A 32-channel charge readout IC for programmable, nonlinearquantization of multichannel detector data

A Charge Readout Integrated Circuit (CRIC) which converts detector charges to digital codes is described. The CRIC provides 32 channels of circuitry needed to form charge-to-digital converters having a total dynamic range of 17 b comprised of 4 b of pre-amp gain control and a conversion range of 13 b. Each channel includes a switched-capacitor integrator, a double-sampling amplifier, a sampling comparator, and a 12-b digital latch, forming a pipeline from which a new conversion result is readout every 50 μs. The data conversion scheme implements a programmable compression curve, which is stored as a lookup table in an off-chip, digital memory. In addition to the lookup table, data conversion requires an off-chip digital-to-analog converter, both of which may be shared by any number of CRIC's. The CRIC was fabricated using a 3-μm, n-well BiCMOS process, and occupies a die area of 5.1 mm×7.5 mm. It operates at 10 MHz, consumes 440 mW from ±5-V supplies, and has a demonstrated input-referred noise performance of 2.2 μV r.m.s., i.e., 1400 e^- on 100 pF of shunt capacitance     

High dynamic range temperature point sensor using greenfluorescence intensity ratio in erbium-doped silica fiber

We propose a sensor based on the temperature dependant behavior of the two lines of green emission of the erbium ion. The ratio of the intensities of these two lines presents a very low dependance on pump wavelength and pump power fluctuations. The sensitivity of the ratio is 0.013/°C between room temperature and 600°C. In addition, the measurement is self-calibrated     

Complete single mode wavelength coverage over 40 nm with a superstructure grating DBR laser

The spectral characteristics of a widely tunable super structure grating distributed Bragg reflector (SSG-DBR) laser are investigated and the design considerations of the grating reflectors are given. By systematically adjusting the control currents of the two reflector sections and the phase section it is experimentally shown that every wavelength in an interval of 40 nm can be reached with a side-mode suppression usually better than 30 dB     

QCD corrections to the forward-backward asymmetries of c and b quarks at the Z pole

Measurements of the forward-backward production asymmetry of heavy quarks in Z decays provide a precise determination of . The asymmetries are sensitive to QCD effects, in particular hard gluon radiation. In this paper QCD corrections for and are discussed. The interplay between the experimental techniques used to measure the asymmetries and the QCD effects is investigated using simulated events. A procedure to estimate the correction needed for experimental measurements is proposed, and some specific examples are given. Received: 26 February 1998 / Published online: 2 June 1998     

Penetration of electromagnetic fields through an elliptical hole ina wall of finite thickness

The penetration of electromagnetic fields through an elliptical hole of variable eccentricity in a wall of finite thickness is analyzed. Six cases are considered: p≈0, 0.2, 0.4, 0.6, 0.8, 1, where p=(a-b)/(a+b), a and b being semimajor and semiminor axes of the ellipse. Polarizabilities and susceptibilities are calculated. Results for zero-thickness wall are compared to known analytical expressions     

Samuelson maps—recent results

Samuelson maps are maps whose Jacobian matrix has nowhere vanishing leading principal minors. This paper surveys some recent results on invertibility of Samuelson maps and their decomposition into maps that fix all but one coordinate. The most noteworthy result is that real, rational, everywhere defined Samuelson maps are invertible. Proofs are sketched or omitted entirely.     

Rotational discontinuity in magnetohydrodynamics

Novosibirsk. Translated fromSibirskiî Matematicheskiî Zhurnal, Vol. 34, No. 3, pp. 3–18, May–June, 1993.     

Optical fiber-polymer guide coupling by a tapered graded indexglass guide

A new four layer tapered coupler (FLTC) has been studied and tested, able to transfer light efficiently from a monomode fiber to a polymer film guide by means of an auxiliary graded index glass waveguide. A simple theory has been developed to calculate the maximum efficiency of these structures. Experiments have been performed, at λ=1.321 μm, on several FLTC samples, containing K⁺-Na⁺ ion-exchanged glass waveguides and spin coated poly-3BCMU films. Insertion losses in the range 3-6.5 dB have been measured, depending on the taper configuration. The agreement between theoretical and experimental data is good, provided that a suitable ripple of the taper profile is assumed. The application of the new coupler to future integrated waveguide systems, including passive glass components and polymer based all optical devices, is assessed