance being too small, or due to the mismatch between the mean energy from the UNILAC and synchronous energy of the SIS. The beam losses as measured by a DC beam transformer however show in addition to the sharp initial drop, for the above reasons, a much slower decay in the beam intensity. The speculated cause comes from the incoherent transverse tune shift of the bunched beam, which forces particles into transverse resonant conditions. The longitudinal emittance growth is also another important issue for SIS. Past measurements from Schottky-noise pick-ups have shown a factor of 3-5 increase in the longitudinal emittance depending on the extraction energy; a large factor when compared against expectations from theory. These factors were calculated from the ratio between the normalized relative momentum spread of the DC beam before RF capture and after debunching. In this present work, tomographical techniques have been used to reconstruct the phasespace from a series of bunch profile measurements from a Beam Position Monitor (BPM). Therefore one can find the rate of growth in the longitudinal emittance from a series of high resolution BPM measurements along the RF ramp. Furthermore the initial phasespace density matrix from these reconstructions has been used to generate the initial population of macroparticles for the ESME longitudinal dynamics Particle-In-Cell code, thereby enabling a comparison between the longitudinal emittance growth of the beam under ideal conditions and that of the experiment. The longitudinal emittance growth (rms) during the acceleration (˜540ms) was approximately 20%, and that during the RF capture was estimated to have an upper limit of about 40%. Later measurements have also

  20. EMITTANCE CONTROL FOR VERY SHORT BUNCHES

    SciTech Connect

    Bane, K

    2004-07-20

    Many recent accelerator projects call for the production of high energy bunches of electrons or positrons that are simultaneously short, intense, and have small emittances. Examples of such projects are the Self-Amplified Spontaneous Emission (SASE) FEL's, such as the Linac Coherent Light Source (LCLS). A major challenge is keeping in check forces that increase beam emittances in accelerator components, such as: wakefields of accelerator structures and surface roughness, and coherent synchrotron radiation. We describe such forces and discuss emittance control.

  1. Emittance Growth in the NLCTA First Chicane

    SciTech Connect

    Sun, Yipeng; Adolphsen, Chris; /SLAC

    2011-08-19

    In this paper, the emittance growth in the NLCTA (Next Linear Collider Test Accelerator) first chicane region is evaluated by simulation studies. It is demonstrated that the higher order fields of the chicane dipole magnet and the dipole corrector magnet (which is attached on the quadrupoles) are the main contributions for the emittance growth, especially for the case with a large initial emittance ({gamma}{epsilon}{sub 0} = 5 {micro}m for instance). These simulation results agree with the experimental observations.

  2. Estimation of emittances and surface temperatures from AVHRR data

    NASA Technical Reports Server (NTRS)

    Schutt, John B.; Holben, Brent N.

    1991-01-01

    An approach to the estimation of surface temperatures and emissivities using AVHRR (Advanced Very High Resolution Radiometer) data acquired near noon is presented. Thermal data in channels 3, 4, and 5 were used to estimate the reflective component in 3. For three water bodies in Oregon the average emittances found for channels 3 and 4 were 0.979 and 0.991, respectively. Also studied were agricultural sites and forests, comprising both primary (PF) and secondary (SF) types. For the agricultural sites, the average emittances were 0.919 and 0.943 for channels 3 and 4. For the PF and SF the results were 0.976 and 0.983 for channel 3 and 0.988 and 0.995 for channel 4.

  3. Minimum emittance in TBA and MBA lattices

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Peng, Yue-Mei

    2015-03-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.

  4. An ESS system for ECRIS Emittance Research

    SciTech Connect

    Cao, Y.; Sun, L.T.; He, W.; Ma, L.; Zhang, Z.M.; Zhao, H.Y.; Zhao, H.W.; Zhang, X.Z.; Guo, X.H.; Ma, B.H.; Li, J.; Wang, H.; Li, J.Y.; Li, X.X.; Feng, Y.C.; Lu, W.

    2005-03-15

    An emittance scanner named Electric-Sweep Scanner had been designed and fabricated in IMP. And it has been set up on the LECR3 beam line for the ion beam quality study. With some development, the ESS system has become a relatively dependable and reliable emittance scanner. Its experiment error is about 10 percent. We have done a lot of experiments of emittance measurement on LECR3 ion source, and have researched the relations between ion beam emittance and the major parameters of ECR ion source. The reliability and accuracy test results are presented in this paper. And the performance analysis is also discussed.

  5. Hybrid emitter all back contact solar cell

    DOEpatents

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  6. Advanced data readout technique for Multianode Position Sensitive Photomultiplier Tube applicable in radiation imaging detectors

    NASA Astrophysics Data System (ADS)

    Popov, V.

    2011-01-01

    Most of the best performing PSPMT tubes from Hamamatsu and Burle are designed with a pad-matrix anode layout. However, for obtaining a high resolution, a small-sized anode photomultiplier tubes are preferable; these tubes may have 64, 256 or 1024 anodes per tube. If the tubes are used in array to get a larger area detector, the number of analog channels may range from hundreds to thousands. Multichannel analog readout requires special electronics ICs, ASICs etc., which are attached to multichannel DAQ system. As a result, the data file and data processing time will be increased. Therefore, this readout could not be performed in a small project. Usually, most of radiation imaging applications allow the use of analog data processing in front-end electronics, significantly reducing the number of the detector's output lines to data acquisition without reducing the image quality. The idea of pad-matrix decoupling circuit with gain correction was invented and intensively tested in JLab. Several versions of PSPMT readout electronics were produced and studied. All developments were done and optimized specifically for radiation imaging projects. They covered high resolution SPECT, high speed PET, fast neutron imaging, and single tube and multi tube array systems. This paper presents and discusses the summary of the observed results in readout electronics evaluation with different PSPMTs and radiation imaging systems, as well as the advantages and limitations of the developed approach to radiation imaging detectors readout.

  7. Chemical regeneration of emitter surface increases thermionic diode life

    NASA Technical Reports Server (NTRS)

    Breiteieser, R.

    1966-01-01

    Chemical regeneration of sublimated emitter electrode increases the operating efficiency and life of thermionic diodes. A gas which forms chemical compounds with the sublimated emitter material is introduced into the space between the emitter and the collector. The compounds migrate to the emitter where they decompose and redeposit the emitter material.

  8. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    SciTech Connect

    Le Sage, G P

    2002-11-05

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the beam profile will be described.

  9. Low Emittance, High Brilliance Relativistic Electron Beams from a Laser-Plasma Accelerator

    SciTech Connect

    Brunetti, E.; Shanks, R. P.; Manahan, G. G.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Raj, G.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A.

    2010-11-19

    Progress in laser wakefield accelerators indicates their suitability as a driver of compact free-electron lasers (FELs). High brightness is defined by the normalized transverse emittance, which should be less than 1{pi} mm mrad for an x-ray FEL. We report high-resolution measurements of the emittance of 125 MeV, monoenergetic beams from a wakefield accelerator. An emittance as low as 1.1{+-}0.1{pi} mm mrad is measured using a pepper-pot mask. This sets an upper limit on the emittance, which is comparable with conventional linear accelerators. A peak transverse brightness of 5x10{sup 15} A m{sup -1} rad{sup -1} makes it suitable for compact XUV FELs.

  10. Design of the ATLAS IBL Readout System

    NASA Astrophysics Data System (ADS)

    Polini, Alessandro; Bruni, Graziano; Bruschi, Marco; D'Antone, Ignazio; Dopke, Jens; Falchieri, Davide; Flick, Tobias; Gabrielli, Alessandro; Grosse-Knetter, Joern; Joseph, John; Krieger, Nina; Kugel, Andreas; Morettini, Paolo; Rizzi, Matteo; Schroer, Nicolai; Travaglini, Riccardo; Zannoli, Samuele; Zoccoli, Antonio

    An Insertable B-Layer is planned for the upgrade of the ATLAS detector and will add a fourth and innermost pixel layer to the existing Pixel Detector. 12 million pixels attached to new FE-I4 readout ASICs will require new off-detector electronics which is currently realized with two VME-based boards: a Back Of Crate module implementing optical I/O functionality and a Readout Driver module for data processing. This paper illustrates the new readout chain, focusing on the design of the new Readout Driver Card, which, with a fourfold integration with respect to the previous design, builds up the detector data, controls the calibration procedures and interacts via Gigabit links with a novel calibration farm. Future prospects and back compatibility to the existing system are also addressed.

  11. Back-Side Readout Silicon Photomultiplier

    PubMed Central

    Choong, Woon-Seng; Holland, Stephen E.

    2012-01-01

    We present a novel structure for the back-side readout silicon photomultipler (SiPM). Current SiPMs are front-illuminated structures with front-side readout, which have relatively small geometric fill factor leading to degradation in their photon detection efficiency (PDE). Back-side readout devices will provide an advantageous solution to achieve high PDE. We designed and investigated a novel structure that would allow back-side readout while creating a region of high electric field optimized for avalanche breakdown. In addition, this structure has relatively high fill factor and also allow direct coupling of individual micro-cell of the SiPM to application-specific integrated circuits. We will discuss the performance that can be attained with this structure through device simulation and the process flow that can be used to fabricate this structure through process simulation. PMID:23564969

  12. Back-Side Readout Silicon Photomultiplier.

    PubMed

    Choong, Woon-Seng; Holland, Stephen E

    2012-07-19

    We present a novel structure for the back-side readout silicon photomultipler (SiPM). Current SiPMs are front-illuminated structures with front-side readout, which have relatively small geometric fill factor leading to degradation in their photon detection efficiency (PDE). Back-side readout devices will provide an advantageous solution to achieve high PDE. We designed and investigated a novel structure that would allow back-side readout while creating a region of high electric field optimized for avalanche breakdown. In addition, this structure has relatively high fill factor and also allow direct coupling of individual micro-cell of the SiPM to application-specific integrated circuits. We will discuss the performance that can be attained with this structure through device simulation and the process flow that can be used to fabricate this structure through process simulation.

  13. Readout and DAQ for Pixel Detectors

    NASA Astrophysics Data System (ADS)

    Platkevic, Michal

    2010-01-01

    Data readout and acquisition control of pixel detectors demand the transfer of significantly a large amounts of bits between the detector and the computer. For this purpose dedicated interfaces are used which are designed with focus on features like speed, small dimensions or flexibility of use such as digital signal processors, field-programmable gate arrays (FPGA) and USB communication ports. This work summarizes the readout and DAQ system built for state-of-the-art pixel detectors of the Medipix family.

  14. Satellite Direct Readout: Opportunities for Science Education

    DTIC Science & Technology

    1994-02-01

    AD-A276 257 1UIIIIIlii 253860-1-X (R) SATELLITE DIRECT READOUT: OPPORTUNITIES FOR SCIENCE EDUCATION Thomas W. Wagner February 1994 C, Submitted to...Their Classroom ..................... 10 LIST OF TABLES 1. Summary Statement of Work .............................. 1 2. Science Education Goals and...with emphasis on newly emerging national Science Education Standards. Section 3 provides the specifications of the portable ERIM Direct Readout

  15. SPIDR, a general-purpose readout system for pixel ASICs

    NASA Astrophysics Data System (ADS)

    van der Heijden, B.; Visser, J.; van Beuzekom, M.; Boterenbrood, H.; Kulis, S.; Munneke, B.; Schreuder, F.

    2017-02-01

    The SPIDR (Speedy PIxel Detector Readout) system is a flexible general-purpose readout platform that can be easily adapted to test and characterize new and existing detector readout ASICs. It is originally designed for the readout of pixel ASICs from the Medipix/Timepix family, but other types of ASICs or front-end circuits can be read out as well. The SPIDR system consists of an FPGA board with memory and various communication interfaces, FPGA firmware, CPU subsystem and an API library on the PC . The FPGA firmware can be adapted to read out other ASICs by re-using IP blocks. The available IP blocks include a UDP packet builder, 1 and 10 Gigabit Ethernet MAC's and a "soft core" CPU . Currently the firmware is targeted at the Xilinx VC707 development board and at a custom board called Compact-SPIDR . The firmware can easily be ported to other Xilinx 7 series and ultra scale FPGAs. The gap between an ASIC and the data acquisition back-end is bridged by the SPIDR system. Using the high pin count VITA 57 FPGA Mezzanine Card (FMC) connector only a simple chip carrier PCB is required. A 1 and a 10 Gigabit Ethernet interface handle the connection to the back-end. These can be used simultaneously for high-speed data and configuration over separate channels. In addition to the FMC connector, configurable inputs and outputs are available for synchronization with other detectors. A high resolution (≈ 27 ps bin size) Time to Digital converter is provided for time stamping events in the detector. The SPIDR system is frequently used as readout for the Medipix3 and Timepix3 ASICs. Using the 10 Gigabit Ethernet interface it is possible to read out a single chip at full bandwidth or up to 12 chips at a reduced rate. Another recent application is the test-bed for the VeloPix ASIC, which is developed for the Vertex Detector of the LHCb experiment. In this case the SPIDR system processes the 20 Gbps scrambled data stream from the VeloPix and distributes it over four 10 Gigabit

  16. The capacitive division image readout: a novel imaging device for microchannel plate detectors

    NASA Astrophysics Data System (ADS)

    Lapington, J. S.; Conneely, T. M.; Leach, S. A.; Moore, L.

    2013-09-01

    The Capacitive Division Image Readout (C-DIR) is a simple and novel image readout for photon counting detectors offering major performance advantages. C-DIR is a charge centroiding device comprising three elements; (i) a resistive anode providing event charge localization, event current return path and electrical isolation from detector high voltage, (ii) a dielectric substrate which capacitively couples the event transient signal to the third element, (iii) the readout device; an array of capacitively coupled electrodes which divides the signal among the readout charge measurement nodes. The resistive anode and dielectric substrate constitute the rear interface of the detector and capacitively couple the signal to the external C-DIR readout device. The C-DIR device is a passive, multilayer printed circuit board type device comprising a matrix of isolated electrodes whose geometries define the capacitive network. C-DIR is manufactured using conventional PCB geometries and is straightforward and economical to construct. C-DIR's robustness and simplicity belie its performance advantages. Its capacitive nature avoids partition noise, the Poisson noise associated with collection of discrete charges. The dominant noise limiting position resolution is electronic noise. However C-DIR also presents a low input capacitance to the readout electronics, minimising this noise component thus maximising spatial resolution. Optimisation of the C-DIR pattern-edge geometry can provide ~90% linear dynamic range. We present data showing image resolution and linearity of the C-DIR device in a microchannel plate detector and describe various electronic charge measurement scheme designed to exploit the full performance potential of the C-DIR device.

  17. A continuous read-out TPC for the ALICE upgrade

    NASA Astrophysics Data System (ADS)

    Lippmann, C.

    2016-07-01

    The largest gaseous Time Projection Chamber (TPC) in the world, the ALICE TPC, will be upgraded based on Micro Pattern Gas Detector technology during the second long shutdown of the CERN Large Hadron Collider in 2018/19. The upgraded detector will operate continuously without the use of a triggered gating grid. It will thus be able to read all minimum bias Pb-Pb events that the LHC will deliver at the anticipated peak interaction rate of 50 kHz for the high luminosity heavy-ion era. New read-out electronics will send the continuous data stream to a new online farm at rates up to 1 TByte/s. A fractional ion feedback of below 1% is required to keep distortions due to space charge in the TPC drift volume at a tolerable level. The new read-out chambers will consist of quadruple stacks of Gas Electron Multipliers (GEM), combining GEM foils with a different hole pitch. Other key requirements such as energy resolution and operational stability have to be met as well. A careful optimisation of the performance in terms of all these parameters was achieved during an extensive R&D program. A working point well within the design specifications was identified with an ion backflow of 0.63%, a local energy resolution of 11.3% (sigma) and a discharge probability comparable to that of standard triple GEM detectors.

  18. High-sensitivity SQUIDs with dispersive readout for scanning microscopy

    NASA Astrophysics Data System (ADS)

    Mol, J. M.; Foroughi, F.; Arps, J.; Kammerloher, E.; Bethke, P.; Gibson, G. W., Jr.; Fung, Y. K. K.; Klopfer, B.; Nowack, K.; Kratz, P. A.; Huber, M. E.; Moler, K. A.; Kirtley, J. R.; Bluhm, H.

    2014-03-01

    In a scanning SQUID microscope, the high magnetic flux sensitivity is utilized to image magnetic properties of sample surfaces. As an alternative to the widely used DC SQUIDs, we present Nb SQUIDs for scanning with dispersive microwave readout, featuring significantly higher bandwidth and sensitivity. An on-chip shunt capacitor in parallel with the junction and flux pickup loops forms an LC resonator whose resonance depends on the flux in the SQUID. The readout utilizes a phase-sensitive detection of the reflected drive signal at the SQUID's resonance frequency. Highest sensitivities are achieved by making use of the inherent nonlinearity of the device at high excitation powers. We present a study of the characteristics and noise measurements of our sensors at 4 K. Extrapolations from our results to 300 mK indicate that flux sensitivities as low as 50 nΦ0Hz- 1 / 2 could be possible. Using high-resolution lithography, our sensors promise sub-micron spatial resolution. Integrated into a scanning microscope, they will provide a powerful tool for the study of weak magnetic effects and quantum coherent phenomena. This work was supported by NSF IMR-MIP grant No. 0957616 and the Alfried Krupp von Bohlen und Halbach - Foundation.

  19. Selective Emitter Pumped Rare Earth Laser

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L. (Inventor); Patton, Martin O. (Inventor)

    2001-01-01

    A selective emitter pumped rare earth laser provides an additional type of laser for use in many laser applications. Rare earth doped lasers exist which are pumped with flashtubes or laser diodes. The invention uses a rare earth emitter to transform thermal energy input to a spectral band matching the absorption band of a rare earth in the laser in order to produce lasing.

  20. Emittance growth in rippled solenoidal magnetic fields

    SciTech Connect

    Adler, R.J.

    1987-01-01

    Emittance growth results due to accelerating gaps, and magnetic field gaps in induction accelerators. The analytic technique previously used to study electric field induced emittance growth for immersed source beams is extended to include solenoid fringing field effects in the present work. These results have application to industrial induction accelerators and to high brightness Free Electron Laser drivers. 1 ref., 2 figs.

  1. An X-ray imaging device based on a GEM detector with delay-line readout

    NASA Astrophysics Data System (ADS)

    Zhou, Yi; Li, Cheng; Sun, Yong-Jie; Shao, Ming

    2010-01-01

    An X-ray imaging device based on a triple-GEM (Gas Electron Multiplier) detector, a fast delay-line circuit with 700 MHz cut-off frequency and two dimensional readout strips with 150 μm width on the top and 250 μm width on the bottom, is designed and tested. The localization information is derived from the propagation time of the induced signals on the readout strips. This device has a good spatial resolution of 150 μm and works stably at an intensity of 105 Hz/mm2 with 8 keV X-rays.

  2. Electronic readout system for the Belle II imaging Time-Of-Propagation detector

    NASA Astrophysics Data System (ADS)

    Kotchetkov, Dmitri

    2017-07-01

    The imaging Time-Of-Propagation (iTOP) detector, constructed for the Belle II experiment at the SuperKEKB e+e- collider, is an 8192-channel high precision Cherenkov particle identification detector with timing resolution below 50 ps. To acquire data from the iTOP, a novel front-end electronic readout system was designed, built, and integrated. Switched-capacitor array application-specific integrated circuits are used to sample analog signals. Triggering, digitization, readout, and data transfer are controlled by Xilinx Zynq-7000 system on a chip devices.

  3. Negative Ion Beam Extraction and Emittance

    SciTech Connect

    Holmes, Andrew J. T.

    2007-08-10

    The use of magnetic fields to both aid the production of negative ions and suppress the co-extracted electrons causes the emittance and hence the divergence of the negative ion beam to increase significantly due to the plasma non-uniformity from jxB drift. This drift distorts the beam-plasma meniscus and experimental results of the beam emittance are presented, which show that non-uniformity causes the square of the emittance to be proportional to the 2/3 power of the extracted current density. This can cause the divergence of the negative ion beam to be significantly larger than its positive ion counterpart. By comparing results from positive and negative ion beam emittances from the same source, it is also possible to draw conclusions about their vulnerability to magnetic effects. Finally emittances of caesiated and un-caesiated negative ion beams are compared to show how the surface and volume modes of production interact.

  4. Directional emittance surface measurement system and process

    NASA Technical Reports Server (NTRS)

    Puram, Chith K. (Inventor); Daryabeigi, Kamran (Inventor); Wright, Robert (Inventor); Alderfer, David W. (Inventor)

    1994-01-01

    Apparatus and process for measuring the variation of directional emittance of surfaces at various temperatures using a radiometric infrared imaging system. A surface test sample is coated onto a copper target plate provided with selective heating within the desired incremental temperature range to be tested and positioned onto a precision rotator to present selected inclination angles of the sample relative to the fixed positioned and optically aligned infrared imager. A thermal insulator holder maintains the target plate on the precision rotator. A screen display of the temperature obtained by the infrared imager, and inclination readings are provided with computer calculations of directional emittance being performed automatically according to equations provided to convert selected incremental target temperatures and inclination angles to relative target directional emittance values. The directional emittance of flat black lacquer and an epoxy resin measurements obtained are in agreement with the predictions of the electromagnetic theory and with directional emittance data inferred from directional reflectance measurements made on a spectrophotometer.

  5. New approach to obtain boron selective emitters

    SciTech Connect

    Moehlecke, A.; Luque, A.

    1994-12-31

    Selective emitters, used in high efficiency solar cells, need a series of oxidations and photolithographic steps that render the process more expensive. In this paper, a new way to make selective emitters using boron is presented. The main feature of this approach is to save oxide growths and photolithographic processes and it is based on the property of boron doped silicon surfaces to be resistant to anisotropic etchings like the one performed during the texturization. Using this characteristic of boron emitter surfaces, the authors can obtain a highly doped emitter under metal grid and simultaneously a shield to avoid texture on these surfaces. First cells were processed and short wavelength response of p{sup +}nn{sup +} solar cells was enhanced by using lightly doped boron emitters in the uncovered area.

  6. TPV Systems with Solar Powered Tungsten Emitters

    SciTech Connect

    Vlasov, A. S.; Khvostikov, V. P.; Khvostikova, O. A.; Gazaryan, P. Y.; Sorokina, S. V.; Andreev, V. M.

    2007-02-22

    A solar TPV generator development and characterization are presented. A double stage sunlight concentrator ensures 4600x concentration ratio. TPV modules based on tungsten emitters and GaSb cells were designed, fabricated and tested at indoor and outdoor conditions. The performance of tungsten emitter under concentrated solar radiation was analyzed. Emitter temperatures in the range of 1400-2000 K were measured, depending on the emitter size. The light distribution in the module has been characterized, 1x1 cm GaSb TPV cells were fabricated with the use of the Zn-diffusion and LPE technologies. The cell efficiency of 19% under illumination by a tungsten emitter (27% under spectra cut-off at {lambda} > 1820 nm) heated up to 1900-2000 K had been derived from experimentally measured PV parameters. The series connection of PV cells was ensured by the use of BeO ceramics. The possibilities of system performance improvement are discussed.

  7. Emittance measurements of the CLIO electron beam

    NASA Astrophysics Data System (ADS)

    Chaput, R.; Devanz, G.; Joly, P.; Kergosien, B.; Lesrel, J.

    1997-02-01

    We have designed a setup to measure the transverse emittance at the CLIO accelerator exit, based on the "3 gradients" method. The beam transverse size is measured simply by scanning it with a steering coil across a fixed jaw and recording the transmitted current, at various quadrupole strengths. A code then performs a complete calculation of the emittance using the transfer matrix of the quadrupole instead of the usual classical lens approximation. We have studied the influence of various parameters on the emittance: Magnetic field on the e-gun and the peak current. We have also improved a little the emittance by replacing a mismatched pipe between the buncher and accelerating section to avoid wake-field effects; The resulting improvements of the emittance have led to an increase in the FEL emitted power.

  8. Sources of Emittance in RF Photocathode Injectors

    SciTech Connect

    Dowell, David

    2016-12-11

    Advances in electron beam technology have been central to creating the current generation of x-ray free electron lasers and ultra-fast electron microscopes. These once exotic devices have become essential tools for basic research and applied science. One important beam technology for both is the electron source which, for many of these instruments, is the photocathode RF gun. The invention of the photocathode gun and the concepts of emittance compensation and beam matching in the presence of space charge and RF forces have made these high-quality beams possible. Achieving even brighter beams requires a taking a finer resolution view of the electron dynamics near the cathode during photoemission and the initial acceleration of the beam. In addition, the high brightness beam is more sensitive to degradation by the optical aberrations of the gun’s RF and magnetic lenses. This paper discusses these topics including the beam properties due to fundamental photoemission physics, space charge effects close to the cathode, and optical distortions introduced by the RF and solenoid fields. Analytic relations for these phenomena are derived and compared with numerical simulations.

  9. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  10. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, Joanna S.; MacGregor, Robert R.; Wolf, Alfred P.; Langstrom, Bengt

    1990-01-01

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  11. Positron emitter labeled enzyme inhibitors

    SciTech Connect

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-04-03

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  12. Microlensless interdigitated photoconductive terahertz emitters.

    PubMed

    Singh, Abhishek; Prabhu, S S

    2015-01-26

    We report here fabrication of interdigitated photoconductive antenna (iPCA) terahertz (THz) emitters based on plasmonic electrode design. Novel design of this iPCA enables it to work without microlens array focusing, which is otherwise required for photo excitation of selective photoconductive regions to avoid the destructive interference of emitted THz radiation from oppositely biased regions. Benefit of iPCA over single active region PCA is, photo excitation can be done at larger area hence avoiding the saturation effect at higher optical excitation density. The emitted THz radiation power from plasmonic-iPCAs is ~2 times more than the single active region plasmonic PCA at 200 mW optical excitation, which will further increase at higher optical powers. This design is expected to reduce fabrication cost of photoconductive THz sources and detectors.

  13. Code-division-multiplexed readout of large arrays of TES microcalorimeters

    NASA Astrophysics Data System (ADS)

    Morgan, K. M.; Alpert, B. K.; Bennett, D. A.; Denison, E. V.; Doriese, W. B.; Fowler, J. W.; Gard, J. D.; Hilton, G. C.; Irwin, K. D.; Joe, Y. I.; O'Neil, G. C.; Reintsema, C. D.; Schmidt, D. R.; Ullom, J. N.; Swetz, D. S.

    2016-09-01

    Code-division multiplexing (CDM) offers a path to reading out large arrays of transition edge sensor (TES) X-ray microcalorimeters with excellent energy and timing resolution. We demonstrate the readout of X-ray TESs with a 32-channel flux-summed code-division multiplexing circuit based on superconducting quantum interference device (SQUID) amplifiers. The best detector has energy resolution of 2.28 ± 0.12 eV FWHM at 5.9 keV and the array has mean energy resolution of 2.77 ± 0.02 eV over 30 working sensors. The readout channels are sampled sequentially at 160 ns/row, for an effective sampling rate of 5.12 μs/channel. The SQUID amplifiers have a measured flux noise of 0.17 μΦ0/√Hz (non-multiplexed, referred to the first stage SQUID). The multiplexed noise level and signal slew rate are sufficient to allow readout of more than 40 pixels per column, making CDM compatible with requirements outlined for future space missions. Additionally, because the modulated data from the 32 SQUID readout channels provide information on each X-ray event at the row rate, our CDM architecture allows determination of the arrival time of an X-ray event to within 275 ns FWHM with potential benefits in experiments that require detection of near-coincident events.

  14. Low Emittance Electron Beam Studies

    SciTech Connect

    Tikhoplav, Rodion

    2006-01-01

    We have studied the properties of a low emittance electron beam produced by laser pulses incident onto an rf gun photocathode. The experiments were carried out at the A0 photoinjector at Fermilab. Such beam studies are necessary for fixing the design of new Linear Colliders as well as for the development of Free Electron Lasers. An overview of the A0 photoinjector is given in Chapter 1. In Chapter 2 we describe the A0 photoinjector laser system. A stable laser system is imperative for reliable photoinjector operation. After the recent upgrade, we have been able to reach a new level of stability in the pulse-to-pulse fluctuations of the pulse amplitude, and of the temporal and transverse profiles. In Chapter 3 we present a study of transverse emittance versus the shape of the photo-cathode drive-laser pulse. For that purpose a special temporal profile laser shaping device called a pulse-stacker was developed. In Chapter 4 we discuss longitudinal beam dynamics studies using a two macro-particle bunch; this technique is helpful in analyzing pulse compression in the magnetic chicane, as well as velocity bunching effects in the rf-gun and the 9-cell accelerating cavity. In Chapter 5 we introduce a proposal for laser acceleration of electrons. We have developed a laser functioning on the TEM*01 mode, a mode with a longitudinal electric field component which is suitable for such a process. Using this technique at energies above 40 MeV, one would be able to observe laser-based acceleration.

  15. Streak Camera Performance with Large-Format CCD Readout

    SciTech Connect

    Lerche, R A; Andrews, D S; Bell, P M; Griffith, R L; McDonald, J W; Torres, P III; Vergel de Dios, G

    2003-07-08

    The ICF program at Livermore has a large inventory of optical streak cameras that were built in the 1970s and 1980s. The cameras include micro-channel plate image-intensifier tubes (IIT) that provide signal amplification and early lens-coupled CCD readouts. Today, these cameras are still very functional, but some replacement parts such as the original streak tube, CCD, and IIT are scarce and obsolete. This article describes recent efforts to improve the performance of these cameras using today's advanced CCD readout technologies. Very sensitive, large-format CCD arrays with efficient fiber-optic input faceplates are now available for direct coupling with the streak tube. Measurements of camera performance characteristics including linearity, spatial and temporal resolution, line-spread function, contrast transfer ratio (CTR), and dynamic range have been made for several different camera configurations: CCD coupled directly to the streak tube, CCD directly coupled to the IIT, and the original configuration with a smaller CCD lens coupled to the IIT output. Spatial resolution (limiting visual) with and without the IIT is 8 and 20 lp/mm, respectively, for photocathode current density up to 25% of the Child-Langmuir (C-L) space-charge limit. Temporal resolution (fwhm) deteriorates by about 20% when the cathode current density reaches 10% of the C-L space charge limit. Streak tube operation with large average tube current was observed by illuminating the entire slit region through a Ronchi ruling and measuring the CTR. Sensitivity (CCD electrons per streak tube photoelectron) for the various configurations ranged from 7.5 to 2,700 with read noise of 7.5 to 10.5 electrons. Optimum spatial resolution is achieved when the IIT is removed. Maximum dynamic range requires a configuration where a single photoelectron from the photocathode produces a signal that is 3 to 5 times the read noise.

  16. Readout of two-kilopixel transition-edge sensor arrays for Advanced ACTPol

    NASA Astrophysics Data System (ADS)

    Henderson, Shawn W.; Stevens, Jason R.; Amiri, Mandana; Austermann, Jason; Beall, James A.; Chaudhuri, Saptarshi; Cho, Hsiao-Mei; Choi, Steve K.; Cothard, Nicholas F.; Crowley, Kevin T.; Duff, Shannon M.; Fitzgerald, Colin P.; Gallardo, Patricio A.; Halpern, Mark; Hasselfield, Matthew; Hilton, Gene; Ho, Shuay-Pwu Patty; Hubmayr, Johannes; Irwin, Kent D.; Koopman, Brian J.; Li, Dale; Li, Yaqiong; McMahon, Jeff; Nati, Federico; Niemack, Michael; Reintsema, Carl D.; Salatino, Maria; Schillaci, Alessandro; Schmitt, Benjamin L.; Simon, Sara M.; Staggs, Suzanne T.; Vavagiakis, Eve M.; Ward, Jonathan T.

    2016-07-01

    Advanced ACTPol is an instrument upgrade for the six-meter Atacama Cosmology Telescope (ACT) designed to measure the cosmic microwave background (CMB) temperature and polarization with arcminute-scale angular resolution. To achieve its science goals, Advanced ACTPol utilizes a larger readout multiplexing factor than any previous CMB experiment to measure detector arrays with approximately two thousand transition-edge sensor (TES) bolometers in each 150 mm detector wafer. We present the implementation and testing of the Advanced ACTPol time-division multiplexing readout architecture with a 64-row multiplexing factor. This includes testing of individual multichroic detector pixels and superconducting quantum interference device (SQUID) multiplexing chips as well as testing and optimizing of the integrated readout electronics. In particular, we describe the new automated multiplexing SQUID tuning procedure developed to select and optimize the thousands of SQUID parameters required to readout each Advanced ACTPol array. The multichroic detector pixels in each array use separate channels for each polarization and each of the two frequencies, such that four TESes must be read out per pixel. Challenges addressed include doubling the number of detectors per multiplexed readout channel compared to ACTPol and optimizing the Nyquist inductance to minimize detector and SQUID noise aliasing.

  17. Applications using high-Tc superconducting terahertz emitters

    NASA Astrophysics Data System (ADS)

    Nakade, Kurama; Kashiwagi, Takanari; Saiwai, Yoshihiko; Minami, Hidetoshi; Yamamoto, Takashi; Klemm, Richard A.; Kadowaki, Kazuo

    2016-03-01

    Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Michelson interferometer used as a phase-sensitive reflection-type imaging system. The third is a system with precise temperature control to measure the liquid absorption coefficient. The detailed characteristics of these systems are discussed.

  18. Applications using high-Tc superconducting terahertz emitters

    PubMed Central

    Nakade, Kurama; Kashiwagi, Takanari; Saiwai, Yoshihiko; Minami, Hidetoshi; Yamamoto, Takashi; Klemm, Richard A.; Kadowaki, Kazuo

    2016-01-01

    Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Michelson interferometer used as a phase-sensitive reflection-type imaging system. The third is a system with precise temperature control to measure the liquid absorption coefficient. The detailed characteristics of these systems are discussed. PMID:26983905

  19. Portable infrared reflectometer for evaluating emittance

    NASA Astrophysics Data System (ADS)

    Jaworske, Donald A.; Skowronski, Timothy J.

    2000-01-01

    Optical methods are frequently used to evaluate the emittance of candidate spacecraft thermal control materials. One new optical method utilizes a portable infrared reflectometer capable of obtaining spectral reflectance of an opaque surface in the range of 2 to 25 microns using a Michelson-Type FTIR interferometer. This miniature interferometer collects many infrared spectra over a short period of time. It also allows the size of the instrument to be small such that spectra can be collected in the laboratory or in the field. Infrared spectra are averaged and integrated with respect to the room temperature black body spectrum to yield emittance at 300 K. Integrating with respect to other black body spectra yields emittance values at other temperatures. Absorption bands in the spectra may also be used for chemical species identification. The emittance of several samples was evaluated using this portable infrared reflectometer, an old infrared reflectometer equipped with dual rotating black body cavities, and a bench top thermal vacuum chamber. Samples for evaluation were purposely selected such that a range of emittance values and thermal control material types would be represented, including polished aluminum, Kapton®, silvered Teflon®, and the inorganic paint Z-93-P. Results indicate an excellent linear relationship between the room temperature emittance calculated from infrared spectral data and the emittance obtained from the dual rotating black body cavities and thermal vacuum chamber. The prospect of using the infrared spectral data for chemical species identification will also be discussed. .

  20. The preservation of low emittance flat beams

    SciTech Connect

    Raubenheimer, T.O.

    1993-04-01

    Many future linear collider designs require beams with very small transverse emittances and large emittance ratios {epsilon}{sub x} {much_gt} {epsilon}{sub y}. In this paper, we will discuss issues associated with the preservation of these small emittances during the acceleration of the beams. The primary sources of transverse emittance dilution in a high energy linear accelerator are the transverse wakefields, the dispersive errors, RF deflections, and betatron coupling. We will discuss the estimation of these effects and the calculation of tolerances that will limit the emittance dilution with a high degree of confidence. Since the six-dimensional emittance is conserved and only the projected emittances are increased, these dilutions can be corrected if the beam has not filamented (phase mixed). We discuss methods of correcting the dilutions and easing the tolerances with beam-based alignment and steering techniques, and non-local trajectory bumps. Finally, we discuss another important source of luminosity degradation, namely, pulse-to-pulse jitter.

  1. Multinozzle Emitter Arrays for Nanoelectrospray Mass Spectrometry

    PubMed Central

    Mao, Pan; Wang, Hung-Ta; Yang, Peidong; Wang, Daojing

    2011-01-01

    Mass spectrometry (MS) is the enabling technology for proteomics and metabolomics. However, dramatic improvements in both sensitivity and throughput are still required to achieve routine MS-based single cell proteomics and metabolomics. Here, we report the silicon-based monolithic multinozzle emitter array (MEA), and demonstrate its proof-of-principle applications in high-sensitivity and high-throughput nanoelectrospray mass spectrometry. Our MEA consists of 96 identical 10-nozzle emitters in a circular array on a 3-inch silicon chip. The geometry and configuration of the emitters, the dimension and number of the nozzles, and the micropillar arrays embedded in the main channel, can be systematically and precisely controlled during the microfabrication process. Combining electrostatic simulation and experimental testing, we demonstrated that sharpened-end geometry at the stem of the individual multinozzle emitter significantly enhanced the electric fields at its protruding nozzle tips, enabling sequential nanoelectrospray for the high-density emitter array. We showed that electrospray current of the multinozzle emitter at a given total flow rate was approximately proportional to the square root of the number of its spraying-nozzles, suggesting the capability of high MS sensitivity for multinozzle emitters. Using a conventional Z-spray mass spectrometer, we demonstrated reproducible MS detection of peptides and proteins for serial MEA emitters, achieving sensitivity and stability comparable to the commercial capillary emitters. Our robust silicon-based MEA chip opens up the possibility of a fully-integrated microfluidic system for ultrahigh-sensitivity and ultrahigh-throughput proteomics and metabolomics. PMID:21728281

  2. Multinozzle Emitter Arrays for Nanoelectrospray Mass Spectrometry

    SciTech Connect

    Mao, Pan; Wang, Hung-Ta; Yang, Peidong; Wang, Daojing

    2011-06-16

    Mass spectrometry (MS) is the enabling technology for proteomics and metabolomics. However, dramatic improvements in both sensitivity and throughput are still required to achieve routine MS-based single cell proteomics and metabolomics. Here, we report the silicon-based monolithic multinozzle emitter array (MEA), and demonstrate its proof-of-principle applications in high-sensitivity and high-throughput nanoelectrospray mass spectrometry. Our MEA consists of 96 identical 10-nozzle emitters in a circular array on a 3-inch silicon chip. The geometry and configuration of the emitters, the dimension and number of the nozzles, and the micropillar arrays embedded in the main channel, can be systematically and precisely controlled during the microfabrication process. Combining electrostatic simulation and experimental testing, we demonstrated that sharpened-end geometry at the stem of the individual multinozzle emitter significantly enhanced the electric fields at its protruding nozzle tips, enabling sequential nanoelectrospray for the high-density emitter array. We showed that electrospray current of the multinozzle emitter at a given total flow rate was approximately proportional to the square root of the number of its spraying-nozzles, suggesting the capability of high MS sensitivity for multinozzle emitters. Using a conventional Z-spray mass spectrometer, we demonstrated reproducible MS detection of peptides and proteins for serial MEA emitters, achieving sensitivity and stability comparable to the commercial capillary emitters. Our robust silicon-based MEA chip opens up the possibility of a fully-integrated microfluidic system for ultrahigh-sensitivity and ultrahigh-throughput proteomics and metabolomics.

  3. X-ray and gamma ray detector readout system

    DOEpatents

    Tumer, Tumay O; Clajus, Martin; Visser, Gerard

    2010-10-19

    A readout electronics scheme is under development for high resolution, compact PET (positron emission tomography) imagers based on LSO (lutetium ortho-oxysilicate, Lu.sub.2SiO.sub.5) scintillator and avalanche photodiode (APD) arrays. The key is to obtain sufficient timing and energy resolution at a low power level, less than about 30 mW per channel, including all required functions. To this end, a simple leading edge level crossing discriminator is used, in combination with a transimpedance preamplifier. The APD used has a gain of order 1,000, and an output noise current of several pA/ Hz, allowing bipolar technology to be used instead of CMOS, for increased speed and power efficiency. A prototype of the preamplifier and discriminator has been constructed, achieving timing resolution of 1.5 ns FWHM, 2.7 ns full width at one tenth maximum, relative to an LSO/PMT detector, and an energy resolution of 13.6% FWHM at 511 keV, while operating at a power level of 22 mW per channel. Work is in progress towards integration of this preamplifier and discriminator with appropriate coincidence logic and amplitude measurement circuits in an ASIC suitable for a high resolution compact PET instrument. The detector system and/or ASIC can also be used for many other applications for medical to industrial imaging.

  4. Narrowband terahertz emitters using metamaterial films.

    PubMed

    Alves, Fabio; Kearney, Brian; Grbovic, Dragoslav; Karunasiri, Gamani

    2012-09-10

    In this article we report on metamaterial-based narrowband thermal terahertz (THz) emitters with a bandwidth of about 1 THz. Single band emitters designed to radiate in the 4 to 8 THz range were found to emit as high as 36 W/m(2) when operated at 400 °C. Emission into two well-separated THz bands was also demonstrated by using metamaterial structures featuring more complex unit cells. Imaging of heated emitters using a microbolometer camera fitted with THz optics clearly showed the expected higher emissivity from the metamaterial structure compared to low-emissivity of the surrounding aluminum.

  5. Emittance growth due to Tevatron flying wires

    SciTech Connect

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  6. Thermophotovoltaic emitter material selection and design

    SciTech Connect

    Saxton, P.C.; Moran, A.L.; Harper, M.J.; Lindler, K.W.

    1997-07-01

    Thermophotovoltaics (TPV) is a potentially attractive direct energy conversion technology. It reduces the need for complex machinery with moving parts and maintenance. TPV generators can be run from a variety of heat sources including waste heat for smaller scale operations. The US Naval Academy`s goal was to build a small experimental thermophotovoltaic generator powered by combustion gases from a General Electric T-58 helicopter gas turbine. The design of the generator imposes material limitations that directly affect emitter and structural materials selection. This paper details emitter material goals and requirements, and the methods used to select suitable candidate emitter materials for further testing.

  7. Online clustering algorithms for radar emitter classification.

    PubMed

    Liu, Jun; Lee, Jim P Y; Senior; Li, Lingjie; Luo, Zhi-Quan; Wong, K Max

    2005-08-01

    Radar emitter classification is a special application of data clustering for classifying unknown radar emitters from received radar pulse samples. The main challenges of this task are the high dimensionality of radar pulse samples, small sample group size, and closely located radar pulse clusters. In this paper, two new online clustering algorithms are developed for radar emitter classification: One is model-based using the Minimum Description Length (MDL) criterion and the other is based on competitive learning. Computational complexity is analyzed for each algorithm and then compared. Simulation results show the superior performance of the model-based algorithm over competitive learning in terms of better classification accuracy, flexibility, and stability.

  8. An 8×8 Row-Column Summing Readout Electronics for Preclinical Positron Emission Tomography Scanners

    PubMed Central

    Shih, Y. C.; Sun, F. W.; MacDonald, L. R.; Otis, B. P.; Miyaoka, R. S.; McDougald, W.; Lewellen, T. K.

    2010-01-01

    This work presents a row/column summing readout electronics for an 8×8 silicon photomultiplier array. The summation circuit greatly reduces the number of electronic channels, which is desirable for pursuing higher resolution positron emission tomography scanners. By using a degenerated common source topology in the summation circuit, more fan-in is possible and therefore a greater reduction in the number of electronic channels can be achieved. The timing signal is retrieved from a common anode, which allows the use of a single fast-sampling analog to digital converter (ADC) for the timing channel and slower, lower power ADCs for the 64 spatial channels. Preliminary results of one row summation of the 8×8 readout electronics exhibited FWHM energy resolution of 17.8% and 18.3% with and without multiplexing, respectively. The measured timing resolution is 2.9ns FWHM. PMID:20729983

  9. Spectral contents readout of birefringent sensor

    NASA Technical Reports Server (NTRS)

    Redner, Alex S.

    1989-01-01

    The technical objective of this research program was to develop a birefringent sensor, capable of measuring strain/stress up to 2000 F and a readout system based on Spectral Contents analysis. As a result of the research work, a data acquisition system was developed, capable of measuring strain birefringence in a sensor at 2000 F, with multi-point static and dynamic capabilities. The system uses a dedicated spectral analyzer for evaluation of stress-birefringence and a PC-based readout. Several sensor methods were evaluated. Fused silica was found most satisfactory. In the final evaluation, measurements were performed up to 2000 F and the system performance exceeded expectations.

  10. Gravity Probe B gyroscope readout system

    NASA Astrophysics Data System (ADS)

    Muhlfelder, B.; Lockhart, J.; Aljabreen, H.; Clarke, B.; Gutt, G.; Luo, M.

    2015-11-01

    We describe the Gravity Probe B London-moment readout system successfully used on-orbit to measure two gyroscope spin axis drift rates predicted by general relativity. The system couples the magnetic signal of a spinning niobium-coated rotor into a low noise superconducting quantum interference device. We describe the multi-layered magnetic shield needed to attenuate external fields that would otherwise degrade readout performance. We discuss the ∼35 nrad/yr drift rate sensitivity that was achieved on-orbit.

  11. Silicon drift photodetectors for scintillation readout in medical imaging

    NASA Astrophysics Data System (ADS)

    Fiorini, C.; Gola, A.; Zanchi, M.; Longoni, A.; Soltau, H.; Strüder, L.

    2007-02-01

    In the attempt to improve system performances of position-sensitive γ-ray detectors with contemporary ease of use and compactness, the use of silicon photodetectors for scintillation readout has become of increasing interest. With respect to the long-established photomultiplier tubes (PMTs), silicon photodiodes (PDs) have the advantages of higher quantum efficiency (QE), smaller dimensions and lower biasing voltages. Avalanche photodiodes (APDs) combine the high QE and compactness of PDs with the benefit of a moderate avalanche multiplication gain, which reduced the electronics noise contribution. However, the statistical component is again affected by the statistics of the multiplication itself (noise factor), and the noise component is still appreciable mainly in the high energy range. Moreover, the sensitivity of the gain to temperature and biasing variations represents a potential practical drawback in the use of APDs arrays for the application. As an alternative to the mentioned photodetectors, silicon drift detectors (SDDs) have recently shown to achieve excellent performances in scintillation light detection. The SDD is a photodetector characterized by an area-independent, low-value output capacitance (˜100 fF), which is one of the major factors limiting the noise performances of the other silicon detectors' technologies. SDDs used for CsI(Tl) scintillation readout have already shown to achieve state-of-the-art energy resolution in γ-ray spectroscopy, and monolithic arrays of SDDs have been recently experimented for the development of Anger cameras for high-resolution γ-ray imaging. In this work, is the performances achievable with SDDs in both energy and spatial resolution are discussed together with a review of the most important results achieved with first prototypes of SDD-based γ-ray detectors.

  12. Efficient readout electronics for multi-anode photomultiplier

    NASA Astrophysics Data System (ADS)

    Lerche, Christoph W.; Herrero-Bosch, Vicente; Ferrando-Jodar, Nestor; Gadea-Girones, Rafa; Sanchez-Martinez, Filomeno; Mora-Más, Francisco J.

    2010-08-01

    We present a novel active and analog readout and preprocessing topology for position sensitive photodetectors (PSPD) that allows to readout a large variety of PSPD devices with different pixel numbers. Additionally, the topology was designed to allow for a significant reduction of analog-to-digital conversion channels. The circuit topology replaces the common passive charge divider and consists of N input stages, N × M weighting stages and M analog adder stages, where N is the number of the input channels, i.e. the number of photodetector pixels and M is the number of outputs. The circuit performs the multiplication of a matrix (the weights) with a vector (signals). For this, the input stage makes M copies of each of the N input signals, the weighting stage multiplies these signal copies with N × M different weights and the output stage adds all weighted copies with the same copy index. For high flexibility, the weights are programmable and the topology allows to interconnect several identical circuits for larger N. Measurements with a first prototype ASIC show that the achieved energy and centroid resolutions equal the resolutions from detectors with passive charge division circuits. However, the presented topology presents important advantages such as scalability. As a first application, we used the prototype ASIC to correct the sensitivity inhomogeneity of position sensitive photomultiplier tubes. As a second application for the circuit, we present a Neural Network based positioning scheme for γ-ray imaging detectors with thick, monolithic scintillation crystals. This allows to correct the strong border artifacts of the center of gravity positioning scheme in monolithic scintillation crystals and thus enhances the spatial resolution of the γ-ray imaging detector.

  13. Hadron detection with a dual-readout fiber calorimeter

    NASA Astrophysics Data System (ADS)

    Lee, S.; Cardini, A.; Cascella, M.; Choi, S.; Ciapetti, G.; Ferrari, R.; Franchino, S.; Fraternali, M.; Gaudio, G.; Ha, S.; Hauptman, J.; Kim, H.; Lanza, A.; Li, F.; Livan, M.; Meoni, E.; Park, J.; Scuri, F.; Sill, A.; Wigmans, R.

    2017-09-01

    In this paper, we describe measurements of the response functions of a fiber-based dual-readout calorimeter for pions, protons and multiparticle ;jets; with energies in the range from 20 to 180 GeV. The calorimeter uses lead as absorber material and has a total mass of 1350 kg. It is complemented by leakage counters made of scintillating plastic, with a total mass of 500 kg. The effects of these leakage counters on the calorimeter performance are studied as well. In a separate section, we investigate and compare different methods to measure the energy resolution of a calorimeter. Using only the signals provided by the calorimeter, we demonstrate that our dual-readout calorimeter, calibrated with electrons, is able to reconstruct the energy of proton and pion beam particles to within a few percent at all energies. The fractional widths of the signal distributions for these particles (σ / E) scale with the beam energy as 30% /√{ E }, without any additional contributing terms.

  14. Single Crystal Diamond Beam Position Monitors with Radiofrequency Electronic Readout

    SciTech Connect

    Solar, B.; Graafsma, H.; Potdevin, G.; Trunk, U.; Morse, J.; Salome, M.

    2010-06-23

    Over the energy range 5{approx}30 keV a suitably contacted, thin ({approx}100 {mu}m) diamond plate can be operated in situ as a continuous monitor of X-ray beam intensity and position as the diamond absorbs only a small percentage of the incident beam. Single crystal diamond is a completely homogeneous material showing fast (ns), spatially uniform signal response and negligible (readout corresponding to the RF accelerator frequency. The instrumentation for these monitors must cover a large range of operating conditions: different beam sizes, fluxes, energies and time structure corresponding to the synchrotron fill patterns. Sophisticated new RF sampling electronics can satisfy most requirements: using a modified Libera Brilliance readout system, we measured the center of gravity position of a 25 {mu}m beam at the DORIS III F4 beam line at a rate of 130 Msample/s with narrowband filtering of a few MHz bandwidth. Digitally averaging the signal further provided a spatial resolution {approx}20 nm.

  15. New Approach for 2D Readout of GEM Detectors

    SciTech Connect

    Hasell, Douglas K

    2011-10-29

    Detectors based on Gas Electron Multiplication (GEM) technology are becoming more and more widely used in nuclear and high energy physics and are being applied in astronomy, medical physics, industry, and homeland security. GEM detectors are thin, low mass, insensitive to magnetic fields, and can currently provide position resolutions down to {approx}50 microns. However, the designs for reconstructing the position, in two dimensions (2D), of the charged particles striking a GEM detector are often complicated to fabricate and expensive. The objective of this proposal is to investigate a simpler procedure for producing the two dimensional readout layer of GEM detectors using readily available printed circuit board technology which can be tailored to the detector requirements. We will use the established GEM laboratory and facilities at M.I.T. currently employed in developing GEM detectors for the STAR forward tracking upgrade to simplify the testing and evaluation of the new 2D readout designs. If this new design proves successful it will benefit future nuclear and high energy physics experiments already being planned and will similarly extend and simplify the application of GEM technology to other branches of science, medicine, and industry. These benefits would be not only in lower costs for fabrication but also it increased flexibility for design and application.

  16. The New APD Based Readout for the Crystal Barrel Calorimeter

    NASA Astrophysics Data System (ADS)

    Urban, M.; Honisch, Ch; Steinacher, M.; CBELSA/TAPS Collaboration

    2015-02-01

    The CBELSA/TAPS experiment at ELSA measures double polarization observables in meson photoproduction off protons and neutrons. To be able to measure purely neutral reactions off polarized neutrons with high efficiency, the main calorimeter has to be integrated into the first level trigger. This requires to exchange the existing PIN photo diode by a new avalanche photo diode (APD) readout. The newly developed readout electronics will provide an energy resolution compatible to the previous set-up and a fast trigger signal down to 10 MeV energy deposit per crystal. After the successful final tests with a 3x3 CsI crystal matrix in Bonn at ELSA and in Mainz at MAMI all front-end electronics were produced in fall 2013. Automated test routines for the front-end electronics were developed and the characterization measurements of all APDs were successfully accomplished in Bonn. The project is supported by the Deutsche Forschungsgemeinschaft (SFB/TR16) and Schweizerischer Nationalfonds.

  17. Intrinsic emittance reduction in transmission mode photocathodes

    NASA Astrophysics Data System (ADS)

    Lee, Hyeri; Cultrera, Luca; Bazarov, Ivan

    2016-03-01

    High quantum efficiency (QE) and low emittance electron beams provided by multi-alkali photocathodes make them of great interest for next generation high brightness photoinjectors. Spicer's three-step model well describes the photoemission process; however, some photocathode characteristics such as their thickness have not yet been completely exploited to further improve the brightness of the generated electron beams. In this work, we report on the emittance and QE of a multi-alkali photocathode grown onto a glass substrate operated in transmission and reflection modes at different photon energies. We observed a 20% reduction in the intrinsic emittance from the reflection to the transmission mode operation. This observation can be explained by inelastic electron-phonon scattering during electrons' transit towards the cathode surface. Due to this effect, we predict that thicker photocathode layers will further reduce the intrinsic emittance of electron beams generated by photocathodes operated in transmission mode.

  18. Intrinsic emittance reduction in transmission mode photocathodes

    SciTech Connect

    Lee, Hyeri Cultrera, Luca; Bazarov, Ivan

    2016-03-21

    High quantum efficiency (QE) and low emittance electron beams provided by multi-alkali photocathodes make them of great interest for next generation high brightness photoinjectors. Spicer's three-step model well describes the photoemission process; however, some photocathode characteristics such as their thickness have not yet been completely exploited to further improve the brightness of the generated electron beams. In this work, we report on the emittance and QE of a multi-alkali photocathode grown onto a glass substrate operated in transmission and reflection modes at different photon energies. We observed a 20% reduction in the intrinsic emittance from the reflection to the transmission mode operation. This observation can be explained by inelastic electron-phonon scattering during electrons' transit towards the cathode surface. Due to this effect, we predict that thicker photocathode layers will further reduce the intrinsic emittance of electron beams generated by photocathodes operated in transmission mode.

  19. Beam emittance measurements on multicusp ion sources

    NASA Astrophysics Data System (ADS)

    Sarstedt, M.; Lee, Y.; Leung, K. N.; Perkins, L. T.; Pickard, D. S.; Weber, M.; Williams, M. D.

    1996-03-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source is planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 μm patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of a rf-generated plasma.

  20. Arc-textured high emittance radiator surfaces

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor)

    1991-01-01

    High emittance radiator surfaces are produced by arc-texturing. This process produces such a surface on a metal by scanning it with a low voltage electric arc from a carbon electrode in an inert environment.

  1. Emitters of N-photon bundles.

    PubMed

    Muñoz, C Sánchez; Del Valle, E; Tudela, A González; Müller, K; Lichtmannecker, S; Kaniber, M; Tejedor, C; Finley, J J; Laussy, F P

    2014-07-01

    Controlling the ouput of a light emitter is one of the basic tasks of photonics, with landmarks such as the laser and single-photon sources. The development of quantum applications makes it increasingly important to diversify the available quantum sources. Here, we propose a cavity QED scheme to realize emitters that release their energy in groups, or "bundles" of N photons, for integer N. Close to 100% of two-photon emission and 90% of three-photon emission is shown to be within reach of state of the art samples. The emission can be tuned with system parameters so that the device behaves as a laser or as a N-photon gun. The theoretical formalism to characterize such emitters is developed, with the bundle statistics arising as an extension of the fundamental correlation functions of quantum optics. These emitters will be useful for quantum information processing and for medical applications.

  2. A Full Parallel Event Driven Readout Technique for Area Array SPAD FLIM Image Sensors

    PubMed Central

    Nie, Kaiming; Wang, Xinlei; Qiao, Jun; Xu, Jiangtao

    2016-01-01

    This paper presents a full parallel event driven readout method which is implemented in an area array single-photon avalanche diode (SPAD) image sensor for high-speed fluorescence lifetime imaging microscopy (FLIM). The sensor only records and reads out effective time and position information by adopting full parallel event driven readout method, aiming at reducing the amount of data. The image sensor includes four 8 × 8 pixel arrays. In each array, four time-to-digital converters (TDCs) are used to quantize the time of photons’ arrival, and two address record modules are used to record the column and row information. In this work, Monte Carlo simulations were performed in Matlab in terms of the pile-up effect induced by the readout method. The sensor’s resolution is 16 × 16. The time resolution of TDCs is 97.6 ps and the quantization range is 100 ns. The readout frame rate is 10 Mfps, and the maximum imaging frame rate is 100 fps. The chip’s output bandwidth is 720 MHz with an average power of 15 mW. The lifetime resolvability range is 5–20 ns, and the average error of estimated fluorescence lifetimes is below 1% by employing CMM to estimate lifetimes. PMID:26828490

  3. Gas proportional detectors with interpolating cathode pad readout for high track multiplicities

    SciTech Connect

    Yu, Bo

    1991-12-01

    New techniques for position encoding in very high rate particle and photon detectors will be required in experiments planned for future particle accelerators such as the Superconducting Super Collider and new, high intensity, synchrotron sources. Studies of two interpolating cathode ``pad`` readout systems are described in this thesis. They are well suited for high multiplicity, two dimensional unambiguous position sensitive detection of minimum ionizing particles and heavy ions as well as detection of x-rays at high counting rates. One of the readout systems uses subdivided rows of pads interconnected by resistive strips as the cathode of a multiwire proportional chamber (MWPC). A position resolution of less than 100 {mu}m rms, for 5.4 keV x-rays, and differential non-linearity of 12% have been achieved. Low mass ({approximately}0.6% of a radiation length) detector construction techniques have been developed. The second readout system uses rows of chevron shaped cathode pads to perform geometrical charge division. Position resolution (FWHM) of about 1% of the readout spacing and differential non-linearity of 10% for 5.4 keV x-rays have been achieved. A review of other interpolating methods is included. Low mass cathode construction techniques are described. In conclusion, applications and future developments are discussed. 54 refs.

  4. Gas proportional detectors with interpolating cathode pad readout for high track multiplicities

    SciTech Connect

    Yu, Bo.

    1991-12-01

    New techniques for position encoding in very high rate particle and photon detectors will be required in experiments planned for future particle accelerators such as the Superconducting Super Collider and new, high intensity, synchrotron sources. Studies of two interpolating cathode pad'' readout systems are described in this thesis. They are well suited for high multiplicity, two dimensional unambiguous position sensitive detection of minimum ionizing particles and heavy ions as well as detection of x-rays at high counting rates. One of the readout systems uses subdivided rows of pads interconnected by resistive strips as the cathode of a multiwire proportional chamber (MWPC). A position resolution of less than 100 {mu}m rms, for 5.4 keV x-rays, and differential non-linearity of 12% have been achieved. Low mass ({approximately}0.6% of a radiation length) detector construction techniques have been developed. The second readout system uses rows of chevron shaped cathode pads to perform geometrical charge division. Position resolution (FWHM) of about 1% of the readout spacing and differential non-linearity of 10% for 5.4 keV x-rays have been achieved. A review of other interpolating methods is included. Low mass cathode construction techniques are described. In conclusion, applications and future developments are discussed. 54 refs.

  5. Study of the readout configuration of the GAMMA-400 silicon tracker sensors

    NASA Astrophysics Data System (ADS)

    Berra, A.; Bonvicini, V.; Lietti, D.; Prest, M.; Vallazza, E.

    2015-10-01

    The GAMMA-400 satellite is an upcoming international space mission designed to detect gamma and cosmic rays in a broad energy range up to 3 TeV, with an excellent angular and energy resolution. The present design foresees a 10 layers Si-W tracker formed by single sided silicon sensors with 80 μm strip pitch, with a readout pitch of 240 μm; the sensors are arranged in four towers, each one with an area of 50×50 cm2, for a total of more than 150k channels. This paper presents an analysis of the spatial resolution of the proposed readout configuration, compared with different readout approaches, both in terms of readout pitch and strip/implant widths. The study has been performed with two specially developed silicon modules, each one divided into zones with different characteristics. The tests have been performed on the CERN PS-T9 beamline using 10 GeV negative particles.

  6. Improved Readout For Micromagnet/Hall-Effect Memories

    NASA Technical Reports Server (NTRS)

    Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.

    1993-01-01

    Two improved readout circuits for micromagnet/Hall-effect random-access memories designed to eliminate current shunts introducing errors into outputs of older readout circuits. Incorporate additional switching transistors to isolate Hall sensors as needed.

  7. Energy efficiency of electron plasma emitters

    SciTech Connect

    Zalesski, V. G.

    2011-12-15

    Electron emission influence from gas-discharge plasma on plasma emitter energy parameters is considered. It is shown, that electron emission from plasma is accompanied by energy contribution redistribution in the gas-discharge from plasma emitter supplies sources-the gas-discharge power supply and the accelerating voltage power supply. Some modes of electron emission as a result can be realized: 'a probe measurements mode,' 'a transitive mode,' and 'a full switching mode.'.

  8. Enhanced Light Emitters Based on Metamaterials

    DTIC Science & Technology

    2015-03-30

    Enhanced Light Emitters based on Metamaterials We report the development of light emitters based on hyperbolic metamaterials . During the 18 month...layer, use of a high refractive index contrast grating to out-couple light from active hyperbolic metamaterials . We also successfully demonstrated for...the first time simultaneous enhancement in spontaneous emission ad light extraction from active metamaterial structures. The views, opinions and/or

  9. Coaxial inverted geometry transistor having buried emitter

    NASA Technical Reports Server (NTRS)

    Hruby, R. J.; Cress, S. B.; Dunn, W. R. (Inventor)

    1973-01-01

    The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.

  10. Charge neutrality in heavily doped emitters

    SciTech Connect

    del Alamo, J.A.

    1981-09-01

    The applicability of the quasineutrality approximation to modern emitters of solar cells is analytically reviewed. It is shown that this approximation is fulfilled in more than 80% of the depth of a typical solar-cell emitter, being particularly excellent in the heavily doped regions beneath the surface where most of the heavy doping effects arise. Our conclusions are in conflict with Redfield's recent affirmations.

  11. Alpha-emitters for medical therapy workshop

    SciTech Connect

    Feinendegen, L.E.; McClure, J.J.

    1996-12-31

    A workshop on ``Alpha-Emitters for Medical Therapy`` was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference.

  12. PANDA straw tube detectors and readout

    NASA Astrophysics Data System (ADS)

    Strzempek, P.

    2016-07-01

    PANDA is a detector under construction dedicated to studies of production and interaction of particles in the charmonium mass range using antiproton beams in the momentum range of 1.5 - 15 GeV/c at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt. PANDA consists of two spectrometers: a Target Spectrometer with a superconducting solenoid and a Forward Spectrometer using a large dipole magnet and covering the most forward angles (Θ < 10 °). In both spectrometers, the particle's trajectories in the magnetic field are measured using self-supporting straw tube detectors. The expected high count rates, reaching up to 1 MHz/straw, are one of the main challenges for the detectors and associated readout electronics. The paper presents the readout chain of the tracking system and the results of tests performed with realistic prototype setups. The readout chain consists of a newly developed ASIC chip (PASTTREC < PANDASTTReadoutChip >) with amplification, signal shaping, tail cancellation, discriminator stages and Time Readout Boards as digitizer boards.

  13. Raman-based microarray readout: a review.

    PubMed

    Haisch, Christoph

    2016-07-01

    For a quarter of a century, microarrays have been part of the routine analytical toolbox. Label-based fluorescence detection is still the commonest optical readout strategy. Since the 1990s, a continuously increasing number of label-based as well as label-free experiments on Raman-based microarray readout concepts have been reported. This review summarizes the possible concepts and methods and their advantages and challenges. A common label-based strategy is based on the binding of selective receptors as well as Raman reporter molecules to plasmonic nanoparticles in a sandwich immunoassay, which results in surface-enhanced Raman scattering signals of the reporter molecule. Alternatively, capture of the analytes can be performed by receptors on a microarray surface. Addition of plasmonic nanoparticles again leads to a surface-enhanced Raman scattering signal, not of a label but directly of the analyte. This approach is mostly proposed for bacteria and cell detection. However, although many promising readout strategies have been discussed in numerous publications, rarely have any of them made the step from proof of concept to a practical application, let alone routine use. Graphical Abstract Possible realization of a SERS (Surface-Enhanced Raman Scattering) system for microarray readout.

  14. Readout of the upgraded ALICE-ITS

    NASA Astrophysics Data System (ADS)

    Szczepankiewicz, A.

    2016-07-01

    The ALICE experiment will undergo a major upgrade during the second long shutdown of the CERN LHC. As part of this program, the present Inner Tracking System (ITS), which employs different layers of hybrid pixels, silicon drift and strip detectors, will be replaced by a completely new tracker composed of seven layers of monolithic active pixel sensors. The upgraded ITS will have more than twelve billion pixels in total, producing 300 Gbit/s of data when tracking 50 kHz Pb-Pb events. Two families of pixel chips realized with the TowerJazz CMOS imaging process have been developed as candidate sensors: the ALPIDE, which uses a proprietary readout and sparsification mechanism and the MISTRAL-O, based on a proven rolling shutter architecture. Both chips can operate in continuous mode, with the ALPIDE also supporting triggered operations. As the communication IP blocks are shared among the two chip families, it has been possible to develop a common Readout Electronics. All the sensor components (analog stages, state machines, buffers, FIFOs, etc.) have been modelled in a system level simulation, which has been extensively used to optimize both the sensor and the whole readout chain design in an iterative process. This contribution covers the progress of the R&D efforts and the overall expected performance of the ALICE-ITS readout system.

  15. Daily weather direct readout microprocessor study

    NASA Technical Reports Server (NTRS)

    Davisson, L. D.; Davisson, J. B.

    1976-01-01

    The work completed included a study of the requirements and hardware and software implementation techniques for NIMBUS ESMR and TWERLE direct readout applications using microprocessors. Many microprocessors were studied for this application. Because of the available Interdata development capabilities, it was concluded that future implementations be on an Interdata microprocessor which was found adequate for the task.

  16. A Review of Infrared Readout Electronics for Space Science Sensors

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata; Fossum, Eric R.

    1993-01-01

    A review of infrared readout electornics for space science sensors is presented. General requirements for scientific IR FPA readout are discussed. Specific approaches to the unit cell electronics are described with respect to operation, complexity, noise and other operating parameters. Recent achievements in IR FPA readout electronics are reviewed. Implementation technologies for realization of IR FPA readout electronics are discussed. Future directions for addressing NASA and other scientific users' needs are suggested.

  17. Non-linear excitation of quantum emitters in hexagonal boron nitride multiplayers

    NASA Astrophysics Data System (ADS)

    Schell, Andreas W.; Tran, Toan Trong; Takashima, Hideaki; Takeuchi, Shigeki; Aharonovich, Igor

    2016-12-01

    Two-photon absorption is an important non-linear process employed for high resolution bio-imaging and non-linear optics. In this work, we realize two-photon excitation of a quantum emitter embedded in a two-dimensional (2D) material. We examine defects in hexagonal boron nitride (hBN) and show that the emitters exhibit similar spectral and quantum properties under one-photon and two-photon excitation. Furthermore, our findings are important to deploy two-dimensional hexagonal boron nitride for quantum non-linear photonic applications.

  18. Readout techniques and radiation damage of undoped cesium iodide

    SciTech Connect

    Woody, C.L.; Levy, P.W.; Kierstead, J.A.; Skwarnicki, T.; Sobolewski, Z.; Goldberg, M.; Horwitz, N.; Souder, P.; Anderson, D.F.; Syracuse Univ., NY . Dept. of Physics; Fermi National Accelerator Lab., Batavia, IL )

    1989-01-01

    Several readout techniques for undoped CsI have been studied which utilize the fast scintillation component for speed, and the high photon yield for good energy resolution. Quantum yields have been measured for samples up to 30 cm in length using photomultiplier tubes, wavelength shifters, and silicon photodiodes. A study has also been made of the scintillation properties of undoped CsI. It is found that the light output and decay time of the 310 nm fast component increases and the emission spectrum shifts to longer wavelengths at lower temperatures. The effects on the optical transmission and scintillation light output due to radiation damage from {sup 60}Co gamma rays has been measured for doses up to {approximately}10{sup 6} rad. It is found that the radiation resistance of undoped CsI is substantially higher than has been reported for thallium doped CsI. 16 refs., 11 figs., 3 tabs.

  19. Submicrosecond-timescale readout of carbon nanotube mechanical motion

    NASA Astrophysics Data System (ADS)

    Meerwaldt, H. B.; Johnston, S. R.; van der Zant, H. S. J.; Steele, G. A.

    2013-07-01

    We report fast readout of the motion of a carbon nanotube mechanical resonator. A close-proximity high electron mobility transistor amplifier is used to increase the bandwidth of the measurement of nanotube displacements from the kHz to the MHz regime. Using an electrical detection scheme with the nanotube acting as a mixer, we detect the amplitude of its mechanical motion at room temperature with an intermediate frequency of 6 MHz and a timeconstant of 780 ns, both up to five orders of magnitude faster than achieved before. The transient response of the mechanical motion indicates a ring-down time faster than our enhanced time resolution, placing an upper bound on the contribution of energy relaxation processes to the room temperature mechanical quality factor.

  20. Properties Of Lyman Alpha Emitters At Z~1

    NASA Astrophysics Data System (ADS)

    Barger, Amy

    intergalactic medium and where the Ly-alpha emitters are, for the first time, comparable in luminosity to the high-redshift galaxies. Using deep NUV grism spectra from GALEX of heavily studied fields and a novel code that we have developed to make three-dimensional data cubes from these data, we will search for objects with detectable Ly-alpha emission lines but weak continuum. This will give us a complete flux-selected Ly-alpha sample. We will also search for Ly-alpha emission in the data cubes using known z~1 galaxies in the fields. Our primary science goals are to (1) construct a robust z~1 Ly-alpha emitter galaxy luminosity function well below L_star to study the evolution of the population with cosmic time, (2) compare the z~1 Ly-alpha emitters with the z~1 UV-continuum selected population with the same luminosities but without detected Ly-alpha to determine the types of galaxies that are selected in Ly-alpha samples, and (3) measure the Ly-alpha to Balmer line flux ratios in optically selected galaxies at z~1 to determine the Ly-alpha escape fraction and its dependence on galaxy properties. In particular, we aim to examine whether the paradigm that we developed from studying z~0.3 Ly-alpha emitters---namely, that Ly-alpha emitters are in the early stages of galaxy formation---is consistent with the much more luminous z~1 sample. The proposed work will also be invaluable for finding z~1 galaxies where high-resolution spectroscopy can be obtained with HST to study the shape and wavelength offsets of the emerging Ly-alpha lines.

  1. Measurements of entrance-surface vs. conventional single-ended readout of a monolithic scintillator

    PubMed Central

    Hunter, William C. J.; Li; McDougald, Wendy; Griesmer, Jerome J.; Shao, Lingxiong; Zahn, Robert; Lewellen, Tom K.; Miyaoka, Robert S.

    2012-01-01

    Availability of compact high-gain, low-noise Silicon Photomultipliers (SiPM) prompts us to examine readout sensors on the entrance surface (SES) as compared to the conventional single-ended readout with sensors on the opposing surface. We measured detector response statistics versus 3D position for these configurations using an 8×8 SiPM array on a 15-mm-thick by 32-mm-wide LYSO block. We calibrate an independently distributed multivariate-normal likelihood model and use it to generate maximum-likelihood estimates of 3D interaction position. Spatial resolution improved 14% and timing resolution improved 10% for the SES device. Bias was unaffected. Photodetection efficiency of our prototype SiPM may have limited further improvement in positioning and timing performance. In future work, we will look to utilize SiPM arrays with enhanced photodetection efficiency. PMID:23202544

  2. Research of time discrimination circuits for PMT signal readout over large dynamic range in LHAASO WCDA

    NASA Astrophysics Data System (ADS)

    Ma, C.; Zhao, L.; Dong, R.; Jiang, Z.; Chu, S.; Gao, X.; Liu, S.; An, Q.

    2016-11-01

    In the readout electronics of the Water Cerenkov Detector Array (WCDA) in the Large High Altitude Air Shower Observatory (LHAASO), both high-resolution charge and time measurement are required over a dynamic range from 1 photoelectron (P.E.) to 4000 P.E. for the PMT signal readout. In this paper, we present our work on the design of time discrimination circuits in LHAASO WCDA, especially on improvement to reduce the circuit dead time. Several approaches were studied through analysis and simulations, and actual circuits were designed and tested in the laboratory to evaluate the performance. Test results indicate that a time resolution better than 500 ps RMS is achieved in the whole large dynamic range, and the circuit dead time is successfully reduced to less than 200 ns.

  3. Measurements of entrance-surface vs. conventional single-ended readout of a monolithic scintillator.

    PubMed

    Hunter, William C J; Li; McDougald, Wendy; Griesmer, Jerome J; Shao, Lingxiong; Zahn, Robert; Lewellen, Tom K; Miyaoka, Robert S

    2011-01-01

    Availability of compact high-gain, low-noise Silicon Photomultipliers (SiPM) prompts us to examine readout sensors on the entrance surface (SES) as compared to the conventional single-ended readout with sensors on the opposing surface. We measured detector response statistics versus 3D position for these configurations using an 8×8 SiPM array on a 15-mm-thick by 32-mm-wide LYSO block. We calibrate an independently distributed multivariate-normal likelihood model and use it to generate maximum-likelihood estimates of 3D interaction position. Spatial resolution improved 14% and timing resolution improved 10% for the SES device. Bias was unaffected. Photodetection efficiency of our prototype SiPM may have limited further improvement in positioning and timing performance. In future work, we will look to utilize SiPM arrays with enhanced photodetection efficiency.

  4. Spatial uniformity of the current emitted by an array of passively fed electrospray porous emitters

    NASA Astrophysics Data System (ADS)

    Guerra-Garcia, C.; Krejci, D.; Lozano, P.

    2016-03-01

    Ionic liquid ion sources (ILIS) have a broad range of applications ranging from focused ion beams (FIB) to spacecraft propulsion. For space thrusters, having a beam of ions of high velocity and low energy spread results in high specific impulse (a measure of the efficiency of propellant consumption) and high power efficiency. For FIB applications, these traits benefit focusing and resolution respectively. Since typical current levels emitted by individual ILIS range from tens of nA to a few μA, both applications often require using arrays of emitters in order to increase the total beam current; i.e. the thrust level in the case of a thruster or the throughput in ion milling applications. So far, most studies of emitter arrays have dealt with experimental measurements of global, spatially-averaged, properties and theoretical analyses generally assume that all emitters operate in a similar manner, so that scaling of the current is linear with the number of emitters. In this work we use a current probe to explore the uniformity properties of the current emitted by an array of porous emitters. We present measurements of the current density of both the array and individual tips, and analyze the reason and implications of the experimental observations.

  5. Shortwave-infrared (SWIR) emitters for biological imaging: a review of challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Thimsen, Elijah; Sadtler, Bryce; Berezin, Mikhail Y.

    2017-06-01

    Shortwave infrared radiation (SWIR) is the portion of the electromagnetic spectrum from approximately 900 nm to 2500 nm. Recent advances in imaging systems have expanded the application of SWIR emitters from traditional fields in materials science to biomedical imaging, and the new detectors in SWIR opened an opportunity of deep tissue imaging. Achieving deep photon penetration while maintaining high resolution is one of the main objectives and challenges in bioimaging used for the investigation of diverse processes in living organisms. The application of SWIR emitters in biological settings is, however, hampered by low quantum efficiency. So far, photoluminescent properties in the SWIR region have not been improved by extending concepts that have been developed for the visible (400-650 nm) and near-infrared (NIR, 700-900 nm) wavelengths, which indicates that the governing behavior is fundamentally different in the SWIR. The focus of this minireview is to examine the mechanisms behind the low efficiency of SWIR emitters as well as to highlight the progress in their design for biological applications. Several common mechanisms will be considered in this review: (a) the effect of the energy gap between the excited and ground state on the quantum efficiency, (b) the coupling of the excited electronic states in SWIR emitters to vibrational states in the surrounding matrix, and (c) the role of environment in quenching the excited states. General strategies to improve the quantum yields for a diverse type of SWIR emitters will be also presented.

  6. Field-emitter arrays for vacuum microelectronics

    NASA Technical Reports Server (NTRS)

    Spindt, C. A.; Holland, C. E.; Rosengreen, A.; Brodie, Ivor

    1991-01-01

    An ongoing program on microfabricated field-emitter arrays has produced a gated field-emitter tip structure with submicrometer dimensions and techniques for fabricating emitter arrays with tip packaging densities of up to 1.5 x 10 exp 7 tips/sq cm. Arrays have been fabricated over areas varying from a few micrometers up to 13 cm in diameter. Very small overall emitter size, materials selection, and rigorous emitter-tip processing procedures have contributed to reducing the potential required for field emission to tens of volts. Emission current densities of up to 100 A/sq cm have been achieved with small arrays of tips, and 100-mA total emission is commonly produced with arrays 1 mm in diameter containing 10,000 tips. Transconductances of 5.0 micro-S per tip have been demonstrated, indicating that 50 S/sq cm should be achievable with tip densities of 10 exp 7 tips/sq cm. Details of the cathode arrays and a variety of performance characteristics are discussed.

  7. Variable emittance behavior of smart radiative coating

    NASA Astrophysics Data System (ADS)

    Guo, Li; Fan, Desong; Li, Qiang

    2016-02-01

    Smart radiative coating on yttria stabilized zirconia (YSZ) substrate was prepared by the sol-gel La{}1-xSr x MnO3 (x = 0.125, 0.175 and 0.2) nanoparticles and the binder composed of terpineol and ethyl cellulose. The crystallized structure, grain size, chemical compositions, magnetization and the surface morphology were characterized. The thermal radiative properties of coating in the infrared range was evaluated from infrared reflectance spectra at various temperatures. A single perovskite structure is detected in sol-gel nanoparticles with size 200 nm. Magnetization measurement reveals that room temperature phase transition samples can be obtained by appropriate Sr substitution. The influence of surface conditions and sintering temperature on the emittance of coating was observed. For rough coatings with root-mean-square roughness 640 nm (x = 0.125) and 800 nm (x = 0.175) , its emittance increment is 0.24 and 0.26 in in the temperature range of 173-373 K. Increasing sintering temperature to 1673 K, coating emittance variation improves to 0.3 and 0.302 respectively. After mechanical polishing treatment, the emittance increment of coatings are enhanced to 0.31 and 0.3, respectively. The results suggested that the emittance variation can be enhanced by reducing surface roughness and increasing sintering temperature of coating.

  8. Emittance control in Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Cheshkov, S.; Tajima, T.; Chiu, C.; Breitling, F.

    2001-05-01

    In this paper we summarize our recent effort and results in theoretical study of the emittance issues of multistaged Laser Wakefield Accelerator (LWFA) in TeV energy range. In such an energy regime the luminosity and therefore the emittance requirements become very stringent and tantamount to the success or failure of such an accelerator. The system of such a machine is very sensitive to jitters due to misalignment between the beam and the wakefield. In particular, the effect of jitters in the presence of a strong focusing wakefield and initial longitudinal phase space spread of the beam leads to severe transverse emittance degradation of the beam. To improve the emittance we introduce several methods: a mitigated wakefield focusing by working with a plasma channel, an approximately synchronous acceleration in a superunit setup, the "horn" model based on exactly synchronous acceleration achieved through plasma density variation and lastly an algorithm based on minimization of the final beam emittance to actively control the stage displacement of such an accelerator.

  9. Integrated photonic crystal selective emitter for thermophotovoltaics

    NASA Astrophysics Data System (ADS)

    Zhou, Zhiguang; Yehia, Omar; Bermel, Peter

    2016-01-01

    Converting blackbody thermal radiation to electricity via thermophotovoltaics (TPV) is inherently inefficient. Photon recycling using cold-side filters offers potentially improved performance but requires extremely close spacing between the thermal emitter and the receiver, namely a high view factor. Here, we propose an alternative approach for thermal energy conversion, the use of an integrated photonic crystal selective emitter (IPSE), which combines two-dimensional photonic crystal selective emitters and filters into a single device. Finite difference time domain and current transport simulations show that IPSEs can significantly suppress sub-bandgap photons. This increases heat-to-electricity conversion for photonic crystal based emitters from 35.2 up to 41.8% at 1573 K for a GaSb photovoltaic (PV) diode with matched bandgaps of 0.7 eV. The physical basis of this enhancement is a shift from a perturbative to a nonperturbative regime, which maximized photon recycling. Furthermore, combining IPSEs with nonconductive optical waveguides eliminates a key difficulty associated with TPV: the need for precise alignment between the hot selective emitter and cool PV diode. The physical effects of both the IPSE and waveguide can be quantified in terms of an extension of the concept of an effective view factor.

  10. Segmented AC-coupled readout from continuous collection electrodes in semiconductor sensors

    DOEpatents

    Sadrozinski, Hartmut F. W.; Seiden, Abraham; Cartiglia, Nicolo

    2017-04-04

    Position sensitive radiation detection is provided using a continuous electrode in a semiconductor radiation detector, as opposed to the conventional use of a segmented electrode. Time constants relating to AC coupling between the continuous electrode and segmented contacts to the electrode are selected to provide position resolution from the resulting configurations. The resulting detectors advantageously have a more uniform electric field than conventional detectors having segmented electrodes, and are expected to have much lower cost of production and of integration with readout electronics.

  11. Characterization of the CDMS Ionization Readout

    NASA Astrophysics Data System (ADS)

    Phipps, Arran

    2007-10-01

    Current cosmological models predict that a large portion of the total mass of the universe, about eighty percent, consists of putative dark matter. Theory predicts this dark matter may be in the form of particles constantly passing through the Earth. A class of these particles may interact with ordinary matter, earning the name weakly-interacting massive particles (WIMPs). The Cryogenic Dark Matter Search (CDMS) aims to directly detect the existence of WIMPs. CDMS has designed ZIP (Z-dependent Ionization & Phonon) detectors which measure phonon production and ionization of an interaction, making it possible to determine the interacting particle. The low-energy threshold of the ZIP detectors is determined by the signal-to-noise ratio of the ionization readout. A characterization of the signal-to-noise ratio of the ionization readout, along with possible modifications for improved sensitivity will be presented.

  12. Characterization of Silicon Detector Readout Electronics

    SciTech Connect

    Jones, M.

    2015-07-22

    Configuration and calibration of the front-end electronics typical of many silicon detector configurations were investigated in a lab activity based on a pair of strip sensors interfaced with FSSR2 read-out chips and an FPGA. This simple hardware configuration, originally developed for a telescope at the Fermilab Test Beam Facility, was used to measure thresholds and noise on individual readout channels and to study the influence that different configurations of the front-end electronics had on the observed levels of noise in the system. An understanding of the calibration and operation of this small detector system provided an opportunity to explore the architecture of larger systems such as those currently in use at LHC experiments.

  13. Sub electron readout noise & photon counting devices

    NASA Astrophysics Data System (ADS)

    Gach, J.-L.; Balard, Ph.; Daigle, O.; Destefanis, G.; Feautrier, Ph.; Guillaume, Ch.; Rothman, J.

    We present recent advances on ultra low noise visible detectors at Laboratoire d'Astrophysique de Marseille, photon counting and EMCCD developments in collaboration with Observatoire de haute provence, Laboratoire d'astrophysique de l'observatoire de Grenoble and Laboratoire d'Astrophysique Experimentale (Montreal). After a review of the progress with third generation Image Photon Counting Systems (IPCS), we present the OCAM camera, based on the E2V CCD220 EMCCD, part of the Opticon JRA2 programme, and the CCCP controller, a new controller for the 3DNTT instrument that reduces the clock induced charge of an EMCCD by a factor 10, making it competitive with IPCS detectors for very faint fluxes. We will finally present the RAPID project and the concept of photon counting avalanche photodiode CMOS device (in collaboration with CEA-LETI) which is foreseen to be the ultimate detector for the visible-IR range providing no readout noise, high QE and extremely fast readout.

  14. Readout electrode assembly for measuring biological impedance

    NASA Technical Reports Server (NTRS)

    Montgomery, L. D.; Moody, D. L., Jr. (Inventor)

    1976-01-01

    The invention comprises of a pair of readout ring electrodes which are used in conjunction with apparatus for measuring the electrical impedance between different points in the body of a living animal to determine the amount of blood flow therebetween. The readout electrodes have independently adjustable diameters to permit attachment around different parts of the body between which it is desired to measure electric impedance. The axial spacing between the electrodes is adjusted by a pair of rods which have a first pair of ends fixedly attached to one electrode and a second pair of ends slidably attached to the other electrode. Indicia are provided on the outer surface of the ring electrodes and on the surface of the rods to permit measurement of the circumference and spacing between the ring electrodes.

  15. A 97 dB dynamic range CSA-based readout circuit with analog temperature compensation for MEMS capacitive sensors

    NASA Astrophysics Data System (ADS)

    Tao, Yin; Chong, Zhang; Huanming, Wu; Qisong, Wu; Haigang, Yang

    2013-11-01

    This paper presents a charge-sensitive-amplifier (CSA) based readout circuit for capacitive microelectro-mechanical-system (MEMS) sensors. A continuous-time (CT) readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier (OTA) structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35 μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF / √Hz capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/°C after optimized compensation.

  16. LSST camera readout chip ASPIC: test tools

    NASA Astrophysics Data System (ADS)

    Antilogus, P.; Bailly, Ph; Jeglot, J.; Juramy, C.; Lebbolo, H.; Martin, D.; Moniez, M.; Tocut, V.; Wicek, F.

    2012-02-01

    The LSST camera will have more than 3000 video-processing channels. The readout of this large focal plane requires a very compact readout chain. The correlated ''Double Sampling technique'', which is generally used for the signal readout of CCDs, is also adopted for this application and implemented with the so called ''Dual Slope integrator'' method. We have designed and implemented an ASIC for LSST: the Analog Signal Processing asIC (ASPIC). The goal is to amplify the signal close to the output, in order to maximize signal to noise ratio, and to send differential outputs to the digitization. Others requirements are that each chip should process the output of half a CCD, that is 8 channels and should operate at 173 K. A specific Back End board has been designed especially for lab test purposes. It manages the clock signals, digitizes the analog differentials outputs of ASPIC and stores data into a memory. It contains 8 ADCs (18 bits), 512 kwords memory and an USB interface. An FPGA manages all signals from/to all components on board and generates the timing sequence for ASPIC. Its firmware is written in Verilog and VHDL languages. Internals registers permit to define various tests parameters of the ASPIC. A Labview GUI allows to load or update these registers and to check a proper operation. Several series of tests, including linearity, noise and crosstalk, have been performed over the past year to characterize the ASPIC at room and cold temperature. At present, the ASPIC, Back-End board and CCD detectors are being integrated to perform a characterization of the whole readout chain.

  17. FIPSER: Performance study of a readout concept with few digitization levels for fast signals

    NASA Astrophysics Data System (ADS)

    Limyansky, B.; Reese, R.; Cressler, J. D.; Otte, A. N.; Taboada, I.; Ulusoy, C.

    2016-11-01

    We discuss the performance of a readout system, Fixed Pulse Shape Efficient Readout (FIPSER), to digitize signals from detectors with a fixed pulse shape. In this study we are mainly interested in the readout of fast photon detectors like photomultipliers or Silicon photomultipliers. But the concept can be equally applied to the digitization of other detector signals. FIPSER is based on the flash analog to digital converter (FADC) concept, but has the potential to lower costs and power consumption by using an order of magnitude fewer discrete voltage levels. Performance is bolstered by combining the discretized signal with the knowledge of the underlying pulse shape. Simulated FIPSER data was reconstructed with two independent methods. One using a maximum likelihood method and the other using a modified χ2 test. Both methods show that utilizing 12 discrete voltage levels with a sampling rate of 4 samples per full width half maximum (FWHM) of the pulse achieves an amplitude resolution that is better than the Poisson limit for photon-counting experiments. The time resolution achieved in this configuration ranges between 0.02 and 0.16 FWHM and depends on the pulse amplitude. In a situation where the waveform is composed of two consecutive pulses the pulses can be separated if they are at least 0.05-0.30 FWHM apart with an amplitude resolution that is better than 20%.

  18. Qubit readout with the Josephson Photomultiplier

    NASA Astrophysics Data System (ADS)

    Ribeill, Guilhem

    Recent demonstrations of error correction in many qubit circuits, as well as efforts to build a logical qubit, have shown the need for a simple and scalable superconducting quantum bit (qubit) readout. Current solutions based on heterodyne detection and cryogenic amplification of microwave readout tones may prove difficult to scale, while photon counting presents an attractive alternative. However, the development of counters operating at these frequencies has proved technically challenging. In this thesis, we describe the development of the Josephson Photomultiplier (JPM), a microwave photon counting circuit. We discuss the JPM theoretically, and describe the fabrication of the JPM using standard thin film lithography techniques. We measure its properties as a microwave photon counter using a qubit as an in-situ calibrated source of photons. We measure a JPM quantum efficiency at the few percent level. We then use the JPM to perform readout of a transmon qubit in both the dispersive and bright regimes. We observe raw measurement fidelities of 35% and 62% respectively. We discuss how the JPM and measurement protocol could be further optimized to achieve fidelities in excess of 90%.

  19. Cryogenic readout techniques for germanium detectors

    SciTech Connect

    Benato, G.; Cattadori, C.; Di Vacri, A.; Ferri, E.

    2015-07-01

    High Purity Germanium detectors are used in many applications, from nuclear and astro-particle physics, to homeland security or environment protection. Although quite standard configurations are often used, with cryostats, charge sensitive amplifiers and analog or digital acquisition systems all commercially available, it might be the case that a few specific applications, e.g. satellites, portable devices, cryogenic physics experiments, etc. also require the development of a few additional or complementary techniques. An interesting case is for sure GERDA, the Germanium Detector Array experiment, searching for neutrino-less double beta decay of {sup 76}Ge at the Gran Sasso National Laboratory of INFN - Italy. In GERDA the entire detector array, composed of semi-coaxial and BEGe naked crystals, is operated suspended inside a cryostat filled with liquid argon, that acts not only as cooling medium and but also as an active shield, thanks to its scintillation properties. These peculiar circumstances, together with the additional requirement of a very low radioactive background from all the materials adjacent to the detectors, clearly introduce significant constraints on the design of the Ge front-end readout electronics. All the Ge readout solutions developed within the framework of the GERDA collaboration, for both Phase I and Phase II, will be briefly reviewed, with their relative strength and weakness compared together and with respect to ideal Ge readout. Finally, the digital processing techniques developed by the GERDA collaboration for energy estimation of Ge detector signals will be recalled. (authors)

  20. Development of maskless electron-beam lithography using nc-Si electron-emitter array

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Ikegami, N.; Yoshida, T.; Miyaguchi, H.; Muroyama, M.; Nishino, H.; Yoshida, S.; Sugata, M.; Cakir, S.; Ohyi, H.; Koshida, N.; Esashi, M.

    2013-03-01

    This study demonstrated our prototyped Micro Electro Mechanical System (MEMS) electron emitter which is a nc-Si (nanocrystalline silicon) ballistic electron emitter array integrated with an active-matrix driving LSI for high-speed Massively Parallel Electron Beam Direct Writing (MPEBDW) system. The MPEBDW system consists of the multi-column, and each column provides multi-beam. Each column consists of emitter array, a MEMS condenser lens array, an MEMS anode array, a stigmator, three-stage deflectors to align and to scan the multi beams, and a reduction lens as an objective lens. The emitter array generates 100x100 electron beams with binary patterns. The pattern exposed on a target is stored in one of the duplicate memories in the active matrix LSI. After the emission, each electron beam is condensed into narrow beam in parallel to the axis of electron optics of the system with the condenser lens array. The electrons of the beams are accelerated and pass through the anode array. The stigmator and deflectors make fine adjustments to the position of the beams. The reduction lens in the final stage focuses all parallel beams on the surface of the target wafer. The lens reduces the electron image to 1%-10% in size. Electron source in this system is nc-Si ballistic surface electron emitter. The characteristics of the emitter of 1:1 projection of e-beam have been demonstrated in our previous work. We developed a Crestec Surface Electron emission Lithography (CSEL) for mass production of semiconductor devices. CSEL system is 1:1 electron projection lithography using surface electron emitter. In first report, we confirmed that a test bench of CSEL resolved below 30 nm pattern over 0.2 um square area. Practical resolution of the system is limited by the chromatic aberration. We also demonstrated the CSEL system exposed deep sub-micron pattern over full-field for practical use. As an interim report of our development of MPEBDW system, we evaluated characteristics of the

  1. Quantitative deconvolution of human thermal infrared emittance.

    PubMed

    Arthur, D T J; Khan, M M

    2013-01-01

    The bioheat transfer models conventionally employed in etiology of human thermal infrared (TIR) emittance rely upon two assumptions; universal graybody emissivity and significant transmission of heat from subsurface tissue layers. In this work, a series of clinical and laboratory experiments were designed and carried out to conclusively evaluate the validity of the two assumptions. Results obtained from the objective analyses of TIR images of human facial and tibial regions demonstrated significant variations in spectral thermophysical properties at different anatomic locations on human body. The limited validity of the two assumptions signifies need for quantitative deconvolution of human TIR emittance in clinical, psychophysiological and critical applications. A novel approach to joint inversion of the bioheat transfer model is also introduced, levering the deterministic temperature-dependency of proton resonance frequency in low-lipid human soft tissue for characterizing the relationship between subsurface 3D tissue temperature profiles and corresponding TIR emittance.

  2. Head erosion with emittance growth in PWFA

    SciTech Connect

    Li, S. Z.; Adli, E.; England, R. J.; Frederico, J.; Gessner, S. J.; Hogan, M. J.; Litos, M. D.; Walz, D. R.; Muggli, P.; An, W.; Clayton, C. E.; Joshi, C.; Lu, W.; Marsh, K. A.; Mori, W.; Vafaei, N.

    2012-12-21

    Head erosion is one of the limiting factors in plasma wakefield acceleration (PWFA). We present a study of head erosion with emittance growth in field-ionized plasma from the PWFA experiments performed at the FACET user facility at SLAC. At FACET, a 20.3 GeV bunch with 1.8 Multiplication-Sign 10{sup 10} electrons is optimized in beam transverse size and combined with a high density lithium plasma for beam-driven plasma wakefield acceleration experiments. A target foil is inserted upstream of the plasma source to increase the bunch emittance through multiple scattering. Its effect on beamplasma interaction is observed with an energy spectrometer after a vertical bend magnet. Results from the first experiments show that increasing the emittance has suppressed vapor field-ionization and plasma wakefields excitation. Plans for the future are presented.

  3. Solid-state single-photon emitters

    NASA Astrophysics Data System (ADS)

    Aharonovich, Igor; Englund, Dirk; Toth, Milos

    2016-10-01

    Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.

  4. Measurement of transverse emittance and coherence of double-gate field emitter array cathodes

    NASA Astrophysics Data System (ADS)

    Tsujino, Soichiro; Das Kanungo, Prat; Monshipouri, Mahta; Lee, Chiwon; Miller, R. J. Dwayne

    2016-12-01

    Achieving small transverse beam emittance is important for high brightness cathodes for free electron lasers and electron diffraction and imaging experiments. Double-gate field emitter arrays with on-chip focussing electrode, operating with electrical switching or near infrared laser excitation, have been studied as cathodes that are competitive with photocathodes excited by ultraviolet lasers, but the experimental demonstration of the low emittance has been elusive. Here we demonstrate this for a field emitter array with an optimized double-gate structure by directly measuring the beam characteristics. Further we show the successful application of the double-gate field emitter array to observe the low-energy electron beam diffraction from suspended graphene in minimal setup. The observed low emittance and long coherence length are in good agreement with theory. These results demonstrate that our all-metal double-gate field emitters are highly promising for applications that demand extremely low-electron bunch-phase space volume and large transverse coherence.

  5. Measurement of transverse emittance and coherence of double-gate field emitter array cathodes

    PubMed Central

    Tsujino, Soichiro; Das Kanungo, Prat; Monshipouri, Mahta; Lee, Chiwon; Miller, R.J. Dwayne

    2016-01-01

    Achieving small transverse beam emittance is important for high brightness cathodes for free electron lasers and electron diffraction and imaging experiments. Double-gate field emitter arrays with on-chip focussing electrode, operating with electrical switching or near infrared laser excitation, have been studied as cathodes that are competitive with photocathodes excited by ultraviolet lasers, but the experimental demonstration of the low emittance has been elusive. Here we demonstrate this for a field emitter array with an optimized double-gate structure by directly measuring the beam characteristics. Further we show the successful application of the double-gate field emitter array to observe the low-energy electron beam diffraction from suspended graphene in minimal setup. The observed low emittance and long coherence length are in good agreement with theory. These results demonstrate that our all-metal double-gate field emitters are highly promising for applications that demand extremely low-electron bunch-phase space volume and large transverse coherence. PMID:28008918

  6. Current Injection Pumping of Organic Light Emitters

    DTIC Science & Technology

    1989-09-28

    MOT-OOO1AF I Current Injection Pumping of Organic Light Emitters Prepared by DI Jeffrey C. Buchholz E L ri: 8 James P. Stec OCT C "t989 Mary C...Schutte Micro -Optics Technologies, Inc. 8608 University Green #5 Middleton, WI 53562 28 September 1989 D,:?UqflON SA2". N’.’ _ Disuibunon Uanu-ted Contract...Title Report Date Current Injection Pumping of Organic Light Emitters 28 September 1989 Authors Jeffrey C. Buchholz, James P. Stec, Mary C. Schutte

  7. Field emitter technologies for nanovision science

    NASA Astrophysics Data System (ADS)

    Mimura, H.; Neo, Y.; Aoki, T.; Nagao, M.; Yoshida, T.; Kanemaru, S.

    2009-10-01

    We have been investigating an ultra fine field emission display (FED) and an ultra fine CdTe X-ray image sensor for creating nanovision science. For an ultra fine FED with a sub-micron pixel, we have developed a volcano-structured double-gated field emitter arrays with a capability of focusing electron beam without serous reduction in emission current. For an ultra fine X-ray image sensor, we have proposed and demonstrated a novel CdTe X-ray sensor consisting of a CdTe diode and field emitter array.

  8. Coupling single emitters to quantum plasmonic circuits

    NASA Astrophysics Data System (ADS)

    Huck, Alexander; Andersen, Ulrik L.

    2016-09-01

    In recent years, the controlled coupling of single-photon emitters to propagating surface plasmons has been intensely studied, which is fueled by the prospect of a giant photonic nonlinearity on a nanoscaled platform. In this article, we will review the recent progress on coupling single emitters to nanowires towards the construction of a new platform for strong light-matter interaction. The control over such a platform might open new doors for quantum information processing and quantum sensing at the nanoscale and for the study of fundamental physics in the ultrastrong coupling regime.

  9. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, J.M.; Kurtz, S.R.

    1994-05-31

    A high-efficiency heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer. 1 fig.

  10. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, Jerry M.; Kurtz, Sarah R.

    1994-01-01

    A high-efficiency heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer.

  11. Efficient, deep-blue TADF-emitters for OLED display applications (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Volz, Daniel; Baumann, Thomas

    2016-09-01

    Currently, the mobile display market is strongly shifting towards AMOLED technology, in order to enable curved and flexible displays. This leads to a growing demand for highly efficient OLED emitters to reduce the power consumption and increase display resolution at the same time. While highly efficient green and red OLEDs already found their place in commercial OLED-displays, the lack of efficient blue emitters is still an issue. Consequently, the active area for blue is considerably larger than for green and red pixels, to make up for the lower efficiency. We intend to close this efficiency-gap with novel emitters based on thermally activated delayed fluorescence (TADF) technology. Compared to state-of-the-art fluorescent dopants, the efficiency of TADF-emitters is up to four times higher. At the same time, it is possible to design them in a way to maintain deep blue emission, i.e. CIE y < 0.2. These aspects are relevant to produce efficient high resolution AMOLED displays. Apart from these direct customer benefits, our TADF technology does not contain any rare elements, which allows for the fabrication of sustainable OLED technology. In this work, we highlight one of our recently developed blue TADF materials. Basic material properties as well as first device results are discussed. In a bottom-emitting device, a CIEx/CIEy coordinate of (0.16/0.17) was achieved with efficiency values close to 20% EQE.

  12. Maximal adaptive-decision speedups in quantum-state readout

    NASA Astrophysics Data System (ADS)

    D'Anjou, Benjamin; Kuret, Loutfi; Childress, Lilian; Coish, William A.

    The average time T required for high-fidelity readout of quantum states can be significantly reduced via a real-time adaptive decision rule. An adaptive decision rule stops the readout as soon as a desired level of confidence has been achieved, as opposed to setting a fixed readout time tf. The performance of the adaptive decision is characterized by the ``adaptive-decision speedup'', tf / T . In this work, we reformulate this readout problem in terms of the first-passage time of a particle undergoing stochastic motion. This formalism allows us to theoretically establish the maximum achievable adaptive-decision speedups for several physical two-state readout implementations. We show that for two common readout schemes (the Gaussian latching readout and a readout relying on state-dependent decay), the speedup is bounded by 4 and 2, respectively, in the limit of high single-shot readout fidelity. We experimentally study the achievable speedup in a real-world scenario by applying the adaptive decision rule to a readout of the nitrogen-vacancy-center (NV-center) charge state. We find a speedup of ~ 2 with our experimental parameters. Our results should lead to immediate improvements in nano-scale magnetometry based on spin-to-charge conversion of the NV-center spin. We acknowledge support from NSERC, INTRIQ, CIFAR and the Walter C. Sumner Foundation.

  13. Determination and error analysis of emittance and spectral emittance measurements by remote sensing

    NASA Technical Reports Server (NTRS)

    Dejesusparada, N. (Principal Investigator); Kumar, R.

    1977-01-01

    The author has identified the following significant results. From the theory of remote sensing of surface temperatures, an equation of the upper bound of absolute error of emittance was determined. It showed that the absolute error decreased with an increase in contact temperature, whereas, it increased with an increase in environmental integrated radiant flux density. Change in emittance had little effect on the absolute error. A plot of the difference between temperature and band radiance temperature vs. emittance was provided for the wavelength intervals: 4.5 to 5.5 microns, 8 to 13.5 microns, and 10.2 to 12.5 microns.

  14. Improved Readout Scheme for SQUID-Based Thermometry

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin

    2007-01-01

    An improved readout scheme has been proposed for high-resolution thermometers, (HRTs) based on the use of superconducting quantum interference devices (SQUIDs) to measure temperature- dependent magnetic susceptibilities. The proposed scheme would eliminate counting ambiguities that arise in the conventional scheme, while maintaining the superior magnetic-flux sensitivity of the conventional scheme. The proposed scheme is expected to be especially beneficial for HRT-based temperature control of multiplexed SQUIDbased bolometer sensor arrays. SQUID-based HRTs have become standard for measuring and controlling temperatures in the sub-nano-Kelvin temperature range in a broad range of low-temperature scientific and engineering applications. A typical SQUIDbased HRT that utilizes the conventional scheme includes a coil wound on a core made of a material that has temperature- dependent magnetic susceptibility in the temperature range of interest. The core and the coil are placed in a DC magnetic field provided either by a permanent magnet or as magnetic flux inside a superconducting outer wall. The aforementioned coil is connected to an input coil of a SQUID. Changes in temperature lead to changes in the susceptibility of the core and to changes in the magnetic flux detected by the SQUID. The SQUID readout instrumentation is capable of measuring magnetic-flux changes that correspond to temperature changes down to a noise limit .0.1 nK/Hz1/2. When the flux exceeds a few fundamental flux units, which typically corresponds to a temperature of .100 nK, the SQUID is reset. The temperature range can be greatly expanded if the reset events are carefully tracked and counted, either by a computer running appropriate software or by a dedicated piece of hardware.

  15. Trigger and Readout System for the Ashra-1 Detector

    NASA Astrophysics Data System (ADS)

    Aita, Y.; Aoki, T.; Asaoka, Y.; Morimoto, Y.; Motz, H. M.; Sasaki, M.; Abiko, C.; Kanokohata, C.; Ogawa, S.; Shibuya, H.; Takada, T.; Kimura, T.; Learned, J. G.; Matsuno, S.; Kuze, S.; Binder, P. M.; Goldman, J.; Sugiyama, N.; Watanabe, Y.

    Highly sophisticated trigger and readout system has been developed for All-sky Survey High Resolution Air-shower (Ashra) detector. Ashra-1 detector has 42 degree diameter field of view. Detection of Cherenkov and fluorescence light from large background in the large field of view requires finely segmented and high speed trigger and readout system. The system is composed of optical fiber image transmission system, 64 × 64 channel trigger sensor and FPGA based trigger logic processor. The system typically processes the image within 10 to 30 ns and opens the shutter on the fine CMOS sensor. 64 × 64 coarse split image is transferred via 64 × 64 precisely aligned optical fiber bundle to a photon sensor. Current signals from the photon sensor are discriminated by custom made trigger amplifiers. FPGA based processor processes 64 × 64 hit pattern and correspondent partial area of the fine image is acquired. Commissioning earth skimming tau neutrino observational search was carried out with this trigger system. In addition to the geometrical advantage of the Ashra observational site, the excellent tau shower axis measurement based on the fine imaging and the night sky background rejection based on the fine and fast imaging allow zero background tau shower search. Adoption of the optical fiber bundle and trigger LSI realized 4k channel trigger system cheaply. Detectability of tau shower is also confirmed by simultaneously observed Cherenkov air shower. Reduction of the trigger threshold appears to enhance the effective area especially in PeV tau neutrino energy region. New two dimensional trigger LSI was introduced and the trigger threshold was lowered. New calibration system of the trigger system was recently developed and introduced to the Ashra detector

  16. A study of emittance growth in the recycler ring

    SciTech Connect

    Krishnaswamy Gounder et al.

    2001-07-20

    We investigate processes contributing to emittance growth in the Fermilab Recycler Ring. In addition to beam-gas multiple scattering, we also examine other external factors such as Main Injector ramping affecting the emittance growth.

  17. Emittance Characteristics of High-Brightness H- Ion Sources

    NASA Astrophysics Data System (ADS)

    Welton, R. F.; Stockli, M. P.; Keller, R.; Thomae, R. W.; Thomason, J.; Sherman, J.; Alessi, J.

    2002-11-01

    A survey of emittance characteristics from high-brightness, H- ion sources has been undertaken. Representative examples of each important type of H- source for accelerator application are investigated: A magnetron surface plasma source (BNL) a multi-cusp-surface-conversion source (LANL) a Penning source (RAL-ISIS) and a multi-cusp-volume source (LBNL). Presently, comparisons between published emittance values from different ion sources are difficult largely because of different definitions used in reported emittances and the use of different data reduction techniques in analyzing data. Although seldom discussed in the literature, rms-emittance values often depend strongly on the method employed to separate real beam from background. In this work, the problem of data reduction along with software developed for emittance analysis is discussed. Raw emittance data, obtained from the above laboratories, is analyzed using a single technique and normalized rms and 90% area-emittance values are determined along with characteristic emittance versus beam fraction curves.

  18. Second coordinate readout in drift chambers by timing of the electromagnetic wave propagating along the anode wire

    SciTech Connect

    Boie, R.A.; Radeka, V.; Rehak, P.; Xi, D.M.

    1980-11-01

    The feasibility of using an anode wire and surrounding electrodes in drift chambers as a transmission line for second coordinate readout has been studied. The method is based on propagation of the electromagnetic wave along the anode wire is determined by measurement, in an optimized electronic readout system, of the time difference between the arrivals of the signal to the ends of the wire. The resolution obtained on long wires (approx. 2 meters) is about 2 cm FWHM for minimum ionizing particles at a gas gain of approx. = 10/sup 5/.

  19. Emittance growth rates for displaced beams

    SciTech Connect

    Anderson, O.A. |

    1993-05-01

    Emittance growth rates have been previously analyzed for nonuniform beams in linear channels and for initially uniform mismatched beams in nonlinear channels. These studies were for centered beams. Additional emittance growth can arise in cases where the beam is initially displaced. The purpose of this study is to obtain growth rates for displaced beams. This work differs from studies involving random displacement of electrodes. Our analysis assumes instead that the focusing system is perfectly aligned but that the beam is initially displaced with respect to the equilibrium axis. If the focusing force is slightly nonlinear, we find a gradual transfer of the potential energy of beam displacement into kinetic energy associated with emittance growth. We present explicit results for the emittance growth distance as a function of the nonlinearity of the channel. These results will have practical importance for designers of accelerators and transport systems when setting realistic tolerances for initial beam alignment. These tolerances will depend on the nonlinearity and the length of the system.

  20. Aluminum oxide film thickness and emittance

    SciTech Connect

    Thomas, J.K.; Ondrejcin, R.S.

    1991-11-01

    Aluminum reactor components which are not actively cooled could be subjected to high temperatures due to gamma heating after the core coolant level dropped during the ECS phase of a hypothetical LOCA event. Radiative heat transfer is the dominant heat transfer process in this scenario and therefore the emittance of these components is of interest. Of particular interest are the safety rod thimbles and Mark 60B blanket assemblies; for the K Reactor, these components have been exposed to low temperature (< 55{degrees}C) moderator for about a year. The average moderator temperature was assumed to be 30{degrees}C. The Al oxide film thickness at this temperature, after one year of exposure, is predicted to be 6.4 {mu}m {plus minus} 10%; insensitive to exposure time. Dehydration of the film during the gamma heating accident would result in a film thickness of 6.0 {mu}m {plus minus} 11%. Total hemispherical emittance is predicted to be 0.69 at 96{degrees}C, decreasing to 0.45 at 600{degrees}C. Some phenomena which would tend to yield thicker oxide films in the reactor environment relative to those obtained under experimental conditions were neglected and the predicted film thickness values are therefore conservative. The emittance values predicted for a given film thickness are also conservative. The conservativisms inherent in the predicted emittance are particularly relevant for uncertainty analysis of temperatures generated using these values.

  1. Aluminum oxide film thickness and emittance

    SciTech Connect

    Thomas, J.K.; Ondrejcin, R.S.

    1991-11-01

    Aluminum reactor components which are not actively cooled could be subjected to high temperatures due to gamma heating after the core coolant level dropped during the ECS phase of a hypothetical LOCA event. Radiative heat transfer is the dominant heat transfer process in this scenario and therefore the emittance of these components is of interest. Of particular interest are the safety rod thimbles and Mark 60B blanket assemblies; for the K Reactor, these components have been exposed to low temperature (< 55{degrees}C) moderator for about a year. The average moderator temperature was assumed to be 30{degrees}C. The Al oxide film thickness at this temperature, after one year of exposure, is predicted to be 6.4 {mu}m {plus_minus} 10%; insensitive to exposure time. Dehydration of the film during the gamma heating accident would result in a film thickness of 6.0 {mu}m {plus_minus} 11%. Total hemispherical emittance is predicted to be 0.69 at 96{degrees}C, decreasing to 0.45 at 600{degrees}C. Some phenomena which would tend to yield thicker oxide films in the reactor environment relative to those obtained under experimental conditions were neglected and the predicted film thickness values are therefore conservative. The emittance values predicted for a given film thickness are also conservative. The conservativisms inherent in the predicted emittance are particularly relevant for uncertainty analysis of temperatures generated using these values.

  2. Light modulated electron beam driven radiofrequency emitter

    DOEpatents

    Wilson, M.T.; Tallerico, P.J.

    1979-10-10

    The disclosure relates to a light modulated electron beam-driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

  3. Light modulated switches and radio frequency emitters

    DOEpatents

    Wilson, Mahlon T.; Tallerico, Paul J.

    1982-01-01

    The disclosure relates to a light modulated electron beam driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

  4. Simple-to-prepare multipoint field emitter

    NASA Astrophysics Data System (ADS)

    Sominskii, G. G.; Taradaev, E. P.; Tumareva, T. A.; Mishin, M. V.; Kornishin, S. Yu.

    2015-07-01

    We investigate multitip field emitters prepared by electroerosion treatment of the surface of molybdenum samples. Their characteristics are determined for operation with a protecting activated fullerene coating. Our experiments indicate that such cathodes are promising for high-voltage electron devices operating in technical vacuum.

  5. Emittance growth from electron beam modulation

    SciTech Connect

    Blaskiewicz, M.

    2009-12-01

    In linac ring colliders like MeRHIC and eRHIC a modulation of the electron bunch can lead to a modulation of the beam beam tune shift and steering errors. These modulations can lead to emittance growth. This note presents simple formulas to estimate these effects which generalize some previous results.

  6. Optical transition radiation beam emittance diagnostics

    SciTech Connect

    Fiorito, R.B.; Rule, D.W.

    1994-10-10

    We have developed several analytic and experimental techniques to measure the divergence and emittance of charged particle beams, which employ optical transition radiation (OTR) produced from thin intercepting foils. OTR`s directionality, promptness, linearity, polarization, and the sensitivity of its angular distribution to energy and divergence, can be all exploited to diagnose the spatial distribution, energy, and emittance of a charged particle beam. We describe the techniques we have developed to separately determine the {ital x} and {ital y} emittances of a beam at an {ital x} or {ital y} waist using OTR from a single foil or a two foil OTR interferometer. These methods have proven to be especially valuable for diagnosing low emittance electron beams produced by FEL accelerators, which range in energy from 17 to 110 Mev. However, we have shown that there is no inherent theoretical limit to the utility of these methods for much higher energy lepton or hadron beams. The advantages of OTR methods over those commonly used to diagnose beam properties are described.

  7. Emittance growth from space-charge forces

    SciTech Connect

    Wangler, T.P.

    1991-01-01

    Space-charge-induced emittance growth has become a topic of much recent interest for designing the low-velocity sections of high- intensity, high-brightness accelerators and beam-transport channels. In this paper we review the properties of the space-charge force, and discuss the concepts of matching, space-charge and emittance-dominated beams, and equilibrium beams and their characteristics. This is followed by a survey of some of the work over the past 25 years to identify the mechanisms of this emittance growth in both ion and electron accelerators. We summarize the overall results in terms of four distinct mechanisms whose characteristics we describe. Finally, we show numerical simulation results for the evolution of initial rms-mismatched laminar beams. The examples show that for space-charge dominated beams, the nonlinear space-charge forces produce a highly choatic filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. In the examples we have studied the halo contains only a few percent of the particles, but contributes about half of the emittance growth. 39 refs., 2 figs., 1 tab.

  8. A Neutron Sensitive Microchannel Plate Detector with Cross Delay Line Readout

    SciTech Connect

    Berry, Kevin D.; Bilheux, Hassina Z.; Crow, Lowell; Diawara, Yacouba; Feller, W. Bruce; Iverson, Erik B.; Martin, Adrian; Robertson, J. Lee

    2012-01-01

    Microchannel plates containing neutron absorbing elements such as boron and gadolinium in the bulk glass are used as the sensing element in high spatial resolution, high rate neutron imaging systems. In this paper we describe one such device, using both 10B and natural Gd, which employs cross delay line signal readout, with time-of-flight capability. This detector has a measured spatial resolution under 40 m FWHM, thermal neutron efficiency of 19%, and has recorded rates in excess of 500 kHz. A physical and functional description is presented, followed by a discussion of measurements of detector performance and a brief survey of some practical applications.

  9. Development of silicon pad detectors and readout electronics for a Compton camera

    NASA Astrophysics Data System (ADS)

    Studen, A.; Cindro, V.; Clinthorne, N. H.; Czermak, A.; Dulinski, W.; Fuster, J.; Han, L.; Jalocha, P.; Kowal, M.; Kragh, T.; Lacasta, C.; Llosá, G.; Meier, D.; Mikuž, M.; Nygård, E.; Park, S. J.; Roe, S.; Rogers, W. L.; Sowicki, B.; Weilhammer, P.; Wilderman, S. J.; Yoshioka, K.; Zhang, L.

    2003-03-01

    Applications in nuclear medicine and bio-medical engineering may profit using a Compton camera for imaging distributions of radio-isotope labelled tracers in organs and tissues. These applications require detection of photons using thick position-sensitive silicon sensors with the highest possible energy and good spatial resolution. In this paper, research and development on silicon pad sensors and associated readout electronics for a Compton camera are presented. First results with low-noise, self-triggering VATAGP ASIC's are reported. The measured energy resolution was 1.1 keV FWHM at room temperature for the 241Am photo-peak at 59.5 keV.

  10. Nullspace MUSIC and Improved Radio Frequency Emitter Geolocation from a Mobile Antenna Array

    NASA Astrophysics Data System (ADS)

    Kintz, Andrew L.

    This work advances state-of-the-art Radio Frequency (RF) emitter geolocation from an airborne or spaceborne antenna array. With an antenna array, geolocation is based on Direction of Arrival (DOA) estimation algorithms such as MUSIC. The MUSIC algorithm applies to arbitrary arrays of polarization sensitive antennas and yields high resolution. However, MUSIC fails to obtain its theoretical resolution for simultaneous, closely spaced, co-frequency signals. We propose the novel Nullspace MUSIC algorithm, which outperforms MUSIC and its existing modifications while maintaining MUSIC(apostrophe)s fundamental orthogonality test. Nullspace MUSIC applies a divide-and-conquer approach and estimates a single DOA at a time. Additionally, an antenna array on an aircraft cannot be perfectly calibrated. RF waves are blocked, reflected, and scattered in a time-varying fashion by the platform around the antenna array. Consequently, full-wave electromagnetics simulations or demanding measurements of the entire platform cannot eliminate the mismatch between the true, in-situ antenna patterns and the antenna patterns that are available for DOA estimation (the antenna array manifold). Platform-induced manifold mismatch severely degrades MUSIC(apostrophe)s resolution and accuracy. We show that Nullspace MUSIC improves DOA accuracy for well separated signals that are incident on an airborne antenna array. Conventionally, geolocation from a mobile platform draws Lines of Bearing (LOB) from the antenna array along the DOAs to find the locations where the DOAs intersect with the ground. However, averaging the LOBs in the global coordinate system yields large errors due to geometric dilution of precision. Since averaging positions fails, a single emitter is typically located by finding the position on the ground that yields the Minimum Apparent Angular Error (MAAE) for the DOA estimates over a flight. We extend the MAAE approach to cluster LOBs from multiple emitters. MAAE clustering

  11. Self-powered radiation detector with conductive emitter support

    SciTech Connect

    Bauer, R.F.; Goldstein, N.P.; Playfoot, K.C.

    1981-05-12

    A more reliable self-powered radiation detector structure and method of manufacture is provided by a detector structure in which a relatively ductile centrally disposed conductive emitter wire supports and is in electrical contact with a generally tubular emitter electrode. The detector is fabricated by swaging and the ductile center wire insures that electrical discontinuities of the emitter are minimized.

  12. Electron gun using carbon-nanofiber field emitter.

    PubMed

    Sakai, Y; Haga, A; Sugita, S; Kita, S; Tanaka, S-I; Okuyama, F; Kobayashi, N

    2007-01-01

    An electron gun constructed using carbon-nanofiber (CNF) emitters and an electrostatic Einzel lens system has been characterized for the development of a high-resolution x-ray source. The CNFs used were grown on tungsten and palladium tips by plasma-enhanced chemical-vapor deposition. Electron beams with the energies of 10

  13. Characterisation of the PXIE Allison-type emittance scanner

    SciTech Connect

    D'Arcy, R.; Alvarez, M.; Gaynier, J.; Prost, L.; Scarpine, V.; Shemyakin, A.

    2016-01-26

    An Allison-type emittance scanner has been designed for PXIE at FNAL with the goal of providing fast and accurate phase space reconstruction. The device has been modified from previous LBNL/SNS designs to operate in both pulsed and DC modes with the addition of water-cooled front slits. Extensive calibration techniques and error analysis allowed confinement of uncertainty to the <5% level (with known caveats). With a 16-bit, 1 MHz electronics scheme the device is able to analyse a pulse with a resolution of 1 μs, allowing for analysis of neutralisation effects. As a result, this paper describes a detailed breakdown of the R&D, as well as post-run analysis techniques.

  14. T-ray profile synthesis using photoconductive emitter array

    NASA Astrophysics Data System (ADS)

    Hattori, Toshiaki; Masuda, Masayoshi; Sakamoto, Masaya; Egawa, Kazuhiro; Itatani, Taro; Ohi, Akihiko

    2007-09-01

    We have observed coherent synthesis of spatial profiles of THz radiation emitted from a photoconductive antenna array. The antenna array is composed of seven independently addressable photoconductive antenna units having interdigitated electrodes. The antennas were pumped by amplified 800 nm femtosecond optical pulses. Emitted THz radiation was focused, and the time-resolved spatial profile of the THz radiation on the focal plane was observed using a newly developed real-time imaging apparatus, which can correct the terahertz field images for nonuniformity in birefringence of the EO crystal. By scanning the delay time, frequency-resolved images were also obtained, which exhibit frequency-dependent field profiles. Field profiles observed were coherent superpositions of terahertz waves emitted from the antenna units constituting the array. By inverting the bias voltage to the central unit of the emitter array, we observed super-resolution beam size of terahertz waves, which are smaller than the diffraction limit.

  15. Characterisation of the PXIE Allison-type emittance scanner

    DOE PAGES

    D'Arcy, R.; Alvarez, M.; Gaynier, J.; ...

    2016-01-26

    An Allison-type emittance scanner has been designed for PXIE at FNAL with the goal of providing fast and accurate phase space reconstruction. The device has been modified from previous LBNL/SNS designs to operate in both pulsed and DC modes with the addition of water-cooled front slits. Extensive calibration techniques and error analysis allowed confinement of uncertainty to the <5% level (with known caveats). With a 16-bit, 1 MHz electronics scheme the device is able to analyse a pulse with a resolution of 1 μs, allowing for analysis of neutralisation effects. As a result, this paper describes a detailed breakdown ofmore » the R&D, as well as post-run analysis techniques.« less

  16. What is so super about super-emitters? Characterizing methane high emitters from natural gas infrastructure

    NASA Astrophysics Data System (ADS)

    Zavala Araiza, D.; Lyon, D. R.; Alvarez, R.; Harriss, R. C.; Palacios, V.; Hamburg, S.

    2015-12-01

    Methane emissions across the natural gas supply chain are dominated at any one time by a few high-emitters (super-emitters or fat-tail of the distribution), often underrepresented in published datasets used to construct emission inventories. Characterization of high-emitters is essential for improving emission estimates based on atmospheric data (top-down) and emission inventories (bottom-up). The population of high-emitters (e.g. 10-20% of sites that account for 80-90% of the emissions) is temporally and spatially dynamic. As a consequence, it is challenging to design sampling methods and construct estimates that accurately represent their frequency and magnitude of emissions. We present new methods to derive facility-specific emission distribution functions that explicitly integrate the influence of the relatively rare super-emitters. These methods were applied in the Barnett Shale region to construct a custom emission inventory that is then compared to top-down emission estimates for the region. We offer a methodological framework relevant to the design of future sampling campaigns, in which these high-emitters are seamlessly incorporated to representative emissions distributions. This framework can be applied to heterogeneous oil and gas production regions across geographies to obtain accurate regional emission estimates. Additionally, we characterize emissions relative to the fraction of a facility's total methane throughput; an effective metric to identify sites with excess emissions resulting from avoidable operating conditions, such as malfunctioning equipment (defined here as functional super-emitters). This work suggests that identifying functional super-emitters and correcting their avoidable operating conditions would result in significant emission reductions. However, due to their spatiotemporal dynamic behavior, achieving and maintaining uniformly low emissions across the entire population of sites will require mitigation steps (e.g. leak detection

  17. Facet engineering of high power single emitters

    NASA Astrophysics Data System (ADS)

    Yanson, Dan; Levi, Moshe; Shamay, Moshe; Tesler, Renana; Rappaport, Noam; Don, Yaroslav; Karni, Yoram; Schnitzer, Itzhak; Sicron, Noam; Shusterman, Sergey

    2011-03-01

    The ever increasing demand for high-power, high-reliability operation of single emitters at 9xx nm wavelengths requires the development of laser diodes with improved facet regions immune to both catastrophic and wear-out failure modes. In our study, we have evaluated several laser facet definition technologies in application to 90 micron aperture single emitters in asymmetric design (In)GaAs/AlGaAs based material emitting at 915, 925 and 980nm. A common epitaxy and emitter design makes for a straightforward comparison of the facet technologies investigated. Our study corroborates a clear trend of increasing difficulty in obtaining reliable laser operation from 980nm down to 915nm. At 980nm, one can employ dielectric facet passivation with a pre-clean cycle delivering a device lifetime in excess of 3,000 hours at increasing current steps. At 925nm, quantum-well intermixing can be used to define non-absorbing mirrors giving good device reliability, albeit with a large efficiency penalty. Vacuum cleaved emitters have delivered excellent reliability at 915nm, and can be expected to perform just as well at 925 and 980nm. Epitaxial regrowth of laser facets is under development and has yet to demonstrate an appreciable reliability improvement. Only a weak correlation between start-of-life catastrophic optical mirror damage (COMD) levels and reliability was established. The optimized facet design has delivered maximum powers in excess of 19 MW/sq.cm (rollover limited) and product-grade 980nm single emitters with a slope efficiency of >1 W/A and a peak efficiency of >60%. The devices have accumulated over 1,500 hours of CW operation at 11W. A fiber-coupled device emits 10W ex-fiber with 47% efficiency.

  18. A Readout Mechanism for Latency Codes.

    PubMed

    Zohar, Oran; Shamir, Maoz

    2016-01-01

    Response latency has been suggested as a possible source of information in the central nervous system when fast decisions are required. The accuracy of latency codes was studied in the past using a simplified readout algorithm termed the temporal-winner-take-all (tWTA). The tWTA is a competitive readout algorithm in which populations of neurons with a similar decision preference compete, and the algorithm selects according to the preference of the population that reaches the decision threshold first. It has been shown that this algorithm can account for accurate decisions among a small number of alternatives during short biologically relevant time periods. However, one of the major points of criticism of latency codes has been that it is unclear how can such a readout be implemented by the central nervous system. Here we show that the solution to this long standing puzzle may be rather simple. We suggest a mechanism that is based on reciprocal inhibition architecture, similar to that of the conventional winner-take-all, and show that under a wide range of parameters this mechanism is sufficient to implement the tWTA algorithm. This is done by first analyzing a rate toy model, and demonstrating its ability to discriminate short latency differences between its inputs. We then study the sensitivity of this mechanism to fine-tuning of its initial conditions, and show that it is robust to wide range of noise levels in the initial conditions. These results are then generalized to a Hodgkin-Huxley type of neuron model, using numerical simulations. Latency codes have been criticized for requiring a reliable stimulus-onset detection mechanism as a reference for measuring latency. Here we show that this frequent assumption does not hold, and that, an additional onset estimator is not needed to trigger this simple tWTA mechanism.

  19. A Readout Mechanism for Latency Codes

    PubMed Central

    Zohar, Oran; Shamir, Maoz

    2016-01-01

    Response latency has been suggested as a possible source of information in the central nervous system when fast decisions are required. The accuracy of latency codes was studied in the past using a simplified readout algorithm termed the temporal-winner-take-all (tWTA). The tWTA is a competitive readout algorithm in which populations of neurons with a similar decision preference compete, and the algorithm selects according to the preference of the population that reaches the decision threshold first. It has been shown that this algorithm can account for accurate decisions among a small number of alternatives during short biologically relevant time periods. However, one of the major points of criticism of latency codes has been that it is unclear how can such a readout be implemented by the central nervous system. Here we show that the solution to this long standing puzzle may be rather simple. We suggest a mechanism that is based on reciprocal inhibition architecture, similar to that of the conventional winner-take-all, and show that under a wide range of parameters this mechanism is sufficient to implement the tWTA algorithm. This is done by first analyzing a rate toy model, and demonstrating its ability to discriminate short latency differences between its inputs. We then study the sensitivity of this mechanism to fine-tuning of its initial conditions, and show that it is robust to wide range of noise levels in the initial conditions. These results are then generalized to a Hodgkin-Huxley type of neuron model, using numerical simulations. Latency codes have been criticized for requiring a reliable stimulus-onset detection mechanism as a reference for measuring latency. Here we show that this frequent assumption does not hold, and that, an additional onset estimator is not needed to trigger this simple tWTA mechanism. PMID:27812332

  20. Authenticated communication from quantum readout of PUFs

    NASA Astrophysics Data System (ADS)

    Škorić, Boris; Pinkse, Pepijn W. H.; Mosk, Allard P.

    2017-08-01

    Quantum readout of physical unclonable functions (PUFs) is a recently introduced method for remote authentication of objects. We present an extension of the protocol to enable the authentication of data: A verifier can check if received classical data were sent by the PUF holder. We call this modification QR-d or, in the case of the optical-PUF implementation, QSA-d. We discuss how QSA-d can be operated in a parallel way. We also present a protocol for authenticating quantum states.

  1. Asynchronous data readout system for multichannel ASIC

    NASA Astrophysics Data System (ADS)

    Ivanov, P. Y.; Atkin, E. V.

    2016-02-01

    The data readout system of multichannel data-driven ASIC, requiring high-speed (320 Mb/s) output data serialization is described. Its structure, based on a limited number of FIFO blocks, provides a lossless data transfer. The solution has been realized as a separate test IP block in the prototyped 8 channel ASIC, intended for the muon chamber of CBM experiment at FAIR. The block was developed for the UMC 0.18 μm MMRF CMOS process and prototyped via Europractice. Main parameters of the chip are given.

  2. Spin readout of trapped electron qubits

    NASA Astrophysics Data System (ADS)

    Peng, Pai; Matthiesen, Clemens; Häffner, Hartmut

    2017-01-01

    We propose a scheme to read out the spin of a single electron quantum bit in a surface Paul trap using oscillating magnetic-field gradients. The readout sequence is composed of cooling, driving, amplification, and detection of the electron's motion. We study the scheme in the presence of noise and trap anharmonicities at liquid-helium temperatures. An analysis of the four procedures shows short measurement times (25 μ s ) and high fidelities (99.7 % ) are achievable with realistic experimental parameters. Our scheme performs the function of fluorescence detection in ion trapping schemes, highlighting the potential to build all-electric quantum computers based on trapped electron-spin qubits.

  3. ARTICLES: Optoelectronic readout with an injection laser

    NASA Astrophysics Data System (ADS)

    Luc, Vu V.; Eliseev, P. G.; Man'ko, Margarita A.; Mikaelyan, T. T.; Okhotnikov, O. G.; Sokolov, S. N.

    1982-09-01

    An investigation was made of the possibility of utilizing an injection heterolaser in optical devices for data retrieval. An injection laser was used both as a source and detector of its own radiation reflected from a data carrier (optoelectronic readout). The influence of the reflected radiation was due to quasisteady modulation of the Q factor of the resonator, which was accompanied by modulation of the voltage across the laser diode. A study was made of the influence of the pump current on the useful signal and it was found that this current was related to the differential resistance of the laser diode.

  4. Mass-based readout for agglutination assays

    NASA Astrophysics Data System (ADS)

    Chunara, Rumi; Godin, Michel; Knudsen, Scott M.; Manalis, Scott R.

    2007-11-01

    We present a mass-based readout for agglutination assays. The suspended microchannel resonator (SMR) is used to classify monomers and dimers that are formed during early stage aggregation, and to relate the total count to the analyte concentration. Using a model system of streptavidin functionalized microspheres and biotinylated antibody as the analyte, we obtain a dose-response curve over a concentration range of 0.63-630nM and show that the results are comparable to what has been previously achieved by image analysis and conventional flow cytometry.

  5. Scintillation counter with WLS fiber readout

    NASA Astrophysics Data System (ADS)

    Bukin, D. A.; Druzhinin, V. P.; Golubev, V. B.; Serednyakov, S. I.

    1997-02-01

    The parameters of a cylindrical scintillation counter of 126 mm in diameter and 370 mm in length with wavelength shifter (WLS) fiber readout are presented. The fibers are glued into machined grooves along the scintillator. Light from both ends of the WLS fibers is transmitted to separate photomultipliers by 1 m long clear optical fibers. The average total signal, collected from both sides of the counter is equivalent to 8 photoelectrons per minimum ionizing particle. The described cylindrical scintillation counter is a part of inner system of collider detector SND.

  6. Evaluation of the x-ray response of a position-sensitive microstrip detector with an integrated readout chip

    SciTech Connect

    Rossington, C.; Jaklevic, J.; Haber, C.; Spieler, H. ); Reid, J. . Dept. of Physics)

    1990-08-01

    The performance of an SVX silicon microstrip detector and its compatible integrated readout chip have been evaluated in response to Rh K{alpha} x-rays (average energy 20.5 keV). The energy and spatial discrimination capabilities, efficient data management and fast readout rates make it an attractive alternative to the CCD and PDA detectors now being offered for x-ray position sensitive diffraction and EXAFS work. The SVX system was designed for high energy physics applications and thus further development of the existing system is required to optimize it for use in practical x-ray experiments. For optimum energy resolution the system noise must be decreased to its previously demonstrated low levels of 2 keV FWHM at 60 keV or less, and the data handling rate of the computer must be increased. New readout chips are now available that offer the potential of better performance. 15 refs., 7 figs.

  7. Prototype readout electronics for the upgraded ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Sielewicz, K. M.; Aglieri Rinella, G.; Bonora, M.; Ferencei, J.; Giubilato, P.; Rossewij, M. J.; Schambach, J.; Vanat, T.

    2017-01-01

    The ALICE Collaboration is preparing a major upgrade to the experimental apparatus. A key element of the upgrade is the construction of a new silicon-based Inner Tracking System containing 12 Gpixels in an area of 10 m2. Its readout system consists of 192 readout units that control the pixel sensors and the power units, and deliver the sensor data to the counting room. A prototype readout board has been designed to test: the interface between the sensor modules and the readout electronics, the signal integrity and reliability of data transfer, the interface to the ALICE DAQ and trigger, and the susceptibility of the system to the expected radiation level.

  8. Dependence of transmon qubit relaxation rate on readout drive power

    NASA Astrophysics Data System (ADS)

    Mundhada, S. O.; Shankar, S.; Narla, A.; Zalys-Geller, E.; Girvin, S. M.; Devoret, M. H.

    In circuit QED experiments, microwave drives are applied to the readout mode for qubit measurement, control and to realize various multi-photon processes. These microwave drives have been observed to detrimentally affect the qubit mode by increasing the qubit relaxation rates for both upward and downward transitions. These transitions demolish the qubit state during a measurement, limiting the maximum measurement strength and thus the readout fidelity and speed. Here, we experimentally investigate this effect for transmon qubits coupled to different realizations of the readout mode: 3-dimensional microwave cavities, strip-line resonators and nonlinear readout modes in a waveguide. Work supported by: NSF, ARO, AFOSR and YINQE.

  9. 100 Gbps PCI-Express readout for the LHCb upgrade

    NASA Astrophysics Data System (ADS)

    Durante, P.; Neufeld, N.; Schwemmer, R.; Balbi, G.; Marconi, U.

    2015-04-01

    We present a new data acquisition system under development for the next upgrade of the LHCb experiment at CERN. We focus in particular on the design of a new generation of readout boards, the PCIe40, and on the viability of PCI-Express as an interconnect technology for high speed readout. We show throughput measurements across the PCI-Express bus, on Altera Stratix 5 devices, using a DMA mechanism and different synchronization schemes between the FPGA and the readout unit. Finally we discuss hardware and software design considerations necessary to achieve a data throughput of 100 Gbps in the final readout board.

  10. 4 pi direction sensitive gamma imager with RENA-3 readout ASIC

    NASA Astrophysics Data System (ADS)

    Du, Yanfeng; Li, Wen; Yanoff, Brian; Gordon, Jeffrey; Castleberry, Donald

    2007-09-01

    A 4π direction-sensitive gamma imager is presented, using a 1 cm 3 3D CZT detector from Yinnel Tech and the RENA-3 readout ASIC from NOVA R&D. The measured readout system electronic noise is around 4-5 keV FWHM for all anode channels. The measured timing resolution between two channels within a single ASIC is around 10 ns and the resolution is 30 ns between two separate ASIC chips. After 3D material non-uniformity and charge trapping corrections, the measured single-pixel-event energy resolution is around 1% for Cs-137 at 662 keV using a 1 cm 3 CZT detector from Yinnel Tech with an 8 x 8 anode pixel array at 1.15 mm pitch. The energy resolution for two pixel events is 2.9%. A 10 uCi Cs-137 point source was moved around the detector to test the image reconstruction algorithms and demonstrate the source direction detection capability. Accurate source locations were reconstructed with around 200 two-pixel events within a total energy window +/-10 keV around the 662 keV full energy peak. The angular resolution FWHM at four of the five positions tested was between 0.05-0.07 steradians.

  11. An Ultra-Bright Pulsed Electron Beam With Low Longitudinal Emittance

    SciTech Connect

    Zolotorev, M.; Commins, E.D.; Denes, P.; Hussain, Z.; Lebedev, G.V.; Lidia, S.M.; Robin, D.; Sannibale, F.; Schoenlein, R.W.; Vogel, R.A.; Wan, W.; Heifets, S.A.; /SLAC

    2006-02-10

    Most existing electron sources extract electrons from conductors. Since the actual temperature inside the conductor is much less than the Fermi temperature of the conduction electrons, the electron degeneracy {delta}{sub f} is close to 1, the maximum allowed by the Pauli exclusion principle. However, during extraction several factors conspire together to reduce {delta}{sub f} many orders of magnitude, limiting the achieved values to {approx} 10{sup -5}. A new concept is described for building a novel electron source designed to produce a pulsed beam with {delta}{sub f} {approx} 2 10{sup -3} and longitudinal emittance four orders of magnitude smaller than currently achieved values. This high brightness, low longitudinal emittance regime enables a wide range of novel applications that utilize angstrom-scale spatial resolution and eV-scale energy resolution. The current state of a proof-of-principle experiment conducted at LBNL is also described.

  12. An Ultra-Bright Pulsed Electron Beam with Low LongitudinalEmittance

    SciTech Connect

    Zolotorev, Max; Commins, Eugene D.; Denes, P.; Heifets, Samuel; Hussain, Zahid; Lebedev, Gennnadi V.; Lidia, Steven M.; Robin, David S.; Sannibale, Fernando; Schoenlein, Robert W.; Vogel, Robert; Wan, Weishi

    2005-05-01

    Most existing electron sources extract electrons from conductors. Since the actual temperature inside the conductor is much less than the Fermi temperature of the conduction electrons, the electron degeneracy ({delta}{sub f}) is close to 1, the maximum allowed by the Pauli exclusion principle. However, during extraction several factors conspire together to reduce {delta}{sub f} many orders of magnitude, limiting the achieved values to approx 10{sup -5}. A new concept is described for building a novel electron source designed to produce a pulsed beam with {delta}{sub f} approx 2 10{sup -3} and longitudinal emittance four orders of magnitude smaller than currently achieved values. This high brightness, low longitudinal emittance regime enables a wide range of novel applications that utilize angstrom-scale spatial resolution and eV-scale energy resolution. The current state of a proof-of-principle experiment conducted at LBNL is also described.

  13. Ultracompact Microwatt CMOS Current Readout With Picoampere Noise and Kilohertz Bandwidth for Biosensor Arrays.

    PubMed

    Li, Haitao; Parsnejad, Sina; Ashoori, Ehsan; Thompson, Cort; Purcell, Erin K; Mason, Andrew J

    2017-10-05

    High-density on-chip electrochemical biosensor arrays are advancing toward a crucial role in health monitoring and development of new medicines and medical treatments. Nanopore and ion channel based sensors especially have great potential but present demanding resolution/speed/power/area requirements on instrumentation circuits. This paper presents a pixel-level current readout circuit and new group-cluster architecture to address the circuit challenges in high-performance biosensor arrays. Fabricated in 0.5 μm CMOS, this electrochemical voltammetry circuit achieves 7.2 pA[Formula: see text] noise in an 11.5-kHz bandwidth and only consumes 21-μW power and 0.06 mm2 area per readout channel. Cyclic voltammetry experiments in a potassium ferricyanide solution and patch-clamp whole-cell experiments were performed to validate the circuit's feasibility for electrochemical biosensor applications.

  14. Two-dimensional GEM imaging detector with delay-line readout

    NASA Astrophysics Data System (ADS)

    Guedes, G. P.; Breskin, A.; Chechik, R.; Vartsky, D.; Bar, D.; Barbosa, A. F.; Marinho, P. R. B.

    2003-11-01

    A 100×100 mm 2 2D imaging detector, based on a triple-GEM gaseous multiplier, striped x- y readout anode and discrete delay-line readout, is presented. The fast (2.1 ns tap -1) delay-line circuit was designed to match the anode-charge signal profile, namely its rise-time and length. The detector's imaging capability was systematically studied in Ar/CO 2 (70/30) with 5.9 keV X-rays; x- y resolution of σ=0.05 and 0.1 mm for top and bottom anode strips, respectively, and integral non-linearity of ˜0.15% are demonstrated.

  15. Small-Scale Readout System Prototype for the STAR PIXEL Detector

    SciTech Connect

    Szelezniak, Michal; Anderssen, Eric; Greiner, Leo; Matis, Howard; Ritter, Hans Georg; Stezelberger, Thorsten; Sun, Xiangming; Thomas, James; Vu, Chinh; Wieman, Howard

    2008-10-10

    Development and prototyping efforts directed towards construction of a new vertex detector for the STAR experiment at the RHIC accelerator at BNL are presented. This new detector will extend the physics range of STAR by allowing for precision measurements of yields and spectra of particles containing heavy quarks. The innermost central part of the new detector is a high resolution pixel-type detector (PIXEL). PIXEL requirements are discussed as well as a conceptual mechanical design, a sensor development path, and a detector readout architecture. Selected progress with sensor prototypes dedicated to the PIXEL detector is summarized and the approach chosen for the readout system architecture validated in tests of hardware prototypes is discussed.

  16. Demonstration of digital readout circuit for superconducting nanowire single photon detector.

    PubMed

    Ortlepp, T; Hofherr, M; Fritzsch, L; Engert, S; Ilin, K; Rall, D; Toepfer, H; Meyer, H-G; Siegel, M

    2011-09-12

    We demonstrate the transfer of single photon triggered electrical pulses from a superconducting nanowire single photon detector (SNSPD) to a single flux quantum (SFQ) pulse. We describe design and test of a digital SFQ based SNSPD readout circuit and demonstrate its correct operation. Both circuits (SNSPD and SFQ) operate under the same cryogenic conditions and are directly connected by wire bonds. A future integration of the present multi-chip configuration seems feasible because both fabrication process and materials are very similar. In contrast to commonly used semiconductor amplifiers, SFQ circuits combine very low power dissipation (a few microwatts) with very high operation speed, thus enabling count-rates of several gigahertz. The SFQ interface circuit simplifies the SNSPD readout and enables large numbers of detectors for future compact multi-pixel systems with single photon counting resolution. The demonstrated circuit has great potential for scaling the present interface solution to 1,000 detectors by using a single SFQ chip.

  17. Detection of human κ-opioid antibody using microresonators with integrated optical readout.

    PubMed

    Timurdogan, Erman; Ozber, Natali; Nargul, Sezin; Yavuz, Serhat; Kilic, M Salih; Kavakli, I Halil; Urey, Hakan; Alaca, B Erdem

    2010-09-15

    Label-free detection of the interaction between hexahistidine-tagged human κ-opioid receptor membrane protein and anti-His antibody is demonstrated in liquid by an optical microelectromechanical system utilizing electromagnetically actuated microresonators. Shift in resonance frequency due to accretion of mass on the sensitive surface of microresonators is monitored via an integrated optical readout. A frequency resolution of 2Hz is obtained. Together with a sensitivity of 7 ppm/(ng/ml) this leads to a minimum detectable antibody concentration of 5.7 ng/ml for a 50-kHz device. The measurement principle is shown to impart immunity to environmental noise, facilitate operation in liquid media and bring about the prospect for further miniaturization of actuator and readout leading to a portable biochemical sensor.

  18. Readout electronics for the Wide Field of view Cherenkov/Fluorescence Telescope Array

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Zhang, S.; Zhang, Y.; Zhou, R.; Bai, L.; Zhang, J.; Huang, J.; Yang, C.; Cao, Z.

    2015-08-01

    The aim of the Large High Altitude Air Shower Observatory (LHAASO), supported by IHEP of the Chinese Academy of Sciences, is a multipurpose project with a complex detectors array for high energy gamma ray and cosmic ray detection. The Wide Field of view Cherenkov Telescope Array (WFCTA), as one of the components of the LHAASO project, aim to tag each primary particle that causes an air shower. The WFCTA is a portable telescope array used to detect cosmic ray spectra. The design of the readout electronics of the WFCTA is described in this paper Sixteen photomultiplier tubes (PMTs), together with their readout electronics are integrated into a single sub-cluster. To maintain good resolution and linearity over a wide dynamic range, a dual-gain amplification configuration on an analog board is used The digital board contains two 16channel 14-bit, 50 Msps analog-to-digital converters (ADC) and its power consumption, noise level, and relative deviation are all tested.

  19. A 64-channel readout ASIC for nanowire biosensor array with electrical calibration scheme.

    PubMed

    Chai, Kevin T C; Choe, Kunil; Bernal, Olivier D; Gopalakrishnan, Pradeep K; Zhang, Guo-Jun; Kang, Tae Goo; Je, Minkyu

    2010-01-01

    A 1.8-mW, 18.5-mm(2) 64-channel current readout ASIC was implemented in 0.18-µm CMOS together with a new calibration scheme for silicon nanowire biosensor arrays. The ASIC consists of 64 channels of dedicated readout and conditioning circuits which incorporate correlated double sampling scheme to reduce the effect of 1/f noise and offset from the analog front-end. The ASIC provides a 10-bit digital output with a sampling rate of 300 S/s whilst achieving a minimum resolution of 7 pA(rms). A new electrical calibration method was introduced to mitigate the issue of large variations in the nano-scale sensor device parameters and optimize the sensor sensitivity. The experimental results show that the proposed calibration technique improved the sensitivity by 2 to 10 times and reduced the variation between dataset by 9 times.

  20. Dual-Readout Calorimetry for High-Quality Energy Measurements. Final Report

    SciTech Connect

    Wigmans, Richard; Nural, Akchurin

    2013-09-01

    This document constitutes the final report on the project Dual-Readout Calorimetry for High-Quality Energy Measurements. The project was carried out by a consortium of US and Italian physicists, led by Dr. Richard Wigmans (Texas tech University). This consortium built several particle detectors and tested these at the European Center for Nuclear Research (CERN) in Geneva, Switzerland. The idea arose to use scintillating crystals as dual-readout calorimeters. Such crystals were of course already known to provide excellent energy resolution for the detection of particles developing electromagnetic (em) showers. The efforts to separate the signals from scintillating crystals into scintillation and Cerenkov components led to four different methods by which this could be accomplished. These methods are based on a) the directionality, b) spectral differences, c) the time structure, and d) the polarization of the signals.

  1. A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

    NASA Technical Reports Server (NTRS)

    Kimble, Randy A.; Pain, B.; Norton, T. J.; Haas, P.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution for the readout while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest or by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

  2. Spectral and Total Normal Emittance of Reusable Surface Insulation Materials

    NASA Technical Reports Server (NTRS)

    Kantsios, A. G.; Edwards, S. F.; Dicus, D. L.

    1973-01-01

    Measurements of spectral and total normal emittance have been made on three types of reusable external insulation materials proposed for space shuttles. Emittances were measured in the spectral range 1 to 15 micrometer at temperatures of 800 K and 1100 K using a radiometric measurement technique. Results indicated that the total normal emittance of these materials was less than 0.8 between 800 K and 1300 K. The total normal emittance decreased with increasing temperature. The three ceramic coating candidate materials exhibited a similar spectral emittance distribution.

  3. Characterization and performance of monolithic detector blocks with a dedicated ASIC front-end readout for PET imaging of the human brain

    NASA Astrophysics Data System (ADS)

    Rato Mendes, Pedro; Sarasola Martín, Icíar; Cañadas, Mario; de Acilu, Paz García; Cuypers, Robin; Manuel Pérez, José; Willmott, Carlos

    2011-05-01

    We are developing a human brain PET scanner prototype compatible with MRI based on monolithic scintillator crystals, APD matrices and a dedicated ASIC front-end readout. In this work we report on the performance of individual detector modules and on the operation of such modules in PET coincidence. Results will be presented on the individual characterization of detector blocks and its ASIC front-end readout, with measured energy resolutions of 13% full-width half-maximum (FWHM) at 511 keV and spatial resolutions of the order of 2 mm FWHM. First results on PET coincidence performance indicate spatial resolutions as good as 2.1 mm FWHM for SSRB/FBP reconstruction of tomographic data obtained using a simple PET demonstrator based on a pair of monolithic detector blocks with ASIC readout.

  4. Maximal Adaptive-Decision Speedups in Quantum-State Readout

    NASA Astrophysics Data System (ADS)

    D'Anjou, B.; Kuret, L.; Childress, L.; Coish, W. A.

    2016-01-01

    The average time T required for high-fidelity readout of quantum states can be significantly reduced via a real-time adaptive decision rule. An adaptive decision rule stops the readout as soon as a desired level of confidence has been achieved, as opposed to setting a fixed readout time tf . The performance of the adaptive decision is characterized by the "adaptive-decision speedup," tf/T . In this work, we reformulate this readout problem in terms of the first-passage time of a particle undergoing stochastic motion. This formalism allows us to theoretically establish the maximum achievable adaptive-decision speedups for several physical two-state readout implementations. We show that for two common readout schemes (the Gaussian latching readout and a readout relying on state-dependent decay), the speedup is bounded by 4 and 2, respectively, in the limit of high single-shot readout fidelity. We experimentally study the achievable speedup in a real-world scenario by applying the adaptive decision rule to a readout of the nitrogen-vacancy-center (NV-center) charge state. We find a speedup of ≈2 with our experimental parameters. In addition, we propose a simple readout scheme for which the speedup can, in principle, be increased without bound as the fidelity is increased. Our results should lead to immediate improvements in nanoscale magnetometry based on spin-to-charge conversion of the NV-center spin, and provide a theoretical framework for further optimization of the bandwidth of quantum measurements.

  5. DEVELOPMENT OF EMITTANCE ANALYSIS SOFTWARE FOR ION BEAM CHARACTERIZATION

    SciTech Connect

    Padilla, M. J.; Liu, Y.

    2007-01-01

    Transverse beam emittance is a crucial property of charged particle beams that describes their angular and spatial spread. It is a fi gure of merit frequently used to determine the quality of ion beams, the compatibility of an ion beam with a given beam transport system, and the ability to suppress neighboring isotopes at on-line mass separator facilities. Generally a high quality beam is characterized by a small emittance. In order to determine and improve the quality of ion beams used at the Holifi eld Radioactive Ion beam Facility (HRIBF) for nuclear physics and nuclear astrophysics research, the emittances of the ion beams are measured at the off-line Ion Source Test Facilities. In this project, emittance analysis software was developed to perform various data processing tasks for noise reduction, to evaluate root-mean-square emittance, Twiss parameters, and area emittance of different beam fractions. The software also provides 2D and 3D graphical views of the emittance data, beam profi les, emittance contours, and RMS. Noise exclusion is essential for accurate determination of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion (SCUBEEx) method is employed. Numerical data analysis techniques such as interpolation and nonlinear fi tting are also incorporated into the software. The software will provide a simplifi ed, fast tool for comprehensive emittance analysis. The main functions of the software package have been completed. In preliminary tests with experimental emittance data, the analysis results using the software were shown to be accurate.

  6. EMITTANCE GROWTH IN THE FEL RF-GUN

    SciTech Connect

    Novokhatski, Alexander

    2002-08-20

    A high brightness and low emittance is of crucial importance for the SASE-FEL at the TESLA Test Facility. Therefore a Photo-RF-Gun has been installed as particle source. Numerical simulations with codes like ASTRA [1] and MAFIA [2] show that the space charge dominated processes inside the RF-Gun contribute significantly to the emittance. In this paper we present the results of detailed studies with MAFIA TS2 which clarify the effects resulting in emittance growth for space charge dominated beams. It is shown that the resulting emittance can be minimized by changing the laser parameters like pulse length and spot size on the cathode. Additionally we present the concept of slice emittances which allows a more precise prediction of the real transverse emittance achievable with an emittance compensation scheme.

  7. Edge enhancement control in linear arrays of ungated field emitters

    NASA Astrophysics Data System (ADS)

    Harris, J. R.; Jensen, K. L.; Shiffler, D. A.

    2016-01-01

    In arrays of ungated field emitters, the field enhancement factor of each emitter decreases as the distance between the emitters decreases, an effect known as screening. At the edge of these arrays, emitters experience reduced screening, leading to higher field enhancement factors than emitters at the array center, causing nonuniform emission across the array. Here, we consider this effect in linear arrays of ungated field emitters spaced at distances comparable to their heights, which is the regime that generally maximizes their average current density. A Line Charge Model is used to assess the degree to which these edge effects propagate into the array interior, and to study the impact of varying the height, location, and tip radius of emitters at the ends of an array on the edge enhancement. It is shown that each of these techniques can accomplish this edge enhancement control, but each has advantages and disadvantages that will be discussed.

  8. Nonlinear excitation of single quantum emitters in hexagonal boron nitride (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Schell, Andreas W.; Tran, Trong Toan; Aharonovich, Igor; Takashima, Hideaki; Takeuchi, Shigeki

    2017-02-01

    Recently, two-dimensional materials have gained much interest for various applications in nanophotonics and quantum optics, as they possess a strong luminescence and are able to host single quantum emitters. Excitation of quantum emitters via a two-photon process can be employed for high resolution imaging and has applications in quantum optics. Here, we present one- and two-photon excitation of single defects in hexagonal boron nitride (hBN) and analyse the properties of the emitted light [1]. We find clear antibunching signals that prove the single emitter character in both excitation cases. To gain further knowledge, we also obtain saturation curves. From a comparison of one- and two-photon case insights about the level structure of the defects can be obtained. These results will not only help the fundamental understanding of defects in hBN, but also help to introduce this class of emitters in optical imaging, as the defects in hBN are of small spatial extend, photostable and emit their fluorescence well in the wavelength region of the biological optical window. [1] A. W. Schell et al. arXiv:1606.09364 (2016)

  9. Side readout of long scintillation crystal elements with digital SiPM for TOF-DOI PET

    PubMed Central

    Yeom, Jung Yeol; Vinke, Ruud; Levin, Craig S.

    2014-01-01

    Purpose: Side readout of scintillation light from crystal elements in positron emission tomography (PET) is an alternative to conventional end-readout configurations, with the benefit of being able to provide accurate depth-of-interaction (DOI) information and good energy resolution while achieving excellent timing resolution required for time-of-flight PET. This paper explores different readout geometries of scintillation crystal elements with the goal of achieving a detector that simultaneously achieves excellent timing resolution, energy resolution, spatial resolution, and photon sensitivity. Methods: The performance of discrete LYSO scintillation elements of different lengths read out from the end/side with digital silicon photomultipliers (dSiPMs) has been assessed. Results: Compared to 3 × 3 × 20 mm3 LYSO crystals read out from their ends with a coincidence resolving time (CRT) of 162 ± 6 ps FWHM and saturated energy spectra, a side-readout configuration achieved an excellent CRT of 144 ± 2 ps FWHM after correcting for timing skews within the dSiPM and an energy resolution of 11.8% ± 0.2% without requiring energy saturation correction. Using a maximum likelihood estimation method on individual dSiPM pixel response that corresponds to different 511 keV photon interaction positions, the DOI resolution of this 3 × 3 × 20 mm3 crystal side-readout configuration was computed to be 0.8 mm FWHM with negligible artifacts at the crystal ends. On the other hand, with smaller 3 × 3 × 5 mm3 LYSO crystals that can also be tiled/stacked to provide DOI information, a timing resolution of 134 ± 6 ps was attained but produced highly saturated energy spectra. Conclusions: The energy, timing, and DOI resolution information extracted from the side of long scintillation crystal elements coupled to dSiPM have been acquired for the first time. The authors conclude in this proof of concept study that such detector configuration has the potential to enable outstanding

  10. Side readout of long scintillation crystal elements with digital SiPM for TOF-DOI PET.

    PubMed

    Yeom, Jung Yeol; Vinke, Ruud; Levin, Craig S

    2014-12-01

    Side readout of scintillation light from crystal elements in positron emission tomography (PET) is an alternative to conventional end-readout configurations, with the benefit of being able to provide accurate depth-of-interaction (DOI) information and good energy resolution while achieving excellent timing resolution required for time-of-flight PET. This paper explores different readout geometries of scintillation crystal elements with the goal of achieving a detector that simultaneously achieves excellent timing resolution, energy resolution, spatial resolution, and photon sensitivity. The performance of discrete LYSO scintillation elements of different lengths read out from the end/side with digital silicon photomultipliers (dSiPMs) has been assessed. Compared to 3 × 3 × 20 mm(3) LYSO crystals read out from their ends with a coincidence resolving time (CRT) of 162 ± 6 ps FWHM and saturated energy spectra, a side-readout configuration achieved an excellent CRT of 144 ± 2 ps FWHM after correcting for timing skews within the dSiPM and an energy resolution of 11.8% ± 0.2% without requiring energy saturation correction. Using a maximum likelihood estimation method on individual dSiPM pixel response that corresponds to different 511 keV photon interaction positions, the DOI resolution of this 3 × 3 × 20 mm(3) crystal side-readout configuration was computed to be 0.8 mm FWHM with negligible artifacts at the crystal ends. On the other hand, with smaller 3 × 3 × 5 mm(3) LYSO crystals that can also be tiled/stacked to provide DOI information, a timing resolution of 134 ± 6 ps was attained but produced highly saturated energy spectra. The energy, timing, and DOI resolution information extracted from the side of long scintillation crystal elements coupled to dSiPM have been acquired for the first time. The authors conclude in this proof of concept study that such detector configuration has the potential to enable outstanding detector performance in terms of timing

  11. Integrated compact optical vortex beam emitters.

    PubMed

    Cai, Xinlun; Wang, Jianwei; Strain, Michael J; Johnson-Morris, Benjamin; Zhu, Jiangbo; Sorel, Marc; O'Brien, Jeremy L; Thompson, Mark G; Yu, Siyuan

    2012-10-19

    Emerging applications based on optical beams carrying orbital angular momentum (OAM) will probably require photonic integrated devices and circuits for miniaturization, improved performance, and enhanced functionality. We demonstrate silicon-integrated optical vortex emitters, using angular gratings to extract light confined in whispering gallery modes with high OAM into free-space beams with well-controlled amounts of OAM. The smallest device has a radius of 3.9 micrometers. Experimental characterization confirms the theoretical prediction that the emitted beams carry exactly defined and adjustable OAM. Fabrication of integrated arrays and demonstration of simultaneous emission of multiple identical optical vortices provide the potential for large-scale integration of optical vortex emitters on complementary metal-oxide-semiconductor compatible silicon chips for wide-ranging applications.

  12. Ghost signals in Allison emittance scanners

    SciTech Connect

    Stockli, Martin P.; Leitner, M.; Moehs, D.P.; Keller, R.; Welton, R.F.; /SNS Project, Oak Ridge /Tennessee U.

    2004-12-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%.

  13. Photonic Crystal Emitters for Thermophotovoltaic Energy Conversion

    NASA Astrophysics Data System (ADS)

    Stelmakh, Veronika; Chan, Walker R.; Ghebrebrhan, Michael; Soljacic, Marin; Joannopoulos, John D.; Celanovic, Ivan

    2015-12-01

    This paper reports the design, fabrication, and characterization of 2D photonic crystal (PhC) thermal emitters for a millimeter-scale hydrocarbon TPV microgenerator as a possible replacement for batteries in portable microelectronics, robotics, etc. In our TPV system, combustion heats a PhC emitter to incandescence and the resulting radiation is converted by a low-bandgap TPV cell. The PhC tailors the photonic density of states to produce spectrally confined thermal emission that matches the bandgap of the TPV cell, enabling high heat-to-electricity conversion efficiency. The work builds on a previously developed fabrication process to produce a square array of cylindrical cavities in a metal substrate. We will present ongoing incremental improvements in the optical and thermo-mechanical properties, the fabrication process, and the system integration, as recently combined with fabrication using novel materials, such as sputtered coatings, to enable a monolithic system.

  14. Computing Eigen-Emittances from Tracking Data

    SciTech Connect

    Alexahin, Y.

    2014-09-18

    In a strongly nonlinear system the particle distribution in the phase space may develop long tails which contribution to the covariance (sigma) matrix should be suppressed for a correct estimate of the beam emittance. A method is offered based on Gaussian approximation of the original particle distribution in the phase space (Klimontovich distribution) which leads to an equation for the sigma matrix which provides efficient suppression of the tails and cannot be obtained by introducing weights. This equation is easily solved by iterations in the multi-dimensional case. It is also shown how the eigen-emittances and coupled optics functions can be retrieved from the sigma matrix in a strongly coupled system. Finally, the developed algorithm is applied to 6D ionization cooling of muons in HFOFO channel.

  15. FIrpic: archetypal blue phosphorescent emitter for electroluminescence.

    PubMed

    Baranoff, Etienne; Curchod, Basile F E

    2015-05-14

    FIrpic is the most investigated bis-cyclometallated iridium complex in particular in the context of organic light emitting diodes (OLEDs) because of its attractive sky-blue emission, high emission efficiency, and suitable energy levels. In this Perspective we review the synthesis, structural characterisations, and key properties of this emitter. We also survey the theoretical studies and summarise a series of selected monochromatic electroluminescent devices using FIrpic as the emitting dopant. Finally we highlight important shortcomings of FIrpic as an emitter for OLEDs. Despite the large body of work dedicated to this material, it is manifest that the understanding of photophysical and electrochemical processes are only broadly understood mainly because of the different environment in which these properties are measured, i.e., isolated molecules in solvent vs. device.

  16. Front contact solar cell with formed emitter

    DOEpatents

    Cousins, Peter John

    2014-11-04

    A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

  17. Front contact solar cell with formed emitter

    DOEpatents

    Cousins, Peter John [Menlo Park, CA

    2012-07-17

    A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

  18. Is there life after thermal emitters?

    NASA Astrophysics Data System (ADS)

    Malyutenko, V.

    2007-04-01

    In this report, we examine whether photonic IR emitters are able to compete with advanced thermal microemitter technology in testing and stimulating IR sensors, including forward-looking IR missile warning systems, IR search-and-track devices, and missile seekers. We consider fundamentals, technology, and parameters of photonic devices as well as their pros and cons in respect to thermal emitters. In particular, we show that photonic devices can from platform for next generation of multi-spectral and hyper-spectral dynamic scene simulation devices operating inside MWIR and LWIR bands with high spectral output density and able to simulate dynamically cold scenes (without cryogenic cooling) and low observable with very high frame rate.

  19. Reverse Emittance Exchange for Muon Colliders

    SciTech Connect

    V. Ivanov, A. Afanasev, C.M. Ankenbrandt, R.P. Johnson, G.M. Wang, S.A. Bogacz, Y.S. Derbenev

    2009-05-01

    Muon collider luminosity depends on the number of muons in the storage ring and on the transverse size of the beams in collision. Ionization cooling as it is currently envisioned will not cool the beam sizes sufficiently well to provide adequate luminosity without large muon intensities. Six-dimensional cooling schemes will reduce the longitudinal emittance of a muon beam so that smaller high frequency RF cavities can be used for later stages of cooling and for acceleration. However, the bunch length at collision energy is then shorter than needed to match the interaction region beta function. New ideas to shrink transverse beam dimensions by lengthening each bunch will help achieve high luminosity in muon colliders. Analytic expressions for the reverse emittance exchange mechanism were derived, including a new resonant method of beam focusing.

  20. RF Emitter Tracking and Intent Assessment

    DTIC Science & Technology

    2013-03-21

    the US Navy. The paper communicated that the Navy requires accurate detecting , locating and tracking of mobile RF emitters. The system design used...x3 are voltage readings taken from different locations in the substation . PA and PB represent the probabilities of a real fault and fake fault...Borghetti, “A Review of Anomaly Detection in Automated Surveillance,” IEEE Transactions on Systems , Man, and Cybernetics, Part C: Applications and Reviews

  1. Controlled emittance blow up in the Tevatron

    SciTech Connect

    Tan, C.Y.; Steimel, J.; /Fermilab

    2009-04-01

    We have designed and commissioned a system which blows up the transverse emittance of the anti-proton beam without affecting the proton beam. It consists of a bandwidth limited noise source centered around the betatron tune, a power amplifier and a directional stripline kicker. The amount of blow up is controlled by the amount of energy delivered to the anti-protons betatron bands.

  2. Complementary methods of transverse emittance measurement

    SciTech Connect

    Zagel, James; Hu, Martin; Jansson, Andreas; Thurman-Keup, Randy; Yan, Ming-Jen; /Fermilab

    2008-05-01

    Several complementary transverse emittance monitors have been developed and used at the Fermilab accelerator complex. These include Ionization profile Monitors (IPM), Flying Wires, Schottky detectors and a Synchrotron Light Monitor (Synchlite). Mechanical scrapers have also been used for calibration purposes. This paper describes the various measurement devices by examining their basic features, calibration requirements, systematic uncertainties, and applications to collider operation. A comparison of results from different kinds of measurements is also presented.

  3. Emittance of a Field Emission Electron Source

    DTIC Science & Technology

    2010-01-05

    mode within the wiggler in order for the laser threshold to be reached. The mode is characterized by a waist radius w and a divergence , the product...the field line red or curved compared to a massive particle trajectory blue or straight. The field lines originate on the surface at s ,zs and...emitter surface s ,zs and along the evalu- ation plane h ,zh. The equivalent sphere characterized by a , is also shown. The red curved line

  4. Read-out electronics for DC squid magnetic measurements

    DOEpatents

    Ganther, Jr., Kenneth R.; Snapp, Lowell D.

    2002-01-01

    Read-out electronics for DC SQUID sensor systems, the read-out electronics incorporating low Johnson noise radio-frequency flux-locked loop circuitry and digital signal processing algorithms in order to improve upon the prior art by a factor of at least ten, thereby alleviating problems caused by magnetic interference when operating DC SQUID sensor systems in magnetically unshielded environments.

  5. Some studies of avalanche photodiode readout of fast scintillators

    SciTech Connect

    Holl, I.; Lorenz, E.; Natkaniez, S.; Renker, D.; Schmelz, C. |; Schwartz, B.

    1995-08-01

    Photomultipliers (PMs) are the classical readout element for scintillation detectors in high energy particle physics, nuclear physics, medical physics, industrial radiation monitors etc. Here, large area avalanche photodiodes with high performance, narrow operation tolerances and high reliability have recently become available. The authors report on some tests of their performance in the readout of fast scintillators.

  6. Heterodyne readout for read-write holographic memories

    NASA Technical Reports Server (NTRS)

    Mezrich, R. S.; Stewart, W. C.

    1973-01-01

    A heterodyne readout technique for read-write holographic memory systems that reconstruct a virtual image wavefront is described and demonstrated. The conventionally recorded hologram is illuminated simultaneously with a suitable combination of temporally modulated reference and modified object waves for readout. Best performance is obtained for temporal phase modulation. The coupling of the illuminating wavefronts by the hologram is analyzed.

  7. a Photon-Counting Imaging Detector Using Mcps with Delay Line Readout

    NASA Astrophysics Data System (ADS)

    Williams, Mark Bennett

    1990-01-01

    This dissertation describes work done toward the development of a large area (124 mm diameter) photon counting x-ray detector for protein crystallography. The detector is to be composed of a thin scintillator coupled to an imaging phototube containing a photocathode, microchannel plates (MCPs), and an electronic readout. A delay line anode has been developed consisting of an orthogonal pair of flat, bifilar helices upon which the MCP charge is collected. Results are presented on the performance of a 140 mm times 140 mm delay line anode in reading out MCPs directly excited by UV light. The readout spatial resolution is evaluated and compared with the theoretical resolution due to electronic noise. Integral positional nonlinearity, and x-y correlations are measured and described. An investigation is made into the ultimate resolution achievable with the readout. Two prototype phototubes with a 40 mm diameter active areas have been constructed. The tubes include a bialkali photocathode, a chevron pair of MCPs and a 134 mm times 134 mm delay line anode. Problems associated with a high internal pressure in the first tube are documented and their effects on imaging performance and tube component degradation are described. For the second phototube, measurements are made of photocathode spectral response and spatial uniformity. Photoelectron transmission through the MCP oxide film is investigated and the film thickness is determined. The MCP pulse height distribution is characterized as a function of position across the detector surface. Preliminary results are presented on the detector counting efficiency for 6 keV x-rays. The origins, magnitudes, and character of the phototube dark count are described. Contributions to the measured phototube spatial resolution are enumerated and quantified. The geometric linearity is evaluated over the phototube active area.

  8. A novel readout system for wireless passive pressure sensors

    NASA Astrophysics Data System (ADS)

    Zhang, Huixin; Hong, Yingping; Ge, Binger; Liang, Ting; Xiong, Jijun

    2014-03-01

    This paper presents a novel readout system for wireless passive pressure sensors based on the inductively coupled inductor and cavity (LC) resonant circuits. The proposed system consists of a reader antenna inductively coupled to the sensor circuit, a readout circuit, and a personal computer (PC) post processing unit. The readout circuit generates a voltage signal representing the sensor's capacitance. The frequency of the reader antenna driving signal is a constant, which is equal to the sensor's resonant frequency at zero pressure. Based on mechanical and electrical modeling, the pressure sensor design based on the high temperature co-fired ceramic (HTCC) technology is conducted and discussed. The functionality and accuracy of the readout system are tested with a voltage-capacitance measurement system and demonstrated in a realistic pressure measurement environment, so that the overall performance and the feasibility of the readout system are proved.

  9. Fast Multiplexed Readout of Xmon Qubits Part I: Design

    NASA Astrophysics Data System (ADS)

    Sank, Daniel; Jeffrey, E.; Mutus, J. Y.; White, T. C.; Barends, R.; Kelly, J.; Chen, Y.; Roushan, P.; Campbell, B.; Chen, Z.; Chiaro, B.; Dunsworth, A.; Megrant, A.; Neill, C.; O'Malley, P.; Quintana, C.; Vainsencher, A.; Wenner, J.; Cleland, A. N.; Martinis, J. M.

    2014-03-01

    Realization of a surface code quantum computer requires fast scalable qubit readout. Previous systems have shown accurate readout in continuous wave mode. This neglects the transient response time which is crucial for the operation of the surface code and for measurement accuracy in the presence of finite qubit T1. We have designed a readout system, based on an integrated band pass filter, which achieves very fast transient response while maintaining long qubit T1. Our design uses separate readout resonators for each qubit. This allows individual qubit readout with frequency multiplexing while preventing correlated measurement errors. By connecting each resonator to a single filter the device requires zero additional on chip area and no extra control lines. We present design considerations, theory of operation, and physical layout of the device. With high fidelity gates this system forms the final element needed for a surface code cell.

  10. Emissivity Tuned Emitter for RTPV Power Sources

    SciTech Connect

    Carl M. Stoots; Robert C. O'Brien; Troy M. Howe

    2012-03-01

    Every mission launched by NASA to the outer planets has produced unexpected results. The Voyager I and II, Galileo, and Cassini missions produced images and collected scientific data that totally revolutionized our understanding of the solar system and the formation of the planetary systems. These missions were enabled by the use of nuclear power. Because of the distances from the Sun, electrical power was produced using the radioactive decay of a plutonium isotope. Radioisotopic Thermoelectric Generators (RTGs) used in the past and currently used Multi-Mission RTGs (MMRTGs) provide power for space missions. Unfortunately, RTGs rely on thermocouples to convert heat to electricity and are inherently inefficient ({approx} 3-7% thermal to electric efficiency). A Radioisotope Thermal Photovoltaic (RTPV) power source has the potential to reduce the specific mass of the onboard power supply by increasing the efficiency of thermal to electric conversion. In an RTPV, a radioisotope heats an emitter, which emits light to a photovoltaic (PV) cell, which converts the light into electricity. Developing an emitter tuned to the desired wavelength of the photovoltaic is a key part in increasing overall performance. Researchers at the NASA Glenn Research Center (GRC) have built a Thermal Photovoltaic (TPV) system, that utilizes a simulated General Purpose Heat Source (GPHS) from a MMRTG to heat a tantalum emitter. The GPHS is a block of graphite roughly 10 cm by 10 cm by 5 cm. A fully loaded GPHS produces 250 w of thermal power and weighs 1.6 kgs. The GRC system relies on the GPHS unit radiating at 1200 K to a tantalum emitter that, in turn, radiates light to a GaInAs photo-voltaic cell. The GRC claims system efficiency of conversion of 15%. The specific mass is around 167 kg/kWe. A RTPV power source that utilized a ceramic or ceramic-metal (cermet) matrix would allow for the combination of the heat source, canister, and emitter into one compact unit, and allow variation in size

  11. Architecture of PAU survey camera readout electronics

    NASA Astrophysics Data System (ADS)

    Castilla, Javier; Cardiel-Sas, Laia; De Vicente, Juan; Illa, Joseph; Jimenez, Jorge; Maiorino, Marino; Martinez, Gustavo

    2012-07-01

    PAUCam is a new camera for studying the physics of the accelerating universe. The camera will consist of eighteen 2Kx4K HPK CCDs: sixteen for science and two for guiding. The camera will be installed at the prime focus of the WHT (William Herschel Telescope). In this contribution, the architecture of the readout electronics system is presented. Back- End and Front-End electronics are described. Back-End consists of clock, bias and video processing boards, mounted on Monsoon crates. The Front-End is based on patch panel boards. These boards are plugged outside the camera feed-through panel for signal distribution. Inside the camera, individual preamplifier boards plus kapton cable completes the path to connect to each CCD. The overall signal distribution and grounding scheme is shown in this paper.

  12. Fast readout of carbon nanotube mechanical resonators

    NASA Astrophysics Data System (ADS)

    Meerwaldt, Harold; Singh, Vibhor; Schneider, Ben; Schouten, Raymond; van der Zant, Herre; Steele, Gary

    2013-03-01

    We perform fast readout measurements of carbon nanotube mechanical resonators. Using an electronic mixing scheme, we can detect the amplitude of the mechanical motion with an intermediate frequency (IF) of 46 MHz and a timeconstant of 1 us, up to 5 orders of magnitude faster than before. Previous measurements suffered from a low bandwidth due to the combination of the high resistance of the carbon nanotube and a large stray capacitance. We have increased the bandwidth significantly by using a high-impedance, close-proximity HEMT amplifier. The increased bandwidth should allow us to observe the nanotube's thermal motion and its transient response, approaching the regime of real-time detection of the carbon nanotube's mechanical motion.

  13. Recombination processes in passivated boron-implanted black silicon emitters

    NASA Astrophysics Data System (ADS)

    von Gastrow, Guillaume; Ortega, Pablo; Alcubilla, Ramon; Husein, Sebastian; Nietzold, Tara; Bertoni, Mariana; Savin, Hele

    2017-05-01

    In this paper, we study the recombination mechanisms in ion-implanted black silicon (bSi) emitters and discuss their advantages over diffused emitters. In the case of diffusion, the large bSi surface area increases emitter doping and consequently Auger recombination compared to a planar surface. The total doping dose is on the contrary independent of the surface area in implanted emitters, and as a result, we show that ion implantation allows control of emitter doping without compromise in the surface aspect ratio. The possibility to control surface doping via implantation anneal becomes highly advantageous in bSi emitters, where surface passivation becomes critical due to the increased surface area. We extract fundamental surface recombination velocities Sn through numerical simulations and obtain the lowest values at the highest anneal temperatures. With these conditions, an excellent emitter saturation current (J0e) is obtained in implanted bSi emitters, reaching 20 fA/cm2 ± 5 fA/cm2 at a sheet resistance of 170 Ω/sq. Finally, we identify the different regimes of recombination in planar and bSi emitters as a function of implantation anneal temperature. Based on experimental data and numerical simulations, we show that surface recombination can be reduced to a negligible contribution in implanted bSi emitters, which explains the low J0e obtained.

  14. Electrostatic readout of DNA microarrays with charged microspheres

    PubMed Central

    Clack, Nathan G; Salaita, Khalid; Groves, Jay T

    2014-01-01

    DNA microarrays are used for gene-expression profiling, single-nucleotide polymorphism detection and disease diagnosis1–3. A persistent challenge in this area is the lack of microarray screening technology suitable for integration into routine clinical care4,5. Here, we describe a method for sensitive and label-free electrostatic readout of DNA or RNA hybridization on microarrays. The electrostatic properties of the microarray are measured from the position and motion of charged microspheres randomly dispersed over the surface. We demonstrate nondestructive electrostatic imaging with 10-μm lateral resolution over centimeter-length scales, which is four-orders of magnitude larger than that achievable with conventional scanning electrostatic force microscopy. Changes in surface charge density as a result of specific hybridization can be detected and quantified with 50-pM sensitivity, single base-pair mismatch selectivity and in the presence of complex background. Because the naked eye is sufficient to read out hybridization, this approach may facilitate broad application of multiplexed assays. PMID:18587384

  15. ASIC Readout Circuit Architecture for Large Geiger Photodiode Arrays

    NASA Technical Reports Server (NTRS)

    Vasile, Stefan; Lipson, Jerold

    2012-01-01

    The objective of this work was to develop a new class of readout integrated circuit (ROIC) arrays to be operated with Geiger avalanche photodiode (GPD) arrays, by integrating multiple functions at the pixel level (smart-pixel or active pixel technology) in 250-nm CMOS (complementary metal oxide semiconductor) processes. In order to pack a maximum of functions within a minimum pixel size, the ROIC array is a full, custom application-specific integrated circuit (ASIC) design using a mixed-signal CMOS process with compact primitive layout cells. The ROIC array was processed to allow assembly in bump-bonding technology with photon-counting infrared detector arrays into 3-D imaging cameras (LADAR). The ROIC architecture was designed to work with either common- anode Si GPD arrays or common-cathode InGaAs GPD arrays. The current ROIC pixel design is hardwired prior to processing one of the two GPD array configurations, and it has the provision to allow soft reconfiguration to either array (to be implemented into the next ROIC array generation). The ROIC pixel architecture implements the Geiger avalanche quenching, bias, reset, and time to digital conversion (TDC) functions in full-digital design, and uses time domain over-sampling (vernier) to allow high temporal resolution at low clock rates, increased data yield, and improved utilization of the laser beam.

  16. Electrostatic readout of DNA microarrays with charged microspheres

    SciTech Connect

    Clack, Nathan G.; Salaita, Khalid; Groves, Jay T.

    2008-06-29

    DNA microarrays are used for gene-expression profiling, single-nucleotide polymorphism detection and disease diagnosis. A persistent challenge in this area is the lack of microarray screening technology suitable for integration into routine clinical care. In this paper, we describe a method for sensitive and label-free electrostatic readout of DNA or RNA hybridization on microarrays. The electrostatic properties of the microarray are measured from the position and motion of charged microspheres randomly dispersed over the surface. We demonstrate nondestructive electrostatic imaging with 10-μm lateral resolution over centimeter-length scales, which is four-orders of magnitude larger than that achievable with conventional scanning electrostatic force microscopy. Changes in surface charge density as a result of specific hybridization can be detected and quantified with 50-pM sensitivity, single base-pair mismatch selectivity and in the presence of complex background. Lastly, because the naked eye is sufficient to read out hybridization, this approach may facilitate broad application of multiplexed assays.

  17. Longitudinally segmented shashlik calorimeters with SiPM readout

    NASA Astrophysics Data System (ADS)

    Berra, A.; Cecchini, S.; Cindolo, F.; Ferdinando, D. Di; Jollet, C.; Longhin, A.; Ludovici, L.; Mandrioli, G.; Mauri, N.; Meregaglia, A.; Paoloni, A.; Pasqualini, L.; Patrizii, L.; Pozzato, M.; Pupilli, F.; Prest, M.; Sirri, G.; Terranova, F.; Vallazza, E.; Votano, L.

    2017-02-01

    The goal of the INFN SCENTT R&D project is to develop the calorimeter technologies for the instrumentation of decay tunnels in conventional neutrino beams. This instrumentation is required to achieve a substantial improvement in the uncertainty on neutrino fluxes for the next generation cross section experiments. In particular, we are designing a positron tagger based on purely calorimetric techniques that is able to measure the rate and the spectrum of the positrons produced in the K+ →e+π0νe decay. The νe flux is inferred from the positron rate in the decay tunnel. Considering the large dimensions of the tagger, the most cost effective technology is based on small modules of Fe/Scintillator shashlik calorimeters, with adequate segmentation and energy resolution to efficiently tag the positrons over the charged pion background. This contribution presents preliminary results obtained with two shashlik calorimeter prototypes readout with an array of Silicon PhotoMultipliers and tested at the CERN PS-T9 beamline.

  18. Laser switch for stroboscopic read-out of magnetic flux

    NASA Astrophysics Data System (ADS)

    Ferrara, Marco; Carelli, Pasquale; Chiarello, Fabio; Castellano, Maria Gabriella; Torrioli, Guido; Cosmelli, Carlo

    2004-06-01

    We have realized and tested a fast stroboscopic detector for magnetic flux measurements. The key element of our detector is a hysteretic dc superconducting quantum interference device (SQUID). Stroboscopic read-out of the magnetic flux coupled with the SQUID is accomplished by biasing the SQUID with fast current pulses. The shorter these pulses, the more stroboscopic and less invasive the measurement we are performing. In order to reduce the duration of the current pulses, we take advantage of the superconducting-normal transition induced by laser light in thin superconducting films. The interaction of laser light with superconducting thin films has been investigated thoroughly in the past and many applications have been proposed which rely on the fast typical times with which superconductivity is broken and a resistive behavior arises. We have measured a threshold resolution of 6.9mΦ0 at 4.2 K, and this value corresponds to the thermodynamic limit of the SQUID. The detector has been accurately characterized: An improved and more sensitive version might prove useful for quantum mechanics and quantum computation experiments, for example, in detecting the state of flux qubits.

  19. Fast, High-Precision Readout Circuit for Detector Arrays

    NASA Technical Reports Server (NTRS)

    Rider, David M.; Hancock, Bruce R.; Key, Richard W.; Cunningham, Thomas J.; Wrigley, Chris J.; Seshadri, Suresh; Sander, Stanley P.; Blavier, Jean-Francois L.

    2013-01-01

    The GEO-CAPE mission described in NASA's Earth Science and Applications Decadal Survey requires high spatial, temporal, and spectral resolution measurements to monitor and characterize the rapidly changing chemistry of the troposphere over North and South Americas. High-frame-rate focal plane arrays (FPAs) with many pixels are needed to enable such measurements. A high-throughput digital detector readout integrated circuit (ROIC) that meets the GEO-CAPE FPA needs has been developed, fabricated, and tested. The ROIC is based on an innovative charge integrating, fast, high-precision analog-to-digital circuit that is built into each pixel. The 128×128-pixel ROIC digitizes all 16,384 pixels simultaneously at frame rates up to 16 kHz to provide a completely digital output on a single integrated circuit at an unprecedented rate of 262 million pixels per second. The approach eliminates the need for off focal plane electronics, greatly reducing volume, mass, and power compared to conventional FPA implementations. A focal plane based on this ROIC will require less than 2 W of power on a 1×1-cm integrated circuit. The ROIC is fabricated of silicon using CMOS technology. It is designed to be indium bump bonded to a variety of detector materials including silicon PIN diodes, indium antimonide (InSb), indium gallium arsenide (In- GaAs), and mercury cadmium telluride (HgCdTe) detector arrays to provide coverage over a broad spectral range in the infrared, visible, and ultraviolet spectral ranges.

  20. Wavelength locking of single emitters and multi-emitter modules: simulation and experiments

    NASA Astrophysics Data System (ADS)

    Yanson, Dan; Rappaport, Noam; Peleg, Ophir; Berk, Yuri; Dahan, Nir; Klumel, Genady; Baskin, Ilya; Levy, Moshe

    2016-03-01

    Wavelength-stabilized high-brightness single emitters are commonly used in fiber-coupled laser diode modules for pumping Yb-doped lasers at 976 nm, and Nd-doped ones at 808 nm. We investigate the spectral behavior of single emitters under wavelength-selective feedback from a volume Bragg (or hologram) grating (VBG) in a multi-emitter module. By integrating a full VBG model as a multi-layer thin film structure with commercial raytracing software, we simulated wavelength locking conditions as a function of beam divergence and angular alignment tolerances. Good correlation between the simulated VBG feedback strength and experimentally measured locking ranges, in both VBG misalignment angle and laser temperature, is demonstrated. The challenges of assembling multi-emitter modules based on beam-stacked optical architectures are specifically addressed, where the wavelength locking conditions must be achieved simultaneously with high fiber coupling efficiency for each emitter in the module. It is shown that angular misorientation between fast and slow-axis collimating optics can have a dramatic effect on the spectral and power performance of the module. We report the development of our NEON-S wavelength-stabilized fiber laser pump module, which uses a VBG to provide wavelength-selective optical feedback in the collimated portion of the beam. Powered by our purpose-developed high-brightness single emitters, the module delivers 47 W output at 11 A from an 0.15 NA fiber and a 0.3 nm linewidth at 976 nm. Preliminary wavelength-locking results at 808 nm are also presented.

  1. An induced charge readout scheme incorporating image charge splitting on discrete pixels

    NASA Astrophysics Data System (ADS)

    Kataria, D. O.; Lapington, J. S.

    2003-11-01

    Top hat electrostatic analysers used in space plasma instruments typically use microchannel plates (MCPs) followed by discrete pixel anode readout for the angular definition of the incoming particles. Better angular definition requires more pixels/readout electronics channels but with stringent mass and power budgets common in space applications, the number of channels is restricted. We describe here a technique that improves the angular definition using induced charge and an interleaved anode pattern. The technique adopts the readout philosophy used on the CRRES and CLUSTER I instruments but has the advantages of the induced charge scheme and significantly reduced capacitance. Charge from the MCP collected by an anode pixel is inductively split onto discrete pixels whose geometry can be tailored to suit the scientific requirements of the instrument. For our application, the charge is induced over two pixels. One of them is used for a coarse angular definition but is read out by a single channel of electronics, allowing a higher rate handling. The other provides a finer angular definition but is interleaved and hence carries the expense of lower rate handling. Using the technique and adding four channels of electronics, a four-fold increase in the angular resolution is obtained. Details of the scheme and performance results are presented.

  2. Validation of a highly integrated SiPM readout system with a TOF-PET demonstrator

    NASA Astrophysics Data System (ADS)

    Niknejad, T.; Setayeshi, S.; Tavernier, S.; Bugalho, R.; Ferramacho, L.; Di Francesco, A.; Leong, C.; Rolo, M. D.; Shamshirsaz, M.; Silva, J. C.; Silva, R.; Silveira, M.; Zorraquino, C.; Varela, J.

    2016-12-01

    We have developed a highly integrated, fast and compact readout electronics for Silicon Photomultiplier (SiPM) based Time of Flight Positron Emission Tomography (TOF-PET) scanners. The readout is based on the use of TOP-PET Application Specific Integrated Circuit (PETsys TOFPET1 ASIC) with 64 channels, each with its amplifier, discriminator, Time to Digital Converter (TDC) and amplitude determination using Time Over Threshold (TOT). The ASIC has 25 ps r.m.s. intrinsic time resolution and fully digital output. The system is optimised for high rates, good timing, low power consumption and low cost. For validating the readout electronics, we have built a technical PET scanner, hereafter called ``demonstrator'', with 2'048 SiPM channels. The PET demonstrator has 16 compact Detector Modules (DM). Each DM has two ASICs reading 128 SiPM pixels in one-to-one coupling to 128 Lutetium Yttrium Orthosilicate (LYSO) crystals measuring 3.1 × 3.1 × 15 mm3 each. The data acquisition system for the demonstrator has two Front End Boards type D (FEB/D), each collecting the data of 1'024 channels (8 DMs), and transmitting assembled data frames through a serial link (4.8 Gbps), to a single Data Acquisition (DAQ) board plugged into the Peripheral Component Interconnect Express (PCIe) bus of the data acquisition PC. Results obtained with this PET demonstrator are presented.

  3. 3D reconstruction of nuclear reactions using GEM TPC with planar readout

    NASA Astrophysics Data System (ADS)

    Bihałowicz, Jan Stefan

    2015-02-01

    The research program of the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) laboratory under construction in Magurele, Romania facilities the need of developing a gaseous active-target detector providing 3D reconstruction of charged products of nuclear reactions induced by gamma beam. The monoenergetic, high-energy (Eγ > 19 MeV) gamma beam of intensity 1013γ/s allows studying nuclear reactions in astrophysics. A Time Projection Chamber with crossed strip readout (eTPC) is proposed as one of the imaging detectors. The special feature of the readout electrode structure is a 2D reconstruction based on the information read out simultaneously from three arrays of strips that form virtual pixels. It is expected to reach similar spatial resolution as for pixel readout at largely reduced cost of electronics. The paper presents the current progress and first results of the small scale prototype TPC which is a one of implementation steps towards eTPC detector proposed in the Technical Design Report of Charged Particles Detection at ELI-NP.

  4. 3D reconstruction of nuclear reactions using GEM TPC with planar readout

    SciTech Connect

    Bihałowicz, Jan Stefan

    2015-02-24

    The research program of the Extreme Light Infrastructure – Nuclear Physics (ELI-NP) laboratory under construction in Magurele, Romania facilities the need of developing a gaseous active-target detector providing 3D reconstruction of charged products of nuclear reactions induced by gamma beam. The monoenergetic, high-energy (E{sub γ} > 19 MeV) gamma beam of intensity 10{sup 13}γ/s allows studying nuclear reactions in astrophysics. A Time Projection Chamber with crossed strip readout (eTPC) is proposed as one of the imaging detectors. The special feature of the readout electrode structure is a 2D reconstruction based on the information read out simultaneously from three arrays of strips that form virtual pixels. It is expected to reach similar spatial resolution as for pixel readout at largely reduced cost of electronics. The paper presents the current progress and first results of the small scale prototype TPC which is a one of implementation steps towards eTPC detector proposed in the Technical Design Report of Charged Particles Detection at ELI-NP.

  5. A novel method of encoded multiplexing readout for micro-pattern gas detectors

    NASA Astrophysics Data System (ADS)

    Qi, Bin-Xiang; Liu, Shu-Bin; Ji, Heng; Shen, Zhong-Tao; Ma, Si-Yuan; Liu, Hong-Bang; Huang, Wen-Qian; An, Qi

    2016-05-01

    The requirement of a large number of electronic channels poses a big challenge to the further applications of Micro-pattern Gas Detectors (MPGDs). By using the redundancy that at least two neighboring strips record the signal of a particle, a novel method of encoded multiplexing readout for MPGDs is presented in this paper. The method offers a feasible and easily-extensible way of encoding and decoding, and can significantly reduce the number of readout channels. A verification test was carried out on a 5 cm × 5 cm Thick Gas Electron Multiplier (THGEM) detector using a 8 keV Cu X-ray source with 100 μm slit, where 166 strips were read out by 21 encoded readout channels. The test results show good linearity in its position response, and the spatial resolution root-mean-square (RMS) of the test system is about 260 μm. This method has potential to build large area detectors and can be easily adapted to other detectors similar to MPGDs. Supported by National Natural Science Foundation of China (11222552, 11265003)

  6. Delay modeling of bipolar ECL/EFL (Emitter-Coupled Logic/Emitter-Follower-Logic) circuits

    NASA Astrophysics Data System (ADS)

    Yang, Andrew T.

    1986-08-01

    This report deals with the development of a delay-time model for timing simulation of large circuits consisting of Bipolar ECL(Emitter-Coupled Logic) and EFL (Emitter-Follower-Logic) networks. This model can provide adequate information on the performance of the circuits with a minimum expenditure of computation time. This goal is achieved by the use of proper circuit transient models on which analytical delay expressions can be derived with accurate results. The delay-model developed in this report is general enough to handle complex digital circuits with multiple inputs or/and multiple levels. The important effects of input slew rate are also included in the model.

  7. Merlin: a fast versatile readout system for Medipix3

    NASA Astrophysics Data System (ADS)

    Plackett, R.; Horswell, I.; Gimenez, E. N.; Marchal, J.; Omar, D.; Tartoni, N.

    2013-01-01

    This contribution reports on the development of a new high rate readout system for the Medipix3 hybrid pixel ASIC developed by the Detector Group at Diamond Light Source. It details the current functionality of the system and initial results from tests on Diamond's B16 beamline. The Merlin system is based on a National Instruments PXI/FlexRIO system running a Xilinx Virtex5 FPGA. It is capable of recording Medipix3 256 by 256 by 12 bit data frames at over 1 kHz in bursts of 1200 frames and running at over 100 Hz continuously to disk or over a TCP/IP link. It is compatible with the standard Medipix3 single chipboards developed at CERN and is capable of driving them over cable lengths of up to 10 m depending on the data rate required. In addition to a standalone graphical interface, a system of remote TCP/IP control and data transfer has been developed to allow easy integration with third party control systems and scripting languages. Two Merlin systems are being deployed on the B16 and I16 beamlines at Diamond and the system has been integrated with the EPICS/GDA control systems used. Results from trigger synchronisation, fast burst and high rate tests made on B16 in March are reported and demonstrate an encouraging reliability and timing accuracy. In addition to normal high resolution imaging applications of Medipix3, the results indicate the system could profitably be used in `pump and probe' style experiments, where a very accurate, high frame rate is especially beneficial. In addition to these two systems, Merlin is being used by the Detector Group to test the Excalibur 16 chip hybrid modules, and by the LHCb VELO Pixel Upgrade group in their forthcoming testbeams. Additionally the contribution looks forward to further developments and improvements in the system, including full rate quad chip readout capability, multi-FPGA support, long distance optical communication and further functionality enhancements built on the capabilities of the Medipix3 chips.

  8. Rare Earth Doped Yttrium Aluminum Garnet (YAG) Selective Emitters

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Pal, AnnaMarie T.; Patton, Martin O.; Jenkins, Phillip P.

    1999-01-01

    As a result of their electron structure, rare earth ions in crystals at high temperature emit radiation in several narrow bands rather than in a continuous blackbody manner. This study presents a spectral emittance model for films and cylinders of rare earth doped yttrium aluminum garnets. Good agreement between experimental and theoretical film spectral emittances was found for erbium and holmium aluminum garnets. Spectral emittances of films are sensitive to temperature differences across the film. For operating conditions of interest, the film emitter experiences a linear temperature variation whereas the cylinder emitter has a more advantageous uniform temperature. Emitter efficiency is also a sensitive function of temperature. For holminum aluminum garnet film the efficiency is 0.35 at 1446K but only 0.27 at 1270 K.

  9. The Quantum Efficiency and Thermal Emittance of Metal Photocathodes

    SciTech Connect

    Dowell, David H.; Schmerge, John F.; /SLAC

    2009-03-04

    Modern electron beams have demonstrated the brilliance needed to drive free electron lasers at x-ray wavelengths, with the principle improvements occurring since the invention of the photocathode gun. The state-of-the-art normalized emittance electron beams are now becoming limited by the thermal emittance of the cathode. In both DC and RF photocathode guns, details of the cathode emission physics strongly influence the quantum efficiency and the thermal emittance. Therefore improving cathode performance is essential to increasing the brightness of beams. It is especially important to understand the fundamentals of cathode quantum efficiency and thermal emittance. This paper investigates the relationship between the quantum efficiency and the thermal emittance of metal cathodes using the Fermi-Dirac model for the electron distribution. We derive the thermal emittance and its relationship to the quantum efficiency, and compare our results to those of others.

  10. Emittance measurements of Space Shuttle orbiter reinforced carbon-carbon

    NASA Technical Reports Server (NTRS)

    Caram, Jose M.; Bouslog, Stanley A.; Cunnington, George R., Jr.

    1992-01-01

    The spectral and total normal emittance of the Reinforced Carbon-Carbon (RCC) used on Space Shuttle nose cap and wing leading edges has been measured at room temperature and at surface temperatures of 1200 to 2100 K. These measurements were made on virgin and two flown RCC samples. Room temperature directional emittance data were also obtained and were used to determine the total hemispherical emittance of RCC as a function of temperature. Results of the total normal emittance for the virgin samples showed good agreement with the current RCC emittance design curve; however, the data from the flown samples showed an increase in the emittance at high temperature possibly due to exposure from flight environments.

  11. Characterization of radiant emitters used in food processing.

    PubMed

    Lloyd, B J; Farkas, B E; Keener, K M

    2003-01-01

    Radiant emissions from short, medium, and long wavelength thermal radiant emitter systems typically used for food processing applications were quantified. Measurements included heat flux intensity, emitter surface temperature, and spectral wavelength distribution. Heat flux measurements were found highly dependent on the incident angle and the distance from the emitter facing. The maximum flux measured was 5.4 W/cm2. Emitter surface temperature measurements showed that short wavelength radiant systems had the highest surface temperature and greatest thermal efficiency. The emitter spectral distributions showed that radiant emitter systems had large amounts of far infrared energy emission greater than 3 microm when compared to theoretical blackbody curves. The longer wavelength energy would likely cause increased surface heating for most high moisture content food materials.

  12. Plasmonic superradiance of two emitters near a metal nanorod

    NASA Astrophysics Data System (ADS)

    Protsenko, I. E.; Uskov, A. V.; Chen, Xue-Wen; Xu, Hongxing

    2017-06-01

    Quantum emitters, such as quantum dots or dye molecules, pumped and situated close to plasmonic nanostructures resonantly excite surface plasmon-polaritons (SPPs). Excitation efficiency increases with the number of emitters because the SPP field synchronizes dipole oscillations of emitters, in analogy with superradiance (SR) in free space. Using a fully quantum mechanical model for two emitters coupled to a single metal nanorod, we predict that plasmonic SR increases the SPP generation yield of a single emitter by up to 15%. Such ‘plasmonic SR’ enhancement of SPP generation is stationary and takes place even at strong dissipation, dephasing and under incoherent pumping. Solid-state quantum emitters with blinking behaviors may be used to demonstrate plasmonic SR. Plasmonic SR may be useful for excitation of non-radiative SPP modes in plasmonic waveguides and lowering the threshold of plasmonic nanolasers.

  13. Plasmon-emitter interaction using integrated ring grating-nanoantenna structures.

    PubMed

    Rahbany, Nancy; Geng, Wei; Bachelot, Renaud; Couteau, Christophe

    2017-05-05

    Overcoming the diffraction limit to achieve high optical resolution is one of the main challenges in the fields of plasmonics, nanooptics and nanophotonics. In this work, we introduce novel plasmonic structures consisting of nanoantennas (nanoprisms, single bowtie nanoantennas and double bowtie nanoantennas) integrated in the center of ring diffraction gratings. Propagating surface plasmon polaritons (SPPs) are generated by the ring grating and coupled with localized surface plasmons (LSPs) at the nanoantennas exciting emitters placed in their gap. SPPs are widely used for optical waveguiding but provide low resolution due to their weak spatial confinement. In contrast, LSPs provide excellent sub-wavelength confinement but induce large losses. The phenomenon of SPP-LSP coupling witnessed in our structures allows for achieving more precise focusing at the nanoscale, causing an increase in the fluorescence emission of the emitters. Finite-difference time-domain simulations as well as experimental fabrication and optical characterization results are presented to study plasmon-emitter coupling between an ensemble of dye molecules and our integrated plasmonic structures. A comparison is given to highlight the importance of each structure on the photoluminescence and radiative decay enhancement of the molecules.

  14. Systematic Comparison of the MINOS Near and Far Detector Readout Systems

    SciTech Connect

    Cabrera, Anatael

    2005-06-22

    The MINOS experiment is a neutrino oscillation baseline experiment intending to use high resolution L/E neutrinos to measure the atmospheric neutrino oscillations parameters to unprecedented precision. Two detectors have been built to realize the measurements, a Near detector, located about 1km downstream from the beam target at the Fermi Laboratory, and a Far detector, located at 736km, at the Soudan Laboratory. The technique relies on the Near detector to measure the un-oscillated neutrino spectrum, while the Far detector measures the neutrino spectrum once oscillated. The comparison between the two measurements is expected to allow MINOS to measure Δm2 beyond 10% precision level. The Near and Far detectors have been built similarly to minimize possible systematic effects. Both detectors have been endowed with different readout systems, as the beam event rates are very different. The MINOS calibration detector (CalDet), installed at CERN, was instrumented with both readout systems such that they can simultaneously measure and characterize the energy deposition (response and event topology) of incident known particle from test-beams. This thesis presents the investigations to quantify the impact of the performance of both readout systems on the MINOS results using the measurements obtained with CalDet. The relative comparison of the responses of both readout systems have been measured to be consistent with being identical within a systematic uncertainty of 0.6%. The event topologies have been found to be negligibly affected. In addition, the performance of the detector simulations have been thoroughly investigated and validated to be in agreement with data within similar level of uncertainties.

  15. Active spacecraft potential control: An ion emitter experiment. [Cluster mission

    NASA Technical Reports Server (NTRS)

    Riedler, W.; Goldstein, R.; Hamelin, M.; Maehlum, B. N.; Troim, J.; Olsen, R. C.; Pedersen, A.; Grard, R. J. L.; Schmidt, R.; Rudenauer, F.

    1988-01-01

    The cluster spacecraft are instrumented with ion emitters for charge neutralization. The emitters produce indium ions at 6 keV. The ion current is adjusted in a feedback loop with instruments measuring the spacecraft potential. The system is based on the evaporation of indium in the apex field of a needle. The design of the active spacecraft potential control instruments, and the ion emitters is presented.

  16. Separation of temperature and emittance in remotely sensed radiance measurements

    NASA Technical Reports Server (NTRS)

    Kahle, Anne B.; Alley, Ronald E.

    1992-01-01

    The remote determination of surface temperature and surface spectral emittance by use of airborne or satellite-borne thermal infrared instruments is not straightforward. The radiance measured is a function of surface temperature, the unknown surface spectral emittance, and absorption and emission in the intervening atmosphere. With a single measurement, the solution for temperature and spectral emittance is undedetermined. This article reviews two of the early approximate methods which have been fairly widely used to approach this problem.

  17. Thermal emittance measurements of a cesium potassium antimonide photocathode

    NASA Astrophysics Data System (ADS)

    Bazarov, Ivan; Cultrera, Luca; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Li, Yulin; Liu, Xianghong; Maxson, Jared; Roussel, William

    2011-05-01

    Thermal emittance measurements of a CsK2Sb photocathode at several laser wavelengths are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. The thermal emittance is 0.56±0.03 mm mrad/mm(rms) at 532 nm wavelength. The results are compared with a simple photoemission model and found to be in a good agreement.

  18. Sub-nm emittance lattice design for CANDLE storage ring

    NASA Astrophysics Data System (ADS)

    Sargsyan, A.; Zanyan, G.; Sahakyan, V.; Tsakanov, V.

    2016-10-01

    The most effective way to increase the brilliance of synchrotron light sources is the reduction of beam emittance. Following the recent developments in low emittance lattice design, a new sub-nm emittance lattice based on implementation of multi-band achromat concept and application of longitudinal gradient bending magnets was developed for CANDLE storage ring. The paper presents the main design considerations, linear and non-linear beam dynamics aspects of the new lattice proposed.

  19. Emittance calculations for the Stanford Linear Collider injector

    SciTech Connect

    Sheppard, J.C.; Clendenin, J.E.; Helm, R.H.; Lee, M.J.; Miller, R.H.; Blocker, C.A.

    1983-03-01

    A series of measurements have been performed to determine the emittance of the high intensity, single bunch beam that is to be injected into the Stanford Linear Collider. On-line computer programs were used to control the Linac for the purpose of data acquisition and to fit the data to a model in order to deduce the beam emittance. This paper will describe the method of emittance calculation and present some of the measurement results.

  20. A low-noise and fast pre-amplifier and readout system for SiPMs

    NASA Astrophysics Data System (ADS)

    Biroth, M.; Achenbach, P.; Downie, E.; Thomas, A.

    2015-07-01

    To operate silicon photomultipliers (SiPMs) in a demanding environment with large temperature gradients, different amplifier concepts were characterized by analyzing SiPM pulse-shapes and charge distributions. A fully differential 4-wire SiPM pre-amplifier with separated tracks for the bias voltage and with good common-mode noise suppression was developed and successfully tested. To achieve highest single-pixel resolutions an online after-pulse and pile-up suppression was realized with fast readout electronics based on digital filters.

  1. 14-bit pipeline-SAR ADC for image sensor readout circuits

    NASA Astrophysics Data System (ADS)

    Wang, Gengyun; Peng, Can; Liu, Tianzhao; Ma, Cheng; Ding, Ning; Chang, Yuchun

    2015-03-01

    A two stage 14bit pipeline-SAR analog-to-digital converter includes a 5.5bit zero-crossing MDAC and a 9bit asynchronous SAR ADC for image sensor readout circuits built in 0.18um CMOS process is described with low power dissipation as well as small chip area. In this design, we employ comparators instead of high gain and high bandwidth amplifier, which consumes as low as 20mW of power to achieve the sampling rate of 40MSps and 14bit resolution.

  2. High-speed readout for the H8500 flat panel PSPMT

    NASA Astrophysics Data System (ADS)

    Orsolini Cencelli, Valentino; de Notaristefani, Francesco; D'Abramo, Enrico

    2007-02-01

    In this paper we present a new readout system for the H8500 flat panel photomultiplier. The system is based on the MAX1320 analog-to-digital converter and reads all of 64 anodic signals simultaneously at a rate that approaches the 250 ksample/s typical of MAX1320 with a resolution of 14 bits. The data are read through an FPGA by a chip computer, the ETRAX 100LX, and either transmitted via Ethernet or stored on a USB mass storage device.

  3. Environmental awareness for sensor and emitter employment

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kenneth K.; Wilson, D. Keith

    2010-04-01

    Environmental Awareness for Sensor and Emitter Employment (EASEE) is a flexible, object-oriented software design for predicting environmental effects on the performance of battlefield sensors and detectability of signal emitters. Its decision-support framework facilitates many sensor and emitter modalities and can be incorporated into battlespace command and control (C2) systems. Other potential applications include immersive simulation, force-on-force simulation, and virtual prototyping of sensor systems and signal-processing algorithms. By identifying and encoding common characteristics of Army problems involving multimodal signal transmission and sensing into a flexible software architecture in the Java programming language, EASEE seeks to provide an application interface enabling rapid integration of diverse signal-generation, propagation, and sensor models that can be implemented in many client-server environments. Its explicit probabilistic modeling of signals, systematic consideration of many complex environmental and mission-related factors affecting signal generation and propagation, and computation of statistical metrics characterizing sensor performance facilitate a highly flexible approach to signal modeling and simulation. EASEE aims to integrate many disparate statistical formulations for modeling and processing many types of signals, including infrared, acoustic, seismic, radiofrequency, and chemical/biological. EASEE includes objects for representing sensor data, inferences for target detection and/or direction, signal transmission and processing, and state information (such as time and place). Various transmission and processing objects are further grouped into platform objects, which fuse data to make various probabilistic predictions of interest. Objects representing atmospheric and terrain environments with varying degrees of fidelity enable modeling of signal generation and propagation in diverse and complex environments.

  4. Infrared spectral normal emittance/emissivity comparison

    NASA Astrophysics Data System (ADS)

    Hanssen, L.; Wilthan, B.; Filtz, J.-R.; Hameury, J.; Girard, F.; Battuello, M.; Ishii, J.; Hollandt, J.; Monte, C.

    2016-01-01

    The National Measurement Institutes (NMIs) of the United States, Germany, France, Italy and Japan, have joined in an inter-laboratory comparison of their infrared spectral emittance scales. This action is part of a series of supplementary inter-laboratory comparisons (including thermal conductivity and thermal diffusivity) sponsored by the Consultative Committee on Thermometry (CCT) Task Group on Thermophysical Quantities (TG-ThQ). The objective of this collaborative work is to strengthen the major operative National Measurement Institutes' infrared spectral emittance scales and consequently the consistency of radiative properties measurements carried out worldwide. The comparison has been performed over a spectral range of 2 μm to 14 μm, and a temperature range from 23 °C to 800 °C. Artefacts included in the comparison are potential standards: oxidized Inconel, boron nitride, and silicon carbide. The measurement instrumentation and techniques used for emittance scales are unique for each NMI, including the temperature ranges covered as well as the artefact sizes required. For example, all three common types of spectral instruments are represented: dispersive grating monochromator, Fourier transform and filter-based spectrometers. More than 2000 data points (combinations of material, wavelength and temperature) were compared. Ninety-eight percent (98%) of the data points were in agreement, with differences to weighted mean values less than the expanded uncertainties calculated from the individual NMI uncertainties and uncertainties related to the comparison process. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. The prototype readout electronics system for the External Target Experiment in CSR of HIRFL

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Kang, L.; Li, M.; Liu, S.; Zhou, J.; An, Q.

    2014-07-01

    A prototype readout electronics system was designed for the External Target Experiment in the Cooling Storage Ring (CSR) of the Heavy Ion Research Facility in Lanzhou (HIRFL). The kernel parts include the 128-channel 100 ps high-resolution time digitization module, the 16-channel 25 ps high-resolution time and charge measurement module, and the trigger electronics, as well as the clock generation circuits, which are all integrated within the PXI-6U crate. The laboratory test results indicate that a good resolution is achieved, better than the requirement. We also have conducted initial commissioning tests with the detectors to confirm the functions of the system. Through the research of this prototype electronics, preparation for the future extended system is made.

  6. FASTBUS readout system for the CDF DAQ upgrade

    SciTech Connect

    Andresen, J.; Areti, H.; Black, D.

    1993-11-01

    The Data Acquisition System (DAQ) at the Collider Detector at Fermilab is currently being upgraded to handle a minimum of 100 events/sec for an aggregate bandwidth that is at least 25 Mbytes/sec. The DAQ System is based on a commercial switching network that has interfaces to VME bus. The modules that readout the front end crates (FASTBUS and RABBIT) have to deliver the data to the VME bus based host adapters of the switch. This paper describes a readout system that has the required bandwidth while keeping the experiment dead time due to the readout to a minimum.

  7. Emittance and energy control in the NLC main linacs

    SciTech Connect

    Adolphsen, C.; Bane, K.L.F.; Kubo, K.; Raubenheimer, T.; Ruth, R.D.; Thompson, K.A.; Zimmermann, F.

    1995-06-01

    The authors discuss tolerances and correction schemes needed to control single- and multi-bunch emittance in the NLC main linacs. Specifications and design of emittance diagnostic stations will be presented. Trajectory correction schemes appropriate to simultaneously controlling the emittance of a multibunch train and the emittance of individual bunches within the train will be discussed. The authors discuss control of bunch-to-bunch energy spread using a ramped RF pulse generated by phase-modulating the SLED-II input. Tolerances on ions, wake fields, quadrupole alignment, and accelerating structure alignment will be given.

  8. Analysis of Slice Transverse Emittance Evolution ina Photocathode RF Gun

    SciTech Connect

    Huang, Z.; Ding, Y.; Qiang, J.; /LBL, Berkeley

    2007-10-17

    The slice transverse emittance of an electron beam is of critical significance for an x-ray FEL. In a photocathode RF gun, the slice transverse emittance is not only determined by the emission process, but also influenced strongly by the non-linear space charge effect. In this paper, we study the slice transverse emittance evolution in a photocathode RF gun using a simple model that includes effects of RF acceleration, focusing, and space charge force. The results are compared with IMPACT-T space charge simulations and may be used to understand the development of the slice emittance in an RF gun.

  9. Theoretical study of transverse-longitudinal emittance coupling

    SciTech Connect

    Qin, H; Davidson, R C; Chung, M; Barnard, J J; Wang, T F

    2011-04-14

    The effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions is investigated using the generalized Courant-Snyder theory for coupled lattices. Recently, the concept and technique of transverse-longitudinal emittance coupling have been proposed for applications in the Linac Coherent Light Source and other free-electron lasers to reduce the transverse emittance of the electron beam. Such techniques can also be applied to the driver beams for the heavy ion fusion and beam-driven high energy density physics, where the transverse emittance budget is typically tighter than the longitudinal emittance. The proposed methods consist of one or several coupling components which completely swap the emittances of one of the transverse directions and the longitudinal direction at the exit of the coupling components. The complete emittance exchange is realized in one pass through the coupling components. In the present study, we investigate the effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions. A weak coupling component is introduced at every focusing lattice, and we would like to determine if such a lattice can realize the function of emittance exchange.

  10. Efficient low-temperature thermophotovoltaic emitters from metallic photonic crystals.

    PubMed

    Nagpal, Prashant; Han, Sang Eon; Stein, Andreas; Norris, David J

    2008-10-01

    We examine the use of metallic photonic crystals as thermophotovoltaic emitters. We coat silica woodpile structures, created using direct laser writing, with tungsten or molybdenum. Optical reflectivity and thermal emission measurements near 650 degrees C demonstrate that the resulting structures should provide efficient emitters at relatively low temperatures. When matched to InGaAsSb photocells, our structures should generate over ten times more power than solid emitters while having an optical-to-electrical conversion efficiency above 32%. At such low temperatures, these emitters have promise not only in solar energy but also in harnessing geothermal and industrial waste heat.

  11. Injection of large transverse emittance EBIS beams in booster

    SciTech Connect

    Gardner, C.

    2011-10-10

    During the commissioning of EBIS beams in Booster in November 2010 and in April, May and June 2011, it was found that the transverse emittances of the EBIS beams just upstream of Booster were much larger than expected. Beam emittances of 11{pi} mm milliradians had been expected, but numbers 3 to 4 times larger were measured. Here and throughout this note the beam emittance, {pi}{epsilon}{sub 0}, is taken to be the area of the smallest ellipse that contains 95% of the beam. We call this smallest ellipse the beam ellipse. If the beam distribution is gaussian, the rms emittance of the distribution is very nearly one sixth the area of the beam ellipse. The normalized rms emittance is the rms emittance times the relativistic factor {beta}{gamma} = 0.06564. This amounts to 0.12{pi} mm milliradians for the 11{pi} mm milliradian beam ellipse. In [1] we modeled the injection and turn-by-turn evolution of an 11{pi} mm milliradian beam ellipse in the horizontal plane in Booster. It was shown that with the present injection system, up to 4 turns of this beam could be injected and stored in Booster without loss. In the present note we extend this analysis to the injection of larger emittance beams. We consider only the emittance in the horizontal plane. Emittance in the vertical plane and the effects of dispersion are treated in [2].

  12. A low power front-end architecture for SiPM readout with integrated ADC and multiplexed readout

    NASA Astrophysics Data System (ADS)

    Sacco, I.; Fischer, P.; Ritzert, M.; Peric, I.

    2013-01-01

    Silicon Photo-Multiplier (SiPM) detectors are becoming widely used for optical photon and, in conjunction with suited scintillators, for gamma detection in both medical imaging and particle physics experiments. The spatial resolution can be improved by using smaller SiPMs with a corresponding increase in front-end channels density. The timing resolution of the whole system is a function of the detector parameters and of the characteristics of the front-end electronics. We present a low power front-end readout architecture which allows reading out several SiPMs though a single line in order to maximize the number of SiPMs. The design offers good timing performance and includes a simple charge digitizer in every channel. Four different single-ended channel designs have been designed, submitted for fabrication and characterized electronically and with SiPMs. The timing performance is obtained by using a low input impedance, precise threshold setting of a leading edge discriminator and a programmable input dc potential to set the SiPM HV bias on a channel per channel basis. Programmable low- and high-pass filters should allow reducing baseline fluctuations and noise. A simple ADC is implemented by first integrating the signal current and then discharging it at a constant rate until the baseline is reached again. The current consumption of the single channel is typically less than 10 mA. The time and energy information are sent out on a single wire. In order to keep as low as possible the output cabling the signals from different channels can be multiplexed on the same cable. The processing of these signals (extraction of time, ADC amplitude determination and channel number decoding) is performed by an external FPGA. The overall architecture, the front-end designs, and measurements with SiPMs are presented.

  13. Multi-channel polarized thermal emitter

    DOEpatents

    Lee, Jae-Hwang; Ho, Kai-Ming; Constant, Kristen P

    2013-07-16

    A multi-channel polarized thermal emitter (PTE) is presented. The multi-channel PTE can emit polarized thermal radiation without using a polarizer at normal emergence. The multi-channel PTE consists of two layers of metallic gratings on a monolithic and homogeneous metallic plate. It can be fabricated by a low-cost soft lithography technique called two-polymer microtransfer molding. The spectral positions of the mid-infrared (MIR) radiation peaks can be tuned by changing the periodicity of the gratings and the spectral separation between peaks are tuned by changing the mutual angle between the orientations of the two gratings.

  14. High efficiency quasi-monochromatic infrared emitter

    NASA Astrophysics Data System (ADS)

    Brucoli, Giovanni; Bouchon, Patrick; Haïdar, Riad; Besbes, Mondher; Benisty, Henri; Greffet, Jean-Jacques

    2014-02-01

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  15. High efficiency quasi-monochromatic infrared emitter

    SciTech Connect

    Brucoli, Giovanni; Besbes, Mondher; Benisty, Henri Greffet, Jean-Jacques; Bouchon, Patrick; Haïdar, Riad

    2014-02-24

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  16. Multiple emitter location and signal parameter estimation

    NASA Astrophysics Data System (ADS)

    Schmidt, R. O.

    1986-03-01

    Multiple signal classification (MUSIC) techniques involved in determining the parameters of multiple wavefronts arriving at an antenna array are discussed. A MUSIC algorithm is described, which provides asymptotically unbiased estimates of (1) the number of signals, (2) directions of arrival (or emitter locations), (3) strengths and cross correlations among the incident waveforms, and (4) the strength of noise/interference. The example of the use of the algorithm as a multiple frequency estimator operating on time series is examined. Comparisons of this method with methods based on maximum likelihood and maximum entropy, as well as conventional beamforming, are presented.

  17. Emittance growth from transient coherent synchrotron radiation

    SciTech Connect

    Bohn, C.L.; Li, R.; Bisognano, J.J.

    1996-10-01

    If the energies of individual particles in a bunch change as the bunch traverses a bending system, even if it is achromatic, betatron oscillations can be excited. Consequently, the transverse emittance of the bunch will grow as it moves downstream. Short bunches may be particularly susceptible to emission of coherent synchrotron radiation which can act back on the particles to change their energies and trajectories. Because a bend spans a well-defined length and angle, the bunch-excited wakefield and its effect back on the bunch are inherently transient. We outline a recently developed theory of this effect and apply it to example bending systems.

  18. Monitoring airborne alpha-emitter contamination

    SciTech Connect

    Kerr, P.L.; Koster, J.E.; Conaway, J.G.; Bounds, J.A.; Whitley, C.W.; Steadman, P.A.

    1998-02-01

    Facilities that may produce airborne alpha emitter contamination require a continuous air monitoring (CAM) system. However, these traditional CAMs have difficulty in environments with large quantities of non-radioactive particulates such as dust and salt. Los Alamos has developed an airborne plutonium sensor (APS) for the REBOUND experiment at the Nevada Test Site which detects alpha contamination directly in the air, and so is less vulnerable to the problems associated with counting activity on a filter. In addition, radon compensation is built into the detector by the use of two measurement chambers.

  19. A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

    NASA Technical Reports Server (NTRS)

    Kimble, Randy A.; Pain, Bedabrata; Norton, Timothy J.; Haas, J. Patrick; Oegerle, William R. (Technical Monitor)

    2002-01-01

    Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest of by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

  20. Barium depletion in hollow cathode emitters

    NASA Astrophysics Data System (ADS)

    Polk, James E.; Mikellides, Ioannis G.; Capece, Angela M.; Katz, Ira

    2016-01-01

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al2O3 source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values.

  1. Barium depletion in hollow cathode emitters

    SciTech Connect

    Polk, James E. Mikellides, Ioannis G.; Katz, Ira; Capece, Angela M.

    2016-01-14

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al{sub 2}O{sub 3} source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values.

  2. Micro-electrospray with stainless steel emitters.

    PubMed

    Shui, Wenqing; Yu, Yanling; Xu, Xuejiao; Huang, Zhenyu; Xu, Guobing; Yang, Pengyuan

    2003-01-01

    The physical processes underlying micro-electrospray (micro-ES) performance were investigated using a stainless steel (SS) emitter with a blunt tip. Sheathless micro-ES could be generated at a blunt SS tip without any tapering or sanding if ESI conditions were optimized. The Taylor cone was found to shrink around the inner diameter of the SS tubing, which permitted a low flow rate of 150 nL/min for sheathless microspray on the blunt tip (100 microm i.d. x 400 microm o.d.). It is believed that the wettability and/or hydrophobicity of SS tips are responsible for their micro-ES performance. The outlet orifice was further nipped to reduce the size of the spray cone and limit the flow rate to 50-150 nL/min, resulting in peptide detection down to attomole quantities consumed per spectrum. The SS emitter was also integrated into a polymethylmethacrylate microchip and demonstrated satisfactory performance in the analysis and identification of a myoglobin digest.

  3. Emittance measurements from the LLUMC proton accelerator

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Gillespie, G. H.; Hubbard, J.; Sanders, E.

    2005-12-01

    A new method of calculating beam emittances at the extraction point of a particle accelerator is presented. The technique uses the optimization programs NPSOL and MINOS developed at Stanford University in order to determine the initial values of beam size, divergence and correlation parameters (i.e. beam sigma matrix, σij) that best fit measured beam parameters. These σij elements are then used to compute the Twiss parameters α, β, and the phase space area, ε, of the beam at the extraction point. Beam size measurements in X and Y throughout the transport line were input to the optimizer along with the magnetic elements of bends, quads, and drifts. The σij parameters were optimized at the accelerator's extraction point by finding the best agreement between these measured beam sizes and those predicted by TRANSPORT. This expands upon a previous study in which a "trial and error" technique was used instead of the optimizer software, and which yielded similar results. The Particle Beam Optics Laboratory (PBO Lab™) program used for this paper integrates particle beam optics and other codes into a single intuitive graphically-based computing environment. This new software provides a seamless interface between the NPSOL and MINOS optimizer and TRANSPORT calculations. The results of these emittance searches are presented here for the eight clinical energies between 70 and 250 MeV currently being used at LLUMC.

  4. Muon Emittance Exchange with a Potato Slicer

    SciTech Connect

    Summers, D. J.; Hart, T. L.; Acosta, J. G.; Cremaldi, L. M.; Oliveros, S. J.; Perera, L. P.; Neuffer, D. V.

    2015-04-15

    We propose a novel scheme for final muon ionization cooling with quadrupole doublets followed by emittance exchange in vacuum to achieve the small beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low beta region occupied by a dense, low Z absorber. After final cooling, normalized transverse, longitudinal, and angular momentum emittances of 0.100, 2.5, and 0.200 mm-rad are exchanged into 0.025, 70, and 0.0 mm-rad. A skew quadrupole triplet transforms a round muon bunch with modest angular momentum into a flat bunch with no angular momentum. Thin electrostatic septa efficiently slice the flat bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 µs, one quarter of a synchrotron oscillation period. A linear long wavelength RF bucket gives each bunch a different energy causing the bunches to drift in the ring until they merge into one bunch and can be captured in a short wavelength RF bucket with a 13% muon decay loss and a packing fraction as high as 87 %.

  5. Optical readout of liquid argon ionisation

    NASA Astrophysics Data System (ADS)

    Spooner, N. J. C.; Lightfoot, P. K.; Barker, G. J.; Ramachers, Y. A.; Mavrokoridis, K.

    2011-07-01

    Reading out the charge from a very large liquid argon detector, such as proposed for next generation proton decay and long baseline neutrino detectors, represents a significant challenge. Current proposals suggest using wires in the liquid or a two-phase approach that can provide some gain via amplification in the gas phase. We present here work on an alternative new approach in which the charge is read out by optical means following generation of electroluminescence, such as in a THGEM (Thick Gas Electron Multiplier) mounted within the liquid. This has the potential for significant advantages by providing both simpler readout electronics and significant charge gain, without the need for the complexities of dual phase operation. Tests with a silicon photomultiplier (SiPM) mounted above a THGEM, all submerged in liquid argon, have allowed first demonstration of the technique. Sensitivity to 5.9 keV 55Fe gamma events was observed with an estimated gain of 150 photoelectrons per drifted electron. We review the concepts and results.

  6. The Belle II SVD data readout system

    NASA Astrophysics Data System (ADS)

    Thalmeier, R.; Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Bulla, L.; Casarosa, G.; Ceccanti, M.; Cervenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doleźal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyś, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnićka, P.; Lanceri, L.; Lettenbicher, J.; Lueck, T.; Maki, M.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rao, K. K.; Rashevskaya, I.; Rizzo, G.; Rozanska, M.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Suzuki, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.

    2017-02-01

    The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the standard model. 172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC). Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network. We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing.

  7. Optimal signal processing for continuous qubit readout

    NASA Astrophysics Data System (ADS)

    Ng, Shilin; Tsang, Mankei

    2014-08-01

    The measurement of a quantum two-level system, or a qubit in modern terminology, often involves an electromagnetic field that interacts with the qubit, before the field is measured continuously and the qubit state is inferred from the noisy field measurement. During the measurement, the qubit may undergo spontaneous transitions, further obscuring the initial qubit state from the observer. Taking advantage of some well-known techniques in stochastic detection theory, here we propose a signal processing protocol that can infer the initial qubit state optimally from the measurement in the presence of noise and qubit dynamics. Assuming continuous quantum-nondemolition measurements with Gaussian or Poissonian noise and a classical Markov model for the qubit, we derive analytic solutions to the protocol in some special cases of interest using Itō calculus. Our method is applicable to multihypothesis testing for robust qubit readout and relevant to experiments on qubits in superconducting microwave circuits, trapped ions, nitrogen-vacancy centers in diamond, semiconductor quantum dots, or phosphorus donors in silicon.

  8. Development of the readout controller for KASINICS

    NASA Astrophysics Data System (ADS)

    Cho, Seoung-hyun; Jin, Ho; Nam, Uk-Won; Lee, Sungho; Kong, Kyung-Nam; Yuk, In-Soo; Park, Youngsik; Pak, Soojong; Han, Wonyong; Kim, Sungsoo S.

    2006-06-01

    Korea Astronomy and Space Science Institute (KASI) is developing the KASI Near Infrared Camera System (KASINICS) which will be installed on the 61 cm telescope at the Sobaeksan Optical Astronomy Observatory (SOAO) in Korea. KASINICS is equipped with a ALADDIN III Quadrant (512×512 InSb array, manufactured by Raytheon). For this instrument, we make a new IR array control electronics system. The controller consists of DSP, Bias, Clock, and Video boards which are installed on a VME bus system. The DSP board includes TMS320C6713, FPGA, and 384MB SDRAM. Clock patterns are downloaded from a PC and stored on the FPGA. USB 2.0 is used for the communication with the PC and UART for the serial communication with peripherals. Each of two video boards has 4 video channels. The Bias board provides 16 voltage sources and the Clock board has 15 clock channels. Our goal of readout speed is 10 frames sec -1. We have successfully finished operational tests of the controller using a 256×256 ROIC (CRC744). We are now upgrading the system for the ALADDIN III array. We plan to operate KASINICS by the end of 2006.

  9. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Astrophysics Data System (ADS)

    Henderson, S. W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Calabrese, E.; Choi, S. K.; Coughlin, K. P.; Crowley, K. T.; Datta, R.; Devlin, M. J.; Duff, S. M.; Dunkley, J.; Dünner, R.; van Engelen, A.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Hills, F.; Hilton, G. C.; Hincks, A. D.; Hloẑek, R.; Ho, S. P.; Hubmayr, J.; Huffenberger, K.; Hughes, J. P.; Irwin, K. D.; Koopman, B. J.; Kosowsky, A. B.; Li, D.; McMahon, J.; Munson, C.; Nati, F.; Newburgh, L.; Niemack, M. D.; Niraula, P.; Page, L. A.; Pappas, C. G.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Sehgal, N.; Sherwin, B. D.; Sievers, J. L.; Simon, S. M.; Spergel, D. N.; Staggs, S. T.; Stevens, J. R.; Thornton, R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-08-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies—imaged in intensity and polarization at few arcminute-scale resolution—will enable precision cosmological constraints and also a wide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the Advanced ACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the Advanced ACTPol cryogenic detector arrays.

  10. A PCIe Gen3 based readout for the LHCb upgrade

    NASA Astrophysics Data System (ADS)

    Bellato, M.; Collazuol, G.; D'Antone, I.; Durante, P.; Galli, D.; Jost, B.; Lax, I.; Liu, G.; Marconi, U.; Neufeld, N.; Schwemmer, R.; Vagnoni, V.

    2014-06-01

    The architecture of the data acquisition system foreseen for the LHCb upgrade, to be installed by 2018, is devised to readout events trigger-less, synchronously with the LHC bunch crossing rate at 40 MHz. Within this approach the readout boards act as a bridge between the front-end electronics and the High Level Trigger (HLT) computing farm. The baseline design for the LHCb readout is an ATCA board requiring dedicated crates. A local area standard network protocol is implemented in the on-board FPGAs to read out the data. The alternative solution proposed here consists in building the readout boards as PCIe peripherals of the event-builder servers. The main architectural advantage is that protocol and link-technology of the event-builder can be left open until very late, to profit from the most cost-effective industry technology available at the time of the LHC LS2.

  11. A radiation-tolerant electronic readout system for portal imaging

    NASA Astrophysics Data System (ADS)

    Östling, J.; Brahme, A.; Danielsson, M.; Iacobaeus, C.; Peskov, V.

    2004-06-01

    A new electronic portal imaging device, EPID, is under development at the Karolinska Institutet and the Royal Institute of Technology. Due to considerable demands on radiation tolerance in the radiotherapy environment, a dedicated electronic readout system has been designed. The most interesting aspect of the readout system is that it allows to read out ˜1000 pixels in parallel, with all electronics placed outside the radiation beam—making the detector more radiation resistant. In this work we are presenting the function of a small prototype (6×100 pixels) of the electronic readout board that has been tested. Tests were made with continuous X-rays (10-60 keV) and with α particles. The results show that, without using an optimised gas mixture and with an early prototype only, the electronic readout system still works very well.

  12. Focal plane infrared readout circuit with automatic background suppression

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor); Yang, Guang (Inventor); Sun, Chao (Inventor); Shaw, Timothy J. (Inventor); Wrigley, Chris J. (Inventor)

    2002-01-01

    A circuit for reading out a signal from an infrared detector includes a current-mode background-signal subtracting circuit having a current memory which can be enabled to sample and store a dark level signal from the infrared detector during a calibration phase. The signal stored by the current memory is subtracted from a signal received from the infrared detector during an imaging phase. The circuit also includes a buffered direct injection input circuit and a differential voltage readout section. By performing most of the background signal estimation and subtraction in a current mode, a low gain can be provided by the buffered direct injection input circuit to keep the gain of the background signal relatively small, while a higher gain is provided by the differential voltage readout circuit. An array of such readout circuits can be used in an imager having an array of infrared detectors. The readout circuits can provide a high effective handling capacity.

  13. Balanced homodyne readout for quantum limited gravitational wave detectors.

    PubMed

    Fritschel, Peter; Evans, Matthew; Frolov, Valery

    2014-02-24

    Balanced homodyne detection is typically used to measure quantum-noise-limited optical beams, including squeezed states of light, at audio-band frequencies. Current designs of advanced gravitational wave interferometers use some type of homodyne readout for signal detection, in part because of its compatibility with the use of squeezed light. The readout scheme used in Advanced LIGO, called DC readout, is however not a balanced detection scheme. Instead, the local oscillator field, generated from a dark fringe offset, co-propagates with the signal field at the anti-symmetric output of the beam splitter. This article examines the alternative of a true balanced homodyne detection for the readout of gravitational wave detectors such as Advanced LIGO. Several practical advantages of the balanced detection scheme are described.

  14. Point-to-point readout for the ALICE EMCal detector

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Muller, Hans; Awes, Terry. C.; Martoiu, Sorin; Kral, Jiri; Silvermyr, David; Martinez, Alfonso Tarazona; Huang, Guangming; Zhou, Daicui

    2014-01-01

    It is anticipated that the LHC will deliver Pb+Pb collisions at a minimum bias interaction rate of about 50 kHz after the second long shutdown of the LHC in 2018. This will be roughly two orders of magnitude greater than the current data recording rate capability of the ALICE experiment. Therefore a major upgrade of the ALICE detector is planned for the next shutdown to enable ALICE to record data at the full Pb+Pb minimum bias interaction rate delivered by the LHC. A new point-to-point readout system for the electromagnetic calorimeter (EMCal) of ALICE has been developed, to replace the legacy readout bus, that essentially accomplishes this goal, and is being installed during the current LHC shutdown (2013-2014). The new readout uses the existing EMCal front end electronics yet provides more than an order of magnitude decrease in the readout time, to about 21 μs, with modest cost and effort.

  15. TES Detector Noise Limited Readout Using SQUID Multiplexers

    NASA Technical Reports Server (NTRS)

    Staguhn, J. G.; Benford, D. J.; Chervenak, J. A.; Khan, S. A.; Moseley, S. H.; Shafer, R. A.; Deiker, S.; Grossman, E. N.; Hilton, G. C.; Irwin, K. D.

    2004-01-01

    The availability of superconducting Transition Edge Sensors (TES) with large numbers of individual detector pixels requires multiplexers for efficient readout. The use of multiplexers reduces the number of wires needed between the cryogenic electronics and the room temperature electronics and cuts the number of required cryogenic amplifiers. We are using an 8 channel SQUID multiplexer to read out one-dimensional TES arrays which are used for submillimeter astronomical observations. We present results from test measurements which show that the low noise level of the SQUID multiplexers allows accurate measurements of the TES Johnson noise, and that in operation, the readout noise is dominated by the detector noise. Multiplexers for large number of channels require a large bandwidth for the multiplexed readout signal. We discuss the resulting implications for the noise performance of these multiplexers which will be used for the readout of two dimensional TES arrays in next generation instruments.

  16. Compact Rare Earth Emitter Hollow Cathode

    NASA Technical Reports Server (NTRS)

    Watkins, Ronald; Goebel, Dan; Hofer, Richard

    2010-01-01

    A compact, high-current, hollow cathode utilizing a lanthanum hexaboride (LaB6) thermionic electron emitter has been developed for use with high-power Hall thrusters and ion thrusters. LaB6 cathodes are being investigated due to their long life, high current capabilities, and less stringent xenon purity and handling requirements compared to conventional barium oxide (BaO) dispenser cathodes. The new cathode features a much smaller diameter than previously developed versions that permit it to be mounted on axis of a Hall thruster ( internally mounted ), as opposed to the conventional side-mount position external to the outer magnetic circuit ("externally mounted"). The cathode has also been reconfigured to be capable of surviving vibrational loads during launch and is designed to solve the significant heater and materials compatibility problems associated with the use of this emitter material. This has been accomplished in a compact design with the capability of high-emission current (10 to 60 A). The compact, high-current design has a keeper diameter that allows the cathode to be mounted on the centerline of a 6- kW Hall thruster, inside the iron core of the inner electromagnetic coil. Although designed for electric propulsion thrusters in spacecraft station- keeping, orbit transfer, and interplanetary applications, the LaB6 cathodes are applicable to the plasma processing industry in applications such as optical coatings and semiconductor processing where reactive gases are used. Where current electrical propulsion thrusters with BaO emitters have limited life and need extremely clean propellant feed systems at a significant cost, these LaB6 cathodes can run on the crudest-grade xenon propellant available without impact. Moreover, in a laboratory environment, LaB6 cathodes reduce testing costs because they do not require extended conditioning periods under hard vacuum. Alternative rare earth emitters, such as cerium hexaboride (CeB6) can be used in this

  17. Group-III Nitride Field Emitters

    NASA Technical Reports Server (NTRS)

    Bensaoula, Abdelhak; Berishev, Igor

    2008-01-01

    Field-emission devices (cold cathodes) having low electron affinities can be fabricated through lattice-mismatched epitaxial growth of nitrides of elements from group III of the periodic table. Field emission of electrons from solid surfaces is typically utilized in vacuum microelectronic devices, including some display devices. The present field-emission devices and the method of fabricating them were developed to satisfy needs to reduce the cost of fabricating field emitters, make them compatible with established techniques for deposition of and on silicon, and enable monolithic integration of field emitters with silicon-based driving circuitry. In fabricating a device of this type, one deposits a nitride of one or more group-III elements on a substrate of (111) silicon or other suitable material. One example of a suitable deposition process is chemical vapor deposition in a reactor that contains plasma generated by use of electron cyclotron resonance. Under properly chosen growth conditions, the large mismatch between the crystal lattices of the substrate and the nitride causes strains to accumulate in the growing nitride film, such that the associated stresses cause the film to crack. The cracks lie in planes parallel to the direction of growth, so that the growing nitride film becomes divided into microscopic growing single-crystal columns. The outer ends of the fully-grown columns can serve as field-emission tips. By virtue of their chemical compositions and crystalline structures, the columns have low work functions and high electrical conductivities, both of which are desirable for field emission of electrons. From examination of transmission electron micrographs of a prototype device, the average column width was determined to be about 100 nm and the sharpness of the tips was determined to be characterized by a dimension somewhat less than 100 nm. The areal density of the columns was found to about 5 x 10(exp 9)/sq cm . about 4 to 5 orders of magnitude

  18. Manipulation And Readout Of A Tunable Flux Qubit With Integrated Readout: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Cosmelli, Carlo; Carelli, Pasquale; Castellano, Maria Gabriella; Chiarello, Fabio; Gangemi, Lorenzo; Leoni, Roberto; Poletto, Stefano; Simeone, Daniela; Torrioli, Guido

    2006-09-01

    We show a tunable flux qubit with built-in readout, realized with a double SQUID with a supplementary Josephson junction. State preparation and manipulation of the qubit are achieved by applying pulses of magnetic flux in two externally coupled coils, a feature that suits very well with a future integration with RSFQ integrated logic. We show how the system can be read out and prepared in a definite flux state, moreover we show the results of manipulation (lowering of the potential barrier between states) in incoherent regime at liquid helium temperature.

  19. System design for precise digitization and readout of the CSNS-WNS BaF2 spectrometer

    NASA Astrophysics Data System (ADS)

    Zhang, De-Liang; Cao, Ping; Wang, Qi; He, Bing; Zhang, Ya-Xi; Qi, Xin-Cheng; Yu, Tao; An, Qi

    2017-02-01

    The BaF2 (barium fluoride) spectrometer is one of the experiment facilities at the CSNS-WNS (White Neutron Source at China Spallation Neutron Source), currently under construction. It is designed to precisely measure the (n, γ) cross section, with 92 crystal elements and complete 4π steradian coverage. In order to improve the precision of measurement, in this paper, a new precise digitization and readout method is proposed. Waveform digitizing with 1 GSps sampling rate and 12-bit resolution is used to precisely capture the detector signal. To solve the problem of massive data readout and processing, the readout electronics is designed as a distributed architecture with 4 PXIe crates. The digitized signal is concentrated to the PXIe crate controller through a PCIe bus on the backplane and transmitted to the data acquisition system over gigabit Ethernet in parallel. Besides, the clock and trigger can be fanned out synchronously to every electronic channel over a high-precision distribution network. Test results show that the prototype of the readout electronics can achieve good performance and meet the requirements of the CSNS-WNS BaF2 spectrometer. Supported by National Research and Development plan (2016YFA0401602) and NSAF (U1530111)

  20. Large Format Geiger Mode Avalanche Photodiode Arrays and Readout Circuits

    DTIC Science & Technology

    2017-06-01

    a detector wafer with a transparent substrate; the arrays can therefore be bump bonded to CMOS readouts by the same process used for InP- based... bump bond to a more advanced 3D integration requires heterogeneous integration technique. We have demonstrated wafer bonding of InP detector arrays...digital CMOS readout circuits using bump bonding or 3D integration techniques. Silicon is the material of choice for ultraviolet, visible, and near

  1. The Philosophy and Feasibility of Dual Readout Calorimetry

    SciTech Connect

    Hauptman, John

    2006-10-27

    I will discuss the general physical ideas behind dual-readout calorimetry, their implementation in DREAM (Dual REAdout Module) with exact separation of scintillation and Cerenkov light, implementation with mixed light in DREAM fibers, anticipated implementation in PbWO4 crystals with applications to the 4th Concept detector and to CMS, use in high energy gamma-ray and cosmic ray astrophysics with Cerenkov and N2 fluorescent light, and implementation in the 4th Concept detector for muon identification.

  2. Issues and directions in IR detector readout electronics

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R.

    1990-01-01

    An introduction to the major issues encountered in the readout of imaging detector arrays in the infrared are presented. These include circuit issues such as multiplexing, buffering, and noise, as well as materials issues. Future directions in infrared readout electronics will also be discussed. These include on-chip signal processing and advanced hybridization schemes. Finally, recent work at Columbia on 2DEG-charge coupled devices for IR detector multiplexing are described.

  3. FPIX2, the BTeV pixel readout chip

    SciTech Connect

    David C. Christian et al.

    2003-12-10

    A radiation tolerant pixel readout chip, FPIX2, has been developed at Fermilab for use by BTeV. Some of the requirements of the BTeV pixel readout chip are reviewed and contrasted with requirements for similar devices in LHC experiments. A description of the FPIX2 is given, and results of initial tests of its performance are presented, as is a summary of measurements planned for the coming year.

  4. Simple Bulk Readout of Digital Nucleic Acid Quantification Assays.

    PubMed

    Morinishi, Leanna S; Blainey, Paul

    2015-09-24

    Digital assays are powerful methods that enable detection of rare cells and counting of individual nucleic acid molecules. However, digital assays are still not routinely applied, due to the cost and specific equipment associated with commercially available methods. Here we present a simplified method for readout of digital droplet assays using a conventional real-time PCR instrument to measure bulk fluorescence of droplet-based digital assays. We characterize the performance of the bulk readout assay using synthetic droplet mixtures and a droplet digital multiple displacement amplification (MDA) assay. Quantitative MDA particularly benefits from a digital reaction format, but our new method applies to any digital assay. For established digital assay protocols such as digital PCR, this method serves to speed up and simplify assay readout. Our bulk readout methodology brings the advantages of partitioned assays without the need for specialized readout instrumentation. The principal limitations of the bulk readout methodology are reduced dynamic range compared with droplet-counting platforms and the need for a standard sample, although the requirements for this standard are less demanding than for a conventional real-time experiment. Quantitative whole genome amplification (WGA) is used to test for contaminants in WGA reactions and is the most sensitive way to detect the presence of DNA fragments with unknown sequences, giving the method great promise in diverse application areas including pharmaceutical quality control and astrobiology.

  5. PAUCam readout electronics assembly, integration and test (AIT)

    NASA Astrophysics Data System (ADS)

    Jiménez, Jorge; Illa, José M.; Cardiel-Sas, Laia; de Vicente, Juan; Castilla, Javier; Casas, Ricard

    2014-08-01

    The PAUCam is an optical camera with an array of 18 CCDs (Hamamatsu Photonics K.K.) and up to 45 narrow and broad band filters. The camera will be installed on the William Herschel Telescope (WHT) in the Canary Islands, Spain. In order to fulfill with the specifications for the camera readout system, it was necessary to test the different readout electronics subsystems individually before to integrate the final readout work package, which is composed of 4 MONSOON (NOAO) front-ends, 6 fan out boards (MIX), each one driving up to 5 CCDs signals and a pre-amplification stage (PREAMP) located inside the cryostat. To get the subsystems integration, it was built a small camera prototype using the same technology as used in the main camera: a carbon fiber cryostat refrigerated by a cryotiger cooling system but with capacity to allocate just 2 CCDs, which were readout and re-characterized to measure the electronics performance as conversion factor or gain, readout noise, stability, linearity, etc. while the cross-talk was measured by using a spot-light. The aim of this paper is to review the whole process of assembly, integration and test (AIT) of the readout electronics work package and present the main results to demonstrate the viability of the proposed systems to be use with the PAUCam camera.

  6. Emittance growth due to negative-mass instability above transition

    SciTech Connect

    Ng, King-Yuen

    1994-08-01

    Due to space-charge effect, there is a growth of bunch emittance across transition as a result of negative-mass instability. The models of growth at cutoff frequency and growth from high-frequency Schottky noise are reviewed. The difficulties of performing reliable simulations are discussed. An intuitive self-bunching model for estimating emittance growth is presented.

  7. Emittance growth due to dipole ripple and sextupole

    SciTech Connect

    Shih, H.J.; Ellison, J.A.; Syphers, M.J.; Newberger, B.S.

    1993-05-01

    Ripple in the power supplies for storage ring magnets can have adverse effects on the circulating beams: orbit distortion and emittance growth from dipole ripple, tune modulation and dynamic aperture reduction from quadrupole ripple, etc. In this paper, we study the effects of ripple in the horizontal bending field of the SSC in the presence of nonlinearity, in particular, the growth in beam emittance.

  8. Close proximity electrostatic effect from small clusters of emitters

    NASA Astrophysics Data System (ADS)

    Dall’Agnol, Fernando F.; de Assis, Thiago A.

    2017-10-01

    Using a numerical simulation based on the finite-element technique, this work investigates the field emission properties from clusters of a few emitters at close proximity, by analyzing the properties of the maximum local field enhancement factor (γm ) and the corresponding emission current. At short distances between the emitters, we show the existence of a nonintuitive behavior, which consists of the increasing of γm as the distance c between the emitters decreases. Here we investigate this phenomenon for clusters with 2, 3, 4 and 7 identical emitters and study the influence of the proximity effect in the emission current, considering the role of the aspect ratio of the individual emitters. Importantly, our results show that peripheral emitters with high aspect-ratios in large clusters can, in principle, significantly increase the emitted current as a consequence only of the close proximity electrostatic effect (CPEE). This phenomenon can be seen as a physical mechanism to produce self-oscillations of individual emitters. We discuss new insights for understanding the nature of self-oscillations in emitters based on the CPEE, including applications to nanometric oscillators.

  9. Surface Coatings for Low Emittance in the Thermal Surveillance Band

    DTIC Science & Technology

    1984-08-01

    transparent but conducting coatings on glass [4] and (3) the solar energy industry , where surface coatings are required for solar collectors which...increase in coating emittance [10]. 0 Research into low emittance paint is mainly carried out in the solar energy industry [11, 12] and can be

  10. Spectral beam combining of multi-single emitters

    NASA Astrophysics Data System (ADS)

    Wang, Baohua; Guo, Weirong; Guo, Zhijie; Xu, Dan; Zhu, Jing; Zhang, Qiang; Yang, Thomas; Chen, Xiaohua

    2016-03-01

    Spectral beam combination expands the output power while keeps the beam quality of the combined beam almost the same as that of a single emitter. Spectral beam combination has been successfully achieved for high power fiber lasers, diode laser arrays and diode laser stacks. We have recently achieved the spectral beam combination of multiple single emitter diode lasers. Spatial beam combination and beam transformation are employed before beams from 25 single emitter diode lasers can be spectrally combined. An average output power about 220W, a spectral bandwidth less than 9 nm (95% energy), a beam quality similar to that of a single emitter and electro-optical conversion efficiency over 46% are achieved. In this paper, Rigorous Coupled Wave analysis is used to numerically evaluate the influence of emitter width, emitter pitch and focal length of transform lens on diffraction efficiency of the grating and spectral bandwidth. To assess the chance of catastrophic optical mirror damage (COMD), the optical power in the internal cavity of a free running emitter and the optical power in the grating external cavity of a wavelength locked emitter are theoretically analyzed. Advantages and disadvantages of spectral beam combination are concluded.

  11. Experimental Results of a Single Emittance Compensation Solenoidal Magnet

    NASA Astrophysics Data System (ADS)

    Palmer, D. T.; Wang, X. J.; Ben-Zvi, I.; Miller, R. H.; Skaritka, J.

    1997-05-01

    A new iron dominated single emittance compensation solenoidal magnet was designed to be integrated with the BNL/SLAC/UCLA 1.6 cell S-Band Photocathode RF Gun. This emittance compensated photoinjector is now in operation at the Brookhaven Accelerator Test Facility. It has produced a 300 pC electron bunches with a normalized rms transverse emittance of ɛ_n,rms = 0.7 π mm mrad. POISSON field maps were used with PARMELA to optimize the emittance compensation solenoidal magnet design. Magnetic field measurements show that at the cathode plane Bz <= 10 gauss for a peak magnetic field of B_z,max = 3 KG. Which is in agreement with POISSON simulation. A single emittance compensation solenoidal magnet will produces a initial angular momentum of the electron bunch that manifests itself in a initial magnetic emittance term that cannot be eliminated. This magnetic emittance ɛ_mag,n,rms scales as 0.01 π mm mrad per gauss at the cathode. Which is in agreement with PARMELA simulations. Experimental beam dynamics results are presented that show spot size and emittance as a function of cathode magnetic field. These results are compared to theory and simulations.

  12. Sharpening of field emitter tips using high-energy ions

    DOEpatents

    Musket, Ronald G.

    1999-11-30

    A process for sharpening arrays of field emitter tips of field emission cathodes, such as found in field-emission, flat-panel video displays. The process uses sputtering by high-energy (more than 30 keV) ions incident along or near the longitudinal axis of the field emitter to sharpen the emitter with a taper from the tip or top of the emitter down to the shank of the emitter. The process is particularly applicable to sharpening tips of emitters having cylindrical or similar (e.g., pyramidal) symmetry. The process will sharpen tips down to radii of less than 12 nm with an included angle of about 20 degrees. Because the ions are incident along or near the longitudinal axis of each emitter, the tips of gated arrays can be sharpened by high-energy ion beams rastered over the arrays using standard ion implantation equipment. While the process is particularly applicable for sharpening of arrays of field emitters in field-emission flat-panel displays, it can be effectively utilized in the fabrication of other vacuum microelectronic devices that rely on field emission of electrons.

  13. A Balloon-Borne, Advanced Scintillator Compton Telescope with Silicon Photomultiplier Readout

    NASA Astrophysics Data System (ADS)

    Bloser, Peter

    Telescope (ASCOT) with SiPM readout and fly it on an engineering balloon flight from Ft. Sumner, NM. The instrument will be of sufficient scale to image the Crab Nebula in a one-day flight. The results of this work will demonstrate conclusively that the energy, timing, and position resolution of this technology are sufficient to achieve an order of magnitude improvement in sensitivity in the medium-energy gamma-ray band, were it to be applied to a 1 cubic meter instrument on a ULDB or Explorer platform. Such an instrument would be able to make groundbreaking gamma- ray measurements of bright relativistic particle accelerators, such as galactic black holes, pulsars, solar flares, and gamma-ray bursts.

  14. Common Readout Unit (CRU) - A new readout architecture for the ALICE experiment

    NASA Astrophysics Data System (ADS)

    Mitra, J.; Khan, S. A.; Mukherjee, S.; Paul, R.

    2016-03-01

    The ALICE experiment at the CERN Large Hadron Collider (LHC) is presently going for a major upgrade in order to fully exploit the scientific potential of the upcoming high luminosity run, scheduled to start in the year 2021. The high interaction rate and the large event size will result in an experimental data flow of about 1 TB/s from the detectors, which need to be processed before sending to the online computing system and data storage. This processing is done in a dedicated Common Readout Unit (CRU), proposed for data aggregation, trigger and timing distribution and control moderation. It act as common interface between sub-detector electronic systems, computing system and trigger processors. The interface links include GBT, TTC-PON and PCIe. GBT (Gigabit transceiver) is used for detector data payload transmission and fixed latency path for trigger distribution between CRU and detector readout electronics. TTC-PON (Timing, Trigger and Control via Passive Optical Network) is employed for time multiplex trigger distribution between CRU and Central Trigger Processor (CTP). PCIe (Peripheral Component Interconnect Express) is the high-speed serial computer expansion bus standard for bulk data transport between CRU boards and processors. In this article, we give an overview of CRU architecture in ALICE, discuss the different interfaces, along with the firmware design and implementation of CRU on the LHCb PCIe40 board.

  15. LWIR focal plane with digital readout demonstrating a passive free-space optical readout link

    NASA Astrophysics Data System (ADS)

    Mandl, William J.; Ennulat, Reinhard D.; Terrill, Conrad W.; Goossen, Keith W.

    1999-07-01

    Future high performance IR imaging system require high density focal planes containing up to one million or more detectors. Technological advances are needed to handle the resulting readout data rates in excess of Gbauds/sec and to minimize the on-focal-plane heat load caused by the currently used drivers and signal carrying cables connecting the focal plane inside the vacuum dewar with the outside signal processor. Optical interconnects are a practical alternative only for digital data because of the high non- linearity of the electrical to optical conversion process. We propose to solve these problems by A/D converting the detector signals on the focal pane (FPA) and using on-focal- plane quantum well light modulators to transform the electrical to optical signals. The latter are transmitted by a light beam from the FPA to the signal processor or the display electronics. The enabling technologies are the recently demonstrated on-focal-plane MOSAD converter achieving 14 bit dynamic range and the quantum well light modulators being develop by Lucent Technologies for highspeed bistable optical switches called SEED's for use in telecommunication. We will demonstrate one optical readout channel servicing 4 columns of a LWIR detector array mounted in an experimental dewar.

  16. Microfabricated emitter array for an ionic liquid electrospray thruster

    NASA Astrophysics Data System (ADS)

    Nakagawa, Kaito; Tsuchiya, Toshiyuki; Takao, Yoshinori

    2017-06-01

    We have fabricated needle-shaped emitters on a Si wafer by a MEMS process, and measured the voltage-current characteristics and the frequency dependence of a bipolar pulse voltage for ionic liquid electrospray thrusters, which can be mounted on nanosatellites ( ≲ 10 kg). Although the extracted current did not increase with increasing number of emitters, probably owing to the lack of uniformity of the emitters fabricated, we have demonstrated that the emitted current depends on the gap distance between the emitter and the extractor grid electrode, and low frequencies of the bipolar pulse voltage are desirable for thruster operation. Moreover, the Bosch process is required for fabricating a reservoir of ionic liquid, which prevents undesirable electrical short circuits, and the minimum emitter pitch to prevent loss of ion beams to the extractor is estimated to be about 400 µm.

  17. Power flow from a dipole emitter near an optical antenna.

    PubMed

    Huang, Kevin C Y; Jun, Young Chul; Seo, Min-Kyo; Brongersma, Mark L

    2011-09-26

    Current methods to calculate the emission enhancement of a quantum emitter coupled to an optical antenna of arbitrary geometry rely on analyzing the total Poynting vector power flow out of the emitter or the dyadic Green functions from full-field numerical simulations. Unfortunately, these methods do not provide information regarding the nature of the dominant energy decay pathways. We present a new approach that allows for a rigorous separation, quantification, and visualization of the emitter output power flow captured by an antenna and the subsequent reradiation power flow to the far field. Such analysis reveals unprecedented details of the emitter/antenna coupling mechanisms and thus opens up new design strategies for strongly interacting emitter/antenna systems used in sensing, active plasmonics and metamaterials, and quantum optics.

  18. Transit time and charge storage measurements in heavily doped emitters

    NASA Technical Reports Server (NTRS)

    Neugroschel, A.; Park, J. S.; Hwang, B. Y.

    1986-01-01

    A first direct measurement of the minority-carrier transit time in a transparent heavily doped emitter layer is reported. The value was obtained by a high-frequency conductance method recently developed and used for low-doped Si. The transit time coupled with the steady-state current enables the determination of the quasi-static charge stored in the emitter and the quasi-static emitter capacitance. Using a transport model, from the measured transit time, the value for the minority-carrier diffusion coefficient and mobility is estimated. The measurements were done using a heavily doped emitter of the Si p(+)-n-p bipolar transistor. The new result indicates that the position-averaged minority-carrier diffusion coefficients may be much smaller than the corresponding majority-carrier values for emitters having a concentration ranging from about 3 x 10 to the 19th per cu cm to 10 to the 20th per cu cm.

  19. Radiative performance of rare earth garnet thin film selective emitters

    SciTech Connect

    Lowe, R.A.; Chubb, D.L.; Good, B.S.

    1994-08-01

    In this paper the authors present the first emitter efficiency results for the thin film 40 percent Er-1.5 percent Ho YAG (Yttrium Aluminum Garnet, Y3Al5O12) and 25 percent Ho YAG selective emitter at 1500 K with a platinum substrate. Spectral emittance and emissive power measurements were made (1.2 less than lambda less than 3.2 microns). Emitter efficiency and power density are significantly improved with the addition of multiple rare earth dopants. Predicted efficiency results are presented for an optimized (equal power density in the Er, (4)I[sub 15/2]-(4)I[sub 13/2] at 1.5 microns, and Ho, (5)I[sub 7]-(5)I[sub 8] at 2.0 micron emission bands) Er-Ho YAG thin film selective emitter.

  20. Transit time and charge storage measurements in heavily doped emitters

    NASA Technical Reports Server (NTRS)

    Neugroschel, A.; Park, J. S.; Hwang, B. Y.

    1986-01-01

    A first direct measurement of the minority-carrier transit time in a transparent heavily doped emitter layer is reported. The value was obtained by a high-frequency conductance method recently developed and used for low-doped Si. The transit time coupled with the steady-state current enables the determination of the quasi-static charge stored in the emitter and the quasi-static emitter capacitance. Using a transport model, from the measured transit time, the value for the minority-carrier diffusion coefficient and mobility is estimated. The measurements were done using a heavily doped emitter of the Si p(+)-n-p bipolar transistor. The new result indicates that the position-averaged minority-carrier diffusion coefficients may be much smaller than the corresponding majority-carrier values for emitters having a concentration ranging from about 3 x 10 to the 19th per cu cm to 10 to the 20th per cu cm.

  1. Evaluations of carbon nanotube field emitters for electron microscopy

    NASA Astrophysics Data System (ADS)

    Nakahara, Hitoshi; Kusano, Yoshikazu; Kono, Takumi; Saito, Yahachi

    2009-11-01

    Brightness of carbon nanotube (CNT) emitters was already reported elsewhere. However, brightness of electron emitter is affected by a virtual source size of the emitter, which strongly depends on electron optical configuration around the emitter. In this work, I- V characteristics and brightness of a CNT emitter are measured under a practical field emission electron gun (e-gun) configuration to investigate availability of CNT for electron microscopy. As a result, it is obtained that an emission area of MWNT is smaller than its tip surface area, and the emission area corresponds to a five-membered-ring with 2nd nearest six-membered-rings on the MWNT cap surface. Reduced brightness of MWNT is measured as at least 2.6×109 A/m 2 sr V. It is concluded that even a thick MWNT has enough brightness under a practical e-gun electrode configuration and suitable for electron microscopy.

  2. Radiative Performance of Rare Earth Garnet Thin Film Selective Emitters

    NASA Technical Reports Server (NTRS)

    Lowe, Roland A.; Chubb, Donald L.; Good, Brian S.

    1994-01-01

    In this paper we present the first emitter efficiency results for the thin film 40 percent Er-1.5 percent Ho YAG (Yttrium Aluminum Garnet, Y3Al5O12) and 25 percent Ho YAG selective emitter at 1500 K with a platinum substrate. Spectral emittance and emissive power measurements were made (1.2 less than lambda less than 3.2 microns). Emitter efficiency and power density are significantly improved with the addition of multiple rare earth dopants. Predicted efficiency results are presented for an optimized (equal power density in the Er, (4)I(sub 15/2)-(4)I(sub 13/2) at 1.5 microns, and Ho, (5)I(sub 7)-(5)I(sub 8) at 2.0 micron emission bands) Er-Ho YAG thin film selective emitter.

  3. GTF Transverse and Longitudinal Emittance Data Analysis Technique

    SciTech Connect

    Not Available

    2010-12-07

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Measurements at the GTF include quadrupole scan transverse emittance measurements and linac phase scan longitudinal emittance measurements. Typically the beam size is measured on a screen as a function of a quadrupole current or linac phase and the beam matrix is then fit to the measured data. Often the emittance which is the final result of the measurement is the only number reported. However, the method used to reduce the data to the final emittance value can have a significant effect on the result. This paper describes in painful detail the methods used to analyze the transverse and longitudinal emittance data collected at the GTF.

  4. Handheld chemiresistive gas sensor readout system

    NASA Astrophysics Data System (ADS)

    Joubert, Trudi-Heleen; du Toit, Jurie; Mkwakikunga, Bonex; Bosscha, Peter

    2016-02-01

    Low-cost and non-invasive diabetes diagnosis is increasingly important [1], and this paper presents a handheld readout system for chemiresistive gas sensors in a breath acetone diagnostic application. The sensor contains reference and detection devices, used for the detection of gas concentration. Fabrication is by dropcasting a metaloxide nanowire solution onto gold interdigitated electrodes, which had been manufactured on silicon. The resulting layer is a wide bandgap n-type semiconductor material sensitive to acetone, producing a change in resistance between the electrode terminals [2]. Chemiresistive sensors typically require temperatures of 300-500 °C, while variation of sensing temperature is also employed for selective gas detection. The nano-structured functional material requires low temperatures due to large surface area, but heating is still required for acceptable recovery kinetics. Furthermore, UV illumination improves the sensor recovery [3], and is implemented in this system. Sensor resistances range from 100 Ω to 50 MΩ, while the sensor response time require a sampling frequency of 10Hz. Sensor resistance depends on temperature, humidity, and barometric pressure. The GE CC2A23 temperature sensor is used over a range of -10°C to 60°C, the Honeywell HIH5031 humidity sensor operates up to 85% over this temperature range, and the LPS331AP barometric pressure sensor measures up to 1.25 bar. Honeywell AWM43300V air flow sensors monitor the flow rate up to 1000 sccm. An LCD screen displays all the sensor data, as well as real time date and time, while all measurements are also logged in CSV-format. The system operates from a rechargeable battery.

  5. High-speed optical shutter coupled to fast-readout CCD camera

    NASA Astrophysics Data System (ADS)

    Yates, George J.; Pena, Claudine R.; McDonald, Thomas E., Jr.; Gallegos, Robert A.; Numkena, Dustin M.; Turko, Bojan T.; Ziska, George; Millaud, Jacques E.; Diaz, Rick; Buckley, John; Anthony, Glen; Araki, Takae; Larson, Eric D.

    1999-04-01

    A high frame rate optically shuttered CCD camera for radiometric imaging of transient optical phenomena has been designed and several prototypes fabricated, which are now in evaluation phase. the camera design incorporates stripline geometry image intensifiers for ultra fast image shutters capable of 200ps exposures. The intensifiers are fiber optically coupled to a multiport CCD capable of 75 MHz pixel clocking to achieve 4KHz frame rate for 512 X 512 pixels from simultaneous readout of 16 individual segments of the CCD array. The intensifier, Philips XX1412MH/E03 is generically a Generation II proximity-focused micro channel plate intensifier (MCPII) redesigned for high speed gating by Los Alamos National Laboratory and manufactured by Philips Components. The CCD is a Reticon HSO512 split storage with bi-direcitonal vertical readout architecture. The camera main frame is designed utilizing a multilayer motherboard for transporting CCD video signals and clocks via imbedded stripline buses designed for 100MHz operation. The MCPII gate duration and gain variables are controlled and measured in real time and up-dated for data logging each frame, with 10-bit resolution, selectable either locally or by computer. The camera provides both analog and 10-bit digital video. The camera's architecture, salient design characteristics, and current test data depicting resolution, dynamic range, shutter sequences, and image reconstruction will be presented and discussed.

  6. [Application of brain diffusion-weighted imaging performed using readout segmentation of long variable echo trains].

    PubMed

    Ishida, Go; Oishi, Makoto; Morii, Ken; Hasegawa, Kenji; Saito, Akihiko; Sato, Mitsuya; Takizawa, Osamu; Murata, Katsutoshi; Porter, D A; Matsuzawa, Hitoshi; Fujii, Yukihiko

    2015-01-01

    We report the preliminary use of the readout segmentation of long variable echo trains(RESOLVE)sequence, a novel magnetic resonance(MR)scanning technique based on a readout segmented echo planar imaging(EPI)strategy. RESOLVE enables high-resolution diffusion-weighted imaging(DWI)by minimizing susceptibility distortions and T2* blurring. The software for this sequence was provided by Siemens AG, Germany. Previously, we determined appropriate sequence parameters to obtain sufficiently high-resolution images through phantom studies. Then, we applied the sequence to some clinical cases with neurological disorders and analyzed the RESOLVE-DWI data with diffusion tensor imaging(DTI)techniques. In this article, we report clinical application of the RESOLVE sequence in two cases, one with cerebellar infarction and one with an intracranial epidermoid cyst. In both cases, RESOLVE-DWI clearly exposed structures that were obscured or severely distorted by artifacts on usual single-shot EPI-DWI. DTI analyses for RESOLVE-DWI data provided detailed information about fiber tracts and cranial nerves.

  7. Common Bias Readout for TES Array on Scanning Transmission Electron Microscope

    NASA Astrophysics Data System (ADS)

    Yamamoto, R.; Sakai, K.; Maehisa, K.; Nagayoshi, K.; Hayashi, T.; Muramatsu, H.; Nakashima, Y.; Mitsuda, K.; Yamasaki, N. Y.; Takei, Y.; Hidaka, M.; Nagasawa, S.; Maehata, K.; Hara, T.

    2016-07-01

    A transition edge sensor (TES) microcalorimeter array as an X-ray sensor for a scanning transmission electron microscope system is being developed. The technical challenge of this system is a high count rate of ˜ 5000 counts/second/array. We adopted a 64 pixel array with a parallel readout. Common SQUID bias, and common TES bias are planned to reduce the number of wires and the resources of a room temperature circuit. The reduction rate of wires is 44 % when a 64 pixel array is read out by a common bias of 8 channels. The possible degradation of the energy resolution has been investigated by simulations and experiments. The bias fluctuation effects of a series connection are less than those of a parallel connection. Simple calculations expect that the fluctuations of the common SQUID bias and common TES bias in a series connection are 10^{-7} and 10^{-3}, respectively. We constructed 8 SQUIDs which are connected to 8 TES outputs and a room temperature circuit for common bias readout and evaluated experimentally. Our simulation of crosstalk indicates that at an X-ray event rate of 500 cps/pixel, crosstalk will broaden a monochromatic line by about 0.01 %, or about 1.5 eV at 15 keV. Thus, our design goal of 10 eV energy resolution across the 0.5-15 keV band should be achievable.

  8. SiPM arrays and miniaturized readout electronics for compact gamma camera

    NASA Astrophysics Data System (ADS)

    Dinu, N.; Imando, T. Ait; Nagai, A.; Pinot, L.; Puill, V.; Callier, S.; Janvier, B.; Esnault, C.; Verdier, M.-A.; Raux, L.; Vandenbussche, V.; Charon, Y.; Menard, L.

    2015-07-01

    This article reports on the design and features of a very compact and light gamma camera based on SiPM arrays and miniaturized readout electronics dedicated to tumor localization during radio-guided cancer surgery. This gamma camera, called MAGICS, is composed of four (2×2) photo-detection elementary modules coupled to an inorganic scintillator. The 256 channels photo-detection system covers a sensitive area of 54×53 m2. Each elementary module is based on four (2×2) SiPM monolithic arrays, each array consisting of 16 SiPM photo-sensors (4×4) with 3×3 mm2 sensitive area, coupled to a miniaturized readout electronics and a dedicated ASIC. The overall dimensions of the electronics fit the size of the detector, enabling to assemble side-by-side several elementary modules in a close-packed arrangement. The preliminary performances of the system are very encouraging, showing an energy resolution of 9.8% and a spatial resolution of less than 1 mm at 122 keV.

  9. Radiative interactions with micromachined surfaces: Spectral polarized emittance

    SciTech Connect

    Zemel, J.N.

    1991-01-01

    The spectral, angular, polarized emittance (SAPE) is a simple means for observing the allowed electromagnetic energy states associated with periodic structures whose dimensions are comparable to the wavelength of the observed light. Other methods for measuring absorption are far more time consuming when a broad survey is of interest. An extensive body of SAPE data was obtained on 350-- 400{degrees}C intrinsic silicon lamellar gratings. Current approximations to the vector wave equation such as guided wave, modal and Bloch wave methods provided insight into our experiments. A qualitative picture of the stationary electromagnetic states (SES) of lamellar gratings has been developed which agrees with experiment for a number of polarizations, and angular orientations of the emission k vector relative to the gratings. However, one type of emission does not fit any simple model we have examined and raises intriguing questions about emission from grating structures. A new, higher angular resolution emissometer (0.8{degrees} instead of 5{degrees}) has been completed. This system significantly increases the wavelength range from the current 3--14 {mu}m range to 2-25{mu}m, a doubling of the spectral regime. The system is currently in a shakedown'' mode. Preliminary data indicates that the new emissometer meets the design goals. 24 refs., 10 figs.

  10. Theory and measurements of emittance preservation in plasma wakefield acceleration

    SciTech Connect

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  11. Highly multiplexed signal readout for a time-of-flight positron emission tomography detector based on silicon photomultipliers.

    PubMed

    Cates, Joshua W; Bieniosek, Matthew F; Levin, Craig S

    2017-01-01

    Maintaining excellent timing resolution in the generation of silicon photomultiplier (SiPM)-based time-of-flight positron emission tomography (TOF-PET) systems requires a large number of high-speed, high-bandwidth electronic channels and components. To minimize the cost and complexity of a system's back-end architecture and data acquisition, many analog signals are often multiplexed to fewer channels using techniques that encode timing, energy, and position information. With progress in the development SiPMs having lower dark noise, after pulsing, and cross talk along with higher photodetection efficiency, a coincidence timing resolution (CTR) well below 200 ps FWHM is now easily achievable in single pixel, bench-top setups using 20-mm length, lutetium-based inorganic scintillators. However, multiplexing the output of many SiPMs to a single channel will significantly degrade CTR without appropriate signal processing. We test the performance of a PET detector readout concept that multiplexes 16 SiPMs to two channels. One channel provides timing information with fast comparators, and the second channel encodes both position and energy information in a time-over-threshold-based pulse sequence. This multiplexing readout concept was constructed with discrete components to process signals from a [Formula: see text] array of SensL MicroFC-30035 SiPMs coupled to [Formula: see text] Lu1.8Gd0.2SiO5 (LGSO):Ce (0.025 mol. %) scintillators. This readout method yielded a calibrated, global energy resolution of 15.3% FWHM at 511 keV with a CTR of [Formula: see text] FWHM between the 16-pixel multiplexed detector array and a [Formula: see text] LGSO-SiPM reference detector. In summary, results indicate this multiplexing scheme is a scalable readout technique that provides excellent coincidence timing performance.

  12. Powerful ultrawideband rf emitters: status and challenges

    NASA Astrophysics Data System (ADS)

    Agee, Forrest J.; Scholfield, David W.; Prather, William D.; Burger, Jeffrey W.

    1995-09-01

    Ultra-wideband emitters are of interest for a variety of potential applications that range from radar transmitters to communications applications. This technology is of current interest to the USAF Phillips Laboratory where theoretical and experimental efforts have been underway for a number of years. Research into the production of ultra-wideband sources at the Phillips Laboratory has been accomplished along several different technology lines. The approaches include three main thrusts: 1) very powerful hydrogen spark gap pulsers, 2) compact hydrogen gas switches in conjunction with high gain ultra-wideband antennas and, 3) solid state switched array antennas. This paper reviews the progress-to-date along these lines and identifies some pacing research obastacles that limit further improvements.

  13. Odd-odd deformed proton emitters.

    PubMed

    Ferreira, L S; Maglione, E

    2001-02-26

    Proton decay from odd-odd deformed nuclei is a long-standing unsolved problem. We present for the first time an exact solution using single particle Nilsson resonances. The lifetime is found to depend strongly on the single particle level occupied by the unpaired neutron, allowing a clear assignment of its Nilsson level. The emitters 112Cs, 140Ho, 150Lu, and 150Lu(m) are considered. The agreement with the experimental data is very good with deformations 0.1

  14. Plasma treatment for producing electron emitters

    DOEpatents

    Coates, Don Mayo; Walter, Kevin Carl

    2001-01-01

    Plasma treatment for producing carbonaceous field emission electron emitters is disclosed. A plasma of ions is generated in a closed chamber and used to surround the exposed surface of a carbonaceous material. A voltage is applied to an electrode that is in contact with the carbonaceous material. This voltage has a negative potential relative to a second electrode in the chamber and serves to accelerate the ions toward the carbonaceous material and provide an ion energy sufficient to etch the exposed surface of the carbonaceous material but not sufficient to result in the implantation of the ions within the carbonaceous material. Preferably, the ions used are those of an inert gas or an inert gas with a small amount of added nitrogen.

  15. Gamma emitters in Hong Kong water

    SciTech Connect

    Shun-Yin, L.; Chung-Keung, M.; Wai-Kwok, N.; Shiu-Chun, A. )

    1990-01-01

    Radioactivity in water originates from natural and artificial sources. The development of a nuclear powerplant near Hong Kong necessitates that attention be given to formulating techniques to assess the possible resultant environmental radioactive contamination. Water samples collected from various sites in Hong Kong in the spring and summer of 1987, representing seawater, river water, reservoir water, drinking water, and underground water were studied through gamma-ray spectral analysis. Only gamma emitters in the U238 and Th232 series and K40 were detected. No fission product was detected with specific activity above 0.1 Bq/kg. The data could be the baseline for future monitoring of the radioactivity released from a nuclear plant being built at a 50-km distance from Hong Kong. The variation of detected specific activities may be due to geological differences and the effect of plants. 1 ref., 3 tabs.

  16. New strongly deformed proton emitter: 117La

    NASA Astrophysics Data System (ADS)

    Soramel, F.; Guglielmetti, A.; Stroe, L.; Müller, L.; Bonetti, R.; Poli, G. L.; Malerba, F.; Bianchi, E.; Andrighetto, A.; Guo, J. Y.; Li, Z. C.; Maglione, E.; Scarlassara, F.; Signorini, C.; Liu, Z. H.; Ruan, M.; Ivaşcu, M.; Broude, C.; Bednarczyk, P.; Ferreira, L. S.

    2001-03-01

    The decay by proton emission of the 117La nucleus has been studied via the 310 MeV 58Ni+64Zn reaction. The nucleus has two levels that decay to the ground state of 116Ba with Ep=783(6) keV (T1/2=22(5) ms] and Ep=933(10) keV [T1/2=10(5) ms]. Calculations performed for a deformed proton emitter reproduce quite well the experimental results confirming that 117La is strongly deformed (β2~0.3). Spin and parity of the two p-decaying levels have been determined as well: 3/2+ for the ground state and 9/2+ for the Ex=151(12) keV excited state.

  17. Lyman Alpha Emitters and Galaxy Formation Scenarios

    NASA Astrophysics Data System (ADS)

    Malhotra, S.; Kovac, K.; Somerville, R.; Moustakas, L.; Rhoads, J. E.

    2002-12-01

    The Large Area Lyman Alpha (LALA) survey has successfully identified the population of young Lyman-alpha emitting galaxies predicted about 35 years ago. High equivalent widths of the Lyman-alpha line in these sources suggest that they are a very young (age < 107 years), metal poor, population of stars at redshifts 4.5 and 5.7, making them very interesting objects to study in the context of galaxy formation scenarios. We have begun to do exactly this using the correlation function of LALA galaxies. While the strong correlation function indicates massive halos, the volume density of Lyman-alpha sources and the faint continuum levels indicate low-mass stellar systems. This discrepancy can be resolved by postulating multiple emitters in a single halo.

  18. Multiwire secondary-emission monitor and the emittance measurement of the AGS beam

    SciTech Connect

    Weng, W.T.; Chiang, I.H.; Smith, G.A.; Soukas, A.

    1983-01-01

    For CBA injection the transverse emittances and the Twiss parameters of the AGS beam have to be well defined to minimize the phase space dilution in CBA. Althoug there exists a profile monitor device at U165, there are three reasons why construction of multiwire profile monitor system at three locations from U500 to U168 is required: (1) the dispersion function is not zero at U165 which makes it harder to interpret the measurement; (2) the original single wire device takes five minutes to traverse the whole beam; (3) a three station multiwire system can provide the profile information at all locations in one pulse which makes on-line analysis possible. In summary, a set of three stations of Multiwire Secondary Emission Monitor (MSEM) has been built and installed in the fast external beam line for the measurement of beam profiles. Each unit consists of two planes each with 30 nickel wires having a diameter of 5 mils. The signal is linear within the range of 10/sup 10/ to 10/sup 13/ incident protons on the wire and the resolution of the signal is well within a few percent. A least-square fitting routine has been used to extract the emittance and phase space parameters of the beam. The emittances obtained at various intensities will help us to understand the AGS acceleration process and to choose the optimal injection scheme for CBA.

  19. Detectability of a Direct Sequence Emitter within a Network of Direct Sequence Emitters,

    DTIC Science & Technology

    1988-01-01

    interception over 1/R propagation paths requires very large, ground-based antennas in order to achieve a usable intercept Signal-to- Noise Ratio (SNR). On...the other hand, free space, 1/R 2 propagation paths provide intercept receivers with signal power levels well above tne thermal noise power even when...large enough to resolve individual emitters are too large to put on aircraft as required to achieve the necessary free space propagation. Hence, the

  20. Determination and error analysis of emittance and spectral emittance measurements by remote sensing. [of leaves, soil and plant canopies

    NASA Technical Reports Server (NTRS)

    Kumar, R.

    1977-01-01

    Theoretical and experimental determinations of the emittance of soils and leaves are reviewed, and an error analysis of emittance and spectral emittance measurements is developed as an aid to remote sensing applications. In particular, an equation for the upper bound of the absolute error in an emittance determination is derived. The absolute error is found to decrease with an increase in contact temperature and to increase with an increase in environmental integrated radiant flux density. The difference between temperature and band radiance temperature is plotted as a function of emittance for the wavelength intervals 4.5 to 5.5 microns, 8 to 13.5 microns and 10.2 to 12.5 microns.

  1. Physical electrostatics of small field emitter arrays/clusters

    NASA Astrophysics Data System (ADS)

    Forbes, Richard G.

    2016-08-01

    This paper aims to improve qualitative understanding of electrostatic influences on apex field enhancement factors (AFEFs) for small field emitter arrays/clusters. Using the "floating sphere at emitter-plate potential" (FSEPP) model, it re-examines the electrostatics and mathematics of three simple systems of identical post-like emitters. For the isolated emitter, various approaches are noted. An adequate approximation is to consider only the effects of sphere charges and (for significantly separated emitters) image charges. For the 2-emitter system, formulas are found for charge-transfer ("charge-blunting") effects and neighbor-field effects, for widely spaced and for "sufficiently closely spaced" emitters. Mutual charge-blunting is always the dominant effect, with a related (negative) fractional AFEF-change δtwo. For sufficiently small emitter spacing c, |δtwo| varies approximately as 1/c; for large spacing, |δtwo| decreases as 1/c3. In a 3-emitter equispaced linear array, differential charge-blunting and differential neighbor-field effects occur, but differential charge-blunting effects are dominant, and cause the "exposed" outer emitters to have higher AFEF (γ0) than the central emitter (γ1). Formulas are found for the exposure ratio Ξ = γ0/γ1, for large and for sufficiently small separations. The FSEPP model for an isolated emitter has accuracy around 30%. Line-charge models (LCMs) are an alternative, but an apparent difficulty with recent LCM implementations is identified. Better descriptions of array electrostatics may involve developing good fitting equations for AFEFs derived from accurate numerical solution of Laplace's equation, perhaps with equation form(s) guided qualitatively by FSEPP-model results. In existing fitting formulas, the AFEF-reduction decreases exponentially as c increases, which is different from the FSEPP-model formulas. This discrepancy needs to be investigated, using systematic Laplace-based simulations and appropriate results

  2. Avalanche current read-out circuit for low jitter parallel photon timing.

    PubMed

    Crotti, M; Rech, I; Gulinatti, A; Ghioni, M

    2013-08-01

    We propose a novel circuit for single photon avalanche diode (SPAD) current read-out, for photon timing applications. The circuit consists of a single transistor trans-impedance amplifier with a GHz bandwidth: the feedback loop fixes the SPAD anode voltage and allows us to obtain a high time resolution with a very high equivalent current threshold (almost 700 μA). The trans-impedance stage is followed by a low pass filter that reduces the crosstalk of other on-chip detectors and makes the designed structure suitable for multi-detector systems. The discrete components prototype presented in this letter achieves a state-of-art resolution of 34.4 ps FWHM, presents negligible crosstalk between the different pixels and opens the way for the development of an integrated structure with a large number of channels.

  3. Double side read-out technique for mitigation of radiation damage effects in PbWO4 crystals

    NASA Astrophysics Data System (ADS)

    Lucchini, M. T.; Auffray, E.; Benaglia, A.; Cavallari, F.; Cockerill, D.; Dolgopolov, A.; Faure, J. L.; Golubev, N.; Hobson, P. R.; Jain, S.; Korjik, M.; Mechinski, V.; Singovski, A.; Tabarelli de Fatis, T.; Tarasov, I.; Zahid, S.

    2016-04-01

    Test beam results of a calorimetric module based on 3×3×22 cm3 PbWO4 crystals, identical to those used in the CMS ECAL Endcaps, read out by a pair of photodetectors coupled to the two opposite sides (front and rear) of each crystal are presented. Nine crystals with different level of induced absorption, from 0 to 20 m-1, have been tested using electrons in the 50-200 GeV energy range. Photomultiplier tubes have been chosen as photodetectors to allow for a precise measurement of highly damaged crystals. The information provided by this double side read-out configuration allows to correct for event-by-event fluctuations of the longitudinal development of electromagnetic showers. By strongly mitigating the effect of non-uniform light collection efficiency induced by radiation damage, the double side read-out technique significantly improves the energy resolution with respect to a single side read-out configuration. The non-linearity of the response arising in damaged crystals is also corrected by a double side read-out configuration and the response linearity of irradiated crystals is restored. In high radiation environments at future colliders, as it will be the case for detectors operating during the High Luminosity phase of the Large Hadron Collider, defects can be created inside the scintillator volume leading to a non-uniform response of the calorimetric cell. The double side read-out technique presented in this study provides a valuable way to improve the performance of calorimeters based on scintillators whose active volumes are characterized by high aspect ratio cells similar to those used in this study.

  4. R&D on a novel spectro-imaging polarimeter with Micromegas detectors and a Caliste readout system

    NASA Astrophysics Data System (ADS)

    Attié, D.; Blondel, C.; Boilevin-Kayl, L.; Desforges, D.; Ferrer-Ribas, E.; Giomataris, I.; Gevin, O.; Jeanneau, F.; Limousin, O.; Meuris, A.; Papaevangelou, T.; Peyaud, A.

    2015-07-01

    Micromegas detectors, part of the Micro-Pattern Gaseous Detectors (MPGD) family, are used in a very wide range of applications in the High Energy Physics community but also in astroparticle and neutrino physics. In most of the Micromegas applications the design of the detector vessel and the readout plane is extremely coupled. A way of dissociating these two components would be by separating the amplification structure and the detector volume from the readout plane and electronics. This is achieved with the so called piggyback Micromegas detectors. They open up new possibilities of applications in terms of adaptability to new electronics. In particular piggyback resistive Micromegas can be easily coupled to modern pixel array electronic ASICs. First tests have been carried out with a Medipix chip where the protection of the resistive layer has been proved. The results of very recent tests coupling piggyback Micromegas with the readout module of Caliste are presented. Caliste is a high performance spectro-imager with event time-tagging capability, able to detect photons between 2 keV and 250 keV in the context of a spatial micro spectro-imaging polarimetrer. In the current application, with the Piggyback Micromegas, we use the readout module only as the sensitive detector. We benefit of the good spatial resolution thanks to the high density readout pixels ( 600 μm pixel pitch), to the low noise, to the low power and to the radiation hard integrated front-end IDEF-X electronics. The advantage of such a device is to have a high gain, low noise, low threshold, and robust detector operating at room temperature. This would be very attractive for spatial applications, for instance X-ray polarisation.

  5. Double side read-out technique for mitigation of radiation damage effects in PbWO4 crystals

    DOE PAGES

    Lucchini, Marco Toliman; Auffray, E.; Benaglia, A.; ...

    2016-04-18

    Test beam results of a calorimetric module based on 3×3×22 cm3 PbWO4 crystals, identical to those used in the CMS ECAL Endcaps, read out by a pair of photodetectors coupled to the two opposite sides (front and rear) of each crystal are presented. Nine crystals with different level of induced absorption, from 0 to 20 m-1, have been tested using electrons in the 50–200 GeV energy range. Photomultiplier tubes have been chosen as photodetectors to allow for a precise measurement of highly damaged crystals. The information provided by this double side read-out configuration allows to correct for event-by-event fluctuations ofmore » the longitudinal development of electromagnetic showers. By strongly mitigating the effect of non-uniform light collection efficiency induced by radiation damage, the double side read-out technique significantly improves the energy resolution with respect to a single side read-out configuration. The non-linearity of the response arising in damaged crystals is also corrected by a double side read-out configuration and the response linearity of irradiated crystals is restored. In high radiation environments at future colliders, as it will be the case for detectors operating during the High Luminosity phase of the Large Hadron Collider, defects can be created inside the scintillator volume leading to a non-uniform response of the calorimetric cell. As a result, the double side read-out technique presented in this study provides a valuable way to improve the performance of calorimeters based on scintillators whose active volumes are characterized by high aspect ratio cells similar to those used in this study.« less

  6. Double side read-out technique for mitigation of radiation damage effects in PbWO4 crystals

    SciTech Connect

    Lucchini, Marco Toliman; Auffray, E.; Benaglia, A.; Cavallari, F.; Cockerill, D.; Dolgopolov, A.; Faure, J. L.; Hobson, P. R.; Jain, S.; Korjik, M.; Mechinski, V.; Singovski, A.; de Fatis, T. Tabarelli; Tarasov, I.; Zahid, S.

    2016-04-18

    Test beam results of a calorimetric module based on 3×3×22 cm3 PbWO4 crystals, identical to those used in the CMS ECAL Endcaps, read out by a pair of photodetectors coupled to the two opposite sides (front and rear) of each crystal are presented. Nine crystals with different level of induced absorption, from 0 to 20 m-1, have been tested using electrons in the 50–200 GeV energy range. Photomultiplier tubes have been chosen as photodetectors to allow for a precise measurement of highly damaged crystals. The information provided by this double side read-out configuration allows to correct for event-by-event fluctuations of the longitudinal development of electromagnetic showers. By strongly mitigating the effect of non-uniform light collection efficiency induced by radiation damage, the double side read-out technique significantly improves the energy resolution with respect to a single side read-out configuration. The non-linearity of the response arising in damaged crystals is also corrected by a double side read-out configuration and the response linearity of irradiated crystals is restored. In high radiation environments at future colliders, as it will be the case for detectors operating during the High Luminosity phase of the Large Hadron Collider, defects can be created inside the scintillator volume leading to a non-uniform response of the calorimetric cell. As a result, the double side read-out technique presented in this study provides a valuable way to improve the performance of calorimeters based on scintillators whose active volumes are characterized by high aspect ratio cells similar to those used in this study.

  7. Design and Measurement of a Low-Noise 64-Channels Front-End Readout ASIC for CdZnTe Detectors

    SciTech Connect

    Gan, Bo; Wei, Tingcun; Gao, Wu; Liu, Hui; Hu, Yann

    2015-07-01

    Cadmium zinc telluride (CdZnTe) detectors, as one of the principal detectors for the next-generation X-ray and γ-ray imagers, have high energy resolution and supporting electrode patterning in the radiation environment at room-temperature. In the present, a number of internationally renowned research institutions and universities are actively using these detector systems to carry out researches of energy spectrum analysis, medical imaging, materials characterization, high-energy physics, nuclear plant monitoring, and astrophysics. As the most important part of the readout system for the CdZnTe detector, the front-end readout application specific integrated circuit (ASIC) would have an important impact on the performances of the whole detector system. In order to ensure the small signal to noise ratio (SNR) and sufficient range of the output signal, it is necessary to design a front-end readout ASIC with very low noise and very high dynamic range. In addition, radiation hardness should be considered when the detectors are utilized in the space applications and high energy physics experiments. In this paper, we present measurements and performances of a novel multi-channel radiation-hardness low-noise front-end readout ASIC for CdZnTe detectors. The readout circuits in each channel consist of charge sensitive amplifier, leakage current compensation circuit (LCC), CR-RC shaper, S-K filter, inverse proportional amplifier, peak detect and hold circuit (PDH), discriminator and trigger logic, time sequence control circuit and driving buffer. All of 64 readout channels' outputs enter corresponding inputs of a 64 channel multiplexer. The output of the mux goes directly out of the chip via the output buffer. The 64-channel readout ASIC is implemented using the TSMC 0.35 μm mixed-signal CMOS technology. The die size of the prototype chip is 2.7 mm x 8 mm. At room temperature, the equivalent noise level of a typical channel reaches 66 e{sup -} (rms) at zero farad for a power

  8. Transmission type flat-panel X-ray source using ZnO nanowire field emitters

    SciTech Connect

    Chen, Daokun; Song, Xiaomeng; Zhang, Zhipeng; Chen, Jun; Li, Ziping; She, Juncong; Deng, Shaozhi; Xu, Ningsheng

    2015-12-14

    A transmission type flat-panel X-ray source in diode structure was fabricated. Large-scale patterned ZnO nanowires grown on a glass substrate by thermal oxidation were utilized as field emitters, and tungsten thin film coated on silica glass was used as the transmission anode. Uniform distribution of X-ray generation was achieved, which benefited from the uniform electron emission from ZnO nanowires. Self-ballasting effect induced by the intrinsic resistance of ZnO nanowire and decreasing of screening effect caused by patterned emitters account for the uniform emission. Characteristic X-ray peaks of W-L lines and bremsstrahlung X-rays have been observed under anode voltages at a range of 18–20 kV, the latter of which were the dominant X-ray signals. High-resolution X-ray images with spatial resolution less than 25 μm were obtained by the flat-panel X-ray source. The high resolution was attributed to the small divergence angle of the emitted X-rays from the transmission X-ray source.

  9. Controlled mode tuning in 1-D 'RIM' plasmonic crystal trench cavities probed with coupled optical emitters.

    PubMed

    Liu, Tsung-li; Russell, Kasey J; Cui, Shanying; Hu, Evelyn L

    2013-12-02

    We present a design of plasmonic cavities that consists of two sets of 1-D plasmonic crystal reflectors on a plasmonic trench waveguide. A 'reverse image mold' (RIM) technique was developed to pattern high-resolution silver trenches and to embed emitters at the cavity field maximum, and FDTD simulations were performed to analyze the frequency response of the fabricated devices. Distinct cavity modes were observed from the photoluminescence spectra of the organic dye embedded within these cavities. The cavity geometry facilitates tuning of the modes through a change in cavity dimensions. Both the design and the fabrication technique presented could be extended to making trench waveguide-based plasmonic devices and circuits.

  10. Design of linear sweep source based on DDS used in readout system for wireless passive pressure sensor

    NASA Astrophysics Data System (ADS)

    Hong, Yingping; Zheng, Tingli; Liang, Ting; Cao, Qun; Zhang, Hairui; Xiong, Jijun

    2014-12-01

    This paper proposes the design and research on the high bandwidth linear frequency sweep signal source involved in the readout unit module of the wireless passive pressure sensor in high temperature based on the principle of mutual inductance coupling which is applied widely at present. The operating principle of the linear sweep frequency source based on the direct digital frequency synthesis (DDS) technology is introduced, and the implementation method of the hardware circuit and logic sequential control process required in our system has been realized utilizing this technology. Through the experiments under different conditions of the step value, the sweep range and other related design indicators, the influence on the extraction method of resonance frequency information, extraction accuracy, and others during the readout system of the mutual inductance coupling sensor are analyzed and studied. The design of the linear frequency sweep signal source is realized with a resonance frequency change resolution of 6 kHz, a minimum step value of 1 kHz, and a precision of frequency for 0.116 Hz within the sweep width of 1 MHz-100 MHz. Due to the use of the integrated commercial chip, the linear sweep frequency source is made small in size, high working frequency, high resolution and low step values for the readout unit modularized of a higher application value.

  11. A MEMS-based infrared emitter array for combat identification

    NASA Astrophysics Data System (ADS)

    San, Haisheng; Chen, Xuyuan; Xu, Peng; Li, Fangqiang; Cheng, Meiying

    2008-04-01

    The silicon-based MEMS (MEMS: microelectromechanical systems) Infrared (IR) emitter arrays of 1x2, 2x2 and 3x3 elements are presented. The MEMS infrared emitters were fabricated on silicon-on-insulator (SOI) wafer. The resistively heated poly-silicon membrane fabricated by using deep reactive ion etching (DRIE) process on backside of SOI wafer make a low thermal mass structure, thus this IR-emitter can be modulated at high frequency. A heavily boron doping technology enable the supporting silicon layer to absorb the infrared radiation. As a result, the self-heating effect will reduce the power loss. By using the SOI wafer, the fabrication processes are simplified, and the production costs are decreased. In experiment, the surface temperature distribution of IR emitter arrays were measured by thermal imaging system, and the optical spectrum and modulation characteristics were measured by spectroradiometer. The measured results show that the IR emitter arrays exhibit a strong emission in middle infrared range, and the modulation frequency at 0.5 modulation depth is about 30Hz. The emitter arrays are expected to improve performance by using suspended membrane and sealed package structure. It is expected that the IR emitter arrays can be used for increasing the visible intensity and distance in the application of infrared Combat Identification.

  12. Emittance growth mechanisms for laser-accelerated proton beams.

    PubMed

    Kemp, Andreas J; Fuchs, J; Sentoku, Y; Sotnikov, V; Bakeman, M; Antici, P; Cowan, T E

    2007-05-01

    In recent experiments the transverse normalized rms emittance of laser-accelerated MeV ion beams was found to be < 0.002 mm mrad, which is at least 100 times smaller than the emittance of thermal ion sources used in accelerators [T. E. Cowan, Phys. Rev. Lett. 92, 204801 (2004)]. We investigate the origin for the low emittance of laser-accelerated proton beams by studying several candidates for emittance-growth mechanisms. As our main tools, we use analytical models and one- and two-dimensional particle-in-cell simulations that have been modified to include binary collisions between particles. We find that the dominant source of emittance is filamentation of the laser-generated hot electron jets that drive the ion acceleration. Cold electron-ion collisions that occur before ions are accelerated contribute less than ten percent of the final emittance. Our results are in qualitative agreement with the experiment, for which we present a refined analysis relating emittance to temperature, a better representative of the fundamental beam physics.

  13. DETECTORS AND EXPERIMENTAL METHODS: Design and test of a Multi-gap Resistive Plate Chamber with Long readout-strip (LMRPC)

    NASA Astrophysics Data System (ADS)

    Sun, Yong-Jie; Li, Cheng; Zhou, Yi; Shao, Ming; Zhao, Yan-E.; Chen, Hong-Fang

    2009-02-01

    A new kind (two end readout) of Multi-gap Resistive Plate Chamber with long readout-strip (LMRPC) is developed to be used at the large-area Muon Telescope Detector (MTD) at mid-rapidity at RHIC/STAR experiment for Time-of-Flight (TOF) measurement. The LMRPC has an active area of 87 cm × 17 cm, 10 gas gaps of 250 μm arranged in 2 stacks, with readout strips of 2.5 cm wide and 90 cm long. The considerations in LMRPC design related to its performance are discussed in this paper. The cosmic ray test results of a prototype LMRPC show a detection efficiency >95% and the time resolution ~70 ps.

  14. Effect of readout direction in the edge profile on the modulation transfer function of computed radiographic systems by use of the edge method.

    PubMed

    Tanaka, Nobukazu; Morishita, Junji; Tsuda, Norisato; Ohki, Masafumi

    2013-07-01

    We investigated the effect of the readout direction of the edge profile obtained by the edge method on the presampled modulation transfer function (MTF) in various computed radiographic (CR) systems. There were no differences in the MTFs derived from two edge profiles in the sub-scanning direction of four CR systems used in this study. On the other hand, the MTFs measured at a readout direction from the low (edge) to the high (direct exposure) exposure region were higher than those measured at a readout direction from the high to the low exposure region in the laser-beam scanning direction for three of the four CR systems. Although this phenomenon depends on the CR system, it is important to understand and indicate both MTFs at the two edge profiles in the laser-beam scanning direction for accurate assessment of the resolution property.

  15. FASTBUS Readout Controller card for high speed data acquisition

    SciTech Connect

    Zimmermann, S. Rio Grande do Sul Univ., Porto Alegre, RS . Dept. of Electrical Engineering); Areti, V.H.; Foster, G.W.; Joshi, U.; Treptow, K. )

    1991-10-01

    This article describes a FASTBUS Readout Controller (FRC) for high speed data acquisition in FASTBUS based systems. The controller has two main interfaces: to FASTBUS and to a Readout Port. The FASTBUS interface performs FASTBUS master and slave operations at a maximum transfer rate exceeding 40 MBytes/s. The Readout Port can be adapted for a variety of protocols. Currently, it will be interfaced to a VME bus based processor with a VSB port. The on-board LR33000 embedded processor controls the readout, executing a list of operations download into its memory. It scans the FASTBUS modules and stores the data in a triple port DRAM (TPDRAM), through one of the Serial Access Memory (SAM) ports of the (TPDRAM). Later, it transfers this data to the readout port using the other SAM. The FRC also supports serial communication via RS232 and Ethernet interfaces. This device is intended for use in the data acquisition system at the Collider Detector at Fermilab. 5 refs., 3 figs.

  16. Hyper Suprime-Cam: development of the CCD readout electronics

    NASA Astrophysics Data System (ADS)

    Nakaya, Hidehiko; Uchida, Tomohisa; Miyatake, Hironao; Fujimori, Hiroki; Mineo, Sogo; Aihara, Hiroaki; Furusawa, Hisanori; Kamata, Yukiko; Karoji, Hiroshi; Kawanomoto, Satoshi; Komiyama, Yutaka; Miyazaki, Satoshi; Morokuma, Tomoki; Obuchi, Yoshiyuki; Okura, Yuki; Tanaka, Manobu; Tanaka, Yoko; Uraguchi, Fumihiro; Utsumi, Yosuke

    2010-07-01

    Hyper Suprime-Cam (HSC) employs 116 of 2k×4k CCDs with 464 signal outputs in total. The image size exceeds 2 GBytes, and the data can be readout every 10 seconds which results in the data rate of 210 Mbytes / sec. The data is digitized to 16-bit. The readout noise of the electronics at the readout time of 20 seconds is ~0.9 ADU, and the one with CCD is ~1.5 ADU which corresponds to ~4.5 e. The linearity error fits within +/- 0.5 % up to 150,000 e. The CCD readout electronics for HSC was newly developed based on the electronics for Suprime-Cam. The frontend electronics (FEE) is placed in the vacuum dewar, and the backend electronics (BEE) is mounted on the outside of the dewar on the prime focus unit. The FEE boards were designed to minimize the outgas and to maximize the heat transfer efficiency to keep the vacuum of the dewar. The BEE boards were designed to be simple and small as long as to achieve the readout time within 10 seconds. The production of the system has been finished, and the full set of the boards are being tested with several CCDs installed in the HSC dewar. We will show the system design, performance, and the current status of the development.

  17. A 2.5 mW/ch, 50 Mcps, 10-Analog Channel, Adaptively Biased Read-Out Front-End IC With Low Intrinsic Timing Resolution for Single-Photon Time-of-Flight PET Applications With Time-Dependent Noise Analysis in 90 nm CMOS.

    PubMed

    Cruz, Hugo; Huang, Hong-Yi; Luo, Ching-Hsing; Lee, Shuenn-Yuh

    2017-04-01

    This paper presents a 10-channel time-of-flight application-specific integrated circuit (ASIC) for positron emission tomography in a 90 nm standard CMOS process. To overcome variations in channel-to-channel timing resolution caused by mismatch and process variations, adaptive biases and a digital-to-analog converter (DAC) are utilized. The main contributions of this work are as follows. First, multistage architectures reduce the total power consumption, and detection bandwidths of analog preamplifiers and comparators are increased to 1 and 1.5 GHz, respectively, relative to those in previous studies. Second, a total intrinsic electronic timing resolution of 9.71 ps root-mean-square (RMS) is achieved (13.88 ps peak and 11.8 ps average of the 10 channels in 5 ASICs). Third, the proposed architecture reduces variations in channel-to-channel timing resolution to 2.6 bits (equivalent to 4.17 ps RMS) by calibrating analog comparator threshold levels. A 181.5 ps full-width-at-half-maximum timing resolution is measured with an avalanche photo diode and a laser setup. The power consumption is 2.5 mW using 0.5 and 1.2 V power supplies. The proposed ASIC is implemented in a 90 nm TSMC CMOS process with a total area of 3.3 mm × 2.7 mm.

  18. Stimulated longitudinal emittance growth in the Main Ring

    SciTech Connect

    Jackson, G.; Ieiri, T.

    1989-03-01

    During fixed target operations -- beam intensity is limited by coherent instabilities in both the Main Ring and Tevatron. The growth rates for instabilities are generally inversely proportional to the proton bunch length. Since fixed target operations are insensitive to the longitudinal emittance of the beams, bunch spreaders are employed to increase the emittance, and hence the bunch length. Emittance growth is stimulated by injecting noise onto either the RF phase or amplitude control voltages. Test results of the efficiency of various stimulation schemes are reported. The design of a bunch length monitor, used to measure the effect of the bunch spreader, is also presented. 12 refs., 5 figs.

  19. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    SciTech Connect

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 #6;± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  20. Thermal limit to the intrinsic emittance from metal photocathodes

    SciTech Connect

    Feng, Jun Nasiatka, J.; Wan, Weishi; Karkare, Siddharth; Padmore, Howard A.; Smedley, John

    2015-09-28

    Measurements of the intrinsic emittance and transverse momentum distributions obtained from a metal (antimony thin film) photocathode near and below the photoemission threshold are presented. Measurements show that the intrinsic emittance is limited by the lattice temperature of the cathode as the incident photon energy approaches the photoemission threshold. A theoretical model to calculate the transverse momentum distributions near this photoemission threshold is presented. An excellent match between the experimental measurements and the theoretical calculations is demonstrated. These measurements are relevant to low emittance electron sources for Free Electron Lasers and Ultrafast Electron Diffraction experiments.