Superconducting magnets for induction linac phase-rotation in a neutrino factory (open access)

Superconducting magnets for induction linac phase-rotation in a neutrino factory

The neutrino factory[1-3] consists of a target section where pions are produced and captured in a solenoidal magnetic field. Pions in a range of energies from 100 Mev to 400 MeV decay into muons in an 18-meter long channel of 1.25 T superconducting solenoids. The warm bore diameter of these solenoids is about 600 mm. The phase rotation section slows down the high-energy muon and speeds up the low energy muons to an average momentum of 200 MeV/c. The phase-rotation channel consists of three induction linac channels with a short cooling section and a magnetic flux reversal section between the first and second induction linacs and a drift space between the second and third induction linacs. The length of the phase rotation channel will be about 320 meters. The superconducting coils in the channel are 0.36 m long with a gap of 0.14 m between the coils. The magnetic induction within the channel will be 1.25. For 260 meters of the 320-meter long channel, the solenoids are inside the induction linac. This paper discusses the design parameters for the superconducting solenoids in the neutrino factory phase-rotation channel.
Date: May 9, 2001
Creator: Green, M.A. & Yu, S.
Object Type: Article
System: The UNT Digital Library
Mechanical and acoustic properties of weakly cemented granular rocks (open access)

Mechanical and acoustic properties of weakly cemented granular rocks

This paper presents the results of laboratory measurements on the mechanical and acoustic properties of weakly cemented granular rock. Artificial rock samples were fabricated by cementing sand and glass beads with sodium silicate binder. During uniaxial compression tests, the rock samples showed stress-strain behavior which was more similar to that of soils than competent rocks, exhibiting large permanent deformations with frictional slip. The mechanical behavior of the samples approached that of competent rocks as the amount of binder was increased. For very weak samples, acoustic waves propagating in these rocks showed very low velocities of less than 1000 m/sec for compressional waves. A borehole made within this weakly cemented rock exhibited a unique mode of failure that is called ''anti-KI mode fracture'' in this paper. The effect of cementation, grain type, and boundary conditions on this mode of failure was also examined experimentally.
Date: May 9, 2001
Creator: Nakagawa, S. & Myer, L.R.
Object Type: Article
System: The UNT Digital Library
Parametric Timing Analysis (open access)

Parametric Timing Analysis

Embedded systems often have real-time constraints. Traditional timing analysis statically determines the maximum execution time of a task or a program in a real-time system. These systems typically depend on the worst-case execution time of tasks in order to make static scheduling decisions so that tasks can meet their deadlines. Static determination of worst-case execution times imposes numerous restrictions on real-time programs, which include that the maximum number of iterations of each loop must be known statically. These restrictions can significantly limit the class of programs that would be suitable for a real-time embedded system. This paper describes work-in-progress that uses static timing analysis to aid in making dynamic scheduling decisions. For instance, different algorithms with varying levels of accuracy may be selected based on the algorithm's predicted worst-case execution time and the time allotted for the task. We represent the worst-case execution time of a function or a loop as a formula, where the unknown values affecting the execution time are parameterized. This parametric timing analysis produces formulas that can then be quickly evaluated at run-time so dynamic scheduling decisions can be made with little overhead. Benefits of this work include expanding the class of applications that can be …
Date: May 9, 2001
Creator: Vivancos, E; Healy, C; Mueller, F & Whalley, D
Object Type: Article
System: The UNT Digital Library
Pressure Wave Measurements from Thermal Cook-off of an HMX Based Explosive (open access)

Pressure Wave Measurements from Thermal Cook-off of an HMX Based Explosive

A better understanding of thermal cook-off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement are important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook-off explosive containing fixture is of obvious interest for assessing many scenarios.
Date: May 9, 2001
Creator: Forbes, J W; Tarver, C M; Urtiew, P A; Garcia, F; Greenwood, D W & Vandersall, K S
Object Type: Article
System: The UNT Digital Library
Radiation dose measurements of the insertion devices. (open access)

Radiation dose measurements of the insertion devices.

Results of radiation dose measurements of the insertion devices for the year 2000 have been added as Figures 29-35.
Date: May 9, 2001
Creator: Alderman, J.; Semones, E. & Job, P. K.
Object Type: Report
System: The UNT Digital Library