Evaluation of Two Guralp Preamplifiers for GS13 Seismometer Application.

Energy Technology Data Exchange (ETDEWEB)

Merchant, Bion J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

Sandia National Laboratories has tested and evaluated a new preamplifier, the Guralp Preamplifier for GS13, manufactured by Guralp. These preamplifiers are used to interface between Guralp digitizers and Geotech GS13 Seismometers. The purpose of the preamplifier evaluation was to measure the performance characteristics in such areas as power consumption, input impedance, sensitivity, full scale, self-noise, dynamic range, system noise, response, passband, and timing. The Guralp GS13 Preamplifiers are being evaluated for potential use in the International Monitoring System (IMS) of the Comprehensive Nuclear Test-Ban-Treaty Organization (CTBTO).

A 16-channel reconfigurable OCDMA/DWDM system using continuous phase-shift SSFBGs

OpenAIRE

Chun, Tian; Zhang, Zhaowei; Ibsen, M.; Petropoulos, P.; Richardson, D.J.

2007-01-01

We demonstrate a reconfigurable 16-channel optical code-division multiple access (OCDMA)/dense wavelength division multiplexing (DWDM) system (4 OCDMA times 4 DWDM times 625 Mb/s) based on novel 31-chip, 40 Gchip/s quaternary phase coding gratings operating at a channel spacing of just 50 GHz. The system performance is studied for cases of both fixed and code-reconfigurable decoders. Error-free performance is achieved in both cases and for all 16 channels.

Monolithic junction field-effect transistor charge preamplifier for calorimetry at high luminosity hadron colliders

International Nuclear Information System (INIS)

Radeka, V.; Rescia, S.; Rehn, L.A.; Manfredi, P.F.; Speziali, V.

1991-11-01

The outstanding noise and radiation hardness characteristics of epitaxial-channel junction field-effect transistors (JFET) suggest that a monolithic preamplifier based upon them may be able to meet the strict specifications for calorimetry at high luminosity colliders. Results obtained so far with a buried layer planar technology, among them an entire monolithic charge-sensitive preamplifier, are described

A low-noise, wideband, integrated CMOS transimpedance preamplifier for photodiode applications

International Nuclear Information System (INIS)

Binkley, D.M.; Paulus, M.J.; Casey, M.E.; Rochelle, J.M.

1992-01-01

In this paper, a low-noise, wideband, integrated CMOS transimpedance preamplifier is presented for silicon avalanche photodiode (APD) applications. The preamplifier, fabricated in a standard 2μ CMOS technology, features a transimpedance gain of 45 kΩ, a risetime of 22 ns, a series noise of 1.6nV/Hz 1/2 , and a wideband equivalent input-noise current of 12 nA for a source capacitance of 12 pF. The measured 22 Na timing resolution of 9.2-ns FWHM and energy resolution of 22.4% FWHM for the RCA C30994 BGO/APD detector module coupled to the preamplifier is comparable to the performance reported using charge-sensitive preamplifiers. This illustrates that transimpedance preamplifiers should be considered for APD applications, especially where APD noise current dominates noise from feedback resistors in the 1--kΩ to 50-kΩ range

Study of multi-channel readout ASIC and its discrete module for particle detector

International Nuclear Information System (INIS)

Wang Ke; Fan Lei; Zhang Shengjun; Li Xian

2013-01-01

Recently, kinds of particle detectors have used Application Specific Integrated Circuits (ASIC) in their electronics readout systems, it is the key part for the whole system. This project designed a multi-channel readout ASIC for general detectors. The chip has Preamplifier, Shaper and Peak Detector embedded for easy readout. For each channel, signal which is preprocessed by a low-noise preamplifier is sent to the shaper to form a quasi-Gaussian pulse and keep its peak for readout. This chip and modules of individual Preamplifier, Shaper and Peak Detector have been manufactured and tested. The discrete modules work well, and the 6-channel chip NPRE 6 is ready for test in some particle detection system. (authors)

Comparison of Preamplifiers for Low-power Consumption Design

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Hyun; Kim, Han Soo; Lee, Kyu Hong; Choi, Hyo Jeong; Na, Teresa W.; Ha, Jang Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chai, Jong Seo [Sungkyunkwan University, Suwon (Korea, Republic of)

2011-10-15

The commonly used electronic devices in radiation detector system are the preamplifier, the amplifier, ADC, and etc. to extract the signal from the detector and to process the signal. These components are composed of semiconductor devices like BJT, MOSFET, OPAMP, and etc. Performance and power consumption of these components are various according to the composition of semiconductor devices. In this study, preamplifiers, which are composed of high efficiency semiconductor devices, are compared to design low-power consumption and high performance preamplifier. To confirm the purpose, preamplifiers are designed for low-power consumption and high gain by some OPAMP (Operational Amplifier). The comparison was performed by experimental result and design simulation

Fission chamber assembly and matching preamplifier

International Nuclear Information System (INIS)

DeLorenzo, J.T.

1982-12-01

The preamplifier for the wide-range counting channel at the High Flux Isotope Reactor was redesigned. This new design incorporates current state-of-the-art components as replacements for the obsolete components of the earlier design. To accommodate the new design, a test and maintenance manual was prepared for use by qualified technicians and field engineers. The test procedures described herein do not require special test equipment and have been successfully applied to the prototype design

A MONOLITHIC PREAMPLIFIER-SHAPER FOR MEASUREMENT LOSS AND TRANSITION RADIATION.

Energy Technology Data Exchange (ETDEWEB)

KANDASAMY,A.

1999-11-08

A custom monolithic circuit has been developed for the Time Expansion Chamber (TEC) of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). This detector identifies particles by sampling their ionization energy loss (dE/dx) over a 3 cm drift space and by detecting associated transition radiation (TR) photons. The requirement of being simultaneously sensitive to dE/dx and TR events requires a dual-gain system. We have developed a compact solution featuring an octal preamplifier/shaper (P/S) IC with a split gain stage. The circuit, fabricated in 1.2 {micro}m CMOS process, incorporates a trans-impedance preamplifier and a 70 ns unipolar CR-RC{sup 4} shaper with ion tail compensation and active DC offset cancellation. Digitally selectable gain, peaking time, and tail cancellation as well as channel-by-channel charge injection and disable can be configured in the system via a 3-wire interface. The 3.5 x 5 mm{sup 2} die is packaged in a fine-pitch 64-pin PQFP. Equivalent input noise is less than 1500 rms electrons at a power dissipation of 30 mW per channel. On a sample of 2400 chips, the DC offset was 2.3 {+-} 3 mV rms without trimming. A chamber-mounted TEC-PS Printed Circuit Board (PCB) houses four PIS chips, on-board calibration circuit, and 64 analog differential line drivers which transmit the shaped pulses to crate-mounted flash ADC's. 7 m apart An RS-422 link provides digital configuration downloading and read back, and supplies the calibration strobe. The 24.6 cm x 9.5 cm board dissipates 8.5 W.

A MONOLITHIC PREAMPLIFIER-SHAPER FOR MEASUREMENT LOSS AND TRANSITION RADIATION

International Nuclear Information System (INIS)

KANDASAMY, A.

1999-01-01

A custom monolithic circuit has been developed for the Time Expansion Chamber (TEC) of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). This detector identifies particles by sampling their ionization energy loss (dE/dx) over a 3 cm drift space and by detecting associated transition radiation (TR) photons. The requirement of being simultaneously sensitive to dE/dx and TR events requires a dual-gain system. We have developed a compact solution featuring an octal preamplifier/shaper (P/S) IC with a split gain stage. The circuit, fabricated in 1.2 microm CMOS process, incorporates a trans-impedance preamplifier and a 70 ns unipolar CR-RC 4 shaper with ion tail compensation and active DC offset cancellation. Digitally selectable gain, peaking time, and tail cancellation as well as channel-by-channel charge injection and disable can be configured in the system via a 3-wire interface. The 3.5 x 5 mm 2 die is packaged in a fine-pitch 64-pin PQFP. Equivalent input noise is less than 1500 rms electrons at a power dissipation of 30 mW per channel. On a sample of 2400 chips, the DC offset was 2.3 ± 3 mV rms without trimming. A chamber-mounted TEC-PS Printed Circuit Board (PCB) houses four PIS chips, on-board calibration circuit, and 64 analog differential line drivers which transmit the shaped pulses to crate-mounted flash ADC's. 7 m apart An RS-422 link provides digital configuration downloading and read back, and supplies the calibration strobe. The 24.6 cm x 9.5 cm board dissipates 8.5 W

Preamplifier-discriminator for a photomultiplier

International Nuclear Information System (INIS)

Groshev, V.Ya.; Zabrodskij, V.A.

1986-01-01

A simple preamplifier-discriminator intended for processing fluxes of low-energy X-radiation in combination with a scintillation detector is suggested. Utilization of the 564LE5 microcircuit in the preamplifier-discriminator permits to use general supply, with digital logical microcircuits. Operation of the preamplifier-discriminator during some years as a part of the RPP-1 X-ray densitometer displayed good repeatibility of parameters of the device and its reliability

A low noise preamplifier with optoelectronic overload protection for radioactivity measurement

International Nuclear Information System (INIS)

Sephton, J.P.; Williams, J.M.; Johansson, L.C.; Philips, H.C.

2012-01-01

Pulses from detectors used for radioactivity measurement can vary in size by several orders of magnitude. Large pulses will lead to saturation at the preamplifier output and extension of the pulse length. As a consequence, the dead time of the system increases and pulses may be lost. Electronic design techniques employed to protect against overloading tend to increase the amplifier noise level. However, an optoelectronic method of overload protection has been devised which has only a negligible effect on noise. An infrared light emitting diode interfaced to the output of the preamplifier is linked by fibre optic cable to an ultra-low leakage photodiode at the input. The conduction of the photodiode increases with the amplitude of the preamplifier output signal. Excess current is thereby prevented from entering the preamplifier and causing saturation. The preamplifier has been tested on 4π beta–gamma and gas counting systems and found to give good protection against overloading. - Highlights: ► A preamplifier for radioactivity measurements has been developed. ► Low noise. ► Current sensitive. ► Optoelectronic overload protection.

Fabrication of preamplifier for proportional counter

International Nuclear Information System (INIS)

Lotfi, Y.; Yazdanpanah, M.; Talebi, B.; Mohammadi, A.; Etaati, Gh.

2002-01-01

We have tried to describe techniques of preamplifier fabrication for proportional counter. At first electronic circuit of preamplifier has been analyzed by means of Or cad 9.1. Then we assembled the circuit. Thereafter essential and standard parameters of preamplifier has been measured and compared with foreign made one, according to IEEE standard method. (IEEE Std 301-1988) Specification for our preamplifier is: 1. Rise time of output plus: 25 nsec. 2. Fall time of output pulse: 50μ sec. 3. Charge sensitive: 46.3 mV/pc. 4. Average noise: 500 ion pair (rms) 5. Count R ate L imit: 9.14*10 10 Count/sec. 6. Resolution: %1.3 7. Spectrum of Bf3 detector to 300μ Ci Am-Be source for this preamplifier is the same as foreign one. On the Whole comparison of this preamplifier with the foreign one shows that their parameters similarity is about %95

Development of voltage sensitive preamplifier using pulse ionization chamber emanometer

International Nuclear Information System (INIS)

Huang He; Peng Xincun; Fu Zhijian; Zhu Zhifu; Zhang Xiongjie

2011-01-01

The voltage preamplifier for the instrument that detecting the Rn and its radon daughter elements is designed. The related circuit are designed and tested. It shows that this preamplifier satisfies the requirement of nuclear measurement system. (authors)

Preamplifier with ultra low frequency cutoff for infrasonic condenser microphone

DEFF Research Database (Denmark)

Kinnerup, Rasmus Trock; Marbjerg, Kresten; Rasmussen, Per

2012-01-01

low frequencies becomes a challenge. The electric preamplifier presented in this paper together with a prepolarized condenser microphone form a measurement system. The developed preamplifier connects the microphone signal directly to the input of an operational amplifier with ultra high input...

Liquid helium-cooled MOSFET preamplifier for use with astronomical bolometer

Science.gov (United States)

Goebel, J. H.

1977-01-01

A liquid helium-cooled p-channel enhancement mode MOSFET, the 3N167, is found to have sufficiently low noise for use as a preamplifier with helium-cooled bolometers that are used in infrared astronomy. Its characteristics at 300, 77, and 4.2 K are presented. It is also shown to have useful application with certain photoconductive and photovoltaic infrared detectors.

Charge pulse preamplifier

International Nuclear Information System (INIS)

Libs, Gerard.

1973-01-01

A charge pulse preamplifier with very low background noise is described. The inlet stage of that preamplifier comprises a cooled field-effect transistor receiving the signal to be amplified at its gate input. Preferably, the charge resistor of said transistor is a field effect transistor, the source inlet of which is connected to the drain inlet of the former transistor through a self-induction coil and a resistor mounted in series. This can be applied to the treatment of the signals delivered by a particle detector in the form of a semi-conductor [fr

A 240-channel thick film multi-chip module for readout of silicon drift detectors

International Nuclear Information System (INIS)

Lynn, D.; Bellwied, R.; Beuttenmueller, R.; Caines, H.; Chen, W.; DiMassimo, D.; Dyke, H.; Elliott, D.; Grau, M.; Hoffmann, G.W.; Humanic, T.; Jensen, P.; Kleinfelder, S.A.; Kotov, I.; Kraner, H.W.; Kuczewski, P.; Leonhardt, B.; Li, Z.; Liaw, C.J.; LoCurto, G.; Middelkamp, P.; Minor, R.; Mazeh, N.; Nehmeh, S.; O'Conner, P.; Ott, G.; Pandey, S.U.; Pruneau, C.; Pinelli, D.; Radeka, V.; Rescia, S.; Rykov, V.; Schambach, J.; Sedlmeir, J.; Sheen, J.; Soja, B.; Stephani, D.; Sugarbaker, E.; Takahashi, J.; Wilson, K.

2000-01-01

We have developed a thick film multi-chip module for readout of silicon drift (or low capacitance ∼200 fF) detectors. Main elements of the module include a custom 16-channel NPN-BJT preamplifier-shaper (PASA) and a custom 16-channel CMOS Switched Capacitor Array (SCA). The primary design criteria of the module were the minimizations of the power (12 mW/channel), noise (ENC=490 e - rms), size (20.5 mmx63 mm), and radiation length (1.4%). We will discuss various aspects of the PASA design, with emphasis on the preamplifier feedback network. The SCA is a modification of an integrated circuit that has been previously described [1]; its design features specific to its application in the SVT (Silicon Vertex Tracker in the STAR experiment at RHIC) will be discussed. The 240-channel multi-chip module is a circuit with five metal layers fabricated in thick film technology on a beryllia substrate and contains 35 custom and commercial integrated circuits. It has been recently integrated with silicon drift detectors in both a prototype system assembly for the SVT and a silicon drift array for the E896 experiment at the Alternating Gradient Synchrotron at the Brookhaven National Laboratory. We will discuss features of the module's design and fabrication, report the test results, and emphasize its performance both on the bench and under experimental conditions

Design and construction of a preamplifier for research reactor control system using Russia’s neutron detectors

International Nuclear Information System (INIS)

Trinh Dinh Hai; Vo Van Tai; Le Van Diep; Nguyen Nhi Dien

2016-01-01

This paper presents the design and construction of a preamplifier device for Research Reactor Control System, using Russia’s Neutron Detectors of ionization and fission chambers. In this work, the preamplifier device which consists of a wide range Current to Frequency Converter block used with a compensation ionization chamber type KNK-3 to measure the thermal neutron flux in the range of 1x10"6 - 1x10"1"1 n/cm"2.s, a Pulse Preamplifier block used with a fission chamber type KNK-15 to measure the thermal neutron flux in the range of 1x10"0 - 1x10"6 n/cm"2.s, and a Power Supply block, was designed and tested in different conditions in the laboratory and at Dalat Nuclear Research Reactor (DNRR). Obtained results show that, the above blocks have almost design specifications as equivalent or better in comparison with the same function blocks of the DNRR Control System which were designed by the former Soviet Union. They also meet the utilization requirements as well as the experimental and training purposes. (author)

Designing charge-sensitive preamplifiers based on low-noise analog integrated circuits

International Nuclear Information System (INIS)

Agakhanyan, T.M.

1998-01-01

The methodology for designing charge-sensitive preamplifiers on the low-noise analog integral circuits, including all the stages: the mathematical synthesis with optimization of the intermediate function; the scheme-technical synthesis with parametric optimization of the scheme and analysis of draft projects with the parameter verification is presented. The designing is conducted on the basis of requirements for signal parameters and noise indices of the preamplifier. The system of automated designing of the charge-sensitive preamplifiers on the low-noise analog integral circuits is developed [ru

Low noise preamplifier ASIC for the PANDA experiment

International Nuclear Information System (INIS)

Flemming, H; Wieczorek, P

2011-01-01

For the electromagnetic calorimeter of the PANDA detector a preamplifier ASIC named APFEL (ASIC for Panda Front-end ELectronics) has been developed at GSI. It is optimized for the readout of large area avalanche photodiodes (LAAPDs) with a capacitance of 300 pF and an event rate of 350 kHz. The ASIC has two equivalent analog channels each consisting of a charge sensitive amplifier, a shaper stage and differential output drivers. For operating the ASIC in a wide temperature range programmable voltage references are implemented on chip.

Cryogenic Preamplifiers for Magnetic Resonance Imaging

DEFF Research Database (Denmark)

Johansen, Daniel H.; Sanchez-Heredia, Juan D.; Petersen, Jan R.

2018-01-01

Pursuing the ultimate limit of detection in magnetic resonance imaging (MRI) requires cryogenics to decrease the thermal noise of the electronic circuits. As cryogenic coils for MRI are slowly emerging cryogenic preamplifiers are required to fully exploit their potential. A cryogenic preamplifier...

Noise analysis of switched integrator preamplifiers

International Nuclear Information System (INIS)

Sun Hongbo; Li Yulan; Zhu Weibin

2004-01-01

The main noise sources of switched integrator preamplifiers are discussed, and their noise performance are given combined PSpice simulation and experiments on them. Then, some practical methods on how to reduce noise of preamplifiers in two different integrator modes are provided. (authors)

Charge preamplifier

International Nuclear Information System (INIS)

Chaminade, R.; Passerieux, J.P.

1961-01-01

We describe a charge preamplifier having the following properties: - large open loop gain giving both stable gain and large input charge transfer; - stable input grid current with aging and without any adjustment; - fairly fast rise; - nearly optimum noise performance; - industrial material. (authors)

Design of monolithic preamplifiers employing diffused n-JFETs for ionization chamber colorimeters

International Nuclear Information System (INIS)

Demicheli, M.; Manfredi, P.F.; Speziali, V.; Radeka, V.; Rescia, S.

1990-01-01

Silicon n-channel JFETs obtained by diffusing the gate into the epitaxial layer which contains the channel still feature unsurpassed noise performances in charge measurements with radiation detectors. Compared to implanted-gate junction field-effect devices, they have a better behaviour in the low-frequency noise, while the thermal noise in the channel more closely conforms to the expected g m -dependence. With respect to MOSFETs they feature, besides lower noise, superior radiation hardness and resistance to electrostatic discharges into the gate. The actual paper discusses the basic design considerations of a preamplifier for ionization chamber calorimeters, which is intended for monolithic integration based on a dielectrically isolated process. (orig.)

Amplifier channel for a fission fragment semiconductor detector

International Nuclear Information System (INIS)

Tyurin, G.P.

1981-01-01

To compensate the decrease of the transformation coefficient of fission fragment semiconductor detector (SCD) developed is a special amplification channel with controlled transfer coefficient. The block diagram of the channel is presented, the main functional units of which are as follows: preamplifying head with charge-sensitive and timing preamplifiers, linear amplifier and the circuit of spectrum position stabilization, which includes a differential discriminator, integrator and reference signal generator. The amplification channel is made in the CAMAC standard and has the following specifications: dinamical input capacitance of charge-sensitive amplifier c=10000 n PHI, signal amplitude at output of the linear amplifier at energy of fission fragments of 120 MeV has negative polarity and is equal to 5 V. Pulse amplitude change at SCD sensitivity decrease to 50% constitutes not more than 1%. Timing preamplifier has the gain factor at voltage of K=80 at front duration of 3.5 nc. Time resolution of the amplification channel is not worse than 1 nc. Dimensions of preamplifying head are 40x40x15 mm. The amplification channel permitted to use SCD for long-term measurements of fission fragment spectra [ru

Consistent analysis of peripheral reaction channels and fusion for the 16,18O+58Ni systems

International Nuclear Information System (INIS)

Alves, J.J.S.; Gomes, P.R.S.; Lubian, J.; Chamon, L.C.; Pereira, D.; Anjos, R.M.; Rossi, E.S.; Silva, C.P.; Alvarez, M.A.G.; Nobre, G.P.A.; Gasques, L.R.

2005-01-01

We have measured elastic scattering and peripheral reaction channel cross sections for the 16,18 O+ 58 Ni systems at ELab=46 MeV. The data were analyzed through extensive coupled-channel calculations. It was investigated the consistency of the present analysis with a previous one at sub-barrier energies. Experimental fusion cross sections for these systems are also compared with the corresponding predictions of the coupled-channel calculations

On the design of fully-integrated charge preamplifiers for the Superconducting Super Collider

International Nuclear Information System (INIS)

VanPeteghem, P.M.; Ling, K.Y.; Lee, S.Y.; Liu, H.H.; DiBitonto, D.

1990-01-01

The specifications imposed on the charge preamplifiers, to be used in the Superconducting Supercollider are very demanding: the rise time should be less than 100 nsec and noise should be less than 1,000 electrons RMS for a total power consumption of less than 80 mWatt. Furthermore, several hundreds of thousands (or even millions) of channels have to be manufactured. Hence, integrated circuit (IC) implementations can be more economical than discrete implementations, due to the compact size and ease of manufacturing. BiFET IC technology is currently the most attractive technology, because it is a mature IC technology, and readily available from several industrial vendors. As a case study, a BiFET prototype preamplifier is presented, where circuit performance has been tested for total radiation doses up to 1.4 MegaRads

A low-cost, ultra-fast and ultra-low noise preamplifier for silicon avalanche photodiodes

Science.gov (United States)

Gasmi, Khaled

2018-02-01

An ultra-fast and ultra-low noise preamplifier for amplifying the fast and weak electrical signals generated by silicon avalanche photodiodes has been designed and developed. It is characterized by its simplicity, compactness, reliability and low cost of construction. A very wide bandwidth of 300 MHz, a very good linearity from 1 kHz to 280 MHz, an ultra-low noise level at the input of only 1.7 nV Hz-1/2 and a very good stability are its key features. The compact size (70 mm  ×  90 mm) and light weight (45 g), as well as its excellent characteristics, make this preamplifier very competitive compared to any commercial preamplifier. The preamplifier, which is a main part of the detection system of a homemade laser remote sensing system, has been successfully tested. In addition, it is versatile and can be used in any optical detection system requiring high speed and very low noise electronics.

General considerations of noise in microphone preamplifiers

NARCIS (Netherlands)

van der Donk, A.G.H.; van der Donk, A.G.H.; Voorthuyzen, J.A.; Voorthuyzen, J.A.; Bergveld, Piet

1991-01-01

In this paper a study of the noise performance of electret microphone systems as a part of hearing aids is presented. The signal-to-noise ratio of the microphone-preamplifier combination, containing a field-effect transistor (FET) and a high value resistive bias element in a hybrid configuration, is

Energy-dependent losses in pulsed-feedback preamplifiers

International Nuclear Information System (INIS)

Landis, D.A.; Madden, N.W.; Goulding, F.S.

1978-11-01

Energy dependent counting losses occur in most pulsed-feedback preamplifiers due to the loss of those pulses which activate the recharge system. A pulsed-feedback system that overcomes this inefficiency is described. Pulsed-light feedback as used with germanium gamma-ray spectrometers is discussed as used at high energies and high rates where those losses become significant. Experimental results are presented

Study of low noise preamplifier systems for use with room temperature mercuric iodide (HgI2) x-ray detectors

International Nuclear Information System (INIS)

Iwanczyk, J.S.; Dabrowski, A.J.; Huth, G.C.; Del Duca, A.; Schenpple, W.

1980-01-01

An analysis of different preamplification systems for use with room temperature mercuric iodide x-ray detectors has been performed. Resistor-, drain-, and light-feedback preamplifiers have been studied. Energy resolution of 295 eV (FWHM) for Fe-55 source (5.9 keV) and 225 eV (FWHM) for the pulser have been obtained with both the detector and the input FET at room temperature using the pulsed-light feedback preamplifier. It has been shown that cooling the input FET using a small Peltier element allows the energy resolution to be improved up to 25%

Design of a charge sensitive preamplifier on high resistivity silicon

International Nuclear Information System (INIS)

Radeka, V.; Rehak, P.; Rescia, S.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Strueder, L.; Kemmer, J.

1987-01-01

A low noise, fast charge sensitive preamplifier was designed on high resistivity, detector grade silicon. It is built at the surface of a fully depleted region of n-type silicon. This allows the preamplifier to be placed very close to a detector anode. The preamplifier uses the classical input cascode configuration with a capacitor and a high value resistor in the feedback loop. The output stage of the preamplifier can drive a load up to 20pF. The power dissipation of the preamplifier is 13mW. The amplifying elements are ''Single Sided Gate JFETs'' developed especially for this application. Preamplifiers connected to a low capacitance anode of a drift type detector should achieve a rise time of 20ns and have an equivalent noise charge (ENC), after a suitable shaping, of less than 50 electrons. This performance translates to a position resolution better than 3μm for silicon drift detectors. 6 refs., 9 figs

Training-based Channel Estimation for Signal Equalization and OPM in 16-QAM Optical Transmission Systems

DEFF Research Database (Denmark)

Pittalà, Fabio; Hauske, Fabian N.; Ye, Yabin

2012-01-01

Efficient channel estimation for signal equalization and OPM based on short CAZAC sequences with QPSK and 8PSK constellation formats is demonstrated in a 224-Gb/s PDM 16-QAM optical linear transmission system....

16-channel analog store and multiplexer unit

Energy Technology Data Exchange (ETDEWEB)

Brossard, M; Kulka, Z [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire

1979-03-15

A 16-channel analog store and multiplexer unit is described. The unit enables storing and selection of analog information which is then digitally encoded by single ADC. This solution becomes economically attractive particularly in multidetector pulse height analysis systems.

Low-noise audio amplifiers and preamplifier for use with intrinsic thermocouples

International Nuclear Information System (INIS)

Langner, G.C.; Sachs, R.D.; Stewart, F.L.

1979-03-01

Two simple, low-noise audio amplifiers and one low-noise preamplifier for use with intrinsic thermocouples were designed, built, and tested. The amplifiers and the preamplifier have different front end designs. One amplifier uses ultralow-noise operational amplifiers; the other amplifier uses a hybrid component. The preamplifier uses ultralow-noise discrete components. The amplifiers' equivalent noise inputs, at maximum gain, are 4.09 nV and 50 nV; the preamplifier's input is 4.05 μV. Their bandwidths are 15 600 Hz, 550 Hz, and 174 kHz, respectively. the amplifiers' equivalent noise inputs were measured from approx. 0 to 100 Hz, whereas the preamplifier's equivalent noise input was measured from approx. 0 to 174 kHz

Low noise charge sensitive preamplifier DC stabilized without a physical resistor

Science.gov (United States)

Bertuccio, Giuseppe; Rehak, Pavel; Xi, Deming

1994-09-13

The invention is a novel charge sensitive preamplifier (CSP) which has no resistor in parallel with the feedback capacitor. No resetting circuit is required to discharge the feedback capacitor. The DC stabilization of the preamplifier is obtained by means of a second feedback loop between the preamplifier output and the common base transistor of the input cascode. The input transistor of the preamplifier is a Junction Field Transistor (JFET) with the gate-source junction forward biased. The detector leakage current flows into this junction. This invention is concerned with a new circuit configuration for a charge sensitive preamplifier and a novel use of the input Field Effect Transistor of the CSP itself. In particular this invention, in addition to eliminating the feedback resistor, eliminates the need for external devices between the detector and the preamplifier, and it eliminates the need for external circuitry to sense the output voltage and reset the CSP. Furthermore, the noise level of the novel CSP is very low, comparable with the performance achieved with other solutions. Experimental tests prove that this configuration for the charge sensitive preamplifier permits an excellent noise performance at temperatures including room temperature. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using a commercial JFET as input device of the preamplifier.

A low noise single-transistor transimpedance preamplifier for Fourier-transform mass spectrometry using a T feedback network.

Science.gov (United States)

Lin, Tzu-Yung; Green, Roger J; O'Connor, Peter B

2012-09-01

A novel single-transistor transimpedance preamplifier has been introduced for improving performance in Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry. A low noise junction field-effect transistor (JFET), BF862, is used as the main amplification stage of this trans-impedance preamplifier, and a T-shaped feedback network is introduced as both the feedback and the gate biasing solutions. The T feedback network has been studied using an operational amplifier (Op Amp), AD8099. Such a feedback system allows ~100-fold less feedback resistance at a given transimpedance, hence preserving bandwidth, which is beneficial to applications demanding high gain. The single-transistor preamplifier yields a tested transimpedance of ~10(4) Ω (80 dBΩ) in the frequency range between 1 kHz and 1 MHz (mass-to-charge ratio, m/z, of around 180-180k for a 12-T FT-ICR system), with a low power consumption of ~6 mW, which implies that this preamplifier is well suited to a 12-T FT-ICR mass spectrometer. In trading noise performance for higher trans-impedance, an alternative preamplifier design, an AD8099 preamplifier with the T feedback network, has also been studied with a capability of ~10(6) Ω (120 dBΩ) transimpedance in the same frequency range. The resistive components in the T feedback network reported here can be replaced by complex impedances, which allows adaptation of this feedback system to other frequency, transimpedance, and noise characteristics for applications not only in other mass spectrometers, such as Orbitrap, time-of-flight (TOF), and ion trap systems, but also in other charge/current detecting systems such as spectroscopy systems, microscopy systems, optical communication systems, or charge-coupled devices (CCDs).

An efficient ASIC implementation of 16-channel on-line recursive ICA processor for real-time EEG system.

Science.gov (United States)

Fang, Wai-Chi; Huang, Kuan-Ju; Chou, Chia-Ching; Chang, Jui-Chung; Cauwenberghs, Gert; Jung, Tzyy-Ping

2014-01-01

This is a proposal for an efficient very-large-scale integration (VLSI) design, 16-channel on-line recursive independent component analysis (ORICA) processor ASIC for real-time EEG system, implemented with TSMC 40 nm CMOS technology. ORICA is appropriate to be used in real-time EEG system to separate artifacts because of its highly efficient and real-time process features. The proposed ORICA processor is composed of an ORICA processing unit and a singular value decomposition (SVD) processing unit. Compared with previous work [1], this proposed ORICA processor has enhanced effectiveness and reduced hardware complexity by utilizing a deeper pipeline architecture, shared arithmetic processing unit, and shared registers. The 16-channel random signals which contain 8-channel super-Gaussian and 8-channel sub-Gaussian components are used to analyze the dependence of the source components, and the average correlation coefficient is 0.95452 between the original source signals and extracted ORICA signals. Finally, the proposed ORICA processor ASIC is implemented with TSMC 40 nm CMOS technology, and it consumes 15.72 mW at 100 MHz operating frequency.

Development of a charge-sensitive preamplifier using commercially available components

International Nuclear Information System (INIS)

Fagionato, Esnel A.; Genezini, Frederico A.; Zahn, Guilherme S.

2013-01-01

Signals produced in radiation detectors are very fast and with low intensity; these signals are not able to directly excite a regular MCA multichannel circuit, so some sort of amplification is needed. This work proposes the construction of a nuclear detector preamplifier using commercially available components that are not specifically designed for the use in nuclear instrumentation. The preamplifier was then tested and its performance was compared to that of an Ortec 142 preamplifier. (author)

Charge-sensitive preamplifier IC for silicon calorimetry at colliders

International Nuclear Information System (INIS)

Baturitsky, M.A.; Chekhovsky, V.A.; Emel'yanchik, I.F.; Shumeiko, N.M.; Golutvin, I.A.; Zamyatin, N.I.; Dvornikov, O.V.

1995-01-01

Four versions of a fast monolithic charge-sensitive preamplifier (CSP) were designed using microwave BJT-JFET technology. The best one has a 3.5 ns rise time for input detector capacitance C d =100 pF and approximately 8 mW power dissipation for 5 V supply voltage. The ENC performance at shaping time 30 ns is 1350 e+17 e/pF for C d up to 600 pF. Crosstalk in a four-channel amplifier made in the same chip was measured to be about -46 dB for C d =100 pF. The linear output voltage swing is 0.8 V for voltage supply 5 V. The IC has revealed good radiation hardness to neutron irradiation. ((orig.))

An application specific integrated circuit and data acquisition system for digital X-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Beuville, E.; Cederstroem, B.; Danielsson, M.; Luo, L.; Nygren, D.; Oltman, E.; Vestlund, J. [Lawrence Berkeley National Lab., CA (United States)

1998-04-01

We have developed an application specific integrated circuit (ASIC) and data acquisition system for digital X-ray imaging. The chip consists of 16 parallel channels, each containing preamplifier, shaper, comparator and a 16 bit counter. We have demonstrated noiseless single-photon counting over a threshold of 7.2 keV using Silicon detectors and are presently capable of maximum counting rates of 2 MHz per channel. The ASIC is controlled by a personal computer through a commercial PCI card, which is also used for data acquisition. The content of the 16 bit counters are loaded into a shift register and transferred to the PC at any time at a rate of 20 MHz. The system is non-complicated, low cost and high performance and is optimised for digital X-ray imaging applications. (orig.). 11 refs.

An application specific integrated circuit and data acquisition system for digital X-ray imaging

International Nuclear Information System (INIS)

Beuville, E.; Cederstroem, B.; Danielsson, M.; Luo, L.; Nygren, D.; Oltman, E.; Vestlund, J.

1998-01-01

We have developed an application specific integrated circuit (ASIC) and data acquisition system for digital X-ray imaging. The chip consists of 16 parallel channels, each containing preamplifier, shaper, comparator and a 16 bit counter. We have demonstrated noiseless single-photon counting over a threshold of 7.2 keV using Silicon detectors and are presently capable of maximum counting rates of 2 MHz per channel. The ASIC is controlled by a personal computer through a commercial PCI card, which is also used for data acquisition. The content of the 16 bit counters are loaded into a shift register and transferred to the PC at any time at a rate of 20 MHz. The system is non-complicated, low cost and high performance and is optimised for digital X-ray imaging applications. (orig.)

A new principle for an all-digital preamplifier and equalizer

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

1987-01-01

A new principle for an all-digital preamplifier and equalizer, to be used together with a Compact Disc player, is described. The principle makes it possible to obtain an arbitrary gain transfer function together with a linear phase. The gain can be varied 20 dB from point to point, when specified...... on a logarithmic frequency axis with 30 divisions from 20 Hz to 20 kHz. The deviation in the passband is a maximum of 0.3 dB. Taking advantage of the digital signal from the preamplifier, a high-efficiency power amplifier can be developed. A prototype of the preamplifier built with commercially obtainable...

A New principle for an all digital preamplifier and equalizer

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

1986-01-01

A new principle for an all digital preamplifier and equalizer, to be used together with a compact disc player, is described. The principle makes it possible to obtain an arbitrary gain transfer function together with a linear phase. The gain can be varied 20 dB from point to point, when specified...... on a logarithmic frequency axis with 30 divisions from 20 Hz to 20 kHz. The deviation in the passbands is max. 0. 2 dB. Taking advantage of the digital signal from the preamplifier, a high-efficiency power amplifier can be developed. A prototype of the preamplifier built with commercially obtainable components has...

Development of low noise preamplifier for the detection and position determination of single electrons in a Cerenkov Ring Imaging Detector by charge division

International Nuclear Information System (INIS)

Spencer, E.; Coyle, P.; Williams, D

1987-10-01

A preamplifier having 500 electrons noise (rms) has been developed for the detection and location of single electrons in a CRID detector at the SLD. A single channel contains preamp, RC-CR shaper, gain adjustment, driver, and calibration circuitry. Noise and linearity measurements are presented

The ICARUS Front-end Preamplifier Working at Liquid Argon Temperature

CERN Document Server

Baibussinov, B; Casagrande, F; Cennini, P; Centro, S; Curioni, A; Meng, G; Picchi, P; Pietropaolo, F; Rubbia, C; Sergiampietri, F; Ventura, S

2011-01-01

We describe characteristics and performance of the low-noise front-end preamplifier used in the ICARUS 50-litre liquid Argon Time Projection Chamber installed in the CERN West Area Neutrino Facility during the 1997-98 neutrino runs. The preamplifiers were designed to work immersed in ultra-pure liquid Argon at a temperature of 87K.

The software and hardware design of a 16 channel online dose rate monitoring system

International Nuclear Information System (INIS)

Tang Wenjuan; Yan Yonghong; Yang Shiming; Li Xiaonan; Min Jian

2011-01-01

The software and hardware design of a 16 channel online dose rate monitoring system is presented. After being amplified and A/D converted, the output signal of the sensors was sent to a microprocessor through an FPGA, where the low-frequency filter, calculation, temperature compensation and pedestal deduction were accomplished. Such steps corrected the variation of dark current dependent on temperature fluctuations in a effective way, and finally the instantaneous dose rate results with enough precise were obtained. (authors)

High speed preamplifier circuit, detection electronics, and radiation detection systems therefrom

Science.gov (United States)

Riedel, Richard A [Knoxville, TN; Wintenberg, Alan L [Knoxville, TN; Clonts, Lloyd G [Knoxville, TN; Cooper, Ronald G [Oak Ridge, TN

2010-09-21

A preamplifier circuit for processing a signal provided by a radiation detector includes a transimpedance amplifier coupled to receive a current signal from a detector and generate a voltage signal at its output. A second amplification stage has an input coupled to an output of the transimpedance amplifier for providing an amplified voltage signal. Detector electronics include a preamplifier circuit having a first and second transimpedance amplifier coupled to receive a current signal from a first and second location on a detector, respectively, and generate a first and second voltage signal at respective outputs. A second amplification stage has an input coupled to an output of the transimpedance amplifiers for amplifying the first and said second voltage signals to provide first and second amplified voltage signals. A differential output stage is coupled to the second amplification stage for receiving the first and second amplified voltage signals and providing a pair of outputs from each of the first and second amplified voltage signals. Read out circuitry has an input coupled to receive both of the pair of outputs, the read out circuitry having structure for processing each of the pair of outputs, and providing a single digital output having a time-stamp therefrom.

Preamplifier-shaper prototype for the Fast Transition Detector of the Compressed Baryonic Matter (CBM) experiment at FAIR

CERN Document Server

Soltveit, Hans Kristian

2007-01-01

In this work a preamplifier-shaper prototype for the Fast Transition Detector of the Compressed BaryonicMatter (CBM) experiment at FAIR fabricated using a 0.35 μm CMOS technology will be presented. The ASIC integrates 16 identical Charge Sensitive Amplifiers (CSA) followed by a Pole-Zero network, two bridged-T filters, Common-Mode FeedBack (CMFB) network and two non-inverting level shifting stages. The circuit is optimized for a detector capacitance Cd of (5-10)pF. Measurement results confirm the noise of 330 e− + 12 e−/pF obtained in simulations for a pulse with a Full Width Half Maximum (FWHM) of 71 ns. The circuit recovers to the baseline within 200 ns. The conversion gain is 12.64 mV/fC. An integral nonlinearity of 0.7% is also achieved. The maximum output swing is 2 V. The power consumption is 16 mW/channel where the main contributors are the input transistor and the level shifting stage with 5.3 mW and 6.6 mW, respectively. The total area of the chip is 12 mm2. Although the circuit was designed for...

Transistor reset preamplifier for high-rate high-resolution spectroscopy

International Nuclear Information System (INIS)

Landis, D.A.; Cork, C.P.; Madden, N.W.; Goulding, F.S.

1981-10-01

Pulsed transistor reset of high resolution charge sensitive preamplifiers used in cooled semiconductor spectrometers can sometimes have an advantage over pulsed light reset systems. Several versions of transistor reset spectrometers using both silicon and germanium detectors have been built. This paper discusses the advantages of the transistor reset system and illustrates several configurations of the packages used for the FET and reset transistor. It also describes the preamplifer circuit and shows the performance of the spectrometer at high rates

ICON, a current model preamplifier in CMOS technology for use with high rate particle detectors

International Nuclear Information System (INIS)

Anghinolfi, F.; Aspell, P.; Campbell, M.; Heijne, E.H.M.; Jarron, P.; Meddeler, G.; Santiard, J.C.

1993-01-01

The ICON current mode preamplifier is intended for use in experiments at high rate hadron colliders. The transient response and noise performance have been analyzed. One chip has been made using an ICON circuit with resistive feedback to produce a preamplifier with a peaking time of below 10 ns. This fast preamplifier has a gain of 870 mV/pC and a power dissipation of around 1 mW. Another chip was made which uses the ICON circuit as the front-end to a dual port analog memory. The noise measured is between 2,400 e - and 3,000 e - . An important characteristic of ICON is that it can tolerate a detector leakage current of 10 μA at the DC coupled input. Therefore, it is very suitable for silicon detector systems under severe radiation conditions

A high resolution 16 k multi-channel analyzer PC add-on card

International Nuclear Information System (INIS)

Kulkarni, C.P.; Paulson, Molly; Vaidya, P.P.

2001-01-01

This paper describes the system details of a 16 K channel resolution Multi-Channel Analyzer (MCA) developed at Electronics Division, BARC, which is used in high resolution nuclear spectroscopy systems for pulse height analysis. The high resolution data acquisition PC add-on card is architectured using a state of the art digital circuit design technology which makes use of a Field Programmable Gate Array (FPGA), and some of the most modern and advanced analog counterparts like low power, high speed and high precision comparators, Op-amps, ADCs and DACs etc. The 16 K MCA card gives an economic, compact, and low power alternative for nuclear pulse spectroscopy use. (author)

Intermolecular Interactions in the TMEM16A Dimer Controlling Channel Activity.

Science.gov (United States)

Scudieri, Paolo; Musante, Ilaria; Gianotti, Ambra; Moran, Oscar; Galietta, Luis J V

2016-12-08

TMEM16A and TMEM16B are plasma membrane proteins with Ca 2+ -dependent Cl - channel function. By replacing the carboxy-terminus of TMEM16A with the equivalent region of TMEM16B, we obtained channels with potentiation of channel activity. Progressive shortening of the chimeric region restricted the "activating domain" to a short sequence close to the last transmembrane domain and led to TMEM16A channels with high activity at very low intracellular Ca 2+ concentrations. To elucidate the molecular mechanism underlying this effect, we carried out experiments based on double chimeras, Forster resonance energy transfer, and intermolecular cross-linking. We also modeled TMEM16A structure using the Nectria haematococca TMEM16 protein as template. Our results indicate that the enhanced activity in chimeric channels is due to altered interaction between the carboxy-terminus and the first intracellular loop in the TMEM16A homo-dimer. Mimicking this perturbation with a small molecule could be the basis for a pharmacological stimulation of TMEM16A-dependent Cl - transport.

A preamplifier with reduced background noise

International Nuclear Information System (INIS)

Taieb, J.

1950-01-01

A description is given of a preamplifier in use with a mass spectrometer for rapid gas mixtures analysis, described in Report CEA-42. The instrument can be employed for amplifying any weak currents from high-impedance sources, in the frequency range 10 to 5000 cycle/sec

New preamplifier for particle detectors

International Nuclear Information System (INIS)

Yarema, R.J.

1984-11-01

A new preamplifier for particle detectors has been designed and built for the Fermilab VTPC by Fujitsu of Japan. The device, designated MB43458, is a semi-custom monolithic assembled in a small, low mass package. The purpose of this report is to document the preliminary tests which have been done thus far. Tests are continuing to expand upon the results presented herein

Development of an integrated four-channel fast avalanche-photodiode detector system with nanosecond time resolution

Science.gov (United States)

Li, Zhenjie; Li, Qiuju; Chang, Jinfan; Ma, Yichao; Liu, Peng; Wang, Zheng; Hu, Michael Y.; Zhao, Jiyong; Alp, E. E.; Xu, Wei; Tao, Ye; Wu, Chaoqun; Zhou, Yangfan

2017-10-01

A four-channel nanosecond time-resolved avalanche-photodiode (APD) detector system is developed at Beijing Synchrotron Radiation. It uses a single module for signal processing and readout. This integrated system provides better reliability and flexibility for custom improvement. The detector system consists of three parts: (i) four APD sensors, (ii) four fast preamplifiers and (iii) a time-digital-converter (TDC) readout electronics. The C30703FH silicon APD chips fabricated by Excelitas are used as the sensors of the detectors. It has an effective light-sensitive area of 10 × 10 mm2 and an absorption layer thickness of 110 μm. A fast preamplifier with a gain of 59 dB and bandwidth of 2 GHz is designed to readout of the weak signal from the C30703FH APD. The TDC is realized by a Spartan-6 field-programmable-gate-array (FPGA) with multiphase method in a resolution of 1ns. The arrival time of all scattering events between two start triggers can be recorded by the TDC. The detector has been used for nuclear resonant scattering study at both Advanced Photon Source and also at Beijing Synchrotron Radiation Facility. For the X-ray energy of 14.4 keV, the time resolution, the full width of half maximum (FWHM) of the detector (APD sensor + fast amplifier) is 0.86 ns, and the whole detector system (APD sensors + fast amplifiers + TDC readout electronics) achieves a time resolution of 1.4 ns.

Research on development of multi-channel analyzer used for monitoring and warning radiation equipment

International Nuclear Information System (INIS)

Nguyen Van Sy; Dang Quang Thieu; Nguyen Thi Bao My

2015-01-01

The subject assigned to this paper presents research on development of multi-channel analyzer used for monitoring and warning environmental radiation equipment under the project KC.05.16/11-15 Research on manufacturing equipment monitoring and warning radiation. In this thematic we have two subjects that need to be resolved such as: i) Designing spectroscopy amplifier block (AMP) duty pulse signals obtained about few hundred millivolts output from scintillation detector preamplifier, amplified as a few volts and the standard Gaussian pulses shaped to connect to the analog-to-digital converter. The spectroscopy amplifier block can change the gain by digital control to respond to the problem of automatic spectrum stability for multi-channel analyzer systems. ii) Designing analog-to-digital converter block (ADC) in accordance with the actual conditions, such as high stability, fast conversion time, high throughput, and it consumes low energy. Selecting suitable microprocessor for fast connection ability, to operate reliably paired with the analog-to-digital converter into a multi-channel analyzer (MCA) serving analysis. (author)

New Technology-Driven Approaches in the Design of Preamplifiers for Condenser Microphones

DEFF Research Database (Denmark)

Haas-Christensen, Jelena

The topic of this thesis is the design of CMOS preamplifiers for condenser microphones. Increasingly popular type of condenser microphones are MEMS (micro-electro-mechanical) microphones which pose a stringent requirements to the design of interface electronics among other due to their increased...... noise. Besides that, as MEMS microphones are easy to integrate with CMOS circuitry, CMOS circuit design gains importance because it can contribute to the overall improved performance of the system by introducing extra functionalities. Possible methods of sensing a signal from the microphone...... of a CMOS interface for a capacitive sensor. Finally, in the fourth part, a novel preamplifier designed demonstrating a concept of differential operation of two microphones biased with voltages of opposite polarities has been described. The amplifier shows how accompanying electronic circuitry can be used...

Transistor design considerations for low-noise preamplifiers

International Nuclear Information System (INIS)

Fair, R.B.

1976-01-01

A review is presented of design considerations for GaAs Schottky-barrier FETs and other types of transistors in low-noise amplifiers for capacitive sources which are used in nuclear radiation detectors and high speed fiber-optic communication systems. Ultimate limits on performance are evaluated in terms of the g/sub m//C/sub i/ ratio and the gate leakage current to minimize the noise sources. Si bipolar transistors and the future prospects of GaAs, Si and InAs MISFETs are discussed, and performance is compared to FETs currently being used in low-noise preamplifiers

Development of voltage sensitivity preamplifier to application in radioguided surgical probe

International Nuclear Information System (INIS)

Costa, Fabio Eduardo da; Rela, Paulo Roberto; Hamada, Margarida Mizue

2005-01-01

The methods of nuclear medicine are increasing used to complement standard diagnostic examinations. Some of these are radioguided detection of the sentinel lymph node (SN) and the radioguided localization of occult lesions. The SN technique is used in a small-size breast carcinoma and involves the identification, removal and immediate histological examination. Specifically, particles of colloidal human serum albumin are labelled with low activities of 99m Tc and are inoculated into the breast lesion or close in the case of SN biopsy. Subsequently, a hand-held gamma-ray detecting probe with reduced dimensions is used to locate the lesion or the SN as a hot spot and guide its surgical removal. Many techniques can be used for gamma-ray probes development. Gamma photons can be either directly detected via high atomic numbers semiconductors detectors or indirect detection, as scintillator crystal converts gamma photons into light photons. In all of them, the preamplifier is used as close as possible to the detector for obtaining a good energy resolution and due to the necessary small probe dimension, the preamplifier must have reduced size. The commercial preamplifiers are not small enough to be assembled inside the probe. It was developed a not usually preamplifier configuration for high-resolution spectroscopy energy, adequate in size to be set up in gamma-ray probes. This tension preamplifier can be split between the gamma-ray probe and the read out unit. Due to this configuration the effective size required inside the probe was reduced. The results and the probe assembling are showed in this work. (author)

Low Power High Dynamic Range A/D Conversion Channel

DEFF Research Database (Denmark)

Marker-Villumsen, Niels; Rombach, Pirmin

in the conversion channel in order to avoid distortion for large input signals. In combination with a low resolution A/D converter (ADC) and a digital gain block, the adaptive A/D conversion channel achieves an extended dynamic range beyond that of the ADC. This in turn reduces the current consumption......This work concerns the analysis of an adaptive analog-to-digital (A/D) conversion channel for use with a micro electromechanical system (MEMS) microphone for audio applications. The adaptive A/D conversion channel uses an automatic gain control (AGC) for adjusting the analog preamplifier gain...... of the conversion channel in comparison to a static A/D conversion channel; this at the cost of a reduced peak signal-to-noise ratio (SNR). The adaptive A/D conversion channel compensates for the change in analog gain by a digital gain, thus achieving a constant channel gain in the full dynamic range. However...

Low-backgroud preamplifier with pulse drain negative feedback

International Nuclear Information System (INIS)

Tret'yakov, V.A.; Bakhlanov, S.V.

1978-01-01

A low-noise preamplifier with a pulsed sinking negative feedback, used in an X-ray spectrometer, is described. The structural diagram of the preamplifier is presented, and its operating principle is considered. The criteria for selecting the amplitude and duration of the discharge pulse are discussed. It was established that the Usub(d) amplitude of the discharge pulse should be chosen within Usub(s) < Usub(s) < Usub(l), where Usub(s) is the voltage on the sink of the field transistor at which the avalanche production of carriers takes place, and Usub(l) is the limiting voltage at the sink; when it is exceeded, the field transistor goes into the cutoff regime. The duration of the discharge pulse should be chosen as short as possible to reduce the deadtime of the spectrometric tract. The results of an investigation into the energy resolution and the loading capacity of the spectrometer for different tau time constants of the forming filter are presented. It is shown that the energy resolution fo the spectrometer improves with increasing tau and reduces with increasing load. The use of pulsed sinkina feedback in low-noise preamplifiers to stabilize the direct-current regime makes it possible to considerably extend the loading potentialities of X-ray spectrometers

Ca2+-dependent phospholipid scrambling by a reconstituted TMEM16 ion channel.

Science.gov (United States)

Malvezzi, Mattia; Chalat, Madhavan; Janjusevic, Radmila; Picollo, Alessandra; Terashima, Hiroyuki; Menon, Anant K; Accardi, Alessio

2013-01-01

Phospholipid (PL) scramblases disrupt the lipid asymmetry of the plasma membrane, externalizing phosphatidylserine to trigger blood coagulation and mark apoptotic cells. Recently, members of the TMEM16 family of Ca(2+)-gated channels have been shown to be involved in Ca(2+)-dependent scrambling. It is however controversial whether they are scramblases or channels regulating scrambling. Here we show that purified afTMEM16, from Aspergillus fumigatus, is a dual-function protein: it is a Ca(2+)-gated channel, with characteristics of other TMEM16 homologues, and a Ca(2+)-dependent scramblase, with the expected properties of mammalian PL scramblases. Remarkably, we find that a single Ca(2+) site regulates separate transmembrane pathways for ions and lipids. Two other purified TMEM16-channel homologues do not mediate scrambling, suggesting that the family diverged into channels and channel/scramblases. We propose that the spatial separation of the ion and lipid pathways underlies the evolutionary divergence of the TMEM16 family, and that other homologues, such as TMEM16F, might also be dual-function channel/scramblases.

Development of slew-rate-limited time-over-threshold (ToT) ASIC for a multi-channel silicon-based ion detector

Science.gov (United States)

Uenomachi, M.; Orita, T.; Shimazoe, K.; Takahashi, H.; Ikeda, H.; Tsujita, K.; Sekiba, D.

2018-01-01

High-resolution Elastic Recoil Detection Analysis (HERDA), which consists of a 90o sector magnetic spectrometer and a position-sensitive detector (PSD), is a method of quantitative hydrogen analysis. In order to increase sensitivity, a HERDA system using a multi-channel silicon-based ion detector has been developed. Here, as a parallel and fast readout circuit from a multi-channel silicon-based ion detector, a slew-rate-limited time-over-threshold (ToT) application-specific integrated circuit (ASIC) was designed, and a new slew-rate-limited ToT method is proposed. The designed ASIC has 48 channels and each channel consists of a preamplifier, a slew-rate-limited shaping amplifier, which makes ToT response linear, and a comparator. The measured equivalent noise charges (ENCs) of the preamplifier, the shaper, and the ToT on no detector capacitance were 253±21, 343±46, and 560±56 electrons RMS, respectively. The spectra from a 241Am source measured using a slew-rate-limited ToT ASIC are also reported.

A 1microW 85nV/ radicalHz pseudo open-loop preamplifier with programmable band-pass filter for neural interface system.

Science.gov (United States)

Chang, Sun-Il; Yoon, Euisik

2009-01-01

We report an energy efficient pseudo open-loop amplifier with programmable band-pass filter developed for neural interface systems. The proposed amplifier consumes 400nA at 2.5V power supply. The measured thermal noise level is 85nV/ radicalHz and input-referred noise is 1.69microV(rms) from 0.3Hz to 1 kHz. The amplifier has a noise efficiency factor of 2.43, the lowest in the differential topologies reported up to date to our knowledge. By programming the switched-capacitor frequency and bias current, we could control the bandwidth of the preamplifier from 138 mHz to 2.2 kHz to meet various application requirements. The entire preamplifier including band-pass filters has been realized in a small area of 0.043mm(2) using a 0.25microm CMOS technology.

Periodic Thomson scattering diagnostic with 16 spatial channels on ASDEX

International Nuclear Information System (INIS)

Meisel, D.; Murmann, H.; Roehr, H.; Steuer, K.H.; Becker, G.; Bosch, H.S.; Brocken, H.; Eberhagen, A.; Fussmann, G.; Gehre, O.; Gernhardt, J.; Gierke, G. v.; Glock, E.; Gruber, O.; Haas, G.; Hofmann, J.; Janeschitz, G.; Karger, F.; Klueber, O.; Kornherr, M.; Lackner, K.; Lenoci, M.; Lisitano, G.; Mast, F.; Mayer, H.M.; McCormick, K.; Mertens, V.; Niedermeyer, H.; Poschenrieder, W.; Rapp, H.; Roth, J.; Schneider, F.; Setzensack, C.; Siller, G.; Soeldner, F.X.; Wagner, F.; Zasche, D.; Izvozchikov, A.; Ryter, F.

1986-01-01

The Nd-YAG Periodic Scattering System (PSS) was developped in teamwork with IPF of Stuttgart-University. At first a PSS with only one spatial channel was successfully tested in the ASDEX-Tokamak in 1982. Subsequently an upgraded system with 16 spatial channels was constructed. This new system is capable of measuring Te, Ne-profiles at 17 ms intervals during the entire ASDEX-Tokamak-discharge. The PSS has been working successfully for the last one and a half years as a standard diagnostic method in the ASDEX-Tokamak. This means, that the measurement is being automatically performed during all plasma-discharges. The Te- and Ne-values are stored in the ASDEX-computer and every user has the possibility to get the Te(r, t), Ne(r, t)-data for his own needs. (orig.)

The 150 ns detector project: Prototype preamplifier results

Science.gov (United States)

Warburton, W. K.; Russell, S. R.; Kleinfelder, Stuart A.

1994-08-01

The long-term goal of the 150 ns detector project is to develop a pixel area detector capable of 6 MHz frame rates (150 ns/frame). Our milestones toward this goal are: a single pixel, 1×256 1D and 8×8 2D detectors, 256×256 2D detectors and, finally, 1024 × 1024 2D detectors. The design strategy is to supply a complete electronics chain (resetting preamp, selectable gain amplifier, analog-to-digital converter (ADC), and memory) for each pixel. In the final detectors these will all be custom integrated circuits. The front-end preamplifiers are integrated first, since their design and performance are the most unusual and also critical to the project's success. Similarly, our early work is concentrated on devising and perfecting detector structures. In this paper we demonstrate the performance of prototypes of our integrated preamplifiers. While the final design will have 64 preamps to a chip, including a switchable gain stage, the prototypes were integrated 8 channels to a "Tiny Chip" and tested in 4 configurations (feedback capacitor Cf equal 2.5 or 4.0 pF, output directly or through a source follower). These devices have been tested thoroughly for reset settling times, gain, linearity, and electronic noise. They generally work as designed, being fast enough to easily integrate detector charge, settle, and reset in 150 ns. Gain and linearity appear to be acceptable. Current values of electronic noise, in double-sampling mode, are about twice the design goal of {2}/{3} of a single photon at 6 keV. We expect this figure to improve with the addition of the onboard amplifier stage and improved packaging. Our next test chip will include these improvements and allow testing with our first detector samples, which will be 1×256 (50 μm wide pixels) and 8×8 (1 mm 2 pixels) element detector on 1 mm thick silicon.

System for Gamma an X rays fluorescence spectrometric

International Nuclear Information System (INIS)

Alonso Abad, D.; Arista Romeu, E.; Bolanos Perez, L. and others

1997-01-01

A system for spectrometry of gamma or fluorescence X rays is presented. It sis composed by a Si(Li) semiconductors detector, a charge sensitive preamplifier, a high voltage power supply, a spectrometric amplifier and a monolithic 1024 channels multichannel analyzers or an IBM compatible 4096 channels add - on- card multichannel analyzer. The system can be configured as a 1024 or 4096 channels gamma or fluorescent X rays spectrometer

Preamplifier design with wide bandwidth using InGaP/GaAs HBT for 10-Gbps photoreceiver module

International Nuclear Information System (INIS)

Hong, S. E.; Lim, J. M.; Kim, S. I.; Nam, E. S.

2004-01-01

We report a preamplifier with wide bandwidth using high-speed and reliable InGaP/GaAs HBT applicable for 10-Gbps photoreceiver modules. The three-stage preamplifier with a negative feedback resistor demonstrates an effective transimpedance gain of 43 dBΩ, a -3-dB bandwidth of 14 GHz corresponding to a very high transimpedance-bandwidth product of 2.52 THzΩ, and an output return loss of -18 dB up to -3-dB bandwidth. This compact circuit is fabricated with an area of 800 X 700 μm 2 . A photoreceiver module of surface-mountable package type, that is composed of preamplifier and photodiode of surface-illumination type, demonstrates an optical bandwidth of 7.5 GHz at λ = 1.55 μ m and a 45-psec rise/fall time for 10-Gbps. The module shows higher sensitivity for a 10-Gbps optical transmission system.

Coupled channel effects in quasi-elastic barrier distributions of 16,18O + 206Pb systems

International Nuclear Information System (INIS)

Jha, V.; Roy, B.J.; Parkar, V.V.; Kumawat, H.; Pal, U.K.; Pandit, S.K.; Mahata, K.; Shrivastava, A.; Mohanty, A.K.

2013-01-01

The fusion barrier distribution and QEBD for the 16 O + 208 Pb have been studied in great detail. The couplings due to the collective excitations of the colliding nuclei are found to have the dominant effect as deduced by the conventional coupled-channels calculations used to explain the experimental QEBD and fusion barrier distributions. In contrast, for the 18 O + 206 Pb system, the role of single neutron stripping (Q-value= -1.308 MeV) and neutron pair transfer (Q-value = + 1.917 MeV) are expected to be significant. In the present work, the QEBD measurements for the 18 O + 206 Pb system are performed for the investigation of these aspects

A monolithically integrated detector-preamplifier on high-resistivity silicon

International Nuclear Information System (INIS)

Holland, S.; Spieler, H.

1990-02-01

A monolithically integrated detector-preamplifier on high-resistivity silicon has been designed, fabricated and characterized. The detector is a fully depleted p-i-n diode and the preamplifier is implemented in a depletion-mode PMOS process which is compatible with detector processing. The amplifier is internally compensated and the measured gain-bandwidth product is 30 MHz with an input-referred noise of 15 nV/√Hz in the white noise regime. Measurements with an Am 241 radiation source yield an equivalent input noise charge of 800 electrons at 200 ns shaping time for a 1.4 mm 2 detector with on-chip amplifier in an experimental setup with substantial external pickup

Improved Decoupling for 13C coil Arrays Using Non-Conventional Matching and Preamplifier Impedance

DEFF Research Database (Denmark)

Sanchez, Juan Diego; Johansen, Daniel Højrup; Hansen, Rie Beck

In this study, we describe a method to obtain improved preamplifier decoupling for receive-only coils. The method relies on the better decoupling obtained when coils are matched to an impedance higher than 50 . Preamplifiers with inductive imaginary impedance and low real impedance, increase...

Input Stage for Low-Voltage, Low-Noise Preamplifiers Based on a Floating-Gate MOS Transistor

DEFF Research Database (Denmark)

Igor, Mucha

1997-01-01

A novel input stage for low-voltage, low-noise preamplifiers for integrated capacitive sensors is presented. The input stage of the preamplifier employs floating-gate MOS transistors which are capable of storing the operation point of the input stage over several years without any severe degradat......A novel input stage for low-voltage, low-noise preamplifiers for integrated capacitive sensors is presented. The input stage of the preamplifier employs floating-gate MOS transistors which are capable of storing the operation point of the input stage over several years without any severe...... degradation of the performance of the circuit and without the need for a repeating programming. In this way the noise originating from any resistance previously used for the definition of the operating point is avoided completely and, moreover, by avoiding the input high-pass filter both the saturation...

A new wire chamber front-end system, based on the ASD-8 B chip

NARCIS (Netherlands)

Krusemann, BAM; Bassini, R; Ellinghaus, F; Frekers, D; Hagemann, M; Hannen, VM; von Heynitz, H; Heyse, J; Sohlbach, H; Wortche, HJ

1999-01-01

The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in-total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier

Novel charge sensitive preamplifier without high-value feedback resistor

International Nuclear Information System (INIS)

Xi Deming

1992-01-01

A novel charge sensitive preamplifier is introduced. The method of removing the high value feedback resistor, the circuit design and analysis are described. A practical circuit and its measured performances are provided

A high rate, low noise, x-ray silicon strip detector system

International Nuclear Information System (INIS)

Ludewigt, B.; Jaklevic, J.; Kipnis, I.; Rossington, C.; Spieler, H.

1993-11-01

An x-ray detector system, based on a silicon strip detector wire-bonded to a low noise charge-senstive amplifier integrated circuit, has been developed for synchrotron radiation experiments which require very high count rates and good energy resolution. Noise measurements and x-ray spectra were taken using a 6 mm long, 55 μm pitch strip detector in conjunction with a prototype 16-channel charge-sensitive preamplifier, both fabricated using standard 1.2 μm CMOS technology. The detector system currently achieves an energy resolution of 350 eV FWHM at 5.9 key, 2 μs peaking time, when cooled to -5 degree C

A novel charge sensitive preamplifier without the feedback resistor

International Nuclear Information System (INIS)

Bertuccio, G.

1992-01-01

A novel charge sensitive preamplifier which has no resistor in parallel with the feedback capacitor is presented. No external device or circuit is required to discharge the feedback capacitor. The detector leakage and signal current flows away through the gate of the first JFET which works with its gate to source junction slightly forward biased. The DC stabilization of the preamplifier is accomplished by an additional feedback loop, which permits to equalize the current flowing through the forward baised gate to source junction and the current coming from the detector. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using an input JFET with a transconductance to gate capacitance ratio of 4 mS/5.4 pF

Electronic noise in charge sensitive preamplifiers for X-ray spectroscopy and the benefits of a SiC input JFET

Energy Technology Data Exchange (ETDEWEB)

Lioliou, G., E-mail: G.Lioliou@sussex.ac.uk; Barnett, A.M.

2015-11-21

A comprehensive summary and analysis of the electronic noise affecting the resolution of X-ray, γ-ray and particle counting spectroscopic systems which employ semiconductor detectors and charge sensitive preamplifiers is presented. The noise arising from the input transistor of the preamplifier and its contribution to the total noise is examined. A model for computing the noise arising from the front-end transistor is also presented and theoretical calculations comparing the noise contribution of transistors made of different materials are discussed, emphasizing the advantages of wide bandgap transistor technology.

Cryo-EM structures of the TMEM16A calcium-activated chloride channel.

Science.gov (United States)

Dang, Shangyu; Feng, Shengjie; Tien, Jason; Peters, Christian J; Bulkley, David; Lolicato, Marco; Zhao, Jianhua; Zuberbühler, Kathrin; Ye, Wenlei; Qi, Lijun; Chen, Tingxu; Craik, Charles S; Jan, Yuh Nung; Minor, Daniel L; Cheng, Yifan; Jan, Lily Yeh

2017-12-21

Calcium-activated chloride channels (CaCCs) encoded by TMEM16A control neuronal signalling, smooth muscle contraction, airway and exocrine gland secretion, and rhythmic movements of the gastrointestinal system. To understand how CaCCs mediate and control anion permeation to fulfil these physiological functions, knowledge of the mammalian TMEM16A structure and identification of its pore-lining residues are essential. TMEM16A forms a dimer with two pores. Previous CaCC structural analyses have relied on homology modelling of a homologue (nhTMEM16) from the fungus Nectria haematococca that functions primarily as a lipid scramblase, as well as subnanometre-resolution electron cryo-microscopy. Here we present de novo atomic structures of the transmembrane domains of mouse TMEM16A in nanodiscs and in lauryl maltose neopentyl glycol as determined by single-particle electron cryo-microscopy. These structures reveal the ion permeation pore and represent different functional states. The structure in lauryl maltose neopentyl glycol has one Ca 2+ ion resolved within each monomer with a constricted pore; this is likely to correspond to a closed state, because a CaCC with a single Ca 2+ occupancy requires membrane depolarization in order to open (C.J.P. et al., manuscript submitted). The structure in nanodiscs has two Ca 2+ ions per monomer and its pore is in a closed conformation; this probably reflects channel rundown, which is the gradual loss of channel activity that follows prolonged CaCC activation in 1 mM Ca 2+ . Our mutagenesis and electrophysiological studies, prompted by analyses of the structures, identified ten residues distributed along the pore that interact with permeant anions and affect anion selectivity, as well as seven pore-lining residues that cluster near pore constrictions and regulate channel gating. Together, these results clarify the basis of CaCC anion conduction.

Multi-Channel RF System for MRI-Guided Transurethral Ultrasound Thermal Therapy

Science.gov (United States)

Yak, Nicolas; Asselin, Matthew; Chopra, Rajiv; Bronskill, Michael

2009-04-01

MRI-guided transurethral ultrasound thermal therapy is an approach to treating localized prostate cancer which targets precise deposition of thermal energy within a confined region of the gland. This treatment requires a system incorporating a heating applicator with multiple planar ultrasound transducers and associated RF electronics to control individual elements independently in order to achieve accurate 3D treatment. We report the design, construction, and characterization of a prototype multi-channel system capable of controlling 16 independent RF signals for a 16-element heating applicator. The main components are a control computer, microcontroller, and a 16-channel signal generator with 16 amplifiers, each incorporating a low-pass filter and transmitted/reflected power detection circuit. Each channel can deliver from 0.5 to 10 W of electrical power and good linearity from 3 to 12 MHz. Harmonic RF signals near the Larmor frequency of a 1.5 T MRI were measured to be below -30 dBm and heating experiments within the 1.5 T MR system showed no significant decrease in SNR of the temperature images. The frequency and power for all 16 channels could be changed in less than 250 ms, which was sufficiently rapid for proper performance of the control algorithms. A common backplane design was chosen which enabled an inexpensive, modular approach for each channel resulting in an overall system with minimal footprint.

Preamplifier development for high count-rate, large dynamic range readout of inorganic scintillators

Energy Technology Data Exchange (ETDEWEB)

Keshelashvili, Irakli; Erni, Werner; Steinacher, Michael; Krusche, Bernd; Collaboration: PANDA-Collaboration

2013-07-01

Electromagnetic calorimeter are central component of many experiments in nuclear and particle physics. Modern ''trigger less'' detectors run with very high count-rates, require good time and energy resolution, and large dynamic range. In addition photosensors and preamplifiers must work in hostile environments (magnetic fields). Due to later constraints mainly Avalanche Photo Diodes (APD's), Vacuum Photo Triodes (VPT's), and Vacuum Photo Tetrodes (VPTT's) are used. A disadvantage is their low gain which together with other requirements is a challenge for the preamplifier design. Our group has developed special Low Noise / Low Power (LNP) preamplifier for this purpose. They will be used to equip PANDA EMC forward end-cap (dynamic range 15'000, rate 1MHz), where the PWO II crystals and preamplifier have to run in an environment cooled down to -25{sup o}C. Further application is the upgrade of the Crystal Barrel detector at the Bonn ELSA accelerator with APD readout for which special temperature comparison of the APD gain and good time resolution is necessary. Development and all test procedures after the mass production done by our group during past several years in Basel University will be reported.

Application of CMOS charge-sensitive preamplifier in triple-GEM detector

International Nuclear Information System (INIS)

Lai Yongfang; Li Jin; Chinese Academy of Sciences, Beijing; Deng Zhi; Li Yulan; Liu Yinong; Li Yuanjing

2006-01-01

Among the various micro-pattern gas detectors (MPGD) that are available, the gas electron multiplier (GEM) detector is an attractive gas detector that has been used in particle physics experiments. However the GEM detector usually needs thousands of preamplifier units for its large number of micro-pattern readout strips or pads, which leads to considerable difficulties and complexities for front end electronics (FEE). Nowadays, by making use of complementary metal-oxide semiconductor (CMOS)-based application specific integrated circuit (ASIC), it is feasible to integrate hundreds of preamplifier units and other signal process circuits in a small-sized chip, which can be bound to the readout strips or pads of a micro-pattern particle detector (MPPD). Therefore, CMOS ASIC may provide an ideal solution to the readout problem of MPPD. In this article, a triple GEM detector is constructed and one of its readout strips is connected to a CMOS charge-sensitive preamplifier chip. The chip was exposed to an 55 Fe source of 5.9 kev X-ray, and the amplitude spectrum of the chip was tested, and it was found that the energy resolution was approximately 27%, which indicates that the chip can be used in triple GEM detectors. (authors)

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

Science.gov (United States)

Bechstein, S.; Petsche, F.; Scheiner, M.; Drung, D.; Thiel, F.; Schnabel, A.; Schurig, Th

2006-06-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-Tc dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm × 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm × 4 cm × 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

International Nuclear Information System (INIS)

Bechstein, S; Petsche, F; Scheiner, M; Drung, D; Thiel, F; Schnabel, A; Schurig, Th

2006-01-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-T c dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

Energy Technology Data Exchange (ETDEWEB)

Bechstein, S [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Petsche, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Scheiner, M [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Drung, D [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Thiel, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schnabel, A [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schurig, Th [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

2006-06-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/{radical}Hz was specially designed for a 304-channel low-T{sub c} dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

Design and performance of beam test electronics for the PHENIX multiplicity vertex detector

International Nuclear Information System (INIS)

Britton, C.L. Jr.; Bryan, W.L.; Emery, M.S.

1996-01-01

The system architecture and test results of the custom circuits and beam test system for the Multiplicity-Vertex Detector (MVD) for the PHENIX detector collaboration at the Relativistic Heavy Ion Collider (RHIC) are presented in this paper. The final detector per-channel signal processing chain will consist of a preamplifier-gain stage, a current-mode summed multiplicity discriminator, a 64-deep analog memory (simultaneous read-write), a post-memory analog correlator, and a 10-bit 5 μs ADC. The Heap Manager provides all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Beam test (16-cell deep memory) performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 μ n-well CMOS process used for preamplifier fabrication

Design of a preamplifier for an alpha particles spectrometer

International Nuclear Information System (INIS)

Murillo O, R.; Hernandez D, V. M.; Chacon R, A.; Vega C, H. R.

2010-09-01

To detect radiation diverse detector types are used, when these are alpha particles proportional type detectors are used, semiconductor, of scintillation or traces. In this work the design results, the construction and the first tests of a spectrometer (preamplifier) are presented for alpha particles that was designed starting from a Pin type photodiode. The system was designed and simulated with a program for electronic circuits. With the results of the simulation phase was constructed the electronics that is coupled to a spectroscopic amplifier and a multichannel analyzer. The total of the system is evaluated analyzing its performance before a triple source of alphas and that they are produced by two smoke detectors of domestic use. Of the tests phase we find that the system allows to obtain in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

16 channel 200 GHz arrayed waveguide grating based on Si nanowire waveguides

International Nuclear Information System (INIS)

Zhao Lei; An Junming; Zhang Jiashun; Song Shijiao; Wu Yuanda; Hu Xiongwei

2011-01-01

A 16 channel arrayed waveguide grating demultiplexer with 200 GHz channel spacing based on Si nanowire waveguides is designed. The transmission spectra response simulated by transmission function method shows that the device has channel spacing of 1.6 nm and crosstalk of 31 dB. The device is fabricated by 193 nm deep UV lithography in silicon-on-substrate. The demultiplexing characteristics are observed with crosstalk of 5-8 dB, central channel's insertion loss of 2.2 dB, free spectral range of 24.7 nm and average channel spacing of 1.475 nm. The cause of the spectral distortion is analyzed specifically. (semiconductor devices)

PERFORMANCE EVALUATION OF TURBO CODED OFDM SYSTEMS AND APPLICATION OF TURBO DECODING FOR IMPULSIVE CHANNEL

Directory of Open Access Journals (Sweden)

Savitha H. M.

2010-09-01

Full Text Available A comparison of the performance of hard and soft-decision turbo coded Orthogonal Frequency Division Multiplexing systems with Quadrature Phase Shift Keying (QPSK and 16-Quadrature Amplitude Modulation (16-QAM is considered in the first section of this paper. The results show that the soft-decision method greatly outperforms the hard-decision method. The complexity of the demapper is reduced with the use of simplified algorithm for 16-QAM demapping. In the later part of the paper, we consider the transmission of data over additive white class A noise (AWAN channel, using turbo coded QPSK and 16-QAM systems. We propose a novel turbo decoding scheme for AWAN channel. Also we compare the performance of turbo coded systems with QPSK and 16-QAM on AWAN channel with two different channel values- one computed as per additive white Gaussian noise (AWGN channel conditions and the other as per AWAN channel conditions. The results show that the use of appropriate channel value in turbo decoding helps to combat the impulsive noise more effectively. The proposed model for AWAN channel exhibits comparable Bit error rate (BER performance as compared to AWGN channel.

Multi-channel Waveform Sampling ASIC for radiation detection and measurement

International Nuclear Information System (INIS)

Shimazoe, K.; Takahashi, H.; Yeom, J.Y.; Furumiya, T.; Ohi, J.

2013-01-01

We have designed and fabricated a 16-channel Waveform Sampling ASIC for radiation detection and measurement. Waveform sampling is very important for the pulse shape analysis and discrimination, which is often used in radiation detection to discriminate different radiations such as alpha, beta and gamma rays. One channel of the fabricated ASIC consists of a charge-sensitive preamplifier, a VGA (Variable Gain Amplifier), an ADC (Analog to Digital Converter) and digital circuits. The preamplifier converts the current signal to the voltage signal, and the VGA amplifies the signal to appropriate level for the ADC. The ADC was designed to digitize the waveform with a frequency of 100 MHz and a resolution of 6bits. Digital circuits consist of a free-running ADC and a multiplexer which were designed to convert a digitized 100 MHz/6bit signal to a 200 MHz/3bit one, which is effective for the reduction of the number and for the achievement of the high integration in one chip. This chip was designed and fabricated with 0.35 μm CMOS technology by ROHM and the size of the ASIC is 4.9 mm by 4.9 mm. The design concept and some experimental results are shown in this paper. -- Highlights: ► Waveform sampling (WS) ASIC is newly developed for pulse shape discrimination. ► WS ASIC can be used for radiation measurement and discrimination. ► WS ASIC is fabricated by submicron CMOS technology for 5 mm × 5 mm area. ► WS ASIC achieves high integration and can be used in very limited space

Testing the YerPhI Transimpedance Preamplifier with PPC by the T11 PS Beam

CERN Document Server

Parlakian, L K; CERN. Geneva; Martmianov, A N

1997-01-01

We report on the test of the preamplifier, described in [1], by the 3 GeV/c positive particle T11 beam of PS/CERN. We have measured the amplitude and time of flight spectrum, the time resolution and detection efficiency. The preamplifier has shown a stable work and hardness to the chamber discharge. The test results are presented.

Carrier frequency offset estimation for an acoustic-electric channel using 16 QAM modulation

Science.gov (United States)

Cunningham, Michael T.; Anderson, Leonard A.; Wilt, Kyle R.; Chakraborty, Soumya; Saulnier, Gary J.; Scarton, Henry A.

2016-05-01

Acoustic-electric channels can be used to send data through metallic barriers, enabling communications where electromagnetic signals are ineffective. This paper considers an acoustic-electric channel that is formed by mounting piezoelectric transducers on metallic barriers that are separated by a thin water layer. The transducers are coupled to the barriers using epoxy and the barriers are positioned to axially-align the PZTs, maximizing energy transfer efficiency. The electrical signals are converted by the transmitting transducers into acoustic waves, which propagate through the elastic walls and water medium to the receiving transducers. The reverberation of the acoustic signals in these channels can produce multipath distortion with a significant delay spread that introduces inter-symbol interference (ISI) into the received signal. While the multipath effects can be severe, the channel does not change rapidly which makes equalization easier. Here we implement a 16-QAM system on this channel, including a method for obtaining accurate carrier frequency offset (CFO) estimates in the presence of the quasi-static multipath propagation. A raised-power approach is considered but found to suffer from excessive data noise resulting from the ISI. An alternative approach that utilizes a pilot tone burst at the start of a data packet is used for CFO estimation and found to be effective. The autocorrelation method is used to estimate the frequency of the received burst. A real-time prototype of the 16 QAM system that uses a Texas Instruments MSP430 microcontroller-based transmitter and a personal computer-based receiver is presented along with performance results.

Stability of a line receiver (0-T) preamplifier, connected to a capacitive detector via a transmission line

CERN Document Server

Battistoni, G; Fedyakin, N; Ramaioli, P; Shuvalov, R S

1999-01-01

We analyze the stability of a line receiver (0-T) preamplifier proposed to readout the ionization signal of the ATLAS LAr electromagnetic calorimeter. The transport of detector signal to the preamplifier input via a cable is analyzed on the basis of classical theory of wave propagation in transmission lines. It is shown that the analysis of stability can be reduced to the examination of zeros of the expression Z sub i sub n +Z sub D sub C , where Z sub i sub n is the input impedance of the 0-T and Z sub D sub C is the impedance of the detector plus cable, as seen by the preamplifier. An experimental method to measure the preamplifier input impedance in a range 1-200 MHz is described. The stability function Z sub i sub n +Z sub D sub C was built by using the combination of experimental data (Z sub i sub n) and calculations (Z sub D sub C) and was used to analyze the stability of two versions of 0-T preamplifier at different experimental conditions. It is illustrated that if the vector end of this semiempirical...

Microprocessor based beam loss monitor system for the AGS

International Nuclear Information System (INIS)

Witkover, R.L.

1979-01-01

An array of 120 long radiation monitors (LRM) have been installed around the AGS. Each monitor is an extended coaxial ion chamber, 5 meters long, made from hollow core coaxial transmission cable pressured with argon. The LRM's are each connected to a low current preamplifier and voltage-to-frequency converter (VFC). The digital output of each channel is fed to a 16 bit counter chip which bridges the bus of an 8085 microprocessor. This circuit is connected to the AGS PD-10 for data taking or may function as a stand-alone unit. Various operating modes can be selected for data readout. System design and operating performance are described

On-line gas mixing and multi-channel distribution system

International Nuclear Information System (INIS)

Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.; Joshi, Avinash

2009-01-01

In this presentation, we describe a mass-flow controller based on-line gas mixing unit with the multi-channel distribution system. We highlight different aspects such as requirement, design, calibration, control and operation of this system. This unit has the capability to mix up to four different input gases and distribute over 16 output channels. Output in individual channels is controlled accurately by using capillary-based system. At present, we are using this gas mixing unit for prototype of iron calorimeter (ICAL) detector of India-based Neutrino Observatory (INO).

A gain and bandwidth enhanced transimpedance preamplifier for Fourier-transform ion cyclotron resonance mass spectrometry

International Nuclear Information System (INIS)

Lin, Tzu-Yung; Green, Roger J.; O'Connor, Peter B.

2011-01-01

The nature of the ion signal from a 12-T Fourier-transform ion cyclotron resonance mass spectrometer and the electronic noise were studied to further understand the electronic detection limit. At minimal cost, a new transimpedance preamplifier was designed, computer simulated, built, and tested. The preamplifier design pushes the electronic signal-to-noise performance at room temperature to the limit, because of its enhanced tolerance of the capacitance of the detection device, lower intrinsic noise, and larger flat mid-band gain (input current noise spectral density of around 1 pA/√(Hz) when the transimpedance is about 85 dBΩ). The designed preamplifier has a bandwidth of ∼3 kHz to 10 MHz, which corresponds to the mass-to-charge ratio, m/z, of approximately 18 to 61 k at 12 T. The transimpedance and the bandwidth can be easily adjusted by changing the value of passive components. The feedback limitation of the circuit is discussed. With the maximum possible transimpedance of 5.3 MΩ when using an 0402 surface mount resistor, the preamplifier was estimated to be able to detect ∼110 charges in a single scan.

A 16-Channel CMOS Chopper-Stabilized Analog Front-End ECoG Acquisition Circuit for a Closed-Loop Epileptic Seizure Control System.

Science.gov (United States)

Wu, Chung-Yu; Cheng, Cheng-Hsiang; Chen, Zhi-Xin

2018-06-01

In this paper, a 16-channel analog front-end (AFE) electrocorticography signal acquisition circuit for a closed-loop seizure control system is presented. It is composed of 16 input protection circuits, 16 auto-reset chopper-stabilized capacitive-coupled instrumentation amplifiers (AR-CSCCIA) with bandpass filters, 16 programmable transconductance gain amplifiers, a multiplexer, a transimpedance amplifier, and a 128-kS/s 10-bit delta-modulated successive-approximation-register analog-to-digital converter (SAR ADC). In closed-loop seizure control system applications, the stimulator shares the same electrode with the AFE amplifier for effective suppression of epileptic seizures. To prevent from overstress in MOS devices caused by high stimulation voltage, an input protection circuit with a high-voltage-tolerant switch is proposed for the AFE amplifier. Moreover, low input-referred noise is achieved by using the chopper modulation technique in the AR-CSCCIA. To reduce the undesired effects of chopper modulation, an improved offset reduction loop is proposed to reduce the output offset generated by input chopper mismatches. The digital ripple reduction loop is also used to reduce the chopper ripple. The fabricated AFE amplifier has 49.1-/59.4-/67.9-dB programmable gain and 2.02-μVrms input referred noise in a bandwidth of 0.59-117 Hz. The measured power consumption of the AFE amplifier is 3.26 μW per channel, and the noise efficiency factor is 3.36. The in vivo animal test has been successfully performed to verify the functions. It is shown that the proposed AFE acquisition circuit is suitable for implantable closed-loop seizure control systems.

Multi-channel logical circuit module used for high-speed, low amplitude signals processing and QDC gate signals generation

International Nuclear Information System (INIS)

Su Hong; Li Xiaogang; Zhu Haidong; Ma Xiaoli; Yin Weiwei; Li Zhuyu; Jin Genming; Wu Heyu

2001-01-01

A new kind of logical circuit will be introduced in brief. There are 16 independent channels in the module. The module receives low amplitude signals(≥40 mV), and processes them to amplify, shape, delay, sum and etc. After the processing each channel produces 2 pairs of ECL logical signal to feed the gate of QDC as the gate signal of QDC. The module consists of high-speed preamplifier unit, high-speed discriminate unit, delaying and shaping unit, summing unit and trigger display unit. The module is developed for 64 CH. 12 BIT Multi-event QDC. The impedance of QDC is 110 Ω. Each gate signal of QDC requires a pair of differential ECL level, Min. Gate width 30 ns and Max. Gate width 1 μs. It has showed that the outputs of logical circuit module satisfy the QDC requirements in experiment. The module can be used on data acquisition system to acquire thousands of data at high-speed ,high-density and multi-parameter, in heavy particle nuclear physics experiment. It also can be used to discriminate multi-coincidence events

/sup 16/O(/sup 16/O, /sup 12/C)/sup 20/Ne reaction in the framework of the coupled channel formalism

Energy Technology Data Exchange (ETDEWEB)

Krause, O; Scheid, W; Greiner, W [Frankfurt Univ. (Germany, F.R.). Inst. fuer Theoretische Physik

1974-01-01

The transfer reaction /sup 16/O(/sup 16/O, /sup 12/C)/sup 20/Ne is treated in the coupled channel formalism. The influence of the transfer channels on the intermediate structure in the elastic excitation function is discussed. The /sup 16/O and /sup 20/Ne-nuclei are described in an ..cap alpha..-cluster model.

Design of a 32-channel EEG system for brain control interface applications.

Science.gov (United States)

Wang, Ching-Sung

2012-01-01

This study integrates the hardware circuit design and the development support of the software interface to achieve a 32-channel EEG system for BCI applications. Since the EEG signals of human bodies are generally very weak, in addition to preventing noise interference, it also requires avoiding the waveform distortion as well as waveform offset and so on; therefore, the design of a preamplifier with high common-mode rejection ratio and high signal-to-noise ratio is very important. Moreover, the friction between the electrode pads and the skin as well as the design of dual power supply will generate DC bias which affects the measurement signals. For this reason, this study specially designs an improved single-power AC-coupled circuit, which effectively reduces the DC bias and improves the error caused by the effects of part errors. At the same time, the digital way is applied to design the adjustable amplification and filter function, which can design for different EEG frequency bands. For the analog circuit, a frequency band will be taken out through the filtering circuit and then the digital filtering design will be used to adjust the extracted frequency band for the target frequency band, combining with MATLAB to design man-machine interface for displaying brain wave. Finally the measured signals are compared to the traditional 32-channel EEG signals. In addition to meeting the IFCN standards, the system design also conducted measurement verification in the standard EEG isolation room in order to demonstrate the accuracy and reliability of this system design.

A 16-channel combined loop-dipole transceiver array for 7 Tesla body MRI

NARCIS (Netherlands)

Ertürk, M. Arcan; Raaijmakers, Alexander J.E.; Adriany, Gregor; Uğurbil, Kâmil; Metzger, Gregory J.

2017-01-01

Purpose: To develop a 16-channel transceive body imaging array at 7.0 T with improved transmit, receive, and specific absorption rate (SAR) performance by combining both loop and dipole elements and using their respective and complementary near and far field characteristics. Methods: A 16-channel

Centralized Routing and Scheduling Using Multi-Channel System Single Transceiver in 802.16d

Science.gov (United States)

Al-Hemyari, A.; Noordin, N. K.; Ng, Chee Kyun; Ismail, A.; Khatun, S.

This paper proposes a cross-layer optimized strategy that reduces the effect of interferences from neighboring nodes within a mesh networks. This cross-layer design relies on the routing information in network layer and the scheduling table in medium access control (MAC) layer. A proposed routing algorithm in network layer is exploited to find the best route for all subscriber stations (SS). Also, a proposed centralized scheduling algorithm in MAC layer is exploited to assign a time slot for each possible node transmission. The cross-layer optimized strategy is using multi-channel single transceiver and single channel single transceiver systems for WiMAX mesh networks (WMNs). Each node in WMN has a transceiver that can be tuned to any available channel for eliminating the secondary interference. Among the considered parameters in the performance analysis are interference from the neighboring nodes, hop count to the base station (BS), number of children per node, slot reuse, load balancing, quality of services (QoS), and node identifier (ID). Results show that the proposed algorithms significantly improve the system performance in terms of length of scheduling, channel utilization ratio (CUR), system throughput, and average end to end transmission delay.

The Neutron Spectrometry System Using 3He Counter

International Nuclear Information System (INIS)

Dang Lanh; Pham Ngoc Tuan; Tuong Thi Thu Huong; Nguyen Nhi Dien; Nguyen Van Hung

2011-01-01

A spectrometry system was designed for neutron counting at the horizontal channels of Dalat nuclear reactor. The system is able to interface to PC via EZ-USB with full speed. The designed system can be installed for operation not only at the channel No. 4 of the reactor, but also operated with the neutron Howitzer system installed at the Training Center of Nuclear Research Institute for training purposes. Almost results can be achieved effectively while choosing the shaping time of 2 μs of amplifier unit; and an appropriate preamplifier is used to measure neutron spectra. In this work, the multi-channel spectrometer for measuring neutron was designed and tested. (author)

Radiation hardness tests with a demonstrator preamplifier circuit manufactured in silicon on sapphire (SOS) VLSI technology

International Nuclear Information System (INIS)

Bingefors, N.; Ekeloef, T.; Eriksson, C.; Paulsson, M.; Moerk, G.; Sjoelund, A.

1992-01-01

Samples of the preamplifier circuit, as well as of separate n and p channel transistors of the type contained in the circuit, were irradiated with gammas from a 60 Co source up to an integrated dose of 3 Mrad (30 kGy). The VLSI manufacturing technology used is the SOS4 process of ABB Hafo. A first analysis of the tests shows that the performance of the amplifier remains practically unaffected by the radiation for total doses up to 1 Mrad. At higher doses up to 3 Mrad the circuit amplification factor decreases by a factor between 4 and 5 whereas the output noise level remains unchanged. It is argued that it may be possible to reduce the decrease in amplification factor in future by optimizing the amplifier circuit design further. (orig.)

A low-noise/low-power preamplifier for capacitive microphones

DEFF Research Database (Denmark)

Fürst, Claus Erdmann

1996-01-01

A design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply of 1-1.5 V, the current drain is 40 μA. The maximum sound level allowed is more than 120 dB SPL (Sound Pressure Level), with a typical noise level of 25 dB(A) SPL (A...

Data acquisition system of 16-channel EEG based on ATSAM3X8E ARM Cortex-M3 32-bit microcontroller and ADS1299

Science.gov (United States)

Toresano, L. O. H. Z.; Wijaya, S. K.; Prawito, Sudarmaji, A.; Badri, C.

2017-07-01

The prototype of the EEG (electroencephalogram) instrumentation systems has been developed based on 32-bit microcontrollers of Cortex-M3 ATSAM3X8E and Analog Front-End (AFE) ADS1299 (Texas Instruments, USA), and also consists of 16-channel dry-electrodes in the form of EEG head-caps. The ADS1299-AFE has been designed in a double-layer format PCB (Print Circuit Board) with daisy-chain configuration. The communication protocol of the prototype was based on SPI (Serial Peripheral Interface) and tested using USB SPI-Logic Analyzer Hantek4032L (Qingdao Hantek Electronic, China). The acquired data of the 16-channel from this prototype has been successfully transferred to a PC (Personal Computer) with accuracy greater than 91 %. The data acquisition system has been visualized with time-domain format in the multi-graph plotter, the frequency-domain based on FFT (Fast Fourier Transform) calculation, and also brain-mapping display of 16-channel. The GUI (Graphical User Interface) has been developed based on OpenBCI (Brain Computer Interface) using Java Processing and also can be stored of data in the *.txt format. Instrumentation systems have been tested in the frequency range of 1-50 Hz using MiniSim 330 EEG Simulator (NETECH, USA). The validation process has been done with different frequency of 0.1 Hz, 2 Hz, 5 Hz, and 50 Hz, and difference voltage amplitudes of 10 µV, 30 µV, 50 µV, 100 µV, 500 µV, 1 mV, 2 mV and 2.5 mV. However, the acquisition system was not optimal at a frequency of 0.1 Hz and for amplitude potentials of over 1 mV had differences of the order 10 µV.

Multiple wavelength multitimescale optical absorption system

International Nuclear Information System (INIS)

Lubis, R.; Allan, D.; Hodgson, B.W.; Swallow, A.J.

1992-01-01

A new workstation for pulse radiolysis studies has been developed for the Paterson Institute Linear Accelerator Laboratory. It is particularly suited to the study of materials available only in limited quantities. The analysing light beam is dispersed into a plane spectrum by a McPherson 270 monochromator and focused down to a line spectrum by a rod lens. The spectral intensity distribution is sampled by a linear array of optical fibres which conduct the light to photodiodes. A preamplifier unit amplifies and buffers the diode photocurrent signal which then passes to the main electronics unit incorporating further amplification stages, filters, backing-off of the background photocurrent, analog-to-digital conversion, data storage memory and a computer interface. All control of the electronic system is performed from a computer equipped with appropriate software. The system has 10 channels of spectral bandwidth 16 nm, a useful spectral response from 350 nm to 1 μm with a high signal-to-noise ratio, signal sampling rates from 20 MHz to 2 kHz and 8 kbyte of local memory for each channel. (author)

Multiple wavelength multitimescale optical absorption system

Science.gov (United States)

Lubis, R.; Allan, D.; Hodgson, B. W.; Swallow, A. J.

A new workstation for pulse radiolysis studies has been developed for the Paterson Institute Linear Accelerator Laboratory. It is particularly suited to the study of materials available only in limited quantities. The analysing light beam is dispersed into a plane spectrum by a McPherson 270 monochromator and focused down to a line spectrum by a rod lens. The spectral intensity distribution is sampled by a linear array of optical fibres which conduct the light to photodiodes. A preamplifier unit amplifies and buffers the diode photocurrent signal which then passes to the main electronics unit incorporating further amplification stages, filters, backing-off of the background photocurrent, analog-to-digital conversion, data storage memory and a computer interface. All control of the electronic system is performed from a computer equipped with appropriate software. The system has 10 channels of spectral bandwidth 16 nm, a useful spectral response from 350 nm to 1 μm with a high signal-to-noise ratio, signal sampling rates from 20 MHz to 2 kHz and 8 kbyte of local memory for each channel.

A 16-Channel Nonparametric Spike Detection ASIC Based on EC-PC Decomposition.

Science.gov (United States)

Wu, Tong; Xu, Jian; Lian, Yong; Khalili, Azam; Rastegarnia, Amir; Guan, Cuntai; Yang, Zhi

2016-02-01

In extracellular neural recording experiments, detecting neural spikes is an important step for reliable information decoding. A successful implementation in integrated circuits can achieve substantial data volume reduction, potentially enabling a wireless operation and closed-loop system. In this paper, we report a 16-channel neural spike detection chip based on a customized spike detection method named as exponential component-polynomial component (EC-PC) algorithm. This algorithm features a reliable prediction of spikes by applying a probability threshold. The chip takes raw data as input and outputs three data streams simultaneously: field potentials, band-pass filtered neural data, and spiking probability maps. The algorithm parameters are on-chip configured automatically based on input data, which avoids manual parameter tuning. The chip has been tested with both in vivo experiments for functional verification and bench-top experiments for quantitative performance assessment. The system has a total power consumption of 1.36 mW and occupies an area of 6.71 mm (2) for 16 channels. When tested on synthesized datasets with spikes and noise segments extracted from in vivo preparations and scaled according to required precisions, the chip outperforms other detectors. A credit card sized prototype board is developed to provide power and data management through a USB port.

Use of the photovoltaic cells as fission fragment sensors and study of a preamplifier adapted to the cells

International Nuclear Information System (INIS)

Jin Yimeng.

1989-04-01

In the detection of heavy ions and fission fragments, the photovoltaic cells can take the place of traditional silicon surface barrier detectors, if we need a great number of detectors as in the case of 4π multidetector, and do not expect excellent energy and time resolutions at the same time. Made for the purpose of converting the solar energy to the electrical energy, the photovoltaic cells have the similar structure as silicon surface barrier detectors, except for their much thinner pn junctions and, as a result much larger junction capacities, which is a major disadvantage for photovoltaic cells as fission fragment detectors. In order to get an acceptable energy resolution and a time resolution as good as possible, it is necessary to design a preamplifier specially adapted to cells, which plays a very important role in the utilization of photovoltaic cells as detectors. In the present work we analyze the electrical signal from a cell when hit by a fission fragment, and propose a new type cell oriented preamplifier of voltage, with which we can use a cell up to 10 cm 2 , and obtain a time resolution better than 16 ns [fr

Pulse shape discrimination with silicon detectors using charge and current-sensitive preamplifiers

Energy Technology Data Exchange (ETDEWEB)

Hamrita, H.; Rauly, E.; Blumenfeld, Y.; Borderie, B.; Chabot, M.; Edelbruck, P.; Lavergne, L.; Le Bris, J.; Le Neindre, N.; Richard, A.; Rivet, M.F.; Scarpaci, J.A.; Barbey, S.; Becheva, E.; Bzyl, F.R.; D' Esesquelles, P.; Galichet, E.; Lalu, G.; Martinet, G.; Pierre, S. [Institut de Physique Nucleaire, IN2P3-CNRS, 91 - Orsay (France); Legou, Th.; Tillier, J.; Bocage, F.; Bougault, R.; Carniol, B.; Cussol, D.; Etasse, D.; Grevy, S.; Lopez, O.; Tamain, B.; Vient, E. [Caen Univ., LPC, IN2P3-CNRS, ENSI, 14 - Caen (France); Galichet, E. [Conservatoire National des Arts et Metier, 75 - Paris (France); Guinet, D.; Lautesse, Ph. [Villeurbanne Univ., Institut de Physique Nucleaire, IN2P3-CNRS, 69 (France); Lanzalone, G. [Catania Univ., INFN, Laboratori Nazionali del Sud and Dipartimento di Fisica e Astronomia, (Italy); Politi, G. [Catania Univ., INFN, Sezione di Catania and Dipartimento di Fisica e Astronomia (Italy); Rosato, E. [Napoli, Univ., Dipt. di Scienze Fisiche e Sezione INFN (Italy)

2003-07-01

For the first time shapes of current pulses from light charged particles and carbon ions are presented. Capabilities for pulse shape discrimination techniques are demonstrated. In this work, charge and current-sensitive preamplifier prototypes for nuclear structure and dynamics experiments have been developed and tested with the aim of improving PSD (pulse shape discrimination) method by studying in detail current signal shapes from particles and ions over a large energy range. Note that current signal shapes have been recently used in atomic cluster studies to identify partitions of carbon cluster fragmentation. The paper is organized as follows. Section 2 is devoted to characterization of preamplifiers. In section 3, results of on beam tests will be presented, discussed and compared to a simple simulation.

Performance of a fast low noise front-end preamplifier for the MAGIC imaging Cherenkov telescope

International Nuclear Information System (INIS)

Blanch, O.; Blanchot, G.; Bosman, M.

1999-01-01

The observation of high energy cosmic gamma rays with an energy threshold of 15 GeV using the proposed MAGIC ground based air imaging Cherenkov telescope requires the development of new low noise fast preamplifiers for the camera photosensors. The speed and noise performance of a transimpedance preamplifier that resolves the multi photoelectron peaks from a hybrid photomultiplier with a peaking time below 7 ns is presented. The new front-end circuit is designed with RF low noise bipolar transistors and provides fast output pulses that allow for fast trigger settings

A Read-out and Data Acquisition System for the Outputs of Multi-channel Spectroscopy Amplifiers

International Nuclear Information System (INIS)

Kong Jie; Qian Yi; Su Hong; Dong Chengfu

2009-01-01

A read-out and data acquisition system for the outputs of multi-channel spectroscopy amplifiers is introduced briefly in this paper. The 16-channel gating integrator/multiplexer developed by us and PXI-DAQ card are used to construct this system. A virtual instrument system for displaying, indicating,measuring and recording of output waveform is accomplished by integrating the PC, hardware, software together flexibly based on the Lab Windows/CVI platform in our read-out and data acquisition system. In this system, an ADC can face the 16 outputs of 16-channel spectroscopy amplifiers, which can improve the system integration and reduce the cost of data acquisition system. The design provided a new way for building the read-out and data acquisition system using the normal modules and spectroscopy amplifiers. This system has been tested and demonstrated that it is intelligent, reliable, real-time and low cost. (authors)

Test of a 32-channel Prototype ASIC for Photon Counting Application.

Science.gov (United States)

Chen, Y; Cui, Y; O'Connor, P; Seo, Y; Camarda, G S; Hossain, A; Roy, U; Yang, G; James, R B

2015-01-01

A new low-power application-specific integrated circuit (ASIC) for Cadmium Zinc Telluride (CZT) detectors for single-photon emission computed tomography (SPECT) application is being developed at BNL. As the first step, a 32-channel prototype ASIC was designed and tested recently. Each channel has a preamplifier followed by CR-RC 3 shaping circuits and three independent energy bins with comparators and 16-bit counters. The ASIC was fabricated with TSMC 0.35-μm complementary metal-oxide-semiconductor (CMOS) process and tested in laboratories. The power consumption is around 1 mW/ch with a 2.5-V supply. With a gain of 400 mV/fC and the peaking time of 500 ns, the equivalent noise charge (ENC) of 360 e- has been measured in room temperature while the crosstalk rate is less than 0.3%. The 10-bit DACs for global thresholds have an integral nonlinearity (INL) less than 0.56% and differential nonlinearity (DNL) less than 0.33%. In the presentation, we will report the detailed test results with this ASIC.

Monolithic front-end preamplifiers for a broad range of calorimetry applications

Energy Technology Data Exchange (ETDEWEB)

Radeka, V.; Rescia, S. [Brookhaven National Lab., Upton, NY (United States); Manfredi, P.F.; Speziali, V. [Pavia Univ. (Italy). Dipt. di Elettronica]|[INFN--Sezzione di Milano, Milano (Italy)

1993-12-31

The present paper summarizes the salient results of a research and development activity in the area of low noise preamplifiers for different applications in calorimetry. Design target for all circuits considered here are low noise, ability to cope with broad energy ranges and radiation hardness.

Study of a preamplifier for the detection of weak impulses of neutrons from a critical medium (Proserpine) (1960)

International Nuclear Information System (INIS)

Agaisse, R.

1960-01-01

In a critical experiment the small detection instruments supply weak impulses, and these must be brought outside the pile for counting. The important parameter is the ratio of the signal to the background. For the preamplifier studied in this report the background, considered at the input, is 12 micro-volts; a factor 2 is thus gained with respect to ordinary preamplifiers. (author) [fr

32-Channel banana-avg montage is better than 16-channel double banana montage to detect epileptiform discharges in routine EEGs.

Science.gov (United States)

Ochoa, Juan; Gonzalez, Walter; Bautista, Ramon; DeCerce, John

2008-10-01

We designed a study, comparing the yield of standard 16-channel longitudinal bipolar montage (double banana) versus a combined 32-channel longitudinal bipolar plus average referential montage (banana-plus), to detect epileptic abnormalities. We selected 25 consecutive routine EEG samples with a diagnosis of spike or sharp waves in the temporal regions and 25 consecutive focal slowing and 50 normal EEGs. A total of 100 samples were printed in both montages and randomized for reading. Thirty independent EEG readers blinded from the EEG diagnosis were invited to participate. Twenty-two readers successfully completed the test for a total of 4400 answers collected for analysis. The average sensitivity to detect epileptiform discharges for 16 and 32-channel montages was 36.5% and 61%, respectively (Pdouble banana montage. Residents and EEG fellows could improve EEG-reading accuracy if taught on a combined 32-channel montage.

A deadtime reduction circuit for thermal neutron coincidence counters with Amptek preamplifiers

International Nuclear Information System (INIS)

Bourret, S.C.; Krick, M.S.

1994-01-01

We have developed a deadtime reduction circuit for thermal neutron coincidence counters using Amptek preamplifier/amplifier/discriminator circuits. The principle is to remove the overlap between the output pulses from the Amptek circuits by adding a derandomizer between the Amptek circuits and the shift-register coincidence electronics. We implemented the derandomizer as an Actel programmable logic array; the derandomizer board is small and can be mounted in the high-voltage junction box with the Amptek circuits, if desired. Up to 32 Amptek circuits can be used with one derandomizer. The derandomizer has seven outputs: four groups of eight inputs, two groups of 16 inputs, and one group of 32 inputs. We selected these groupings to facilitate detector ring-ratio measurements. The circuit was tested with the five-ring research multiplicity counter, which has five output signals-one for each ring. The counter's deadtime was reduced from 70 to 30 ns

First observations of nuclear rainbow scattering in the 16O+27Al system

International Nuclear Information System (INIS)

Pereira, D.; Oliveira, J.R.B.; Chamon, L.C.; Cunsolo, A.; Cappuzzello, F.; Cavallaro, M.; Carbone, D.

2011-01-01

Nuclear rainbow structures have been unexpectedly predicted in the elastic channel of heavy nuclear systems like 16 O + 27 Al or 58 Ni by a new generation of coupled channel calculations, with inclusion of an imaginary potential for dissipative processes. Rainbow scattering phenomena are very sensitive to the nuclear potential in the surface interior and therefore very important to test different microscopic ion-ion potentials, as mentioned in, as well as the role of reaction couplings in the elastic channel far from the barrier region. The rainbow pattern has been experimentally well established for lighter systems like alpha-nucleus, 12 C + 12 C, 16 O + 12 C, and 16 O + 16 O - the heaviest heavy-ion system so far that has shown a prominent rainbow structure. By using the large acceptance magnetic spectrometer MAGNEX (LNS, Catania, Italy) in a high-sensitivity and high-precision experiment, we have confirmed some of the predictions cited above, for the 16 O + 27 Al system, at 100 MeV beam energy, up to about 80 degrees in the center of mass. An extremely good resolution (around 90 keV) was achieved, allowing for clear separation of the elastic channel from the first excited state of 27 Al (843.8 keV). Cross sections below 10 -4 mb were measured. Additional experiments are scheduled to April, 2011, in order to explore the backward-angle region. In this presentation, the comparison between the rainbow structures detected in this system and those in lighter systems and with weakly bound nuclei will be discussed, in connection with the predicted Airy minima. (author)

High-performance semiconductor optical preamplifier receiver at 10 Gb/s

DEFF Research Database (Denmark)

Mikkelsen, Benny; Jørgensen, Carsten Gudmann; Jensen, N.

1993-01-01

A semiconductor optical preamplifier receiver for bitrates of 10 Gb/s is described. The measured sensitivity is -28 dBm, with a polarization sensitivity of less than 0.5 dB. Using the same transmitter and receiver configuration but with a 980-nm pumped fiber amplifier instead of the semiconductor...... amplifier, the sensitivity is -34 dBm...

Preliminary measurements of gamma ray effects on characteristics of broad-band GaAs field-effect transistor preamplifiers

International Nuclear Information System (INIS)

Jackson, H.G.; Shimizu, T.T.; Leskovar, B.

1985-01-01

The effect of gamma radiation on electrical characteristics of cryogenically cooled broad-band low-noise microwave preamplifiers has been preliminarily evaluated. The change in the gain and noise figure of a 1-2 GHz preamplifier using GaAs microwave transistors was determined at gamma doses between 10 5 rad to 5 /times/ 10 8 rad. The gain and noise figure was measured at ambient temperatures of 300 K and 80 K. 8 refs., 2 figs

Simulation of frontend preamplifiers for the MSGC

International Nuclear Information System (INIS)

Schmitz, J.

1993-01-01

Two candidate architectures for frontend preamplifiers for the Microstrip Gas Counter are tested using a Monte Carlo simulation of the detector and frontend. The simulation describes ionisation in the gas, electron drift and diffusion, gas amplification, signal development and the discriminator. The first architecture is based on the current design of the Fastplex, while the alternative design uses a subtraction method. The simulations indicate that the current Fastplex-design matches the MSGC best when the shaping time is as high as possible (around 50 ns). The signal is extracted more accurately with the alternative design. (orig.)

Design of low noise front-end ASIC and DAQ system for CdZnTe detector

International Nuclear Information System (INIS)

Luo Jie; Deng Zhi; Liu Yinong

2012-01-01

A low noise front-end ASIC has been designed for CdZnTe detector. This chip contains 16 channels and each channel consists of a dual-stage charge sensitive preamplifier, 4th order semi-Gaussian shaper, leakage current compensation (LCC) circuit, discriminator and output buffer. This chip has been fabricated in Chartered 0.35 μm CMOS process, the preliminary results show that it works well. The total channel charge gain can be adjusted from 100 mV/fC to 400 mV/fC and the peaking time can be adjusted from 1 μs to 4 μs. The minimum measured ENC at zero input capacitance is 70 e and minimum noise slope is 20 e/pF. The peak detector and derandomizer (PDD) ASIC developed by BNL and an associated USB DAQ board are also introduced in this paper. Two front-end ASICs can be connected to the PDD ASIC on the USB DAQ board and compose a 32 channels DAQ system for CdZnTe detector. (authors)

Embedded multi-channel data acquisition system on FPGA for Aditya Tokamak

Energy Technology Data Exchange (ETDEWEB)

Rajpal, Rachana, E-mail: rachana@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat (India); Mandaliya, Hitesh, E-mail: hitesh@ipr.res.in [ITER, Cadarache (France); Patel, Jignesh, E-mail: jjp@ipr.res.in [ITER, Cadarache (France); Kumari, Praveena, E-mail: praveena@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat (India); Gautam, Pramila, E-mail: pramila@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat (India); Raulji, Vismaysinh, E-mail: vismay@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat (India); Edappala, Praveenlal, E-mail: praveen@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat (India); Pujara, H.D, E-mail: pujara@ipr.res [Institute for Plasma Research, Gandhinagar, Gujarat (India); Jha, R., E-mail: jha@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat (India)

2016-11-15

Highlights: • 64 channel data acquisition, interface to PC/104 bus, using single board computer. • Integration of all components in single hardware to make it standalone and portable. • Development of application software in Qt on Linux platform for better performance and low cost compared to Windows. • Explored and utilized FPGA resources for hardware interfacing. - Abstract: The 64 channel data acquisition board is designed to meet the future demand of acquisition channels for plasma diagnostics. The inherent features of the board are 16 bit resolution, programmable sampling rate upto 200 kS/s/ch and simultaneous acquisition. To make system embedded and compact, 8 Analog Inputs ADC chip, 4M × 16 bit RAM memory, Field Programmable Gate Arrays, PC/104 platform and single board computer are used. High speed timing control signals for all ADCs and RAMs are generated by FPGA. The system is standalone, portable and interface through Ethernet. The acquisition application is developed in Qt. on Linux platform, in SBC. Due to ethernet connectivity and onboard processing, system can be integrated into Aditya and SST-1 data acquisition system. The performance of hardware is tested on Linux and Windows Embedded OS. The paper describes design, hardware and software architecture, implementation and results of 64 channel DAQ system.

Embedded multi-channel data acquisition system on FPGA for Aditya Tokamak

International Nuclear Information System (INIS)

Rajpal, Rachana; Mandaliya, Hitesh; Patel, Jignesh; Kumari, Praveena; Gautam, Pramila; Raulji, Vismaysinh; Edappala, Praveenlal; Pujara, H.D; Jha, R.

2016-01-01

Highlights: • 64 channel data acquisition, interface to PC/104 bus, using single board computer. • Integration of all components in single hardware to make it standalone and portable. • Development of application software in Qt on Linux platform for better performance and low cost compared to Windows. • Explored and utilized FPGA resources for hardware interfacing. - Abstract: The 64 channel data acquisition board is designed to meet the future demand of acquisition channels for plasma diagnostics. The inherent features of the board are 16 bit resolution, programmable sampling rate upto 200 kS/s/ch and simultaneous acquisition. To make system embedded and compact, 8 Analog Inputs ADC chip, 4M × 16 bit RAM memory, Field Programmable Gate Arrays, PC/104 platform and single board computer are used. High speed timing control signals for all ADCs and RAMs are generated by FPGA. The system is standalone, portable and interface through Ethernet. The acquisition application is developed in Qt. on Linux platform, in SBC. Due to ethernet connectivity and onboard processing, system can be integrated into Aditya and SST-1 data acquisition system. The performance of hardware is tested on Linux and Windows Embedded OS. The paper describes design, hardware and software architecture, implementation and results of 64 channel DAQ system.

Large bandwidth RGC transimpedance preamplifier design in SCA

International Nuclear Information System (INIS)

Wang Ke; Wang Zheng; Liu Zhen'an; Wei Wei; Lu Weiguo; Gary Varner

2009-01-01

A Large Bandwidth RGC Transimpedance Preamplifier is designed for amplifying the high-fidelity timing signal in Switch Capacitance Array chip application. This amplifier have characteristics of low input impedance, large bandwidth, high transimpedance. It will be made under TSMC 0.25μm CMOS technology, and the supply voltage is single 2.5 V. Simulation results indicate: the transimpedance is 5000 ohm, -3dB BW is 953 MHz, and the detector output capacitance have litter effect on the bandwidth in some range. (authors)

TRAO Multibeam Receiver System and Key Science Programs

Science.gov (United States)

Lee, Youngung

2017-06-01

Taeduk Radio Astronomy Observatory (TRAO) is now equipped with a main controling computer with VxWorks operating system, a new receiver system, and a new backend system. The new receiver system(TRAO-SEQUOIA) is equipped with high-performing 16-pixel MMIC pre-amplifiers in a 4x4 array, operating within 85~115 GHz frequency range. The system temperature ranges from 150 K (86~110 GHz) to 450 K (115 GHz). The 2nd IF modules with the narrow band and the 8 channels with 4 FFT spectrometers allow to observe 2 frequencies simultaneously within the 85~100 or 100~115 GHz bands for all 16 pixels of the receiver. Radome replacement was completed successfully as of February 2017. In addition, a new servo system will be installed in 2017 summer. We provide OTF (On-The-Fly) as a main observing mode, and position switching mode is available as well. The backend system (FFT spectrometer) provides the 4096x2 channels with fine velocity resolution of about 0.05 km/sec (15 kHz) per channel, and their full spectra bandwidth is 60 MHz. Beam efficiency of the TRAO was measured to be about 46% - 54% (with less than 2% error) between 86 and 115 GHz bands and pointing errors of the 14m telescope were found be 4.4 arcsec in AZ direction and 6 arcsec in EL direction. Generally, we allocate 18 hours of telescope time a day from January to the middle of May, and from October to December. Three Key Science Programs had been selected in 2015 fall and they are supposed to have higher priority for telescope time.

New start-up channels and multichannel analyzer at the RB reactor; Novi start-up kanali i videkanalni analizator na reaktoru Rb

Energy Technology Data Exchange (ETDEWEB)

Sotic, O; Markovic, H; Vranic, S; Dimitrijevic, Z; Pesic, M [Boris Kidric Institute of Nuclear Sciences Vinca, Beograd (Yugoslavia)

1978-01-15

New start-up channels and a multichannel analyzer were purchased in 1977 for the RB reactor. Both start-up channels contain BF{sub 3} neutron detectors, preamplifier, amplifier, single-channel analyzer, scaler, ratemeter, control unit, recording instrument. This document contains detailed technical description of these devices as well as characteristics of the multichannel analyzer which is being tested and will be used for measuring irradiation in the vicinity of the reactor.

Current feedback operational amplifiers as fast charge sensitive preamplifiers for photomultiplier read out

Energy Technology Data Exchange (ETDEWEB)

Giachero, A; Gotti, C; Maino, M; Pessina, G, E-mail: claudio.gotti@mib.infn.it [INFN - Sezione di Milano-Bicocca, I-20126, Milano (Italy)

2011-05-01

Fast charge sensitive preamplifiers were built using commercial current feedback operational amplifiers for fast read out of charge pulses from a photomultiplier tube. Current feedback opamps prove to be particularly well suited for this application where the charge from the detector is large, of the order of one million electrons, and high timing resolution is required. A proper circuit arrangement allows very fast signals, with rise times down to one nanosecond, while keeping the amplifier stable. After a review of current feedback circuit topology and stability constraints, we provide a 'recipe' to build stable and very fast charge sensitive preamplifiers from any current feedback opamp by adding just a few external components. The noise performance of the circuit topology has been evaluated and is reported in terms of equivalent noise charge.

X-ray and gamma ray detector readout system

Science.gov (United States)

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.

Pre-Amplifier Module for Laser Inertial Confinement Fusion

Energy Technology Data Exchange (ETDEWEB)

Heebner, J E; Bowers, M W

2008-02-06

The Pre-Amplifier Modules (PAMs) are the heart of the National Ignition Facility (NIF), providing most of the energy gain for the most energetic laser in the world. Upon completion, NIF will be the only laboratory in which scientists can examine the fusion processes that occur inside stars, supernovae, and exploding nuclear weapons and that may someday serve as a virtually inexhaustible energy source for electricity. Consider that in a fusion power plant 50 cups of water could provide the energy comparable to 2 tons of coal. Of paramount importance for achieving laser-driven fusion ignition with the least energy input is the synchronous and symmetric compression of the target fuel--a condition known as laser power balance. NIF's 48 PAMs thus must provide energy gain in an exquisitely stable and consistent manner. While building one module that meets performance requirements is challenging enough, our design has already enabled the construction and fielding of 48 PAMs that are stable, uniform, and interchangeable. PAM systems are being tested at the University of Rochester's Laboratory for Laser Energetics, and the Atomic Weapons Enterprise of Great Britain has purchased the PAM power system.

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy Applications

Directory of Open Access Journals (Sweden)

Tomasz Starecki

2017-11-01

Full Text Available All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude.

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy) Applications.

Science.gov (United States)

Starecki, Tomasz; Wieczorek, Piotr Z

2017-11-03

All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude.

On load resistor noise in preamplifiers for semiconductor detectors

International Nuclear Information System (INIS)

Baldin, S.A.; Bajramashvili, I.A.; Gubin, S.F.

1975-01-01

The main causes resulting in the deterioration of energy resolution in preamplifiers for semiconductor detectors (scd) with a resistor in the feedback circuit are discussed. A comparison of noise characteristics has been carried out of a number of high-resistance commercial and experimental resistors. The resistor noise dependence on the nature of drop of the resistor impedance active part in the region up to 100 Kc, as well as on the resistor spurious capacitance in shown

A preamplifier with reduced background noise; Preamplificateur a bruit de fond reduit

Energy Technology Data Exchange (ETDEWEB)

Taieb, J

1950-07-01

A description is given of a preamplifier in use with a mass spectrometer for rapid gas mixtures analysis, described in Report CEA-42. The instrument can be employed for amplifying any weak currents from high-impedance sources, in the frequency range 10 to 5000 cycle/sec.

[Synopsis about the hypothesis of "information channel" of channel-collateral system].

Science.gov (United States)

Chang, Xi-Lang

2008-10-01

The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

A comprehensive search for calcium binding sites critical for TMEM16A calcium-activated chloride channel activity

Science.gov (United States)

Tien, Jason; Peters, Christian J; Wong, Xiu Ming; Cheng, Tong; Jan, Yuh Nung; Jan, Lily Yeh; Yang, Huanghe

2014-01-01

TMEM16A forms calcium-activated chloride channels (CaCCs) that regulate physiological processes such as the secretions of airway epithelia and exocrine glands, the contraction of smooth muscles, and the excitability of neurons. Notwithstanding intense interest in the mechanism behind TMEM16A-CaCC calcium-dependent gating, comprehensive surveys to identify and characterize potential calcium sensors of this channel are still lacking. By aligning distantly related calcium-activated ion channels in the TMEM16 family and conducting systematic mutagenesis of all conserved acidic residues thought to be exposed to the cytoplasm, we identify four acidic amino acids as putative calcium-binding residues. Alterations of the charge, polarity, and size of amino acid side chains at these sites alter the ability of different divalent cations to activate the channel. Furthermore, TMEM16A mutant channels containing double cysteine substitutions at these residues are sensitive to the redox potential of the internal solution, providing evidence for their physical proximity and solvent accessibility. DOI: http://dx.doi.org/10.7554/eLife.02772.001 PMID:24980701

Digital baseline estimation method for multi-channel pulse height analyzing

International Nuclear Information System (INIS)

Xiao Wuyun; Wei Yixiang; Ai Xianyun

2005-01-01

The basic features of digital baseline estimation for multi-channel pulse height analysis are introduced. The weight-function of minimum-noise baseline filter is deduced with functional variational calculus. The frequency response of this filter is also deduced with Fourier transformation, and the influence of parameters on amplitude frequency response characteristics is discussed. With MATLAB software, the noise voltage signal from the charge sensitive preamplifier is simulated, and the processing effect of minimum-noise digital baseline estimation is verified. According to the results of this research, digital baseline estimation method can estimate baseline optimally, and it is very suitable to be used in digital multi-channel pulse height analysis. (authors)

Circle-16QAM for a zero-guard-interval CO-OFDM system

Science.gov (United States)

Kong, Lingyu; Yang, Aiying; Guo, Peng; Lu, Yueming; Qiao, Yaojun

2018-01-01

In this paper, we introduce circle 16 quadrature amplitude modulation (C-16QAM) modulation format in a high spectral efficiency zero-guard-interval (ZGI) coherent optical (CO) orthogonal frequency-division multiplexing (OFDM) system. At transmitter, the C-16QAM has advantages over the conventional square 16QAM in terms of transmission distance and tolerance to laser linewidth and fiber nonlinearities. ZGI CO-OFDM enables to take away the cyclic prefix (CP), so it has the benefit of higher spectral efficiency compared with the conventional CO-OFDM system. At receiver, in order to compensate chromatic dispersion (CD) and phase noise in a single channel ZGI CO-OFDM system, we studied the overlapped frequency domain equalizer (OFDE) and two carrier phase recovery (CPR) algorithms. We simulate the above systems and the results demonstrate that with the C-16QAM, a 28GBaud ZGI CO-OFDM system can have the longer transmission distance, the higher tolerance to laser linewidth and fiber nonlinearities with contrast to the conventional square 16QAM.

Single Channel 106 Gbit/s 16QAM Wireless Transmission in the 0.4 THz Band

DEFF Research Database (Denmark)

Pang, Xiaodan; Jia, Shi; Ozolins, Oskars

2017-01-01

We experimentally demonstrate a single channel 32-GBd 16QAM THz wireless link operating in the 0.4 THz band. Post-FEC net data rate of 106 Gbit/s is successfully achieved without any spatial/frequency multiplexing.......We experimentally demonstrate a single channel 32-GBd 16QAM THz wireless link operating in the 0.4 THz band. Post-FEC net data rate of 106 Gbit/s is successfully achieved without any spatial/frequency multiplexing....

Innovative methods for the design of miniatured state of the art neutronic channels for future FBR

International Nuclear Information System (INIS)

Sivaramakrishna, M.; Shukla, Rahul; Nagaraj, C.P.; Madhusoodanan, K.

2011-01-01

Neutron flux in fast reactor varies over 10 decades from shutdown to full power. This is monitored in all states of the reactor by Neutron flux monitoring systems. The system consists of several sets of detectors and instrument channels. For smooth transition from one set of instrument channel to other, interlocks with auto inhibition in safety logic are provided. In the present reactor, Fission counters are placed in control plug under vessel. The signals from these detectors are connected to preamplifiers near to the sensors. The signals from these preamplifiers are again connected to instrument channels in control building local control centres, which generate parameters such as logarithmic power, period, linear power and reactivity signals. Interlocks with auto inhibition are provided in safety logic for smooth transition from one detector-channel to other. With this arrangement, difficulties are faced such as, two sets of detectors are required at two different locations. Three different types of instrument channels are required. In each channel, there is a trade-off between response time and accuracy. Many interlocks with auto inhibitions are to be provided for transition from one system to another. Volume of electronics involved is very high. The pulses are also not periodical. Hence counting techniques do not result in accurate prediction of frequency and intern power. Either the accuracy of counting or the counting time has to be sacrificed. It can also be seen that as the frequency goes up the pulses over lap. Hence estimating the power using pulse counting can't predict the power correctly. In the Campbell method, which is used in the intermediate range also there is a trade-off between the accuracy and response time and linearity could be seen only for 3 decades. Hence the new approach viz. PCA (principle component analysis) is discussed in this paper. PCA is non-parametric method of extracting relevant information from mixed data by reducing a complex

A fast preamplifier concept for SiPM-based time-of-flight PET detectors

NARCIS (Netherlands)

Huizenga, J.; Seifert, S.; Schreuder, F.; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D. R.; van Dam, H.T.

2012-01-01

Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise

A Multifunction Low-Power Preamplifier for MEMS Capacitive Microphones

DEFF Research Database (Denmark)

Jawed, Syed Arsalan; Nielsen, Jannik Hammel; Gottardi, Massimo

2009-01-01

A multi-function two-stage chopper-stabilized preamplifier (PAMP) for MEMS capacitive microphones (MCM) is presented. The PAMP integrates digitally controllable gain, high-pass filtering and offset control, adding flexibility to the front-end readout of MCMs. The first stage of the PAMP consists...... of a source-follower (SF) while the second-stage is a capacitive gain stage. The second-stage employs chopper-stabilization (CHS), while SF buffer shields the MCM sensor from the switching spurs. The PAMP uses M poly bias resistors for the second-stage, exploiting Miller effect to achieve flat audio...

A NIM (Nuclear Instrumentation Module) system conjugated with optional input for pHEMT amplifier for beta and gamma spectroscopy

International Nuclear Information System (INIS)

Konrad, Barbara; Lüdke, Everton

2014-01-01

This work presents a high speed NIM module (Nuclear Instrumentation Module) to detect radiation, gamma and muons, as part of a system for natural radiation monitoring and of extraterrestrial origin. The subsystem developed consists of a preamplifier and an integrated SCA (Single Channel Analyzer), including power supplies of ± 12 and ± 24V with derivations of +3.6 and ± 5V. The single channel analyzer board, consisting of discrete logic components, operating in window modes, normal and integral. The pulse shaping block is made up of two voltage comparators working at 120 MHz with a response time > 60 ns and a logic anticoincidence system. The preamplifier promotes a noise reduction and introduces the impedance matching between the output of anode / diode photomultiplier tubes (PMTs) and subsequent equipment, providing an input impedance of 1MΩ and output impedance of 40 to 140Ω. The shaper amplifier is non-inverting and has variable input capacitance of 1000 pF. The upper and lower thresholds of the SCA are adjustable from 0 to ± 10V, and the equipment is compatible with various types of detectors, like PMTs coupled to sodium iodide crystals. For use with liquid scintillators and photodiodes with crystals (CsI: Tl) is proposed to include a preamplifier circuit pHEMT (pseudomorphic High Electron Mobility Transistor) integrated. Yet, the system presents the possibility of applications for various purposes of gamma spectroscopy and automatic detection of events producing of beta particles

16-channel DWDM based on 1D defect mode nonlinear photonic crystal

Science.gov (United States)

Kalhan, Abhishek; Sharma, Sanjeev; Kumar, Arun

2018-05-01

We propose a sixteen-channel Dense Wavelength Division Multiplexer (DWDM), using the 1-D defect mode nonlinear photonic crystal which is a function of intensity as well as wavelength. Here, we consider an alternate layer of two semiconductor materials in which we found the bandgap of materials when defect layer is introduced then 16-channel dense wavelength division multiplexer is obtained within bandgap. From the theoretical analysis, we can achieve average quality factor of 7800.4, the uniform spectral line-width of 0.2 nm, crosstalk of -31.4 dB, central wavelength changes 0.07 nm/(1GW/cm2) and 100% transmission efficiency. Thus, Sixteen-channel DWDM has very high quality factor, low crosstalk, near 100% power transmission efficiency and small channel spacing (1.44 nm).

Minimally-Invasive Neural Interface for Distributed Wireless Electrocorticogram Recording Systems.

Science.gov (United States)

Chang, Sun-Il; Park, Sung-Yun; Yoon, Euisik

2018-01-17

This paper presents a minimally-invasive neural interface for distributed wireless electrocorticogram (ECoG) recording systems. The proposed interface equips all necessary components for ECoG recording, such as the high performance front-end integrated circuits, a fabricated flexible microelectrode array, and wireless communication inside a miniaturized custom-made platform. The multiple units of the interface systems can be deployed to cover a broad range of the target brain region and transmit signals via a built-in intra-skin communication (ISCOM) module. The core integrated circuit (IC) consists of 16-channel, low-power push-pull double-gated preamplifiers, in-channel successive approximation register analog-to-digital converters (SAR ADC) with a single-clocked bootstrapping switch and a time-delayed control unit, an ISCOM module for wireless data transfer through the skin instead of a power-hungry RF wireless transmitter, and a monolithic voltage/current reference generator to support the aforementioned analog and mixed-signal circuit blocks. The IC was fabricated using 250 nm CMOS processes in an area of 3.2 × 0.9 mm² and achieved the low-power operation of 2.5 µW per channel. Input-referred noise was measured as 5.62 µV rms for 10 Hz to 10 kHz and ENOB of 7.21 at 31.25 kS/s. The implemented system successfully recorded multi-channel neural activities in vivo from a primate and demonstrated modular expandability using the ISCOM with power consumption of 160 µW.

Comparison of multi-pole shaping and delay line clipping pre-amplifiers for position sensitive NaI(Tl) detectors

International Nuclear Information System (INIS)

Freifelder, R.; Karp, J.S.; Wear, J.A.; Lockyer, N.S.; Newcomer, F.M.; Surti, S.; Berg, R. van

1998-01-01

NaI(Tl) position sensitive detectors have been used in medical imaging for many years. For PET applications without collimators, the high counting rates place severe demands on such large area detectors. The NaI(Tl) detectors in the PENN-PET scanners are read-out via photomultiplier tubes and preamplifiers. Those preamplifiers use a delay-line clipping technique to shorten the characteristic 240 ns fall time of the NaI(Tl) signal. As an alternative, the authors have investigated a pole-zero network to shorten the signal followed by a multi-pole shaper to produce a symmetric signal suitable for high counting rates. This has been compared to the current design by measuring the energy and spatial resolution of a single detector as a function of different preamplifier designs. Data were taken over a range of ADC integration times and countrates. The new design shows improved energy resolution with short integration times. Effects on spatial resolution and deadtime are reported for large position sensitive detectors at different countrates

Quick look report, Entry 3: Three Mile Island Unit 2, October 16, 1980

International Nuclear Information System (INIS)

1981-07-01

This report summarizes tasks performed during the third entry at Three Mile Island Unit 2. During the entry into containment, which was made on October 16, 1980, additional beta, gamma, and neutron surveys were performed to supplement data obtained on previous entries. In addition, several maintenance tasks were completed including testing the operation of both equipment hatch doors, replacing a loose parts monitor system pre-amplifier, and removing a source range monitor. The five-man entry team accomplished these tasks in about 1-1/2 hours

16 channel WDM regeneration in a single phase-sensitive amplifier through optical Fourier transformation

DEFF Research Database (Denmark)

Guan, Pengyu; Da Ros, Francesco; Lillieholm, Mads

2016-01-01

We demonstrate simultaneous phase regeneration of 16-WDM DPSK channels using optical Fourier transformation and a single phase-sensitive amplifier. The BERs of 16-WDM×10-Gbit/s phase noise degraded DPSK signals are improved by 0.4-1.3 orders of magnitude...

Design of A Charge sensitive preamplifier based on DMOS FET

International Nuclear Information System (INIS)

Gao Yanni; Su Hong; Wembe Tafo Evariste

2010-01-01

A charge sensitive preamplifier composed of DMOS for silicon, TSi (Li), CdZnTe and CsI detectors etc was proposed in the paper. It used a circuit structure different from traditional one with resistance and capacitance feedback. It was composed of DMOS only so that it can be developed further easily to make Application Specific Integrated Circuit. We also find it has a rise time less than 15ns and good stability from the result of simulation with Multisim. (authors)

A new method of removing the high value feedback resistor in the charge sensitive preamplifier

International Nuclear Information System (INIS)

Xi Deming

1993-01-01

A new method of removing the high value feedback resistor in the charge sensitive preamplifier is introduced. The circuit analysis of this novel design is described and the measured performances of a practical circuit are provided

X-ray powder crystallography with vertex instrumentation

International Nuclear Information System (INIS)

Chatzisotiriou, V.; Christofis, I.; Dimitriou, N.; Karvelas, S.; Karydas, A.G.; Loukas, D.; Pavlidis, A.; Spirou, S.; Dre, C.; Haralabidis, N.; Misiakos, K.; Tsoi, E.; Perdikatsis, V.; Psycharis, V.; Terzis, A.; Turchetta, R.

1998-01-01

An X-ray Diffractometer for Powder Crystallography is described along with experimental results and future plans. This is an intermediate instrument toward a long linear array system. Three channels of a silicon microstrip detector, are the detecting elements in the present instrument. Each detector channel is followed by a VLSI readout chain, which consists of a charge preamplifier with pulse shaping circuitry, a discriminator, and a 16-bit counter. Control and data acquisition is performed with a custom made PC readout card. A motorized goniometer scans the angle range of interest. Calibration of the system is done with reference samples and data which are captured with a one-channel conventional NaI detector. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

1 Analyse du bruit dans un préamplificateur de harge en ...

African Journals Online (AJOL)

PR BOKO

afriquescience.info. Daniel TEKO et al. Analyse du bruit dans un préamplificateur de ...... Nuclear Sciences and Techniques, Vol.21 (5) (2010) 312-315. [5] - M. Weng, et al. A high-speed low-noise CMOS 16-channel charge-sensitive preamplifier ASIC for.

A novel current mode operating beam counter based on not preamplified HPDs

CERN Document Server

Fujiwara, M.C.

2002-01-01

A novel system to monitor the intensity and the stability of a bunched beam of $\\simeq 1.2\\times 10^{7}$ antiprotons ($\\bar{p}$s) with a length of $\\simeq$ 250 ns (FWHM) and to measure its trapping efficiency in a Penning trap is described. This system operates parasitically detecting the pions from the annihilation of part of the beam in a degrader. Six plastic scintillators have been coupled from one side to six proximity focused HPDs without preamplifiers and operating in current mode. This device works in the stray field of the ATHENA magnet with no loss of efficiency; the gain can be varied from zero to a few thousands with a precision better than 0.1% and the dynamic range is larger than 8 orders of magnitude. Linearity and stability have been measured up to charge responses of 100 nC, corresponding to the beam completely dumped. The beam counter has been calibrated in two different and independent ways giving consistent results.

The application of Multisim software to the analyzing of the charge-sensitive preamplifier

International Nuclear Information System (INIS)

Zhou Chao; Zhao Xiuliang; Yin Chenyan

2007-01-01

This paper told the usage of Multisim software in simulating and analyzing a charge-sensitive preamplifier which is a typical circuit in nuclear electronics. At the foundation of theoretic analysis, some basic characteristic were simulated and analyzed. The simulation result was obtained according with the academic result which have very assistant and reference value on theoretic analysis. (authors)

Phosphatidylinositol 4,5-bisphosphate, cholesterol, and fatty acids modulate the calcium-activated chloride channel TMEM16A (ANO1).

Science.gov (United States)

De Jesús-Pérez, José J; Cruz-Rangel, Silvia; Espino-Saldaña, Ángeles E; Martínez-Torres, Ataúlfo; Qu, Zhiqiang; Hartzell, H Criss; Corral-Fernandez, Nancy E; Pérez-Cornejo, Patricia; Arreola, Jorge

2018-03-01

The TMEM16A-mediated Ca 2+ -activated Cl - current drives several important physiological functions. Membrane lipids regulate ion channels and transporters but their influence on members of the TMEM16 family is poorly understood. Here we have studied the regulation of TMEM16A by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), cholesterol, and fatty acids using patch clamp, biochemistry and fluorescence microscopy. We found that depletion of membrane PI(4,5)P2 causes a decline in TMEM16A current that is independent of cytoskeleton, but is partially prevented by removing intracellular Ca 2+ . On the other hand, supplying PI(4,5)P2 to inside-out patches attenuated channel rundown and/or partially rescued activity after channel rundown. Also, depletion (with methyl-β-cyclodextrin M-βCD) or restoration (with M-βCD+cholesterol) of membrane cholesterol slows down the current decay observed after reduction of PI(4,5)P2. Neither depletion nor restoration of cholesterol change PI(4,5)P2 content. However, M-βCD alone transiently increases TMEM16A activity and dampens rundown whereas M-βCD+cholesterol increases channel rundown. Thus, PI(4,5)P2 is required for TMEM16A function while cholesterol directly and indirectly via a PI(4,5)P2-independent mechanism regulate channel function. Stearic, arachidonic, oleic, docosahexaenoic, and eicosapentaenoic fatty acids as well as methyl stearate inhibit TMEM16A in a dose- and voltage-dependent manner. Phosphatidylserine, a phospholipid whose hydrocarbon tails contain stearic and oleic acids also inhibits TMEM16A. Finally, we show that TMEM16A remains in the plasma membrane after treatment with M-βCD, M-βCD+cholesterol, oleic, or docosahexaenoic acids. Thus, we propose that lipids and fatty acids regulate TMEM16A channels through a membrane-delimited protein-lipid interaction. Copyright © 2017 Elsevier B.V. All rights reserved.

Sensitive pre-amplifier to load for Pin diodes

International Nuclear Information System (INIS)

Jacobo V, R. Y.; Hernandez D, V.; Ramirez J, F. J.

2013-10-01

The electronic instrumentation is indispensable for the measurement and characterization of the radiation. By means of this essential characteristics of the radiation are determined, as activity and their energy components. The nuclear instrumentation is based on the technical characteristics of the radiation detectors and the electronic devices associates (amplifiers, ana logical and digital converters, multichannel analyzers, etc.) The radiation detectors are very important instruments in fields as the nuclear physics, medicine, radiological protection, industry and in other fields, since they are the only method to capture the radiation and to be able to quantify it in precise form. To detect radiation diverse detector types are used, as the semiconductor type, inside them are the photodiodes type Pin. In this work the results that were obtained of the design, simulation, construction and tests of a preamplifier that was designed starting from a photodiode type Pin are presented. The system was designed and simulated with a program for electronic circuits, in this were carried out many tests being obtained a compact design and achieving the best necessary characteristics for its optimization. With the results of the simulation phase the electronics phase was built, which was couples to a spectroscopic amplifier and a multichannel analyzer. The total of the system was evaluated analyzing its performance before a triple source of alphas. Of the tests phase we find that the system allows obtaining, in a multichannel analyzer, the pulses height spectrum, with a good resolution and with this was calibrated the multichannel analyzer

Minimally-Invasive Neural Interface for Distributed Wireless Electrocorticogram Recording Systems

Directory of Open Access Journals (Sweden)

Sun-Il Chang

2018-01-01

Full Text Available This paper presents a minimally-invasive neural interface for distributed wireless electrocorticogram (ECoG recording systems. The proposed interface equips all necessary components for ECoG recording, such as the high performance front-end integrated circuits, a fabricated flexible microelectrode array, and wireless communication inside a miniaturized custom-made platform. The multiple units of the interface systems can be deployed to cover a broad range of the target brain region and transmit signals via a built-in intra-skin communication (ISCOM module. The core integrated circuit (IC consists of 16-channel, low-power push-pull double-gated preamplifiers, in-channel successive approximation register analog-to-digital converters (SAR ADC with a single-clocked bootstrapping switch and a time-delayed control unit, an ISCOM module for wireless data transfer through the skin instead of a power-hungry RF wireless transmitter, and a monolithic voltage/current reference generator to support the aforementioned analog and mixed-signal circuit blocks. The IC was fabricated using 250 nm CMOS processes in an area of 3.2 × 0.9 mm2 and achieved the low-power operation of 2.5 µW per channel. Input-referred noise was measured as 5.62 µVrms for 10 Hz to 10 kHz and ENOB of 7.21 at 31.25 kS/s. The implemented system successfully recorded multi-channel neural activities in vivo from a primate and demonstrated modular expandability using the ISCOM with power consumption of 160 µW.

Anoctamin 9/TMEM16J is a cation channel activated by cAMP/PKA signal.

Science.gov (United States)

Kim, Hyungsup; Kim, Hyesu; Lee, Jesun; Lee, Byeongjun; Kim, Hee-Ryang; Jung, Jooyoung; Lee, Mi-Ock; Oh, Uhtaek

2018-05-01

Anoctamins (ANOs) are multifunctional membrane proteins that consist of 10 homologs. ANO1 (TMEM16A) and ANO2 (TMEM16B) are anion channels activated by intracellular calcium that meditate numerous physiological functions. ANO6 is a scramblase that redistributes phospholipids across the cell membrane. The other homologs are not well characterized. We found ANO9/TMEM16J is a cation channel activated by a cAMP-dependent protein kinase A (PKA). Intracellular cAMP-activated robust currents in whole cells expressing ANO9, which were inhibited by a PKA blocker. A cholera toxin that persistently stimulated adenylate cyclase activated ANO9 as did the application of PKA. The cAMP-induced ANO9 currents were permeable to cations. The cAMP-dependent ANO9 currents were augmented by intracellular Ca 2+ . Ano9 transcripts were predominant in the intestines. Human intestinal SW480 cells expressed high levels of Ano9 transcripts and showed PKA inhibitor-reversible cAMP-dependent currents. We conclude that ANO9 is a cation channel activated by a cAMP/PKA pathway and could play a role in intestine function. Copyright © 2017. Published by Elsevier Ltd.

A hybrid, broadband, low noise charge preamplifier for simultaneous high resolution energy and time information with large capacitance semiconductor detector

International Nuclear Information System (INIS)

Goyot, M.

1975-05-01

A broadband and low noise charge preamplifier was developed in hybrid form, for a recoil spectrometer requiring large capacitance semiconductor detectors. This new hybrid and low cost preamplifier permits good timing information without compromising energy resolution. With a 500 pF external input capacity, it provides two simultaneous outputs: (i) the faster, current sensitive, with a rise time of 9 nsec and 2 mV/MeV on 50 ohms load, (ii) the lower, charge sensitive, with an energy resolution of 14 keV (FWHM Si) using a RC-CR ungated filter of 2 μsec and a FET input protection [fr

Detailed noise statistics for an optically preamplified direct detection receiver

DEFF Research Database (Denmark)

Danielsen, Søren Lykke; Mikkelsen, Benny; Durhuus, Terji

1995-01-01

We describe the exact statistics of an optically preamplified direct detection receiver by means of the moment generating function. The theory allows an arbitrary shaped electrical filter in the receiver circuit. The moment generating function (MGF) allows for a precise calculation of the error...... rate by using the inverse Fast Fourier transform (FFT). The exact results are compared with the usual Gaussian approximation (GA), the saddlepoint approximation (SAP) and the modified Chernoff bound (MCB). This comparison shows that the noise is not Gaussian distributed for all values of the optical...... and calculate the sensitivity degradation due to inter symbol interference (ISI)...

Nuclear molecules in the systems 12C+12C and 16O+16O

International Nuclear Information System (INIS)

Tiereth, W.

1986-01-01

For the two heavy ion systems 12 C+ 12 C and 16 O+ 16 O by means of scattering experiments studies on the phenomena of nuclear molecules were performed. For the 12 C+ 12 C system in the range of the Coulomb wall precision measurements of the elastic scattering were performed. In the two energy ranges of 5.5 ≤ E c.m. ≤ 6.65 MeV and 6.95 ≤ E c.m ≤ 7.375 MeV where the existence of many quasimolecular resonances is known in energy steps of ΔE c.m. = 25 keV angular distributions in the range 10 0 ≤ θ c.m. ≤ 90 0 with Δθ c.m. = 1 0 were measured. For several of the found quasimolecular resonances the spin and the carbon width could be uniquely determined. This was reached by a partial wave analysis of the obtained data. Supplemented were the measurements of the elastic scattering by measurements of the excitation function of the θ 0 exit channel of the reaction 12 ( 12 C, θ) 20 Ne in the energy range from 5.2 ≤ E c.m. ≤ 6.1 MeV. At some known resonances in the 16 O+ 16 O system in the energy range from 15.5 MeV to 18 MeV the spin and the elastic width of these structures could be determined. For this a constrained partial wave analysis on complete angular distributions of the elastic scattering (9 0 ≤ θ c.m. ≤ 90 0 ) which were measured in energy steps of ΔE c.m. = 50 keV was performed. In the 16 O+ 16 O system besides the proof for the existence of a nuclear glory scattering was given. (orig.) [de

Coupled-channel calculation for cross section of fusion and barrier distribution of {}^{16,17,18}O + {}^{16}O reactions

Science.gov (United States)

Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.

2018-03-01

In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.

A MIMO-OFDM Testbed, Channel Measurements, and System Considerations for Outdoor-Indoor WiMAX

Directory of Open Access Journals (Sweden)

Torres

2010-01-01

Full Text Available The design, implementation, and test of a real-time flexible (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing MIMO-OFDM IEEE 802.16 prototype are presented. For the design, a channel measurement campaign on the 3.5 GHz band has been carried out, focusing on outdoor-indoor scenarios. The analysis of measured channels showed that higher capacity can be achieved in case of obstructed scenarios and that (Channel Distribution Information at the Transmitter CDIT capacity is close to (Channel State Information at the Transmitter CSIT with much lower complexity and requirements in terms of channel estimation and feedback. The baseband prototype used an (Field Programmable Gate Array FPGA where enhanced signal processing algorithms are implemented in order to improve system performance. We have shown that for MIMO-OFDM systems, extra signal processing such as enhanced joint channel and frequency offset estimation is needed to obtain a good performance and approach in practice the theoretical capacity improvements.

A MIMO-OFDM Testbed, Channel Measurements, and System Considerations for Outdoor-Indoor WiMAX

Directory of Open Access Journals (Sweden)

Víctor P. Gil Jiménez

2010-01-01

Full Text Available The design, implementation, and test of a real-time flexible 2×2 (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing MIMO-OFDM IEEE 802.16 prototype are presented. For the design, a channel measurement campaign on the 3.5 GHz band has been carried out, focusing on outdoor-indoor scenarios. The analysis of measured channels showed that higher capacity can be achieved in case of obstructed scenarios and that (Channel Distribution Information at the Transmitter CDIT capacity is close to (Channel State Information at the Transmitter CSIT with much lower complexity and requirements in terms of channel estimation and feedback. The baseband prototype used an (Field Programmable Gate Array FPGA where enhanced signal processing algorithms are implemented in order to improve system performance. We have shown that for MIMO-OFDM systems, extra signal processing such as enhanced joint channel and frequency offset estimation is needed to obtain a good performance and approach in practice the theoretical capacity improvements.

Spiking neural P systems with multiple channels.

Science.gov (United States)

Peng, Hong; Yang, Jinyu; Wang, Jun; Wang, Tao; Sun, Zhang; Song, Xiaoxiao; Luo, Xiaohui; Huang, Xiangnian

2017-11-01

Spiking neural P systems (SNP systems, in short) are a class of distributed parallel computing systems inspired from the neurophysiological behavior of biological spiking neurons. In this paper, we investigate a new variant of SNP systems in which each neuron has one or more synaptic channels, called spiking neural P systems with multiple channels (SNP-MC systems, in short). The spiking rules with channel label are introduced to handle the firing mechanism of neurons, where the channel labels indicate synaptic channels of transmitting the generated spikes. The computation power of SNP-MC systems is investigated. Specifically, we prove that SNP-MC systems are Turing universal as both number generating and number accepting devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design of EEG Signal Acquisition System Using Arduino MEGA1280 and EEGAnalyzer

Directory of Open Access Journals (Sweden)

Saptono Debyo

2016-01-01

Full Text Available This study integrates the hardware circuit design and software development to achieve a 16 channels Electroencephalogram (EEG system for Brain Computer Interface (BCI applications. Signals obtained should be strong enough amplitude that is usually expressed in units of millivolts and reasonably clean of noise that appears when the data acquisition process. The process of data acquisition consists of two stages are the acquisition of the original EEG signal can be done by the active electrode with an instrumentation amplifier or a preamplifier and processing the signal to get better signals with improved signal quality by removing noise using filters with IC OPAMP. The design of a preamplifier with high common-mode rejection ratio and high signal-to-noise ratio is very important. Moreover, the friction between the electrode pads and the skin as well as the design of dual power supply. Designs used single-power AC-coupled circuit, which effectively reduces the DC bias and improves the error caused by the effects of part errors. At the same time, the digital way is applied to design the adjustable amplification and filter function, which can design for different EEG frequency bands. The next step, those EEG signals received by the microcontroller through a port Analog to Digital Converter (ADC that integrated and converted into digital signals and stored in the RAM of microcontroller which simultaneously at 16 ports in accordance with the minimal number of points of data collection on the human scalp. Implementation results have shown the series of acquisitions to work properly so that it can be displayed EEG signals via software EEGAnalyzer.

Irradiation Tests on Bipolar Front-End Preamplifier Using the Harris UHF1 Technology

CERN Document Server

Goyot, Michel

1997-01-01

A low noise, low power, radiation hard, full custom integrated circuit has been studied for coupling with photodetectors of the CMS electromagnetic calorimeter. A new version of the prototype preamplifier has been designed with improved performances ( noise, dynamic range, consumption). Irradiation tests on this monolithic circuit have been performed at CERN with a Xray SEIFERT RP149 generator up to 10Mrad ( SiO2). Tests results are presented.

Testing digital recursive filtering method for radiation measurement channel using pin diode detector

International Nuclear Information System (INIS)

Talpalariu, C. M.; Talpalariu, J.; Popescu, O.; Mocanasu, M.; Lita, I.; Visan, D. A.

2016-01-01

In this work we have studied a software filtering method implemented in a pulse counting computerized measuring channel using PIN diode radiation detector. In case our interest was focalized for low rate decay radiation measurement accuracies improvement and response time optimization. During works for digital mathematical algorithm development, we used a hardware radiation measurement channel configuration based on PIN diode BPW34 detector, preamplifier, filter and programmable counter, computer connected. We report measurement results using two digital recursive methods in statically and dynamically field evolution. Software for graphical input/output real time diagram representation was designed and implemented, facilitating performances evaluation between the response of fixed configuration software recursive filter and dynamically adaptive configuration recursive filter. (authors)

A NIM (Nuclear Instrumentation Module) system conjugated with optional input for pHEMT amplifier for beta and gamma spectroscopy; Um sistema de modulos NIM conjugados com entrada opcional por amplificador pHEMT para espectroscopia beta e gama

Energy Technology Data Exchange (ETDEWEB)

Konrad, Barbara; Lüdke, Everton, E-mail: barbarakonradmev@gmail.com, E-mail: eludke@smail.ufsm.br [Universidade Federal de Santa Maria (LAE/UFSM), RS (Brazil). Lab. de Astrofisica e Eletronica

2014-07-01

This work presents a high speed NIM module (Nuclear Instrumentation Module) to detect radiation, gamma and muons, as part of a system for natural radiation monitoring and of extraterrestrial origin. The subsystem developed consists of a preamplifier and an integrated SCA (Single Channel Analyzer), including power supplies of ± 12 and ± 24V with derivations of +3.6 and ± 5V. The single channel analyzer board, consisting of discrete logic components, operating in window modes, normal and integral. The pulse shaping block is made up of two voltage comparators working at 120 MHz with a response time > 60 ns and a logic anticoincidence system. The preamplifier promotes a noise reduction and introduces the impedance matching between the output of anode / diode photomultiplier tubes (PMTs) and subsequent equipment, providing an input impedance of 1MΩ and output impedance of 40 to 140Ω. The shaper amplifier is non-inverting and has variable input capacitance of 1000 pF. The upper and lower thresholds of the SCA are adjustable from 0 to ± 10V, and the equipment is compatible with various types of detectors, like PMTs coupled to sodium iodide crystals. For use with liquid scintillators and photodiodes with crystals (CsI: Tl) is proposed to include a preamplifier circuit pHEMT (pseudomorphic High Electron Mobility Transistor) integrated. Yet, the system presents the possibility of applications for various purposes of gamma spectroscopy and automatic detection of events producing of beta particles.

AVME readout module for multichannel ASIC characterization

International Nuclear Information System (INIS)

Borkar, S.P.; Lalwani, S.K.; Ghodgaonkar, M.D.; Kataria, S.K.; Reynaud, Serge; )

2004-01-01

Electronics Division, BARC has been working on the development of multi-channel ASIC, called SPAIR (Silicon-strip Pulse Amplifier Integrated Readout). It contains 8 channels of preamplifier, shaper and track-and-hold circuitry. Electronics Division has also actively participated in development of test setup for the front-end ASIC, called PACE, for the preshower detector of the Compact Muon Solenoid (CMS) Experiment at CERN, Geneva. PACE is a 32 channel ASIC for silicon strip detector, containing preamplifier, shaper, calibration circuitry, switched capacitor array, readout amplifier per channel and an analog multiplexer. A VME Readout Module, (VRM) is developed which can be utilized in data acquisition from ASICs like PACE and SPAIR. The VRM can also be used as the Detector Dependent Unit for digitally processing the data received from the front-end electronics on the 16-bit LVDS port. The processed, data can be read by the VME system. Thus the VRM is very useful in building an ASIC characterization system and/or the automated ASIC production testing system. It can be used also to build the applications using such ASICs. To cater to various requirements arising in future, variety of VME modules are to be developed like ADCs, DACs and D 1/0. VME interface remains a common part to all these modules. The different functional blocks of these modules can be designed and fabricated on small piggyback boards (called Test Boards) and mounted on the VRM, which provides the common VME interface. The design details and uses of VRM are presented here. (author)

Experimental characterization of the 192 channel Clear-PEM frontend ASIC coupled to a multi-pixel APD readout of LYSO:Ce crystals

International Nuclear Information System (INIS)

Albuquerque, Edgar; Bexiga, Vasco; Bugalho, Ricardo; Carrico, Bruno; Ferreira, Claudia S.; Ferreira, Miguel; Godinho, Joaquim; Goncalves, Fernando; Leong, Carlos; Lousa, Pedro; Machado, Pedro; Moura, Rui; Neves, Pedro; Ortigao, Catarina; Piedade, Fernando; Pinheiro, Joao F.; Rego, Joel; Rivetti, Angelo; Rodrigues, Pedro; Silva, Jose C.

2009-01-01

In the framework of the Clear-PEM project for the construction of a high-resolution scanner for breast cancer imaging, a very compact and dense frontend electronics system has been developed for readout of multi-pixel S8550 Hamamatsu APDs. The frontend electronics are instrumented with a mixed-signal Application-Specific Integrated Circuit (ASIC), which incorporates 192 low-noise charge pre-amplifiers, shapers, analog memory cells and digital control blocks. Pulses are continuously stored in memory cells at clock frequency. Channels above a common threshold voltage are readout for digitization by off-chip free-sampling ADCs. The ASIC has a size of 7.3x9.8mm 2 and was implemented in a AMS 0.35μm CMOS technology. In this paper the experimental characterization of the Clear-PEM frontend ASIC, reading out multi-pixel APDs coupled to LYSO:Ce crystal matrices, is presented. The chips were mounted on a custom test board connected to six APD arrays and to the data acquisition system. Six 32-pixel LYSO:Ce crystal matrices coupled on both sides to APD arrays were readout by two test boards. All 384 channels were operational. The chip power consumption is 660 mW (3.4 mW per channel). A very stable behavior of the chip was observed, with an estimated ENC of 1200-1300e - at APD gain 100. The inter-channel noise dispersion and mean baseline variation is less than 8% and 0.5%, respectively. The spread in the gain between different channels is found to be 1.5%. Energy resolution of 16.5% at 511 keV and 12.8% at 662 keV has been measured. Timing measurements between the two APDs that readout the same crystal is extracted and compared with detailed Monte Carlo simulations. At 511 keV the measured single photon time RMS resolution is 1.30 ns, in very good agreement with the expected value of 1.34 ns.

Data acquisition system for MEGHA

International Nuclear Information System (INIS)

Chappell, S.P.G.; Hunt, R.A.; Smith, D.; Rae, W.D.M.; Clarke, N.M.; Freer, M.; Fulton, B.R.; Jagpal, S.S.; Singer, S.M.; Watson, D.L.

2000-01-01

A multi-channel data acquisition system has been commissioned for the Charissa 'MEGHA' detector array. It is designed to read multiparameter events where there are many potential channels (320) but where only a fraction of these are active in any typical event. Custom-built pre- and main amplifiers process the amplitude (energy) signal from each detector and the system records both amplitude and time of arrival for each signal within an event. The signal amplitude is converted to time using the standard Wilkinson technique and then combined with its time of arrival into a single time trace. These traces are converted by multi-hit TDCs, which only convert the active channels and thus reduce the processing load. Additional custom-built CAMAC modules organise the TDC output into a suitable form for storage and transmission to a network of processor terminals over standard ethernet. This paper presents a description of the data acquisition system from preamplifier through to final storage in a VME-based system and subsequent distribution to a network of Sun terminals over ethernet. The system performance is illustrated with results from heavy-ion elastic scattering recorded with position sensitive strip detectors

A 16-channel real-time digital processor for pulse-shape discrimination in multiplicity assay

International Nuclear Information System (INIS)

Joyce, Malcolm J.; Aspinall, M.D.; Cave, F.D.; Lavietes, A.

2013-06-01

In recent years, real-time neutron/γ-ray pulse-shape discrimination has become feasible for use with scintillator-based detectors that respond extremely quickly, on the order of 25 ns in terms of pulse width, and their application to a variety of nuclear material assays has been reported. For the in-situ analysis of nuclear materials, measurements are often based on the multiplicity assessment of spontaneous fission events. An example of this is the 240 Pu eff assessment stemming from long-established techniques developed for 3 He-based neutron coincidence counters when 3 He was abundant and cheap. However, such measurements when using scintillator detectors can be plagued by low detection efficiencies and low orders of coincidence (often limited to triples) if the number of detectors in use is similarly limited to 3-4 detectors. Conversely, an array of >10 detector modules arranged to optimize efficiency and multiplicity sensitivity, shifts the emphasis in terms of performance requirement to the real-time digital analyzer and, critically, to the scope remaining in the temporal processing window of these systems. In this paper we report on the design, development and commissioning of a bespoke, 16-channel real-time pulse-shape discrimination analyzer specified for the materials assay challenge summarized above. The analyzer incorporates 16 dedicated and independent high-voltage supplies along with 16 independent digital processing channels offering pulse-shape discrimination at a rate of 3 x 10 6 events per second. These functions are configured from a dedicated graphical user interface, and all settings can be adjusted on-the-fly with the analyzer effectively configured one-time-only (where desired) for subsequent plug-and-play connection, for example to a fuel bundle organic scintillation detector array. (authors)

A bipolar monolithic preamplifier for high-capacitance SSC [Superconducting Super Collider] silicon calorimetry

International Nuclear Information System (INIS)

Britton, C.L. Jr.; Kennedy, E.J.; Bugg, W.M.

1990-01-01

This paper describes a preamplifier designed and fabricated specifically to address the requirements of silicon calorimetry for the Superconducting Super Collider (SSC). The topology and its features are discussed in addition to the design methodology employed. The simulated and measured results for noise, power consumption, and speed are presented. Simulated an measured data for radiation damage effects as well as data for post-damage annealing are also presented. 8 refs., 7 figs., 2 tabs

Irradiation tests on bipolar front-end preamplifier using the Harris UHF1 technology

Energy Technology Data Exchange (ETDEWEB)

Goyot, M

1997-09-01

A low noise, low power, radiation hard, full custom integrated circuit has been studied for coupling with photodetectors of the CMS electromagnetic calorimeter. A new version of the prototype preamplifier has been designed with improved performances (noise, dynamic range, consumption). Irradiation tests on this monolithic circuit have been performed at CERN with a X ray SEIFERT RP149 generator up to 10 Mrad equivalent silicon oxide. Tests results are presented. (author) 5 refs.

Omni-channel Retail Information Systems

DEFF Research Database (Denmark)

Tambo, Torben

2014-01-01

key players in the industry of retailing (Wilson, 2012; Verizon, 2012) and covers the idea that anything can be sold anywhere with consistent marketing, reasonable efficiency of the supply chain channels and responsible customer service. This article aims at contributing to a characterisation...... and definition of omni-channel retail information systems (OCRIS) by using the information systems research tradition as a distinctive starting point (Treiblmaier and Strebinger, 2008; Avgerou, 2001; Parboteah et al., 2009). Omni-channel retailing has evolved since 2010 with the ultimate aim of aligning physical...

Integrated synchronous receiver channel for optical instrumentation applications

Science.gov (United States)

Benten, Harold G. P. H.; Ruotsalainen, Tarmo; Maekynen, Anssi J.; Rahkonen, Timo E.; Kopola, Harri K.

1997-09-01

A two-channel synchronous receiver circuit for optical instrumentation applications has been designed and implemented. Each receiver channel comprises a.o. transimpedance preamplifier, voltage amplifiers, programmable feedback networks, and a synchronous detector. The function of the channel is to extract the slowly varying information carrying signal from a modulated carrier which is accompanied by relatively high levels of noise. As a whole, the channel can be characterized as a narrow band filter around the frequency of interest. Medical applications include arterial oxygen saturation (SaO2) measurement and dental pulp vitality measurement. In both cases, two optical signals with different frequencies are received by a single photodiode. The measured performance of the optical receiver shows its suitability for the above mentioned applications. Therefore the circuit will be used in a small sized, battery-operated sensor prototype to test the sensing method in a clinical environment. Other applications include the signal processing of optical position-sensitive detectors. A summary of measured receiver channel performance: input reduced noise current spectral density between 0.20 and 0.30 pA/(root)Hz at all relevant frequencies, total programmable channel transimpedance between 7 M(Omega) and 500 M(Omega) , lower -3 dB frequency of at least 50 Hz, upper -3 dB frequency of 40 kHz, maximum voltage swing at the demodulator output of 2.4 V.

A new wire chamber front-end system, based on the ASD-8 B chip

International Nuclear Information System (INIS)

Kruesemann, B.A.M.; Bassini, R.; Ellinghaus, F.; Frekers, D.; Hagemann, M.; Hannen, V.M.; Heynitz, H. von; Heyse, J.; Rakers, S.; Sohlbach, H.; Woertche, H.J.

1999-01-01

The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl. Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards. The board represents the first successfully running application of the ASD-8 for wire chamber readout. (author)

Fast timing readout for silicon strip detectors

International Nuclear Information System (INIS)

Jhingan, A.; Saneesh, N.; Kumar, M.

2016-01-01

The development and performance of a 16 channel hybrid fast timing amplifier (FTA), for extracting timing information from silicon strip detectors (SSD), is described. The FTA will be used in a time of flight (TOF) measurement, in which one SSD is used to obtain the ion velocity (A) as well as the energy information of a scattered particle. The TOF information with a thin transmission SSD, acting as ΔE detector (Z) in a detector telescope, will provide a unique detection system for the identification of reaction products in the slowed down beam campaign of low energy branch (LEB) at NUSTAR-FAIR. Such a system will also provide large solid angle coverage with ~ 100% detection efficiency, and adequate segmentation for angular information. A good timing resolution (≤ 100 ps) enables to have shorter flight paths, thus a closely packed 4π array should be feasible. Preamplifiers for energy readout in SSD are easily available. A major constraint with SSDs is the missing high density multichannel preamplifiers which can provide both fast timing as well as energy. Provision of both timing and energy processing, generally makes circuit bulky, with higher power consumption, which may not be suitable in SSD arrays. In case of DSSSD, the problem was overcome by using timing from one side and energy from the other side. A custom designed 16 channel FTA has been developed for DSSSD design W from Micron Semiconductors, UK

Three-dimensional (3-D) video systems: bi-channel or single-channel optics?

Science.gov (United States)

van Bergen, P; Kunert, W; Buess, G F

1999-11-01

This paper presents the results of a comparison between two different three-dimensional (3-D) video systems, one with single-channel optics, the other with bi-channel optics. The latter integrates two lens systems, each transferring one half of the stereoscopic image; the former uses only one lens system, similar to a two-dimensional (2-D) endoscope, which transfers the complete stereoscopic picture. In our training centre for minimally invasive surgery, surgeons were involved in basic and advanced laparoscopic courses using both a 2-D system and the two 3-D video systems. They completed analog scale questionnaires in order to record a subjective impression of the relative convenience of operating in 2-D and 3-D vision, and to identify perceived deficiencies in the 3-D system. As an objective test, different experimental tasks were developed, in order to measure performance times and to count pre-defined errors made while using the two 3-D video systems and the 2-D system. Using the bi-channel optical system, the surgeon has a heightened spatial perception, and can work faster and more safely than with a single-channel system. However, single-channel optics allow the use of an angulated endoscope, and the free rotation of the optics relative to the camera, which is necessary for some operative applications.

Experimental demonstration of outdoor 2.2 Tbps super-channel FSO transmission system

KAUST Repository

Esmail, Maged Abdullah

2016-07-26

Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz. © 2016 IEEE.

Experimental demonstration of outdoor 2.2 Tbps super-channel FSO transmission system

KAUST Repository

Esmail, Maged Abdullah; Ragheb, Amr; Fathallah, Habib; Alouini, Mohamed-Slim

2016-01-01

Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz. © 2016 IEEE.

Sodium channel SCN8A (Nav1.6: properties and de novo mutations in epileptic encephalopathy and intellectual disability

Directory of Open Access Journals (Sweden)

Janelle Elizabeth O'Brien

2013-10-01

Full Text Available The sodium channel Nav1.6, encoded by the gene SCN8A, is one of the major voltage-gated channels in human brain. The sequences of sodium channels have been highly conserved during evolution, and minor changes in biophysical properties can have a major impact in vivo. Insight into the role of Nav1.6 has come from analysis of spontaneous and induced mutations of mouse Scn8a during the past 18 years. Only within the past year has the role of SCN8A in human disease become apparent from whole exome and genome sequences of patients with sporadic disease. Unique features of Nav1.6 include its contribution to persistent current, resurgent current, repetitive neuronal firing, and subcellular localization at the axon initial segment and nodes of Ranvier. Loss of Nav1.6 activity results in reduced neuronal excitability, while gain-of-function mutations can increase neuronal excitability. Mouse Scn8a (med mutants exhibit movement disorders including ataxia, tremor and dystonia. Thus far, more than ten human de novo mutations have been identified in patients with two types of disorders, epileptic encephalopathy and intellectual disability. We review these human mutations as well as the unique features of Nav1.6 that contribute to its role in determining neuronal excitability in vivo. A supplemental figure illustrating the positions of amino acid residues within the 4 domains and 24 transmembrane segments of Nav1.6 is provided to facilitate the location of novel mutations within the channel protein.

16-Channel surface coil for 13C-hyperpolarized spectroscopic imaging of cardiac metabolism in pig heart

DEFF Research Database (Denmark)

Frijia, Francesca; Santarelli, Maria Filomena; Koellisch, Ulrich

2016-01-01

Magnetic resonance spectroscopy (MRS) of hyperpolarized 13C pyruvate and its metabolites in large animal models is a powerful tool for assessing cardiac metabolism in patho-physiological conditions. In 13C studies, a high signal-to-noise ratio (SNR) is crucial to overcome the intrinsic data quality...... both targets. In this study, a 16-channel receive surface coil was designed for 13C hyperpolarized studies of the pig heart with a clinical 3-T scanner. The coil performance was characterized by phantom experiments and compared with that of a birdcage coil used in transmit/receive mode. Segmental...... of the 16-channel coil is recommended for studies of septal and anterior LV walls....

Development of ATLAS Liquid Argon Calorimeter Front-end Electronics for the HL-LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00219286; The ATLAS collaboration

2016-01-01

The high-luminosity phase of the Large Hadron Collider will provide 5-7 times greater luminosities than assumed in the original detector design. An improved trigger system requires an upgrade of the readout electronics of the ATLAS Liquid Argon Calorimeter. Concepts for the future readout of the 182,500 calorimeter channels at 40-80 MHz and 16-bit dynamic range and the developments of radiation-tolerant, low-noise, low-power, and high-bandwidth front-end electronic components, including preamplifiers and shapers, 14-bit ADCs, and 10-Gb/s laser diode array drivers, are presented.

A fast preamplifier concept for SiPM-based time-of-flight PET detectors

Energy Technology Data Exchange (ETDEWEB)

Huizenga, J., E-mail: j.huizenga@tudelft.nl [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Seifert, S. [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Schreuder, F. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Dam, H.T. van [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Dendooven, P.; Loehner, H.; Vinke, R. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Schaart, D.R. [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands)

2012-12-11

Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm Multiplication-Sign 3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a 'slow' energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm Multiplication-Sign 3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm Multiplication-Sign 3 mm Multiplication-Sign 5 mm LaBr{sub 3}:Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

A fast preamplifier concept for SiPM-based time-of-flight PET detectors

International Nuclear Information System (INIS)

Huizenga, J.; Seifert, S.; Schreuder, F.; Dam, H.T. van; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D.R.

2012-01-01

Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm×3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a ‘slow’ energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm×3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm×3 mm×5 mm LaBr 3 :Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

Science.gov (United States)

2010-10-01

... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16...

Increased Vessel Depiction of the Carotid Bifurcation with a Specialized 16-Channel Phased Array Coil at 3T

Science.gov (United States)

Tate, Quinn; Kim, Seong-Eun; Treiman, Gerald; Parker, Dennis L.; Hadley, J. Rock

2012-01-01

The purpose of this work was to design and construct a multi-channel receive-only RF coil for 3 Tesla magnetic resonance imaging of the human carotid artery and bifurcation with optimized signal to noise ratio in the carotid vessels along the full extent of the neck. A neck phantom designed to match the anatomy of a subject with a neck representing the body habitus often seen in subjects with carotid arterial disease, was constructed. Sixteen circular coil elements were arranged on a semi-rigid fiberglass former that closely fit the shape of the phantom, resulting in a 16-channel bilateral phased array coil. Comparisons were made between this coil and a typical 4-channel carotid coil in a study of 10 carotid vessels in 5 healthy volunteers. The 16-channel carotid coil showed a 73% average improvement in signal to noise ratio (SNR) at the carotid bifurcation. This coil also maintained an SNR greater than the peak SNR of the 4-channel coil over a vessel length of 10 cm. The resulting increase in SNR improved vessel depiction of the carotid arteries over an extended field of view, and demonstrated better image quality for higher parallel imaging reduction factors compared to the 4-channel coil. PMID:22777692

Integrated PET/MR breast cancer imaging: Attenuation correction and implementation of a 16-channel RF coil

Energy Technology Data Exchange (ETDEWEB)

Oehmigen, Mark, E-mail: mark.oehmigen@uni-due.de; Lindemann, Maike E. [High Field and Hybrid MR Imaging, University Hospital Essen, Essen 45147 (Germany); Lanz, Titus [Rapid Biomedical GmbH, Rimpar 97222 (Germany); Kinner, Sonja [Institute for Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen 45147 (Germany); Quick, Harald H. [High Field and Hybrid MR Imaging, University Hospital Essen, Essen 45147, Germany and Erwin L. Hahn Institute for MR Imaging, University Duisburg-Essen, Essen 45141 (Germany)

2016-08-15

Purpose: This study aims to develop, implement, and evaluate a 16-channel radiofrequency (RF) coil for integrated positron emission tomography/magnetic resonance (PET/MR) imaging of breast cancer. The RF coil is designed for optimized MR imaging performance and PET transparency and attenuation correction (AC) is applied for accurate PET quantification. Methods: A 16-channel breast array RF coil was designed for integrated PET/MR hybrid imaging of breast cancer lesions. The RF coil features a lightweight rigid design and is positioned with a spacer at a defined position on the patient table of an integrated PET/MR system. Attenuation correction is performed by generating and applying a dedicated 3D CT-based template attenuation map. Reposition accuracy of the RF coil on the system patient table while using the positioning frame was tested in repeated measurements using MR-visible markers. The MR, PET, and PET/MR imaging performances were systematically evaluated using modular breast phantoms. Attenuation correction of the RF coil was evaluated with difference measurements of the active breast phantoms filled with radiotracer in the PET detector with and without the RF coil in place, serving as a standard of reference measurement. The overall PET/MR imaging performance and PET quantification accuracy of the new 16-channel RF coil and its AC were then evaluated in first clinical examinations on ten patients with local breast cancer. Results: The RF breast array coil provides excellent signal-to-noise ratio and signal homogeneity across the volume of the breast phantoms in MR imaging and visualizes small structures in the phantoms down to 0.4 mm in plane. Difference measurements with PET revealed a global loss and thus attenuation of counts by 13% (mean value across the whole phantom volume) when the RF coil is placed in the PET detector. Local attenuation ranging from 0% in the middle of the phantoms up to 24% was detected in the peripheral regions of the phantoms at

Channel coding in the space station data system network

Science.gov (United States)

Healy, T.

1982-01-01

A detailed discussion of the use of channel coding for error correction, privacy/secrecy, channel separation, and synchronization is presented. Channel coding, in one form or another, is an established and common element in data systems. No analysis and design of a major new system would fail to consider ways in which channel coding could make the system more effective. The presence of channel coding on TDRS, Shuttle, the Advanced Communication Technology Satellite Program system, the JSC-proposed Space Operations Center, and the proposed 30/20 GHz Satellite Communication System strongly support the requirement for the utilization of coding for the communications channel. The designers of the space station data system have to consider the use of channel coding.

Prototype of IGZO-TFT preamplifier and analog counter for pixel detector

International Nuclear Information System (INIS)

Shimazoe, K.; Koyama, A.; Takahashi, H.; Shindoh, T.; Miyoshi, H.

2017-01-01

IGZO-TFT (Indium Galium Zinc Oxide-Thin Film Transistor) is a promising technology for controlling large display areas and large area sensors because of its very low leakage current in the off state and relatively low cost. IGZO has been used as a switching gate for a large area flat-panel detector. The photon counting capability for X-ray medical imaging has been investigated and expected for low-dose exposure and material determination. Here the design and fabrication of a charge sensitive preamplifier and analog counter using IGZO-TFT processes and its performance are reported for the first time to be used for radiation photon counting applications.

A fast integrated readout system for a cathode pad photon detector

Energy Technology Data Exchange (ETDEWEB)

French, M. (Rutherford Appleton Lab., Chilton (United Kingdom)); Lovell, M. (Rutherford Appleton Lab., Chilton (United Kingdom)); Chesi, E. (CERN, ECP Div., Geneva (Switzerland)); Racz, A. (CERN, ECP Div., Geneva (Switzerland)); Seguinot, J. (Coll. de France, Paris (France)); Ypsilantis, T. (Coll. de France, Paris (France)); Arnold, R. (CRN, Louis Pasteur Univ., Strasbourg (France)); Guyonnet, J.L. (CRN, Louis Pasteur Univ., Strasbourg (France)); Egger, J. (Paul Scherrer Inst., Villigen (Switzerland)); Gabathuler, K. (Paul Scherrer Inst., Villigen (Switzerland))

1994-04-01

A fast integrated electronic chain is presented to read out the cathode pad array of a multiwire photon detector for a fast RICH counter. Two VLSI circuits have been designed and produced. An analog eight channel, low noise, fast, bipolar, current preamplifier and discriminator chip serves as front-end electronics. It has an rms equivalent noise current of 10 nA (2000 e[sup -]), 50 MHz bandwidth with 10 mW of power consumption per channel. Two analogue chips are coupled to a digital 16 channels CMOS readout chip, operating at 20 MHz, that provides a pipelined delay of 1.3 [mu]s and zero suppression with a power consumption of about 6 mW per channel. Readout of a 4000 pad sector requires 3-4 [mu]s depending on the number of hit pads. The full RICH counter is made up of many of such sectors (the prototype has three fully equipped sectors), read out in parallel. The minimum time to separate successive hits on the same pad is about 70 ns. The time skew of the full chain is about 15 ns. (orig.)

KATP Channels in the Cardiovascular System.

Science.gov (United States)

Foster, Monique N; Coetzee, William A

2016-01-01

KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease. Copyright © 2016 the American Physiological Society.

Wireless recording systems: from noninvasive EEG-NIRS to invasive EEG devices.

Science.gov (United States)

Sawan, Mohamad; Salam, Muhammad T; Le Lan, Jérôme; Kassab, Amal; Gelinas, Sébastien; Vannasing, Phetsamone; Lesage, Frédéric; Lassonde, Maryse; Nguyen, Dang K

2013-04-01

In this paper, we present the design and implementation of a wireless wearable electronic system dedicated to remote data recording for brain monitoring. The reported wireless recording system is used for a) simultaneous near-infrared spectrometry (NIRS) and scalp electro-encephalography (EEG) for noninvasive monitoring and b) intracerebral EEG (icEEG) for invasive monitoring. Bluetooth and dual radio links were introduced for these recordings. The Bluetooth-based device was embedded in a noninvasive multichannel EEG-NIRS system for easy portability and long-term monitoring. On the other hand, the 32-channel implantable recording device offers 24-bit resolution, tunable features, and a sampling frequency up to 2 kHz per channel. The analog front-end preamplifier presents low input-referred noise of 5 μ VRMS and a signal-to-noise ratio of 112 dB. The communication link is implemented using a dual-band radio frequency transceiver offering a half-duplex 800 kb/s data rate, 16.5 mW power consumption and less than 10(-10) post-correction Bit-Error Rate (BER). The designed system can be accessed and controlled by a computer with a user-friendly graphical interface. The proposed wireless implantable recording device was tested in vitro using real icEEG signals from two patients with refractory epilepsy. The wirelessly recorded signals were compared to the original signals recorded using wired-connection, and measured normalized root-mean square deviation was under 2%.

Electronic equipment of Cherenkov counters for detection of extensive atmospheric showers; Ehlektronnaya apparatura cherenkovskikh detektorov dlya registratsii shiroki kh atmosfernykh livnej

Energy Technology Data Exchange (ETDEWEB)

Klimov, A I; meleshko, L A; Pan` kov, A A

1996-12-31

Paper describes electronic system of designed to record extensive atmospheric showers based on application of Cherenkov counters. Modules of preamplifier and PM divider, amplifier-scanner of two channel unit of precise time correlation, 8-channel time coder with 0.5 ns channel width and 14-input master unit are developed to realize the suggested operating circuit. 2 refs.

ASD IC for the thin gap chambers in the LHC Atlas experiment

International Nuclear Information System (INIS)

Sasaki, Osamu; Yoshida, Mitsuhiro

1999-01-01

An amplifier-shaper-discriminator (ASD) chip was designed and built for Thin Gap Chambers in the forward muon trigger system of the LHC Atlas experiment. The ASD IC uses SONY Analog Master Slice bipolar technology. The IC contains 4 channels in a QFP48 package. The gain of its first stage (preamplifier) is approximately 0.8V/pC and output from the preamplifier is received by a shaper (main-amplifier) with a gain of 7. The baseline restoration circuit is incorporated in the main-amplifier. The threshold voltage for discriminator section is common to the 4 channels and their digital output level is LVDS-compatible. The IC also has analog output of the preamplifier. The equivalent noise charge at input capacitance of 150 pF is around 7,500 electrons. The power dissipation with LDVS outputs (100 Omega load) is 59mW/ch

ASD IC for the thin gap chambers in the LHC ATLAS experiment

CERN Document Server

Sasaki, O

1998-01-01

An amplifier-shaper-discriminator (ASD) chip was designed and built for Thin Gap Chambers in the forward muon trigger system of the LHC ATLAS experiment. The ASD IC uses SONY Analog Master Slice bipolar technology. The IC contains 4 $9 channels in a QFP48 package. The gain of its first stage (preamplifier) is approximately 0.8 V/pC and output from the preamplifier is received by a shaper (main-amplifier) with a gain of 7. The baseline restoration circuit is $9 incorporated in the main-amplifier. The threshold voltage for the discriminator section is common to the 4 channels and their digital output level is LVDS-compatible. The IC also has analog output for the preamplifier. The equivalent $9 noise charge at input capacitance of 150 pF is around 7500 electrons. The power dissipation with LDVS outputs (100 Omega load) is 59 mW/ch. (8 refs).

ASD IC for the thin gap chambers in the LHC ATLAS Experiment

CERN Document Server

Sasaki, O

1999-01-01

An amplifier-shaper-discriminator (ASD) chip was designed and built for Thin Gap Chambers in the forward muon trigger system of the LHC Atlas experiment. The ASD IC uses SONY Analog Master Slice bipolar technology. The IC contains 4 channels in a QFP48 package. The gain of its first stage (preamplifier) is approximately 0.8 V/pC and output from the preamplifier is received by a shaper (main-amplifier) with a gain of 7. The baseline restoration circuit is incorporated in the main-amplifier. The threshold voltage for discriminator section is common to the 4 channels and their digital output level is LVDS- compatible. The IC also has analog output of the preamplifier. The equivalent noise charge at input capacitance of 150 pF is around 7500 electrons. The power dissipation with LDVS outputs (100 Omega load) is 59 mW/ch.

Subdued, a TMEM16 family Ca²⁺-activated Cl⁻channel in Drosophila melanogaster with an unexpected role in host defense.

Science.gov (United States)

Wong, Xiu Ming; Younger, Susan; Peters, Christian J; Jan, Yuh Nung; Jan, Lily Y

2013-11-05

TMEM16A and TMEM16B are calcium-activated chloride channels (CaCCs) with important functions in mammalian physiology. Whether distant relatives of the vertebrate TMEM16 families also form CaCCs is an intriguing open question. Here we report that a TMEM16 family member from Drosophila melanogaster, Subdued (CG16718), is a CaCC. Amino acid substitutions of Subdued alter the ion selectivity and kinetic properties of the CaCC channels heterologously expressed in HEK 293T cells. This Drosophila channel displays characteristics of classic CaCCs, thereby providing evidence for evolutionarily conserved biophysical properties in the TMEM16 family. Additionally, we show that knockout flies lacking subdued gene activity more readily succumb to death caused by ingesting the pathogenic bacteria Serratia marcescens, suggesting that subdued has novel functions in Drosophila host defense. DOI: http://dx.doi.org/10.7554/eLife.00862.001.

Multi-channel automotive night vision system

Science.gov (United States)

Lu, Gang; Wang, Li-jun; Zhang, Yi

2013-09-01

A four-channel automotive night vision system is designed and developed .It is consist of the four active near-infrared cameras and an Mulit-channel image processing display unit,cameras were placed in the automobile front, left, right and rear of the system .The system uses near-infrared laser light source，the laser light beam is collimated, the light source contains a thermoelectric cooler (TEC),It can be synchronized with the camera focusing, also has an automatic light intensity adjustment, and thus can ensure the image quality. The principle of composition of the system is description in detail,on this basis, beam collimation,the LD driving and LD temperature control of near-infrared laser light source,four-channel image processing display are discussed.The system can be used in driver assistance, car BLIS, car parking assist system and car alarm system in day and night.

Design of a preamplifier for an alpha particles spectrometer; Diseno de un preamplificador para un espectrometro de particulas alfa

Energy Technology Data Exchange (ETDEWEB)

Murillo O, R.; Hernandez D, V. M.; Chacon R, A.; Vega C, H. R., E-mail: fermineutron@yahoo.co [Universidad Autonoma de Zacatecas, Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2010-09-15

To detect radiation diverse detector types are used, when these are alpha particles proportional type detectors are used, semiconductor, of scintillation or traces. In this work the design results, the construction and the first tests of a spectrometer (preamplifier) are presented for alpha particles that was designed starting from a Pin type photodiode. The system was designed and simulated with a program for electronic circuits. With the results of the simulation phase was constructed the electronics that is coupled to a spectroscopic amplifier and a multichannel analyzer. The total of the system is evaluated analyzing its performance before a triple source of alphas and that they are produced by two smoke detectors of domestic use. Of the tests phase we find that the system allows to obtain in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

Simulative Analysis of Inter-Satellite Optical Wireless Communication (IsOWC) Link with EDFA

Science.gov (United States)

Singh, Mehtab; Singh, Navpreet

2018-04-01

In this paper, simulative analysis and performance comparison of different EDFA (Erbium-doped fiber amplifier) configurations in a 10 Gbps inter-satellite optical wireless communication (IsOWC) link have been reported for a 5,000 km long link and 1,550 nm operating wavelength. The results show that system in which both pre-amplifier and booster amplifier stages are implemented simultaneously outperforms systems with only pre-amplifier and booster amplifier stage. From the results, it can be seen that by deploying a transmission power level of 15 dBm, a link distance of 9,600 km can be achieved with a quality factor of 6.01 dB and BER (Bit error rate) of 1.07×10-9. Also, in this paper, the performance of an 8×7 Gbps WDM-IsOWC link has been reported. The results show that by using both EDFA pre-amplifier and booster amplifier stages, a link distance of 8,000 km for each channel is achievable with desired performance levels (Q≥6 and BER≤10-9). Also, the effect of channel spacing on the performance of WDM-IsOWC link is investigated. The results show that the received signal has acceptable performance levels when the channel spacing is 100 GHz but when the channel spacing is reduced to 80 GHz, the quality of the received signal degrades and link distance decreases.

A Nitrogen-16 Power Channel in the Melusine Cooling Circuit; Chaine de puissance azote 16 sur le circuit de refrigeration de melusine

Energy Technology Data Exchange (ETDEWEB)

Tiberghien, R [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires, 38 - Grenoble (France)

1962-07-01

A power channel, which is to be used on Melusine, the 2 MW pool-type reactor built at Grenoble Nuclear Center, is described. It will be used for measuring of {sup 16}N activity of water after passage through the reactor core. The experimental system as well as the measuring instruments are described. Solutions to problems likely to arise are given. The experimental results show that this power measurement is free from neutron flux local deformations, from control rods position, and from experiments. The power indicated is to {+-}2% the same as the thermodynamic power. Since May 1962, this power channel is used as a reference for the operation of the reactor. It is also provided for on the Siloe 10 MW reactor. (author) [French] L'objet de ce rapport est la description d'une nouvelle chaine de puissance pour la pile piscine 'Melusine' de 2 MW du Centre d'etudes Nucleaires de Grenoble. Il s'agit de la mesure de l'activite en azote 16 de l'eau apres son passage dans le coeur du reacteur. Le dispositif experimental ainsi que les appareils de mesure y sont decrits. Les reponses aux differents problemes poses sont donnees. Les resultats experimentaux montrent que cette mesure de puissance est independante des deformations locales de flux de neutrons, de la position des barres de controle et des manipulations. La puissance indiquee par cette chaine est a 2 % pres identique a la puissance thermodynamique. Depuis mai 1962, elle est utilisee comme reference pour le pilotage de la pile. Elle est aussi prevue sur la pile 'Siloe' de 10 MW. (auteur)

Optimal Superimposed Training Sequences for Channel Estimation in MIMO-OFDM Systems

Directory of Open Access Journals (Sweden)

Ratnam V. Raja Kumar

2010-01-01

Full Text Available In this work an iterative time domain Least Squares (LS based channel estimation method using superimposed training (ST for a Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM system over time varying frequency selective fading channels is proposed. The performance of the channel estimator is analyzed in terms of the Mean Square Estimation Error (MSEE and its impact on the uncoded Bit Error Rate (BER of the MIMO-OFDM system is studied. A new selection criterion for the training sequences that jointly optimizes the MSEE and the BER of the OFDM system is proposed. Chirp based sequences are proposed and shown to satisfy the same. These are compared with the other sequences proposed in the literature and are found to yield a superior performance. The sequences, one for each transmitting antenna, offers fairness through providing equal interference in all the data carriers unlike earlier proposals. The effectiveness of the mathematical analysis presented is demonstrated through a comparison with the simulation studies. Experimental studies are carried out to study and validate the improved performance of the proposed scheme. The scheme is applied to the IEEE 802.16e OFDM standard and a case is made with the required design of the sequence.

Energy-Efficient Channel Estimation in MIMO Systems

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available The emergence of MIMO communications systems as practical high-data-rate wireless communications systems has created several technical challenges to be met. On the one hand, there is potential for enhancing system performance in terms of capacity and diversity. On the other hand, the presence of multiple transceivers at both ends has created additional cost in terms of hardware and energy consumption. For coherent detection as well as to do optimization such as water filling and beamforming, it is essential that the MIMO channel is known. However, due to the presence of multiple transceivers at both the transmitter and receiver, the channel estimation problem is more complicated and costly compared to a SISO system. Several solutions have been proposed to minimize the computational cost, and hence the energy spent in channel estimation of MIMO systems. We present a novel method of minimizing the overall energy consumption. Unlike existing methods, we consider the energy spent during the channel estimation phase which includes transmission of training symbols, storage of those symbols at the receiver, and also channel estimation at the receiver. We develop a model that is independent of the hardware or software used for channel estimation, and use a divide-and-conquer strategy to minimize the overall energy consumption.

Rabbit System. Low cost, high reliability front end electronics featuring 16 bit dynamic range

International Nuclear Information System (INIS)

Drake, G.; Droege, T.F.; Nelson, C.A. Jr.; Turner, K.J.; Ohska, T.K.

1985-10-01

A new crate-based front end system has been built which features low cost, compact packaging, command capability, 16 bit dynamic range digitization, and a high degree of redundancy. The crate can contain a variety of instrumentation modules, and is designed to be situated close to the detector. The system is suitable for readout of a large number of channels via parallel multiprocessor data acquisition

A simple pulsed drain feedback preamplifier for high resolution high rate nuclear spectroscopy

International Nuclear Information System (INIS)

Lakatos, T.; Hegyesi, G.; Kalinka, G.

1996-01-01

A non-optical, pulsed reset technique for use in charge sensitive preamplifiers with Si(Li) X-ray semiconductor detectors of conventional polarity is described. The phenomenon of impact ionization in the field effect transistor is used for charge restoration. The process is controlled via the detector capacitance. The method needs no extra components in the input circuitry. No significant resolution degradation can be detected up to 600 kcps Mn K intensity if following the 5 μs resetting pulse the signal processor is inhibited for 50 μs. (orig.)

A simple pulsed drain feedback preamplifier for high resolution high rate nuclear spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Lakatos, T. [Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete; Hegyesi, G. [Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete; Kalinka, G. [Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete

1996-08-21

A non-optical, pulsed reset technique for use in charge sensitive preamplifiers with Si(Li) X-ray semiconductor detectors of conventional polarity is described. The phenomenon of impact ionization in the field effect transistor is used for charge restoration. The process is controlled via the detector capacitance. The method needs no extra components in the input circuitry. No significant resolution degradation can be detected up to 600 kcps Mn K intensity if following the 5 {mu}s resetting pulse the signal processor is inhibited for 50 {mu}s. (orig.).

A 16 channel discriminator VME board with enhanced triggering capabilities

International Nuclear Information System (INIS)

Borsato, E; Garfagnini, A; Menon, G

2012-01-01

Electronics and data acquisition systems used in small and large scale laboratories often have to handle analog signals with varying polarity, amplitude and duration which have to be digitized to be used as trigger signals to validate the acquired data. In the specific case of experiments dealing with ionizing radiation, ancillary particle detectors (for instance plastic scintillators or Resistive Plate Chambers) are used to trigger and select the impinging particles for the experiment. A novel approach using commercial LVDS line receivers as discriminator devices is presented. Such devices, with a proper calibration, can handle positive and negative analog signals in a wide dynamic range (from 20 mV to 800 mV signal amplitude). The clear advantages, with respect to conventional discriminator devices, are reduced costs, high reliability of a mature technology and the possibility of high integration scale. Moreover, commercial discriminator boards with positive input signal and a wide threshold swing are not available on the market. The present paper describes the design and characterization of a VME board capable to handle 16 differential or single-ended input channels. The output digital signals, available independently for each input, can be combined in the board into three independent trigger logic units which provide additional outputs for the end user.

A 16 channel discriminator VME board with enhanced triggering capabilities

Science.gov (United States)

Borsato, E.; Garfagnini, A.; Menon, G.

2012-08-01

Electronics and data acquisition systems used in small and large scale laboratories often have to handle analog signals with varying polarity, amplitude and duration which have to be digitized to be used as trigger signals to validate the acquired data. In the specific case of experiments dealing with ionizing radiation, ancillary particle detectors (for instance plastic scintillators or Resistive Plate Chambers) are used to trigger and select the impinging particles for the experiment. A novel approach using commercial LVDS line receivers as discriminator devices is presented. Such devices, with a proper calibration, can handle positive and negative analog signals in a wide dynamic range (from 20 mV to 800 mV signal amplitude). The clear advantages, with respect to conventional discriminator devices, are reduced costs, high reliability of a mature technology and the possibility of high integration scale. Moreover, commercial discriminator boards with positive input signal and a wide threshold swing are not available on the market. The present paper describes the design and characterization of a VME board capable to handle 16 differential or single-ended input channels. The output digital signals, available independently for each input, can be combined in the board into three independent trigger logic units which provide additional outputs for the end user.

Highly integrated electronics for the star TPC

Energy Technology Data Exchange (ETDEWEB)

Arthur, A.A.; Bieser, F.; Hearn, W.; Kleinfelder, S.; Merrick, T.; Millaud, J.; Noggle, T.; Rai, G.; Ritter, H.G.; Wieman, H. [Lawrence Berkeley Laboratory, CA (United States)

1991-12-31

The concept for the STAR TPC front-end electronics is presented and the progress toward the development of a fully integrated solution is described. It is the goal of the R+D program to develop the complete electronics chain for the STAR central TPC detector at RHIC. It is obvious that solutions chosen e.g. for ALEPH are not adequate for the 150000 channels that need to be instrumented for readout. It will be necessary to perform all the signal processing, digitization and multiplexing directly on the detector in order to reduce per channel cost and the amount of cabling necessary to read out the information. We follow the approach chosen by the EOS TPC project, where the readout electronics on the detector consists of an integrated preamplifier, a hybrid shaping amplifier, an integrated switched capacitor array and a highly multiplexed ADC. The STAR electronics will be further integrated so that approximately 16 channels of the preamplifier, the shaper, the analog store and the ADC will be contained in two integrated circuits located directly on the pad plane.

Chemical Selectivity and Sensitivity of a 16-Channel Electronic Nose for Trace Vapour Detection

Directory of Open Access Journals (Sweden)

Drago Strle

2017-12-01

Full Text Available Good chemical selectivity of sensors for detecting vapour traces of targeted molecules is vital to reliable detection systems for explosives and other harmful materials. We present the design, construction and measurements of the electronic response of a 16 channel electronic nose based on 16 differential microcapacitors, which were surface-functionalized by different silanes. The e-nose detects less than 1 molecule of TNT out of 10+12 N2 molecules in a carrier gas in 1 s. Differently silanized sensors give different responses to different molecules. Electronic responses are presented for TNT, RDX, DNT, H2S, HCN, FeS, NH3, propane, methanol, acetone, ethanol, methane, toluene and water. We consider the number density of these molecules and find that silane surfaces show extreme affinity for attracting molecules of TNT, DNT and RDX. The probability to bind these molecules and form a surface-adsorbate is typically 10+7 times larger than the probability to bind water molecules, for example. We present a matrix of responses of differently functionalized microcapacitors and we propose that chemical selectivity of multichannel e-nose could be enhanced by using artificial intelligence deep learning methods.

Characterization of potassium channel modulators with QPatch automated patch-clamp technology: system characteristics and performance

DEFF Research Database (Denmark)

Kutchinsky, Jonatan; Friis, Søren; Asmild, Margit

2003-01-01

Planar silicon chips with 1-2-microm etched holes (average resistance: 2.04 +/- 0.02 MOmega in physiological buffer, n = 274) have been developed for patch-clamp recordings of whole-cell currents from cells in suspension. An automated 16-channel parallel screening system, QPatch 16, has been deve......-response relationship characterizations of verapamil and rBeKm-1 blockage of hERG currents provided IC(50) values similar to values reported in the literature....

Behavioral Ecology of Narwhals in a Changing Arctic

Science.gov (United States)

2015-09-30

impacted by increasing anthropogenic activities in Baffin Bay (increasing shipping, future transit through the NW Passage, seismic exploration, increasing...whistles being missed). Second, we utlilized a custom made 16 channel vertical array (with a laptop and pre-amplifier inside an insulated aluminium...management considering ongoing and expected significant increases in anthropogenic sound (e.g., seismic exploration, shipping) in the Arctic. The

Reliability Improved Design for a Safety System Channel

Energy Technology Data Exchange (ETDEWEB)

Oh, Eung Se; Kim, Yun Goo [KHNP, Daejeon (Korea, Republic of)

2016-05-15

Nowadays, these systems are implemented with a same platform type, such as a qualified programmable logic controller (PLC). The platform intensively uses digital communication with fiber-optic links to reduce cabling costs and to achieve effective signal isolation. These communication interface and redundancies within a channel increase the complexness of an overall system design. This paper proposes a simpler channel architecture design to reduce the complexity and to enhance overall channel reliability. Simplified safety channel configuration is proposed and the failure probabilities are compared with baseline safety channel configuration using an estimated generic value. The simplified channel configuration achieves 40 percent failure reduction compare to baseline safety channel configuration. If this configuration can be implemented within a processor module, overall safety channel reliability is increase and costs of fabrication and maintenance will be greatly reduced.

Reliability Improved Design for a Safety System Channel

International Nuclear Information System (INIS)

Oh, Eung Se; Kim, Yun Goo

2016-01-01

Nowadays, these systems are implemented with a same platform type, such as a qualified programmable logic controller (PLC). The platform intensively uses digital communication with fiber-optic links to reduce cabling costs and to achieve effective signal isolation. These communication interface and redundancies within a channel increase the complexness of an overall system design. This paper proposes a simpler channel architecture design to reduce the complexity and to enhance overall channel reliability. Simplified safety channel configuration is proposed and the failure probabilities are compared with baseline safety channel configuration using an estimated generic value. The simplified channel configuration achieves 40 percent failure reduction compare to baseline safety channel configuration. If this configuration can be implemented within a processor module, overall safety channel reliability is increase and costs of fabrication and maintenance will be greatly reduced

Role of TRP channels in the cardiovascular system.

Science.gov (United States)

Yue, Zhichao; Xie, Jia; Yu, Albert S; Stock, Jonathan; Du, Jianyang; Yue, Lixia

2015-02-01

The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca(2+)-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca(2+) entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases. Copyright © 2015 the American Physiological Society.

Multi-channel data acquisition system for CT

International Nuclear Information System (INIS)

Cao Fuqiang; He Bin; Liu Guohua; Xu Minjian

2009-01-01

The architecture design and realization of a data acquisition system for multi-channel CT is described. The article introduces the conversion of analog signal to digital signal, the data cache and transmission. This data acquisition system can be widely used in the system which requires the multi-channel, weak current signal detection. (authors)

A 31-channel MR brain array coil compatible with positron emission tomography.

Science.gov (United States)

Sander, Christin Y; Keil, Boris; Chonde, Daniel B; Rosen, Bruce R; Catana, Ciprian; Wald, Lawrence L

2015-06-01

Simultaneous acquisition of MR and positron emission tomography (PET) images requires the placement of the MR detection coil inside the PET detector ring where it absorbs and scatters photons. This constraint is the principal barrier to achieving optimum sensitivity on each modality. Here, we present a 31-channel PET-compatible brain array coil with reduced attenuation but improved MR sensitivity. A series of component tests were performed to identify tradeoffs between PET and MR performance. Aspects studied include the remote positioning of preamplifiers, coax size, coil trace size/material, and plastic housing. We then maximized PET performance at minimal cost to MR sensitivity. The coil was evaluated for MR performance (signal to noise ratio [SNR], g-factor) and PET attenuation. The coil design showed an improvement in attenuation by 190% (average) compared with conventional 32-channel arrays, and no loss in MR SNR. Moreover, the 31-channel coil displayed an SNR improvement of 230% (cortical region of interest) compared with a PET-optimized 8-channel array with similar attenuation properties. Implementing attenuation correction of the 31-channel array successfully removed PET artifacts, which were comparable to those of the 8-channel array. The design of the 31-channel PET-compatible coil enables higher sensitivity for PET/MR imaging, paving the way for novel applications in this hybrid-imaging domain. © 2014 Wiley Periodicals, Inc.

Divergent actions of the pyrethroid insecticides S-bioallethrin, tefluthrin, and deltamethrin on rat Nav1.6 sodium channels

International Nuclear Information System (INIS)

Tan Jianguo; Soderlund, David M.

2010-01-01

We expressed rat Na v 1.6 sodium channels in combination with the rat β 1 and β 2 auxiliary subunits in Xenopus laevis oocytes and evaluated the effects of the pyrethroid insecticides S-bioallethrin, deltamethrin, and tefluthrin on expressed sodium currents using the two-electrode voltage clamp technique. S-Bioallethrin, a type I structure, produced transient modification evident in the induction of rapidly decaying sodium tail currents, weak resting modification (5.7% modification at 100 μM), and no further enhancement of modification upon repetitive activation by high-frequency trains of depolarizing pulses. By contrast deltamethrin, a type II structure, produced sodium tail currents that were ∼ 9-fold more persistent than those caused by S-bioallethrin, barely detectable resting modification (2.5% modification at 100 μM), and 3.7-fold enhancement of modification upon repetitive activation. Tefluthrin, a type I structure with high mammalian toxicity, exhibited properties intermediate between S-bioallethrin and deltamethrin: intermediate tail current decay kinetics, much greater resting modification (14.1% at 100 μM), and 2.8-fold enhancement of resting modification upon repetitive activation. Comparison of concentration-effect data showed that repetitive depolarization increased the potency of tefluthrin ∼ 15-fold and that tefluthrin was ∼ 10-fold more potent than deltamethrin as a use-dependent modifier of Na v 1.6 sodium channels. Concentration-effect data from parallel experiments with the rat Na v 1.2 sodium channel coexpressed with the rat β 1 and β 2 subunits in oocytes showed that the Na v 1.6 isoform was at least 15-fold more sensitive to tefluthrin and deltamethrin than the Na v 1.2 isoform. These results implicate sodium channels containing the Na v 1.6 isoform as potential targets for the central neurotoxic effects of pyrethroids.

Five channel data acquisition system for tracer studies

International Nuclear Information System (INIS)

Narender Reddy, J.; Dhananjay Reddy, Y.; Dheeraj Reddy, J.

2001-01-01

Radioactive tracers are being used by many modern industries for trouble shooting, process control/quality control and optimization in the process plants. A five channel data acquisition system which has five independent scintillation detector based channels for data acquisition has been developed and made available. This system can be used for tracer studies involving Mean residence time, Resident time distribution and other similar parameters involving tracer movement. System developed can acquire data with dwell times ranging from 10 m sec to 100 sec into each channel and has a capacity to acquire data into 10K channels. Each channel electronics, has a 1x1 NaI Scintillation Detector probe, HV, AMP SCA, micro-controller based data acquisition card with independent dot matrix LCD display for visualization. Extensive use of serial bus (I 2 C, microwire) compatible devices has been incorporated in the design. Data acquisition is initiated simultaneously into all the channels. System design permits delayed/prompt data acquisition selectively. Dual counter switching technique has been employed to achieve faster dwell times for data acquisition. (author)

Nuclear Landau-Zener phenomena and the fusion cross sections in the system 13C + 16O → 12C + 17O

International Nuclear Information System (INIS)

Imanishi, B.; Oertzen, W. von.

1990-07-01

Reaction mechanism of the system 13 C+ 16 O- 12 C+ 17 O is investigated with the use of the nucleon molecular-orbital model in the framework of the orthogonalized coupled-reaction-channel (OCRC) theory. The adiabatic potentials obtained are quite different from the diagonal potentials of the original OCRC basis. The Landau-Zener radial coupling explains the backward enhancement of measured differential cross sections of the transfer reaction 13 C( 16 O, 17 O) 12 C. In the OCRC calculation the fusion cross sections of the channel 13 C+ 16 O is enhanced at low bombarding energies, in agreement with the experimental data. (author)

A multi-channel low-power system-on-chip for single-unit recording and narrowband wireless transmission of neural signal.

Science.gov (United States)

Bonfanti, A; Ceravolo, M; Zambra, G; Gusmeroli, R; Spinelli, A S; Lacaita, A L; Angotzi, G N; Baranauskas, G; Fadiga, L

2010-01-01

This paper reports a multi-channel neural recording system-on-chip (SoC) with digital data compression and wireless telemetry. The circuit consists of a 16 amplifiers, an analog time division multiplexer, an 8-bit SAR AD converter, a digital signal processor (DSP) and a wireless narrowband 400-MHz binary FSK transmitter. Even though only 16 amplifiers are present in our current die version, the whole system is designed to work with 64 channels demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. A digital data compression, based on the detection of action potentials and storage of correspondent waveforms, allows the use of a 1.25-Mbit/s binary FSK wireless transmission. This moderate bit-rate and a low frequency deviation, Manchester-coded modulation are crucial for exploiting a narrowband wireless link and an efficient embeddable antenna. The chip is realized in a 0.35- εm CMOS process with a power consumption of 105 εW per channel (269 εW per channel with an extended transmission range of 4 m) and an area of 3.1 × 2.7 mm(2). The transmitted signal is captured by a digital TV tuner and demodulated by a wideband phase-locked loop (PLL), and then sent to a PC via an FPGA module. The system has been tested for electrical specifications and its functionality verified in in-vivo neural recording experiments.

A Fast Channel Switching Method in EPON System for IPTV Service

Science.gov (United States)

Nie, Yaling; Yoshiuchi, Hideya

This paper presents a fast channel switching method in Ethernet Passive Optical Network (EPON) system for IPTV service. Fast channel switching is one of the important features of successful IPTV systems. Users surely prefer IPTV systems with small channel switching time rather than a longer one. Thus a channel switching control module and a channel/permission list in EPON system’s ONU or OLT is designed. When EPON system receives channel switching message from IPTV end user, the channel switching control module will catch the message and search the channel list and permission list maintained in EPON system, then got the matching parameter of EPON for the new channel. The new channel’s data transmission will be enabled by directly updating the optical filter of the ONU that end user connected. By using this method in EPON system, it provides a solution for dealing with channel switching delays in IPTV service.

Differential state-dependent modification of rat Na{sub v}1.6 sodium channels expressed in human embryonic kidney (HEK293) cells by the pyrethroid insecticides tefluthrin and deltamethrin

Energy Technology Data Exchange (ETDEWEB)

He, Bingjun [College of Life Sciences, Nankai University, Tianjin 300071 (China); Soderlund, David M., E-mail: dms6@cornell.edu [Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456 (United States)

2011-12-15

We expressed rat Na{sub v}1.6 sodium channels in combination with the rat {beta}1 and {beta}2 auxiliary subunits in human embryonic kidney (HEK293) cells and evaluated the effects of the pyrethroid insecticides tefluthrin and deltamethrin on expressed sodium currents using the whole-cell patch clamp technique. Both pyrethroids produced concentration-dependent, resting modification of Na{sub v}1.6 channels, prolonging the kinetics of channel inactivation and deactivation to produce persistent 'late' currents during depolarization and tail currents following repolarization. Both pyrethroids also produced concentration dependent hyperpolarizing shifts in the voltage dependence of channel activation and steady-state inactivation. Maximal shifts in activation, determined from the voltage dependence of the pyrethroid-induced late and tail currents, were {approx} 25 mV for tefluthrin and {approx} 20 mV for deltamethrin. The highest attainable concentrations of these compounds also caused shifts of {approx} 5-10 mV in the voltage dependence of steady-state inactivation. In addition to their effects on the voltage dependence of inactivation, both compounds caused concentration-dependent increases in the fraction of sodium current that was resistant to inactivation following strong depolarizing prepulses. We assessed the use-dependent effects of tefluthrin and deltamethrin on Na{sub v}1.6 channels by determining the effect of trains of 1 to 100 5-ms depolarizing prepulses at frequencies of 20 or 66.7 Hz on the extent of channel modification. Repetitive depolarization at either frequency increased modification by deltamethrin by {approx} 2.3-fold but had no effect on modification by tefluthrin. Tefluthrin and deltamethrin were equally potent as modifiers of Na{sub v}1.6 channels in HEK293 cells using the conditions producing maximal modification as the basis for comparison. These findings show that the actions of tefluthrin and deltamethrin of Na{sub v}1.6 channels

Substituted 2-Acylaminocycloalkylthiophene-3-carboxylic Acid Arylamides as Inhibitors of the Calcium-Activated Chloride Channel Transmembrane Protein 16A (TMEM16A).

Science.gov (United States)

Truong, Eric C; Phuan, Puay W; Reggi, Amanda L; Ferrera, Loretta; Galietta, Luis J V; Levy, Sarah E; Moises, Alannah C; Cil, Onur; Diez-Cecilia, Elena; Lee, Sujin; Verkman, Alan S; Anderson, Marc O

2017-06-08

Transmembrane protein 16A (TMEM16A), also called anoctamin 1 (ANO1), is a calcium-activated chloride channel expressed widely mammalian cells, including epithelia, vascular smooth muscle tissue, electrically excitable cells, and some tumors. TMEM16A inhibitors have been proposed for treatment of disorders of epithelial fluid and mucus secretion, hypertension, asthma, and possibly cancer. Herein we report, by screening, the discovery of 2-acylaminocycloalkylthiophene-3-carboxylic acid arylamides (AACTs) as inhibitors of TMEM16A and analysis of 48 synthesized analogs (10ab-10bw) of the original AACT compound (10aa). Structure-activity studies indicated the importance of benzene substituted as 2- or 4-methyl, or 4-fluoro, and defined the significance of thiophene substituents and size of the cycloalkylthiophene core. The most potent compound (10bm), which contains an unusual bromodifluoroacetamide at the thiophene 2-position, had IC 50 of ∼30 nM, ∼3.6-fold more potent than the most potent previously reported TMEM16A inhibitor 4 (Ani9), and >10-fold improved metabolic stability. Direct and reversible inhibition of TMEM16A by 10bm was demonstrated by patch-clamp analysis. AACTs may be useful as pharmacological tools to study TMEM16A function and as potential drug development candidates.

High precision 16K, 16 channel peak sensing CAMAC ADC

International Nuclear Information System (INIS)

Jain, Mamta; Subramaniam, E.T

2013-01-01

A high density, peak sensing, analog to digital converter (ADC) double width module with CAMAC back plane has been developed for nuclear physics experiments with a large number of detectors. This module has sixteen independent channels in plug-in daughter card mother board mode

Evaluation of a stream channel-type system for southeast Alaska.

Science.gov (United States)

M.D. Bryant; P.E. Porter; S.J. Paustian

1991-01-01

Nine channel types within a hierarchical channel-type classification system (CTCS) were surveyed to determine relations between salmonid densities and species distribution, and channel type. Two other habitat classification systems and the amount of large woody debris also were compared to species distribution and salmonid densities, and to stream channel types....

The elusive character of discontinuous deep-water channels: New insights from Lucia Chica channel system, offshore California

Science.gov (United States)

Maier, K.L.; Fildani, A.; Paull, C.K.; Graham, S.A.; McHargue, T.R.; Caress, D.W.; McGann, M.

2011-01-01

New high-resolution autonomous underwater vehicle (AUV) seafloor images, with 1 m lateral resolution and 0.3 m vertical resolution, reveal unexpected seafloor rugosity and low-relief (thalwegs were interpreted originally from lower-resolution images, but newly acquired AUV data indicate that a single sinuous channel fed a series of discontinuous lower-relief channels. These discontinuous channels were created by at least four avulsion events. Channel relief, defined as the height from the thalweg to the levee crest, controls avulsions and overall stratigraphic architecture of the depositional area. Flowstripped turbidity currents separated into and reactivated multiple channels to create a distributary pattern and developed discontinuous trains of cyclic scours and megaflutes, which may be erosional precursors to continuous channels. The diverse features now imaged in the Lucia Chica channel system (offshore California) are likely common in modern and ancient systems with similar overall morphologies, but have not been previously mapped with lower-resolution detection methods in any of these systems. ?? 2011 Geological Society of America.

Channel coincidence counter: version 1

International Nuclear Information System (INIS)

Krick, M.S.; Menlove, H.O.

1980-06-01

A thermal neutron coincidence counter has been designed for the assay of fast critical assembly fuel drawers and plutonium-bearing fuel rods. The principal feature of the detector is a 7-cm by 7-cm by 97-cm detector channel, which provides a uniform neutron detection efficiency of 16% along the central 40 cm of the channel. The electronics system is identical to that used for the High-Level Neutron Coincidence Counter

Improved Sparse Channel Estimation for Cooperative Communication Systems

Directory of Open Access Journals (Sweden)

Guan Gui

2012-01-01

Full Text Available Accurate channel state information (CSI is necessary at receiver for coherent detection in amplify-and-forward (AF cooperative communication systems. To estimate the channel, traditional methods, that is, least squares (LS and least absolute shrinkage and selection operator (LASSO, are based on assumptions of either dense channel or global sparse channel. However, LS-based linear method neglects the inherent sparse structure information while LASSO-based sparse channel method cannot take full advantage of the prior information. Based on the partial sparse assumption of the cooperative channel model, we propose an improved channel estimation method with partial sparse constraint. At first, by using sparse decomposition theory, channel estimation is formulated as a compressive sensing problem. Secondly, the cooperative channel is reconstructed by LASSO with partial sparse constraint. Finally, numerical simulations are carried out to confirm the superiority of proposed methods over global sparse channel estimation methods.

Preamble and pilot symbol design for channel estimation in OFDM systems with null subcarriers

Directory of Open Access Journals (Sweden)

Ohno Shuichi

2011-01-01

Full Text Available Abstract In this article, design of preamble for channel estimation and pilot symbols for pilot-assisted channel estimation in orthogonal frequency division multiplexing system with null subcarriers is studied. Both the preambles and pilot symbols are designed to minimize the l 2 or the l ∞ norm of the channel estimate mean-squared errors (MSE in frequency-selective environments. We use convex optimization technique to find optimal power distribution to the preamble by casting the MSE minimization problem into a semidefinite programming problem. Then, using the designed optimal preamble as an initial value, we iteratively select the placement and optimally distribute power to the selected pilot symbols. Design examples consistent with IEEE 802.11a as well as IEEE 802.16e are provided to illustrate the superior performance of our proposed method over the equi-spaced equi-powered pilot symbols and the partially equi-spaced pilot symbols.

Reaction channel coupling effects for nucleons on 16O: Induced undularity and proton-neutron potential differences

Science.gov (United States)

Keeley, N.; Mackintosh, R. S.

2018-01-01

Background: Precise fitting of scattering observables suggests that the nucleon-nucleus interaction is l dependent. Such l dependence has been shown to be S -matrix equivalent to an undulatory l -independent potential. The undulations include radial regions where the imaginary term is emissive. Purpose: To study the dynamical polarization potential (DPP) generated in proton-16O and neutron-16O interaction potentials by coupling to pickup channels. Undulatory features occurring in these DPPs can be compared with corresponding features of empirical optical model potentials (OMPs). Furthermore, the additional inclusion of coupling to vibrational states of the target will provide evidence for dynamically generated nonlocality. Methods: The fresco code provides the elastic channel S -matrix Sl j for chosen channel couplings. Inversion, Sl j→V (r ) +l .s VSO(r ) , followed by subtraction of the bare potential, yields an l -independent and local representation of the DPP due to the chosen couplings. Results: The DPPs have strongly undulatory features, including radial regions of emissivity. Certain features of empirical DPPs appear, e.g., the full inverted potential has emissive regions. The DPPs for different collective states are additive except near the nuclear center, whereas the collective and reaction channel DPPs are distinctly nonadditive over a considerable radial range, indicating dynamical nonlocality. Substantial differences between the DPPs due to pickup coupling for protons and neutrons occur; these imply a greater difference between proton and neutron OMPs than the standard phenomenological prescription. Conclusions: The onus is on those who object to undularity in the local and l -independent representation of nucleon elastic scattering to show why such undulations do not occur. This work suggests that it is not legitimate to halt model-independent fits to high-quality data at the appearance of undularity.

Design of multi-channel analyzer's monitoring system based on embedded system

International Nuclear Information System (INIS)

Yang Tao; Wei Yixiang

2007-01-01

A new Multi-Channel Analyzer's Monitoring system based on ARM9 Embedded system is introduced in this paper. Some solutions to problem are also discussed during the procedure of design, installation and debugging on Linux system. The Monitoring system is developed by using MiniGUI and Linux software system API, with the functions of collecting, displaying and I/O data controlling 1024 channels datum. They are all realized in real time, with the merits of low cost, small size and portability. All these lay the foundation of developing homemade Digital and Portable nuclear spectrometers. (authors)

Note: Optical receiver system for 152-channel magnetoencephalography

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong [Center for Biosignals, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)

2014-11-15

An optical receiver system composing 13 serial data restore/synchronizer modules and a single module combiner converted optical 32-bit serial data into 32-bit synchronous parallel data for a computer to acquire 152-channel magnetoencephalography (MEG) signals. A serial data restore/synchronizer module identified 32-bit channel-voltage bits from 48-bit streaming serial data, and then consecutively reproduced 13 times of 32-bit serial data, acting in a synchronous clock. After selecting a single among 13 reproduced data in each module, a module combiner converted it into 32-bit parallel data, which were carried to 32-port digital input board in a computer. When the receiver system together with optical transmitters were applied to 152-channel superconducting quantum interference device sensors, this MEG system maintained a field noise level of 3 fT/√Hz @ 100 Hz at a sample rate of 1 kSample/s per channel.

Degenerated-Inverse-Matrix-Based Channel Estimation for OFDM Systems

Directory of Open Access Journals (Sweden)

Makoto Yoshida

2009-01-01

Full Text Available This paper addresses time-domain channel estimation for pilot-symbol-aided orthogonal frequency division multiplexing (OFDM systems. By using a cyclic sinc-function matrix uniquely determined by Nc transmitted subcarriers, the performance of our proposed scheme approaches perfect channel state information (CSI, within a maximum of 0.4 dB degradation, regardless of the delay spread of the channel, Doppler frequency, and subcarrier modulation. Furthermore, reducing the matrix size by splitting the dispersive channel impulse response into clusters means that the degenerated inverse matrix estimator (DIME is feasible for broadband, high-quality OFDM transmission systems. In addition to theoretical analysis on normalized mean squared error (NMSE performance of DIME, computer simulations over realistic nonsample spaced channels also showed that the DIME is robust for intersymbol interference (ISI channels and fast time-invariant channels where a minimum mean squared error (MMSE estimator does not work well.

Control system design for concrete irrigation channels

OpenAIRE

Strecker, Timm; Aamo, Ole Morten; Cantoni, Michael

2017-01-01

Concrete channels find use at the periphery of irrigation networks, for expansion and to replace small earthen channels given the relative ease of maintenance and elimination of seepage losses. In design, it is important to account for control system performance when dimensioning the channel infrastructure. In this paper, the design of a distributed controller is investigated in terms managing water-levels, and thereby the depth profile (i.e., amount of concrete) needed to support peak flow l...

Reaching a few picosecond timing precision with the 16-channel digitizer and timestamper SAMPIC ASIC

Energy Technology Data Exchange (ETDEWEB)

Delagnes, E., E-mail: eric.delagnes@cea.fr [CEA/IRFU/SEDI, Saclay (France); Breton, D. [Laboratoire de L’accélérateur Linéaire from CNRS/IN2P3, Centre scientifique d’Orsay, Bâtiment 200, 91898, Orsay, Cedex (France); Grabas, H. [CEA/IRFU/SEDI, Saclay (France); Maalmi, J.; Rusquart, P. [Laboratoire de L’accélérateur Linéaire from CNRS/IN2P3, Centre scientifique d’Orsay, Bâtiment 200, 91898, Orsay, Cedex (France)

2015-07-01

SAMPIC is a Time and Waveform to Digital Converter (TWDC) multichannel chip. It integrates 16 channels each including DLL-based TDC providing a raw time associated with an ultra-fast analog memory sampling the signal used for precise timing measurements as well as other parameters of the pulse. Every channel also integrates a discriminator that can trigger it independently or participate to a more complex trigger. After triggering, the analog samples are digitized by on-chip ADCs and are sent serially to the acquisition. The paper describes the architecture of SAMPIC and reports the main performance measured on the first prototype chip with a focus on timing resolution in the range of 15 ps RMS using raw data improved to less than 5 ps RMS after a simple calibration.

Analysis of flow distribution instability in parallel thin rectangular multi-channel system

Energy Technology Data Exchange (ETDEWEB)

Xia, G.L. [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an City 710049 (China); Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin City 150001 (China); Su, G.H., E-mail: ghsu@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an City 710049 (China); Peng, M.J. [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin City 150001 (China)

2016-08-15

Highlights: • Flow distribution instability in parallel thin rectangular multi-channel system is studied using RELAP5 codes. • Flow excursion may bring parallel heating channel into the density wave oscillations region. • Flow distribution instability is more likely to happen at low power/flow ratio conditions. • The increase of channel number will not affect the flow distribution instability boundary. • Asymmetry inlet throttling and heating will make system more unstable. - Abstract: The flow distribution instability in parallel thin rectangular multi-channel system has been researched in the present study. The research model of parallel channel system is established by using RELAP5/MOD3.4 codes. The transient process of flow distribution instability is studied at imposed inlet mass flow rate and imposed pressure drop conditions. The influence of heating power, mass flow rate, system pressure and channel number on flow distribution instability are analyzed. Furthermore, the flow distribution instability of parallel two-channel system under asymmetric inlet throttling and heating power is studied. The results show that, if multi-channel system operates at the negative slope region of channel ΔP–G curve, small disturbance in pressure drop will lead to flow redistribution between parallel channels. Flow excursion may bring the operating point of heating channel into the density-wave oscillations region, this will result in out-phase or in-phase flow oscillations. Flow distribution instability is more likely to happen at low power/flow ratio conditions, the stability of parallel channel system increases with system pressure, the channel number has a little effect on system stability, but the asymmetry inlet throttling or heating power will make the system more unstable.

3D Massive MIMO Systems: Channel Modeling and Performance Analysis

KAUST Repository

Nadeem, Qurrat-Ul-Ain

2015-03-01

Multiple-input-multiple-output (MIMO) systems of current LTE releases are capable of adaptation in the azimuth only. More recently, the trend is to enhance the system performance by exploiting the channel\\'s degrees of freedom in the elevation through the dynamic adaptation of the vertical antenna beam pattern. This necessitates the derivation and characterization of three-dimensional (3D) channels. Over the years, channel models have evolved to address the challenges of wireless communication technologies. In parallel to theoretical studies on channel modeling, many standardized channel models like COST-based models, 3GPP SCM, WINNER, ITU have emerged that act as references for industries and telecommunication companies to assess system-level and link-level performances of advanced signal processing techniques over real-like channels. Given the existing channels are only two dimensional (2D) in nature; a large effort in channel modeling is needed to study the impact of the channel component in the elevation direction. The first part of this work sheds light on the current 3GPP activity around 3D channel modeling and beamforming, an aspect that to our knowledge has not been extensively covered by a research publication. The standardized MIMO channel model is presented, that incorporates both the propagation effects of the environment and the radio effects of the antennas. In order to facilitate future studies on the use of 3D beamforming, the main features of the proposed 3D channel model are discussed. A brief overview of the future 3GPP 3D channel model being outlined for the next generation of wireless networks is also provided. In the subsequent part of this work, we present an information-theoretic channel model for MIMO systems that supports the elevation dimension. The model is based on the principle of maximum entropy, which enables us to determine the distribution of the channel matrix consistent with the prior information on the angles of departure and

[Study for portable dynamic ECG monitor and recorder].

Science.gov (United States)

Yang, Pengcheng; Li, Yongqin; Chen, Bihua

2012-09-01

This Paper presents a portable dynamic ECG monitor system based on MSP430F149 microcontroller. The electrocardiogram detecting system consists of ECG detecting circuit, man-machine interaction module, MSP430F149 and upper computer software. The ECG detecting circuit including a preamplifier, second-order Butterworth low-pass filter, high-pass filter, and 50Hz trap circuit to detects electrocardiogram and depresses various kinds of interference effectively. A microcontroller is used to collect three channel analog signals which can be displayed on TFT LCD. A SD card is used to record real-time data continuously and implement the FTA16 file system. In the end, a host computer system interface is also designed to analyze the ECG signal and the analysis results can provide diagnosis references to clinical doctors.

Study of flow instabilities in double-channel natural circulation boiling systems

International Nuclear Information System (INIS)

Durga Prasad, Gonella V.; Pandey, Manmohan; Pradhan, Santosh K.; Gupta, Satish K.

2008-01-01

Natural circulation boiling systems consisting of parallel channels can undergo different types of oscillations (in-phase or out-of-phase) depending on the geometric parameters and operating conditions. Disturbances in one channel affect the flow in other channels, which triggers thermal-hydraulic oscillations. In the present work, the modes of oscillation under different operating conditions and channel-to-channel interaction during power fluctuations and on-power refueling in a double-channel natural circulation boiling system are investigated. The system is modeled using a lumped parameter mathematical model and RELAP5/MOD3.4. Parametric studies are carried out for an equal-power double-channel system, at different operating conditions, with both the models, and the results are compared. Instabilities, non-linear oscillations, and effects of recirculation loop dynamics and geometric parameters on the mode of oscillations, are studied using the lumped model. The two channels oscillate out-of-phase in Type-I region, but in Type-II region, both the modes of oscillation are observed under different conditions. Channel-to-channel interaction and on-power refueling studies are carried out using the RELAP model. At high powers, disturbances in one channel significantly affect the stability of the other channel. During on-power refueling, a near-stagnation condition or low-velocity reverse flow can occur, the possibility of reverse flow being higher at lower pressures

Developments of quad channel pulse height analyzer for radon/thoron measurement

International Nuclear Information System (INIS)

Ashokkumar, P.; Raman, Anand; Babu, D.A.R.; Sharma, D.N.; Topkar, Anita; Mayya, Y.S.

2011-01-01

Radon and thoron are naturally occurring noble radioactive gases, the exposure to which has a linear relationship to lung cancer risk. This paper describes development of an automated Radon/Thoron measurement system using an indigenously developed silicon PIN diode. This system employs the 8051 core architecture based Si-lab microcontroller (C-8051F340) integrated with LCD display, hex key pad, non volatile flash memory besides I/O ports interfaced with humidity-temperature sensors and air sampling pump. Air is sampled through a dehumidifier by using a software controlled dc pump. The positively charged progeny atoms are electro statically collected over the detector surface and the deposited radioactivity is assessed by alpha pulse height discrimination technique. The ionization charges produced due to the interaction of alpha particles in the charge depletion region of the diode which is reverse biased at 40V are collected and measured. The measurement circuit uses a charge sensitive preamplifier developed around a low noise opamp IC. The pulses are further processed through a spectroscopy amplifier to obtain distinct pulse height levels for four of the alpha emitting progenies of Rn and Tn namely 210 Po, 214 Po, 216 Po and 212 Po. These signals are input to the quad channel analyzer which provides four individual TTL pulses corresponding to four nuclides mentioned above. The analyzer outputs are processed by the microcontroller module to obtain the Rn/Tn concentration in Bq/M 3 . This portable system stores one week hourly individual channel data along with the corresponding Rn/Tn concentrations, temperature, humidity and can be transferred to pc. Preliminary studies have indicated that sensitivity as low as 0.50 cph/Bq.m -3 can be achieved by this system. (author)

Monitoring inter-channel nonlinearity based on differential pilot

Science.gov (United States)

Wang, Wanli; Yang, Aiying; Guo, Peng; Lu, Yueming; Qiao, Yaojun

2018-06-01

We modify and simplify the inter-channel nonlinearity (NL) estimation method by using differential pilot. Compared to previous works, the inter-channel NL estimation method we propose has much lower complexity and does not need modification of the transmitter. The performance of inter-channel NL monitoring with different launch power is tested. For both QPSK and 16QAM systems with 9 channels, the estimation error of inter-channel NL is lower than 1 dB when the total launch power is bigger than 12 dBm after 1000 km optical transmission. At last, we compare our inter-channel NL estimation method with other methods.

Channel estimation in few mode fiber mode division multiplexing transmission system

Science.gov (United States)

Hei, Yongqiang; Li, Li; Li, Wentao; Li, Xiaohui; Shi, Guangming

2018-03-01

It is abundantly clear that obtaining the channel state information (CSI) is of great importance for the equalization and detection in coherence receivers. However, to the best of the authors' knowledge, in most of the existing literatures, CSI is assumed to be perfectly known at the receiver. So far, few literature discusses the effects of imperfect CSI on MDM system performance caused by channel estimation. Motivated by that, in this paper, the channel estimation in few mode fiber (FMF) mode division multiplexing (MDM) system is investigated, in which two classical channel estimation methods, i.e., least square (LS) method and minimum mean square error (MMSE) method, are discussed with the assumption of the spatially white noise lumped at the receiver side of MDM system. Both the capacity and BER performance of MDM system affected by mode-dependent gain or loss (MDL) with different channel estimation errors have been studied. Simulation results show that the capacity and BER performance can be further deteriorated in MDM system by the channel estimation, and an 1e-3 variance of channel estimation error is acceptable in MDM system with 0-6 dB MDL values.

SystemC modelling of wireless communication channel

Science.gov (United States)

Conti, Massimo; Orcioni, Simone

2011-05-01

This paper presents the definition in SystemC of wireless channels at different levels of abstraction. The different levels of description of the wireless channel can be easily interchanged allowing the reuse of the application and baseband layers in a high level analysis of the network or in a deep analysis of the communication between the wireless devices.

Isotachophoresis system having larger-diameter channels flowing into channels with reduced diameter and with selectable counter-flow

Energy Technology Data Exchange (ETDEWEB)

Mariella, Jr., Raymond P.

2018-03-06

An isotachophoresis system for separating a sample containing particles into discrete packets including a flow channel, the flow channel having a large diameter section and a small diameter section; a negative electrode operably connected to the flow channel; a positive electrode operably connected to the flow channel; a leading carrier fluid in the flow channel; a trailing carrier fluid in the flow channel; and a control for separating the particles in the sample into discrete packets using the leading carrier fluid, the trailing carrier fluid, the large diameter section, and the small diameter section.

Multi-channel data acquisition and processing system for moessbauer spectroscopy

International Nuclear Information System (INIS)

Jin Ge; Yang Yanming

1987-01-01

A multi-channel data acquisition and processing system for moessbauer spectroscopy is described, which consists of an intelligent interface and a BC3-80 microcomputer. The system has eight data channels, each channel contains a counting circuit and a memory. A Z80-CPU is used as a main unit for control and access. The microcomputer is used for real-time displaying spectrum, saving the data to disk, printing data and data processing. The system is applicable to a high counting rate multi-wire proportional chamber. It can increase greatly the counting rate for measuring moessbauer spectrum. The signals of each wire in the chamber go through a corresponding amplifier and a differential discriminator and are recorded by a corresponding data channel, the data of each channel is added by the microcomputer. In addition, two channels can be used to measure an absorption and a scattering spectrum at the same time and the internal and the surface information of the sample are obtained simultaneously

The new secondary channel control system at TRIUMF

International Nuclear Information System (INIS)

Keitel, R.; Bishop, D.; Dale, D.; England, N.; Harrison, D.

1990-01-01

The control of the secondary channels at TRIUMF has been decentralized. Each channel is now controlled through a single CAMAC crate from an IBM PC in the experimental counting room. Intelligent motor controllers were developed to replace the ageing slit control system. Advanced features of the control software package TICS, such as computer optimization of channel parameters and high-voltage conditioning of the dc separators, are described. (orig.)

Embedded system of image storage based on fiber channel

Science.gov (United States)

Chen, Xiaodong; Su, Wanxin; Xing, Zhongbao; Wang, Hualong

2008-03-01

In domains of aerospace, aviation, aiming, and optic measure etc., the embedded system of imaging, processing and recording is absolutely necessary, which has small volume, high processing speed and high resolution. But the embedded storage technology becomes system bottleneck because of developing slowly. It is used to use RAID to promote storage speed, but it is unsuitable for the embedded system because of its big volume. Fiber channel (FC) technology offers a new method to develop the high-speed, portable storage system. In order to make storage subsystem meet the needs of high storage rate, make use of powerful Virtex-4 FPGA and high speed fiber channel, advance a project of embedded system of digital image storage based on Xilinx Fiber Channel Arbitrated Loop LogiCORE. This project utilizes Virtex- 4 RocketIO MGT transceivers to transmit the data serially, and connects many Fiber Channel hard drivers by using of Arbitrated Loop optionally. It can achieve 400MBps storage rate, breaks through the bottleneck of PCI interface, and has excellences of high-speed, real-time, portable and massive capacity.

Application of a multi-channel system for continuous monitoring and an early warning system.

Science.gov (United States)

Lee, J H; Song, C H; Kim, B C; Gu, M B

2006-01-01

A multi-channel continuous toxicity monitoring system developed in our laboratory, based on two-stage mini-bioreactors, was successfully implemented in the form of computer-based data acquisition. The multi-channel system consists of a series of a two-stage minibioreactor systems connected by a fiber optic probe to a luminometer, and uses genetically engineered bioluminescent bacteria for the detection of the potential toxicity from the soluble chemicals. This system can be stably and continuously operated due to the separation of the culture reactor from the test reactor and accomplish easy and long-term monitoring without system shut down by abrupt inflows of severe polluting chemicals. Four different recombinant bioluminescent bacteria were used in different channels so that the modes of the samples toxicities can be reasonably identified and evaluated based upon the response signature of each channel. The bioluminescent signatures were delivered from four channels by switching one at once, while the data is automatically logged to an IBM compatible computer. We also achieved the enhancement of the system through the manipulation of the dilution rate and the use of thermo-lux fusion strains. Finally, this system is now being implemented to a drinking water reservoir and river for remote sensing as an early warning system.

A MHD channel study for the ETF conceptual design

Science.gov (United States)

Wang, S. Y.; Staiger, P. J.; Smith, J. M.

1981-01-01

The procedures and computations used to identify an MHD channel for a 540 mW(I) EFT-scale plant are presented. Under the assumed constraints of maximum E(x), E(y), J(y) and Beta; results show the best plant performance is obtained for active length, L is approximately 12 M, whereas in the initial ETF studies, L is approximately 16 M. As MHD channel length is reduced from 16 M, the channel enthalpy extraction falls off, slowly. This tends to reduce the MHD power output; however, the shorter channels result in lower heat losses to the MHD channel cooling water which allows for the incorporation of more low pressure boiler feedwater heaters into the system and an increase in steam plant efficiency. The net result of these changes is a net increase in the over all MHD/steam plant efficiency. In addition to the sensitivity of various channel parameters, the trade-offs between the level of oxygen enrichment and the electrical stress on the channel are also discussed.

128 Channel PCI-based data acquisition system for MDSplus

Energy Technology Data Exchange (ETDEWEB)

Llobet, Xavier E-mail: xavier.llobet@epfl.ch; Duval, Basil P. E-mail: basil.duval@epfl.ch

2002-06-01

With the increasing demand for analogue channel acquisition on the TCV tokamak, a new PCI based acquisition has been specified, designed, built and installed into our MDSplus acquisition environment. The design criteria were to not only improve the cost/channel, as compared to our conventional hub based acquisition (CAMAC), but to provide some distributed processing power to avoid the associated acquisition server saturation, both in terms of CPU and network bandwidth. These units were initially intended to satisfy the requirements of general variable rate acquisition from a variety of sources, and many channel acquisition from modern multi-channel diagnostics. Hosted by a i386-Linux PC in a crate with four available PCI slots, each single-PCI slot 32-channel digitiser features sampling frequencies up to 200 kHz, and 64 MB of memory, providing 1 Msample of 16-bit data per channel. The local hard disk is used for immediate local storage of all the acquired data from the selected channels into a local MDSplus database. The host is then accessed as a MDS/IP server that provides, on demand, down-sampled and software filtered traces. The local hard disk capacity is used for medium to long-term storage and availability of the full data set with optional mirror technology to guard against hard disk failure. We have thus obtained a general solution for high resolution, multi-channel routine acquisition using the multi-platform MDSplus environment, in which different software and hardware architectures are intelligently linked across a standard TCP/IP network. The implementation presented here uses ONLY standard components of the MDSplus environment.

128 Channel PCI-based data acquisition system for MDSplus

International Nuclear Information System (INIS)

Llobet, Xavier; Duval, Basil P.

2002-01-01

With the increasing demand for analogue channel acquisition on the TCV tokamak, a new PCI based acquisition has been specified, designed, built and installed into our MDSplus acquisition environment. The design criteria were to not only improve the cost/channel, as compared to our conventional hub based acquisition (CAMAC), but to provide some distributed processing power to avoid the associated acquisition server saturation, both in terms of CPU and network bandwidth. These units were initially intended to satisfy the requirements of general variable rate acquisition from a variety of sources, and many channel acquisition from modern multi-channel diagnostics. Hosted by a i386-Linux PC in a crate with four available PCI slots, each single-PCI slot 32-channel digitiser features sampling frequencies up to 200 kHz, and 64 MB of memory, providing 1 Msample of 16-bit data per channel. The local hard disk is used for immediate local storage of all the acquired data from the selected channels into a local MDSplus database. The host is then accessed as a MDS/IP server that provides, on demand, down-sampled and software filtered traces. The local hard disk capacity is used for medium to long-term storage and availability of the full data set with optional mirror technology to guard against hard disk failure. We have thus obtained a general solution for high resolution, multi-channel routine acquisition using the multi-platform MDSplus environment, in which different software and hardware architectures are intelligently linked across a standard TCP/IP network. The implementation presented here uses ONLY standard components of the MDSplus environment

Channel estimation for physical layer network coding systems

CERN Document Server

Gao, Feifei; Wang, Gongpu

2014-01-01

This SpringerBrief presents channel estimation strategies for the physical later network coding (PLNC) systems. Along with a review of PLNC architectures, this brief examines new challenges brought by the special structure of bi-directional two-hop transmissions that are different from the traditional point-to-point systems and unidirectional relay systems. The authors discuss the channel estimation strategies over typical fading scenarios, including frequency flat fading, frequency selective fading and time selective fading, as well as future research directions. Chapters explore the performa

Effects of the β1 auxiliary subunit on modification of Rat Na{sub v}1.6 sodium channels expressed in HEK293 cells by the pyrethroid insecticides tefluthrin and deltamethrin

Energy Technology Data Exchange (ETDEWEB)

He, Bingjun [College of Life Sciences, Nankai University, Tianjin 300071 (China); Soderlund, David M., E-mail: dms6@cornell.edu [Department of Entomology, Cornell University, Geneva, NY 14456 (United States)

2016-01-15

We expressed rat Na{sub v}1.6 sodium channels with or without the rat β1 subunit in human embryonic kidney (HEK293) cells and evaluated the effects of the pyrethroid insecticides tefluthrin and deltamethrin on whole-cell sodium currents. In assays with the Na{sub v}1.6 α subunit alone, both pyrethroids prolonged channel inactivation and deactivation and shifted the voltage dependence of channel activation and steady-state inactivation toward hyperpolarization. Maximal shifts in activation were ~ 18 mV for tefluthrin and ~ 24 mV for deltamethrin. These compounds also caused hyperpolarizing shifts of ~ 10–14 mV in the voltage dependence of steady-state inactivation and increased in the fraction of sodium current that was resistant to inactivation. The effects of pyrethroids on the voltage-dependent gating greatly increased the size of sodium window currents compared to unmodified channels; modified channels exhibited increased probability of spontaneous opening at membrane potentials more negative than the normal threshold for channel activation and incomplete channel inactivation. Coexpression of Na{sub v}1.6 with the β1 subunit had no effect on the kinetic behavior of pyrethroid-modified channels but had divergent effects on the voltage-dependent gating of tefluthrin- or deltamethrin-modified channels, increasing the size of tefluthrin-induced window currents but decreasing the size of corresponding deltamethrin-induced currents. Unexpectedly, the β1 subunit did not confer sensitivity to use-dependent channel modification by either tefluthrin or deltamethrin. We conclude from these results that functional reconstitution of channels in vitro requires careful attention to the subunit composition of channel complexes to ensure that channels in vitro are faithful functional and pharmacological models of channels in neurons. - Highlights: • We expressed Na{sub v}1.6 sodium channels with or without β1 subunits in HEK293 cells. • Tefluthrin and deltamethrin

Development of wide range charge integration application specified integrated circuit for photo-sensor

Energy Technology Data Exchange (ETDEWEB)

Katayose, Yusaku, E-mail: katayose@ynu.ac.jp [Department of Physics, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501 (Japan); Ikeda, Hirokazu [Institute of Space and Astronautical Science (ISAS)/Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Tanaka, Manobu [National Laboratory for High Energy Physics, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Shibata, Makio [Department of Physics, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501 (Japan)

2013-01-21

A front-end application specified integrated circuit (ASIC) is developed with a wide dynamic range amplifier (WDAMP) to read-out signals from a photo-sensor like a photodiode. The WDAMP ASIC consists of a charge sensitive preamplifier, four wave-shaping circuits with different amplification factors and Wilkinson-type analog-to-digital converter (ADC). To realize a wider range, the integrating capacitor in the preamplifier can be changed from 4 pF to 16 pF by a two-bit switch. The output of a preamplifier is shared by the four wave-shaping circuits with four gains of 1, 4, 16 and 64 to adapt the input range of ADC. A 0.25-μm CMOS process (of UMC electronics CO., LTD) is used to fabricate the ASIC with four-channels. The dynamic range of four orders of magnitude is achieved with the maximum range over 20 pC and the noise performance of 0.46 fC + 6.4×10{sup −4} fC/pF. -- Highlights: ► A front-end ASIC is developed with a wide dynamic range amplifier. ► The ASIC consists of a CSA, four wave-shaping circuits and pulse-height-to-time converters. ► The dynamic range of four orders of magnitude is achieved with the maximum range over 20 pC.

Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

Science.gov (United States)

Singh, D.; Linda, Sneha B.; Giri, Pankaj K.; Mahato, Amritraj; Tripathi, R.; Kumar, Harish; Afzal Ansari, M.; Sathik, N. P. M.; Ali, Rahbar; Kumar, Rakesh; Muralithar, S.; Singh, R. P.

2017-11-01

Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle-γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with 'fast' α and 2α-emission channels are found to be entirely different from fusion-evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

Directory of Open Access Journals (Sweden)

D. Singh

2017-11-01

Full Text Available Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle–γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with ‘fast’ α and 2α-emission channels are found to be entirely different from fusion–evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

Efficient channel estimation in massive MIMO systems - a distributed approach

KAUST Repository

Al-Naffouri, Tareq Y.

2016-01-01

We present two efficient algorithms for distributed estimation of channels in massive MIMO systems. The two cases of 1) generic, and 2) sparse channels is considered. The algorithms estimate the impulse response for each channel observed

Optical transmission modules for multi-channel superconducting quantum interference device readouts

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin-Mok, E-mail: jmkim@kriss.re.kr; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong [Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)

2013-12-15

We developed an optical transmission module consisting of 16-channel analog-to-digital converter (ADC), digital-noise filter, and one-line serial transmitter, which transferred Superconducting Quantum Interference Device (SQUID) readout data to a computer by a single optical cable. A 16-channel ADC sent out SQUID readouts data with 32-bit serial data of 8-bit channel and 24-bit voltage data at a sample rate of 1.5 kSample/s. A digital-noise filter suppressed digital noises generated by digital clocks to obtain SQUID modulation as large as possible. One-line serial transmitter reformed 32-bit serial data to the modulated data that contained data and clock, and sent them through a single optical cable. When the optical transmission modules were applied to 152-channel SQUID magnetoencephalography system, this system maintained a field noise level of 3 fT/√Hz @ 100 Hz.

Multiple Description Coding for Closed Loop Systems over Erasure Channels

DEFF Research Database (Denmark)

Østergaard, Jan; Quevedo, Daniel

2013-01-01

In this paper, we consider robust source coding in closed-loop systems. In particular, we consider a (possibly) unstable LTI system, which is to be stabilized via a network. The network has random delays and erasures on the data-rate limited (digital) forward channel between the encoder (controller......) and the decoder (plant). The feedback channel from the decoder to the encoder is assumed noiseless. Since the forward channel is digital, we need to employ quantization.We combine two techniques to enhance the reliability of the system. First, in order to guarantee that the system remains stable during packet...... by showing that the system can be cast as a Markov jump linear system....

ANUSANSKAR: a 16 channel frontend electronics (FEE) ASIC targeted for silicon pixel array detector based prototype Alice FOCAL

International Nuclear Information System (INIS)

Mukhopadhyay, Sourav; Chandratre, V.B.; Sukhwani, Menka; Pithawa, C.K.; Singaraju, Ramnarayan; Muhuri, Sanjib; Nayak, T.; Khan, S.A.; Saini, Jogendra

2013-01-01

ANUSANSKAR is a 16 channel pulse processing ASIC with analog multiplexed output designed in 0.7 um standard CMOS technology with each channel consisting of CSA, Semi Gaussian pulse shaper, DC cancellation and pedestal control, track and hold, output buffer blocks. The ASIC's analog multiplexed output can be read serially in daisy-chain topology. Testing, characterization and validation of ANUSANSKAR ASIC as readout for prototype ALICE forward calorimeter (FOCAL) has been carried out in PS beam line at CERN with up to 6 GeV of pion and electron beam. This paper describes the ANUSANSKAR ASIC along with the experimental results. (author)

A 16-channel receive, forced current excitation dual-transmit coil for breast imaging at 7T.

Directory of Open Access Journals (Sweden)

Samantha By

Full Text Available To enable high spatial and temporal breast imaging resolution via combined use of high field MRI, array coils, and forced current excitation (FCE multi channel transmit.A unilateral 16-channel receive array insert was designed for use in a transmit volume coil optimized for quadrature operation with dual-transmit RF shimming at 7 T. Signal-to-noise ratio (SNR maps, g-factor maps, and high spatial and temporal resolution in vivo images were acquired to demonstrate the utility of the coil architecture.The dual-transmit FCE coil provided homogeneous excitation and the array provided an increase in average SNR of 3.3 times (max 10.8, min 1.5 compared to the volume coil in transmit/receive mode. High resolution accelerated in vivo breast imaging demonstrated the ability to achieve isotropic spatial resolution of 0.5 mm within clinically relevant 90 s scan times, as well as the ability to perform 1.0 mm isotropic resolution imaging, 7 s per dynamics, with the use of bidirectional SENSE acceleration of up to R = 9.The FCE design of the transmit coil easily accommodates the addition of a sixteen channel array coil. The improved spatial and temporal resolution provided by the high-field array coil with FCE dual-channel transmit will ultimately be beneficial in lesion detection and characterization.

Transmission of Single-Channel 16-QAM Data Signals at Terabaud Symbol Rates

DEFF Research Database (Denmark)

Richter, Thomas; Palushani, Evarist; Schmidt-Langhorst, Carsten

2012-01-01

We present latest results for OTDM transmission systems in combination with digital coherent detection achieving record-high serial data rates in a single-wavelength channel. We show serial data transmission of 5.1 Tb/s (640 GBd) over 80-km and 10.2 Tb/s (1.28 TBd) over 29-km dispersion managed f...

LHC beam dumping system Extraction channel layout and acceptance

CERN Document Server

Goddard, B; Uythoven, J; Veness, R; Weterings, W

2003-01-01

The LHC beam dumping system must safely abort the LHC beams under all conditions, including those resulting from abnormal behaviour of machine elements or subsystems of the beam dumping system itself. The extraction channels must provide sufficient aperture both for the circulating and extracted beams, over the whole energy range and under various beam parameters. These requirements impose tight constraints on the tolerances of various extraction channel components, and also on the allowed range of beam positions in the region of these components. Operation of the beam dumping system under various fault states has been considered, and the resulting apertures calculated. After describing briefly the beam dumping system and the extraction channel geometry, the various assumptions made in the analysis are presented, before deriving tolerance limits for the relevant equipment and beam parameters.

Experimental studies in a single-phase parallel channel natural circulation system. Preliminary results

International Nuclear Information System (INIS)

Bodkha, Kapil; Pilkhwal, D.S.; Jana, S.S.; Vijayan, P.K.

2016-01-01

Natural circulation systems find extensive applications in industrial engineering systems. One of the applications is in nuclear reactor where the decay heat is removed by natural circulation of the fluid under off-normal conditions. The upcoming reactor designs make use of natural circulation in order to remove the heat from core under normal operating conditions also. These reactors employ multiple vertical fuel channels with provision of on-power refueling/defueling. Natural circulation systems are relatively simple, safe and reliable when compared to forced circulation systems. However, natural circulation systems are prone to encounter flow instabilities which are highly undesirable for various reasons. Presence of parallel channels under natural circulation makes the system more complicated. To examine the behavior of parallel channel system, studies were carried out for single-phase natural circulation flow in a multiple vertical channel system. The objective of the present work is to study the flow behavior of the parallel heated channel system under natural circulation for different operating conditions. Steady state and transient studies have been carried out in a parallel channel natural circulation system with three heated channels. The paper brings out the details of the system considered, different cases analyzed and preliminary results of studies carried out on a single-phase parallel channel system.

Channel Extension in Deep-Water Distributive Systems

Science.gov (United States)

Hoyal, D. C.; Sheets, B. A.

2007-12-01

acceleration to Fr'-critical conditions and the formation of a depositional hydraulic jump, which perturbs sediment transport and ends channel extension. Similar morphodynamic length scale controls are observed in shallow water fan-delta experiments (e.g., SAFL DB-03) and in 2-D depositional cyclic steps. The experiments seem to explain two interesting observations from the earlier self-organized fan experiments and from real submarine fans. Firstly, the observation of 'perched' fills at the steep entrances to salt withdrawal minibasins (e.g., in the Gulf of Mexico) suggesting higher sedimentation rates (or inefficient sediment transport) on higher slopes (initially higher than at the slope break downstream). Secondly, strong progradation as the fan evolves and slope decreases in 'perched' fans suggests increasing flow efficiency on lower slopes, at least over a certain window of parameter space. Apparently deep water systems have a tendency to self-regulate even when flows differ significantly in initial density. The observed modulation to Fr'-critical flow appears to be an important control on length scales in deep- water distributive channel systems, potentially explaining strong deepwater progradation or 'delta-like' patterns that have remained paradoxical. Near critical conditions have been inferred from observations of many active submarine fans but the extent to which these results from conservative density currents apply to non-conservative and potentially 'ignitive' turbidity currents is the subject of ongoing investigation.

A Study of an Iterative Channel Estimation Scheme of FS-FBMC System

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YongJu Won

2017-01-01

Full Text Available A filter bank multicarrier on offset-quadrature amplitude modulation (FBMC/OQAM system is an alternative multicarrier modulation scheme that does not need cyclic prefix (CP even in the presence of a multipath fading channel by the properties of prototype filter. The FBMC/OQAM system can be implemented either by using the poly-phase network with fast fourier transform (PPN-FFT or by using the extended FFT on a frequency-spreading (FS domain. In this paper, we propose an iterative channel estimation scheme for each sub channel of a FBMC/OQAM system over a frequency-spreading domain. The proposed scheme first estimates the channel using the received pilot signal in the subchannel domain and interpolates the estimated channel to fine frequency-spreading domain. Then the channel compensated FS domain pilot is despread again to modify the channel state information (CSI estimation. Computer simulation shows that the proposed method outperforms the conventional FBMC/OQAM channel estimator in a frequency selective channel.

Four-channel readout ASIC for silicon pad detectors

International Nuclear Information System (INIS)

Baturitsky, M.A.; Zamiatin, N.I.

2000-01-01

A custom front-end readout ASIC has been designed for silicon calorimeters supposed to be used in high-energy physics experiments. The ASIC was produced using BJT-JFET technology. It contains four channels of a fast low-noise charge-sensitive preamplifier (CSP) with inverting outputs summed by a linear adder (LA) followed by an RC-CR shaping amplifier (SA) with 30 ns peaking time. Availability of separate outputs of the CSPs and the LA makes it possible to join any number of silicon detector layers to obtain the longitudinal and transversal resolution required using only this ASIC in any silicon calorimeter minitower configuration. Noise performance is ENC=1800e - +18e - /pF at 30 ns peaking time for detector capacitance up to C d =400 pF. Rise time is 8 ns at input capacitance C d =100 pF. Power dissipation is less than 50 mW/ chip at voltage supply 5 V

Impact of a bone conduction communication channel on multichannel communication system effectiveness.

Science.gov (United States)

Blue, Misty; McBride, Maranda; Weatherless, Rachel; Letowski, Tomasz

2013-04-01

In this study, the impact of including a bone conduction transducer in a three-channel spatialized communication system was investigated. Several military and security forces situations require concurrent listening to three or more radio channels. In such radio systems, spatial separation between three concurrent radio channels can be achieved by delivering separate signals to the left and right earphone independently and both earphones simultaneously. This method appears to be effective; however, the use of bone conduction as one channel may provide both operational and performance benefits. Three three-channel communication systems were used to collect speech intelligibility data from 18 listeners (System I, three loudspeakers; System 2, stereo headphones; System 3, stereo headphones and a bone conduction vibrator). Each channel presented signals perceived to originate from separate locations. Volunteers listened to three sets of competing sentences and identified a number, color, and object spoken in the target sentence. Each listener participated in three trials (one per system). Each trial consisted of 48 competing sentence sets. Systems 2 and 3 were more intelligible than System I. Systems 2 and 3 were overall equally intelligible; however, the intelligibility of all three channels was significantly more balanced in System 3. Replacing an air conduction transducer with a bone conduction transducer in a multichannel audio device can provide a more effective and balanced simultaneous monitoring auditory environment. These results have important design and implementation implications for spatial auditory communication equipment.

Carbonate Channel-Levee Systems Influenced by Mass-Transport Deposition, Browse Basin, Australia

Science.gov (United States)

Dunlap, D.; Janson, X.; Sanchez-Phelps, C.; Covault, J. A.

2017-12-01

Submarine channels are primary conduits for clastic sediment transport to deep-water basins, thereby controlling the location of marine depocenters and sediment bypass. The evolution and depositional character of submarine channels have broad implications to sediment dispersal, sediment quality, and hydrocarbon exploration potential. Siliciclastic channel systems have been extensively studied in modern environments, seismic and outcrop; however, carbonate channel-levee deposits have only recently been explored. Here we utilize newly released high-resolution (90 Hz) seismic-reflection data from the Australian Browse Basin to document the influence of mass-transport complex (MTC) deposition on the stratigraphic architecture of carbonate channel-levee systems. The 2014 vintage seismic survey is 2500 km2 and hosts numerous large Miocene-age carbonate channel-levee complexes basinward of the shelf edge. Regional horizons and individual channel forms were mapped. Channels range from 200-300 m wide and are bounded by high-relief levee-overbank wedges (>100 ms TWTT). These channels extend across the survey area >70 km. The leveed-channels were sourced from middle and late Miocene slope gullies linked to platform carbonates. Slope-attached and locally derived MTC's are evident throughout the Miocene section likely related to periods of basin inversion and shelf-edge gully incision. We interpret that regionally extensive (>1000 km2) slope-attached MTC's can shut down a channel-levee system and trigger the initiation of a new system, whereas more locally derived (wasting and turbidity currents, which informs depositional models of carbonate slope systems and calls for re-evaluation of the controls on stratigraphic patterns in mixed siliciclastic-carbonate deep-water basins.

Analysis of thermal issues associated with the pre-amplifier modules in the National Ignition Facility

International Nuclear Information System (INIS)

Lam, K.L.

1998-01-01

The design of the National Ignition Facility (NIF) calls for a desired temperature field of 20.00 ± 0.28 C throughout the facility. This design requirement is needed to prevent degradation of the operating performance and net yield of the NIF by heat loads generated within the facility. In particular, the potential interference of waste heat from the lighting fixtures and equipment such as the electronics racks, and pre-amplifier modules (PAMs), and its impact on the operational performance of the laser beam transport tubes and optical alignment components must be evaluated. This report describes the thermal analyses associated with the PAMs. Evaluation of thermal issues for the other equipment is discussed elsewhere

Vision system for precision alignment of coolant channels

International Nuclear Information System (INIS)

Kar, S.; Rao, Y.V.; Valli Kumar; Joshi, D.G.; Chadda, V.K.; Nigam, R.K.; Kayal, J.N.; Panwar, S.; Sinha, R.K.

1997-01-01

This paper describes a vision system which has been developed for precision alignment of Coolant Channel Replacement Machine (CCRM) with respect to the front face of the coolant channel under repair/replacement. It has provisions for automatic as well as semi-automatic alignment. A special lighting scheme has been developed for providing illumination to the front face of the channel opening. This facilitates automatic segmentation of the digitized image. The segmented image is analysed to obtain the centre of the front face of the channel opening and thus the extent of misalignment i.e. offset of the camera with respect to the front face of the channel opening. The offset information is then communicated to the PLC to generate an output signal to drive the DC servo motors for precise positioning of the co-ordinate table. 2 refs., 5 figs

Initial angle resolved measurements of fast neutrals using a multichannel linear AXUV detector system on LHD

International Nuclear Information System (INIS)

Veshchev, E. A.; Ozaki, T.; Goncharov, P. R.; Sudo, S.

2006-01-01

A new multichannel diagnostic for fast ion distribution studies has been developed and successfully tested on the Large Helical Device (LHD) in different plasma heating conditions. The diagnostic is based on a linear array AXUV detector consisting of 20 segments, charge sensitive preamplifiers, and a set of pulse height analysis channels. The main advantage of this system is the possibility to make time, energy, and angle-resolved measurements of charge exchange neutral particles in a single plasma discharge. This feature makes the new diagnostic a very helpful and powerful tool intended to contribute to the understanding of fast ion behavior in a complex helical plasma geometry like the one of LHD

Downlink Channel Estimation in Cellular Systems with Antenna Arrays at Base Stations Using Channel Probing with Feedback

Directory of Open Access Journals (Sweden)

Biguesh Mehrzad

2004-01-01

Full Text Available In mobile communication systems with multisensor antennas at base stations, downlink channel estimation plays a key role because accurate channel estimates are needed for transmit beamforming. One efficient approach to this problem is channel probing with feedback. In this method, the base station array transmits probing (training signals. The channel is then estimated from feedback reports provided by the users. This paper studies the performance of the channel probing method with feedback using a multisensor base station antenna array and single-sensor users. The least squares (LS, linear minimum mean square error (LMMSE, and a new scaled LS (SLS approaches to the channel estimation are studied. Optimal choice of probing signals is investigated for each of these techniques and their channel estimation performances are analyzed. In the case of multiple LS channel estimates, the best linear unbiased estimation (BLUE scheme for their linear combining is developed and studied.

Channel Estimation for Filter Bank Multicarrier Systems in Low SNR Environments

Energy Technology Data Exchange (ETDEWEB)

Driggs, Jonathan; Sibbett, Taylor; Moradiy, Hussein; Farhang-Boroujeny, Behrouz

2017-05-01

Channel estimation techniques are crucial for reliable communications. This paper is concerned with channel estimation in a filter bank multicarrier spread spectrum (FBMCSS) system. We explore two channel estimator options: (i) a method that makes use of a periodic preamble and mimics the channel estimation techniques that are widely used in OFDM-based systems; and (ii) a method that stays within the traditional realm of filter bank signal processing. For the case where the channel noise is white, both methods are analyzed in detail and their performance is compared against their respective Cramer-Rao Lower Bounds (CRLB). Advantages and disadvantages of the two methods under different channel conditions are given to provide insight to the reader as to when one will outperform the other.

A portable cadmium telluride multidetector probe for cardiac function monitoring

CERN Document Server

Arntz, Y; Dumitresco, B; Eclancher, B; Prat, V

1999-01-01

A new nuclear stethoscope based on a matrix of small CdTe semiconductor detectors has been developed for studying the cardiac performance by gamma ventriculography at the equilibrium, in rest and stress conditions, in the early and recovery phases of the coronary disease and to follow the long-term therapy. The light-weight probe consists of an array of 64 detectors 5x5x2 mm grouped in 16 independent units in a lead shielded aluminum box including 16 preamplifiers. The probe is connected to an electronic box containing DC power supply, 16 channel amplifiers, discriminators and counters, two analog-triggering ECG channels, and interface to a PC. The left ventricle activity is, preferentially, detected by using a low-resolution matching convergent collimator. A physical evaluation of the probe has been performed, both with static tests and dynamically with a hydraulic home-built model of beating heart ventricle paced by a rhythm simulator. The sum of the 16 detectors activity provided a radiocardiogram (RCG) wh...

Molecular Mechanisms Underlying Renin-Angiotensin-Aldosterone System Mediated Regulation of BK Channels

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Zhen-Ye Zhang

2017-09-01

Full Text Available Large-conductance calcium-activated potassium channels (BK channels belong to a family of Ca2+-sensitive voltage-dependent potassium channels and play a vital role in various physiological activities in the human body. The renin-angiotensin-aldosterone system is acknowledged as being vital in the body's hormone system and plays a fundamental role in the maintenance of water and electrolyte balance and blood pressure regulation. There is growing evidence that the renin-angiotensin-aldosterone system has profound influences on the expression and bioactivity of BK channels. In this review, we focus on the molecular mechanisms underlying the regulation of BK channels mediated by the renin-angiotensin-aldosterone system and its potential as a target for clinical drugs.

Real space channelization for generic DBT system image quality evaluation with channelized Hotelling observer

Science.gov (United States)

Petrov, Dimitar; Cockmartin, Lesley; Marshall, Nicholas; Vancoillie, Liesbeth; Young, Kenneth; Bosmans, Hilde

2017-03-01

Digital breast tomosynthesis (DBT) is a relatively new 3D mammography technique that promises better detection of low contrast masses than conventional 2D mammography. The parameter space for DBT is large however and finding an optimal balance between dose and image quality remains challenging. Given the large number of conditions and images required in optimization studies, the use of human observers (HO) is time consuming and certainly not feasible for the tuning of all degrees of freedom. Our goal was to develop a model observer (MO) that could predict human detectability for clinically relevant details embedded within a newly developed structured phantom for DBT applications. DBT series were acquired on GE SenoClaire 3D, Giotto Class, Fujifilm AMULET Innovality and Philips MicroDose systems at different dose levels, Siemens Inspiration DBT acquisitions were reconstructed with different algorithms, while a larger set of DBT series was acquired on Hologic Dimensions system for first reproducibility testing. A channelized Hotelling observer (CHO) with Gabor channels was developed The parameters of the Gabor channels were tuned on all systems at standard scanning conditions and the candidate that produced the best fit for all systems was chosen. After tuning, the MO was applied to all systems and conditions. Linear regression lines between MO and HO scores were calculated, giving correlation coefficients between 0.87 and 0.99 for all tested conditions.

Iterative MMSE Detection for MIMO/BLAST DS-CDMA Systems in Frequency Selective Fading Channels - Achieving High Performance in Fully Loaded Systems

Science.gov (United States)

Silva, João Carlos; Souto, Nuno; Cercas, Francisco; Dinis, Rui

A MMSE (Minimum Mean Square Error) DS-CDMA (Direct Sequence-Code Division Multiple Access) receiver coupled with a low-complexity iterative interference suppression algorithm was devised for a MIMO/BLAST (Multiple Input, Multiple Output / Bell Laboratories Layered Space Time) system in order to improve system performance, considering frequency selective fading channels. The scheme is compared against the simple MMSE receiver, for both QPSK and 16QAM modulations, under SISO (Single Input, Single Output) and MIMO systems, the latter with 2Tx by 2Rx and 4Tx by 4Rx (MIMO order 2 and 4 respectively) antennas. To assess its performance in an existing system, the uncoded UMTS HSDPA (High Speed Downlink Packet Access) standard was considered.

Channel estimation in DFT-based offset-QAM OFDM systems.

Science.gov (United States)

Zhao, Jian

2014-10-20

Offset quadrature amplitude modulation (offset-QAM) orthogonal frequency division multiplexing (OFDM) exhibits enhanced net data rates compared to conventional OFDM, and reduced complexity compared to Nyquist FDM (N-FDM). However, channel estimation in discrete-Fourier-transform (DFT) based offset-QAM OFDM is different from that in conventional OFDM and requires particular study. In this paper, we derive a closed-form expression for the demultiplexed signal in DFT-based offset-QAM systems and show that although the residual crosstalk is orthogonal to the decoded signal, its existence degrades the channel estimation performance when the conventional least-square method is applied. We propose and investigate four channel estimation algorithms for offset-QAM OFDM that vary in terms of performance, complexity, and tolerance to system parameters. It is theoretically and experimentally shown that simple channel estimation can be realized in offset-QAM OFDM with the achieved performance close to the theoretical limit. This, together with the existing advantages over conventional OFDM and N-FDM, makes this technology very promising for optical communication systems.

Measurements of fusion cross sections of 16O+46,50Ti systems

International Nuclear Information System (INIS)

Liguori Neto, R.

1986-01-01

Excitation functions for complete fusion of the systems 16 O + 46,50 Ti, with50)Ti, energies near and below the Coulomb barrier, were measured. With the use of the in-beam and out of beam γ spectroscopy, the formation of the compound nucleus was experimentally detected. The fusion cross was then attained by the sum of all observed compound nucleus decay channels. The limitation and advantages of measurements methods are discussed. Theoretical analysis of the experimental results using the semi-classical barrier penetration model allowed us to obtain the fusion barrier height and radius for the studied systems. These values are in good agreement with others reported for this mass range. Using the unidimensional barrier penetration model with different nuclear potentials, describing the heavy ion interactions gave theoretical fusion cross section values systematically smaller than our measured values in the energy region below the Coulomb barrier. The introduction of the nuclear surface zero point vibrations enhances the theoretical fusion cross sections in the sub-Coulomb region, but simultaneoulsy introduces an isotopic difference in the fusion excitation functions that is not observed experimentally. The statistical model predictions for the compound nucleous decay (calculated by the CASCADE program) show reasonable agreement for the more intense decay channels. (author) [pt

Development of a Two-Channel Simultaneous Photoplethysmography Recording System

Directory of Open Access Journals (Sweden)

Kim Soon Chong

2013-09-01

Full Text Available Multi-site photoplethysmograph  (PPG recording enables researchers to study the vascular and hemodynamic  properties of human subjects. Currently, there  is  no  commercial  system  available  in  the  market  to  perform  either  one channel or multi-channel PPG recording. PPG is an optoelectronic technique that measures  changes  in  blood  volume  associated  with  cardiac  contraction.  The measurements  can  be  obtained  from  fingertips,  ear  lobes  and toes  due  to  their low absorption and high degree of vasculature. The main objective of this project is to develop a two-channel simultaneous PPG recording system to acquire PPG signals  from  two  different  physiological  sites  using  a  Nellcor  equivalent  PPG probe.  MATLAB  software  was  used  during  the  development  phase  to  ensure rapid prototyping. The experiment results show that there was no inter -channel delay in the developed two-channel PPG system. Our preliminary results show that the delays between the left and the right arm were from 4 to 12 ms in three healthy random subjects. The system is portable, powered by universal serial bus (USB and allows the user to do the PPG data acquisition in a clinical setting.

Spectral Subtraction Approach for Interference Reduction of MIMO Channel Wireless Systems

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Tomohiro Ono

2005-08-01

Full Text Available In this paper, a generalized spectral subtraction approach for reducing additive impulsive noise, narrowband signals, white Gaussian noise and DS-CDMA interferences in MIMO channel DS-CDMA wireless communication systems is investigated. The interference noise reduction or suppression is essential problem in wireless mobile communication systems to improve the quality of communication. The spectrum subtraction scheme is applied to the interference noise reduction problems for noisy MIMO channel systems. The interferences in space and time domain signals can effectively be suppressed by selecting threshold values, and the computational load with the FFT is not large. Further, the fading effects of channel are compensated by spectral modification with the spectral subtraction process. In the simulations, the effectiveness of the proposed methods for the MIMO channel DS-CDMA is shown to compare with the conventional MIMO channel DS-CDMA.

Maja Valles, Mars: A Multi-Source Fluvio-Volcanic Outflow Channel System

Science.gov (United States)

Keske, A.; Christensen, P. R.

2017-12-01

The resemblance of martian outflow channels to the channeled scablands of the Pacific Northwest has led to general consensus that they were eroded by large-scale flooding. However, the observation that many of these channels are coated in lava issuing from the same source as the water source has motivated the alternative hypothesis that the channels were carved by fluid, turbulent lava. Maja Valles is a circum-Chryse outflow channel whose origin was placed in the late Hesperian by Baker and Kochel (1979), with more recent studies of crater density variations suggesting that its formation history involved multiple resurfacing events (Chapman et al., 2003). In this study, we have found that while Maja Valles indeed host a suite of standard fluvial landforms, its northern portion is thinly coated with lava that has buried much of the older channel landforms and overprinted them with effusive flow features, such as polygons and bathtub rings. Adjacent to crater pedestals and streamlined islands are patches of dark, relatively pristine material pooled in local topographic lows that we have interpreted as ponds of lava remaining from one or more fluid lava flows that flooded the channel system and subsequently drained, leaving marks of the local lava high stand. Despite the presence of fluvial landforms throughout the valles, lava flow features exist in the northern reaches of the system alone, 500-1200 km from the channels' source. The flows can instead be traced to a collection of vents in Lunae Plaum, west of the valles. In previously studied fluvio-volcanic outflow systems, such as Athabasca Valles, the sources of the volcanic activity and fluvial activity have been indistinguishable. In contrast, Maja Valles features numerous fluvio-volcanic landforms bearing similarity to those identified in other channel systems, yet the source of its lava flows is distinct from the source of its channels. Furthermore, in the absence of any channels between the source of the lava

Numerical Investigation of Startup Instabilities in Parallel-Channel Natural Circulation Boiling Systems

Directory of Open Access Journals (Sweden)

S. P. Lakshmanan

2010-01-01

Full Text Available The behaviour of a parallel-channel natural circulation boiling water reactor under a low-pressure low-power startup condition has been studied numerically (using RELAP5 and compared with its scaled model. The parallel-channel RELAP5 model is an extension of a single-channel model developed and validated with experimental results. Existence of in-phase and out-of-phase flashing instabilities in the parallel-channel systems is investigated through simulations under equal and unequal power boundary conditions in the channels. The effect of flow resistance on Type-I oscillations is explored. For nonidentical condition in the channels, the flow fluctuations in the parallel-channel systems are found to be out-of-phase.

An eight channel low-noise CMOS readout circuit for silicon detectors with on-chip front-end FET

International Nuclear Information System (INIS)

Fiorini, C.; Porro, M.

2006-01-01

We propose a CMOS readout circuit for the processing of signals from multi-channel silicon detectors to be used in X-ray spectroscopy and γ-ray imaging applications. The circuit is composed by eight channels, each one featuring a low-noise preamplifier, a 6th-order semigaussian shaping amplifier with four selectable peaking times, from 1.8 up to 6 μs, a peak stretcher and a discriminator. The circuit is conceived to be used with silicon detectors with a front-end FET integrated on the detector chips itself, like silicon drift detectors with JFET and pixel detectors with DEPMOS. The integrated time constants used for the shaping are implemented by means of an RC-cell, based on the technique of demagnification of the current flowing in a resistor R by means of the use of current mirrors. The eight analog channels of the chip are multiplexed to a single analog output. A suitable digital section provides self-resetting of each channel and trigger output and is able to set independent thresholds on the analog channels by means of a programmable serial register and 3-bit DACs. The circuit has been realized in the 0.35 μm CMOS AMS technology. In this work, the main features of the circuit are presented along with the experimental results of its characterization

Emulation of Narrowband Powerline Data Transmission Channels and Evaluation of PLC Systems

OpenAIRE

Liu, Wenqing

2013-01-01

This work proposes advanced emulation of the physical layer behavior of NB-PLC channels and the application of a channel emulator for the evaluation of NB-PLC systems. In addition, test procedures and reference channels are proposed to improve efficiency and accuracy in the system evaluation and classification. This work shows that the channel emulator-based solution opens new ways toward flexible, reliable and technology-independent performance assessment of PLC modems.

A Robust Threshold for Iterative Channel Estimation in OFDM Systems

Directory of Open Access Journals (Sweden)

A. Kalaycioglu

2010-04-01

Full Text Available A novel threshold computation method for pilot symbol assisted iterative channel estimation in OFDM systems is considered. As the bits are transmitted in packets, the proposed technique is based on calculating a particular threshold for each data packet in order to select the reliable decoder output symbols to improve the channel estimation performance. Iteratively, additional pilot symbols are established according to the threshold and the channel is re-estimated with the new pilots inserted to the known channel estimation pilot set. The proposed threshold calculation method for selecting additional pilots performs better than non-iterative channel estimation, no threshold and fixed threshold techniques in poor HF channel simulations.

Sliding-MOMP Based Channel Estimation Scheme for ISDB-T Systems

Directory of Open Access Journals (Sweden)

Ziji Ma

2016-01-01

Full Text Available Compressive sensing based channel estimation has shown its advantage of accurate reconstruction for sparse signal with less pilots for OFDM systems. However, high computational cost requirement of CS method, due to linear programming, significantly restricts its implementation in practical applications. In this paper, we propose a reduced complexity channel estimation scheme of modified orthogonal matching pursuit with sliding windows for ISDB-T (Integrated Services Digital Broadcasting for Terrestrial system. The proposed scheme can reduce the computational cost by limiting the searching region as well as making effective use of the last estimation result. In addition, adaptive tracking strategy with sliding sampling window can improve the robustness of CS based methods to guarantee its accuracy of channel matrix reconstruction, even for fast time-variant channels. The computer simulation demonstrates its impact on improving bit error rate and computational complexity for ISDB-T system.

Bywalled plasma formation in vacuum prolonged channels

International Nuclear Information System (INIS)

Korenev, S.A.; Rubin, N.B.

1982-01-01

To produce homogeneous along the channel length plasma the application of incomplete rate-in surface dielectric discharge for generating the bywalled plasma in prolonged cylindrical channels at a pressure of the residual gas of P approximately 10 -5 Torr is proposed. Experimental set-up consisted of a pulse voltage generator and a plasma channel. The plasma channel was a coaxial system of three tubes inserted into each other. The first outer tube is made of a stainless steel, the second - of a dielectric material, the third - of smallsized stainless steel greed. It is demonstrated that the plasma being formed in the process is sufficiently homogeneous by concentration of the components, by the channel length and azimuth. The length of the experimental channel under investigation was 1.6 m, its diameter amounted 0.05 m. The maximum concentration of electron component was 10 17 m -3

Pricing strategy in a dual-channel and remanufacturing supply chain system

Science.gov (United States)

Jiang, Chengzhi; Xu, Feng; Sheng, Zhaohan

2010-07-01

This article addresses the pricing strategy problems in a supply chain system where the manufacturer sells original products and remanufactured products via indirect retailer channels and direct Internet channels. Due to the complexity of that system, agent technologies that provide a new way for analysing complex systems are used for modelling. Meanwhile, in order to reduce the computational load of searching procedure for optimal prices and profits, a learning search algorithm is designed and implemented within the multi-agent supply chain model. The simulation results show that the proposed model can find out optimal prices of original products and remanufactured products in both channels, which lead to optimal profits of the manufacturer and the retailer. It is also found that the optimal profits are increased by introducing direct channel and remanufacturing. Furthermore, the effect of customer preference, direct channel cost and remanufactured unit cost on optimal prices and profits are examined.

Linearity enhancement design of a 16-channel low-noise front-end readout ASIC for CdZnTe detectors

International Nuclear Information System (INIS)

Zeng, Huiming; Wei, Tingcun; Wang, Jia

2017-01-01

A 16-channel front-end readout application-specific integrated circuit (ASIC) with linearity enhancement design for cadmium zinc telluride (CdZnTe) detectors is presented in this paper. The resistors in the slow shaper are realized using a high-Z circuit to obtain constant resistance value instead of using only a metal–oxide–semiconductor (MOS) transistor, thus the shaping time of the slow shaper can be kept constant for different amounts of input energies. As a result, the linearity of conversion gain is improved significantly. The ASIC was designed and fabricated in a 0.35 µm CMOS process with a die size of 2.60 mm×3.53 mm. The tested results show that a typical channel provides an equivalent noise charge (ENC) of 109.7e − +16.3e − /pF with a power consumption of 4 mW and achieves a conversion gain of 87 mV/fC with a nonlinearity of <0.4%. The linearity of conversion gain is improved by at least 86.6% as compared with the traditional approaches using the same front-end readout architecture and manufacture process. Moreover, the inconsistency among channels is <0.3%. An energy resolution of 2.975 keV (FWHM) for gamma rays of 59.5 keV was measured by connecting the ASIC to a 5 mm×5 mm ×2 mm CdZnTe detector at room temperature. The front-end readout ASIC presented in this paper achieves an outstanding linearity performance without compromising the noise, power consumption, and chip size performances.

Linearity enhancement design of a 16-channel low-noise front-end readout ASIC for CdZnTe detectors

Energy Technology Data Exchange (ETDEWEB)

Zeng, Huiming; Wei, Tingcun, E-mail: weitc@nwpu.edu.cn; Wang, Jia

2017-03-01

A 16-channel front-end readout application-specific integrated circuit (ASIC) with linearity enhancement design for cadmium zinc telluride (CdZnTe) detectors is presented in this paper. The resistors in the slow shaper are realized using a high-Z circuit to obtain constant resistance value instead of using only a metal–oxide–semiconductor (MOS) transistor, thus the shaping time of the slow shaper can be kept constant for different amounts of input energies. As a result, the linearity of conversion gain is improved significantly. The ASIC was designed and fabricated in a 0.35 µm CMOS process with a die size of 2.60 mm×3.53 mm. The tested results show that a typical channel provides an equivalent noise charge (ENC) of 109.7e{sup −}+16.3e{sup −}/pF with a power consumption of 4 mW and achieves a conversion gain of 87 mV/fC with a nonlinearity of <0.4%. The linearity of conversion gain is improved by at least 86.6% as compared with the traditional approaches using the same front-end readout architecture and manufacture process. Moreover, the inconsistency among channels is <0.3%. An energy resolution of 2.975 keV (FWHM) for gamma rays of 59.5 keV was measured by connecting the ASIC to a 5 mm×5 mm ×2 mm CdZnTe detector at room temperature. The front-end readout ASIC presented in this paper achieves an outstanding linearity performance without compromising the noise, power consumption, and chip size performances.

Study on the influence of supplying compressed air channels and evicting channels on pneumatical oscillation systems for vibromooshing

Science.gov (United States)

Glăvan, D. O.; Radu, I.; Babanatsas, T.; Babanatis Merce, R. M.; Kiss, I.; Gaspar, M. C.

2018-01-01

The paper presents a pneumatic system with two oscillating masses. The system is composed of a cylinder (framework) with mass m1, which has a piston with mass m2 inside. The cylinder (framework system) has one supplying channel for compressed air and one evicting channel for each work chamber (left and right of the piston). Functionality of the piston position comparatively with the cylinder (framework) is possible through the supplying or evicting of compressed air. The variable force that keeps the movement depends on variation of the pressure that is changing depending on the piston position according to the cylinder (framework) and to the section form that is supplying and evicting channels with compressed air. The paper presents the physical model/pattern, the mathematical model/pattern (differential equations) and numerical solution of the differential equations in hypothesis with the section form of supplying and evicting channels with compressed air is rectangular (variation linear) or circular (variation nonlinear).

Evaluation of correlated digital back propagation and extended Kalman filtering for non-linear mitigation in PM-16-QAM WDM systems

Science.gov (United States)

Pakala, Lalitha; Schmauss, Bernhard

2017-01-01

We investigate the individual and combined performance of correlated digital back propagation (CDBP) and extended Kalman filtering (EKF) in mitigating inter and intra-channel non-linearities in wavelength division multiplexed (WDM) systems. The afore-mentioned algorithms are verified through numerical simulations on 28 Gbaud polarization multiplexed (PM) 16-quadrature amplitude modulation (16-QAM) 9-channel WDM system with 50 GHz spacing. A single channel CDBP with one-step-per-span based on asymmetric split step Fourier method (A-SSFM) with optimized non-linear coefficient has been employed. We also study an amplitude dependent optimization (AO) of the non-linear coefficient for CDBP which shows an improvement of ≍ 0.8 dB compared to the conventional optimized CDBP, in the non-linear regime. Moreover, our proposed carrier phase and amplitude noise estimation (CPANE) algorithm based on EKF outperforms AO-CDBP in both linear and non-linear regimes with an enhanced performance besides significantly reduced complexity. We further investigate the combined performance of AO-CDBP and EKF which results in an enhanced non-linear tolerance at the expense of increased computational cost trading off to the number of required CDBP steps per span. Furthermore, we also analyze the impact of cross phase modulation (XPM) on the combined performance of AO-CDBP and EKF by varying the number of WDM channels. Numerical results show that the obtained gain from employing AO-CDBP prior to EKF reduces with increasing effects of XPM. Additionally, we also discuss the computational complexity of the aforementioned algorithms.

Channel Access Algorithm Design for Automatic Identification System

Institute of Scientific and Technical Information of China (English)

Oh Sang-heon; Kim Seung-pum; Hwang Dong-hwan; Park Chan-sik; Lee Sang-jeong

2003-01-01

The Automatic Identification System (AIS) is a maritime equipment to allow an efficient exchange of the navigational data between ships and between ships and shore stations. It utilizes a channel access algorithm which can quickly resolve conflicts without any intervention from control stations. In this paper, a design of channel access algorithm for the AIS is presented. The input/output relationship of each access algorithm module is defined by drawing the state transition diagram, dataflow diagram and flowchart based on the technical standard, ITU-R M.1371. In order to verify the designed channel access algorithm, the simulator was developed using the C/C++ programming language. The results show that the proposed channel access algorithm can properly allocate transmission slots and meet the operational performance requirements specified by the technical standard.

Tissue P Systems With Channel States Working in the Flat Maximally Parallel Way.

Science.gov (United States)

Song, Bosheng; Perez-Jimenez, Mario J; Paun, Gheorghe; Pan, Linqiang

2016-10-01

Tissue P systems with channel states are a class of bio-inspired parallel computational models, where rules are used in a sequential manner (on each channel, at most one rule can be used at each step). In this work, tissue P systems with channel states working in a flat maximally parallel way are considered, where at each step, on each channel, a maximal set of applicable rules that pass from a given state to a unique next state, is chosen and each rule in the set is applied once. The computational power of such P systems is investigated. Specifically, it is proved that tissue P systems with channel states and antiport rules of length two are able to compute Parikh sets of finite languages, and such P systems with one cell and noncooperative symport rules can compute at least all Parikh sets of matrix languages. Some Turing universality results are also provided. Moreover, the NP-complete problem SAT is solved by tissue P systems with channel states, cell division and noncooperative symport rules working in the flat maximally parallel way; nevertheless, if channel states are not used, then such P systems working in the flat maximally parallel way can solve only tractable problems. These results show that channel states provide a frontier of tractability between efficiency and non-efficiency in the framework of tissue P systems with cell division (assuming P ≠ NP ).

In-service communication channel sensing based on reflectometry for TWDM-PON systems

Science.gov (United States)

Iida, Daisuke; Kuwano, Shigeru; Terada, Jun

2014-05-01

Many base stations are accommodated in TWDM-PON based mobile backhaul and fronthaul networks for future radio access, and failed connections in an optical network unit (ONU) wavelength channel severely degrade system performance. A cost effective in-service ONU wavelength channel monitor is essential to ensure proper system operation without failed connections. To address this issue we propose a reflectometry-based remote sensing method that provides wavelength channel information with the optical line terminal (OLT)-ONU distance. The method realizes real-time monitoring of ONU wavelength channels without signal quality degradation. Experimental results show it achieves wavelength channel distinction with high distance resolution.

H∞ Channel Estimation for DS-CDMA Systems: A Partial Difference Equation Approach

Directory of Open Access Journals (Sweden)

Wei Wang

2013-01-01

Full Text Available In the communications literature, a number of different algorithms have been proposed for channel estimation problems with the statistics of the channel noise and observation noise exactly known. In practical systems, however, the channel parameters are often estimated using training sequences which lead to the statistics of the channel noise difficult to obtain. Moreover, the received signals are corrupted not only by the ambient noises but also by multiple-access interferences, so the statistics of observation noises is also difficult to obtain. In this paper, we will investigate the H∞ channel estimation problem for direct-sequence code-division multiple-access (DS-CDMA communication systems with time-varying multipath fading channels. The channel estimator is designed by applying a partial difference equation approach together with the innovation analysis theory. This method can give a sufficient and necessary condition for the existence of an H∞ channel estimator.

Perancangan Penguat Awal Menggunakan Tabung Hampa Pada Aras Tegangan Rendah

Directory of Open Access Journals (Sweden)

Matias H.W. Budhiantho

2015-03-01

Full Text Available Vacuum tube amplifiers have been known as softly-cliping audio amplifiers, as opposed to solid-state based amplifiers which exhibit hard-cliping properties. However, vacuum tubes are operated in high voltage level. Meanwhile, in order to work in low voltage level, a vacuum tube amplifier must employ step down transformers that leads to complexity. This study aims to make use of vacuum tubes in a pre-amplifier working on 12 VDC level. First, several measurements were done to obtain graphics of characteristic of triode 12AT7 in low voltage level. Common-cathode topology was cascaded with a common-anode topology to realize such amplifier. The results show that the preamplifier has an input impedance of 1.11 MΩ, output impedance of 3.5 kΩ for the right channel and 3.2 kΩ for the left channel. Maximum Total Harmonic Distortion of 1.7% occurs on frequency of 4 kHz. Voltage gains of 20.08 dB and 20 dB were obtained for the right and left channels, respectively. This pre-amplifier also shows sensitivity of 212 mVrms, maximum output level of 2 Vrms, and relatively flat frequency response within 60 Hz–20 kHz with ripple of ± 0.5dB. This pre-amplifier can be alternatively used in two modes, namely linear mode and distorted mode.

CFO and channel estimation for MISO-OFDM systems

KAUST Repository

Ladaycia, Abdelhamid

2017-11-02

This study deals with the joint channel and carrier frequency offset (CFO) estimation in a Multiple Input Single Output (MISO) communications system. This problem arises in OFDM (Orthogonal Frequency Division Multiplexing) based multi-relay transmission protocols such that the geo-routing one proposed by A. Bader et al in 2012. Indeed, the outstanding performance of this multi-hop relaying scheme relies heavily on the channel and CFO estimation quality at the PHY layer. In this work, two approaches are considered: The first is based on estimating the overall channel (including the CFO) as a time-varying one using an adaptive scheme under the assumption of small or moderate CFOs while the second one performs separately, the channel and CFO parameters estimation based on the considered data model. The two solutions are analyzed and compared in terms of performance, cost and convergence rate.

MODEL OF CHANNEL AIRBORN ELECTRICAL POWER SYSTEM

Directory of Open Access Journals (Sweden)

A. G. Demchenko

2014-01-01

Full Text Available This article is devoted to math modeling of channel of alternate current airborne electrical power-supply system. Considered to modeling of synchronous generator that runs on three-phase static load.

Compensation of the detector capacitance presented to charge-sensitive preamplifiers using the Miller effect

Energy Technology Data Exchange (ETDEWEB)

Kwon, Inyong, E-mail: iykwon@umich.edu [University of Michigan, Ann Arbor, MI (United States); Kang, Taehoon, E-mail: thnkang@umich.edu [University of Michigan, Ann Arbor, MI (United States); Wells, Byron T., E-mail: wells@galtresearch.com [Galt LLC, Ypsilanti, MI (United States); D’Aries, Lawrence J., E-mail: lawrence.j.daries.civ@mail.mil [Picatinny Arsenal, Rockaway Township, NJ (United States); Hammig, Mark D., E-mail: hammig@umich.edu [University of Michigan, Ann Arbor, MI (United States)

2015-06-01

This paper describes an integrated circuit design for a modified charge-sensitive amplifier (CSA) that compensates for the effect of capacitance presented by nuclear radiation detectors and other sensors. For applications that require large area semiconductor detectors or for those semiconductor sensors derived from high permittivity materials such as PbSe, the detector capacitance can degrade the system gain and bandwidth of a front-end preamplifier, resulting in extended rise times and attenuated output voltage signals during pulse formation. In order to suppress the effect of sensor capacitance, we applied a bootstrap technique into a traditional CSA. The technique exploits the Miller effect by reducing the effective voltage difference between the two sides of a radiation detector which minimizes the capacitance presented to the differential common-source amplifier. This new configuration is successfully designed to produce effective gain even at high detector capacitance. The entire circuit, including a core CSA with feedback components and a bootstrap amplifier, are implemented in a 0.18 μm CMOS process with a 3.3 V supply voltage. - Highlights: • A modified CSA was implemented for detector capacitance compensation. • Increasing detector capacitance degrades gain and rise time. • A bootstrap amplifier exploiting the Miller effect is described. • It allows using large area radiation sensors for high radiation-interaction rates. • Intensive noise analyses show that SNR is much better with the technique.

A virtually blind spectrum efficient channel estimation technique for mimo-ofdm system

International Nuclear Information System (INIS)

Ullah, M.O.

2015-01-01

Multiple-Input Multiple-Output antennas in conjunction with Orthogonal Frequency-Division Multiplexing is a dominant air interface for 4G and 5G cellular communication systems. Additionally, MIMO- OFDM based air interface is the foundation for latest wireless Local Area Networks, wireless Personal Area Networks, and digital multimedia broadcasting. Whether it is a single antenna or a multi-antenna OFDM system, accurate channel estimation is required for coherent reception. Training-based channel estimation methods require multiple pilot symbols and therefore waste a significant portion of channel bandwidth. This paper describes a virtually blind spectrum efficient channel estimation scheme for MIMO-OFDM systems which operates well below the Nyquist criterion. (author)

Performance Analysis of Simple Channel Feedback Schemes for a Practical OFDMA System

DEFF Research Database (Denmark)

Pedersen, Klaus, I.; Kolding, Troels; Kovacs, Istvan

2009-01-01

In this paper, we evaluate the tradeoff between the amount of uplink channel feedback information and the orthogonal frequency-division multiple access (OFDMA) downlink performance with opportunistic frequency-domain packet scheduling. Three candidate channel feedback schemes are investigated......, including practical aspects, such as the effects of terminal measurement errors, bandwidth measurement granularity, quantization, and uplink signaling delays. The performance is evaluated by means of system-level simulations with detailed modeling of various radio resource-management algorithms, etc. Our...... results show that the optimal tradeoff between the channel feedback and the downlink OFDMA system performance depends on the radio channel frequency coherence bandwidth. We conclude that the so-called average best-M scheme is the most attractive channel feedback solution, where only the average channel...

Measurements of fusion cross sections of the 16O+46,50Ti systems

International Nuclear Information System (INIS)

Liguori Neto, R.

1986-01-01

Excitation functions for complete fusion of the systems 16 O + 46,50 Ti, with energies near and below the Coulomb barrier, were measured. With the use of the in-beam and out of beam γ spectroscopy, the formation of the compound nucleus was experimentally detected. The fusion cross section was then attained by the sum of all observed compound nucleus decay channels. The limitation and advantages of measurements methods are discussed. Theoretical analysis of the experimental results using the semi-classical barrier penetration model allowed us to obtain the fusion barrier height and radius for the studied systems. These values are in good agreement with others reported for this mass range. Using the unidimensional barrier penetration model with different nuclear potentials, describing the heavy ion interactions gave theoretical fusion cross section values systematically smaller than our measured values in the energy region below the Coulomb barrier. The introduction of the nuclear surface zero point vibrations enhances the theoretical fusion cross sections in the sub-Coulomb region, but simultaneously introduces an isotopic difference in the fusion excitation functions that is not observed experimentally. The statistical model predictions for the compound nucleus decay (calculated by the CASCADE program) show reasonable agreement for the more intense decay channels [pt

A large 2D PSD for thermal neutron detection

International Nuclear Information System (INIS)

Knott, R.B.; Watt, G.; Boldeman, J.W.; Smith, G.C.

1996-01-01

A 2D PSD based on a MWPC has been constructed for a small angle neutron scattering instrument. The active area of the detector was 640 x 640 mm 2 . To meet the specifications for neutron detection efficiency and spatial resolution, and to minimize parallax, the gas mixture was 190 kPa 3 He plus 100 kPa CF 4 and the active volume had a thickness of 30 mm. The design maximum neutron count-rate of the detector was 10 5 events per second. The (calculated) neutron detection efficiency was 60% for 2 angstrom neutrons and the (measured) neutron energy resolution on the anode grid was typically 20% (fwhm). The location of a neutron detection event within the active area was determined using the wire-by-wire method: the spatial resolution (5 x 5 mm 2 ) was thereby defined by the wire geometry. A 16 channel charge-sensitive preamplifier/amplifier/comparator module has been developed with a channel sensitivity of 0.1 V/fC, noise linewidth of 0.4 fC (fwhm) and channel-to-channel cross-talk of less than 5%. The Proportional Counter Operating System (PCOS III) (LeCroy Corp USA) was used for event encoding. The ECL signals produced by the 16 channel modules were latched in PCOS III by a trigger pulse from the anode and the fast encoders produce a position and width for each event. The information was transferred to a UNIX workstation for accumulation and online display

PERFORMANCE ANALYSIS OF PILOT BASED CHANNEL ESTIMATION TECHNIQUES IN MB OFDM SYSTEMS

Directory of Open Access Journals (Sweden)

M. Madheswaran

2011-12-01

Full Text Available Ultra wideband (UWB communication is mainly used for short range of communication in wireless personal area networks. Orthogonal Frequency Division Multiplexing (OFDM is being used as a key physical layer technology for Fourth Generation (4G wireless communication. OFDM based communication gives high spectral efficiency and mitigates Inter-symbol Interference (ISI in a wireless medium. In this paper the IEEE 802.15.3a based Multiband OFDM (MB OFDM system is considered. The pilot based channel estimation techniques are considered to analyze the performance of MB OFDM systems over Liner Time Invariant (LTI Channel models. In this paper, pilot based Least Square (LS and Least Minimum Mean Square Error (LMMSE channel estimation technique has been considered for UWB OFDM system. In the proposed method, the estimated Channel Impulse Responses (CIRs are filtered in the time domain for the consideration of the channel delay spread. Also the performance of proposed system has been analyzed for different modulation techniques for various pilot density patterns.

Channel Estimation and Optimal Power Allocation for a Multiple-Antenna OFDM System

Directory of Open Access Journals (Sweden)

Yao Kung

2002-01-01

Full Text Available We propose combining channel estimation and optimal power allocation approaches for a multiple-antenna orthogonal frequency division multiplexing (OFDM system in high-speed transmission applications. We develop a least-square channel estimation approach, derive the performance bound of the estimator, and investigate the optimal training sequences for initial channel acquisition. Based on the channel estimates, the optimal power allocation solution which maximizes the bandwidth efficiency is derived under power and quality of service (Qos (symbol error rate constraints. It is shown that combining channel tracking and adaptive power allocation can dramatically enhance the outage capacity of an OFDM multiple-antenna system when severing fading occurs.

A Wideband Channel Model for Intravehicular Nomadic Systems

Directory of Open Access Journals (Sweden)

François Bellens

2011-01-01

Full Text Available The increase in electronic entertainment equipments within vehicles has rendered the idea of replacing the wired links with intra-vehicle personal area networks. Ultra-wideband (UWB seems an appropriate candidate technology to meet the required data rates for interconnecting such devices. In particular, the multiband OFDM (MB-OFDM is able to provide very high transfer rates (up to 480 MBps over relatively short distances and low transmit power. In order to evaluate the performances of UWB systems within vehicles, a reliable channel model is needed. In this paper, a nomadic system where a base station placed in the center of the dashboard wants to communicate with fixed devices placed at the rear seat is investigated. A single-input single-output (SISO channel model for intra-vehicular communication (IVC systems is proposed, based on reverberation chamber theory. The model is based on measurements conducted in real traffic conditions, with a varying number of passengers in the car. Temporal variations of the wireless channels are also characterized and parametrized. The proposed model is validated by comparing model-independent statistics with the measurements.

Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

Science.gov (United States)

Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

2018-03-01

In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 μΦ_0/Hz^{1/2}.

46 CFR 16.500 - Management Information System requirements.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Management Information System requirements. 16.500 Section 16.500 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING Management Information System § 16.500 Management Information System requirements. (a...

A multi-channel humidity control system based on LabVIEW

International Nuclear Information System (INIS)

Zhang Aiwu; Xie Yuguang; Liu Hongbang; Liu Yingbiao; Cai Xiao; Yu Boxiang; Lu Junguang; Zhou Li

2011-01-01

A real time multi-channel humidity control system was designed based on LabVIEW, using the dry air branch of BESⅢ drying system. The hardware of this control system consist of mini humidity and temperature sensors, intelligent collection module, switch quantity controller and electromagnetic valves. The humidity can be controlled at arbitrary value from air humidity to 3% with accuracy better than 2%. Multi microenvironment with different humidity can be easily controlled and monitored in real time by this system. It can also be extended to hybrid control of multi channel humidity and temperature. (authors)

16 CFR 1203.16 - Dynamic strength of retention system test.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Dynamic strength of retention system test.... (2) The retention system strength test equipment shall consist of a dynamic impact apparatus that... stirrup. (2) Mark the pre-test position of the retention system, with the entire dynamic test apparatus...

Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels

Directory of Open Access Journals (Sweden)

Salam A. Zummo

2009-02-01

Full Text Available We study the effect of interference on the performance of coded FHSS systems. This is achieved by modeling the physical channel in these systems as a block fading channel. In the derivation of the bit error probability over Nakagami fading channels, we use the exact statistics of the multiple access interference (MAI in FHSS systems. Due to the mathematically intractable expression of the Rician distribution, we use the Gaussian approximation to derive the error probability of coded FHSS over Rician fading channel. The effect of pilot-aided channel estimation is studied for Rician fading channels using the Gaussian approximation. From this, the optimal hopping rate in coded FHSS is approximated. Results show that the performance loss due to interference increases as the hopping rate decreases.

Multi-channel integrated circuits for the detection and measurement of ionizing radiation

International Nuclear Information System (INIS)

Engel, G.L.; Duggireddi, N.; Vangapally, V.; Elson, J.M.; Sobotka, L.G.; Charity, R.J.

2011-01-01

The Integrated Circuits (IC) Design Research Laboratory at Southern Illinois University Edwardsville (SIUE) has collaborated with the Nuclear Reactions Group at Washington University (WU) to develop a family of multi-channel integrated circuits. To date, the collaboration has successfully produced two micro-chips. The first was an analog shaped and peak sensing chip with on-board constant-fraction discriminators and sparsified readout. This chip is known as Heavy-Ion Nuclear Physics-16 Channel (HINP16C). The second chip, christened PSD8C, was designed to logically complement (in terms of detector types) the HINP16C chip. Pulse Shape Discrimination-8 Channel (PSD8C), featuring three settable charge integration windows per channel, performs pulse shape discrimination (PSD). This paper summarizes the design, capabilities, and features of the HINP16C and PSD8C ICs. It proceeds to discuss the modifications, made to the ICs and their associated systems, which have attempted to improve ease of use, increase performance, and extend capabilities. The paper concludes with a brief discussion of what may be the next chip (employing a multi-sampling scheme) to be added to our CMOS ASIC 'tool box' for radiation detection instrumentation.

Efficient channel estimation in massive MIMO systems - a distributed approach

KAUST Repository

Al-Naffouri, Tareq Y.

2016-01-21

We present two efficient algorithms for distributed estimation of channels in massive MIMO systems. The two cases of 1) generic, and 2) sparse channels is considered. The algorithms estimate the impulse response for each channel observed by the antennas at the receiver (base station) in a coordinated manner by sharing minimal information among neighboring antennas. Simulations demonstrate the superior performance of the proposed methods as compared to other methods.

Information-guided communications in MIMO systems with channel state impairments

KAUST Repository

Yang, Yuli

2013-06-20

Information-guided channel hopping (IGCH) is a promising technique for high-data-rate communications using multiple antennas for information mapping at the transmitter and optional antenna diversity at the receiver. Compared with some popular multi-antenna techniques, the advantage of this scheme is proven in ideal channel conditions, where the channel is spatially white and the perfect channel state information is assumed available at the receiver. The main objective of this paper is to present an information theoretical study on IGCH in realistic propagation environments with channel degeneracy due to spatial correlation and keyhole phenomena as well as imperfect channel estimation. It is proven that good performance promised by IGCH can be achieved in a variety of non-ideal channel conditions. Moreover, the analysis in this paper provides a convenient tool for the corresponding system design in practical operating environments. © 2013 John Wiley & Sons, Ltd.

Information-guided communications in MIMO systems with channel state impairments

KAUST Repository

Yang, Yuli; Aï ssa, Sonia

2013-01-01

Information-guided channel hopping (IGCH) is a promising technique for high-data-rate communications using multiple antennas for information mapping at the transmitter and optional antenna diversity at the receiver. Compared with some popular multi-antenna techniques, the advantage of this scheme is proven in ideal channel conditions, where the channel is spatially white and the perfect channel state information is assumed available at the receiver. The main objective of this paper is to present an information theoretical study on IGCH in realistic propagation environments with channel degeneracy due to spatial correlation and keyhole phenomena as well as imperfect channel estimation. It is proven that good performance promised by IGCH can be achieved in a variety of non-ideal channel conditions. Moreover, the analysis in this paper provides a convenient tool for the corresponding system design in practical operating environments. © 2013 John Wiley & Sons, Ltd.

Channel Formation in Physical Experiments: Examples from Deep and Shallow Water Clastic Sedimentary Systems

Science.gov (United States)

Hoyal, D. C.; Sheets, B. A.

2005-12-01

The degree to which experimental sedimentary systems form channels has an important bearing on their applicability as analogs of large-scale natural systems, where channels and their associated landforms are ubiquitous. The internal geometry and properties (e.g., grain size, vertical succession and stacking) of many depositional landforms can be directly linked to the processes of channel initiation and evolution. Unfortunately, strong self-channelization, a prerequisite for certain natural phenomena (e.g. mouth lobe development, meandering, etc.), has been difficult to reproduce at laboratory scales. In shallow-water experiments (sub-aerial), although weak channelization develops relatively easily, as is commonly observed in gutters after a rain storm, strong channelization with well-developed banks has proved difficult to model. In deep water experiments the challenge is even greater. Despite considerable research effort experimental conditions for deep water channel initiation have only recently been identified. Experiments on the requisite conditions for channelization in shallow and deep water have been ongoing at the ExxonMobil Upstream Research Company (EMURC) for several years. By primarily manipulating the cohesiveness of the sediment supply we have developed models of distributive systems with well-defined channels in shallow water, reminiscent of fine grained river-dominated deltas like the Mississippi. In deep water we have developed models that demonstrate strong channelization and associated lobe behavior in a distributive setting, by scaling up an approach developed by another group using salt-water flows and low-density plastic sediment. The experiments highlight a number of important controls on experimental channel formation, including: (1) bed strength or cohesiveness; (2) bedform development; and (3) Reynolds number. Among these controls bed forms disrupt the channel forming instability, reducing the energy available for channelization. The

Inhibition of transmembrane member 16A calcium-activated chloride channels by natural flavonoids contributes to flavonoid anticancer effects.

Science.gov (United States)

Zhang, Xuan; Li, Honglin; Zhang, Huiran; Liu, Yani; Huo, Lifang; Jia, Zhanfeng; Xue, Yucong; Sun, Xiaorun; Zhang, Wei

2017-07-01

Natural flavonoids are ubiquitous in dietary plants and vegetables and have been proposed to have antiviral, antioxidant, cardiovascular protective and anticancer effects. Transmembrane member 16A (TMEM16A)-encoded Ca 2+ -activated Cl - channels play a variety of physiological roles in many organs and tissues. Overexpression of TMEM16A is also believed to be associated with cancer progression. Therefore, inhibition of TMEM16A current may be a potential target for cancer therapy. In this study, we screened a broad spectrum of flavonoids for their inhibitory activities on TMEM16A currents. A whole-cell patch technique was used to record the currents. The BrdU assay and transwell technique were used to investigate cell proliferation and migration. At a concentration of 100 μM, 10 of 20 compounds caused significant (>50%) inhibition of TMEM16A currents. The four most potent compounds - luteolin, galangin, quercetin and fisetin - had IC 50 values ranging from 4.5 to 15 μM). To examine the physiological relevance of these findings, we also studied the effects of these flavonoids on endogenous TMEM16A currents in addition to cell proliferation and migration in LA795 cancer cells. Among the flavonoids tested, we detected a highly significant correlation between TMEM16A current inhibition and cell proliferation or reduction of migration. This study demonstrates that flavonoids inhibit TMEM16A currents and suggests that flavonoids could have anticancer effects via this mechanism. © 2017 The British Pharmacological Society.

Practical and Simple Wireless Channel Models for Use in Multipolarized Antenna Systems

Directory of Open Access Journals (Sweden)

KwangHyun Jeon

2014-01-01

Full Text Available The next-generation wireless systems are expected to support data rates of more than 100 Mbps in outdoor environments. In order to support such large payloads, a polarized antenna may be employed as one of the candidate technologies. Recently, the third generation partnership standards bodies (3GPP/3GPP2 have defined a cross-polarized channel model in SCM-E for MIMO systems; however, this model is quite complex since it considers a great many channel-related parameters. Furthermore, the SCM-E channel model combines the channel coefficients of all the polarization links into one complex output, making it impossible to exploit the MIMO spatial multiplexing or diversity gains in the case of employing polarized antenna at transmitter and receiver side. In this paper, we present practical and simple 2D and 3D multipolarized multipath channel models, which take into account both the cross-polarization discrimination (XPD and the Rician factor. After verifying the proposed channel models, the BER and PER performances and throughput using the EGC and MRC combining techniques are evaluated in multipolarized antenna systems.

Multi-channel medical imaging system

Science.gov (United States)

Frangioni, John V

2013-12-31

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remain in the subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may provide an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide used to capture images. The system may be configured for use in open surgical procedures by providing an operating area that is closed to ambient light. The systems described herein provide two or more diagnostic imaging channels for capture of multiple, concurrent diagnostic images and may be used where a visible light image may be usefully supplemented by two or more images that are independently marked for functional interest.

Sensitive pre-amplifier to load for Pin diodes; Pre-amplificador sensible a carga para diodos PIN

Energy Technology Data Exchange (ETDEWEB)

Jacobo V, R. Y.; Hernandez D, V. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Ramirez J, F. J., E-mail: yoshimarv@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2013-10-15

The electronic instrumentation is indispensable for the measurement and characterization of the radiation. By means of this essential characteristics of the radiation are determined, as activity and their energy components. The nuclear instrumentation is based on the technical characteristics of the radiation detectors and the electronic devices associates (amplifiers, ana logical and digital converters, multichannel analyzers, etc.) The radiation detectors are very important instruments in fields as the nuclear physics, medicine, radiological protection, industry and in other fields, since they are the only method to capture the radiation and to be able to quantify it in precise form. To detect radiation diverse detector types are used, as the semiconductor type, inside them are the photodiodes type Pin. In this work the results that were obtained of the design, simulation, construction and tests of a preamplifier that was designed starting from a photodiode type Pin are presented. The system was designed and simulated with a program for electronic circuits, in this were carried out many tests being obtained a compact design and achieving the best necessary characteristics for its optimization. With the results of the simulation phase the electronics phase was built, which was couples to a spectroscopic amplifier and a multichannel analyzer. The total of the system was evaluated analyzing its performance before a triple source of alphas. Of the tests phase we find that the system allows obtaining, in a multichannel analyzer, the pulses height spectrum, with a good resolution and with this was calibrated the multichannel analyzer.

Phase-Type Models of Channel-Holding Times in Cellular Communication Systems

DEFF Research Database (Denmark)

Christensen, Thomas Kaare; Nielsen, Bo Friis; Iversen, Villy Bæk

2004-01-01

In this paper, we derive the distribution of the channel-holding time when both cell-residence and call-holding times are phase-type distributed. Furthermore, the distribution of the number of handovers, the conditional channel-holding time distributions, and the channel-holding time when cell re...... residence times are correlated are derived. All distributions are of phase type, making them very general and flexible. The channel-holding times are of importance in performance evaluation and simulation of cellular mobile communication systems.......In this paper, we derive the distribution of the channel-holding time when both cell-residence and call-holding times are phase-type distributed. Furthermore, the distribution of the number of handovers, the conditional channel-holding time distributions, and the channel-holding time when cell...

Alpha Channeling in Open-System Magnetic Devices

International Nuclear Information System (INIS)

Fisch, Nathaniel

2016-01-01

The Grant DE-SC0000736, Alpha Channeling in Open-System Magnetic Devices, is a continuation of the Grant DE-FG02-06ER54851, Alpha Channeling in Mirror Machines. In publications funded by DE-SC0000736, the grant DE-FG02-06ER54851 was actually credited. The key results obtained under Grant DE-SC0000736, Alpha Channeling in Open-System Magnetic Devices, appear in a series of publications. The earlier effort under DE-FG02- 06ER54851 was the subject of a previous Final Report. The theme of this later effort has been unusual confinement effects, or de-confinement effects, in open-field magnetic confinement devices. First, the possibilities in losing axisymmetry were explored. Then a number of issues in rotating plasma were addressed. Most importantly, a spinoff application to plasma separations was recognized, which also resulted in a provisional patent application. (That provisional patent application, however, was not pursued further.) Alpha channeling entails injecting waves into magnetically confined plasma to release energy from one particular ion while ejecting that ion. The ejection of the ion is actually a concomitant effect in releasing energy from the ion to the wave. In rotating plasma, there is the opportunity to store the energy in a radial electric field rather than in waves. In other words, the ejected alpha particle loses its energy to the radial potential, which in turn produces plasma rotation. This is a very useful effect, since producing radial electric fields by other means are technologically more difficult. In fact, one can heat ions, and then eject them, to produce the desired radial field. In each case, there is a separation effect of different ions, which generalizes the original alpha-channeling concept of separating alpha ash from hydrogen. In a further generalization of the separation concept, a double-well filter represents a new way to produce high-throughput separations of ions, potentially useful for nuclear waste remediation.

Study of elastic scattering between heavy ions. Reaction channel influence

International Nuclear Information System (INIS)

Doubre, Hubert.

1978-01-01

The role of absorption on the behavior of heavy ion angular distributions and excitaton functions has been investigated on light and medium mass systems. Comparison between 20 Ne+ 12 C and 16 O+ 16 O systems which lead to the same compound nucleus, shows that it originates from the direct channels strongly coupled to the entrance channel. Structures in the excitation functions occur for almost all the light systems and it is shown that the damping observed for heavier systems such as 40 Ca+ 40 Ca, essentially results on the predominance of Coulomb effects which hide the nuclear structure effects. Thus no valuable information on the details of S-matrix can be extracted for such an heavy system. A coherent description of the elastic scattering, based on a splitting of the scattering amplitude into two components, the modulus of each component varying smoothly as a function of energy and angle. The interference between these sub-amplitudes give rise to interference effects in angular distributions and excitation functions. The study of the main reaction channels of the 40 Ca+ 40 Ca system - i.e. deep inelastic reactions and fusion - also shows that the closed-shell nature of the interacting nuclei does not play any role in these processes due to the excitation processes in the first stage of the reactions which destroy the specific structure of the nuclei [fr

A portable cadmium telluride multidetector probe for cardiac function monitoring

Energy Technology Data Exchange (ETDEWEB)

Arntz, Y.; Chambron, J.; Dumitresco, B.; Eclancher, B. E-mail: eclan@alsace.u-strasbg.fr; Prat, V

1999-06-01

A new nuclear stethoscope based on a matrix of small CdTe semiconductor detectors has been developed for studying the cardiac performance by gamma ventriculography at the equilibrium, in rest and stress conditions, in the early and recovery phases of the coronary disease and to follow the long-term therapy. The light-weight probe consists of an array of 64 detectors 5x5x2 mm grouped in 16 independent units in a lead shielded aluminum box including 16 preamplifiers. The probe is connected to an electronic box containing DC power supply, 16 channel amplifiers, discriminators and counters, two analog-triggering ECG channels, and interface to a PC. The left ventricle activity is, preferentially, detected by using a low-resolution matching convergent collimator. A physical evaluation of the probe has been performed, both with static tests and dynamically with a hydraulic home-built model of beating heart ventricle paced by a rhythm simulator. The sum of the 16 detectors activity provided a radiocardiogram (RCG) which well depicted the filling and ejection of the cardiac beats, allowing to compare the clinically relevant parameters of the cardiac performance, proportional variables of the stroke volume (SV), ejection fraction (EF) and ventricular flow-rate with the known absolute values programmed on the model. The portable system is now in operation for clinical assessment of cardiac patients.

A portable cadmium telluride multidetector probe for cardiac function monitoring

International Nuclear Information System (INIS)

Arntz, Y.; Chambron, J.; Dumitresco, B.; Eclancher, B.; Prat, V.

1999-01-01

A new nuclear stethoscope based on a matrix of small CdTe semiconductor detectors has been developed for studying the cardiac performance by gamma ventriculography at the equilibrium, in rest and stress conditions, in the early and recovery phases of the coronary disease and to follow the long-term therapy. The light-weight probe consists of an array of 64 detectors 5x5x2 mm grouped in 16 independent units in a lead shielded aluminum box including 16 preamplifiers. The probe is connected to an electronic box containing DC power supply, 16 channel amplifiers, discriminators and counters, two analog-triggering ECG channels, and interface to a PC. The left ventricle activity is, preferentially, detected by using a low-resolution matching convergent collimator. A physical evaluation of the probe has been performed, both with static tests and dynamically with a hydraulic home-built model of beating heart ventricle paced by a rhythm simulator. The sum of the 16 detectors activity provided a radiocardiogram (RCG) which well depicted the filling and ejection of the cardiac beats, allowing to compare the clinically relevant parameters of the cardiac performance, proportional variables of the stroke volume (SV), ejection fraction (EF) and ventricular flow-rate with the known absolute values programmed on the model. The portable system is now in operation for clinical assessment of cardiac patients

A multi-channel high-resolution time recorder system

International Nuclear Information System (INIS)

Zhang Lingyun; Yang Xiaojun; Song Kezhu; Wang Yanfang

2004-01-01

This paper introduces a multi-channel and high-speed time recorder system, which was originally designed to work in the experiments of quantum cryptography research. The novelty of the system is that all the hardware logic is performed by only one FPGA. The system can achieve several desirable features, such as simplicity, high resolution and high processing speed. (authors)

Energy-efficient power allocation of two-hop cooperative systems with imperfect channel estimation

KAUST Repository

Amin, Osama

2015-06-08

Recently, much attention has been paid to the green design of wireless communication systems using energy efficiency (EE) metrics that should capture all energy consumption sources to deliver the required data. In this paper, we formulate an accurate EE metric for cooperative two-hop systems that use the amplify-and-forward relaying scheme. Different from the existing research that assumes the availability of perfect channel state information (CSI) at the communication cooperative nodes, we assume a practical scenario, where training pilots are used to estimate the channels. The estimated CSI can be used to adapt the available resources of the proposed system in order to maximize the EE. Two estimation strategies are assumed namely disintegrated channel estimation, which assumes the availability of channel estimator at the relay, and cascaded channel estimation, where the relay is not equipped with channel estimator and only forwards the received pilot(s) in order to let the destination estimate the cooperative link. The channel estimation cost is reflected on the EE metric by including the estimation error in the signal-to-noise term and considering the energy consumption during the estimation phase. Based on the formulated EE metric, we propose an energy-aware power allocation algorithm to maximize the EE of the cooperative system with channel estimation. Furthermore, we study the impact of the estimation parameters on the optimized EE performance via simulation examples.

A tone-aided dual vestigial sideband system for digital communications on fading channels

Science.gov (United States)

Hladik, Stephen M.; Saulnier, Gary J.; Rafferty, William

1989-01-01

A spectrally efficient tone-aided dual vestigial sideband (TA/DVSB) system for digital data communications on fading channels is presented and described analytically. This PSK (phase-shift-keying) system incorporates a feed-forward, tone-aided demodulation technique to compensate for Doppler frequency shift and channel- induced, multipath fading. In contrast to other tone-in-band-type systems, receiver synchronization is derived from the complete data VSBs. Simulation results for the Rician fading channel are presented. These results demonstrate the receiver's ability to mitigate performance degradation due to fading and to obtain proper data carrier synchronization, suggesting that the proposed TA/DVSB system has promise for this application. Simulated BER (bit-error rate) data indicate that the TA/DVSB system effectively alleviates the channel distortions of the land mobile satellite application.

FPGA based, DSP integrated, 8-channel SIMCON, ver. 3.0. Initial results for 8-channel algorithm

Energy Technology Data Exchange (ETDEWEB)

Giergusiewicz, W.; Koprek, W.; Jalmuzna, W.; Pozniak, K.T.; Romaniuk, R.S. [Warsaw Univ. of Technology (Poland). Inst. of Electronic Systems

2005-07-01

The paper describes design, construction and initial measurements of an eight channel electronic LLRF device predicted for building of the control system for the VUV-FEL accelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (from the SC cavity simulator and controller) consists of a 16 layer, VME size, PCB, a large FPGA chip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To our knowledge, the proposed device is the first of this kind for the accelerator technology in which there was achieved (the FPGA based) DSP latency below 200 ns. With the optimized data transmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON 3.0 sub-system was applied for initial tests with the ACC1 module of the VUV FEL accelerator (eight channels) and with the CHECHIA test stand (single channel), both at the DESY. The promising results with the SIMCON 3.0. encouraged us to enter the design of SIMCON 3.1. possessing 10 measurement and control channels and some additional features to be reported in the next technical note. SIMCON 3.0. is a modular solution, while SIMCON 3.1. will be an integrated board of the all-in-one type. Two design approaches - modular and all-in-one, after branching off in this version of the Simcon, will be continued. (orig.)

Design of data acquisition system for 2D-ARRAY ionization chamber detector

International Nuclear Information System (INIS)

He Chaohui; Xing Guilai; Wu Zhifang; Wang Zhentao

2012-01-01

The introduction is given on the design and development of data acquisition system for 2D-ARRAY ionization chamber detector, which is used for dose verification of tumor radiotherapy. The paper describes the structure and the principle of the 2D-ARRAY ionization chamber detector system in detail, and focuses on the discussion on the design process of the detector's data acquisition system and the development of data acquisition system which is constituted by preamplifier, preamplifier control board and data acquisition board. The client can setup the parameters of the detector system via TCP/IP and do data processing such as high speed data collection and acquisition, further operation and so on. (authors)

CARMENES-NIR channel spectrograph cooling system AIV: thermo-mechanical performance of the instrument

Science.gov (United States)

Becerril, S.; Mirabet, E.; Lizon, J. L.; Abril, M.; Cárdenas, C.; Ferro, I.; Morales, R.; Pérez, D.; Ramón, A.; Sánchez-Carrasco, M. A.; Quirrenbach, A.; Amado, P.; Ribas, I.; Reiners, A.; Caballero, J. A.; Seifert, W.; Herranz, J.

2016-07-01

CARMENES is the new high-resolution high-stability spectrograph built for the 3.5m telescope at the Calar Alto Observatory (CAHA, Almería, Spain) by a consortium formed by German and Spanish institutions. This instrument is composed by two separated spectrographs: VIS channel (550-1050 nm) and NIR channel (950- 1700 nm). The NIR-channel spectrograph's responsible is the Instituto de Astrofísica de Andalucía (IAACSIC). It has been manufactured, assembled, integrated and verified in the last two years, delivered in fall 2015 and commissioned in December 2015. One of the most challenging systems in this cryogenic channel involves the Cooling System. Due to the highly demanding requirements applicable in terms of stability, this system arises as one of the core systems to provide outstanding stability to the channel. Really at the edge of the state-of-the-art, the Cooling System is able to provide to the cold mass ( 1 Ton) better thermal stability than few hundredths of degree within 24 hours (goal: 0.01K/day). The present paper describes the Assembly, Integration and Verification phase (AIV) of the CARMENES-NIR channel Cooling System implemented at IAA-CSIC and later installation at CAHA 3.5m Telescope, thus the most relevant highlights being shown in terms of thermal performance. The CARMENES NIR-channel Cooling System has been implemented by the IAA-CSIC through very fruitful collaboration and involvement of the ESO (European Southern Observatory) cryo-vacuum department with Jean-Louis Lizon as its head and main collaborator. The present work sets an important trend in terms of cryogenic systems for future E-ELT (European Extremely Large Telescope) large-dimensioned instrumentation in astrophysics.

First signal from a broadband cryogenic preamplifier cooled by circulating liquid nitrogen in a 7 T Fourier transform ion cyclotron resonance mass spectrometer.

Science.gov (United States)

Choi, Myoung Choul; Lee, Jeong Min; Lee, Se Gyu; Choi, Sang Hwan; Choi, Yeon Suk; Lee, Kyung Jae; Kim, SeungYong; Kim, Hyun Sik; Stahl, Stefan

2012-12-18

Despite the outstanding performance of Fourier transform ion cyclotron/mass spectrometry (FTICR/MS), the complexity of the cellular proteome or natural compounds presents considerable challenges. Sensitivity is a key performance parameter of a FTICR mass spectrometer. By improving this parameter, the dynamic range of the instrument can be increased to improve the detection signal of low-abundance compounds or fragment ion peaks. In order to improve sensitivity, a cryogenic detection system was developed by the KBSI (Korean Basic Science Institute) in collaboration with Stahl-Electronics (Mettenheim, Germany). A simple, efficient liquid circulation cooling system was designed and a cryogenic preamplifier implemented inside a FTICR mass spectrometer. This cooling system circulates a cryoliquid from a Dewar to the "liquid circulation unit" through a CF flange to cool a copper block and a cryopreamplifier; the cooling medium is subsequently exhausted into the air. The cryopreamplifier can be operated over a very wide temperature range, from room temperature to low temperature environments (4.2 K). First, ion signals detected by the cryopreamplifier using a circulating liquid nitrogen cooling system were observed and showed a signal-to-noise ratio (S/N) about 130% better than that obtained at room temperature.

A Novel Criterion for Optimum MultilevelCoding Systems in Mobile Fading Channels

Institute of Scientific and Technical Information of China (English)

YUAN Dongfeng; WANG Chengxiang; YAO Qi; CAO Zhigang

2001-01-01

A novel criterion that is "capac-ity rule" and "mapping rule" for the design of op-timum MLC scheme over mobile fading channels isproposed.According to this theory,the performanceof multilevel coding with multistage decoding schemes(MLC/MSD) in mobile fading channels is investi-gated,in which BCH codes are chosen as componentcodes,and three mapping strategies with 8ASK mod-ulation are used.Numerical results indicate that whencode rates of component codes in MLC scheme are de-signed based on "capacity rule",the performance ofthe system with block partitioning (BP) is optimumfor Rayleigh fading channels,while the performance ofthe system with Ungerboeck partioning (UP) is bestfor AWGN channels.

Multi-channel temperature measurement system for automotive battery stack

Science.gov (United States)

Lewczuk, Radoslaw; Wojtkowski, Wojciech

2017-08-01

A multi-channel temperature measurement system for monitoring of automotive battery stack is presented in the paper. The presented system is a complete battery temperature measuring system for hybrid / electric vehicles that incorporates multi-channel temperature measurements with digital temperature sensors communicating through 1-Wire buses, individual 1-Wire bus for each sensor for parallel computing (parallel measurements instead of sequential), FPGA device which collects data from sensors and translates it for CAN bus frames. CAN bus is incorporated for communication with car Battery Management System and uses additional CAN bus controller which communicates with FPGA device through SPI bus. The described system can parallel measure up to 12 temperatures but can be easily extended in the future in case of additional needs. The structure of the system as well as particular devices are described in the paper. Selected results of experimental investigations which show proper operation of the system are presented as well.

Microfluidic in-channel multi-electrode platform for neurotransmitter sensing

Science.gov (United States)

Kara, A.; Mathault, J.; Reitz, A.; Boisvert, M.; Tessier, F.; Greener, J.; Miled, A.

2016-03-01

In this project we present a microfluidic platform with in-channel micro-electrodes for in situ screening of bio/chemical samples through a lab-on-chip system. We used a novel method to incorporate electrochemical sensors array (16x20) connected to a PCB, which opens the way for imaging applications. A 200 μm height microfluidic channel was bonded to electrochemical sensors. The micro-channel contains 3 inlets used to introduce phosphate buffer saline (PBS), ferrocynide and neurotransmitters. The flow rate was controlled through automated micro-pumps. A multiplexer was used to scan electrodes and perform individual cyclic voltammograms by a custom potentiostat. The behavior of the system was linear in terms of variation of current versus concentration. It was used to detect the neurotransmitters serotonin, dopamine and glutamate.

Effective Scheme of Channel Tracking and Estimation for Mobile WiMAX DL-PUSC System

Directory of Open Access Journals (Sweden)

Phuong Thi Thu Pham

2010-01-01

Full Text Available This paper introduces an effective joint scheme of channel estimation and tracking for downlink partial usage of subchannel (DL-PUSC mode of mobile WiMAX system. Based on the pilot pattern of this particular system, some channel estimation methods including conventional interpolations and a more favorable least-squares line fitting (LSLF technique are comparatively studied. Besides, channel estimation performance can be remarkably improved by taking advantage of channel tracking derived from the preamble symbol. System performances in terms of packet error rate (PER and user link throughput are investigated in various channels adopted from the well-known ITU models for mobile environments. Simulation results show a significant performance enhancement when the proposed joint scheme is utilized, at least 5 dB, compared to only commonly used channel estimation approaches.

Capacity limits of spectrum-sharing systems over hyper-fading channels

KAUST Repository

Ekin, Sabit

2011-01-20

Cognitive radio (CR) with spectrum-sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, the achievable capacity gain of spectrum-sharing systems over dynamic fading environments is studied. To perform a general analysis, a theoretical fading model called hyper-fading model that is suitable to the dynamic nature of CR channel is proposed. Closed-form expressions of probability density function (PDF) and cumulative density function (CDF) of the signal-to-noise ratio (SNR) for secondary users (SUs) in spectrum-sharing systems are derived. In addition, the capacity gains achievable with spectrum-sharing systems in high and low power regions are obtained. The effects of different fading figures, average fading powers, interference temperatures, peak powers of secondary transmitters, and numbers of SUs on the achievable capacity are investigated. The analytical and simulation results show that the fading figure of the channel between SUs and primary base-station (PBS), which describes the diversity of the channel, does not contribute significantly to the system performance gain. © 2011 John Wiley & Sons, Ltd.

Capacity limits of spectrum-sharing systems over hyper-fading channels

KAUST Repository

Ekin, Sabit; Yilmaz, Ferkan; Ç elebi, Hasari Burak; Qaraqe, Khalid A.; Alouini, Mohamed-Slim; Serpedin, Erchin

2011-01-01

Cognitive radio (CR) with spectrum-sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, the achievable capacity gain of spectrum-sharing systems over dynamic fading environments is studied. To perform a general analysis, a theoretical fading model called hyper-fading model that is suitable to the dynamic nature of CR channel is proposed. Closed-form expressions of probability density function (PDF) and cumulative density function (CDF) of the signal-to-noise ratio (SNR) for secondary users (SUs) in spectrum-sharing systems are derived. In addition, the capacity gains achievable with spectrum-sharing systems in high and low power regions are obtained. The effects of different fading figures, average fading powers, interference temperatures, peak powers of secondary transmitters, and numbers of SUs on the achievable capacity are investigated. The analytical and simulation results show that the fading figure of the channel between SUs and primary base-station (PBS), which describes the diversity of the channel, does not contribute significantly to the system performance gain. © 2011 John Wiley & Sons, Ltd.

Design and operation of a cryogenic charge-integrating preamplifier for the MuSun experiment

International Nuclear Information System (INIS)

Ryan, R A; Wauters, F; Kammel, P; Peterson, D; Wechel, T van; Osofsky, R; Murray, M H; Gray, F E; Gross, E; Gubanich, M; Orozco, D; Stroud, J; Nadtochy, A; Kochenda, L; Kravtsov, P; Petrov, G E; Trofimov, V; Vasilyev, A; Vznuzdaev, M; Phillips, J D

2014-01-01

The central detector in the MuSun experiment is a pad-plane time projection ionization chamber that operates without gas amplification in deuterium at 31 K; it is used to measure the rate of the muon capture process μ − +d→n+n+ν μ . A new charge-sensitive preamplifier, operated at 140 K, has been developed for this detector. It achieved a resolution of 4.5 keV(D 2 ) or 120 e − RMS with zero detector capacitance at 1.1 μ s integration time in laboratory tests. In the experimental environment, the electronic resolution is 10 keV(D 2 ) or 250 e − RMS at a 0.5 μ s integration time. The excellent energy resolution of this amplifier has enabled discrimination between signals from muon-catalyzed fusion and muon capture on chemical impurities, which will precisely determine systematic corrections due to these processes. It is also expected to improve the muon tracking and determination of the stopping location

Distributed Channel Estimation and Pilot Contamination Analysis for Massive MIMO-OFDM Systems

KAUST Repository

Zaib, Alam

2016-07-22

By virtue of large antenna arrays, massive MIMO systems have a potential to yield higher spectral and energy efficiency in comparison with the conventional MIMO systems. This paper addresses uplink channel estimation in massive MIMO-OFDM systems with frequency selective channels. We propose an efficient distributed minimum mean square error (MMSE) algorithm that can achieve near optimal channel estimates at low complexity by exploiting the strong spatial correlation among antenna array elements. The proposed method involves solving a reduced dimensional MMSE problem at each antenna followed by a repetitive sharing of information through collaboration among neighboring array elements. To further enhance the channel estimates and/or reduce the number of reserved pilot tones, we propose a data-aided estimation technique that relies on finding a set of most reliable data carriers. Furthermore, we use stochastic geometry to quantify the pilot contamination, and in turn use this information to analyze the effect of pilot contamination on channel MSE. The simulation results validate our analysis and show near optimal performance of the proposed estimation algorithms.

Inhibition of Calcium-Activated Chloride Channel ANO1/TMEM16A Suppresses Tumor Growth and Invasion in Human Lung Cancer.

Directory of Open Access Journals (Sweden)

Linghan Jia

Full Text Available Lung cancer or pulmonary carcinoma is primarily derived from epithelial cells that are thin and line on the alveolar surfaces of the lung for gas exchange. ANO1/TMEM16A, initially identified from airway epithelial cells, is a member of Ca2+-activated Cl- channels (CaCCs that function to regulate epithelial secretion and cell volume for maintenance of ion and tissue homeostasis. ANO1/TMEM16A has recently been shown to be highly expressed in several epithelium originated carcinomas. However, the role of ANO1 in lung cancer remains unknown. In this study, we show that inhibition of calcium-activated chloride channel ANO1/TMEM16A suppresses tumor growth and invasion in human lung cancer. ANO1 is upregulated in different human lung cancer cell lines. Knocking-down ANO1 by small hairpin RNAs inhibited proliferation, migration and invasion of GLC82 and NCI-H520 cancel cells evaluated by CCK-8, would-healing, transwell and 3D soft agar assays. ANO1 protein is overexpressed in 77.3% cases of human lung adenocarcinoma tissues detected by immunohistochemistry. Furthermore, the tumor growth in nude mice implanted with GLC82 cells was significantly suppressed by ANO1 silencing. Taken together, our findings provide evidence that ANO1 overexpression contributes to tumor growth and invasion of lung cancer; and suppressing ANO1 overexpression may have therapeutic potential in lung cancer therapy.

Rotated Walsh-Hadamard Spreading with Robust Channel Estimation for a Coded MC-CDMA System

Directory of Open Access Journals (Sweden)

Raulefs Ronald

2004-01-01

Full Text Available We investigate rotated Walsh-Hadamard spreading matrices for a broadband MC-CDMA system with robust channel estimation in the synchronous downlink. The similarities between rotated spreading and signal space diversity are outlined. In a multiuser MC-CDMA system, possible performance improvements are based on the chosen detector, the channel code, and its Hamming distance. By applying rotated spreading in comparison to a standard Walsh-Hadamard spreading code, a higher throughput can be achieved. As combining the channel code and the spreading code forms a concatenated code, the overall minimum Hamming distance of the concatenated code increases. This asymptotically results in an improvement of the bit error rate for high signal-to-noise ratio. Higher convolutional channel code rates are mostly generated by puncturing good low-rate channel codes. The overall Hamming distance decreases significantly for the punctured channel codes. Higher channel code rates are favorable for MC-CDMA, as MC-CDMA utilizes diversity more efficiently compared to pure OFDMA. The application of rotated spreading in an MC-CDMA system allows exploiting diversity even further. We demonstrate that the rotated spreading gain is still present for a robust pilot-aided channel estimator. In a well-designed system, rotated spreading extends the performance by using a maximum likelihood detector with robust channel estimation at the receiver by about 1 dB.

Strangeonium spectroscopy at 11 GeV/c and Cherenkov Ring Imaging at the SLD

International Nuclear Information System (INIS)

Bienz, T.L.

1990-07-01

This thesis is divided into two sections, which describe portions of the data acquisition system and online software for the Cherenkov Ring Imaging Detector (CRID) for the SLD, and analyses of several low cross section strangeonium channels in data from the LASS spectrometer. The CRID section includes a description of the data acquisition system, determination of the preamplifier gain, and development of an online pulse finding algorithm based on deconvolution. Deconvolution uses knowledge of the preamplifier impulse response to aid in pulse finding. The algorithm is fast and shows good single pulse resolution and excellent double pulse resolution in preliminary tests. The strangeonium analyses are based on data from a 4.1 event/nanobarn exposure of the LASS spectrometer in K - p interactions at 11 GeV/c, and include studies of Ληπ + π - , ΛΚ*Κ*, and Λφφ

A Study on the Inter-Channel Communication Independence for SMART I and C System

International Nuclear Information System (INIS)

Jeong, Kwang Il; Keum, Jong Yong; Park, Je Yun

2009-01-01

In nuclear power plants (NPP) the greatest concern is to ensure the safety goal, so it is designed with a protection conception using diversity and redundancy methods. Usually the I and C (Instrumentation and Control) system of NPP is composed of four channels to enhance the performance of the safety functions and performs the monitoring and control functions. In these redundant structures, the most important thing is that a malfunction in one channel cannot affect the safety functions of the redundant channels. The communication network of the digital I and C system is playing a role in intra-channel communication and inter-channel communication in four-channel I and C structure. Recent licensee experience indicates that companies planning to use the interchannel communication must perform a detailed analysis of all credible failure modes. In this paper, we propose some evaluation criteria to evaluate the inter-channel communication independence of SMART I and C system and preliminary design for mitigating methodologies of each credible failure

Iterative Pilot-Layer Aided Channel Estimation with Emphasis on Interleave-Division Multiple Access Systems

Directory of Open Access Journals (Sweden)

Schoeneich Hendrik

2006-01-01

Full Text Available Channel estimation schemes suitable for interleave-division multiple access (IDMA systems are presented. Training and data are superimposed. Training-based and semiblind linear channel estimators are derived and their performance is discussed and compared. Monte Carlo simulation results are presented showing that the derived channel estimators in conjunction with a superimposed pilot sequence and chip-by-chip processing are able to track fast-fading frequency-selective channels. As opposed to conventional channel estimation techniques, the BER performance even improves with increasing Doppler spread for typical system parameters. An error performance close to the case of perfect channel knowledge can be achieved with high power efficiency.

A multi-channel waveform digitizer system

International Nuclear Information System (INIS)

Bieser, F.; Muller, W.F.J.

1990-01-01

The authors report on the design and performance of a multichannel waveform digitizer system for use with the Multiple Sample Ionization Chamber (MUSIC) Detector at the Bevalac. 128 channels of 20 MHz Flash ADC plus 256 word deep memory are housed in a single crate. Digital thresholds and hit pattern logic facilitate zero suppression during readout which is performed over a standard VME bus

Important role of projectile excitation in 16O+60Ni and 16O+27Al scattering at intermediate energies

Science.gov (United States)

Zagatto, V. A. B.; Cappuzzello, F.; Lubian, J.; Cavallaro, M.; Linares, R.; Carbone, D.; Agodi, C.; Foti, A.; Tudisco, S.; Wang, J. S.; Oliveira, J. R. B.; Hussein, M. S.

2018-05-01

The elastic scattering angular distribution of the 16O+60Ni system at 260 MeV was measured in the range of the Rutherford cross section down to seven orders of magnitude. The cross sections of the lowest 2+ and 3- inelastic states of the target were also measured over several orders of magnitude. Coupled-channel (CC) calculations were performed and are shown to be compatible with the whole set of data only when including the excitation of the projectile and when the deformations of the imaginary part of the nuclear optical potential are taken into account. Similar results were obtained when the procedure is applied to the existing data on 16O+27Al elastic and inelastic scattering at 100 and 280 MeV. An analysis in terms of dynamical polarization potentials (DPP) indicates the major role of coupled-channel effects in the overlapping surface region of the colliding nuclei.

A new architecture for a single-chip multi-channel beamformer based on a standard FPGA

DEFF Research Database (Denmark)

Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

2001-01-01

) modulation analog-to-digital converters (ADC). Second, simple second-order ΔΣ modulation ADC with classic topology is used. This allows for simple analog circuitry and a very compact design. Several tens of these together with the corresponding preamplifiers can be fitted together onto a single analog......A new architecture for a compact medical ultrasound beamformer has been developed. Combination of novel and known principles has been utilized, leading to low processing power requirements and simple analog circuitry. Usage of a field programmable gate array (FPGA) for the digital signal processing...... integrated circuit. Third, parameter driven delay generation is used, using 3 input parameters per line per channel for either linear array imaging or phased array imaging. The delays are generated on the fly. The delay generation logic also determines the digital apodization by using 2 additional parameters...

Offset correction system for 128-channel self-triggering readout chip with in-channel 5-bit energy measurement functionality

Energy Technology Data Exchange (ETDEWEB)

Otfinowski, P., E-mail: potfin@agh.edu.pl; Grybos, P.; Szczygiel, R.; Kasinski, K.

2015-04-21

We report on a novel, two-stage 8-bit trimming solution dedicated for multichannel systems with reduced trim DAC area occupancy. The presented design was used for comparator offset correction in a 128-channel particle tracking, self-triggering readout system and manufactured in 180 nm CMOS process. The 8-bit trim DAC has a range of ±165 mV, current consumption of 3.2 µA and occupies an area of 37 µm×17 µm in each channel, which corresponds to a 6-bit conventional current steering DAC with similar linearity.

A Fast LMMSE Channel Estimation Method for OFDM Systems

Directory of Open Access Journals (Sweden)

Zhou Wen

2009-01-01

Full Text Available A fast linear minimum mean square error (LMMSE channel estimation method has been proposed for Orthogonal Frequency Division Multiplexing (OFDM systems. In comparison with the conventional LMMSE channel estimation, the proposed channel estimation method does not require the statistic knowledge of the channel in advance and avoids the inverse operation of a large dimension matrix by using the fast Fourier transform (FFT operation. Therefore, the computational complexity can be reduced significantly. The normalized mean square errors (NMSEs of the proposed method and the conventional LMMSE estimation have been derived. Numerical results show that the NMSE of the proposed method is very close to that of the conventional LMMSE method, which is also verified by computer simulation. In addition, computer simulation shows that the performance of the proposed method is almost the same with that of the conventional LMMSE method in terms of bit error rate (BER.

System-Level Design of a 64-Channel Low Power Neural Spike Recording Sensor.

Science.gov (United States)

Delgado-Restituto, Manuel; Rodriguez-Perez, Alberto; Darie, Angela; Soto-Sanchez, Cristina; Fernandez-Jover, Eduardo; Rodriguez-Vazquez, Angel

2017-04-01

This paper reports an integrated 64-channel neural spike recording sensor, together with all the circuitry to process and configure the channels, process the neural data, transmit via a wireless link the information and receive the required instructions. Neural signals are acquired, filtered, digitized and compressed in the channels. Additionally, each channel implements an auto-calibration algorithm which individually configures the transfer characteristics of the recording site. The system has two transmission modes; in one case the information captured by the channels is sent as uncompressed raw data; in the other, feature vectors extracted from the detected neural spikes are released. Data streams coming from the channels are serialized by the embedded digital processor. Experimental results, including in vivo measurements, show that the power consumption of the complete system is lower than 330 μW.

Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels

KAUST Repository

Yilmaz, Ferkan

2012-03-01

In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present simple and efficient closed-form expression to the higher order moments of the channel capacity of dual hop transmission system with Rayleigh fading channels. In order to analyze the behavior of the higher order capacity statistics and investigate the usefulness of the mathematical analysis, some selected numerical and simulation results are presented. Our results are found to be in perfect agreement. © 2012 IEEE.

A large 2D PSD for thermal neutron detection

Energy Technology Data Exchange (ETDEWEB)

Knott, R.B.; Watt, G.; Boldeman, J.W. [Australian Nucl. Sci. and Tech. Organ., Menai, NSW (Australia). Phys. Div.; Smith, G.C. [Instrumentation Division, Brookhaven National Laboratory, Upton, NY 11973 (United States)

1997-06-21

A 2D PSD based on a MWPC has been constructed for a small angle neutron scattering instrument. The active area of the detector was 640 x 640 mm{sup 2}. To meet the specifications for neutron detection efficiency and spatial resolution, and to minimise parallax, the gas mixture was 190 kPa {sup 3}He plus 100 kPa CF{sub 4}, and the active volume had a thickness of 30 mm. The design maximum neutron count rate of the detector was 10{sup 5} events per second. The (calculated) neutron detection efficiency was 60% for 2 A neutrons and the (measured) neutron energy resolution on the anode grid was typically 20% (fwhm). The location of a neutron detection event within the active area was determined using the wire-by-wire method: the spatial resolution (5 x 5 mm{sup 2}) was thereby defined by the wire geometry. A 16-channel charge-sensitive preamplifier/amplifier/comparator module has been developed with a channel sensitivity of 0.1 V/fC, noise line width of 0.4 fC (fwhm) and channel-to-channel cross-talk of less than 5%. The proportional counter operating system (PCOS III) (LeCroy Corp, USA) was used for event encoding. The ECL signals produced by the 16 channel modules were latched in PCOS III by a trigger pulse from the anode and the fast encoders produce a position and width for each event. The information was transferred to a UNIX workstation for accumulation and online display. (orig.).

Distribution and function of voltage-gated sodium channels in the nervous system.

Science.gov (United States)

Wang, Jun; Ou, Shao-Wu; Wang, Yun-Jie

2017-11-02

Voltage-gated sodium channels (VGSCs) are the basic ion channels for neuronal excitability, which are crucial for the resting potential and the generation and propagation of action potentials in neurons. To date, at least nine distinct sodium channel isoforms have been detected in the nervous system. Recent studies have identified that voltage-gated sodium channels not only play an essential role in the normal electrophysiological activities of neurons but also have a close relationship with neurological diseases. In this study, the latest research findings regarding the structure, type, distribution, and function of VGSCs in the nervous system and their relationship to neurological diseases, such as epilepsy, neuropathic pain, brain tumors, neural trauma, and multiple sclerosis, are reviewed in detail.

Performance of Antenna Selection in MIMO System Using Channel Reciprocity with Measured Data

Directory of Open Access Journals (Sweden)

Peerapong Uthansakul

2011-01-01

Full Text Available The channel capacity of MIMO system increases as a function of antenna pairs between transmitter and receiver but it suffers from multiple expensive RF chains. To reduce cost of RF chains, antenna selection (AS method can offer a good tradeoff between expense and performance. For a transmitting AS system, channel state information (CSI feedback is required to choose the best subset of available antennas. However, the delay and error in feedback channel are the most dominant factors to degrade performances. In this paper, the concept of AS method using reciprocal CSI instead of feedback channel is proposed. The capacity performance of proposed system is investigated by own developing Testbed. The obtained results indicate that the reciprocity technique offers a capacity close to a system with perfect CSI and gains a higher capacity than a system without AS method. This benefit is from 0.9 to 2.2 bps/Hz at SNR 10 dB.

Wireless acquisition of multi-channel seismic data using the Seismobile system

Science.gov (United States)

Isakow, Zbigniew

2017-11-01

This paper describes the wireless acquisition of multi-channel seismic data using a specialized mobile system, Seismobile, designed for subsoil diagnostics for transportation routes. The paper presents examples of multi-channel seismic records obtained during system tests in a configuration with 96 channels (4 landstreamers of 24-channel) and various seismic sources. Seismic waves were generated at the same point using different sources: a 5-kg hammer, a Gisco's source with a 90-kg pile-driver, and two other the pile-drivers of 45 and 70 kg. Particular attention is paid to the synchronization of source timing, the measurement of geometry by autonomous GPS systems, and the repeatability of triggering measurements constrained by an accelerometer identifying the seismic waveform. The tests were designed to the registration, reliability, and range of the wireless transmission of survey signals. The effectiveness of the automatic numbering of measuring modules was tested as the system components were arranged and fixed to the streamers. After measurements were completed, the accuracy and speed of data downloading from the internal memory (SDHC 32GB WiFi) was determined. Additionally, the functionality of automatic battery recharging, the maximum survey duration, and the reliability of battery discharge signalling were assessed.

Green channel cargo inspection system

International Nuclear Information System (INIS)

Shi Yuanping; Yu Jingsheng; Sun Hongqiang; Hao Pu; Cai Wenxia

2011-01-01

A radiation detection device was installed in the lanes of a highway toll station, radioactive rays which was collimated emitted through the measured, and arrived the detector. The average density of the fresh agricultural products belonged to Green channel and other prohibited items vary greatly, the absorption of radiation are different between the Green Channel Cargo and other substances. Prior to the experimental group, different standard samples which represent different models and goods were measured, the different standard samples were stored in a computer database. When the trucks get through the Green Channel, the detector will detect the radiation signal and bring to the computer, the computer will process the measured data, and make a conclusion whether the goods are Green Channel cargo. (authors)

The design and implementation of a PC based multi-channel scaler system

International Nuclear Information System (INIS)

Wang Qiang; Chinese Academy of Sciences, Beijing; Jin Dapeng; Liu Zhen'an; Zhao Dixin

2007-01-01

A multi-channel scaler system is designed for the system check and status monitoring of the BESIII trigger system. It is composed of a PC, two PCI interface multi-channel scaler cards, the corresponding drivers and user programs. Total 64 signals can be scaled and monitored in real time. The scaled data are recorded locally and some of them are distributed to the online system. In this paper, the hardware structure, software development and long time running stability of the system are introduced. (authors)

Channel Equalization and Phase Estimation for Reduced-Guard-Interval CO-OFDM Systems

Science.gov (United States)

Zhuge, Qunbi

Reduced-guard-interval (RGI) coherent optical (CO) orthogonal frequency-division multiplexing (OFDM) is a potential candidate for next generation 100G beyond optical transports, attributed to its advantages such as high spectral efficiency and high tolerance to optical channel impairments. First of all, we review the coherent optical systems with an emphasis on CO-OFDM systems as well as the optical channel impairments and the general digital signal processing techniques to combat them. This work focuses on the channel equalization and phase estimation of RGI CO-OFDM systems. We first propose a novel equalization scheme based on the equalization structure of RGI CO-OFDM to reduce the cyclic prefix overhead to zero. Then we show that intra-channel nonlinearities should be considered when designing the training symbols for channel estimation. Afterwards, we propose and analyze the phenomenon of dispersion-enhanced phase noise (DEPN) caused by the interaction between the laser phase noise and the chromatic dispersion in RGI CO-OFDM transmissions. DEPN induces a non-negligible performance degradation and limits the tolerant laser linewidth. However, it can be compensated by the grouped maximum-likelihood phase estimation proposed in this work.

Channel coding for underwater acoustic single-carrier CDMA communication system

Science.gov (United States)

Liu, Lanjun; Zhang, Yonglei; Zhang, Pengcheng; Zhou, Lin; Niu, Jiong

2017-01-01

CDMA is an effective multiple access protocol for underwater acoustic networks, and channel coding can effectively reduce the bit error rate (BER) of the underwater acoustic communication system. For the requirements of underwater acoustic mobile networks based on CDMA, an underwater acoustic single-carrier CDMA communication system (UWA/SCCDMA) based on the direct-sequence spread spectrum is proposed, and its channel coding scheme is studied based on convolution, RA, Turbo and LDPC coding respectively. The implementation steps of the Viterbi algorithm of convolutional coding, BP and minimum sum algorithms of RA coding, Log-MAP and SOVA algorithms of Turbo coding, and sum-product algorithm of LDPC coding are given. An UWA/SCCDMA simulation system based on Matlab is designed. Simulation results show that the UWA/SCCDMA based on RA, Turbo and LDPC coding have good performance such that the communication BER is all less than 10-6 in the underwater acoustic channel with low signal to noise ratio (SNR) from -12 dB to -10dB, which is about 2 orders of magnitude lower than that of the convolutional coding. The system based on Turbo coding with Log-MAP algorithm has the best performance.

Four-channel high speed synchronized acquisition multiple trigger storage measurement system

International Nuclear Information System (INIS)

Guo Jian; Wang Wenlian; Zhang Zhijie

2010-01-01

A new storage measurement system based on the CPLD, MCU and FLASH (large-capacity flash memory) is proposed. The large capacity storage characteristic of the FLASH MEMORY is used to realize multi channel synchronized acquisition and the function of multiple records and read once. The function of multi channel synchronization, high speed data acquisition, the triggering several times, and the adjustability of working parameters expands the application of storage measurement system. The storage measurement system can be used in a variety of pressure and temperature test in explosion field. (authors)

Polarized Uniform Linear Array System: Beam Radiation Pattern, Beamforming Diversity Order, and Channel Capacity

Directory of Open Access Journals (Sweden)

Xin Su

2015-01-01

Full Text Available There have been many studies regarding antenna polarization; however, there have been few publications on the analysis of the channel capacity for polarized antenna systems using the beamforming technique. According to Chung et al., the channel capacity is determined by the density of scatterers and the transmission power, which is obtained based on the assumption that scatterers are uniformly distributed on a 3D spherical scattering model. However, it contradicts the practical scenario, where scatterers may not be uniformly distributed under outdoor environment, and lacks the consideration of fading channel gain. In this study, we derive the channel capacity of polarized uniform linear array (PULA systems using the beamforming technique in a practical scattering environment. The results show that, for PULA systems, the channel capacity, which is boosted by beamforming diversity, can be determined using the channel gain, beam radiation pattern, and beamforming diversity order (BDO, where the BDO is dependent on the antenna characteristics and array configurations.

A communication-channel-based representation system for software

NARCIS (Netherlands)

Demirezen, Zekai; Tanik, Murat M.; Aksit, Mehmet; Skjellum, Anthony

We observed that before initiating software development the objectives are minimally organized and developers introduce comparatively higher organization throughout the design process. To be able to formally capture this observation, a new communication channel representation system for software is

Image quality of high-resolution CT with 16-channel multidetector-row CT. Comparison between helical scan and conventional step-shoot scan

International Nuclear Information System (INIS)

Sumikawa, Hiromitsu; Johkoh, Takeshi; Koyama, Mitsuhiro

2005-01-01

The aim of this study was to evaluate the image quality of high-resolution CT (HRCT) reconstructed from volumetric data with 16-channel multidetector-row CT (MDCT). Eleven autopsy lungs that were diagnosed histopathologically were scanned by 16-channel MDCT with the step-and-shoot scan mode and three helical scan modes. Each helical mode had each size of focal spot, pitch, and time of gantry rotation. HRCT images were reconstructed from the volumetric data with each helical mode and axial sequence data. Two observers evaluated the image quality and noted the most appropriate diagnosis for each imaging. Visualization of abnormal structures with one helical mode was equal to those with axial mode, whereas those with the other two helical modes were inferior to those with axial mode (Wilcoxon signed rank test; p<0.0001). There was no significant difference in diagnostic efficacy between modes. The image quality of HRCT with appropriate helical mode is equal to that with axial mode and diagnostic efficacy is equal among all modes. These results may indicate that sufficient HRCT images can be obtained by only one helical scan without the addition of conventional axial scans. (author)

Design of micro distribution systems consisting of long channels with arbitrary cross sections

International Nuclear Information System (INIS)

Misdanitis, S; Valougeorgis, D

2012-01-01

Gas flows through long micro-channels of various cross sections have been extensively investigated over the years both numerically and experimentally. In various technological applications including microfluidics, these micro-channels are combined together in order to form a micro-channel network. Computational algorithms for solving gas pipe networks in the hydrodynamic regime are well developed. However, corresponding tools for solving networks consisting of micro-channels under any degree of gas rarefaction is very limited. Recently a kinetic algorithm has been developed to simulate gas distribution systems consisting of long circular channels under any vacuum conditions. In the present work this algorithm is generalized and extended into micro-channels of arbitrary cross-section etched by KOH in silicon (triangular and trapezoidal channels with acute angle of 54.74°). Since a kinetic approach is implemented, the analysis is valid and the results are accurate in the whole range of the Knudsen number, while the involved computational effort is very small. This is achieved by successfully integrating the kinetic results for the corresponding single channels into the general solver for designing the gas pipe network. To demonstrate the feasibility of the approach two typical systems consisting of long rectangular and trapezoidal micro-channels are solved.

THz photonic wireless links with 16-QAM modulation in the 375-450 GHz band

DEFF Research Database (Denmark)

Jia, Shi; Yu, Xianbin; Hu, Hao

2016-01-01

forward error correction (HD-FEC) threshold of 3.8e-3 with 7% overhead. In addition, we also successfully demonstrate hybrid photonic wireless transmission of 40 Gbit/s 16-QAM signal at carrier frequencies of 400 GHz and 425 GHz over 30 km standard single mode fiber (SSMF) between the optical baseband...... signal transmitter and the THz wireless transmitter with negligible induced power penalty.......We propose and experimentally demonstrate THz photonic wireless communication systems with 16-QAM modulation in the 375-450 GHz band. The overall throughput reaches as high as 80 Gbit/s by exploiting four THz channels with 5 Gbaud 16-QAM baseband modulation per channel. We create a coherent optical...

A Low-cost Multi-channel Analogue Signal Generator

CERN Document Server

Müller, F; The ATLAS collaboration; Shen, W; Stamen, R

2009-01-01

A scalable multi-channel analogue signal generator is presented. It uses a commercial low-cost graphics card with multiple outputs in a standard PC as signal source. Each color signal serves as independent channel to generate an analogue signal. A custom-built external PCB was developed to adjust the graphics card output voltage levels for a specific task, which needed differential signals. The system furthermore comprises a software package to program the signal shape. The signal generator was successfully used as independent test bed for the ATLAS Level-1 Trigger Pre-Processor, providing up to 16 analogue signals.

Maximum Likelihood Blind Channel Estimation for Space-Time Coding Systems

Directory of Open Access Journals (Sweden)

Hakan A. Çırpan

2002-05-01

Full Text Available Sophisticated signal processing techniques have to be developed for capacity enhancement of future wireless communication systems. In recent years, space-time coding is proposed to provide significant capacity gains over the traditional communication systems in fading wireless channels. Space-time codes are obtained by combining channel coding, modulation, transmit diversity, and optional receive diversity in order to provide diversity at the receiver and coding gain without sacrificing the bandwidth. In this paper, we consider the problem of blind estimation of space-time coded signals along with the channel parameters. Both conditional and unconditional maximum likelihood approaches are developed and iterative solutions are proposed. The conditional maximum likelihood algorithm is based on iterative least squares with projection whereas the unconditional maximum likelihood approach is developed by means of finite state Markov process modelling. The performance analysis issues of the proposed methods are studied. Finally, some simulation results are presented.

Relay selection in cooperative communication systems over continuous time-varying fading channel

Directory of Open Access Journals (Sweden)

Ke Geng

2017-02-01

Full Text Available In this paper, we study relay selection under outdated channel state information (CSI in a decode-and-forward (DF cooperative system. Unlike previous researches on cooperative communication under outdated CSI, we consider that the channel varies continuously over time, i.e., the channel not only changes between relay selection and data transmission but also changes during data transmission. Thus the level of accuracy of the CSI used in relay selection degrades with data transmission. We first evaluate the packet error rate (PER of the cooperative system under continuous time-varying fading channel, and find that the PER performance deteriorates more seriously under continuous time-varying fading channel than when the channel is assumed to be constant during data transmission. Then, we propose a repeated relay selection (RRS strategy to improve the PER performance, in which the forwarded data is divided into multiple segments and relay is reselected before the transmission of each segment based on the updated CSI. Finally, we propose a combined relay selection (CRS strategy which takes advantage of three different relay selection strategies to further mitigate the impact of outdated CSI.

The Argonne silicon strip-detector array

Energy Technology Data Exchange (ETDEWEB)

Wuosmaa, A H; Back, B B; Betts, R R; Freer, M; Gehring, J; Glagola, B G; Happ, Th; Henderson, D J; Wilt, P [Argonne National Lab., IL (United States); Bearden, I G [Purdue Univ., Lafayette, IN (United States). Dept. of Physics

1992-08-01

Many nuclear physics experiments require the ability to analyze events in which large numbers of charged particles are detected and identified simultaneously, with good resolution and high efficiency, either alone, or in coincidence with gamma rays. The authors have constructed a compact large-area detector array to measure these processes efficiently and with excellent energy resolution. The array consists of four double-sided silicon strip detectors, each 5x5 cm{sup 2} in area, with front and back sides divided into 16 strips. To exploit the capability of the device fully, a system to read each strip-detector segment has been designed and constructed, based around a custom-built multi-channel preamplifier. The remainder of the system consists of high-density CAMAC modules, including multi-channel discriminators, charge-sensing analog-to-digital converters, and time-to-digital converters. The array`s performance has been evaluated using alpha-particle sources, and in a number of experiments conducted at Argonne and elsewhere. Energy resolutions of {Delta}E {approx} 20-30 keV have been observed for 5 to 8 MeV alpha particles, as well as time resolutions {Delta}T {<=} 500 ps. 4 figs.

Integration of 128 channels for monitoring, acquisition and control with existing LHCD DAC system

International Nuclear Information System (INIS)

Joshi, Ramesh; Virani, Chetan; Wadhwani, Archana; Sharma, P.K.

2015-01-01

Lower Hybrid Current Drive (LHCD) data acquisition system needs to be upgraded for additional channel requirement. The existing VME based DAC has been used since long with 32 analog input channels for data monitoring and control. Additional 128 channels require integrating with existing DAC. There are four layers of waveguides which deliver final output power into tokamak. Each layer requires 32 channels for power measurement. For the same requirement 128 analog input channels have been integrated with the help of carrier board and IP modules. Acromag IP330 modules have been procured and finally integrated with additional carrier board with existing VME hardware. Each module provides 32 analog input channels. Device driver has been developed for each module and integrated with existing program. LHCD DAC system has been upgraded with additional 128 channels requirement. It has been successfully testing with recent SST-1 campaign. (author)

A Specialized Multi-Transmit Head Coil for High Resolution fMRI of the Human Visual Cortex at 7T.

Science.gov (United States)

Sengupta, Shubharthi; Roebroeck, Alard; Kemper, Valentin G; Poser, Benedikt A; Zimmermann, Jan; Goebel, Rainer; Adriany, Gregor

2016-01-01

To design, construct and validate radiofrequency (RF) transmit and receive phased array coils for high-resolution visual cortex imaging at 7 Tesla. A 4 channel transmit and 16 channel receive array was constructed on a conformal polycarbonate former. Transmit field efficiency and homogeneity were simulated and validated, along with the Specific Absorption Rate, using [Formula: see text] mapping techniques and electromagnetic simulations. Receiver signal-to-noise ratio (SNR), temporal SNR (tSNR) across EPI time series, g-factors for accelerated imaging and noise correlations were evaluated and compared with a commercial 32 channel whole head coil. The performance of the coil was further evaluated with human subjects through functional MRI (fMRI) studies at standard and submillimeter resolutions of upto 0.8mm isotropic. The transmit and receive sections were characterized using bench tests and showed good interelement decoupling, preamplifier decoupling and sample loading. SNR for the 16 channel coil was ∼ 1.5 times that of the commercial coil in the human occipital lobe, and showed better g-factor values for accelerated imaging. fMRI tests conducted showed better response to Blood Oxygen Level Dependent (BOLD) activation, at resolutions of 1.2mm and 0.8mm isotropic. The 4 channel phased array transmit coil provides homogeneous excitation across the visual cortex, which, in combination with the dual row 16 channel receive array, makes for a valuable research tool for high resolution anatomical and functional imaging of the visual cortex at 7T.

Performance Analysis of Wavelet Channel Coding in COST207-based Channel Models on Simulated Radio-over-Fiber Systems at the W-Band

DEFF Research Database (Denmark)

Cavalcante, Lucas Costa Pereira; Silveira, Luiz F. Q.; Rommel, Simon

2016-01-01

Millimeter wave communications based on photonic technologies have gained increased attention to provide optic fiber-like capacity in wireless environments. However, the new hybrid fiber-wireless channel represents new challenges in terms of signal transmission performance analysis. Traditionally......, such systems use diversity schemes in combination with digital signal processing (DSP) techniques to overcome effects such as fading and inter-symbol interference (ISI). Wavelet Channel Coding (WCC) has emerged as a technique to minimize the fading effects of wireless channels, which is a mayor challenge...... in systems operating in the millimeter wave regime. This work takes the WCC one step beyond by performance evaluation in terms of bit error probability, over time-varying, frequency-selective multipath Rayleigh fading channels. The adopted propagation model follows the COST207 norm, the main international...

A strategy for determination of test intervals of k-out-of-n multi-channel systems

International Nuclear Information System (INIS)

Cho, S.; Jiang, J.

2007-01-01

State space models for determination of the optimal test frequencies for k-out-of-n multi channel systems are developed in this paper. The analytic solutions for the optimal surveillance test frequencies are derived using the Markov process technique. The solutions show that an optimal test frequency which maximizes the target probability can be determined by decomposing the system states to 3 states based on the system configuration and success criteria. Examples of quantification of the state probabilities and the optimal test frequencies of a three-channel system and a four-channel system with different success criteria are presented. The strategy for finding the optimal test frequency developed in this paper can generally be applicable to any k-out-of-n multi-channel standby systems that involve complex testing schemes. (author)

Cross correlation measurement of low frequency conductivity noise

Science.gov (United States)

Jain, Aditya Kumar; Nigudkar, Himanshu; Chakraborti, Himadri; Udupa, Aditi; Gupta, Kantimay Das

2018-04-01

In order to study the low frequency noise(1/f noise)an experimental technique based on cross correlation of two channels is presented. In this method the device under test (DUT)is connected to the two independently powered preamplifiers in parallel. The amplified signals from the two preamplifiers are fed to two channels of a digitizer. Subsequent data processing largelyeliminates the uncorrelated noise of the two channels. This method is tested for various commercial carbon/metal film resistors by measuring equilibrium thermal noise (4kBTR). The method is then modified to study the non-equilibrium low frequency noise of heterostructure samples using fiveprobe configuration. Five contact probes allow two parts of the sample to become two arms of a balanced bridge. This configuration helps in suppressing the effect of power supply fluctuations, bath temperature fluctuations and contact resistances.

Basis expansion model for channel estimation in LTE-R communication system

Directory of Open Access Journals (Sweden)

Ling Deng

2016-05-01

Full Text Available This paper investigates fast time-varying channel estimation in LTE-R communication systems. The Basis Expansion Model (BEM is adopted to fit the fast time-varying channel in a high-speed railway communication scenario. The channel impulse response is modeled as the sum of basis functions multiplied by different coefficients. The optimal coefficients are obtained by theoretical analysis. Simulation results show that a Generalized Complex-Exponential BEM (GCE-BEM outperforms a Complex-Exponential BEM (CE-BEM and a polynomial BEM in terms of Mean Squared Error (MSE. Besides, the MSE of the CE-BEM decreases gradually as the number of basis functions increases. The GCE-BEM has a satisfactory performance with the serious fading channel.

A channel multiplexing for the analog input channel of the advantech PCL-718 ADC-12 bit by using PCLD-889 programmable ampliplexer / multiplexer board have been done

International Nuclear Information System (INIS)

Sudiyanto; Aminus, S; Sujono, Djoko; Ngatinu; Sudaryanto; Wiyana, Badi

1996-01-01

A channel multiplexing for the analog input channels of the Advantech PCL-718 ADC-12 bit by using PCLD-889 programmable Amplifier / multiplexer board have been done. The experiments have been prepared by using Turbo-C software where every PCLD-889 board multiplexes 16 differential input channels into one analog output channel, up to 10 PCLD-889 can be cascaded to expand the analog input of PCL-718 ADC-12 bit to 8 x 16 channels

In-Service Inspection system for coolant channels of Indian PHWRS - evolution and experience

International Nuclear Information System (INIS)

Puri, R.K.; Singh, M.

2006-01-01

In-Service Inspection (ISI) is the most important of all periodic monitoring and surveillance activities for assuring the structural integrity of coolant channels in the life extension and management of pressurized heavy water reactors (PHWR-CANDU). Indian PHWRs (220 MWe) are characterized by consists by 306 coolant channels in each unit. These channels have to be inspected for various parameters over the operating life of the reactor. ISI of coolant channels necessitated the indigenous development of an inspection system called BARCIS (BARC Channel Inspection System) at Bhabha Atomic Research Center. BARCIS consists of mainly three parts; drive and control unit, special sealing plug and an inspection head carrying various NDT sensors. Five such systems have been built and deployed at various power plants. The paper deals with the development of the BARCIS system for meeting the ISI requirements of coolant channels, development cycle of this system from its conception to evolution to the present state, challenges, data generated and experience gained (ISI of nearly 900 coolant channels has been completed). Prior to BARCIS, pressure tube gauging equipment for pre-service inspection of coolant tubes was developed in 1980. Moreover a tool for ISI of coolant channels in dry condition was developed in 1990. The paper also describes evolution of various contingency procedures and devices developed over the last one decade. Future plans taking into account technological advancement, changes in the scope of inspection due to design and operating experiences and plant layout will also be covered. The paper describes the efforts put in to develop drive and control mechanism to suit the different vault layouts. The drive mechanism is responsible for linear and rotary movement of the inspection head to carry out 100% volumetric inspection. Special emphasis has been laid on the safety devices required during the inspection activity. Special measures for heavy water retention in

VEGA: A low-power front-end ASIC for large area multi-linear X-ray silicon drift detectors: Design and experimental characterization

Energy Technology Data Exchange (ETDEWEB)

Ahangarianabhari, Mahdi; Macera, Daniele [Politecnico di Milano, Department of Electronics Engineering, Information Science and Bioengineering, P.za L. da Vinci 32, 20133 Milano (Italy); National Institute of Nuclear Physics, INFN sez. Milano (Italy); Bertuccio, Giuseppe, E-mail: Giuseppe.Bertuccio@polimi.it [Politecnico di Milano, Department of Electronics Engineering, Information Science and Bioengineering, P.za L. da Vinci 32, 20133 Milano (Italy); National Institute of Nuclear Physics, INFN sez. Milano (Italy); Malcovati, Piero; Grassi, Marco [University of Pavia, Department of Electrical Engineering, and National Institute of Nuclear Physics, INFN sez. Pavia, Pavia (Italy)

2015-01-11

We present the design and the first experimental characterization of VEGA, an Application Specific Integrated Circuit (ASIC) designed to read out large area monolithic linear Silicon Drift Detectors (SDD’s). VEGA consists of an analog and a digital/mixed-signal section to accomplish all the functionalities and specifications required for high resolution X-ray spectroscopy in the energy range between 500 eV and 50 keV. The analog section includes a charge sensitive preamplifier, a shaper with 3-bit digitally selectable shaping times from 1.6 µs to 6.6 µs and a peak stretcher/sample-and-hold stage. The digital/mixed-signal section includes an amplitude discriminator with coarse and fine threshold level setting, a peak discriminator and a logic circuit to fulfill pile-up rejection, signal sampling, trigger generation, channel reset and the preamplifier and discriminators disabling functionalities. A Serial Peripherical Interface (SPI) is integrated in VEGA for loading and storing all configuration parameters in an internal register within few microseconds. The VEGA ASIC has been designed and manufactured in 0.35 µm CMOS mixed-signal technology in single and 32 channel versions with dimensions of 200 µm×500 µm per channel. A minimum intrinsic Equivalent Noise Charge (ENC) of 12 electrons r.m.s. at 3.6 µs peaking time and room temperature is measured and the linearity error is between −0.9% and +0.6% in the whole input energy range. The total power consumption is 481 µW and 420 µW per channel for the single and 32 channels version, respectively. A comparison with other ASICs for X-ray SDD’s shows that VEGA has a suitable low noise and offers high functionality as ADC-ready signal processing but at a power consumption that is a factor of four lower than other similar existing ASICs.

3D Massive MIMO Systems: Channel Modeling and Performance Analysis

KAUST Repository

Nadeem, Qurrat-Ul-Ain

2015-01-01

Multiple-input-multiple-output (MIMO) systems of current LTE releases are capable of adaptation in the azimuth only. More recently, the trend is to enhance the system performance by exploiting the channel's degrees of freedom in the elevation

Kv1 channels and neural processing in vestibular calyx afferents

Directory of Open Access Journals (Sweden)

Frances L Meredith

2015-06-01

Full Text Available Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K+ channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K+ channels could help alleviate vestibular dysfunction on earth and in space.

Kv1 channels and neural processing in vestibular calyx afferents.

Science.gov (United States)

Meredith, Frances L; Kirk, Matthew E; Rennie, Katherine J

2015-01-01

Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K(+) channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K(+) channels could help alleviate vestibular dysfunction on earth and in space.

The Ca{sup 2+} channel TRPML3 specifically interacts with the mammalian ATG8 homologue GATE16 to regulate autophagy

Energy Technology Data Exchange (ETDEWEB)

Choi, Suzy; Kim, Hyun Jin, E-mail: kimhyunjin@skku.edu

2014-01-03

Highlights: •Split-ubiquitin MY2H screen identified GATE16 as an interacting protein of TRPML3. •TRPML3 specifically binds to a mammalian ATG8 homologue GATE16, not to LC3B. •The interaction of TRPML3 with GATE16 facilitates autophagosome formation. •GATE16 is expressed in both autophagosome and extra-autophagosomal compartments. -- Abstract: TRPML3 is a Ca{sup 2+} permeable cation channel expressed in multiple intracellular compartments. Although TRPML3 is implicated in autophagy, how TRPML3 can regulate autophagy is not understood. To search interacting proteins with TRPML3 in autophagy, we performed split-ubiquitin membrane yeast two-hybrid (MY2H) screening with TRPML3-loop as a bait and identified GATE16, a mammalian ATG8 homologue. GST pull-down assay revealed that TRPML3 and TRPML3-loop specifically bind to GATE16, not to LC3B. Co-immunoprecipitation (co-IP) experiments showed that TRPML3 and TRPML3-loop pull down only the lipidated form of GATE16, indicating that the interaction occurs exclusively at the organellar membrane. The interaction of TRPML3 with GATE16 and GATE16-positive vesicle formation were increased in starvation induced autophagy, suggesting that the interaction facilitates the function of GATE16 in autophagosome formation. However, GATE16 was not required for TRPML3 trafficking to autophagosomes. Experiments using dominant-negative (DN) TRPML3(D458K) showed that GATE16 is localized not only in autophagosomes but also in extra-autophagosomal compartments, by contrast with LC3B. Since GATE16 acts at a later stage of the autophagosome biogenesis, our results suggest that TRPML3 plays a role in autophagosome maturation through the interaction with GATE16, by providing Ca{sup 2+} in the fusion process.

Novel 16-channel receive coil array for accelerated upper airway MRI at 3 Tesla.

Science.gov (United States)

Kim, Yoon-Chul; Hayes, Cecil E; Narayanan, Shrikanth S; Nayak, Krishna S

2011-06-01

Upper airway MRI can provide a noninvasive assessment of speech and swallowing disorders and sleep apnea. Recent work has demonstrated the value of high-resolution three-dimensional imaging and dynamic two-dimensional imaging and the importance of further improvements in spatio-temporal resolution. The purpose of the study was to describe a novel 16-channel 3 Tesla receive coil that is highly sensitive to the human upper airway and investigate the performance of accelerated upper airway MRI with the coil. In three-dimensional imaging of the upper airway during static posture, 6-fold acceleration is demonstrated using parallel imaging, potentially leading to capturing a whole three-dimensional vocal tract with 1.25 mm isotropic resolution within 9 sec of sustained sound production. Midsagittal spiral parallel imaging of vocal tract dynamics during natural speech production is demonstrated with 2 × 2 mm(2) in-plane spatial and 84 ms temporal resolution. Copyright © 2010 Wiley-Liss, Inc.

Energy independent uniformity improvement for gamma camera systems

International Nuclear Information System (INIS)

Lange, K.

1979-01-01

In a gamma camera system having an array of photomultiplier tubes for detecting scintillation events and preamplifiers connecting each tube to a weighting resistor matrix for determining the position coordinates of the events, means are provided for summing the signals from all photomultipliers to obtain the total energy of each event. In one embodiment, at least two different percentages of the summed voltage are developed and used to change the gain of the preamplifiers as a function of total energy when energies exceed specific levels to thereby obtain more accurate correspondence between the true coordinates of the event and its coordinates in a display

Angular momentum distributions for 16O+144Nd

International Nuclear Information System (INIS)

Duchene, G.; Romain, P.; Beck, F.A.; Benet, P.; Disdier, D.; Haas, B.; Lott, B.; Rauch, V.; Scheibling, F.; Vivien, J.P.; Basu, S.K.; Bozek, E.; Zuber, K.; Di Gregorio, D.; Fernandez-Niello, J.

1993-01-01

Fusion cross sections have been measured for the system 16 O+ 144 Nd at bombarding energies in the range 67 MeV≤E lab ≤90 MeV by detecting directly evaporation residues in Si detectors and in the range 60 MeV≤E lab ≤75 MeV by off-line detection of the K x rays emitted by the radioactive evaporation residues and daughters. In order to obtain the spin distributions in the compound system gamma-ray multiplicity distributions for the most important neutron evaporation channels were also measured using a 4π BaF 2 array, in conjunction with Ge detectors. Results are compared with calculations based on models that consider fluctuations in barrier height due to ground-state zero-point vibrations as well as couplings to various inelastic and transfer channels

The 'KATOD-1' strip readout ASIC for cathode strip chamber

International Nuclear Information System (INIS)

Golutvin, I.A.; Gorbunov, N.V.; Karzhavin, V.Yu.; Khabarov, V.S.; Movchan, S.A.; Smolin, D.A.; Dvornikov, O.V.; Shumejko, N.M.; Chekhovskij, V.A.

2001-01-01

The 'KATOD-1', a 16-channels readout ASIC, has been designed to perform tests of P3 and P4 full-scale prototypes of the cathode strip chamber for the ME1/1 forward muon station of the Compact Muon Solenoid (CMS) experiment. The ASIC channel consists of two charge-sensitive preamplifiers, a three-stage shaper with cancellation, and an output driver. The ASIC is instrumented with control of gain, in the range of (-4.2 : +5.0) mV/fC, and control of output pulse-shape. The equivalent input noise is equal to 2400 e with the slope of 12 e/pF for detector capacity up to 200 pF. The peaking time is 100 ns for the chamber signal. The ASIC has been produced by a microwave Bi-jFET technology

Reactor core protection system using a 4-channel microcomputer

International Nuclear Information System (INIS)

Mertens, U.

1982-12-01

A four channel microcomputer system was fitted in Grafenrheinfeld NPP for local core protection. This system performs continuous on-line monitoring of peak power density, departure from nucleate boiling ratio and fuel duty. The system implements limitation functions with more sophisticated criteria and improved accuracy. The Grafenrheinfeld system points the way to the employment of computer based limitation system, particularly in the field of programming language, demarkation of tasks, commissioning and documentation aids, streamlining of qualification and structuring of the system. (orig.) [de

Networked control of discrete-time linear systems over lossy digital communication channels

Science.gov (United States)

Jin, Fang; Zhao, Guang-Rong; Liu, Qing-Quan

2013-12-01

This article addresses networked control problems for linear time-invariant systems. The insertion of the digital communication network inevitably leads to packet dropout, time delay and quantisation error. Due to data rate limitations, quantisation error is not neglected. In particular, the case where the sensors and controllers are geographically separated and connected via noisy, bandwidth-limited digital communication channels is considered. A fundamental limitation on the data rate of the channel for mean-square stabilisation of the closed-loop system is established. Sufficient conditions for mean-square stabilisation are derived. It is shown that there exists a quantisation, coding and control scheme to stabilise the unstable system over packet dropout communication channels if the data rate is larger than the lower bound proposed in our result. An illustrative example is given to demonstrate the effectiveness of the proposed conditions.

Design and Performance Analysis of MISO-ORM-DCSK System over Rayleigh Fading Channels

Directory of Open Access Journals (Sweden)

Gang Zhang

2016-01-01

Full Text Available A novel chaotic communication system, named Orthogonality-based Reference Modulated-Differential Chaos Shift Keying (ORM-DCSK, is proposed to enhance the performance of RM-DCSK. By designing an orthogonal chaotic generator (OCG, the intrasignal interference components in RM-DCSK are eliminated. Also, the signal frame format is expanded so the average bit energy is reduced. As a result, the proposed system has less interference in decision variables. Furthermore, to investigate the bit error rate (BER performance over Rayleigh fading channels, the MISO-ORM-DCSK is studied. The BER expressions of the new system are derived and analyzed over AWGN channel and multipath Rayleigh fading channel. All simulation results not only show that the proposed system can obtain significant improvement but also verify the analysis in theory.

Ultra-fast secure communication with complex systems in classical channels (Conference Presentation)

KAUST Repository

Mazzone, Valerio

2017-04-28

Developing secure communications is a research area of growing interest. During the past years, several cryptographic schemes have been developed, with Quantum cryptography being a promising scheme due to the use of quantum effects, which make very difficult for an eavesdropper to intercept the communication. However, practical quantum key distribution methods have encountered several limitations; current experimental realizations, in fact, fail to scale up on long distances, as well as in providing unconditional security and speed comparable to classical optical communications channels. Here we propose a new, low cost and ultra-fast cryptographic system based on a fully classical optical channel. Our cryptographic scheme exploits the complex synchronization of two different random systems (one on the side of the sender and another on the side of the receiver) to realize a “physical” one paid system. The random medium is created by an optical chip fabricated through electron beam lithography on a Silicon On Insulator (SOI) substrate. We present experiments with ps lasers and commercial fibers, showing the ultrafast distribution of a random key between two users (Alice and Bob), with absolute no possibility for a passive/active eavesdropper to intercept the communication. Remarkably, this system enables the same security of quantum cryptography, but with the use of a classical communication channel. Our system exploits a unique synchronization that exists between two different random systems, and at such is extremely versatile and can enable safe communications among different users in standards telecommunications channels.

Dual-goniometer system for channeling measurements

International Nuclear Information System (INIS)

Linden, M.; Hellborg, R.

1986-03-01

This paper describes a two-goniometer system for obtaining azimuthally averaged measurements in channeling experiments. The system consists of a tri-axial master goniometer and a bi-axial goniometer. Both goniometers are controlled by stepping motors. The alignment goniometer has a target holder, which permits the beam spot to be placed anywhere in a 6 x 6 mm 2 square on the target crystal without loosing the target orientation. The design, construction and operation of the goniometers as well as stepping motor control units and programs for computer control of the goniometers are described. Two control programs cover orientation of the target crystal and a number of other normal experimental conditions. (author)

Efficient optimal joint channel estimation and data detection for massive MIMO systems

KAUST Repository

Alshamary, Haider Ali Jasim

2016-08-15

In this paper, we propose an efficient optimal joint channel estimation and data detection algorithm for massive MIMO wireless systems. Our algorithm is optimal in terms of the generalized likelihood ratio test (GLRT). For massive MIMO systems, we show that the expected complexity of our algorithm grows polynomially in the channel coherence time. Simulation results demonstrate significant performance gains of our algorithm compared with suboptimal non-coherent detection algorithms. To the best of our knowledge, this is the first algorithm which efficiently achieves GLRT-optimal non-coherent detections for massive MIMO systems with general constellations.

Note: Experimental observation of nano-channel pattern in light sheet laser interference nanolithography system

Energy Technology Data Exchange (ETDEWEB)

Mohan, Kavya; Mondal, Partha Pratim, E-mail: partha@iap.iisc.ernet.in [Nanobioimaging Laboratory, Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India)

2016-06-15

We experimentally observed nano-channel-like pattern in a light-sheet based interference nanolithography system. The optical system created nano-channel-like patterned illumination. Coherent counter-propagating light sheets are made to interfere at and near geometrical focus along the propagation z-axis. This results in the formation of nano-channel-like pattern (of size ≈ 300 nm and inter-channel periodicity of ≈337.5 nm) inside the sample due to constructive and destructive interference. In addition, the technique has the ability to generate large area patterning using larger light-sheets. Exciting applications are in the broad field of nanotechnology (nano-electronics and nano-fluidics).

Linear Modeling and Regulation Quality Analysis for Hydro-Turbine Governing System with an Open Tailrace Channel

Directory of Open Access Journals (Sweden)

Jiandong Yang

2015-10-01

Full Text Available On the basis of the state–space method (SSM, a novel linear mathematical model of the unsteady flow for the tailrace system with an open channel is proposed. This novel model is an elastic linearized model of water hammer. The validity of the model has been verified by several examples of numerical simulation, which are based on a finite difference technique. Then, the complete mathematical model for the hydro-turbine governing system of hydropower station with an open tailrace channel, which is used for simulating the transient process of the hydro-turbine governing system under load disturbance, is established by combining the models of hydro-turbine, generator, governor and open tailrace channel. Finally, according to the complete model, the regulation quality for hydro-turbine governing system with an open tailrace channel under load disturbance is studied, and the effects of open tailrace channel and tailrace surge tank on regulation quality are analyzed. The results indicate that: The open tailrace channel has a strong influence on the regulation quality by observing the water level fluctuations in tailrace surge tank. The surge shows a piecewise periodical change along with the variation in the length of an open channel. The open tailrace channel can be used to improve the regulation quality of hydro-turbine governing system.