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1

Ion Optical Design of the BRF-FNAL-SAIC-UW PET Accelerator  

NASA Astrophysics Data System (ADS)

The BRF-FNAL-SAIC-UW PET Accelerator consists of a He-3 ion source, a low energy beam transport (LEBT) region, a 212 MHz RFQ, a medium energy beam transport (MEBT) region, a 425 MHz RFQ string, and a high energy beam transport (HEBT) region. To efficiently accelerate the He-3 ions to the energy needed for isotope production, it is desirable to doubly ionize the He-3 beam. This is accomplished by first accelerating a 20 keV He-3+ source beam to 1 MeV through a 212 MHz RFQ. At this energy a gas jet stripper can be used to remove the second electron. The resulting He-3++ ions are transported through the MEBT region where the beam parameters are manipulated to match into the subsequent RFQ. The He-3++ beam is then accelerated to approximately 10.5 MeV through the 425 MHz RFQ string. The MEBT region has proven to be the most challenging to design and implement. Due to space and vacuum constraints, a design based on a near-symmetric, 540 degree isochronous triple focus bend has been adopted. High current (28 mA average in the macro pulse) makes space charge concerns important. This paper will discuss briefly the end-to-end ion optics design of the accelerator, with emphasis on the MEBT portion.

Larson, D. J.; Young, P. E.; Sun, D.; Pasquinelli, R. J.; Bieniosek, F.; Ostiguy, J.-F.; Schmidt, C.; Popovic, M.

1997-05-01

2

The FNAL injector upgrade  

SciTech Connect

The present FNAL H{sup -} injector has been operational since the 1970s and consists of two magnetron H{sup -} sources and two 750 keV Cockcroft-Walton Accelerators. In the upgrade, both slit-type magnetron sources will be replaced with circular aperture sources, and the Cockcroft-Waltons with a 200 MHz RFQ (radio frequency quadrupole). Operational experience at BNL (Brookhaven National Laboratory) has shown that the upgraded source and RFQ will be more reliable, improve beam quality and require less manpower than the present system. The present FNAL (Fermi National Accelerator Laboratory) injector has been operational since 1978 and has been a reliable source of H{sup -} beams for the Fermilab program. At present there are two Cockcroft-Walton injectors, each with a magnetron H{sup -} source with a slit aperture. With these two sources in operation, the injector has a reliability of better than 97%. However, issues with maintenance, equipment obsolescence, increased beam quality demands and retirement of critical personnel, have made it more difficult for the continued reliable running of the H{sup -} injector. The recent past has also seen an increase in both downtime and source output issues. With these problems coming to the forefront, a new 750 keV injector is being built to replace the present system. The new system will be similar to the one at BNL (Brookhaven National Laboratory) that has a similar magnetron source with a round aperture and a 200MHz RFQ. This combination has been shown to operate extremely reliably.

Tan, C.Y.; Bollinger, D.S.; Duel, K.L.; Lackey, J.R.; Pellico, W.A.; /Fermilab

2011-03-01

3

Vertical and horizontal test results of 3.9-GHz accelerating cavities at FNAL  

SciTech Connect

The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the VUV FEL, FLASH. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. Seven 9-cell Nb cavities were tested and six of them did reach accelerating gradient up to 24 MV/m almost twice more than design value of 14 MV/m. Two of these cavities are with new HOM couplers with improved design. In this paper we present all results of the vertical and horizontal tests.

Khabiboulline, T.; Edwards, H.; Foley, M.; Harms, E.; Hocker, James Andrew; Mitchell, D.; Rowe, A.; Solyak, N.; /Fermilab

2008-06-01

4

Ion Source Development For The Proposed FNAL 750 keV Injector Upgrade  

SciTech Connect

Currently there is a Proposed FNAL 750 keV Injector Upgrade for the replacement of the 40 year old Fermi National Laboratory (FNAL) Cockcroft-Walton accelerators with a new ion source and 200 MHz Radio Frequency Quadruple (RFQ). The slit type magnetron being used now will be replaced with a round aperture magnetron similar to the one used at Brookhaven National Lab (BNL). Operational experience from BNL has shown that this type of source is more reliable with a longer lifetime due to better power efficiency. The current source development effort is to produce a reliable source with >60 mA of H{sup -} beam current, 15 Hz rep-rate, 100 {mu}s pulse width, and a duty factor of 0.15%. The source will be based on the BNL design along with development done at FNAL for the High Intensity Neutrino Source (HINS).

Bollinger, D. S. [Fermi National Accelerator Laboratory, Box 500, Batavia, IL 60543 (United States)

2011-09-26

5

Proposed FNAL 750 KeV Linac Injector Upgrade  

SciTech Connect

The present FNAL linac H{sup -} injector has been operational since 1978 and consists of a magnetron H{sup -} source and a 750 keV Cockcroft-Walton Accelerator. The proposed upgrade to this injector is to replace the present magnetron source having a rectangular aperture with a circular aperture, and to replace the Cockcroft-Walton with a 200 MHz RFQ. Operational experience at other laboratories has shown that the upgraded source and RFQ will be more reliable and require less manpower than the present system.

Tan, C.Y.; Bollinger, D.S.; Schmidt, C.W.; /Fermilab

2009-04-01

6

FNAL central email systems  

SciTech Connect

The FNAL Email System is the primary point of entry for email destined for an employee or user at Fermilab. This centrally supported system is designed for reliability and availability. It uses multiple layers of protection to help ensure that: (1) SPAM messages are tagged properly; (2) All mail is inspected for viruses; and (3) Valid mail gets delivered. This system employs numerous redundant subsystems to accomplish these tasks.

Schmidt, Jack; Lilianstrom, Al; Pasetes, Ray; Hill, Kevin; /Fermilab

2004-10-01

7

Accelerated laboratory weathering of acrylic lens materials  

NASA Astrophysics Data System (ADS)

Flat samples from PMMA formulations were subjected to accelerated laboratory weathering in an "Atlas Xenotest Alpha +" weathering device operating at 3 Sun irradiance. Measured properties included transmittance, yellowness index, haze and molecular weight. All samples remained transparent after 3.2GJ/m2 radiant exposure (300 - 400nm). Other observations were a reduction of transmittance, an increase of yellowness index and a reduction of molecular weight. The amount of change depended on the PMMA formulation. Higher UV absorber concentrations led to smaller changes in optical properties and molecular weight. First data obtained from EMMAQUA accelerated outdoor exposure showed much smaller changes in optical properties than Alpha weathering data of equal radiant exposures. Data from Alpha exposure at lower temperatures underline the role of temperature as a second acceleration factor.

Arndt, Thomas; Richter, Steffen; Pasierb, Mike

2013-09-01

8

FASTBUS for the particle accelerator laboratories  

SciTech Connect

The FASTBUS modular high speed data acquisition and control system for high energy physics and other applications was described by Costrell and Dawson at the 1983 Particle Accelerator Conference. Both the specification and the implementation of this interlaboratory development have progressed considerably since that time. Because of its many attractive features, FASTBUS is currently in use in several major nuclear and high energy physics laboratories and is also finding application in other areas. 10 refs.

Dawson, W.K.; Costrell, L.; Ikeda, H.; Ponting, P.J.; Walz, H.V.

1985-05-01

9

Electropolishing at ANL/FNAL.  

SciTech Connect

A system for electropolishing of 1.3 GHz elliptical single- and nine-cell cavities is in operation at the joint ANL/FNAL cavity processing facility located at Argonne. The system is one peice of a larger 200 m2 complete single cavity processing and assembly facility which also includes clean rooms and high-pressure rinsing. Recently, the electropolishing system has been used to process a series of single and nine-cell cavities. For single cell cavities a good set of EP parameters has been demonstrated based on more than a half dozen complete processing and cold test cycles at ANL/FNAL. The lastest six single cell cavities each exceed EACC=35 MV/m and, at this gradient, have Q in the range 6 10{sup 9} - 1 10{sup 10}. The first nine cell cavities electropolished at ANL have not yet reached similar fields ({approx}23 MV/m-26 MV/m) and ongoing activities are focussed on demonstrating >30 MV/m in these cavities. Suitable nine cell EP parameters using the ANL/FNAL EP system including acid/water temperatures, flow rates, current, voltage, air flow etc. are all substantially different than for single-cell cavities and are discussed here.

Kelly, M. P.; Gerbick, S. M.; Wu, G.; Bice, D.; Physics; FNAL

2009-01-01

10

Status of FNAL SciBooNE experiment  

SciTech Connect

SciBooNE is a new experiment at FNAL which will make precision neutrino-nucleus cross section measurements in the one GeV region. These measurements are essential for the future neutrino oscillation experiments. We started data taking in the antineutrino mode on June 8, 2007, and collected 5.19 x 10{sup 19} protons on target (POT) before the accelerator shutdown in August. The first data from SciBooNE are reported in this article.

Nakajima, Yasuhiro; /Kyoto U.

2007-12-01

11

McMaster Accelerator Laboratory. Annual report 1988.  

National Technical Information Service (NTIS)

This Annual Report summarizes the research activities at the McMaster Accelerator Laboratory. Included are reports of work carried out during the period of November 1987 to September 1988 with separate subsections for Nuclear Physics Research, Accelerator...

1988-01-01

12

Accelerator-Based Laboratory Nuclear Astrophysics  

NASA Astrophysics Data System (ADS)

Measuring nuclear reaction rates in the Laboratory is essential for interpreting and understanding astrophysical phenomena such as solar neutrinos, the age of globular clusters, nova and supernova nucleosynthesis, etc. Current laboratory innovations are focused on - the development and use of underground facilities to increase measurement sensitivity by reducing cosmic-ray background rates; the production and acceleration of beams of radioactive nuclei in order to measure the rates of reactions involved in explosive nucleosynthesis; together with the continuing development of more and more sophisticated detector systems. Examples will be presented from these areas, including: the status of critical reactions determining the rates of the proton-proton chain neutrinos; the rate of the 14N(p,?) reaction relating to the rate of the CNO cycle and consequently to the age of globular clusters; measurement of the 26mAl(p,?) reaction rate; and first measurements of the properties of nuclei, such as 78Ni and 132Sn, which are relevant to the r-process path.

Parker, Peter D.

2008-05-01

13

H- ion source development for the FNAL 750keV injector upgrade  

NASA Astrophysics Data System (ADS)

The new FNAL 750keV injector upgrade for the replacement of the 40 year old Fermi National Laboratory (FNAL) Cockcroft-Walton accelerators with a new ion source and 200MHz Radio Frequency Quadrupole (RFQ), Low Energy Beam Transport (LEBT) and Medium Energy Beam Transport (MEBT) [1], has been built and is now being tested prior to installation during the 2012 shutdown. The new H- ion source is a round aperture magnetron which was developed at Brookhaven National Lab (BNL) by Jim Alessi[2]. Operational experience from BNL has shown that this type of source is more reliable with a longer lifetime (on the order of 6 to 9 months) due to better power efficiency. With a similar duty factor to BNL, we expect to have a comparable lifetime between source changes. The new source design reliably produces 90mA of H- beam current at 15Hz rep-rate, 250?s pulse width, and a duty factor of 0.38%. The measured emittances at the end of the LEBT are horizontally ?H = 0.21? mm* mrad and vertically ?V = 0.17? mm* mrad. With 35kV extraction the power efficiency is 60mA/kW. The source design, along with data from a test stand and the LEBT, will be presented in this paper.

Bollinger, D. S.

2013-02-01

14

US accelerator contribution to the LHC  

SciTech Connect

In 1998, the United States entered into an agreement with CERN to help build the Large Hadron Collider (LHC), with contributions to the accelerator and to the large HEP detectors. To accomplish this, the US LHC Accelerator Project was formed, encompassing expertise from Brookhaven National Laboratory (BNL), Fermi National Accelerator Laboratory (FNAL) and the Lawrence Berkeley National Laboratory (LBNL). This report is a summary of these contributions including the progress towards project completion, as well as a discussion of future plans for continued US participation in the LHC accelerator.

Lamm, Michael J.; /Fermilab

2005-05-01

15

Fermi National Accelerator Laboratory: Acronyms of High-Energy Physics  

NSDL National Science Digital Library

From the Department of Energy's Fermi National Accelerator Laboratory Web site, (last mentioned in the August 2, 2000 Scout Report) comes the handy Acronyms of High-Energy Physics Web site. Organized into four categories including laboratories, accelerators, detectors and experiments, and other institutions, each acronym is followed by a brief description and a link to the site or further information.

1969-12-31

16

Environmental Survey preliminary report, Fermi National Accelerator Laboratory, Batavia, Illinois.  

National Technical Information Service (NTIS)

This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy (DOE) Fermi National Accelerator Laboratory (Fermilab), conducted September 14 through 25, 1987. The Survey is being conducted by...

1988-01-01

17

Magnet R&D for the US LHC Accelerator Research Program (LARP)  

Microsoft Academic Search

In 2004, the US DOE established the LHC Accelerator Research Program (LARP) with the goal of developing a technology base for future upgrades of the LHC. The focus of the magnet program, which is a collaboration of three US laboratories, BNL, FNAL and LBNL, is on development of high gradient quadrupoles using Nb3Sn superconductor. Other program components address issues regarding

S. A. Gourlay; G. Ambrosio; N. Andreev; M. Anerella; E. Barzi; R. Bossert; S. Caspi; D. R. Dietderich; P. Ferracin; R. Gupta; A. Ghosh; A. R. Hafalia; C. R. Hannaford; M. Harrison; V. S. Kashikhin; V. V. Kashikhin; A. F. Lietzke; S. Mattafirri; A. D. McInturff; F. Nobrega; I. Novitsky; G. L. Sabbi; J. Schmazle; R. Stanek; D. Turrioni; P. Wanderer; R. Yamada; A. V. Zlobin

2006-01-01

18

Los Alamos National Laboratory accelerated tru waste workoff strategies  

Microsoft Academic Search

During 1996, the Los Alamos National Laboratory (LANL) developed two transuranic (TRU) waste workoff strategies that were estimated to save $270 - 340M through accelerated waste workoff and the elimination of a facility. The planning effort included a strategy to assure that LANL would have a significant quantity (3000+ drums) of TRU waste certified for shipment to the Waste Isolation

S. T. Kosiewicz; I. R. Triay; P. Z. Rogers; D. V. Christensen

1997-01-01

19

Plasma Astrophysics in the Laboratory with Accelerator Beams  

Microsoft Academic Search

An ultra-relativistic electron\\/positron or ``fireball'' beam interacting with a laboratory plasma is subject to the current filamentation instability (CFI). In the near future, ultra-short (<100fs), ultra-relativistic (25GeV) electron and positron bunches will become available at the SLAC FACET facility. These bunches are accelerated one half period apart and overlapped in space and time near the final focal point. With an

P. Muggli; S. Martins; L. Silva

2010-01-01

20

Low Energy Accelerator Laboratory Technical Area 53, Los Alamos National Laboratory. Environmental assessment  

SciTech Connect

This Environmental Assessment (EA) analyzes the potential environmental impacts that would be expected to occur if the Department of Energy (DOE) were to construct and operate a small research and development laboratory building at Technical Area (TA) 53 at the Los Alamos National Laboratory (LANL), Los Alamos, New Mexico. DOE proposes to construct a small building to be called the Low Energy Accelerator Laboratory (LEAL), at a previously cleared, bladed, and leveled quarter-acre site next to other facilities housing linear accelerator research activities at TA-53. Operations proposed for LEAL would consist of bench-scale research, development, and testing of the initial section of linear particle accelerators. This initial section consists of various components that are collectively called an injector system. The anticipated life span of the proposed development program would be about 15 years.

NONE

1995-04-01

21

Post-accelerator issues at the IsoSpin Laboratory  

SciTech Connect

The workshop on ``Post-Accelerator Issues at the Isospin Laboratory`` was held at the Lawrence Berkeley Laboratory from October 27--29, 1993. It was sponsored by the Center for Beam Physics in the Accelerator and Fusion Research Division and the ISL Studies Group in the Nuclear Science Division. About forty scientists from around the world participated vigorously in this two and a half day workshop, (c.f. Agenda, Appendix D). Following various invited review talks from leading practitioners in the field on the first day, the workshop focussed around two working groups: (1) the Ion Source and Separators working group and (2) the Radio Frequency Quadrupoles and Linacs working group. The workshop closed with the two working groups summarizing and outlining the tasks for the future. This report documents the proceedings of the workshop and includes the invited review talks, the two summary talks from the working groups and individual contributions from the participants. It is a complete assemblage of state-of-the-art thinking on ion sources, low-{beta}, low(q/A) accelerating structures, e.g. linacs and RFQS, isobar separators, phase-space matching, cyclotrons, etc., as relevant to radioactive beam facilities and the IsoSpin Laboratory. We regret to say that while the fascinating topic of superconducting low-velocity accelerator structure was covered by Dr. K. Shepard during the workshop, we can only reproduce the copies of the transparencies of his talk in the Appendix, since no written manuscript was available at the time of publication of this report. The individual report have been catologed separately elsewhere.

Chattopadhyay, S.; Nitschke, J.M. [eds.

1994-05-01

22

Recent Developments at the Accelerator Laboratory in Jyvaeskylae  

SciTech Connect

Recent developments at the Accelerator Laboratory in Jyvaeskylae are described. In addition to the existing K = 130 a new cyclotron has been added. It is capable of producing of high current proton and deuteron beams at 30 and 15 MeV correspondingly. It should be fully operational in 2010. A new development in Jyvaeskylae is the growing commitment to astroparticle physics. Jyvaeskylae took the main scientific responsibility for a new cosmic-ray experiment EMMA and has joined the LAGUNA project working on the design of the next generation of very large volume detectors for underground observatories.

Trzaska, Wladyslaw Henryk [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL) FI-40014 (Finland)

2010-04-30

23

Status of the accelerator facility at the Environmental Molecular Sciences Laboratory  

Microsoft Academic Search

An accelerator facility dedicated to ion beam materials analysis and modification has been completed at the Environmental Molecular Sciences Laboratory (EMSL), a United States Department of Energy collaborative scientific user facility located at the Pacific Northwest National Laboratory in Richland, WA. The EMSL accelerator facility is based on a Model 9SDH-2 3.4 MV tandem ion accelerator manufactured by National Electrostatics

David E. McCready; S. Thevuthasan; Weilin Jiang; I. L. Morgan J. L. Duggan

1999-01-01

24

Laboratory selection for an accelerated mosquito sexual development rate  

PubMed Central

Background Separating males and females at the early adult stage did not ensure the virginity of females of Anopheles arabiensis (Dongola laboratory strain), whereas two years earlier this method had been successful. In most mosquito species, newly emerged males and females are not able to mate successfully. For anopheline species, a period of 24 h post-emergence is generally required for the completion of sexual maturation, which in males includes a 180 rotation of the genitalia. In this study, the possibility of an unusually shortened sexual maturity period in the laboratory-reared colony was investigated. Methods The effect of two different sex-separation methods on the virginity of females was tested: females separated as pupae or less than 16 h post-emergence were mated with males subjected to various doses of radiation. T-tests were performed to compare the two sex-separation methods. The rate of genitalia rotation was compared for laboratory-reared and wild males collected as pupae in Dongola, Sudan, and analysed by Z-tests. Spermatheca dissections were performed on females mated with laboratory-reared males to determine their insemination status. Results When the sex-separation was performed when adults were less than 16 h post-emergence, expected sterility was never reached for females mated with radio-sterilized males. Expected sterility was accomplished only when sexes were separated at the pupal stage. Observation of genitalia rotation showed that some males from the laboratory strain Dongola were able to successfully mate only 11 h after emergence and 42% of the males had already completed rotation. A small proportion of the same age females were inseminated. Wild males showed a much slower genitalia rotation rate. At 17 h post-emergence, 96% of the laboratory-reared males had completed genitalia rotation whereas none of the wild males had. Conclusion This colony has been cultured in the laboratory for over one hundred generations, and now has accelerated sexual maturation when compared with the wild strain. This outcome demonstrates the kinds of selection that can be expected during insect colonization and maintenance, particularly when generations are non-overlapping and similar-age males must compete for mates.

2011-01-01

25

Environmental Survey preliminary report, Fermi National Accelerator Laboratory, Batavia, Illinois  

SciTech Connect

This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy (DOE) Fermi National Accelerator Laboratory (Fermilab), conducted September 14 through 25, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual participants for the Survey team are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with Fermilab. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations performed at Fermilab, and interviews with site personnel. 110 refs., 26 figs., 41 tabs.

Not Available

1988-10-01

26

Los Alamos National Laboratory accelerated tru waste workoff strategies  

SciTech Connect

During 1996, the Los Alamos National Laboratory (LANL) developed two transuranic (TRU) waste workoff strategies that were estimated to save $270 - 340M through accelerated waste workoff and the elimination of a facility. The planning effort included a strategy to assure that LANL would have a significant quantity (3000+ drums) of TRU waste certified for shipment to the Waste Isolation Pilot Plant (WIPP) beginning in April of 1998, when WIPP was projected to open. One of the accelerated strategies can be completed in less than ten years through a Total Optimization of Parameters Scenario ({open_quotes}TOPS{close_quotes}). {open_quotes}TOPS{close_quotes} fully utilizes existing LANL facilities and capabilities. For this scenario, funding was estimated to be unconstrained at $23M annually to certify and ship the legacy inventory of TRU waste at LANL. With {open_quotes}TOPS{close_quotes} the inventory is worked off in about 8.5 years while shipping 5,000 drums per year at a total cost of $196M. This workoff includes retrieval from earthen cover and interim storage costs. The other scenario envisioned funding at the current level with some increase for TRUPACT II loading costs, which total $16M annually. At this funding level, LANL estimates it will require about 17 years to work off the LANL TRU legacy waste while shipping 2,500 drums per year to WIPP. The total cost will be $277M. This latter scenario decreases the time for workoff by about 19 years from previous estimates and saves an estimated $190M. In addition, the planning showed that a $70M facility for TRU waste characterization was not needed. After the first draft of the LANL strategies was written, Congress amended the WIPP Land Withdrawal Act (LWA) to accelerate the opening of WIPP to November 1997. Further, the No Migration Variance requirement for the WIPP was removed. This paper discusses the LANL strategies as they were originally developed. 1 ref., 3 figs., 2 tabs.

Kosiewicz, S.T.; Triay, I.R.; Rogers, P.Z.; Christensen, D.V.

1997-03-01

27

Tiger Team Assessment of the Fermi National Accelerator Laboratory  

SciTech Connect

This draft report documents the Tiger Team Assessment of the Fermi National Accelerator Laboratory (Fermilab) located in Batavia, Illinois. Fermilab is a program-dedicated national laboratory managed by the Universities Research Association, Inc. (URA) for the US Department of Energy (DOE). The Tiger Team Assessment was conducted from May 11 to June 8, 1992, under the auspices of DOE's Office of Special Projects (OSP) under the Office of the Assistant Secretary for Environment, Safety and Health (EH). The assessment was comprehensive, encompassing environmental, safety and health (ES H), and quality assurance (QA) disciplines; site remediation; facilities management; and waste management operations. Compliance with applicable Federal , State of Illinois, and local regulations; applicable DOE Orders; best management practices; and internal Fermilab requirements was addressed. In addition, an evaluation of the effectiveness of DOE and Fermilab management of the ES H/QA and self-assessment programs was conducted. The Fermilab Tiger Team Assessment is part a larger, comprehensive DOE Tiger Team Independent Assessment Program planned for DOE facilities. The objective of the initiative is to provide the Secretary of Energy with information on the compliance status of DOE facilities with regard to ES H requirements, root causes for noncompliance, adequacy of DOE and contractor ES H management programs, response actions to address the identified problem areas, and DOE-wide ES H compliance trends and root causes.

Not Available

1992-06-01

28

Tiger Team Assessment of the Fermi National Accelerator Laboratory  

SciTech Connect

This draft report documents the Tiger Team Assessment of the Fermi National Accelerator Laboratory (Fermilab) located in Batavia, Illinois. Fermilab is a program-dedicated national laboratory managed by the Universities Research Association, Inc. (URA) for the US Department of Energy (DOE). The Tiger Team Assessment was conducted from May 11 to June 8, 1992, under the auspices of DOE`s Office of Special Projects (OSP) under the Office of the Assistant Secretary for Environment, Safety and Health (EH). The assessment was comprehensive, encompassing environmental, safety and health (ES&H), and quality assurance (QA) disciplines; site remediation; facilities management; and waste management operations. Compliance with applicable Federal , State of Illinois, and local regulations; applicable DOE Orders; best management practices; and internal Fermilab requirements was addressed. In addition, an evaluation of the effectiveness of DOE and Fermilab management of the ES&H/QA and self-assessment programs was conducted. The Fermilab Tiger Team Assessment is part a larger, comprehensive DOE Tiger Team Independent Assessment Program planned for DOE facilities. The objective of the initiative is to provide the Secretary of Energy with information on the compliance status of DOE facilities with regard to ES&H requirements, root causes for noncompliance, adequacy of DOE and contractor ES&H management programs, response actions to address the identified problem areas, and DOE-wide ES&H compliance trends and root causes.

Not Available

1992-06-01

29

Plasma Astrophysics in the Laboratory with Accelerator Beams  

NASA Astrophysics Data System (ADS)

An ultra-relativistic electron/positron or ``fireball'' beam interacting with a laboratory plasma is subject to the current filamentation instability (CFI). In the near future, ultra-short (<100fs), ultra-relativistic (25GeV) electron and positron bunches will become available at the SLAC FACET facility. These bunches are accelerated one half period apart and overlapped in space and time near the final focal point. With an equal number of particles, these two bunches form a neutral, field- and charge-free beam that we call a relativistic fireball beam. The interaction of this beam with laboratory plasma is rather different from that of either the electron or positron bunch alone. No large wakefields are generated. Instead the beam is subject to the CFI, which results in transverse filamentation, accompanied by strong plasma density modulation, generation of large magnetic fields, and generation of radiation that can be detected. This situation is similar to that of space relativistic plasmas, e.g. from supernovae, interacting with the interstellar medium. The CFI generates the magnetic field, and the charged particles emit radiation as in gamma ray bursts afterglow. Detecting the CFI and measuring it characteristics will validate astrophysical models. CFI may also play an important role in the propagation of hot electrons in plasmas for example in the fast igniter concept of ICF. We describe the CFI and the experiment to detect it.

Muggli, P.; Martins, S.; Silva, L.

2010-11-01

30

Operation of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program.

Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

1992-10-01

31

Operation of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program.

Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

1992-01-01

32

The Scanning Electron Microscope As An Accelerator For The Undergraduate Advanced Physics Laboratory  

SciTech Connect

Few universities or colleges have an accelerator for use with advanced physics laboratories, but many of these institutions have a scanning electron microscope (SEM) on site, often in the biology department. As an accelerator for the undergraduate, advanced physics laboratory, the SEM is an excellent substitute for an ion accelerator. Although there are no nuclear physics experiments that can be performed with a typical 30 kV SEM, there is an opportunity for experimental work on accelerator physics, atomic physics, electron-solid interactions, and the basics of modern e-beam lithography.

Peterson, Randolph S. [Department of Physics and Astronomy, University of the South, 735 University Avenue, Sewanee TN 37383 (United States); Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 50 Vassar Street, Cambridge MA 01239 (United States); Berggren, Karl K.; Mondol, Mark [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 50 Vassar Street, Cambridge MA 01239 (United States)

2011-06-01

33

The Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory  

SciTech Connect

CAMS operates an HVEC FN tandem accelerator for use in both basic research and technology development. The accelerator is operated under a distributed computer control system with sophisticated auto-scaling, beam flat-topping, archiving, and recall capabilities, which makes possible rapid and precise switching between experimental configurations daily. Using the spectrometer, the AMS group can routinely measure the isotopes {sup 3}H, {sup 9}Be, {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, and {sup 129}I at abundances as low as 1 part in 10{sup 16}.

Roberts, M.L.; Heikkinen, D.W.; Southon, J.R.; Proctor, I.D.

1996-10-01

34

Resonance control in SRF cavities at FNAL  

SciTech Connect

The Lorentz force can dynamically detune pulsed Superconducting RF cavities. Considerable additional RF power can be required to maintain the accelerating gradient if no effort is made to compensate for this detuning. Compensation systems using piezo actuators have been used successfully at DESY and elsewhere to control Lorentz Force Detuning (LFD). Recently, Fermilab has developed an adaptive compensation system for cavities in the Horizontal Test Stand, in the SRF Accelerator Test Facility, and for the proposed Project X.

Schappert, W.; Pischalnikov, Y.; /Fermilab; Scorrano, M.; /INFN, Pisa

2011-03-01

35

Annotated Bibliography of Accelerator Technology Division (Los Alamos National Laboratory) Research and Development, 1978-1985.  

National Technical Information Service (NTIS)

A bibliography is presented of unclassified published and in-house technical material written by members of the Accelerator Technology Division, Los Alamos National Laboratory, since its inception in January, 1978. The author and subject concordances in t...

R. A. Jameson C. S. Nicol M. A. Cochran

1985-01-01

36

Accelerated Laboratory Corrosion Test for Materials and Finishes Used in Naval Aircraft.  

National Technical Information Service (NTIS)

An accelerated laboratory corrosion test has been developed to screen materials and finishes for use on naval aircraft. Sulfur dioxide is introduced at periodic intervals into a conventional salt fog chamber to simulate conditions produced by the carrier ...

S. J. Ketcham

1977-01-01

37

Operational status of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Design and operation of a 50 MeV Electron Linear Accelerator utilizing a low emittance ({gamma} {var epsilon} = 5 to 10 mm-mrad) radio frequency gun operating at an output energy of 5 MeV and a charge of 1 nC is described. Design calculations and early radio frequency measurements and operational experience with the electron gun utilizing a dummy copper cathode in place of the proposed photocathode emitter are given. 6 refs., 9 figs., 1 tab.

Batchelor, K.; Ben-Zvi, I.; Chou, T.S.; Fernow, R.C.; Fischer, J.; Gallarado, J.; Kirk, H.G.; Palmer, R.B.; Pellegrini, C.; Sheehan, J.; Srinivasan-Rao, T.; Ulc, S.; Van Steenbergen, A.; Woodle, M.; Biglio, I.; Kurnit, N.; McDonald, K.T. (Brookhaven National Lab., Upton, NY (USA); Los Alamos National Lab., NM (USA); Princeton Univ., NJ (USA). Dept. of Physics)

1989-01-01

38

Capture cavity II results at FNAL  

Microsoft Academic Search

As part of the research and development towards the International Linear Collider (ILC), several test facilities have been developed at Fermilab. This paper presents the latest Low Level RF (LLRF) results obtained with Capture Cavity II (CCII) at the ILC Test Accelerator (ILCTA) test facility. The main focus will be on controls and RF operations using the SIMCON based LLRF

Julien Branlard; Brian Chase; G. Cancelo; R. Carcagno; H. Edwards; R. Fliller; B. Hanna; Elvan Harms; A. Hocker; T. Koeth; M. Kucera; A. Makulski; U. Mavric; M. McGee; A. Paytyan; Y. Pischalnikov; P. Prieto; R. Rechenmacher; J. Reid; N. Wilcer; K. Treptow; T. Zmuda

2007-01-01

39

Capture cavity II results at FNAL  

SciTech Connect

As part of the research and development towards the International Linear Collider (ILC), several test facilities have been developed at Fermilab. This paper presents the latest Low Level RF (LLRF) results obtained with Capture Cavity II (CCII) at the ILC Test Accelerator (ILCTA) test facility. The main focus will be on controls and RF operations using the SIMCON based LLRF system developed in DESY [1]. Details about hardware upgrades and future work will be discussed.

Branlard, Julien; Chase, Brian; Cancelo, G.; Carcagno, R.; Edwards, H.; Fliller, R.; Hanna, B.; Harms, Elvan; Hocker, A.; Koeth, T.; Kucera, M.; /Fermilab

2007-06-01

40

ACCELERATION OF LOS ALAMOS NATIONAL LABORATORY TRANSURANIC WASTE DISPOSITION  

Microsoft Academic Search

One of Los Alamos National Laboratory's (LANL's) most significant risks is the site's inventory of transuranic waste retrievably stored above and below-ground in Technical Area (TA) 54 Area G, particularly the dispersible high-activity waste stored above-ground in deteriorating facilities. The high activity waste represents approximately 50% (by activity) of the total 292,000 PE-Ci inventory remaining to be disposed. The transuramic

GERALD A

2007-01-01

41

Acceleration of Los Alamos National Laboratory transuranic waste disposition  

Microsoft Academic Search

One of Los Alamos National Laboratory's (LANL's) most significant risks is the site's inventory of transuranic waste retrievably stored above and below-ground in Technical Area (TA) 54 Area G, particularly the dispersible high-activity waste stored above-ground in deteriorating facilities. The high activity waste represents approximately 50% (by activity) of the total 292,000 PE-Ci inventory remaining to be disposed. The transuranic

G. A. OLeary; B. A. Palmer; T. P. Starke; A. K. Phelps

2007-01-01

42

Observation of Ion Acceleration and Heating during Collisionless Magnetic Reconnection in a Laboratory Plasma  

SciTech Connect

The ion dynamics in a collisionless magnetic reconnection layer are studied in a laboratory plasma. The measured in-plane plasma potential profile, which is established by electrons accelerated around the electron diffusion region, shows a saddle-shaped structure that is wider and deeper towards the outflow direction. This potential structure ballistically accelerates ions near the separatrices toward the outflow direction. Ions are heated as they travel into the high pressure downstream region.

Jongsoo Yoo, Masaaki Yamada, HantaoJi and Clayton E. Myers

2012-12-10

43

Observation of ion acceleration and heating during collisionless magnetic reconnection in a laboratory plasma.  

PubMed

The ion dynamics in a collisionless magnetic reconnection layer are studied in a laboratory plasma. The measured in-plane plasma potential profile, which is established by electrons accelerated around the electron diffusion region, shows a saddle-shaped structure that is wider and deeper towards the outflow direction. This potential structure ballistically accelerates ions near the separatrices toward the outflow direction. Ions are heated as they travel into the high-pressure downstream region. PMID:23745892

Yoo, Jongsoo; Yamada, Masaaki; Ji, Hantao; Myers, Clayton E

2013-05-24

44

Observation of Ion Acceleration and Heating during Collisionless Magnetic Reconnection in a Laboratory Plasma  

NASA Astrophysics Data System (ADS)

The ion dynamics in a collisionless magnetic reconnection layer are studied in a laboratory plasma. The measured in-plane plasma potential profile, which is established by electrons accelerated around the electron diffusion region, shows a saddle-shaped structure that is wider and deeper towards the outflow direction. This potential structure ballistically accelerates ions near the separatrices toward the outflow direction. Ions are heated as they travel into the high-pressure downstream region.

Yoo, Jongsoo; Yamada, Masaaki; Ji, Hantao; Myers, Clayton E.

2013-05-01

45

ACCELERATION OF LOS ALAMOS NATIONAL LABORATORY TRANSURANIC WASTE DISPOSITION  

SciTech Connect

One of Los Alamos National Laboratory's (LANL's) most significant risks is the site's inventory of transuranic waste retrievably stored above and below-ground in Technical Area (TA) 54 Area G, particularly the dispersible high-activity waste stored above-ground in deteriorating facilities. The high activity waste represents approximately 50% (by activity) of the total 292,000 PE-Ci inventory remaining to be disposed. The transuramic waste inventory includes contact-handled and remote-handled waste packaged in drums, boxes, and oversized containers which are retrievably stored both above and below-ground. Although currently managed as transuranic waste, some of the inventory is low-level waste that can be disposed onsite or at approved offsite facilities. Dispositioning the transuranic waste inventory requires retrieval of the containers from above and below-ground storage, examination and repackaging or remediation as necessary, characterization, certification and loading for shipment to the Waste Isolation Pilot Plant in Carlsbad New Mexico, all in accordance with well-defined requirements and controls. Although operations are established to process and characterize the lower-activity contact-handled transuranic waste containers, LAN L does not currently have the capability to repack high activity contact-handled transuranic waste containers (> 56 PE-Ci) or to process oversized containers with activity levels over 0.52 PE-Ci. Operational issues and compliance requirements have resulted in less than optimal processing capabilities for lower activity contact-handled transuranic waste containers, limiting preparation and reducing dependability of shipments to the Waste Isolation Pilot Plant. Since becoming the Los Alamos National Laboratory contract in June 2006, Los Alamos National Security (LANS) L.L.C. has developed a comprehensive, integrated plan to effectively and efficiently disposition the transuranic waste inventory, working in concert with the Department of Energy Los Alamos Site Office, Carlsbad Field Office and the Department of Energy Headquaeters. Rather than simply processing containers as retrieved, the plan places priority on efficient curie disposition, a direct correlation to reducing risk. Key elements of the approch include balancing inventory and operational risks, tailoring methods to meet requirements, optimizing existing facilities, equipment and staff, and incorporating best practices from other Department of Energy sites. With sufficient funding this will enable LANL to ship the above-ground high activity contact-handled transuranic waste offsite by the end of Fiscal Year (FY) 2007 and to disposition the remaining above- and below-ground contact-handled and remote-handled transuranic waste inventory by December 2010. Nearly 70% of the contact-handled transuranic waste containers, including the high activity waste, require processing and repackaging before characterization and certification for shipment to the Waste Isolation Pilot Plant. LANL is employing a balanced risk approach that accomplishes significant long-term risk reduction by accepting short-term increased facility operations risk under well-developed and justified interim controls. Reviews of facility conditions and additional analyses show that the Waste Characterization, Reduction and Repackaging Facility and the Radioassay and Nondestructive Testing Facility are the most appropriate facilities to safetly remediate, repackage, and ship lower activity and the remaining high activity drums. Updated safety documentation supporting limited Hazard Category 2 operations in these facilities has been developed. Once approved, limited-term operations to process the high activity drums can begin in early 2007, building upon the experience base established performing Hazard Category 3 operations processing lower activity waste in these facilities. LANL is also implementing a series of actions to improve and sustain operations for processing contact-handled transuranic waste inventory. Building 412 Decontamination and Volume Facility and Dom

O'LEARY, GERALD A. [Los Alamos National Laboratory

2007-01-04

46

Accelerated laboratory corrosion test for materials and finishes used in naval aircraft. Progress report  

Microsoft Academic Search

An accelerated laboratory corrosion test has been developed to screen materials and finishes for use on naval aircraft. Sulfur dioxide is introduced at periodic intervals into a conventional salt fog chamber to simulate conditions produced by the carrier stack gas\\/marine environment. Procedures for conducting the test are described.

Ketcham

1977-01-01

47

What's new with FASTBUS and what's it done in the particle accelerator laboratories  

Microsoft Academic Search

Implementations of FASTBUS have been made in accelerator laboratories worldwide, resulting in clarifications, modifications and extensions of the specifications. Of tremendous benefit to users have been FASTBUS Standard Routines. The availability of such standard software is unique for high-speed bus systems and resulted from the involvement of hardware and software specialists in all aspects of the development. FASTBUS is the

L. Costrell; W. K. Dawson; P. J. Ponting; E. D. Platner; L. Paffrath; E. J. Barsotti; R. W. Downing; H. Ikeda; R. O. Nelson; I. Kolpakov; D. B. Gustavson; H. V. Walz

1991-01-01

48

Status of the Accelerator Facility at the Environmental Molecular Sciences Laboratory  

SciTech Connect

An accelerator facility dedicated to ion beam materials analysis and modification has been completed at the Environmental Molecular Sciences Laboratory (EMSL), a United States Department of Energy collaborative scientific user facility located at the Pacific Northwest National Laboratory in Richland, WA. The EMSL accelerator facility is based on a Model 9SDH-2 3.4 MV tandem ion accelerator manufactured by National Electrostatics Corporation (NEC, Middleton, WI), which includes RF plasma and sputter ion sources. Three beam lines were originally constructed with integral end stations for materials analysis and modification. Recently, the+30 degrees beam line was extended to accommodate an NEC electrostatic microquad assembly, which provides focused beam spots of 20 mu-m or less on target. Efforts are currently underway to incorporate particle induced x-ray emission (PIXE), Rutherford backscattering spectroscopy (RBS), and nuclear reaction analysis (NRA) capabilities in the microbeam line end station.

McCready, David E. (BATTELLE (PACIFIC NW LAB)); Thevuthasan, Theva (BATTELLE (PACIFIC NW LAB)); Jiang, Weilin (BATTELLE (PACIFIC NW LAB)); J.L. Duggan and I.L. Morgan

1999-01-01

49

Status of the accelerator facility at the Environmental Molecular Sciences Laboratory  

SciTech Connect

An accelerator facility dedicated to ion beam materials analysis and modification has been completed at the Environmental Molecular Sciences Laboratory (EMSL), a United States Department of Energy collaborative scientific user facility located at the Pacific Northwest National Laboratory in Richland, WA. The EMSL accelerator facility is based on a Model 9SDH-2 3.4 MV tandem ion accelerator manufactured by National Electrostatics Corporation (NEC, Middleton, WI), which includes RF plasma and sputter ion sources. Three beam lines were originally constructed with integral end stations for materials analysis and modification. Recently, the +30{degree} beam line was extended to accommodate an NEC electrostatic microquad assembly, which provides focussed beam spots of 20 {mu}m or less on target. Efforts are currently underway to incorporate particle induced x-ray emission (PIXE), Rutherford backscattering spectrometry (RBS), and nuclear reaction analysis (NRA) capabilities in the microbeam line end station. {copyright} {ital 1999 American Institute of Physics.}

McCready, D.E.; Thevuthasan, S.; Jiang, W. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

1999-06-01

50

Status of the accelerator facility at the Environmental Molecular Sciences Laboratory  

SciTech Connect

An accelerator facility dedicated to ion beam materials analysis and modification has been completed at the Environmental Molecular Sciences Laboratory (EMSL), a United States Department of Energy collaborative scientific user facility located at the Pacific Northwest National Laboratory in Richland, WA. The EMSL accelerator facility is based on a Model 9SDH-2 3.4 MV tandem ion accelerator manufactured by National Electrostatics Corporation (NEC, Middleton, WI), which includes RF plasma and sputter ion sources. Three beam lines were originally constructed with integral end stations for materials analysis and modification. Recently, the +30 degree sign beam line was extended to accommodate an NEC electrostatic microquad assembly, which provides focussed beam spots of 20 {mu}m or less on target. Efforts are currently underway to incorporate particle induced x-ray emission (PIXE), Rutherford backscattering spectrometry (RBS), and nuclear reaction analysis (NRA) capabilities in the microbeam line end station.

McCready, D. E.; Thevuthasan, S.; Jiang, W. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

1999-06-10

51

Status of the accelerator facility at the Environmental Molecular Sciences Laboratory  

NASA Astrophysics Data System (ADS)

An accelerator facility dedicated to ion beam materials analysis and modification has been completed at the Environmental Molecular Sciences Laboratory (EMSL), a United States Department of Energy collaborative scientific user facility located at the Pacific Northwest National Laboratory in Richland, WA. The EMSL accelerator facility is based on a Model 9SDH-2 3.4 MV tandem ion accelerator manufactured by National Electrostatics Corporation (NEC, Middleton, WI), which includes RF plasma and sputter ion sources. Three beam lines were originally constructed with integral end stations for materials analysis and modification. Recently, the +30 beam line was extended to accommodate an NEC electrostatic microquad assembly, which provides focussed beam spots of 20 ?m or less on target. Efforts are currently underway to incorporate particle induced x-ray emission (PIXE), Rutherford backscattering spectrometry (RBS), and nuclear reaction analysis (NRA) capabilities in the microbeam line end station.

McCready, D. E.; Thevuthasan, S.; Jiang, W.

1999-06-01

52

Operation of the DC Current Transformer Intensity Monitors at FNAL during Run II.  

National Technical Information Service (NTIS)

Circulating beam intensity measurements at FNAL are provided by five DC current transformers (DCCT), one per machine. With the exception of the DCCT in the Recycler, all DCCT systems were designed and built at FNAL. This paper presents an overview of both...

B. Fellenz D. Heikkinen G. Vogel J. Crisp M. A. Ibrahim T. Meyer

2011-01-01

53

An aerial radiological survey of the Fermi National Accelerator Laboratory and surrounding area, Batavia, Illinois  

SciTech Connect

An aerial radiological gamma survey was conducted over the Fermi National Accelerator Laboratory during 1 through 6 June 1989. Flight lines at 150-foot altitude and 250-foot line spacings assured nearly 100% coverage. The terrestrial exposure at about 6 {mu}R/h was nearly the same as that measured by the previous survey of this area (May 1977). Ten anomalous areas, mostly Na-22 and Mn-54, were detected within buildings and laboratories in the area. Although these locations have changed somewhat from the 1977 survey, the aerial data shows good agreement with the ground-based ion chamber and soil sample data. 7 refs., 15 figs., 1 tab.

Fritzsche, A.E.

1990-11-01

54

Magnet R&D for the US LHC Accelerator Research Program (LARP)  

SciTech Connect

In 2004, the US DOE established the LHC Accelerator Research Program (LARP) with the goal of developing a technology base for future upgrades of the LHC. The focus of the magnet program, which is a collaboration of three US laboratories, BNL, FNAL and LBNL, is on development of high gradient quadrupoles using Nb{sub 3}Sn superconductor. Other program components address issues regarding magnet design, radiation-hard materials, long magnet scale-up, quench protection, fabrication techniques and conductor and cable R&D. This paper presents an overall view of the program with emphasis on the current quadrupole project and outlines the long-term goals of the program.

Gourlay, S.A.; Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Dietderich, D.R.; Ferracin, P.; Gupta, R.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Harrison, M.; Kashikhin, V.S.; Kashikhin, V.V.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmazle, J.; Stanek, R.; Turrioni, D.; Wanderer, P.; Yamada, R.; Zlobin, A.V.

2006-06-01

55

Linking accelerated laboratory and outdoor exposure results for PV polymeric materials: a mechanistic study of EVA  

NASA Astrophysics Data System (ADS)

Linking accelerated laboratory test to field performance for predicting the service life of polymeric materials are being investigated at NIST using the reliability-based methodology. Based on this methodology, a successful linkage between the laboratory and field exposure data for a model polymeric material has been made. Recently, this methodology, for the first time, was introduced to the lifetime assessment of PV polymeric materials. In this paper, a mechanistic study of the degradation of three unstabilized model ethylene vinyl acetate (EVA) systems---uncured EVA, cured EVA and laminated EVA---was carried out under accelerated laboratory exposure and outdoor exposure. The NIST SPHERE (Simulated Photodegradation via High Energy Radiant Exposure) was used for the accelerated laboratory tests, and the outdoor exposure was conducted in Gaithersburg, Maryland. Simultaneous multiple stresses, including temperature, relative humidity and UV radiation, were applied individually or in combination during SPHERE exposure. The effects of the environmental factors on the main degradation mechanisms of different EVA systems were investigated. The results showed that the UV radiation was the most important factor for the degradation of EVA and a synergistic effect occurred between UV radiation and relative humidity. A slower degradation rate was observed for the laminated system as a result of limited diffusion of O2 and H2O into EVA. It was also found that the substantial chemical changes of the uncured EVA system did not yield yellowing, which was dramatically different from the peroxide cured EVA system. Additionally, the chemical degradation modes of the three EVA systems exposed outdoors appeared to be similar to those exposed to the SPHERE. The implication of this work to the current test standards was discussed.

Gu, Xiaohong; Pang, Yongyan; Lin, Chiao-Chi; Liu, Kaipeng; Nguyen, Tinh; Chin, Jaonnie W.

2013-09-01

56

Acceleration to failure in geophysical signals prior to laboratory rock failure and volcanic eruptions (Invited)  

NASA Astrophysics Data System (ADS)

The nucleation processes that ultimately lead to earthquakes, volcanic eruptions, rock bursts in mines, and landslides from cliff slopes are likely to be controlled at some scale by brittle failure of the Earths crust. In laboratory brittle deformation experiments geophysical signals commonly exhibit an accelerating trend prior to dynamic failure. Similar signals have been observed prior to volcanic eruptions, including volcano-tectonic earthquake event and moment release rates. Despite a large amount of effort in the search, no such statistically robust systematic trend is found prior to natural earthquakes. Here we describe the results of a suite of laboratory tests on Mount Etna Basalt and other rocks to examine the nature of the non-linear scaling from laboratory to field conditions, notably using laboratory creep tests to reduce the boundary strain rate to conditions more similar to those in the field. Seismic event rate, seismic moment release rate and rate of porosity change show a classic bathtub graph that can be derived from a simple damage model based on separate transient and accelerating sub-critical crack growth mechanisms, resulting from separate processes of negative and positive feedback in the population dynamics. The signals exhibit clear precursors based on formal statistical model tests using maximum likelihood techniques with Poisson errors. After correcting for the finite loading time of the signal, the results show a transient creep rate that decays as a classic Omori law for earthquake aftershocks, and remarkably with an exponent near unity, as commonly observed for natural earthquake sequences. The accelerating trend follows an inverse power law when fitted in retrospect, i.e. with prior knowledge of the failure time. In contrast the strain measured on the sample boundary shows a less obvious but still accelerating signal that is often absent altogether in natural strain data prior to volcanic eruptions. To test the forecasting power of such constitutive rules in prospective mode, we examine the forecast quality of several synthetic trials, by adding representative statistical fluctuations, due to finite real-time sampling effects, to an underlying accelerating trend. Metrics of forecast quality change systematically and dramatically with time. In particular the model accuracy increases, and the forecast bias decreases, as the failure time approaches.

Main, I. G.; Bell, A. F.; Greenhough, J.; Heap, M. J.; Meredith, P. G.

2010-12-01

57

Aerial radiological survey of the Fermi National Accelerator Laboratory and surrounding area, Batavia, Illinois. Date of survey: June 1989.  

National Technical Information Service (NTIS)

An aerial radiological gamma survey was conducted over the Fermi National Accelerator Laboratory during 1 through 6 June 1989. Flight lines at 150-foot altitude and 250-foot line spacings assured nearly 100% coverage. The terrestrial exposure at about 6 (...

A. E. Fritzsche

1990-01-01

58

Evaluation of effective acceleration and selection of seismic analysis accelerograms for Lawrence Livermore National Laboratory. Final report.  

National Technical Information Service (NTIS)

This report documents evaluation of effective acceleration and development of a set of earthquake accelerograms for use in seismic analyses of Lawrence Livermore National Laboratory (LLNL) facilities. The accelerograms are to be representative of peak gro...

1991-01-01

59

An improved 8 GeV beam transport system for the Fermi National Accelerator Laboratory  

SciTech Connect

A new 8 GeV beam transport system between the Booster and Main Ring synchrotrons at the Fermi National Accelerator Laboratory is presented. The system was developed in an effort to improve the transverse phase space area occupied by the proton beam upon injection into the Main Ring accelerator. Problems with the original system are described and general methods of beamline design are formulated. Errors in the transverse properties of a beamline at the injection point of the second synchrotron and their effects on the region in transverse phase space occupied by a beam of particles are discussed. Results from the commissioning phase of the project are presented as well as measurements of the degree of phase space dilution generated by the transfer of 8 GeV protons from the Booster synchrotron to the Main Ring synchrotron.

Syphers, M.J.

1987-06-01

60

Fire protection review: revisit No. 2, Fermi National Accelerator Laboratory, Batavia, Illinois  

SciTech Connect

A fire protection survey was conducted at Fermi National Accelerator Laboratory, Batavia, Illinois, on June 17 to 21, 24 to 28, 1985 and November 4 to 8, 1985 to review the facility fire protection program and to make recommendations. A number of improvements have been made in Laboratory fire protection systems since the Fire Protection review of 1977. These include the installation of automatic sprinklers in some of the Village Laboratories and several areas in Industrial Buildings. A new 5000 gpm pump has been provided at the Casey's Pond pumping station and new fire and industrial cooling water underground mains have been installed, which has improved the reliability of the overall underground system. There are a number of areas where loss potentials presently exceed $1,000,000. The major defects noted were the lack of redundant water supplies and the need for additional automatic sprinkler or halon protection for grouped electrical cables in the main accelerator, booster ring, antiproton ring facility, beam lines, target areas, including the B-O Experiment and the telephone equipment room in Wilson Hall.

Almon, R.H.; Earley, M.W.; Merritt, R.C.

1986-03-01

61

Installation of a cw radiofrequency quadrupole accelerator at Los Alamos National Laboratory  

SciTech Connect

Chalk River Laboratories (CRL) has had a long history of cw proton beam development for production of intense neutron sources and fissile fuel breeders. In 1986 CRL and Los Alamos National Laboratory (LANL) entered into a collaborative effort to establish a base technologies program for the development of a cw radiofrequency quadrupole (RFQ). The initial cw RFQ design had 50-keV proton injection energy with 600-keV output energy. The 75-mA design current at 600-keV beam energy was obtained in 1990. Subsequently, the RFQ output energy was increased to 1250 keV by replacing the RFQ vanes, still maintaining the 75-m A design current. A new 250-kW cw klystrode rf power source at 267-MHz was installed at CRL. By April of 1993, 55-mA proton beams had been accelerated to 1250 keV. Concurrent developments were taking place on proton source development and on 50-keV low-energy beam transport (LEBT) systems. Development of a dc, high-proton fraction ({ge} 70%) microwave ion source led to utilization of a single-solenoid RFQ direct injection scheme. It was decided to continue this cw RFQ demonstration project at Los Alamos when the CRL project was terminated in April 1993. The LANL goals are to find the current limit of the 1250-keV RFQ, better understand the beam transport properties through the single-solenoid focusing LEBT, continue the application of the cw klystrode tube technology to accelerators, and develop a two-solenoid LEBT which could be the front end of an Accelerator-Driven Transmutation Technologies (ADTT) linear accelerator.

Schneider, J.D.; Bolme, J.; Brown, V. [and others

1994-09-01

62

New photoelectric injector design for the Los Alamos National Laboratory XUV FEL accelerator  

SciTech Connect

The injector for the Los Alamos National Laboratory XUV FEL accelerator has been redesigned to provide more charge to the wiggler. The new design can deliver 8nC of charge within 20 ps with a normalized 90% emittance of <25 /Pi//center dot/mm/center dot/mrad to the wiggler at an energy of 200 MeV. In addition to the new design of the injector, we analyze the emittance growth and subsequent reduction through the injector, including different mechanisms for emittance growth and the methods used to eliminate the correlated emittance. 7 refs., 5 figs.

Carlsten, B.E.

1988-01-01

63

Do you want to build such a machine? : Designing a high energy proton accelerator for Argonne National Laboratory  

Microsoft Academic Search

Argonne National Laboratory's efforts toward researching, proposing and then building a high-energy proton accelerator have been discussed in a handful of studies. In the main, these have concentrated on the intense maneuvering amongst politicians, universities, government agencies, outside corporations, and laboratory officials to obtain (or block) approval and\\/or funds or to establish who would have control over budgets and research

2004-01-01

64

Design of an RFQ-based, H/sup -/ injector for the BNL/FNAL 200 MeV proton linacs  

SciTech Connect

An LBL/BNL/FNAL collaboration has been formed to design an RFQ-based Cockcroft-Walton replacement, suitable for use at the Brookhaven and Fermilab 200 MeV proton linacs. A common design for the ion source and the RFQ will result in an economical construction and testing program compatible with both applications. The technical requirements have been evaluated and it appears that they can be satisfied with identical RFQs, capable of accelerating 50 mA of H/sup -/ from 35 to 750 keV, at a nominal frequency of 200 MHz.

Gough, R.A.; Staples, J.; Tanabe, J.; Yee, D.; Howard, D.; Curtis, C.; Prelec, K.

1986-06-01

65

Acceleration  

Microsoft Academic Search

IN NATURE, NO. 1415, p. 125, Prof. Lodge asserts that the subject of acceleration is at the root of the perennial debate between engineers and teachers of mechanics; and he urges clearness of idea and accuracy of speech on all who deal with the junior student. Towards this end I would suggest that the too common phrase ``acceleration of velocity''

Edward Geoghegan

1897-01-01

66

Brighter H/sup -/ source for the intense pulsed neutron source accelerator system  

SciTech Connect

Further increases in the beam intensity of the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory required the replacement of the H/sup -/ source with a higher current source. A magnetron ion source of Fermi National Accelerator Laboratory (FNAL) design was adapted with a grooved cathode to provide a stable 40 to 50 mA of beam operating at 30 Hz for up to a 90 ..mu..s pulse duration. Problems of space charge blowup due to the lack of neutralization of the H/sup -/ beam were solved by injecting additional gs into the 20 keV transport system. The source has recently been installed in the machine and the available input to the accelerator has more than doubled.

Stipp, V.; DeWitt, A.; Madsen, J.

1983-01-01

67

Radiation environment in the tunnel of a high-energy proton accelerator at energies near 1 TeV  

SciTech Connect

Neutron energy spectra, fluence distributions and rates in the FNAL Tevatron tunnel are summarized. This work has application to radiation damage to electronics and research equipment at high energy accelerators, as well as to radiological protection. 7 refs., 4 figs.

McCaslin, J.B.; Sun, R.K.S.; Swanson, W.P.; Cossairt, J.D.; Elwyn, A.J.; Freeman, W.S.; Joestlein, H.; Moore, C.D.; Yurista, P.M.; Groom, D.E.

1987-12-01

68

Proposed low-level radioactive waste handling building at Fermi National Accelerator Laboratory, Batavia, Illinois  

SciTech Connect

The US Department of Energy (DOE) has prepared an Environmental Assessment (EA), evaluating the impacts associated with the proposed Low-Level Radioactive Waste Building at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. As a result of the high energy physics program at Fermilab, small quantities of low-level radioactive wastes are generated. These wastes are collected, sorted and packaged for shipment to an off-site disposal facility in Hanford, Washington. The proposed project includes the construction of a new building to house, all low-level radioactive waste handling operations. The building would provide workspace for five full-time workers. The proposed project would improve the efficiency and safety of the low-level radioactive waste handling at Fermilab by upgrading equipment and consolidating operations into one facility.

NONE

1995-06-01

69

THE CONTINUOUS ELECTRON BEAM ACCELERATOR FACILITY: CEBAF at the Jefferson Laboratory  

NASA Astrophysics Data System (ADS)

The Jefferson Laboratory's superconducting radiofrequency (srf) Continuous Electron Beam Accelerator Facility (CEBAF) provides multi-GeV continuous-wave (cw) beams for experiments at the nuclear and particle physics interface. CEBAF comprises two antiparallel linacs linked by nine recirculation beam lines for up to five passes. By the early 1990s, accelerator installation was proceeding in parallel with commissioning. By the mid-1990s, CEBAF was providing simultaneous beams at different but correlated energies up to 4 GeV to three experimental halls. By 2000, with srf development having raised the average cavity gradient to 7.5 MV/m, energies up to nearly 6 GeV were routine, at 1-150 A for two halls and 1-100 nA for the other. Also routine are beams of >75% polarization. Physics results have led to new questions about the quark structure of nuclei, and therefore to user demand for a planned 12 GeV upgrade. CEBAF's enabling srf technology is also being applied in other projects.

Leemann, Christoph W.; Douglas, David R.; Krafft, Geoffrey A.

70

Plasma-Surface Interaction Research At The Cambridge Laboratory Of Accelerator Studies Of Surfaces  

NASA Astrophysics Data System (ADS)

The material requirements for plasma-facing components in a nuclear fusion reactor are some of the strictest and most challenging facing us today. These materials are simultaneously exposed to extreme heat loads (20 MW/m2 steady-state, 1 GW/m2 in millisecond transients) and particle fluxes (>1024 m-2 s-1) while also undergoing high neutron irradiation (1018 neutrons/m2 s). At the Cambridge Laboratory of Accelerator Studies of Surfaces (CLASS), many of the most important issues in plasma-surface interaction research, such as plasma-driven material erosion and deposition, material transport and irradiation and hydrogenic retention are investigated with the use of a 1.7 MV tandem ion accelerator. Ion-Beam Analysis (IBA) is used to investigate and quantify changes in materials due to plasma exposure and ion irradiation is used as a proxy for neutron irradiation to investigate plasma-surface interactions for irradiated materials. This report will outline the capabilities and current research activities at CLASS.

Wright, G. M.; Barnard, H. S.; Hartwig, Z. S.; Stahle, P. W.; Sullivan, R. M.; Woller, K. B.; Whyte, D. G.

2011-06-01

71

A new LabVIEW-based control system for the Naval Research Laboratory Trace Element Accelerator Mass Spectrometer  

SciTech Connect

A new LabVIEW-based control system for the existing tandem accelerator and new AMS components has been implemented at the Trace Element Accelerator Mass Spectrometry (TEAMS) facility at the Naval Research Laboratory. Through the use of Device Interfaces (DIs) distributed along a fiber optic network, virtually every component of the accelerator system can be controlled from any networked computer terminal as well as remotely via modem or the internet. This paper discusses the LabVIEW-based control software, including remote operation, automatic calculation of ion optical component parameters, beam optimization, and data logging and retrieval.

DeTurck, T. M.; Treacy, D. J. Jr.; Knies, D. L.; Grabowski, K. S.; Knoll, C.; Kennedy, C. A.; Hubler, G. K. [University of Maryland, Department of Chemistry, College Park, Maryland 20742 (United States); Naval Research Laboratory, Code 6670, Washington, District of Columbia 20375-5345 (United States)

1999-06-10

72

Proceedings of the international workshop on acceleration and radiation generation in space and laboratory plasmas. Volume T52  

SciTech Connect

All of the papers in this Special Issue highlight the role collective plasma processes play in accelerating particles or generating radiation. Some are state-of-the-art presentations of the latest research in a single discipline, while others investigate the applicability of known laboratory mechanisms to explain observations in natural plasmas. The papers in this Issue are organized as follows: In Section 1 are four general papers which serves as an introduction to the physical mechanisms of acceleration and radiation generation in plasmas. The next section includes state-of-the-art papers on laboratory accelerators driven by lasers, microwaves and by particle beams. Also in this section are theoretical papers presenting new work on synchrotron like oscillations in plasma waves and two types of laboratory radiation sources, FEL`s and ionization fronts, and Frantzeskakis et al. described the Hamiltonian analysis of a slow-wave autonomous cyclotron buncher. Section 3 contains papers on astrophysical plasmas. The papers in Section 4 treat fusion plasmas. Section 5, space plasmas, includes papers on acceleration processes in the magnetosphere and the sun. It is evident from the Workshop and the papers collected here that this is indeed a rich field of investigations and that both the natural and laboratory plasma communities can benefit from the cross-fertilization of ideas between them.

Bingham, R.; Dawson, J.M.; Katsouleas, T.; Stenflo, L. [eds.

1994-12-31

73

Ultra-trace analysis of 41Ca in urine by accelerator mass spectrometry: An inter-laboratory comparison  

NASA Astrophysics Data System (ADS)

A 41Ca interlaboratory comparison between Lawrence Livermore National Laboratory (LLNL) and the Purdue Rare Isotope Laboratory (PRIME Lab) has been completed. Analysis of the ratios assayed by accelerator mass spectrometry (AMS) shows that there is no statistically significant difference in the ratios. Further, Bayesian analysis shows that the uncertainties reported by both facilities are correct with the possibility of a slight under-estimation by one laboratory. Finally, the chemistry procedures used by the two facilities to produce CaF2 for the cesium sputter ion source are robust and do not yield any significant differences in the final result.

Jackson, George S.; Hillegonds, Darren J.; Muzikar, Paul; Goehring, Brent

2013-10-01

74

Laboratory laser acceleration and high energy astrophysics: {gamma}-ray bursts and cosmic rays  

SciTech Connect

Recent experimental progress in laser acceleration of charged particles (electrons) and its associated processes has shown that intense electromagnetic pulses can promptly accelerate charged particles to high energies and that their energy spectrum is quite hard. On the other hand some of the high energy astrophysical phenomena such as extremely high energy cosmic rays and energetic components of {gamma}-ray bursts cry for new physical mechanisms for promptly accelerating particles to high energies. The authors suggest that the basic physics involved in laser acceleration experiments sheds light on some of the underlying mechanisms and their energy spectral characteristics of the promptly accelerated particles in these high energy astrophysical phenomena.

Tajima, T. [Univ. of Texas, Austin, TX (United States); Takahashi, Y. [Univ. of Alabama, Huntsville, AL (United States). Dept. of Physics

1998-08-20

75

Fringe Fields and Dynamic Aperture in the FNAL Muon Storage Ring  

Microsoft Academic Search

Quadrupole fringe fields can limit the dynamic aperture of muon storage rings.Using the computer code COSY INFINITY for particle tracking and normal-form analysis, we evaluate the importance of fringe fields in the FNAL muon storage ring, and identify the regions of the machine where they are most critical. Dynamic aperture and linear tune shifts with amplitude are calculated considering an

Frank Zimmermann; M Berz; B Erdlyi; C Johnstone; K Makino; W Wan

2000-01-01

76

Earthquake Dynamics in Laboratory Model and Simulation - Accelerated Creep as Precursor of Instabilities  

NASA Astrophysics Data System (ADS)

Shallow earthquakes can be considered as a result of tribological instabilities, so called stick-slip behaviour [1,2], meaning that sudden slip occurs at already existing rupture zones. From a contact mechanics point of view it is clear, that no motion can arise completely sudden, the material will always creep in an existing contact in the load direction before breaking loose. If there is a measureable creep before the instability, this could serve as a precursor. To examine this theory in detail, we built up an elementary laboratory model with pronounced stick-slip behaviour. Different material pairings, such as steel-steel, steel-glass and marble-granite, were analysed at different driving force rates. The displacement was measured with a resolution of 8 nm. We were able to show that a measureable accelerated creep precedes the instability. Near the instability, this creep is sufficiently regular to serve as a basis for a highly accurate prediction of the onset of macroscopic slip [3]. In our model a prediction is possible within the last few percents of the preceding stick time. We are hopeful to extend this period. Furthermore, we showed that the slow creep as well as the fast slip can be described very well by the Dieterich-Ruina-friction law, if we include the contribution of local contact rigidity. The simulation meets the experimental curves over five orders of magnitude. This friction law was originally formulated for rocks [4,5] and takes into account the dependency of the coefficient of friction on the sliding velocity and on the contact history. The simulations using the Dieterich-Ruina-friction law back up the observation of a universal behaviour of the creep's acceleration. We are working on several extensions of our model to more dimensions in order to move closer towards representing a full three-dimensional continuum. The first step will be an extension to two degrees of freedom to analyse the interdependencies of the instabilities. We also plan to install a larger system which is capable of performing events of different spatial extent and magnitude. [1] Stick-Slip as a Mechanism for Earthquakes. Brace, W.F. und Byerlee, J.D. 1966, Science, Bd. 153, S. 990-992. [2] Detailed Studies of Frictional Sliding of Granite and Implications for the Earthquake Mechanism. Scholz, C. H., Molnar, P. und Johnson, T. 32, 1972, Journal of Geophysical Research, Bd. 77, S. 6392-6409. [3] Accelerated Creep as a Precursor of Friction Instability and Earthquake Prediction. Popov, V. L., et al. 2010, Physical Mesomechanics, Bd. 13, S. 283-291. [4] Modeling of Rock Friction, Part 1: Experimental Results and Constitutive Equations. Dieterich, J.H. B5, 1979, Journal of Geophysical Research, Bd. 84, S. 2161-2168. [5] State Instability and State Variable Friction Law. Ruina, A. B12, 1983, Journal of Geophysical Research, Bd. 88, S. 10359-10370.

Grzemba, B.; Popov, V. L.; Starcevic, J.; Popov, M.

2012-04-01

77

Actinide Measurements by Accelerator Mass Spectrometry at Lawrence Livermore National Laboratory  

SciTech Connect

We report on the development of an accelerator mass spectrometry (AMS) system for the measurement of actinides at Lawrence Livermore National Laboratory. This AMS system is centered on a recently completed heavy isotope beam line that was designed particularly for high sensitivity, robust, high-throughput measurements of actinide concentrations and isotopic ratios. A fast isotope switching capability has been incorporated in the system, allowing flexibility in isotope selection and for the quasi-continuous normalization to a reference isotope spike. Initially, our utilization of the heavy isotope system has concentrated on the measurement of Pu isotopes. Under current operating conditions, background levels equivalent to {approx}1 x 10{sup 5} atoms are observed during routine {sup 239}Pu and {sup 240}Pu measurements. Measurements of samples containing {approx}10{sup 13} {sup 238}U atoms demonstrate that the system provides a {sup 238}U rejection factor during {sup 239}Pu measurements of {approx}10{sup 7}. Measurements of known materials, combined with results from an externally organized inter-comparison program, indicate that our {sup 239}Pu measurements are accurate and precise down to the {micro}Bq level ({approx}10{sup 6} atoms). Recently, we have investigated the performance of our heavy isotope AMS system in measurements of {sup 237}Np and {sup 236}U. Results of these investigations are discussed. The sensitivity shown by our Pu measurements, combined with the high throughput and interference rejection capabilities of our AMS system, demonstrate that AMS can provide a rapid and cost-effective measurement technique for actinides in a wide variety of studies.

Brown, T A; Marchetti, A A; Martinelli, R E; Cox, C C; Knezovich, J P; Hamilton, T F

2003-09-25

78

Near Term Prospects at FNAL and Project X  

NASA Astrophysics Data System (ADS)

Project X, a high-power proton accelerator facility, will support world-leading programs in long baseline neutrino physics, the physics of rare processes, and nuclear studies. It will be unique among accelerator facilities worldwide in its flexibility to support multiple physics programs simultaneously with MWclass beams at the intensity frontier. Project X is based on a 3 GeV continuous-wave superconducting H-linac. Further acceleration to 8 GeV, and injection into Fermilab's existing Recycler/Main Injector complex, will support long-baseline neutrino experiments. Project X will provide 1 MW beam power at 1 GeV, 3 MW beam power at 3 GeV and 2 MW beam power to a neutrino production target at 60-120 GeV. This talk will describe the Reference Design of Project X and the status of the R&D program.

Henderson, Stuart

2013-04-01

79

Accelerator-based techniques for the support of senior-level undergraduate physics laboratories  

Microsoft Academic Search

Approximately three years ago, Auburn University replaced its aging Dynamitron accelerator with a new 2MV tandem machine (Pelletron) manufactured by the National Electrostatics Corporation (NEC). This new machine is maintained and operated for the University by Physics Department personnel, and the accelerator supports a wide variety of materials modification\\/analysis studies. Computer software is available that allows the NEC Pelletron to

J. R. Williams; J. C. Clark; T. Isaacs-Smith

2001-01-01

80

LLNL/UC (Lawrence Livermore National Laboratory)/(University of California) AMS (accelerator mass spectrometry) facility and research program  

SciTech Connect

The Lawrence Livermore National Laboratory (LLNL) and the University of California (UC) now have in operation a large AMS spectrometer built as part of a new multiuser laboratory centered on an FN tandem. AMS measurements are expected to use half of the beam time of the accelerator. LLNL use of AMS is in research on consequences of energy usage. Examples include global warming, geophysical site characterization, radiation biology and dosimetry, and study of mutagenic and carcinogenic processes. UC research activities are in clinical applications, archaeology and anthropology, oceanography, and geophysical and geochemical research. Access is also possible for researchers outside the UC system. The technological focus of the laboratory is on achieving high rates of sample through-put, unattended operation, and advances in sample preparation methods. Because of the expected growth in the research programs and the other obligations of the present accelerator, we are designing a follow-on dedicated facility for only AMS and microprobe analysis that will contain at least two accelerators with multiple spectrometers. 10 refs., 1 fig.

Davis, J.C.; Proctor, I.D.; Southon, J.R.; Caffee, M.W.; Heikkinen, D.W.; Roberts, M.L.; Moore, T.L.; Turteltaub, K.W.; Nelson, D.E.; Loyd, D.H.; Vogel, J.S.

1990-04-18

81

Laboratory simulation of axial and angular projectile accelerations in a rifled gun barrel  

SciTech Connect

A new test technique has been proposed for simulating both the linear and angular acceleration shocks produced during artillery shots. This technique uses a two mass fixture with a screw connection between the two masses. An axial force applied to the first mass is transmitted to the second mass through the screw connection which produces an axial and angular acceleration on the second mass. The ratio of axial to angular acceleration can be controlled by variation in mass properties of the two mass fixture. A simple fixture was constructed to verify the test concept at low shock levels. Test results using this fixture are shown. 1 ref., 6 figs.

Davie, N.T.; Bell, R.G.

1988-01-01

82

Installation of a cw radiofrequency quadrupole accelerator at Los Alamos National Laboratory.  

National Technical Information Service (NTIS)

Chalk River Laboratories (CRL) has had a long history of cw proton beam development for production of intense neutron sources and fissile fuel breeders. In 1986 CRL and Los Alamos National Laboratory (LANL) entered into a collaborative effort to establish...

J. D. Schneider J. Bolme V. Brown

1994-01-01

83

Test of a coaxial blade tuner at HTS FNAL  

SciTech Connect

A coaxial blade tuner has been selected for the 1.3GHz SRF cavities of the Fermilab SRF Accelerator Test Facility. Results from tuner cold tests in the Fermilab Horizontal Test Stand are presented. Fermilab is constructing the SRF Accelerator Test Facility, a facility for accelerator physics research and development. This facility will contain a total of six cryomodules, each containing eight 1.3 GHz nine-cell elliptical cavities. Each cavity will be equipped with a Slim Blade Tuner designed by INFN Milan. The blade tuner incorporates both a stepper motor and piezo actuators to allow for both slow and fast cavity tuning. The stepper motor allows the cavity frequency to be statically tuned over a range of 500 kHz with an accuracy of several Hz. The piezos provide up to 2 kHz of dynamic tuning for compensation of Lorentz force detuning and variations in the He bath pressure. The first eight blade tuners were built at INFN Milan, but the remainder are being manufactured commercially following the INFN design. To date, more than 40 of the commercial tuners have been delivered.

Pischalnikov, Y.; Barbanotti, S.; Harms, E.; Hocker, A.; Khabiboulline, T.; Schappert, W.; /Fermilab; Bosotti, A.; Pagani, C.; Paparella, R.; /LASA, Segrate

2011-03-01

84

Accelerated Aging of Laboratory Handsheets: Reflectance, Moisture Regain, Sonic Modulus, and Differential Thermal Analysis.  

National Technical Information Service (NTIS)

The accelerated aging processes of experimental handsheets in dry and humid gases at 90C have been followed by measuring changes in their blue and green reflectance, the derived whiteness and yellowness indexes, the moisture regain, and the sonic moduli. ...

E. J. Parks R. L. Hebert

1972-01-01

85

SEY and Surface Analysis Measurements on FNAL Main Injector Ring S\\/S Beam Chamber Material  

Microsoft Academic Search

Material was provided by Dr. Weiren Chou, FNAL. Both mildly-activated used, and new sections of stainless steel (type 316L) beam chamber were measured. Centimeter-sized coupons were cleanly dry-cut from the large flat surface (called ''flat side'' in the plots) and from the ID end (inside diameter of the ring, in the case of the used material) and narrow end (in

Robert E. Kirby

2006-01-01

86

Accelerator driven gamma and fast neutron radiography test-bed at Lawrence Livermore National Laboratory  

NASA Astrophysics Data System (ADS)

Accelerator driven fusion gammas and fast neutrons could provide unique radiography capabilities due to their ability to produce both high and low energy mono-energetic gammas and neutrons compared with broadband bremsstrahlung based x-ray sources. The possibility of simultaneously obtaining both gamma and neutron radiographs using one source could allow complex objects composed of a large range of low to high Z materials to be imaged. In this paper we review a 4 MV RFQ accelerator driven radiography test-bed at LLNL designed to study the physics involved in applying these dual output fusion reactions for radiography applications. First experimental neutron images from a carbon target are presented.

Tang, V.; Rusnak, B.; Falabella, S.; Hawkins, S.; McCarrick, J. F.; Wang, H.; Hall, J. M.; Ellsworth, J.

2013-04-01

87

What`s new with FASTBUS and what`s it done in the particle accelerator laboratories  

SciTech Connect

The FASTBUS modular high-speed data acquisition and control system has been described in earlier papers. Implementations have since been made in accelerator laboratories world-wide resulting in clarifications, modifications and extensions. Of tremendous benefit to users have been FASTBUS Standard Routines. The availability of such standard software is unique for high speed bus systems and resulted from the involvement of hardware and software specialists in all aspects of the development. FASTBUS is the highest performance instrumentation and data acquisition bus in existence and its development was essential to handle the outputs of detectors used with high energy accelerators now in operation. It has been an important factor in recent experiments, including the Z{sup 0} measurements at CERN, Fermilab and SLAC. Also among numerous FASTBUS implementations are those for TPC systems at KEK and BNL. 2 refs., 5 figs.

Costrell, L. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Dawson, W.K. [British Columbia Univ., Vancouver, BC (Canada). TRIUMF Facility; Ponting, P.J. [European Organization for Nuclear Research, Geneva (Switzerland); Platner, E.D.; Paffrath, L. [Brookhaven National Lab., Upton, NY (United States); Barsotti, E.J. [Fermi National Accelerator Lab., Batavia, IL (United States); Downing, R.W. [Illinois Univ., Chicago, IL (United States); Ikeda, H. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Nelson, R.O. [Los Alamos National Lab., NM (United States); Kolpakov, I. [Joint Inst. for Nuclear Research, Dubna (USSR); Gustavson, D.B.; Walz, H.W. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

1991-12-31

88

Accelerated Aging of Laboratory Handsheets: Retention of Folding Endurance, Internal Tear, Bursting Strength, and Tensile Strength.  

National Technical Information Service (NTIS)

This report represents a study of the accelerated aging of chemically modified handsheets in air and nitrogen at 90C and 50 percent or 0 percent relative humidity. The handsheets were prepared from a commercial wood pulp that had been either (a) untreated...

E. J. Parks R. L. Hebert

1971-01-01

89

Future Development Of The Flerov Laboratory Accelerator Complex (Project DRIBs-III)  

SciTech Connect

Future development of the FLNR accelerator complex (project DRIBs-III) includes modernization of existing cyclotrons, construction of a new experimental hall, creation of a new high current cyclotron and of next generation experimental set-ups. Realization of the project is planned for 2010-2016.

Gulbekian, G. G.; Dmitriev, S. N.; Itkis, M. G.; Oganessian, Yu. Ts.; Popeko, A. G. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, 141980 (Russian Federation)

2010-04-30

90

Safety-related, task and site-specific training for accelerator crews at Sandia National Laboratories.  

National Technical Information Service (NTIS)

Sandia National Laboratories, and specifically the Radiation Effects and Testing Directorate, have taken aggressive action to comply with the Institute of Nuclear Power Operations (INTO) guidelines concerning conduct of operations. A review of crew perfor...

L. O. Knudson

1991-01-01

91

Rapid Acceleration Leads to Rapid Weakening in Earthquake-Like Laboratory Experiments  

NASA Astrophysics Data System (ADS)

After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earths crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquakes rupture front quickens dynamic weakening by intense wear of the fault zone.

Chang, J. C.; Lockner, D. A.; Reches, Z.

2012-10-01

92

Recent Developments on ALICE (Accelerators and Lasers In Combined Experiments) at Daresbury Laboratory  

SciTech Connect

Progress made in ALICE (Accelerators and Lasers In Combined Experiments) commissioning and a summary of the latest experimental results are presented in this paper. After an extensive work on beam loading effects in SC RF linac (booster) and linac cavities conditioning, ALICE can now operate in full energy recovery mode at the bunch charge of 40pC, the beam energy of 30MeV and train lengths of up to 100us. This improved operation of the machine resulted in generation of coherently enhanced broadband THz radiation with the energy of several tens of uJ per pulse and in successful demonstration of the Compton Backscattering x-ray source experiment. The next steps in the ALICE scientific programme are commissioning of the IR FEL and start of the research on the first non-scaling FFAG accelerator EMMA. Results from both projects will be also reported.

Saveliev, Y M; Buckley, R K; Buckley, S R; Clarke, J A; Corlett, P A; Dunning, D J; Goulden, A R; Hill, S F; Jackson, F; Jamison, S P; Jones, J K; Jones, L B; Leonard, S; McIntosh, P A; McKenzie, J W; Middleman, K J; Militsyn, B L; Moss, A J; Muratori, B D; Orrett, J F; Pattalwar, S M; Phillips, P J; Scott, D J; Seddon, E A; Shepherd, B.J.A.; Smith, S L; Thompson, N; Wheelhouse, A E; Williams, P H; Harrison, P; Holder, D J; Holder, G M; Schofield, A L; Weightman, P; Williams, R L; Laundry, D; Powers, T; Priebe, G

2010-05-01

93

Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments  

USGS Publications Warehouse

After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earths crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquakes rupture front quickens dynamic weakening by intense wear of the fault zone.

Chang, Jefferson C.; Lockner, David A; Reches, Z.

2012-01-01

94

Structure in mixed element plasmas on the Z-accelerator at Sandia National Laboratories  

Microsoft Academic Search

Summary form only given. Mixed-element plasmas were generated on the Z-accelerator by imploding nested arrays of aluminum wires and nickel-clad titanium wires. For the experiment examined in this work, the outer array used aluminum wires and the inner array used nickel-clad titanium wires (adding nickel cladding to titanium wires allows the fabrication of smaller diameter titanium wires). The plasmas were

P. D. LePell; C. A. Coverdale; C. Deeney; Y. Maron

2004-01-01

95

Assembly and Test of SQ01b, a Nb3Sn Quadrupole Magnet for the LHC Accelerator Research Program  

SciTech Connect

The US LHC Accelerator Research Program (LARP) consists of four US laboratories (BNL, FNAL, LBNL, and SLAC) collaborating with CERN to achieve a successful commissioning of the LHC and to develop the next generation of Interaction Region magnets. In 2004, a large aperture Nb{sub 3}Sn racetrack quadrupole magnet (SQ01) has been fabricated and tested at LBNL. The magnet utilized four subscale racetrack coils and was instrumented with strain gauges on the support structure and directly over the coil's turns. SQ01 exhibited training quenches in two of the four coils and reached a peak field in the conductor of 10.4 T at a current of 10.6 kA. After the test, the magnet was disassembled, inspected with pressure indicating films, and reassembled with minor modifications. A second test (SQ01b) was performed at FNAL and included training studies, strain gauge measurements and magnetic measurements. Magnet inspection, test results, and magnetic measurements are reported and discussed, and a comparison between strain gauge measurements and 3D finite element computations is presented

Ferracin, P.; Ambrosio, G.; Bartlett, S. E.; Bordini, B.; Carcagno, R.H.; Caspi, S.; Dietderich, D.R.; Feher, S.; Gourlay, S.A.; Hafalia, A.R.; Lamm, M.J.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Orris, D.F.; Pischalnikov, Y.M.; Sabbi, G.L.; Sylvester, C.D.; Tartaglia, M.A.; Velev, G.V.; Zlobin, A.V.; Kashikhin, V.V.

2006-06-01

96

Laboratory Experiments with the Concordia College High-Speed Dust Particle Accelerator  

NASA Astrophysics Data System (ADS)

During the Apollo Era, NASA's Goddard Space Flight Center built a 2MeV high-speed, dust particle accelerator. This facility was used to test and calibrate the LEAM instrument which was flown to the lunar surface by Apollo 17. As the Apollo project wound down, NASA no longer had need of the dust particle accelerator, and in 1975, it was move to Concordia College in Moorhead, MN. Through the years, it has been maintained and some modifications and improvements have been made to it. In the past decade, the facility has been revived and used by several collaborating institutions to study dust detector instrumentation as well as the effects of dust impacts on various materials. We have tested a prototype, space-flight dust particle detector. Also, piezoelectric pins which can be used as dust detectors were studied to learn the pin's response to single particle impacts of different energies and momenta, and then those measured responses were compared with theoretical models. The effects of high speed impacts on ultra-high temperature ceramics, aerogel, and several different thin films have also been studied at our facility. The results of these experiments will be presented.

Manning, H. L.

2011-12-01

97

Future directions in controlling the LAMPF-PSR Accelerator Complex at Los Alamos National Laboratory  

SciTech Connect

Four interrelated projects are underway whose purpose is to migrate the LAMPF-PSR Accelerator Complex control systems to a system with a common set of hardware and software components. Project goals address problems in performance, maintenance and growth potential. Front-end hardware, operator interface hardware and software, computer systems, network systems and data system software are being simultaneously upgraded as part of these efforts. The efforts are being coordinated to provide for a smooth and timely migration to a client-sever model-based data acquisition and control system. An increased use of the distributed intelligence at both the front-end and operator interface is a key element of the projects. 2 refs., 2 figs.

Stuewe, R.; Schaller, S.; Bjorklund, E.; Burns, M.; Callaway, T.; Carr, G.; Cohen, S.; Kubicek, D.; Harrington, M.; Poore, R.; Schultz, D.

1991-01-01

98

Stunt Barbie - A Laboratory Practicum Combining Constant Velocity and Constant Acceleration  

NASA Astrophysics Data System (ADS)

In preparing to teach the advanced physics course at my high school, I found it useful to work through the end-of-chapter problems in the book1 used by the advanced class. A problem on motion in one dimension involved a stunt woman in free fall from a tree limb onto a horse running beneath her.2 The problem presents a connected learning opportunity for students because it requires the use of the constant velocity model xf = v*t + xi and the constant acceleration model yf = * g* t2 + vyi* t + yi (where g = 9.8 m/s/s) to solve it. I named the stunt woman Barbie and created an activity titled ``Stunt Barbie.''

Hertting, Scott

2011-04-01

99

Characteristics of Molybdenum Plasmas Created on the Z-Accelerator at Sandia National Laboratory  

NASA Astrophysics Data System (ADS)

Recent experiments on the Z Accelerator have used molybdenum wires in imploding arrays to create hot dense plasmas that efficiently radiate multi-keV energy x-rays. These molybdenum (Z=42) plasmas create a broad spectrum of x-rays ranging from 2.3 to 3.5 keV when stripped to the sodium-, neon- and fluorine-like states. Spectrscopic measurements of these x-rays will be presented, including measurements of a low energy continuum in the range of 1 to 2 keV, representative of 0.4 keV electron temperature. This data as well as other soft x-ray measurements will be used to generate synthetic spectra, from which determination of plasma temperatures and densities will be made. These analyses will be presented.

Lepell, P. David; Coverdale, Christine A.; Deeney, Christopher; Hansen, Stephanie; Shlyaptseva, Alla S.; Bell, David E.

2001-10-01

100

The Fermi LAT view of Cygnus: a laboratory to understand cosmic-ray acceleration and transport  

NASA Astrophysics Data System (ADS)

Cygnus X is a conspicuous massive-star forming region in the Local Arm of the Galaxy at 1.4kpc from the solar system. ?-ray observations can be used to trace cosmic rays (CRs) interacting with the ambient interstellar gas and low-energy radiation fields. Using the Fermi Large Area Telescope (LAT) we have discovered the presence of a 50-pc wide cocoon of freshly-accelerated CRs in the region bounded by the ionization fronts from the young stellar clusters. On the other hand, the LAT data show that the CR population averaged over the whole Cygnus complex on a scale of 400pc is similar to that found in the interstellar space near the Sun. These results confirm the long-standing hypothesis that massive star-forming regions host CR factories and shed a new light on the early phases of CR life in such a turbulent environment.

Tibaldo, L.; Grenier, I. A.

2013-06-01

101

Further improvement in the precision of 233U measurements by accelerator mass spectrometry at the Lawrence Livermore National Laboratory.  

SciTech Connect

In response to sponsor interest in October 2005 we proposed two methods for enhancing the precision of {sup 233}U accelerator mass spectrometry (AMS) capabilities at the Lawrence Livermore National Laboratory (LLNL). In a previous report we evaluated the first method and demonstrated that by increasing sample loading by a factor of four coupled with performing four replicates of each sample, we could achieve measurement precision of {approx}1%. Recent modifications to our system have enabled us to test the second proposed method. By changing our setup to normalize {sup 233}U ions counted in a gas ionization chamber to {sup 238}U measured as a current in an off-axis Faraday cup we were able to attain 1% precision without the need for replicate analysis. This method could be further refined to achieve 0.5% precision in samples of interest.

Tumey, S J; Brown, T A; Hamilton, T F; Buchholz, B A

2008-02-04

102

World penduluma distributed remotely controlled laboratory (RCL) to measure the Earth's gravitational acceleration depending on geographical latitude  

NASA Astrophysics Data System (ADS)

We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy ?g ~ 0.01 m s-2). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part describes the physical origin of this phenomenon g(phiv), that the Earth's effective gravitational acceleration g depends on the angle of latitude phiv. Then, we present all necessary formula to deduce g(phiv) from oscillations of a string pendulum. The technical part explains tips and tricks to realize such an apparatus to measure all necessary values with sufficient accuracy. In addition, we justify the precise dimensions of a physical pendulum such that the formula for a mathematical pendulum is applicable to determine g(phiv) without introducing errors. To conclude, we describe the internet versionthe string pendulum as a remotely controlled laboratory. The teaching relevance and educational value will be discussed in detail at the end of this paper including global experimenting, using the internet and communication techniques in teaching and new ways of teaching and learning methods.

Grber, S.; Vetter, M.; Eckert, B.; Jodl, H.-J.

2007-05-01

103

ACCELERATED SITE TECHNOLOGY DEPLOYMENT COST AND PERFORMANCE REPORT COMPARABILITY OF ISOCS INSTRUMENT IN RADIONUCLIDE CHARACTERICATION AT BROOKHAVEN NATIONAL LABORATORY  

SciTech Connect

This report describes a DOE Accelerated Site Technology Deployment project being conducted at Brookhaven National Laboratory to deploy innovative, radiological, in situ analytical techniques. The technologies are being deployed in support of efforts to characterize the Brookhaven Graphite Research Reactor (BGRR) facility, which is currently undergoing decontamination and decommissioning. This report focuses on the deployment of the Canberra Industries In Situ Object Counting System (ISOCS) and assesses its data comparability to baseline methods of sampling and laboratory analysis. The battery-operated, field deployable gamma spectrometer provides traditional spectra of counts as a function of gamma energy. The spectra are then converted to radionuclide concentration by applying innovative efficiency calculations using monte carlo statistical methods and pre-defined geometry templates in the analysis software. Measurement of gamma emitting radionuclides has been accomplished during characterization of several BGRR components including the Pile Fan Sump, Above Ground Ducts, contaminated cooling fans, and graphite pile internals. Cs-137 is the predominant gamma-emitting radionuclide identified, with smaller quantities of Co-60 and Am-241 detected. The Project used the Multi-Agency Radiation Survey and Site Investigation Manual guidance and the Data Quality Objectives process to provide direction for survey planning and data quality assessment. Analytical results have been used to calculate data quality indicators (DQI) for the ISOCS measurements. Among the DQIs assessed in the report are sensitivity, accuracy, precision, bias, and minimum detectable concentration. The assessment of the in situ data quality using the DQIs demonstrates that the ISOCS data quality can be comparable to definitive level laboratory analysis when the field instrument is supported by an appropriate Quality Assurance Project Plan. A discussion of the results obtained by ISOCS analysis of objects that could not be analyzed readily by conventional methods demonstrates a powerful application of the instrument. In conclusion, a comparison of costs associated with the analysis on the ISOCS instrument to the costs of conventional sampling and laboratory analysis is presented.

KALB,P.; LUCKETT,L.; MILLER,K.; GOGOLAK,C.; MILIAN,L.

2001-03-01

104

Representing Value as Digital Object: A Discussion of Transferability and Anonymity; Digital Library Initiatives of the Deutsche Forschungsgemeinschaft; CrossRef Turns One; Fermi National Accelerator Laboratory (Fermilab).  

ERIC Educational Resources Information Center

|Includes four articles that discuss the use of digital objects to represent value in a network environment; digital library initiatives at the central public funding organization for academic research in Germany; an application of the Digital Object Identifier System; and the Web site of the Fermi National Accelerator Laboratory. (LRW)|

Kahn, Robert E.; Lyons, Patrice A.; Brahms, Ewald; Brand, Amy; van den Bergen, Mieke

2001-01-01

105

Initial far-field otr images generated by 120-GeV protons at FNAL.  

SciTech Connect

We have successfully imaged for the first time the angular distribution patterns of optical transition radiation (OTR) generated by 120-GeV proton beams passing through an Al metal plane. These experiments were performed at Fermilab (FNAL) with the same chamber, foil, and camera design as with the near-field experiments previously reported. In this case the lens-to-CID-chip separation was remotely adjusted to provide the focus-at- infinity, or far-field optical imaging. Data have been obtained in transport lines both before the antiproton production target and before the NuMI target with particle intensities of about 5 to 22 times 10{sup 12}. A two-foil interferometer calculation was also performed. Single-foil experimental and modeling results will be presented.

Lumpkin, A. H.; Scarpine, V. E.; Tassotto, G. R.; High Energy Physics; FNAL

2008-01-01

106

Preliminary test results from a telescope of Hughes pixel arrays at FNAL  

SciTech Connect

In December of 1991 three silicon hybrid pixel detectors each having 2.56 [times] 2.56 pixels 30 [mu]m square, made by the Hughes Aircraft Company, were placed in a high energy muon beam at the Fermi National Accelerator Laboratory. Straight tracks were recorded in these detectors at angles to the normal to the plane of the silicon ranging from 0 to 45[degrees]. In this note, preliminary results are presented on the straight through tracks, i.e., those passing through the telescope at normal incidence. Pulse height data, signal-to-noise data, and preliminary straight line fits to the data resulting in residual distributions are presented. Preliminary calculations show spatial resolution of less than 5 [mu]m in two dimensions.

Jernigan, J.G.; Arens, J.; Vezie, D. (California Univ., Berkeley, CA (United States). Space Sciences Lab.); Shapiro, S.L. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Collins, T. (Hughes Aircraft Co., Carlsbad, CA (United States)); Krider, J. (Fermi National Accelerator Lab., Batavia, IL (United States)); Skubic, P. (Oklahoma Univ., Norman, OK (United States))

1992-09-01

107

Preliminary test results from a telescope of Hughes pixel arrays at FNAL  

SciTech Connect

In December of 1991 three silicon hybrid pixel detectors each having 2.56 {times} 2.56 pixels 30 {mu}m square, made by the Hughes Aircraft Company, were placed in a high energy muon beam at the Fermi National Accelerator Laboratory. Straight tracks were recorded in these detectors at angles to the normal to the plane of the silicon ranging from 0 to 45{degrees}. In this note, preliminary results are presented on the straight through tracks, i.e., those passing through the telescope at normal incidence. Pulse height data, signal-to-noise data, and preliminary straight line fits to the data resulting in residual distributions are presented. Preliminary calculations show spatial resolution of less than 5 {mu}m in two dimensions.

Jernigan, J.G.; Arens, J.; Vezie, D. [California Univ., Berkeley, CA (United States). Space Sciences Lab.; Shapiro, S.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Collins, T. [Hughes Aircraft Co., Carlsbad, CA (United States); Krider, J. [Fermi National Accelerator Lab., Batavia, IL (United States); Skubic, P. [Oklahoma Univ., Norman, OK (United States)

1992-09-01

108

Recent experience in the fabrication and brazing of ceramic beam tubes for kicker magnets at FNAL  

SciTech Connect

Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil (titanium/incusil) alloy brazing material are stacked in the furnace and then brazed in the furnace at 1000 C. The ceramic specified is 99.8% Alumina, Al{sub 2}O{sub 3}, a strong recrystallized high-alumina fabricated by slip casting. Recent experience at Fermilab with the fabrication and brazing of these tubes has brought to light numerous problems including tube breakage and cracking and also the difficulty of brazing the tube to produce a leak-tight joint. These problems may be due to the ceramic quality, voids in the ceramic, thinness of the wall, and micro-cracks in the ends which make it difficult to braze because it cannot fill tiny surface cracks which are caused by grain pullout during the cutting process. Solutions which are being investigated include lapping the ends of the tubes before brazing to eliminate the micro-cracks and also metallization of the tubes.

Ader, C.R.; Jensen, C.; Reilly, R.; Snee, D.; Wilson, J.H.; /Fermilab

2008-06-01

109

World penduluma distributed remotely controlled laboratory (RCL) to measure the Earth's gravitational acceleration depending on geographical latitude  

Microsoft Academic Search

We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy ?g ? 0.01 m s?2). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part describes the physical origin of this phenomenon g(?), that the Earth's effective gravitational acceleration

S Grber; M Vetter; B Eckert; H-J Jodl

2007-01-01

110

World pendulum---a distributed remotely controlled laboratory (RCL) to measure the Earth's gravitational acceleration depending on geographical latitude  

Microsoft Academic Search

We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy Deltag ~ 0.01 m s-2). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part describes the physical origin of this phenomenon g(phiv), that the Earth's effective gravitational acceleration

S. Grber; M. Vetter; B. Eckert; H.-J. Jodl

2007-01-01

111

High Power Beam Test and Measurement of Emittance Evolution of a 1.6-Cell Photocathode RF Gun at Pohang Accelerator Laboratory  

NASA Astrophysics Data System (ADS)

A Brookhaven National Laboratory (BNL) GUN-IV type photocathode rf gun has been fabricated to use in femtosecond electron diffraction (FED), femtosecond far infrared radiation (fs-FIR) facility, and X-ray free electron laser (XFEL) facilities at the Pohang Accelerator Laboratory (PAL). The gun consists of a 1.6-cell cavity with a copper cathode, a solenoid magnet, beam diagnostic components and auxiliary systems. We report here the measurement of the basic beam parameters which confirm a successful fabrication of the photocathode RF gun system. The emittance evolution is measured by an emittance meter and compared with the PARMELA simulation, which shows a good agreement.

Park, Jang-Ho; Park, Sung-Ju; Kim, Changbum; Parc, Yong-Woon; Hong, Ju-Ho; Huang, Jung-Yun; Xiang, Dao; Wang, Xijie; Ko, In Soo

2007-04-01

112

Integrating knowledge-based systems into operations at the McMaster University FN tandem accelerator laboratory  

SciTech Connect

The introduction of computer-based expertise in accelerator operations has resulted in the development of an Accelerator Operators' Companion which incorporates a knowledge-based front-end that is tuned to user operational expertise. The front-end also provides connections to traditional software packages such as database and spreadsheet programs. During work on the back-end, that is, real-time expert system control development, the knowledge engineering phase has revealed the importance of modifying expert procedures when a multitasking environment is involved.

Poehlman, W.F.S. (McMaster Univ., Hamilton, ON (Canada)); Stark, J.W. (McMaster Univ., Hamilton, ON (Canada). Tandem Accelerator Lab.)

1989-10-01

113

SEY and Surface Analysis Measurements on FNAL Main Injector Ring S/S Beam Chamber Material  

SciTech Connect

Material was provided by Dr. Weiren Chou, FNAL. Both mildly-activated used, and new sections of stainless steel (type 316L) beam chamber were measured. Centimeter-sized coupons were cleanly dry-cut from the large flat surface (called ''flat side'' in the plots) and from the ID end (inside diameter of the ring, in the case of the used material) and narrow end (in the case of the new material). The unused material was ultra-soniced in acetone (to remove storage residue), then rinsed with ethanol and blown dry with filtered N{sub 2}-gas, to simulate new chamber installation final rinse. Used material was installed, as cut. Surface chemistry was measured using x-ray photoelectron spectroscopy (sometimes called ''ESCA''). With this technique, soft x-rays (1486 eV) illuminate the sample, penetrating into the surface ten microns. Photoelectrons are generated from energy levels of the constituent compounds/elements present. Those electrons, within 5 nm or so of the surface, escape without energy loss and preserve valence information about the atomic levels from which they were generated. An electron energy analyzer, of good energy resolution, measures the photoelectron energy, thereby yielding both valence (chemical) information and relative atomic abundances in the top 5 nm of surface. Using appropriate sensitivity factors, these intensities are converted to a semi-quantitative (surface atom %) concentration in the analyzed layer. As a benchmark, the limit for carbon contamination on vacuum components for UHV use at SLAC is 50 at%. That corresponds to about 8-10 monolayers of elemental carbon. XPS does not detect hydrogen because it has no electrons after bonding. Generally, hydrides do not show evidence of ''chemical shift'' of the binding energy of the metal lines.

Kirby, Robert E.; /SLAC

2006-09-18

114

World Pendulum--A Distributed Remotely Controlled Laboratory (RCL) to Measure the Earth's Gravitational Acceleration Depending on Geographical Latitude  

ERIC Educational Resources Information Center

|We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy [delta]g is approximately equal to 0.01 m s[superscript -2]). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part

Grober, S.; Vetter, M.; Eckert, B.; Jodl, H.-J.

2007-01-01

115

Study of new FNAL-NICADD extruded scintillator as active media of large EMCal of ALICE at LHC  

SciTech Connect

The current conceptual design of proposed Large EMCal of ALICE at LHC is based largely on the scintillating mega-tile/fiber technology implemented in CDF Endplug upgrade project and in both barrel and endcap electromagnetic calorimeters of the STAR. The cost of scintillating material leads us to the choice of extruded polystyrene based scintillator, which is available in new FNAL-NICADD facility. Result of optical measurements, such as light yield and light yield variation, show that it is possible to use this material as active media of Large EMCal of ALICE at LHC.

Oleg A. Grachov et al.

2004-05-04

116

Accelerating technology transfer from federal laboratories to the private sector by industrial R and D collaborations - A new business model  

SciTech Connect

Many important products and technologies were developed in federal laboratories and were driven initially by national needs and for federal applications. For example, the clean room technology that enhanced the growth of the semiconductor industry was developed at Sandia National Laboratories (SNL) decades ago. Similarly, advances in micro-electro-mechanical-systems (MEMS)--an important set of process technologies vital for product miniaturization--are occurring at SNL. Each of the more than 500 federal laboratories in the US, are sources of R and D that contributes to America's economic vitality, productivity growth and, technological innovation. However, only a fraction of the science and technology available at the federal laboratories is being utilized by industry. Also, federal laboratories have not been applying all the business development processes necessary to work effectively with industry in technology commercialization. This paper addresses important factors that federal laboratories, federal agencies, and industry must address to translate these under utilized technologies into profitable products in the industrial sector.

LOMBANA,CESAR A.; ROMIG JR.,ALTON D.; LINTON,JONATHAN D.; MARTINEZ,J. LEONARD

2000-04-13

117

Relativistic electron acceleration by compressional-mode ULF waves: Evidence from correlated Cluster, Los Alamos National Laboratory spacecraft, and ground-based magnetometer measurements  

NASA Astrophysics Data System (ADS)

Simultaneous observations by Cluster and Los Alamos National Laboratory (LANL) spacecraft and Canadian Array for Real-Time Investigations of Magnetic Activity and International Monitor for Auroral Geomagnetic Effects magnetometer arrays during a sudden storm commencement on 25 September 2001 show evidence of relativistic electron acceleration by compressional-mode ULF waves. The waves are driven by the quasiperiodic solar wind dynamical pressure fluctuations that continuously buffet the magnetosphere for 3 h. The compressional-mode ULF waves are identified by comparing the power of magnetic field magnitude fluctuations with the total magnetic field power. The radial distribution and azimuthal propagation of both toroidal and poloidal-mode ULF waves are derived from ground-based magnetometer data. The energetic electron fluxes measured by LANL show modulation of low-energy electrons and acceleration of high-energy electrons by the compressional poloidal-mode electric field oscillations. The energy threshold of accelerated electrons at the geosynchronous orbit is 0.4 MeV, which is roughly consistent with drift-resonant interaction of magnetospheric electrons with compressional-mode ULF waves.

Tan, Lun C.; Shao, X.; Sharma, A. S.; Fung, Shing F.

2011-07-01

118

Investigation of the effects of acid rain on the deterioration of cement concrete using accelerated tests established in laboratory  

Microsoft Academic Search

Deterioration of cement concrete specimens caused by simulated acid rain was investigated by laboratory tests. Before and after cement concrete specimens were exposed to simulated acid rain, the neutralized depth, the compressive strength and the chemical compositions in the hardened cement paste were measured. The mineralogical composition of the concrete specimens was analyzed with XRD. The results lead to the

Shaodong Xie; Li Qi; Ding Zhou

2004-01-01

119

PV module degradation caused by thermomechanical stress: real impacts of outdoor weathering versus accelerated testing in the laboratory  

Microsoft Academic Search

Temperature cycling tests are part of the IEC 61215 qualification testing of crystalline silicon (c-Si) PV modules for evaluating PV module degradation caused by the impact of thermo-mechanically induced stresses. The defined temperature gradient and the cycle time by far exceed the actual impact of natural weathering, however. As a contribution to comparisons between laboratory testing and natural weathering our

W. Herrmann; N. Bogdanski; F. Reil; M. Khl; K.-A. Weiss; M. Assmus; M. Heck

2010-01-01

120

PV module degradation caused by thermomechanical stress: real impacts of outdoor weathering versus accelerated testing in the laboratory  

NASA Astrophysics Data System (ADS)

Temperature cycling tests are part of the IEC 61215 qualification testing of crystalline silicon (c-Si) PV modules for evaluating PV module degradation caused by the impact of thermo-mechanically induced stresses. The defined temperature gradient and the cycle time by far exceed the actual impact of natural weathering, however. As a contribution to comparisons between laboratory testing and natural weathering our work provides data from standard temperature cycling tests as defined in IEC 61215 and extended from 200 (standard) to 800 cycles. The results of these tests for seven commercial c-Si PV modules from various manufacturers are compared with results from identical module types exposed outdoors in different climates for a period of 3 years. Degradation effects are evaluated with respect to changes in output power, changes in insulation properties and with respect to interruptions in the electrical interconnection circuits such as cell interconnects. Temperature gradients obtained at the different exposure locations are used to model the thermo-mechanical stress arising from the mismatches of the thermal expansion coefficients of the employed materials.

Herrmann, W.; Bogdanski, N.; Reil, F.; Khl, M.; Weiss, K.-A.; Assmus, M.; Heck, M.

2010-08-01

121

Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory  

SciTech Connect

The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and for evaluation of homolog chemical properties. CAMS also offers an environment for testing these systems 'online' by incorporating automated chemical systems into the beamline so that tracers can be created, transported, and chemically separated all on the shorter timescales required for transactinide experiments. Even though CAMS is limited in the types and energies of ions they can accelerate, there are still a wide variety of reactions that can be performed there with commercially available target materials. The half-lives of these isotopes vary over a range that could be used for both online chemistry (where shorter half-lives are required) and benchtop tracers studies (where longer lived isotopes are preferred). In this document, they present a summary of tracer production reactions that could be performed at CAMS, specifically for online, automated chemical studies. They are from chemical groups four through seven, 13, and 14, which would be appropriate for studies of elements 104-107, 113, and 114. Reactions were selected that had (a) commercially available target material, (b) half-lives long enough for transport from a target chamber to an automated chemistry system, and (c) cross-sections at CAMS available projectile energies that were large enough to produce enough atoms to result in a statistically relevant signal after losses for transport and chemistry were considered. In addition, the resulting product atoms had to decay with an observable gamma-ray using standard Ge gamma-ray detectors. The table includes calculations performed for both metal targets and their corresponding oxides.

Moody, K J; Shaughnessy, D A; Gostic, J M

2011-11-29

122

Accelerator mass spectrometry of 63Ni at the Munich Tandem Laboratory for estimating fast neutron fluences from the Hiroshima atomic bomb.  

PubMed

After the release of the present dosimetry system DS86 in 1987, measurements have shown that DS86 may substantially underestimate thermal neutron fluences at large distances (>1,000 m) from the hypocenter in Hiroshima. This discrepancy casts doubts on the DS86 neutron source term and, consequently, the survivors' estimated neutron doses. However, the doses were caused mainly by fast neutrons. To determine retrospectively fast neutron fluences in Hiroshima, the reaction 63Cu(n, p)63Ni can be used, if adequate copper samples can be found. Measuring 63Ni (half life 100 y) in Hiroshima samples requires a very sensitive technique, such as accelerator mass spectrometry (AMS), because of the relatively small amounts of 63Ni expected (approximately 10(5)-10(6) atoms per gram of copper). Experiments performed at Lawrence Livermore National Laboratory have demonstrated in 1996 that AMS can be used to measure 63Ni in Hiroshima copper samples. Subsequently, a collaboration was established with the Technical University of Munich in view of its potential to perform more sensitive measurements of 63Ni than the Livermore facility and in the interest of interlaboratory validation. This paper presents the progress made at the Munich facility in the measurement of 63Ni by AMS. The Munich accelerator mass spectrometry facility is a combination of a high energy tandem accelerator and a detection system featuring a gas-filled magnet. It is designed for high sensitivity measurements of long-lived radioisotopes. Optimization of the ion source setup has further improved the sensitivity for 63Ni by reducing the background level of the 63Cu isobar interference by about two orders of magnitude. Current background levels correspond to a ratio of 63Ni/Ni<2x10(-14) and suggest that, with adequate copper samples, the assessment of fast neutron fluences in Hiroshima and Nagasaki is possible for ground distances of up to 1500 m, and--under favorable conditions--even beyond. To demonstrate this capability, we have measured successfully 6Ni/Ni ratios as low as (3.5 +/- 0.6) x 10(-13). The latter are, based on DS86, representative of a ratio expected from a typical Hiroshima copper sample at about 1,300-m ground range. PMID:11007457

Rhm, W; Knie, K; Rugel, G; Marchetti, A A; Faestermann, T; Wallner, C; McAninch, J E; Straume, T; Korschinek, G

2000-10-01

123

An integrated diagnostic package for intense proton and lithium-ion beam measurements on the sandia national laboratories' PBFA-II accelerator  

NASA Astrophysics Data System (ADS)

A review of the diagnostic packages used at Sandia National Laboratories to measure the parameters of intense proton and lithium beams generated on the PBFA-II accelerator will be presented. These diagnostics consist of several types, namely: K ? X-ray pinhole cameras, a multiframe dE/dx ion pinhole camera, a p-i-n diode array ion pinhole camera, Thomson parabola spectrographs, a Rutherford magnetic spectrograph, plasma visible spectroscopy and several nuclear activation diagnostics. These components, when taken together, provide a rather thorough description of the 5 MV, 10 TW ion beams presently being produced. Specifically, the beam parameters measured by the diagnostic array include spatial profile (off and on axis), absolute number, species, voltage, current density and focal power density. A unique feature of these diagnostics is that they are capable of operating in hard (several MeV) X-ray bremsstrahlung backgrounds of some 109-1011rad/s. The operating principles of each diagnostic will be summarized in the paper, along with a discussion of how the diagnostics are integrated together to form a complete system. The paper will close with a discussion of a new nuclear track counting system that has been developed for automatic counting of solid-state nuclear track detectors.

Leeper, R. J.; Stygar, W. A.; Maenchen, J.; Ruiz, C. L.; Kensek, R. P.; Bailey, J.; Cooper, G.; Johnson, D. J.; Lee, J. R.; Lockner, T. R.; Mehlhorn, T. A.; Mix, L. P.; Stinnett, R. W.

1989-04-01

124

High-intensity accelerators  

SciTech Connect

The design of high-intensity accelerators is described, using examples of machines being built at the Los Alamos National Laboratory. The major design problem with these accelerators is associated with control of beam loss when accelerator intensity is increased. Beam dynamics, beam loss, and the radio-frequency quadrupole structure are discussed in the first part of the chapter followed by an explanation of plans to achieve high-intensity operation in three projects: the Fusion Material Irradiation Tests (a joint effort with the Hanford Development Laboratory in Richland, Washington), the Proton Storage Ring (an addition to the LAMPF accelerator), and the Racetrack Microtron Project (with the National Bureau of Standards).

Knapp, E.A.

1981-01-01

125

Accelerating projects  

SciTech Connect

This chapter describes work at ORNL in the period around 1950, when the laboratory was evolving from its original mission of research aimed at producing the atomic bomb, to a new mission, which in many ways was unclear. The research division from Y-12 merged with the laboratory, which gave an increased work force, access to a wide array of equipment, and the opportunity to work on a number of projects related to nuclear propulsion. The first major project was for a nuclear aircraft. From work on this program, a good share of the laboratories work in peaceful application of nuclear energy would spring. A major concern was the development of light weight shielding to protect the crew and materials in such a plane. To do such shielding work, the laboratory employed existing, and new reactors. The original plans called for the transfer of reactor work to Argonne, but because of their own research load, and the needs of the lab, new reactor projects were started at the lab. They included the Low Intensity Test Reactor, the Swimming Pool Reactor, the Bulk Shielding Reactor, the Tower Shielding Facility, and others. The laboratory was able to extend early work on calutrons to accelerator development, pursuing both electrostatic accelerators and cyclotrons. The aircraft project also drove the need for immense quantities of scientific data, with rapid analysis, which resulted the development of divisions aimed at information support and calculational support. The laboratory also expanded its work in the effects of radiation and cells and biological systems, as well as in health physics.

Not Available

1992-01-01

126

Survey of Hydrophone Acceleration Responses. Addendum.  

National Technical Information Service (NTIS)

A set of fourteen hydrophone types, some submitted for test by manufacturers and others the property of the Marine Physical Laboratory, were tested for acceleration response. The acceleration was introduced as vertical acceleration along the suspending ca...

E. D. Squier

1972-01-01

127

US Particle Accelerators at Age 50.  

ERIC Educational Resources Information Center

|Reviews the development of accelerators over the past 50 years. Topics include: types of accelerators, including cyclotrons; sociology of accelerators (motivation, financing, construction, and use); impact of war; national laboratories; funding; applications; future projects; foreign projects; and international collaborations. (JN)|

Wilson, R. R.

1981-01-01

128

Digitral Down Conversion Technology for Tevatron Beam Line Tuner at FNAL  

SciTech Connect

Fermilab is presently in Run II collider operations and is developing instrumentation to improve luminosity. Improving the orbit matching between accelerator components using a Beam Line Tuner (BLT) can improve the luminosity. Digital Down Conversion (DDC) has been proposed as a method for making more accurate beam position measurements. Fermilab has implemented a BLT system using a DDC technique to measure orbit oscillations during injections from the Main Injector to the Tevatron. The output of a fast ADC is downconverted and filtered in software. The system measures the x and y positions, the intensity, and the time of arrival for each proton or antiproton bunch, on a turn-by-turn basis, during the first 1024 turns immediately following injection. We present results showing position, intensity, and time of arrival for both injected and coasting beam. Initial results indicate a position resolution of {approx}20 to 40 microns and a phase resolution of {approx}25 ps.

Schappert, W.; Lorman, E.; Scarpine, V.; Ross, M.C.; Sebek, J.; Straumann, T.; /Fermilab /SLAC

2008-03-17

129

Staged laser plasma accelerators  

NASA Astrophysics Data System (ADS)

We present current results on staged electron acceleration in the LOASIS program at the Lawrence Berkeley National Laboratory. The goal is to experimentally demonstrate laser driven electron acceleration in two stages, where each stage is driven by a separate laser pulse. This technology could provide the key to built compact laser driven accelerators which could potentially reach up to TeV in electron energy.

Sokollik, Thomas; Shiraishi, Satomi; Shaw, Brian; Gonsalves, Antony; Nakamura, Kei; van Tilborg, Jeroen; Esarey, Eric; Schroeder, Carl B.; Benedetti, Carlo; Toth, Csaba; Leemans, Wim

2012-12-01

130

Extruded Scintillator for the Calorimetry Applications.  

National Technical Information Service (NTIS)

An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develo...

A. Dyshkant A. Pla-Dalmau D. Beznosko V. Rykalin

2006-01-01

131

Linear Accelerators  

SciTech Connect

In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

Sidorin, Anatoly [Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna (Russian Federation)

2010-01-05

132

High Acceleration Cockpit Simulator Evaluation.  

National Technical Information Service (NTIS)

Since 1970, the Aerospace Medical Research Laboratory (AMRL) and the Air Force Flight Dynamics Laboratory (AFFDL) have jointly sponsored a unique and innovative approach to fighter cockpit design termed the High Acceleration Cockpit (HAC). As a result of ...

E. P. Prouhet P. V. Kulwicki

1977-01-01

133

Acceleration of /sup 14/C beams in electrostatic accelerators  

SciTech Connect

Operational problems in the production and acceleration of /sup 14/C beams for nuclear structure research in Los Alamos National Laboratory's Van de Graaff accelerators are discussed. Methods for the control of contamination in ion sources, accelerators and personnel are described. Sputter source target fabrication techniques and the relative beam production efficiencies of various types of bound particulate carbon sputter source targets are presented.

Rowton, L.J.; Tesmer, J.R.

1981-01-01

134

Linear Accelerators  

SciTech Connect

In the linear accelerators the particles are accelerated by either electrostatic fields or oscillating radio frequency (RF) fields. Accordingly the linear accelerators are divided by three large groups: electrostatic, induction and RF accelerators. Overview of different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of the beam focusing in linacs are described.

Sidorin, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2007-11-26

135

Strong ground motion data recorded at the Idaho National Laboratory during the 1983 Borah Peak, Idaho earthquake. [Appendix contains plot generated by accelerogram showing peak valves amplitude, response spectra, displacement, veolocity and acceleration  

SciTech Connect

The Idaho National Engineering Laboratory (INEL) is located approximately 80 km southeast of the epicenter for the 1983 M{sub S} 7.3 Borah Peak Idaho earthquake. Thirteen strong-motion accelerographs located at various facilities around the INEL Site recorded strong-ground motions from the Borah Peak earthquake. The strong-motion records were digitized and processed resulting in corrected acceleration, velocity, and displacement time-histories and response and Fourier spectra. Peak horizontal accelerations had a range of 0.022 to 0.078 g for accelerographs located at free-field and basement sites. Values of 0.037 {minus} 0.817 g were recorded at accelerographs located within structures above basement level. Peak vertical accelerations ranged from 0.16 (basement level) to 0.059 g (top of structures). The peak amplitudes of the response and Fourier Spectra occur in the 2 -- 10 hz frequency range. Appendices include Borah Peak earthquake accelerograph data printouts. 8 refs., 4 figs., 7 tabs.

Jackson, S.M.; King, J.J.; Anderson, D.M.; Carpenter, G.S.; Adams, H.A.

1991-06-01

136

Plasma accelerators  

SciTech Connect

In this paper we discuss plasma accelerators which might provide high gradient accelerating fields suitable for TeV linear colliders. In particular we discuss two types of plasma accelerators which have been proposed, the Plasma Beat Wave Accelerator and the Plasma Wake Field Accelerator. We show that the electric fields in the plasma for both schemes are very similar, and thus the dynamics of the driven beams are very similar. The differences appear in the parameters associated with the driving beams. In particular to obtain a given accelerating gradient, the Plasma Wake Field Accelerator has a higher efficiency and a lower total energy for the driving beam. Finally, we show for the Plasma Wake Field Accelerator that one can accelerate high quality low emittance beams and, in principle, obtain efficiencies and energy spreads comparable to those obtained with conventional techniques.

Ruth, R.D.; Chen, P.

1986-03-01

137

What Can We Expect from Future Accelerators.  

National Technical Information Service (NTIS)

This talk covers a general but highly subjective overview of the expectation for new accelerator development. An updated version of the Livingston chart demonstrates the exponential growth in time of the equivalent laboratory energy of accelerators. A sim...

W. K. H. Panofsky

1984-01-01

138

Diagnostics for induction accelerators  

SciTech Connect

The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960`s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore`s Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail.

Fessenden, T.J.

1996-04-01

139

Future accelerators (?)  

SciTech Connect

I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

John Womersley

2003-08-21

140

Accelerator search for cosmic SIMPs  

Microsoft Academic Search

We give limits on the contribution to the cosmic dark matter density of neutral, stable, strongly interacting massive particles (SIMPs). The limits are inferred from an accelerator mass spectrometry (AMS) experiment at the Purdue Rare Isotope Measurement Laboratory (PRIME Lab). The experiment accelerated nuclei of both gold and iron. The SIMP signal would be discovery of nuclei of these elements

V. Teplitz; D. Javorsek; E. Fischbach; R. Mohapatra

2003-01-01

141

Report on accelerated corrosion studies  

Microsoft Academic Search

Sandia National Laboratories (SNL) conducted accelerated atmospheric corrosion testing for the U.S. Consumer Product Safety Commission (CPSC) to help further the understanding of the development of corrosion products on conductor materials in household electrical components exposed to environmental conditions representative of homes constructed with problem drywall. The conditions of the accelerated testing were chosen to produce corrosion product growth that

Curtis Dale Mowry; Sarah Jill Glass; Neil Robert Sorensen

2011-01-01

142

Review of Activities using the Pulsed Neutron Facility and 2.5-GeV Electron Linac at Pohang Accelerator Laboratory  

SciTech Connect

We report on activities using a pulsed neutron facility consisting of an electron linear accelerator, a water-cooled Ta target with a water moderator, and a 12 m time-of-flight path. It is possible to measure neutron total cross sections in the neutron energy range from 0.01 eV to a few hundred eV by using the neutron time-of-flight method; photo-neutron cross sections can also measure by using the bremsstrahlung from the electron linac. A {sup 6}LiZnS(Ag) glass scintillator was used as a neutron detector. The neutron flight path from the water-cooled Ta target to the neutron detector was 12.1 m. In this paper, we report total cross sections of Nb and also resonance parameters obtained using the SAMMY fitting program. The present results are compared with the previous experimental results and the evaluated data in ENDF/B-VII. We also report on the mass-yield distribution of fission products in the 2.5-GeV bremsstrahlung-induced fission of {sup nat}Pb and {sup 209}Bi measured at the 2.5-GeV electron linac using a recoil catcher and an off-line {gamma}-ray spectrometric technique.

Kim, Guinyun; Lee, Manwoo; Kim, Kyung Sook; Yang, Sungchul [Department of Physics,Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701 (Korea, Republic of); Kim, Eunae; Shvetshov, Valery; Cho, Moo-Hyun [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of); Naik, Haladhara [Radiochemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India)

2011-12-13

143

Accelerator and electrodynamics capability review  

SciTech Connect

Los Alamos National Laboratory (LANL) uses capability reviews to assess the science, technology and engineering (STE) quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). Laboratory Management will use this report for STE assessment and planning. LANL has defined fifteen STE capabilities. Electrodynamics and Accelerators is one of the seven STE capabilities that LANL Management (Director, PADSTE, technical Associate Directors) has identified for review in Fiscal Year (FY) 2010. Accelerators and electrodynamics at LANL comprise a blend of large-scale facilities and innovative small-scale research with a growing focus on national security applications. This review is organized into five topical areas: (1) Free Electron Lasers; (2) Linear Accelerator Science and Technology; (3) Advanced Electromagnetics; (4) Next Generation Accelerator Concepts; and (5) National Security Accelerator Applications. The focus is on innovative technology with an emphasis on applications relevant to Laboratory mission. The role of Laboratory Directed Research and Development (LDRD) in support of accelerators/electrodynamics will be discussed. The review provides an opportunity for interaction with early career staff. Program sponsors and customers will provide their input on the value of the accelerator and electrodynamics capability to the Laboratory mission.

Jones, Kevin W [Los Alamos National Laboratory

2010-01-01

144

Accelerated Reader.  

ERIC Educational Resources Information Center

|This paper provides an overview of Accelerated Reader, a system of computerized testing and record-keeping that supplements the regular classroom reading program. Accelerated Reader's primary goal is to increase literature-based reading practice. The program offers a computer-aided reading comprehension and management program intended to motivate

Education Commission of the States, Denver, CO.

145

Radical Acceleration  

ERIC Educational Resources Information Center

|Research has found that teachers' objections to accelerating gifted students are mainly based on a fear that acceleration will lead to social or emotional damage. Ironically, it is the academic and emotional maturity which characterizes intellectually gifted students, coupled with their high levels of academic achievement, which makes them such

Gross, Miraca U. M.; Van Vliet, Helen E.

2005-01-01

146

Laboratory simulation  

Microsoft Academic Search

A description is presented of hypervelocity accelerators for the simulation of micrometeoroids, taking into account explosive accelerators, rockets, the light-gas gun, plasma drag accelerators, electromagnetic accelerators, electrostatic accelerators, and the basic requirements which a suitable accelerator facility will have to satisfy. High velocity impact processes are examined, giving attention to the initial partition of energy, the melting and even evaporation

H. Fechtig; E. Gruen; J. Kissel

1978-01-01

147

Accelerator Technology Program  

NASA Astrophysics Data System (ADS)

Highlights of major projects in the Accelerator Technology Division of the Los Alamos National Laboratory are presented. The first section deals with the Fusion Materials Irradiation Test Facility's 2-MeV accelerator on which tests began in May, as scheduled. Then, activities are reported on beam dynamics, inertial fusion, structure development, the racetrack microtron, the CERN high-energy physics experiment NA-12, and LAMPF II. The Proton Storage Ring is discussed next, with emphasis on the computer control system, diagnostics interfacing, and theoretical support. Other sections summarize progress on a portable radiographic linac, developments on the klystron code, and on permanent magnets. Activities of the Theory and Simulation Group are outlined next, followed by discussion of the oscillator experiment and the energy-recovery experiment in the free electron laser project. The last section reports on the accelerator test stand.

Jameson, R. A.

1984-07-01

148

Wakefield accelerators  

SciTech Connect

The search for new methods to accelerate particle beams to high energy using high gradients has resulted in a number of candidate schemes. One of these, wakefield acceleration, has been the subject of considerable R D in recent years. This effort has resulted in successful proof of principle experiments and in increased understanding of many of the practical aspects of the technique. Some wakefield basics plus the status of existing and proposed experimental work is discussed, along with speculations on the future of wake field acceleration. 10 refs., 6 figs.

Simpson, J.D.

1990-01-01

149

Accelerated Degradation of Polymers  

NSDL National Science Digital Library

For this laboratory exercise, you will monitor changes in the visual appearance of the samples, chemical changes and molecular weight changes as a function of exposure condition. Analysis of the neat and degraded systems will be done using visual evaluation, FTIR analysis and GPC analysis. After in-class presentation, completion of hands-on laboratory experiment and review of the information provided, you should be able to: Confidently discuss the mechanism of breakdown for a polymeric material exposed to various environmental conditions. Prepare samples and record an accurate account of their preparation for use in an outdoor environment and in an accelerated weathering chamber (Q-sun).

Derosa, Rebecca L.

2008-09-26

150

Podcast: Acceleration  

NSDL National Science Digital Library

The Podcast: Acceleration is a segment of the Force and Motion Short Course. The podcast is 2 minutes 13 seconds in duration. Presented by science experts and NSTA staff, the NSTA Online Short Courses are professional development opportunities de

2009-07-06

151

Acceleration switch  

DOEpatents

The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

Abbin, Jr., Joseph P. (Albuquerque, NM); Devaney, Howard F. (Cedar Crest, NM); Hake, Lewis W. (Albuquerque, NM)

1982-08-17

152

Angular Acceleration  

NSDL National Science Digital Library

The simulation of a rotating wheel below shows the relationship between angular position, angular velocity, and angular acceleration. Graphs of angular position and angular velocity as a function of time are shown.

Christian, Wolfgang; Belloni, Mario

2008-02-19

153

ION ACCELERATOR  

DOEpatents

An arrangement for the drift tubes in a linear accelerator is described whereby each drift tube acts to shield the particles from the influence of the accelerating field and focuses the particles passing through the tube. In one embodiment the drift tube is splii longitudinally into quadrants supported along the axis of the accelerator by webs from a yoke, the quadrants. webs, and yoke being of magnetic material. A magnetic focusing action is produced by energizing a winding on each web to set up a magnetic field between adjacent quadrants. In the other embodiment the quadrants are electrically insulated from each other and have opposite polarity voltages on adjacent quadrants to provide an electric focusing fleld for the particles, with the quadrants spaced sufficienily close enough to shield the particles within the tube from the accelerating electric field.

Bell, J.S.

1959-09-15

154

Acceleration using total internal reflection  

SciTech Connect

This report considers the use of a dielectric slab undergoing total internal reflection as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of the dielectric for polarized incident waves. We present an experimental arrangement for testing the performance of the method, using apparatus under construction for the Grating Acceleration experiment at Brookhaven National Laboratory. 13 refs., 4 figs., 2 tabs.

Fernow, R.C.

1991-06-07

155

Commissioning of the Electron Linear Accelerator for Education (ELLE)  

NASA Astrophysics Data System (ADS)

A 30-keV linear accelerator is being commissioned by the Accelerator Systems Division at Argonne National Laboratory. As its name implies, the Electron Linear Accelerator for Education (ELLE) will briefly describe and model the science and technology that guides accelerator development. Details on the thermionic gun, vacuum, magnet, and high-voltage system will be presented here.

Biedron, S. G.; Galayda, J. N.; Johnson, P. W.; Popp, J. E.

1998-04-01

156

A microwave inverse Cerenkov Accelerator  

SciTech Connect

The objective of this Phase II SBIR research program was to complete the final design originated during Phase I for a prototype Microwave Inverse Cerenkov Accelerator (MICA), to fabricate the-prototype MICA, and to test its performance as an electron accelerator. This report contains details of the design, predictions of accelerator performance, results of cold tests on the MICA structure, and details of the installation of MICA on the Yale Beam Physics Laboratory 6-MeV beamline. Discussion of future work is also included.

Jay L. Hirshfield

1999-07-01

157

Improvement of Accelerated Aging Methods for Coated Fabrics.  

National Technical Information Service (NTIS)

A study was made by the Reasearch Directorate, Weapons Laboratory at Rock Island to update and standardize methods and equipment for use in the evaluation of accelerated deterioration of coated fabrics. The coated fabrics were exposed to accelerated and n...

T. J. Koehler

1971-01-01

158

Accelerator Breeders: Will They Replace Liquid Metal Fast Breeders.  

National Technical Information Service (NTIS)

Investigation of accelerator breeders at Brookhaven National Laboratory indicate that the AB-LWR fuel cycle is economically competitive with the LMFBR fuel cycle. The same can be said about the accelerator breeder-High Temperature Gas Reactor symbiosis. T...

P. Grand J. R. Powell M. Steinberg H. Takahashi

1983-01-01

159

Accelerator Technology Program. Status Report, April-September 1985.  

National Technical Information Service (NTIS)

This report presents highlights of major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. Radio-frequency and microwave technology are dealt with. The p-bar gravity experiment, accelerator theory and simulation a...

R. A. Jameson S. O. Schriber

1986-01-01

160

Boeing shock physics laboratory  

NASA Astrophysics Data System (ADS)

The experimental capability of the Boeing Shock Physics Laboratory is described. Various laboratory facilities include a 64-mm bore light-gas gun, a 1.5-mm and a 3-mm bore two-stage hypervelocity projecctile gun, an exploding-foil facility, an FX-75 flash X-ray and electron beam accelerator, and a 600-G geotechnical centrifuge with a 100-kg payload capacity. A short bibliography is included which summarizes recent research activities.

Schmidt, R. M.

1982-04-01

161

MUON ACCELERATION  

SciTech Connect

One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

BERG,S.J.

2003-11-18

162

Disaster Scenarios at Nuclear Accelerators  

Microsoft Academic Search

The Bevalac accelerator was created at Lawrence Berkeley Laboratory in 1974 to study dense nuclear matter. The possibility that Lee-Wick density isomers could be formed and destroy the Earth was considered by an internal committee which concluded that the possibility was remote and the experiments should proceed. This was mentioned in an article in Physics Today in 1993, which resulted

Joseph Kapusta

2005-01-01

163

US particle accelerators: an historical perspective  

SciTech Connect

The history of the development of particle accelerators, especially in the US, is reviewed. The development is traced from the earliest efforts of Cockroft and Walton through the early cyclotrons, e.g., that of E.O. Lawrence, to the modern high energy machines such as those at Fermilab and CERN. Linear accelerators and meson factories are also described. Sociological factors, funding and the role of national laboratories are discussed. The outlook for higher energy accelerators in the future is briefly considered.

Wilson, R.R.

1985-01-01

164

Sabre, A 10-mv Linear Induction Accelerator  

Microsoft Academic Search

SABRE (Sandia Accelerator and Beam Research Experiment) is a 10-MV, 250-kA, 40-ns linear induction accelerator. It was designed to be used in positive polarity output. Positive polarity accelerators are important for application to Sandia's ICF (Inertial Confinement Fusion) and LMF (Laboratory Microfusion Facility) program efforts. SABRE was built to allow a more detailed study of pulsed power issues associated with

J. P. Corley; S. A. Alexander; P. J. Pankuch; C. E. Heath; D. L. Johnson; J. J. Ramirez; G. J. Denison

1991-01-01

165

Spatially accelerating flow in smooth open channel  

Microsoft Academic Search

Laboratory experiments on the structure of fully developed smooth and steady open channel flows gradually subjected to spatial acceleration are reported. Mean velocity and turbulence intensity profiles as well as friction velocity were measured. It was found that: self-similarity is not preserved over the entire depth of the accelerated flow; a very thin universal wall layer is likely to prevail;

W. H. Graf; A. Cardoso; G. Gust

1988-01-01

166

Spatially accelerating flow in smooth open channel  

Microsoft Academic Search

Laboratory experiments on the structure of fully developed smooth and steady open channel flows gradually subjected to spatial acceleration are reported. Mean velocity, turbulence intensity profiles, and friction velocity were measured. The following were found: self similarity is not preserved over the entire depth of the accelerated flow; a very thin universal wall layer is likely to prevail; the turbulence

A. H. Cardoso; Walter H. Graf; G. Gust

1991-01-01

167

25 MV Tandem Accelerator at Oak Ridge.  

National Technical Information Service (NTIS)

A new heavy-ion accelerator facility is under construction at the Oak Ridge National Laboratory. A brief description of the scope and status of this project is presented with emphasis on the first operational experience with the 25 MV tandem accelerator. ...

C. M. Jones

1980-01-01

168

Hanford as a site for large accelerators  

Microsoft Academic Search

The Ramsey Panel recommended that two very large accelerators be ;\\u000a constructed during the next few years to meet urgent U. S. needs in high energy ;\\u000a physics. Two studies have been made. The Lawrence Radiation Laboratory at ;\\u000a Berkeley has studied a 200 to 300 BeV accelerator, while the Brooknaven National ;\\u000a Laboratory on Long Island has made an

B. R. Jr

1965-01-01

169

Accelerators and the Accelerator Community  

SciTech Connect

In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

Malamud, Ernest; Sessler, Andrew

2008-06-01

170

Ring accelerators  

SciTech Connect

We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package.

Gisler, G.; Faehl, R.

1983-01-01

171

Plasma accelerators; Plazmennye uskoriteli  

Microsoft Academic Search

Papers concerning the physical processes in plasma accelerators are ; included, covering some specific accelerator types, magnetic plasma compressors, ; plasma diagnostics methods, and plasma accelerator applications in thermonuclear ; studies, gasdynamics, and space studies. The topics also include plasma ; acceleration control problems, high-vacuum technology, plasma accelerator designs ; with narrow and broad acceleration zones, and electrode processes in

Artsimovich

1973-01-01

172

TRACKING ACCELERATOR SETTINGS.  

SciTech Connect

Recording setting changes within an accelerator facility provides information that can be used to answer questions about when, why, and how changes were made to some accelerator system. This can be very useful during normal operations, but can also aid with security concerns and in detecting unusual software behavior. The Set History System (SHS) is a new client-server system developed at the Collider-Accelerator Department of Brookhaven National Laboratory to provide these capabilities. The SHS has been operational for over two years and currently stores about IOOK settings per day into a commercial database management system. The SHS system consists of a server written in Java, client tools written in both Java and C++, and a web interface for querying the database of setting changes. The design of the SHS focuses on performance, portability, and a minimal impact on database resources. In this paper, we present an overview of the system design along with benchmark results showing the performance and reliability of the SHS over the last year.

D OTTAVIO,T.; FU, W.; OTTAVIO, D.P.

2007-10-15

173

Electrochemical form grinding. Fnal report  

Microsoft Academic Search

Electrochemical form grinding cutting tests were performed on 25 17-4 PH stainless steel bars by a copper resin aluminum oxide wheel formed from a diamond form block. Tests investigated methods of dressing a form into a grinding wheel, nozzle design, optimum machine settings, and tolerance capabilities. The electrolyte was distributed evenly onto the wheel by a form-fitting nozzle, and a

1980-01-01

174

VLHC accelerator physics  

SciTech Connect

A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

Michael Blaskiewicz et al.

2001-11-01

175

Mass spectrometry with accelerators.  

PubMed

As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH?2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative methods of isobar separation. These techniques are discussed in the latter part of the review. PMID:22031277

Litherland, A E; Zhao, X-L; Kieser, W E

2010-12-23

176

STATUS OF THE DIELECTRIC WALL ACCELERATOR  

SciTech Connect

The dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL) uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system is capable of accelerating any charge to mass ratio particle. Applications of high gradient proton and electron versions of this accelerator will be discussed. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, photoconductive switches and compact proton sources.

Caporaso, G J; Chen, Y; Sampayan, S; Akana, G; Anaya, R; Blackfield, D; Carroll, J; Cook, E; Falabella, S; Guethlein, G; Harris, J; Hawkins, S; Hickman, B; Holmes, C; Horner, A; Nelson, S; Paul, A; Pearson, D; Poole, B; Richardson, R; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J; Weir, J

2009-04-22

177

FFAG ACCELERATOR PROTON DRIVER FOR NEUTRINO FACTORY.  

SciTech Connect

This paper is the summary of a conceptual study of a Proton Driver for Neutrino Factory based on the use of a Fixed-Field Alternating-Gradient (FFAG) Accelerator. The required proton energy range for an optimum neutrino production is 5 to 12 GeV. This can be accomplished with a group of three concentric rings each with 807 m circumference [1]. FFAG Accelerators [2] have the capability to accelerate charged particles over a large momentum range ({+-}30-50%) and the feature of constant bending and focusing fields. Particles can be accelerated very fast at the rate given by the accelerating field of RF cavities placed in proper locations between magnets. The performance of FFAG accelerators is to be placed between that of Super-Conducting Linear Accelerators (SCL), with which they share the fast acceleration rate, and Rapid-Cycling Synchrotrons (RCS), as they allow the beam to re-circulate over fewer revolutions. Brookhaven National Laboratory is involved in the study of feasibility of FFAG Accelerators to accelerate intense beams of protons in the GeV energy range for a variety of applications the most important of which is the Upgrade of the Alternating Gradient Synchrotron (AGS) with a new FFAG injector [3] accelerating from 400 MeV to 1.5 GeV. The ring would be housed in the AGS tunnel and has henceforth a circumference of 807 m.

RUGGIERO, A.

2005-06-21

178

Propagating Magnetic Wave Plasmoid Accelerator  

NASA Astrophysics Data System (ADS)

A high velocity plasma accelerator has been designed and constructed that has direct application to space propulsion as well as new innovative high energy density approaches to fusion. The Propagating Magnetic Wave (PMW) plasmoid accelerator could also find application as a fueler for ITER, as well as current tokamaks for adding rotational momentum and velocity shear for stability and transport control. Nevertheless, the PMW has a natural application to high power electric propulsion in space. The PMW operates naturally at both high power and efficiency with no need for electrodes or grids, and can also operate over a wide range in both exhaust velocity and propellant mass. To efficiently accelerate plasmoids to high velocities an acceleration method other than the simple tapered coil must be employed. The rapid acceleration of a compact plasmoid is realized through the application of an externally applied propagating magnetic field. Here, the large axial JxB force is generated from the induced azimuthal current inside the plasmoid and the radial component of the external, axially propagating magnetic field. This accelerating force is sustained as long as the plasmoid remains in phase with the wave field. Exit velocities greater than 200 km/sec for plasmoid masses on the order of 0.1 mg are anticipated from the device that is currently being tested, and the results from the initial experiments will be presented. This research is being supported by the U.S. Air Force Research Laboratory, Edwards AFB.

Smith, Jedidiah

2005-10-01

179

Shock experiments with magnetically accelerated flyer plates  

Microsoft Academic Search

The interaction of shock waves with inhomogeneous media is important in many astrophysical phenomena. Modelling these phenomena in the laboratory yields additional information to improve both simulations and the interpretation of astrophysical observations. Scaled experiments using magnetically accelerated flyers impacting on low density foam targets have been proposed for the Z machine at the Sandia National Laboratories (R.P. Drake, Phys.

Stephan Neff; Sandra Wright; David Martinez; Christopher Plechaty; Radu Presura

2008-01-01

180

Acceleration schedules for a recirculating heavy-ion accelerator  

SciTech Connect

Recent advances in solid-state switches have made it feasible to design programmable, high-repetition-rate pulsers for induction accelerators. These switches could lower the cost of recirculating induction accelerators, such as the ''small recirculator'' at Lawrence Livermore National Laboratory (LLNL), by substantially reducing the number of induction modules. Numerical work is reported here to determine what effects the use of fewer pulsers at higher voltage would have on the beam quality of the LLNL small recirculator. Lattices with different numbers of pulsers are examined using the fluid/envelope code CIRCE, and several schedules for acceleration and compression are compared for each configuration. For selected schedules, the phase-space dynamics is also studied using the particle-in-cell code WARP3d.

Sharp, W.M.; Grote, D.P.

2002-05-01

181

Teleportation of accelerated information  

NASA Astrophysics Data System (ADS)

A theoretical quantum teleportation protocal is suggested to teleport accelerated and non-accelerated information over different classes of accelerated quantum channels. For the accelerated information, it is shown that the fidelity of the teleported state increases as the entanglement of the initial quantum channel increases. However as the difference between the accelerated channel and the accelerated information decreases the fidelity increases. The fidelity of the non accelerated information increases as the entanglement of the initial quantum channel increases, while the accelerations of the quantum channel has a little effect. The possibility of sending quantum information over accelerated quantum channels is much better than sending classical information.

Metwally, Nasser

2013-01-01

182

2011 Dielectric Laser Acceleration Workshop (DLA2011)  

SciTech Connect

The first ICFA Mini-workshop on Dielectric Laser Accelerators was held on September 15-16, 2011 at SLAC National Accelerator Laboratory. We present the results of the Workshop, and discuss the main conclusions of the Accelerator Applications, Photonics, and Laser Technologies working groups. Over 50 participants from 4 countries participated, discussing the state of the art in photonic structures, laser science, and nanofabrication as it pertains to laser-driven particle acceleration in dielectric structures. Applications of this new and promising acceleration concept to discovery science and industrial, medical, and basic energy sciences were explored. The DLA community is presently focused on making demonstrations of high gradient acceleration and a compatible attosecond injector source - two critical steps towards realizing the potential of this technology.

Bermel, Peter; /MIT; Byer, Robert L.; /Stanford U., Phys. Dept.; Colby, Eric R.; /SLAC; Cowan, Benjamin M.; /Tech-X, Boulder; Dawson, Jay; /LLNL, Livermore; England, R.Joel; /SLAC; Noble, Robert J.; /SLAC; Qi, Ming-Hao; /Purdue U.; Yoder, Rodney B.; /Manhattanville Coll., Purchase

2012-04-17

183

The ion beam materials analysis laboratory at the environmental molecular sciences laboratory  

Microsoft Academic Search

The Environmental Molecular Sciences Laboratory (EMSL), a Department of Energy (DOE) collaborative scientific user facility located at Pacific Northwest National Laboratory (PNNL), is completing an accelerator facility dedicated to ion beam modification and analysis of materials. This facility consists of a new 3.4MV tandem accelerator from National Electrostatic Corporation (NEC), two ion sources including an Alphatross source and a SNICS

S. Thevuthasan; C. H. F Peden; M. H Engelhard; D. R Baer; G. S Herman; W. Jiang; Y. Liang; W. J Weber

1999-01-01

184

Separations technology development to support accelerator-driven transmutation concepts  

Microsoft Academic Search

This is the final report of a one-year Laboratory-Directed Research and Development (LDRD) Project at the Los Alamos National Laboratory (LANL). This project investigated separations technology development needed for accelerator-driven transmutation technology (ADTT) concepts, particularly those associated with plutonium disposition (accelerator-based conversion, ABC) and high-level radioactive waste transmutation (accelerator transmutation of waste, ATW). Specific focus areas included separations needed for

F. Venneri; E. Arthur; C. Bowman

1996-01-01

185

FXR accelerator cavity impedance experiments  

SciTech Connect

One of the goals of the present Flash X-Ray (FXR) accelerator upgrade effort [1][2] at Lawrence Livermore National Laboratory (LLNL) is to reduce the cavity transverse impedance, since it has been shown that beam stability is significantly affected by this parameter [3]. Recently, we have evaluated various techniques and cell modifications to accomplish that, both through lab measurements and computer models. A spare cell, identical in every way to cells in the accelerator, was specially modified for the experiments. The impedance measurements were done without the beam, by applying twin-wire techniques. This report describes the results of these experiments and suggests possible cell modifications to improve their performance. The techniques and modifications which are suggested might also be applicable to AHF and DARHT-2 long-pulse accelerator development.

Avalle, C.A.

1998-01-05

186

Disaster Scenarios at Nuclear Accelerators  

NASA Astrophysics Data System (ADS)

The Bevalac accelerator was created at Lawrence Berkeley Laboratory in 1974 to study dense nuclear matter. The possibility that Lee-Wick density isomers could be formed and destroy the Earth was considered by an internal committee which concluded that the possibility was remote and the experiments should proceed. This was mentioned in an article in Physics Today in 1993, which resulted in the authors being put on the Unabomber's list. The RHIC accelerator at Brookhaven National Laboratory began operation in 2000 to create quark-gluon plasma. Concerns that strange quark matter or mini-black holes could be formed that would destroy the Earth were aired in the Sunday Times of London in 1999, which resulted in an open committee review whose report was published in Reviews of Modern Physics.

Kapusta, Joseph

2005-04-01

187

Linear Accelerator (LINAC)  

MedlinePLUS

... of page Equipment View larger with caption The linear accelerator uses microwave technology (similar to that used for radar) to accelerate electrons in a part of the accelerator called the "wave guide," then allows these electrons to collide with ...

188

The accelerating universe  

NASA Astrophysics Data System (ADS)

From keV electrons in the aurorae to Ultra High Energy Cosmic Rays in unidentified "Zevatrons", the cosmos shows a perverse, yet pervasive, proclivity to select a tiny minority of particles and boost them to high energy. The mechanisms involved can be traced back to the ideas of Faraday, Fermi and Alfvn though we are learning that the details are idiosyncratic to the many environments that we have explored. Much can be learned from comparing and contrasting particle acceleration in laboratory, interplanetary, interstellar and intergalactic locations. As it celebrates its centenary, cosmic ray physics, has assumed a new importance in solving one of the greatest problems consuming its illustrious scion - elementary particle physics - namely the nature of dark matter.

Blandford, Roger

2013-02-01

189

Muon Collider Progress: Accelerators  

SciTech Connect

A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 10{sup 34} cm{sup 2}s{sup 1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (cooling). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

Zisman, Michael S.

2011-09-10

190

International X-Band Linear Collider Accelerator Structure R&D  

SciTech Connect

For more than fifteen years before the International Technology Recommendation Panel (ITRP) decision in August, 2004, there were intensive R&D activities and broad international collaboration among the groups at SLAC, KEK, FNAL, LLNL and other labs for the room temperature X-Band accelerator structures. The goal was to provide an optimized design of the main linac structure for the NLC (Next Linear Collider) or GLC (Global Linear Collider). There have been two major challenges in developing X-band accelerator structures for the linear colliders. The first is to demonstrate stable, long-term operation at the high gradient (65 MV/m) that is required to optimize the machine cost. The second is to strongly suppress the beam induced long-range wakefields, which is required to achieve high luminosity. More than thirty X-band accelerator structures with various RF parameters, cavity shapes and coupler types have been fabricated and tested since 1989. A summary of the main achievements and experiences are presented in this talk including the structure design, manufacturing techniques, high power performance, and other structure related issues. Also, the new progress in collaborating with the CLIC, high gradient structures and X-Band structure applications for RF deflectors and others are briefly introduced.

Wang, J.W.; /SLAC

2009-03-04

191

Laboratory Reagents  

SciTech Connect

Replaced by WMH-310, Section 4.17. This document outlined the basic methodology for preparing laboratory reagents used in the 222-S Standards Laboratory. Included were general guidelines for drying, weighing, transferring, dissolving, and diluting techniques common when preparing laboratory reagents and standards. Appendix A contained some of the reagents prepared by the laboratory.

CARLSON, D.D.

1999-10-08

192

Plasma Opening Switch Development for the Particle Beam Fusion Accelerator II (PBFA II)  

Microsoft Academic Search

We have conducted plasma opening switch (POS) experiments on Sandia National Laboratories' new Particle Beam Fusion Accelerator II (PBFA II) (12 MV, 100 TW, 50 ns), on the Supermite accelerator (2 MV, 2 TW, 50 ns) and on the Naval Research Laboratory's Gamble II accelerator (1.8 MV, 1.6 TW, 70 ns). The POS systems on the PBFA II and Supermite

R. W. Stinnett; D. H. Mcdaniel; G. E. Rochau; W. B. Moore; E. W. Gray; T. J. Renk; H. N. Woodall; T. W. Hussey; S. S. Payne; R. J. Commisso; J. M. Grossmann; D. D. Hinshelwood; R. A. Meger; J. M. Neri; W. F. Oliphant; P. F. Ottinger; B. V. Weber

1987-01-01

193

Accelerator Technology Program: Status report, October 1985March 1986: Volume 1  

Microsoft Academic Search

This report presents highlights of the major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. The first section details progress associated with the accelerator test stand. Following sections cover achievements in accelerator theory and simulation, LAMPF II accomplishments, and updates on BEAR, beam dynamics, the rf laboratory, p-bar gravity experiment, University of Illinois racetrack microtron,

R. A. Jameson; S. O. Schriber

1988-01-01

194

Accelerators for nuclear physics  

Microsoft Academic Search

This article describes the principal charged particle accelerators being used today for research in nuclear physics in the energy range up to about 1000 MeV. The accelerators include Van de Graaffs, sector cyclotrons and linear accelerators for both positive ions and electrons. For each type of accelerator a brief treatment is given of the recent history, operating principles, some special

D J Clark

1972-01-01

195

Future accelerator technology  

SciTech Connect

A general discussion is presented of the acceleration of particles. Upon this foundation is built a categorization scheme into which all accelerators can be placed. Special attention is devoted to accelerators which employ a wake-field mechanism and a restricting theorem is examined. It is shown how the theorem may be circumvented. Comments are made on various acceleration schemes.

Sessler, A.M.

1986-05-01

196

Accelerating machines: a review  

Microsoft Academic Search

This paper presents an overview of accelerating machines. We begin by exploring the history of the accelerating machine model and the potential power that it provides. We look at a number of computations that could be performed with an accelerating machine, and review various possible implementation methods that have been proposed. Finally, we expose the limitations of accelerating machines and

Robert Fraser; Selim G. Akl

2008-01-01

197

Development of solid-state induction modulators for high PRF accelerators  

Microsoft Academic Search

Lawrence Livermore National Laboratory (LLNL) and EG&G Energy Measurements are developing a new solid-state power system for two proposed accelerators. One of the accelerators is a circular arrangement of induction cells called a recirculator for accelerating heavy ions for inertial fusion, the other is a linear induction accelerator for electron beams called the Advanced Radiographic Machine (ARM). The need for

H. Kirbie; S. Hawkins; B. Hickman; B. Lee; M. Newton; C. Ollis; C. Brooksby; D. Gilbert; D. Longinotti; E. Eubank

1995-01-01

198

Advanced Accelerator Test Facility (AATF) upgrade plan  

SciTech Connect

We have successfully demonstrated the principles of wake-field acceleration using structures (cavity, dielectric) and plasmas as wake-field devices using the AATF at Argonne National Laboratory. Due to the limited driver electron pulse intensity and relative long pulse length, only modest accelerating gradients were observed. In order to study the wake field effects in much greater detail and demonstrate the feasibility of wake-field accelerator for high energy physics, we are considering construction of a laser photocathode injector on the existing 20 MeV Chem-Linac to produce very intense and short electron pulses. 10 refs., 5 figs.

Gai, W.; Ho, C.; Konecny, R.; Mtingwa, S.; Norem, J.; Rosenzweig, J.; Schoessow, P.; Simpson, J.; Cole, B.; Rosing, M.

1989-01-01

199

National accelerated coated conductor initiative  

NASA Astrophysics Data System (ADS)

The national Accelerated Coated Conductor Initiative (ACCI) is committed to assuring continued U.S. leadership in the development of high-temperature superconducting (HTS) wire for electric power and other applications of national interest. Increased energy efficiency, power density, and power-to-weight ratio are just a few of the tangible benefits that will be possible if today's meter lengths of HTS wire based upon the compound yttrium-barium-copper-oxygen (YBCO) can be scaled up by U.S. industry to kilometer lengths. This paper presents an evaluation of the current state of the development of coated conductor technology and a vision for its future. The challenges that U.S. Department of Energy (DOE) laboratories and their industrial and university partners face will be presented against the backdrop of the history of superconductivity program achievements. It is the purpose of this initiative to accelerate the development, commercialization, and application of high temperature superconductors through joint efforts among DOE laboratories, American industry, and universities, so that future challenges of the electric power industry can be met. Based on their advances in HTS coated conductor development in a program funded by the DOE's Office of Power Technologies, Los Alamos and Oak Ridge National Laboratories lead and support this effort by improving their own capabilities, including equipment, facilities, and technical expertise. Each laboratory has, in 2001, acquired new laboratory space, new capital equipment, and new personnel with the goal of working closely with U.S. companies to take technologies invented in the labs and demonstrated in 1-m lengths and transfer these technologies to the commercial sector. The present status of the performance of the second-generation YBCO wires will be described, and the future plans of the national laboratories will be presented. Opportunities for collaboration are discussed, as well. .

Hawsey, Robert A.; Peterson, Dean E.

2002-01-01

200

Radiation Environment and Shielding Requirements for the Sandia Particle-Beam Fusion Accelerator PBFA-II.  

National Technical Information Service (NTIS)

The Sandia National Laboratories Particle Beam Fusion Accelerator PBFA-II is expected to produce significant amounts of penetrating radiation. The present study considers a postulated operational scenario for the accelerator and determines the amount of s...

S. A. Dupree

1982-01-01

201

Model for Combined Environment Accelerated Aging Applied to a Neoprene Cable Jacketing Material.  

National Technical Information Service (NTIS)

Some results are presented of a continuing program at Sandia Laboratories whose main goal is to develop more reliable accelerated aging techniques for testing the effects of aging on materials. An interesting situation in accelerated aging occurs when two...

K. T. Gillen E. A. Salazar

1978-01-01

202

Analysis of multilayer insulation between 80K and 300K  

Microsoft Academic Search

A model has been developed that can be used to determine the temperature distribution and heat transfer through a multilayer insulation (MLI) blanket. Predictions from the model were compared with a series of temperature measurements made during laboratory experiments and during a test of five superconducting magnets (dipoles) installed in a string and tested at Fermi National Accelerator Laboratory, FNAL

S. D. Augustynowicz; J. A. Demko; V. I. Datskov

1993-01-01

203

PROPOSAL FOR AN EXPERIMENT PROGRAM IN NEUTRINO PHYSICS AND PROTON DECAY IN THE HOMESTAKE LABORATORY.  

SciTech Connect

This report is intended to describe first, the principal physics reasons for an ambitious experimental program in neutrino physics and proton decay based on construction of a series of massive water Cherenkov detectors located deep underground (4850 ft) in the Homestake Mine of the South Dakota Science and Technology Authority (SDSTA); and second, the engineering design of the underground chambers to house the Cherenkov detector modules; and third, the conceptual design of the water Cherenkov detectors themselves for this purpose. In this proposal we show the event rates and physics sensitivity for beams from both FNAL (1300 km distant from Homestake) and BNL (2540 km distant from Homestake). The program we propose will benefit with a beam from FNAL because of the high intensities currently available from the Main Injector with modest upgrades. The possibility of tuning the primary proton energy over a large range from 30 to 120 GeV also adds considerable flexibility to the program from FNAL. On the other hand the beam from BNL over the larger distance will produce very large matter effects, and consequently a hint of new physics (beyond CP violation) can be better tested with that configuration. In this proposal we focus on the CP violation physics. Included in this document are preliminary costs and time-to-completion estimates which have been exposed to acknowledged experts in their respective areas. This presentation is not, however, to be taken as a technical design report with the extensive documentation and contingency costs that a TDR usually entails. Nevertheless, some contingency factors have been included in the estimates given here. The essential ideas expressed here were first laid out in a letter of intent to the interim director of the Homestake Laboratory on July 26, 2001. Since that time, the prospect of a laboratory in the Homestake Mine has been realized, and the design of a long baseline neutrino experiment has been refined. The extrapolation contained in this proposal is within the common domain of thinking in the area of physics discussed here. It needs now only the encouragement of the funding agencies, NSF and DOE.

DIWAN, M.; KETTELL, S.; LITTENBERG, W.; MARIANO, W.; PARSA, Z.; SAMIOS, N.; WHITE, S.; ET AL.

2006-07-24

204

A portable accelerator control toolkit  

SciTech Connect

In recent years, the expense of creating good control software has led to a number of collaborative efforts among laboratories to share this cost. The EPICS collaboration is a particularly successful example of this trend. More recently another collaborative effort has addressed the need for sophisticated high level software, including model driven accelerator controls. This work builds upon the CDEV (Common DEVice) software framework, which provides a generic abstraction of a control system, and maps that abstraction onto a number of site-specific control systems including EPICS, the SLAC control system, CERN/PS and others. In principle, it is now possible to create portable accelerator control applications which have no knowledge of the underlying and site-specific control system. Applications based on CDEV now provide a growing suite of tools for accelerator operations, including general purpose displays, an on-line accelerator model, beamline steering, machine status displays incorporating both hardware and model information (such as beam positions overlaid with beta functions) and more. A survey of CDEV compatible portable applications will be presented, as well as plans for future development.

Watson, W.A. III

1997-06-01

205

Brazing techniques for side-coupled electron accelerator structures  

SciTech Connect

The collaboration between the Los Alamos National Laboratory and the National Bureau of Standards (NBS), started in 1979, has led to the development of an advanced c-w microtron accelerator design. The four 2380-MHz NBS accelerating structures, containing a total of 184 accelerating cavities, have been fabricated and delivered. New fabrication methods, coupled with refinements of hydrogen-furnace brazing techniques described in this paper, allow efficient production of side-coupled structures. Success with the NBS RTM led to Los Alamos efforts on similar 2450-MHz accelerators for the microtron accelerator operated by the Nuclear Physics Department of the University of Illinois. Two accelerators (each with 17 cavities) have been fabricated; in 1986, a 45-cavity accelerator is being fabricated by private industry with some assistance from Los Alamos. Further private industry experience and refinement of the described fabrication techniques may allow future accelerators of this type to be completely fabricated by private industry.

Hansborough, L.D.; Clark, W.L.; DePaula, R.A.; Martinez, F.A.; Roybal, P.L.; Wilkerson, L.C.; Young, L.M.

1986-01-01

206

Technologies using accelerator-driven targets under development at BNL  

SciTech Connect

Recent development work conducted at Brookhaven National Laboratory on technologies which use particle accelerator-driven targets is summarized. These efforts include development of the Spallation-Induced Lithium Conversion (SILC) Target for the Accelerator Production of Tritium (APT), the Accelerator-Driven Assembly for Plutonium Transformation (ADAPT) Target for the Accelerator-Based Conversion (ABC) of excess weapons plutonium, The PHOENIX Concept for the accelerator-driven transmutation of minor actinides and fission products from the waste stream of commercial nuclear power plants, and other potential applications.

Van Tuyle, Gregory J. [Dept. of Advanced Technologies Brookhaven National Laboratory, Upton, New York 11973 (United States)

1995-09-15

207

Acceleration of electrons using relativistic plasma waves  

NASA Astrophysics Data System (ADS)

The plasma beat-wave accelerator in the Neptune Laboratory at UCLA uses a 1 terawatt two-wavelength CO2 laser pulse to tunnel ionize hydrogen gas at conditions of resonance for driving a relativistic plasma wave. This plasma wave is used as an accelerating structure for an externally injected, 12 MeV, electron beam from the Neptune Photo-injector. The accelerated electron energy spectrum is measured using an electron spectrometer, consisting of a dipole magnet, and an array of surface barrier detectors and phosphors. Accelerated electrons have been detected out to 50 MeV using this setup. These experiments are also modeled in 2-D particle-in-cell simulations. These simulations show the self-channeling of the laser beam due to ion motion, which overcomes the defocusing caused by ionization induced refraction, effectively increasing the interaction length between the injected electrons and the plasma wave. Simulations are also performed to study the guiding of shorter (50--500 fs), but more intense, 0.8 mum laser pulses by preformed plasma channels. The three laser acceleration schemes, laser wake-field acceleration, plasma beat-wave acceleration, and self-modulated laser wake-field acceleration, are explored.

Narang, Ritesh

208

Ion sources for medical accelerators  

SciTech Connect

Advanced injector systems for proton synchrotrons and accelerator-based boron neutron capture therapy systems are being developed at the Lawrence Berkeley National Laboratory. Multicusp ion sources, particularly those driven by radio frequency, have been tested for these applications. The use of a radio frequency induction discharge provides clean, reliable, and long-life source operation. It has been demonstrated that the multicusp ion source can provide good-quality positive hydrogen ion beams with a monatomic ion fraction higher than 90{percent}. The extractable ion current densities from this type of source can meet the injector requirements for both proton synchrotron and accelerator-based boron neutron capture therapy projects. {copyright} {ital 1998 American Institute of Physics.}

Barletta, W.A.; Chu, W.T.; Leung, K.N. [Lawrence Berkeley National Laboratory, University of California, Berkeley, California94720 (United States)

1998-02-01

209

The Radiological Research Accelerator Facility  

SciTech Connect

The Radiological Research Accelerator Facility (RARAF) is based on a 4-MV Van de Graaff accelerator, which is used to generate a variety of well-characterized radiation beams for research in radiobiology, radiological physics, and radiation chemistry. It is part of the Center for Radiological Research (CRR) -- formerly the Radiological Research Laboratory (RRL) -- of Columbia University, and its operation is supported as a National Facility by the US Department of Energy (DOE). As such, RARAF is available to all potential users on an equal basis, and scientists outside the CRR are encouraged to submit proposals for experiments at RARAF. The operation of the Van de Graaff is supported by the DOE, but the research projects themselves must be supported separately. Experiments performed from May 1991--April 1992 are described.

Hall, E.J.

1992-05-01

210

The Radiological Research Accelerator Facility  

SciTech Connect

The Radiological Research Accelerator Facility (RARAF) is based on a 4-MV Van de Graaff accelerator, which is used to generate a variety of well-characterized radiation beams for research in radiobiology, radiological physics, and radiation chemistry. It is part of the Center for Radiological Research (CRR) - formerly the Radiological Research Laboratory of Columbia University, and its operation is supported as a National Facility by the US Department of Energy (DOE). As such, RARAF is available to all potential users on an equal basis and scientists outside the CRR are encouraged to submit proposals for experiments at RARAF. The operation of the Van de Graaff is supported by the DOE, but the research projects themselves must be supported separately. This report provides a listing and brief description of experiments performed at RARAF during the May 1, 1992 through April 30, 1993.

Hall, E.J.; Marino, S.A.

1993-05-01

211

Accelerated leach test development program  

SciTech Connect

In FY 1989, a draft accelerated leach test for solidified waste was written. Combined test conditions that accelerate leaching were validated through experimental and modeling efforts. A computer program was developed that calculates test results and models leaching mechanisms. This program allows the user to determine if diffusion controls leaching and, if this is the case, to make projections of releases. Leaching mechanisms other than diffusion (diffusion plus source term partitioning and solubility limited leaching) are included in the program is indicators of other processes that may control leaching. Leach test data are presented and modeling results are discussed for laboratory scale waste forms composed of portland cement containing sodium sulfate salt, portland cement containing incinerator ash, and vinyl ester-styrene containing sodium sulfate. 16 refs., 38 figs., 5 tabs.

Fuhrmann, M.; Pietrzak, R.F.; Heiser, J.; Franz, E.M.; Colombo, P.

1990-11-01

212

Laboratory microfusion capability study  

SciTech Connect

The purpose of this study is to elucidate the issues involved in developing a Laboratory Microfusion Capability (LMC) which is the major objective of the Inertial Confinement Fusion (ICF) program within the purview of the Department of Energy's Defense Programs. The study was initiated to support a number of DOE management needs: to provide insight for the evolution of the ICF program; to afford guidance to the ICF laboratories in planning their research and development programs; to inform Congress and others of the details and implications of the LMC; to identify criteria for selection of a concept for the Laboratory Microfusion Facility and to develop a coordinated plan for the realization of an LMC. As originally proposed, the LMC study was divided into two phases. The first phase identifies the purpose and potential utility of the LMC, the regime of its performance parameters, driver independent design issues and requirements, its development goals and requirements, and associated technical, management, staffing, environmental, and other developmental and operational issues. The second phase addresses driver-dependent issues such as specific design, range of performance capabilities, and cost. The study includes four driver options; the neodymium-glass solid state laser, the krypton fluoride excimer gas laser, the light-ion accelerator, and the heavy-ion induction linear accelerator. The results of the Phase II study are described in the present report.

Not Available

1993-05-01

213

EDITORIAL: Laser and plasma accelerators Laser and plasma accelerators  

NASA Astrophysics Data System (ADS)

This special issue on laser and plasma accelerators illustrates the rapid advancement and diverse applications of laser and plasma accelerators. Plasma is an attractive medium for particle acceleration because of the high electric field it can sustain, with studies of acceleration processes remaining one of the most important areas of research in both laboratory and astrophysical plasmas. The rapid advance in laser and accelerator technology has led to the development of terawatt and petawatt laser systems with ultra-high intensities and short sub-picosecond pulses, which are used to generate wakefields in plasma. Recent successes include the demonstration by several groups in 2004 of quasi-monoenergetic electron beams by wakefields in the bubble regime with the GeV energy barrier being reached in 2006, and the energy doubling of the SLAC high-energy electron beam from 42 to 85 GeV. The electron beams generated by the laser plasma driven wakefields have good spatial quality with energies ranging from MeV to GeV. A unique feature is that they are ultra-short bunches with simulations showing that they can be as short as a few femtoseconds with low-energy spread, making these beams ideal for a variety of applications ranging from novel high-brightness radiation sources for medicine, material science and ultrafast time-resolved radiobiology or chemistry. Laser driven ion acceleration experiments have also made significant advances over the last few years with applications in laser fusion, nuclear physics and medicine. Attention is focused on the possibility of producing quasi-mono-energetic ions with energies ranging from hundreds of MeV to GeV per nucleon. New acceleration mechanisms are being studied, including ion acceleration from ultra-thin foils and direct laser acceleration. The application of wakefields or beat waves in other areas of science such as astrophysics and particle physics is beginning to take off, such as the study of cosmic accelerators considered by Chen et al where the driver, instead of being a laser, is a whistler wave known as the magnetowave plasma accelerator. The application to electron--positron plasmas that are found around pulsars is studied in the paper by Shukla, and to muon acceleration by Peano et al. Electron wakefield experiments are now concentrating on control and optimisation of high-quality beams that can be used as drivers for novel radiation sources. Studies by Thomas et al show that filamentation has a deleterious effect on the production of high quality mono-energetic electron beams and is caused by non-optimal choice of focusing geometry and/or electron density. It is crucial to match the focusing with the right plasma parameters and new types of plasma channels are being developed, such as the magnetically controlled plasma waveguide reported by Froula et al. The magnetic field provides a pressure profile shaping the channel to match the guiding conditions of the incident laser, resulting in predicted electron energies of 3GeV. In the forced laser-wakefield experiment Fang et al show that pump depletion reduces or inhibits the acceleration of electrons. One of the earlier laser acceleration concepts known as the beat wave may be revived due to the work by Kalmykov et al who report on all-optical control of nonlinear focusing of laser beams, allowing for stable propagation over several Rayleigh lengths with pre-injected electrons accelerated beyond 100 MeV. With the increasing number of petawatt lasers, attention is being focused on different acceleration regimes such as stochastic acceleration by counterpropagating laser pulses, the relativistic mirror, or the snow-plough effect leading to single-step acceleration reported by Mendonca. During wakefield acceleration the leading edge of the pulse undergoes frequency downshifting and head erosion as the laser energy is transferred to the wake while the trailing edge of the laser pulse undergoes frequency up-shift. This is commonly known as photon deceleration and acceleration and is the result of a modulational instability. Simula

Bingham, Robert

2009-02-01

214

Advanced modeling of high intensity accelerators  

SciTech Connect

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goals of this project were three-fold: (1) to develop a new capability, based on high performance (parallel) computers, to perform large scale simulations of high intensity accelerators; (2) to apply this capability to modeling high intensity accelerators under design at LANL; and (3) to use this new capability to improve the understanding of the physics of intense charge particle beams, especially in regard to the issue of beam halo formation. All of these goals were met. In particular, the authors introduced split-operator methods as a powerful and efficient means to simulate intense beams in the presence of rapidly varying accelerating and focusing fields. They then applied these methods to develop scaleable, parallel beam dynamics codes for modeling intense beams in linacs, and in the process they implemented a new three-dimensional space charge algorithm. They also used the codes to study a number of beam dynamics issues related to the Accelerator Production of Tritium (APT) project, and in the process performed the largest simulations to date for any accelerator design project. Finally, they used the new modeling capability to provide direction and validation to beam physics studies, helping to identify beam mismatch as a major source of halo formation in high intensity accelerators. This LDRD project ultimately benefited not only LANL but also the US accelerator community since, by promoting expertise in high performance computing and advancing the state-of-the-art in accelerator simulation, its accomplishments helped lead to approval of a new DOE Grand Challenge in Computational Accelerator Physics.

Ryne, R.D.; Habib, S.; Wangler, T.P.

1998-11-01

215

Collective Acceleration of Ions.  

National Technical Information Service (NTIS)

The collective method for acceleration of ions is described. The problem of the formation of an electron ring cluster charged with ions, its stability and focusing, and some questions of acceleration are discussed. (Author)

A. B. Kuznetsov E. A. Parelshtein I. N. Ivanov K. A. R. Reshetnikov V. A. Preizendorf

1973-01-01

216

Acceleration of Gravity 1  

NSDL National Science Digital Library

This lab is a Level 2 inquiry activity that should be taught after students understand acceleration but before they learn the equations for calculating the acceleration of a body dropped from a certain height. After this activity, students should understa

Horton, Michael

2009-05-30

217

Accelerator Technology Division  

NASA Astrophysics Data System (ADS)

In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

1992-04-01

218

A Solid state accelerator  

SciTech Connect

We present a solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal. Acceleration gradients of order 100 GV/cm are theoretically possible, but channeling radiation limits the maximum attainable energy to 10/sup 5/ TeV for protons. Beam dechanneling due to multiple scattering is substantially reduced by the high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed.

Chen, P.; Noble, R.J.

1986-11-06

219

Acceleration: It's Elementary  

ERIC Educational Resources Information Center

Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between

Willis, Mariam

2012-01-01

220

Hig accelerator system  

Microsoft Academic Search

The design criteria and operational capabilities of the Hi-g accelerator system, a pneumatically operated device are described. The system was designed to accelerate an experiment package up the experimental tube of the Sandia Annular Core Pulse Reactor. A variety of experimental sizes can be accommodated by the system and a wide range of acceleration levels is possible.

J. P. Atencio

1976-01-01

221

Acceleration: It's Elementary  

ERIC Educational Resources Information Center

|Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between

Willis, Mariam

2012-01-01

222

Direction of Acceleration  

NSDL National Science Digital Library

In this short lab, students observe the movement of an air bubble in a small level, attached to a toy truck, as it is moved from a stop, to a steady speed and back to a stop. This gives a visual to the concepts positive acceleration, zero acceleration and negative acceleration.

Mary Spaulding, Clearbrook-Gonvick Public School, Clearbrook Minnesota, based on an original activity from Physics Principles and Problems (1995) page 75.

223

Angular Acceleration without Torque?  

ERIC Educational Resources Information Center

|Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.|

Kaufman, Richard D.

2012-01-01

224

Force, mass and acceleration  

Microsoft Academic Search

Force, mass and acceleration are everyday words but often used inaccurately. Force is a physical influence, which when applied to an object causes it to accelerate in the direction from which it was applied. Mass is the amount of matter in an object and is expressed in kilograms. Acceleration is the rate of change of velocity of an object in

Phil Dalrymple; Richard Griffiths

2005-01-01

225

Mechanical Rotary Acceleration Sensor.  

National Technical Information Service (NTIS)

The mechanical rotary acceleration device senses both acceleration and deceleration of a rotating member and responds to control switches or the like to correct the acceleration. The device is used in the field of airlaunched, towed targetry in which a co...

E. J. McQuillen

1965-01-01

226

Covariant Uniform Acceleration  

NASA Astrophysics Data System (ADS)

We derive a 4D covariant Relativistic Dynamics Equation. This equation canonically extends the 3D relativistic dynamics equation , where F is the 3D force and p = m0?v is the 3D relativistic momentum. The standard 4D equation is only partially covariant. To achieve full Lorentz covariance, we replace the four-force F by a rank 2 antisymmetric tensor acting on the four-velocity. By taking this tensor to be constant, we obtain a covariant definition of uniformly accelerated motion. This solves a problem of Einstein and Planck. We compute explicit solutions for uniformly accelerated motion. The solutions are divided into four Lorentz-invariant types: null, linear, rotational, and general. For null acceleration, the worldline is cubic in the time. Linear acceleration covariantly extends 1D hyperbolic motion, while rotational acceleration covariantly extends pure rotational motion. We use Generalized Fermi-Walker transport to construct a uniformly accelerated family of inertial frames which are instantaneously comoving to a uniformly accelerated observer. We explain the connection between our approach and that of Mashhoon. We show that our solutions of uniformly accelerated motion have constant acceleration in the comoving frame. Assuming the Weak Hypothesis of Locality, we obtain local spacetime transformations from a uniformly accelerated frame K' to an inertial frame K. The spacetime transformations between two uniformly accelerated frames with the same acceleration are Lorentz. We compute the metric at an arbitrary point of a uniformly accelerated frame. We obtain velocity and acceleration transformations from a uniformly accelerated system K' to an inertial frame K. We introduce the 4D velocity, an adaptation of Horwitz and Piron s notion of "off-shell." We derive the general formula for the time dilation between accelerated clocks. We obtain a formula for the angular velocity of a uniformly accelerated object. Every rest point of K' is uniformly accelerated, and its acceleration is a function of the observer's acceleration and its position. We obtain an interpretation of the Lorentz-Abraham-Dirac equation as an acceleration transformation from K' to K.

Friedman, Yaakov; Scarr, Tzvi

2013-04-01

227

Electron acceleration in the aurora and beyond  

Microsoft Academic Search

Duncan Bryant is a retired space plasma physicist who spent most of his career at the Rutherford-Appleton Laboratory in Oxfordshire, England. For many years he has been challenging a widely accepted theory, that auroral electrons are accelerated by double layers, on the grounds that it contains a fundamental error (allegedly, an implicit assumption that charged particles can gain energy from

K. G. McClements

1999-01-01

228

Accelerator physics at the Superconducting Super Collider  

Microsoft Academic Search

This book is a collection of lectures given at the Superconducting Super Collider Laboratory over a span of one year (from October 1, 1992 to September 30, 1993). These lectures are on varied topics covering beam dynamics, beam emittance, collective effects and beam diagnostics. These topics deal with various aspects of accelerator physics. There were twenty-six lectures presented and twenty-one

Y. T. Yan; J. P. Naples; M. J. Syphers

1995-01-01

229

Radiation safety training for accelerator facilities  

SciTech Connect

In November 1992, a working group was formed within the U.S. Department of Energy`s (DOE`s) accelerator facilities to develop a generic safety training program to meet the basic requirements for individuals working in accelerator facilities. This training, by necessity, includes sections for inserting facility-specific information. The resulting course materials were issued by DOE as a handbook under its technical standards in 1996. Because experimenters may be at a facility for only a short time and often at odd times during the day, the working group felt that computer-based training would be useful. To that end, Lawrence Livermore National Laboratory (LLNL) and Argonne National Laboratory (ANL) together have developed a computer-based safety training program for accelerator facilities. This interactive course not only enables trainees to receive facility- specific information, but time the training to their schedule and tailor it to their level of expertise.

Trinoskey, P.A.

1997-02-01

230

Biological assessments for the low energy demonstration accelerator, 1996  

SciTech Connect

This report discusses the biological impact to the area around the Los Alamos National Laboratory of the Low Energy Demonstration Accelerator. In particular the impact to the soils, water quality, vegetation, and wildlife are discussed.

Cross, S.

1997-03-01

231

Resonance Control for a CW (Continuous Wave) Accelerator.  

National Technical Information Service (NTIS)

A resonance-control technique is described that has been successfully applied to several cw accelerating structures built by the Los Alamos National Laboratory for the National Bureau of Standards and for the University of Illinois. The technique involves...

L. M. Young R. S. Biddle

1987-01-01

232

Proceedings of the Advanced Hadron Facility Accelerator Design Workshop.  

National Technical Information Service (NTIS)

The International Workshop on Hadron Facility Technology was held February 22-27, 1988, at the Study Center at Los Alamos National Laboratory. The program included papers on facility plans, beam dynamics, and accelerator hardware. The parallel sessions we...

H. A. Thiessen

1989-01-01

233

Development of an Accelerated Corrosion Test for Screening Antifreeze Compounds.  

National Technical Information Service (NTIS)

The objective of this study was to develop an accelerated laboratory corrosion test for screening all antifreeze compounds, eliminating the need to conduct the costly and time-consuming simulated service test. The results of this phase of research indicat...

J. H. Conley R. G. Jamison

1982-01-01

234

Accelerator Technology Program. Progress Report, January-December 1979.  

National Technical Information Service (NTIS)

The activities of Los Alamos Scientific Laboratory's (LASL) Accelerator Technology (AT) Division during the calendar year 1979 are highlighted, with references to more detailed reports. This report is organized around the major projects of the Division, r...

E. A. Knapp R. A. Jameson

1980-01-01

235

Accelerator Technology Program. Progress Report, July-December 1980.  

National Technical Information Service (NTIS)

The activities of Los Alamos National Laboratory's Accelerator Technology Division are discussed. This report covers the last six months of calendar 1980 and is organized around the Division's major projects. These projects reflect a wide variety of appli...

E. A. Knapp R. A. Jameson

1982-01-01

236

Plasma Accelerators Race to 10 GeV and Beyond  

Microsoft Academic Search

This paper reviews the concepts, recent progress and current challenges for realizing the tremendous electric fields in relativistic plasma waves for applications ranging from tabletop particle accelerators to high-energy physics. Experiments in the 90's on laser-driven plasma wakefield accelerators at several laboratories around the world demonstrated the potential for plasma wakefields to accelerate intense bunches of self-trapped particles at rates

Tom Katsouleas

2005-01-01

237

Brazing techniques for side-coupled electron accelerator structures  

Microsoft Academic Search

The collaboration between the Los Alamos National Laboratory and the National Bureau of Standards (NBS), started in 1979, has led to the development of an advanced c-w microtron accelerator design. The four 2380-MHz NBS accelerating structures, containing a total of 184 accelerating cavities, have been fabricated and delivered. New fabrication methods, coupled with refinements of hydrogen-furnace brazing techniques described in

L. D. Hansborough; W. L. Clark; R. A. DePaula; F. A. Martinez; P. L. Roybal; L. C. Wilkerson; L. M. Young

1986-01-01

238

Prospects of High Energy Laboratory Astrophysics  

SciTech Connect

Ultra high energy cosmic rays (UHECR) have been observed but their sources and production mechanisms are yet to be understood. We envision a laboratory astrophysics program that will contribute to the understanding of cosmic accelerators with efforts to: (1) test and calibrate UHECR observational techniques, and (2) elucidate the underlying physics of cosmic acceleration through laboratory experiments and computer simulations. Innovative experiments belonging to the first category have already been done at the SLAC FFTB. Results on air fluorescence yields from the FLASH experiment are reviewed. Proposed future accelerator facilities can provided unprecedented high-energy-densities in a regime relevant to cosmic acceleration studies and accessible in a terrestrial environment for the first time. We review recent simulation studies of nonlinear plasma dynamics that could give rise to cosmic acceleration, and discuss prospects for experimental investigation of the underlying mechanisms.

Ng, J.S.T.; Chen, P.; /SLAC

2006-09-21

239

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  

SciTech Connect

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.

Hays, Steve; Piekarz, Henryk; Pfeffer, Howie; Claypool, Brad; /Fermilab

2007-06-01

240

Steady gradually accelerating flow in a smooth open channel  

Microsoft Academic Search

Laboratory experiments on the structure of spatially accelerating flows in a smooth open channel are reported. The influence of acceleration on the bottom shear stress are investigated. The most important conclusions of the study are summarized as follows. The velocity distributions cannot be represented entirely by the universal log-law. However, this law seems to follow the data very close to

A. H. Cardoso; Walter H. Graf; G. Gust

1991-01-01

241

Steady gradually accelerating flow in a smooth open channel  

Microsoft Academic Search

Laboratory experiments on the structure of spatially accelerating flows in a smooth open channel are reported. The influences of acceleration (i) on the velocity profiles; (ii) on the turbulence intensity profiles; and (iii) on the longitudinal evolution of the bottom shear stress are investigated.The most important conclusions of the study can be summarized as follows:a. The velocity distributions cannot be

A. H. Cardoso; W. H. Graf; G. Gust

1991-01-01

242

Accelerator technology program. Progress report, July-December 1981  

Microsoft Academic Search

We report on the major projects of the Los Alamos National Laboratory's Accelerator Technology Division during the last 6 months of calendar year 1981. We have continued work on the radio-frequency quadrupole linear accelerator; we are doing studies of octupole focusing. We have completed the design study on an unusual electron-linear radiographic machine that could obtain x rays of turbine

E. A. Knapp; R. A. Jameson

1982-01-01

243

Pulsed power accelerators for particle beam fusion  

SciTech Connect

Sandia National Laboratories is completing the construction phase of the Particle Beam Fusion Accelerator-I (PBFA-I). Testing of the 36 module, 30 TW, 1 MJ output accelerator is in the initial stages. The 4 MJ, PBFA Marx generator has provided 3.6 MA into water-copper sulfate load resistors with a spread from first to last Marx firing between 15 to 25 ns and an output power of 5.7 TW. This accelerator is a modular, lower voltage, pulsed power device that is capable of scaling to power levels exceeding 100 TW. The elements of the PBFA technology and their integration into an accelerator system for particle beam fusion will be discussed.

Martin, T.H.; Barr, G.W.; VanDevender, J.P.; White, R.A.; Johnson, D.L.

1980-01-01

244

Proceedings of the 2003 Particle Accelerator Conference  

SciTech Connect

The twentieth biennial Particle Accelerator Conference on Accelerator Science and Technology was held May 12 ? 16, 2003 at the Hilton Hotel in Portland, Oregon. The Stanford Linear Accelerator Center and the Lawrence Berkeley National Laboratory organized PAC 2003, and it was held under the auspices of the Nuclear and Plasma Sciences Society of the Institute of Electrical and Electronics Engineers and the Division of Physics of Beams of the American Physical Society. The attendance was 1025 registrants from 21 countries. The Program Committee was co-chaired by Alan Jackson and Ed Lee. The program they arranged had opening and closing plenary sessions that covered the most important accomplishments, opportunities, and applications of accelerators. During the remainder of the conference there were parallel sessions with oral and poster presentations. In addition, there was an industrial exhibit during the first three days. The Proceedings present a total of 1154 papers from the invited, contributed orals, and poster sessions.

various,

2004-03-01

245

Physics Classroom: The Acceleration of Gravity  

NSDL National Science Digital Library

This tutorial introduces the concept of gravitational acceleration. This tutorial explains the notation, numerical value, and how the numerical value of the gravitational acceleration is obtained. This tutorial includes two widgets: one where one can see the strength of the acceleration of gravity from any location on Earth, and another one where one can see a comparison of the acceleration of gravity of planets in our solar system to everyday objects, and to other objects in the solar system. The tutorial also includes a pictorial example, along with the widgets, along with links to tutorials to other general Physics concepts, simulations, and student activities. This is part of The Physics Classroom. This web site also includes interactive tools to help students with concepts and problem solving, worksheets for student assignments, and recommendations for simple introductory laboratories.

Henderson, Tom

2012-04-28

246

Radio-frequency quadrupole linear accelerator  

SciTech Connect

The radio-frequency quadrupole (RFQ) is a new linear accelerator concept in which rf electric fields are used to focus, bunch, and accelerate the beam. Because the RFQ can provide strong focusing at low velocities, it can capture a high-current dc ion beam from a low-voltage source and accelerate it to an energy of 1 MeV/nucleon within a distance of a few meters. A recent experimental test at the Los Alamos Scientific Laboratory (LASL) has confirmed the expected performance of this structure and has stimulated interest in a wide variety of applications. The general properties of the RFQ are reviewed and examples of applications of this new accelerator are presented.

Wangler, T.P.; Stokes, R.H.

1980-01-01

247

High brightness electron accelerator  

DOEpatents

A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

Sheffield, Richard L. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM); Young, Lloyd M. (Los Alamos, NM)

1994-01-01

248

An introduction to acceleration mechanisms  

SciTech Connect

This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration. (LSP)

Palmer, R.B.

1987-05-01

249

Self-accelerating Warped Braneworlds  

SciTech Connect

Braneworld models with induced gravity have the potential to replace dark energy as the explanation for the current accelerating expansion of the Universe. The original model of Dvali, Gabadadze and Porrati (DGP) demonstrated the existence of a ''self-accelerating'' branch of background solutions, but suffered from the presence of ghosts. We present a new large class of braneworld models which generalize the DGP model. Our models have negative curvature in the bulk, allow a second brane, and have general brane tensions and localized curvature terms. We exhibit three different kinds of ghosts, associated to the graviton zero mode, the radion, and the longitudinal components of massive graviton modes. The latter two species occur in the DGP model, for negative and positive brane tension respectively. In our models, we find that the two kinds of DGP ghosts are tightly correlated with each other, but are not always linked to the feature of self-acceleration. Our models are a promising laboratory for understanding the origins and physical meaning of braneworld ghosts, and perhaps for eliminating them altogether.

Carena, Marcela; Lykken, Joseph; /Fermilab; Park, Minjoon; /UC, Davis; Santiago, Jose; /Fermilab

2006-11-01

250

Self-accelerating warped braneworlds  

SciTech Connect

Braneworld models with induced gravity have the potential to replace dark energy as the explanation for the current accelerating expansion of the Universe. The original model of Dvali, Gabadadze, and Porrati (DGP) demonstrated the existence of a 'self-accelerating' branch of background solutions, but suffered from the presence of ghosts. We present a new large class of braneworld models which generalize the DGP model. Our models have negative curvature in the bulk, allow a second brane, and have general brane tensions and localized curvature terms. We exhibit three different kinds of ghosts, associated to the graviton zero mode, the radion, and the longitudinal components of massive graviton modes. The latter two species occur in the DGP model, for negative and positive brane tension, respectively. In our models, we find that the two kinds of DGP ghosts are tightly correlated with each other, but are not always linked to the feature of self-acceleration. Our models are a promising laboratory for understanding the origins and physical meaning of braneworld ghosts, and perhaps for eliminating them altogether.

Carena, Marcela; Lykken, Joseph; Santiago, Jose [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois 60510 (United States); Park, Minjoon [Department of Physics, University of California, Davis, California 95616 (United States)

2007-01-15

251

Compensation techniques in accelerator physics  

NASA Astrophysics Data System (ADS)

Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

Sayed, Hisham Kamal

252

Particle-accelerator decommissioning  

SciTech Connect

Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given.

Opelka, J.H.; Mundis, R.L.; Marmer, G.J.; Peterson, J.M.; Siskind, B.; Kikta, M.J.

1979-12-01

253

Plasma inverse transition acceleration  

SciTech Connect

It can be proved fundamentally from the reciprocity theorem with which the electromagnetism is endowed that corresponding to each spontaneous process of radiation by a charged particle there is an inverse process which defines a unique acceleration mechanism, from Cherenkov radiation to inverse Cherenkov acceleration (ICA) [1], from Smith-Purcell radiation to inverse Smith-Purcell acceleration (ISPA) [2], and from undulator radiation to inverse undulator acceleration (IUA) [3]. There is no exception. Yet, for nearly 30 years after each of the aforementioned inverse processes has been clarified for laser acceleration, inverse transition acceleration (ITA), despite speculation [4], has remained the least understood, and above all, no practical implementation of ITA has been found, until now. Unlike all its counterparts in which phase synchronism is established one way or the other such that a particle can continuously gain energy from an acceleration wave, the ITA to be discussed here, termed plasma inverse transition acceleration (PITA), operates under fundamentally different principle. As a result, the discovery of PITA has been delayed for decades, waiting for a conceptual breakthrough in accelerator physics: the principle of alternating gradient acceleration [5, 6, 7, 8, 9, 10]. In fact, PITA was invented [7, 8] as one of several realizations of the new principle.

Xie, Ming

2001-06-18

254

Paleomagnetics Laboratory  

NSDL National Science Digital Library

At this website, the California Institute of Technology's Paleomagnetics Laboratory promotes its research of weakly magnetic geologic and biological materials. Users can learn about the facilities such as the biomagnetics lab and the automatic sampler. The website features the laboratory's recent research on many topics including extraterrestrial magnetism, magnetofossils, and historical geomagnetic field behavior. Visitors can find out more about the many laboratory members' research activities through links to their home pages. Researchers can download a selection of the group's publications. Everyone can enjoy the amazing images from recent geologic field trips across the globe.

255

Federal laboratories for the 21st century  

SciTech Connect

Federal laboratories have successfully filled many roles for the public; however, as the 21st Century nears it is time to rethink and reevaluate how Federal laboratories can better support the public and identify new roles for this class of publicly-owned institutions. The productivity of the Federal laboratory system can be increased by making use of public outcome metrics, by benchmarking laboratories, by deploying innovative new governance models, by partnerships of Federal laboratories with universities and companies, and by accelerating the transition of federal laboratories and the agencies that own them into learning organizations. The authors must learn how government-owned laboratories in other countries serve their public. Taiwan`s government laboratory, Industrial Technology Research Institute, has been particularly successful in promoting economic growth. It is time to stop operating Federal laboratories as monopoly institutions; therefore, competition between Federal laboratories must be promoted. Additionally, Federal laboratories capable of addressing emerging 21st century public problems must be identified and given the challenge of serving the public in innovative new ways. Increased investment in case studies of particular programs at Federal laboratories and research on the public utility of a system of Federal laboratories could lead to increased productivity of laboratories. Elimination of risk-averse Federal laboratory and agency bureaucracies would also have dramatic impact on the productivity of the Federal laboratory system. Appropriately used, the US Federal laboratory system offers the US an innovative advantage over other nations.

Gover, J. [Sandia National Labs., Albuquerque, NM (United States); Huray, P.G. [Univ. of South Carolina, Columbia, SC (United States)

1998-04-01

256

Rethinking Laboratories.  

ERIC Educational Resources Information Center

Presents an inquiry analysis tool and adaptation principles to help teachers evaluate and adapt laboratory instructional materials to be more inquiry-oriented. Based on the National Research Council's (NRC) essential features of inquiry. (NB)

Volkmann, Mark J.; Abell, Sandra K.

2003-01-01

257

Laboratory Methods  

Center for Food Safety and Applied Nutrition (CFSAN)

The FDA sets scientific standards for testing foods for various contaminants. Laboratories and food companies worldwide use these standards to make ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

258

Rethinking Laboratories  

NSDL National Science Digital Library

Although research demonstrates the value of inquiry-based science, many curriculum materials are still based on traditional approaches that fail to engage students in inquiry. Using an example of a typical cookbook laboratory--the "rusty nail," this article describes an inquiry analysis tool and adaptation principles that were created to help teachers evaluate and adapt laboratory instructional materials to be more inquiry-oriented.

Volkmann, Mark J.; Abell, Sandra K.

2003-09-01

259

Linear induction accelerator  

SciTech Connect

A linear induction accelerator of charged particles, containing inductors and an acceleration circuit, characterized by the fact that, for the purpose of increasing the power of the accelerator, each inductor is made in the form of a toroidal line with distributed parameters, from one end of which in the gap of the line a ring commutator is included, and from the other end of the ine a resistor is hooked up, is described.

Bosamykin, V.S.; Pavlovskiy, A.I.

1984-03-01

260

Linear inductive accelerator  

SciTech Connect

A proposed accelerator, differing from existing ones in that it is loaded through a capacitor on a solenoid which is uniformly distributed throughout the accelerating system and connected to an independent electrical current source, is discussed. The design of the system makes it possible to improve the uniformity of the electrical field and increase the longitudinal focusing magnetic field. This is especially important for high-current accelerators.

Bosamykin, V.S.; Gerasimov, A.I.; Pavlovskiy, A.I.

1983-11-01

261

ACCELERATION RESPONSIVE SWITCH  

DOEpatents

An acceleration-responsive device with dual channel capabilities whereby a first circuit is actuated upon attainment of a predetermined maximum acceleration level and when the acceleration drops to a predetermined minimum acceleriltion level another circuit is actuated is described. A fluid-damped sensing mass slidably mounted in a relatively frictionless manner on a shaft through the intermediation of a ball bushing and biased by an adjustable compression spring provides inertially operated means for actuating the circuits. (AEC)

Chabrek, A.F.; Maxwell, R.L.

1963-07-01

262

Accelerated cleanup risk reduction  

SciTech Connect

There is no proven technology for remediating contaminant plume source regions in a heterogeneous subsurface. This project is an interdisciplinary effort to develop the requisite new technologies so that will be rapidly accepted by the remediation community. Our technology focus is hydrous pyrolysis/oxidation (HPO) which is a novel in situ thermal technique. We have expanded this core technology to leverage the action of steam injection and place an in situ microbial filter downstream to intercept and destroy the accelerated movement of contaminated groundwater. Most contaminant plume source regions, including the chlorinated solvent plume at LLNL, are in subsurface media characterized by a wide range in hydraulic conductivity. At LLNL, the main conduits for contaminant transport are buried stream channels composed of gravels and sands; these have a hydraulic conductivity in the range of 10{sup -1} to 10{sup -2} cm/s. Clay and silt units with a hydraulic conductivity of 10{sup -1} to 10{sup -6} cm/s bound these buried channels; these are barriers to groundwater movement and contain the highest contaminant concentrations in the source region. New remediation technologies are required because the current ones preferentially access the high conductivity units. HPO is an innovative process for the in situ destruction of contaminants in the entire subsurface. It operates by the injection of steam. We have demonstrated in laboratory experiments that many contaminants rapidly oxidize to harmless compounds at temperatures easily achieved by injecting steam, provided sufficient dissolved oxygen is present. One important challenge in a heterogeneous source region is getting heat, contaminants, and an oxidizing agent in the same place at the same time. We have used the NUFT computer program to simulate the cyclic injection of steam into a contaminated aquifer for design of a field demonstration. We used an 8 hour, steam/oxygen injection cycle followed by a 56 hour relaxation period in which the well was `capped`. Our results show the formation of an inclined gas phase during injection and a fast collapse of the steam zone within an hour of terminating steam injection. The majority of destruction occurs during the collapse phase, when contaminant laden water is drawn back towards the well. Little to no noncondensible gasses are created in this process, removing any possibility of sparging processes interfering with contaminant destruction. Our models suggest that the thermal region should be as hot and as large as possible. To have HPO accepted, we need to demonstrate the in situ destruction of contaminants. This requires the ability to inexpensively sample at depth and under high temperatures. We proved the ability to implies monitoring points at depths exceeding 150 feet in highly heterogeneous soils by use of cone penetrometry. In addition, an extractive system has been developed for sampling fluids and measuring their chemistry under the range of extreme conditions expected. We conducted a collaborative field test of HPO at a Superfund site in southern California where the contaminant is mainly creosote and pentachlorophenol. Field results confirm the destruction of contaminants by HPO, validate our field design from simulations, demonstrate that accurate field measurements of the critical fluid parameters can be obtained using existing monitoring wells (and minimal capital cost) and yield reliable cost estimates for future commercial application. We also tested the in situ microbial filter technology as a means to intercept and destroy the accelerated flow of contaminants caused by the injection of steam. A series of laboratory and field tests revealed that the selected bacterial species effectively degrades trichloroethene in LLNL Groundwater and under LLNL site conditions. In addition, it was demonstrated that the bacteria effectively attach to the LLNL subsurface media. An in-well treatability study indicated that the bacteria initially degrade greater than 99% of the contaminant, to concentrations less than regulatory limit

Knapp, R.B.; Aines, R.M.; Blake, R.G.; Copeland, A.B.; Newmark, R.L.; Tompson, A.F.B.

1998-02-01

263

FFAGS FOR MUON ACCELERATION.  

SciTech Connect

Due to their finite lifetime, muons must be accelerated very rapidly. It is challenging to make the magnets ramp fast enough to accelerate in a synchrotron, and accelerating in a linac is very expensive. One can use a recirculating accelerator (like CEBAF), but one needs a different arc for each turn, and this limits the number of turns one can use to accelerate, and therefore requires significant amounts of RF to achieve the desired energy gain. An alternative method for muon acceleration is using a fixed field alternating gradient (FFAG) accelerator. Such an accelerator has a very large energy acceptance (a factor of two or three), allowing one to use the same arc with a magnetic field that is constant over time. Thus, one can in principle make as many turns as one can tolerate due to muon decay, therefore reducing the RF cost without increasing the arc cost. This paper reviews the current status of research into the design of FFAGs for muon acceleration. Several current designs are described and compared. General design considerations are also discussed.

BERG,J.S.KAHN,S.PALMER,R.TRBOJEVIC,D.JOHNSTONE,C.KEIL,Y.OGITSU,T.OHMORI,C.SESSLER,A.KOSCIELNIAK,S.

2003-06-26

264

Accelerator Technology Program. Status report, April-September 1985  

SciTech Connect

This report presents highlights of major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. Radio-frequency and microwave technology are dealt with. The p-bar gravity experiment, accelerator theory and simulation activities, the Proton Storage Ring, and the Fusion Materials Irradiation Test accelerator are discussed. Activities on the proposed LAMPF II accelerator, the BEAR (Beam Experiment Aboard Rocket) project, beam dynamics, the National Bureau of Standards racetrack microtron, and the University of Illinois racetrack microtron are covered. Papers published by AT-Division personnel during this reporting period are listed.

Jameson, R.A.; Schriber, S.O. (comps.)

1986-09-01

265

Acceleration of polarized protons in circular accelerators  

SciTech Connect

The theory of depolarization in circular accelerators is presented. The spin equation is first expressed in terms of the particle orbit and then converted to the equivalent spinor equation. The spinor equation is then solved for three different situations: (1) a beam on a flat top near a resonance, (2) uniform acceleration through an isolated resonance, and (3) a model of a fast resonance jump. Finally, the depolarization coefficient, epsilon, is calculated in terms of properties of the particle orbit and the results are applied to a calculation of depolarization in the AGS.

Courant, E.D.; Ruth, R.D.

1980-09-12

266

Compact accelerator concept for proton therapy  

NASA Astrophysics Data System (ADS)

A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is being developed as a compact flash X-ray radiography source. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be presented.

Caporaso, G. J.; Sampayan, S.; Chen, Y.-J.; Harris, J.; Hawkins, S.; Holmes, C.; Krogh, M.; Nelson, S.; Nunnally, W.; Paul, A.; Poole, B.; Rhodes, M.; Sanders, D.; Selenes, K.; Sullivan, J.; Wang, L.; Watson, J.

2007-08-01

267

What can we expect from future accelerators  

SciTech Connect

This talk covers a general but highly subjective overview of the expectation for new accelerator development. An updated version of the Livingston chart demonstrates the exponential growth in time of the equivalent laboratory energy of accelerators. A similar Livingston chart pertaining only to electron-positron colliders shows an exponential growth but in the past only one technology - electron-positron storage rings - have been responsible for this development. The question addressed is whether the type of exponential growth reflected by these two charts can be sustained in the future.

Panofsky, W.K.H.

1984-06-01

268

Estimating the Reliability of the Lawrence Livermore National Laboratory (LLNL) Flash X-ray (FXR) Machine.  

National Technical Information Service (NTIS)

At Lawrence Livermore National Laboratory (LLNL), our flash X-ray accelerator (FXR) is used on multi-million dollar hydrodynamic experiments. Because of the importance of the radiographs, FXR must be ultrareliable. Flash linear accelerators that can gener...

B. R. Kreitzer J. M. Zentler M. M. Ong R. Kihara W. J. DeHope

2007-01-01

269

Resource Letter AFHEP-1: Accelerators for the Future of High-Energy Physics  

NASA Astrophysics Data System (ADS)

This Resource Letter provides a guide to literature concerning the development of accelerators for the future of high-energy physics. Research articles, books, and Internet resources are cited for the following topics: motivation for future accelerators, present accelerators for high-energy physics, possible future machine, and laboratory and collaboration websites.

Barletta, William A.

2012-02-01

270

Understanding particle acceleration at supernova shocks  

NASA Astrophysics Data System (ADS)

One century after the pioneering discovery of cosmic rays by V. Hess, the present generation of X- and gamma-ray telescopes is finally unravelling the origin of such an extraterrestrial radiation, at least for what concerns particles with energies below 10^8 GeV, which are thought to be accelerated at the forward shocks of Galactic supernova remnants (SNRs). I discuss the present theoretical understanding of efficient particle acceleration at non-relativistic, collisionless shocks, addressing with both analytical and numerical (particle-in-cell) techniques the crucial interplay between accelerated ions and magnetic turbulence. In SNRs, in fact, magnetic fields turn out to be a factor of 10-100 larger than in the interstellar medium, because of plasma instabilities triggered by energetic particles. In particular, I show 2D and 3D hybrid (fluid electrons - kinetic ions) simulations of non-relativistic collisionless shocks, pointing out the efficiency of Fermi acceleration and the role of the cosmic-ray-induced filamentation instability in amplifying the magnetic field up to the levels inferred at the blast waves of young Galactic remnants. Finally, I outline the observational counterparts of such a theory of particle acceleration at strong shocks in terms of SNR multi-wavelength emission, with a special attention to Tycho's SNR, arguably the best laboratory where to test hadron acceleration.

Caprioli, Damiano

2013-04-01

271

A REVIEW OF METHODS FOR DEVELOPING ACCELERATED TESTING CRITERIA  

Microsoft Academic Search

Accelerated vibration testing seeks to compress long service exposures to vibration into a reduced length laboratory test by increasing the amplitude and\\/or frequency of the applied inputs during the laboratory test relative to the amplitude and\\/or frequency experienced during service. This testing procedure provides an important tool that can reduce testing time associated with a new design and reduce time

Charles R. Farrar; Thomas A. Duffey; Phillip J. Cornwell; Matthew T. Bement

272

TOPICAL REVIEW: Plasma based charged-particle accelerators  

NASA Astrophysics Data System (ADS)

Studies of charged-particle acceleration processes remain one of the most important areas of research in laboratory, space and astrophysical plasmas. In this paper, we present the underlying physics and the present status of high gradient and high energy plasma accelerators. We will focus on the acceleration of charged particles to relativistic energies by plasma waves that are created by intense laser and particle beams. The generation of relativistic plasma waves by intense lasers or electron beams in plasmas is important in the quest for producing ultra-high acceleration gradients for accelerators. With the development of compact short pulse high brightness lasers and electron positron beams, new areas of studies for laser/particle beam-matter interactions is opening up. A number of methods are being pursued vigorously to achieve ultra-high acceleration gradients. These include the plasma beat wave accelerator mechanism, which uses conventional long pulse (~100 ps) modest intensity lasers (I ~ 1014-1016 W cm-2), the laser wakefield accelerator (LWFA), which uses the new breed of compact high brightness lasers (<1 ps) and intensities >1018 W cm-2, the self-modulated LWFA concept, which combines elements of stimulated Raman forward scattering, and electron acceleration by nonlinear plasma waves excited by relativistic electron and positron bunches. In the ultra-high intensity regime, laser/particle beam-plasma interactions are highly nonlinear and relativistic, leading to new phenomena such as the plasma wakefield excitation for particle acceleration, relativistic self-focusing and guiding of laser beams, high-harmonic generation, acceleration of electrons, positrons, protons and photons. Fields greater than 1 GV cm-1 have been generated with particles being accelerated to 200 MeV over a distance of millimetre. Plasma wakefields driven by positron beams at the Stanford Linear Accelerator Center facility have accelerated the tail of the positron beam. In the near future, laser plasma accelerators will be producing GeV particles.

Bingham, R.; Mendona, J. T.; Shukla, P. K.

2004-01-01

273

Laboratory directed research and development  

SciTech Connect

The purposes of Argonne's Laboratory Directed Research and Development (LDRD) Program are to encourage the development of novel concepts, enhance the Laboratory's R D capabilities, and further the development of its strategic initiatives. Among the aims of the projects supported by the Program are establishment of engineering proof-of-principle''; development of an instrumental prototype, method, or system; or discovery in fundamental science. Several of these project are closely associated with major strategic thrusts of the Laboratory as described in Argonne's Five Year Institutional Plan, although the scientific implications of the achieved results extend well beyond Laboratory plans and objectives. The projects supported by the Program are distributed across the major programmatic areas at Argonne. Areas of emphasis are (1) advanced accelerator and detector technology, (2) x-ray techniques in biological and physical sciences, (3) advanced reactor technology, (4) materials science, computational science, biological sciences and environmental sciences. Individual reports summarizing the purpose, approach, and results of projects are presented.

Not Available

1991-11-15

274

Accelerating the Development of Hardware Accelerators  

Microsoft Academic Search

ASC (1), A Stream Compiler, is designed to enable rapid development of hardware accelerators while still producing results that match hand-crafted equivalents. An ASC pro- gram represents a dataflow system which can be seen as a stream; to avoid the difficulties often associated with be- havioural synthesis, ASC allows direct implementation of a hardware design based on the programmer's input.

Lee W. Howes; Oliver Pell; Oskar Mencer; Olav Beckmann

275

Larp Nb3Sn Quadrupole Magnets for the Lhc Luminosity Upgrade  

Microsoft Academic Search

The US LHC Accelerator Research Program (LARP) is a collaboration between four US laboratories (BNL, FNAL, LBNL, and SLAC) aimed at contributing to the commissioning and operation of the LHC and conducting R&D on its luminosity upgrade. Within LARP, the Magnet Program's main goal is to demonstrate that Nb3Sn superconducting magnets are a viable option for a future upgrade of

P. Ferracin

2010-01-01

276

Analysis of ER string test thermally instrumented interconnect 80-K MLI blanket.  

National Technical Information Service (NTIS)

An 80-K Multi Layer Insulation (MLI) blanket in the interconnect region between magnets DD0019 and DD0027 in the Fermi National Accelerator Laboratory (FNAL) ER string was instrumented with temperature sensors to obtain the steady-state temperature gradie...

E. Daly R. Pletzer

1992-01-01

277

Accelerator Toolbox for MATLAB.  

National Technical Information Service (NTIS)

This paper introduces Accelerator Toolbox (AT) - a collection of tools to model particle accelerators and beam transport lines in the MATLAB environment. At SSRL, it has become the modeling code of choice for the ongoing design and future operation of the...

A. Terebilo

2001-01-01

278

Accelerators for energy production  

NASA Astrophysics Data System (ADS)

A tremendous progress of accelerators for these several decades, has been motivated mainly by the research on subnuclear physics. The culmination in high energy accelerators might be SSC, 20 TeV collider in USA, probably the ultimate accelerator being built with the conventional principle. The technology cultivated and integrated for the accelerator development, can now stably offer the high power beam which could be used for the energy problems. The Inertial Confinement Fusion (ICF) with high current, 10 kA and short pulse, 20 ns heavy ion beam (HIB) of mass number approximately 200, would be the most promising application of accelerators for energy production. In this scenario, the fuel containing D-T mixture, will be compressed to the high temperature, approximately 10 keV and to the high density state, approximately 1000 times the solid density with the pressure of ablative plasma or thermal X ray produced by bombarding of high power HIB. The efficiency, beam power/electric power for accelerator, and the repetition rate of HIB accelerators could be most suitable for the energy production. In the present paper, the outline of HIB ICF (HIF) is presented emphasizing the key issues of high current heavy ion accelerator system.

Katayama, Takeshi

1993-11-01

279

KEK digital accelerator  

NASA Astrophysics Data System (ADS)

The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

2011-07-01

280

Review of Accelerator Alignment  

Microsoft Academic Search

SUMMARY The history of twentieth century science and technology is intimately tied to the development of particle accelerators and the discoveries made using them. Today the breadth of science concerned by, and studied using particle accelerators is truly staggering. It ranges from attempts to understand the origin of our universe and what constitutes matter and radiation; to questions concerning the

David MARTIN

2010-01-01

281

Neutrino physics at accelerators  

Microsoft Academic Search

Present and future neutrino experiments at accelerators are mainly concerned with understanding the neutrino oscillation phenomenon and its implications. Here a brief account of neutrino oscillations is given together with a description of the supporting data. Some current and planned accelerator neutrino experiments are also explained. Neutrinos are particles that interact only weakly and this gives them a somewhat special

Enrique Fernandez

282

Twisted waveguide accelerating structure..  

National Technical Information Service (NTIS)

A hollow waveguide with a uniform cross section may be used for accelerating charged particles if the phase velocity of an accelerating mode is equal to or less than the fiee space speed of light. Regular straight hollow waveguides have phase velocities o...

Y. W. Kang

2000-01-01

283

Accelerators (3/5)  

ScienceCinema

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

284

Accelerators (4/5)  

ScienceCinema

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

285

Accelerators (5/5)  

ScienceCinema

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

286

Accelerators Beyond The Tevatron?  

SciTech Connect

Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?.

Lach, Joseph [Fermi National Accelerator Laboratory, P.O Box 500, Batavia Illinois (United States)

2010-07-29

287

Ion Induction Accelerators  

NASA Astrophysics Data System (ADS)

The description of beams in RF and induction accelerators share many common features. Likewise, there is considerable commonality between electron induction accelerators (see Chap. 7) and ion induction accelerators. However, in contrast to electron induction accelerators, there are fewer ion induction accelerators that have been operated as application-driven user facilities. Ion induction accelerators are envisioned for applications (see Chap. 10) such as Heavy Ion Fusion (HIF), High Energy Density Physics (HEDP), and spallation neutron sources. Most ion induction accelerators constructed to date have been limited scale facilities built for feasibility studies for HIF and HEDP where a large numbers of ions are required on target in short pulses. Because ions are typically non-relativistic or weakly relativistic in much of the machine, space-charge effects can be of crucial importance. This contrasts the situation with electron machines, which are usually strongly relativistic leading to weaker transverse space-charge effects and simplified longitudinal dynamics. Similarly, the bunch structure of ion induction accelerators relative to RF machines results in significant differences in the longitudinal physics.

Barnard, John J.; Horioka, Kazuhiko

288

Acceleration of Gravity 2  

NSDL National Science Digital Library

This lab is between a Level 2 and Level 3 inquiry activity in that it should be assigned after students understand acceleration but before they learn about the acceleration gravity. Because there are many sources of error when using a pendulum, students c

Horton, Michael

2009-05-30

289

Exploring acceleration through vectors  

NSDL National Science Digital Library

This in class worksheet is designed to get students to think about and manipulate different accelerations in their head. Students work together with written descriptions of velocity and acceleration and draw the vectors in part one, and then turn that around in part two where they write descriptions of a car's motion based on the vector pictures they are given.

290

Brookhaven National Laboratory: Chemistry Department  

NSDL National Science Digital Library

At this website, the Brookhaven National Laboratory presents its chemistry research dealing primarily with imaging and neuroscience, charge transfer for energy conversion, chemistry with ionizing radiation, catalysis and surface science, nanoscience, combustion, and nuclear chemistry. Within each category, users can find instructive text and supportive images about the specific projects and the leading researchers. Visitors can learn about the Beamline U7A at the National Synchrotron Light Source, the Laser-Electron Accelerator Facility (LEAF), the Positron Emission Tomography (PET) Facility, and other exceptional research facilities. The website features histories of the chemistry department and of the Brookhaven National Laboratory.

291

The principle of phase stability and the accelerator program at Berkeley, 1945--1954  

SciTech Connect

The discovery of the Principle of Phase Stability by Vladimir Veksler and Edwin McMillian and the end of the war released a surge of accelerator activity at the Lawrence Berkeley Laboratory (then The University of California Radiation Laboratory). Six accelerators incorporating the Principle of Phase Stability were built in the period 1945--1954.

Lofgren, E.J.

1994-07-01

292

Open accelerating structures  

SciTech Connect

An ''Open'' Accelerating Structure must first perform the mode matching function of any accelerating structure, i.e., it must couple an incoming free field to an accelerating mode. The simplest open periodic structure that can be considered is a grating. There has been an attempt to employ an inverse Purcell effect by illuminating a grating from directly above with plane parallel light and passing the particles over the surface of the grating at right angles to the lines. Unfortunately, it has been shown by the Lawson theorem that these geometries fail to accelerate relativistic particles. This paper will restate Lawson's theorem but show that it applies only to the simple two-dimensional situation. It is shown that accelerating fields above grating can be made to fall off exponentially from that surface. Several structures are examined that deal with the problem of fields spreading over the whole grating surface.

Palmer, R.B.

1986-12-01

293

Teaching and Research with Accelerators at Tarleton State University  

NASA Astrophysics Data System (ADS)

Tarleton State University students began performing both research and laboratory experiments using accelerators in 1998 through visitation programs at the University of North Texas, US Army Research Laboratory, and the Naval Surface Warfare Center at Carderock. In 2003, Tarleton outfitted its new science building with a 1 MV pelletron that was donated by the California Institution of Technology. The accelerator has been upgraded and supports a wide range of classes for both the Physics program and the ABET accredited Engineering Physics program as well as supplying undergraduate research opportunities on campus. A discussion of various laboratory activities and research projects performed by Tarleton students will be presented.

Marble, Daniel K.

2009-03-01

294

Laboratory Buildings.  

ERIC Educational Resources Information Center

The need for flexibility in science research facilities is discussed, with emphasis on the effect of that need on the design of laboratories. The relationship of office space, bench space, and special equipment areas, and the location and distribution of piping and air conditioning, are considered particularly important. This building type study

Barnett, Jonathan

295

Upgrade of Fermilab/NICADD photoinjector laboratory  

SciTech Connect

The Fermilab/NICADD photoinjector laboratory is a 16 MeV electron accelerator dedicated to beam dynamics and advanced accelerator physics studies. FNPL will soon be capable of operating at {approx} 40 MeV, after the installation of a high gradient TESLA cavity. In this paper we present the foreseen design for the upgraded facility along with its performance. We discuss the possibilities of using of FNPL as an injector for the superconducting module and test facility (SM&TF).

Piot, P.; Edwards, H.; /Fermilab; Huning, M.; /DESY; Li, J.; Tikhoplav, R.; /Rochester U.; Koeth, T.; /Rutgers U., Piscataway

2005-05-01

296

Argonne's Laboratory Computing Resource Center : 2005 annual report  

Microsoft Academic Search

Argonne National Laboratory founded the Laboratory Computing Resource Center in the spring of 2002 to help meet pressing program needs for computational modeling, simulation, and analysis. The guiding mission is to provide critical computing resources that accelerate the development of high-performance computing expertise, applications, and computations to meet the Laboratory's challenging science and engineering missions. The first goal of the

R. B. Bair; S. C Coghlan; D. K. Kaushik; K. R. Riley; J. V. Valdes; G. P. Pieper

2007-01-01

297

Materials for Accelerator Technologies Beyond the Niobium Family  

SciTech Connect

Three niobium-based materials make up the entire present portfolio of superconducting technology for accelerators: Nb-Ti and Nb{sub 3}Sn magnet wires and pure niobium for RF cavities. Because these materials are at a high level of maturity, limits imposed by the boundaries of their superconductivity constrain the energy reach of accelerators to several TeV. We sketch here a plan for targeted development of emerging higher field and higher temperature superconductors that could enable accelerators at significantly higher energies. Niobium-based superconductors are the crucial enablers of present accelerators. The Nb-Ti LHC dipole and quadrupole wires, with transition temperature T{sub c} of 9 K and upper critical field H{sub c2} of 15 T, represent the highest form of superconductor strand art: massive, quarter-ton conductor billets are drawn from 300 mm diameter to {approx}1 mm as a single, multi-kilometer-long piece, while retaining uniformity of the several thousand Nb-Ti filaments to within 5% at the scale of a few micrometers. Strands are twisted into fully transposed cables with virtually no loss, preserving a carefully tuned nanostructure that generates the high flux-pinning forces and high current densities to enable high magnetic fields. Nb{sub 3}Sn, with twice the T{sub c} and H{sub c2}, is now approaching this level of conductor art, where over the last 5 years the LHC Accelerator Research Program (LARP) and the Next European Dipole (NED) program have demonstrated that Nb{sub 3}Sn can be made into 4 meter long quadrupoles with 12 T fields and 250 T/m gradients. Linear accelerators at TJNAF, ORNL (SNS), and under construction for the European XFEL exploit niobium superconducting radio-frequency (SRF) technology, with gradients at {approx}20 MV/m. Tremendous research and development is underway to realize high-power goals for Project X at FNAL and for a possible ILC at 35 MV/m gradients. Despite these impressive achievements, the very maturity of these niobium-based technologies makes them incapable of additional leaps from the several-TeV scale. Nb-Ti is already nearly perfect and operates at the limit of the superconducting phase. Further perfection of Nb cavities and Nb{sub 3}Sn magnets might provide 50 % growth in energy, based on proof-of-principle demonstrations that approach theoretical limits, e.g. 52 MV/m gradient in re-entrant Nb cavities and 18 T dipoles made from Nb3Sn strand. However, operation close to superconducting margins is risky, and cost tradeoffs to execute such a high degrees of perfection are likely to be negative.

Cooley, Lance; Larbalestier, David; Ghosh, Arup; Tollestrup, Alvin; /Fermilab

2009-01-01

298

Proceedings of: 2005 Particle Acceleration Confence  

SciTech Connect

The 21st Particle Accelerator Conference, PAC05, took place at the Knoxville Convention Center (KCC) from Monday through Friday, May 16-20, 2005. Sponsored by the American Physical Society (APS), the Institute of Electrics and Electronics Engineers (IEEE) with its subdivision of Nuclear and Plasma Sciences Society (NPSS), the conference was hosted by the Oak Ridge National Laboratory (ORNL) Spallation Neutron Source (SNS) Project and Thomas Jefferson National Accelerator Facility (JLab). The conference was chaired by Norbert Holtkamp, and the Local Organizing Committee was made up of staff from the ORNL SNS Project under the chairmanship of Stuart Henderson. The conference welcomed over 1400 delegates from the United States, Europe, Asia, the Middle East, South America and from as far away as Australia. Almost 1400 papers where processed during the conference and will be published on the Joint Accelerator Conferences Website (JACoW) page.

Henderson, Stuart

2006-01-01

299

Clinical requirements and accelerator concepts for BNCT  

SciTech Connect

Accelerator-based neutron sources are an attractive alternative to nuclear reactors for providing epithermal neutron beams for Boron Neutron Capture Therapy. Based on clinical requirements and neutronics modeling the use of proton and deuteron induced reactions in {sup 7}Li and {sup 9}Be targets has been compared. Excellent epithermal neutron beams can be produced via the {sup 7}Li(p,n){sup 7}Be reaction at proton energies of {approximately}2.5 MeV. An electrostatic quadrupole accelerator and a lithium target, which can deliver and handle 2.5 MeV protons at beam currents up to 50 mA, are under development for an accelerator-based BNCT facility at the Lawrence Berkeley National Laboratory.

Ludewigt, B.A.; Bleuel, D.L.; Chu, W.T.; Donahue, R.J.; Kwan, J.; Leung, K.N.; Reginato, L.L.; Wells, R.P.

1997-05-01

300

Accelerator for the production of tritium (APT)  

SciTech Connect

A collaborative study by Los Alamos and Brookhaven National Laboratories, supported by the Westinghouse Hanford Company, investigating a facility to produce tritium for the nation's defense needs indicates that a 1.6-GeV, 250-mA proton accelerator is required. A reference design of this accelerator starts with two parallel 125-keV injectors feeding 350-MHz radio-frequency quadrupoles (RFQ) that funnel at 2.5 MeV into a 700-MHz drift-tube linac (DTL). The DTL injects at 100 MeV into a 1400-MHz side-coupled linac (SCL). The accelerator will cost about $1.2 B and require 746 MW of electricity. 3 refs., 3 tabs.

Wilson, M.T.; Bhatia, T.S.; Guy, F.W.; Neuschaefer, G.H.; Wangler, T.P.; Young, L.M.

1989-01-01

301

The EMMA Accelerator, a Diagnostic Systems Overview  

SciTech Connect

The 'EMMA' Non-Scaling Fixed Field Alternating Gradient (ns-FFAG) international project is currently being commissioned at Daresbury Laboratory, UK. This accelerator has been equipped with a number of diagnostic systems to facilitate this. These systems include a novel time-domain-multiplexing BPM system, moveable screen systems, a time-of-flight instrument, Faraday cups, and injection/extraction tomography sections to analyze the single bunch beams. An upgrade still to implement includes the installation of wall current monitors. This paper gives an overview of these systems and shows some data and results from the diagnostics that have contributed to the successful demonstration of a serpentine acceleration by this novel accelerator.

Kalinin, A.; Berg, J.; Bliss, N. Cox, G.; Dufau, M.; Gallagher, A.; Hill, C.; Jones, J.; Ma, L.; McIntosh, P.; Muratori, B.; Oates, A.; Shepherd B.; Smith, R.; Hock, K.; Holder, D.; Ibison, M., Kirkman I.; Borrell, R.; Crisp, J.; Fellenz, B.; Wendt, M.

2011-09-04

302

Large electrostatic accelerators  

SciTech Connect

The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

Jones, C.M.

1984-01-01

303

Shock experiments with magnetically accelerated flyer plates  

NASA Astrophysics Data System (ADS)

The interaction of shock waves with inhomogeneous media is important in many astrophysical phenomena. Modelling these phenomena in the laboratory yields additional information to improve both simulations and the interpretation of astrophysical observations. Scaled experiments using magnetically accelerated flyers impacting on low density foam targets have been proposed for the Z machine at the Sandia National Laboratories (R.P. Drake, Phys. Plasmas 2002). Carrying out such experiments on smaller machines like the UNR pulsed power generator Zebra reduces the costs significantly and thus enables a broader scan of experimental parameters. Our experiments at the Nevada Terawatt Facility study the flyer acceleration (reaching flyer velocities of up to 5 km/s) and the impact of the flyers on transparent targets with low sound speeds in order to create shock waves. Optical diagnostics are used to study the interaction of the flyers with the transparent target.

Neff, Stephan; Wright, Sandra; Martinez, David; Plechaty, Christopher; Presura, Radu

2008-11-01

304

Dogbone geometry for recirculating accelerators.  

National Technical Information Service (NTIS)

Most scenarios for accelerating muons require recirculating acceleration. A racetrack shape for the accelerator requires particles with lower energy in early passes to traverse almost the same length of arc as particles with the highest energy. This extra...

S. Berg Johnstone Summers

2001-01-01

305

Twisted waveguide accelerating structure.  

SciTech Connect

A hollow waveguide with a uniform cross section may be used for accelerating charged particles if the phase velocity of an accelerating mode is equal to or less than the free space speed of light. Regular straight hollow waveguides have phase velocities of propagating electromagnetic waves greater than the free-space speed of light. if the waveguide is twisted, the phase velocities of the waveguide modes become slower. The twisted waveguide structure has been modeled and computer simulated in 3-D electromagnetic solvers to show the slow-wave properties for the accelerating mode.

Kang, Y. W.

2000-08-15

306

Advanced Accelerator Concepts  

NASA Astrophysics Data System (ADS)

Current particle accelerators rely on conventional or superconducting radio frequency cavities to accelerate beams of protons or electrons for nuclear and particle research and for medical and materials science studies. New methods for achieving larger accelerating gradients have been proposed and are being studied. These include the use of high power lasers, laser driven plasmas, wake fields generated by intense low energy beams, and millimeter wavelength EM structures. The studies to date, and the prospects for practical applications of these new ideas will be discussed.

Siemann, Robert

1998-04-01

307

Lunar laboratory  

SciTech Connect

An international research laboratory can be established on the Moon in the early years of the 21st Century. It can be built using the transportation system now envisioned by NASA, which includes a space station for Earth orbital logistics and orbital transfer vehicles for Earth-Moon transportation. A scientific laboratory on the Moon would permit extended surface and subsurface geological exploration; long-duration experiments defining the lunar environment and its modification by surface activity; new classes of observations in astronomy; space plasma and fundamental physics experiments; and lunar resource development. The discovery of a lunar source for propellants may reduce the cost of constructing large permanent facilities in space and enhance other space programs such as Mars exploration. 29 refs.

Keaton, P.W.; Duke, M.B.

1986-01-01

308

Deuterium accelerator experiments for APT.  

SciTech Connect

Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

2005-08-01

309

Laboratory reverie.  

PubMed

As a general rule, HMN believes you should avoid making the laboratory business separate from the practice and should maintain the lab technician on the same footing as the rest of the staff with regard to working hours and salary. However, this does not apply to every practice. Sometimes there are distinct advantages to channeling money out of your practice. The discussion above will help you to evaluate your individual situation. PMID:8059764

1994-08-01

310

Portable radiography using linear accelerators  

SciTech Connect

There are numerous instances where the availability of a portable high-energy radiography machine that could be transported to the inspection site with relative ease would save time, money, and make radiography of permanent installations, such as bridges, possible. One such machine, the Minac built by Schoenberg Radiation Inc., is commercially available. It operates at 9.3 GHz, has an electron energy on target of 3.5 MeV, and an output dose rate of 100 R/min. A second portable accelerator, recently completed at the Los Alamos National Laboratory, operates at 2.998 GHz, has electron energies on target of 6, 8, and 10 MeV, and an output dose rate of 800 R/min at 8 MeV. This paper discusses the need for and applications of portable accelerators for radiography. Physical characteristics and beam parameters of both machines are examined in detail. Problems of operating at higher frequencies to further minimize size and weight are discussed.

Reid, D.W.

1984-01-01

311

Acceleration cueing simulation device  

US Patent & Trademark Office Database

An acceleration cueing simulation device is disclosed for applying sustai, as well as dynamic, acceleration forces to a trainee pilot as he operates an aircraft simulator. The acceleration cueing device comprises a pair of Helmholtz coils for generating a uniform magnetic field; an aircraft control device for generating a control data signal which is responsive to simulated flight maneuvers performed by the trainee pilot; and a computer system for producing a plurality of digital logic signals which are in response to the control data signal. The plurality of digital logic signals, when converted to analog signals, will energize a plurality of coils which are embedded in a suit and a helmet worn by the trainee pilot. When the trainee pilot is within the magnetic field generated by the Helmholtz coils, the coils embedded within the suit and the helmet provide a plurality of simulated acceleration forces which are exerted upon the trainee pilot.

1981-01-13

312

Far field acceleration.  

National Technical Information Service (NTIS)

Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is gi...

R. C. Fernow

1995-01-01

313

Accelerated testing of batteries.  

National Technical Information Service (NTIS)

Three methods of evaluating accelerated battery test data are described. Criteria for each method are used to determine the minimum test matrix required for accurate predictions. Other test methods involving high current discharge and real time techniques...

S. C. Levy P. Bro

1992-01-01

314

Non-accelerator experiments  

SciTech Connect

This report discusses several topics which can be investigated without the use of accelerators. Topics covered are: (1) proton decay, (2) atmospheric neutrinos, (3) neutrino detection, (4) muons from Cygnus X-3, and (5) the double-beta decay.

Goldhaber, M.

1986-01-01

315

Acceleration Recorder Device.  

National Technical Information Service (NTIS)

The patent application describes a device for use in measuring peak acceleration (g) levels experienced by munitions during rough handling, ballistic launching or at terminal impact. The device is a self-contained mechanical concept based on the predictab...

L. D. Post

1982-01-01

316

Rare Isotope Accelerators  

NASA Astrophysics Data System (ADS)

The next frontier for low-energy nuclear physics involves experimentation with accelerated beams of short-lived radioactive isotopes. A new facility, the Rare Isotope Accelerator (RIA), is proposed to produce large amount of these rare isotopes and post-accelerate them to energies relevant for studies in nuclear physics, astrophysics and the study of fundamental interactions at low energy. The basic science motivation for this facility will be introduced. The general facility layout, from the 400 kW heavy-ion superconducting linac used for production of the required isotopes to the novel production and extraction schemes and the highly efficient post-accelerator, will be presented. Special emphasis will be put on a number of technical breakthroughs and recent R&D results that enable this new facility.

Savard, Guy

2002-04-01

317

Introduction to Acceleration Mechanisms.  

National Technical Information Service (NTIS)

This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, ...

R. B. Palmer

1987-01-01

318

Accelerated Corrosion Testing.  

National Technical Information Service (NTIS)

Available methods for accelerated testing of corrosion behavior yield results which are not sufficiently accurate or reliable for predicting the service life of aircraft components and materials which degrade or fail due to environmental attack. Research ...

M. Khobaib

1982-01-01

319

Accelerating Translational Research  

Cancer.gov

Accelerating Translational Research Coordinating and facilitating translational research initiatives across the NCI and the cancer research community. NCI Translational Science Meetings NCI Translates - July 28-29, 2011 NCI Translates - 2009 NCI Translates

320

Wake field acceleration experiments  

SciTech Connect

Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics. I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs.

Simpson, J.D.

1988-01-01

321

Inductive Plasma Accelerator Development.  

National Technical Information Service (NTIS)

The work described in the report comprises: (a) Theoretical studies of the performance of an electromagnetic induction plasma accelerator for radiation-cooled applications, and for pulsed operation. (b) The improvement of pre-existing instrumentation for ...

G. Fonda-Bonardi R. Rosen

1968-01-01

322

Broadband Accelerator Control Network.  

National Technical Information Service (NTIS)

A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz...

J. Skelly T. Clifford R. Frankel

1983-01-01

323

Collective field accelerator  

DOEpatents

A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a .nu./.gamma. of .about. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam.

Luce, John S. (Livermore, CA)

1978-01-01

324

Motion with Constant Acceleration  

NSDL National Science Digital Library

The purpose of this experiment is to track the motion for an air cart on a sloped track to fall a distance x with constant acceleration a = g sinq. You will verify that the distance and velocity along the incline are given by the parabola x = xo + vo t +1/2at2 and the line v = vo +at. Finally, you will determine the acceleration due to gravity.

Herman, Russell

2008-02-19

325

CEBAF Accelerator Achievements  

NASA Astrophysics Data System (ADS)

In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

Chao, Y. C.; Drury, M.; Hovater, C.; Hutton, A.; Krafft, G. A.; Poelker, M.; Reece, C.; Tiefenback, M.

2011-05-01

326

APT accelerator. Topical report  

Microsoft Academic Search

The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE\\/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual

G. Lawrence; D. Rusthoi

1995-01-01

327

Computational studies and optimization of wakefield accelerators  

NASA Astrophysics Data System (ADS)

Laser- and particle beam-driven plasma wakefield accelerators produce accelerating fields thousands of times higher than radio-frequency accelerators, offering compactness and ultrafast bunches to extend the frontiers of high energy physics and to enable laboratory-scale radiation sources. Large-scale kinetic simulations provide essential understanding of accelerator physics to advance beam performance and stability and show and predict the physics behind recent demonstration of narrow energy spread bunches. Benchmarking between codes is establishing validity of the models used and, by testing new reduced models, is extending the reach of simulations to cover upcoming meter-scale multi-GeV experiments. This includes new models that exploit Lorentz boosted simulation frames to speed calculations. Simulations of experiments showed that recently demonstrated plasma gradient injection of electrons can be used as an injector to increase beam quality by orders of magnitude. Simulations are now also modeling accelerator stages of tens of GeV, staging of modules, and new positron sources to design next-generation experiments and to use in applications in high energy physics and light sources.

Geddes, C. G. R.; Bruhwiler, D. L.; Cary, J. R.; Mori, W. B.; Vay, J.-L.; Martins, S. F.; Katsouleas, T.; Cormier-Michel, E.; Fawley, W. M.; Huang, C.; Wang, X.; Cowan, B.; Decyk, V. K.; Esarey, E.; Fonseca, R. A.; Lu, W.; Messmer, P.; Mullowney, P.; Nakamura, K.; Paul, K.; Plateau, G. R.; Schroeder, C. B.; Silva, L. O.; Toth, C.; Tsung, F. S.; Tzoufras, M.; Antonsen, T.; Vieira, J.; Leemans, W. P.

2008-07-01

328

High Quality Electron Beams from Laser Accelerators  

NASA Astrophysics Data System (ADS)

Twenty five years ago, laser driven accelerators were proposed as an alternative to conventional accelerator systems.[1] The appeal was and is the large accelerating gradients (up to hundreds of GV/m) that can allow the development of compact devices capable of producing multi-GeV electron beams. Until recently, all experiments produced large gradients but beams with 100 % energy spread and only a small amount of electrons at high energy. This has recently changed. At the multi-beam L'OASIS facility at LBNL we have produced beams with narrow energy spread using a channel guided laser accelerator.[2] At Rutherford Appleton Laboratories (UK)[3] and at the Ecole Polytechnique (France),[4] beams with narrow energy spread were produced by using laser beams with relatively large focal spots. These results demonstrate that laser-plasma based accelerator can produce high quality electron beams. A review of the L'OASIS experiments will be presented as well as our plans and activities for producing a GeV-class electron beam. [1] T. Tajima and J.M. Dawson, Phys. Rev. Lett. 43, 267-270 (1979). [2] C.G.R. Geddes et al., Nature 431, 538- 541(2004). [3] S.P.D. Mangles et al., Nature 431, 535 --538 (2004). [4] J. Faure et al., Nature 431, 541-544 (2004).

Leemans, Wim

2005-04-01

329

Computational studies and optimization of wakefield accelerators  

SciTech Connect

Laser- and particle beam-driven plasma wakefield accelerators produce accelerating fields thousands of times higher than radio-frequency accelerators, offering compactness and ultrafast bunches to extend the frontiers of high energy physics and to enable laboratory-scale radiation sources. Large-scale kinetic simulations provide essential understanding of accelerator physics to advance beam performance and stability and show and predict the physics behind recent demonstration of narrow energy spread bunches. Benchmarking between codes is establishing validity of the models used and, by testing new reduced models, is extending the reach of simulations to cover upcoming meter-scale multi-GeV experiments. This includes new models that exploit Lorentz boosted simulation frames to speed calculations. Simulations of experiments showed that recently demonstrated plasma gradient injection of electrons can be used as an injector to increase beam quality by orders of magnitude. Simulations are now also modeling accelerator stages of tens of GeV, staging of modules, and new positron sources to design next-generation experiments and to use in applications in high energy physics and light sources.

Tsung, Frank S.; Bruhwiler, David L.; Cary, John R.; Esarey, Eric H.; Mori, Warren B.; Vay, Jean-Luc; Martins, Samuel F.; Katsouleas, Tom; Cormier-Michel, Estelle; Fawley, William M.; Huang, Chengkun; Wang, Xiadong; Cowan, Ben; Decyk, Victor K.; Fonseca, Ricardo A.; Lu, Wei; Messmer, Peter; Mullowney, Paul; Nakamura, Kei; Paul, Kevin; Plateau, Guillaume R.; Schroeder, Carl B.; Silva, Luis O.; Toth, Csaba; Geddes, C.G.R.; Tzoufras, Michael; Antonsen, Tom; Vieira, Jorge; Leemans, Wim P.

2008-06-16

330

Laser Plasma Accelerators  

NASA Astrophysics Data System (ADS)

The continuing development of powerful laser systems has permitted to extend the interaction of laser beams with matter far into the relativistic domain, and to demonstrate new approaches for producing energetic particle beams. The extremely large electric fields, with amplitudes exceeding the TV/m level, that are produced in plasma medium are of relevance particle acceleration. Since the value of this longitudinal electric field, 10,000 times larger than those produced in conventional radio-frequency cavities, plasma accelerators appear to be very promising for the development of compact accelerators. The incredible progresses in the understanding of laser plasma interaction physic, allows an excellent control of electron injection and acceleration. Thanks to these recent achievements, laser plasma accelerators deliver today high quality beams of energetic radiation and particles. These beams have a number of interesting properties such as shortness, brightness and spatial quality, and could lend themselves to applications in many fields, including medicine, radio-biology, chemistry, physics and material science,security (material inspection), and of course in accelerator science.

Malka, Victor

331

Acceleration Disturbances onboard of Geodetic Precision Space Laboratories  

NASA Astrophysics Data System (ADS)

Bartlomiej Oszczak, b@dgps.pl University of Warmia and Mazury in Olsztyn, Poland, Olsztyn, Poland Olga Maciejczyk, omaciejczyk@gmail.com Poland In this paper there is presented the study on the parameters of the ASG-EUPOS real-time RTK service NAWGEO such as: accuracy, availability, integrity and continuity. Author's model is used for tests. These parameters enable determination of the quality of received information and practical applications of the service. Paper includes also the subject related to the NAWGEO service and algorithms used in determination of mentioned parameters. The results of accuracy and precision analyses and study on availability demonstrated that NAWGEO service enables a user a position determination with a few centimeters accuracy with high probability in any moment of time.

Peterseim, Nadja; Jakob, Flury; Schlicht, Anja

332

FSL in Review, 2004, Forest Systems Laboratory, Boulder, Colorado.  

National Technical Information Service (NTIS)

The mission of the Forecast Systems Laboratory is transferring advances in science and technology to the nations operational weather services. To keep pace with accelerating technological change, FSL has also changed its efforts to anticipate the needs of...

2005-01-01

333

Stone Preservatives: Methods of Laboratory Testing and Preliminary Performance Criteria.  

National Technical Information Service (NTIS)

Although numerous materials have been proposed as preservatives for stone in historic buildings and monuments, their efficacy is difficult to establish. A laboratory research program of accelerated simulated stone decay was used to obtain data on stone pr...

G. A. Sleater

1977-01-01

334

Laboratory Astrophysics on High Power Lasers and Pulsed Power Facilities.  

National Technical Information Service (NTIS)

Over the past decade a new genre of laboratory astrophysics has emerged, made possible by the new high energy density (HED) experimental facilities, such as large lasers, z-pinch generators, and high current particle accelerators. (Remington, 1999; 2000; ...

B. A. Remington

2002-01-01

335

The APT Accelerator.*  

NASA Astrophysics Data System (ADS)

The accelerator for the Accelerator Production of Tritium (APT) project is a high-power RF linac designed to produce a 100-mA CW proton beam at an energy of 1300 MeV. A heavy-metal target produces large quantities of spallation neutrons, which are slowed to thermal energies and captured in a feed material to make tritium. The baseline accelerator design consists of a 75-keV proton injector, a 7-MeV radio-frequency quadrupole (RFQ), a 100-MeV coupled-cavity drift-tube linac (CCDTL), and a 1300-MeV side-coupled linac (SCL). The RFQ operates at a frequency of 350 MHz, while the CCDTL and SCL operate at 700-MHz. A quadrupole-magnet transport system conveys the 1300-MeV beam to production target/blanket assemblies where beam expanders using non-linear magnetic elements transform the linac output distribution into large-area rectangular distributions having a nearly uniform density. All the linac accelerating structures use conventional water-cooled copper technology. The SCL section is based on the well-proven 800-MeV LANSCE high-duty-factor linac at Los Alamos. The CCDTL is a new hybrid accelerating structure that combines the best features of the conventional drift-tube linac and the coupled-cavity linac to provide efficient and stable acceleration in the intermediate velocity range. Approximately 263 1-MW CW klystrons are needed to drive the 130-MW proton beam. The total ac-power requirement for the APT plant is about 438 MW, most of which is needed for the accelerator. An advanced-technology option is being considered that would replace the conventional SCL with a superconducting RF linac composed of sequences of 4-cell elliptical-type cavities. This option would reduce the electric power consumption significantly and would provide increased operational flexibility. * Work supported by the US Department of Energy.

Lawrence, George P.

1996-05-01

336

Performance of capillary discharge guided laser plasma wakefield accelerator  

Microsoft Academic Search

A GeV-class laser-driven plasma-based wakefield accelerator has been realized at the Lawrence Berkeley National Laboratory (LBNL). The device consists of the 40 TW high repetition rate Ti:sapphire LOASIS laser system at LBNL and a gas-filled capillary discharge waveguide developed at Oxford University. The operation of the capillary discharge guided laser plasma wakefield accelerator with a capillary of 225 mum diameter

Kei Nakamura; Eric Esarey; Cameron G. R. Geddes; Anthony J. Gonsalves; Wim P. Leemans; Dmitriy Panasenko; Carl B. Schroeder; Csaba Toth; S. M. Hooker

2007-01-01

337

High energy electron beam processing experiments with induction accelerators  

Microsoft Academic Search

Induction accelerators are capable of producing very high electron beam power for processing at energies of 110 MeV. A high energy electron beam (HEEB) material processing system based on all-solid-state induction accelerator technology is in operation at Science Research Laboratory. The system delivers 50 ns 500 A current pulses at 1.5 MeV and is capable of operating at high power

D. L. Goodman; D. L. Birx; V. R. Dave

1995-01-01

338

Energy Stabilization of Electrostatic Accelerators  

Microsoft Academic Search

Electrostatic accelerators, such as the Van de Graaf generator, are among the most established and well-developed particle accelerators. One of the key issues in the maturation of these accelerators has been the development of methods used to stabilize the energies of the particles they produce. Energy Stabilization of Electrostatic Accelerators presents a comprehensive overview of the key methods of stabilizing

J. Takcs

1997-01-01

339

Plasma-based accelerator structures  

SciTech Connect

Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

Schroeder, Carl B.

1999-12-01

340

Heavy Ion Fusion Accelerator Research (HIFAR) year-end report, April 1, 1990--September 30, 1990  

SciTech Connect

The basic objective of the Heavy Ion Fusion Accelerator Research (HIFAR) program is to assess the suitability of heavy ion accelerators as igniters for Inertial Confinement Fusion (ICF). A specific accelerator technology, induction acceleration, is being studied at the Lawrence Berkeley Laboratory and at the Lawrence Livermore National Laboratory. The HIFAR program addresses the generation of high-power, high-brightness beams of heavy ions, the understanding of the scaling laws in this novel physics regime, and the validation of new accelerator strategies to cut costs. Key elements to be addressed include: (1) beam quality limits set by transverse and longitudinal beam physics; (2) development of induction accelerating modules, and multiple-beam hardware, at affordable costs; (3) acceleration of multiple beams with current amplification without significant dilution of the optical quality of the beams; (4) final bunching, transport, and accurate focusing on a small target.

Not Available

1990-12-01

341

Laser acceleration with open waveguides  

SciTech Connect

A unified framework based on solid-state open waveguides is developed to overcome all three major limitations on acceleration distance and hence on the feasibility of two classes of laser acceleration. The three limitations are due to laser diffraction, acceleration phase slippage, and damage of waveguide structure by high power laser. The two classes of laser acceleration are direct-field acceleration and ponderomotive-driven acceleration. Thus the solutions provided here encompass all mainstream approaches for laser acceleration, either in vacuum, gases or plasmas.

Xie, Ming

1999-03-01

342

Linear induction accelerators  

SciTech Connect

The development of linear induction accelerators has been motivated by applications requiring high-pulsed currents of charged particles at voltages exceeding the capability of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine, but the 50-MeV, 10-kA Advanced Test Accelerator (ATA) at LLNL is the highest voltage machine in existence at this time. The advent of magnetic pulse power systems makes sustained operation at high-repetition rates practical, and this capability for high-average power is very likely to open up many new applications of induction machines in the future. This paper surveys the US induction linac technology with primary emphasis on electron machines. A simplified description of how induction machines couple energy to the electron beam is given, to illustrate many of the general issues that bound the design space of induction linacs.

Briggs, R.J.

1986-06-01

343

Advanced accelerator theory development  

SciTech Connect

A new accelerator technology, the dielectric wall accelerator (DWA), is potentially an ultra compact accelerator/pulsed power driver. This new accelerator relies on three new components: the ultra-high gradient insulator, the asymmetric Blumlein and low jitter switches. In this report, we focused our attention on the first two components of the DWA system the insulators and the asymmetric Blumlein. First, we sought to develop the necessary design tools to model and scale the behavior of the high gradient insulator. To perform this task we concentrated on modeling the discharge processes (i.e., initiation and creation of the surface discharge). In addition, because these high gradient structures exhibit favorable microwave properties in certain accelerator configurations, we performed experiments and calculations to determine the relevant electromagnetic properties. Second, we performed circuit modeling to understand energy coupling to dynamic loads by the asymmetric Blumlein. Further, we have experimentally observed a non-linear coupling effect in certain asymmetric Blumlein configurations. That is, as these structures are stacked into a complete module, the output voltage does not sum linearly and a lower than expected output voltage results. Although we solved this effect experimentally, we performed calculations to understand this effect more fully to allow better optimization of this DWA pulse-forming line system.

Sampayan, S.E.; Houck, T.L.; Poole, B.; Tishchenko, N.; Vitello, P.A.; Wang, I.

1998-02-09

344

Microelectromechanical acceleration-sensing apparatus  

SciTech Connect

An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

Lee, Robb M. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM); Polosky, Marc A. (Albuquerque, NM); Hoke, Darren A. (Albuquerque, NM); Vernon, George E. (Rio Rancho, NM)

2006-12-12

345

Collaboration tools for the global accelerator network: Workshop Report  

SciTech Connect

The concept of a ''Global Accelerator Network'' (GAN) has been put forward as a means for inter-regional collaboration in the operation of internationally constructed and operated frontier accelerator facilities. A workshop was held to allow representatives of the accelerator community and of the collaboratory development community to meet and discuss collaboration tools for the GAN environment. This workshop, called the Collaboration Tools for the Global Accelerator Network (GAN) Workshop, was held on August 26, 2002 at Lawrence Berkeley National Laboratory. The goal was to provide input about collaboration tools in general and to provide a strawman for the GAN collaborative tools environment. The participants at the workshop represented accelerator physicists, high-energy physicists, operations, technology tool developers, and social scientists that study scientific collaboration.

Agarwal, Deborah; Olson, Gary; Olson, Judy

2002-09-15

346

Virtual Laboratory  

NSDL National Science Digital Library

The website for the Virtual Laboratory contains a bold and direct statement: "Conventional teaching all too often accepts memorization and pattern recognition as true learning" After reading this statement, it makes sense that the goal of this site is "to help students to recognize, confront, correct, and expand their understanding of subject or a technique." The site contains five different sets of course materials that use interactive materials, short quizzes, and embedded demonstrations to assist students and teachers alike. One set of materials that should not be missed is in the Teaching & Learning Biology area. Here visitors will find links, fact sheets, and pedagogical suggestions for teaching a college-level biology course. Moving on, the Chemistry, Life, the Universe and Everything section contains a new perspective on how to reform the garden-variety general chemistry course.

2012-04-27

347

Laboratory Simulations  

NASA Astrophysics Data System (ADS)

Geophysical properties of near-Earth objects (NEOs) can best be studied using radio tomography and seismology. Reflection and transmission radio tomography is best suited for measuring the complex electric permittivity of poorly conducting materials to reveal the internal structure of NEOs. Such NEOs are primarily comet nuclei and carbonaceous asteroids. Seismic experiments are most suitable for studying elastic properties of consolidated materials to reveal material strengths of stony and iron-nickel asteroids. Thus, the two methods are complementary for investigating comets and asteroids of all types. Analysis of reflection and transmission radio tomography of heterogeneous irregular shaped bodies is very difficult. Scattering by internal and outer boundaries, differences in the refractive indices of heterogeneous materials, and attenuation by electric conductivity complicate the analyses. For this reason laboratory simulations with scaled objects and scaled wavelengths is extremely useful to check the reliability of inversion techniques of radio signals to arrive at the interior structure of an NEO. Another approach to obtaining quantitative information on the composition and structure of an NEO is through induced seismology. There are two approaches to producing seismic waves: small explosive charges and impactors. Experimental work has been performed in the laboratory to examine the impulse delivered by explosives. Wave travel times can be used to back out basic material properties and first order structure of an NEO. For example, if distinct arrival pulses for P and S waves are recorded and the explosive initiation/impact time and location are known, then it is possible to determine the elastic properties of bulk and shear modulus. Reflections in the seismograms allow a determination of material boundaries in an NEO. Original arrival time is important since Q numbers for stony NEO material are presumed to be high, as they were on the Moon, and thus it is expected that there will be extensive ringing and noise. Other types of NEO materials will have differing seismic characteristics.

Huebner, W. F.; Walker, J.; Gustafson, B.

348

Miniature penetrator (MinPen) acceleration recorder development test  

SciTech Connect

The Telemetry Technology Development Department at Sandia National Laboratories actively develops and tests acceleration recorders for penetrating weapons. This new acceleration recorder (MinPen) utilizes a microprocessor-based architecture for operational flexibility while maintaining electronics and packaging techniques developed over years of penetrator testing. MinPen has been demonstrated to function in shock environments up to 20,000 Gs. The MinPen instrumentation development has resulted in a rugged, versatile, miniature acceleration recorder and is a valuable tool for penetrator testing in a wide range of applications.

Franco, R.J.; Platzbecker, M.R.

1998-08-01

349

Design of a dedicated heavy ion accelerator for radiotherapy  

SciTech Connect

A new heavy-ion accelerator facility for radiotherapy is being designed at the Lawrence Berkeley Laboratory. Performance requirements have been established. Ions from helium to argon can be accelerated to a maximum energy of 800 MeV/nucleon with intensities in the range 10/sup 8/ to 10/sup 9/ particles per second. The accelerator subsystems consist of a linac injector, a synchrotron, and a beam-delivery system. Specifications have been developed for many of the technical components, and some details of the technical design are presented.

Gough, R.; Alonso, J.; Elioff, T.

1983-03-01

350

Laboratory source of synchrotron radiation: TROLL-2  

NASA Astrophysics Data System (ADS)

A laboratory synchrotron radiation (SR) source TROLL-2 is described. Its main parameters are as follows: the energy of the accelerated particles = 24 MeV; the orbit radius = 20 mm; the SR pulse half-width = 2 ms, the maximum spectral radiant power (at ? = 350 nm) = 1.2106 W/m.

Anevsky, S. I.; Vernyi, A. E.; Panasjuk, V. S.; Khromchenko, V. B.

1987-11-01

351

Road transportable analytical laboratory (RTAL) system  

Microsoft Academic Search

Remediation of DOE contaminated areas requires extensive sampling and analysis. Reliable, road transportable, fully independent laboratory systems that could perform on-site a full range of analyses meeting high levels of quality assurance and control, would accelerate and thereby reduce the cost of cleanup and remediation efforts by (1) providing critical analytical data more rapidly, and (2) eliminating the handling, shipping,

Finger

1996-01-01

352

Acceleration of metal plates  

SciTech Connect

High-explosive charges have been used to accelerate stainless steel plates to velocities of 6-7 km/s. A two-stage system has been used in which the first stage is a plane-wave detonating system that accelerates the plate down a short barrel. The second stage consists of a hollow cylindrical charge through which the moving plate passes. After an adjustable delay this charge is detonated on the outer circumference of the entry side of the charge. Flash radiographs and witness plates show no breakup in the first stage but bowing and frequent breakup in the second stage. 6 figs.

Marsh, S.P.; McQueen, R.G.; Tan, T.H.

1989-01-01

353

Accelerated molecular dynamics methods  

SciTech Connect

The molecular dynamics method, although extremely powerful for materials simulations, is limited to times scales of roughly one microsecond or less. On longer time scales, dynamical evolution typically consists of infrequent events, which are usually activated processes. This course is focused on understanding infrequent-event dynamics, on methods for characterizing infrequent-event mechanisms and rate constants, and on methods for simulating long time scales in infrequent-event systems, emphasizing the recently developed accelerated molecular dynamics methods (hyperdynamics, parallel replica dynamics, and temperature accelerated dynamics). Some familiarity with basic statistical mechanics and molecular dynamics methods will be assumed.

Perez, Danny [Los Alamos National Laboratory

2011-01-04

354

Interfacing to accelerator instrumentation  

SciTech Connect

As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed.

Shea, T.J.

1995-12-31

355

Accelerator technology program  

NASA Astrophysics Data System (ADS)

Highlights in beam dynamics, accelerator inertial fusion, radio frequency structure development, the racetrack microtron, CERN high energy physics experiment NA-12, and high flux radiographic linac study are reported. Selected proton Storage Ring activities and an update on the free electron laser are discussed. The fusion materials irradiation test facility work and progress on the klystron development project and on the gyrocon project are examined. The activities of the newly formed theory and simulation group are outlined. Activities concerning the accelerator test stand for the neutral particle beam program are outlined.

Jameson, R. A.

1984-05-01

356

Photocathodes in accelerator applications  

SciTech Connect

Some electron accelerator applications require bursts of short pulses at high microscopic repetition rates and high peak brightness. A photocathode, illuminated by a mode-locked laser, is well suited to filling this need. The intrinsic brightness of a photoemitter beam is high; experiments are under way at Los Alamos to study the brightness of short bunches with high space charge after acceleration. A laser-illuminated Cs/sub 3/Sb photoemitter is located in the first rf cavity of an injector linac. Diagnostics include a pepper-pot emittance analyzer, a magnetic spectrometer, and a streak camera.

Fraser, J.S.; Sheffield, R.L.; Gray, E.R.; Giles, P.M.; Springer, R.W.; Loebs, V.A.

1987-01-01

357

Particle acceleration in Blazars  

NASA Astrophysics Data System (ADS)

Understanding the variable emission of blazars observed with gamma-ray telescopes and Fermi has become a major challenge for theoretical models of particle acceleration. Here, we introduce a novel time-dependent emission model in which the maximum energy of particles is determined from a balance between Fermi type I and II acceleration energy gains and radiative energy losses, allowing for an explanation of both the characteristic spectral energy distribution of blazars and their intrinsic sub-hour variability. Additionally, we can determine the physical condition of the emitting plasma concerning its turbulence and typical shock speeds.

Weidinger, Matthias; Spanier, Felix

2011-06-01

358

Linear accelerator for production of tritium: Physics design challenges  

SciTech Connect

In the summer of 1989, a collaboration between Los Alamos National Laboratory and Brookhaven National Laboratory conducted a study to establish a reference design of a facility for accelerator production of tritium (APT). The APT concept is that of a neutron-spallation source, which is based on the use of high-energy protons to bombard lead nuclei, resulting in the production of large quantities of neutrons. Neutrons from the lead are captured by lithium to produce tritium. This paper describes the design of a 1.6-GeV, 250-mA proton cw linear accelerator for APT.

Wangler, T.P.; Lawrence, G.P.; Bhatia, T.S.; Billen, J.H.; Chan, K.C.D.; Garnett, R.W.; Guy, F.W.; Liska, D.; Nath, S.; Neuschaefer, G.; Shubaly, M.

1990-01-01

359

Laser Wakefield Accelerators towards table-top accelerators and bright synchrotron sources  

NASA Astrophysics Data System (ADS)

Laser wakefield accelerators (LWFA) have the potential to lead a new generation of compact table top accelerators. In particular, they could be an attractive driver for a whole range of light source applications. Recently it has been demonstrated that LWFAs can be a source of very bright x-rays. These x-rays are generated due to the transverse (betatron) oscillations of the electron beam as it is being accelerated. Experiments with 100 TW class lasers have shown the peak brightness of this betatron source to be comparable to 3rd generation light sources (S. Kneip et al, Nature Physics 6, 980-983 (2010)). I will present results from recent experiments on x-ray production using the 250 TW Astra Gemini Laser located at the Rutherford Appleton Laboratory.

Bloom, M.; Streeter, M. J.; Kneip, S.; Bendoyro, R.; Dpp, A.; Holloway, J.; Jiang, J.; Lopes, N.; Najmudin, Z.; Nakamura, H.; Symes, D.; Mangles, S. P. D.

2011-11-01

360

High current electron linacs (advanced test accelerator/experimental test accelerator)  

SciTech Connect

The high current induction accelerator development at the Lawrence Livermore National Laboratory is described. The ATA facility is designed for 10 kA peak currents, 50 nsec pulse lengths and 50 MeV energies. At this time, half of the design current has been accelerated through the entire machine to particle energies of about 45 MeV. Current problem areas and operational experience to date will be discussed. Several key technical areas required development for the ATA machine; this report will survey these developments. The control of transverse beam instabilities required an accelerating cavity design with very low Q. Electron sources capable of 10 kA operation at high rep rates were developed using a plasma sparkboard approach. The pulse power systems on ATA, using the same type of spark gap switches as ETA, have exhibited excellent operational reliability.

Briggs, R.J.

1984-04-30

361

The influence of the type of accelerant, type of burned material, time of burning and availability of air on the possibility of detection of accelerants traces  

Microsoft Academic Search

The presented research consisted in a series of field experiments and laboratory analyses of obtained samples. Their aim was to investigate how different factors influence the possibility of identification of accelerant traces in conditions that are as similar as possible to those of real fires. The studied factors were: type of burned material, type of accelerant, length of time between

R. Borusiewicz; J. Zi?ba-Palus; G. Zadora

2006-01-01

362

Negative hydrogen ion sources for accelerators  

SciTech Connect

A variety of H{sup -} ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H{sup -} ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H{sup -} production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.

Moehs, D.P.; /Fermilab; Peters, J.; /DESY; Sherman, J.; /Los Alamos

2005-08-01

363

Report on accelerated corrosion studies.  

SciTech Connect

Sandia National Laboratories (SNL) conducted accelerated atmospheric corrosion testing for the U.S. Consumer Product Safety Commission (CPSC) to help further the understanding of the development of corrosion products on conductor materials in household electrical components exposed to environmental conditions representative of homes constructed with problem drywall. The conditions of the accelerated testing were chosen to produce corrosion product growth that would be consistent with long-term exposure to environments containing humidity and parts per billion (ppb) levels of hydrogen sulfide (H{sub 2}S) that are thought to have been the source of corrosion in electrical components from affected homes. This report documents the test set-up, monitoring of electrical performance of powered electrical components during the exposure, and the materials characterization conducted on wires, screws, and contact plates from selected electrical components. No degradation in electrical performance (measured via voltage drop) was measured during the course of the 8-week exposure, which was approximately equivalent to 40 years of exposure in a light industrial environment. Analyses show that corrosion products consisting of various phases of copper sulfide, copper sulfate, and copper oxide are found on exposed surfaces of the conductor materials including wires, screws, and contact plates. The morphology and the thickness of the corrosion products showed a range of character. In some of the copper wires that were observed, corrosion product had flaked or spalled off the surface, exposing fresh metal to the reaction with the contaminant gasses; however, there was no significant change in the wire cross-sectional area.

Mowry, Curtis Dale; Glass, Sarah Jill; Sorensen, Neil Robert

2011-03-01

364

Two-beam accelerator  

SciTech Connect

In the two-beam accelerator (TBA) concept, an electron linear accelerator structure is established in which two beams propagate. One is an intense low energy beam that is made to undergo free electron lasing to produce microwaves. These microwaves are then coupled to another part of the structure where they act to produce a high longitudinal electric gradient that is used to accelerate a second relatively low intensity electron beam to very high energies. The TBA was originally suggested by Sessler as a possible means for economically achieving linear collider energies of 100 GeV and above. Although still in a conceptual stage, the TBA is an inherently plausible concept that combines the free electron laser (FEL) with several well-known technologies - high current induction linacs, microwave waveguides, and traveling-wave linac structures - in a novel and interesting way. Two characteristics of the TBA that make it a particularly suitable candidate for achieving high energies are its ability to operate at higher frequencies than typical present-day linacs (say 30 GHz as compared with 3 GHz), and to be an efficient means for delivering power to a hitherto unattainable high-gradient structure (say 250 MV/m) that the higher frequency makes possible. These high accelerating gradients will permit much shorter linac structures for a given energy.

Selph, F.B.

1984-09-01

365

Radioisotope Dating with Accelerators.  

ERIC Educational Resources Information Center

|Explains a new method of detecting radioactive isotopes by counting their accelerated ions rather than the atoms that decay during the counting period. This method increases the sensitivity by several orders of magnitude, and allows one to find the ages of much older and smaller samples. (GA)|

Muller, Richard A.

1979-01-01

366

Plasma based accelerators  

NASA Astrophysics Data System (ADS)

A plasma medium can support a variety of wave motions which may be useful for accelerating charged particles. For highly relativistic beams the longitudinal electrostatic wave is most suitable and may be driven by laser or by particle beams. The basic principles, limitations and prospects for these devices are discussed.

Evans, R. G.

1987-05-01

367

Acceleration of convergence  

SciTech Connect

Acceleration of the convergence of approximate operator iteration schemes is discussed. Algorithms based on both residual minimization and use of conjugate vector spaces are presented. It is shown that both give dramatic improvement, at very low computational cost, in the iterative solution of radiative transfer problems in the presence of scattering. 13 refs., 7 figs.

Auer, L.

1990-01-01

368

COLLECTIVE PHENOMENA IN ACCELERATORS  

Microsoft Academic Search

Recent years have witnessed the development of accelerators of ever-larger current, both peak and average, as well as a proliferation of storage rings of ever-greater luminosity. Consequently, there is considerable interest in and growing concern with, the phenomena which limit beam currents and beam densities, namely, the collective modes of behavior of relativistic particle beams. Furthermore, it has been demonstrated

Sessler; Andrew M

1972-01-01

369

European particle accelerator conference  

SciTech Connect

This book contains the following topics: The LEP project, Superconducting RF cavities for accelerator application, Commissioning of super-ACO, Pulsed high-power beams, RF Power sources, Astrid, A storage ring for ions and electrons, Linear collider studies in Europe.

Tazzari, S.

1988-01-01

370

Medical proton accelerator facility.  

PubMed

This paper presents a specialized medical accelerator facility designed for proton radiation therapy and for production of short-lived nuclide-labelled radiopharmaceuticals. General features of the facility structure, the choice of principles of beam delivery, physical and technical problems connected with clinical work, and biomedical research are discussed. PMID:2846478

Khoroshkov, V S; Goldin, L L

1988-10-01

371

Commissioning the GTA accelerator  

Microsoft Academic Search

The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth`s magnetic field and travel in straight lines unless they enter the earth`s atmosphere and become charged by stripping. Heavy particles are difficult to stop and

O. R. Sander; W. H. Atkins; G. O. Bolme; S. Bowling; S. Brown; R. Cole; J. D. Gilpatrick; R. Garnett; F. W. Guy; W. B. Ingalls; K. F. Johnson; D. Kerstiens; C. Little; R. A. Lohsen; S. Lloyd; W. P. Lysenko; C. T. Mottershead; G. Neuschaefer; J. Power; D. P. Rusthoi; Sandoval D. P. Stevens R. R. Jr; G. Vaughn; E. A. Wadlinger; V. Yuan; R. Connolly; R. Weiss; K. Saadatmand

1992-01-01

372

Commissioning the GTA accelerator  

Microsoft Academic Search

The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth's magnetic field and travel in straight lines unless they enter the earth's atmosphere and become charged by stripping. Heavy particles are difficult to stop and

O. R. Sander; W. H. Atkins; G. O. Bolme; S. Bowling; S. Brown; R. Cole; J. D. Gilpatrick; R. Garnett; F. W. Guy; W. B. Ingalls; K. F. Johnson; D. Kerstiens; C. Little; R. A. Lohsen; S. Lloyd; W. P. Lysenko; C. T. Mottershead; G. Neuschaefer; J. Power; D. P. Rusthoi; Sandoval D. P. Stevens R. R. Jr; G. Vaughn; E. A. Wadlinger; V. Yuan; R. Connolly; R. Weiss

1992-01-01

373

The Physics Hypertextbook: Acceleration  

NSDL National Science Digital Library

This resource offers support in understanding equations related to acceleration and includes several problems for numerical practice. Scroll to the bottom for a list of links to additional engaging and innovative activities for high school students. This is part of an online textbook in introductory physics.

Elert, Glenn

2006-10-19

374

Acceleration of cheese ripening  

Microsoft Academic Search

The characteristic aroma, flavour and texture of cheese develop during ripening of the cheese curd through the action of numerous enzymes derived from the cheese milk, the coagulant, starter and non-starter bacteria. Ripening is a slow and consequently an expensive process that is not fully predictable or controllable. Consequently, there are economic and possibly technological incentives to accelerate ripening. The

P. F. Fox; J. M. Wallace; S. Morgan; C. M. Lynch; E. J. Niland; J. Tobin

1996-01-01

375

The neutrino electron accelerator  

SciTech Connect

It is shown that a wake of electron plasma oscillations can be created by the nonlinear ponderomotive force of an intense neutrino flux. The electrons trapped in the plasma wakefield will be accelerated to high energies. Such processes may be important in supernovas and pulsars. {copyright} {ital 1998 American Institute of Physics.}

Shukla, P.K. [Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Stenflo, L. [Department of Plasma Physics, Umea University, S-90187 Umea (Sweden); Bingham, R. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom); Bethe, H.A. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Dawson, J.M. [Department of Physics, University of California, Los Angeles, California 90024 (United States); Mendonca, J.T. [Department of Physics, University of Lisbon, 1096 Lisbon (Portugal)

1998-01-01

376

Accelerated Testing Technology.  

National Technical Information Service (NTIS)

The report, in two volumes, is devoted to an investigation into the state-of-the-art of methods for reducing the time and expense associated with life testing, particularly as it relates to parts. The areas investigated are divided into accelerated testin...

W. Yurkowsky R. E. Schafer J. M. Finkelstein

1967-01-01

377

Incineration by accelerator.  

National Technical Information Service (NTIS)

The use MOX fuel allows to hope a stabilization of plutonium production around 500 tons for the French park. In return, the flow of minor actinides is increased to several tons. INCA (INCineration by Accelerator), dedicated instrument, would allow to tran...

M. Cribier G. FIoni R. Legrain F. Lelievre S. Leray

1997-01-01

378

Accelerating Gifted Children  

ERIC Educational Resources Information Center

To have young children disconnected from school is not in their best interest. Yet, some bright students feel disconnected because the curriculum is well below their readiness level. For academically gifted students, acceleration is an effective-and cost-effective-way of meeting their learning and social needs. We hope the Nation Deceived report

Colangelo, Nicholas; Assouline, Susan G.

2005-01-01

379

Cryopumped, condensed hydrogen jet target for the National Accelerator Laboratory main accelerator  

Microsoft Academic Search

From cryogenic engineering conference; Boulder, Colorado, USA (9 Aug ; 1972). CONF-720803-. A jet target designed to carry out proton--proton ; interaction experiments in the inner beam of the NAL Synchrotron is described. ; The target produces a pulsed jet of condensed hydrogen with a 10 mm diameter, a ; 300 ms duration, and a density of 10⁻⁶g\\/cm³. The Jet

V. Bartenev; A. Kuznetsov; B. Morozov; V. Nikitin; Y. Pilipenko; V. Popov; L. Zolin; R. Carrigan; J. Klen; E. Malamud; B. Strauss; D. Sutter; R. Yamada

1973-01-01

380

Test Stand for Linear Induction Accelerator Optimization  

SciTech Connect

Lawrence Livermore National Laboratory has designed and constructed a test stand to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot size. Studying the interaction of the beam and pulse-power system with the accelerator cell will improve the design of high-current accelerators at Livermore and elsewhere. On the test stand, a standard FXR cell is driven by a flexible pulse-power system and the beam current is simulated with a switched center conductor. The test stand is fully instrumented with high-speed digitizers to document the effect of impedance mismatches when the cell is operated under various full-voltage conditions. A time-domain reflectometry technique was also developed to characterize the beam and cell interactions by measuring the impedance of the accelerator and pulse-power component. Computer models are being developed in parallel with the testing program to validate the measurements and evaluate different design changes. Both 3D transient electromagnetic and circuit models are being used.

Ong, M; DeHope, B; Griffin, K; Goerz, D; Kihara, R; Vogtlin, G; Zentler, J M; Scarpetti, R

2003-06-03

381

Superconducting cavities for the APT accelerator  

SciTech Connect

The design of an Accelerator Production of Tritium (APT) facility being investigated at Los Alamos includes a linear accelerator using superconducting rf-cavities for the acceleration of a high-current cw proton beam. For electron accelerators with particles moving at the speed of light ({beta} {approx} 1.0), resonators with a rounded shape, consisting of ellipsoidal and cylindrical sections, are well established. They are referred to as elliptical cavities. For the APT-design, this shape has been adapted for much slower proton beams with {beta} ranging from 0.60 to 0.94. This is a new energy range, in which resonators of an elliptical type have never been used before. Simulations with the well-proven electromagnetic modeling tools MAFIA and SUPERFISH were performed. The structures have been optimized for their rf and mechanical properties as well as for beam dynamics requirements. The TRAK-RF simulation code is used to investigate potential multipacting in these structures. All the simulations will be put to a final test in experiments performed on single cell cavities that have started in the structures laboratory.

Krawczyk, F.L.; Gentzlinger, R.C.; Haynes, B.; Montoya, D.I.; Rusnak, B.; Shapiro, A.H.

1997-10-01

382

``Accelerators and Beams,'' multimedia computer-based training in accelerator physics  

Microsoft Academic Search

We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the user's rate of learning and length of retention of the material. They integrate interactive ``On-Screen Laboratories,'' hypertext, line drawings, photographs, two- and three-dimensional animations,

R. R. Silbar; A. A. Browman; W. C. Mead; R. A. Williams

1999-01-01

383

Accelerators and Beams, multimedia computer-based training in accelerator physics  

Microsoft Academic Search

We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the users rate of learning and length of retention of the material. They integrate interactive On-Screen Laboratories, hypertext, line drawings, photographs, two- and three-dimensional animations,

R. R. Silbar; A. A. Browman; W. C. Mead; R. A. Williams

1999-01-01

384

Stacked insulator induction accelerator gaps  

SciTech Connect

Stacked insulators, with alternating layers of insulating material and conducting film, have been shown to support high surface electrical field stresses. We have investigated the application of the stacked insulator technology to the design of induction accelerator modules for the Relativistic-Klystron Two-Beam Accelerator program. The rf properties of the accelerating gaps using stacked insulators, particularly the impedance at frequencies above the beam pipe cutoff frequency, are investigated. Low impedance is critical for Relativistic-Klystron Two-Beam Accelerator applications where a high current, bunched beam is trsnsported through many accelerating gaps. An induction accelerator module designs using a stacked insulator is presented.

Houck, T.I.; Westenskow, G.A.; Kim, J.S.; Eylon, S.; Henestroza, E.; Yu, S.S.; Vanecek, D.

1997-05-01

385

Accelerator Markup Language and the Universal Accelerator Parser.  

National Technical Information Service (NTIS)

A major obstacle to collaboration on accelerator projects has been the sharing of lattice description files between modeling codes. To address this problem, a lattice description format called Accelerator Markup Language (AML) has been created. AML is bas...

A. Wolski D. Sagan D. A. Bates F. Schmidt M. Forster N. J. Walker

2006-01-01

386

Accelerators for heavy-charged-particle radiation therapy.  

PubMed

This paper focuses on current and future designs of medical hadron accelerators for treating cancers and other diseases. Presently, five vendors and several national laboratories have produced heavy-particle medical accelerators for accelerating nuclei from hydrogen (protons) up through carbon and oxygen. Particle energies are varied to control the beam penetration depth in the patient. As of the end of 2006, four hospitals and one clinic in the United States offer proton treatments; there are five more such facilities in Japan. In most cases, these facilities use accelerators designed explicitly for cancer treatments. The accelerator types are a combination of synchrotrons, cyclotrons, and linear accelerators; some carry advanced features such as respiration gating, intensity modulation, and rapid energy changes, which contribute to better dose conformity on the tumor when using heavy charged particles. Recent interest in carbon nuclei for cancer treatment has led some vendors to offer carbon-ion and proton capability in their accelerator systems, so that either ion can be used. These features are now being incorporated for medical accelerators in new facilities. PMID:17668952

Coutrakon, George B

2007-08-01

387

A brief history of high power RF proton linear accelerators  

SciTech Connect

The first mention of linear acceleration was in a paper by G. Ising in 1924 in which he postulated the acceleration of positive ions induced by spark discharges which produced electric fields in gaps between a series of {open_quotes}drift tubes{close_quotes}. Ising apparently was not able to demonstrate his concept, most likely due to the limited state of electronic devices. Ising`s work was followed by a seminal paper by R. Wideroe in 1928 in which he demonstrated the first linear accelerator. Wideroe was able to accelerate sodium or potassium ions to 50 keV of energy using drift tubes connected alternately to high frequency waves and to ground. Nuclear physics during this period was interested in accelerating protons, deuterons, electrons and alpha particles and not heavy ions like sodium or potassium. To accelerate the light ions required much higher frequencies than available at that time. So linear accelerators were not pursued heavily at that time. Research continued during the 1930s but the development of high frequency RF tubes for radar applications in World War 2 opened the potential for RF linear accelerators after the war. The Berkeley laboratory of E. 0. Lawrence under the leadership of Luis Alvarez developed a new linear proton accelerator concept that utilized drift tubes that required a full RF period to pass through as compared to the earlier concepts. This development resulted in the historic Berkeley 32 MeV proton linear accelerator which incorporated the {open_quotes}Alvarez drift tube{close_quotes} as the basic acceleration scheme using surplus 200 MHz radar components.

Browne, J.C.

1996-12-31

388

Residual activation of thin accelerator components  

SciTech Connect

A method to calculate residual activation of thin accelerator components is presented. A model for residual dose estimation for thick objects made of arbitrary composite materials for arbitrary irradiation and cooling times is employed in this study. A scaling procedure is described to apply the model to thin objects with linear dimensions less than a fraction of a nuclear interaction length. The scaling has been performed for various materials and corresponding factors have been determined for objects of certain shapes (slab, solid and hollow cylinder) which are important from practical standpoint and can serve as models for beam pipes, magnets and collimators. Both contact residual dose and dose attenuation in air outside the objects were considered. A comparison between calculations and measurements performed at the Fermi National Accelerator Laboratory using a 120 GeV proton beam is presented.

Mokhov, N.V.; /Fermilab; Rakhno, E.I.; /North Central Coll.; Rakhno, I.L.; /Fermilab

2006-05-01

389

Precise charge measurement for laser plasma accelerators  

NASA Astrophysics Data System (ADS)

A comprehensive study of charge diagnostics was conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. Using an integrating current transformer as a calibration reference, the sensitivity of the Lanex Fast was found to decrease by 1% per 100 MeV increase of the energy. By using electron beams from LPA, cross calibrations of the charge were carried out with an integrating current transformer, scintillating screen (Lanex from Kodak), and activation based measurement. The diagnostics agreed within 8%, showing that they all can provide accurate charge measurements for LPAs provided necessary cares.

Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Sokollik, Thomas; Shiraishi, Satomi; van Tilborg, Jeroen; Smith, Alan; Rodgers, Dave; Donahue, Rick; Byrne, Warren; Leemans, Wim

2011-11-01

390

Advanced Accelerator Concepts: Seventh Workshop. Proceedings  

SciTech Connect

These proceedings are based on the Seventh Workshop on Advanced Accelerator Concepts held in October, 1996 at Lake Tahoe, California. This workshop was sponsored by the US Department of Energy(High Energy Physics Division, Advanced Technology Branch) and by the center for Beam Physics at the Lawrence Berkeley National Laboratory of the University of California. A wide range of applications was covered at the workshop, from high energy colliders to synchrotron radiation sources. This scope included topics such as new methods of particle acceleration, production of ultrahigh gradient electromagnetic fields, diagnostics and control of particle/photon beams in ultrashort dimensions and ultrafast time scales, and various energy and beam sources. There were 87 papers presented at the workshop and out of these, 65 have been abstracted for the Energy Science and Technology database.(AIP)

Chattopadhyay, S.; McCullough, J.; Dahl, P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1997-09-01

391

Charge Diagnostics for Laser Plasma Accelerators  

SciTech Connect

The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. The sensitivity of the Lanex Fast decreased by 1percent per 100 MeV increase of the energy. The linear response of the screen against the charge was verified with charge density and intensity up to 160 pC/mm2 and 0.4 pC/ps/mm2, respectively. For electron beams from the laser plasma accelerator, a comprehensive study of charge diagnostics has been performed using a Lanex screen, an integrating current transformer, and an activation based measurement. The charge measured by each diagnostic was found to be within +/-10 percent.

Nakamura, K.; Gonsalves, A. J.; Lin, C.; Sokollik, T.; Smith, A.; Rodgers, D.; Donahue, R.; Bryne, W.; Leemans, W. P.

2010-06-01

392

Charge Diagnostics for Laser Plasma Accelerators  

SciTech Connect

The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. The sensitivity of the Lanex Fast decreased by 1% per 100 MeV increase of the energy. The linear response of the screen against the charge was verified with charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/ps/mm{sup 2}, respectively. For electron beams from the laser plasma accelerator, a comprehensive study of charge diagnostics has been performed using a Lanex screen, an integrating current transformer, and an activation based measurement. The charge measured by each diagnostic was found to be within {+-}10%.

Nakamura, K.; Gonsalves, A. J.; Lin, C.; Sokollik, T.; Smith, A.; Rodgers, D.; Donahue, R.; Bryne, W.; Leemans, W. P. [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States)

2010-11-04

393

The munich accelerator for fission fragments (MAFF)  

SciTech Connect

An accelerator (MAFF) for the new Munich high flux reactor FRM-II is under design in order to deliver intense beams of very neutron-rich fission fragments of up to 10{sup 12} particles per second with final energies between 3.7 and 5.9 MeV/u to perform experiments for the production of heavy elements. To obtain an efficient acceleration in a short LINAC, charge breeding of the 1{sup +}-ion beam from the reactor to a q/A{>=}0.16 is required. New measurements with an electron cyclotron resonance ion source (ECRIS) have shown that the requirements for a low duty cycle LINAC (10%) can be fulfilled by the ECRIS. To reach a high flexibility in the final energy with a small number of structures, new kinds of IH-structures are under development at the Munich tandem laboratory.

Kester, Oliver; Habs, Dietrich; Gross, Martin; Sieber, Thomas; Bongers, Henning; Kolbe, Alfred; Maier, Hans Juergen; Thirolf, Peter [Ludwig-Maximilians Universitaet Muenchen, 85748 Garching (Germany); Egidy, Till von; Koester, Ulli; Steichele, Erich; Kienle, Paul; Koerner, Hans Joachim [Technische Universitaet Muenchen, 85748 Garching (Germany); Schempp, Alwin [J. W. Goethe Universitaet Frankfurt, 60325 Frankfurt (Germany); Ratzinger, Ulrich [GSI, Postfach 110552, 64220 Darmstadt (Germany)

1999-04-26

394

Particle Acceleration in Pulsar Magnetospheres.  

National Technical Information Service (NTIS)

The structure of pulsar magnetospheres and the acceleration mechanism for charged particles in the magnetosphere was studied, using a pulsar model which required large acceleration of the particles near the surface of the star. A theorem was developed whi...

K. B. Baker

1978-01-01

395

Accelerator operation management using objects.  

National Technical Information Service (NTIS)

Conflicts over control of shared devices or resources in an accelerator control system, and problems that can occur due to applications performing conflicting operations, are usually resolved by accelerator operators. For these conflicts to be detected by...

H. Nishimura C. Timossi M. Valdez

1995-01-01

396

New Accelerated Corrosion Test Methods.  

National Technical Information Service (NTIS)

A project which established accelerated corrosion test methods for conventional Al and new AlLi alloys and surface protection schemes is described. New accelerated testing methods will allow the selection of material and protection schemes with increased ...

U. Koch T. Hack

1991-01-01

397

Photonic Acceleration in Astrophysics  

NASA Astrophysics Data System (ADS)

Gamma Ray Bursts (GRB) deliver very high intensity photons with energies from 10 keV to over 100 MeV at a irradiance of 10^30 (30 km/R)^2 Watt/cm^2. This is in the nonlinear QED regime and the induced wakefield is close to the Schwinger field (E ~^16 V/cm). Protons and electrons can be accelerated in such a strong field to 10^21 eV/km in the vicinity of the GRB source. The maximum acceleration is limited by the critical Schwinger field times the length of the field: q ( E (= 10^16.5 V/cm) ( L ((1000 km) = 10^24 eV. Trains of such wakefields are expected in the outflow of photons from GRB's, which gives a Chapman-Kolmogorov type power energy spectrum [Chandrasekhar, 1953; Mima et al. 1991], which is close to a Bremsstrahlung-type spectrum, f(E) = E^-a (a = 1). Some of the accelerated protons can have energies as high as 10^23 eV. The secondary pions and their daughters (neutrinos) that may be produced in-situ near the acceleration site of the GRB can have energies around 10^22 eV (= 1.6 ( 10^10 erg). The neutrino flux from the semi-daily occurrence of GRB's (with energy output of ~ 10^52 erg can provide a flux of high intensity EHE neutrinos in the universe as a function of the acceleration efficiency coefficient (k): I( (E ( 10^21 eV) = 5k (10^52 eV)/(1.6 ( 10^10 erg)/4(pi)R^2/day = 1 /km^2 yr (for k = 1% *). *(cf. Laser wakefield experiments with Petawatt indicated k = 5 ~ 10% for protons [M. Key, 1999].) A compact photonic acceleration mechanism is thus suggested as a candidate for the origin of extremely high energy cosmic rays (EECR). Observed characteristics of EECR beyond energies of several 1019 eV pose a number of challenges and opportunities for physics and astrophysics. Foremost among them is the apparent defiance or violation of the proton energy cutoff of Greisen-Zatsepin-Kuzmin (GZK). The other is the apparent correlation in some of ECR events. And the most important is the difficulty to accelerate particles by the conventional Fermi mechanism to reach such high energies. We suggest that the intense photon flux emanating from a gamma ray burst is capable of yielding a sufficiently robust and rugged plasma structure suitable to accelerate protons and other charged particles to extreme high energies ( ~ 10^22 eV) over thousands of kilometers in the GRB atmosphere. Photon flux above a certain threshold can self-modulate in the plasma to create longitudinal (as well as transverse) structures that help snowplow and accelerate charged particles. The sustained large flux of photons maintains the acceleration by successive flux to repeat the process once a particular class of photons give up energies to particles and red-shift. The decrease of plasma density away from the GRB further facilitates this process, providing ever greater coherence (acceleration) length. The stochastic repetition of this process yields a power-law energy spectrum with an exponent of -1. Such compact prompt intense acceleration of protons in the vicinity of GRB manifests through neutrinos (by proton-proton or proton-photon collisions near GRB). These neutrinos can propagate over a cosmological distance without decay or loss until reaching and colliding with relic neutrinos in our Super-Cluster (Virgo), eventually converting themselves into EECR particles such as protons and photons of energies of ~ 10^20 eV. The estimated neutrino energy flux and spectrum are consistent with observation and have a number of implications on EHECR, cosmological origin, and neutrino physics. Other high field astronomical sites such as the core and jets of Active Galactic Nuclei can have lesser but similar accelerations.

Takahashi, Yoshiyuki

2000-04-01

398

Progress on laser plasma accelerators  

SciTech Connect

Several laser plasma accelerator schemes are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA). Theory indicates that a very high acceleration gradient, of order 1 GeV/m, can exist in the plasma wave driven by the beating lasers. Experimental results obtained on the PBWA experiment at UCLA confirms this. Parameters related to the PBWA as an accelerator system are derived, among them issues concerning the efficiency and the laser power and energy requirements are discussed.

Chen, P.

1986-04-01

399

SUPERDIFFUSIVE SHOCK ACCELERATION  

SciTech Connect

The theory of diffusive shock acceleration is extended to the case of superdiffusive transport, i.e., when the mean square deviation grows proportionally to t{sup {alpha}}, with {alpha} > 1. Superdiffusion can be described by a statistical process called Levy random walk, in which the propagator is not a Gaussian but it exhibits power-law tails. By using the propagator appropriate for Levy random walk, it is found that the indices of energy spectra of particles are harder than those obtained where a normal diffusion is envisaged, with the spectral index decreasing with the increase of {alpha}. A new scaling for the acceleration time is also found, allowing substantially shorter times than in the case of normal diffusion. Within this framework we can explain a number of observations of flat spectra in various astrophysical and heliospheric contexts, for instance, for the Crab Nebula and the termination shock of the solar wind.

Perri, S.; Zimbardo, G. [Dipartimento di Fisica, Universita della Calabria, Ponte P. Bucci Cubo 31C, I-87036 Rende (Italy)

2012-05-10

400

Accelerator research studies  

NASA Astrophysics Data System (ADS)

The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER-40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK 1, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams; TASK 2, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK 3, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks.

401

D-2 acceleration characterization  

NASA Astrophysics Data System (ADS)

During the second German Spacelab Mission D-2, extensive onboard measurements of the residual acceleration were performed. The payload was equipped with accelerometer packages distributed over the entire Spacelab module. The microgravity measurement assembly (MMA) was the core system comprising fixed mounted as well as mobile sensor packages. Additional autonomous accelerometer systems were mounted within the payload elements MEDEA and Werkstofflabor. On-board video recording has been performed to correlate the measured accelerations to mission events. The D-2 microgravity characterization program also included numerical calculations to predict low frequency effects due to atmospheric drag, tidal force, and spacecraft rotation. Results of characteristic quiet mission phases show that the microgravity level is essentially below the requirements defined for the space station. Other results of some other mission phases revealed that a wealth can be done by improving payload design and operation to improve the microgravity quality of Spacelab missions.

Hamacher, Hans; Bluemel, U.

1994-07-01

402

Electron acceleration above thunderclouds  

NASA Astrophysics Data System (ADS)

The acceleration of electrons results in observable electromagnetic waves which can be used for remote sensing. Here, we make use of 4 Hz-66 MHz radio waves emitted by two consecutive intense positive lightning discharges to investigate their impact on the atmosphere above a thundercloud. It is found that the first positive lightning discharge initiates a sprite where electrons are accelerated during the exponential growth and branching of the sprite streamers. This preconditioned plasma above the thundercloud is subsequently exposed to a second positive lightning discharge associated with a bouncing-wave discharge. This discharge process causes a re-brightening of the existing sprite streamers above the thundercloud and initiates a subsequent relativistic electron beam.

Fllekrug, Martin; Kolmasova, Ivana; Santolik, Ondrej; Farges, Thomas; Br, Jzsef; Bennett, Alec; Parrot, Michel; Rison, William; Zanotti, Ferruccio; Arnone, Enrico; Mezentsev, Andrew; Lan, Radek; Uhlir, Ludek; Harrison, Giles; Soula, Serge; van der Velde, Oscar; Pinon, Jean-Louis; Helling, Christiane; Diver, Declan

2013-09-01

403

Electron acceleration above thunderclouds  

NASA Astrophysics Data System (ADS)

The acceleration of electrons results in observable electromagnetic waves which can be used for remote sensing. Here, we make use of ?4 Hz66 MHz radio waves emitted by two consecutive intense positive lightning discharges to investigate their impact on the atmosphere above a thundercloud. It is found that the first positive lightning discharge initiates a sprite where electrons are accelerated during the exponential growth and branching of the sprite streamers. This preconditioned plasma above the thundercloud is subsequently exposed to a second positive lightning discharge associated with a bouncing-wave discharge. This discharge process causes a re-brightening of the existing sprite streamers above the thundercloud and initiates a subsequent relativistic electron beam.

Fllekrug, Martin; Kolmasova, Ivana; Santolik, Ondrej; Farges, Thomas; Br, Jzsef; Bennett, Alec; Parrot, Michel; Rison, William; Zanotti, Ferruccio; Arnone, Enrico; Mezentsev, Andrew; Lan, Radek; Uhlir, Ludek; Harrison, Giles; Soula, Serge; van der Velde, Oscar; Pinon, Jean-Louis; Helling, Christiane; Diver, Declan

2013-09-01

404

Photon acceleration from rest  

SciTech Connect

In this paper we present a new mechanism for generating coherent radiation from a laser-ionized gas-filled capacitor array. The scheme directly converts a static electric field of wave number {ital k}{sub 0} into coherent radiation pulses. The physical mechanism is analogous to photon acceleration in plasma waves, and in this sense, photons are accelerated from zero frequency (zero energy) to a frequency {omega}{sup 2}{sub {ital p}}/2{ital k}{sub 0}{ital c}. The frequency (energy) of the photons is controlled by the gas pressure and/or capacitor spacing and has broad tunability over several orders of magnitude. We calculate the output frequency and power and compare theoretical predictions to 2D PIC simulations. {copyright} 1995 {ital American Institute of Physics}.

Katsouleas, T.; Lai, C.H. [Department of Electrical Engineering-Electrophysics, University of Southern California Los Angeles, California 90089 (United States); Dawson, J.M.; Mori, W.B. [UCLA Department of Electrical Engineering, Los Angeles, California 90024 (United States)

1995-06-01

405

Accelerator research studies  

SciTech Connect

The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks.

Not Available

1993-01-01

406

Self-Accelerated Universe  

NASA Astrophysics Data System (ADS)

It is widely believed that the large redshifts for distant supernovae are due to the vacuum energy dominance, which is responsible for the anti-gravitation effect. A tacit assumption is that particles move along geodesics for the background metric. This is in the same spirit as the consensus regarding the uniform Galilean motion of a free electron. However, apart from the Galilean solution, there is a self-accelerated solution to the Lorentz-Dirac equation governing the behavior of a radiating electron. Likewise, a runaway solution to the entire system of equations, both gravitation and matter equations of motion including, may exist, which provides an alternative explanation for the accelerated expansion of the Universe.

Kosyakov, B. P.

407

Commissioning the GTA accelerator  

SciTech Connect

The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth's magnetic field and travel in straight lines unless they enter the earth's atmosphere and become charged by stripping. Heavy particles are difficult to stop and can probe the interior of space vehicles; hence, NPB can function as a discriminator between warheads and decoys. We are using GTA to resolve the physics and engineering issues related to accelerating, focusing, and steering a high-brightness, high-current H{sup -} beam and then neutralizing it. Our immediate goal is to produce a 24-MeV, 50mA device with a 2% duty factor.

Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Brown, S.; Cole, R.; Gilpatrick, J.D.; Garnett, R.; Guy, F.W.; Ingalls, W.B.; Johnson, K.F.; Kerstiens, D.; Little, C.; Lohsen, R.A.; Lloyd, S.; Lysenko, W.P.; Mottershead, C.T.; Neuschaefer, G.; Power, J.; Rusthoi, D.P.; Sandoval, D.P. Stevens, R.R. Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V. (Los Alamos National Lab., NM (United States)); Connolly, R.; Weiss, R. (Gr

1992-01-01

408

Commissioning the GTA accelerator  

SciTech Connect

The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth`s magnetic field and travel in straight lines unless they enter the earth`s atmosphere and become charged by stripping. Heavy particles are difficult to stop and can probe the interior of space vehicles; hence, NPB can function as a discriminator between warheads and decoys. We are using GTA to resolve the physics and engineering issues related to accelerating, focusing, and steering a high-brightness, high-current H{sup -} beam and then neutralizing it. Our immediate goal is to produce a 24-MeV, 50mA device with a 2% duty factor.

Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Brown, S.; Cole, R.; Gilpatrick, J.D.; Garnett, R.; Guy, F.W.; Ingalls, W.B.; Johnson, K.F.; Kerstiens, D.; Little, C.; Lohsen, R.A.; Lloyd, S.; Lysenko, W.P.; Mottershead, C.T.; Neuschaefer, G.; Power, J.; Rusthoi, D.P.; Sandoval, D.P. Stevens, R.R. Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V. [Los Alamos National Lab., NM (United States); Connolly, R.; Weiss, R. [Grumman Space and Electronics Corp., Princeton, NJ (United States); Saadatmand, K. [Grumman Corp., Bethpage, NY (United States). Corporate Research Center

1992-09-01

409

Adaptive control for accelerators  

DOEpatents

An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

Eaton, Lawrie E. (Los Alamos, NM); Jachim, Stephen P. (Los Alamos, NM); Natter, Eckard F. (Santa Fe, NM)

1991-01-01

410

Accelerator research studies  

SciTech Connect

The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks.

Not Available

1992-01-01

411

Advanced medical accelerator design  

SciTech Connect

This report describes the design of an advanced medical facility dedicated to charged particle radiotherapy and other biomedical applications of relativistic heavy ions. Project status is reviewed and some technical aspects discussed. Clinical standards of reliability are regarded as essential features of this facility. Particular emphasis is therefore placed on the control system and on the use of technology which will maximize operational efficiency. The accelerator will produce a variety of heavy ion beams from helium to argon with intensities sufficient to provide delivered dose rates of several hundred rad/minute over large, uniform fields. The technical components consist of a linac injector with multiple PIG ion sources, a synchrotron and a versatile beam delivery system. An overview is given of both design philosophy and selected accelerator subsystems. Finally, a plan of the facility is described.

Alonso, J.R.; Elioff, T.; Garren, A.

1982-11-01

412

Future accelerators and experiments  

SciTech Connect

This article describes the status of major new accelerator projects and prospects as of mid 1988. It looks at hadron colliders and electron positron colliders. The author looks both at the technology of the machines, and how it will have to be developed for future devices, and the effort required to extract the important physics information from the resulting reaction cascades which are exected to come out of these devices.

Richter, B.

1993-08-01

413

Frontiers of accelerator instrumentation  

SciTech Connect

New technology has permitted significant performance improvements of established instrumentation techniques including beam position and profile monitoring. Fundamentally new profile monitor strategies are required for the next generation of accelerators, especially linear colliders (LC). Beams in these machines may be three orders of magnitude smaller than typical beams in present colliders. In this paper we review both the present performance levels achieved by conventional systems and present some new ideas for future colliders.

Ross, M.

1992-08-01

414

Accelerated plate tectonics.  

PubMed

The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence. PMID:17799689

Anderson, D L

1975-03-21

415

Photonic Acceleration in Astrophysics  

Microsoft Academic Search

Gamma Ray Bursts (GRB) deliver very high intensity photons with energies from 10 keV to over 100 MeV at a irradiance of 10^30 (30 km\\/R)^2 Watt\\/cm^2. This is in the nonlinear QED regime and the induced wakefield is close to the Schwinger field (E ~^16 V\\/cm). Protons and electrons can be accelerated in such a strong field to 10^21 eV\\/km

Yoshiyuki Takahashi

2000-01-01

416

Progress of RIBF accelerators  

NASA Astrophysics Data System (ADS)

In order to greatly expand scientific opportunities with radioactive isotope (RI) beams, RIKEN has constructed a new heavy-ion accelerator facility, called "RI Beam Factory (RIBF)." Three new ring cyclotrons with K-values of 570 MeV, 980 MeV, and 2600 MeV, respectively, boost the energies of the output beams from the existing K540-MeV ring cyclotron up to 440 MeV/u for light ions and 345 MeV/u for very heavy ions. These energetic heavy-ion beams are converted into intense radioactive isotope (RI) beams via projectile fragmentation of stable isotopes or in-flight fission of uranium isotopes by a superconducting fragment separator, BigRIPS. The three ring cyclotrons were commissioned in 2006, and RI beams from uranium were first obtained in 2007. The beam intensities and available ion species are increasing at RIBF, owing to the continuous efforts that have been made since the first beam. So far, we have accelerated deuteron, helium, nitrogen, oxygen, aluminum, calcium, zinc, krypton, xenon, and uranium beams with the superconducting ring cyclotron (SRC). The extracted beam intensities reached 1000 pnA for the helium and oxygen beams, and the calcium beam intensity exceeded 400 pnA recently. The intensities of the xenon and uranium beams are also increasing; they reached 24 and 3.6 pnA, respectively. This paper illustrates the construction, commissioning, and various improvements carried out for the RIBF accelerators, as well as the present accelerator performance.

Okuno, H.; Fukunishi, N.; Kamigaito, O.

2012-12-01

417

New techniques for particle accelerators  

SciTech Connect

A review is presented of the new techniques which have been proposed for use in particle accelerators. Attention is focused upon those areas where significant progress has been made in the last two years--in particular, upon two-beam accelerators, wakefield accelerators, and plasma focusers. 26 refs., 5 figs., 1 tab.

Sessler, A.M.

1990-06-01

418

Accelerator operation management using objects  

Microsoft Academic Search

Conflicts over control of shared devices or resources in an accelerator control system, and problems that can occur due to applications performing conflicting operations, are usually resolved by accelerator operators. For these conflicts to be detected by the control system, a model of accelerator operation must be available to the system. We present a design for an operation management system

H. Nishimura; C. Timossi; M. Valdez

1995-01-01

419

Superconducting cavities for particle accelerators  

Microsoft Academic Search

RF Superconductivity has become an important technology for particle accelerators for high energy physics, nuclear physics, and free electron lasers. More than 100 MVolts of Superconducting RF (SRF) cavities have been installed in accelerators for heavy ions and operated at gradients of 2-3 MV\\/m in excess of 105 hours. More than 500 MVolts are installed in electron accelerators and operated

H. Padamsee

1992-01-01

420

A novel rotary acceleration sensor  

Microsoft Academic Search

The authors developed a new type of rotary acceleration sensor. It has the capability to sense an angular acceleration independently to the rotational speed and has an unlimited rotation range. The authors believe that this sensor can be used in robust motor control, vibration control, and any other application where a reliable acceleration signal is needed. The sensor's structure and

Ivan Godler; Akira Akahane; Kouhei Ohnishi; Tadashi Yamashita

1995-01-01

421

Accelerated Profile HMM Searches.  

PubMed

Profile hidden Markov models (profile HMMs) and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV) algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches. PMID:22039361

Eddy, Sean R

2011-10-20

422

Cell accelerated cryoablation simulation.  

PubMed

Tumor cryoablation is a clinical procedure where supercooled probes are used to destroy cancerous lesions. Cryoablation is a safe and effective palliative treatment for skeletal metastases, providing immediate and long term pain relief, increasing mobility and improving quality of life. Ideally, lesions are encompassed by an ice ball and frozen to a sufficiently low temperature to ensure cell death. "Lethal ice" is the term used to describe regions within the ice ball where cell death occurs. Failure to achieve lethal ice in all portions of a lesion may explain the high recurrence rate currently observed. Tracking growth of lethal ice is critical to success of percutaneous ablations, however, no practical methods currently exist for non-invasive temperature monitoring. Physicians lack planning tools which provide accurate estimation of the ice formation. Simulation of ice formation, while possible, is computationally demanding and too time consuming to be of clinical utility. We developed the computational framework for the simulation, acceleration strategies for multicore Intel x86 and IBM Cell architectures, and performed preliminary validation of the simulation. Our results demonstrate that the streaming SIMD implementation has better performance and scalability. Both accelerated and non-accelerated algorithms demonstrate good agreement between simulation and manually identified ice ball boundaries in phantom and patient images. Our results show promise for the development of novel cryoablation planning tools with real-time monitoring capability for clinical use. PMID:19854531

Blezek, Daniel J; Carlson, David G; Cheng, Lionel T; Christensen, Jared A; Callstrom, Matthew R; Erickson, Bradley J

2009-10-24

423

ACCELERATION INTEGRATING MEANS  

DOEpatents

An acceleration responsive device is described. A housing has at one end normally open electrical contacts and contains a piston system with a first part of non-magnetic material having metering orifices in the side walls for forming an air bearing between it and the walls of the housing; this first piston part is normally held against the other end of the housing from the noted contacts by a second piston or reset part. The reset part is of partly magnetic material, is separable from the flrst piston part, and is positioned within the housing intermediate the contacts and the first piston part. A magnet carried by the housing imposes a retaining force upon the reset part, along with a helical compression spring that is between the reset part and the end with the contacts. When a predetermined acceleration level is attained, the reset part overcomes the bias or retaining force provided by the magnet and the spring'' snaps'' into a depression in the housing adjacent the contacts. The first piston part is then free to move toward the contacts with its movement responsive tc acceleration forces and the metering orifices. (AEC)

Wilkes, D.F.

1961-08-29

424

BNL Sources Development Laboratory  

SciTech Connect

The NSLS has a long-standing interest in providing the best possible synchrotron radiation sources for its user community, and hence, has recently established the Source Development Laboratory (SDL) to pursue research into fourth generation synchrotron radiation sources. A major element of the program includes development of a high peak power FEL meant to operate in the vacuum ultraviolet. The objective of the program is to develop the source, and experimental technology together to provide the greatest impact on UV science. The accelerator under construction for the SDL consists of a high brightness RF photocathode electron gun followed by a 230 MeV short pulse linac incorporating a magnetic chicane for pulse compression. The gun drive laser is a wide bandwidth Ti: Sapphire regenerative amplifier capable of pulse shaping which will be used to study non- linear emittance compensation. Using the compressor, 1 nC bunches with a length as small as 50 {mu}m sigma (2 kA peak current) are available for experiments. In this paper we briefly describe the facility and detail our plans for utilizing the 10 m long NISUS wiggler to carry out single pass FEL experiments. These include a 1 {mu}m SASE demonstration, a seeded beam demonstration at 300 nm, and a High Gain Harmonic Generation experiment at 200 mn. The application of chirped pulse amplification to this type of FEL will also be discussed.

Ben-Zvi, I.; Graves, W.; Heese, R.; Johnson, E.D.; Krinsky, S.; Yu, L.H.

1997-01-01

425

Accelerator and transport line survey and alignment  

SciTech Connect

This paper summarizes the survey and alignment processes of accelerators and transport lines and discusses the propagation of errors associated with these processes. The major geodetic principles governing the survey and alignment measurement space are introduced and their relationship to a lattice coordinate system shown. The paper continues with a broad overview about the activities involved in the step sequence from initial absolute alignment to final smoothing. Emphasis is given to the relative alignment of components, in particular to the importance of incorporating methods to remove residual systematic effects in surveying and alignment operations. Various approaches to smoothing used at major laboratories are discussed. 47 refs., 19 figs., 1 tab.

Ruland, R.E.

1991-10-01

426

Accelerator Physics: An Undergraduate Course in Experimental Nuclear Physics  

ERIC Educational Resources Information Center

|Discusses a 2-semester-hour experimental physics course utilizing a 0.5 MeV Van de Graaff accelerator. The course requires the completion of six or seven laboratory projects including complete written reports, and theory is emphasized only to the extent needed to understand the projects. (MLH)|

Fielder, Douglas S.

1976-01-01

427

Performance of Capillary Discharge Guided Laser Plasma Wakefield Accelerator.  

National Technical Information Service (NTIS)

A GeV-class laser-driven plasma-based wakefield accelerator has been realized at the Lawrence Berkeley National Laboratory (LBNL). The device consists of the 40TW high repetition rate Ti:sapphire LOASIS laser system at LBNL and a gas-filled capillary disc...

A. J. Gonsalves C. G. R. Geddes E. Esarey K. Nakamura W. P. Leemans

2007-01-01

428

BOOK REVIEW: Electron acceleration in the aurora and beyond  

Microsoft Academic Search

Duncan Bryant is a retired space plasma physicist who spent most of his career at the Rutherford-Appleton Laboratory in Oxfordshire, England. For many years he has been challenging a widely accepted theory, that auroral electrons are accelerated by double layers, on the grounds that it contains a fundamental error (allegedly, an implicit assumption that charged particles can gain energy from

D. Bryant

1999-01-01

429

The Accelerated Ageing of Some Commercial Polyurethane Rubbers.  

National Technical Information Service (NTIS)

Nineteen commercial polyester urethane rubbers, and one commercial polyether urethane rubber were subjected to accelerated laboratory ageing for periods of up to two years under hot/dry, hot/wet, and hot/humid conditions, and for up to two years immersed ...

B. L. Hollingsworth K. J. Ledbury A. L. Stokoe

1967-01-01

430

Accelerator Mass Spectrometry in Biology and Health Care  

NSDL National Science Digital Library

This video, developed at Lawrence Livermore National Laboratory, describes the instrumentation for accelerator mass spectrometry and its applications. The content describes the instrumentation and its application for carbon dating and measurements of drug distribution. Running time for the video is 49:31.

2011-06-06

431

Ohio University Tandem van de Graaff Accelerator. Final Report.  

National Technical Information Service (NTIS)

A summary is given of the work carried out at the John Edwards Tandem Accelerator Laboratory of Ohio University during the period 1970 to 1977 on studies of neutron-nucleus interactions and nuclear structure using neutrons as probes. This work utilizes th...

R. O. Lane

1977-01-01

432

Cryogenic systems for large superconducting accelerators/storage rings  

SciTech Connect

Particle accelerators and storage rings which utilize superconducting magnets have presented cryogenic system designers, as well as magnet designers, with many new challenges. When such accelerators were first proposed, little operational experience existed to guide the design. Two superconducting accelerators, complete with cryogenic systems, have been designed and are now under construction. These are the Fermilab Doubler Project and the Brookhaven National Laboratory ISABELLE Project. The cryogenic systems which developed at these two laboratories share many common characteristics, especially as compared to earlier cryogenic systems. Because of this commonality, these characteristics can be reasonably taken as also being representative of future systems. There are other areas in which the two systems are dissimilar. In those areas, it is not possible to state which, if either, will be chosen by future designers. Some of the design parameters for the two systems are given.

Brown, D P

1981-01-01

433

Separations technology development to support accelerator-driven transmutation concepts  

SciTech Connect

This is the final report of a one-year Laboratory-Directed Research and Development (LDRD) Project at the Los Alamos National Laboratory (LANL). This project investigated separations technology development needed for accelerator-driven transmutation technology (ADTT) concepts, particularly those associated with plutonium disposition (accelerator-based conversion, ABC) and high-level radioactive waste transmutation (accelerator transmutation of waste, ATW). Specific focus areas included separations needed for preparation of feeds to ABC and ATW systems, for example from spent reactor fuel sources, those required within an ABC/ATW system for material recycle and recovery of key long-lived radionuclides for further transmutation, and those required for reuse and cleanup of molten fluoride salts. The project also featured beginning experimental development in areas associated with a small molten-salt test loop and exploratory centrifugal separations systems.

Venneri, F.; Arthur, E.; Bowman, C. [and others

1996-10-01

434

Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic  

SciTech Connect

The design and current status of experiments to couple the Tapered Hybrid Undulator (THUNDER) to the Lawrence Berkeley National Laboratory (LBNL) laser plasma accelerator (LPA) to measure electron beam energy spread and emittance are presented.

Bakeman, M.S.; Van Tilborg, J.; Nakamura, K.; Gonsalves, A.; Osterhoff, J.; Sokollik, T.; Lin, C.; Robinson, K.E.; Schroeder, C.B.; Toth, Cs.; Weingartner, R.; Gruner, F.; Esarey, E.; Leemans, W.P.

2010-06-01

435

Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic  

NASA Astrophysics Data System (ADS)

The design and current status of experiments to couple the Tapered Hybrid Undulator (THUNDER) to the Lawrence Berkeley National Laboratory (LBNL) laser plasma accelerator (LPA) to measure electron beam energy spread and emittance are presented.

Bakeman, M. S.; van Tilborg, J.; Nakamura, K.; Gonsalves, A.; Osterhoff, J.; Sokollik, T.; Lin, C.; Robinson, K. E.; Schroeder, C. B.; Tth, Cs.; Weingartner, R.; Grner, F.; Esarey, E.; Leemans, W. P.

2010-11-01

436

Establishing the Biodynamics Data Resource (BDR): Human Volunteer Impact Acceleration Research Data in the BDR.  

National Technical Information Service (NTIS)

One of the most noteworthy collections of impact exposure data was generated at the U.S. Naval Biodynamics Laboratory (NBDL). Over 25 years, NBDL conducted thousands of impact acceleration exposures with hundreds of human research volunteers. The resultin...

A. E. Austermann A. L. Schmidt B. S. Shender K. B. Vasquez V. C. Chancey

2010-01-01

437

Effect of Transverse Venting on Flame Acceleration and Transition to Detonation in a Large Channel.  

National Technical Information Service (NTIS)

The FLAME facility was built at Sandia National Laboratory, Albuquerque, NM for the US Nuclear Regulatory Commission to study flame acceleration, transition to detonation, and other hydrogen combustion problems relevant to nuclear reactor safety. The size...

M. P. Sherman S. R. Tiezsen W. B. Benedick J. W. Fisk M. Carcassi

1985-01-01

438

Accelerators and Superconductivity: A Marriage of Convenience. Second John Adams Memorial Lecture.  

National Technical Information Service (NTIS)

This lecture deals with the relationship between accelerator technology in high-energy-physics laboratories and the development of superconductors. It concentrates on synchrotron magnets, showing how their special requirements have brought about significa...

M. Wilson

1987-01-01

439

Laser-Driven Proton Beams: Acceleration Mechanism, Beam Optimization, and Radiographic Applications  

Microsoft Academic Search

This paper reviews recent experimental activity in the area of optimization, control, and application of laser-accelerated proton beams, carried out at the Rutherford Appleton Laboratory and the Laboratoire pour lpsilaUtilisation des Lasers Intenses 100 TW facility in France. In particular, experiments have investigated the role of the scale length at the rear of the plasma in reducing target-normal-sheath-acceleration acceleration efficiency.

Marco Borghesi; Carlo Alberto Cecchetti; Toma Toncian; Julien Fuchs; Lorenzo Romagnani; Satyabrata Kar; P. A. Wilson; Patrizio Antici; Patrick Audebert; Erik Brambrink; Ariane Pipahl; Munib Amin; Ralph Jung; Jens Osterholz; Oswald Willi; Wigen Nazarov; Robert J. Clarke; Margaret Notley; David Neely; Patrick Mora; Thomas Grismayer; Guy Schurtz; Angelo Schiavi; Yasuhiko Sentoku

2008-01-01

440

STUDIES OF A FREE ELECTRON LASER DRIVEN BY A LASER-PLASMA ACCELERATOR  

Microsoft Academic Search

A free electron laser (FEL) uses an undulator, a set of alternating magnets producing a periodic magnetic fi eld, to stimulate emission of coherent radiation from a relativistic electron beam. The Lasers, Optical Accelerator Systems Integrated Studies (LOASIS) group at Lawrence Berkeley National Laboratory (LBNL) will use an innovative laser- plasma wakefi eld accelerator to produce an electron beam to

ANDREA MONTGOMERY; CARL SCHROEDER; WILLIAM FAWLEY

441

On the g/2 Acceleration of a Pulse in a Vertical Chain  

NASA Astrophysics Data System (ADS)

We have frequently enhanced our department's laboratory experiment involving standing transverse waves in a taut horizontal cord. In addition to the standard experiment, students in these labs investigate the surprising concept that the acceleration of a pulse in a chain hanging vertically is a constant and is equal to half the acceleration of gravity.

Foster, Theodore; van Wyngaarden, Willem; Cary, Arthur; Mottmann, John

2013-10-01

442

SETUP AND PERFORMANCE OF THE RHIC INJECTOR ACCELERATORS FOR THE 2005 RUN WITH COPPER IONS.  

SciTech Connect

Copper ions for the 2005 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of these accelerators with copper are reviewed in this paper.

AHRENS, L.; ALESSI, J.; GARDNER, C.J.

2005-05-16

443

Design of accelerated corrosion tests for electronic components in automotive applications  

Microsoft Academic Search

Two new accelerated laboratory corrosion tests for electronic components in automotive applications have been developed, based on the use of metallic copper as a meter for corrosivity. The accelerated tests are designed so that they reproduce the same kind of corrosion effects as observed with exposure of copper in real vehicle environments. The test cycle that best simulates the corrosion

Peter Eriksson; Bo Carlsson; I. O. Wallinder

2001-01-01

444

Drive Beam Shaping and Witness Bunch Generation for the Plasma Wakefield Accelerator  

SciTech Connect

High transformer ratio operation of the plasma wake field accelerator requires a tailored drive beam current profile followed by a short witness bunch. We discuss techniques for generating the requisite dual bunches and for obtaining the desired drive beam profile, with emphasis on the FACET experiment at SLAC National Accelerator Laboratory.

England, R. J.; Frederico, J.; Hogan, M. J. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Muggli, P. [University of Southern California, Los Angeles, CA 90089 (United States); Joshi, C. [University of California Los Angeles, Los Angeles, CA 90024 (United States)

2010-11-04

445

Accelerator R&D: Research for Science - Science for Society  

SciTech Connect

In September 2011 the US Senate Appropriations Committee requested a ten-year strategic plan from the Department of Energy (DOE) that would describe how accelerator R&D today could advance applications directly relevant to society. Based on the 2009 workshop 'Accelerators for America's Future' an assessment was made on how accelerator technology developed by the nation's laboratories and universities could directly translate into a competitive strength for industrial partners and a variety of government agencies in the research, defense and national security sectors. The Office of High Energy Physics, traditionally the steward for advanced accelerator R&D within DOE, commissioned a task force under its auspices to generate and compile ideas on how best to implement strategies that would help fulfill the needs of industry and other agencies, while maintaining focus on its core mission of fundamental science investigation.

The HEP Accelerator R& D Task Force: N.R. Holtkamp,S. Biedron, S.V. Milton, L. Boeh, J.E. Clayton, G. Zdasiuk, S.A. Gourlay, M.S. Zisman,R.W. Hamm, S. Henderson, G.H. Hoffstaetter, L. Merminga, S. Ozaki, F.C. Pilat, M. White

2012-07-01

446

Dust Accelerators And Their Applications In High-Temperature Plasmas  

NASA Astrophysics Data System (ADS)

The perennial presence of dust in high-temperature plasma and fusion devices has been firmly established. Dust inventory must be controlled, in particular in the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and potentially interfere with fusion energy production. Although much effort has been devoted to getting rid of the dust nuisance, there are instances where a controlled use of dust can be beneficial. We have recognized a number of dust-accelerators applications in magnetic fusion, including in plasma diagnostics, in studying dust-plasma interactions, and more recently in edge localized mode (ELM)'s pacing. With the applications in mind, we will compare various acceleration methods, including electrostatic, gas-drag, and plasma-drag acceleration. We will also describe laboratory experiments and results on dust acceleration.

Tico?, C?t?lin M.; Wang, Zhehui

2011-06-01

447

Vacuum insulator development for the dielectric wall accelerator  

NASA Astrophysics Data System (ADS)

At Lawrence Livermore National Laboratory, we are developing a new type of accelerator, known as a dielectric wall accelerator, in which compact pulse-forming lines directly apply an accelerating field to the beam through an insulating vacuum boundary. The electrical strength of this insulator may define the maximum gradient achievable in these machines. To increase the system gradient, we use ``high-gradient insulators'' composed of alternating layers of dielectric and metal for the vacuum insulator. In this paper, we present our recent results from experiment and simulation, including successful testing of a high-gradient insulator in a functioning dielectric wall accelerator cell. Our results indicate that proper high-voltage conditioning of the insulators can delay the onset of flashover, that the observed conditioning consists of both a permanent and a temporary part, and that the insulators' voltage-holding capability increases with increasing dielectric layer thickness.

Harris, J. R.; Blackfield, D.; Caporaso, G. J.; Chen, Y.-J.; Hawkins, S.; Kendig, M.; Poole, B.; Sanders, D. M.; Krogh, M.; Managan, J. E.

2008-07-01

448

Solvent-free cleaning using a centrifugal cryogenic pellet accelerator  

SciTech Connect

An advanced centrifuge that accelerates frozen CO{sub 2} pellets to high speeds for surface cleaning and paint removal is being developed at the Oak Ridge National Laboratory. The centrifuge-based accelerator was designed, fabricated, and tested under a program sponsored by the Warner Robins Air Logistics Center, Robins Air Force Base, Georgia. In comparison to the more conventional compressed air ``sandblast`` pellet accelerators, the centrifugal accelerator system can achieve higher pellet speeds, has precise speed control, and is more than ten times as energy efficient. Furthermore, the use of frozen CO{sub 2} pellets instead of conventional metal, plastic, sand, or other abrasive materials that remain solid at room temperature, minimizes the waste stream. This apparatus has been used to demonstrate cleaning of various surfaces, including removal of paint, oxide coatings, metal coatings, organic coatings, and oil and grease coatings from a variety of surfaces. The design and operation of the apparatus is discussed.

Haines, J.R.; Fisher, P.W.; Foster, C.A.

1995-06-01

449

The History and Role of Accelerators in Radiation Oncology  

NASA Astrophysics Data System (ADS)

Over one million people are diagnosed with cancer (excluding skin cancer) each year in the United States - about half of those patients will receive radiation as part of their treatment. Radiation Oncology is the field of medicine that specializes in the treatment of cancer with radiation. The evolution of Radiation Oncology, and its success as a cancer treatment modality, has generally paralleled developments in imaging and accelerator technologies. Accelerators, the topic of this paper, have proven to be highly reliable, safe and efficient sources of radiation for cancer treatment. Advances in accelerator technology, especially those that have provided higher energies and dose rates, and more localized (to the tumor volume) dose distributions, have enabled significant improvements in the outcomes of cancer treatments. The use of Cobalt 60 beams has greatly declined in the past decade. Radiation beams used in cancer treatment include x-rays, electrons, protons, negative pions, neutrons, and ions of helium, carbon, neon and silicon. X-rays and electrons, produced by linear electron accelerators, have been the most widely used. The history of medical accelerators can be traced from Roentgen's discovery of x-rays in 1895. The evolution of medical electron accelerators will be discussed and the use of x-ray tubes, electrostatic accelerators, betatrons, and linear accelerators will be described. Heavy particle cancer treatments began in 1955 using proton beams from the Berkeley 184-inch cyclotron. Accelerators that have been used for heavy particle therapy include the Berkeley Bevalac, Los Alamos Pion Facility, Fermi Laboratory, and various research and medical cyclotrons and synchrotrons. Heavy particle accelerators and their application for cancer treatment will be discussed.

Smith, Alfred

2003-04-01

450

Recent Advances in Plasma Acceleration  

ScienceCinema

The costs and the time scales of colliders intended to reach the energy frontier are such that it is important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators a drive beam, either laser or particle, produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultra-high accelerating fields over a substantial length to achieve a significant energy gain. More than 42 GeV energy gain was achieved in an 85 cm long plasma wakefield accelerator driven by a 42 GeV electron drive beam in the Final Focus Test Beam (FFTB) Facility at SLAC. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx}52 GV/m. This effectively doubles their energy, producing the energy gain of the 3 km long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. Prospects for a drive-witness bunch configuration and high-gradient positron acceleration experiments planned for the SABER facility will be discussed.

451

Muon Acceleration - RLA and FFAG  

SciTech Connect

Various acceleration schemes for muons are presented. The overall goal of the acceleration systems: large acceptance acceleration to 25 GeV and 'beam shaping' can be accomplished by various fixed field accelerators at different stages. They involve three superconducting linacs: a single pass linear Pre-accelerator followed by a pair of multi-pass Recirculating Linear Accelerators (RLA) and finally a non-scaling FFAG ring. The present baseline acceleration scenario has been optimized to take maximum advantage of appropriate acceleration scheme at a given stage. The solenoid based Pre-accelerator offers very large acceptance and facilitates correction of energy gain across the bunch and significant longitudinal compression trough induced synchrotron motion. However, far off-crest acceleration reduces the effective acceleration gradient and adds complexity through the requirement of individual RF phase control for each cavity. The RLAs offer very efficient usage of high gradient superconducting RF and ability to adjust path-length after each linac pass through individual return arcs with uniformly periodic FODO optics suitable for chromatic compensation of emittance dilution with sextupoles. However, they require spreaders/recombiners switchyards at both linac ends and significant total length of the arcs. The non-scaling Fixed Field Alternating Gradient (FFAG) ring combines compactness with very large chromatic acceptance (twice the injection energy) and it allows for large number of passes through the RF (at least eight, possibly as high as 15).

Alex Bogacz

2011-10-01

452

Recent Advances in Plasma Acceleration  

SciTech Connect

The costs and the time scales of colliders intended to reach the energy frontier are such that it is important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators a drive beam, either laser or particle, produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultra-high accelerating fields over a substantial length to achieve a significant energy gain. More than 42 GeV energy gain was achieved in an 85 cm long plasma wakefield accelerator driven by a 42 GeV electron drive beam in the Final Focus Test Beam (FFTB) Facility at SLAC. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx}52 GV/m. This effectively doubles their energy, producing the energy gain of the 3 km long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. Prospects for a drive-witness bunch configuration and high-gradient positron acceleration experiments planned for the SABER facility will be discussed.

Hogan, Mark

2007-03-19

453

BotEC: Spacecraft Acceleration  

NSDL National Science Digital Library

Question Suppose someone offered you a ride to the nearest star in a new spacecraft that could travel at half the speed of light, or about 150,000 km/second. In order to reach such a cruising speed, you and the spacecraft must accelerate from a standstill to half the speed of light. Acceleration means uncomfortable (and maybe even fatal!) "g" forces, that pressed-into-the-seat feeling you get when a car or airplane accelerates. More than 3 g's of acceleration are tough to take for very long, so your spacecraft's engines are designed to accelerate you at not more than 29 meters/second/second (3 times the acceleration due to gravity at the Earth's surface). How long will it take you and your spacecraft to accelerate to half light speed?

Tewksbury, Barb

454

A review of accelerator concepts for the Advanced Hydrotest Facility  

SciTech Connect

The Advanced Hydrotest Facility (AHF) is a facility under consideration by the Department of Energy (DOE) for conducting explosively-driven hydrodynamic experiments. The major diagnostic tool at AHF will be a radiography accelerator having radiation output capable of penetrating very dense dynamic objects on multiple viewing axes with multiple pulses on each axis, each pulse having a time resolution capable of freezing object motion ({approx}50-ns) and achieving a spatial resolution {approx}1 mm at the object. Three accelerator technologies are being considered for AHF by the DOE national laboratories at Los Alamos (LANL), Livermore (LLNL), and Sandia (SNL). Two of these are electron accelerators that will produce intense x-ray pulses from a converter target yielding a dose {approx}1,000--2,000 Rads {at} 1 meter. LLNL has proposed a 16--20 MeV, 3--6 kA linear induction accelerator (LIA) driven by FET-switched modulators driving metglas loaded cavities. SNL has proposed a 12-MeV, 40-kA Inductive Voltage Adder (IVA) accelerator based on HERMES III pulsed power technology. The third option is a 25--50-GeV proton accelerator capable of {approx}10{sup 13} protons/pulse proposed by LANL. This paper will review the current status of the three accelerator concepts for AHF.

Toepfer, A.J. [Science Applications International Corp., Albuquerque, NM (United States)

1998-08-01

455

Laser plasma accelerators  

SciTech Connect

This review article highlights the tremendous evolution of the research on laser plasma accelerators which has, in record time, led to the production of high quality electron beams at the GeV level, using compact laser systems. I will describe the path we followed to explore different injection schemes and I will present the most significant breakthrough which allowed us to generate stable, high peak current and high quality electron beams, with control of the charge, of the relative energy spread and of the electron energy.

Malka, V. [Laboratoire d'Optique Appliquee, ENSTA-ParisTech, CNRS, Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2012-05-15

456

Kinematics: Speed, Velocity & Acceleration  

NSDL National Science Digital Library

The following resource is a NFL sponsored, National Science Foundation funded program intended to teach students about scientific concepts by using the popular sport of Football. Each lesson is accompanied by an informative and fast paced video. In this lesson, students will explore kinematics on the playing field. NSF-funded scientists Tony Schmitz from the University of Florida and John Ziegert of Clemson University explain how the kinematic concepts of position, velocity and acceleration can be used to define how a running back moves.

2010-01-01

457

Thomas Jefferson National Accelerator  

NSDL National Science Digital Library

Thomas Jefferson National Accelerator Facility (Jefferson Lab) is funded by the Office of Science for the United States Department of Energy (DoE) with strong support from the City of Newport News, the Commonwealth of Virginia, and the United States Congress. As a user facility for scientists worldwide, its primary mission is to conduct basic research of the atomâs nucleus at the quark level. The page features information of different scientific programs, public connections and information on the Jefferson Lab in its working form.

2009-04-06

458

Acceleration in Weyl geometry  

NASA Astrophysics Data System (ADS)

We study homogeneous and isotropic cosmologies in a Weyl spacetime. We show that the field equations can be reduced to the Einstein equations with a two-fluid source and analyze the qualitative, asymptotic behavior of the models. Assuming an interaction of the two fluids we impose conditions so that the solutions of the corresponding dynamical system remain in the physically acceptable phase space. We show that in Weyl integrable spacetime, the corresponding scalar field acts as a phantom field and therefore, it may give rise to a late accelerated expansion of the Universe.

Miritzis, J.

2013-08-01

459

ORNL 25 MV tandem accelerator control system  

SciTech Connect

The CAMAC-based control system for the 25 MV tandem electrostatic accelerator of the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory (ORNL) was specified by ORNL and built by the National Electrostatics Corporation. Two Perkin-Elmer 32-bit minicomputers are used in the system, a message switching computer and a supervisory computer. The message switching computer transmits and receives control information on six serial highways. This computer shares memory with the supervisory computer. Operator consoles are located on a serial highway; control is by means of a console CRT, trackball, and assignable shaft encoders and meters. Two identical consoles operate simultaneously: one is located in the tandem control room; the other is located in the cyclotron control room to facilitate operation during injection of tandem beams into the cyclotron or when beam lines under control of the cyclotron control system are used. The supervisory computer is used for accelerator parameter setup calculations, actual accelerator setup for new beams based on scaled, recorded parameters from previously run beams, and various other functions. Nearly seven years of control system operation and improvements will be discussed.

Juras, R.C.; Biggerstaff, J.A.; Hoglund, D.E.

1985-01-01

460

Measurement of gravitational acceleration by dropping atoms  

NASA Astrophysics Data System (ADS)

Laser-cooling of atoms and atom-trapping are finding increasing application in many areas of science. One important use of laser-cooled atoms is in atom interferometers. In these devices, an atom is placed into a superposition of two or more spatially separated atomic states; these states are each described by a quantum-mechanical phase term, which will interfere with one another if they are brought back together at a later time. Atom interferometers have been shown to be very precise inertial sensors for acceleration,, rotation and for the measurement of the fine structure constant. Here we use an atom interferometer based on a fountain of laser-cooled atoms to measure g, the acceleration of gravity. Through detailed investigation and elimination of systematic effects that may affect the accuracy ofthe measurement, we achieve an absolute uncertainty of ?g/g ~ 3 10-9, representing a million-fold increase in absoluteaccuracy compared with previous atom-interferometer experiments. We also compare our measurement with the value of g obtained at the same laboratory site using a Michelson interferometer gravimeter (a modern equivalent of Galileo's `leaning tower' experiment in Pisa). We show that the macroscopic glass object used in this instrument falls with the same acceleration, to within 7 parts in 109, as a quantum-mechanical caesium atom.

Peters, Achim; Chung, Keng Yeow; Chu, Steven

1999-08-01

461

Domain vector accelerator (DVA): A query accelerator for relational operations  

Microsoft Academic Search

A fast method is described for performing relational operations and, in particular, for an equijoin between two relations that stand in a one-to-many relationship. The method is based on a bit-vector technique called domain vector acceleration (DVA). The approach to join acceleration is described and compared analytically with two other join accelerators, hybrid-hash join and join indices. Results show that

William Perrizo; James Gustafson; Daniel Thureen; David Wenberg; William Davidson

1991-01-01

462

Transverse electron resonance accelerator  

SciTech Connect

Transverse (to the velocity, v, of the particles to be accelerated) electron oscillations are generated in high (e.g. solid) density plasmas by either an electromagnetic wave or by the field of charged particles traveling parallel to v. The generating field oscillates with frequency ..omega.. = ..omega../sub p/, where ..omega../sub p/ is the plasma frequency. The plasma is confined to a sequence of microstructures with typical dimensions of d approx. = 2..pi..c/..omega../sub p/, allowing the generating fields to penetrate. Since ..omega../sub p/ is now high, the time scales, T, are correspondingly reduced. The microstructures are allowed to explode after t = T, until then they are confined by ion inertia. As a result of resonance, the electric field, E, inside the microstructures can exceed the generating field E/sub L/. The generating force is proportional to E/sub L/ (as opposed to E/sub L//sup 2/). Phase matching of particles is possible by appropriate spacing of the microstructures or by a gas medium. The generating beam travels outside the plasma, filamentation is not a problem. The mechanism is relatively insensitive to the exact shape and position of the microstructures. This device contains features of various earlier proposed acceleration mechanisms and may be considered as the limiting case of several of those for small d, T and high E.

Csonka, P.L.

1985-01-01

463

Accelerating the loop expansion  

SciTech Connect

This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi/sup 4/ theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs.

Ingermanson, R.

1986-07-29

464

Broadband accelerator control network  

SciTech Connect

A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz bandwidth Digital Control channel using CSMA-CA protocol is provided for digital data transmission, with 8 access nodes available over the length of the RELWAY. Each node consists of an rf modem and a microprocessor-based store-and-forward message handler which interfaces the RELWAY to a branch line implemented in GPIB. A gateway to the RELWAY control channel for the (preexisting) AGS Computerized Accelerator Operating system has been constructed using an LSI-11/23 microprocessor as a device in a GPIB branch line. A multilayer communications protocol has been defined for the Digital Control Channel, based on the ISO Open Systems Interconnect layered model, and a RELWAY Device Language defined as the required universal language for device control on this channel.

Skelly, J.; Clifford, T.; Frankel, R.

1983-01-01

465

Obesity accelerates thymic aging  

PubMed Central

As the expanding obese population grows older, their successful immunologic aging will be critical to enhancing the health span. Obesity increases risk of infections and cancer, suggesting adverse effects on immune surveillance. Here, we report that obesity compromises the mechanisms regulating T-cell generation by inducing premature thymic involution. Diet-induced obesity reduced thymocyte counts and significantly increased apoptosis of developing T-cell populations. Obesity accelerated the age-related reduction of T-cell receptor (TCR) excision circle bearing peripheral lymphocytes, an index of recently generated T cells from thymus. Consistent with reduced thymopoiesis, dietary obesity led to reduction in peripheral naive T cells with increased frequency of effector-memory cells. Defects in thymopoiesis in obese mice were related with decrease in the lymphoid-primed multipotent progenitor (Lin?Sca1+Kit+ Flt3+) as well as common lymphoid progenitor (Lin?Sca1+CD117loCD127+) pools. The TCR spectratyping analysis showed that obesity compromised V-? TCR repertoire diversity. Furthermore, the obesity induced by melanocortin 4 receptor deficiency also constricted the T-cell repertoire diversity, recapitulating the thymic defects observed with diet-induced obesity. In middle-aged humans, progressive adiposity with or without type 2 diabetes also compromised thymic output. Collectively, these findings establish that obesity constricts T-cell diversity by accelerating age-related thymic involution.

Yang, Hyunwon; Youm, Yun-Hee; Vandanmagsar, Bolormaa; Rood, Jennifer; Kumar, K. Ganesh; Butler, Andrew A.

2009-01-01

466

[Laboratory-acquired brucellosis].  

PubMed

Brucellosis is a rare disease in Denmark. We describe one case of laboratory-acquired brucellosis from an index patient to a laboratory technician following exposure to an infected blood culture in a clinical microbiology laboratory. PMID:18565306

Fabiansen, Christian; Knudsen, Jenny Dahl; Lebech, Anne-Mette K

2008-06-01

467

Chemistry Laboratory Safety Check  

ERIC Educational Resources Information Center

|An accident prevention/safety check list for chemistry laboratories is printed. Included are checks of equipment, facilities, storage and handling of chemicals, laboratory procedures, instruction procedures, and items to be excluded from chemical laboratories. (SL)|

Patnoe, Richard L.

1976-01-01

468

Laser acceleration and its future.  

PubMed

Laser acceleration is based on the concept to marshal collective fields that may be induced by laser. In order to exceed the material breakdown field by a large factor, we employ the broken-down matter of plasma. While the generated wakefields resemble with the fields in conventional accelerators in their structure (at least qualitatively), it is their extreme accelerating fields that distinguish the laser wakefield from others, amounting to tiny emittance and compact accelerator. The current research largely falls on how to master the control of acceleration process in spatial and temporal scales several orders of magnitude smaller than the conventional method. The efforts over the last several years have come to a fruition of generating good beam properties with GeV energies on a table top, leading to many applications, such as ultrafast radiolysis, intraoperative radiation therapy, injection to X-ray free electron laser, and a candidate for future high energy accelerators. PMID:20228616

Tajima, Toshiki

2010-01-01

469

Magnetic Insulation for Electrostatic Accelerators  

SciTech Connect

The voltage gradient which can be sustained between electrodes without electrical breakdowns is usually one of the most important parameters in determining the performance which can be obtained in an electrostatic accelerator. We have recently proposed a technique which might permit reliable operation of electrostatic accelerators at higher electric field gradients, perhaps also with less time required for the conditioning process in such accelerators. The idea is to run an electric current through each accelerator stage so as to produce a magnetic field which envelopes each electrode and its electrically conducting support structures. Having the magnetic field everywhere parallel to the conducting surfaces in the accelerator should impede the emission of electrons, and inhibit their ability to acquire energy from the electric field, thus reducing the chance that local electron emission will initiate an arc. A relatively simple experiment to assess this technique is being planned. If successful, this technique might eventually find applicability in electrostatic accelerators for fusion and other applications.

Grisham, L. R. [Princeton Plasma Physics Laboratory, P. O. Box 451, Princeton, New Jersey 08543 (United States)

2011-09-26

470

Short bunch research at Brookhaven National Laboratory  

SciTech Connect

Research into the production and utilization of short electron bunches at Brookhaven National Laboratory is underway at the Source Development Laboratory (SDL) and Accelerator Test Facility (ATF). Projects planned for the SDL facility include a 210 MeV electron linac with a dipole chicane that is designed to produce 100 {mu}m long bunches and a compact electron storage ring that will use superconducting RF to produce sub-millimeter bunches.The ATF has a 30-70 MeV linac that will serve as the injector for laser accelerators that will bunch the beam into to micron-length bunches. Coherent transition and synchrotron radiation from the short bunches will be used for beam diagnostics and infrared experiments.

Blum, E.B.

1995-12-31

471

Accelerator Technology Program. Progress report, January-June 1980  

SciTech Connect

The activities of Los Alamos Scientific Laboratory's (LASL) Accelerator Technology (AT) Division during the first six months of calendar 1980 are discussed. This report is organized around major projects of the Division, reflecting a wide variety of applications and sponsors. The first section summarizes progress on the Proton Storage Ring to be located between LAMPF and the LASL Pulsed Neutron Research facility, followed by a section on the gyrocon, a new type of high-power, high-efficiency radio-frequency (rf) amplifier. The third section discusses the racetrack microtron being developed jointly by AT Division and the National Bureau of Standards; the fourth section concerns the free-electron studies. The fifth section covers the radio-frequency quadrupole linear accelerator, a new concept for the acceleration of low-velocity particles; this section is followed by a section discussing heavy ion fusion accelerator development. The next section reports activities in the Fusion Materials Irradiation Test program, a collaborative effort with the Hanford Engineering Development Laboratory. The final section deals first with development of H/sup -/ ion sources and injectors, then with accelerator instrumentation and beam dynamics.

Knapp, E.A.; Jameson, R.A. (Comps.)

1980-03-01

472

Coherent multimoded dielectric wakefield accelerators.  

SciTech Connect

There has recently been a study of the potential uses of multimode dielectric structures for wakefield acceleration [1]. This technique is based on adjusting the wakefield modes of the structure to constructively interfere at certain delays with respect to the drive bunch, thus providing an accelerating gradient enhancement over single mode devices. In this report we examine and attempt to clarify the issues raised by this work in the light of the present state of the art in wakefield acceleration.

Power, J.

1998-07-16

473

Plasma acceleration of particle beams  

SciTech Connect

Plasmas, being fully ionized gases, are immune from electrical breakdown and so can support ultra-high accelerating fields (order GeV/cm) in the form of relativistic plasma waves. Several schemes to excite these waves and use them for particle acceleration are reviewed in this article. These include the beat wave accelerator (laser driven) and the plasma wakefield transformer (particle beam driven). In addition, the possible use of plasmas to provide strong final focusing of beams (the plasma lens) is described.

Katsouleas, T.; Dawson, J. M.

1989-04-05

474

Status of the FMIT accelerator  

SciTech Connect

The linear accelerator being designed and constructed for the Fusion Materials Irradiation Test (FMIT) facility also has great utility as an R and D program that will provide operating information on large, continuous-wave, high-intensity particle accelerators now being considered for various applications, including electronuclear breeding for fuel, power, or tritium production. A 5-MeV FMIT prototype accelerator is under construction at Los Alamos, with operation to 2 MeV planned in early 1983.

Jameson, R.A.

1982-01-01

475

Modern electron accelerators for radiography  

SciTech Connect

Over the past dozen years or so there have been significant advances in electron accelerators designed specifically for radiography of hydrodynamic experiments. Accelerator technology has evolved to accomodate the radiographers' contitiuing quest for multiple images in t h e and space:, improvements in electron beam quality have resulted in smaller radiographic spot sizes for better resolution, while higher radiation do% now provides imprcwed penetration of large, dense objects. Inductive isolation and acceleration techniques have played a ley rob in these advances.

Ekdahl, C. A. (Carl A.)

2001-01-01

476

IFMIF accelerator conceptual design activities  

SciTech Connect

A Conceptual Design Evaluation (CDE) for the International Fusion Materials Irradiation Facility (IFMIF) began in 1997 and will be completed in 1998, as an international program of the IEA involving the European Community, Japan, Russia and the United States. The IFMIF accelerator system, comprising two 125 mA, 40 MeV deuterium accelerators operating at 175 MHz, is a key element of the IFMIF facility. The objectives and accomplishments of the CDE accelerator studies are outlined.

Jameson, R.A. [Los Alamos National Lab., NM (United States); Lagniel, J.M. [CEA Saclay (France); Sugimoto, M. [JAERI (Japan); Kein, H.; Piaszczyk, C.; Tiplyakov, V.

1998-12-31

477

Low energy demonstration accelerator technical area 53  

SciTech Connect

As part of the Department of Energy`s (DOE) need to maintain the capability of producing tritium in support of its historic and near-term stewardship of the nation`s nuclear weapons stockpile, the agency has recently completed a Programmatic Environmental Impact Statement for Tritium Supply and Recycling. The resulting Record of Decision (ROD) determined that over the next three years the DOE would follow a dual-track acquisition strategy that assures tritium production for the nuclear weapon stockpile in a rapid, cost effective, and safe manner. Under this strategy the DOE will further investigate and compare two options for producing tritium: (1) purchase of an existing commercial light-water reactor or irradiation services with an option to purchase the reactor for conversion to