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Open Cavity Solutions to the Rf in Magnetic Field Problem. (open access)

Open Cavity Solutions to the Rf in Magnetic Field Problem.

It has been observed [1] that breakdown in an 805 MHz pill-box cavity occurs at much lower gradients as an external axial magnetic field is increased. This effect was not observed with on open iris cavity. It is proposed that this effect depends on the relative angles of the magnetic and maximum electric fields: parallel in the pill-box case; at an angle in the open iris case. If so, using an open iris structure with solenoid coils in the irises should perform even better. A lattice, using this principle, is presented, for use in 6D cooling for a Muon Collider. Experimental layouts to test this principle are proposed.
Date: August 6, 2007
Creator: Palmer, R. B.; Berg, J. S.; Fernow, R. C.; Gallardo, J. C. & Kirk, H. G.
System: The UNT Digital Library
Using Ffags in the Creation of Neutrino Beams. (open access)

Using Ffags in the Creation of Neutrino Beams.

A number of accelerator-based facilities have been proposed for the creation of neutrino beams: superbeams, neutrino factories, and beta beams. Fixed field alternating gradient accelerators (FFAGs) have potential uses in all of these facilities. Superbeams and neutrino factories require high power proton drivers for the production of pions; FFAGs can beneficial for accelerating protons for those machines. FFAGs can reduce the cost of accelerating muons in a neutrino factory because they enable the muons to make many passes through the RF cavities and still accelerate rapidly. FFAGs have potential uses in production of radioactive ions for a beta beam facility, since radioactive ions that decay into high energy neutrinos in their rest frame may potentially be produced in a ring, and the large energy acceptance of an FFAG may be useful for maximizing beam lifetime in such a ring. Finally, FFAGs have been contemplated for use in ionization cooling rings for neutrino factories, since the equilibrium distribution in ionization cooling has a large energy spread for which an FFAG's large energy acceptance is needed, and FFAGs may make it feasible to inject and extract from such a ring.
Date: August 6, 2007
Creator: Berg, J. S.
System: The UNT Digital Library
The US Long Baseline Neutrino Experiment Study (open access)

The US Long Baseline Neutrino Experiment Study

The US Long Baseline Neutrino Experiment Study was commissioned jointly by Brookhaven National Laboratory (BNL)and Fermi National Accelerator Laboratory (FNAL) to investigate the potential for future U.S. based long baseline neutrino oscillation experiments using MW class conventional neutrino beams that can be produced at FNAL. The experimental baselines are based on two possible detector locations: (1) off-axis to the existing FNAL NuMI beamline at baselines of 700 to 810 km and (2) NSF's proposed future Deep Underground Science and Engineering Laboratory (DUSEL) at baselines greater than 1000km. Two detector technologies are considered: a megaton class Water Cherenkov detector deployed deep underground at a DUSEL site, or a 100kT Liquid Argon Time-Projection Chamber (TPC) deployed on the surface at any of the proposed sites. The physics sensitivities of the proposed experiments are summarized. We find that conventional horn focused wide-band neutrino beam options from FNAL aimed at a massive detector with a baseline of > 1000km have the best sensitivity to CP violation and the neutrino mass hierarchy for values of the mixing angle {theta}{sub 13} down to 2{sup o}.
Date: August 6, 2007
Creator: Bishai, M.
System: The UNT Digital Library
R AND D TOPICS FOR NEUTRINO FACTORY ACCELERATION. (open access)

R AND D TOPICS FOR NEUTRINO FACTORY ACCELERATION.

The muons in a neutrino factory must be accelerated from the energy of the capture, phase rotation, and cooling systems (around 120 MeV kinetic energy) to the energy of the storage ring (around 25 GeV). This is done with a sequence of accelerators of different types: a linac, one or more recirculating linear accelerators, and finally one or more fixed field alternating gradient accelerators (FFAGs). I discuss the R&D that is needed to arrive at a complete system which we can have confidence will accelerate the beam and for which we can obtain a cost estimate.
Date: August 6, 2007
Creator: SCOTT,J.S.
System: The UNT Digital Library
The Emma Lattice. (open access)

The Emma Lattice.

EMMA is a 10 to 20MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). I will give a basic review of the EMMA lattice parameters. Then I will review the different lattice configurations that we would like to have for EMMA. Finally, I will briefly discuss the process of commissioning each lattice configuration.
Date: August 6, 2007
Creator: Berg, J. S.
System: The UNT Digital Library
A High Resolution Hydrometer Phase Classifier Based on Analysis of Cloud Radar Doppler Spectra. (open access)

A High Resolution Hydrometer Phase Classifier Based on Analysis of Cloud Radar Doppler Spectra.

The lifecycle and radiative properties of clouds are highly sensitive to the phase of their hydrometeors (i.e., liquid or ice). Knowledge of cloud phase is essential for specifying the optical properties of clouds, or else, large errors can be introduced in the calculation of the cloud radiative fluxes. Current parameterizations of cloud water partition in liquid and ice based on temperature are characterized by large uncertainty (Curry et al., 1996; Hobbs and Rangno, 1998; Intriery et al., 2002). This is particularly important in high geographical latitudes and temperature ranges where both liquid droplets and ice crystal phases can exist (mixed-phase cloud). The mixture of phases has a large effect on cloud radiative properties, and the parameterization of mixed-phase clouds has a large impact on climate simulations (e.g., Gregory and Morris, 1996). Furthermore, the presence of both ice and liquid affects the macroscopic properties of clouds, including their propensity to precipitate. Despite their importance, mixed-phase clouds are severely understudied compared to the arguably simpler single-phase clouds. In-situ measurements in mixed-phase clouds are hindered due to aircraft icing, difficulties distinguishing hydrometeor phase, and discrepancies in methods for deriving physical quantities (Wendisch et al. 1996, Lawson et al. 2001). Satellite-based retrievals of cloud …
Date: August 6, 2007
Creator: Luke,E. & Kollias, P.
System: The UNT Digital Library
Comment on "Paleoclassical Transport in Low-Collisionality Toroidal Plasmas" [Phys. Plasmas 12, 092512 (2005)] (open access)

Comment on "Paleoclassical Transport in Low-Collisionality Toroidal Plasmas" [Phys. Plasmas 12, 092512 (2005)]

None
Date: August 6, 2007
Creator: LoDestro, L.
System: The UNT Digital Library
SENSITIVITIES OF FUTURE LONG BASELINE EXPERIMENTS IN THE U.S. (open access)

SENSITIVITIES OF FUTURE LONG BASELINE EXPERIMENTS IN THE U.S.

Sensitivities to neutrino oscillation parameters for possible very long baseline neutrino oscillation experiments are discussed. The reach for observing a non-zero mixing angle {theta}{sub 13}, establishing CP violation and determining the mass hierarchy are compared between various experimental options. Different possibilities for neutrino beams are briefly described, as well as the assumptions about the performance of a large water Cherenkov and liquid Argon detector.
Date: August 6, 2007
Creator: DIERCKXSENS,M.
System: The UNT Digital Library
CHALLENGES WITH RETRIEVING TRANSURANIC WASTE FROM THE HANFORD BURIAL GROUNDS (open access)

CHALLENGES WITH RETRIEVING TRANSURANIC WASTE FROM THE HANFORD BURIAL GROUNDS

The U.S. DOE's Hanford Reservation produced plutonium and other nuclear materials for the nation's defense starting in World War II. The defense mission generated wastes that were either retrievably stored (i.e. retrievably stored waste) and/or disposed of in burial grounds. Challenges have emerged from retrieving suspect TRU waste including adequacy of records, radiological concerns, container integrity, industrial hygiene and safety issues, the lack of processing/treatment facilities, and the integration of regulatory requirements. All retrievably stored waste is managed as mixed waste and assumed to be TRU waste, unless documented otherwise. Mixed waste is defined as radioactive waste that contains hazardous constituents. The Atomic Energy Act governs waste with radionuclides, and the Resource Conservation and Recovery Act (RCRA) governs waste with hazardous constituents. Waste may also be governed by the Toxic Substances Control Act (TSCA), and a portion may be managed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). In 1970, TRU waste was required to be placed in 20-year retrievable storage and segregated from other Waste. Prior to that date, segregation did not occur. Because of the changing definition of TRU over the years, and the limitations of early assay equipment, all retrievably stored waste in the burial …
Date: August 6, 2007
Creator: SWAN, R.J. & LAKES, M.E.
System: The UNT Digital Library