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1

US LHC Accelerator Research Program For the BNL-FNAL-LBNL LHC Accelerator Collaboration  

E-print Network

US LHC Accelerator Research Program Jim Strait For the BNL-FNAL-LBNL LHC Accelerator Collaboration LHC Symposium 3 May 2003 brookhaven - fermilab - berkeley US LHC Accelerator Research Program #12;LHC Symposium - 3 May 03 US LHC Accelerator Research Program - J. Strait 2 Outline Program Goals R&D to Maximize

Large Hadron Collider Program

2

LHC Upgrades For the BNL-FNAL-LBNL LHC Accelerator Collaboration  

E-print Network

LHC Upgrades Jim Strait For the BNL-FNAL-LBNL LHC Accelerator Collaboration DOE Review 10 June 2003 brookhaven - fermilab - berkeley US LHC Accelerator Research Program #12;DOE Review ­ 10-11 June 03 LHC in Luminosity Upgrades Energy Upgrades? Conclusions #12;DOE Review ­ 10-11 June 03 LHC Upgrades - J. Strait 3

Large Hadron Collider Program

3

FNAL-NICADD extruded scintillator  

SciTech Connect

The possibility to produce a scintillator that satisfies the demands of physicists from different science areas has emerged with the installation of an extrusion line at Fermi National Accelerator Laboratory (FNAL). The extruder is the product of the fruitful collaboration between FNAL and Northern Illinois Center for Accelerator and Detector Development (NICADD) at Northern Illinois University (NIU). The results from the light output, light attenuation length and mechanical tolerance indicate that FNAL-NICADD scintillator is of high quality. Improvements in the extrusion die will yield better scintillator profiles and decrease the time needed for initial tuning. This paper will present the characteristics of the FNAL-NICADD scintillator based on the measurements performed. They include the response to MIPs from cosmic rays for individual extruded strips and irradiation studies where extruded samples were irradiated up to 1 Mrad. We will also discuss the results achieved with a new die design. The attractive perspective of using the extruded scintillator with MRS (Metal Resistive Semiconductor) photodetector readout will also be shown.

Beznosko, D.; /Northern Illinois U.; Bross, A.; /Fermilab; Dyshkant, A.; /Northern Illinois U.; Pla-Dalmau, A.; /Fermilab; Rykalin, V.; /Northern Illinois U.

2005-09-01

4

Parameter degeneracies in FNAL-Homestake LBNE setup  

E-print Network

LBNE (Longbaseline Neutrino Oscillation Experiments) provide a powerful experimental setup to study sensitivities and exlcusion limits in neutrino oscillation parameter space. A longbaseline experiment is being planned, at USA, from FNAL (Fermilab National Accelerator Laboratory) to an underground laboratory at Homestake in South Dakota, at an angle of 5.84 degrees from FNAL (at a distance of 1289 km). The prospect of a new beamline towards this location from FNAL, and a 300 Kiloton water Cerenkov detector at the site is in planning stage, for the studies of the neutrino physics program. The long baseline provides sufficient matter effects for neutrino travel, and a large detrecor will help towards better statistics. In this work, we present, upto what extent, the parameter degeneracies, present in oscillation parameter space, can be resolved, using this FNAL-LBNE setup.

Bora, Kalpana

2011-01-01

5

Parameter degeneracies in FNAL-Homestake LBNE setup  

E-print Network

LBNE (Longbaseline Neutrino Oscillation Experiments) provide a powerful experimental setup to study sensitivities and exlcusion limits in neutrino oscillation parameter space. A longbaseline experiment is being planned, at USA, from FNAL (Fermilab National Accelerator Laboratory) to an underground laboratory at Homestake in South Dakota, at an angle of 5.84 degrees from FNAL (at a distance of 1289 km). The prospect of a new beamline towards this location from FNAL, and a 300 Kiloton water Cerenkov detector at the site is in planning stage, for the studies of the neutrino physics program. The long baseline provides sufficient matter effects for neutrino travel, and a large detrecor will help towards better statistics. In this work, we present, upto what extent, the parameter degeneracies, present in oscillation parameter space, can be resolved, using this FNAL-LBNE setup.

Kalpana Bora

2011-11-30

6

Installation and commissioning of the new Fermi National Accelerator Laboratory H- Magnetron  

NASA Astrophysics Data System (ADS)

The Fermi National Accelerator Laboratory (FNAL) 40 year old Cockcroft-Walton 750 keV injectors with slit aperture magnetron ion sources have been replaced with a circular aperture magnetron, Low Energy Beam Transport, Radio Frequency Quadrupole Accelerator, and Medium Energy Beam Transport, as part of the FNAL Proton Improvement Plan. The injector design is based on a similar system at Brookhaven National Laboratory. The installation, commissioning efforts, and source operations to date will be covered in this paper along with plans for additional changes to the original design to improve reliability by reducing extractor spark rates and arc current duty factor.

Bollinger, D. S.

2014-02-01

7

FNAL E866/NuSea Collaboration Abilene Christian University  

E-print Network

FNAL E866/NuSea Collaboration Abilene Christian University Donald Isenhower, Mike Sadler, Rusty National Accelerator Laboratory Chuck Brown, Bill Cooper Georgia State University Gus Petitt, Xiao­chun He Garvey, Mike Leitch, Pat McGaughey, Joel Moss, Jen­Chieh Peng, Paul E. Reimer, Walt Sondheim New Mexico

8

ATLAS accelerator laboratory report  

SciTech Connect

The operation of the ATLAS Accelerator is reported. Modifications are reported, including the installation of conductive tires for the Pelletron chain pulleys, installation of a new high frequency sweeper system at the entrance to the linac, and improvements to the rf drive ports of eight resonators to correct failures in the thermally conductive ceramic insulators. Progress is reported on the positive-ion injector upgrade for ATLAS. Also reported are building modifications and possible new uses for the tandem injector. (LEW)

Den Hartog, P.

1986-01-01

9

CERN-US July 1, 2004 Accelerator Systems Plan -S.Peggs 1 bnl fnal -lbnl -slac  

E-print Network

Accelerator Research Program Accelerator Systems Plan S. Peggs, BNL for LARP Accelerator Systems US Monitoring - Required on day "1" - Independent of beam dynamics functionality (LDM) 2) "LARP should avoid ownership of a critical device" 3) No additional funding after FY04 4) LARP shifts LDM to a potential future

Large Hadron Collider Program

10

Ion Source Development For The Proposed FNAL 750 keV Injector Upgrade  

NASA Astrophysics Data System (ADS)

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). [1] 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 [2]. The current source development effort is to produce a reliable source with >60 mA of H- beam current, 15 Hz rep-rate, 100 ?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) [3].

Bollinger, D. S.

2011-09-01

11

FNAL system patching design  

SciTech Connect

FNAL has over 5000 PCs running either Linux or Windows software. Protecting these systems efficiently against the latest vulnerabilities that arise has prompted FNAL to take a more central approach to patching systems. Due to different levels of existing support infrastructures, the patching solution for linux systems differs from that of windows systems. In either case, systems are checked for vulnerabilities by Computer Security using the Nessus tool.

Schmidt, Jack; Lilianstrom, Al; Romero, Andy; Dawson, Troy; Sieh, Connie; /Fermilab

2004-01-01

12

The Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies.

Batchelor, K.

1992-01-01

13

The Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies.

Batchelor, K.

1992-09-01

14

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

15

Vehicle Systems Integration Laboratory Accelerates Powertrain Development  

ScienceCinema

ORNL's Vehicle Systems Integration (VSI) Laboratory accelerates the pace of powertrain development by performing prototype research and characterization of advanced systems and hardware components. The VSI Lab is capable of accommodating a range of platforms from advanced light-duty vehicles to hybridized Class 8 powertrains with the goals of improving overall system efficiency and reducing emissions.

None

2014-06-25

16

Vehicle Systems Integration Laboratory Accelerates Powertrain Development  

SciTech Connect

ORNL's Vehicle Systems Integration (VSI) Laboratory accelerates the pace of powertrain development by performing prototype research and characterization of advanced systems and hardware components. The VSI Lab is capable of accommodating a range of platforms from advanced light-duty vehicles to hybridized Class 8 powertrains with the goals of improving overall system efficiency and reducing emissions.

None

2014-04-15

17

Numerical and laboratory simulations of auroral acceleration  

SciTech Connect

The existence of parallel electric fields is an essential ingredient of auroral physics, leading to the acceleration of particles that give rise to the auroral displays. An auroral flux tube is modelled using electrostatic Vlasov simulations, and the results are compared to simulations of a proposed laboratory device that is meant for studies of the plasma physical processes that occur on auroral field lines. The hot magnetospheric plasma is represented by a gas discharge plasma source in the laboratory device, and the cold plasma mimicking the ionospheric plasma is generated by a Q-machine source. In both systems, double layers form with plasma density gradients concentrated on their high potential sides. The systems differ regarding the properties of ion acoustic waves that are heavily damped in the magnetosphere, where the ion population is hot, but weakly damped in the laboratory, where the discharge ions are cold. Ion waves are excited by the ion beam that is created by acceleration in the double layer in both systems. The efficiency of this beam-plasma interaction depends on the acceleration voltage. For voltages where the interaction is less efficient, the laboratory experiment is more space-like.

Gunell, H.; De Keyser, J. [1Belgian Institute for Space Aeronomy, Avenue Circulaire 3, B-1180 Brussels (Belgium)] [1Belgian Institute for Space Aeronomy, Avenue Circulaire 3, B-1180 Brussels (Belgium); Mann, I. [EISCAT Scientific Association, P.O. Box 812, SE-981 28 Kiruna, Sweden and Department of Physics, Ume University, SE-901 87 Ume (Sweden)] [EISCAT Scientific Association, P.O. Box 812, SE-981 28 Kiruna, Sweden and Department of Physics, Ume University, SE-901 87 Ume (Sweden)

2013-10-15

18

Numerical and laboratory simulations of auroral acceleration  

NASA Astrophysics Data System (ADS)

The existence of parallel electric fields is an essential ingredient of auroral physics, leading to the acceleration of particles that give rise to the auroral displays. An auroral flux tube is modelled using electrostatic Vlasov simulations, and the results are compared to simulations of a proposed laboratory device that is meant for studies of the plasma physical processes that occur on auroral field lines. The hot magnetospheric plasma is represented by a gas discharge plasma source in the laboratory device, and the cold plasma mimicking the ionospheric plasma is generated by a Q-machine source. In both systems, double layers form with plasma density gradients concentrated on their high potential sides. The systems differ regarding the properties of ion acoustic waves that are heavily damped in the magnetosphere, where the ion population is hot, but weakly damped in the laboratory, where the discharge ions are cold. Ion waves are excited by the ion beam that is created by acceleration in the double layer in both systems. The efficiency of this beam-plasma interaction depends on the acceleration voltage. For voltages where the interaction is less efficient, the laboratory experiment is more space-like.

Gunell, H.; De Keyser, J.; Mann, I.

2013-10-01

19

US LHC Accelerator Project  

NSDL National Science Digital Library

As the US part of the Large Hadron Collider Program, US LHC "consists of efforts of Brookhaven National Laboratory (BNL), Fermi National Accelerator Laboratory (FNAL), and Lawrence Berkeley National Laboratory (LBNL) to support the construction of the LHC at CERN." This Web site provides visitors with links to each of the three participating laboratories as well as information on recent papers, reports, and other materials related to the project. While a bit dated, there is also a press release covering the production of the highest energy producing superconducting accelerator in the world; it utilizes over 6,000 superconducting magnets.

20

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

21

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

22

RIKEN Nishina Center for Accelerator-Based Science Quantum Hadron Physics Laboratory  

E-print Network

Team Detector Team Accelerator Applications Research Group Radiation Biology Team RI Applications Team Nuclear Physics Laboratory Strangeness Nuclear Physics Laboratory Mathematical Physics Laboratory Radiation Laboratory Advanced Meson Science Laboratory Radioactive Isotope Physics Laboratory Spin Isospin

Fukai, Tomoki

23

A national laboratory funded by the Office of Science of the Department of Energy. www.fnal.gov Fermi National Accelerator Laboratory October 2013  

E-print Network

pictures of ancient starlight from billions of light years away. Dark Energy Camera By the numbers The Dark pictures were taken on Sept. 12, 2012. The Dark Energy Survey is a collaborative effort between scientists? As the name implies, the Dark Energy Survey will hopefully help us understand the force we call Dark Energy

Quigg, Chris

24

A national laboratory funded by the Office of Science of the Department of Energy. www.fnal.gov Fermi National Accelerator Laboratory March 2013  

E-print Network

includes approximately 282 species of birds, 56 species of butterflies,10 species of frogs and endangered Blanding's turtles. Native species have been returning to the area as the prairie restoration proceeds

Quigg, Chris

25

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

26

The target laboratory of the Pelletron Accelerator's facilities  

NASA Astrophysics Data System (ADS)

A short report on the activities developed in the Target Laboratory, since 1970, will be presented. Basic target laboratory facilities were provided to produce the necessary nuclear targets as well as the ion beam stripper foils. Vacuum evaporation units, a roller, a press and an analytical balance were installed in the Oscar Sala building. A brief historical report will be presented in commemoration of the 40th year of the Pelletron Accelerator.

Ueta, Nobuko; Pereira Engel, Wanda Gabriel

2013-05-01

27

The target laboratory of the Pelletron Accelerator's facilities  

SciTech Connect

A short report on the activities developed in the Target Laboratory, since 1970, will be presented. Basic target laboratory facilities were provided to produce the necessary nuclear targets as well as the ion beam stripper foils. Vacuum evaporation units, a roller, a press and an analytical balance were installed in the Oscar Sala building. A brief historical report will be presented in commemoration of the 40{sup th} year of the Pelletron Accelerator.

Ueta, Nobuko; Pereira Engel, Wanda Gabriel [Nuclear Physics Department - University of Sao Paulo (Brazil)

2013-05-06

28

http://wdrs.fnal.gov/orientation/checklist.pdf DEPARTMENT ORIENTATION CHECKLIST  

E-print Network

://bss.fnal.gov/telecomm/instructionsfinal.html) Learn office security policies (ID badge, parking, vehicle sticker, etc.) Keep diary of first for national laboratory and DOE information Recommended websites for reference and learning Orientation Video Technical videos as appropriate Other Laboratory videos MEET WITH MANAGER

Quigg, Chris

29

Reproduction of natural corrosion by accelerated laboratory testing methods  

SciTech Connect

Various laboratory corrosion tests have been developed to study the behavior of glass waste forms under conditions similar to those expected in an engineered repository. The data generated by laboratory experiments are useful for understanding corrosion mechanisms and for developing chemical models to predict the long-term behavior of glass. However, it is challenging to demonstrate that these test methods produce results that can be directly related to projecting the behavior of glass waste forms over time periods of thousands of years. One method to build confidence in the applicability of the test methods is to study the natural processes that have been taking place over very long periods in environments similar to those of the repository. In this paper, we discuss whether accelerated testing methods alter the fundamental mechanisms of glass corrosion by comparing the alteration patterns that occur in naturally altered glasses with those that occur in accelerated laboratory environments. This comparison is done by (1) describing the alteration of glasses reacted in nature over long periods of time and in accelerated laboratory environments and (2) establishing the reaction kinetics of naturally altered glass and laboratory reacted glass waste forms.

Luo, J.S.; Wronkiewicz, D.J.; Mazer, J.J.; Bates, J.K.

1996-05-01

30

The Brookhaven National Laboratory (BNL) Accelerator Test Facility  

SciTech Connect

The design of the Brookhaven National Laboratory Accelerator Test Facility is presented including the design goals and computational results. The heart of the system is a radiofrequency electron gun utilizing a photo-excited metal cathode followed by a conventional electron linac. The Nd:YAG laser used to drive the cathode with 6 ps long pulses can be synchronized to a high peak power CO{sub 2} laser in order to study laser acceleration of electrons. Current operational status of the project will be presented along with early beam tests.

Batchelor, K.

1990-01-01

31

Brookhaven National Laboratory's Accelerator Test Facility: research highlights and plans  

NASA Astrophysics Data System (ADS)

The Accelerator Test Facility (ATF) at Brookhaven National Laboratory has served as a user facility for accelerator science for over a quarter of a century. In fulfilling this mission, the ATF offers the unique combination of a high-brightness 80 MeV electron beam that is synchronized to a 1 TW picosecond CO2 laser. We unveil herein our plan to considerably expand the ATF's floor space with an upgrade of the electron beam's energy to 300 MeV and the CO2 laser's peak power to 100 TW. This upgrade will propel the ATF even further to the forefront of research on advanced accelerators and radiation sources, supporting the most innovative ideas in this field. We discuss emerging opportunities for scientific breakthroughs, including the following: plasma wakefield acceleration studies in research directions already active at the ATF; laser wakefield acceleration (LWFA), where the longer laser wavelengths are expected to engender a proportional increase in the beam's charge while our linac will assure, for the first time, the opportunity to undertake detailed studies of seeding and staging of the LWFA; proton acceleration to the 100-200 MeV level, which is essential for medical applications; and others.

Pogorelsky, I. V.; Ben-Zvi, I.

2014-08-01

32

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

33

The cyclotron laboratory and the RFQ accelerator in Bern  

SciTech Connect

Two proton accelerators have been recently put in operation in Bern: an 18 MeV cyclotron and a 2 MeV RFQ linac. The commercial IBA 18/18 cyclotron, equipped with a specifically conceived 6 m long external beam line ending in a separate bunker, will provide beams for routine 18-F and other PET radioisotope production as well as for novel detector, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. The accelerator is embedded into a complex building hosting two physics laboratories and four Good Manufacturing Practice (GMP) laboratories. This project is the result of a successful collaboration between the Inselspital, the University of Bern and private investors, aiming at the constitution of a combined medical and research centre able to provide the most cutting-edge technologies in medical imaging and cancer radiation therapy. The cyclotron is complemented by the RFQ with the primary goals of elemental analysis via Particle Induced Gamma Emission (PIGE), and the detection of potentially dangerous materials with high nitrogen content using the Gamma-Resonant Nuclear Absorption (GRNA) technique. In this context, beam instrumentation devices have been developed, in particular an innovative beam profile monitor based on doped silica fibres and a setup for emittance measurements using the pepper-pot technique. On this basis, the establishment of a proton therapy centre on the campus of the Inselspital is in the phase of advanced study.

Braccini, S.; Ereditato, A.; Kreslo, I.; Nirkko, M.; Weber, M. [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Scampoli, P. [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland and Department of Physical Sciences, University Federico II, Via Cintia, I-60126 Napoli (Italy); Bremen, K. von [SWAN Isotopen AG, Inselspital, CH-3010 Bern (Switzerland)

2013-07-18

34

PREFACE: Acceleration and radiation generation in space and laboratory plasmas  

NASA Astrophysics Data System (ADS)

Sixty-six leading researchers from ten nations gathered in the Homeric village of Kardamyli, on the southern coast of mainland Greece, from August 29-September 4, 1993 for the International Workshop on Acceleration and Radiation Generation in Space and Laboratory Plasmas. This Special Issue represents a cross-section of the presentations made at and the research stimulated by that meeting. According to the Iliad, King Agamemnon used Kardamyli as a dowry offering in order to draw a sulking Achilles into the Trojan War. 3000 years later, Kardamyli is no less seductive. Its remoteness and tranquility made it an ideal venue for promoting the free exchange of ideas between various disciplines that do not normally interact. Through invited presen tations, informal poster discussions and working group sessions, the Workshop brought together leaders from the laboratory and space/astrophysics communities working on common problems of acceleration and radiation generation in plasmas. It was clear from the presentation and discussion sessions that there is a great deal of common ground between these disciplines which is not at first obvious due to the differing terminologies and types of observations available to each community. 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 investi gate the applicability of known laboratory mechanisms to explain observations in natural plasmas. Notable among the latter are the papers by Marshall et al. on kHz radiation in the magnetosphere ; Barletta et al. on collective acceleration in solar flares; and by Dendy et al. on ion cyclotron emission. The papers in this Issue are organized as follows: In Section 1 are four general papers by Dawson, Galeev, Bingham et al. and Mon 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 (Nakajima et al., Shukla, Johnson et al.), microwaves (Nishida et al., Bogomolov et al.) and by particle beams (Ogata et al.). Also in this section are theoretical papers presenting new work on synchrotron like oscillations in plasma waves (Fedele) and two types of laboratory radiation sources, FEL's (Marshall et al.) and ionization fronts (Lai et al.), and Frantzeskakis et al. described the Hamiltonian analysis of a slow-wave autonomous cyclotron buncher. Section 3 contains papers on astrophysical plasmas, with the general presentations of Colgate and Krishnan. Kazanas and Krishnan address active galactic nuclei (AGNs). Thielheim discusses general acceleration mech anisms in rotating magnetized systems. Asseo discussed Langmuir solitons in pulsars and Blackman et al. treat magnetic reconnection relativistically. Su et al. analyze the possibility of plasma wave excitation and particle acceleration by neu trinos from supernovae. Dogiel et al. on cosmic ray scattering by MHD fluctuations. The papers in Section 4 treat fusion plasmas (Dendy et al. and Lashmore-Davies et al.). Section 5, space plasmas, includes papers on acceleration processes in the magnetosphere (Anagnostopoulos and Marshall et al.) and the sun (Barletta et al.). 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. We wish to thank the authors and attendees for their contributions to the success of this workshop, Dr Philip Debenham and Dr David Sutter of the U.S. D.o.E. and Dr Charles Roberson of the U.S. O.N.R. for their financial support (Grants DE-FGO3-93ER40776 and N00014-93-1-0814), and the ECC Twinning Grant SC1*-CT92-0773. We appreciate the considerable local support from Mr Glegles and his staff at the Agricultural Bank of Greece. We thank Mr V. Tataronis, mayor of Kardamyli, and

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

1994-01-01

35

K.T. McDonald June 18, 2009 DUSEL Workshop @ FNAL 1 Strategies for Liquid Argon Detectors at DUSEL  

E-print Network

K.T. McDonald June 18, 2009 DUSEL Workshop @ FNAL 1 Strategies for Liquid Argon Detectors at DUSEL proposal is to build a 5 kton liquid argon detector for use at that time. However, that size is too small desire a giant liquid argon detector in its first round of accelerator neutrino physics. We should rise

McDonald, Kirk

36

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

37

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

38

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

39

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

40

Investigations of the output energy deviation and other parameters during commissioning of the four-rod radio frequency quadrupole at the Fermi National Accelerator Laboratory  

SciTech Connect

After 30 years of operation, the Cockcroft-Walton based injector at FNAL (Fermi National Accelerator Laboratory) has been replaced by a new beam line including a dimpled magnetron 35 keV source in combination with a 750 keV 4-rod Radio Frequency Quadrupole (RFQ). The new injector is followed by the existing drift tube linac (DTL). Prior to installation, a test beam line was built which included the magnetron source and the 4-rod RFQ with a number of beam measurement instrumentation. The first beam test with the RFQ showed an output energy deviation greater than 2.5%. Other problems also showed up which led to investigations of the output energy, power consumption and transmission properties using RF simulations which were complemented with additional beam measurements. The sources of this deviation and the mechanical modifications of the RFQ to solve this matter will be presented in this paper. Meanwhile, the nominal output energy of 750 keV has been confirmed and the new injector with the 4-rod RFQ is in full operation.

Schmidt, J.S.; et al.,

2014-03-01

41

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

42

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

43

Operational status of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2{pi}/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures.

Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, A.S.; Gallardo, J.; Jialin, Xie; Kirk, H.G.; Malone, R.G.; Parsa, Z.; Palmer, R.B.; Rao, T.; Rogers, J.; Sheehan, J.; Tsang, T.Y.F.; Ulc, S.; van Steenbergen, A.; Woodle, M.; Zhang, R.S. (Brookhaven National Lab., Upton, NY (USA)); Bigio, I.; Kurnit, N.; Shimada, T. (Los Alamos National Lab., NM (USA)); McDonald, K.T.; Russel, D.P. (Princeton Univ., NJ (USA)); Jiang,

1990-01-01

44

The Accelerator Facility at the Environmental Molecular Sciences Laboratory (EMSL)  

NASA Astrophysics Data System (ADS)

The EMSL, a new Department of Energy (DOE) user facility located at PNNL, will have several state-of-the-art systems, including an accelerator facility that can be used by scientists from around the world. The accelerator facility at EMSL consists of a model 9SDH-2 Pelletron 3.4 MV electrostatic tandem ion accelerator with three beam lines. These beam lines are dedicated to UHV ion scattering capabilities, implantation capabilities, and HV ion scattering capabilities, respectively. The end station attached to the UHV beam line has several electron spectroscopies such as low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) in addition to the ion scattering capabilities. This end station will be interfaced with the EMSL transfer capability that allows a sample to be synthesized, processed, and characterized in several surface science UHV systems. We will discuss the accelerator facility and the capabilities along with some initial results. (Work supported by the DOE/ER/OHER)

Thevuthasan, S.; Peden, C. H. F.; Engelhard, M. H.; Baer, D. R.; Herman, G. S.; Liang, Y.

1997-03-01

45

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

46

Early operating experience with the Brookhaven National Laboratory radio frequency quadrupole accelerator  

SciTech Connect

The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole (RFQ) for acceleration between the polarized H/sup -/ source and the Alvarez Linac. The RFQ accelerator is now in operation with low beam currents. The results of low and high power rf testing will be reported together with initial results of operation in the polarized H/sup -/ beam line.

Brown, H.; Clifford, T.; Giordano, S.; Khiari, F.; McKenzie-Wilson, R.; Puglisi, M.; Warner, P.

1984-05-01

47

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

48

Chemical depth profiling of photovoltaic backsheets after accelerated laboratory weathering  

NASA Astrophysics Data System (ADS)

Polymeric multilayer backsheets provide protection for the backside of photovoltaic (PV) module from the damage of moisture and ultraviolet (UV). Due to the nature of multilayer films, certain material property characterization of a backsheet could only be studied by examining its cross-section parallel to the thickness direction of the film. In this study, commercial PPE (polyethylene terephthalate (PET)/PET/ethylene vinyl acetate (EVA)) backsheet films were aged on the NIST (National Institute of Standards and Technology) SPHERE (Simulated Photodegradation via High Energy Radiant Exposure) with UV irradiance at 170 W/m2 (300 nm to 400 nm) under accelerated weathering conditions of 85C and two relative humidity (R.H.) levels of 5% (low) and 60% (high). Cryo-microtomy was used to obtain cross-sectional PPE samples with a flat surface parallel to the thickness direction, and chemical depth profiling of multilayers was conducted by Raman microscopic mapping. Atomic force microscopy with peak force tapping mode was used complementarily for cross-sectional imaging. The results revealed that the PPE backsheet films were comprised of five main layers, including pigmented-PET, core PET, inner EVA, pigmented-EVA and outer EVA, along with their interfacial regions and two adhesive layers. UV and moisture degradation on the outer pigmented PET layer was clearly observed; while the damage on the core PET layer was less significance, indicating that the outer pigmented PET layer effectively reduced the damage from UV. In high R.H. exposure, both adhesive layers were severely deteriorated. It was found that the EVA layers were susceptible to moisture at elevated temperature, especially for the pigmented-EVA. Based on the results of accelerated weathering, this depth profiling study brings new understanding to the mechanisms of failure observed in polymeric multilayer backsheets during field exposure.

Lin, Chiao-Chi; Krommenhoek, Peter J.; Watson, Stephanie S.; Gu, Xiaohong

2014-10-01

49

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

50

Photo Credit: Peter GinterSLAC National Accelerator Laboratory Dark Energy  

E-print Network

Photo Credit: Peter GinterSLAC National Accelerator Laboratory #12;Dark Energy 70% Dark Matter 26 and Advanced Camera for Surveys #12;Dark Energy 70% Dark Matter 26% Ordinary Matter 4% #12;Dark Energy 70% Dark Matter 26% Ordinary Matter 4% #12;Dark Energy 70% Dark Matter 26% Ordinary Matter 4% #12;Dark Energy 70

Osheroff, Douglas D.

51

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

Microsoft Academic Search

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

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

2011-01-01

52

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

Microsoft Academic Search

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

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

2011-01-01

53

Linear induction accelerators at the Los Alamos National Laboratory DARHT facility  

Microsoft Academic Search

The Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory consists of two linear induction accelerators at right angles to each other. The First Axis, operating since 1999, produces a nominal 20-MeV, 2-kA single beam-pulse with 60-nsec width. In contrast, the DARHT Second Axis, operating since 2008, produces up to four pulses in a variable pulse format by

Nath; Subrata

2010-01-01

54

The Performance and Plume Characterization of a Laboratory Gridless Ion Thruster with Closed Electron Drift Acceleration  

Microsoft Academic Search

The design and characteristics of a laboratory-model two-stage gridless ion thruster with closed electron drift are presented. The scaling and design of the electron bombardment ionization stage and the acceleration stage are described. The performance characterization of the thruster in single and two-stage is presented and discussed. The thruster plume was characterized with an ExB probe and gridded Faraday probe.

Peter Y. Peterson; Alec D. Gallimore

55

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

56

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

57

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

58

Challenges for forecasting based on accelerating rates of earthquakes at volcanoes and laboratory analogues  

NASA Astrophysics Data System (ADS)

'Mean-field' models have been proposed as falsifiable hypotheses for the acceleration in earthquake rate and other geophysical parameters prior to laboratory rock failure and volcanic eruptions. Importantly, such models may permit forecasting failure or eruption time. However, in existing retrospective analyses it is common to find examples of inappropriate techniques for fitting these models to data. Here we test the two main competing hypothesesexponential and power-law accelerationusing maximum likelihood techniques and an information criterion for model choice, based on a Poisson process with variable rate. For examples from the laboratory and Mt Etna, the power law is clearly the best model, both in terms of the fit and the resulting error structure, which is consistent with the Poisson approximation. For examples from Kilauea and Mauna Loa the results are less clear-cut and the confidence interval underestimates the number of outliers. Deviations from the models most likely reflect local interactions and/or non-stationary loading processes not captured by the mean-field approach. In addition, we use simulations to demonstrate an inherent problem with model preference, in that a power-law model will only be preferred if failure or eruption occurs close to the singularity. Although mean-field models may well provide valuable insight into the physical process responsible for precursory accelerations in earthquake rate, our findings highlight major difficulties that must be overcome to use such models for forecasting.

Bell, Andrew F.; Greenhough, John; Heap, Michael J.; Main, Ian G.

2011-05-01

59

Accelerating drug discovery by integrative implementation of laboratory automation in the work flow.  

PubMed

Acceleration of the drug discovery process in pre-clinical pharmaceutical research is a highly desirable goal and combinatorial chemistry united with automation technology promised to accomplish this task. Through the accumulation of experience with automated devices over time it became evident that only by harmonisation and streamlining of work-flow procedures the efficiency of the overall process can be improved. An open architecture of efficient data management and appropriate utilisation of automated laboratory protocols provides the opportunity to react in a flexible and advisable way. Only an integrative workflow concept promotes the enhancement of the overall performance. However, the foundation of any efforts towards the accelerated synthesis of new and desired compound arrays lies in the development of reliable chemistry protocols amenable to solid- and solution phase chemistry. PMID:12470254

Nettekoven, Matthias; Thomas, Andrew W

2002-12-01

60

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

61

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

62

Electron-Cloud Build-up in the FNAL Main Injector M. A. Furman,  

E-print Network

LBNL-62738 Electron-Cloud Build-up in the FNAL Main Injector M. A. Furman, Center for Beam Physics for the electron-cloud buildup in the context of the proposed FNAL Main Injector (MI) intensity upgrade [1 for the electron flux at the vacuum chamber wall with the corresponding measure- ments obtained with the RFA we

Furman, Miguel

63

Operation of the DC current transformer intensity monitors at FNAL during run II  

SciTech Connect

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 DCCT systems, including the sensor, the electronics, and the front-end instrumentation software, as well as their performance during Run II.

Crisp, J.; Fellenz, B.; Heikkinen, D.; Ibrahim, M.A.; Meyer, T.; Vogel, G.; /Fermilab

2012-01-01

64

The UNAM sets up the first Laboratory on Accelerator Mass Spectrometry (LEMA) in Mexico  

NASA Astrophysics Data System (ADS)

A new Accelerator Mass Spectrometry system is being installed at the Institute of Physics of the National Autonomous University of Mexico (IFUNAM) with support of CONACYT and UNAM. The AMS system is based on a tandetron accelerator of 1MV purchased from the High Voltage Engineering Europe B.V., Amersfoort, the Netherlands. Mass spectrometry experiments will be conducted at the AMS laboratory (LEMA), for analysis of 14 C and other isotopes as the 10Be, 26Al, 129I and Pu. This is a highly sensitive technique that allows to measure concentrations up to one part in 1015 from different nuclei. LEMA is the first laboratory in Mexico of its kind and the second in Latin America, after Brazil. The first research line of LEMA is to apply AMS for dating with 14C. Once the dating methodologies will be implemented, we will incorporate the analysis of other radioisotopes in research projects in different areas such as the Geophysical and Environmental sciences. In this presentation, the AMS system as well as details on the sample preparation will be described. Also, results from installation and acceptance tests will be presented.

Sols, C.; Chvez, E.; Ortz, M. E.; Andrade, E.

2013-05-01

65

US LHC Accelerator Research Program J. Strait, Fermilab  

E-print Network

-CERN Committee for the LARP 1 July 2004, CERN bnl ­ fnal - lbnl - slac US LHC Accelerator Research Program http://www-td.fnal.gov/LHC/USLARP.html #12;CERN-US Meeting - 1 July 2004 Overview - J.Strait 2 Goals of the US LARP Advance High Energy September 2003 Collaboration Meeting · SLAC proposal to join LARP and develop phase II collimators. · CERN

Large Hadron Collider Program

66

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

67

Proposed Casey`s Pond Improvement Project, Fermi National Accelerator Laboratory  

SciTech Connect

The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA), evaluating the impacts associated with the proposed Casey`s Pond Improvement Project at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. The improvement project would maximize the efficiency of the Fermilab Industrial Cooling Water (ICW) distribution system, which removes (via evaporation) the thermal load from experimental and other support equipment supporting the high energy physics program at Fermilab. The project would eliminate the risk of overheating during fixed target experiments, ensure that the Illinois Water Quality Standards are consistently achieved and provide needed additional water storage for fire protection. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required.

NONE

1995-05-01

68

Application of the National Ignition Facility distinguishable-from-background program to accelerator facilities at Lawrence Livermore National Laboratory.  

PubMed

Lawrence Livermore National Laboratory must control potentially activated materials and equipment in accordance with U.S. Department of Energy (DOE) Order 458.1, Radiation Protection of the Public and the Environment, which requires DOE approval of the process used to release volumetrically contaminated personal property and establishes a dose constraint of 10 Sv y(-1) (1 mrem y(-1)) for clearance of such property. The National Ignition Facility at Lawrence Livermore National Laboratory developed a technical basis document and protocol for determining the radiological status of property that is potentially activated from exposure to neutron radiation produced via fusion of tritium and deuterium. The technical basis included assessment of the neutron energy, the type of materials potentially exposed and the likely activation products, and the sensitivity of radiation detectors used to survey the property. This paper evaluates the National Ignition Facility technical basis document for applicability to the release of property from Lawrence Livermore National Laboratory's various accelerator facilities considering the different types of particles accelerated, radiations produced, and resultant activation products. Extensive process knowledge regarding the accelerators' operations, accompanied by years of routine surveys, provides an excellent characterization of these facilities. Activation studies conducted at the Stanford Linear Accelerator and the High Energy Accelerator Research Organization in Japan corroborate that the long-lived radionuclides produced at accelerator facilities are of the same variety produced at the National Ignition Facility. Consequently, Lawrence Livermore National Laboratory concludes that the release protocol developed for the National Ignition Facility can be used appropriately at all its accelerator facilities. PMID:23629069

Packard, Eric D; Mac Kenzie, Carolyn

2013-06-01

69

Advocacy for the Archives and History Office of the SLAC National Accelerator Laboratory: Stages and Methods  

SciTech Connect

Advocating for the good of the SLAC Archives and History Office (AHO) has not been a one-time affair, nor has it been a one-method procedure. It has required taking time to ascertain the current and perhaps predict the future climate of the Laboratory, and it has required developing and implementing a portfolio of approaches to the goal of building a stronger archive program by strengthening and appropriately expanding its resources. Among the successful tools in the AHO advocacy portfolio, the Archives Program Review Committee has been the most visible. The Committee and the role it serves as well as other formal and informal advocacy efforts are the focus of this case study My remarks today will begin with a brief introduction to advocacy and outreach as I understand them, and with a description of the Archives and History Office's efforts to understand and work within the corporate culture of the SLAC National Accelerator Laboratory. I will then share with you some of the tools we have employed to advocate for the Archives and History Office programs and activities; and finally, I will talk about how well - or badly - those tools have served us over the past decade.

Deken, Jean Marie; /SLAC

2009-06-19

70

Data Plots from FNAL-E907: Main Injector Particle Production Experiment (MIPP)  

DOE Data Explorer

There are approximately 40 data plots available to the public from E907. A proposal to upgrade the MIPP experiment (E-P-960) has been deferred. See the MIPP homepage at http://ppd.fnal.gov/experiments/e907/

71

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

PubMed Central

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 don't yield any significant differences in the final result. PMID:24179312

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

2013-01-01

72

Linear induction accelerators at the Los Alamos National Laboratory DARHT facility  

SciTech Connect

The Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory consists of two linear induction accelerators at right angles to each other. The First Axis, operating since 1999, produces a nominal 20-MeV, 2-kA single beam-pulse with 60-nsec width. In contrast, the DARHT Second Axis, operating since 2008, produces up to four pulses in a variable pulse format by slicing micro-pulses out of a longer {approx}1.6-microseconds (flat-top) pulse of nominal beam-energy and -current of 17 MeV and 2 kA respectively. Bremsstrahlung x-rays, shining on a hydro-dynamical experimental device, are produced by focusing the electron beam-pulses onto a high-Z target. Variable pulse-formats allow for adjustment of the pulse-to-pulse doses to record a time sequence of x-ray images of the explosively driven imploding mock device. Herein, we present a sampling of the numerous physics and engineering aspects along with the current status of the fully operational dual axes capability. First successful simultaneous use of both the axes for a hydrodynamic experiment was achieved in 2009.

Nath, Subrata [Los Alamos National Laboratory

2010-09-07

73

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

74

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

75

Experience with copper oxide production in antiproton source components at Fermi National Accelerator Laboratory  

SciTech Connect

The Antiproton (Pbar) Source at Fermi National Accelerator Laboratory is a facility comprised of a target station, two rings called the Debuncher and Accumulator and the transport lines between those rings and the remainder of the particle accelerator complex. Water is by far the most common medium for carrying excess heat away from components, primarily electromagnets, in this facility. The largest of the water systems found in Pbar is the 95 degree Fahrenheit Low Conductivity Water (LCW) system. LCW is water which has had free ions removed, increasing its resistance to electrical current. This water circuit is used to cool magnets, power supplies, and stochastic cooling components and typically has a resistivity of 11--18 megaohms-cm. For more than ten years the Antiproton rings were plagued with overheating magnets due to plugged water-cooling channels. Various repairs have been tried over the years with no permanent success. Throughout all of this time, water samples have indicated copper oxide, CuO, as the source of the contamination. Matters came to a head in early 1997 following a major underground LCW leak between the Central Utilities Building and the Antiproton Rings enclosures. Over a span of several weeks following system turn-on, some twenty magnets overheated leading to unreliable Pbar source operation. Although it was known that oxygen in the system reacts with the copper tubing to form CuO, work to remedy this problem was not undertaken until this time period. Leaks, large quantities of make-up water, infrequent filter replacement, and thermal cycling also result in an increase in the corrosion product release rate. A three-pronged approach has been implemented to minimize the amount of copper oxide available to plug the magnets: (1) installation of an oxygen removal system capable of achieving dissolved oxygen concentrations in the parts per billion (ppb) range; (2) regular closed-loop filter/flushing of the copper headers and magnets and stainless steel header during down periods; and (3) installation of a full-flow filtration system designed to remove any CuO produced by the trace amounts of dissolved oxygen in the LCW system. All three items have been completed. The dissolved oxygen concentration is now routinely on the order of 15 ppb and returns to that level within 8--12 hours following an upset condition such as a leak. Prior to installation of the oxygen removal system, oxygen levels were approximately 3,000 ppb. Particle analysis of the water before-and-after filter and flushing of the LCW system indicates a cleaner system. Another round of filter/flushing occurred shortly before the scheduled start-up and will be performed during down periods when deemed necessary by newly-installed instrumentation. The full-flow filtration system has been recently commissioned. The system consists of two parallel filter housings, with a rated total flow capacity of 2,500 gpm at 300 psi, piping to the LCW supply header and associated instrumentation.

Christine R. Ader; Elvin R. Harms Jr.; and James P. Morgan

2000-05-10

76

Do sediment type and test durations affect results of laboratory-based, accelerated testing studies of permeable pavement clogging?  

PubMed

Previous studies have attempted to quantify the clogging processes of Permeable Interlocking Concrete Pavers (PICPs) using accelerated testing methods. However, the results have been variable. This study investigated the effects that three different sediment types (natural and silica), and different simulated rainfall intensities, and testing durations had on the observed clogging processes (and measured surface infiltration rates) of laboratory-based, accelerated PICP testing studies. Results showed that accelerated simulated laboratory testing results are highly dependent on the type, and size of sediment used in the experiments. For example, when using real stormwater sediment up to 1.18mm in size, the results showed that neither testing duration, nor stormwater application rate had any significant effect on PICP clogging. However, the study clearly showed that shorter testing durations generally increased clogging and reduced the surface infiltration rates of the models when artificial silica sediment was used. Longer testing durations also generally increased clogging of the models when using fine sediment (<300?m). Results from this study will help researchers and designers better anticipate when and why PICPs are susceptible to clogging, reduce maintenance and extend the useful life of these increasingly common stormwater best management practices. PMID:25618819

Nichols, Peter W B; White, Richard; Lucke, Terry

2015-04-01

77

Performance of the accelerator driver of Jefferson Laboratory's free-electron laser  

Microsoft Academic Search

The driver for Jefferson Lab's kW-level infrared free-electron laser (FEL) is a superconducting, recirculating accelerator that recovers about 75% of the electron-beam power and converts it to radiofrequency power. In achieving first lasing, the accelerator operated straight-ahead to deliver 38 MeV, 1.1 mA cw current through the wiggler for lasing at wavelengths in the vicinity of 5 ?m. Just prior

C. L. Bohn; S. Benson; G. Biallas; I. Campisi; D. Douglas; R. Evans; J. Fugitt; R. Hill; K. Jordan; G. Krafft; R. Li; L. Merminga; G. Neil; P. Piot; J. Preble; M. Shinn; T. Siggins; R. Walker; B. Yunn

1999-01-01

78

Laboratory investigation of a fine structure of field-aligned currents and electric fields and their relationship to charged particle acceleration  

Microsoft Academic Search

In conditions of a laboratory model experiment physical mechanisms of auroral charged particles acceleration due to parallel electric fields generation in the field-aligned current layers are investigated. The experiment allows to study an appearance of field-aligned electrical fields and charged particles acceleration in all totality of the interconnected events: generation of plasma flow, its evolution in the magnetic field, polarization

B. G. Gavrilov; D. B. Sobyanin; J. I. Zetzer; I. M. Podgorny

2003-01-01

79

Can Accelerators Accelerate Learning?  

NASA Astrophysics Data System (ADS)

The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

2009-03-01

80

Laboratory accelerated and natural weathering of styreneethylenebutylenestyrene (SEBS) block copolymer  

Microsoft Academic Search

Indoor accelerated and outdoor weathering of polystyrene-b-(ethylene-co-butylene)-b-styrene (SEBS) was studied by infrared spectroscopy. Accelerated conditions involved simultaneous exposure of specimens to ultravioletvisible radiation between 295nm and 450nm and each of four temperature\\/relative humidity (RH) environments, i.e., (a) 30C1C at <1% RH, (b) 30C1C at 80% RH, (c)55C1C at <1% RH, and (d) 55C1C at 80% RH. Outdoor exposure was conducted

C. C. White; K. T. Tan; D. L. Hunston; T. Nguyen; D. J. Benatti; J. W. Chin

2011-01-01

81

DEVELOPMENT OF A HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN NATIONAL LABORATORY*  

E-print Network

954 DEVELOPMENT OF A HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN, New York 11973 and K. McDonald Princeton [Jniversity Abstract An electron gun utilizing a radio). Here we report on the de;$n of the electron gun which will provide r.f. bunches of up to 10 electrons

McDonald, Kirk

82

The target laboratory of the Pelletron accelerator at the University of So Paulo  

NASA Astrophysics Data System (ADS)

A brief description of the facilities installed in the target laboratory will be given. Successes and problems encountered during last year's target making as well as progress made toward the installation of a carbon arc apparatus will be described.

Ueta, N.; Engel, W. G. P.

1989-10-01

83

Bulk ion acceleration and particle heating during magnetic reconnection in a laboratory plasma  

SciTech Connect

Bulk ion acceleration and particle heating during magnetic reconnection are studied in the collisionless plasma of the Magnetic Reconnection Experiment (MRX). The plasma is in the two-fluid regime, where the motion of the ions is decoupled from that of the electrons within the ion diffusion region. The reconnection process studied here is quasi-symmetric since plasma parameters such as the magnitude of the reconnecting magnetic field, the plasma density, and temperature are compatible on each side of the current sheet. Our experimental data show that the in-plane (Hall) electric field plays a key role in ion heating and acceleration. The electrostatic potential that produces the in-plane electric field is established by electrons that are accelerated near the electron diffusion region. The in-plane profile of this electrostatic potential shows a well structure along the direction normal to the reconnection current sheet. This well becomes deeper and wider downstream as its boundary expands along the separatrices where the in-plane electric field is strongest. Since the in-plane electric field is 34 times larger than the out-of-plane reconnection electric field, it is the primary source of energy for the unmagnetized ions. With regard to ion acceleration, the Hall electric field causes ions near separatrices to be ballistically accelerated toward the outflow direction. Ion heating occurs as the accelerated ions travel into the high pressure downstream region. This downstream ion heating cannot be explained by classical, unmagnetized transport theory; instead, we conclude that ions are heated by re-magnetization of ions in the reconnection exhaust and collisions. Two-dimensional (2-D) simulations with the global geometry similar to MRX demonstrate downstream ion thermalization by the above mechanisms. Electrons are also significantly heated during reconnection. The electron temperature sharply increases across the separatrices and peaks just outside of the electron diffusion region. Unlike ions, electrons acquire energy mostly from the reconnection electric field, and the energy gain is localized near the X-point. However, the increase in the electron bulk flow energy remains negligible. These observations support the assertion that efficient electron heating mechanisms exist around the electron diffusion region and that the heat generated there is quickly transported along the magnetic field due to the high parallel thermal conductivity of electrons. Classical Ohmic dissipation based on the perpendicular Spitzer resistivity is too small to balance the measured heat flux, indicating the presence of anomalous electron heating.

Yoo, Jongsoo; Yamada, Masaaki; Ji, Hantao; Jara-Almonte, Jonathan; Myers, Clayton E. [Center for Magnetic Self-Organization, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Center for Magnetic Self-Organization, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-05-15

84

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

85

FNAL LARP Workshop 6/9/2003 1 US-LHC Accelerator Research Program  

E-print Network

solution · no active components before mixer and 455KHz filter has been tested, looks promising · Large position and tune jumps at transition ­ t quads · Phase compensation during ramping - anomalous (mixer fix of increasing frequency: measured amplitude increases in vertical, decreases in horizontal, tune shifts. .23 .22

Large Hadron Collider Program

86

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

87

The SNR W44: an ideal laboratory for Cosmic-Ray acceleration  

NASA Astrophysics Data System (ADS)

W44 (G34.7-0.4) is one of the most studied Supernova Remnants (SNRs) because it is an ideal system to study Cosmic-Ray (CR) production, acceleration and propagation. In the last years, SNR study showed an increasingly complex scenario with a continuous rielaboration of theoretical models; moreover, until now, providing an experimental unambiguous proof of the CR origin has been elusive, despite many decades of attempts and controversial analysis. In this context the AGILE ?-ray satellite has an important role. During its five years of life it observed a great amount of different astrophysical sources, including SNRs. In case of W44 AGILE observed a spectrum extending to energies below E = 200 MeV that allows us to exclude leptonic emission as the main contribution to the ?-ray emission [36]. Moreover, refined AGILE data show that W44 spectrum could be the sum of two (or more) contributions from two different regions of the remnant where different processes influence CR acceleration and propagation. Future AGILE data will lead us to understand the intricate link between SNRs and CRs.

Cardillo, M.; Giuliani, A.; Tavani, M.; Agile Collaboration

2012-10-01

88

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

89

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

90

Status of the darht 2nd axis accelerator at the Los Alamos national laboratory  

Microsoft Academic Search

The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) was constructed at Los Alamos National Laboratory as a radiographic facility to provide dual-axis multi-time radiography to support the US Stockpile Stewardship Program. The DARHT 1st Axis has been operational since 1999 and has been providing excellent radiographs. The DARHT 2nd Axis construction project was completed in early 2003. However, during the

R. D. Scarpetti?; S. Nath; J. Barraza; C. A. Ekdahl; E. Jacquez; B. T. McCuistian; K. Nielsen; M. Schulze; J. Seitz; G. J. Caporaso; Y.-J. Chen; G. Logan; F. Bieniosek

2007-01-01

91

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

92

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

93

Prediction and accelerated laboratory discovery of previously unknown 18-electron ABX compounds  

NASA Astrophysics Data System (ADS)

Chemists and material scientists have often focused on the properties of previously reported compounds, but neglect numerous unreported but chemically plausible compounds that could have interesting properties. For example, the 18-valence electron ABX family of compounds features examples of topological insulators, thermoelectrics and piezoelectrics, but only 83 out of 483 of these possible compounds have been made. Using first-principles thermodynamics we examined the theoretical stability of the 400 unreported members and predict that 54 should be stable. Of those previously unreported missing materials now predicted to be stable, 15 were grown in this study; X-ray studies agreed with the predicted crystal structure in all 15 cases. Among the predicted and characterized properties of the missing compounds are potential transparent conductors, thermoelectric materials and topological semimetals. This integrated processprediction of functionality in unreported compounds followed by laboratory synthesis and characterizationcould be a route to the systematic discovery of hitherto missing, realizable functional materials.

Gautier, Romain; Zhang, Xiuwen; Hu, Linhua; Yu, Liping; Lin, Yuyuan; Sunde, Tor O. L.; Chon, Danbee; Poeppelmeier, Kenneth R.; Zunger, Alex

2015-04-01

94

SLAC NATIONAL ACCELERATOR LABORATORY 2575 SAND HILL ROAD MENLO PARK CALIFORNIA 94025 USA SLAC is operated by Stanford University for the U.S. Department of Energy  

E-print Network

SLAC NATIONAL ACCELERATOR LABORATORY · 2575 SAND HILL ROAD · MENLO PARK · CALIFORNIA · 94025 · USA.S. Agent) at 2575 Sand Hill Road, Menlo Park, CA 94025 to act as a lawful U.S. agent on my behalf. From

Wechsler, Risa H.

95

Progress on plasma accelerators  

SciTech Connect

Several plasma accelerator concepts are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wake Field Accelerator (PWFA). Various accelerator physics issues regarding these schemes are discussed, and numerical examples on laboratory scale experiments are given. The efficiency of plasma accelerators is then revealed with suggestions on improvements. Sources that cause emittance growth are discussed briefly.

Chen, P.

1986-05-01

96

Irradiation facility for radiobiology and molecular biophysics studies at the University of So Paulo Pelletron Accelerator laboratory  

NASA Astrophysics Data System (ADS)

In this work, we describe the new facility for Radiobiology and Molecular Biophysics studies with charged particle beams, built at the University of So Paulo Pelletron Accelerator Laboratory. It consists of a dedicated beam line, sample holder and dose monitoring system. The beam line is designed in such a way that a 15 mm diameter and 2% uniformity external beam is delivered to the sample. In order to reach these beam features, the beam line is composed of one focusing system with tantalum slits and a Faraday cup, two scattering chambers with 1 mm tantalum collimators and 2 mg/cm 2 Au diffusing foils, and one 10 ?m thick mylar foil serving as exit window. The sample holder has x, y and z movement with 10 ?m precision and the dose monitoring system consists of one Si detector inside each scattering chamber, and one Si detector in air at the sample location. A multiwire position sensitive detector will be soon installed right before the exit window to monitor the beam shape and help in the beam uniformity measurements. The facility and tests of the beam uniformity and dose monitoring system are described. The dose tests are performed through the irradiation of LiF TLD-100 crystals and the comparison of their results with the calculated values based on the counting rate on the Si detectors.

Carlin, N.; de Souza, J. C.; Szanto, E. M.; Acquadro, J. C.; Okuno, E.; Takahashi, J.; Umisedo, N. K.; de Oliveira Filho, F. J.; Vasconcelos, J. A. C.

2005-03-01

97

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

SciTech Connect

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 programs. These ''top-down'' studies are very important but they can also serve to divorce such proceedings from the individuals actually involved in the ground-level research which physically served to create theories, designs, machines, and experiments. This can lead to a skewed picture, on the one hand, of a lack of effect that so-called scientific and technological factors exert and, on the other hand, of the apparent separation of the so-called social or political from the concrete practice of doing physics. An exception to this approach can be found in the proceedings of a conference on ''History of the ZGS'' held at Argonne at the time of the Zero Gradient Synchrotron's decommissioning in 1979. These accounts insert the individuals quite literally as they are, for the most part, personal reminiscences of those who took part in these efforts on the ground level. As such, they are invaluable raw material for historical inquiry but generally lack the rigor and perspective expected in a finished historical work. The session on ''Constructing Cold War Physics'' at the 2002 annual History of Science Society Meeting served to highlight new approaches circulating towards history of science and technology in the post-WWII period, especially in the 1950s. There is new attention towards the effects of training large numbers of scientists and engineers as well as the caution not to equate ''national security'' with military preparedness, but rather more broadly--at certain points--with the explicit ''struggle for the hearts and minds of men.'' There is a call for greater detail in periodization as events such as Stalin's death and Khruschev's subsequent speech, the end of the Korean conflict, the hydrogen bomb test, Eisenhower's Atoms for Peace initiative, the 1955 Geneva conference, and Sputnik each served to drastically change the landscape in the United States. Furthermore, Harvard University Press recently published the first detailed and scholarly account of a history of the national laboratories; the work argues that the ''systemicity'' of the organization must be considered as a necessary piece when examining any of the myriad of related puzzles.

Paris, E.

2004-04-05

98

The NESSiE way to searches for sterile neutrinos at FNAL  

E-print Network

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle $\\theta_{13}$ in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small $L/E$, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. Its recent proposal refers to the use of magnetic spectrometers at two different sites, Near and Far ones. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the undergoing project of a multi-site Liquid-Argon detectors at FNAL. The experiment to be possibly setup at Booster will allow to definitively clarify the current $\

L. Stanco; A. Anokhina; A. Bagulya; M. Benettoni; P. Bernardini; R. Brugnera; M. Calabrese; A. Cecchetti; S. Cecchini; M. Chernyavskiy; P. Creti; F. Dal Corso; O. Dalkarov; A. Del Prete; G. De Robertis; M. De Serio; L. Degli Esposti; D. Di Ferdinando; S. Dusini; T. Dzhatdoev; C. Fanin; R. A. Fini; G. Fiore; A. Garfagnini; S. Golovanov; M. Guerzoni; B. Klicek; U. Kose; K. Jakovcic; G. Laurenti; I. Lippi; F. Loddo; A. Longhin; M. Malenica; G. Mancarella; G. Mandriol; A. Margiotta; G. Marsella; N. Mauri; E. Medinaceli; A. Mengucci; R. Mingazheva; O. Morgunova; M. T. Muciaccia; M. Nessi; D. Orecchini; A. Paoloni; G. Papadia; L. Paparella; L. Pasqualini; A. Pastore; L. Patrizii; N. Polukhina; M. Pozzato; M. Roda; T. Roganova; G. Rosa; Z. Sahnoun; S. Simone; C. Sirignano; G. Sirri; M. Spurio; N. Starkov; M. Stipcevic; A. Surdo; M. Tenti; V. Togo; M. Ventura; M. Vladymyrov

2014-10-15

99

Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster  

E-print Network

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle $\\theta_{13}$ in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small $L/E$, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current $\

A. Anokhina; A. Bagulya; M. Benettoni; P. Bernardini; R. Brugnera; M. Calabrese; A. Cecchetti; S. Cecchini; M. Chernyavskiy; P. Creti; F. Dal Corso; O. Dalkarov; A. Del Prete; G. De Robertis; M. De Serio; L. Degli Esposti; D. Di Ferdinando; S. Dusini; T. Dzhatdoev; C. Fanin; R. A. Fini; G. Fiore; A. Garfagnini; S. Golovanov; M. Guerzoni; B. Klicek; U. Kose; K. Jakovcic; G. Laurent; I. Lippi; F. Loddo; A. Longhin; M. Malenica; G. Mancarella; G. Mandrioli; A. Margiotta; G. Marsella; N. Mauri; E. Medinaceli; A. Mengucci; R. Mingazheva; O. Morgunova; M. T. Muciaccia; M. Nessi; D. Orecchini; A. Paoloni; G. Papadia; L. Paparella; L. Pasqualini; A. Pastore; L. Patrizii; N. Polukhina; M. Pozzato; M. Roda; T. Roganova; G. Rosa; Z. Sahnoun; S. Simone; C. Sirignano; G. Sirri; M. Spurio; L. Stanco; N. Starkov; M. Stipcevic; A. Surdo; M. Tenti; V. Togo; M. Ventura; M. Vladymyrov

2014-04-09

100

Note: Recent achievements at the 60-MeV linac for sub-picosecond terahertz radiation at the Pohang Accelerator Laboratory.  

PubMed

A femtosecond (fs) terahertz (THz) linac has been constructed to generate fs-THz radiation by using ultrashort electron beam at the Pohang Accelerator Laboratory. To generate an ultrashort electron beam with 60-MeV energy, a chicane bunch compressor has been adopted. Simulation studies have been conducted to design the linac. In this note, recent achievements at 60-MeV linac are presented. PMID:22047342

Yim, Changmook; Hong, Juho; Parc, Yongwoon; Jung, Seonghoon; Han, Daehun; Ryu, Jaehyun; Park, Jaehun; Kang, Heung-Sik; Ko, In Soo

2011-10-01

101

Note: Recent achievements at the 60-MeV Linac for sub-picosecond terahertz radiation at the Pohang Accelerator Laboratory  

SciTech Connect

A femtosecond (fs) terahertz (THz) linac has been constructed to generate fs-THz radiation by using ultrashort electron beam at the Pohang Accelerator Laboratory. To generate an ultrashort electron beam with 60-MeV energy, a chicane bunch compressor has been adopted. Simulation studies have been conducted to design the linac. In this note, recent achievements at 60-MeV linac are presented.

Yim, Changmook; Hong, Juho; Parc, Yongwoon; Ko, In Soo [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of); Jung, Seonghoon; Park, Jaehun; Kang, Heung-Sik [Pohang Accelerator Laboratory, POSTECH, Pohang 790-784 (Korea, Republic of); Han, Daehun [Department of Physics, KAIST, Daejeon 305-701 (Korea, Republic of); Ryu, Jaehyun [Department of Chemistry, POSTECH, Pohang 790-784 (Korea, Republic of)

2011-10-15

102

US-LARP Progress on LHC IR Upgrades Tanaji Sen, John Johnstone, Nikolai Mokhov, FNAL, Batavia, IL 60510  

E-print Network

US-LARP Progress on LHC IR Upgrades Tanaji Sen, John Johnstone, Nikolai Mokhov, FNAL, Batavia, IL the progress on LHC IR upgrades made by the US-LARP collaboration since the last CARE meeting in November 2004 the luminosity in the LHC will require upgrades to the interaction regions (IRs) as well as to the injector chain

Sen, Tanaji

103

Current and Planned High Proton Flux Operations at the FNAL Booster  

E-print Network

The Fermilab Proton Source machines, constituted by Pre-Injector, conventional Linac and Booster synchrotron, at Fermi National Accelerator Laboratory (Fermilab) had have a long history of successful beam operations. Built in late '60s, the Fermilab Proton Source began operations early in the '70s and since then it has successful provided protons to support the laboratory physics experiments. During the past decade, Booster performance reached unprecedented proton flux delivery of the order of 1.0-1.1E17 protons per hour, corresponding to 40 kW of beam power while maintained an allowed upper limit of 525 W of beam loss in the tunnel. In order to achieve this historical performance, major hardware upgrades were made in the machine combined with improvements in beam orbit control and operational awareness. Once again, the Proton Source has been charged to double their beam throughput, while maintaining the present residual activation levels, to meet the laboratory Intensity Frontier program goals until new mach...

Garcia, F G

2014-01-01

104

Design of 325 MHz single and triple spoke resonators at FNAL  

SciTech Connect

The proposed 8-GeV driver at FNAL is based on approximately 400 independently phased SC resonators. In this paper the design of 325 MHz Spoke Resonators, two single spoke resonators ({beta}=0.22 and {beta}=0.4) and a triple spoke resonator ({beta}=0.62), for the High Intensity Neutrino Source (HINS) front end is presented. We describe the optimization of the spoke resonators geometry, the goal being to minimize the E{sub peak}/E{sub acc} and B{sub peak}/E{sub acc} ratios. We report on the coupled ANSYS-MWS analysis on the resonators mechanical properties and power coupler RF design. The current status of mechanical design, slow tuning mechanism and cryostat are also presented.

Lanfranco, G.; Apollinari, G.; Gonin, I.; Khabiboulline, T.; McConologue, F.; Romanov, G.; Wagner, R.; /Fermilab

2006-08-01

105

Electron-Cloud Build-up in the FNAL Main Injector  

SciTech Connect

We present a summary on ongoing simulation results for the electron-cloud buildup in the context of the proposed FNAL Main Injector (MI) intensity upgrade [1] in a fieldfree region at the location of the RFA electron detector [2]. By combining our simulated results for the electron flux at the vacuum chamber wall with the corresponding measurements obtained with the RFA we infer that the peak secondary electron yield (SEY) {delta}{sub max} is {approx}> 1.4, and the average electron density is n{sub e} {approx}> 10{sup 10} m{sup -3} at transition energy for the specific fill pattern and beam intensities defined below. The sensitivity of our results to several variables remains to be explored in order to reach more definitive results. Effects from the electron cloud on the beam are being investigated separately [3].

Furman, M.A.

2007-06-04

106

GLADE Global Liquid Argon Detector Experiment: a letter of intent to FNAL  

SciTech Connect

The recent measurements of the {theta}{sub 13} mixing angle, which controls the observable size of any CP violation effects, open a window of opportunity to take advantage of the world's most powerful existing neutrino beam together with recent successes in development of the ultimate detector technology for the detection of electron neutrinos : a liquid argon (LAr) time projection chamber. During this proposed project a 5kt LAr detector (GLADE) will be developed by European groups to be put in a cryostat in the NuMI neutrino beam at Fermi National Accelerator Laboratory in the US and will start taking data in 3-5 years time to address the neutrino mass ordering. The successful fruition of this project, along with nominal exposure at NO{nu}A and T2K, together with information from double beta decay experiments could ascertain that neutrinos are Dirac particles in the next decade.

Thomas, Jennifer

2012-05-13

107

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

108

Laboratory investigation of physical mechanisms of auroral charged particle acceleration in the field-aligned current layers  

Microsoft Academic Search

One of the major topics of space weather research is to understand auroral structure and the processes that guide, accelerate, and otherwise control particle precipitation and during substorms. The problem is that it is not clear the structure of the magnetic field-aligned electric fields and how they are supported in the magnetospheric plasma. The objective of this research is to

B. G. Gavrilov; J. I. Zetzer; D. B. Sobyanin; I. M. Podgorny

2005-01-01

109

Laboratory investigation of physical mechanisms of auroral charged particle acceleration in the field-aligned currents layers  

Microsoft Academic Search

One of the major topics of space weather research is to understand auroral structure and the processes that guide, accelerate, and otherwise control particle precipitation and produce auroral substorms. Navigation, communications and radars in the high latitude regions are severely affected through the effects on the ionosphere. It has long been recognized that the direct cause of the aurora is

B. Gavrilov; J. Zetzer; D. Sobyanin; I. Podgorny

2002-01-01

110

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 describes

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

2007-01-01

111

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

112

Accelerating Ocean Energy to the Marketplace Environmental Research at the U.S. Department of Energy National Laboratories  

SciTech Connect

The U.S. Department of Energy (US DOE) has mobilized its National Laboratories to address the broad range of environmental effects of ocean and river energy development. The National Laboratories are using a risk-based approach to set priorities among environmental effects, and to direct research activities. Case studies will be constructed to determine the most significant environmental effects of ocean energy harvest for tidal systems in temperate estuaries, for wave energy installations in temperate coastal areas, wave installations in sub-tropical waters, and riverine energy installations in large rivers. In addition, the National Laboratories are investigating the effects of energy removal from waves, tides and river currents using numerical modeling studies. Laboratory and field research is also underway to understand the effects of electromagnetic fields (EMF), acoustic noise, toxicity from anti-biofouling coatings, effects on benthic habitats, and physical interactions with tidal and wave devices on marine and freshwater organisms and ecosystems. Outreach and interactions with stakeholders allow the National Laboratories to understand and mitigate for use conflicts and to provide useful information for marine spatial planning at the national and regional level.

Copping, Andrea E.; Cada, G. F.; Roberts, Jesse; Bevelhimer, Mark

2010-10-06

113

Evaluation of a commercial system for CAMAC-based control of the Chalk River Laboratories tandem-accelerator-superconducting-cyclotron complexcomplex  

SciTech Connect

This paper discusses the control system of the Tandem Accelerator Superconducting Cyclotron (TASCC) of AECL Research at its Chalk River Laboratories which is presently based on a PDP-11 computer and the IAS operating system. The estimated expense of a custom conversion of the system to a current, equivalent operating system is prohibitive. The authors have evaluated a commercial control package from VISTA Control Systems based on VAX microcomputers and the VMS operating system. Vsystem offers a modern, graphical operator interface, an extensive software toolkit for configuration of the system and a multi-feature data-logging capability, all of which far surpass the functionality of the present control system. However, the implementation of some familiar, practical features that TASCC operators find to be essential has proven to be challenging. The assessment of Vsystem, which is described in terms of presently perceived strengths and weaknesses, is, on balance, very positive.

Greiner, B.F.; Caswell, D.J.; Slater, W.R. (TASCC Accelerators and Development, Nuclear Physics Branch, AECL Research, Chalk River Lab., Chalk River, Ontario K0J 1J0 (CA))

1992-04-01

114

Accelerator mass spectrometry of 63Ni using a gas-filled magnet at the Munich Tandem Laboratory  

NASA Astrophysics Data System (ADS)

The detection of 63Ni ( T1/2=100.1 yr) by means of accelerator mass spectrometry (AMS) using a gas-filled magnet (GFM) is described. The experimental setup includes a dedicated ion source, a 14 MV MP tandem, a GFM and a multi-anode ionization chamber. First results indicate a background level of 63Ni/Ni ratios as low as 210 -14. This sensitivity will allow - for the first time ever - to detect 63Ni induced by fast neutrons in copper samples from Hiroshima and Nagasaki, even for distances beyond 1500 m from the hypocenters. Thus, it will be possible to reconstruct experimentally the neutron doses of the A-bomb survivors from Hiroshima and Nagasaki.

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

2000-10-01

115

Electron-Cloud Build-Up Simulations for the FNAL Main Injector  

SciTech Connect

We present a summary on ongoing simulation results for the electron-cloud (EC) buildup in the context of the proposed FNAL Main Injector (MI) intensity upgrade effort [1]. Most of the results presented here are for the field-free region at the location of the retarding field analyzer (RFA) electron detector [2-4]. The primary input variable we exercise is the peak secondary electron yield (SEY) {delta}{sub max}, which we let vary in the range 1.2 {le} {delta}{sub max} {le} 1.7. By combining our simulated results for the electron flux at the vacuum chamber wall with the corresponding RFA measurements we infer that 1.25 {approx}< {delta}{sub max} {approx}< 1.35 at this location. From this piece of information we estimate features of the EC distribution for various fill patterns, including the average electron number density n{sub e}. We then compare the behavior of the EC for a hypothetical RF frequency f{sub RF} = 212 MHz with the current 53 MHz for a given total beam population N{sub tot}. The density n{sub e} goes through a clear threshold as a function of N{sub tot} in a field-free region. As expected, the higher frequency leads to a weaker EC effect: the threshold in N{sub tot} is a factor {approx} 2 higher for f{sub RF} = 212 MHz than for 53 MHz, and ne is correspondingly lower by a factor {approx} 2 when N{sub tot} is above threshold. We briefly describe further work that needs to be carried out, sensitivities in the calculation, and puzzles in the results that remain to be addressed.

Furman, Miguel .A.

2008-08-25

116

The new external microbeam facility at the 5 MV Tandetron accelerator laboratory in Madrid: beam characterisation and first results  

NASA Astrophysics Data System (ADS)

This paper describes the new external microbeam on the 15 beamline of the 5 MV Tandetron accelerator recently installed at the CMAM in Madrid. The focusing and beam extraction system was supplied by Oxford Microbeams Ltd. and consists of a high precision quadrupole doublet with an interchangeable Kapton window exit nozzle and front-viewing video microscope. The sample is positioned in the beam using a stepper motor stage. The beam current and beam profile have been determined under different experimental conditions. A simple method based on the signal processing of ion-induced luminescence from quartz targets has been used to determine the beam profile in two dimensions simultaneously, without scanning. This is the first step in the development of a real time beam profile monitoring system, which could be used as part of an automated beam focusing procedure. The beam line will be primarily devoted to archaeometry and cultural heritage studies. As an example we report the characterisation of two Tang appearance antique porcelains.

Enguita, Olga; Fernndez-Jimnez, M. T.; Garca, G.; Climent-Font, A.; Caldern, T.; Grime, G. W.

2004-06-01

117

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

118

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

119

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

120

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

121

Accelerating the Whiteshell Laboratories Decommissioning Through the Implementation of a Projectized and Delivery-Focused Organization - 13074  

SciTech Connect

Whiteshell Laboratories (WL) is a nuclear research site in Canada that was commissioned in 1964 by Atomic Energy of Canada Limited. It covers a total area of approximately 4,375 hectares (10,800 acres) and includes the main campus site, the Waste Management Area (WMA) and outer areas of land identified as not used for or impacted by nuclear development or operations. The WL site employed up to 1100 staff. Site activities included the successful operation of a 60 MW organic liquid-cooled research reactor from 1965 to 1985, and various research programs including reactor safety research, small reactor development, fuel development, biophysics and radiation applications, as well as work under the Canadian Nuclear Fuel Waste Management Program. In 1997, AECL made a business decision to discontinue research programs and operations at WL, and obtained government concurrence in 1998. The Nuclear Legacy Liabilities Program (NLLP) was established in 2006 by the Canadian Government to remediate nuclear legacy liabilities in a safe and cost effective manner, including the WL site. The NLLP is being implemented by AECL under the governance of a Natural Resources Canada (NRCan)/AECL Joint Oversight Committee (JOC). Significant progress has since been made, and the WL site currently holds the only Canadian Nuclear Safety Commission (CNSC) nuclear research site decommissioning license in Canada. The current decommissioning license is in place until the end of 2018. The present schedule planned for main campus decommissioning is 30 years (to 2037), followed by institutional control of the WMA until a National plan is implemented for the long-term management of nuclear waste. There is an impetus to advance work and complete decommissioning sooner. To accomplish this, AECL has added significant resources, reorganized and moved to a projectized environment. This presentation outlines changes made to the organization, the tools implemented to foster projectization, and the benefits and positive impacts on schedule and delivery. A revised organizational structure was implemented in two phases, starting 2011 April 1, to align WL staff with the common goal of decommissioning the site through the direction of the WL Decommissioning Project General Manager. On 2011 September 1, the second phase of the reorganization was implemented and WL Decommissioning staff was organized under five Divisions: Programs and Regulatory Compliance, General Site Services, Decommissioning Strategic Planning, Nuclear Facilities and Project Delivery. A new Mission, Vision and Objectives were developed for the project, and several productivity enhancements are being implemented. These include the use of an integrated and fully re-sourced Site Wide Schedule that is updated and reviewed at Plan-of-the-Week meetings, improved work distribution throughout the year, eliminating scheduling 'push' mentality, project scoreboards, work planning implementation, lean practices and various process improvement initiatives. A revised Strategic Plan is under development that reflects the improved project delivery capabilities. As a result of these initiatives, and a culture change towards a projectized approach, the decommissioning schedule will be advanced by approximately 10 years. (authors)

Wilcox, Brian; Mellor, Russ; Michaluk, Craig [Atomic Energy of Canada Limited, Whiteshell Laboratories, Pinawa, Manitoba (Canada)] [Atomic Energy of Canada Limited, Whiteshell Laboratories, Pinawa, Manitoba (Canada)

2013-07-01

122

Investigations of the output energy deviation and other parameters during commissioning of the four-rod radio frequency quadrupole at the Fermi National Accelerator Laboratory  

NASA Astrophysics Data System (ADS)

After 30 years of operation, the Cockcroft-Walton based injector at the Fermi National Accelerator Laboratory has been replaced by a new beam line including a dimpled magnetron 35 keV source in combination with a 750 keV four-rod radio frequency quadrupole (RFQ). The new injector is followed by the existing drift tube linac. Prior to installation, a test beam line was built which included the magnetron source and the four-rod RFQ with a number of beam measurement instrumentation. The first beam test with the RFQ showed an output energy deviation greater than 2.5%. Other problems also showed up which led to investigations of the output energy, power consumption and transmission properties using rf simulations which were complemented with additional beam measurements. The sources of this deviation and the mechanical modifications of the RFQ to solve this matter will be presented in this paper. Meanwhile, the nominal output energy of 750 keV has been confirmed and the new injector with the four-rod RFQ is in full operation.

Schmidt, J. S.; Koubek, B.; Schempp, A.; Tan, C. Y.; Bollinger, D. S.; Duel, K. L.; Karns, P. R.; Pellico, W. A.; Scarpine, V. E.; Schupbach, B. A.; Kurennoy, S. S.

2014-03-01

123

Acceleration in astrophysics  

Microsoft Academic Search

The origin of cosmic rays and applicable laboratory experiments are discussed. The principle problems of shock acceleration for the production of cosmic rays in the context of astrophysical conditions are found to be: (1) The presumed unique explanation of the power law spectrum is shown instead to be expected as a universal property of all accelerators with high loss; (2)

Stirling A Colgate

1994-01-01

124

LBNL-4215E/CBP Note 868 (Jan. 25, 2011) Ecloud Build-Up Simulations for the FNAL MI for a Mixed Fill Pattern  

E-print Network

the electron-cloud build-up and decay in a specific region of the chamber under the action of a prescribed beam simulation results of the build-up of the electron-cloud density ne in three regions of the FNAL Main to assess the impact of the electron-cloud ef- fect on the MI upgrade [1] has motivated the measurement

Furman, Miguel

125

COMPASS, the COMmunity Petascale project for Accelerator Science and Simulation, a broad computational accelerator physics  

E-print Network

COMPASS, the COMmunity Petascale project for Accelerator Science and Simulation, a broad for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation at Lawrence Livermore National Laboratory. #12;COMPASS, the COMmunity Petascale project for Accelerator

Geddes, Cameron Guy Robinson

126

Fermilab: Fermi National Accelerator Laboratory  

NSDL National Science Digital Library

FERMILAB's Home Page is the place to go to find out about Top Quark, The Nature of Nature, and Fermilab at Work. The Nature of Nature provides a brief overview of high-energy physics, an article on how scientists do high-eneregy physics, and an article on the benefits of high-energy physics research. There is also access to The Drell Panel Report.

1997-01-01

127

Optimization and validation of an accelerated laboratory extraction method to estimate nitrogen release patterns of slow- and controlled-release fertilizers.  

PubMed

Several technologies have been proposed to characterize the nutrient release and availability patterns of enhanced-efficiency fertilizers (EEFs), especially slow-release fertilizers (SRFs) and controlled-release fertilizers (CRFs) during the last few decades. These technologies have been developed mainly by manufacturers and are product-specific based on the regulation and analysis of each EEF product. Despite previous efforts to characterize EEF materials, no validated method exists to assess their nutrient release patterns. However, the increased use of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. A series of experiments were conducted to evaluate the effect of temperature, fertilizer test portion size, and extraction time on the performance of a 74 h accelerated laboratory extraction method to measure SRF and CRF nutrient release profiles. Temperature was the only factor that influenced nutrient release rate, with a highly marked effect for phosphorus and to a lesser extent for nitrogen (N) and potassium. Based on the results, the optimal extraction temperature set was: Extraction No. 1-2:00 h at 25 degrees C; Extraction No. 2-2:00 h at 50 degrees C; Extraction No. 3-20:00 h at 55 degrees C; and Extraction No. 4-50:00 h at 60 degrees C. Ruggedness of the method was tested by evaluating the effect of small changes in seven selected factors on method behavior using a fractional multifactorial design. Overall, the method showed ruggedness for measuring N release rates of coated CRFs. PMID:25051611

Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

2014-01-01

128

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

129

Overview of accelerators in medicine  

SciTech Connect

Accelerators used for medicine include synchrotrons, cyclotrons, betatrons, microtrons, and electron, proton, and light ion linacs. Some accelerators which were formerly found only at physics laboratories are now being considered for use in hospital-based treatment and diagnostic facilities. This paper presents typical operating parameters for medical accelerators and gives specific examples of clinical applications for each type of accelerator, with emphasis on recent developments in the field.

Lennox, A.J. [Fermi National Accelerator Lab., Batavia, IL (US)]|[Rush Univ., Chicago, IL (US)

1993-06-01

130

Acceleration in astrophysics  

SciTech Connect

The origin of cosmic rays and applicable laboratory experiments are discussed. Some of the problems of shock acceleration for the production of cosmic rays are discussed in the context of astrophysical conditions. These are: The presumed unique explanation of the power law spectrum is shown instead to be a universal property of all lossy accelerators; the extraordinary isotropy of cosmic rays and the limited diffusion distances implied by supernova induced shock acceleration requires a more frequent and space-filling source than supernovae; the near perfect adiabaticity of strong hydromagnetic turbulence necessary for reflecting the accelerated particles each doubling in energy roughly 10{sup 5} to {sup 6} scatterings with negligible energy loss seems most unlikely; the evidence for acceleration due to quasi-parallel heliosphere shocks is weak. There is small evidence for the expected strong hydromagnetic turbulence, and instead, only a small number of particles accelerate after only a few shock traversals; the acceleration of electrons in the same collisionless shock that accelerates ions is difficult to reconcile with the theoretical picture of strong hydromagnetic turbulence that reflects the ions. The hydromagnetic turbulence will appear adiabatic to the electrons at their much higher Larmor frequency and so the electrons should not be scattered incoherently as they must be for acceleration. Therefore the electrons must be accelerated by a different mechanism. This is unsatisfactory, because wherever electrons are accelerated these sites, observed in radio emission, may accelerate ions more favorably. The acceleration is coherent provided the reconnection is coherent, in which case the total flux, as for example of collimated radio sources, predicts single charge accelerated energies much greater than observed.

Colgate, S.A.

1993-12-31

131

Breakthrough: Fermilab Accelerator Technology  

SciTech Connect

There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

None

2012-04-23

132

Breakthrough: Fermilab Accelerator Technology  

ScienceCinema

There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

None

2014-08-12

133

Studies of E-Cloud Build up for the FNAL Main Injector and for theLHC  

SciTech Connect

We present a summary of recent simulation studies of the electron-cloud (EC) build-up for the FNAL MI and for the LHC. In the first case we pay particular attention to the dependence on bunch intensity N{sub b} at injection energy assuming the nominal bunch spacing t{sub b} = 19 ns, and we focus on the dipole magnets and field-free regions. The saturated value of the average EC density shows a clear threshold in N{sub b} beyond which the beam will be approximately neutralized on average. For the case of the LHC we limit our discussion to arc dipoles at collision energy, and bunch spacings t{sub b} = 25 ns or t{sub b} = 75 ns. The main variables exercised in this study are N{sub b} and the peak value of the secondary emission yield (SEY) {delta}{sub max}. For t{sub b} = 25 ns we conclude that the EC power deposition is comfortably below the available cooling capacity of the cryogenic system if {delta}{sub max} is below {approx} 1.2 at nominal N{sub b}. For t{sub b} = 75 ns, the EC power deposition is insignificant. As a byproduct of this exercise, we reach a detailed understanding of the significant role played by the backscattered secondary electrons. This article summarizes the results, an slightly extends the discussions, presented in Refs. 1 and 2.

Furman, M.A.

2006-06-14

134

Mitigation Plans for the Microbunching-Instability-Related COTR at ASTA/FNAL  

SciTech Connect

At the Advanced Superconducting Test Accelerator (ASTA) now under construction at Fermilab, we anticipate the appearance of the microbunching instability related to the longitudinal space charge (LSC) impedances. With a photoinjector source and up to two chicane compressors planned, the conditions should result in the shift of some microbunched features into the visible light regime. The presence of longitudinal microstructures (microbunching) in the electron beam or the leading edge spikes can result in strong, spatially localized coherent enhancements of optical transition radiation (COTR) that mask the actual beam profile. Several efforts on mitigation of the effects in the diagnostics task have been identified. At ASTA we have designed the beam profiling stations to have mitigation features based on spectral filtering, scintillator choice, and the timing of the trigger to the digital camera's CCD chip. Since the COTR is more intense in the NIR than UV we have selectable bandpass filters centered at 420 nm which also overlap the spectral emissions of the LYSO:Ce scintillators. By delaying the CCD trigger timing of the integration window by 40-50 ns, we can reject the prompt OTR signal and integrate on the delayed scintillator light predominately. This combination of options should allow mitigation of COTR enhancements of order 100-1000 in the distribution.

Lumpkin, A. H.; Johnson, A. M.

2013-05-01

135

Rutting Performance of Airport Hot-Mix Asphalt Characterized by Laboratory Performance Testing, Full-Scale Accelerated Pavement Testing, and Finite Element Modeling  

E-print Network

Hot Mix Asphalt (HMA) laboratory mixture design is intended to provide a durable, rut-resistant mixture for a given traffic type. Current mixture design procedures using the Superpave Gyratory Compactor (SGC) rely on volumetric properties...

Rushing, John Ford

2014-04-25

136

Android Acceleration  

NSDL National Science Digital Library

Students prepare for the associated activity in which they investigate acceleration by collecting acceleration vs. time data using the accelerometer of a sliding Android device. Based on the experimental set-up for the activity, students form hypotheses about the acceleration of the device. Students will investigate how the force on the device changes according to Newton's Second Law. Different types of acceleration, including average, instantaneous and constant acceleration, are introduced. Acceleration and force is described mathematically and in terms of processes and applications.

2014-09-18

137

The Brookhaven Accelerator Test Facility  

SciTech Connect

The Accelerator Test Facility (ATF), presently under construction at Brookhaven National laboratory, is described. It consists of a 50-MeV electron beam synchronizable to a high-peak power CO{sub 2} laser. The interaction of electrons with the laser field will be probed, with some emphasis on exploring laser-based acceleration techniques. 5 refs., 2 figs.

Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Jialin, Xie; Kirk, H.G.; Parsa, Z.; Palmer, R.B.; Rao, T.; Rogers, J.; Sheehan, J.; Tsang, T.Y.F.; Ulc, S.; Van Steenbergen, A.; Woodle, M.; Zhang, R.S. (Brookhaven National Lab., Upton, NY (United States)); McDonald, K.T.; Russell, D.P. (Princeton Univ., NJ (United States)); Jiang, Z.Y. (State Univ. of New York, Stony Brook, NY (Un

1990-01-01

138

The Brookhaven Accelerator Test Facility  

Microsoft Academic Search

The Accelerator Test Facility (ATF), presently under construction at Brookhaven National laboratory, is described. It consists of a 50-MeV electron beam synchronizable to a high-peak power CO laser. The interaction of electrons with the laser field will be probed, with some emphasis on exploring laser-based acceleration techniques. 5 refs., 2 figs.

K. Batchelor; I. Ben-Zvi; R. C. Fernow; J. Fischer; A. S. Fisher; J. Gallardo; Xie Jialin; H. G. Kirk; Z. Parsa; R. B. Palmer; T. Rao; J. Rogers; J. Sheehan; T. Y. F. Tsang; S. Ulc; A. Van Steenbergen; M. Woodle; R. S. Zhang; K. T. McDonald; D. P. Russell; Z. Y. Jiang

1990-01-01

139

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

Variable Gravity Laboratory studies are discussed. The following subject areas are covered: (1) conceptual design and engineering analysis; (2) control strategies (fast crawling maneuvers, main perturbations and their effect upon the acceleration level); and (3) technology requirements.

Lucchetti, F.

1989-01-01

140

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

141

Electrostatic accelerators  

E-print Network

The principle of electrostatic accelerators is presented. We consider Cockcroft? Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

Hinterberger, F

2006-01-01

142

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

143

First charge breeding of a rare-isotope beam with the electron-beam ion trap of the ReA post-accelerator at the National Superconducting Cyclotron Laboratory.  

PubMed

An electron-beam ion trap (EBIT) charge breeder is being brought into operation at the National Superconducting Cyclotron Laboratory at Michigan State University. The EBIT is part of the ReA post-accelerator for reacceleration of rare isotopes, which are thermalized in a gas "stopping" cell after being produced at high energy by projectile fragmentation. The ReA EBIT has a distinctive design; it is characterized by a high-current electron gun and a two-field superconducting magnet to optimize the capture and charge-breeding efficiency of continuously injected singly charged ion beams. Following a brief overview of the reaccelerator system and the ReA EBIT, this paper presents the latest commissioning results, particularly, charge breeding and reacceleration of the highly charged rare isotopes, (76)Ga(24 +, 25 +). PMID:24593600

Lapierre, A; Schwarz, S; Baumann, T M; Cooper, K; Kittimanapun, K; Rodriguez, A J; Sumithrarachchi, C; Williams, S J; Wittmer, W; Leitner, D; Bollen, G

2014-02-01

144

Rail accelerator research at Lewis Research Center  

NASA Technical Reports Server (NTRS)

A rail accelerator was chosen for study as an electromagnetic space propulsion device because of its simplicity and existing technology base. The results of a mission feasibility study using a large rail accelerator for direct launch of ton-size payloads from the Earth's surface to space, and the results of initial tests with a small, laboratory rail accelerator are presented. The laboratory rail accelerator has a bore of 3 by 3 mm and has accelerated 60 mg projectiles to velocities of 300 to 1000 m/s. Rail materials of Cu, W, and Mo were tested for efficiency and erosion rate.

Kerslake, W. R.; Cybyk, B. Z.

1982-01-01

145

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

146

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

147

SPEAR3 Accelerator Physics Update  

SciTech Connect

The SPEAR3 storage ring at Stanford Synchrotron Radiation Laboratory has been delivering photon beams for three years. We will give an overview of recent and ongoing accelerator physics activities, including 500 mA fills, work toward top-off injection, long-term orbit stability characterization and improvement, fast orbit feedback, new chicane optics, low alpha optics & short bunches, low emittance optics, and MATLAB software. The accelerator physics group has a strong program to characterize and improve SPEAR3 performance

Safranek, James A.; Corbett, W.Jeff; Gierman, S.; Hettel, R.O.; Huang, X.; Nosochkov, Yuri; Sebek, Jim; Terebilo, Andrei; /SLAC

2007-11-02

148

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

149

UCLA Neptune Facility for Advanced Accelerator Studies  

SciTech Connect

The Neptune Laboratory at UCLA is being used for exploring concepts useful for advanced accelerators. This facility hosts a TW-class CO2 laser system and a high-brightness photoinjector producing a 14 MeV electron beam. The goal for the laboratory is to carry out experiments on high-gradient acceleration of externally injected electrons in both laser-driven relativistic plasma waves and EM laser field in vacuum. Experiments on plasma beat-wave acceleration using a prebunched electron beam, a high-energy gain 10-{mu}m inverse free electron laser accelerator, longitudinal electron beam shaping and laser based light-sources are planned.

Tochitsky, Sergei Ya.; Clayton, Christopher E.; Marsh, Kenneth A.; Joshi, Chandrashekhar [Neptune Laboratory, Department of Electrical Engineering, University of California at Los Angeles, 405 Hilgard avenue, Los Angeles, CA 90095 (United States); Rosenzweig, James B.; Pellegrini, Claudio [Neptune Laboratory, Department of Physics, University of California at Los Angeles, 405 Hilgard avenue, Los Angeles, CA 90095 (United States)

2004-12-07

150

US LHC Accelerator Research Program FY 2005 Task Sheet  

E-print Network

$310k Topic Institution FY05 FTE Participants IR optics design FNAL 0.5 T. Sen, M. Syphers, Post-doc 1 IR optics design BNL 0.2 S. Tepikian Energy Deposition FNAL 0.4 N. Mokhov, Post-doc 2 IR design related B-B FNAL 0.3 T. Sen, Post-doc 1 Strong-strong simulations LBNL 0.2 J. Qiang Statement of work

Large Hadron Collider Program

151

Acceleration Environment of the International Space Station  

NASA Technical Reports Server (NTRS)

Measurement of the microgravity acceleration environment on the International Space Station has been accomplished by two accelerometer systems since 2001. The Microgravity Acceleration Measurement System records the quasi-steady microgravity environment, including the influences of aerodynamic drag, vehicle rotation, and venting effects. Measurement of the vibratory/transient regime, comprised of vehicle, crew, and equipment disturbances, has been accomplished by the Space Acceleration Measurement System-II. Until the arrival of the Columbus Orbital Facility and the Japanese Experiment Module, the location of these sensors, and therefore, the measurement of the microgravity acceleration environment, has been limited to within the United States Laboratory. Japanese Aerospace Exploration Agency has developed a vibratory acceleration measurement system called the Microgravity Measurement Apparatus which will be deployed within the Japanese Experiment Module to make distributed measurements of the Japanese Experiment Module's vibratory acceleration environment. Two Space Acceleration Measurement System sensors from the United States Laboratory will be re-deployed to support vibratory acceleration data measurement within the Columbus Orbital Facility. The additional measurement opportunities resulting from the arrival of these new laboratories allows Principal Investigators with facilities located in these International Space Station research laboratories to obtain microgravity acceleration data in support of their sensitive experiments. The Principal Investigator Microgravity Services project, at NASA Glenn Research Center, in Cleveland, Ohio, has supported acceleration measurement systems and the microgravity scientific community through the processing, characterization, distribution, and archival of the microgravity acceleration data obtained from the International Space Station acceleration measurement systems. This paper summarizes the PIMS capabilities available to the International Space Station scientific community, introduces plans for extending microgravity analysis results to the newly arrived scientific laboratories, and provides summary information for known microgravity environment disturbers.

McPherson, Kevin; Kelly, Eric; Keller, Jennifer

2009-01-01

152

Plasma accelerator  

DOEpatents

There has been invented an apparatus for acceleration of a plasma having coaxially positioned, constant diameter, cylindrical electrodes which are modified to converge (for a positive polarity inner electrode and a negatively charged outer electrode) at the plasma output end of the annulus between the electrodes to achieve improved particle flux per unit of power.

Wang, Zhehui (Los Alamos, NM); Barnes, Cris W. (Santa Fe, NM)

2002-01-01

153

Particle acceleration  

NASA Technical Reports Server (NTRS)

Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

1986-01-01

154

Accelerated Achievement  

ERIC Educational Resources Information Center

This article focuses on the accelerated associate degree program at Ivy Tech Community College (Indiana) in which low-income students will receive an associate degree in one year. The three-year pilot program is funded by a $2.3 million grant from the Lumina Foundation for Education in Indianapolis and a $270,000 grant from the Indiana Commission

Ford, William J.

2010-01-01

155

A linear accelerator bunch length monitor  

SciTech Connect

A monitor has been developed that provides an indication of the bunching efficiency of the Saskatchewan Accelerator Laboratory`s Linear Accelerator (Linac). By adjusting the prebuncher phase at the injector, a decrease in energy spread of 15% at the end of the linac was observed. With more rigorous optimization, it is believed that a reduction of 20% or greater in energy spread can be achieved.

Jessie, D.; Norum, E. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Saskatchewan Accelerator Lab.] [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Saskatchewan Accelerator Lab.

1996-06-01

156

25 MV tandem accelerator at Oak Ridge  

SciTech Connect

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.

Jones, C.M.

1980-01-01

157

Numerical Model of the DARHT Accelerating Cell  

Microsoft Academic Search

The DARHT-2 facility at Los Alamos National Laboratory accelerates a 2?sec electron beam using a series of inductive accelerating cells. The cell inductance is provided by large Metglas cores, which are driven by a pulse-forming network. The original cell design was susceptible to electrical breakdown near the outer radius of the cores. We developed a numerical model for the cell,

T. P. Hughes; T. C. Genoni; H. A. Davis; M. Kang; B. A. Prichard

2005-01-01

158

Linear accelerator for tritium production  

SciTech Connect

For many years now, Los Alamos National Laboratory has been working to develop a conceptual design of a facility for accelerator production of tritium (API). The APT accelerator will produce high energy protons which will bombard a heavy metal target, resulting in the production of large numbers of spallation neutrons. These neutrons will be captured by a low-Z target to produce tritium. This paper describes the latest design of a room-temperature, 1.0 GeV, 100 mA, cw proton accelerator for tritium production. The potential advantages of using superconducting cavities in the high-energy section of the linac are also discussed and a comparison is made with the baseline room-temperature accelerator.

Garnett, R.W.; Billen, J.H.; Chan, K.C.D. [and others

1995-12-31

159

Compact accelerator  

DOEpatents

A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Kirbie, Hugh C. (Los Alamos, NM)

2007-02-06

160

Ecloud Build-Up Simulations for the FNAL MI for a Mixed Fill Pattern: Dependence on Peak SEY and Pulse Intensity During the Ramp  

SciTech Connect

We present simulation results of the build-up of the electron-cloud density n{sub e} in three regions of the FNAL Main Injector (MI) for a beam fill pattern made up of 5 double booster batches followed by a 6th single batch. We vary the pulse intensity in the range N{sub t} = (2-5) x 10{sup 13}, and the beam kinetic energy in the range E{sub k} = 8-120 GeV. We assume a secondary electron emission model qualitatively corresponding to TiN, except that we let the peak value of the secondary electron yield (SEY) {delta}{sub max} vary as a free parameter in a fairly broad range. Our main conclusions are: (1) At fixed N{sub t} there is a clear threshold behavior of n{sub e} as a function of {delta}{sub max} in the range {approx} 1.1-1.3. (2) At fixed {delta}{sub max}, there is a threshold behavior of n{sub e} as a function of N{sub t} provided {delta}{sub max} is sufficiently high; the threshold value of N{sub t} is a function of the characteristics of the region being simulated. (3) The dependence on E{sub k} is weak except possibly at transition energy. Most of these results were informally presented to the relevant MI personnel in April 2010.

Furman, M. A.

2010-12-11

161

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

162

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

163

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

164

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

165

The Echo Sounding Rocket Payloads as a Laboratory in Space to Study the Dynamics of the Natural Aurora Acceleration Mechanism and Other Important Contributions John Winckler has Made to the Field  

NASA Astrophysics Data System (ADS)

It is with great honor that I have the opportunity to talk about some of the contributions Prof. John Winckler has made to space science and auroral physics in particular. John's interest in the aurora began on the first day of the IGY during a balloon flight designed to be the start of a campaign to do a latitudinal survey of the cosmic ray cut-off during the IGY. The detectors of this flight unexpectedly measured 50-100 keV x-rays produced by auroral electrons bombarding the top of the atmosphere. After retiring from teaching, John's interest in the dynamics of low-latitude aurora came full circle from its starting point during that first day of the IGY almost thirty years earlier. With ground photometers, cameras and stereoscopic TV, he made extensive observations of the pulsation phase of auroras during the peak of solar cycle 22. Although pulsating aurora had been studied for decades at auroral zone latitudes, John's work at sub-auroral latitudes discovered new phenomena and made observations of known phenomena in greater detail. The intent of this talk is primarily to consider Winckler's pioneering work with electron beam injections into the magnetosphere from sounding rockets. The motivation for this work initially was to map auroral field lines and to study large scale magnetospheric electric fields. The aspect of the work that I was most intimately involved in was the mechanism of neutralizing the rocket after it had injected nearly a coulomb of negative charge into space. It was initially argued that the beams would become unstable and therefore be destroyed and useless as probes of the magnetosphere. This was not the case, hence the neutralization mechanism became a significant study of the program. Although not realized at the time, it turns out that the beam injections at rocket altitude in essence became a laboratory in space in which many of the features of the aurora itself were reproduced. It is accepted that the electrons of a discrete aurora are accelerated by a potential structure one or two Re above the atmosphere. The requirement for field-aligned current demanded by the magnetic field reconfiguration in the Earth's tail during substorms is, presumably, the reason for this potential. Electrons that have interacted with this potential structure are known to contain signatures of ion cyclotron waves, perhaps a clue as to the source of the potential itself. Data will be shown from a recent rocket flight measuring both cold ionospheric electrons of field-aligned bursts and inverted V electrons originating from the tail which bear this signature. Data from the Echo rockets show very similar results. There is a need for return current to the electron-emitting payload if the beam is to escape. Ambient electrons are measured to be accelerated within a few tens of meters of the payload to carry this current. These electrons produce auroral light in collisions with residual neutral gas around the payload. Both the light and the neutralizing electrons fluctuate in intensity at heavy ion cyclotron frequencies.

Arnoldy, R. L.

2001-12-01

166

Impact accelerations  

NASA Technical Reports Server (NTRS)

The degree to which impact acceleration is an important factor in space flight environments depends primarily upon the technology of capsule landing deceleration and the weight permissible for the associated hardware: parachutes or deceleration rockets, inflatable air bags, or other impact attenuation systems. The problem most specific to space medicine is the potential change of impact tolerance due to reduced bone mass and muscle strength caused by prolonged weightlessness and physical inactivity. Impact hazards, tolerance limits, and human impact tolerance related to space missions are described.

Vongierke, H. E.; Brinkley, J. W.

1975-01-01

167

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

168

Accelerator search for cosmic SIMPs  

NASA Astrophysics Data System (ADS)

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 with anomalous masses. Since no such signal was observed for SIMP masses up to over 1 TeV, cosmic SIMP density limits may be given. Determining the minimum time of exposure to SIMPs trapped in the galaxy is a crucial element in the analysis of each sample.

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

2003-07-01

169

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

170

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

171

The Accelerating Universe  

SciTech Connect

From keV electrons in terrestrial aurorae to Ultra High Energy Cosmic Rays from unidentified "Zevatrons", the cosmos shows a plutocratic proclivity to concentrate energy in a tiny minority of suprathermal particles. 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 observed and that much can be learned from comparing and contrasting particle acceleration in laboratory and diverse astronomical locations. It will be argued that new mechanisms are required to account for recent observations of galactic nuclei, pulsar wind nebulae and interplanetary, interstellar and intergalactic media and some candidates will be discussed.

Blandford, Roger [Stanford University

2013-05-15

172

APT accelerator. Topical report  

SciTech Connect

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 production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

Lawrence, G.; Rusthoi, D. [comp.] [ed.

1995-03-01

173

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

174

Space Radiation Effects Laboratory  

NASA Technical Reports Server (NTRS)

The SREL User's Handbook is designed to provide information needed by those who plan experiments involving the accelerators at this laboratory. Thus the Handbook will contain information on the properties of the machines, the beam parameters, the facilities and services provided for experimenters, etc. This information will be brought up to date as new equipment is added and modifications accomplished. This Handbook is influenced by the many excellent models prepared at other accelerator laboratories. In particular, the CERN Synchrocyclotron User's Handbook (November 1967) is closely followed in some sections, since the SREL Synchrocyclotron is a duplicate of the CERN machine. We wish to thank Dr. E. G. Michaelis for permission to draw so heavily on his work, particularly in Section II of this Handbook. We hope that the Handbook will prove useful, and will welcome suggestions and criticism.

1969-01-01

175

for sequence accelerators  

E-print Network

Wynn's -algorithm for sequence accelerators using high precision arithmetic Rachel Baumann University of Arizona Wynn's -algorithm for sequence accelerators using high precision arithmetic Rachel Baumann University of Arizona April 17, 2012 #12;Wynn's -algorithm for sequence accelerators using high

Zakharov, Vladimir

176

Chemical Accelerators The phrase "chemical accelerators"  

E-print Network

that there is a wealth of important chemistry occurring only at higher energies (of the order of the strength of chemicalMeetings Chemical Accelerators The phrase "chemical accelerators" is scarcely older than for one or two dozen people grew to include nearly a hundred. Chemical accelerators is a name sug- gested

Zare, Richard N.

177

Fifty years of accelerator based physics at Chalk River  

SciTech Connect

The Chalk River Laboratories of Atomic Energy of Canada Ltd. was a major centre for Accelerator based physics for the last fifty years. As early as 1946, nuclear structure studies were started on Cockroft-Walton accelerators. A series of accelerators followed, including the world's first Tandem, and the MP Tandem, Superconducting Cyclotron (TASCC) facility that was opened in 1986. The nuclear physics program was shut down in 1996. This paper will describe some of the highlights of the accelerators and the research of the laboratory.

McKay, John W. [P.O. Box 463, Deep River, Ontario, K0J 1P0 (Canada)

1999-04-26

178

The Accelerator Test Facility at Brookhaven: Main capabilities  

SciTech Connect

Brookhaven National Laboratory's (BNL's) Accelerator Test Facility (ATF) is a user facility for accelerator- and beam- physics. Researchers from national and foreign universities, the DOE's national laboratories, and small businesses can carry out their experiments here, thereby relieving their institutions and companies from the large investment in accelerators, lasers, control and diagnostic equipment, and trained accelerator operators, all of which BNL's ATF offers. The main emphasis of this paper is on the capabilities of the ATF that I illustrate by discussing a few experiments. More detailed information can be obtained from the ATF web site: http://www.bnl.gov/atf.

Yakimenko, Vitaly [Brookhaven National Laboratory, Upton, NY, 11790 (United States)

2004-12-07

179

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

180

Lessons from the Bevatron Accelerator Demolition - 12191  

SciTech Connect

The Bevatron accelerator at Lawrence Berkeley National Laboratory is the first DOE accelerator to be demolished. While there are many lessons learned from its demolition, this paper focuses on the following lessons learned that may be useful for other D and D projects: bounding project scope to ensure success, hazards mapping for focused characterization and remediation, establishing radiological evaluation criteria, and forecasting activation products. With D and D of many DOE accelerators likely to occur in the near future, these lessons learned should be considered in planning those projects. These lessons learned are likely to be applicable to other D and D projects as well. (authors)

Harkins, Joseph [Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); Cronin, Robert [CH2M HILL, Englewood, Colorado, 80112 (United States)

2012-07-01

181

Acceleration without Horizons  

E-print Network

We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} velocity or, equivalently, by an acceleration parameter and terminal velocity.

Doria, Alaric

2015-01-01

182

Acceleration without Horizons  

E-print Network

We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} velocity or, equivalently, by an acceleration parameter and terminal velocity.

Alaric Doria; Gerardo Munoz

2015-02-18

183

Laser driven ion accelerator  

DOEpatents

A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

Tajima, Toshiki

2005-06-14

184

Induction linear accelerators  

Microsoft Academic Search

Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very

Daniel Birx

1992-01-01

185

Laser driven ion accelerator  

DOEpatents

A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

Tajima, Toshiki

2006-04-18

186

Thomas Jefferson National Accelerator Facility  

SciTech Connect

The Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia, USA, is one of ten national laboratories under the aegis of the Office of Science of the U.S. Department of Energy (DOE). It is managed and operated by Jefferson Science Associates, LLC. The primary facility at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF) as shown in an aerial photograph in Figure 1. Jefferson Lab was created in 1984 as CEBAF and started operations for physics in 1995. The accelerator uses superconducting radio-frequency (srf) techniques to generate high-quality beams of electrons with high-intensity, well-controlled polarization. The technology has enabled ancillary facilities to be created. The CEBAF facility is used by an international user community of more than 1200 physicists for a program of exploration and study of nuclear, hadronic matter, the strong interaction and quantum chromodynamics. Additionally, the exceptional quality of the beams facilitates studies of the fundamental symmetries of nature, which complement those of atomic physics on the one hand and of high-energy particle physics on the other. The facility is in the midst of a project to double the energy of the facility and to enhance and expand its experimental facilities. Studies are also pursued with a Free-Electron Laser produced by an energy-recovering linear accelerator.

Joseph Grames, Douglas Higinbotham, Hugh Montgomery

2010-09-01

187

ISIS upgrades David Findlay  

E-print Network

ISIS upgrades David Findlay Head, Accelerator Division ISIS Department Rutherford Appleton Laboratory / STFC Proton Accelerators for Science and Innovation, 12­14 January 2012, FNAL #12;2 ISIS World for research in the physical and life sciences National and international community of >2000 scientists -- ISIS

McDonald, Kirk

188

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

189

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

190

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

191

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

192

Archimedes: Accelerator Reveals Ancient Text  

SciTech Connect

Archimedes (287-212 BC), who is famous for shouting 'Eureka' (I found it) is considered one of the most brilliant thinkers of all times. The 10th-century parchment document known as the 'Archimedes Palimpsest' is the unique source for two of the great Greek's treatises. Some of the writings, hidden under gold forgeries, have recently been revealed at the Stanford Synchrotron Radiation Laboratory at SLAC. An intense x-ray beam produced in a particle accelerator causes the iron in original ink, which has been partly erased and covered, to send out a fluorescence glow. A detector records the signal and a digital image showing the ancient writings is produced. Please join us in this fascinating journey of a 1,000-year-old parchment from its origin in the Mediterranean city of Constantinople to a particle accelerator in Menlo Park.

Bergmann, Uwe

2004-02-24

193

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

194

Reduction of Effective Acceleration to Microgravity Levels  

NASA Technical Reports Server (NTRS)

Acceleration due to earth's gravity causes buoyancy driven convection and sedimentation in solutions. In addition. pressure gradients occur as a function of the height within a liquid column. Hence gravity effects both equilbria conditions and phase transitions as a result of hydrostatic pressure gradients. The affect of gravity on the rate of heat and man transfer in solutal processes can be particularly important in polymer processing due to the high sensitivity of polymeric materials to processing conditions. The term microgravity has been coined to describe an environment in which the affects of gravitational acceleration am greatly reduced. It may seem odd to talk in term of reducing the effects of gravitational acceleration since gravitational attraction is a basic property of matter. However, die presence of gravity on in situ processing or measurements can be negated by achieving conditions in which the laboratory, or more specifically the container of the experimental materials, a subjected to the same acceleration as the materials themselves. With regard to the laboratory reference frame, there is virtually no force on the experimental solutions. This is difficult to achieve but can be done. A short review of Newtonian physics provides an explanation on both how processes we affected by gravity and how microgravity conditions are achieved. The fact that fluids deform when subject to a force bid solids do not indicates that solids have a structure able to exert an opposing force that negates an externally applied force. Liquids deform when a force is applied, indicating that a liquid structure cannot completely negate an applied force. Just how easily a liquid resists deformation is related to its viscosity. Spaceflight provides an environment in which the laboratory reference frame i.e. the spacecraft and all the equipment therein an experiencing virtually identical forces. There is no solid foundation underneath such a laboratory, so the laboratory accelerates according to the force of gravity as do the experimental fluids within the lab. Hence, the magnitude of the form excited by the laboratory on the experimental solutions within are greatly reduced. When compared with a laboratory on the ground and averaged over time, the fluids in a spaceflight laboratory experience approximately a 10 (sup -6)decrease in acceleration relative to their laboratory reference frame hence the term microgravity.

Downey, James P.

2000-01-01

195

Accelerated/abbreviated test methods for predicting life of solar cell encapsulants to Jet Propulsion Laboratory California Institute of Technology for the encapsulation task of the low-cost solar array project  

NASA Technical Reports Server (NTRS)

An important principle is that encapsulants should be tested in a total array system allowing realistic interaction of components. Therefore, micromodule test specimens were fabricated with a variety of encapsulants, substrates, and types of circuitry. One common failure mode was corrosion of circuitry and solar cell metallization due to moisture penetration. Another was darkening and/or opacification of encapsulant. A test program plan was proposed. It includes multicondition accelerated exposure. Another method was hyperaccelerated photochemical exposure using a solar concentrator. It simulates 20 year of sunlight exposure in a short period of one to two weeks. The study was beneficial in identifying some cost effective encapsulants and array designs.

Kolyer, J. M.

1978-01-01

196

Accelerator and Fusion Research Division: Summary of activities, 1986  

SciTech Connect

This report contains a summary of activities at the Lawrence Berkeley Laboratory's Accelerator and Fusion Research Division for the year 1986. Topics and facilities investigated in individual papers are: 1-2 GeV Synchrotron Radiation Source, the Center for X-Ray Optics, Accelerator Operations, High-Energy Physics Technology, Heavy-Ion Fusion Accelerator Research and Magnetic Fusion Energy. Six individual papers have been indexed separately. (LSP)

Not Available

1987-04-15

197

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

198

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

199

Accelerator and Fusion Research Division 1989 summary of activities  

SciTech Connect

This report discusses the research being conducted at Lawrence Berkeley Laboratory's Accelerator and Fusion Research Division. The main topics covered are: heavy-ion fusion accelerator research; magnetic fusion energy; advanced light source; center for x-ray optics; exploratory studies; high-energy physics technology; and bevalac operations.

Not Available

1990-06-01

200

Simulation Studies of the Pulse Line Ion Accelerator  

Microsoft Academic Search

The Heavy Ion Fusion Science Virtual National Laboratory has been studying the Pulse Line Ion Accelerator (PLIA) concept, motivated by the desire for an inexpensive way to accelerate intense short pulse heavy ion beams to regimes of interest for studies of high energy density matter and fusion ignition conditions. The PLIA uses a slow-wave structure based on a helical winding,

Enrique Henestroza; Roxanne Martinez

2007-01-01

201

Accelerator Science and Technology Centre ASTeC Annual Report  

E-print Network

by Photographic Reprographic Services. Daresbury Laboratory. www.astec.ac.uk #12;2 ASTeC Annual Report 2004 - 2005Accelerator Science and Technology Centre ASTeC Annual Report 2004 2005 CCLRC Rutherford Appleton Centre Accelerator Science and Technology Centre Annual Report 2004 2005 This report covers the work

202

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

203

Turning Laboratory \\  

Microsoft Academic Search

Sometimes, a student laboratory exercise will fail. Our normal approach to such an event is to work to prevent its occurrence. Students frequently get frustrated when laboratory results differ from their expectations, and instructors may be embarrassed, disappointed, or even panic-stricken by the outcomes. Laboratory failures can provide excellent learning opportunities for students, however, if they are handled properly. Unexpected

L. Brent Jenkins

204

Industrialization of Superconducting RF Accelerator Technology  

NASA Astrophysics Data System (ADS)

Superconducting RF (SRF) accelerator technology has basically existed for 50 years. It took about 20 years to conduct basic R&D and prototyping at universities and international institutes before the first superconducting accelerators were built, with industry supplying complete accelerator cavities. In parallel, the design of large scale accelerators using SRF was done worldwide. In order to build those accelerators, industry has been involved for 30 years in building the required cavities and/or accelerator modules in time and budget. To enable industry to supply these high tech components, technology transfer was made from the laboratories in the following three regions: the Americas, Asia and Europe. As will be shown, the manufacture of the SRF cavities is normally accomplished in industry whereas the cavity testing and module assembly are not performed in industry in most cases, yet. The story of industrialization is so far a story of customized projects. Therefore a real SRF accelerator product is not yet available in this market. License agreements and technology transfer between leading SRF laboratories and industry is a powerful tool for enabling industry to manufacture SRF components or turnkey superconducting accelerator modules for other laboratories and users with few or no capabilities in SRF technology. Despite all this, the SRF accelerator market today is still a small market. The manufacture and preparation of the components require a range of specialized knowledge, as well as complex and expensive manufacturing installations like for high precision machining, electron beam welding, chemical surface preparation and class ISO4 clean room assembly. Today, the involved industry in the US and Europe comprises medium-sized companies. In Japan, some big enterprises are involved. So far, roughly 2500 SRF cavities have been built by or ordered from industry worldwide. Another substantial step might come from the International Linear Collider (ILC) project currently being designed by the international collaboration GDE (`global design effort'). If the ILC will be built, about 18,000 SRF cavities need to be manufactured worldwide within about five years. The industrialization of SRF accelerator technology is analyzed and reviewed in this article in view of the main accelerator projects of the last two to three decades.

Peiniger, Michael; Pekeler, Michael; Vogel, Hanspeter

2012-01-01

205

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

Michael Horton

2009-05-30

206

Linear Accelerator (LINAC)  

MedlinePLUS

... equipment? How is safety ensured? What is this equipment used for? A linear accelerator (LINAC) is the ... pg=stereotactic) . top of page How does the equipment work? View larger with caption The linear accelerator ...

207

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

208

The LLNL multi-user tandem laboratory  

NASA Astrophysics Data System (ADS)

An FN tandem laboratory, cofunded by several Lawrence Livermore National Laboratory Divisions, Sandia Livermore, and the University of California Regents, is now operational at Livermore. The accelerator, formerly the University of Washington injector, has been upgraded with SF 6, Dowlish tubes, and a NEC pelletron charging system. A conventional duoplasmatron, a tritium source, and two Cs sputtering sources will be fielded on the accelerator. Pulsed beams will be available from two source positions. The laboratory has been designed to accommodate up to 19 experimental positions with excellent optics and working vacuum. The facility is unshielded with both accelerator and radiological systems under the control of a distributed microprocessor system. Research activities at the tandem include nuclear physics and astrophysics, materials science and characterization programs, and accelerator mass spectrometry for archaeology, biomedical, environmental and geoscience investigators.

Davis, J. C.

1989-04-01

209

Pulsars and Acceleration Sites  

NASA Technical Reports Server (NTRS)

Rotation-powered pulsars are excellent laboratories for the studying particle acceleration as well as fundamental physics of strong gravity, strong magnetic fields and relativity. But even forty years after their discovery, we still do not understand their pulsed emission at any wavelength. I will review both the basic physics of pulsars as well as the latest developments in understanding their high-energy emission. Special and general relativistic effects play important roles in pulsar emission, from inertial frame-dragging near the stellar surface to aberration, time-of-flight and retardation of the magnetic field near the light cylinder. Understanding how these effects determine what we observe at different wavelengths is critical to unraveling the emission physics. Fortunately the Gamma-Ray Large Area Space Telescope (GLAST), with launch in May 2008 will detect many new gamma-ray pulsars and test the predictions of these models with unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 300 GeV.

Harding, Alice

2008-01-01

210

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

211

Transresonant Electron Acceleration  

Microsoft Academic Search

ttelliwell and Bell have suggested synchronous acceleration of electrons by electromagnetic waves in the whistler range in the geomagnetic field. The acceleration of trapped electrons by electromagnetic waves is here generalized to include nonsynchronous or transresonant acceleration. It is shown that whistlers will scatter the electron velocity, by an amount inversely proportional to the square root of the time rate

E. N. Parker; Enrico Fermi

1961-01-01

212

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

213

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

214

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

215

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.

216

Far field acceleration  

SciTech Connect

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 given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.

Fernow, R.C.

1995-07-01

217

Pulsed power for particle beam accelerators in military applications  

SciTech Connect

Techniques useful for generating and conditioning power for high energy pulsed accelerators with potential weapon applications are described. Pulsed electron accelerators are exemplified by ETA and ATA at Lawrence Livermore Laboratories and RADLAC at Sandia Laboratories Albuquerque. Pulse-power techniques used in other applications are briefly mentioned, including some that may be useful for collective ion accelerators. The limitations of pulse-power and the general directions of desirable development are illustrated. The main needs are to increase repetition rate and to decrease size.

Smith, I.D.

1980-06-20

218

Virtual Accelerator for Accelerator Optics Improvement  

SciTech Connect

Through determination of all quadrupole strengths and sextupole feed-downs by fitting quantities derivable from precision orbit measurement, one can establish a virtual accelerator that matches the real accelerator optics. These quantities (the phase advances, the Green's functions, and the coupling ellipses tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a model-independent analysis (MIA). Instead of trying to identify magnet errors, a limited number of quadrupoles are chosen for optimized strength adjustment to improve the virtual accelerator optics and then applied to the real accelerator accordingly. These processes have been successfully applied to PEP-II rings for beta beating fixes, phase and working tune adjustments, and coupling reduction to improve PEP-II luminosity.

Yan, Y.T.; Cai, Y.; Decker, F-J.; Ecklund, S.; Irwin, J.; Seeman, J.; Sillivan, M.; Turner, J.; Wienands, U.; /SLAC

2005-09-30

219

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

220

Compensation Techniques in Accelerator Physics  

SciTech Connect

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.

Hisham Kamal Sayed

2011-05-31

221

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

222

Cryogenic Technology for Superconducting Accelerators  

NASA Astrophysics Data System (ADS)

Superconducting devices such as magnets and cavities are key components in the accelerator field for increasing the beam energy and intensity, and at the same time making the system compact and saving on power consumption in operation. An effective cryogenic system is required to cool and keep the superconducting devices in the superconducting state stably and economically. The helium refrigeration system for application to accelerators will be discussed in this review article. The concept of two cooling modes -- the liquefier and refrigerator modes -- will be discussed in detail because of its importance for realizing efficient cooling and stable operation of the system. As an example of the practical cryogenic system, the TRISTAN cryogenic system of KEK Laboratory will be treated in detail and the main components of the cryogenic system, including the high-performance multichannel transfer line and liquid nitrogen circulation system at 80K, will also be discussed. In addition, we will discuss the operation of the cryogenic system, including the quench control and safety of the system. The satellite refrigeration system will be discussed because of its potential for wide application in medium-size accelerators and in industry.

Hosoyama, Kenji

2012-01-01

223

Laboratory Tests  

MedlinePLUS

... factors can affect test results, including: sex age race medical history general health specific foods drugs you are taking how closely your follow preparatory instructions variations in laboratory ...

224

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

225

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

226

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

227

Acceleration Measurements Using Smartphone Sensors: Dealing with the Equivalence Principle  

E-print Network

Acceleration sensors built into smartphones, i-pads or tablets can conveniently be used in the Physics laboratory. By virtue of the equivalence principle, a sensor fixed in a non-inertial reference frame cannot discern between a gravitational field and an accelerated system. Accordingly, acceleration values read by these sensors must be corrected for the gravitational component. A physical pendulum was studied by way of example, and absolute acceleration and rotation angle values were derived from the measurements made by the accelerometer and gyroscope. Results were corroborated by comparison with those obtained by video analysis. The limitations of different smartphone sensors are discussed.

Monteiro, Martn; Mart, Arturo C

2014-01-01

228

Vacuum Insulator Development for the Dielectric Wall Accelerator  

SciTech Connect

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 are using '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 the first test of a High Gradient Insulator in a functioning Dielectric Wall Accelerator cell.

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

2008-03-17

229

Improvement of Space Shuttle Main Engine Low Frequency Acceleration Measurements  

NASA Technical Reports Server (NTRS)

The noise floor of low frequency acceleration data acquired on the Space Shuttle Main Engines is higher than desirable. Difficulties of acquiring high quality acceleration data on this engine are discussed. The approach presented in this paper for reducing the acceleration noise floor focuses on a search for an accelerometer more capable of measuring low frequency accelerations. An overview is given of the current measurement system used to acquire engine vibratory data. The severity of vibration, temperature, and moisture environments are considered. Vibratory measurements from both laboratory and rocket engine tests are presented.

Stec, Robert C.

1999-01-01

230

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

231

E.O. Lawrence Berkeley National Laboratory Environment, Health, and Safety Division  

E-print Network

Calvin Laboratory 6 Advanced Light Source (ALS) 16 Accelerator and Fusion Research 26 Radioanalytical, Chemical, and Life Sciences Research 71 Accelerator and Fusion Research 72 Low-Background Facility 74 Life

232

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

233

The Naples University 3 MV tandem accelerator  

SciTech Connect

The 3 MV tandem accelerator of the Naples University is used for research activities and applications in many fields. At the beginning of operation (1977) the main utilization was in the field of nuclear physics. Later, the realization of new beam lines allowed the development of applied activities as radiocarbon dating, ion beam analysis, biophysics, ion implantation etc. At present, the availability of different ion sources and many improvements on the accelerator allow to run experiments in a wide range of subjects. An overview of the characteristics and major activities of the laboratory is presented.

Campajola, L.; Brondi, A. [Dipartimento di Scienze Fisiche, Universita di Napoli ''Federico II'' Complesso Universitario di Monte S.Angelo via Cintia 80126 Napoli, Italy and Istituto Nazionale di Fisica Nucleare, Sez. di Napoli (Italy)

2013-07-18

234

The Naples University 3 MV tandem accelerator  

NASA Astrophysics Data System (ADS)

The 3 MV tandem accelerator of the Naples University is used for research activities and applications in many fields. At the beginning of operation (1977) the main utilization was in the field of nuclear physics. Later, the realization of new beam lines allowed the development of applied activities as radiocarbon dating, ion beam analysis, biophysics, ion implantation etc. At present, the availability of different ion sources and many improvements on the accelerator allow to run experiments in a wide range of subjects. An overview of the characteristics and major activities of the laboratory is presented.

Campajola, L.; Brondi, A.

2013-07-01

235

Teaching and Research with Accelerators at Tarleton State University  

SciTech Connect

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. [Department of Engineering and Physisc, Box T-390, Tarleton State University, Stephenville, Texas, 76402 (United States)

2009-03-10

236

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

237

Leaky Fermi accelerators  

E-print Network

A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

2015-01-01

238

Leaky Fermi accelerators  

E-print Network

A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

Kushal Shah; Vassili Gelfreich; Vered Rom-Kedar; Dmitry Turaev

2015-04-03

239

THE DIELECTRIC WALL ACCELERATOR  

SciTech Connect

The Dielectric Wall Accelerator (DWA), a class of induction accelerators, employs a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge to mass ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.

Caporaso, G J; Chen, Y; Sampayan, S E

2009-08-17

240

Optically pulsed electron accelerator  

DOEpatents

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20

241

Optically pulsed electron accelerator  

DOEpatents

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)

1987-01-01

242

Android Acceleration Application  

NSDL National Science Digital Library

In the first of two sequential lessons, students create mobile apps that collect data from an Android device's accelerometer and then store that data to a database. This lesson provides practice with MIT's App Inventor software and culminates with students writing their own apps for measuring acceleration. In the second lesson, students are given an app for an Android device, which measures acceleration. They investigate acceleration by collecting acceleration vs. time data using the accelerometer of a sliding Android device. Then they use the data to create velocity vs. time graphs and approximate the maximum velocity of the device.

IMPART RET Program, College of Information Science & Technology,

243

Particle acceleration in flares  

NASA Technical Reports Server (NTRS)

Particle acceleration is intrinsic to the primary energy release in the impulsive phase of solar flares, and we cannot understand flares without understanding acceleration. New observations in soft and hard X-rays, gamma-rays and coherent radio emissions are presented, suggesting flare fragmentation in time and space. X-ray and radio measurements exhibit at least five different time scales in flares. In addition, some new observations of delayed acceleration signatures are also presented. The theory of acceleration by parallel electric fields is used to model the spectral shape and evolution of hard X-rays. The possibility of the appearance of double layers is further investigated.

Benz, Arnold O.; Kosugi, Takeo; Aschwanden, Markus J.; Benka, Steve G.; Chupp, Edward L.; Enome, Shinzo; Garcia, Howard; Holman, Gordon D.; Kurt, Victoria G.; Sakao, Taro

1994-01-01

244

Accelerators and Nobel Laureates  

NSDL National Science Digital Library

This online article written by Sven Kullander at the Nobel e-Museum discusses the importance of particle accelerators to physics in a historical context. After studying their basic operatation, users can then learn about the many accelerator inventions and their assistance in various discoveries such as x-rays and electrons. The website provides links to descriptions of the many Nobel Prize winners who have utilized accelerators in their important work. Users can view images of the large accelerators from all over the world including the United Kingdom, Sweden, and the United State.

Kullander, Sven

245

Charged particle accelerator grating  

DOEpatents

A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

Palmer, Robert B. (Shoreham, NY)

1986-01-01

246

Accelerator-based BNCT.  

PubMed

The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. PMID:24365468

Kreiner, A J; Baldo, M; Bergueiro, J R; Cartelli, D; Castell, W; Thatar Vento, V; Gomez Asoia, J; Mercuri, D; Padulo, J; Suarez Sandin, J C; Erhardt, J; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Igarzabal, M; Minsky, D M; Herrera, M S; Capoulat, M E; Gonzalez, S J; del Grosso, M F; Gagetti, L; Suarez Anzorena, M; Gun, M; Carranza, O

2014-06-01

247

Accelerating Research with  

E-print Network

Accelerating Academic Research with Cloud Computing Published: September 2014 For the latest, maintained, and updated by expert staff. Worries about data loss from disasters (natural disasters, flooding

Bernstein, Phil

248

Laboratory formularies.  

PubMed

Clinical laboratories face increasing costs along with increased expectation to ensure appropriate use of diagnostic tests by physicians. One administrative mechanism that has been used successfully for this purpose is the laboratory formulary. Modeled after drug formularies, this is simply a list of diagnostic tests approved for use in a particular setting, possibly including additional restrictions regarding who may order a particular test and under what circumstances. This brief review summarizes the principles underlying laboratory formularies and suggests strategies for using them effectively. PMID:24091098

Jackson, Brian R

2014-01-01

249

Summary of the 2011 Dielectric Laser Accelerator Workshop  

NASA Astrophysics Data System (ADS)

The first ICFA Mini-Workshop on dielectric laser accelerators (DLA) 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 four 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 atto-second injector source, two critical steps towards realizing the potential of this technology.

Bermel, Peter; Byer, Robert L.; Colby, Eric R.; Cowan, Benjamin M.; Dawson, Jay; Joel England, R.; Noble, Robert J.; Qi, Minghao; Yoder, Rodney B.

2014-01-01

250

Optimization of a small scale reluctance linear solenoid accelerator  

NASA Astrophysics Data System (ADS)

Small scale accelerator technologies provide opportunities in innovative and efficient transportation systems. Accelerator technologies are ever decreasing in size and complexity. The goal of the research was to develop more efficient small scale accelerators by optimizing high current flow through the accelerating solenoid. To do this; low temperature liquid nitrogen cooling systems and Cockcroft-Walton voltage multiplier power supply systems were examined closely to maximize the magnetic field inside the solenoid. Additionally,ferromagnetic fluids were examined in conjunction with these technologies to investigate the possibility of controlled braking of an accelerated object. The experimentation provides a high quality laboratory experiment for undergraduates interested in accelerator physics. Additionally, it provides a useful demonstration apparatus for undergraduate students studying lower division electricity and magnetism courses. A demonstration of the current development on these technologies will be offered at the time of the lecture.

Barrera, Thor; Beard, Robby

2011-04-01

251

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

252

Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams  

SciTech Connect

Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

Siemann, R.H.; /SLAC

2011-10-24

253

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.

Mark J. Volkmann

2003-09-01

254

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

255

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

256

Microscale acceleration history discriminators  

DOEpatents

A new class of micromechanical acceleration history discriminators is claimed. These discriminators allow the precise differentiation of a wide range of acceleration-time histories, thereby allowing adaptive events to be triggered in response to the severity (or lack thereof) of an external environment. Such devices have applications in airbag activation, and other safety and surety applications.

Polosky, Marc A. (Albuquerque, NM); Plummer, David W. (Albuquerque, NM)

2002-01-01

257

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; /Fermilab

2010-07-01

258

Ion Cyclotron Resonance Accelerator  

Microsoft Academic Search

The Ion Cyclotron Resonance Accelerator (ICRA) is based on the operating principles of cyclotrons and gyrotrons, and should provide beam suitable for the production of radioisotopes for positron emission tomography (PET) or neutrons at a fraction of the cost of present day cyclotrons and linacs. The concept extends cyclotron resonance acceleration to ions by using a superconducting solenoid and a

T. L. Grimm; C. T. Ramsell; R. C. York

1997-01-01

259

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

260

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.

261

Induction linear accelerators  

NASA Astrophysics Data System (ADS)

Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very large beam pipes. This combination increases the beam breakup limited maximum currents to of order kiloamperes. The micropulse lengths of these machines are measured in 10's of nanoseconds and duty factors as high as 10-4 have been achieved. Until recently the major problem with these machines has been associated with the pulse power drive. Beam currents of kiloamperes and accelerating potentials of megavolts require peak power drives of gigawatts since no energy is stored in the structure. The marriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.

Birx, Daniel

1992-03-01

262

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.

None

2011-10-06

263

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.

None

2011-10-06

264

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.

None

2011-10-06

265

NEW ACCELERATION METHODS  

Microsoft Academic Search

But a glance at the Livingston chart, Fig. 1, of accelerator particle energy as a function of time shows that the energy has steadily, exponentially, increased. Equally significant is the fact that this increase is the envelope of diverse technologies. If one is to stay on, or even near, the Livingston curve in future years then new acceleration techniques need

Sessler

1984-01-01

266

ACCELERATOR RESEARCH STUDIES  

SciTech Connect

ACCELERATOR RESEARCH STUDIES Task A: Study of the Physics of Space-Charge Dominated Beams for Advanced Accelerator Applications Task B: Studies of High-Power Gyroklystrons and Application to Linear Colliders Task C: Theory and Simulation of the Physics Space-Charge Dominated Beams Annual Report for the Period June 1, 2003 to May 31, 2004

P.G. O'Shea, M. Reiser, V. L. Granatstein, W. Lawson, I. Haber, R. Kishek

2004-01-23

267

Scaling FFAG accelerator for muon acceleration  

SciTech Connect

Recent developments in scaling fixed field alternating gradient (FFAG) accelerators have opened new ways for lattice design, with straight sections, and insertions like dispersion suppressors. Such principles and matching issues are detailed in this paper. An application of these new concepts is presented to overcome problems in the PRISM project.

Lagrange, JB.; Planche, T. [Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku Kyoto, 615-8530 (Japan); Mori, Y. [Kyoto University Research Reactor Institute, Department of Nuclear Science and Engineering, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka, 590-0494 (Japan)

2011-10-06

268

BNL ACCELERATOR TEST FACILITY CONTROL SYSTEM UPGRADE.  

SciTech Connect

Brookhaven National Laboratory's Accelerator Test Facility (ATF) has embarked on a complete upgrade of its decade old computer system. The planned improvements affect every major component: processors (Intel Pentium replaces VAXes), operating system (Linux/Real-Time Linux supplants OpenVMS), and data acquisition equipment (fast Ethernet equipment replaces CAMAC serial highway.) This paper summarizes the strategies and progress of the upgrade along with plans for future expansion.

MALONE,R.; BEN-ZVI,I.; WANG,X.; YAKIMENKO,V.

2001-06-18

269

S-band accelerating structures for the PAL-XFEL  

NASA Astrophysics Data System (ADS)

One hundred seventy-two accelerating structures are required for the Pohang Accelerator Laboratory X-ray free-electron laser's (PAL-XFEL's) 10-GeV main linear accelerator. So far, we have purchased 80 structures from Mitsubishi Heavy Industry (MHI), which have quasi-symmetric couplers in the accelerating structure to reduce the quadruple and the sextuple components of the electric field in the coupling cavity. High-power tests have been conducted for the first structure of the MHI structure, and Research Instruments (RI) has developed a 3-m long accelerating structure that has an operating frequency of 2856 MHz and in/out couplers of quasi-symmetric racetrack shape for the PAL-XFEL linear accelerator. This structure also has been tested by PAL and RI in the Pohang accelerator laboratory (PAL) to check the maximum available electric field gradient. We will describe the test results of these structures and the current status for the fabrication of the other accelerating structures in this paper.

Lee, Heung-Soo; Park, Young Jung; Joo, Young-Do; Heo, Hoon; Heo, Jinyul; Kim, Sang-Hee; Park, Soung-Soo; Hwang, Woon Ha; Kang, Heung-Sik; Kim, Kwang-woo; Ko, In-Soo; Oh, Kyoung-Min; Noh, Sung-Joo; Bak, Yong Hwan; Matsumoto, Hiroshi

2015-02-01

270

Accelerator Facilities for Radiation Research  

NASA Technical Reports Server (NTRS)

HSRP Goals in Accelerator Use and Development are: 1.Need for ground-based heavy ion and proton facility to understand space radiation effects discussed most recently by NAS/NRC Report (1996). 2. Strategic Program Goals in facility usage and development: -(1) operation of AGS for approximately 600 beam hours/year; (2) operation of Loma Linda University (LLU) proton facility for approximately 400 beam hours/year; (3) construction of BAF facility; and (4) collaborative research at HIMAC in Japan and with other existing or potential international facilities. 3. MOA with LLU has been established to provide proton beams with energies of 40-250 important for trapped protons and solar proton events. 4. Limited number of beam hours available at Brookhaven National Laboratory's (BNL) Alternating Gradient Synchrotron (AGS).

Cucinotta, Francis A.

1999-01-01

271

E.O. Lawrence Berkeley National Laboratory Environment, Health, and Safety Division  

E-print Network

or Function 1 Donner Laboratory 3 Melvin Calvin Laboratory 6 Advanced Light Source (ALS) 26 Radioanalytical, Chemical, and Life Sciences Research 71 Heavy Ion Linear Accelerator (HILAC)/Instrument Calibration 72 Low

272

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

273

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

274

Space Acceleration Measurement Systems  

NASA Technical Reports Server (NTRS)

The Space Acceleration Measurement Systems (SAMS) Project develops and deploys the measurement systems for the Acceleration Measurement Program (AMP). At this time there are two types of measurement systems available, quasi-steady and vibratory. Orbital Acceleration Research Experiment (OARE) and Microgravity Acceleration Measurement System (MAMS) are the current quasi-steady systems available. OARE has flown numerous times supporting STS missions. MAMS has been delivered to Kennedy Space Center (KSC) for its deployment on the International Space Station (ISS). Vibratory measurements have been made and will be made by the Space Acceleration Measurement System (SAMS-I) Generation I, Space Acceleration Measurement System Generation II (SAMS-II), and Space Acceleration Measurement System Free Flyer or Generation III (SAMS-FF). SAMS-I supported 21 STS missions and has been retired. SAMS-II will be delivered to KSC to support ISS-6A launch (currently April 19, 2001). SAMS-FF has replaced SAMS-I in support of STS missions and has been deployed on sounding rockets, the KC-135 and ground facilities. SAMS-FF hardware shall be deployed on ISS in the future to provide a more compact solution.

Foster, William

2000-01-01

275

Amps particle accelerator definition study  

NASA Technical Reports Server (NTRS)

The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

Sellen, J. M., Jr.

1975-01-01

276

Entropic Accelerating Universe  

E-print Network

To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann-Lemaitre equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the entropy and temperature intrinsic to the horizon of the universe due to the information holographically stored there. Dark energy is thereby obviated and the acceleration is due to an entropic force naturally arising from the information storage on the horizon surface screen. We consider an additional quantitative approach inspired by surface terms in general relativity and show that this leads to the entropic accelerating universe.

Damien A. Easson; Paul H. Frampton; George F. Smoot

2010-10-24

277

Entropic accelerating universe  

NASA Astrophysics Data System (ADS)

To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann-Lematre equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the entropy and temperature intrinsic to the horizon of the universe due to the information holographically stored there. Dark energy is thereby obviated and the acceleration is due to an entropic force naturally arising from the information storage on the horizon surface screen. We consider an additional quantitative approach inspired by surface terms in general relativity and show that this leads to the entropic accelerating universe.

Easson, Damien A.; Frampton, Paul H.; Smoot, George F.

2011-01-01

278

Accelerator Production of Radionuclides  

NASA Astrophysics Data System (ADS)

While many radioactive isotopes in use today are found in nature, many more are artificially produced by irradiating target materials with nuclear particles. Two different technologies can provide the energetic particles needed: nuclear reactors, which produce a flux of neutrons, and particle accelerators, which produce a flux of charged particles. This chapter will deal with the important aspects of the production of radionuclides with accelerators, along with some details on their applications, commercially-available accelerator systems used for this purpose, and the size of the equipment business.

Schlyer, David J.; Ruth, Thomas J.

2012-06-01

279

The MESA accelerator  

SciTech Connect

The MESA accelerator will operate for particle and nuclear physics experiments in two different modes. A first option is conventional c.w. acceleration yielding 150-200MeV spin-polarized external beam. Second, MESA will be operated as a superconducting multi-turn energy recovery linac (ERL), opening the opportunity to perform experiments with a windowless target with beam current of up to 10 mA. The perspectives for innovative experiments with such a machine are discussed together with a sketch of the accelerator physics issues that have to be solved.

Aulenbacher, Kurt [Institut fr Kernphysik, Johannnes-Gutenberg-Universitt Mainz (Germany)

2013-11-07

280

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

281

New underground laboratories: Europe, Asia and the Americas  

NASA Astrophysics Data System (ADS)

Deep underground laboratories provide the low radioactive background environment necessary to explore the highest energy scales that cannot be reached with accelerators, by searching for extremely rare phenomena. In addition, these laboratories provide unique opportunities to sectors of other fields: geodynamics, rock mechanics, hydrology and the study of life under extreme conditions. Underground laboratories of different size and depth exist in all the regions. This article is focussed on future perspectives, reviewing the newer facilities, those still under project and the space becoming available at the older laboratories. We shall not discuss the existing or proposed facilities dedicated to detectors of long base line experiment with reactor or accelerator beams.

Bettini, Alessandro

2014-09-01

282

2006JINST1P11003 PUBLISHED BY INSTITUTE OF PHYSICS PUBLISHING AND SISSA  

E-print Network

, MI 49931, U.S.A. b Fermi National Accelerator Laboratory, Batavia, IL 60510, U.S.A. cNew Mexico University, University Park, PA 16802, U.S.A. E-mail: mmalek@fnal.gov ABSTRACT: The Central Laser Facility

283

Magneto-Thermal Stability in LARP Nb_{3}Sn TQS Magnets  

Microsoft Academic Search

In the framework of the US LHC Accelerator Program (LARP), three US laboratories BNL, FNAL and LBNL are developing Nb3Sn quadrupole magnets for the Large Hadron Collider (LHC) luminosity upgrade. At present CERN is supporting this activity by testing some of the LARP 1 m long 90 mm aperture magnets. Recently two magnets using a shell based key and bladder

B. Bordini; M. Bajko; S. Caspi; D. Dietderich; H. Felice; P. Ferracin; L. Rossi; G. L. Sabbi; E. Takala

2010-01-01

284

Magneto-Thermal Stability in LARP TQS Magnets  

Microsoft Academic Search

In the framework of the US LHC Accelerator Program (LARP), three US laboratories BNL, FNAL and LBNL are developing Nb3Sn quadrupole magnets for the Large Hadron Collider (LHC) luminosity upgrade. At present CERN is supporting this activity by testing some of the LARP 1 m long 90 mm aperture magnets. Recently two magnets using a shell based key and bladder

B. Bordini; M. Bajko; S. Caspi; D. Dietderich; H. Felice; P. Ferracin; L. Rossi; G. L. Sabbi; E. Takala

2010-01-01

285

Cell design for the DARHT linear induction accelerators  

Microsoft Academic Search

The dual-axis radiographic hydrotest facility at Los Alamos National Laboratory will employ two linear induction accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. The accelerator cell design for a 3-kA, 16-20-MeV, 60-ns flattop, high-brightness electron beam is presented. The cell is optimized for high-voltage stand-off while also minimizing the transverse impedance. Measurements of high-voltage RF characteristics are summarized

M. Burns; P. Allison; L. Earley; D. Liska; C. Mockler; J. Ruhe; H. Tucker; L. Walling

1991-01-01

286

Microgravity Acceleration Measurement System for the International Space Station  

Microsoft Academic Search

The Microgravity Acceleration Measurement System (MAMS) is a high resolution and wide dynamic range dual sensor-based accelerometry instrumentation system to be installed within the International Space Station's (ISS) US Laboratory Module. The MAMS instrument will provide highly accurate acceleration measurement data over the nano-g to milli-g range characterizing the Lab Module environment in the frequency spectrum from 10-4 Hz to

James E. Rice; James C. Fox; William G. Lange; Robert W. Dietrich; W. O. Wagar

1999-01-01

287

Laboratory diagnosis  

Technology Transfer Automated Retrieval System (TEKTRAN)

One of the first major goals of the microbiology laboratory is to isolate or detect clinically significant microorganisms from an affected site and, if more than one type of microorganism is present, to isolate them in approximately the same ratio as occurs in vivo. Whether an isolate is clinically...

288

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

289

Appalachian Laboratory  

NSDL National Science Digital Library

Located in Frostburg, Maryland, AL conducts research in aquatic ecology, landscape and watershed ecology, conservation biology and restoration ecology, behavioral and evolutionary ecology, and study both freshwater and terrestrial ecosystems of Maryland and other locations in the United States and the world. Site contains information regarding the facilities, faculty, on going research, education opportunities, and seminars. Also features information on the other UMCES laboratories.

290

TESLA superconducting accelerating structures  

NASA Astrophysics Data System (ADS)

Superconducting standing wave structures have been used for charged particle acceleration for almost 40 years. A brief introduction to this application with examples, test procedures and recently achieved results are discussed in this paper.

Sekutowicz, J.

2007-08-01

291

Learning about Accelerated Learning.  

ERIC Educational Resources Information Center

When accelerated learning programs succeed, they do so in part because they invoke and integrate skills and basic information, theoretical understanding, and natural knowledge. The trainer must blend these elements appropriately. (JOW)

Caine, Geoffrey; Caine, Renate Nummela

1989-01-01

292

Accelerator on a Chip  

SciTech Connect

SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

England, Joel

2014-06-30

293

Accelerator on a Chip  

ScienceCinema

SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

England, Joel

2014-07-16

294

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

295

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

296

Superconducting Accelerator Structures: An Historical Overview  

NASA Astrophysics Data System (ADS)

In 1961 I began doing active research on RF superconducting cavities at the High Energy Physics Laboratory (HEPL) at Stanford University. At that time there were already nascent research programs exploring superconducting cavities at four other laboratories around the world, including the one at the Stanford physics department. However, all attempts to produce a substantial accelerating field in a superconducting cavity had failed. Since a cavity that is capable of acceleration always has a surface electric field, I decided that my first research effort would be to build and test a cavity with only a magnetic field at the surface. The frequency would need to be 2856 MHz, that of the electron linac at HEPL, so that available instrumentation could be used. In order to have only a magnetic field at the surface, the cavity would have to operate in the so-called TE mode. But there was a problem: at 2856 MHz such a cavity would be considerably larger than the single-cell accelerating mode cavities previously built at the Stanford physics department. In collaboration with the low temperature physics group in the Stanford physics department, a larger electroplating facility was built that was capable of handling the cylindrical cavity body and two end plates. The initial measurements gave stunning results: a Q factor of about 10^8 at 4 K for a lead-plated cavity was obtained, and there was no degradation in Q up to a surface magnetic field of about 10 mT, (limited by the oscillator power). The results were published in 1963. Experimentation on superconducting accelerator cavities increased rapidly in the decade or so following this initial success. Successful niobium TM-mode (accelerating mode) cavities were built with Q's of about 10^11. Within a few years the multipactor problem in accelerating cavities was solved by changing the shape of the outer boundary. The initial impetus for superconducting accelerator research at Stanford was to design and build a long pulse superconducting linac with an energy of about one GeV. Such a linac has still not been realized, but in the years from 1970 to 1990 there have been successful applications of RF superconducting structures to storage rings, rf separators, drive linacs for FEL's, and heavy ion accelerators. The evolution superconducting structures and their applications, as outlined above, will be discussed in more detail in my talk

Wilson, Perry

2011-03-01

297

Impulsive acceleration of strongly magnetized relativistic flows  

NASA Astrophysics Data System (ADS)

The strong variability of magnetic central engines of active galactic nuclei (AGNs) and gamma-ray bursts (GRBs) may result in highly intermittent strongly magnetized relativistic outflows. We find a new magnetic acceleration mechanism for such impulsive flows that can be much more effective than the acceleration of steady-state flows. This impulsive acceleration results in kinetic-energy-dominated flows that are conducive to efficient dissipation at internal magnetohydrodynamic shocks on astrophysically relevant distances from the central source. For a spherical flow, a discrete shell ejected from the source over a time t0 with Lorentz factor ? 1 and initial magnetization ?0=B20/4??0c2? 1 quickly reaches a typical Lorentz factor ??1/30 and magnetization ??2/30 at the distance R0?ct0. At this point, the magnetized shell of width ?R0 in the laboratory frame loses causal contact with the source and continues to accelerate by spreading significantly in its own rest frame. The expansion is driven by the magnetic pressure gradient and leads to relativistic relative velocities between the front and back of the shell. While the expansion is roughly symmetric in the centre of the momentum frame, in the laboratory frame, most of the energy and momentum remains in a region (or shell) of width ?R0 at the head of the flow. This acceleration proceeds as ? (?0R/R0)1/3 and ??2/30 (R/R0)-1/3 until reaching a coasting radius RcR0?20, where the kinetic energy becomes dominant: ??0 and ? 1 at Rc. The shell then starts coasting and spreading (radially), its width growing as ?R0(R/Rc), causing its magnetization to drop as ?Rc/R at R > Rc. Given the typical variability time-scales of AGNs and GRBs, the magnetic acceleration in these sources is a combination of the quasi-steady-state collimation acceleration close to the source and the impulsive (conical or locally quasi-spherical) acceleration farther out. The interaction with the external medium, which can significantly affect the dynamics, is briefly addressed in the discussion.

Granot, Jonathan; Komissarov, Serguei S.; Spitkovsky, Anatoly

2011-02-01

298

Status of RF superconductivity at Argonne National Laboratory  

Microsoft Academic Search

Argonne National Laboratory now has two groups working on the application of RF superconductivity to particle accelerators. In the Physics Division, work in RFSC began in 1971 and led to the first superconducting heavy-ion accelerator (ATLAS). Recently, work has focused on the upgrade of the facility by replacing the existing tandem injector by a new positive ion injector comprised of

C. L. Bohn; J. R. Delayen; W. L. Kennedy; G. L. Nichols; C. T. Roche; L. Sagalovsky; P. M. Markovitch; K. W. Shepard; G. P. Zinkhann

1991-01-01

299

An active particle accelerator  

SciTech Connect

Although a static charge is difficult to maintain on macroscopic particles, it is straightforward to construct a small object with a regularly oscillating electric dipole moment. For objects of a given size, one may then construct an accelerator by appropriately matching the frequency and separations of an external array of electrodes to this size. Physically feasible size ranges, an accelerator design, and possible applications of such systems are discussed. 8 refs., 9 figs.

Goldman, T.

1991-01-01

300

Rolamite acceleration sensor  

DOEpatents

A rolamite acceleration sensor is described which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently. 6 figures.

Abbin, J.P.; Briner, C.F.; Martin, S.B.

1993-12-21

301

Uniformly accelerated black holes  

Microsoft Academic Search

The static and stationary C-metric are revisited in a generic framework and\\u000atheir interpretations studied in some detail. Specially those with two event\\u000ahorizons, one for the black hole and another for the acceleration. We found\\u000athat: i) The spacetime of an accelerated static black hole is plagued by either\\u000aconical singularities or lack of smoothness and compactness of the

Patricio S. Letelierand; Samuel R. Oliveira

2001-01-01

302

Rolamite acceleration sensor  

DOEpatents

A rolamite acceleration sensor which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently.

Abbin, Joseph P. (Albuquerque, NM); Briner, Clifton F. (Albuquerque, NM); Martin, Samuel B. (Albuquerque, NM)

1993-01-01

303

CEBAF accelerator achievements  

SciTech Connect

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.

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

2011-06-01

304

Laser electron accelerator  

Microsoft Academic Search

An intense electromagnetic pulse can create weak plasma oscillations through the action of the nonlinear ponderomotive force. Electrons trapped in the wake can be accelerated to high energy. Existing glass lasers of power density 10 to the 18th W\\/sq cm shone on plasmas of densities 10 to the 18th\\/cu cm can yield gigaelectronvolts of electron energy per centimeter of acceleration

T. Tajima; J. M. Dawson

1979-01-01

305

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

306

Effect of gasoline octane quality on vehicle acceleration performance  

SciTech Connect

A study was conducted under the auspices of the Coordinating Research Council, Inc. (CRC) to assess the potential effects of gasoline octane quality on vehicle acceleration performance. Twelve participating laboratories, representing both the oil and the automotive industries, tested a total of 182 vehicles as part of the 1989 CRC Octane Number Requirement Survey. The vehicles consisted of 78 with electronic knock control systems and 104 without. All testing was performed using the 1989/1990 CRC FBRU fuel series. The results showed that acceleration performance of vehicles with knock sensors was significantly affected by gasoline octane quality. Octane effects on acceleration performance were most pronounced at maximum-throttle (detent) conditions and at octane levels below the vehicles' octane requirements; however, some knock-sensor vehicles did show improved acceleration performance with fuels at octane levels above the octane number requirement. Acceleration performance in non-knock sensor vehicles was unaffected by octane quality.

Not Available

1991-07-01

307

High transformer ratio drive beams for wakefield accelerator studies  

SciTech Connect

For wakefield based acceleration schemes, use of an asymmetric (or linearly ramped) drive bunch current profile has been predicted to enhance the transformer ratio and generate large accelerating wakes. We discuss plans and initial results for producing such bunches using the 20 to 23 GeV electron beam at the FACET facility at SLAC National Accelerator Laboratory and sending them through plasmas and dielectric tubes to generate transformer ratios greater than 2 (the limit for symmetric bunches). The scheme proposed utilizes the final FACET chicane compressor and transverse collimation to shape the longitudinal phase space of the beam.

England, R. J.; Ng, C.-K.; Frederico, J.; Hogan, M. J.; Litos, M.; Muggli, P.; Joshi, C.; An, W.; Andonian, G.; Mori, W.; Lu, W. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Max Planck Institute for Physics, 80805 Munich (Germany); University of California Los Angeles, Los Angeles, CA 90095 (United States); Tsinghua University, Beijing (China)

2012-12-21

308

HF Accelerated Electron Fluxes, Spectra, and Ionization  

NASA Astrophysics Data System (ADS)

Wave particle interactions, an essential aspect of laboratory, terrestrial, and astrophysical plasmas, have been studied for decades by transmitting high power HF radio waves into Earth's weakly ionized space plasma, to use it as a laboratory without walls. Application to HF electron acceleration remains an active area of research (Gurevich in Usp Fizicheskikh Nauk 177(11):1145-1177, 2007) today. HF electron acceleration studies began when plasma line observations proved (Carlson et al. in J Atmos Terr Phys 44:1089-1100, 1982) that high power HF radio wave-excited processes accelerated electrons not to ~eV, but instead to -100 times thermal energy (10 s of eV), as a consequence of inelastic collision effects on electron transport. Gurevich et al (J Atmos Terr Phys 47:1057-1070, 1985) quantified the theory of this transport effect. Merging experiment with theory in plasma physics and aeronomy, enabled prediction (Carlson in Adv Space Res 13:1015-1024, 1993) of creating artificial ionospheres once ~GW HF effective radiated power could be achieved. Eventual confirmation of this prediction (Pedersen et al. in Geophys Res Lett 36:L18107, 2009; Pedersen et al. in Geophys Res Lett 37:L02106, 2010; Blagoveshchenskaya et al. in Ann Geophys 27:131-145, 2009) sparked renewed interest in optical inversion to estimate electron spectra in terrestrial (Hysell et al. in J Geophys Res Space Phys 119:2038-2045, 2014) and planetary (Simon et al. in Ann Geophys 29:187-195, 2011) atmospheres. Here we present our unpublished optical data, which combined with our modeling, lead to conclusions that should meaningfully improve future estimates of the spectrum of HF accelerated electron fluxes. Photometric imaging data can significantly improve detection of emissions near ionization threshold, and confirm depth of penetration of accelerated electrons many km below the excitation altitude. Comparing observed to modeled emission altitude shows future experiments need electron density profiles to derive more accurate HF electron flux spectra.

Carlson, Herbert C.; Jensen, Joseph B.

2014-12-01

309

Accelerator technology program. Progress report, January-June 1981  

SciTech Connect

This report covers the activities of Los Alamos National Laboratory's Accelerator Technology Division during the first 6 months of calendar 1981. We discuss the Division's major projects, which reflect a variety of applications and sponsors. The varied technologies concerned with the Proton Storage ring are concerned with the Proton Storage Ring are continuing and are discussed in detail. For the racetrack microtron (RTM) project, the major effort has been the design and construction of the demonstration RTM. Our development of the radio-frequency quadrupole (RFQ) linear accelerator continues to stimulate interest for many possible applications. Frequent contacts from other laboratories have revealed a wide acceptance of the RFQ principle in solving low-velocity acceleration problems. In recent work on heavy ion fusion we have developed ideas for funneling beams from RFQ linacs; the funneling process is explained. To test as many aspects as possible of a fully integrated low-energy portion of a Pion generator for Medical Irradiation (PIGMI) Accelerator, a prototype accelerator was designed to take advantage of several pieces of existing accelerator hardware. The important principles to be tested in this prototype accelerator are detailed. Our prototype gyrocon has been extensively tested and modified; we discuss results from our investigations. Our work with the Fusion Materials Irradiation Test Facility is reviewed in this report.

Knapp, E.A.; Jameson, R.A. (comps.)

1982-05-01

310

Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing  

NASA Technical Reports Server (NTRS)

Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

2011-01-01

311

LLNL multi-user tandem laboratory  

NASA Astrophysics Data System (ADS)

The Physics Department at Lawrence Livermore National Laboratory (LLNL) is building a new tandem Van de Graaff laboratory for nuclear physics and applied physics and technology programs. The laboratory has been funded by a coalition of users including several LLNL divisions, Sandia National Laboratories Livermore, and the University of California. The tandem is the former University of Washington injector FN. The accelerator is upgraded with a Pelletron charging system, Dowlish spiral inclined field beam tubes and SF 6 insulation. The laboratory incorporates several novel design concepts. Initial operation will be in June, 1987 with full operation in October, 1987. Design features, radiological controls, computer assisted operation, and experimental facilities of the laboratory are discussed.

Proctor, I. D.; Davis, J. C.; Eaton, M. R.; Garibaldi, J. L.; Moore, T. L.; Schumacher, B. J.; Southon, J. R.; Zimmerman, T. A.

1988-05-01

312

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

313

Laboratory accreditation  

SciTech Connect

Accreditation can offer many benefits to a testing or calibration laboratory, including increased marketability of services, reduced number of outside assessments, and improved quality of services. Compared to ISO 9000 registration, the accreditation process includes a review of the entire quality system, but in addition a review of testing or calibration procedures by a technical expert and participation in proficiency testing in the areas of accreditation. Within the DOE, several facilities have recently become accredited in the area of calibration, including Sandia National Laboratories, Oak Ridge, AlliedSignal FM and T; Lockheed Martin Idaho Technologies Co., and Pacific Northwest National Lab. At the national level, a new non-profit organization was recently formed called the National Cooperation for Laboratory Accreditation (NACLA). The goal of NACLA is to develop procedures, following national and international requirements, for the recognition of competent accreditation bodies in the US. NACLA is a voluntary partnership between the public and private sectors with the goal of a test or calibration performed once and accepted world wide. The NACLA accreditation body recognition process is based on the requirements of ISO Guide 25 and Guide 58. A membership drive will begin some time this fall to solicit organizational members and an election of a permanent NACLA Board of Directors will follow later this year or early 1999.

Pettit, R.B.

1998-08-01

314

US LHC Accelerator Research Program  

E-print Network

US LHC Accelerator Research Program Instrumentation Collaboration Meeting John Marriner May 9, 2003 #12;2/14/03 US LARP Instrumentation Collaboration Mtg 2 US LARP LARP = LHC Accelerator Research Program LARP is an outgrowth of the US LHC Accelerator Project The US LHC Accelerator Project built

Large Hadron Collider Program

315

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

316

Accelerator-based Neutron Sources  

Microsoft Academic Search

Since the earliest experiments defining the properties of the neutron, accelerators have played an important role in providing neutrons for research and applications. For many years, neutrons produced at accelerator facilities have complemented capabilities available from reactor-based sources. Now, with the declining availability of reactor facilities, upgrades of existing accelerator facilities and proposed new, more powerful accelerator-based sources will be

James B. Ball

1997-01-01

317

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

318

Studies of accelerated compact toruses  

SciTech Connect

In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa < 1), increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency.

Hartman, C.W.; Eddleman, J.; Hammer, J.H.

1983-01-04

319

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

The scope of the study is to investigate ways of controlling the microgravity environment of the International Space Station by means of a tethered system. Four main study tasks were performed. First, researchers analyzed the utilization of the tether systems to improve the lowest possible steady gravity level on the Space Station and the tether capability to actively control the center of gravity position in order to compensate for activities that would upset the mass distribution of the Station. The purpose of the second task was to evaluate the whole of the experiments performable in a variable gravity environment and the related beneficial residual accelerations, both for pure and applied research in the fields of fluid, materials, and life science, so as to assess the relevance of a variable g-level laboratory. The third task involves the Tethered Variable Gravity Laboratory. The use of the facility that would crawl along a deployed tether and expose experiments to varying intensities of reduced gravity is discussed. Last, a study performed on the Attitude Tether Stabilizer concept is discussed. The stabilization effect of ballast masses tethered to the Space Station was investigated as a means of assisting the attitude control system of the Station.

Lucchetti, F.

1990-01-01

320

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

321

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) = 1.210 6 W/m.

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

1987-11-01

322

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

323

Dielectric laser accelerators  

NASA Astrophysics Data System (ADS)

The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the GV /m regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

England, R. Joel; Noble, Robert J.; Bane, Karl; Dowell, David H.; Ng, Cho-Kuen; Spencer, James E.; Tantawi, Sami; Wu, Ziran; Byer, Robert L.; Peralta, Edgar; Soong, Ken; Chang, Chia-Ming; Montazeri, Behnam; Wolf, Stephen J.; Cowan, Benjamin; Dawson, Jay; Gai, Wei; Hommelhoff, Peter; Huang, Yen-Chieh; Jing, Chunguang; McGuinness, Christopher; Palmer, Robert B.; Naranjo, Brian; Rosenzweig, James; Travish, Gil; Mizrahi, Amit; Schachter, Levi; Sears, Christopher; Werner, Gregory R.; Yoder, Rodney B.

2014-10-01

324

Numerical simulations of laser wakefield accelerators in optimal Lorentz frames  

Microsoft Academic Search

The simulation of laser wakefield accelerators with particle-in-cell codes in relativistic reference frames is described, with emphasis on the computational speed-ups, which may potentially exceed three orders of magnitude in comparison with laboratory frame configurations. The initialization of laboratory quantities in a relativistically moving frame is depicted, and the method for result comparison with the plasma rest frame is described.

Samuel F. Martins; Ricardo A. Fonseca; Lus O. Silva; Wei Lu; Warren B. Mori

2010-01-01

325

FERMI NATIONAL ACCELERATOR LABORATORY WORKFORCE DEVELOPMENT & RESOURCES SECTION  

E-print Network

,500 employee paper records and 3,500 performance reviews filed Over 4,000 online personnel data entries 1 course completions and 933 training days 40 employees completed 107 courses through the Tuition.6% retirement rate 49 OnCall employees met temporary work needs 161 summer students employed 301 fulltime

Quigg, Chris

326

SLAC National Accelerator Laboratory Building 219, 274 and 278  

E-print Network

Extension 4821Emergency assembly point leader Larry Cadapan Buildings too small no sweepers needed Sweeper by emergency assembly point leaders, sweepers, and other emergency personnel for purposes such as taking roll

Wechsler, Risa H.

327

Stanford Linear Accelerator Center Stanford Synchrotron Radiation Laboratory  

E-print Network

(Nature Materials, 2006). Steps toward hydrogen vehiclesResearchers have shown that carbon nano- tubes (weakly diffracting crystals, ultra high resolution and large unit cells) and microcrystal experiments, based on an in-vacuum undulator source Soft x-ray microscopy, scattering, and advanced spectroscopy

Kay, Mark A.

328

Fermi National Accelerator Laboratory TARGET: Science & Engineering Program  

E-print Network

are to encourage high school students to undertake college study and pursue careers grounded in physics at the college level and consequently the workforce. Lastly, the program affords high school students of underrepresented groups (Black, Hispanic, Native American and women) in the sciences and engineering

Quigg, Chris

329

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

330

Stirling laboratory research engine survey report  

NASA Technical Reports Server (NTRS)

As one step in expanding the knowledge relative to and accelerating the development of Stirling engines, NASA, through the Jet Propulsion Laboratory (JPL), is sponsoring a program which will lead to a versatile Stirling Laboratory Research Engine (SLRE). An objective of this program is to lay the groundwork for a commercial version of this engine. It is important to consider, at an early stage in the engine's development, the needs of the potential users so that the SLRE can support the requirements of educators and researchers in academic, industrial, and government laboratories. For this reason, a survey was performed, the results of which are described.

Anderson, J. W.; Hoehn, F. W.

1979-01-01

331

Chaos in Accelerators  

SciTech Connect

Chaos is a general phenomenon in nonlinear dynamical systems. Accelerators--storage rings in particular--in which particles are stored for 10{sup 10} revolutions constitute a particularly intricate nonlinear dynamical system. (In comparison, the earth has revolved around the sun for only 10{sup 9} turns.) Storage rings therefore provide an ideal testing ground for chaos physics. In fact, it is the chaos phenomenon that imposes one of the key design criteria for these accelerators. One might arguably say that the demise of the Superconducting Super Collider project originated from a misjudgement in its chaos analysis at one point along its design path, leading to its first substantial cost escalation. This talk gives an elementary introduction to the study of chaos in accelerators.

Chao, Alex

1999-05-11

332

Archimedes Laboratory  

NSDL National Science Digital Library

Proving that geometry can be more fun than a barrel of monkeys, Archimedes Laboratory is "an 'intuitive' puzzle site with fewer formulas and more visuals, which may encourage students learning this science or just constitute a platform for reflection." Probably the most strictly educational section of the site is Math to Discover, which contains discussions of the history of numbers and mathematical patterns, to name a few. Also of interest are the Puzzles to Make and Puzzles to Solve sections. Visitors can follow online instructions to create geometrical curiosities or browse a small selection of impossible object images.

333

The international atomic energy agency's programme on utilization of accelerators  

NASA Astrophysics Data System (ADS)

Low-energy accelerators have in the past produced a major part of our current knowledge of nuclear physics. Today they are mainly used for applied research and industrial applications. In view of this, the International Atomic Energy Agency (IAEA) has during recent years initiated several Coordinated Research Projects (CRPs) concerning Ion Beam Analysis of Materials, Accelerator Mass Spectrometry and Nuclear Microprobe Techniques. The CRPs involve laboratories from developing as well as developed Member States, networking on a common topic coordinated by the IAEA. In order to facilitate networking, the IAEA has recently published the "World Survey of Accelerator Based Analytical Techniques" available on the Internet and as a CD-ROM. The IAEA maintains also a beamline at a 6 MV Van de Graaff accelerator in the Ru ?jer Bo\\vskovi? Institute, Zagreb, Croatia. Small and medium power accelerator driven spallation neutron sources will become more important as many small neutron producing research reactors are approaching the end of their useful working life. The IAEA has, within its Department for Nuclear Sciences and Applications, a programme on the Effective Utilization of Accelerators. This programme helps Member States, in particular developing Member States, in finding new areas of applications for their low and medium energy accelerators through increased participation in activities such as Coordinated Research Projects, Technical Meetings and Conferences. This paper describes the IAEA's current programme on accelerator utilization and proposed future activities.

Dytlewski, Nikolai; Mank, Gnter; Rosengard, Ulf; Bamford, Samuel; Markowicz, Andrzej; Wegrzynek, Dariusz

2006-06-01

334

High intensity hadron accelerators  

SciTech Connect

This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.

Teng, L.C.

1989-05-01

335

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

336

Acceleration of metal plates  

NASA Astrophysics Data System (ADS)

High-explosive charges were used to accelerate stainless steel plates to velocities of 6 to 7 km/s. A two-stage system was 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.

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

1989-08-01

337

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

338

An accelerator technology legacy  

SciTech Connect

Accelerator technology has been a major beneficiary of the investment made over the last decade. It is the intention of this paper to provide the reader with a glimpse of the broad nature of those advances. Development has been on a broad front and this paper can highlight only a few of those. Two spin-off applications will be outlined -- a concept for a compact, active, beam probe for solar body exploration and the concept for an accelerator-driven transmutation system for energy production.

Heighway, E.A.

1994-11-01

339

Accelerating cosmologies from compactification.  

PubMed

A solution of the (4+n)-dimensional vacuum Einstein equations is found for which spacetime is compactified on an n-dimensional compact hyperbolic manifold (n> or =2) of time-varying volume to a flat four-dimensional Friedmann-Lemaitre-Robertson-Walker cosmology undergoing a period of accelerated expansion in the Einstein conformal frame. This shows that the "no-go" theorem forbidding acceleration in "standard" (time-independent) compactifications of string or M theory does not apply to "cosmological" (time-dependent) hyperbolic compactifications. PMID:12935064

Townsend, Paul K; Wohlfarth, Mattias N R

2003-08-01

340

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

341

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

342

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

343

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

344

The NASA Space Radiation Laboratory at Brookhaven National Laboratory: Preparation and delivery of ion beams for space radiation research  

Microsoft Academic Search

The NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) was commissioned in October 2002 and became operational in July 2003. The NSRL was constructed in collaboration with NASA for the purpose of performing space radiation research as part of the NASA space program. The NSRL can accept a wide variety of ions from BNLs Collider Accelerator Department (CAD)

Kevin Brown; Leif Ahrens; I Hung Chiang; Christopher Gardner; David Gassner; Lee Hammons; Margaret Harvey; Nicholas Kling; John Morris; Phillip Pile; Adam Rusek; Mike Sivertz; Dannie Steski; Nick Tsoupas; Keith Zeno

2010-01-01

345

Ion sources for accelerators  

Microsoft Academic Search

A survey of different types of ion sources used for accelerator applications is given. Typical problems like the source life time, or the special need for technical solutions for specific elements will demonstrate the advantage of each type of ion source. In any case reliability is a main topic. Besides the plasma generation of the desired element, beam formation and

P. Spdtke; J. Bossler; H. Emig; K. D Leible; C. Mhle; H. Schulte; K. Tinschert

1998-01-01

346

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

347

Accelerating incomplete feature selection  

Microsoft Academic Search

Feature selection from incomplete data aims to retain the discriminatory power of original features in rough set theory. Many feature selection algorithms are computationally time-consuming. To overcome this drawback, we introduce a theoretic framework based on rough set theory, called positive approximation, which can be used to accelerate a heuristic process of feature selection from incomplete data. Based on the

Yuhua Qian; Jiye Liang; Wei Wei

2009-01-01

348

Prospects for Accelerator Technology  

NASA Astrophysics Data System (ADS)

Accelerator technology today is a greater than US$5 billion per annum business. Development of higher-performance technology with improved reliability that delivers reduced system size and life cycle cost is expected to significantly increase the total accelerator technology market and open up new application sales. Potential future directions are identified and pitfalls in new market penetration are considered. Both of the present big market segments, medical radiation therapy units and semiconductor ion implanters, are approaching the "maturity" phase of their product cycles, where incremental development rather than paradigm shifts is the norm, but they should continue to dominate commercial sales for some time. It is anticipated that large discovery-science accelerators will continue to provide a specialty market beset by the unpredictable cycles resulting from the scale of the projects themselves, coupled with external political and economic drivers. Although fraught with differing market entry difficulties, the security and environmental markets, together with new, as yet unrealized, industrial material processing applications, are expected to provide the bulk of future commercial accelerator technology growth.

Todd, Alan

2011-02-01

349

Compact plasma accelerator device  

Microsoft Academic Search

A compact plasma accelerator concept based on plasma production at a magnetic cusp was designed and fabricated. Plume and discharge characteristics of the device were documented using a Faraday probe and a retarding potential analyzer. The discharge current variations with increasing discharge voltage were nonlinear with the discharge current increasing rapidly with voltage. The device demonstrated the capability of generating

John E. Foster

2002-01-01

350

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.

351

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

352

DE91 C15841 The Brookhaven Accelerator Test Facility  

E-print Network

.C. Fernow, J. Fischer, A.S. Fisher, J. Gallardo, Xie Jialin, H.G. Kirk, Z. Parsa, R.B. Palmer, T. Rao, J Laboratory Upton, NY 11973 K.T. McDonald D.P. Russell Princeton University Princeton, NJ 08544 Z.Y. Jiang by D.P. Russell Abstract The Accelerator Test Facility (ATF), presently under construction

McDonald, Kirk

353

Influence of in situ concrete variability on accelerated carbonation test  

Microsoft Academic Search

Probabilistic approaches to design reinforced concrete structures require the knowledge of distribution laws governing the statistical variability of concrete properties used as models inputs. The present work focuses on the variability of carbonation resistance throughout the construction period and inside an existing structure. Accelerated carbonation tests were carried out in a laboratory on more than 120 samples taken from two

Ph. Turcry; A. Younsi; F. Jacquemot; A. At-Mokhtar; P. Rougeau

2012-01-01

354

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

355

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

ERIC Educational Resources Information Center

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

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

2013-01-01

356

Development of ADS virtual accelerator based on XAL  

NASA Astrophysics Data System (ADS)

XAL is a high level accelerator application framework that was originally developed by the Spallation Neutron Source (SNS), Oak Ridge National Laboratory. It has an advanced design concept and has been adopted by many international accelerator laboratories. Adopting XAL for ADS is a key subject in the long term. This paper will present the modifications to the original XAL applications for ADS. The work includes a proper relational database schema modification in order to better suit the requirements of ADS configuration data, redesigning and re-implementing db2xal application, and modifying the virtual accelerator application. In addition, the new device types and new device attributes for ADS online modeling purpose are also described here.

Wang, Peng-Fei; Cao, Jian-She; Ye, Qiang

2014-07-01

357

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

358

Laboratory investigations  

NASA Technical Reports Server (NTRS)

Laboratory studies related to cometary grains and the nuclei of comets can be broken down into three areas which relate to understanding the spectral properties, the formation mechanisms, and the evolution of grains and nuclei: (1) Spectral studies to be used in the interpretation of cometary spectra; (2) Sample preparation experiments which may shed light on the physical nature and history of cometary grains and nuclei by exploring the effects on grain emissivities resulting from the ways in which the samples are created; and (3) Grain processing experiments which should provide insight on the interaction of cometary grains with the environment in the immediate vicinity of the cometary nucleus as the comet travels from the Oort cloud through perihelion, and perhaps even suggestions regarding the relationship between interstellar grains and cometary matter. A summary is presented with a different view of lab experiments than is found in the literature, concentrating on measurement techniques and sample preparations especially relevant to cometary dust.

Russell, Ray W.

1988-01-01

359

Nighttime Clouds in Martian Arctic (Accelerated Movie)  

NASA Technical Reports Server (NTRS)

An angry looking sky is captured in a movie clip consisting of 10 frames taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander.

The clip accelerates the motion. The images were take around 3 a.m. local solar time at the Phoenix site during Sol 95 (Aug. 30), the 95th Martian day since landing.

The swirling clouds may be moving generally in a westward direction over the lander.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

360

European accelerator-based neutrino projects  

E-print Network

Future neutrino projects in Europe will follow two distinct time lines. On the medium term, they will be dominated by the CERN-Gran Sasso long-baseline project, with two experiments OPERA and ICARUS, mainly concentrated on $\\tau$ appearance. On the longer term, several projects are under discussion. A new proton driver at CERN that accelerates a 4 MW beam to 2.2 GeV of energy would open the possibility of a low-energy super-beam, possibly sent to the French laboratory under the Frejus. A new radioactive heavy ion facility could produce a pure $\

Mario Campanelli

2002-04-04

361

Acceleration and Classical Electromagnetic Radiation  

E-print Network

Classical radiation from an accelerated charge is reviewed along with the reciprocal topic of accelerated observers detecting radiation from a static charge. This review commemerates Bahram Mashhoon's 60th birthday.

E. N. Glass

2008-01-09

362

Dust accelerators and their applications in high-temperature plasmas  

SciTech Connect

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. Much effort has been devoted to gening rid of the dust nuisance. 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.

Wang, Zhehui [Los Alamos National Laboratory; Ticos, Catakin M [NILPRP, ROMANIA

2010-01-01

363

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

364

Simulation Studies of the Pulse Line Ion Accelerator  

NASA Astrophysics Data System (ADS)

The Heavy Ion Fusion Science Virtual National Laboratory has been studying the Pulse Line Ion Accelerator (PLIA) concept, motivated by the desire for an inexpensive way to accelerate intense short pulse heavy ion beams to regimes of interest for studies of high energy density matter and fusion ignition conditions. The PLIA uses a slow-wave structure based on a helical winding, on which a voltage pulse is launched and propagated to generate the accelerating fields. The PLIA has the ability to accelerate ion bunches to energies much greater than the peak applied voltage and over distances much larger than the voltage pulse ramp length; furthermore, the PLIA can axially confine the heavy ion beam bunch. These properties make it a good candidate for a high intensity, short bunch injector. We will present self-consistent numerical simulation studies of the beam dynamics in the PLIA.

Henestroza, Enrique; Martinez, Roxanne

2007-11-01

365

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

366

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

367

Preliminary description of the ground test accelerator cryogenic cooling system  

SciTech Connect

The Ground Test Accelerator (GTA) under construction at the Los Alamos National Laboratory is part of the Neutral Particle Beam Program supported by the Strategic Defense Initiative Office. The GTA is a full-sized test facility to evaluate the feasibility of using a negative ion accelerator to produce a neutral particle beam (NPB). The NPB would ultimately be used outside the earth's atmosphere as a target discriminator or as a directed energy weapon. The operation of the GTA at cryogenic temperature is advantageous for two reasons: first, the decrease of temperature caused a corresponding decrease in the rf heating of the copper in the various units of the accelerator, and second, at the lower temperature the decrease in the thermal expansion coefficient also provides greater thermal stability and consequently, better operating stability for the accelerator. This paper discusses the cryogenic cooling system needed to achieve these advantages. 5 figs., 3 tabs.

Edeskuty, F.J.; Stewart, W.F.

1988-01-01

368

A plasma wakefield acceleration experiment using CLARA beam  

NASA Astrophysics Data System (ADS)

We propose a Plasma Accelerator Research Station (PARS) based at proposed FEL test facility CLARA (Compact Linear Accelerator for Research and Applications) at Daresbury Laboratory. The idea is to use the relativistic electron beam from CLARA, to investigate some key issues in electron beam transport and in electron beam driven plasma wakefield acceleration, e.g. high gradient plasma wakefield excitation driven by a relativistic electron bunch, two bunch experiment for CLARA beam energy doubling, high transformer ratio, long bunch self-modulation and some other advanced beam dynamics issues. This paper presents the feasibility studies of electron beam transport to meet the requirements for beam driven wakefield acceleration and presents the plasma wakefield simulation results based on CLARA beam parameters. Other possible experiments which can be conducted at the PARS beam line are also discussed.

Xia, G.; Angal-Kalinin, D.; Clarke, J.; Smith, J.; Cormier-Michel, E.; Jones, J.; Williams, P. H.; Mckenzie, J. W.; Militsyn, B. L.; Hanahoe, K.; Mete, O.; Aimidula, A.; Welsch, C. P.

2014-03-01

369

Constellation Acceleration Study December 18, 2008  

E-print Network

Constellation Acceleration Study Report December 18, 2008 #12;Constellation Acceleration Study ........................................................................................................... 31 #12;Constellation Acceleration Study Report 12/18/08 Executive Summary In 2004, the White House

Christian, Eric

370

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

371

Particle Acceleration at Relativistic Shocks  

E-print Network

I review the current status of Fermi acceleration theory at relativistic shocks. I first discuss the relativistic shock jump conditions, then describe the non-relativistic Fermi mechanism and the differences introduced by relativistic flows. I present numerical calculations of the accelerated particle spectrum, and examine the maximum energy attainable by this process. I briefly consider the minimum energy for Fermi acceleration, and a possible electron pre-acceleration mechanism.

Yves A. Gallant

2002-01-15

372

Exploring Acceleration with an Android  

NSDL National Science Digital Library

Students conduct an experiment to study the acceleration of a mobile Android device. During the experiment, they run an application created with MIT's App Inventor that monitors linear acceleration in one-dimension. Students use an acceleration vs. time equation to construct an approximate velocity vs. time graph. Students will understand the relationship between the object's mass and acceleration and how that relates to the force applied to the object, which is Newton's second law of motion.

IMPART RET Program, College of Information Science & Technology,

373

Principles of Charged Particle Acceleration  

NSDL National Science Digital Library

This learning resources comprise a healthy introduction to charged particle acceleration. The site, by Stanley Humphries, a professor of electrical and computer engineering at University of New Mexico, amounts to an online textbook (.pdf) introducing the theory of charged particle acceleration. The book's fifteen chapters (with bibliography) summarize "the principles underlying all particle accelerators" and provide "a reference collection of equations and material essential to accelerator development and beam applications."

374

Magnetically accelerated foils for shock wave experiments  

NASA Astrophysics Data System (ADS)

Many astrophysical phenomena involve the interaction of a shock wave with an inhomogeneous background medium. Using scaled experiments with inhomogeneous foam targets makes it possible to study relevant physics in the laboratory to better understand the mechanisms of shock compression and to benchmark astrophysical simulation codes. First experiments on Zebra at the Nevada Terawatt Facility (NTF) have demonstrated flyer acceleration to sufficiently high velocities (up to 5 km/s) and that laser shadowgraphy can image sound fronts in transparent targets. Based on this, we designed an optimized setup to improve the flyer parameters (higher speed and mass) to create shock waves in transparent media. Once x-ray backlighting with the Leopard laser at NTF is operational, we will switch to foam targets with parameters relevant for laboratory astrophysics.

Neff, S.; Ford, J.; Wright, S.; Martinez, D.; Plechaty, C.; Presura, R.

2009-08-01

375

The LUE-200 accelerator at the IREN facility: Current status and development  

NASA Astrophysics Data System (ADS)

The general scheme and current status of an electron linear accelerator with an S-band travelling wave ( f = 2856 MHz) accelerating structurea driver for a pulsed neutron source (the Intense Resonance Neutron source (IREN)) at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Researchare presented. The parameters of the accelerating system and the measured parameters of the electron beampulse-beam current, duration of the current pulse, repetition rate, electron-energy spectrum, and loading characteristics of the accelerating structureare given. The beginning of the implementation of the project of the second stage of the IREN facility, which forms the basis for the development of the accelerator aimed at increasing its beam power, is reported. Technical solutions underlying the modernization of the accelerator's electrophysical systems are discussed: accelerating system, RF power supplies, and modulators.

Boettcher, Ju.; Golubkov, E. A.; Egorov, V. A.; Zaytseva, Yu. K.; Zamrij, V. N.; Kayukov, A. S.; Kobets, V. V.; Korokin, A. Zh.; Minashkin, V. F.; Pyataev, V. G.; Repkin, A. N.; Skrypnik, A. V.; Sumbaev, A. P.; Udovichenko, K. V.; Shabratov, V. G.; Schvets, V. A.; Shvetsov, V. N.; Pavlov, V. M.

2014-09-01

376

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

377

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

378

Effects of horizontal acceleration on human visual acuity and stereopsis.  

PubMed

The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy. PMID:25607601

Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

2015-01-01

379

Breeding nuclear fuels with accelerators replacement for breeder reactors  

NASA Astrophysics Data System (ADS)

High-current, high-energy linear accelerators are potential competitors to breeder reactors and fusion devices for the production of fissile fuel. Accelerator breeder studies, conducted at Chalk River (Canada) and Brookhaven National Laboratory during the last decade, indicate that the technology is available and system's costs competitive with that of the LMFBR and Fusion-Hybrid systems. This paper addresses the technical issues to be faced in an accelerator specifically designed for commercial operation of this kind, the neutronics and engineering feasibility of target systems, and related fuel-cycle cost/benefit analysis. A nearly optimized accelerator breeder concept consisting of a 1.5 GeV, 300 mA linear accelerator, and of a H 2O-cooled, U-metal target (or thorium) has been designed and costed. Accelerator efficiency, beam-to-plug, is estimated at 50% and target power generation efficiency, beam-to-thermal output, at about 600% (U-metal case). Fuel costs produced by the facility are practically entirely driven by capital investment costs. This is also true for any competing system. On the basis, the accelerator breeder is economically competitive with the LMFBR while offering real advantages in terms of safety, fuel cycle flexibility, and resource independence.

Grand, P.; Takahashi, H.

1985-05-01

380

Effects of Horizontal Acceleration on Human Visual Acuity and Stereopsis  

PubMed Central

The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy. PMID:25607601

Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

2015-01-01

381

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

382

Accelerometer: Centripetal Acceleration  

NSDL National Science Digital Library

Students work as physicists to understand centripetal acceleration concepts. They also learn about a good robot design and the accelerometer sensor. They also learn about the relationship between centripetal acceleration and centripetal forcegoverned by the radius between the motor and accelerometer and the amount of mass at the end of the robot's arm. Students graph and analyze data collected from an accelerometer, and learn to design robots with proper weight distribution across the robot for their robotic arms. Upon using a data logging program, they view their own data collected during the activity. By activity end , students understand how a change in radius or mass can affect the data obtained from the accelerometer through the plots generated from the data logging program. More specifically, students learn about the accuracy and precision of the accelerometer measurements from numerous trials.

2014-09-18

383

Hypervelocity plate acceleration  

SciTech Connect

Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

Marsh, S.P.; Tan, T.H.

1991-01-01

384

Review of ion accelerators  

SciTech Connect

The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.

Alonso, J.

1990-06-01

385

Pulsed electromagnetic gas acceleration  

NASA Technical Reports Server (NTRS)

Experimental data were combined with one-dimensional conservation relations to yield information on the energy deposition ratio in a parallel-plate accelerator, where the downstream flow was confined to a constant area channel. Approximately 70% of the total input power was detected in the exhaust flow, of which only about 20% appeared as directed kinetic energy, thus implying that a downstream expansion to convert chamber enthalpy into kinetic energy must be an important aspect of conventional high power MPD arcs. Spectroscopic experiments on a quasi-steady MPD argon accelerator verified the presence of A(III) and the absence of A(I), and indicated an azimuthal structure in the jet related to the mass injection locations. Measurements of pressure in the arc chamber and impact pressure in the exhaust jet using a piezocrystal backed by a Plexiglas rod were in good agreement with the electromagnetic thrust model.

Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

1971-01-01

386

Plasma wave accelerator. II  

SciTech Connect

It was shown that the insertion of a cross magnetic field prevents the particles from getting out of phase with the electric field of the plasma wave in the beat wave accelerator scheme. Thus, using a CO/sub 2/ laser, n/sub c//n/sub e/ = (..omega../sub 0//..omega../sub p/)/sup 2/ approx. 35, and a 300 kG magnetic field, electrons can be (in principle) accelerated to 100 GeV in 2 meters. For comparison without the magnetic field, the same energies may be obtained in a n/sub c//n/sub e/ approx. 10/sup 5/ plasma over a distance of 100 meters.

Mori, W.; Joshi, C.; Dawson, J.M.

1982-01-01

387

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

388

Linear induction accelerator  

DOEpatents

A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

Buttram, M.T.; Ginn, J.W.

1988-06-21

389

Accelerating QDP++ using GPUs  

E-print Network

Graphic Processing Units (GPUs) are getting increasingly important as target architectures in scientific High Performance Computing (HPC). NVIDIA established CUDA as a parallel computing architecture controlling and making use of the compute power of GPUs. CUDA provides sufficient support for C++ language elements to enable the Expression Template (ET) technique in the device memory domain. QDP++ is a C++ vector class library suited for quantum field theory which provides vector data types and expressions and forms the basis of the lattice QCD software suite Chroma. In this work accelerating QDP++ expression evaluation to a GPU was successfully implemented leveraging the ET technique and using Just-In-Time (JIT) compilation. The Portable Expression Template Engine (PETE) and the C API for CUDA kernel arguments were used to build the bridge between host and device memory domains. This provides the possibility to accelerate Chroma routines to a GPU which are typically not subject to special optimisation. As an application example a smearing routine was accelerated to execute on a GPU. A significant speed-up compared to normal CPU execution could be measured.

Frank Winter

2011-05-11

390

Accelerated Profile HMM Searches  

PubMed Central

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.

2011-01-01

391

Oxidised cosmic acceleration  

SciTech Connect

We give detailed proofs of several new no-go theorems for constructing flat four-dimensional accelerating universes from warped dimensional reduction. These new theorems improve upon previous ones by weakening the energy conditions, by including time-dependent compactifications, and by treating accelerated expansion that is not precisely de Sitter. We show that de Sitter expansion violates the higher-dimensional null energy condition (NEC) if the compactification manifold M is one-dimensional, if its intrinsic Ricci scalar R-ring vanishes everywhere, or if R-ring and the warp function satisfy a simple limit condition. If expansion is not de Sitter, we establish threshold equation-of-state parameters w below which accelerated expansion must be transient. Below the threshold w there are bounds on the number of e-foldings of expansion. If M is one-dimensional or R-ring everywhere vanishing, exceeding the bound implies the NEC is violated. If R-ring does not vanish everywhere on M, exceeding the bound implies the strong energy condition (SEC) is violated. Observationally, the w thresholds indicate that experiments with finite resolution in w can cleanly discriminate between different models which satisfy or violate the relevant energy conditions.

Wesley, Daniel H., E-mail: D.H.Wesley@damtp.cam.ac.uk [Centre for Theoretical Cosmology, DAMTP, Cambridge University, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2009-01-15

392

Calibration of rotational acceleration for the rotarod test of rodent motor coordination  

PubMed Central

The latency of mice and rats to fall from the accelerating rotarod can differ markedly between laboratories using the same brand of rod as well as between studies using different kinds of rods. These discrepancies can arise from different rod diameters, surface textures, test protocols, or laboratory environmental factors beyond the test itself, but it is also possible that the actual acceleration rates of the different rods do not correspond to the nominal rates set on the devices. This paper describes a simple method to measure acceleration rate of the rotarod and to set the rate to a desired value for any brand of rod. PMID:19041892

Bohlen, Martin; Cameron, Andy; Metten, Pamela; Crabbe, John C.; Wahlsten, Douglas

2015-01-01

393

Acceleration in Linear and Circular Motion  

ERIC Educational Resources Information Center

Describes the construction of a simple accelerometer and explains its use in demonstrating acceleration, deceleration, constant speed, measurement of acceleration, acceleration and the inclined plane and angular and radial acceleration. (GS)

Kellington, S. H.; Docherty, W.

1975-01-01

394

Testbeam and laboratory test results of irradiated 3D CMS pixel detectors  

NASA Astrophysics Data System (ADS)

The CMS silicon pixel detector is the tracking device closest to the LHC p-p collisions, which precisely reconstructs the charged particle trajectories. The planar technology used in the current innermost layer of the pixel detector will reach the design limit for radiation hardness at the end of Phase I upgrade and will need to be replaced before the Phase II upgrade in 2020. Due to its unprecedented performance in harsh radiation environments, 3D silicon technology is under consideration as a possible replacement of planar technology for the High Luminosity-LHC or HL-LHC. 3D silicon detectors are fabricated by the Deep Reactive-Ion-Etching (DRIE) technique which allows p- and n-type electrodes to be processed through the silicon substrate as opposed to being implanted through the silicon surface. The 3D CMS pixel devices presented in this paper were processed at FBK. They were bump bonded to the current CMS pixel readout chip, tested in the laboratory, and testbeams carried out at FNAL with the proton beam of 120 GeV/c. In this paper we present the laboratory and beam test results for the irradiated 3D CMS pixel devices.

Bubna, Mayur; Alagoz, Enver; Cervantes, Mayra; Krzywda, Alex; Arndt, Kirk; Obertino, Margherita; Solano, Ada; Dalla Betta, Gian-Franco; Menace, Dario; Moroni, Luigi; Uplegger, Lorenzo; Rivera, Ryan; Osipenkov, Ilya; Andresen, Jeff; Bolla, Gino; Bortoletto, Daniela; Boscardin, Maurizio; Marie Brom, Jean; Brosius, Richard; Chramowicz, John; Cumalat, John; Dinardo, Mauro; Dini, Paolo; Jensen, Frank; Kumar, Ashish; Kwan, Simon; Lei, C. M.; Povoli, Marco; Prosser, Alan; Ngadiuba, Jennifer; Perera, Lalith; Shipsey, Ian; Tan, Ping; Tentindo, Silvia; Terzo, Stefano; Tran, Nhan; Wagner, Stephen R.

2013-12-01

395

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

396

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

397

Switching system for the FXR accelerator  

SciTech Connect

A switching system has been designed for a 20 MeV flash x-ray linear induction accelerator which is being built at Lawrence Livermore Laboratory. The switching system fans out a single command pulse and amplifies it to obtain the voltage necessary for reliable, low-jitter triggering of the accelerator components. This system consists of two major subsystems: (1) the Blumlein Charging Subsystem which first triggers thirteen Marx generators, and then charges 54 water-filled Blumleins, and (2) the Blumlein Triggering Subsystem which triggers the already-charged Blumleins to produce a 90 nanosecond, 400 kV pulse in each of 54 ferrite-loaded accelerator modules. The first subsystem consists of charged high voltage cabling with two parallel switch gaps either of which will trigger the Marx generators. The major components of the second subsystem are three stages of switch gaps along with the necessary high voltage cabling. Two parallel first stage switch gaps trigger thirteen second stage gaps, which in turn trigger 54 third stage Blumlein switch gaps synchronous with the passage of the electron beam pulse. These spark gaps are operated at a voltage of 150 to 350 kV with a 1/3 hertz repetition rate. Varying the cable lengths creates the actual delay times in the triggering of each component. Redundancy is built into the system to insure the high reliability which is essential for the flash radiography application.

Scarpetti, R.D.; Parkinson, C.D.

1980-01-01

398

Testing a combined vibration and acceleration environment.  

SciTech Connect

Sandia National Laboratories has previously tested a capability to impose a 7.5 g-rms (30 g peak) radial vibration load up to 2 kHz on a 25 lb object with superimposed 50 g acceleration at its centrifuge facility. This was accomplished by attaching a 3,000 lb Unholtz-Dickie mechanical shaker at the end of the centrifuge arm to create a 'Vibrafuge'. However, the combination of non-radial vibration directions, and linear accelerations higher than 50g's are currently not possible because of the load capabilities of the shaker and the stresses on the internal shaker components due to the combined centrifuge acceleration. Therefore, a new technique using amplified piezo-electric actuators has been developed to surpass the limitations of the mechanical shaker system. They are lightweight, modular and would overcome several limitations presented by the current shaker. They are 'scalable', that is, adding more piezo-electric units in parallel or in series can support larger-weight test articles or displacement/frequency regimes. In addition, the units could be mounted on the centrifuge arm in various configurations to provide a variety of input directions. The design along with test results will be presented to demonstrate the capabilities and limitations of the new piezo-electric Vibrafuge.

Jepsen, Richard Alan; Romero, Edward F.

2005-01-01

399

Magnetically accelerated foils for shock wave experiments  

NASA Astrophysics Data System (ADS)

The interaction of shock waves with inhomogeneous media is important in many astrophysical problems, e.g. the role of shock compression in star formation. Using scaled experiments with inhomogeneous foam targets makes it possible to study relevant physics in the laboratory, to better understand the mechanisms of shock compression and to benchmark astrophysical simulation codes. Experiments with flyer-generated shock waves have been performed on the Z machine in Sandia. The Zebra accelerator at the Nevada Terawatt Facility (NTF) allows for complementary experiments with high repetition rate. First experiments on Zebra demonstrated flyer acceleration to sufficiently high velocities (around 2 km/s) and that laser shadowgraphy can image sound fronts in transparent targets. Based on this, we designed an optimized setup to improve the flyer parameters (higher speed and mass) to create shock waves in transparent media. Once x-ray backlighting with the Leopard laser at NTF is operational, we will switch to foam targets with parameters relevant for laboratory astrophysics.

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

2008-04-01

400

Hurricane Isabel gives accelerators a severe test  

SciTech Connect

Hurricane Isabel was at category five--the most violent on the Saffir-Simpson scale of hurricane strength--when it began threatening the central Atlantic seaboard of the US. Over the course of several days, precautions against the extreme weather conditions were taken across the Jefferson Lab site in south-east Virginia. On 18 September 2003, when Isabel struck North Carolina's Outer Banks and moved northward, directly across the region around the laboratory, the storm was still quite destructive, albeit considerably reduced in strength. The flood surge and trees felled by wind substantially damaged or even devastated buildings and homes, including many belonging to Jefferson Lab staff members. For the laboratory itself, Isabel delivered an unplanned and severe challenge in another form: a power outage that lasted nearly three-and-a-half days, and which severely tested the robustness of Jefferson Lab's two superconducting machines, the Continuous Electron Beam Accelerator Facility (CEBAF) and the superconducting radiofrequency ''driver'' accelerator of the laboratory's free-electron laser. Robustness matters greatly for science at a time when microwave superconducting linear accelerators (linacs) are not only being considered, but in some cases already being built for projects such as neutron sources, rare-isotope accelerators, innovative light sources and TeV-scale electron-positron linear colliders. Hurricane Isabel interrupted a several-week-long maintenance shutdown of CEBAF, which serves nuclear and particle physics and represents the world's pioneering large-scale implementation of superconducting radiofrequency (SRF) technology. The racetrack-shaped machine is actually a pair of 500-600 MeV SRF linacs interconnected by recirculation arc beamlines. CEBAF delivers simultaneous beams at up to 6 GeV to three experimental halls. An imminent upgrade will double the energy to 12 GeV and add an extra hall for ''quark confinement'' studies. On a smaller scale, Jefferson Lab's original kilowatt-scale infrared free-electron laser (FEL) is ''driven'' by a high-current cousin of CEBAF, a 70 MeV SRF linac with a high-current injector. The FEL serves multidisciplinary science and technology as the world's highest-average-power source of tunable coherent infrared light. An upgrade to 10 kW is in commissioning--as it was when Isabel began threatening.

Swapan Chattopadhyay

2004-01-01

401

Operational and design aspects of accelerators for medical applications  

NASA Astrophysics Data System (ADS)

Originally, the typical particle accelerators as well as their associated beam transport equipment were designed for particle and nuclear physics research and applications in isotope production. In the past few decades, such accelerators and related equipment have also been applied for medical use. This can be in the original physics laboratory environment, but for the past 20 years also in hospital-based or purely clinical environments for particle therapy. The most important specific requirements of accelerators for radiation therapy with protons or ions will be discussed. The focus will be on accelerator design, operational, and formal aspects. We will discuss the special requirements to reach a high reliability for patient treatments as well as an accurate delivery of the dose at the correct position in the patient using modern techniques like pencil beam scanning. It will be shown that the technical requirements, safety aspects, and required reliability of the accelerated beam differ substantially from those in a nuclear physics laboratory. It will be shown that this difference has significant implications on the safety and interlock systems. The operation of such a medical facility should be possible by nonaccelerator specialists at different operating sites (treatment rooms). The organization and role of the control and interlock systems can be considered as being the most crucially important issue, and therefore a special, dedicated design is absolutely necessary in a facility providing particle therapy.

Schippers, Jacobus Maarten; Seidel, Mike

2015-03-01

402

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

403

Accelerating Venture Creation and Building on Mutual Strengths in Experimental Business Labs  

ERIC Educational Resources Information Center

This paper articulates the opportunity of using an experimental business laboratory approach as a means of accelerating the creation, incubation and testing of new venture ideas. Such a strategy leads to the establishment of a micro-ecosystem of aspiring entrepreneurs and others in a business laboratory environment. The goal is to create a mini

Curley, Martin G.; Formica, Piero

2010-01-01

404

Development of a 20-MeV Dielectric-Loaded Accelerator Test Facility  

SciTech Connect

This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron inector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to {approx} 8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRl, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator.

Gold, S.H.; Kinkead, A.K.; Gai, W.; Power, J.G.; Konecny, R.; Jing, C.G.; Tantawi, S.G.; Nantista, C.D.; Hu, Y.; Chen, H.; Tang, C.; Lin, Y.; Bruce, R.W.; Bruce, R.L.; Fliflet, A.W.; Lewis, D.; /Naval Research Lab, Wash., D.C. /LET Corp., Washington /Argonne /SLAC /Tsinghua U., Beijing

2005-06-22

405

Development of a 20 MeV Dielectric-Loaded Accelerator Test Facility  

SciTech Connect

This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the StanFord Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron injector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to {approx}8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRL, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator.

Gold, Steven H.; Fliflet, Arne W. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Kinkead, Allen K. [LET Corporation, Washington, DC 20007 (United States); Gai Wei; Power, John G.; Konecny, Richard; Jing Chunguang [Argonne National Laboratory, Argonne, IL 60439 (United States); Tantawi, Sami G.; Nantista, Christopher D. [Stanford Linear Accelerator Center, Menlo Park, CA 94025 (United States); Hu, Y.; Chen, H.; Tang, C.; Lin, Y. [Tsinghua University, Beijing 100084 (China); Bruce, Ralph W.; Bruce, Robert L. [RWBruce Associates, Inc., Arnold, MD 21012 (United States); Lewis, David III [Material Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2004-12-07

406

"DIANA" - A New, Deep-Underground Accelerator Facility for Astrophysics Experiments  

SciTech Connect

The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory to build a nuclear astrophysics accelerator facility 1.4 km below ground. DIANA is part of the US proposal DUSEL (Deep Underground Science and Engineering Laboratory) to establish a cross-disciplinary underground laboratory in the former gold mine of Homestake in South Dakota, USA. DIANA would consist of two high-current accelerators, a 30 to 400 kV variable, high-voltage platform, and a second, dynamitron accelerator with a voltage range of 350 kV to 3 MV. As a unique feature, both accelerators are planned to be equipped with either high-current microwave ion sources or multi-charged ECR ion sources producing ions from protons to oxygen. Electrostatic quadrupole transport elements will be incorporated in the dynamitron high voltage column. Compared to current astrophysics facilities, DIANA could increase the available beam densities on target by magnitudes: up to 100 mA on the low energy accelerator and several mA on the high energy accelerator. An integral part of the DIANA project is the development of a high-density super-sonic gas-jet target which can handle these anticipated beam powers. The paper will explain the main components of the DIANA accelerators and their beam transport lines and will discuss related technical challenges.

Leitner, M.; Leitner, D.; Lemut, A.; Vetter, P.; Wiescher, M.

2009-05-28

407

Introduction to Korean Accelerator Science and Activities in Industrial Accelerators  

NASA Astrophysics Data System (ADS)

After 20 years of the first large-scale accelerator in Korea, the Pohang Light Source (PLS) of 2.0 GeV at POSTECH, its upgrade (PLS-II) is now under commissioning with energy of 3.0 GeV. The users' service for synchrotron radiation is scheduled in April 2012. There are five big accelerator projects in various stages of construction, namely a high-intensity proton linac of 100 MeV, the PAL-XFEL of 10-GeV, a carbon therapy cyclotron of 400 MeV/u, and rare isotope accelerators for isotope separator on-line (ISOL) and In-flight Fragmentation (IFF). There are also strong demands for industrial uses of accelerators, especially in sterilization applications. In this paper, we report the current status of accelerator projects and its science in Korea, along with a brief review of accelerator R&D going back to the early 1960s at universities.

Namkung, Won

2012-03-01

408

Accelerating Commercial Remote Sensing  

NASA Technical Reports Server (NTRS)

Through the Visiting Investigator Program (VIP) at Stennis Space Center, Community Coffee was able to use satellites to forecast coffee crops in Guatemala. Using satellite imagery, the company can produce detailed maps that separate coffee cropland from wild vegetation and show information on the health of specific crops. The data can control coffee prices and eventually may be used to optimize application of fertilizers, pesticides and irrigation. This would result in maximal crop yields, minimal pollution and lower production costs. VIP is a mechanism involving NASA funding designed to accelerate the growth of commercial remote sensing by promoting general awareness and basic training in the technology.

1995-01-01

409

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

410

Accelerated Innovation Pilot  

NASA Technical Reports Server (NTRS)

Opportunities: I. Engage NASA team (examples) a) Research and technology calls . provide suggestions to AES, HRP, OCT. b) Use NASA@Work to solicit other ideas; (possibly before R+D calls). II. Stimulate collaboration (examples) a) NHHPC. b) Wharton Mack Center for Technological Innovation (Feb 2013). c) International ] DLR ] :envihab (July 2013). d) Accelerated research models . NSF, Myelin Repair Foundation. III. Engage public Prizes (open platform: InnoCentive, yet2.com, NTL; Rice Business Plan, etc.) IV. Use same methods to engage STEM.

Davis, Jeffrey

2012-01-01

411

A multi-purpose computing center: FNAL  

SciTech Connect

The Fermilab Computing Center is described with a special emphasis given to the scientific computing systems and the data storage and archiving systems. The scope and focus of this paper is the Fermilab scientific computing facility. It does not cover, or does not cover very well, related issues such as data Grids, cloud computing and storage, commercial storage, data integrity, authorization, access rates, and novel storage technologies. These are all important considerations in discussing data centers and should be kept in mind when one explores issues related to computing centers and long-term data storage.

Wolbers, Stephen; /Fermilab

2009-01-01

412

Muon circulation in the FNAL precooler  

SciTech Connect

The pions produced simultaneously with antiprotons are utilized to provide a circulating beam of decay muons that can serve as a source of neutrinos. The considered design indicates a primary produced flux of 1.5 x 10/sup 9/ decay muons per incident proton pulse.

Colton, E.P.

1980-01-01

413

Accelerator Technology Program. Status report, October 1983-March 1984  

SciTech Connect

This report covers major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. The first sections highlight activities related to beam dynamics, inertial fusion, structure development, the racetrack microtron, and the CERN high-energy physics experiment NA-12. Discussed next is the Fusion Materials Irradiation Test Facility, followed by a summary of progress on the Proton Storage Ring and activities of the Theory and Simulation Group. The report concludes with a discussion of the H- accelerator program and a listing of papers published by AT-Division personnel during this reporting period.

Jameson, R.A. (comp.)

1985-01-01

414

THE 13TH ADVANCED ACCELERATOR CONCEPTS WORKSHOP (AAC'8)  

SciTech Connect

The Thirteenth Workshop on Advanced Accelerator Concepts (AAC) was held from July 27 to August 2, 2008 at the Chaminade Conference Center in Santa Cruz, California, USA, organized by the Lawrence Berkeley National Laboratory and the University of California at Berkeley. There were unprecedented levels of interest in the 2008 AAC Workshop, and participation was by invitation, with 215 workshop attendees, including 58 students. Reflecting the world-wide growth of the advanced accelerator community, there was significant international participation, with participants from twelve countries attending.

Leemans, Wim [UC Berkeley] [UC Berkeley; Schroder, Carl B.; Esarey, Eric

2008-07-15

415

University of Washington, Nuclear Physics Laboratory annual report, 1995  

SciTech Connect

The Nuclear Physics Laboratory of the University of Washington supports a broad program of experimental physics research. The current program includes in-house research using the local tandem Van de Graff and superconducting linac accelerators and non-accelerator research in double beta decay and gravitation as well as user-mode research at large accelerator and reactor facilities around the world. This book is divided into the following areas: nuclear astrophysics; neutrino physics; nucleus-nucleus reactions; fundamental symmetries and weak interactions; accelerator mass spectrometry; atomic and molecular clusters; ultra-relativistic heavy ion collisions; external users; electronics, computing, and detector infrastructure; Van de Graff, superconducting booster and ion sources; nuclear physics laboratory personnel; degrees granted for 1994--1995; and list of publications from 1994--1995.

NONE

1995-04-01

416

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 a defense facility; and (2) design, build, and test critical components of a system for accelerator production of tritium (APT). The final decision to select the primary production option will be made by the Secretary of Energy in the October 1998 time frame. The alternative not chosen as the primary production method, if feasible, would be developed as a back-up tritium supply source. This Environmental Assessment (EA) analyzes the potential environmental effects that would be expected to occur if the DOE were to design, build, and test critical prototypical components of the accelerator system for tritium production, specifically the front-end low-energy section of the accelerator, at Los Alamos National Laboratory. The Low Energy Demonstration Accelerator (LEDA) would be incrementally developed and tested in five separate stages over the next seven years. The following issues were evaluated for the proposed action: utility demands, air, human health, environmental restoration, waste management, transportation, water, threatened and endangered species, wetlands, cultural resources, and environmental justice.

NONE

1996-04-01

417

LUNA: a Laboratory for Underground Nuclear Astrophysics  

E-print Network

It is in the nature of astrophysics that many of the processes and objects one tries to understand are physically inaccessible. Thus, it is important that those aspects that can be studied in the laboratory be rather well understood. One such aspect are the nuclear fusion reactions, which are at the heart of nuclear astrophysics. They influence sensitively the nucleosynthesis of the elements in the earliest stages of the universe and in all the objects formed thereafter, and control the associated energy generation, neutrino luminosity, and evolution of stars. We review an experimental approach for the study of nuclear fusion reactions based on an underground accelerator laboratory, named LUNA.

H. Costantini; A. Formicola; G. Imbriani; M. Junker; C. Rolfs; F. Strieder

2009-06-05

418

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

419

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

420

COMMISSIONING OF THE ERLP SRF SYSTEMS AT DARESBURY LABORATORY  

Microsoft Academic Search

The Energy Recovery Linac Prototype (ERLP) has been installed at Daresbury Laboratory and its baseline commissioning completed. The SRF systems for ERLP comprise two 9-cell, 1.3 GHz accelerating cavities in the injector (or Booster) cryomodule, which provide a nominal energy gain of 8 MeV for the injected 350 keV beam from the photo-injector. The beam is then accelerated in an

R. Bate; R. Buckley; S. Buckley; P. Corlett; A. Goulden; P. McIntosh; A. Moss; J. Orrett

421

Particle acceleration in pulsar magnetospheres  

NASA Technical Reports Server (NTRS)

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 which showed that particle acceleration cannot be expected when the angle between the magnetic field lines and the rotation axis is constant (e.g. radial field lines). If this angle is not constant, however, acceleration must occur. The more realistic model of an axisymmetric neutron star with a strong dipole magnetic field aligned with the rotation axis was investigated. In this case, acceleration occurred at large distances from the surface of the star. The magnitude of the current can be determined using the model presented. In the case of nonaxisymmetric systems, the acceleration is expected to occur nearer to the surface of the star.

Baker, K. B.

1978-01-01

422

Magnetic Insulation for Electrostatic Accelerators  

NASA Astrophysics Data System (ADS)

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.

2011-09-01

423

Laser acceleration and its future  

PubMed Central

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

424

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

425

The LILIA (laser induced light ions acceleration) experiment at LNF  

NASA Astrophysics Data System (ADS)

Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50-75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given.

Agosteo, S.; Anania, M. P.; Caresana, M.; Cirrone, G. A. P.; De Martinis, C.; Delle Side, D.; Fazzi, A.; Gatti, G.; Giove, D.; Giulietti, D.; Gizzi, L. A.; Labate, L.; Londrillo, P.; Maggiore, M.; Nassisi, V.; Sinigardi, S.; Tramontana, A.; Schillaci, F.; Scuderi, V.; Turchetti, G.; Varoli, V.; Velardi, L.

2014-07-01

426

Numerical Simulations of a Pulse Line Ion Accelerator.  

NASA Astrophysics Data System (ADS)

The Neutralized Drift Compression Experiment (NDCX) is being constructed at the Lawrence Berkeley National Laboratory. NDCX will help develop novel, still unexplored beam manipulation techniques in order to establish the physics limits on compression of heavy ion beams for creating high energy density matter and fusion ignition conditions. A critical early component being developed in this series of experiments is the accelerating scheme for the high-current, short-bunch ion beams that are of interest for HEDP applications. The Pulse Line Ion Accelerator (PLIA) uses a slow-wave structure based on a helical winding, on which a voltage pulse is launched and propagated to generate the accelerating fields. An oil dielectric helix has the ability to accelerate ion bunches to energies much greater than the peak applied voltage and over distances much larger than the ramp length. Low peak voltage experiments ranging from 10-80 kV have begun on a 1-m PLIA test section to verify the ability to accelerate an ion bunch and to investigate breakdown issues. Short-pulsed, pencil-like beams with energy ranges of 200-400 keV have been used for the acceleration experiments. Numerical simulations of the PLIA beam dynamics will be presented.

Henestroza, Enrique

2005-10-01

427

The BNL Accelerator Test Facility and experimental program  

SciTech Connect

The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high power laser pulses synchronized to the electron beam, suitable for studies of new methods of high gradient acceleration and state of the art free electron lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 to 100 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps Nd:YAG laser and a 100 mJ, 10 ps CO{sub 2} laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various acceleration schemes, Free-Electron Laser experiments and a program on the development of high brightness electron beams. The AFT's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the High power laser will begin operation this year. 28 refs., 4 figs.

Ben-Zvi, I. (Brookhaven National Lab., Upton, NY (United States) State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics)

1991-01-01

428

The BNL Accelerator Test Facility and experimental program  

SciTech Connect

The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high-power laser pulses synchronized to the electron beam, suitable for studies of new methods of high-gradient acceleration and state-of-the-art Free-Electron Lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps ND:YAG laser and a 500 mJ, 10 to 100 ps C0{sub 2} laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various laser acceleration schemes, Free-Electron Laser experiments and a program on the development of high-brightness electron beams. The ATF's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the high-power laser will begin operation this year.

Ben-Zvi, I. (Brookhaven National Lab., Upton, NY (United States) State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics)

1992-01-01

429

The BNL Accelerator Test Facility and experimental program  

SciTech Connect

The Accelerator Test Facility (ATF) at BNL is a users` facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high-power laser pulses synchronized to the electron beam, suitable for studies of new methods of high-gradient acceleration and state-of-the-art Free-Electron Lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps ND:YAG laser and a 500 mJ, 10 to 100 ps C0{sub 2} laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various laser acceleration schemes, Free-Electron Laser experiments and a program on the development of high-brightness electron beams. The ATF`s experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the high-power laser will begin operation this year.

Ben-Zvi, I. [Brookhaven National Lab., Upton, NY (United States)]|[State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics

1992-09-01

430

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

431

Acceleration in de Sitter spacetimes  

NASA Astrophysics Data System (ADS)

We propose a definition of uniform accelerated frames in de Sitter spacetimes applying the Nachtmann method of introducing coordinates using suitable point-dependent isometries. In order to recover the well-known Rindler approach in the flat limit, we require the transformation between the static frame and the accelerated one to depend continuously on acceleration, obtaining thus the natural generalization of the Rindler transformation to the de Sitter spacetimes of any dimensions.

Cotaescu, Ion I.

2015-02-01

432

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

433

Laboratory for Atmospheric and  

E-print Network

--------------------------------------------------------------------------- 2 LASP: A Brief History of work undertaken by the Laboratory, it has been clear for some time that more office and laboratory

Mojzsis, Stephen J.

434

Compact accelerator for medical therapy  

DOEpatents

A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

2010-05-04

435

High field gradient particle accelerator  

DOEpatents

A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

Nation, John A. (Ithaca, NY); Greenwald, Shlomo (Haifa, IL)

1989-01-01

436

High field gradient particle accelerator  

DOEpatents

A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications is disclosed. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle. 10 figs.

Nation, J.A.; Greenwald, S.

1989-05-30

437

Project X RFQ EM Design  

SciTech Connect

Project X is a proposed multi-MW proton facility at Fermi National Accelerator Laboratory (FNAL). The Project X front-end would consist of an H- ion source, a low-energy beam transport (LEBT), a CW 162.5 MHz radio-frequency quadrupole (RFQ) accelerator, and a medium-energy beam transport (MEBT). Lawrence Berkeley National Laboratory (LBNL) and FNAL collaboration is currently developing the designs for various components in the Project X front end. This paper reports the detailed EM design of the CW 162.5 MHz RFQ that provides bunching of the 1-10 mA H- beam with acceleration from 30 keV to 2.1 MeV.

Romanov, Gennady; /Fermilab; Hoff, Matthew; Li, Derun; Staples, John; Virostek, Steve; /LBNL

2012-05-09

438

A Summary of the Quasi-Steady Acceleration Environment on-Board STS-94 (MSL-1)  

NASA Technical Reports Server (NTRS)

The continuous free-fall state of a low Earth orbit experienced by NASA's Orbiters results in a unique reduced gravity environment. While microgravity science experiments are conducted in this reduced gravity environment, various accelerometer systems measure and record the microgravity acceleration environment for real-time and post-flight correlation with microgravity science data. This overall microgravity acceleration environment is comprised of quasi-steady, oscillatory, and transient contributions. The First Microgravity Science Laboratory (MSL-1) payload was dedicated to experiments studying various microgravity science disciplines, including combustion, fluid physics, and materials processing. In support of the MSL-1 payload, two systems capable of measuring the quasi-steady acceleration environment were flown: the Orbital Acceleration Research Experiment (OARE) and the Microgravity Measurement Assembly (MMA) system's Accelerometre Spatiale Triaxiale most evident in the quasi-steady acceleration regime. Utilizing such quasi-steady events, a comparison and summary of the quasi-steady acceleration environment for STS-94 will be presented

McPherson, Kevin M.; Nati, Maurizio; Touboul, Pierre; Schuette, Andreas; Sablon, Gert

1999-01-01

439

Heavy Ion Fusion Accelerator Research (HIFAR) year-end report, April 1--September 30, 1988  

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, the induction linac, has been studied at the Lawrence Berkeley Laboratory and has reached the point at which its viability for ICF applications can be assessed over the next few years. 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: beam quality limits set by transverse and longitudinal beam physics; development of induction accelerating modules, and multiple-beam hardware, at affordable costs; acceleration of multiple beams with current amplification --both new features in a linac -- without significant dilution of the optical quality of the beams; final bunching, transport, and accurate focusing on a small target.

Not Available

1988-12-01

440

Heavy Ion Fusion Accelerator Research (HIFAR) year-end report, October 1, 1987--March 31, 1988  

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, the induction linac, has been studied at Lawrence Berkeley Laboratory and has reached the point at which its viability for ICF applications can be assessed over the next few years. 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: beam quality limits set by transverse and longitudinal beam physics; development of induction accelerating modules, and multiple-beam hardware, at affordable costs; acceleration of multiple beams with current amplification -- both new features in a linac -- without significant dilution of the optical quality of beams; and final bunching, transport, and accurate focusing on a small target.

Not Available

1988-06-01

441

Accelerating Spectrum Sharing Technologies  

SciTech Connect

Spectrum sharing potentially holds the promise of solving the emerging spectrum crisis. However, technology innovators face the conundrum of developing spectrum sharing technologies without the ability to experiment and test with real incumbent systems. Interference with operational incumbents can prevent critical services, and the cost of deploying and operating an incumbent system can be prohibitive. Thus, the lack of incumbent systems and frequency authorization for technology incubation and demonstration has stymied spectrum sharing research. To this end, industry, academia, and regulators all require a test facility for validating hypotheses and demonstrating functionality without affecting operational incumbent systems. This article proposes a four-phase program supported by our spectrum accountability architecture. We propose that our comprehensive experimentation and testing approach for technology incubation and demonstration will accelerate the development of spectrum sharing technologies.

Juan D. Deaton; Lynda L. Brighton; Rangam Subramanian; Hussein Moradi; Jose Loera

2013-09-01

442

Lectures in accelerator theory  

SciTech Connect

Lecture I deals with the behavior of particles in the nonlinear field arising from the electromagnetic interaction of colliding beams. The case treated, that of counter-rotating proton beams crossing each other at a non-zero angle, has the simple feature that the force between the beam is one dimensional. In lecture II, an analysis of the development of traveling waves on particle beams is presented. The situation studied is that of a uniform beam current in a circular accelerator and the excitation for the coherent motion is induced by the resistivity of the vacuum chamber wall. Finally, in lecture III, a description of the current accumulation process used at the proton storage rings at CERN (The ISR) is given. Particle pulses of rather low average current are injected and stored along the length and width of the vacuum chamber. The efficiency is very high and large currents (over 40 amperes) have been achieved.

Month, M

1980-01-01

443

Paraelectric gas flow accelerator  

NASA Technical Reports Server (NTRS)

A substrate is configured with first and second sets of electrodes, where the second set of electrodes is positioned asymmetrically between the first set of electrodes. When a RF voltage is applied to the electrodes sufficient to generate a discharge plasma (e.g., a one-atmosphere uniform glow discharge plasma) in the gas adjacent to the substrate, the asymmetry in the electrode configuration results in force being applied to the active species in the plasma and in turn to the neutral background gas. Depending on the relative orientation of the electrodes to the gas, the present invention can be used to accelerate or decelerate the gas. The present invention has many potential applications, including increasing or decreasing aerodynamic drag or turbulence, and controlling the flow of active and/or neutral species for such uses as flow separation, altering heat flow, plasma cleaning, sterilization, deposition, etching, or alteration in wettability, printability, and/or adhesion.

Sherman, Daniel M. (Inventor); Wilkinson, Stephen P. (Inventor); Roth, J. Reece (Inventor)

2001-01-01

444

Accelerator mass spectrometry  

SciTech Connect

Accelerator mass spectroscopy (AMS) can be used for efficient detection of long-lived isotopes at part-per-quadrillion sensitivities with good precision. In this article we present an overview of AMS and its recent use in archaeology, geochemistry and biomolecular tracing. All AMS systems use cesium sputter ion sources to produce negative ions from a small button of a solid sample containing the element of interest, such as graphite, metal halide, or metal oxide, often mixed with a metal powder as binder and thermal conductor. Experience shows that both natural and biomedical samples are compatible in a single AMS system, but few other AMS sites make routine {sup 14}C measurements for both dating and tracing. AMS is, in one sense, just `a very sensitive decay counter`, but if AMS sensitivity is creatively coupled to analytical chemistry of certain isotopes, whole new areas of geosciences, archaeology, and life sciences can be explored. 29 refs., 2 figs., 1 tab.

Vogel, J.S.; Turteltaub, K.W.; Finkel, R. [Lawrence Livermore National Lab., CA (United States); Nelson, D.E.

1995-06-01

445

Accelerating the Solar Wind  

NASA Astrophysics Data System (ADS)

At 1 AU the fast solar wind reaches speeds that are 2-3 times greater than can be accounted for by the pressure gradient due to the high coronal temperatures. This paper introduces a mechanism that may account for this shortfall, namely, the force due to the gradient of the magnetic pressure of an azimuthal magnetic field, B?, generated by a current jr flowing along the open-ended flux tube guiding the wind. The electromotive force (EMF) driving this current is due to the difference between the thermoelectric force acting on the electron gas within a flux tube and that in the ambient plasma. Using observed values of the magnetic field, we show that this mechanism is capable of accelerating the solar wind up to speeds of 800 km s-1 and higher. It also produces a profile of the radial wind speed v(r) that is nearly flat beyond about 0.15 AU, as is observed.

Ashbourn, J. M. A.; Woods, L. C.

2005-04-01

446

Pulsed Plasma Accelerator Modeling  

NASA Technical Reports Server (NTRS)

This report presents the main results of the modeling task of the PPA project. The objective of this task is to make major progress towards developing a new computational tool with new capabilities for simulating cylindrically symmetric 2.5 dimensional (2.5 D) PPA's. This tool may be used for designing, optimizing, and understanding the operation of PPA s and other pulsed power devices. The foundation for this task is the 2-D, cylindrically symmetric, magnetohydrodynamic (MHD) code PCAPPS (Princeton Code for Advanced Plasma Propulsion Simulation). PCAPPS was originally developed by Sankaran (2001, 2005) to model Lithium Lorentz Force Accelerators (LLFA's), which are electrode based devices, and are typically operated in continuous magnetic field to the model, and implementing a first principles, self-consistent algorithm to couple the plasma and power circuit that drives the plasma dynamics.

Goodman, M.; Kazeminezhad, F.; Owens, T.

2009-01-01

447

Network acceleration techniques  

NASA Technical Reports Server (NTRS)

Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP).

Crowley, Patricia (Inventor); Awrach, James Michael (Inventor); Maccabe, Arthur Barney (Inventor)

2012-01-01

448

Pulsed electromagnetic acceleration  

NASA Technical Reports Server (NTRS)

Direct measurements of the power deposited in the anode of a multimegawatt MPD accelerator using thermocouples attached to a thin shell anode reveal a dramatic decrease in the fractional anode power from 50% at 200 KW input power to less than 10% at 20 MW power. The corresponding local power flux peak at a value of 10,000 W/sq cm at the lip of the anode exhaust orifice, a distribution traced to a corresponding peak in the local current density at the anode. A comparison of voltage-current characteristics and spectral photographs of the MPD discharge using quartz, boron nitride and plexiglas insulators with various mass injection configurations led to the identification of different voltage modes and regions of ablation free operation. The technique of piezoelectric impact pressure measurement in the MPD exhaust flow was refined to account for the effects due to probe yaw angle.

Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

1973-01-01

449

The SSC linear accelerator  

SciTech Connect

The SSC linear accelerator will generate a 25 mA, 600 MeV, H-beam with transverse normalized rms emittance less than 0.3 {pi} mm{center_dot}mrad in 9.6 ps pulses at a 10 Hz repetition rate. The Linac will ultimately have to operate with an availability for Collider filling in excess of 98%. In addition, the Linac will provide beams to service the Test Beams facility and may be delivering beam to a Proton Radiotherapy Facility. This paper presents an overview of the status of design, procurement, fabrication, civil construction, foreign contributions and commissioning plans, and directs the reader to additional details available in other presentations to this Conference.

Funk, L.W.

1993-05-01

450

Energy Release, Acceleration, and Escape of Solar Energetic Ions  

NASA Astrophysics Data System (ADS)

Solar flares are prodigious producers of energetic particles, and thus a rich laboratory for studying particle acceleration. The acceleration occurs through the release of magnetic energy, a significant fraction of which can go into the acceleration of particles. Coronal mass ejections (CMEs) certainly produce shocks that both accelerate particles and provide a mechanism for escape into the interplanetary medium (IP). What is less well understood is whether accelerated particles produced from the flare reconnection process escape, and if so, how these same particles are related to solar energetic particles (SEPs) detected in-situ. Energetic electron SEPs have been shown to be correlated with Type III radio bursts, hard X-ray emission, and EUV jets, making a very strong case for the connection between acceleration at the flare and escape along open magnetic field lines. Because there has not been a clear signature of ion escape, as is the case with the Type III radio emission for electrons, sorting out the avenues of escape for accelerated flare ions and the possible origin of the impulsive SEPs continues to be a major challenge. The key to building a clear picture of particle escape relies on the ability to map signatures of escape such as EUV jets at the Sun and to follow the progression of these escape signatures as they evolve in time. Furthermore, nuclear ?-ray emissions provide critical context relating ion acceleration to that of escape. With the advent observations from Fermi as well as RHESSI and the Solar Dynamics Observatory (SDO), the challenge of ion escape from the Sun can now be addressed. We present a preliminary study of the relationship of EUV jets with nuclear ?-ray emission and Type III radio observations and discuss the implications for possible magnetic topologies that allow for ion escape from deep inside the corona to the interplanetary medium.

de Nolfo, G. A.; Ireland, J.; Ryan, J. M.; Young, C. A.

2013-12-01

451

NDCX-II, A New Induction Linear Accelerator for Warm Dense Matter Research  

SciTech Connect

The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL), a collaboration between Lawrence Berkeley National Laboratory (LBNL), Lawrence Livermore National Laboratory (LLNL), and Princeton Plasma Physics Laboratory (PPPL), is currently constructing a new induction linear accelerator, called Neutralized Drift Compression eXperiment NDCX-II. The accelerator design makes effective use of existing components from LLNL's decommissioned Advanced Test Accelerator (ATA), especially induction cells and Blumlein voltage sources that have been transferred to LBNL. We have developed an aggressive acceleration 'schedule' that compresses the emitted ion pulse from 500 ns to 1 ns in just 15 meters. In the nominal design concept, 30 nC of Li{sup +} are accelerated to 3.5 MeV and allowed to drift-compress to a peak current of about 30 A. That beam will be utilized for warm dense matter experiments investigating the interaction of ion beams with matter at high temperature and pressure. Construction of the accelerator will be complete within a period of approximately two and a half years and will provide a worldwide unique opportunity for ion-driven warm dense matter experiments as well as research related to novel beam manipulations for heavy ion fusion drivers.

Leitner, M.; Bieniosek, F.; Kwan, J.; Logan, G.; Waldron, W.; Barnard, J.J.; Friedman, A.; Sharp, B.; Gilson, E.; Davidson, R.

2009-06-01

452

Transformer ratio improvement for beam based plasma accelerators  

SciTech Connect

Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R {<=} 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab.

O'Shea, Brendan; Rosenzweig, James; Barber, Samuel; Fukasawa, Atsushi; Williams, Oliver; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl [University of California, Los Angeles, Department of Physics and Astronomy, Los Angeles, CA 90095 (United States); University of Southern California, Department of Electrical Engineering, Los Angeles, CA 90089 U.S.A. and Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Accelerator Test Facility, Brookhaven National Lab, Upton, NY, 11973 (United States)

2012-12-21

453

Accelerator technology program. Status report, July-December 1982  

SciTech Connect

Major projects of the Los Alamos National Laboratory's Accelerator Technology Division are discussed, covering activities that occurred during the last six months of calendar 1982. The first sections report 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. Next we report on selected proton Storage Ring activities that have made significant progress during this reporting period, followed by an update on the free electron laser. The Fusion Materials Irradiation Test Facility work is discussed next, then progress on the klystron development project and on the gyrocon project. The activities of the newly formed Theory and Simulation Group are outlined. The last section covers activities concerning the accelerator test stand for the neutral particle beam program.

Jameson, R.A. (comp.)

1984-05-01

454

Effects of Spatial Gradients on Electron Runaway Acceleration  

NASA Technical Reports Server (NTRS)

The runaway process is known to accelerate electrons in many laboratory plasmas and has been suggested as an acceleration mechanism in some astrophysical plasmas, including solar flares. Current calculations of the electron velocity distributions resulting from the runaway process are greatly restricted because they impose spatial homogeneity on the distribution. We have computed runaway distributions which include consistent development of spatial gradients in the energetic tail. Our solution for the electron velocity distribution is presented as a function of distance along a finite length acceleration region, and is compared with the equivalent distribution for the infinitely long homogenous system (i.e., no spatial gradients), as considered in the existing literature. All these results are for the weak field regime. We also discuss the severe restrictiveness of this weak field assumption.

MacNeice, Peter; Ljepojevic, N. N.

1996-01-01

455

COAXIAL TWO-CHANNEL DIELECTRIC WAKE FIELD ACCELERATOR  

SciTech Connect

Theory, computations, and experimental apparatus are presented that describe and are intended to confirm novel properties of a coaxial two-channel dielectric wake field accelerator. In this configuration, an annular drive beam in the outer coaxial channel excites multimode wakefields which, in the inner channel, can accelerate a test beam to an energy much higher than the energy of the drive beam. This high transformer ratio is the result of judicious choice of the dielectric structure parameters, and of the phase separation between drive bunches and test bunches. A structure with cm-scale wakefields has been build for tests at the Argonne Wakefield Accelerator Laboratory, and a structure with mm-scale wakefields has been built for tests at the SLAC FACET facility. Both tests await scheduling by the respective facilities.

Hirshfield, Jay L. [Omega-P, Inc.

2013-04-30

456

SuperB Progress Report for Accelerator  

SciTech Connect

This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. With this document we propose a new electron positron colliding beam accelerator to be built in Italy to study flavor physics in the B-meson system at an energy of 10 GeV in the center-of-mass. This facility is called a high luminosity B-factory with a project name 'SuperB'. This project builds on a long history of successful e+e- colliders built around the world, as illustrated in Figure 1.1. The key advances in the design of this accelerator come from recent successes at the DAFNE collider at INFN in Frascati, Italy, at PEP-II at SLAC in California, USA, and at KEKB at KEK in Tsukuba Japan, and from new concepts in beam manipulation at the interaction region (IP) called 'crab waist'. This new collider comprises of two colliding beam rings, one at 4.2 GeV and one at 6.7 GeV, a common interaction region, a new injection system at full beam energies, and one of the two beams longitudinally polarized at the IP. Most of the new accelerator techniques needed for this collider have been achieved at other recently completed accelerators including the new PETRA-3 light source at DESY in Hamburg (Germany) and the upgraded DAFNE collider at the INFN laboratory at Frascati (Italy), or during design studies of CLIC or the International Linear Collider (ILC). The project is to be designed and constructed by a worldwide collaboration of accelerator and engineering staff along with ties to industry. To save significant construction costs, many components from the PEP-II collider at SLAC will be recycled and used in this new accelerator. The interaction region will be designed in collaboration with the particle physics detector to guarantee successful mutual use. The accelerator collaboration will consist of several groups at present universities and national laboratories. In Italy these may include INFN Frascati and the University of Pisa, in the United States SLAC, LBNL, BNL and several universities, in France IN2P3, LAPP, and Grenoble, in Russia BINP, in Poland Krakow University, and in the UK the Cockcroft Institute. The construction time for this collider is a total of about four years. The new tunnel can be bored in about a year. The new accelerator components can be built and installed in about 4 years. The shipping of components from PEP-II at SLAC to Italy will take about a year. A new linac and damping ring complex for the injector for the rings can be built in about three years. The commissioning of this new accelerator will take about a year including the new electron and positron sources, new linac, new damping ring, new beam transport lines, two new collider rings and the Interaction Region. The new particle physics detector can be commissioned simultaneously with the accelerator. Once beam collisions start for particle physics, the luminosity will increase with time, likely reaching full design specifications after about two to three years of operation. After construction, the operation of the collider will be the responsibility of the Italian INFN governmental agency. The intent is to run this accelerator about ten months each year with about one month for accelerator turn-on and nine months for colliding beams. The collider will need to operate for about 10 years to provide the required 50 ab{sup -1} requested by the detector collaboration. Both beams as anticipated in this collider will have properties that are excellent for use as sources for synchrotron radiation (SR). The expected photon properties are comparable to those of PETRA-3 or NSLS-II. The beam lines and user facilities needed to carry out this SR program are being investigated.

Biagini, M.E.; Boni, R.; Boscolo, M.; Buonomo, B.; Demma, T.; Drago, A.; Esposito, M.; Guiducci, S.; Mazzitelli, G.; Pellegrino, L.; Preger, M.A.; Raimondi, P.; Ricci, R.; Rotundo, U.; Sanelli, C.; Serio, M.; Stella, A.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Brachman, A.; /SLAC /Novosibirsk, IYF /INFN, Pisa /Pisa U. /Orsay, LAL /Annecy, LAPP /LPSC, Grenoble /IRFU, SPP, Saclay /DESY /Cockroft Inst. Accel. Sci. Tech. /U. Liverpool /CERN

2012-02-14

457

Use of Linear Induction Accelerators for Flash Radiography  

NASA Astrophysics Data System (ADS)

Induction accelerators have been used for over a decade as flash x-ray sources for radiography. A new machine is presently under construction at Los Alamos National Laboratory and a second machine is under design for installation adjacent to the first one to form the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. This second accelerator will provide a 2 microsecond pulse which will be subdivided by a fast kicker system to provide a sequence of four or more 70 ns pulses along a single line of sight. An advanced system to provide multiple pulses over a longer time interval and over many lines of sight will be discussed along with the technological advances in solid-state pulsed power, fast kickers and target systems necessary to make the concept a reality. *This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No.W-7405-Eng-48.

Caporaso, George

1998-04-01

458

DIANA - A deep underground accelerator for nuclear astrophysics experiments  

NASA Astrophysics Data System (ADS)

DIANA (Dakota Ion Accelerator for Nuclear Astrophysics) is a proposed facility designed to be operated deep underground. The DIANA collaboration includes nuclear astrophysics groups from Lawrence Berkeley National Laboratory, Michigan State University, Western Michigan University, Colorado School of Mines, and the University of North Carolina, and is led by the University of Notre Dame. The scientific goals of the facility are measurements of low energy nuclear cross-sections associated with sun and pre-supernova stars in a laboratory setup at energies that are close to those in stars. Because of the low stellar temperatures associated with these environments, and the high Coulomb barrier, the reaction cross-sections are extremely low. Therefore these measurements are hampered by small signal to background ratios. By going underground the background due to cosmic rays can be reduced by several orders of magnitude. We report on the design status of the DIANA facility with focus on the 3 MV electrostatic accelerator.

Winklehner, Daniel; Lemut, Alberto; Leitner, Daniela; Couder, Manoel; Hodgkinson, Adrian; Wiescher, Michael

2013-04-01

459

DIANA - A deep underground accelerator for nuclear astrophysics experiments  

SciTech Connect

DIANA (Dakota Ion Accelerator for Nuclear Astrophysics) is a proposed facility designed to be operated deep underground. The DIANA collaboration includes nuclear astrophysics groups from Lawrence Berkeley National Laboratory, Michigan State University, Western Michigan University, Colorado School of Mines, and the University of North Carolina, and is led by the University of Notre Dame. The scientific goals of the facility are measurements of low energy nuclear cross-sections associated with sun and pre-supernova stars in a laboratory setup at energies that are close to those in stars. Because of the low stellar temperatures associated with these environments, and the high Coulomb barrier, the reaction cross-sections are extremely low. Therefore these measurements are hampered by small signal to background ratios. By going underground the background due to cosmic rays can be reduced by several orders of magnitude. We report on the design status of the DIANA facility with focus on the 3 MV electrostatic accelerator.

Winklehner, Daniel; Leitner, Daniela [Michigan State University, 640 S Shaw Lane, East Lansing MI 48824 (United States); Lemut, Alberto; Hodgkinson, Adrian [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley CA 94720 (United States); Couder, Manoel; Wiescher, Michael [University of Notre Dame, Notre Dame, IN 46556 (United States)

2013-04-19

460

Electronics Packaging Issues for Future Accelerators and Experiments  

SciTech Connect

Standard instrument modules for physics reached their zenith of industrial development from the early 1960s through late 1980s. Started by laboratory engineering groups in Europe and North America, modular electronic standards were successfully developed and commercialized. In the late 1980's a major shift in large detector design toward custom chips mounted directly on detectors started a decline in the use of standard modules for data acquisition. With the loss of the detector module business, commercial support declined. Today the engineering communities supporting future accelerators and experiments face a new set of challenges that demand much more reliable system design. The dominant system metric is Availability. We propose (1) that future accelerator and detector systems be evaluated against a Design for Availability (DFA) metric; (2) that modular design and standardization applied to all electronic and controls subsystems are key to high Availability; and (3) that renewed Laboratory-Industry collaboration(s) could make an invaluable contribution to design and implementation.

Larsen, R.

2004-11-11

461

Development of the accelerator-driven energy production concept  

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). Accelerator Driven Transmutation Technology (ADTT) offers a means of generating nuclear energy in a clean, safe way that can be attractive to the general public. However, there are issues associated with the energy story (both at the system level and technical detail) that have to be seriously addressed before the scientific community, the public, and potential industrial sponsors can be compellingly convinced of its cost/benefit.

Venneri, F.; Beard, C.; Bowman, C. [and others

1996-10-01

462

Jefferson Lab Accelerator Operations Training and Development Program  

SciTech Connect

The mission of the Jefferson Lab Operations Group is to provide safe and efficient delivery of high quality electron beam for Jefferson Laboratory's nuclear and accelerator physics programs. The Operations staff must be able to setup, transport, maintain, and troubleshoot beam to all three experimental halls in a safe, efficient, and expeditious manner. Due to the nature of shift work, high employee turnover is always as issue. This creates a unique situation where highly trained staff members must quickly be produced and maintained in order to meet the needs of the Laboratory. Some methods used to address this problem will be presented here.

Michael A. Epps

2008-01-23

463

Accelerator Based Neutron Beams for Neutron Capture Therapy  

SciTech Connect

The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and compared the RBE characteristics of the MIT Reactor M67 clinical beam, The Brookhaven Medical Research Reactor clinical beam (both of which were used in Phase I/II clinical trials of BNCT) and the MIT LABA BNCS beam. Additional research initiated under this program involved an investigation of the potential of BNCT for the prevention of restenosis and the development of accelerator-based fast neutron brachytherapy. A total of 10 student research theses (2 Undergraduate, 4 Masters, and 4 Doctoral) were completed as part of this research program.

Yanch, Jacquelyn C.

2003-04-11

464

Space Acceleration Measurement System (SAMS)/Orbital Acceleration Research Experiment (OARE)  

NASA Technical Reports Server (NTRS)

The Life and Microgravity Spacelab (LMS) payload flew on the Orbiter Columbia on mission STS-78 from June 20th to July 7th, 1996. The LMS payload on STS-78 was dedicated to life sciences and microgravity experiments. Two accelerometer systems managed by the NASA Lewis Research Center (LERC) flew to support these experiments, namely the Orbital Acceleration Research Experiment (OARE) and the Space Acceleration Measurements System (SAMS). In addition, the Microgravity Measurement Assembly (NOAA), managed by the European Space Research and Technology Center (ESA/ESTEC), and sponsored by NASA, collected acceleration data in support of the experiments on-board the LMS mission. OARE downlinked real-time quasi-steady acceleration data, which was provided to the investigators. The SAMS recorded higher frequency data on-board for post-mission analysis. The MMA downlinked real-time quasi-steady as well as higher frequency acceleration data, which was provided to the investigators. The Principal Investigator Microgravity Services (PIMS) project at NASA LERC supports principal investigators of microgravity experiments as they evaluate the effects of varying acceleration levels on their experiments. A summary report was prepared by PIMS to furnish interested experiment investigators with a guide to evaluate the acceleration environment during STS-78, and as a means of identifying areas which require further study. The summary report provides an overview of the STS-78 mission, describes the accelerometer systems flown on this mission, discusses some specific analyses of the accelerometer data in relation to the various activities which occurred during the mission, and presents plots resulting from these analyses as a snapshot of the environment during the mission. Numerous activities occurred during the STS-78 mission that are of interest to the low-gravity community. Specific activities of interest during this mission were crew exercise, radiator deployment, Vernier Reaction Control System (VRCS) reboost, venting operations, Flight Control System (FCS) checkout, rack excitation, operation of the Life Sciences Laboratory Equipment Refrigerator/Freezer (LSLE R/F), operation of the JSC Projects Centrifuge, crew sleep, and attitude changes. The low-gravity environment related to these activities is discussed in the summary report.

Hakimzadeh, Roshanak

1998-01-01

465

National Renewable Energy Laboratory  

E-print Network

National Renewable Energy Laboratory Innovation for Our Energy Future ponsorship Format Reversed Color:White rtical Format Reversed-A ertical Format Reversed-B National Renewable Energy Laboratory National Renewable Energy Laboratory Innovation for Our Energy Future National Renewable Energy Laboratory

466

General purpose programmable accelerator board  

DOEpatents

A general purpose accelerator board and acceleration method comprising use of: one or more programmable logic devices; a plurality of memory blocks; bus interface for communicating data between the memory blocks and devices external to the board; and dynamic programming capabilities for providing logic to the programmable logic device to be executed on data in the memory blocks.

Robertson, Perry J. (Albuquerque, NM); Witzke, Edward L. (Edgewood, NM)

2001-01-01

467

New directions in linear accelerators  

SciTech Connect

Current work on linear particle accelerators is placed in historical and physics contexts, and applications driving the state of the art are discussed. Future needs and the ways they may force development are outlined in terms of exciting R and D challenges presented to today's accelerator designers. 23 references, 7 figures.

Jameson, R.A.

1984-01-01

468

Thomas Edison Accelerated Elementary School.  

ERIC Educational Resources Information Center

This paper describes early outcomes of a Sacramento, California, elementary school that participated in the Accelerated Schools Project. The school, which serves many minority and poor students, began training for the project in 1992. Accelerated Schools were designed to advance the learning rate of students through a gifted and talented approach,

Levin, Henry M.; Chasin, Gene

469

Electron acceleration in ionizable gas  

SciTech Connect

A flat-panel gas discharge cathodoluminescent display includes a plurality of mutually parallel, electron-transmissive accelerator electrodes respectively connected to sources of high positive voltage levels to increase the acceleration voltage of the display without causing ionization of the gas.

Glaser, D.

1983-07-12

470