Harold D. Skank

Measurement of texture and formability parameters with a fully automated, ultrasonic instrument

A fully automatic, ultrasonic instrument to measure texture and formability parameters on metal sheet is described. Arrays of EMAT transducers are used to transmit and receiveSo Lamb waves propagating at 0°, 45°, and 90° with respect to the rolling direction. By analyzing the frequency dependence of the phase of the received signals, the long wavelength limit of the velocities is obtained. Included is a discussion of this algorithm, and subsequent processing steps to predict the ODCsW400,W420, andW440. On steel, the prediction of drawability parametersr and Δr based on a correlation developed previously by Mould and Johnson is also discussed. Results of blind field trials at facilities of three suppliers/users of steel sheet for automotive applications and one supplier of aluminum sheet for beverage can production are reported. The former confirmed the Mould-Johnson correlation for lowr material but indicated that refinements are needed for modern steels with highr. The aluminum data suggest a correlation between W440 and the degree of four-fold earing.

A digital phase shifter for multiple pulse NMR

An eight bit digital phase shifter is described which is suitable for multiple pulse NMR of solids in terms of settling time (≂2 μs) and phase resolution (1.406°). The unit incorporates an 8‐bit Merrimac digital phase shifter model PSDW‐84‐1, and an amplification‐damping‐pulse shaping circuit to solve the problem of variable attenuation as a function of phase setting. Results of multiple quantum spin counting and homonuclear dipolar decoupling experiments on ensembles of strongly dipolar coupled spin 1/2 systems are used to demonstrate the capability of the unit.

Ultrasonic instrument to predict drawability of sheet metal

An ultrasonic instrument has been designed and fabricated to predict drawability of sheet metal. Using S/sub 0/ mode Lamb waves generated and detected by EMATs (electromagnetic-acoustic transducers), the instrument automatically measures ultrasonic phase delay in three directions: 0 degrees , 45 degrees , and 90 degrees with respect to the rolling direction. The delay is measured by a Fourier transform phase-versus-frequency slope algorithm applied to flash AD recorded EMAT signals. From the delays, the computer-based instrument calculates velocities and the directional Youngs modulus E(O) in the rolling plane. From the average E in the plane, a correlation curve is used to find the average plastic strain ratio, which is the drawability prediction parameter.<<ETX>>

Digitally controlled measurement of sonic elastic moduli and internal friction by phase analysis

An automated system is described for measuring internal friction and elastic moduli using sonic resonance techniques. This mirocomputer‐controlled device does phase angle analysis in addition to traditional decay and peak‐width internal friction measurement. The apparatus may be programmed to make measurements at any sequence of temperatures between room temperature and 1600 °C.

A high mass trigger for the E864 experiment at the AGS accelerator

Abstract The E864 experiment at the AGS is designed to carry out high sensitivity searches for a variety of possible new particles using relativistic heavy ion Au beams on Pb and Pt targets. In order to reach the desired sensitivities, a level-2 “late energy” trigger was built to select events in which a heavy particle is detected in a hadronic calorimeter with deposited energy and time-of-flight from the target exceeding preset values. The physics motivation for the trigger is discussed and and details of its hardware and software design are given. Performance results from recent E864 data taking runs are presented.

Design and Fabrication of an Industrial-Grade Instrument to Measure Texture and Predict Drawability in Sheet Metal

Texture in sheet metal must be controlled in the rolling process to assure the fabrication properties desired in later manufacturing. Drawability is one of the required engineering properties in a family of applications including beverage cans, propane tanks, and automotive parts.

The PHENIX Level-1 Trigger system

The PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) will study the dynamics of ultra-relativistic heavy ion collisions and search for exotic states of matter, most notably the quark gluon plasma (QGP). Substantial event selectivity is needed at RHIC to enhance interesting events relative to more common ones and to satisfy the requirements of the data acquisition system. The first on-line screening is achieved by the Level-1 Trigger. The Level-1 Trigger is a beamclock parallel-pipeline system that uses six Local Level-1 (LL1) algorithms pertaining to the six fastest PHENIX subdetectors, followed by a Global Level-1 (GL1) system that processes encoded LL1 reduced-bit data to issue up to 128 triggers. The GLI system is also responsible for organizing the partitioned running of the PHENIX detector. The LL1 algorithms operate on raw data to produce a first estimate of the number of electrons, photons, muons and hadrons as well as the transverse energy, event multiplicity, interaction time and vertex. The latency of the entire system is less than 40 beam crossings. The Level-1 Trigger is implemented using custom-designed 9U VME-P format boards.

A spectrometer for study of high mass objects created in relativistic heavy ion reactions

Abstract Experiment E864 at the Brookhaven AGS accelerator uses a high sensitivity, large acceptance spectrometer, designed to search for strangelets and other novel forms of matter produced in high-energy heavy ion collisions. The spectrometer has excellent acceptance and rate capabilities for measuring the production properties of known particles and nuclei such as p, d and 6 He . The experiment uses a magnetic spectrometer and employs redundant time of flight and position detectors and a hadronic calorimeter. In this paper we describe the design and performance of the spectrometer.

PHENIX Level-1 Trigger systems for RHIC run-3

The PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) will study the dynamics of ultra-relativistic heavy ion collisions and search for exotic states of matter, most notably the Quark Gluon Plasma (QGP). Substantial event selectivity is needed at RHIC to enhance interesting events relative to more common ones and to satisfy the requirements of the data acquisition system. The first on-line screening is achieved by the Level-1 Trigger. The Level-1 Trigger is a beam-clock parallel-pipeline system that uses Local Level-1 (LL1) algorithms pertaining to the fastest PHENIX subdetectors, followed by a Global Level-1 (GL1) system that processes encoded LL1 reduced-bit data to issue up to 32 triggers. In this paper we discuss a new set of LL1 trigger systems that will be deployed for the third RHIC run. These new trigger systems utilize the same basic hardware designed around commercial FPGA logic in order to provide a common platform for a wide variety of physics triggers.

PHENIX trigger system

Abstract A two level trigger system has been implemented in the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). Level 1 trigger system (LVL1) processes the reduced data from a part of the detector subsystems in parallel and makes a decision on each beam crossing. For each accepted event the information from LVL1 is added to the detector data stream. A detector partitioning mechanism accomplished in LVL1 permits to operate PHENIX both as a whole detector (single partition) as well as a group of different combinations of the detector subsystems (multiple partitions). The Level 2 trigger system (LVL2) makes a fast analysis of each accepted event and decides if its data have to be stored or to be discarded. A description of the components and operation of the PHENIX trigger system is presented in this article.