Coupled optics reconstruction from TBT data using MAD-X (open access)

Coupled optics reconstruction from TBT data using MAD-X

Turn-by-turn BPM data provide immediate information on the coupled optics functions at BPM locations. In the case of small deviations from the known (design) uncoupled optics some cognizance of the sources of perturbation, BPM calibration errors and tilts can also be inferred without detailed lattice modeling. In practical situations, however, fitting the lattice model with the help of some optics code would lead to more reliable results. We present an algorithm for coupled optics reconstruction from TBT data on the basis of MAD-X and give examples of its application for the Fermilab Tevatron accelerator.
Date: June 1, 2007
Creator: Alexahin, Y.; Gianfelice-Wendt, E.; /Fermilab; Kapin, V.; Inst., /Moscow Phys. Eng.; Schmidt, F. et al.
Object Type: Article
System: The UNT Digital Library
Coupling interaction between the power coupler and the third harmonic superconducting cavity (open access)

Coupling interaction between the power coupler and the third harmonic superconducting cavity

Fermilab has developed a third harmonic superconducting cavity operating at the frequency of 3.9 GHz to improve the beam performance for the FLASH user facility at DESY. It is interesting to investigate the coupling interaction between the SRF cavity and the power coupler with or without beam loading. The coupling of the power coupler to the cavity needs to be determined to minimize the power consumption and guarantee the best performance for a given beam current. In this paper, we build and analyze an equivalent circuit model containing a series of lumped elements to represent the resonant system. An analytic solution of the required power from the generator as a function of the system parameters has also been given based on a vector diagram.
Date: June 1, 2007
Creator: Li, Jianjian; Solyak, Nikolay & Wong, Thomas
Object Type: Article
System: The UNT Digital Library
Coupling interaction between the power coupler and the third harmonic superconducting cavity (open access)

Coupling interaction between the power coupler and the third harmonic superconducting cavity

None
Date: June 1, 2007
Creator: Li, Jianjian; Solyak, Nikolay & Wong, Thomas
Object Type: Article
System: The UNT Digital Library
Defense: FY2008 Authorization and Appropriations (open access)

Defense: FY2008 Authorization and Appropriations

This report provides information about the FY2008 Authorization and Appropriations on defense. This report act as a guide to one of the regu;lar appropriation bills that Congress considered each year.
Date: June 1, 2007
Creator: Towell, Pat; Daggett, Stephen & Belasco, Amy
Object Type: Report
System: The UNT Digital Library
Delegating responsibility in digital systems: horton's 'who doneit?' (open access)

Delegating responsibility in digital systems: horton's 'who doneit?'

Delegation is a fundamental part of human society. If digital systems are to mediate ever more of our interactions, we must be able to delegate responsibility within them. While some systems support the controlled delegation of authority, and other systems support assignment of responsibility, today we have no means for delegating responsibility, that is, delegating authority coupled with assigning responsibility for using that authority. Horton demonstrates how delegation of responsibility can be added to systems that already support delegation of authority-object-capability systems.
Date: June 1, 2007
Creator: Miller, Mark S.; Donnelley, Jed & Karp, Alan H.
Object Type: Article
System: The UNT Digital Library
Demonstration of Femtosecond-Phase Stabilization in 2 km OpticalFiber (open access)

Demonstration of Femtosecond-Phase Stabilization in 2 km OpticalFiber

Long-term phase drifts of less than a femtosecond per hour have been demonstrated in a 2 km length of single-mode optical fiber, stabilized interferometrically at 1530 nm. Recent improvements include a wide-band phase detector that reduces the possibility of fringe jumping due to fast external perturbations of the fiber and locking of the master CW laser wavelength to an atomic absorption line. Mode-locked lasers may be synchronized using two wavelengths of the comb, multiplexed over one fiber, each wavelength individually interferometrically stabilized.
Date: June 1, 2007
Creator: Staples, J. W.; Wilcox, R. & Byrd, J. M.
Object Type: Article
System: The UNT Digital Library
Deployment Issues for Biodiesel: Fuel Quality and Emission Impacts (open access)

Deployment Issues for Biodiesel: Fuel Quality and Emission Impacts

None
Date: June 1, 2007
Creator: McCormick, R. L.
Object Type: Article
System: The UNT Digital Library
Descriptive Model of Generic WAMS (open access)

Descriptive Model of Generic WAMS

The Department of Energy’s (DOE) Transmission Reliability Program is supporting the research, deployment, and demonstration of various wide area measurement system (WAMS) technologies to enhance the reliability of the Nation’s electrical power grid. Pacific Northwest National Laboratory (PNNL) was tasked by the DOE National SCADA Test Bed Program to conduct a study of WAMS security. This report represents achievement of the milestone to develop a generic WAMS model description that will provide a basis for the security analysis planned in the next phase of this study.
Date: June 1, 2007
Creator: Hauer, John F. & DeSteese, John G.
Object Type: Report
System: The UNT Digital Library
Design and commissioning of Fermilab's vertical test stand for ILC SRF cavities. (open access)

Design and commissioning of Fermilab's vertical test stand for ILC SRF cavities.

As part of its ILC program, Fermilab is developing a facility for vertical testing of SRF cavities. It operates at a nominal temperature of 2K, using a cryoplant that can supply LHe in excess of 20g/sec and provide bath pumping capacity of 125W at 2K. The below-grade cryostat consists of a vacuum vessel and LHe vessel, equipped with magnetic shielding to reduce the ambient magnetic field to <10mG. Internal fixed and external movable radiation shielding ensures that exposure to personnel is minimized. The facility features an integrated personnel safety system consisting of RF switches, interlocks, and area radiation monitors.
Date: June 1, 2007
Creator: Ozelis, Joseph P.; Carcagno, Ruben; Ginsburg, Camille M.; Huang, Yuenian; Norris, Barry; Peterson, Thomas et al.
Object Type: Article
System: The UNT Digital Library
Design and commissioning of Fermilab's vertical test stand for ILC SRF cavities. (open access)

Design and commissioning of Fermilab's vertical test stand for ILC SRF cavities.

None
Date: June 1, 2007
Creator: Ozelis, Joseph P.; Carcagno, Ruben; Ginsburg, Camille M.; Huang, Yuenian; Norris, Barry; Peterson, Thomas et al.
Object Type: Article
System: The UNT Digital Library
Design and fabrication of a multi-element corrector magnet for the Fermilab Booster synchrotron (open access)

Design and fabrication of a multi-element corrector magnet for the Fermilab Booster synchrotron

To better control the beam position, tune, and chromaticity in the Fermilab Booster synchrotron, a new package of six corrector elements has been designed, incorporating both normal and skew orientations of dipole, quadrupole, and sextupole magnets. The devices are under construction and installation at 48 locations is planned. The density of elements and the rapid slew rate have posed special challenges. The magnet construction is presented along with DC measurements of the magnetic field.
Date: June 1, 2007
Creator: Harding, D. J.; DiMarco, J.; Drennan, C. C.; Kashikhin, V. S.; Kotelnikov, S.; Lackey, J. R. et al.
Object Type: Article
System: The UNT Digital Library
Design and Fabrication of a Supporting Structure for 3.6m Long Nb3Sn Racetrack Coils (open access)

Design and Fabrication of a Supporting Structure for 3.6m Long Nb3Sn Racetrack Coils

As part of the LHC Accelerator Research Program (LARP), three US national laboratories (BNL, FNAL, and LBNL) are currently engaged in the development of superconducting magnets for the LHC Interaction Regions (IR) beyond the current design. As a first step towards the development of long Nb{sub 3}Sn quadrupole magnets, a 3.6 m long structure, based on the LBNL Subscale Common-Coil Magnet design, will be fabricated, assembled, and tested with aluminum-plate 'dummy coils'. The structure features an aluminum shell pre-tensioned over iron yokes using pressurized bladders and locking keys (bladder and key technology). Pre-load homogeneity and mechanical responses are monitored with pressure sensitive films and strain gauges mounted on the aluminum shell and the dummy coils. The details of the design and fabrication are presented and discussed, and the expected mechanical behavior is analyzed with finite element models.
Date: June 1, 2007
Creator: Ambrosio, G.; Anerella, M.; Barzi, E.; Caspi, Shlomo; Cheng, Daniel; Dietderich, Daniel et al.
Object Type: Article
System: The UNT Digital Library
Design and Test of a Nb3Sn Subscale Dipole Magnet for Training Studies (open access)

Design and Test of a Nb3Sn Subscale Dipole Magnet for Training Studies

As part of a collaboration between CEA/Saclay and the Superconducting Magnet Group at LBNL, a subscale dipole structure has been developed to study training in Nb3Sn coils under variable pre-stress conditions. This design is derived from the LBNL Subscale Magnet and relies on the use of identical Nb{sub 3}Sn racetrack coils. Whereas the original LBNL subscale magnet was in a dual bore 'common-coil' configuration, the new subscale dipole magnet (SD) is assembled as a single bore dipole made of two superposed racetrack coils. The dipole is supported by a new mechanical structure developed to withstand the horizontal and axial Lorentz forces and capable of applying variable vertical, horizontal and axial preload. The magnet was tested at LBNL as part of a series of training studies aiming at understanding of the relation between pre-stress and magnet performance. Particular attention is given to the coil ends where the magnetic field peaks and stress conditions are the least understood. After a description of SD design, assembly, cool-down and tests results are reported and compared with the computations of the OPERA3D and ANSYS magnetic and mechanical models.
Date: June 1, 2007
Creator: Felice, Helene; Caspi, Shlomo; Dietderich, Daniel R.; Felice, Helene; Ferracin, Paolo; Gourlay, Steve A. et al.
Object Type: Article
System: The UNT Digital Library
Design considerations of a power supply system for fast cycling superconducting accelerator magnets of 2 Tesla b-field generated by a conductor of 100 kA current (open access)

Design considerations of a power supply system for fast cycling superconducting accelerator magnets of 2 Tesla b-field generated by a conductor of 100 kA current

Recently proposed fast cycling accelerators for proton drivers (SF-SPS, CERN and SF-MR, SF-BOOSTER, FNAL) neutrino sources require development of new magnet technology. In support of this magnet development a power supply system will need to be developed that can support the high current and high rate of power swing required by the fast cycling (1 sec rise and fall in the SF-MR, 5Hz in Booster). This paper will outline a design concept for a +/- 2000 V and 100,000 A fast ramping power supply system. This power supply design is in support of a 6.44 km magnet system at 0.020 H and 330 m 5 Hz, 0.00534 H superconducting loads. The design description will include the layout and plan for extending the present FNAL Main Injector style ramping power supply to the higher currents needed for this operation. This will also include the design for a harmonic filter and power factor corrector that will be needed to control the large power swings caused by the fast cycle time. A conceptual design for the current regulation system and control will also be outlined. The power circuit design will include the bridge, filter and transformer plan based on existing designs.
Date: June 1, 2007
Creator: Hays, Steve; Piekarz, Henryk; Pfeffer, Howie; Claypool, Brad & /Fermilab
Object Type: Article
System: The UNT Digital Library
Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids (open access)

Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids

It can be shown that, by superposing two solenoid-like thin windings that are oppositely skewed (tilted) with respect to the bore axis, the combined current density on the surface is 'cos-theta' like and the resulting magnetic field in the bore is a pure dipole. As a proof of principle, such a magnet was designed, built and tested as part of a summer undergraduate intern project. The measured field in the 25mm bore, 4 single strand layers using NbTi superconductor, exceeded 1 T. The simplicity of this high field quality design, void of typical wedges end-spacers and coil assembly, is especially suitable for insert-coils using High Temperature Superconducting wire as well as for low cost superconducting accelerator magnets for High Energy Physics. Details of the design, construction and test are reported.
Date: June 1, 2007
Creator: Caspi, S.; Dietderich, D. R.; Ferracin, P.; Finney, N. R.; Fuery, M. J.; Gourlay, S. A. et al.
Object Type: Article
System: The UNT Digital Library
Design of a VHF-band RF Photoinjector with Megahertz BeamRepetition Rate (open access)

Design of a VHF-band RF Photoinjector with Megahertz BeamRepetition Rate

New generation accelerator-based X-ray light sources require high quality beams with high average brightness. Normal conducting L- and S-band photoinjectors are limited in repetition rate and D-C (photo)injectors are limited in field strength at the cathode. We propose a low frequency normal-conducting cavity, operating at 50 to 100MHz CW, to provide beam bunches of up to the cavity frequency. The photoinjector uses a re-entrant cavity structure, requiring less than 100 kW CW, with a peak wall power density less than 10 W/cm{sup 2}. The cavity will support a vacuum down to 10 picoTorr, with a load-lock mechanism for easy replacement of photocathodes. The photocathode can be embedded in a magnetic field to provide correlations useful for emittance exchange. Beam dynamics simulations indicate that normalized emittances smaller than 1 mm-mrad are possible with gap voltage of 750 kV, with fields up to 20 MV/m at the photocathode, for 1 nanocoulomb charge per bunch after acceleration and emittance compensation. Long-bunch operation (10's of picosecond) is made possible by the low cavity frequency, permitting low bunch current at the 750 kV gap voltage.
Date: June 1, 2007
Creator: Staples, J. W.; Baptiste, K. M.; Corlett, J. N.; Kwiatkowski, S.; Lidia, S. M.; Qiang, J. et al.
Object Type: Article
System: The UNT Digital Library
Design of an electro-optical sampling experiment at the AWA facility (open access)

Design of an electro-optical sampling experiment at the AWA facility

The free space electro-optical (EO) sampling technique is a powerful tool for analyzing the longitudinal charge density of an ultrashort e-beam. In this paper, we present (1) experimental results for a laser-based mock-up of the EO experiment [1] and (2) a design for a beam-based, single-shot, EO sampling experiment using the e-beam from the Argonne Wakefield Accelerator (AWA) RF photoinjector. For the mock-up, a tabletop terahertz experiment is conducted in the AWA laser room. The mock-up uses an IR beam incident on <110> ZnTe crystal to produce a THz pulse via optical rectification. Detection is based on the cross correlation between the THz field and the probe IR laser field in a second <110> ZnTe crystal.
Date: June 1, 2007
Creator: Ruan, J.; Edwards, H.; Tan, Cheng Yang; Thurman-Keup, R.; Scarpine, V.; /Fermilab et al.
Object Type: Article
System: The UNT Digital Library
Design of an electro-optical sampling experiment at the AWA facility (open access)

Design of an electro-optical sampling experiment at the AWA facility

None
Date: June 1, 2007
Creator: Ruan, J.; Edwards, H.; Tan, Cheng Yang; Thurman-Keup, R.; Scarpine, V.; /Fermilab et al.
Object Type: Article
System: The UNT Digital Library
Design of an Integrated Laboratory Scale Test for Hydrogen Production via High Temperature Electrolysis (open access)

Design of an Integrated Laboratory Scale Test for Hydrogen Production via High Temperature Electrolysis

The Idaho National Laboratory (INL) is researching the feasibility of high-temperature steam electrolysis for high-efficiency carbon-free hydrogen production using nuclear energy. Typical temperatures for high-temperature electrolysis (HTE) are between 800º-900ºC, consistent with anticipated coolant outlet temperatures of advanced high-temperature nuclear reactors. An Integrated Laboratory Scale (ILS) test is underway to study issues such as thermal management, multiple-stack electrical configuration, pre-heating of process gases, and heat recuperation that will be crucial in any large-scale implementation of HTE. The current ILS design includes three electrolysis modules in a single hot zone. Of special design significance is preheating of the inlet streams by superheaters to 830°C before entering the hot zone. The ILS system is assembled on a 10’ x 16’ skid that includes electronics, power supplies, air compressor, pumps, superheaters, , hot zone, condensers, and dew-point sensor vessels. The ILS support system consists of three independent, parallel supplies of electrical power, sweep gas streams, and feedstock gas mixtures of hydrogen and steam to the electrolysis modules. Each electrolysis module has its own support and instrumentation system, allowing for independent testing under different operating conditions. The hot zone is an insulated enclosure utilizing electrical heating panels to maintain operating conditions. The target hydrogen …
Date: June 1, 2007
Creator: Housley, G. K.; Condie, K. G.; O'Brien, J. E. & Stoots, C. M.
Object Type: Article
System: The UNT Digital Library
Design of Nb3Sn Coils for LARP Long Magnets (open access)

Design of Nb3Sn Coils for LARP Long Magnets

The LHC Accelerator Research Program (LARP) has a primary goal to develop, assemble, and test full size Nb{sub 3}Sn quadrupole magnet models for a luminosity upgrade of the Large Hadron Collider (LHC). A major milestone in this development is to assemble and test, by the end of 2009, two 4 m-long quadrupole cold masses, which will be the first Nb{sub 3}Sn accelerator magnet models approaching the length of real accelerator magnets. The design is based on the LARP Technological Quadrupoles (TQ), under development at FNAL and LBNL, with gradient higher than 200 T/m and aperture of 90 mm. The mechanical design will be chosen between two designs presently explored for the TQs: traditional collars and Al-shell based design (preloaded by bladders and keys). The fabrication of the first long quadrupole model is expected to start in the last quarter of 2007. Meanwhile the fabrication of 4 m-long racetrack coils started this year at BNL. These coils will be tested in an Al-shell based supporting structure developed at LBNL. Several challenges have to be addressed for the successful fabrication of long Nb{sub 3}Sn coils. This paper presents these challenges with comments and solutions adopted or under study for these magnets. The …
Date: June 1, 2007
Creator: Ferracin, Paolo; Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R. et al.
Object Type: Article
System: The UNT Digital Library
Design Studies of Nb3Sn High-Gradient Quadrupole Models for LARP (open access)

Design Studies of Nb3Sn High-Gradient Quadrupole Models for LARP

Insertion quadrupoles with large aperture and high gradient are required to achieve the luminosity upgrade goal of 10{sup 35} cm{sup -2} s{sup -1} at the Large Hadron Collider (LHC). In 2004, the US Department of Energy established the LHC Accelerator Research Program (LARP) to develop a technology base for the upgrade. Nb{sub 3}Sn conductor is required in order to operate at high field and with sufficient temperature margin. We report here on the conceptual design studies of a series of 1 m long 'High-gradient Quadrupoles' (HQ) that will explore the magnet performance limits in terms of peak fields, forces and stresses. The HQ design is expected to provide coil peak fields of more than 15 T, corresponding to gradients above 300 T/m in a 90 mm bore. Conductor requirements, magnetic, mechanical and quench protection issues for candidate HQ designs will be presented and discussed.
Date: June 1, 2007
Creator: Sabbi, GianLuca; Andreev, Nikolai; Caspi, Shlomo; Dietderich, Daniel; Ferracin, Paolo; Ghosh, Arup et al.
Object Type: Article
System: The UNT Digital Library
Design Studies of Nb3Sn High-Gradient Quadrupole Models for LARP (open access)

Design Studies of Nb3Sn High-Gradient Quadrupole Models for LARP

Insertion quadrupoles with large aperture and high gradient are required to achieve the luminosity upgrade goal of 10{sup 35} cm{sup -2} s{sup -1} at the Large Hadron Collider (LHC). In 2004, the US Department of Energy established the LHC Accelerator Research Program (LARP) to develop a technology base for the upgrade. Nb{sub 3}Sn conductor is required in order to operate at high field and with sufficient temperature margin. We report here on the conceptual design studies of a series of 1 m long 'High-gradient Quadrupoles' (HQ) that will explore the magnet performance limits in terms of peak fields, forces and stresses. The HQ design is expected to provide coil peak fields of more than 15 T, corresponding to gradients above 300 T/m in a 90 mm bore. Conductor requirements, magnetic, mechanical and quench protection issues for candidate HQ designs will be presented and discussed.
Date: June 1, 2007
Creator: Andreev, Nikolai; Caspi, Shlomo; Dietderich, Daniel; Ferracin, Paolo; Ghosh, Arup; Kashikhin, Vadim et al.
Object Type: Article
System: The UNT Digital Library
Design study of 2-in-1 large aperture ir dipole (D2) for the LHC luminosity upgrade (open access)

Design study of 2-in-1 large aperture ir dipole (D2) for the LHC luminosity upgrade

This paper analyses possible D2 magnet designs for the 'dipole-first' option of the LHC luminosity upgrade based on Nb3Sn superconductor and compares them in terms of the maximum field, field quality, and Lorentz forces in the coils.
Date: June 1, 2007
Creator: Kashikhin, Vadim V. & Zlobin, Alexander V.
Object Type: Article
System: The UNT Digital Library
Designing PV Incentive Programs to Promote Performance: A Reviewof Current Practice (open access)

Designing PV Incentive Programs to Promote Performance: A Reviewof Current Practice

Increasing levels of financial support for customer-sited photovoltaic (PV) systems, provided through publicly-funded incentive programs, has heightened concerns about the long-term performance of these systems. Given the barriers that customers face to ensuring that their PV systems perform well, and the responsibility that PV incentive programs bear to ensure that public funds are prudently spent, these programs should, and often do, play a critical role in ensuring that PV systems receiving incentives perform well. To provide a point of reference for assessing the current state of the art, and to inform program design efforts going forward, we examine the approaches to encouraging PV system performance used by 32 prominent PV incentive programs in the U.S. We identify eight general strategies or groups of related strategies that these programs have used to address performance issues, and highlight important differences in the implementation of these strategies among programs.
Date: June 1, 2007
Creator: Barbose, Galen; Wiser, Ryan & Bolinger, Mark
Object Type: Article
System: The UNT Digital Library