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Because of the broad interest in high energy and nuclear physics community, mass production capacities of lead tungstate crystals have been established. The optical and scintillation properties of lead tungstate crystals, 20 each from two major vendors, were evaluated. The transmittance, emission and excitation spectra, light output and light response uniformity of these samples were measured. The degradations of these properties under irradiation, and the emission weighted radiation induced absorption coefficient (EW RI AC) were also studied. It was found that currently mass-produced lead tungstate crystals are radiation hard enough for radiation environments where expected dose rates do not exceed a few hundred rad/h. Index Terms--Crystal, emission, lead tungstate, light output, radiation damage, scintillator, transmission.

Ten pieces of Y-Ba-Cu-O bulk current leads are fabricated and transport properties in liquid nitrogen at an applied magnetic field of 0.5 T is investigated. A transport model of this type of current leads for predicting the I - V characteristics and the critical current, and confirmed that the predicted behavior agrees well with the experimental results.

The effect of the imprint on the operation of ferroelectric random access memory (FeRAM) is estimated. A quansitheoretical model is used that includes the hysteresis shift along the voltage axis and the depolarization induced by the hysteresis shift.

Research describing the the mechanical damping effect of lead metaniobate is presented. For the research, an instrument for determining viscoelastic measurements in bending and torsion was used.

The investigation performed up to now on single crystals of PbW[O.sub.4] (PWO) provides the evidence of the possibility to optimise the optical properties of an intrinsic scintillator such as PWO: the control of essential requirements in the crystal preparation (raw material purity, growing methods and post-growth annealing) as well as the introduction of selected dopants at suitable concentrations (particularly trivalent and pentavalent ions) were found to be very successful in lowering the concentration of point defects in the lattice which strongly affect scintillation properties and radiation hardness. The optical transmission as well as light yield before and after irradiation was measured. The systematic investigation effort to better understand the scintillation characteristics and to improve the quality of PWO crystals is due to their use for the CMS electromagnetic calorimeter.

It has recently been shown that lead sulfate (Pb[SO.sub.4]) is a promising scintillator material for use in PET detector systems. However, for lead sulfate scintillators to be useful in such an application, a technique must be developed to grow large optical quality crystals of this material. This paper describes our research into the high-temperature solution growth of Pb[SO.sub.4] crystals. We report on the systematic selection of solvent materials including KCl, LiCl, Pb[Cl.sub.2], [Na.sub.2][SO.sub.4] and [Li.sub.2][SO.sub.4]. Our studies indicate that [Na.sub.2][SO.sub.4] is the best solvent. With [Na.sub.2][SO.sub.4] as the flux, we obtained Pb[SO.sub.4] single crystals of several millimeters in size by Bridgman crystal growth method. We employed ACRT (Accelerated Crucible Rotation Technique), to resolve the constitutional supercooling problem, thus increased the crystal yield and reduced the number of grains. Finally, we compared the scintillation properties of synthetic Pb[SO.sub.4] crystals we grew with previous measurements on natural anglesite and other synthetic crystals, and found them nearly identical.

A study has been made on the properties of lead fluoride as a Cherenkov material for use in electromagnetic calorimetry. A prototype calorimeter module consisting of a 5 x 5 array of 2.1 x 2.1 x 18.5 |cm.sup.3~ crystals has been built and tested in a test beam at the Brookhaven AGS. Results are given on energy resolution, shower size and e/|Pi~ separation for electrons and pions in the range from 1-4 GeV. The light output has been measured to give |greater than or similar to~ 1000 photoelectrons per MeV in good quality crystals, and to provide useful signals down to as low as 32 MeV. Measurements were also made on radiation damage in lead fluoride using 60Co gamma rays and high energy ionizing particles, as well as on thermoluminescence after irradiation. It was found that only modest damage occurs up to a level of |similar to~ 30 Krad in large, calorimeter size crystals, and that the damage can be easily removed by optical bleaching.

We report on the scintillation properties of lead sulfate ([PbSO.sub.4]), a scintillator that shows promise as a high energy photon detector. its physical properties are well suited for gamma detection, as it has a density of 6.4 [gm/cm.sup.3], a 1/e attenuation length for 511 keV photons of 1.2 cm, is not affected by air or moisture, and is cut and polished easily. In 99.998% pure [PbSO.sup.4] crystals at room temperature excited by 511 keV annihilation photons, the fluorescence decay lifetime contains significant fast components having 1.8 ns (5%) and 19 ns (36%) decay times, but with longer components having 95 ns (36%) and 425 ns (23%) decay times. The peak emission wavelength is 335 nm, which is transmitted by borosilicate glass windowed photomultiplier tubes. The total scintillation light output increases with decreasing temperature from 3,200 photons/MeV at +45 [degrees] C to 4,900 photons/MeV at room temperature (+25 [degrees] C) and 68,500 photons/MeV at -145 [degrees] C. In an imperfect, 3 mm cube of a naturally occurring mineral form of [PbSO.sup.4] (anglesite) at room temperature, a 511 keV photopeak is seen with a total light output of 60% that of BGO. There are significant sample to sample variations of the light output among anglesite samples, so the light output of lead sulfate may improve when large synthetic crystals become available.