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The Young Physicists' Forum was an opportunity for the younger members of the particle-physics community to gather at Snowmass 2001 and to study and debate major issues that face the field over the next twenty years. Discussions were organized around three major topics: outreach and education, the impact of globalization, and building a robust and balanced field. We report on the results of these discussions, as presented on July 17, 2001.

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Head-on and long-range induced tunespread of about 0.025 in the Tevatron collider at Run II (together with the increased strength of the resonances) can significantly deteriorate the {bar p} lifetime and the collider luminosity. It was proposed to employ the so-called Tevatron Electron Lenses (TEL) to compress the beam-beam footprint and eliminate completely the bunch-to-bunch tunespread (PACMAN effect) for small amplitude particles. The first lens has been recently installed and tested [1]. This report presents results of analytical studies and tracking simulations of the linear beam-beam compensation (elimination of the bunch-to-bunch tune variation). Compression of the beam-beam footprint (nonlinear compensation) is discussed in [2].

In a highly collaborative research and development project with mining and university partners, sensors and data-analysis tools are being developed for rock-mass characterization and real-time measurement of mineral content. Determining mineralogy prior to mucking in an open-pit mine is important for routing the material to the appropriate processing stream. A possible alternative to lab assay of dust and cuttings obtained from drill holes is continuous on-line sampling and real-time x-ray fluorescence (XRF) spectroscopy. Results presented demonstrate that statistical analyses combined with XRF data can be employed to identify minerals and, possibly, different rock types. The objective is to create a detailed three-dimensional mineralogical map in real time that would improve downstream process efficiency.

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is beginning its second year of operation. A cesium sputter ion source injecting into a tandem Van de Graaff provides the gold ions for RHIC. The ion source is operated in the pulsed beam mode and produces a 500{micro}sec long pulse of Au{sup -} with a peak intensity of 290pA at the entrance of the tandem. After acceleration in the tandem and post stripping, this results in a beam of Au{sup +32} with an intensity of 80e{micro}A and an energy of 182MeV. Over the last several years, a series of improvements have been made to increase the intensity of the pulsed beam from the ion source. Details of the source performance and improvements will be presented. In addition, an effort is under way to provide other beam species for RHIC collisions.

The Fanout system is part of the Silicon Vertex Tracker, a new trigger processor designed to reconstruct charged particle trajectories at Level 2 of the CDF trigger, with a latency of 10 {micro}s and an event rate up to 100 kHz. The core of SVT is organized as 12 identical slices, which process in parallel the data from the 12 independent azimuthal wedges of the Silicon Vertex Detector (SVXII). Each SVT slice links the digitized pulse heights found within one SVXII wedge to the tracks reconstructed by the Level 1 fast track finder (XFT) in the corresponding 30{sup o} angular region of the Central Outer Tracker. Since the XFT tracks are transmitted to SVT as a single data stream, their distribution to the proper SVT slices requires dedicated fanout logic. The Fanout system has been implemented as a multi-board project running on a common 20 MHz clock. Track fanout is performed in two steps by one ''Fanout A'' and two ''Fanout B'' boards. The architecture, design, and implementation of this system are described.

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Since October 1999 we carry out continuous measurements of the slow ground motion on and nearby Fermilab site with a primary goal to provide experimental data for the Very Large Hadron Collider (VLHC) and Next Linear Collider (NLC) projects. Here we give a general description of the experimental set-up, present main results and discuss consequences for the colliders.

The Savannah River Site Evaporators have run with limited operation problems for almost 40 years. In October 1999, one evaporator was shut down due to the inability to lift the concentrate solutions from the pot. Different methods of pot liquid heating, cooling, and selection of optimum method were discussed.

This paper summarizes efforts related to developing a technically justifiable approach for addressing the axial burnup distribution in PWR burnup-credit criticality safety analyses. The paper reviews available data on the axial variation in burnup and the effect of axial burnup profiles on reactivity in a SNF cask. A publicly available database of profiles is examined to identify profiles that maximize the neutron multiplication factor, k{sub eff}, assess its adequacy for general PWR burnup credit analyses, and investigate the existence of trends with fuel type and/or reactor operations. For this assessment, a statistical evaluation of the k{sub eff} values associated with the profiles in the axial burnup profile database was performed that identifies the most reactive profiles as statistical outliers that are not representative of typical discharged SNF assemblies. The impact of these bounding profiles on the neutron multiplication factor for a high-density burnup credit cask is quantified. Finally, analyses are presented to quantify the potential reactivity consequence of assemblies with axial profiles that are not bounded by the existing database. The paper concludes with findings for addressing the axial burnup distribution in burnup credit analyses.

Improvements in the Fermilab operating 400-MeV linear accelerator injector are required to achieve the beam intensity and emittance requirement of the Proton Driver design study [5]. It has been determined that these requirements can be achieved by replacing the components in the Linac below 10 MeV. An improved H{sup {minus}} ion source with an electrostatic transport to a two-section Radio-Frequency Quadrupole (RFQ) accelerator, with the RFQ sections separated by a magnetic five-dimensional phase-space imaging system as used in an earlier Fermilab/SAIC PET Project, and a new 10-MeV drift-tube linac cavity have been studied. It appears possible that an H{sup {minus}} intensity of 4.5 x 10{sup 13} ions per pulse with an improvement in beam emittance from the present system can be achieved with the proposed changes.

Mass transport and thermodynamic properties of Li{sub x}CoO{sub 2} were studied by the potentiostatic intermittent titration technique (PITT) using solid-state thin-film batteries that provide a well-defined diffusion geometry. Both the chemical diffusion coefficient and the thermodynamic factor have minima at the phase boundaries of the Li/vacancy ordered phase ''Li{sub 0.5}CoO{sub 2}''. The self-diffusion coefficient of Li has a minimum at x = 0.5 associated with the Li/vacancy ordering. As the degree of ordering increases, the nonmonotonic variations become more pronounced when approaching x = 0.5 in Li{sub x}CoO{sub 2}. We also show that thin-film LiCoO{sub 2} cathodes having grains of sub-micrometer size combined with the Li upon electrolyte exhibit excellent capacity retention when charged up to 4.5 V.

The authors present a search for t {r_arrow} bH{sup +} in t{bar t} candidate events at D0 based on two methods. The first seeks a deficit in signal relative to expectations from the standard model (SM). Such a deficit would imply the presence of a non-SM decay of the top quark. This search involves the full data sample of {approx} 110 pb{sup {minus}1} of p{bar p} collisions at {radical}s = 1.8 TeV, collected with the D0 detector. The second method looks for charged Higgs decays to {tau} leptons (and associated neutrinos), and is based on a 62 pb{sup {minus}1} subset of the aforementioned data sample.

We investigated the inhibition by chromate ions of the localized corrosion of aluminum by electrochemical transient measurements. In agreement with other work, the measurements demonstrated that chromate is a cathodic inhibitor for aluminum in open circuit. The reduction of hexavalent chromium to trivalent chromium is assumed to take place on catalyzed sites of the surface. The resulting products inhibit oxygen reduction reactions at these sites, thereby retarding pitting corrosion.

The Melt Attack and Coolability Experiments (MACE) program has been underway at Argonne National Laboratory addressing the ability of water to quench and thermally stabilize a molten core concrete interaction (MCCI) when the interaction is flooded from above. In this program, which has been sponsored by the EPRI-headed Advanced Containment Experiments (ACE) international consortium, large scale reactor material integral effects experiments have been conducted, in parallel with related modeling efforts. Plans are currently being developed for continued utilization of the MACE facility under the sponsorship of the Nuclear Energy Agency (NEA) to achieve the following objectives: (i) resolution of the ex-vessel debris coolability issue through a redirected program which focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests; and (ii) address remaining uncertainties related to long-term two-dimensional MCCI under dry cavity conditions. In terms of the ex-vessel debris coolability issue, separate effects tests are planned to provide data on key melt coolability mechanisms identified in MACE integral effects tests. The results of these tests will provide both confirmatory evidence and test data to support development of validated models for extrapolation to plant conditions. In terms of dry cavity conditions, reactor …

Metal hydrides offer safe, compact and efficient ways to process tritium in areas including storage, pumping, compression, transportation and purification. Westinghouse at Savannah River Site in USA has developed and implemented metal hydride based technology for various tritium applications over the past 20 years. This paper presents our experience in designing different types of metal hydride vessels for tritium processing.

The CDF Online Silicon Vertex Tracker reconstructs 2-D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker. The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B{sub s} mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II.

The Tevatron in Run IIa will operate with three trains of twelve bunches each. The impact of the long-range interactions on beam stability will be more significant compared to Run I. We study these beam-beam interactions (head-on and long-range) with particle tracking using two different codes. The model includes machine nonlinearities such as the field errors of the Interaction Region quadrupoles and the chromaticity sextupoles. Tune footprints and dynamic apertures are calculated for different bunches in a train.

A Time-of-Flight detector (TOF), with a technique based on plastic scintillators and fine-mesh photomultipliers, has been added to the CDF-II experiment. The main physics motivation is to improve neutral B meson flavor determination by K{sup {+-}} identification. The expected time resolution is 100 ps, which provides at least two standard deviations separation between K{sup {+-}} and {pi}{sup {+-}} for momenta p < 1.6 GeV/c and better than 1.2 standard deviations separation over all momenta when combining TOF identification with dE/dx identification using the new drift chamber.

We have been pursuing the spectroscopic properties of actinide ions in silicate matrices. One facet of these studies involves the behavior of Stokes and anti-Stokes emissions exhibited by Am'' in these hosts. Several attributes have been found to influence the spectral profile, which include excitation wavelength, laser power, and dopant-concentration. Excitation with the 514.5 nm (19435 cm{sup -1}) line of argon laser provides anti-Stokes emissions at 21100 and -19920 cm{sup -1} in the boro-silicate matrices. This up-conversion was found to proceed through a multi-photon scheme, and its' efficiency increases with increased dopant concentration. Based on our concentration-dependent studies, the up-conversion is suggested to involve a cross-relaxation process [({sup 5}D{sub 1}, {sup 7}F{sub 0}{sup 7}F{sub 6}, {sup 7}F{sub 2})] between neighboring americium ions.

Excellent progress has been made in the operation of the BNL Electron Beam Ion Source (EBIS), which is a prototype for an EBIS that could meet requirements for a RHIC preinjector. We have achieved very stable operation of the electron beam at 10 A through the EBIS trap. Ion injection of low charge gold ions from a LEVA [1] ion source and subsequent extraction of these ions with most probable charge state AU{sup 34+} has been demonstrated with electron beams up to 8A. The total ion charge for gold measured on current transformer at the EBIS exit was 55nC after a 30ms confinement period. This corresponds to {approx}85% of the theoretical ion trap capacity and exceeds our goal of 50% neutralization. The collected ion charge is proportional to the electron current and the gold charge state scales with the electron current density. Details of the EBIS configuration, total charge measurements, and TOF spectra are given.

Gas electron multipliers (GEMS) have been made by a deep X-ray lithography technique (LIGA process) using synchrotron radiation on polymethylmethacrylate (PMMA) and by UV processes using a UV etchable glass. Gain, stability and rate capability for these detectors are described.The LIGA detectors described consist of PMMA sheets of various thicknesses, 125mm to 350mm, and have 150mm x 150mm square holes spaced with a pitch of 300mm. Thin copper electrodes are plated on the top and bottom surfaces using a Damascene method, followed by electroless plating of the copper onto a palladium-tin base layer. For various thicknesses of PMMA measurements have been made of absolute gain vs. voltage, time stability of gain, and rate capability. The operating gas mixture was usually Ar/CO2 (70/30) gas, but some tests were also done using P10 gas. We also made GEM-like detectors using the UV etchable glass called Foturan, patterned by exposure to UV light and subsequent etching. A few measurements using these detectors will be reported, including avalanche gain and time stability.

Activation of various structural and shielding materials is an important issue for many applications. A model developed recently to calculate residual activity of arbitrary composite materials for arbitrary irradiation and cooling times is presented in the paper. Measurements have been performed at the Fermi National Accelerator Laboratory using a 120 GeV proton beam to study induced radioactivation of materials used for beam line components and shielding. The calculated residual dose rates for the samples studied behind the target and outside of the thick shielding are presented and compared with the measured ones. Effects of energy spectra, sample material and dimensions, their distance from the shielding, and gaps between the shielding modules and walls as well as between the modules themselves were studied in detail.