Session E2: HEN2: High Energy/Nuclear

The LUX Two-Phase-Xenon Dark Matter Search Experiment

The race to be the first experiment to detect collisions between atoms and a new type of weakly interacting massive particle (WIMP) that is conjectured to explain dark matter is heating up. The Large Underground Xenon (LUX) detector is a second-generation WIMP dark matter search experiment that employs a liquid xenon target and provides background discrimination based on the ratio of ionization to scintillation produced in subatomic particle interactions. This experiment is designed to reach the heart of the favored parameter space for supersymmetric WIMPs and has a genuine chance to be the discovery experiment. The concept, design, schedule and reach of the experiment will be discussed.   

A Wavelength Shifting Readout method for Large Gaseous Particle Detectors.

A new method to readout the ionization of a gaseous-based particle detector is being investigated as part of the research and development effort to develop very large detectors for future WIMP search experiments. In this approach, a grooved plastic scintillator cylinder is used to wavelength-shift the vacuum ultraviolet light produced from proportional scintillation in gaseous xenon. The design and construction of the test chamber is discussed along with preliminary findings.   

Development of a new WIMP detector concept based on High Pressure Xenon Gas

Although a number of proven approaches exist, there is a continuing effort to develop WIMP detectors with improved sensitivity and more economical operation. One approach that shows great promise is based on the ratio of Scintillation to Ionization in pressurized, room temperature Gaseous Nobles (SIGN). Recent research and development results to determine basic properties of pressurized xenon for particle detection as well as background discrimination for WIMP detection will be presented.   

Investigation of New Methods for Ultra-Low-Background Counting

Components of future detectors for dark matter and neutrino physics will require increasingly sensitive radioisotope screening to allow the detectors to reach their needed sensitivities. A selection of potential new approaches will be discussed along with preliminary test data.   

A dual-axis duo-lateral position sensitive silicon detector upgrade to the FAUST detector Array.

In looking at current Silicon detector technology and the design constraints of the Forward Array Using Silicon Technology (FAUST), a dual-axis dual-lateral position sensitive silicon detector has been designed and manufactured to allow for linear position sensitivity in two dimensions without sacrificing isotopic resolution in heavy ion reactions. The design has two conductive strip contacts along opposite edges on each side of the detector. The contacts on the front are perpendicular to those on the back. Each side has a different resistivity. When an incident particle hits the detector, the charge is split between the contacts on each resistive layer. This allows for the total energy to be determined by the summation of either the contacts on the front or the back of the detector. The position of each axis can easily determined using standard formulas such as X $\propto$ (Q1-Q2)/(Q1+Q2), where Q is the charged collected from one contact. Results from preliminary testing show a good energy resolution as well as indicate a linear position response.   

Calibrating Scintillator position measurement for testing RPC modules for PHENIX at RHIC

PHENIX is a large, high-energy experiment at the Relativistic Heavy Ion Collider. One of PHENIX's many goals is to study the spin structure of the proton through observing W-boson decays from quark-anti quark interactions in polarized p-p collisions. An upgraded trigger system using Resistive Plate Chambers that are being built for PHENIX will increase the rejection factor of unfavorable events by two orders of magnitude so that this measurement is possible. As these RPCs are manufactured and assembled into larger sections for installation, an important step in quality assurance is testing each module in a cosmic ray test stand triggered by hodoscopes. These scintillators will also provide a position measurement, giving us positioning information in directions where the stacked RPCs have low spatial resolution. With careful timing calibration the information from the scintillators will enable us to test aspects of the RPC manufacturing that will lead to much higher quality monitoring. This talk will include methods and some results from this positioning measurement.   

New Suberconducting Technology to Enable the Next Generation of High Energy Research

Two innovations in superconducting technology have the potential to shape the future capabilities for discovery in high energy physics. First, a hybrid dipole has been devised that would utilize windings of the high-temperature superconductor Bi-2212 and the low-temperature superconductor Nb$_{3}$Sn to produce a field strength of 25 Tesla. The dipole would be suitable to replace the magnet ring in CERN's LHC, and would triple its collision energy in proton-proton colliding beams. Second, a polyhedral cavity has been devised for the high-gradient accelerating structure of an electron-positron linac collider. The polyhedral geometry provides access to the crucial inner surface during all stages of fabrication, and opens the possibility to prepare a heterostructure there that could support rf fields beyond the BCS limit. It also naturally suppresses deflecting modes so that the overall energy efficiency could be significantly improved. These features lead to a possibility for making high-luminosity e+e- collisions at TeV energy.   

Polyhedral Superconducting Cavities for Linac Colliders

The next priority for research facilities in high-energy physics is an electron-positron linac collider. The technological heart of the project is a $\sim$20 km string of superconducting cavities that must accelerate the two beams to a collision energy of about 1 TeV. The success of the project will depend upon efforts to push the performance and reduce the cost for manufacturing the cavities. A novel approach to cavity design is being developed at Texas A{\&}M, in which the cavities are constructed as a polyhedron. The critical inner surface is accessible through the whole fabrication process. This approach has several interesting benefits: it makes it possible to kill deflecting modes that could limit luminosity, it makes possible a simpler means to refrigerate the cavities, and eliminates the `breathing' of cavities from the Lorentz pressure when they are energized. The open geometry allows for the use of advanced superconducting materials to push performance. The cavity design will be presented, and work to develop and test models will be described.