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Oecm MCCI Small-Scale Water Ingression and Crust Strength Tests (Sswics) Sswics-2 Final Data Report, Rev. 0 February 12, 2003.
The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench …
Date:
May 23, 2011
Creator:
Lomperski, S.; Farmer, M. T.; Kilsdonk, D. & Aeschlimann, B. (Nuclear Engineering Division)
Object Type:
Report
System:
The UNT Digital Library
Science and Technology Review June 2011
None
Date:
May 23, 2011
Creator:
Nikolic, R. J.
Object Type:
Report
System:
The UNT Digital Library
Thermal properties for the thermal-hydraulics analyses of the BR2 maximum nominal heat flux.
This memo describes the assumptions and references used in determining the thermal properties for the various materials used in the BR2 HEU (93% enriched in {sup 235}U) to LEU (19.75% enriched in {sup 235}U) conversion feasibility analysis. More specifically, this memo focuses on the materials contained within the pressure vessel (PV), i.e., the materials that are most relevant to the study of impact of the change of fuel from HEU to LEU. This section is regrouping all of the thermal property tables. Section 2 provides a summary of the thermal properties in form of tables while the following sections present the justification of these values. Section 3 presents a brief background on the approach used to evaluate the thermal properties of the dispersion fuel meat and specific heat capacity. Sections 4 to 7 discuss the material properties for the following materials: (i) aluminum, (ii) dispersion fuel meat (UAlx-Al and U-7Mo-Al), (iii) beryllium, and (iv) stainless steel. Section 8 discusses the impact of irradiation on material properties. Section 9 summarizes the material properties for typical operating temperatures. Appendix A elaborates on how to calculate dispersed phase's volume fraction. Appendix B shows the evolution of the BR2 maximum heat flux with burnup.
Date:
May 23, 2011
Creator:
Dionne, B.; Kim, Y. S. & Hofman, G. L. (Nuclear Engineering Division)
Object Type:
Report
System:
The UNT Digital Library
Uncompensated magnetization and exchange-bias field in La0.7Sr0.3MnO3/YMnO3 bilayers: The influence of the ferromagnetic layer
None
Date:
May 23, 2011
Creator:
Zandalazini, C.; Esquinazi, P.; Bridoux, G.; Barzola-Quiquia, J.; Ohldag, H. & Arenholz, E.
Object Type:
Article
System:
The UNT Digital Library
Angular distribution of laser ablation plasma
An expansion of a laser induced plasma is fundamental and important phenomena in a laser ion source. To understand the expanding direction, an array of Langmuir probes were employed. The chosen ion for the experiment was Ag{sup 1+} which was created by a second harmonics of a Nd-YAG laser. The obtained angular distribution was about {+-}10 degree. This result also indicates a proper positioning of a solenoid magnet which enhances ion beam current.
Date:
May 23, 2010
Creator:
Kondo, K.; Kanesue, T.; Dabrowski, R. & Okamura, M.
Object Type:
Article
System:
The UNT Digital Library
ASSEMBLY AND TEST OF A 120 MM BORE 15 T NB3SN QUADRUPOLE FOR THE LHC UPGRADE
In support of the Large Hadron Collider (LHC) luminosity upgrade, the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a design short sample gradient of 219 T/m at 1.9 K and a peak field approaching 15 T, one of the main challenges of this magnet is to provide appropriate mechanical support to the coils. Compared to the previous LARP Technology Quadrupole and Long Quadrupole magnets, the purpose of HQ is also to demonstrate accelerator quality features such as alignment and cooling. So far, 8 HQ coils have been fabricated and 4 of them have been assembled and tested in HQ01a. This paper presents the mechanical assembly and test results of HQ01a.
Date:
May 23, 2010
Creator:
Felice, H.; Caspi, S.; Cheng, D.; Dietderich, D.; Ferracin, P.; Hafalia, R. et al.
Object Type:
Article
System:
The UNT Digital Library
Beam break-up estimates for the ERL at BNL
A prototype Ampere-class superconducting energy recovery linac (ERL) is under advanced construction at BNL. The ERL facility is comprised of a five-cell SC Linac plus a half-cell SC photo-injector RF electron gun, both operating at 703.75 MHz. The facility is designed for either a high-current mode of operation up to 0.5 A at 703.75 MHz or a high-bunch-charge mode of 5 nC at 10 MHz bunch frequency. The R&D facility serves a test bed for an envisioned electron-hadron collider, eRHIC. The high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory, and requires the determination of HOM tolerances for a cavity upgrade. The niobium cavity has been tested at superconducting temperatures and has provided measured quality factors (Q) for a large number of modes. These numbers were used for the estimate of the beam breakup instability (BBU). The facility will be assembled with a highly flexible lattice covering a vast operational parameter space for verification of the estimates and to serve as a test bed for the concepts directed at future projects.
Date:
May 23, 2010
Creator:
Ben-Zvi, Ilan; Calaga, R.; Hahn, H.; Hammons, L.; Johnson, E.; Kayran, D. et al.
Object Type:
Article
System:
The UNT Digital Library
BEAM CONTAINMENT SYSTEM FOR NSLS-II
The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (and potentially to measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R&D program will be presented.
Date:
May 23, 2010
Creator:
Kramer, S. L.; Casey, W. & Job, P. K.
Object Type:
Article
System:
The UNT Digital Library
Bunch Length Effects in the Beam-Beam Compensation With an Electron Lens
N/A
Date:
May 23, 2010
Creator:
Fischer, W.
Object Type:
Article
System:
The UNT Digital Library
CesrTA Retarding Field Analyzer Modeling Results
Retarding field analyzers (RFAs) provide an effective measure of the local electron cloud density and energy distribution. Proper interpretation of RFA data can yield information about the behavior of the cloud, as well as the surface properties of the instrumented vacuum chamber. However, due to the complex interaction of the cloud with the RFA itself, understanding these measurements can be nontrivial. This paper examines different methods for interpreting RFA data via cloud simulation programs. Techniques include postprocessing the output of a simulation code to predict the RFA response; and incorporating an RFA model into the cloud modeling program itself.
Date:
May 23, 2010
Creator:
Calvey, J. R.; Celata, C. M.; Crittenden, J. A.; Dugan, G. F.; Greenwald, S.; Leong, Z. et al.
Object Type:
Article
System:
The UNT Digital Library
Chromaticity Feedback at RHIC
Chromaticity feedback during the ramp to high beam energies has been demonstrated in the Relativistic Heavy Ion Collider (RHIC). In this report we review the feedback design and measurement technique. Commissioning experiences including interaction with existing tune and coupling feedback are presented together with supporting experimental data.
Date:
May 23, 2010
Creator:
Marusic, A.; Minty, M. & Tepikian, S.
Object Type:
Article
System:
The UNT Digital Library
E-Cloud Drivent Single-Bunch Instabilities in PS2
One of the proposals under consideration for future upgrades of the LHC injector complex entails the replacement of the PS with the PS2, a longer circumference and higher energy synchrotron, with electron cloud effects representing a potentially serious limitation to the achievement of the upgrade goals. We report on ongoing numerical studies aiming at estimating the e-cloud density threshold for the occurrence of single bunch instabilities.
Date:
May 23, 2010
Creator:
Venturini, M.; Furman, M.; Penn, G.; Secondo, R.; Vay, J. L.; De Maria, R. et al.
Object Type:
Article
System:
The UNT Digital Library
Confinement of laser plasma by solenoidal field for laser ion source
A laser ion source can provide high current, highly charged ions with a simple structure. However, it was not easy to control the ion pulse width. To provide a longer ion beam pulse, the plasma drift length, which is the distance between laser target and extraction point, has to be extended and as a result the plasma is diluted severely. Previously, we applied a solenoid field to prevent reduction of ion density at the extraction point. Although a current enhancement by a solenoid field was observed, plasma behavior after a solenoid magnet was unclear because plasma behavior can be different from usual ion beam dynamics. We measured a transverse ion distribution along the beam axis to understand plasma motion in the presence of a solenoid field.
Date:
May 23, 2010
Creator:
Okamura, M.; Kanesue,T.; Kondo, K. & Dabrowski, R.
Object Type:
Article
System:
The UNT Digital Library
The Design and Development of The EBIS LEBT Solenoid Power Supply
This power supply was designed and developed at Brookhaven National Laboratory (BNL) as part of a new ion preinjector system called EBIS (Electron Beam Ion Source). It consists of a charging power supply, a capacitor bank, a discharge and recovery circuit and control circuits. The output is fed through cables into a solenoid magnet. The magnet's inductance is 1.9mH. The maximum charging voltage is 1000V. The power supply output is a half sine wave of 13ms duration. The repetition rate is 5Hz. The power supply output can be set to any value between 250A and 1900A in one second in order to accommodate the varying species of ions specified by different machine users.
Date:
May 23, 2010
Creator:
Tan, Y.; Addessi, J.; Alessi, J.; Lambiase, R.; Liaw, C. J.; Pikin, A. et al.
Object Type:
Article
System:
The UNT Digital Library
DPIS for warm dense matter
Warm Dense Matter (WDM) offers an challenging problem because WDM, which is beyond ideal plasma, is in a low temperature and high density state with partially degenerate electrons and coupled ions. WDM is a common state of matter in astrophysical objects such as cores of giant planets and white dwarfs. The WDM studies require large energy deposition into a small target volume in a shorter time than the hydrodynamical time and need uniformity across the full thickness of the target. Since moderate energy ion beams ({approx} 0.3 MeV/u) can be useful tool for WDM physics, we propose WDM generation using Direct Plasma Injection Scheme (DPIS). In the DPIS, laser ion source is connected to the Radio Frequency Quadrupole (RFQ) linear accelerator directly without the beam transport line. DPIS with a realistic final focus and a linear accelerator can produce WDM.
Date:
May 23, 2010
Creator:
Kondo, K.; Kanesue, T.; Horioka, K. & Okamura, M.
Object Type:
Article
System:
The UNT Digital Library
Effect of Triplet Magnet Vibrations on RHIC Performance with High Energy Protons
In this report we present recent experimental data from the Relativistic Heavy Ion Collider (RHIC) illustrating effects resulting from {approx}10 Hz vibrations of the triplet quadrupole magnets in the interactions regions and evaluate the impact of these vibrations on RHIC collider performance. Measurements revealed modulation of the betatron tunes of appreciable magnitude relative to the total beam-beam parameter. Comparison of the discrete frequencies in the spectra of the measured beam positions and betatron tunes confirmed a common source. The tune modulations were shown to result from feed-down in the sextupole magnets in the interaction regions. In addition we show that the distortions to the closed orbit of the two counter-rotating beams produced a modulated crossing angle at the interaction point(s).
Date:
May 23, 2010
Creator:
Minty, M.
Object Type:
Article
System:
The UNT Digital Library
Electron Cloud at Low Emittance in CesrTA
The Cornell Electron Storage Ring (CESR) has been reconfigured as a test accelerator (CesrTA) for a program of electron cloud (EC) research at ultra low emittance. The instrumentation in the ring has been upgraded with local diagnostics for measurement of cloud density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the cloud. A range of EC mitigation methods have been deployed and tested and their effectiveness is discussed. Measurements of the electron cloud's effect on the beam under a range of conditions are discussed along with the simulations being used to quantitatively understand these results.
Date:
May 23, 2010
Creator:
Alexander, J. P.; Billing, M. G.; Calvey, J.; Crittenden, J. A.; Dugan, G.; Eggert, N. et al.
Object Type:
Article
System:
The UNT Digital Library
Experience with split transition lattices at RHIC
During the acceleration process, heavy ion beams in RHIC cross the transition energy. When RHIC was colliding deuterons and gold ions during Run-8, lattices with different integer tunes were used for the two rings. This resulted in the two rings crossing transition at different times, which proved beneficial for the 'Yellow' ring, the RF system of which is slaved to the 'Blue' ring. For the symmetric gold-gold run in FY2010, lattices with different transition energies but equal tunes were implemented. We report the optics design concept as well as operational experience with this configuration.
Date:
May 23, 2010
Creator:
Montag, C.; Tepikian, S.; Blaskiewicz, M. & Brennan, J. M.
Object Type:
Article
System:
The UNT Digital Library
Future Electron-Hadron Colliders
Outstanding research potential of electron-hadron colliders (EHC) was clearly demonstrated by first - and the only - electron-proton collider HERA (DESY, Germany). Physics data from HERA revealed new previously unknown facets of Quantum Chromo-Dynamics (QCD). EHC is an ultimate microscope probing QCD in its natural environment, i.e. inside the hadrons. In contrast with hadrons, electrons are elementary particles with known initial state. Hence, scattering electrons from hadrons provides a clearest pass to their secrets. It turns EHC into an ultimate machine for high precision QCD studies and opens access to rich physics with a great discovery potential: solving proton spin puzzle, observing gluon saturation or physics beyond standard model. Access to this physics requires high-energy high-luminosity EHCs and a wide reach in the center-of-mass (CM) energies. This paper gives a brief overview of four proposed electron-hadron colliders: ENC at GSI (Darmstadt, Germany), ELIC/MEIC at TJNAF (Newport News, VA, USA), eRHIC at BNL (Upton, NY, USA) and LHeC at CERN (Geneva, Switzerland). Future electron-hadron colliders promise to deliver very rich physics not only in the quantity but also in the precision. They are aiming at very high luminosity two-to-four orders of magnitude beyond the luminosity demonstrated by the very successful HERA. …
Date:
May 23, 2010
Creator:
Litvinenko, V.
Object Type:
Article
System:
The UNT Digital Library
Global Orbit Feedback in RHIC
For improved reproducibility of good operating conditions and ramp commissioning efficiency, new dual-plane slow orbit feedback during the energy ramp was implemented during run-10 in the Relativistic Heavy Ion Collider (RHIC). The orbit feedback is based on steering the measured orbit, after subtraction of the dispersive component, to either a design orbit or to a previously saved reference orbit. Using multiple correctors and beam position monitors, an SVD-based algorithm is used for determination of the applied corrections. The online model is used as a basis for matrix computations. In this report we describe the feedback design, review the changes made to realize its implementation, and assess system performance.
Date:
May 23, 2010
Creator:
Minty, M.; Hulsart, R.; Marusic, A.; Michnoff, R.; Ptitsyn, V.; Robert-Demolaize, G. et al.
Object Type:
Article
System:
The UNT Digital Library
Heat load of a P-doped GaAs photocathode in SRF electron gun
Many efforts were made over the last decades to develop a better polarized electron source for the high energy physics. Several laboratories operate DC guns with the Gallium-Arsenide photo-cathode, which yield a highly polarized electron beam. However, the beam's emittance might well be improved using a Superconducting RF electron gun, which delivers beams of higher brightness than DC guns does, because the field gradient at the cathode is higher. SRF guns with metal cathodes and CsTe cathodes have been tested successfully. To produce polarized electrons, a Gallium-Arsenide photo-cathode must be used: an experiment to do so in a superconducting RF gun is under way at BNL. Since the cathode will be normal conducting, the problem about the heat load stemming from the cathode arises. We present our measurements of the electrical resistance of GaAs at cryogenic temperatures, a prediction of the heat load and the verification by measuring the quality factor of the gun with and without cathode.
Date:
May 23, 2010
Creator:
Wang, E.; Ben-Zvi, Ilan; Kewisch, J.; Burrill, A.; Rao, T.; Wu, Q. et al.
Object Type:
Article
System:
The UNT Digital Library
High Precision Tune and Coupling Feedback and Beam Transfer Function Measurements in RHIC
Precision measurement and control of the betatron tunes and betatron coupling in the Relativistic Heavy Ion Collider (RHIC) are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.
Date:
May 23, 2010
Creator:
Minty, M.; Curcio, A.; Dawson, C.; Degen, C.; Luo, Y.; Marr, G. et al.
Object Type:
Article
System:
The UNT Digital Library
Inelastic X-ray Scattering Investigations of Lattice Dynamics in SmFeAsO1-xFy Superconductors
We report measurements of the phonon density of states as measured with inelastic x-ray scattering in SmFeAsO{sub 1-x}F{sub y} powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted for oxygen. Phonon dispersion measurements on SmFeAsO{sub 1-x}F{sub y} single crystals allow us to identify the 21 meV A{sub 1g} in-phase (Sm,As) and the 26 meV B{sub 1g} (Fe,O) modes to be responsible for this renormalization, and may reaveal unusual electron-phonon coupling through the spin channel in iron-based superconductors.
Date:
May 23, 2010
Creator:
Hill, J. P.; Le Tacon, M.; Forrest, T. R.; Ruegg, Ch.; Bosak, A.; Noffsinger, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Interaction region design for the electron-nucleon collider ENC at FAIR
To facilitate studies of collisions between polarized electron and protons at {radical}s = 14 GeV; constructing an electron-nucleon collider at the FAIR facility has been proposed. This machine would collide the stored 15 GeV polarized proton beam in the HESR with a polarized 3.3 GeV electron beam circulating in an additional storage ring. We describe the interaction region design of this facility, which utilizes the PANDA detector.
Date:
May 23, 2010
Creator:
Montag, C.; Jankowiak, A. & Lehrach, A.
Object Type:
Article
System:
The UNT Digital Library