118179130
Search for Monopoles Above the 15-Foot Bubble Chamber
Magnetic monopoles having energies less than about 40 TeV will be slowed to their terminal velocity by the earth's atmosphere. They may then be gathered by the fringing magnetic field of the 15-foot bubble chamber. We propose placing detectors of Lexan and nuclear emulsion at convenient locations above and below the bubble chamber. Such a systom would be sensitive to monopole masses between 10 GeV and 100 TeV and to monopole charges between {approx}0.7 and 10 hc/2e. The experiment would require the construction of a special light roof and would run for 5 weeks during a time when the bubble chamber is filled with air and not in use for other experiments. This study would lower the existing limit on in-flight detection of monopoles (at the earth's surface) by a factor of 20.
119457260
Detecting near ultraviolet radiation in the presence of visible light
We describe a system which suppresses the detection of visible sodium vapor light by a factor of about 108 relative to near ultraviolet radiation.
123909158
DESIGN AND OPERATION OF THE PRINCETON-PENNSYLVANIA PROTON SYNCHROTRON
The 16 sector magnet is weak focusing with n = 0.6 over a useful radial region of 16.5 cm and 6.1 cm vertically. A d-c biased, sine wave excitation at 19 cps is employed, the energy storage being in a resonant capacitor-inductor system. Injection at 3 Mev is provided by an electrostatic generator. Acceleration is achieved by a combination of drift tubes and resonant cavities which must provide 120 kv per turn, and must be precisely tuned over a 12: 1 range in frequency. To date, 2 x 10/sup 10/ protons per pulse have been injected, of which about 10% are captured by the r-f. A method for extracting the proton beam, which is similar to Piccionis' system, but freer of aberrations, is now under design. (auth)
120485938
The Acceleration of Heavy Ions to Very High Energies and Their Scientific Significance
118661436
The Princeton-Pennsylvania 3 GeV Proton Accelerator as a Nuclear Tool
I would like to describe the Princeton-Pennsylvania Accelerator as a tool for nuclear research. Some people tend to think of the PPA as being too high in energy for nuclear research and, therefore, regard it as only an elementary particle research tool. While much of our work has, in fact, been related to the study of mesons, especially K-mesons, and to the study of the invariance principles, such as C, P, T, about 15% of the research has been either purely nuclear, or with strong nuclear overtones. As examples of the purely nuclear, I mention spallation reactions at 3 BeV and the study of the resulting neutron deficient nuclei. On the other side of the valley are the baryon stable, neutron rich, light fragments, 19N and 21O, which have been discovered in confirmation of Garvey’s mass formula. Negative pion scattering by twelve different complex nuclei from Be to Au over the energy range 600-1600 MeV has been used to determine optical model potentials. Neutron total cross sections over the momentum range 500-2800 MeV/c are now being studied for a wide variety of target nuclei, including the Physical Review! An especially beautiful experiment, begun as a missing mass search in the reaction p+d → He3+X° not only studied things of interest to elementary particle physics, the so-called ABC region, but simultaneously, and inadvertently, provided a hadronic probe, the proton, at correlation distances far smaller than, ever achieved before.
121688128
Proposed uv-FEL user facility at BNL
Abstract The NSLS at Brookhaven National Laboratory is proposing the construction of a UV-FEL operating in the wavelength range from visible to 750 A. Nanocoulomb electron pulses will be generated at a laser photocathode rf gun at a repetition rate of 10 kHz. The 6 ps pulses will be accelerated to 250 MeV in a superconducting linac. The FEL output will serve four stations with independent wavelength tuning, using two wigglers and two rotating mirror beam switches. Seed radiation for the FEL amplifiers will be provided by conventional tunable lasers, and the final frequency multiplication from the visible or near UV to the VUV will be carried out in the FEL itself. Each FEL will be comprised of an initial wiggler resonant to the seed wavelength, a dispersion section, and a second wiggler resonant to the output wavelength. The facility will provide pump-probe capability, FEL on FEL, and FEL on synchrotron light from an insertion device on the NSLS X-ray ring.
1938181
Determining SUSY model parameters and masses at the LHC using cross-sections, kinematic edges and other observables.
We address the problem of mass measurements of supersymmetric particles at the Large Hadron Collider, using the ATLAS detector as an example. By using Markov Chain sampling techniques to combine standard measurements of kinematic edges in the invariant mass distributions of decay products with a measurement of a missing pT cross-section, we show that the precision of mass measurements at the LHC can be dramatically improved, even when we do not assume that we have measured the kinematic endpoints precisely, or that we have identified exactly which particles are involved in the decay chain causing the endpoints. The generality of the technique is demonstrated in a preliminary investigation of a non-universal SUGRA model, in which we relax the requirements of mSUGRA by breaking the degeneracy of the GUT scale gaugino masses. The model studied is compatible with the WMAP limits on dark matter relic density.
125390779
Proton compton scattering and neutral-pion photoproduction at large angles
The differential cross sections for ..gamma..p ..-->.. ..gamma..p and ..gamma..p ..-->.. ..pi../sup 0/p have been measured from abs. value (t) = 0.7 to 4.3 GeV/sup 2/ and for incident energies in the range 2 to 6 GeV. The energy dependence of Compton scattering is well described by parton model ideas. However, the energy dependences of ..pi../sup 0/ photoproduction and the ratio of Compton scattering to ..pi../sup 0/ photoproduction are not consistent with dimensional counting arguments.
118494817
Mass Estimation without using MET in early LHC data
Many techniques exist to reconstruct New Physics masses from LHC data, though these tend to either require high luminosity O(100) fb^-1, or an accurate measurement of missing transverse energy (MET) which may not be available in the early running of the LHC. Since in popular models such as SUSY a fairly sharp, triangular dilepton invariant mass spectrum can emerge already at low luminosity O(1) fb^-1, a Decay Kinematics (DK) technique can be used on events near the dilepton mass endpoint to estimate squark, slepton, and neutralino masses without relying on MET. With the first 2 fb^-1 of 7 TeV LHC data SPS1a masses can thus be found to 20% or better accuracy, at least several times better than what has been taken to be achievable.
46688174
Diffusion of Gases in Air and Its Affect on Oxygen Deficiency Hazard Abatement
Density differences between air and released gases of cryogenic systems have been used to either require special oxygen deficiency hazard (ODH) control measures, or as a means of abatement. For example, it is not uncommon to assume that helium spills will quickly collect at the ceiling of a building or enclosure and will efficiently exit at the nearest vertical penetration or vent. Oxygen concentration reduction was found to be detectable during a localized helium spill throughout the entire 6.3 km Tevatron tunnel. This prompted us to perform diffusion tests in air with common gases used at Fermilab. The tests showed that gases, more readily than expected, diffused through an air column in the direction opposing buoyancy. Test results for helium and sulfur hexafluoride are presented. A system of tests were performed to better understand how easily released gases would fully mix with air and whether they remained fully mixed. The test results have been applied to a new system at Fermilab for ODH abatement.
14135931
Three body kinematic endpoints in SUSY models with non-universal Higgs masses
We derive and present expressions for the kinematic endpoints that arise in the invariant mass distributions of visible decay products of cascade decays featuring a two body decay followed by a three body decay. This is an extension of a current technique that addresses chains of successive two body decays. We then apply these to a supergravity model with Non-Universal Higgs Masses (NUHM), having simulated a data set using the ATLFAST detector simulation. We find that, should such a model be chosen by nature, the endpoints will be visible in ATLAS data, and we discuss the problems associated with mass reconstruction in models with a similar phenomenology.