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Design, Installation, and Initial Commissioning of the MTA Beamline

Description: A new experimental area designed to develop, test and verify muon ionization cooling apparatus using the 400-MeV Fermilab Linac proton beam has been fully installed and is presently being commissioned. Initially, this area was used for cryogenic tests of liquid-hydrogen absorbers for the MUCOOL R&D program and, now, for high-power beam tests of absorbers, high-gradient rf cavities in the presence of magnetic fields (including gas-filled cavities), and other prototype muon-cooling apparatus. The experimental scenarios being developed for muon facilities involve collection, capture, and cooling of large-emittance, high-intensity muon beams--{approx}10{sup 13} muons, so that conclusive tests of the apparatus require full Linac beam, which is 1.6 x 10{sup 13} p/pulse. To support the muon cooling facility, this new primary beamline extracts and transports beam directly from the Linac to the test facility. The design concept for the MuCool facility is taken from an earlier proposal [1], but modifications were necessary to accommodate high-intensity beam, cryogenics, and the increased scale of the cooling experiments. Further, the line incorporates a specialized section and utilizes a different mode of operation to provide precision measurements of Linac beam parameters. This paper reports on the technical details of the MuCool beamline for both modes.
Date: May 1, 2010
Creator: Moore, Craig; /Fermilab; Anderson, John; /Fermilab; Garcia, Fernanda; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Final Results on RF and Wake Kicks Caused by the Couplers for the ILC Cavity

Description: In the paper the results are presented for calculation of the transverse wake and RF kick from the power and HOM couplers of the ILC acceleration structure. The RF kick was calculated stand-alone by HFSS, CST MWS and COMSOL codes while the wake kick was calculated by GdfidL. The calculation precision and convergence for both cases are discussed and compared to the results obtained independently by other group.
Date: May 1, 2010
Creator: Lunin, Andrei; /Fermilab; Gonin, Ivan; /Fermilab; Solyak, Nikolay; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Dynamics of Flat Bunches with Second Harmonic RF

Description: We investigate the dynamics of longitudinally flat bunches created with a second harmonic cavity in a high energy collider. We study Landau damping in a second harmonic cavity with analytical and numerical methods. The latter include particle tracking and evolution of the phase space density. The results are interpreted in the context of possible application to the LHC. A possible path to a luminosity upgrade at the LHC is through the creation of longitudinally flat bunches. They can increase the luminosity roughly by 40% when the beam intensities are at the beam-beam limit. Lower momentum spread which can reduce backgrounds and make collimation easier as well lower peak fields which can mitigate electron cloud effects are other advantages. Use of a second harmonic rf system is a frequently studied method to create such flat bunches. Here we consider some aspects of longitudinal dynamics of these bunches in the LHC at top energy. First we consider intensity limits set by the loss of Landau damping against rigid dipole oscillations. Next we describe numerical simulations using both particle tracking and evolution of the phase space density. These simulations address the consequences of driving a bunch at a frequency that corresponds to the maximum of the synchrotron frequency.
Date: May 1, 2010
Creator: Sen, Tanaji; /Fermilab; Bhat, Chandra; /Fermilab; Kim, Hyung Jin; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

IBS in a CAM-Dominated Electron Beam

Description: We report on the performance and planned upgrades to the Fermilab Accumulator Stacktail Stochastic Cooling System. The current system has achieved a maximum flux of 16.5e10/hour, limited by the input flux of antiprotons. The upgrades are designed to handle flux in excess of 40e10/hour.
Date: December 1, 2005
Creator: Burov, Alexey V.; /Fermilab; Gusachenko, I.; U., /Novosibirsk State; Nagaitsev, S.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Model for Initiation of Quality Factor Degradation at High Accelerating Fields in Superconducting Radio-Frequency Cavaties

Description: A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Since magnetic fields at the cavity equator are tied to accelerating electric fields by a simple geometric factor, the onset of magnetic flux penetration determines the onset of Q-drop. We consider breakdown of the surface barrier at triangular grooves to predict the magnetic field of first flux penetration H{sub pen}. Such defects were argued to be the worst case by Buzdin and Daumens, [1998 Physica C 294 257], whose approach, moreover, incorporates both the geometry of the groove and local contamination via the Ginzburg-Landau parameter {kappa}. Since previous Q-drop models focused on either topography or contamination alone, the proposed model allows new comparisons of one effect in relation to the other. The model predicts equivalent reduction of H{sub pen} when either roughness or contamination were varied alone, so smooth but dirty surfaces limit cavity performance about as much as rough but clean surfaces do. Still lower H{sub pen} was predicted when both effects were combined, i.e. contamination should exacerbate the negative effects of roughness and vice-versa. To test the model with actual data, coupons were prepared by buffered chemical polishing and electropolishing, and stylus profilometry was used to obtain distributions of angles. From these data, curves for surface resistance generated by simple flux flow as a function of magnetic field were generated by integrating over the distribution of angles for reasonable values of {kappa}. This showed that combined effects of roughness and contamination indeed reduce the Q-drop onset field by {approx}20%, and that that contamination contributes to Q-drop as much as roughness. The latter point may be overlooked by SRF cavity research, since access to the cavity interior by spectroscopy tools is very difficult, whereas optical images ...
Date: July 13, 2010
Creator: Dzyuba, A.; U., /Fermilab /Novosibirsk State; Romanenko, A.; /Fermilab; Cooley, L.D. & /Fermilab
Partner: UNT Libraries Government Documents Department

VME Data Acquisition Modules for MINERvA Experiment

Description: This document describes two VME modules developed for MINERvA experiment at Fermilab. The Chain ReadOut Controller (CROC) module has four serial data channels and can interface with up to 48 front-ends using standard CAT5e networking cable. The data transmission rate of each channel is 160 Mbit/s. The maximum data transmission rate via VME bus is {approx}18 MB/s. The Chain Readout Interface Module (CRIM) is designed to provide various interface functions for the CROC module. It is compatible with MINOS MTM timing module and can be used to distribute timing signals to four CROC modules. The CRIM module also has a data port compatible with the CROC serial data interface. The data port can be used for diagnostic purpose and can generate triggers from front-end events. The CRIM module is a standard D08(O) interrupter module.
Date: January 1, 2010
Creator: Baldin, B. & /fermilab
Partner: UNT Libraries Government Documents Department

Fermilab Steering Group Report

Description: The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOvA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC ...
Date: December 1, 2007
Creator: Steering Group, Fermilab
Partner: UNT Libraries Government Documents Department

Physics at an upgraded Fermilab proton driver

Description: In 2004 the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future, primarily motivated by the recent exciting developments in neutrino physics. Over the last few months a physics study has developed the physics case for the Fermilab Proton Driver. The potential physics opportunities are discussed.
Date: July 1, 2005
Creator: Geer, S. & /Fermilab
Partner: UNT Libraries Government Documents Department

Recent results from D0 and CDF

Description: A summary of the Tevatron's measurements and searches for pentaquarks and X(3872) are presented. No evidence for pentaquarks has been observed, while the X(3872) has been confirmed and some characterization has been performed. While the initial measurements are of a simple nature, the X(3872) behaves similarly to the {psi}(2S), suggesting the X(3872) may be a form of unanticipated charmonium rather than a more exotic bound state of D mesons. In addition, a selected number of lifetime measurements of b-quark carrying hadrons are presented. While preliminary, these measurements are becoming competitive in precision with the B factories. These Proceedings end with some interesting measurements of the inclusive Pt and dijet mass cross-sections of b-quark containing jets.
Date: December 1, 2004
Creator: Lincoln, Don & /Fermilab
Partner: UNT Libraries Government Documents Department

Phase trombone program migration for the Recycler Ring at Fermilab

Description: A best matching algorithm was found using a test program written in Mathematica, and was integrated into an accelerator control on-line program. This on-line program now gets rid of network communication, and does not need to run code MAD. In this report, we first describe the matching conditions, and 4 cases of constrains. Using a test program written in Mathematic, given a change of tunes, we were able to find the possible combination of the quadrupole strength in trombone section for each case. We then tested the calculation results by simulations using code MAD and by experiments on the Recycler ring. Finally we found the best matching algorithm and integrated it into an accelerator control on-line program. The test results for the setting and measured tune values by running on-line program on console are also presented.
Date: May 1, 2005
Creator: Xiao, Meiqin & /Fermilab
Partner: UNT Libraries Government Documents Department

Pressure drop in D0 Run2B stave

Description: The D0 Run2b stave structure has been tested to determine the pressure drop along the cooling line and suggest a possible cooling pipe size. The measured pressure drop, charted versus the flow rate, shows good agreement with what is theoretically predicted, the latter underestimating the experimental data in the worst case with a 5.5% error. At a fixed flow rate of 175-ml/min and bulk temperature of -15 C, a cooling pipe formed from a 0.158'' (4.0mm) ID tube would meet the 3.0 psi target pressure drop. With the same piping and a bulk temperature of -10 C the pressure drop is around 2.3 psi.
Date: December 1, 2001
Creator: Lanfranco, Giobatta & /Fermilab
Partner: UNT Libraries Government Documents Department

D0 top quark results and their dependence on successful grid computing

Description: The heaviest known Fermion particle--the top quark--was discovered at Fermilab in the first run of the Tevatron in 1995. However, besides its mere existence one needs to study its properties precisely in order to verify or falsify the predictions of the Standard Model. With the top quark's extremely high mass and short lifetime such measurements probe yet unexplored regions of the theory and bring us closer to solving the open fundamental questions of our universe of elementary particles such as why three families of quarks and leptons exist and why their masses differ so dramatically. To perform these measurements hundreds of millions of recorded proton-antiproton collisions must be reconstructed and filtered to extract the few top quarks produced. Simulated background and signal events with full detector response need to be generated and reconstructed to validate and understand the results. Since the start of the second run of the Tevatron the D0 collaboration has brought Grid computing to its aid for the production of simulated events. Data processing on the Grid has recently been added and thereby enabled us to effectively triple the amount of data available with the highest quality reconstruction methods. We will present recent top quark results D0 obtained from these improved data and explain how they benefited from the availability of computing resources on the Grid.
Date: July 1, 2005
Creator: Wicke, Daniel & /Fermilab
Partner: UNT Libraries Government Documents Department

The Dark Energy Survey

Description: Dark Energy is the dominant constituent of the universe and they have little understanding of it. They describe a new project aimed at measuring the dark energy equation of state parameter, w, to a statistical precision of {approx} 5%, with four separate techniques. The survey will image 5000 deg{sup 2} in the southern sky and collect 300 million galaxies, 30,000 galaxy clusters, and 2000 Type Ia supernovae. The survey will be carried out using a new 3 deg{sup 2} mosaic camera mounted at the prime focus of the 4m Blanco telescope at CTIO.
Date: November 1, 2004
Creator: Flaugher, Brenna & /Fermilab
Partner: UNT Libraries Government Documents Department

Data reprocessing on worldwide distributed systems

Description: The D0 experiment faces many challenges in terms of enabling access to large datasets for physicists on four continents. The strategy for solving these problems on worldwide distributed computing clusters is presented. Since the beginning of Run II of the Tevatron (March 2001) all Monte-Carlo simulations for the experiment have been produced at remote systems. For data analysis, a system of regional analysis centers (RACs) was established which supply the associated institutes with the data. This structure, which is similar to the tiered structure foreseen for the LHC was used in Fall 2003 to reprocess all D0 data with a much improved version of the reconstruction software. This makes D0 the first running experiment that has implemented and operated all important computing tasks of a high energy physics experiment on systems distributed worldwide.
Date: December 1, 2004
Creator: Wicke, Daniel & /Fermilab
Partner: UNT Libraries Government Documents Department

CLHEP infrastructure improvements

Description: CLHEP is a set of HEP-specific foundation and utility classes such as random number generators, physics vectors, and particle data tables. Although CLHEP has traditionally been distributed as one large library, the user community has long wanted the ability to build and use CLHEP packages separately. With the release of CLHEP 1.9, CLHEP has been reorganized and enhanced to enable building and using CLHEP packages individually as well as collectively. The revised build strategy employs all the components of the standard autotools suite: automake, autoconf, and libtool. In combination with the reorganization, the use of these components makes it easy not only to rebuild any single package (e.g., when that package changes), but also to add new packages.
Date: December 1, 2004
Creator: Garren, L. & /Fermilab
Partner: UNT Libraries Government Documents Department

Diffusion due to beam-beam resonances in hadron colliders

Description: Beam-beam tune spread in hadron colliders usually is small enough to avoid most dangerous low-order betatron resonances. However, even weak high-order resonances can be detrimental due to cooperative effect of the external noise. Mechanisms of such cooperation are considered, simple analytical estimates of the diffusion rate being verified with numerical simulations. The developed theory is used to evaluate the beam-beam resonance contribution to the emittance growth in the Tevatron.
Date: May 1, 2005
Creator: Alexahin, Y. & /Fermilab
Partner: UNT Libraries Government Documents Department

Early history of the Fermilab Main Ring

Description: This note is written in response to a request from Phil Livdahl for corrections, and additions to a TM he is writing on Staffing Levels at Fermilab during Initial Construction Years and to a note that Hank Hinterberger is preparing on milestones. In my spare time over the past few years I have taken the original files of the Main Ring Section, my own notes from that period, and various other collections of relevant paper, and arranged them in a set of 44 large loose leaf binders in chronological order. I call this set of volumes the 'Main Ring Chronological Archives'. In response to Phil's request I have recently skimmed through these records of the period and extracted a small subset of documents which relate to the specific questions that Phil is addressing: staffing. administration, and milestones.
Date: October 1, 1983
Creator: Malamud, E. & /Fermilab
Partner: UNT Libraries Government Documents Department

Creep test results on D0 RunIIB stave

Description: The D0 RunIIb final design stave has been tested to verify its response to long term loading (creep). Two stave mockups have been investigated. Mechanical stave No.3 has been under continuous loading for 8 weeks. The maximum deflection was 3.6 {micro}m, with 80% of the total sag reached after the first two weeks. Mechanical stave No.2, despite the denomination, has been assembled successively with improved gluing assembly process and tested for six weeks. No creep mechanism has been observed in this surveyed mockup.
Date: December 1, 2003
Creator: Lanfranco, Giobatta & /Fermilab
Partner: UNT Libraries Government Documents Department

Deflection test results on D0 Run IIB stave

Description: The D0 RunIIb final design stave has been tested to verify its actual mechanical performance. The effectiveness of four G-11 (fiberglass/epoxy) braces to bridge the two channels has been investigated as well. All staves have met the goal stiffness for the silicon area. The stave mockups with braces have shown excellent stiffness in complete agreement with what theoretically calculated.
Date: September 1, 2003
Creator: Lanfranco, Giobatta & /Fermilab
Partner: UNT Libraries Government Documents Department

Design of an upgraded D0 silicon microstrip tracker for Run IIb at the Tevatron

Description: The D0 collaboration planned to upgrade the Silicon Tracker to withstand the radiation dose corresponding to above 2 fb{sup -1} of data. This new detector was designed to be functional up to at least 15 fb{sup -1}. The authors report on the design of the new Silicon Tracker with details of the innermost layer.
Date: January 1, 2004
Creator: Hanagaki, K. & /Fermilab
Partner: UNT Libraries Government Documents Department

Unveiling neutrino mixing and leptonic CP violation

Description: We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle {theta}{sub 13} and the CP-phase {delta}. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture.
Date: January 1, 2005
Creator: Mena, Olga & /Fermilab
Partner: UNT Libraries Government Documents Department