The effects of microbiological activities on the surface composition of Alloy 22 was investigated. Prior studies suggesting microbially-generated selective dissolution of chromium from Alloy 22 were based solely on analyzing solubilized Alloy 22 elements. These and other investigations point to the insufficiencies of analyzing solubilized (or solubilized and reprecipitated) alloying elements to discern between homogeneous/stoichiometric dissolution and selective/non-stoichiometric dissolution of alloying elements. Therefore, an approach using X-ray Photoelectron Spectroscopy (XPS) to interrogate the surface layers of treated Alloy 22 specimens was taken to resolve this issue. Sputtering into the surface of the samples, coupled with XPS analysis at given intervals, allowed a high resolution quantitative elemental evaluation of the alloy as a function of depth. Biotically-incubated Alloy 22 show a region that could be depleted of chromium. Surfacial XPS analysis of these same coupons did not detect the presence of re-precipitated Alloy 22 component elements, also supporting the possible occurrence of non-stoichiometric dissolution. Thus, these preliminary data do not exclude the possibility of selective dissolution. It also appears that this experimental approach shows promise to unequivocally resolve this issue. Further tests using smoother-surface, more highly polished coupons should allow for better resolution between surface layers to permit a decisive determination …

A technique for inhibiting the growth of laser-induced surface damage on fused silica, initiated and propagated at the 351 nm laser wavelength, has been investigated. The technique exposes the damage sites to single pulses of a CO{sub 2} laser operating at the 10.6 {micro}m wavelength at or near beam focus. This method results in a very localized treatment of the laser damage site and modifies the site such that laser damage does not propagate further. A laser damage site initiated with a single pulse of 355 nm laser light at {approx} 45 J cm{sup -2} and 7.5 ns pulse duration grows rapidly upon further illumination at 8 J cm{sup -2} with 100% probability. Treatment of these sites with single pulses of 10.6 {micro}m laser light for one second at a power level of between 17 and 37 Watts with a beam diameter of 5 mm alters the damage site such that it does not grow with subsequent 351 nm laser illumination at 8 J cm{sup -2} 10 ns pulse duration for > 1000 shots. The technique has been found to be 100% effective at stopping the growth of the laser damage.

The Tevatron Run 2 has begun. The Tevatron program in the next six years offers a real opportunity to significantly advance our understanding of the fundamental properties of the universe. It is an exciting, challenging program that goes straight to the highest priorities of high energy physics worldwide. The accelerator and detectors are being commissioned and seem to be performing well. We anticipate first physics results in the summer of 2002.

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The CDF silicon tracking system for Run II of the Fermilab Tevatron consists of eight layers arranged in cylinders spanning radii from 1.35cm to 28cm, and lengths from 90cm to nearly two meters for a total of six square meters of silicon and 722,000 readout channels. With an innermost layer (Layer 00) utilizing radiation tolerant p{sup +}-in-n silicon and low-mass readout cables between the sensors and readout electronics, double-sided vertexing layers (SVXII) designed for use with a deadtimeless secondary-vertex trigger, and outermost layers (ISL) utilizing mass-producible modules attached to a carbon fiber spaceframe, this system is a starting point for the next generation of silicon trackers for the LHC and Tevatron.

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In future experiments the readout electronics for pixel detectors is required to be resistant to a very high radiation level. In this paper we report on irradiation tests performed on several preFPIX2 prototype pixel readout chips for the BTeV experiment exposed to a 200 MeV proton beam. The prototype chips have been implemented in commercial 0.25 {micro}m CMOS processes following radiation tolerant design rules. The results show that this ASIC design tolerates a large total radiation dose, and that radiation induced Single Event Effects occur at a manageable level.

The CDF Layer 00 detector consists of single-sided silicon sensors assembled on the beampipe, forming the innermost of eight silicon layers in the CDF detector for Run II of the Fermilab Tevatron. Radiation tolerant p-in-n silicon with 25(50) {micro}m implant(readout) pitch are mounted on a lightweight, cooled support structure and connect to electronics outside the tracking volume via long, fine-pitch cables. Layer 00 will significantly improve the impact parameter resolution and enhance the longevity of the silicon system, benefiting a large portion of the physics program for Run II.

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We describe a study of the underlying event in jet and minimum bias events using data from the CDF detector. The underlying event contribution to the jet energy has been calculated in jet events and compared to the results of two Monte Carlo programs: Herwig and Pythia. The analysis has been carried out at two different center of mass energies: {radical}s = 1800 and 630 GeV. For most observables, good agreement is obtained with at least one of the Monte Carlo programs. Neither program describes all features of the data.

We investigate the uncertainties of the heavy-quark parton distribution functions in the variable avor number scheme. Because the charm- and bottom-quark parton distribution functions (PDFs) are constructed predominantly from the gluon PDF, it is a common practice to assume that the heavy-quark and gluon uncertainties are the same. We show that this approximation is a reasonable first guess, but it is better for bottom quarks than charm quarks. We calculate the PDF uncertainty for t-channel single-top-quark production using the Hessian matrix method, and predict a cross section of 2.12{sub -0.29}{sup +0.32} pb at run II of the Tevatron.

The CDF detector collected during 1992-95 (Run I) a data sample of 110 pb{sup -1} p{bar p} collisions at a center of mass energy {radical}s = 1.8 TeV. A large variety of physical studies and measurements has been performed using these data. The current paper wants to review results obtained using this data sample as well as discuss the CDF-II upgrades and physical potential of the upgraded CDF Detector (CDF-II) in the Run II.