Low energy current accumulator for high-energy proton rings

International Nuclear Information System (INIS)

Month, M.

1977-01-01

Building current in high-energy p-p colliding beam machines is most appropriately done in a low-energy (small circumference) current accumulator. Three significant factors favor such a procedure: First, large rings tend to be susceptible to unstable longitudinal density oscillations. These can be avoided by pumping up the beam in the accumulator. When the current stack is injected into the storage ring, potentially harmful instability is essentially neutralized. Second, high-field magnets characteristic of future high energy proton rings are designed with superconducting coils within the iron magnetic shield. This means coil construction and placement errors propagate rapidly within the beam aperture. An intermediate ''stacking ring'' allows the minimum use of the superconducting ring aperture. Finally, the coils are vulnerable to radiation heating and possible magnet quenching. By minimizing beam manipulaion in the superconducting environment and using only the central portion of the beam aperture, coil vulnerability can be put at a minimum

Future Synchrotron Light Sources Based on Ultimate Storage Rings

International Nuclear Information System (INIS)

Cai, Yunhai

2012-01-01

The main purpose of this talk is to describe how far one might push the state of the art in storage ring design. The talk will start with an overview of the latest developments and advances in the design of synchrotron light sources based on the concept of an 'ultimate' storage ring. The review will establish how bright a ring based light source might be, where the frontier of technological challenges are, and what the limits of accelerator physics are. Emphasis will be given to possible improvements in accelerator design and developments in technology toward the goal of achieving an ultimate storage ring. An ultimate storage ring (USR), defined as an electron ring-based light source having an emittance in both transverse planes at the diffraction limit for the range of X-ray wavelengths of interest for a scientific community, would provide very high brightness photons having high transverse coherence that would extend the capabilities of X-ray imaging and probe techniques beyond today's performance. It would be a cost-effective, high-coherence 4th generation light source, competitive with one based on energy recovery linac (ERL) technology, serving a large number of users studying material, chemical, and biological sciences. Furthermore, because of the experience accumulated over many decades of ring operation, it would have the great advantage of stability and reliability. In this paper we consider the design of an USR having 10-pm-rad emittance. It is a tremendous challenge to design a storage ring having such an extremely low emittance, a factor of 100 smaller than those in existing light sources, especially such that it has adequate dynamic aperture and beam lifetime. In many ultra-low emittance designs, the injection acceptances are not large enough for accumulation of the electron beam, necessitating on-axis injection where stored electron bunches are completely replaced with newly injected ones. Recently, starting with the MAX-IV 7-bend achromatic cell, we

Future Synchrotron Light Sources Based on Ultimate Storage Rings

Energy Technology Data Exchange (ETDEWEB)

Cai, Yunhai; /SLAC

2012-04-09

The main purpose of this talk is to describe how far one might push the state of the art in storage ring design. The talk will start with an overview of the latest developments and advances in the design of synchrotron light sources based on the concept of an 'ultimate' storage ring. The review will establish how bright a ring based light source might be, where the frontier of technological challenges are, and what the limits of accelerator physics are. Emphasis will be given to possible improvements in accelerator design and developments in technology toward the goal of achieving an ultimate storage ring. An ultimate storage ring (USR), defined as an electron ring-based light source having an emittance in both transverse planes at the diffraction limit for the range of X-ray wavelengths of interest for a scientific community, would provide very high brightness photons having high transverse coherence that would extend the capabilities of X-ray imaging and probe techniques beyond today's performance. It would be a cost-effective, high-coherence 4th generation light source, competitive with one based on energy recovery linac (ERL) technology, serving a large number of users studying material, chemical, and biological sciences. Furthermore, because of the experience accumulated over many decades of ring operation, it would have the great advantage of stability and reliability. In this paper we consider the design of an USR having 10-pm-rad emittance. It is a tremendous challenge to design a storage ring having such an extremely low emittance, a factor of 100 smaller than those in existing light sources, especially such that it has adequate dynamic aperture and beam lifetime. In many ultra-low emittance designs, the injection acceptances are not large enough for accumulation of the electron beam, necessitating on-axis injection where stored electron bunches are completely replaced with newly injected ones. Recently, starting with the MAX-IV 7-bend

INJECTION CARBON STRIPPING FOIL ISSUES IN THE SNS ACCUMULATOR RING

International Nuclear Information System (INIS)

BEEBE-WANG, J.; LEE, Y.Y.; RAPARIA, D.; WEI, J.

2001-01-01

We are reporting the results of studies on issues related to the injection stripping foil in the Spallation Neutron Source (SNS) accumulator ring. The problems related to foil heating and foil lifetime, such as current density distribution and temperature distribution in the foil, are investigated. The impact of injection errors on the beam losses at the foil is studied. The particle traversal rate and the beam losses due to scattering in the foil are summarized. Finally, SNS end-to-end simulation results of the foil-missing rate, the foil-hitting rate and the maximum foil temperature are presented

Design and commissioning of the photon monitors and optical transport lines for the advanced photon source positron accumulator ring

International Nuclear Information System (INIS)

Berg, W.; Yang, B.; Lumpkin, A.; Jones, J.

1996-01-01

Two photon monitors have been designed and installed in the positron accumulator ring (PAR) of the Advanced Photon Source. The photon monitors characterize the beam's transverse profile, bunch length, emittance, and energy spread in a nonintrusive manner. An optical transport line delivers synchrotron light from the PAR out of a high radiation environment. Both charge-coupled device and fast-gated, intensified cameras are used to measure the transverse beam profile (0.11 - 1 mm for damped beam) with a resolution of 0.06 mm. A streak camera (θ τ =I ps) is used to measure the bunch length which is in the range of 0.3-1 ns. The design of the various transport components and commissioning results of the photon monitors will be discussed

E-P instability in the NSNS accumulator ring

Energy Technology Data Exchange (ETDEWEB)

Ruggiero, A.G.; Blaskiewicz, M.

1997-08-01

It has been speculated that the intensity limitation observed in the Los Alamos Proton Storage Ring (PSR) is caused by a coherent instability induced by the presence of pockets of electrons generated by scattering with the molecules of the vacuum residual gas. A theoretical explanation of the e-p instability of course does exist, and is similar to the one developed for the ion-induced instability in electron storage rings. Considering the large beam power (3 MW) involved in the NSNS Accumulator Ring, and the consequences caused by even a small amount of beam loss, we need to carefully assess the effects of electrons that may be generated in the vacuum chamber.

Field distributions and particle optics in main bending dipoles of Oak Ridge Spallation Neutron Source accumulator ring

International Nuclear Information System (INIS)

Wang, J.G.

2013-01-01

The SNS accumulator ring employs 32 electro-magnetic dipoles to bend proton beams. The dipoles are typical sector magnets with relatively large aperture and short length. Thus, how to correctly treat magnetic fringe fields in the devices remains as a question. We have performed 3D computer simulations to study magnetic field distributions in the dipoles. Further, we have analyzed particle optics based on the space-dependent curvature and focusing functions in the magnets. The effect of magnetic fringe fields on the particle motion, especially the focusing/defocusing and dispersion, is investigated. The lens parameters, including the second-order aberrations, are derived and compared with the design hard-edge parameters used in the ring lattice calculations

ION EFFECTS IN THE APS PARTICLE ACCUMULATOR RING

Energy Technology Data Exchange (ETDEWEB)

Calvey, J.; Harkay, K.; Yao, CY.

2017-06-25

Trapped ions in the APS Particle Accumulator Ring (PAR) lead to a positive coherent tune shift in both planes, which increases along the PAR cycle as more ions accumulate. This effect has been studied using an ion simulation code developed at SLAC. After modifying the code to include a realistic vacuum profile, multiple ionization, and the effect of shaking the beam to measure the tune, the simulation agrees well with our measurements. This code has also been used to evaluate the possibility of ion instabilities at the high bunch charge needed for the APS-Upgrade.

Biomonitoring airborne parent and alkylated three-ring PAHs in the Greater Cologne Conurbation I: Temporal accumulation patterns

International Nuclear Information System (INIS)

Lehndorff, E.; Schwark, L.

2009-01-01

Polycyclic aromatic hydrocarbons (PAHs) comprise an important group of air pollutants, with three-ring components (PAH-3) often dominating. Spatiotemporal variation in atmospheric PAH-3 can be analyzed by biomonitoring but high vapour pressure and low octanol-air-partitioning of PAH-3 cause dynamic accumulation on plant surfaces. This study for the first time shows that PAH-3 exhibit systematic accumulation trends on pine needles of 3-48 months of exposure time at six sites in Germany. Correlation of needle exposure time with PAH-3 concentration was r 2 = 0.83 for phenanthrene and methylphenanthrenes, r 2 = 0.77 for cyclopenta[def]phenanthrene, r 2 = 0.60 for dibenzothiophene, r 2 = 0.57 for dimethylphenanthrenes and r 2 = 0.32 for retene. Variations in PAH-3 for summer and winter collected needles emphasize vegetation-air-partitioning influence on cumulative PAH-3 loads. PAH-3 ratios calculated for needle cohorts indicate persistence of original PAH patterns thus demonstrating the source-diagnostic potential of pine needle biomonitoring, which is utilized in part II of this study where spatial distribution of PAH-3 is investigated and related to emission sources. - Accumulation of volatile three-ring PAHs on pine needles was found to be systematic over a period of 50 months thus qualifying PAHs for regional air quality studies

Ring insertions as light sources

International Nuclear Information System (INIS)

Green, G.K.

1975-01-01

Bending magnets can be inserted in the long straight sections of electron storage rings to produce synchrotron radiation. If the design is carefully proportioned, the bending magnets create only a small perturbation of the properties of the ring. The resulting spectra have favorable optical properties as sources for spectroscopy and diffraction studies. The characteristics of the source are discussed, and the geometrical requirements of the magnets are presented

Biomonitoring airborne parent and alkylated three-ring PAHs in the Greater Cologne Conurbation I: Temporal accumulation patterns

Energy Technology Data Exchange (ETDEWEB)

Lehndorff, E. [Department of Geology and Mineralogy, University of Cologne, Zuelpicher Str. 49a, 50674 Cologne (Germany); Schwark, L. [Department of Geology and Mineralogy, University of Cologne, Zuelpicher Str. 49a, 50674 Cologne (Germany); Institute of Geosciences, Kiel University, Ludewig-Meyn-Str. 10, 24118 Kiel (Germany)], E-mail: ls@gpi.uni-kiel.de

2009-04-15

Polycyclic aromatic hydrocarbons (PAHs) comprise an important group of air pollutants, with three-ring components (PAH-3) often dominating. Spatiotemporal variation in atmospheric PAH-3 can be analyzed by biomonitoring but high vapour pressure and low octanol-air-partitioning of PAH-3 cause dynamic accumulation on plant surfaces. This study for the first time shows that PAH-3 exhibit systematic accumulation trends on pine needles of 3-48 months of exposure time at six sites in Germany. Correlation of needle exposure time with PAH-3 concentration was r{sup 2} = 0.83 for phenanthrene and methylphenanthrenes, r{sup 2} = 0.77 for cyclopenta[def]phenanthrene, r{sup 2} = 0.60 for dibenzothiophene, r{sup 2} = 0.57 for dimethylphenanthrenes and r{sup 2} = 0.32 for retene. Variations in PAH-3 for summer and winter collected needles emphasize vegetation-air-partitioning influence on cumulative PAH-3 loads. PAH-3 ratios calculated for needle cohorts indicate persistence of original PAH patterns thus demonstrating the source-diagnostic potential of pine needle biomonitoring, which is utilized in part II of this study where spatial distribution of PAH-3 is investigated and related to emission sources. - Accumulation of volatile three-ring PAHs on pine needles was found to be systematic over a period of 50 months thus qualifying PAHs for regional air quality studies.

Optimizing ring-based CSR sources

International Nuclear Information System (INIS)

Byrd, J.M.; De Santis, S.; Hao, Z.; Martin, M.C.; Munson, D.V.; Li, D.; Nishimura, H.; Robin, D.S.; Sannibale, F.; Schlueter, R.D.; Schoenlein, R.; Jung, J.Y.; Venturini, M.; Wan, W.; Zholents, A.A.; Zolotorev, M.

2004-01-01

Coherent synchrotron radiation (CSR) is a fascinating phenomenon recently observed in electron storage rings and shows tremendous promise as a high power source of radiation at terahertz frequencies. However, because of the properties of the radiation and the electron beams needed to produce it, there are a number of interesting features of the storage ring that can be optimized for CSR. Furthermore, CSR has been observed in three distinct forms: as steady pulses from short bunches, bursts from growth of spontaneous modulations in high current bunches, and from micro modulations imposed on a bunch from laser slicing. These processes have their relative merits as sources and can be improved via the ring design. The terahertz (THz) and sub-THz region of the electromagnetic spectrum lies between the infrared and the microwave . This boundary region is beyond the normal reach of optical and electronic measurement techniques and sources associated with these better-known neighbors. Recent research has demonstrated a relatively high power source of THz radiation from electron storage rings: coherent synchrotron radiation (CSR). Besides offering high power, CSR enables broadband optical techniques to be extended to nearly the microwave region, and has inherently sub-picosecond pulses. As a result, new opportunities for scientific research and applications are enabled across a diverse array of disciplines: condensed matter physics, medicine, manufacturing, and space and defense industries. CSR will have a strong impact on THz imaging, spectroscopy, femtosecond dynamics, and driving novel non-linear processes. CSR is emitted by bunches of accelerated charged particles when the bunch length is shorter than the wavelength being emitted. When this criterion is met, all the particles emit in phase, and a single-cycle electromagnetic pulse results with an intensity proportional to the square of the number of particles in the bunch. It is this quadratic dependence that can

A new storage-ring light source

Energy Technology Data Exchange (ETDEWEB)

Chao, Alex [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2015-06-01

A recently proposed technique in storage ring accelerators is applied to provide potential high-power sources of photon radiation. The technique is based on the steady-state microbunching (SSMB) mechanism. As examples of this application, one may consider a high-power DUV photon source for research in atomic and molecular physics or a high-power EUV radiation source for industrial lithography. A less challenging proof-of-principle test to produce IR radiation using an existing storage ring is also considered.

Studies on beam extraction from the 1 GeV proton accumulator ring

International Nuclear Information System (INIS)

Goyal, Pradeep Kumar; Sharma, Amalendu; Kumar, Vinit; Ghodke, A.D.

2015-01-01

For the proposed Indian Spallation Neutron Source (ISNS), a 1 GeV proton Accumulator Ring (AR) is presently being designed at RRCAT. Two optics configurations of AR, namely FODO and Hybrid lattices are under consideration. Each lattice configuration has four superperiods. In this paper, preliminary studies on beam extraction from AR are presented for both the optics configurations. The extraction system will be accommodated in one of the long dispersion free straight sections. Bunch length of the proton beam in AR is 700 ns, and the revolution time of the bunch in AR is 1 ms. This leaves a gap of ∼300 ns for bunch extraction. The proton bunch will be extracted to Ring to Target Beam Transport (RTBT) line, with the help of fast kicker and septum magnets. In this paper, we present the details of the beam extraction scheme with suitable number of kicker magnets, and find out their optimal location and strength. Estimation of field error tolerances for kicker magnets is also presented. (author)

Electron Storage Ring Development for ICS Sources

Energy Technology Data Exchange (ETDEWEB)

Loewen, Roderick [Lyncean Technologies, Inc., Palo Alto, CA (United States)

2015-09-30

There is an increasing world-wide interest in compact light sources based on Inverse Compton Scattering. Development of these types of light sources includes leveraging the investment in accelerator technology first developed at DOE National Laboratories. Although these types of light sources cannot replace the larger user-supported synchrotron facilities, they offer attractive alternatives for many x-ray science applications. Fundamental research at the SLAC National Laboratory in the 1990’s led to the idea of using laser-electron storage rings as a mechanism to generate x-rays with many properties of the larger synchrotron light facilities. This research led to a commercial spin-off of this technology. The SBIR project goal is to understand and improve the performance of the electron storage ring system of the commercially available Compact Light Source. The knowledge gained from studying a low-energy electron storage ring may also benefit other Inverse Compton Scattering (ICS) source development. Better electron storage ring performance is one of the key technologies necessary to extend the utility and breadth of applications of the CLS or related ICS sources. This grant includes a subcontract with SLAC for technical personnel and resources for modeling, feedback development, and related accelerator physics studies.

Damping the e-p instability in the SNS accumulator ring

Science.gov (United States)

Evans, N. J.; Deibele, C.; Aleksandrov, A.; Xie, Z.

2018-03-01

A broadband, digital damper system for both transverse planes developed for the SNS accumulator ring has recently damped the first indications of the broadband 50-150 MHz e-p instability in a 1.2 MW neutron production beam. This paper presents details of the design and operation of the SNS damper system as well as results of active damping of the e-p instability in the SNS ring showing a reduction in power of betatron oscillation over the 10-300 MHz band of up to 70%. The spectral content of the beam during operation, with and without the damper system is presented and performance of the damper system is evaluated.

Commissioning of the diamond light source storage ring vacuum system

International Nuclear Information System (INIS)

Cox, M P; Boussier, B; Bryan, S; Macdonald, B F; Shiers, H S

2008-01-01

The Diamond storage ring has been operating with a 3 GeV electron beam since September 2006 and 190 A.h of beam dose have been accumulated. The pressure in the storage ring is 4.2 10 -10 mbar without beam, rising to 7.9 10 -10 mbar with 125 mA of stored beam. Data on the storage ring vacuum performance and experience from commissioning and beam conditioning are presented

The kicker magnet system for TRISTAN Accumulation Ring injection

International Nuclear Information System (INIS)

Sakamoto, Y.; Satoh, K.; Nakayama, H.

1994-12-01

The injection of electron beams to TRISTAN Accumulation Ring (AR) was started in November 1983 and the positron injection started in November 1985. For the injection of electron and positron beams to AR, the unique kicker system was developed. In the kicker power supply the charging to the main capacitor was done with the resonant charge system together with the auxiliary charging unit. The impedance matching circuit was added to the kicker magnet for getting the required current form with least reflecting oscillation. In this paper we report the performance of this kicker system. (author)

Minimum emittance of isochronus rings for synchrotron light source

CERN Document Server

Shoji, Y

1999-01-01

Theoretically achievable minimum emittances of isochronus rings for synchrotron light source are calculated. The rings discussed in this paper consist of isochronus and achromatic bending cells, isochronus TBA (triple bend achromat) cells with negative dispersion, isochronus TBA cells with inverse bends or isochronus QBA (four bend achromat) cells. We show that the minimum emittances of these rings are roughly 2 or 3 times of those of the optimized non-isochronus rings.

Beam dynamics in Compton ring gamma sources

Directory of Open Access Journals (Sweden)

Eugene Bulyak

2006-09-01

Full Text Available Electron storage rings of GeV energy with laser pulse stacking cavities are promising intense sources of polarized hard photons which, via pair production, can be used to generate polarized positron beams. In this paper, the dynamics of electron bunches circulating in a storage ring and interacting with high-power laser pulses is studied both analytically and by simulation. Both the common features and the differences in the behavior of bunches interacting with an extremely high power laser pulse and with a moderate pulse are discussed. Also considerations on particular lattice designs for Compton gamma rings are presented.

Upgraded cavities for the positron accumulator ring of the APS

International Nuclear Information System (INIS)

Kang, Y.W.; Jiang, X.; Mangra, D.

1997-01-01

Upgraded versions of cavities for the APS positron accumulator ring (PAR) have been built and are being tested. Two cavities are in the PAR: a fundamental 9.8-MHz cavity and a twelfth harmonic 117.3-MHz cavity. Both cavities have been manufactured for higher voltage operation with improved Q-factors, reliability, and tuning capability. Both cavities employ current-controlled ferrite tuners for control of the resonant frequency. The harmonic cavity can be operated in either a pulsed mode or a CW mode. The rf properties of the cavities are presented

Halo and space charge issues in the SNS Ring

International Nuclear Information System (INIS)

Fedotov, A.V.; Abell, D.T.; Beebe-Wang, J.; Lee, Y.Y.; Malitsky, N.; Wei, J.; Gluckstern, R.L.

2000-01-01

The latest designs for high-intensity proton rings require minimizing beam-induced radioactivation of the vacuum chamber. Although the tune depression in the ring is much smaller than in high-intensity linacs, space-charge contributions to halo formation and, hence, beam loss may be significant. This paper reviews our current understanding of halo formation issues for the Spallation Neutron Source (SNS) accumulator ring

Halo and space charge issues in the SNS Ring

Energy Technology Data Exchange (ETDEWEB)

Fedotov, A.V.; Abell, D.T.; Beebe-Wang, J.; Lee, Y.Y.; Malitsky, N.; Wei, J.; Gluckstern, R.L.

2000-06-30

The latest designs for high-intensity proton rings require minimizing beam-induced radioactivation of the vacuum chamber. Although the tune depression in the ring is much smaller than in high-intensity linacs, space-charge contributions to halo formation and, hence, beam loss may be significant. This paper reviews our current understanding of halo formation issues for the Spallation Neutron Source (SNS) accumulator ring.

SNS RING STUDY AT THE AGS BOOSTER.

Energy Technology Data Exchange (ETDEWEB)

ZHANG, S.Y.; AHRENS, L.; BEEBE-WANG, J.; BLASKIEWICZ, M.; FEDOTOV, A.; GARDNER, C.; LEE, Y.Y.; LUCCIO, A.; MALITSKY, N.; ROSER, T.; WENG, W.T.; WEI, J.; ZENO, K.; REECE, K.; WANG, J.G.

2000-06-30

During the g-2 run at the BNL AGS in early 2000, a 200 MeV storage-ring-like magnetic cycle has been set-up and tuned at the Booster in preparing for the Spallation Neutron Source (SNS) accumulator ring study. In this article, we report the progress of the machine set-up, tuning, some preliminary studies, and the future plan.

Longitudinal bunch deformation of a multi-bunched beam in the TRISTAN Accumulation Ring

International Nuclear Information System (INIS)

Obina, T.; Satoh, K.; Kasuga, T.; Funakoshi, Y.; Tobiyama, M.

1997-01-01

A remarkable bunch deformation has been observed in the TRISTAN Accumulation Ring (AR) during multi-bunch operations. When two bunches that have different populations are stored in the ring, the bunch length of the weaker bunch is longer than that of the stronger one. The phenomenon can be explained as an effect of wake fields due to higher-order modes (HOMs) of accelerating cavities. We tried to find out the frequency of the mode and the strength of the wake field, and introduced a new technique called a test bunch measurement. The estimated field strength from the experiment shows a reasonable agreement with the calculation of HOM impedance. copyright 1997 American Institute of Physics

Construction of vacuum system for Tristan accumulation ring

International Nuclear Information System (INIS)

Ishimaru, H.; Horikoshi, G.; Kobayashi, M.; Kubo, T.; Mizuno, H.; Momose, T.; Narushima, K.; Watanabe, H.; Yamaguchi, H.

1983-01-01

An all aluminum-alloy vacuum system for the TRISTAN accumulation ring is now under construction. Aluminum and aluminum alloys are preferred materials for ultrahigh vacuum systems of large electron storage rings because of their good thermal conductivity, extremely low outgassing rate, and low residual radioactivity. Vacuum beam chambers for the dipole and quadrupole magnets are extruded using porthole dies. The aluminum alloy 6063-T6 provides superior performance in extrusion. For ultrahigh vacuum performance, a special extrusion technique is applied which, along with the outgassing procedure used, is described in detail. Aluminum alloy 3004 seamless elliptical bellows are inserted between the dipole and quadrupole magnet chambers. These bellows are produced by the hydraulic forming of a seamless tube. The seamless bellows and the beam chambers are joined by fully automatic welding. The ceramic chambers for the kicker magnets, the fast bump magnets, and the slow beam intensity monitor are inserted in the aluminum alloy beam chambers. The ceramic chamber (98% alumina) and elliptical bellows are brazed with brazing sheets (4003-3003-4003) in a vacuum furnace. The brazing technique is described. The inner surface of the ceramic chamber is coated with a TiMo alloy by vacuum evaporation to permit a smooth flow of the RF wall current. Other suitable aluminum alloy components, including fittings, feedthroughs, gauges, optical windows, sputter ion pumps, turbomolecular pumps, and valves have been developed; their fabrication is described

Piranti Lunak Pengujian Struktur Matematika Grup, Ring, Field Berbasis Osp (Open Source Program

Directory of Open Access Journals (Sweden)

Ngarap Im Manik

2014-06-01

Full Text Available This design of a computer software is a development and continuation of the software made on the previous research (2009/2010. However, this further research developed and expanded the scopes of testing more on the Siclic Group, Isomorphism Group, Semi Group, Sub Group and Abelian Group, Factor Ring, Sub Ring and Polynomial Ring; developed on the OSP (Open Source Program-based. The software was developed using the OSP-based language programming, such Java, so it is open and free to use for its users. This research succeeded to develop an open source software of Java program that can be used for testing specific mathematical Groups, such Ciclic Group, Isomorphism Group, Semi Group, Sub Group and Abelian Group, and Rings, Commutative Ring, Division Ring, Ideal Sub Ring, Ring Homomorphism, Ring Epimorphism and Fields. By the results, the software developed was able to test as same as the results from manual testing.

New Storage Ring Light Sources on the Horizon

CERN Document Server

Podobedov, Boris

2005-01-01

The world's appetite for light sources keeps growing as new ones are under construction or being proposed for every continent but Antarctica. While some viable alternatives are emerging, the great majority of new light sources are based on mature electron storage ring technology. We review the design and performance of the new machines worldwide and speculate on the future directions.

An unusually strong Einstein ring in the radio source PKS1830-211

International Nuclear Information System (INIS)

Jauncey, D.L.

1991-01-01

RADIO observations of the strong, flat-spectrum radio source PKS1830-211 revealed a double structure, with a separation of 1 arcsec, suggesting that it might be a gravitationally lensed object. We have now obtained high-resolution radio images of PKS1830-211 from several interferometric radiotelescope networks, which show an unusual elliptical ring-like structure connecting the two brighter components. The presence of the ring, and the similarity of the two brighter spots, argue strongly that this is indeed a gravitationally lensed system, specifically an Einstein ring in which lens and lensed object are closely aligned. Although the source is close to the galactic plane, it seems that both the lens and background (lensed) object are extragalactic. This object is one hundred times brighter than either of the two previously discovered radio Einstein rings, and is among the six brightest flat-spectrum sources in the sky. Its brightness makes it a peculiar object: it must involve either a chance alignment of a lensing object with an unusually bright background source, or an alignment with a less bright object but amplified to an unusual degree. (author)

Assessment of neutron skyshine near unmodified Accumulator Debuncher storage rings under Mu2e operational conditions

Energy Technology Data Exchange (ETDEWEB)

Cossairt, J.Donald; /Fermilab

2010-12-01

Preliminary plans for providing the proton beam needed by the proposed Mu2e experiment at Fermilab will require the transport of 8 GeV protons to the Accumulator/Debuncher where they be processed into an intensity and time structure useful for the experiment. The intensities involved are far greater that those encountered with antiprotons of the same kinetic energy in the same beam enclosures under Tevatron Collider operational conditions, the operating parameters for which the physical facilities of the Antiproton Source were designed. This note explores some important ramifications of the proposed operation for radiation safety and demonstrates the need for extensive modifications of significant portions of the shielding of the Accumulator Debuncher storage rings; notably that underneath the AP Service Buildings AP10, AP30, and AP50. While existing shielding is adequate for the current operating mode of the Accumulator/Debuncher as part of the Antiproton Source used in the Tevatron Collider program, without significant modifications of the shielding configuration in the Accumulator/Debuncher region and/or beam loss control systems far more effective than seen in most applications at Fermilab, the proposed operational mode for Mu2e is not viable for the following reasons: 1. Due to skyshine alone, under normal operational conditions large areas of the Fermilab site would be exposed to unacceptable levels of radiation where most of the Laboratory workforce and some members of the general public who regularly visit Fermilab would receive measurable doses annually, contrary to workforce, public, and DOE expectations concerning the As Low as Reasonably Achievable (ALARA) principle. 2. Under normal operational conditions, a sizeable region of the Fermilab site would also require fencing due to skyshine. The size of the areas involved would likely invite public inquiry about the significant and visible enlargement of Fermilab's posted radiological areas. 3. There

Design considerations for a feedback system to control self-bunching in ion-storage rings

International Nuclear Information System (INIS)

Ziemann, V.

2001-02-01

We discuss the feasibility of a feedback system to cure self-bunching of the electron-cooled coasting ion-beam in CELSIUS. Such a system may also aid stable operation of accumulator rings for future spallation neutron sources or heavy ion rings used for inertial fusion energy production

LASL high-current proton storage rings

International Nuclear Information System (INIS)

Lawrence, G.P.; Cooper, R.K.; Hudgings, D.W.; Spalek, G.; Jason, A.J.; Higgins, E.F.; Gillis, R.E.

1980-01-01

The Proton Storage Ring at LAMPF is a high-current accumulator designed to convert long 800-MeV linac pulses into very short high-intensity proton bunches ideally suited to driving a pulsed polyenergetic neutron source. The Ring, authorized for construction at $19 million, will operate in a short-bunch high-frequency mode for fast neutron physics and a long-bunch low-frequency mode for thermal neutron-scattering programs. Unique features of the project include charge-changing injection with initial conversion from H - to H 0 , a high repetition rate fast-risetime extraction kicker, and high-frequency and first-harmonic bunching system

Proton accumulator ring injection studies

International Nuclear Information System (INIS)

Cooper, R.K.; Neil, V.K.

1977-01-01

Protons may be created in an accelerator or storage ring by stripping electrons from neutral hydrogen atoms that have been injected into the machine. Because Liouville's theorem is violated by this type of injection, particles may be continually injected into a region of phase space that is already populated, and the density in that region increases with time. A computational investigation was made of the evolution of the distribution of particles in longitudinal phase space during such an injection process for a storage ring operating below the transition energy. In one calculation, an rf cavity is present in the ring and particles are injected into the stable phase region once each revolution. The purpose of this calculation is to determine the rf voltage necessary to overcome the longitudinal self-forces and contain the particles within the region of stable phase. In a second calculation, the rf is turned off, so that there is spreading in azimuth of the injected particles (i.e., de-bunching). The de-bunching occurs because of the initial energy spread and the action of the self-forces. One purpose of the calculation is to determine the total energy spread after a given number of revolutions. Another purpose is to elucidate the effect of finite resistance in the vacuum tank walls. For sufficiently high current, the finite resistance can cause bunching of a beam that is initially uniform in azimuth. Therefore it might be expected that the finite resistance would inhibit or prevent de-bunching once the number of particles injected reaches some threshold, and that this threshold would depend upon the energy spread in the beam

BERKELEY: ALS ring

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-06-15

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

BERKELEY: ALS ring

International Nuclear Information System (INIS)

Anon.

1993-01-01

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

Induced spin-accumulation and spin-polarization in a quantum-dot ring by using magnetic quantum dots and Rashba spin-orbit effect

International Nuclear Information System (INIS)

Eslami, L.; Faizabadi, E.

2014-01-01

The effect of magnetic contacts on spin-dependent electron transport and spin-accumulation in a quantum ring, which is threaded by a magnetic flux, is studied. The quantum ring is made up of four quantum dots, where two of them possess magnetic structure and other ones are subjected to the Rashba spin-orbit coupling. The magnetic quantum dots, referred to as magnetic quantum contacts, are connected to two external leads. Two different configurations of magnetic moments of the quantum contacts are considered; the parallel and the anti-parallel ones. When the magnetic moments are parallel, the degeneracy between the transmission coefficients of spin-up and spin-down electrons is lifted and the system can be adjusted to operate as a spin-filter. In addition, the accumulation of spin-up and spin-down electrons in non-magnetic quantum dots are different in the case of parallel magnetic moments. When the intra-dot Coulomb interaction is taken into account, we find that the electron interactions participate in separation between the accumulations of electrons with different spin directions in non-magnetic quantum dots. Furthermore, the spin-accumulation in non-magnetic quantum dots can be tuned in the both parallel and anti-parallel magnetic moments by adjusting the Rashba spin-orbit strength and the magnetic flux. Thus, the quantum ring with magnetic quantum contacts could be utilized to create tunable local magnetic moments which can be used in designing optimized nanodevices.

RF cavities for the positron accumulator ring (PAR) of the Advanced Photon Source (APS)

International Nuclear Information System (INIS)

Kang, Y.W.; Nassiri, A.; Bridges, J.F.; Smith, T.L.; Song, J.J.

1995-01-01

The cavities for the dual frequency system of the APS PAR are described. The system uses two frequencies: a 9.78MHz fundamental system for the particle accumulation and a 117.3MHz twelfth harmonic system for the bunch compression. The cavities have been built, installed, tested, and used for storing the beam in the PAR for about a year. The fundamental cavity is a reentrant coaxial type with a capacitive loading plunger and has 1.6m length. The harmonic cavity is a symmetrical reentrant coaxial type and is 0.8m long. Ferrite tuners are used for frequency tuning. During the accumulation period, the ferrite tuner of the harmonic cavity works as a damper to disable the cavity. During an injection cycle the 9.78MHz system accumulates 24 positron bunches in a bucket and the 117.3MHz system compresses the bunch into a shorter bunch. Measurements were made on the rf properties of the cavities

A feasibility study of a neutrino source based on a muon storage ring

CERN Document Server

Finley, D

2001-01-01

We present the results of a study commissioned by the Fermilab Director on the feasibility of an intense neutrino source, based on a muon storage ring. Muon colliders have been discussed as an alternate route to very high-energy lepton colliders. As a by-product, such a collider would produce very intense neutrino beams because of the decaying muons circulating in the storage ring. In a dedicated storage ring, these neutrino beams could be produced in long straight sections which would point towards long, medium or short baseline detectors, opening up a whole new class of neutrino physics experiments because of the enormous neutrino flux that, in principle, could be achieved in such a facility as compared to more standard fixed target sources. Intense pion sources in combination with powerful emittance cooling strategies for the comparatively large muon emittance are necessary to make this type of neutrino source as well as a muon collider, feasible for a possible future high energy physics facility. The Neut...

High Intensity Effects in the SNS Accumulator Ring

International Nuclear Information System (INIS)

Holmes, Jeffrey A.; Cousineau, Sarah M.; Danilov, Viatcheslav; Plum, Michael A.; Shishlo, Andrei P.

2008-01-01

Currently operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, RF bunching, and beam scattering, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. At each stage of the power ramp-up, we use all available resources to understand and to minimize beam losses. From the standpoint of beam dynamics, the losses observed so far under normal operating conditions have not involved collective phenomena. We are now entering the intensity regime in which this may change. In dedicated high intensity beam studies, we have already observed resistive wall, extraction kicker impedance-driven, and electron cloud activities. The analysis and simulation of this data are important ongoing activities at SNS. This paper discusses the status of this work, as well as other considerations necessary to the successful full power operation of SNS.

INJECTION EFFICIENCY IN COMPTON RING NESTOR

Directory of Open Access Journals (Sweden)

P. I. Gladkikh

2017-12-01

Full Text Available NESTOR is the hard X-ray source that is under commissioning at NSC KIPT. NESTOR based on the Compton scattering of laser photons on relativistic electrons. The structure of the facility can be represented as the following components: a linear accelerator, a transport channel, a storage ring, and a laser-optical system. Electrons are stored in the storage ring for energy of 40-200 MeV. Inevitable alignment errors of magnetic elements are strongly effect on the beam dynamics in the storage ring. These errors lead to a shift of the equilibrium orbit relative to the ideal one. Significant shift of the equilibrium orbit could lead to loss of the beam on physical apertures. Transverse sizes of electron and laser beams are only few tens of microns at the interaction point. The shift of electron beam at the interaction point could greatly complicate the operation adjustment of storage ring without sufficient beam position diagnostic system. This article presents the simulation results of the efficiency of electron beam accumulation in the NESTOR storage ring. Also, this article is devoted to electron beam dynamics due to alignment errors of magnetic element in the ring.

Test Accumulation Ring for NUMATRON Project - TARN -

International Nuclear Information System (INIS)

Hirao, Y.; Chida, K.; Hattori, T.; Hori, T.; Katayama, T.

1979-03-01

TARN is now under construction at INS, University of Tokyo. Heavy ions from the SF Cyclotron such as N 5+ with an energy of 8.5 MeV per nucleon, are planned to be injected and stacked in the ring by a combination of multiturn injection and RF stacking method. Expected intensity of the stacked beam, e.g. N 5+ , is 2 x 10 10 particles, and survival rate of 90% is anticipated at the pressure of 1 x 10 -10 torr during a stacking time of 1 sec. In this paper the present status of the ring is described as well as the performances of the major subsystems. (author)

Evaluated Rayleigh integrals for pulsed planar expanding ring sources

International Nuclear Information System (INIS)

Warshaw, S.I.

1985-01-01

Time-domain analytic and semianalytic pressure fields acoustically radiated from expanding pulsed ring sources imbedded in a planar rigid baffle have been calculated. The source functions are radially symmetric delta-function distributions whose amplitude and argument have simple functional dependencies on radius and time. Certain cases yield closed analytic results, while others result in elliptic integrals, which are evaluated to high accuracy by Gauss-Chebyshev and modified Gauss-Legendre quadrature. These results are of value for calibrating computer simulations and convolution procedures, and estimating fields from more complex planar radiators. 3 refs., 4 figs

Design of a quasi-isochronous storage ring for THz light source

International Nuclear Information System (INIS)

Zhu Jiapeng; Xu Hongliang; Feng Guangyao; Lan Jieqin

2012-01-01

A quasi-isochronous storage ring is designed by manipulating lattice parameters to introduce a negative dispersion function to the dispersion section. This quasi-isochronous storage ring is designed for a THz synchrotron radiation source. The simulation of the optics function and beam emittance shows its feasibility, and the tracing result of particles indicates that the designed ring has a good particle dynamic aperture. In addition, a three-dimensional model of the vacuum chamber used for photon radiation in the quasi-isochronous mode is also designed. The eigenmodes of the chamber are simulated, and characteristic parameters such as quality factor, power loss and characteristic impedance are also calculated. The result shows that the vacuum chamber has little effect on the circulating beam. (authors)

Positron Accumulator Ring (PAR) power supply

International Nuclear Information System (INIS)

Fathizadeh, M.

1995-01-01

The Positron Accumulator Ring (PAR) consists of 8 dipole magnets connected in series. These magnets are energized via one 12-pulse dc power supply. The power supply consists of four phase controlled half-wave wye group converters. Each of the two half-wave converters are connected through an interphase transformer to obtain a full-wave converter with 120 degrees conduction. The input voltage for these two half-wave converters are 180 degrees apart. The two full-wave converters are connected in parallel through a third interphase transformer. This type of connection of the converters not only provides the required output current, it also improves the input power factor of the power supply. The output of the wye group converters is filtered through a passive L-R-C filter to reduce the ripple content of the output current. At low current values of the power supply the current ripple is high, thus a large filter is needed, which adds to the cost of the power supply, however at high output current levels, the current ripple is less severe. The large size of the filter can be reduced by adding an anti-parallel rectifier diode(D1) to the output of the power supply. A freewheeling diode(D2) is connected before the choke to circulate the current once the power supply is turned off. In order to measure the current in the magnet a high precision, low drift, zero flux current transductor is used. This transductor senses the magnet current which provides a feedback signal to control the gating of the converter's thyristors. A true 14 bit Digital to Analog Converter (DAC) is programmed by the control computer for the required current value, providing a reference for the current regulator. Fast correction of the line transients is provided by a relatively fast voltage loop controlled by a high gain slow response current loop

A zone plate soft x-ray microscope using monochromatized undulator radiation at the beamline NE1B of the TRISTAN Accumulation Ring

International Nuclear Information System (INIS)

Wang, J.; Kagoshima, Y.; Miyahara, T.; Ando, M.; Aoki, S.; Anderson, E.; Attwood, D.; Kern, D.

1995-01-01

A soft x-ray microscope has been developed at the beamline NE1B of the 6.5-GeV TRISTAN Accumulation Ring (AR). It makes use of undulator radiation as its source and a zone plate with the outermost zone width of 50 nm as its imaging element. It has two main features. First, the undulator radiation is monochromatized by a grazing incidence grating monochromator to match to the monochromaticity requirement of the zone plate. Second, a visible light prefocus unit consisting of two objectives has been designed and installed in the x-ray microscope. The x-ray optical system of the microscope can be adjusted easily, quickly, and precisely by using this unit. The microscope can resolve 55-nm lines and spaces in a zone plate test pattern

Fabrication and test of prototype ring magnets for the ALS [Advanced Light Source

International Nuclear Information System (INIS)

Tanabe, J.; Avery, R.; Caylor, R.; Green, M.I.; Hoyer, E.; Halbach, K.; Hernandez, S.; Humphries, D.; Kajiyama, Y.; Keller, R.; Low, W.; Marks, S.; Milburn, J.; Yee, D.

1989-03-01

Prototype Models for the Advanced Light Source (ALS) Booster Dipole, Quadrupole and Sextupole and the Storage Ring Gradient Magnet, Quadrupole and Sextupole have been constructed. The Booster Magnet Prototypes have been tested. The Storage Ring Magnets are presently undergoing tests and magnetic measurements. This paper reviews the designs and parameters for these magnets, briefly describes features of the magnet designs which respond to the special constraints imposed by the requirements for both accelerator rings, and reviews some of the results of magnet measurements for the prototype. 13 refs., 7 figs., 1 tab

Application of FEL technique for constructing high-intensity, monochromatic, polarized gamma-sources at storage rings

Energy Technology Data Exchange (ETDEWEB)

Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others

1995-12-31

A possibility to construct high-intensity tunable monochromatic{gamma}-source at high energy storage rings is discussed. It is proposed to produce {gamma}-quanta by means of Compton backscattering of laser photons on electrons circulating in the storage. The laser light wavelength is chosen in such a way that after the scattering, the electron does not leave the separatrix. So as the probability of the scattering is rather small, energy oscillations are damped prior the next scattering. As a result, the proposed source can operate in {open_quotes}parasitic{close_quote} mode not interfering with the main mode of the storage ring operation. Analysis of parameters of existent storage rings (PETRA, ESRF, Spring-8, etc) shows that the laser light wavelength should be in infrared, {lambda}{approximately} 10 - 400 {mu}m, wavelength band. Installation at storage rings of tunable free-electron lasers with the peak and average output power {approximately} 10 MW and {approximately} 1 kW, respectively, will result in the intensity of the {gamma}-source up to {approximately} 10{sup 14}s{sup -1} with tunable {gamma}-quanta energy from several MeV up to several hundreds MeV. Such a {gamma}-source will reveal unique possibilities for precision investigations in nuclear physics.

A low-frequency high-voltage rf-barrier-bunching system for high-intensity neutron source compressor rings

International Nuclear Information System (INIS)

Hardek, T.W.; Ziomek, C.; Rees, D.

1995-01-01

A Los Alamos design for a 1-MW pulsed neutron source incorporates a ring utilizing an rf-barrier bunching system. This bunching concept allows uniform longitudinal beam distributions with low momentum spread. Bunching cavities are operated at the revolution frequency (1.5 MHz in this case) and each of the 2nd, 3rd, 4th, and 5th revolution frequency harmonics. Their effects combine to maintain a beam free gap in the longitudinal distribution of the accumulated beam. The cavities are driven by low-plate-resistance common-cathode configured retrode amplifiers incorporating local rf feedback. Additional adaptive feed-forward hardware is included to reduce the beam-induced bunching-gap voltages well below that achievable solely with rf feedback. Details of this system are presented along with a discussion of the various feed-back and feed-forward techniques incorporated

Electron cloud instabilities in the Proton Storage Ring and Spallation Neutron Source

Directory of Open Access Journals (Sweden)

M. Blaskiewicz

2003-01-01

Full Text Available Electron cloud instabilities in the Los Alamos Proton Storage Ring and those foreseen for the Oak Ridge Spallation Neutron Source are examined theoretically, numerically, and experimentally.

BNL feasibility studies of spallation neutron sources

International Nuclear Information System (INIS)

Lee, Y.Y.; Ruggiero, A.G.; Van Steenbergen, A.; Weng, W.T.

1995-01-01

This paper is the summary of conceptual design studies of a 5 MW Pulsed Spallation Neutron Source (PSNS) conducted by an interdepartmental study group at Brookhaven National Laboratory. The study was made of two periods. First, a scenario based on the use of a 600 MeV Linac followed by two fast-cycling 3.6 GeV Synchrotrons was investigated. Then, in a subsequent period, the attention of the study was directed toward an Accumulator scenario with two options: (1) a 1.25 GeV normal conducting Linac followed by two Accumulator Rings, and (2) a 2.4 GeV superconducting Linac followed by a single Accumulator Ring. The study did not make any reference to a specific site

The future of the antiproton accumulator

International Nuclear Information System (INIS)

Autin, B.

1983-01-01

When the Antiproton Accumulator was designed in 1977, it was considered as an element of the high energy proton-antiproton collision experiments in the CERN Super Proton Synchrotron. Since that time, antiproton physics has become more and more popular: a second experimental area was built in the SPS, the Intersecting Storage Rings started a special antiproton programme and a considerable interest has bloomed in the energy range of nuclear physics with the LEAR machine. Moreover, any projection on hadron physics in the coming years shows an insatiable appetite of experimentalists for more antiprotons. Therefore, basic studies have been pursued since the beginning of last year to transform the accumulator into an abundant source of antiprotons

Vortex and source rings

DEFF Research Database (Denmark)

Branlard, Emmanuel Simon Pierre

2017-01-01

The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... the analogy to a doublet field is made. The following section derive the value of the vector potential and velocity field in the full domain. The expression for the velocity gradient is also provided since it may be relevant in a simulation with vortex particles and vortex rings. Most of this chapter...

Undulator sources at a 8 GeV storage ring

International Nuclear Information System (INIS)

Harami, Taikan.

1989-06-01

The use of undulators plays an important role as a high brilliance sources of synchrotron photon at a facility having an electron (or positron) storage ring. This paper describes the characteristics, tunability from gap variation and brilliance of synchrotron photon from undulators at a 8 GeV storage ring. The numerical studies show the following results. (1) Undulators for a 8 GeV storage ring can cover the first harmonic photon energy range from about 0.3 to 30 keV and the third harmonic photon from 0.85 to 70 keV. (2) The brilliance of undulator can be expected to be the order of 10 21 photons/(sec mm 2 mrad 2 0.1% band width mA), without size and angular spread in the electron beam (diffraction limit). (3) The peak brilliance has a broad maximum as a function of β function of the lattice and is shown to be practically independent on the β function. The peak brilliance is calculated to be the order of 10 16 photons/(sec mm 2 mrad 2 0.1% band width mA) at the electron beam emittance of 5 x 10 -9 m·rad (undulator length 2 m). (4) The nuclei of 57 Fe, 119 Sn and 238 U are expected to be the candidates for the Moessbauer scattering experiment using synchrotron photon from a 8 GeV storage ring. (author)

Design considerations for a digital feedback system to control self-bunching in ion-storage rings

Directory of Open Access Journals (Sweden)

V. Ziemann

2001-04-01

Full Text Available We discuss the feasibility of a digital feedback system to cure self-bunching of the electron-cooled coasting ion beam in ion-storage rings such as CELSIUS [S. Holm, A. Johansson, S. Kullander, and D. Reistad, Phys. Scr. 34, 513–532 (1986]. Such a system is based on a fast digital filter that acts as a tunable artificial wake potential. It may also aid stable operation of accumulator rings for future spallation neutron sources or heavy ion rings used for inertial fusion energy production.

Performance and upgrades of the NSLS storage rings and photon sources

International Nuclear Information System (INIS)

1991-01-01

The usefulness of synchrotron radiation sources is not only determined by current, energy and magnetic field but also orbit stability and lifetime. The status and developments at NSLS in storage ring performance are discussed. Efforts at NSLS to look toward the future in source development are presented. In particular, small gap undulator development and studies toward development of UV Free Electron Laser at the Accelerator Test Facility are described. 5 refs., 2 figs., 1 tab

Dynamic response analysis of the LBL Advanced Light Source synchrotron radiation storage ring

International Nuclear Information System (INIS)

Leung, K.

1993-05-01

This paper presents the dynamic response analysis of the photon source synchrotron radiation storage ring excited by ground motion measured at the Lawrence Berkeley Laboratory advanced light source building site. The high spectral brilliance requirement the photon beams of the advanced light source storage ring specified displacement of the quadrupole focusing magnets in the order of 1 micron in vertical motion.There are 19 magnets supported by a 430-inch steel box beam girder. The girder and all magnets are supported by the kinematic mount system normally used in optical equipment. The kinematic mount called a six-strut magnet support system is now considered as an alternative system for supporting SSC magnets in the Super Collider. The effectively designed and effectively operated six-strut support system is now successfully operated for the Advanced Light Source (ALS) accelerator at the Lawrence Berkeley Laboratory. This paper will present the method of analysis and results of the dynamic motion study at the center of the magnets under the most critical excitation source as recorded at the LBL site

Measurement of RF characteristics of magnetic alloys for an RF cavity of the accumulator cooler ring

International Nuclear Information System (INIS)

Watanabe, M.; Chiba, Y.; Katayama, T.; Koseki, T.; Ohtomo, K.; Tsutsui, H.

2004-01-01

The magnetic alloy (MA)-loaded RF cavity has been studied for an RF stacking system of the accumulator cooler ring (ACR). RF characteristics of several high-permeability MA cores were measured in the frequency range between 1 and 50 MHz. The effects of the cut-core configuration, cutting the core and leaving air gaps between two circular halves, were also investigated. The results show that the shunt impedance remains high and the appropriate inductance and Q-value can be obtained by increasing the gap width of the cut core in the frequency region of the ACR cavity

Performance of quadrupole and sextupole magnets for the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Kim, S.H.; Doose, C.L.; Kim, K.; Thompson, K.M.; Turner, L.R.

1993-01-01

From the magnetic measurement data of several production quadrupole and sextupole magnets for the storage ring of the Advanced Photon Source, the excitation efficiencies and systematic and random multipole coefficients of the magnets are summarized. The designs of the magnets, which are constrained due to the geometry of the vacuum chamber have rotation symmetries of 180 degrees and 120 degrees. The production data meet the allowed tolerances of a few parts in 10 -4 for the storage ring

Precision Magnetic Elements for the SNS Storage Ring

International Nuclear Information System (INIS)

Danby, G.; Jackson, J.; Spataro, C.

1999-01-01

Magnetic elements for an accumulator storage ring for a 1 GeV Spallation Neutron Source (SNS) have been under design. The accumulation of very high intensity protons in a storage ring requires beam optical elements of very high purity to minimize higher order resonances in the presence of space charge. The parameters of the elements required by the accumulator lattice design have been reported. The dipoles have a 17 cm gap and are 124 cm long. The quadrupoles have a physical length to aperture diameter ratio of 40 cm/21 cm and of 45 cm/31 cm. Since the elements have a large aperture and short length, optimizing the optical effects of magnet ends is the major design challenge. Two dimensional (2D) computer computations can, at least on paper, produce the desired accuracy internal to magnets, i.e. constant dipole fields and linear quadrupole gradients over the desired aperture to 1 x 10 -4 . To minimize undesirable end effects three dimensional (3D) computations can be used to design magnet ends. However, limitations on computations can occur, such as necessary finite boundary conditions, actual properties of the iron employed, hysteresis effects, etc., which are slightly at variance with the assumed properties. Experimental refinement is employed to obtain the desired precision

Access control and interlock system at the Advanced Photon Source

International Nuclear Information System (INIS)

Forrestal, J.; Hogrefe, R.; Knott, M.; McDowell, W.; Reigle, D.; Solita, L.; Koldenhoven, R.; Haid, D.

1997-01-01

The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel from prompt radiation generated by the linac, PAR, synchrotron, and storage ring. This paper describes the ACIS's design philosophy, configuration, hardware, functionality, validation requirements, and operational experience

Ring energy selection and extra long straight sections for the Advanced Photon Source

International Nuclear Information System (INIS)

1987-04-01

Recommended criteria are given for the performance of Advanced Photon Source (APS), taking into consideration undulator tunability criteria and their relationship to the storage ring energy and undulator gap, length of straight sections

Kickers and power supplies for the Fermilab Tevatron I antiproton source

International Nuclear Information System (INIS)

Castellano, T.; Bartoszek, L.; Tilles, E.; Petter, J.; McCarthy, J.

1985-05-01

The Fermilab Antiproton Source Accumulator and Debuncher rings require 5 kickers in total. These range in design from conventional ferrite delay line type magnets, with ceramic beam tubes to mechanically complex shuttered kickers situated entirely in the Accumulator Ring's 10 -10 torr vacuum. Power supplies are thyratron switched pulse forming networks that produce microsecond width pulses of several kiloamps with less than 30 nanoseconds rise and fall times. Kicker and power supply design requirements for field strength, vacuum, rise and fall time, timing and magnetic shielding of the stacked beam in the accumulator by the eddy current shutter will be discussed. 8 refs., 3 figs., 2 tabs

Ring-patterned plasmonic photonic crystal thermal light source for miniaturized near-infrared spectrometers

Science.gov (United States)

Labib, Shady R.; Elsayed, Ahmed A.; Sabry, Yasser M.; Khalil, Diaa

2018-02-01

There is a growing number of spectroscopy applications in the near-infrared (NIR) range including gas sensing, food analysis, pharmaceutical and industrial applications that requires highly efficient, more compact and low-cost miniaturized spectrometers. One of the key components for such systems is the wideband light source that can be fabricated using Silicon technology and hence integrated with other components on the same chip. In this work, we report a ring-patterned plasmonic photonic crystal (PC) thermal light source for miniaturized near-infrared spectrometers. The design is based on silicon and tuned to achieve wavelength selectivity in the emitted spectrum. The design is optimized by using Rigorous Coupled-Wave Analysis (RCWA) simulation, which is used to compute the power reflectance and transmittance that are used to predict the emissivity of the structure. The design consists of a PC of silicon rings coated with platinum. The period of the structure is about 2 μm and the silicon is highly-doped with n-type doping level in the order of 1019-1020 cm-3 to enhance the free-carrier absorption. The ring etching depth, diameter and shell thickness are optimized to increase its emissivity within a specific wavelength range of interest. The simulation results show an emissivity exceeding 0.9 in the NIR range up to 2.5 μm, while the emissivity is decreased significantly for longer wavelengths suppressing the emission out of the range of interest, and hence increasing the efficiency for the source. The reported results open the door for black body radiation engineering in integrated silicon sources for spectrometer miniaturization.

Design parameters for a small storage ring optimized as an x-ray lithography source

International Nuclear Information System (INIS)

Grobman, W.D.

1983-01-01

This paper examines the design parameters for a ''compact storage ring'' which is matched well to x-ray lithographic requirements, but is as small as possible. This calculation uses a model of a lithographic system which obtains its input parameters from a technology of mask, resist and beam line based on the IBM program at the Brookhaven National Laboratory vacuum ultraviolet electron storage ring. Based on this lithographic system, we model exposure throughput as a function of storage ring parameters to understand which storage ring designs provide adequate but not excessive soft x-ray flux in the lithographically important region. Our scan of storage ring sources will cover a wide range of energies and magnetic fields, to permit consideration of superconducting as well as more standard strong- or weak-focusing designs. Furthermore, we will show that the results of the calculations presented here can be scaled in a simple way to cover a wide range of x-ray lithography system assumptions

Design status of the 2.5 GeV National Synchrotron Light Source x-ray ring

International Nuclear Information System (INIS)

Krinsky, S.; Blumberg, L.; Bittner, J.; Galayda, J.; Heese, R.; Schuchman, J.C.; van Steenbergen, A.

1979-01-01

The present state of the design of the 2.5 GeV electron storage ring for the National Synchrotron Light Source is described. This ring will serve as a dedicated source of synchrotron radiation in the wavelength range 0.1 A to 30 A. While maintaining the basic high brigtness features of the eariler developed lattice structure, recent work resulted in a more economical magnet system, is simplified chromaticity corrections, and improved distribution of the X-ray beam lines. In addition, the adequacy of the dynamic aperture for stable betatron oscillations has been verified for a variety of betatron tunes

BEAM-LOSS DRIVEN DESIGN OPTIMIZATION FOR THE SPALLATION NEUTRON SOURCE (SNS) RING.

Energy Technology Data Exchange (ETDEWEB)

WEI,J.; BEEBE-WANG,J.; BLASKIEWICZ,M.; CAMERON,P.; DANBY,G.; GARDNER,C.J.; JACKSON,J.; LEE,Y.Y.; LUDEWIG,H.; MALITSKY,N.; RAPARIA,D.; TSOUPAS,N.; WENG,W.T.; ZHANG,S.Y.

1999-03-29

This paper summarizes three-stage design optimization for the Spallation Neutron Source (SNS) ring: linear machine design (lattice, aperture, injection, magnet field errors and misalignment), beam core manipulation (painting, space charge, instabilities, RF requirements), and beam halo consideration (collimation, envelope variation, e-p issues etc.).

Beam-Loss Driven Design Optimization for the Spallation Neutron Source (SNS) Ring

International Nuclear Information System (INIS)

Wei, J.

1999-01-01

This paper summarizes three-state design optimization for the Spallation Neutron Source (SNS) ring: linear machine design (lattice, aperture, injection, magnet field errors and misalignment), beam core manipulation (painting, space charge, instabilities, RF requirements), and beam halo consideration (collimation, envelope variation, e-p issues etc.)

Electron cloud development in the Proton Storage Ring and in the Spallation Neutron Source

International Nuclear Information System (INIS)

Pivi, M.T.F.; Furman, M.A.

2002-01-01

We have applied our simulation code ''POSINST'' to evaluate the contribution to the growth rate of the electron-cloud instability in proton storage rings. Recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR) at Los Alamos are presented in this paper. A key ingredient in our model is a detailed description of the secondary emitted-electron energy spectrum. A refined model for the secondary emission process including the so-called true secondary, rediffused and backscattered electrons has recently been included in the electron-cloud code

Plans to increase source brightness of NSLS x-ray ring

International Nuclear Information System (INIS)

Safranek, J.; Krinsky, S.

1993-01-01

We discuss plans to increase the NSLS X-Ray ring source brightness by an order of magnitude. Proposed improvements include doubling current from 250 mA to 500 mA, reducing vertical emittance by a factor of 6 and reducing insertion device gaps and periods by up to a factor of two. Experimental results are reported which indicate we have succeeded in reducing the vertical emittance below 2 Angstrom

Noise Source Identification of a Ring-Plate Cycloid Reducer Based on Coherence Analysis

Directory of Open Access Journals (Sweden)

Bing Yang

2013-01-01

Full Text Available A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and control of the ring-plate-type cycloid reducer.

Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation

Science.gov (United States)

Kobayashi, Takanori; Nagasaka, Seiji; Senoura, Takeshi; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Nishizawa, Naoko K.

2013-01-01

Iron is essential for most living organisms. Plants transcriptionally induce genes involved in iron acquisition under conditions of low iron availability, but the nature of the deficiency signal and its sensors are unknown. Here we report the identification of new iron regulators in rice, designated Oryza sativa Haemerythrin motif-containing Really Interesting New Gene (RING)- and Zinc-finger protein 1 (OsHRZ1) and OsHRZ2. OsHRZ1, OsHRZ2 and their Arabidopsis homologue BRUTUS bind iron and zinc, and possess ubiquitination activity. OsHRZ1 and OsHRZ2 are susceptible to degradation in roots irrespective of iron conditions. OsHRZ-knockdown plants exhibit substantial tolerance to iron deficiency, and accumulate more iron in their shoots and grains irrespective of soil iron conditions. The expression of iron deficiency-inducible genes involved in iron utilization is enhanced in OsHRZ-knockdown plants, mostly under iron-sufficient conditions. These results suggest that OsHRZ1 and OsHRZ2 are iron-binding sensors that negatively regulate iron acquisition under conditions of iron sufficiency. PMID:24253678

Radiation studies in the antiproton source

International Nuclear Information System (INIS)

Church, M.

1990-01-01

Experiment E760 has a lead glass (Pb-G) calorimeter situated in the antiproton source tunnel in the accumulator ring at location A50. This location is exposed to radiation from several sources during antiproton stacking operations. A series of radiation studies has been performed over the last two years to determine the sources of this radiation and as a result, some shielding has been installed in the antiproton source in order to protect the lead glass from radiation damage

CONSTRUCTION AND POWER TEST OF THE EXTRACTION KICKER MAGNET FOR SNS ACCUMULATOR RING

International Nuclear Information System (INIS)

PAI, C.; HAHN, H.; HSEUH, H.; LEE, Y.; MENG, W.; MI, J.; SANDBERG, J.; TODD, R.

2005-01-01

Two extraction kicker magnet assemblies that contain seven individual pulsed magnet modules each will kick the proton beam vertically out of the SNS accumulator ring into the aperture of the extraction Lambertson septum magnet. The proton beam then travels to the 1.4 MW SNS target assembly. The 14 kicker magnets and major components of the kicker assembly have been fabricated in BNL. The inner surfaces of the kicker magnets were coated with TiN to reduce the secondary electron yield. All 14 PFN power supplies have been built, tested and delivered to OWL. Before final installation, a partial assembly of the kicker system with three kicker magnets was assembled to test the functions of each critical component in the system. In this paper we report the progress of the construction of the kicker components, the TIN coating of the magnets, the installation procedure of the magnets and the full power test of the kicker with the PFN power supply

Kharkov 3-GeV pulse stretcher ring as a source of synchrotron radiation

International Nuclear Information System (INIS)

Boldyshev, V.F.; Gladkikh, P.I.; Grigor'ev, Y.N.; Guk, I.S.; Efimov, S.V.; Karnaukhov, I.M.; Kononenko, S.G.; Mocheshnikov, N.I.; Popkov, Y.P.; Tarasenko, A.S.; Telegin, Y.N.; Chechetenko, V.F.; Shcherbakov, A.A.; Titov, V.A.; Nagaenko, M.G.

1989-01-01

The article discusses the possibility of using the pulse stretcher ring, designed at the Kharkov Institute of Physics and Technology, as a synchrotron radiation source (SRS). Comparison is made between our SRS design parameters and those of other dedicated SRSs

Rotating dust ring in an RF discharge coupled with a dc-magnetron sputter source. Experiment and simulation

International Nuclear Information System (INIS)

Matyash, K; Froehlich, M; Kersten, H; Thieme, G; Schneider, R; Hannemann, M; Hippler, R

2004-01-01

During an experiment involving coating of dust grains trapped in an RF discharge using a sputtering dc-magnetron source, a rotating dust ring was observed and investigated. After the magnetron was switched on, the dust cloud levitating above the RF electrode formed a ring rotating as a rigid body. Langmuir probe diagnostics were used for the measurement of plasma density and potential. It was discovered that the coupling of the dc-magnetron source to the RF discharge causes steep radial gradients in electron density and plasma potential. The rotation of the dust ring is attributed to the azimuthal component of the ion drag force, which appears due to the azimuthal drift of the ions caused by crossed radial electric and axial magnetic fields. In order to get more insight into the mechanism of dust ring rotation, a Particle-in-Cell simulation of a rotating dust cloud was performed. The results of the experiment and simulation are presented and discussed

Rotating dust ring in an RF discharge coupled with a dc-magnetron sputter source. Experiment and simulation

Energy Technology Data Exchange (ETDEWEB)

Matyash, K [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Froehlich, M [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany); Kersten, H [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Thieme, G [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany); Schneider, R [Max-Planck-Institut fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, 17489 Greifswald (Germany); Hannemann, M [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Hippler, R [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany)

2004-10-07

During an experiment involving coating of dust grains trapped in an RF discharge using a sputtering dc-magnetron source, a rotating dust ring was observed and investigated. After the magnetron was switched on, the dust cloud levitating above the RF electrode formed a ring rotating as a rigid body. Langmuir probe diagnostics were used for the measurement of plasma density and potential. It was discovered that the coupling of the dc-magnetron source to the RF discharge causes steep radial gradients in electron density and plasma potential. The rotation of the dust ring is attributed to the azimuthal component of the ion drag force, which appears due to the azimuthal drift of the ions caused by crossed radial electric and axial magnetic fields. In order to get more insight into the mechanism of dust ring rotation, a Particle-in-Cell simulation of a rotating dust cloud was performed. The results of the experiment and simulation are presented and discussed.

Vacuum system for the test accumulation ring for the NUMATRON project (TARN)

International Nuclear Information System (INIS)

Mizobuchi, Akira

1979-01-01

The vacuum system for the test accumulation ring for the NUMATRON project (TARN) being constructed in the Institute for Nuclear Study, University of Tokyo, for the purpose of accumulating fundamental data on high energy, heavy ion acceleration is presented. The main specifications of TARN are as follows: repetition rate 1 Hz, average radius 5.06 m, the radius of curvature 1.333 m, circumference 31.795 m, the length of a unit cell 3.974 m, the length of a long straight section 1.8 m, the number of unit cells 8, superperiodicity 8, and the structure of a unit cell FODO. The vacuum level of TARN lower than 1 x 10 -10 Torr is necessary. The preliminary test apparatuses, number one and two, for obtaining the basic data on superhigh vacuum were constructed. The characteristics of a molecular vacuum pump and the high temperature baking effect were tested with the number one test apparatus. The glow discharge cleaning effect of the model vacuum chamber for deflecting magnets was tested, utilizing the number two test apparatus. The pressure curve in course of time during pump down, the residual gas components, the residual gas spectrum in vacuum state and the change of residual gas components before and after the glow discharge cleaning are shown as these testing results. The vacuum gauges, which are used for TARN for measuring both the total pressure and the partial pressure of gas, are explained. The vacuum system, the vacuum chamber, the vacuum pumps, the expected exhausting speed and the partial functional test results for the vacuum system are introduced. (Nakai, Y.)

Proton injection and RF capture in the national spallation neutron source

International Nuclear Information System (INIS)

Luccio, A.U.; Beebe-Wang, J.; Maletic, D.

1997-01-01

The accelerator system for the 1 to 5 MW National Spallation Neutron Source (NSNS) consists of a linac followed by a 1 GeV proton accumulator ring. Since the ring is a very high current machine, the injection and rf capture of the protons is deeply affected by transverse and longitudinal space charge effects. Results of numerical simulation of the process are presented together with considerations on methods and results of space charge treatment in high intensity proton storage rings

Adiabatic energization in the ring current and its relation to other source and loss terms

Science.gov (United States)

Liemohn, M. W.; Kozyra, J. U.; Clauer, C. R.; Khazanov, G. V.; Thomsen, M. F.

2002-04-01

The influence of adiabatic energization and deenergization effects, caused by particle drift in radial distance, on ring current growth rates and loss lifetimes is investigated. Growth and loss rates from simulation results of four storms (5 June 1991, 15 May 1997, 19 October 1998, and 25 September 1998) are examined and compared against the y component of the solar wind electric field (Ey,sw). Energy change rates with and without the inclusion of adiabatic energy changes are considered to isolate the influence of this mechanism in governing changes of ring current strength. It is found that the influence of adiabatic drift effects on the energy change rates is very large when energization and deenergization are considered separately as gain and loss mechanisms, often about an order of magnitude larger than all other source or loss terms combined. This is true not only during storm times, when the open drift path configuration of the hot ions dominates the physics of the ring current, but also during quiet times, when the small oscillation in L of the closed trajectories creates a large source and loss of energy each drift orbit. However, the net energy change from adiabatic drift is often smaller than other source and loss processes, especially during quiet times. Energization from adiabatic drift dominates ring current growth only during portions of the main phase of storms. Furthermore, the net-adiabatic energization is often positive, because some particles are lost in the inner magnetosphere before they can adiabatically deenergize. It is shown that the inclusion of only this net-adiabatic drift effect in the total source rate or loss lifetime (depending on the sign of the net-adiabatic energization) best matches the observed source and loss values from empirical Dst predictor methods (that is, for consistency, these values should be compared between the calculation methods). While adiabatic deenergization dominates the loss timescales for all Ey,sw values

Charged-particle beam diagnostics for the Advanced Photon Source (APS)

International Nuclear Information System (INIS)

Lumpkin, A.H.; Decker, G.; Kahana, E.; Patterson, D.; Sellyey, W.; Wang, X.; Chung, Y.

1992-01-01

Plans, prototypes, and initial test results for the charged-particle beam (e - , e + ) diagnostic systems on the injector rings, their transport lines, and the storage ring for the Advanced Photon Source (APS) are presented. The APS will be a synchrotron radiation user facility with one of the world's brightest x-ray sources in the 10-keV to 100-keV regime. Its 200-MeV electron linac, 450-MeV positron linac, positron accumulator ring, 7-GeV booster synchrotron, 7-GeV storage ring, and undulator test lines will also demand the development and demonstration of key particle-beam characterization techniques over a wide range of parameter space. Some of these parameter values overlap or approach those projected for fourth generation light sources (linac-driven FELs and high brightness storage rings) as described at a recent workshop. Initial results from the diagnostics prototypes on the linac test stand operating at 45-MeV include current monitor data, beam loss monitor data, and video digitization using VME architecture

A divide-down RF source generation system for the Advanced Photon Source

International Nuclear Information System (INIS)

Horan, D.; Lenkszus, F.; Laird, R.

1997-01-01

A divide-down rf source system has been designed and built at Argonne National Laboratory to provide harmonically-related and phase-locked rf source signals between the APS 352-MHz storage ring and booster synchrotron rf systems and the 9.77-MHz and 117-MHz positron accumulator ring rf systems. The design provides rapid switching capability back to individual rf synthesizers for each one. The system also contains a digital bucket phase shifter for injection bucket selection. Input 352-MHz rf from a master synthesizer is supplied to a VXI-based ECL divider board which produces 117-MHz and 9.77-MHz square-wave outputs. These outputs are passed through low-pass filters to produce pure signals at the required fundamental frequencies. These signals, plus signals at the same frequencies from independent synthesizers, are fed to an interface chassis where source selection is made via local/remote control of coaxial relays. This chassis also produces buffered outputs at each frequency for monitoring and synchronization of ancillary equipment

Design and simulation of fast pulsed kicker/bumper units for the positron accumulator ring at APS

International Nuclear Information System (INIS)

Wang, Ju; Volk, G.J.

1991-01-01

In the design of fast pulsed kicker/burner units for a positron accumulator ring (PAR) at APS, different pulse forming networks (PFN) are considered and different structures for the magnet are studied and simulated. Three fast pulsed kicker/bumper magnets are required in PAR for the beam injection and/or extraction at 450 MeV. These magnets have the same design because they have identical specifications and are expected to produce identical magnetic fields. Each kicker/bumper magnet is required to generate a magnetic field of 0.06 T with rise-time of 80 ns, a flat-top of 80 ns and a fall-time of 80 ns. This paper describes some design considerations and computer simulation results of different designs

RF Beam Position Monitor for the SNS Ring

International Nuclear Information System (INIS)

Vetter, Kurt; Cameron, Peter; Dawson, Craig; Degen, Chris; Kesselman, Martin; Mead, Joseph

2004-01-01

The Spallation Neutron Source Ring accumulates 1060 pulses of 38-mA peak current 1-GeV H-minus particles from the Linac through the HEBT line, then delivers this accumulated beam in a single pulse to a mercury target via the RTBT line. The dynamic range over the course of the accumulation cycle is 60 dB. As a result of particle energy distribution the 402.5-MHz RF bunching frequency quickly de-coheres during the first few turns. In order to measure first-turn position a dual-mode BPM has been designed to process 402.5-MHz signal energy during the first few turns then switch to a Baseband mode to process de-cohered energy in the low MHz region. The design has been implemented as a dual mother/daughter board PCI architecture. Both Baseband and RF calibration are included on the RF BPM board. A prototype system has been installed in the SNS Linac

H- charge exchange injection for the NSNS accumulator

International Nuclear Information System (INIS)

Blumberg, L.N.; Lee, Y.Y.

1997-01-01

A scheme for injection into the FODO cell of the National Spallation Neutron Source (NSNS) Accumulator ring is discussed. A 400 μg/cm 2 carbon foil is chosen for a high stripping efficiency and for heating of the foil consideration. Additional schemes to reduce losses due to nuclear and Coulomb scattering at the foil are discussed. Subsequent loss from magnetic field ionization of the residual H 0 component is estimated to be small comparable to nuclear loss. A method for sweeping and collecting the stripped electrons from the foil is presented

Energization of the Ring Current through Convection of Substorm Enhancements of the Plasma Sheet Source.

Science.gov (United States)

Menz, A.; Kistler, L. M.; Mouikis, C.; Spence, H. E.; Henderson, M. G.; Matsui, H.

2017-12-01

It has been shown that electric field strength and night-side plasma sheet density are the two best predictors of the adiabatic energy gain of the ring current during geomagnetic storms (Liemohn and Khazanov, 2005). While H+ dominates the ring current during quiet times, O+ can contribute substantially during geomagnetic storms. Substorm activity provides a mechanism to enhance the energy density of O+ in the plasma sheet during geomagnetic storms, which is then convected adiabatically into the inner-magnetosphere. Using the Van Allen Probes data in the the plasma sheet source region (defined as L>5.5 during storms) and the inner magnetosphere, along with LANL-GEO data to identify substorm injection times, we show that adiabatic convection of O+ enhancements in the source region can explain the observed enhancements in the inner magnetosphere. We use the UNH-IMEF electric field model to calculate drift times from the source region to the inner magnetosphere to test whether enhancements in the inner-magnetosphere can be explained by dipolarization driven enhancements in the plasma sheet source hours before.

Ion production and trapping in electron rings

International Nuclear Information System (INIS)

Gluckstern, R.C.; Ruggiero, A.G.

1979-08-01

The electron beam in the VUV and X-ray rings of NSLS will ionize residual gas by collisions. Positive ions will be produced with low velocity, and will be attracted by the electron beam to the beam axis. If they are trapped in stable (transverse) orbits, they may accumulate, thereby increasing the ν/sub x,z/ of the individual electrons. Since the accumulated ions are unlikely to be of uniform density, a spread in ν/sub x,z/ will also occur. Should these effects be serious, it may be necessary to introduce clearing electrodes, although this may increase Z/n in the rings, thereby adding to longitudinal instability problems. The seriousness of the above effect for the VUV and X-ray rings is estimated

Containing Ebola at the Source with Ring Vaccination.

Directory of Open Access Journals (Sweden)

Stefano Merler

2016-11-01

Full Text Available Interim results from the Guinea Ebola ring vaccination trial suggest high efficacy of the rVSV-ZEBOV vaccine. These findings open the door to the use of ring vaccination strategies in which the contacts and contacts of contacts of each index case are promptly vaccinated to contain future Ebola virus disease outbreaks. To provide a numerical estimate of the effectiveness of ring vaccination strategies we introduce a spatially explicit agent-based model to simulate Ebola outbreaks in the Pujehun district, Sierra Leone, structurally similar to previous modelling approaches. We find that ring vaccination can successfully contain an outbreak for values of the effective reproduction number up to 1.6. Through an extensive sensitivity analysis of parameters characterising the readiness and capacity of the health care system, we identify interventions that, alongside ring vaccination, could increase the likelihood of containment. In particular, shortening the time from symptoms onset to hospitalisation to 2-3 days on average through improved contact tracing procedures, adding a 2km spatial component to the vaccination ring, and decreasing human mobility by quarantining affected areas might contribute increase our ability to contain outbreaks with effective reproduction number up to 2.6. These results have implications for future control of Ebola and other emerging infectious disease threats.

Storage ring development at the National Synchrotron Light Source

International Nuclear Information System (INIS)

Krinsky, S.; Bittner, J.; Fauchet, A.M.; Johnson, E.D.; Keane, J.; Murphy, J.; Nawrocky, R.J.; Rogers, J.; Singh, O.V.; Yu, L.H.

1991-09-01

This report contains papers on the following topics: Transverse Beam Profile Monitor; Bunch Length Measurements in the VUV Storage Ring; Photoelectric Effect Photon Beam Position Monitors; RF Receivers for Processing Electron Beam Pick-up Electrode Signals; Real-Time Global Orbit Feedback Systems; Local Orbit Feedback; Active Interlock System for High Power Insertion Devices in the X-ray Ring; Bunch Lengthening Cavity for the VUV Ring; SXLS Storage Ring Design

The Circular RFQ Storage Ring

International Nuclear Information System (INIS)

Ruggiero, A. G.

1999-01-01

This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features of conventional storage rings and ion traps, and is basically a linear RFQ bent on itself. The advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

Digital closed orbit feedback system for the advanced photon source storage ring

International Nuclear Information System (INIS)

Chung, Y.; Barr, D.; Decker, G.

1995-01-01

The Advanced Photon Source (APS) is a dedicated third-generation synchrotron light source with a nominal energy of 7 GeV and a circumference of 1104 m. The closed orbit feedback system for the APS storage ring employs unified global and local feedback systems for stabilization of particle and photon beams based on digital signal processing (DSP). Hardware and software aspects of the system will be described in this paper. In particular, we will discuss global and local orbit feedback algorithms, PID (proportional, integral, and derivative) control algorithm, application of digital signal processing to compensate for vacuum chamber eddy current effects, resolution of the interaction between global and local systems through decoupling, self-correction of the local bump closure error, user interface through the APS control system, and system performance in the frequency and time domains. The system hardware including the DSPs is distributed in 20 VME crates around the ring, and the entire feedback system runs synchronously at 4-kHz sampling frequency in order to achieve a correction bandwidth exceeding 100 Hz. The required data sharing between the global and local feedback systems is facilitated via the use of fiber-optically-networked reflective memories

Establishment of a tolerance budget for the advanced photon source storage ring

International Nuclear Information System (INIS)

Bizek, H.; Crosbie, E.; Lessner, E.; Teng, L.

1993-01-01

The limitations on the dynamic aperture of the Advanced Photon Source storage ring due to magnet misalignments and fabrication errors are presented. The reduction of the dynamic aperture is analyzed first for each error considered individually, and then for combined error multipole fields in dipole, quadrupole, and sextupole magnets, excluding and including magnet misalignments. Since misalignments of the strong quadrupoles in the ring induce large orbit distortions, the effects on the dynamic aperture are investigated before and after orbit correction. Effects of off-momentum particles and the tune dependence with momentum are also presented. This extensive analysis leads to the establishment of a tolerance budget. With all the errors set at the tolerance level, and with the orbit distortions corrected, the dynamic aperture reduction is no greater than 50% of that of the ideal machine

Establishment of a tolerance budget for the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Bizek, H.; Crosbie, E.; Lessner, E.; Teng, L.

1993-01-01

The limitations on the dynamic aperture of the Advanced Photon Source storage ring due to magnet misalignments and fabrication errors are presented. The reduction of the dynamic aperture is analyzed first for each error considered individually, and then for combined error multipole fields in dipole, quadrupole, and sextupole magnets, excluding and including magnet misalignments. Since misalignments of the strong quadrupoles in the ring induce large orbit distortions, the effects on the dynamic aperture are investigated before and after orbit correction. Effects of off-momentum particles and the tune dependence with momentum are also presented. This extensive analysis leads to the establishment of a tolerance budget. With all the errors set at the tolerance level and with the orbit distortions corrected, the dynamic aperture reduction is no greater than 50% of that of the ideal machine

Seasonal transfer of oxygen isotopes from precipitation and soil to the tree ring: source water versus needle water enrichment.

Science.gov (United States)

Treydte, Kerstin; Boda, Sonja; Graf Pannatier, Elisabeth; Fonti, Patrick; Frank, David; Ullrich, Bastian; Saurer, Matthias; Siegwolf, Rolf; Battipaglia, Giovanna; Werner, Willy; Gessler, Arthur

2014-05-01

For accurate interpretation of oxygen isotopes in tree rings (δ(18) O), it is necessary to disentangle the mechanisms underlying the variations in the tree's internal water cycle and to understand the transfer of source versus leaf water δ(18) O to phloem sugars and stem wood. We studied the seasonal transfer of oxygen isotopes from precipitation and soil water through the xylem, needles and phloem to the tree rings of Larix decidua at two alpine sites in the Lötschental (Switzerland). Weekly resolved δ(18) O records of precipitation, soil water, xylem and needle water, phloem organic matter and tree rings were developed. Week-to-week variations in needle-water (18) O enrichment were strongly controlled by weather conditions during the growing season. These short-term variations were, however, not significantly fingerprinted in tree-ring δ(18) O. Instead, seasonal trends in tree-ring δ(18) O predominantly mirrored trends in the source water, including recent precipitation and soil water pools. Modelling results support these findings: seasonal tree-ring δ(18) O variations are captured best when the week-to-week variations of the leaf water signal are suppressed. Our results suggest that climate signals in tree-ring δ(18) O variations should be strongest at temperate sites with humid conditions and precipitation maxima during the growing season. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

The circular RFQ storage ring

International Nuclear Information System (INIS)

Ruggiero, A.G.

1998-01-01

This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features used in a conventional storage ring and an ion trap, and is basically a linear RFQ bend on itself. In summary the advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

Design of a 4.8-m ring for inverse Compton scattering x-ray source

Directory of Open Access Journals (Sweden)

H. S. Xu

2014-07-01

Full Text Available In this paper we present the design of a 50 MeV compact electron storage ring with 4.8-meter circumference for the Tsinghua Thomson scattering x-ray source. The ring consists of four dipole magnets with properly adjusted bending radii and edge angles for both horizontal and vertical focusing, and a pair of quadrupole magnets used to adjust the horizontal damping partition number. We find that the dynamic aperture of compact storage rings depends essentially on the intrinsic nonlinearity of the dipole magnets with small bending radius. Hamiltonian dynamics is found to agree well with results from numerical particle tracking. We develop a self-consistent method to estimate the equilibrium beam parameters in the presence of the intrabeam scattering, synchrotron radiation damping, quantum excitation, and residual gas scattering. We also optimize the rf parameters for achieving a maximum x-ray flux.

The Advanced Photon Source list of parameters

International Nuclear Information System (INIS)

Bizek, H.M.

1996-07-01

The Advanced Photon Source (APS) is a third-generation synchrotron radiation source that stores positrons in a storage ring. The choice of positrons as accelerating particles was motivated by the usual reason: to eliminate the degradation of the beam caused by trapping of positively charged dust particles or ions. The third-generation synchrotron radiation sources are designed to have low beam emittance and many straight sections for insertion devices. The parameter list is comprised of three basic systems: the injection system, the storage ring system, and the experimental facilities system. The components of the injection system are listed according to the causal flow of positrons. Below we briefly list the individual components of the injection system, with the names of people responsible for managing these machines in parentheses: the linac system; electron linac-target-positron linac (Marion White); low energy transport line from linac to the PAR (Michael Borland); positron accumulator ring or PAR (Michael Borland); low energy transport line from PAR to injector synchrotron (Michael Borland); injector synchrotron (Stephen Milton); high energy transport line from injector synchrotron to storage ring (Stephen Milton). The storage ring system, managed by Glenn Decker, uses the Chasman-Green lattice. The APS storage ring, 1104 m in circumference, has 40 periodic sectors. Six are used to house hardware and 34 serve as insertion devices. Another 34 beamlines emit radiation from bending magnets. The experimental facilities system's parameters include parameters for both an undulator and a wiggler

Broadband pulsed difference frequency generation laser source centered 3326 nm based on ring fiber lasers

Science.gov (United States)

Chen, Guangwei; Li, Wenlei

2018-03-01

A broadband pulsed mid-infrared difference frequency generation (DFG) laser source based on MgO-doped congruent LiNbO3 bulk is experimentally demonstrated, which employs a homemade pulsed ytterbium-doped ring fiber laser and a continuous wave erbium-doped ring fiber laser to act as seed sources. The experimental results indicate that the perfect phase match crystal temperature is about 74.5∘C. The maximum spectrum bandwidth of idler is about 60 nm with suitable polarization states of fundamental lights. The central wavelength of idlers varies from 3293 nm to 3333 nm over the crystal temperature ranges of 70.4-76∘C. A jump of central wavelength exists around crystal temperature of 72∘C with variation of about 30 nm. The conversion efficiency of DFG can be tuned with the crystal temperature and polarization states of fundamental lights.

A multicenter study to quantify systematic variations and associated uncertainties in source positioning with commonly used HDR afterloaders and ring applicators for the treatment of cervical carcinomas

Energy Technology Data Exchange (ETDEWEB)

Awunor, O., E-mail: onuora.awunor@stees.nhs.uk [The Medical Physics Department, The James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, England (United Kingdom); Berger, D. [Department of Radiotherapy, General Hospital of Vienna, Vienna A-1090 (Austria); Kirisits, C. [Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Vienna A-1090 (Austria)

2015-08-15

Purpose: The reconstruction of radiation source position in the treatment planning system is a key part of the applicator reconstruction process in high dose rate (HDR) brachytherapy treatment of cervical carcinomas. The steep dose gradients, of as much as 12%/mm, associated with typical cervix treatments emphasize the importance of accurate and precise determination of source positions. However, a variety of methodologies with a range in associated measurement uncertainties, of up to ±2.5 mm, are currently employed by various centers to do this. In addition, a recent pilot study by Awunor et al. [“Direct reconstruction and associated uncertainties of {sup 192}Ir source dwell positions in ring applicators using gafchromic film in the treatment planning of HDR brachytherapy cervix patients,” Phys. Med. Biol. 58, 3207–3225 (2013)] reported source positional differences of up to 2.6 mm between ring sets of the same type and geometry. This suggests a need for a comprehensive study to assess and quantify systematic source position variations between commonly used ring applicators and HDR afterloaders across multiple centers. Methods: Eighty-six rings from 20 European brachytherapy centers were audited in the form of a postal audit with each center collecting the data independently. The data were collected by setting up the rings using a bespoke jig and irradiating gafchromic films at predetermined dwell positions using four afterloader types, MicroSelectron, Flexitron, GammaMed, and MultiSource, from three manufacturers, Nucletron, Varian, and Eckert & Ziegler BEBIG. Five different ring types in six sizes (Ø25–Ø35 mm) and two angles (45° and 60°) were used. Coordinates of irradiated positions relative to the ring center were determined and collated, and source position differences quantified by ring type, size, and angle. Results: The mean expanded measurement uncertainty (k = 2) along the direction of source travel was ±1.4 mm. The standard deviation

Preparation for electron ring - plasma ring merging experiments in RECE-MERGE

International Nuclear Information System (INIS)

Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.

1986-01-01

The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged

Dispersion and betatron function correction in the Advanced Photon Source storage ring using singular value decomposition

International Nuclear Information System (INIS)

Emery, L.

1999-01-01

Magnet errors and off-center orbits through sextuples perturb the dispersion and beta functions in a storage ring (SR), which affects machine performance. In a large ring such as the Advanced Photon Source (APS), the magnet errors are difficult to determine with beam-based methods. Also the non-zero orbit through sextuples result from user requests for steering at light source points. For expediency, a singular value decomposition (SVD) matrix method analogous to orbit correction was adopted to make global corrections to these functions using strengths of several quadrupoles as correcting elements. The direct response matrix is calculated from the model of the perfect lattice. The inverse is calculated by SVD with a selected number of singular vectors. Resulting improvement in the lattice functions and machine performance will be presented

BIOBUTANOL ACCUMULATION USING ALTERNATIVE SUBSTRATES BY CULTIVATION OF Clostridium acetobutylicum STRAINS

Directory of Open Access Journals (Sweden)

О. О. Тigunova

2017-10-01

Full Text Available The aim of the research was to investigate the accumulation of biobutanol by strains Clostridium acetobutylicum using alternative substrates (Jerusalem artichoke juice, technical glycerol, crude glycerol, shredded biomass of soy, rape, wheat and switchgrass. In order to increase the accumulation of butanol in the process of cultivation, the cells of C. acetobutylicum were statically immobilized on carriers (belting strips, ferrite rings and Raschig rings by the method of adsorption immobilization. The cells were precipitated by centrifugation, the supernatant was distilled and then fermentation products were determined. Gas chromatography was used to determine the presence of solvents in the culture fluid. The biggest accumulation of butanol (2 g/dm3 was at concentration of crude glycerol 16 g/dm3 in the medium, and complete inhibition of culture development — at glycerol concentration 25 g/dm3. The accumulation of butanol by the strain C. acetobutylicum ІМВ В-7407 using fill and draw method depended on the amount of sequestered and infused medium. Immobilization of the culture using the Raschig rings allowed increasing the bioconversion to butanol twice. So it is shown the possibility to use non-traditional substrates for the production of biobutanol. The most accumulation of butanol was achieved using glycerol (11 g/dm3 as water-soluble substrate, and using switchgrass as lignocelluloses substrate (2,6 g/dm3. Immobilization of C. acetobutylicum culture cells on carriers increased the accumulation of butanol. The use of Raschig rings, as carriers for immobilization, allowed increasing the accumulation of butanol twice.

Comparing Sources of Storm-Time Ring Current O+

Science.gov (United States)

Kistler, L. M.

2015-12-01

The first observations of the storm-time ring current composition using AMPTE/CCE data showed that the O+ contribution to the ring current increases significantly during storms. The ring current is predominantly formed from inward transport of the near-earth plasma sheet. Thus the increase of O+ in the ring current implies that the ionospheric contribution to the plasma sheet has increased. The ionospheric plasma that reaches the plasma sheet can come from both the cusp and the nightside aurora. The cusp outflow moves through the lobe and enters the plasma sheet through reconnection at the near-earth neutral line. The nightside auroral outflow has direct access to nightside plasma sheet. Using data from Cluster and the Van Allen Probes spacecraft, we compare the development of storms in cases where there is a clear input of nightside auroral outflow, and in cases where there is a significant cusp input. We find that the cusp input, which enters the tail at ~15-20 Re becomes isotropized when it crosses the neutral sheet, and becomes part of the hot (>1 keV) plasma sheet population as it convects inward. The auroral outflow, which enters the plasma sheet closer to the earth, where the radius of curvature of the field line is larger, does not isotropize or become significantly energized, but remains a predominantly field aligned low energy population in the inner magnetosphere. It is the hot plasma sheet population that gets accelerated to high enough energies in the inner magnetosphere to contribute strongly to the ring current pressure. Thus it appears that O+ that enters the plasma sheet further down the tail has a greater impact on the storm-time ring current than ions that enter closer to the earth.

Design and project status of the National Synchrotron Light Source; storage rings (2.5 GeV, 0.7 GeV) for the generation of bright synchrotron radiation sources

International Nuclear Information System (INIS)

van Steenbergen, A.

1980-01-01

Two high intensity storage rings are being constructed at Brookhaven National Laboratory for the generation of intense fluxes of synchrotron radiation in the vuv wavelength region (700 MeV ring, lambda/sub c/ = 31.5 A) and in the x-ray wavelength region (2.5 GeV ring, lambda/sub c/ = 2.5 A). A description is given of the facility, the main features of the storage rings are presented and the basic parameters are enumerated. High field superconducting wigglers, to lower the short wavelength cutoff in the x-ray ring, and undulators, for flux enhancement or a free electron laser experiment will be incorporated and parameters are given here. Special design aspects to optimize the electron storage rings as dedicated synchrotron radiation sources will be emphasized and the status of the project will be given

Direct reconstruction and associated uncertainties of 192Ir source dwell positions in ring applicators using gafchromic film in the treatment planning of HDR brachytherapy cervix patients

Science.gov (United States)

Awunor, O. A.; Dixon, B.; Walker, C.

2013-05-01

This paper details a practical method for the direct reconstruction of high dose rate 192Ir source dwell positions in ring applicators using gafchromic film in the treatment planning of brachytherapy cervix patients. It also details the uncertainties associated with such a process. Eight Nucletron interstitial ring applicators—Ø26 mm (×4), Ø30 mm (×3) and Ø34 mm (×1), and one 60 mm intrauterine tube were used in this study. RTQA2 and XRQA2 gafchromic films were irradiated at pre-programmed dwell positions with three successive 192Ir sources and used to derive the coordinates of the source dwell positions. The source was observed to deviate significantly from its expected position by up to 6.1 mm in all ring sizes. Significant inter applicator differences of up to 2.6 mm were observed between a subset of ring applicators. Also, the measured data were observed to differ significantly from commercially available source path models provided by Nucletron with differences of up to 3.7 mm across all ring applicator sizes. The total expanded uncertainty (k = 2) averaged over all measured dwell positions in the rings was observed to be 1.1 ± 0.1 mm (Ø26 mm and Ø30 mm rings) and 1.0 ± 0.3 mm (Ø34 mm ring) respectively, and when transferred to the treatment planning system, equated to maximum %dose changes of 1.9%, 13.2% and 1.5% at regions representative of the parametrium, lateral fornix and organs at risk respectively.

Digital closed orbit feedback system for the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Chung, Y.; Barr, D.; Decker, G.; Galayda, J.; Lenkszus, F.; Lumpkin, A.; Votaw, A.J.

1995-01-01

Closed orbit feedback for the Advanced Photon Source (APS) storage ring employs unified global an local feedback systems for stabilization of particle and photon beams based on digital signal processing (DSP). Hardware and software aspects of the system will be described. In particular, we will discuss global and local orbit feedback algorithms, PID (proportional, integral, and derivative) control algorithm. application of digital signal processing to compensate for vacuum chamber eddy current effects, resolution of the interaction between global and local systems through decoupling, self-correction of the local bump closure error, user interface through the APS control system, and system performance in the frequency and time domains. The system hardware, including the DSPS, is distributed in 20 VNE crates around the ring, and the entire feedback system runs synchronously at 4-kHz sampling frequency in order to achieve a correction bandwidth exceeding 100 Hz. The required data sharing between the global and local feedback systems is facilitated via the use of fiber-optically-networked reflective memories

Functional roles of the pepper RING finger protein gene, CaRING1, in abscisic acid signaling and dehydration tolerance.

Science.gov (United States)

Lim, Chae Woo; Hwang, Byung Kook; Lee, Sung Chul

2015-09-01

Plants are constantly exposed to a variety of biotic and abiotic stresses, which include pathogens and conditions of high salinity, low temperature, and drought. Abscisic acid (ABA) is a major plant hormone involved in signal transduction pathways that mediate the defense response of plants to abiotic stress. Previously, we isolated Ring finger protein gene (CaRING1) from pepper (Capsicum annuum), which is associated with resistance to bacterial pathogens, accompanied by hypersensitive cell death. Here, we report a new function of the CaRING1 gene product in the ABA-mediated defense responses of plants to dehydration stress. The expression of the CaRING1 gene was induced in pepper leaves treated with ABA or exposed to dehydration or NaCl. Virus-induced gene silencing of CaRING1 in pepper plants exhibited low degree of ABA-induced stomatal closure and high levels of transpirational water loss in dehydrated leaves. These led to be more vulnerable to dehydration stress in CaRING1-silenced pepper than in the control pepper, accompanied by reduction of ABA-regulated gene expression and low accumulation of ABA and H2O2. In contrast, CaRING1-overexpressing transgenic plants showed enhanced sensitivity to ABA during the seedling growth and establishment. These plants were also more tolerant to dehydration stress than the wild-type plants because of high ABA accumulation, enhanced stomatal closure and increased expression of stress-responsive genes. Together, these results suggest that the CaRING1 acts as positive factor for dehydration tolerance in Arabidopsis by modulating ABA biosynthesis and ABA-mediated stomatal closing and gene expression.

Lattices for antiproton rings

International Nuclear Information System (INIS)

Autin, B.

1984-01-01

After a description of the constraints imposed by the cooling of Antiprotons on the lattice of the rings, the reasons which motivate the shape and the structure of these machines are surveyed. Linear and non-linear beam optics properties are treated with a special amplification to the Antiproton Accumulator. (orig.)

Fourth-generation storage rings

International Nuclear Information System (INIS)

Galayda, J. N.

1999-01-01

It seems clear that a linac-driven free-electron laser is the accepted prototype of a fourth-generation facility. This raises two questions: can a storage ring-based light source join the fourth generation? Has the storage ring evolved to its highest level of performance as a synchrotrons light source? The answer to the second question is clearly no. The author thinks the answer to the first question is unimportant. While the concept of generations has been useful in motivating thought and effort towards new light source concepts, the variety of light sources and their performance characteristics can no longer be usefully summed up by assignment of a ''generation'' number

Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

2010-10-01

Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

The Spallation Neutron Source accelerator system design

Science.gov (United States)

Henderson, S.; Abraham, W.; Aleksandrov, A.; Allen, C.; Alonso, J.; Anderson, D.; Arenius, D.; Arthur, T.; Assadi, S.; Ayers, J.; Bach, P.; Badea, V.; Battle, R.; Beebe-Wang, J.; Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E.; Blaskiewicz, M.; Blind, B.; Blokland, W.; Bookwalter, V.; Borovina, D.; Bowling, S.; Bradley, J.; Brantley, C.; Brennan, J.; Brodowski, J.; Brown, S.; Brown, R.; Bruce, D.; Bultman, N.; Cameron, P.; Campisi, I.; Casagrande, F.; Catalan-Lasheras, N.; Champion, M.; Champion, M.; Chen, Z.; Cheng, D.; Cho, Y.; Christensen, K.; Chu, C.; Cleaves, J.; Connolly, R.; Cote, T.; Cousineau, S.; Crandall, K.; Creel, J.; Crofford, M.; Cull, P.; Cutler, R.; Dabney, R.; Dalesio, L.; Daly, E.; Damm, R.; Danilov, V.; Davino, D.; Davis, K.; Dawson, C.; Day, L.; Deibele, C.; Delayen, J.; DeLong, J.; Demello, A.; DeVan, W.; Digennaro, R.; Dixon, K.; Dodson, G.; Doleans, M.; Doolittle, L.; Doss, J.; Drury, M.; Elliot, T.; Ellis, S.; Error, J.; Fazekas, J.; Fedotov, A.; Feng, P.; Fischer, J.; Fox, W.; Fuja, R.; Funk, W.; Galambos, J.; Ganni, V.; Garnett, R.; Geng, X.; Gentzlinger, R.; Giannella, M.; Gibson, P.; Gillis, R.; Gioia, J.; Gordon, J.; Gough, R.; Greer, J.; Gregory, W.; Gribble, R.; Grice, W.; Gurd, D.; Gurd, P.; Guthrie, A.; Hahn, H.; Hardek, T.; Hardekopf, R.; Harrison, J.; Hatfield, D.; He, P.; Hechler, M.; Heistermann, F.; Helus, S.; Hiatt, T.; Hicks, S.; Hill, J.; Hill, J.; Hoff, L.; Hoff, M.; Hogan, J.; Holding, M.; Holik, P.; Holmes, J.; Holtkamp, N.; Hovater, C.; Howell, M.; Hseuh, H.; Huhn, A.; Hunter, T.; Ilg, T.; Jackson, J.; Jain, A.; Jason, A.; Jeon, D.; Johnson, G.; Jones, A.; Joseph, S.; Justice, A.; Kang, Y.; Kasemir, K.; Keller, R.; Kersevan, R.; Kerstiens, D.; Kesselman, M.; Kim, S.; Kneisel, P.; Kravchuk, L.; Kuneli, T.; Kurennoy, S.; Kustom, R.; Kwon, S.; Ladd, P.; Lambiase, R.; Lee, Y. Y.; Leitner, M.; Leung, K.-N.; Lewis, S.; Liaw, C.; Lionberger, C.; Lo, C. C.; Long, C.; Ludewig, H.; Ludvig, J.; Luft, P.; Lynch, M.; Ma, H.; MacGill, R.; Macha, K.; Madre, B.; Mahler, G.; Mahoney, K.; Maines, J.; Mammosser, J.; Mann, T.; Marneris, I.; Marroquin, P.; Martineau, R.; Matsumoto, K.; McCarthy, M.; McChesney, C.; McGahern, W.; McGehee, P.; Meng, W.; Merz, B.; Meyer, R.; Meyer, R.; Miller, B.; Mitchell, R.; Mize, J.; Monroy, M.; Munro, J.; Murdoch, G.; Musson, J.; Nath, S.; Nelson, R.; Nelson, R.; O`Hara, J.; Olsen, D.; Oren, W.; Oshatz, D.; Owens, T.; Pai, C.; Papaphilippou, I.; Patterson, N.; Patterson, J.; Pearson, C.; Pelaia, T.; Pieck, M.; Piller, C.; Plawski, T.; Plum, M.; Pogge, J.; Power, J.; Powers, T.; Preble, J.; Prokop, M.; Pruyn, J.; Purcell, D.; Rank, J.; Raparia, D.; Ratti, A.; Reass, W.; Reece, K.; Rees, D.; Regan, A.; Regis, M.; Reijonen, J.; Rej, D.; Richards, D.; Richied, D.; Rode, C.; Rodriguez, W.; Rodriguez, M.; Rohlev, A.; Rose, C.; Roseberry, T.; Rowton, L.; Roybal, W.; Rust, K.; Salazer, G.; Sandberg, J.; Saunders, J.; Schenkel, T.; Schneider, W.; Schrage, D.; Schubert, J.; Severino, F.; Shafer, R.; Shea, T.; Shishlo, A.; Shoaee, H.; Sibley, C.; Sims, J.; Smee, S.; Smith, J.; Smith, K.; Spitz, R.; Staples, J.; Stein, P.; Stettler, M.; Stirbet, M.; Stockli, M.; Stone, W.; Stout, D.; Stovall, J.; Strelo, W.; Strong, H.; Sundelin, R.; Syversrud, D.; Szajbler, M.; Takeda, H.; Tallerico, P.; Tang, J.; Tanke, E.; Tepikian, S.; Thomae, R.; Thompson, D.; Thomson, D.; Thuot, M.; Treml, C.; Tsoupas, N.; Tuozzolo, J.; Tuzel, W.; Vassioutchenko, A.; Virostek, S.; Wallig, J.; Wanderer, P.; Wang, Y.; Wang, J. G.; Wangler, T.; Warren, D.; Wei, J.; Weiss, D.; Welton, R.; Weng, J.; Weng, W.-T.; Wezensky, M.; White, M.; Whitlatch, T.; Williams, D.; Williams, E.; Wilson, K.; Wiseman, M.; Wood, R.; Wright, P.; Wu, A.; Ybarrolaza, N.; Young, K.; Young, L.; Yourd, R.; Zachoszcz, A.; Zaltsman, A.; Zhang, S.; Zhang, W.; Zhang, Y.; Zhukov, A.

2014-11-01

The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ~100 high-power RF power systems, a 2 K cryogenic plant, ~400 DC and pulsed power supply systems, ~400 beam diagnostic devices and a distributed control system handling ~100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

Advances in orbit drift correction in the advanced photon source storage ring

International Nuclear Information System (INIS)

Emery, L.; Borland, M.

1997-01-01

The Advanced Photon Source storage ring is required to provide X-ray beams of high positional stability, specified as 17 μm rms in the horizontal plane and 4.4 μm rms in the vertical plane. The author reports on the difficult task of stabilizing the slow drift component of the orbit motion down to a few microns rms using workstation-based orbit correction. There are two aspects to consider separately the correction algorithm and the configuration of the beam position monitors (BPMs) and correctors. Three notable features of the correction algorithm are: low-pass digital filtering of BPM readbacks; open-quotes despikingclose quotes of the filtered orbit to desensitize the orbit correction to spurious BPM readbacks without having to change the correction matrix; and BPM intensity-dependent offset compensation. The BPM/corrector configuration includes all of the working BPMs but only a small set of correctors distributed around the ring. Thus only those orbit modes that are most likely to be representative of real beam drift are handled by the correction algorithm

Noise Source Identification of a Ring-Plate Cycloid Reducer Based on Coherence Analysis

OpenAIRE

Yang, Bing; Liu, Yan

2013-01-01

A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and ...

Conceptual design of a permanent ring magnet based helicon plasma source module intended to be used in a large size fusion grade ion source

Energy Technology Data Exchange (ETDEWEB)

Pandey, Arun; Sudhir, Dass; Bandyopadhyay, M., E-mail: mainak@iter-india.org; Chakraborty, A.

2016-02-15

A conceptual design of a permanent magnet based single driver helicon plasma source module along with its design approach is described in this paper. The module unit is intended to be used in a large size ion source. The conceptual design of the helicon source module has been carried out using a computer code, HELIC. The magnetic field topology for the ring magnet is simulated with another code, BFieldM and the magnetic field values obtained from the calculation are further used as input in HELIC calculation for the conceptual design. The module is conceptualized based on a cylindrical glass vessel to produce plasma of diameter ∼50 mm, height ∼50 mm. The inner diameter of the permanent ring magnets is also of the same dimension with thickness ∼10 mm each, placed slightly above the backplate to maintain the required magnetic field. The simulated results show that for hydrogen gas, expected plasma density can be achieved as high as ∼10{sup 12}–10{sup 13} cm{sup −3} in the proposed helicon source configuration using 1 kW 13.56 MHz RF generator. An experimental setup to characterize a Helicon source module unit, consisting of a cylindrical glass (plasma) chamber along with the vacuum system, RF power supplies, probes and data acquisition system is being installed.

National synchrotron light source VUV storage ring

International Nuclear Information System (INIS)

Blumberg, L.; Bittner, J.; Galayda, J.; Heese, R.; Krinsky, S.; Schuchman, J.; van Steenbergen, A.

1979-01-01

A 700 MeV electron storage ring designed for synchrotron radiation applications is described. Lattice and stability calculations are presented and the vacuum, correction and injection systems are discussed

Modelling Accumulator Stripper Foil Heating for ESSNUSB Facility

CERN Document Server

Martini, Michel

2015-01-01

It is proposed to use the 2.0 GeV, 5 MW proton linac, 2.86 ms long pulses at 14 Hz of the European Spallation Source [1], [2] being built in Lund, Sweden to deliver, alternately with the spallation neutron production a very intense neutrino beam to enable the discovery of leptonic CP violation. To this end the linac would be upgraded to supply, in addition to the 2.86 ms long proton pulses at 14 Hz, four 0.72 ms H short pulses at 70 Hz for neutrino production. Because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production will need to be compressed to a few s with the aid of an accumulator ring. Charge exchange injection of an H- beam from the linac will be used, the linac delivering 1.1E15 H- per pulse. This paper is about stripping foil heating considerations, emphasizing the detailed evaluation of the foil temperature over the multiple ring re-fills

Study of radioactive sources accumulation with application of thermoluminescence dosemeters on the base of alkaline earth metals sulfates

International Nuclear Information System (INIS)

Tokbergenov, I.; Sadykov, T.

2001-01-01

Methodic for study of accumulation and distribution of radioactive sources in a nature objects is developed. An essence of the method consists of in that quantity of accumulated radioactive sources in a nature objects is defining by absorption dose measured with help of thermoluminescent dosemeters on the base of alkaline earth metals sulfates such as CaSO 4 :Dy and SrSO 4 :Eu

Compact electron storage rings

International Nuclear Information System (INIS)

Williams, G.P.

1987-01-01

There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

Spatial and frequency domain ring source models for the single muscle fiber action potential

DEFF Research Database (Denmark)

Henneberg, Kaj-åge; R., Plonsey

1994-01-01

In the paper, single-fibre models for the extracellular action potential are developed that will allow the potential to the evaluated at an arbitrary field point in the extracellular space. Fourier-domain models are restricted in that they evaluate potentials at equidistant points along a line...... parallel to the fibre axis. Consequently, they cannot easily evaluate the potential at the boundary nodes of a boundary-element electrode model. The Fourier-domain models employ axial-symmetric ring source models, and thereby provide higher accuracy that the line source model, where the source is lumped...... including anisotropy show that the spatial models require extreme care in the integration procedure owing to the singularity in the weighting functions. With adequate sampling, the spatial models can evaluate extracellular potentials with high accuracy....

Final environmental impact statement, construction and operation of the Spallation Neutron Source Facility. Summary

International Nuclear Information System (INIS)

1999-04-01

DOE proposes to construct and operate a state-of-the-art, short-pulsed, spallation neutron source comprised of an ion source, a linear accelerator, a proton accumulator ring, and an experiment building containing a liquid mercury target and a suite of neutron scattering instrumentation. The proposed Spallation Neutron Source would be designed to operate at a proton beam power of 1 megawatt. The design would accommodate future upgrades to a peak operating power of 4 megawatts. These upgrades may include construction of a second proton accumulator ring and a second target. This document analyzes the potential environmental impacts from the proposed action and the alternatives. The analysis assumes a facility operating at a power of 1 MW and 4 MW over the life of the facility. The two primary alternatives analyzed in this FEIS are: the proposed action (to proceed with building the Spallation Neutron Source) and the No-Action Alternative. The No-Action Alternative describes the expected condition of the environment if no action were taken. Four siting alternatives for the Spallation Neutron Source are evaluated: Oak Ridge National Laboratory, Oak Ridge, TN, (preferred alternative); Argonne National Laboratory, Argonne, IL; Brookhaven National Laboratory, Upton, NY; and Los Alamos National Laboratory, Los Alamos, NM

Final environmental impact statement, construction and operation of the Spallation Neutron Source. Volume 1

International Nuclear Information System (INIS)

1999-04-01

DOE proposes to construct and operate a state-of-the-art, short-pulsed, spallation neutron source comprised of an ion source, a linear accelerator, a proton accumulator ring, and an experiment building containing a liquid mercury target and a suite of neutron scattering instrumentation. The proposed Spallation neutron Source would be designed to operate at a proton beam power of 1 megawatt. The design would accommodate future upgrades to a peak operating power of 4 megawatts. These upgrades may include construction of a second proton accumulator ring and a second target. This document analyzes the potential environmental impacts from the proposed action and the alternatives. The analysis assumes a facility operating at a power of 1 MW and 4 MW over the life of the facility. The two primary alternatives analyzed in this FEIS are: the proposed action (to proceed with building the Spallation Neutron Source) and the No-Action Alternative. The No-Action Alternative describes the expected condition of the environment if no action were taken. Four siting alternatives for the Spallation Neutron Source are evaluated: Oak Ridge National Laboratory, Oak Ridge, TN, (preferred alternative); Argonne National Laboratory, Argonne, IL; Brookhaven National Laboratory, Upton, NY; and Los Alamos National Laboratory, Los Alamos, NM

Inside Hall 193 for the Antiproton Accumulator (AA) ring

CERN Multimedia

1979-01-01

Installation work is in full swing. A model quadrupole on the left shows where the magnet ring will be. The cables wound on drums are part of the pulse-forming network for the injection kicker. See Annual Report 1979 p. 103, Fig. 9 and photo 7911303. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .

Concepts for a low emittance-high capacity storage ring for the Diamond Light Source

CERN Document Server

Bartolini, Riccardo; Evans, Gwyndaf; Sawhney, Kawal; Zegenhagen, Joerg

2017-01-01

The Diamond Light Source is investigating several paths for a possible machine upgrade to Diamond II. The exercise is driven by a joint assessment of the science capabilities opened by a very low emittance ring and the machine design that will underpin them. The consultation is made on a beamline-by-beamline basis and has highlighted a significant preference for lattices that combine both a low emittance and large capacity for IDs.

Status of magnet power supply development for the APS [Advanced Photon Source] storage ring

International Nuclear Information System (INIS)

McGhee, D.

1989-01-01

To simplify installation and speed testing of the Advanced Photon Source (APS) storage ring magnets, vacuum chambers and magnet power supplies, a modular approach was developed. All but the dipole magnets are independently controlled. Pulse width modulated dc-to-dc converters are used to power the individual magnets, with 12-pulse power supplies providing the raw dc to the converters. A magnet support base is the heart of a module and may hold as many as 7 magnets with 8 individually powered coils. The dc-to-dc converters are part of each magnet base module. This paper will show the modular approach which is used for the storage ring magnet systems and will give the test results of the prototype topology for the dc-to-dc converters that are being built and tested to power 680 quadrupole and sextupole magnets. 4 refs., 11 figs., 1 tab

Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods

Directory of Open Access Journals (Sweden)

Petro E. Mabeyo

2015-01-01

Full Text Available Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3′-diaminobenzidine hydrochloride (DABH as a chromogen. The mean concentrations in the leaves were found to range from 7.90±0.40 to 1.95±0.12 μg/g dry weight (DW, with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12±0.10 μg/g in Amaranthus sp. to 5.35±0.78 μg/g DW in C. maxima and was hence significantly different (P<0.01. The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods.

Mucin-producing signet ring cell adenoma of the thyroid

Directory of Open Access Journals (Sweden)

Gulwani Hanni

2008-10-01

Full Text Available Signet ring cell adenoma of the thyroid, though rare, is well documented. This change is chiefly due to intracellular accumulation of thyroglobulin that appears mucinous. Awareness of this entity is important as it may closely simulate a metastatic mucin-secreting signet ring cell carcinoma. Although the mucinous material in signet ring cells has been reported to stain positive with thyroglobulin, in some cases it may not be so. We herein describe a rare case of a 46-year-old man who was hypothyroid and the mass removed from the thyroid showed a mucin-producing signet ring cell adenoma of the thyroid.

Development of an abort gap monitor for high-energy proton rings

International Nuclear Information System (INIS)

Beche, Jean-Francois; Byrd, John; De Santis, Stefano; Denes, Peter; Placidi, Massimo; Turner, William; Zolotorev, Max

2004-01-01

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

Development of an Abort Gap Monitor for High-Energy Proton Rings

International Nuclear Information System (INIS)

Beche, J.-F.; Byrd, J.; De Santis, S.; Denes, P.; Placidi, M.; Turner, W.; Zolotorev, M.

2004-01-01

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the 'abort gap', and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

Antiproton Accumulator (AA)

CERN Multimedia

Photographic Service

1980-01-01

The AA in its final stage of construction, before it disappeared from view under concrete shielding. Antiprotons were first injected, stochastically cooled and accumulated in July 1980. From 1981 on, the AA provided antiprotons for collisions with protons, first in the ISR, then in the SPS Collider. From 1983 on, it also sent antiprotons, via the PS, to the Low-Energy Antiproton Ring (LEAR). The AA was dismantled in 1997 and shipped to Japan.

Antiproton chain of the FAIR storage rings

International Nuclear Information System (INIS)

Katayama, T; Kamerdzhiev, V; Lehrach, A; Maier, R; Prasuhn, D; Stassen, R; Stockhorst, H; Herfurth, F; Lestinsky, M; Litvinov, Yu A; Steck, M; Stöhlker, T

2015-01-01

In the Modularized Start Version of the Facility of Antiproton and Ion Research (FAIR) at Darmstadt Germany, the 3 GeV antiprotons are precooled in the collector ring and accumulated in the high energy storage ring (HESR). They are further accelerated to 14 GeV or decelerated to 1 GeV for the experiments with a high-density internal target. The powerful beam cooling devices, stochastic cooling and electron cooling will support the provision of a high-resolution antiproton beam. The other option of FAIR is to prepare the low energy, 300 keV antiproton beam connecting the existing storage rings ESR and CRYRING with HESR. Beam physics issues related with these concepts are described. (paper)

Qubit entanglement between ring-resonator photon-pair sources on a silicon chip

Science.gov (United States)

Silverstone, J. W.; Santagati, R.; Bonneau, D.; Strain, M. J.; Sorel, M.; O'Brien, J. L.; Thompson, M. G.

2015-01-01

Entanglement—one of the most delicate phenomena in nature—is an essential resource for quantum information applications. Scalable photonic quantum devices must generate and control qubit entanglement on-chip, where quantum information is naturally encoded in photon path. Here we report a silicon photonic chip that uses resonant-enhanced photon-pair sources, spectral demultiplexers and reconfigurable optics to generate a path-entangled two-qubit state and analyse its entanglement. We show that ring-resonator-based spontaneous four-wave mixing photon-pair sources can be made highly indistinguishable and that their spectral correlations are small. We use on-chip frequency demultiplexers and reconfigurable optics to perform both quantum state tomography and the strict Bell-CHSH test, both of which confirm a high level of on-chip entanglement. This work demonstrates the integration of high-performance components that will be essential for building quantum devices and systems to harness photonic entanglement on the large scale. PMID:26245267

Stable CSR in storage rings: A model

International Nuclear Information System (INIS)

Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Venturini, Marco; Abo-Bakr, Michael; Feikes, Jorge; Holldack, Karsten; Kuske, Peter; Wustefeld, Godehart; Hubers, Heinz-Willerm; Warnock, Robert

2005-01-01

A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user s shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

Stable CSR in Storage Rings: A Model

International Nuclear Information System (INIS)

Sannibale, F.

2005-01-01

A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user's shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

Method for assessing the probability of accumulated doses from an intermittent source using the convolution technique

International Nuclear Information System (INIS)

Coleman, J.H.

1980-10-01

A technique is discussed for computing the probability distribution of the accumulated dose received by an arbitrary receptor resulting from several single releases from an intermittent source. The probability density of the accumulated dose is the convolution of the probability densities of doses from the intermittent releases. Emissions are not assumed to be constant over the brief release period. The fast fourier transform is used in the calculation of the convolution

Design study of an Antiproton Collector for the Antiproton Accumulator (ACOL)

International Nuclear Information System (INIS)

Wilson, E.J.N.

1983-01-01

The Report gives a full description of an Antiproton Collector Ring which, placed around the existing Antiproton Accumulator at CERN, would enhance the antiproton flux available to both the SPS and LEAR by a factor of ten. The new ring and the focusing devices which precede it are designed to accept a much larger fraction of the antiproton production cone from the target. Each pulse of particles will be pre-cooled before being fed to the Antiproton Accumulator, where improved stochastic cooling systems will build up the stack. A full list of parameters is included. (orig.)

Construction and operation of the Spallation Neutron Source: Draft environmental impact statement. Volume 2

International Nuclear Information System (INIS)

1998-12-01

DOE proposes to construct and operate a state-of-the-art, short-pulsed spallation neutron source comprised of an ion source, a linear accelerator, a proton accumulator ring, and an experiment building containing a liquid mercury target and a suite of neutron scattering instrumentation. The proposed Spallation Neutron Source would be designed to operate at a proton beam power of 1 megawatt. The design would accommodate future upgrades to a peak operating power of 4 megawatts. These upgrades may include construction of a second proton accumulation ring and a second target. Volume 1 of this document analyzes the potential environmental impacts from the proposed action and the alternatives. The analysis assumes a facility operating at a power of 1 MW and 4 MW over the life of the facility. The two primary alternatives analyzed in this EIS are: the proposed action (to proceed with building the Spallation Neutron Source) and the No-Action Alternative. This volume contains the following appendices: (A) SNS accident source terms for EIS input; (B) Reports on the selection of alternative sites for the SNS; (C) Letters of consultation on protected species and cultural resources; (D) Ecological resource survey reports and summaries; (E) Descriptions of ORNL research projects in the Walker Branch Watershed; (F) Atmospheric dispersion and dose calculations for normal and accident conditions; (G) Projected air quality modeling effects at NOAA's Walker Branch Monitoring Tower

High resolution beam line of the U400M cyclotron and RIB accumulation and cooling in the K4 storage ring

International Nuclear Information System (INIS)

Rodin, A.M.; Sidorchuk, S.I.; Stepantsov, S.V.

1996-01-01

The high resolution beam line ACCULINNA put into operation on a primary beam line of the JINR U400M cyclotron is discussed in the framework of the TREBLE project. The capability of the beam line for producing radioactive ion beams is demonstrated by means of nuclear fragmentation of the primary 14 N beam, with the energy of 51 MeV · A, on the 170 mg/cm 2 carbon target. Characteristics of the obtained 6 He, 8 He and 8 B radioactive beams are presented. A scheme of accumulation and cooling on the orbit of the storage ring K4 is proposed for a low intensity radioactive beam obtained from this beam line. 8 refs., 6 figs., 1 tab

Ion source requirements for pulsed spallation neutron sources

International Nuclear Information System (INIS)

Alonso, J.R.

1995-10-01

The neutron scattering community has endorsed the need for a high- power (1 to 5 MW) accelerator-driven source of neutrons for materials research. Properly configured, the accelerator could produce very short (sub-microsecond) bursts of cold neutrons, said time structure offering advantages over the continuous flux from a reactor for a large class of experiments. The recent cancellation of the ANS reactor project has increased the urgency to develop a comprehensive strategy based on the best technological scenarios. Studies to date have built on the experience from ISIS (the 160 KW source in the UK), and call for a high-current (approx. 100 mA peak) H - source-linac combination injecting into one or more accumulator rings in which beam may be further accelerated. The 1 to 5 GeV proton beam is extracted in a single turn and brought to the target-moderator stations. The high current, high duty-factor, high brightness and high reliability required of the ion source present a very large challenge to the ion source community. A workshop held in Berkeley in October 1994, analyzed in detail the source requirements for proposed accelerator scenarios, the present performance capabilities of different H - source technologies, and identified necessary R ampersand D efforts to bridge the gap

Dual-etalon cavity ring-down frequency-comb spectroscopy with broad band light source

Science.gov (United States)

Chandler, David W; Strecker, Kevin E

2014-04-01

In an embodiment, a dual-etalon cavity-ring-down frequency-comb spectrometer system is described. A broad band light source is split into two beams. One beam travels through a first etalon and a sample under test, while the other beam travels through a second etalon, and the two beams are recombined onto a single detector. If the free spectral ranges ("FSR") of the two etalons are not identical, the interference pattern at the detector will consist of a series of beat frequencies. By monitoring these beat frequencies, optical frequencies where light is absorbed may be determined.

Positron annihilation imaging device using multiple offset rings of detectors

International Nuclear Information System (INIS)

Thompson, C.J.

1982-01-01

A means is provided for recording more than one tomographic image simultaneously through different cross-sections of a patient, using positron emission tomography. Separate rings of detectors are used to construct every odd-numbered slice, and coincident events that occur between adjacent rings of detectors provide a center or even-numbered slice. Detector rings are offset with respect to one another by half the angular separation of the detectors, allowing an image to be reconstructed from the central slice without the necessity of physically rotating the detector array while accumulating data

The multi-bend achromat storage rings

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Mikael [MAX IV Laboratory Ole Römers v. 1 22100 Lund Sweden (Sweden)

2016-07-27

Not very long ago, the 3{sup rd} generation storage ring technology was judged as mature. Most of the 3{sup rd} generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

The multi-bend achromat storage rings

International Nuclear Information System (INIS)

Eriksson, Mikael

2016-01-01

Not very long ago, the 3"r"d generation storage ring technology was judged as mature. Most of the 3"r"d generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

CESAR, 2 MeV electron storage ring.

CERN Multimedia

CERN PhotoLab

1967-01-01

CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

Conceptual Design Report. Antiproton - Proton Collider Upgrade 20 GeV Rings. Technical Components and Civil Construction May, 1988

Energy Technology Data Exchange (ETDEWEB)

None

1988-05-01

This report contains a description of the design and cost estimate of two new 20 GeV rings which will be required to support the upgrade of the Fermilab Collider with a luminosity goal of 5x10 ³¹ cm^-2s^-1. The new rings include an antiproton post-accumulator, denoted the Antiproton Super Booster (ASB), and a proton post-booster, denoted the Proton Super Booster (PSB). The siting of the rings is shown in Figure I-1. Both rings are capable of operation at 20 GeV, eliminating the need for ever again injecting beam into the Main Ring below transition, and significantly enhancing Main Ring performance. The Antiproton Super Booster is designed to accept and accumulate up to 4x10¹² antiprotons from the existing Antiproton Accumulator, and deliver them to the Main Ring at 20 GeV for acceleration and injection into the Collider. It is also designed to accept diluted antiprotons from the Main Ring at 20 GeV for recooling. The PSB accepts 8.9 GeV protons from the existing Booster and accelerates them to 20 GeV for injection into the Main Ring. The PSB is designed to operate at 5 Hz. The siting shown in Figure I-1 has the attractive feature that it removes all Main Ring injection hardware from the AO straight section, opening the possibility of installing a third proton-antiproton interaction region in the Tevatron Collider.

Recent developments at 3rd generation storage ring light sources (2/4)

CERN Multimedia

CERN. Geneva

2009-01-01

Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

Recent developments at 3rd generation storage ring light sources (4/4)

CERN Multimedia

CERN. Geneva

2009-01-01

Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

Recent developments at 3rd generation storage ring light sources (3/4)

CERN Multimedia

CERN. Geneva

2009-01-01

Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

Recent developments at 3rd generation storage ring light sources (1/4)

CERN Multimedia

CERN. Geneva

2009-01-01

Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

Polarized gas targets for storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1990-01-01

It is widely recognized that polarized gas targets in electron storage rings represent a new opportunity for precision nuclear physics studies. New developments in polarized target technology specific to internal applications will be discussed. In particular, polarized gas targets have been used in the VEPP-3 electron ring in Novosibirsk. A simple storage cell was used to increase the total target thickness by a factor of 15 over the simple gas jet target from an atomic beam source. Results from the initial phase of this project will be reported. In addition, the plans for increasing the luminosity by an additional order or magnitude will be presented. The application of this work to polarized hydrogen and deuterium targets for the HERA ring will be noted. The influence of beam-induced depolarization, a phenomena encountered in short-pulse electron storage rings, will be discussed. Finally, the performance tests of laser-driven sources will be presented. 8 refs., 12 figs., 1 tab

Infrared synchrotron radiation from electron storage rings

International Nuclear Information System (INIS)

Duncan, W.D.; Williams, G.P.

1983-01-01

Simple and useful approximations, valid at infrared wavelengths, to the equations for synchrotron radiation are presented and used to quantify the brightness and power advantage of current synchrotron radiation light sources over conventional infrared broadband laboratory sources. The Daresbury Synchrotron Radiation Source (SRS) and the Brookhaven National Synchrotron Light Source (vacuum ultraviolet) [NSLS(VUV)] storage rings are used as examples in the calculation of the properties of infrared synchrotron radiation. The pulsed nature of the emission is also discussed, and potential areas of application for the brightness, power, and time structure advantages are presented. The use of infrared free electron lasers and undulators on the next generation of storage ring light sources is briefly considered

Henry's law and accumulation of weak source for crust-derived helium: A case study of Weihe Basin, China

Directory of Open Access Journals (Sweden)

Yuhong Li

2017-12-01

Full Text Available Crust-derived helium is generated from the radioactive decay of uranium, thorium and other radioactive elements in geological bodies. Compared with conventional natural gas, helium is a typical weak source gas as a result of extremely slow generation rate and absence of helium-generating peak. It is associated with methane or carbon dioxide reservoirs frequently and related to groundwater closely. Helium can meet the industry standard with 0.1% in volume fraction. In order to study the accumulation mechanism of helium, the previous research on Henry's coefficient and solubility of helium, nitrogen and methane are summarized and the key roles of Henry's Law in the helium migration, accumulation and preservation are discussed by simulating calculation taking Weihe Basin as an example. According to the Law, the gas solubility in dilute solution is controlled by the gas partial pressure and the Henry's coefficient. Compared with the carrier gases, the Henry's constant of helium is high, with striking difference at low and high temperature. In addition, the helium partial pressure is greatly different in helium source rocks and gas reservoirs, resulting in the great differences of helium solubility in the two places. The accumulation progresses are as follows. Firstly, helium can dissolve into water and migrate out of helium source rocks due to the high helium solubility, which is caused by high helium partial pressure and high temperature in source rock. Secondly, when dissolved helium is transported to the shallow gas reservoir, it is prone to be out of solution and into reservoir due to the extremely low partial pressure and low temperature. Meanwhile part of carrier gases dissolves into water, as if helium is “replaced” out. Furthermore, the low concentration funnel of dissolved helium is formed near the gas reservoir, then other dissolved helium continues to migrate towards the gas reservoir, which greatly improves the helium accumulation

Coherent instability of the heavy ion beam in the storage ring

International Nuclear Information System (INIS)

Noda, A.

1981-01-01

The storage ring as the final part of a driver for heavy ion fusion is required to provide heavy ions (A asymptotically equals 200) with energy of 5 -- 10 GeV and such a high intensity as 1 -- 6 x 10 15 ions/pulse. So as to raise the number of ions which can be accumulated in a ring, singlly charged heavy ion is used for its relatively smaller incoherent space charge force compared with higher charge states. The intensity limit due to incoherent space charge force is 0.7 -- 1.4 x 10 15 ions for U 1 + . Much more severe limits exist due to coherent motion of heavy ion beams (0.8 -- 2 x 10 13 for longitudinal motion and 0.9 -- 1.1 x 10 12 for transverse motion), because of the relatively lower velocity of the accumulated ions. It seems unrealistic to use a lot of rings in order to operate below such intensity limits of the above instability. Therefore the number of the storage rings is constrained within a reasonable value (3 -- 7) and the possibility of compressing the bunches of heavy ion beams before the instability grows fatally large is studied. (author)

SU-G-201-13: Investigation of Dose Variation Induced by HDR Ir-192 Source Global Shift Within the Varian Ring Applicator Using Monte Carlo Methods

Energy Technology Data Exchange (ETDEWEB)

Yang, Y; Cai, J; Meltsner, S; Chang, Z; Craciunescu, O [Duke University Medical Center, Durham, NC (United States)

2016-06-15

Purpose: The Varian tandem and ring applicators are used to deliver HDR Ir-192 brachytherapy for cervical cancer. The source path within the ring is hard to predict due to the larger interior ring lumen. Some studies showed the source could be several millimeters different from planned positions, while other studies demonstrated minimal dosimetric impact. A global shift can be applied to limit the effect of positioning offsets. The purpose of this study was to assess the necessities of implementing a global source shift using Monte Carlo (MC) simulations. Methods: The MCNP5 radiation transport code was used for all MC simulations. To accommodate TG-186 guidelines and eliminate inter-source attenuation, a BrachyVision plan with 10 dwell positions (0.5cm step sizes) was simulated as the summation of 10 individual sources with equal dwell times for simplification. To simplify the study, the tandem was also excluded from the MC model. Global shifts of ±0.1, ±0.3, ±0.5 cm were then simulated as distal and proximal from the reference positions. Dose was scored in water for all MC simulations and was normalized to 100% at the normalization point 0.5 cm from the cap in the ring plane. For dose comparison, Point A was 2 cm caudal from the buildup cap and 2 cm lateral on either side of the ring axis. With seventy simulations, 108 photon histories gave a statistical uncertainties (k=1) <2% for (0.1 cm)3 voxels. Results: Compared to no global shift, average Point A doses were 0.0%, 0.4%, and 2.2% higher for distal global shifts, and 0.4%, 2.8%, and 5.1% higher for proximal global shifts, respectively. The MC Point A doses differed by < 1% when compared to BrachyVision. Conclusion: Dose variations were not substantial for ±0.3 cm global shifts, which is common in clinical practice.

SU-G-201-13: Investigation of Dose Variation Induced by HDR Ir-192 Source Global Shift Within the Varian Ring Applicator Using Monte Carlo Methods

International Nuclear Information System (INIS)

Yang, Y; Cai, J; Meltsner, S; Chang, Z; Craciunescu, O

2016-01-01

Purpose: The Varian tandem and ring applicators are used to deliver HDR Ir-192 brachytherapy for cervical cancer. The source path within the ring is hard to predict due to the larger interior ring lumen. Some studies showed the source could be several millimeters different from planned positions, while other studies demonstrated minimal dosimetric impact. A global shift can be applied to limit the effect of positioning offsets. The purpose of this study was to assess the necessities of implementing a global source shift using Monte Carlo (MC) simulations. Methods: The MCNP5 radiation transport code was used for all MC simulations. To accommodate TG-186 guidelines and eliminate inter-source attenuation, a BrachyVision plan with 10 dwell positions (0.5cm step sizes) was simulated as the summation of 10 individual sources with equal dwell times for simplification. To simplify the study, the tandem was also excluded from the MC model. Global shifts of ±0.1, ±0.3, ±0.5 cm were then simulated as distal and proximal from the reference positions. Dose was scored in water for all MC simulations and was normalized to 100% at the normalization point 0.5 cm from the cap in the ring plane. For dose comparison, Point A was 2 cm caudal from the buildup cap and 2 cm lateral on either side of the ring axis. With seventy simulations, 108 photon histories gave a statistical uncertainties (k=1) <2% for (0.1 cm)3 voxels. Results: Compared to no global shift, average Point A doses were 0.0%, 0.4%, and 2.2% higher for distal global shifts, and 0.4%, 2.8%, and 5.1% higher for proximal global shifts, respectively. The MC Point A doses differed by < 1% when compared to BrachyVision. Conclusion: Dose variations were not substantial for ±0.3 cm global shifts, which is common in clinical practice.

Injection into the LNLS UVX electron storage ring

International Nuclear Information System (INIS)

Lin, Liu

1991-01-01

To inject the 1.15 GeV electron storage ring - UVX - a beam from a linear accelerator - MAIRA - is used. The electrons are injected and accumulated at low energy (100MeV) until the nominal current of 100 mA is reached and than are ramped to the nominal energy. A study on a conventional injection scheme has been carried out. Two injection modes are investigated: injection with the phase ellipse parameters matched and mismatched to the ring's acceptance. The mismatched mode is optimized to fit the maximum of the injected beam into the acceptance

Ion source requirements for pulsed spallation neutron sources

International Nuclear Information System (INIS)

Alonso, J.R.

1996-01-01

The neutron scattering community has endorsed the need for a high-power (1 to 5 MW) accelerator-driven source of neutrons for materials research. Properly configured, the accelerator could produce very short (sub-microsecond) bursts of cold neutrons, said time structure offering advantages over the continuous flux from a reactor for a large class of experiments. The recent cancellation of the ANS reactor project has increased the urgency to develop a comprehensive strategy based on the best technological scenarios. Studies to date have built on the experience from ISIS (the 160 kW source in the UK), and call for a high-current (approx. 100 mA peak) H - source-linac combination injecting into one or more accumulator rings in which beam may be further accelerated. The 1 to 5 GeV proton beam is extracted in a single turn and brought to the target-moderator stations. The high current, high duty-factor, high brightness and high reliability required of the ion source present a very large challenge to the ion source community. A workshop held in Berkeley in October 1994, analyzed in detail the source requirements for proposed accelerator scenarios, the present performance capabilities of different H - source technologies, and identified necessary R ampersand D efforts to bridge the gap. copyright 1996 American Institute of Physics

Modeled Sources, Transport, and Accumulation of Dissolved Solids in Water Resources of the Southwestern United States.

Science.gov (United States)

Anning, David W

2011-10-01

Information on important source areas for dissolved solids in streams of the southwestern United States, the relative share of deliveries of dissolved solids to streams from natural and human sources, and the potential for salt accumulation in soil or groundwater was developed using a SPAtially Referenced Regressions On Watershed attributes model. Predicted area-normalized reach-catchment delivery rates of dissolved solids to streams ranged from Salton Sea accounting unit.

A linac for the Spallation Neutron Source

International Nuclear Information System (INIS)

Jason, A.J.

1998-01-01

The Spallation Neutron Source Project (SNS), to be constructed at Oak Ridge National Laboratory, accelerates H - ions to an energy of 1.0 GeV with an average current of 1-mA for injection into an accumulator ring that produces the short intense burst of protons needed for the spallation-neutron source. The linac will be the most intense source of H - ions and as such requires advanced design techniques to meet project technical goals. In particular, low beam loss is stressed for the chopped beam placing strong requirements on the beam dynamics and linac construction. Additionally, the linac is to be upgraded to the 2- and 4-MW beam-power levels with no increase in duty factor. The author gives an overview of the linac design parameters and design choices made

Compressible Vortex Ring

Science.gov (United States)

Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

1999-11-01

The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database

Science.gov (United States)

Buta, Ronald J.

2017-11-01

Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.

Survey and alignment of photon factory storage ring at KEK

International Nuclear Information System (INIS)

Araki, A.; Honjo, I.; Katoh, M.; Kamiya, Y.; Kihara, M.

1987-01-01

The heights of the magnets for both the ring and the beam transport line (BT-line) have been periodically measured at the Photon Factory. The accumulated data showed that the ring was considerably declined due to the construction of the large experimental hall and the tunnel of the TRISTAN project, and that the BT-line also sank several centimeters at some locations. These displacements of the magnets produce a significantly large closed orbit distortion and the vertical dispersion

Ion accumulation and space charge neutralization in intensive electron beams for ion sources and electron cooling

International Nuclear Information System (INIS)

Shirkov, G.D.

1996-01-01

The Electron Beam Ion Sources (EBIS), Electron Beam Ion Traps (EBIT) and electron beams for electron cooling application have the beam parameters in the same ranges of magnitudes. EBIS and EBIT produce and accumulate ions in the beam due to electron impact ionization. The cooling electron beam accumulates positive ions from the residual gas in the accelerator chamber during the cooling cycle. The space charge neutralization of cooling beam is also used to reduce the electron energy spread and enhance the cooling ability. The advanced results of experimental investigations and theoretical models of the EBIS electron beams are applied to analyze the problem of beam neutralization in the electron cooling techniques. The report presents the analysis of the most important processes connected with ion production, accumulation and losses in the intensive electron beams of ion sources and electron cooling systems for proton and ion colliders. The inelastic and elastic collision processes of charged particles in the electron beams are considered. The inelastic processes such as ionization, charge exchange and recombination change the charge states of ions and neutral atoms in the beam. The elastic Coulomb collisions change the energy of particles and cause the energy redistribution among components in the electron-ion beams. The characteristic times and specific features of ionization, beam neutralization, ion heating and loss in the ion sources and electron cooling beams are determined. The dependence of negative potential in the beam cross section on neutralization factor is studied. 17 refs., 5 figs., 1 tab

A Dynamic Momentum Compaction Factor Lattice for Improvements to Stochastic Cooling in Storage Rings

Energy Technology Data Exchange (ETDEWEB)

Olivieri, David Nicholas [Massachusetts U., Amherst

1996-01-01

A dynamic momentum compaction factor, also referred to as a dynamic $\\Delta \\gamma \\tau$, lattice for the FNAL Antiproton Source Debuncher Storage Ring is studied, both theoretically and experimentally, for the purpose of improving stochastic precooling, and hence, improving the global antiproton production and stacking performance. A dynamic $\\Delta \\gamma \\tau$ lattice is proposed due to the competing requirements inherent within the Debuncher storage ring upon $\\gamma \\tau$· Specifically, the Debuncher storage ring performs two disparate functions, $(i)$ accepting and debunching a large number of $\\overline{p}$s/pulse at the outset of the production cycle, which would perform ideally with a large value of $\\gamma\\tau$, and $(ii)$ subsequently employing stochastic cooling throughout the remainder of the $\\overline{p}$ production cycle for improved transfer and stacking efficiency into the Accumulator, for which a small value $\\gamma \\tau$ is ideal in order to reduce the diffusive heating caused by the mixing factor. In the initial design of the Debuncher optical lattice, an intermediate value of $\\gamma \\tau$ was chosen as a compromise between the two functional requirements. The goal of the thesis is to improve stochastic precooling by changing $\\gamma \\tau$ between two desired values during each p production cycle. In particular, the dynamic $\\Delta \\gamma \\tau$ lattice accomplishes a reduction in $\\gamma \\tau$, and hence the mixing factor, through an uniform increase to the dispersion throughout the arc sections of the storage ring. Experimental measurements of cooling rates and system performance parameters, with the implementation of the dynamic $\\Delta \\gamma \\tau$ lattice, are in agreement with theoretical predictions based upon a detailed integration of the stochastic cooling Fokker Planck equations. Based upon the consistency between theory and experiment, predictions of cooling rates are presented for future operational

The accumulation pattern of ferruginol in the heartwood-forming Cryptomeria japonica xylem as determined by time-of-flight secondary ion mass spectrometry and quantity analysis

Science.gov (United States)

Kuroda, Katsushi; Fujiwara, Takeshi; Hashida, Koh; Imai, Takanori; Kushi, Masayoshi; Saito, Kaori; Fukushima, Kazuhiko

2014-01-01

Background and Aims Heartwood formation is a unique phenomenon of tree species. Although the accumulation of heartwood substances is a well-known feature of the process, the accumulation mechanism remains unclear. The aim of this study was to determine the accumulation process of ferruginol, a predominant heartwood substance of Cryptomeria japonica, in heartwood-forming xylem. Methods The radial accumulation pattern of ferruginol was examined from sapwood and through the intermediate wood to the heartwood by direct mapping using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The data were compared with quantitative results obtained from a novel method of gas chromatography analysis using laser microdissection sampling and with water distribution obtained from cryo-scanning electron microscopy. Key Results Ferruginol initially accumulated in the middle of the intermediate wood, in the earlywood near the annual ring boundary. It accumulated throughout the entire earlywood in the inner intermediate wood, and in both the earlywood and the latewood in the heartwood. The process of ferruginol accumulation continued for more than eight annual rings. Ferruginol concentration peaked at the border between the intermediate wood and heartwood, while the concentration was less in the latewood compared wiht the earlywood in each annual ring. Ferruginol tended to accumulate around the ray parenchyma cells. In addition, at the border between the intermediate wood and heartwood, the accumulation was higher in areas without water than in areas with water. Conclusions TOF-SIMS clearly revealed ferruginol distribution at the cellular level. Ferruginol accumulation begins in the middle of intermediate wood, initially in the earlywood near the annual ring boundary, then throughout the entire earlywood, and finally across to the whole annual ring in the heartwood. The heterogeneous timing of ferruginol accumulation could be related to the distribution of ray parenchyma cells

Correlations and fixation of some elements in tree rings

International Nuclear Information System (INIS)

Goldberg, E.L.; Zolotarev, K.B.; Maksimovskaya, V.V.; Kondratyev, V.I.; Ovchinnikov, D.V.; Naurzbaev, M.M.

2007-01-01

High-resolution scanning with Synchrotron Radiation X-ray Fluorescence Analysis (SRXFA) was applied to investigate element distributions in tree rings. Two cores of Siberia Larch have been investigated with resolution 100-200 mkm. Two groups of elements in tree rings with different trends have been found. The members of the first group are Br, Zn, Cl, whose trends correlate with each other. Moreover, trends of Br, Zn, Cl in tree rings are similar to the trend of atmosphere precipitation in the region investigated. Other group of elements are represented by K, Ca, Sr, Mn, Fe, but their trends differ sufficiently from trend of elements of the first group. Extended fixation of elements in tree rings is observed for elements of the first group over the whole interval investigated (150 years). In contrast, elements of the second group mainly accumulate in external part of tree stem

Source rock contributions to the Lower Cretaceous heavy oil accumulations in Alberta: a basin modeling study

Science.gov (United States)

Berbesi, Luiyin Alejandro; di Primio, Rolando; Anka, Zahie; Horsfield, Brian; Higley, Debra K.

2012-01-01

The origin of the immense oil sand deposits in Lower Cretaceous reservoirs of the Western Canada sedimentary basin is still a matter of debate, specifically with respect to the original in-place volumes and contributing source rocks. In this study, the contributions from the main source rocks were addressed using a three-dimensional petroleum system model calibrated to well data. A sensitivity analysis of source rock definition was performed in the case of the two main contributors, which are the Lower Jurassic Gordondale Member of the Fernie Group and the Upper Devonian–Lower Mississippian Exshaw Formation. This sensitivity analysis included variations of assigned total organic carbon and hydrogen index for both source intervals, and in the case of the Exshaw Formation, variations of thickness in areas beneath the Rocky Mountains were also considered. All of the modeled source rocks reached the early or main oil generation stages by 60 Ma, before the onset of the Laramide orogeny. Reconstructed oil accumulations were initially modest because of limited trapping efficiency. This was improved by defining lateral stratigraphic seals within the carrier system. An additional sealing effect by biodegraded oil may have hindered the migration of petroleum in the northern areas, but not to the east of Athabasca. In the latter case, the main trapping controls are dominantly stratigraphic and structural. Our model, based on available data, identifies the Gordondale source rock as the contributor of more than 54% of the oil in the Athabasca and Peace River accumulations, followed by minor amounts from Exshaw (15%) and other Devonian to Lower Jurassic source rocks. The proposed strong contribution of petroleum from the Exshaw Formation source rock to the Athabasca oil sands is only reproduced by assuming 25 m (82 ft) of mature Exshaw in the kitchen areas, with original total organic carbon of 9% or more.

Low emittance electron storage rings

Science.gov (United States)

Levichev, E. B.

2018-01-01

Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

Storage Rings

International Nuclear Information System (INIS)

Fischer, W.

2010-01-01

. Storage rings have instrumentation to monitor the electrical and mechanical systems, and the beam quality. Computers are used to control the operation. Large storage rings have millions of control points from all systems. The time dependent beam intensity I(t) can often be approximated by an exponential function I(t) = I(0) exp(-t/τ) (1) where the decay time τ and, correspondingly, the store time ranges from a few turns to 10 days (ISR). τ can be dominated by a variety of effects including lattice nonlinearities, beam-beam, space charge, intrabeam and Touschek scattering, interaction with the residual gas or target, or the lifetime of the stored particle. In this case, the beam lifetime measurement itself can be the purpose of a storage ring experiment. The main consideration in the design of a storage ring is the preservation of the beam quality over the store length. The beam size and momentum spread can be reduced through cooling, often leading to an increase in the store time. For long store times vacuum considerations are important since the interaction rate of the stored particles with the residual gas molecules is proportional to the pressure, and an ultra-high vacuum system may be needed. Distributed pumping with warm activated NEG surfaces or cold surfaces in machines with superconducting magnets are ways to provide large pumping speeds and achieve low pressures even under conditions with dynamic gas loads. The largest application of storage rings today are synchrotron light sources, of which about 50 exist world wide. In experiments where the beam collides with an internal target or another beam, a storage ring allows to re-use the accelerated beam many times if the interaction with the target is sufficiently small. In hadron collider and ion storage rings store times of many hours or even days are realized, corresponding to up to 1011 turns and thereby target passages. Ref. (3) is the first proposal for a collider storage ring. A number of storage rings

Annex to 7-GeV Advanced Photon Source Conceptual Design Report

International Nuclear Information System (INIS)

1988-05-01

The Annex to the 7-GeV Advanced Photon Source Conceptual Design Report updates the Conceptual Design Report of 1987 (CDR-87) to include the results of further optimization and changes of the design during the past year. The design changes can be summarized as affecting three areas: the accelerator system, conventional facilities, and experimental systems. Most of the changes in the accelerator system result from inclusion of a positron accumulator ring (PAR), which was added at the suggestion of the 1987 DOE Review Committee, to speed up the filling rate of the storage ring. The addition of the PAR necessitates many minor changes in the linac system, the injector synchrotron, and the low-energy beam transport lines. 63 figs., 18 tabs

Linac-driven spallation-neutron source

International Nuclear Information System (INIS)

Jason, A.J.

1995-01-01

Strong interest has arisen in accelerator-driven spallation-neutron sources that surpass existing facilities (such as ISIS at Rutherford or LANSCE at Los Alamos) by more than an order of magnitude in beam power delivered to the spallation target. The approach chosen by Los Alamos (as well as the European Spallation Source) provides the full beam energy by acceleration in a linac as opposed to primary acceleration in a synchrotron or other circular device. Two modes of neutron production are visualized for the source. A short-pulse mode produces 1 MW of beam power (at 60 pps) in pulses, of length less than 1 ms, by compression of the linac macropulse through multi-turn injection in an accumulator ring. A long-pulse mode produces a similar beam power with 1-ms-long pulses directly applied to a target. This latter mode rivals the performance of existing reactor facilities to very low neutron energies. Combination with the short-pulse mode addresses virtually all applications

Construction and operation of the Spallation Neutron Source: Draft environmental impact statement. Volume 1

International Nuclear Information System (INIS)

1998-12-01

DOE proposes to construct and operate a state-of-the-art, short-pulsed spallation neutron source comprised of an ion source, a linear accelerator, a proton accumulator ring, and an experiment building containing a liquid mercury target and a suite of neutron scattering instrumentation. The proposed Spallation Neutron Source would be designed to operate at a proton beam power of 1 megawatt. The design would accommodate future upgrades to a peak operating power of 4 megawatts. These upgrades may include construction of a second proton accumulation ring and a second target. The US needs a high-flux, short-pulsed neutron source to provide the scientific and industrial research communities with a much more intense source of pulsed neutrons for neutron scattering research than is currently available, and to assure the availability of a state-of-the-art facility in the decades ahead. This next-generation neutron source would create new scientific and engineering opportunities. In addition, it would help replace the neutron science capacity that will be lost by the eventual shutdown of existing sources as they reach the end of their useful operating lives in the first half of the next century. This document analyzes the potential environmental impacts from the proposed action and the alternatives. The analysis assumes a facility operating at a power of 1 MW and 4 MW over the life of the facility. The two primary alternatives analyzed in this EIS are: the proposed action (to proceed with building the Spallation Neutron Source) and the No-Action Alternative. The No-Action Alternative describes the expected condition of the environment if no action were taken. Four siting alternatives for the Spallation Neutron Source are evaluated: Oak Ridge National Laboratory, Oak Ridge, TN, (preferred alternative); Argonne National Laboratory, Argonne, IL (US); Brookhaven National Laboratory, Upton, NY; and Los Alamos National Laboratory, Los Alamos, NM

Lord of the Rings - Return of the King: Swift-XRT observations of dust scattering rings around V404 Cygni

Science.gov (United States)

Beardmore, A. P.; Willingale, R.; Kuulkers, E.; Altamirano, D.; Motta, S. E.; Osborne, J. P.; Page, K. L.; Sivakoff, G. R.

2016-10-01

On 2015 June 15, the black hole X-ray binary V404 Cygni went into outburst, exhibiting extreme X-ray variability which culminated in a final flare on June 26. Over the following days, the Swift-X-ray Telescope detected a series of bright rings, comprising five main components that expanded and faded with time, caused by X-rays scattered from the otherwise unobservable dust layers in the interstellar medium in the direction of the source. Simple geometrical modelling of the rings' angular evolution reveals that they have a common temporal origin, coincident with the final, brightest flare seen by INTEGRAL's JEM X-1, which reached a 3-10 keV flux of ˜25 Crab. The high quality of the data allows the dust properties and density distribution along the line of sight to the source to be estimated. Using the Rayleigh-Gans approximation for the dust scattering cross-section and a power-law distribution of grain sizes a, ∝ a-q, the average dust emission is well modelled by q = 3.90^{+0.09}_{-0.08} and maximum grain size of a_+ = 0.147^{+0.024}_{-0.004} { μ m}, though significant variations in q are seen between the rings. The recovered dust density distribution shows five peaks associated with the dense sheets responsible for the rings at distances ranging from 1.19 to 2.13 kpc, with thicknesses of ˜40-80 pc and a maximum density occurring at the location of the nearest sheet. We find a dust column density of Ndust ≈ (2.0-2.5) × 1011 cm-2, consistent with the optical extinction to the source. Comparison of the inner rings' azimuthal X-ray evolution with archival Wide-field Infrared Survey Explorer mid-IR data suggests that the second most distant ring follows the general IR emission trend, which increases in brightness towards the Galactic north side of the source.

Hybrid plasmonic waveguide-assisted Metal–Insulator–Metal ring resonator for refractive index sensing

Science.gov (United States)

Butt, M. A.; Khonina, S. N.; Kazanskiy, N. L.

2018-05-01

A highly sensitive refractive index sensor based on an integrated hybrid plasmonic waveguide (HPWG) and a Metal-Insulator-Metal (M-I-M) micro-ring resonator is presented. In our design, there are two slot-waveguide-based micro-rings that encircle a gold disc. The outer slot WG is formed by the combination of Silicon-Air-Gold ring and the inner slot-waveguide is formed by Gold ring-Air-Gold disc. The slot-waveguide rings provide an interaction length sufficient to accumulate a detectable wavelength shift. The transmission spectrum and electric field distribution of this sensor structure are simulated using Finite Element Method (FEM). The sensitivity of this micro-ring resonator is achieved at 800 nm/RIU which is about six times higher than that of the conventional Si ring with the same geometry. Our proposed sensor design has a potential to find further applications in biomedical science and nano-photonic circuits.

Injection and accumulation method in the TARN

International Nuclear Information System (INIS)

Yamada, S.; Katayama, T.

1979-03-01

The test accumulation ring for NUMATRON (TARN) is being constructed at INS, University of Tokyo. The main purpose of the TARN is to establish some techniques related to beam injection and RF stacking, ultrahigh vacuum, and beam monitoring and handling. In this paper, the injection and accumulation methods in the TARN are described. The combination of multiturn injection and RF stacking is applied to the TARN. Heavy ions from the INS sector focusing (SF) cyclotron are injection through a magnetic and an electrostatic inflectors. Two pulse magnets and a bump field excited by square wave current are used for the multiturn injection method. The procedure of the RF stacking is as follows. The beam from the cyclotron is transported to the ring, and is injected by a multiturn method. Then, the RF accelerating voltage is put on, and the beam is captured in the stable region of the RF acceleration. The RF voltage and the frequency are adiabatically changed, and the beam is moved to the stacking orbit. The RF voltage is put off, and the beam remains on the stacking orbit. In the present system, a repetitive stacking scheme is applied for the RF stacking. The momentum spread after the RF stacking is approximately proportional to the stacking number in synchrotron phase space. The stacking number is chosen so that the total aperture required for the combined method may not exceed the available aperture in the ring doughnut. (Kato, T.)

CESAR, 2 MeV electron storage ring; general view.

CERN Multimedia

CERN PhotoLab

1964-01-01

CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

Novel method of charging an accumulator ring

International Nuclear Information System (INIS)

Maschke, A.W.

1977-01-01

For high power fusion applications, a circular accelerator for heavy ions is not likely to be competitive with a linear accelerator. This is principally because one requires rather high accelerator efficiencies, and quite large average power. Efficiencies greater than or equal to 10 percent, and perhaps 30 and 50 MW of average beam power are needed. On the other hand, the linear accelerator can be built to satisfy these constraints, and in addition, it is ideally suited for multi-turn injection. A difficulty with multi-turn injection is that in typical application it is rather lossy. With care, and sufficient phase space dilution, one might hope to obtain greater than or equal to 90 percent injection efficiency, but even at these levels the large amount of beam power lost in the accumulator might have serious consequences for the machine operation. Therefore, it is desirable to be able to use ''box car'' stacking, which is essentially 100 percent without particle loss. A method of operating the linear accelerator so that the output beam is of suitable instantaneous current to permit box-car stacking with the linac output is proposed

Layout of the LER [Low Energy Ring] Arc

International Nuclear Information System (INIS)

Hutton, A.

1990-01-01

We have recently been trying to accumulate all of the information necessary to decide on the layout of the regular curved arcs of the Low Energy Ring (LER) and there have been several ABC Notes published on different aspects of the problem. This note will describe the layout that has been derived from these considerations

The injection system of the stretcher ring ELSA

International Nuclear Information System (INIS)

Dreist, A.

1989-07-01

For the stretcher ring ELSA in the framwork of this thesis an injection system has been concipated and constructed which should allow all projected operational modes of this stretcher ring, the stretcher, the post-acceleration, and the accumulation mode. The proof could be performed that the realized concept allows all these operational modes. Furthermore it could be shown that the injection shifted from the equilibrium orbit has no disadvantageous effects on a uniform extraction and by this on a high touching ratio. In fact it is even possible to apply the decay of the coherent betatron oscillations around the equilibrium orbit, caused by injection of the incident beam shifted from the equilibrium orbit, to diagnosis purposes: By reproduction of this damping process in a simulation model statements on nonlinearities present in the ring and by this statements on the actual phase-space structure are possible. It has so been shown that the concept presented in this thesis and realized for this thesis represents a suited injection system for the stretcher ring ELSA. (orig.) [de

UHV seal studies for the advanced photon source storage ring vacuum system

International Nuclear Information System (INIS)

Gonczy, J.D.; Ferry, R.J.; Niemann, R.C.; Roop, B.

1991-01-01

The Advanced Photon Source (APS) Storage Ring Vacuum Chambers (SRVC) are constructed of aluminum. The chamber design incorporates aluminum alloy 2219-T87 Conflat flanges welded to an aluminum alloy 6063-T5 extruded chamber body. Vacuum connections to the aluminum Conflat chamber flanges are by means of 304 stainless steel Conflat flanges. To evaluate the Conflat seal assemblies relative to vacuum bake cycles, a Conflat Bake Test Assembly (CBTA) was constructed, and thermal cycling tests were performed between room temperature and 150 degrees C on both stainless steel to aluminum Conflat assemblies and aluminum to aluminum Conflat assemblies. A Helicoflex Bake Test Assembly (HBTA) was similarly constructed to evaluate Helicoflex seals. Both Conflat and Helicoflex seals were studied in a SRVC Sector String Test arrangement of five SRVC sections. The CBTA, HBTA and SRVC tests and their results are reported. 3 refs., 2 figs., 2 tabs

Beam Commissioning of the PEP-II High Energy Ring

International Nuclear Information System (INIS)

Wienands, U.; Anderson, S.; Assmann, R.; Bharadwaj, V.; Cai, Y.; Clendenin, J.; Corredoura, P.; Decker, F.J.; Donald, M.; Ecklund, S.; Emma, P.; Erickson, R.; Fox, J.; Fieguth, T.; Fisher, A.; Heifets, S.; Hill, A.; Himel, T.; Iverson, R.; Johnson, R.; Judkins, J.; Krejcik, P.; Kulikov, A.; Lee, M.; Mattison, T.; Minty, M.; Nosochkov, Y.; Phinney, N.; Placidi, M.; Prabhakar, S.; Ross, M.; Smith, S.; Schwarz, H.; Stanek, M.; Teytelman, D.; Traller, R.; Turner, J.; Zimmermann, F.; Barry, W.; Chattopadhyay, S.; Corlett, J.; Decking, W.; Furman, M.; Nishimura, H.; Portmann, G.; Rimmer, R.; Zholents, A.; Zisman, M.; Kozanecki, W.; Hofmann, A.; Zotter, B.; Steier, C.; Bialowons, W.; Lomperski, M.; Lumpkin, A.; Reichel, I.; Safranek, J.; Smith, V.; Tighe, R.; Sullivan, M.; Byrd, J.; Li, D.

1998-01-01

The PEP-II High Energy Ring (HER), a 9 GeV electron storage ring, has been in commissioning since spring 1997. Initial beam commissioning activities focused on systems checkout and commissioning and on determining the behavior of the machine systems at high beam currents. This phase culminated with the accumulation of 0.75 A of stored beam-sufficient to achieve design luminosity--in January 1998 after 3.5 months of beam time. Collisions with the 3 GeV positron beam of the Low Energy Ring (LER) were achieved in Summer of 1998. At high beam currents, collective instabilities have been seen. Since then, commissioning activities for the HER have shifted in focus towards characterization of the machine and a rigorous program to understand the machine and the beam dynamics is presently underway

Calibration of the nonlinear ring model at the Diamond Light Source

CERN Document Server

Bartolini, R; Rehm, G; Martin, I P S

2011-01-01

Nonlinear beam dynamics plays a crucial role in defining the performance of a storage ring. The beam lifetime, the injection efficiency, and the dynamic and momentum apertures available to the beam are optimized during the design phase by a proper optimization of the linear lattice and of the distribution of sextupole families. The correct implementation of the design model, especially the nonlinear part, is a nontrivial accelerator physics task. Several parameters of the nonlinear dynamics can be used to compare the real machine with the model and eventually to correct the accelerator. Most of these parameters are extracted from the analysis of turn-by-turn data after the excitation of betatron oscillations of the particles in the ring. We present the experimental results of the campaign of measurements carried out at the Diamond storage ring to characterize the nonlinear beam dynamics. A combination of frequency map analysis with the detuning with momentum measurements has allowed for a precise calibration ...

Average dose to an organ per microcurie-day accumulated by a radionuclide in a source organ

International Nuclear Information System (INIS)

Snyder, W.S.; Ford, M.R.

1975-01-01

Methods are discussed that are used in calculations of the average radiation dose to an organ per microcurie/day accumulated by a radionuclide in a source organ. The dosimetric data on photons are obtained by Monte Carlo type computer calculations on a non-homogeneous phantom having the general form of the human body. (U.S.)

Advanced Photon Source accelerator ultrahigh vacuum guide

International Nuclear Information System (INIS)

Liu, C.; Noonan, J.

1994-03-01

In this document the authors summarize the following: (1) an overview of basic concepts of ultrahigh vacuum needed for the APS project, (2) a description of vacuum design and calculations for major parts of APS, including linac, linac waveguide, low energy undulator test line, positron accumulator ring (PAR), booster synchrotron ring, storage ring, and insertion devices, and (3) cleaning procedures of ultrahigh vacuum (UHV) components presently used at APS

Stripper foil failure modes and cures at the Oak Ridge Spallation Neutron Source

Directory of Open Access Journals (Sweden)

M. A. Plum

2011-03-01

Full Text Available The Oak Ridge Spallation Neutron Source comprises a 1 GeV, 1.5 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H^{0} excited states created during the H^{-} charge-exchange injection into the accumulator ring, the stripper foil is located inside one of the chicane dipoles. This has some interesting consequences that were not fully appreciated until the beam power reached about 840 kW. One consequence was sudden failure of the stripper foil system due to convoy electrons stripped from the incoming H^{-} beam, which circled around to strike the foil bracket and cause bracket failure. Another consequence is that convoy electrons can reflect back up from the electron catcher and strike the foil and bracket. An additional contributor to foil system failure is vacuum breakdown due to the charge developed on the foil by secondary electron emission. In this paper we detail these and other interesting failure mechanisms and describe the improvements we have made to mitigate them.

High-current negative-ion sources for pulsed spallation neutron sources: LBNL workshop, October 1994

International Nuclear Information System (INIS)

Alonso, J.R.

1995-09-01

The neutron scattering community has endorsed the need for a high-power (1 to 5 MW) accelerator-driven source of neutrons for materials research. Properly configured, the accelerator could produce very short (sub-microsecond) bursts of cold neutrons, said time structure offering advantages over the continuous flux from a reactor. The recent cancellation of the ANS reactor project has increased the urgency to develop a comprehensive strategy based on the best technological scenarios. Studies to date have built on the experience from ISIS (the 160 kW source in the UK), and call for a high-current (approx. 100 mA peak) H- source-linac combination injecting into one or more accumulator rings in which beam may be further accelerated. The I to 5 GeV proton beam is extracted in a single turn and brought to the target-moderator stations. The high current, high duty-factor, high brightness and high reliability required of the ion source present a very large challenge to the ion source community. The Workshop reported on here, held in Berkeley in October 1994, analyzed in detail the source requirements for proposed accelerator scenarios, the present performance capabilities of different H- source technologies, and identified necessary R ampersand D efforts to bridge the gap

Effects of Trophic Modes, Carbon Sources, and Salinity on the Cell Growth and Lipid Accumulation of Tropic Ocean Oilgae Strain Desmodesmus sp. WC08.

Science.gov (United States)

Zhao, Zhenyu; Ma, Shasha; Li, Ang; Liu, Pinghuai; Wang, Meng

2016-10-01

The effects of trophic modes, carbon sources, and salinity on the growth and lipid accumulation of a marine oilgae Desmodesmus sp. WC08 in different trophic cultures were assayed by single factor experiment based on the blue-green algae medium (BG-11). The results implied that biomass and lipid accumulation culture process were optimized depending on the tophic modes, sorts, and concentration of carbon sources and salinity in the cultivation. There was no significant difference in growth or lipid accumulation with Na 2 CO 3 amendment or NaHCO 3 amendment. However, Na 2 CO 3 amendment did enhance the biomass and lipid accumulation to some extent. The highest Desmodesmus sp. WC08 biomass and lipid accumulation was achieved in the growth medium with photoautotrophic cultivation, 0.08 g L -1 Na 2 CO 3 amendment and 15 g L -1 sea salt, respectively.

Ring magnetron ionizer

International Nuclear Information System (INIS)

Alessi, J.G.

1986-01-01

A ring magnetron D - charge exchange ionizer has been built and tested. An H - current of 500 μA was extracted with an estimated H 0 density in the ionizer of 10 12 cm -3 . This exceeds the performance of ionizers presently in use on polarized H - sources. The ionizer will soon be tested with a polarized atomic beam

Privacy in wireless sensor networks using ring signature

Directory of Open Access Journals (Sweden)

Ashmita Debnath

2014-07-01

Full Text Available The veracity of a message from a sensor node must be verified in order to avoid a false reaction by the sink. This verification requires the authentication of the source node. The authentication process must also preserve the privacy such that the node and the sensed object are not endangered. In this work, a ring signature was proposed to authenticate the source node while preserving its spatial privacy. However, other nodes as signers and their numbers must be chosen to preclude the possibility of a traffic analysis attack by an adversary. The spatial uncertainty increases with the number of signers but requires larger memory size and communication overhead. This requirement can breach the privacy of the sensed object. To determine the effectiveness of the proposed scheme, the location estimate of a sensor node by an adversary and enhancement in the location uncertainty with a ring signature was evaluated. Using simulation studies, the ring signature was estimated to require approximately four members from the same neighbor region of the source node to sustain the privacy of the node. Furthermore, the ring signature was also determined to have a small overhead and not to adversely affect the performance of the sensor network.

Calibration of the nonlinear ring model at the Diamond Light Source

Directory of Open Access Journals (Sweden)

R. Bartolini

2011-05-01

Full Text Available Nonlinear beam dynamics plays a crucial role in defining the performance of a storage ring. The beam lifetime, the injection efficiency, and the dynamic and momentum apertures available to the beam are optimized during the design phase by a proper optimization of the linear lattice and of the distribution of sextupole families. The correct implementation of the design model, especially the nonlinear part, is a nontrivial accelerator physics task. Several parameters of the nonlinear dynamics can be used to compare the real machine with the model and eventually to correct the accelerator. Most of these parameters are extracted from the analysis of turn-by-turn data after the excitation of betatron oscillations of the particles in the ring. We present the experimental results of the campaign of measurements carried out at the Diamond storage ring to characterize the nonlinear beam dynamics. A combination of frequency map analysis with the detuning with momentum measurements has allowed for a precise calibration of the nonlinear model that can accurately reproduce the nonlinear beam dynamics in Diamond.

The vibration measurements at the photon factory storage ring building

International Nuclear Information System (INIS)

Haga, K.; Nakayama, M.; Masuda, K.; Ishizaki, H.; Kura, M.; Meng, L.; Oku, Y.

1999-01-01

The Photon Factory is a 2.5 GeV electron storage ring and has been operating since 1982 as a dedicated SR source. At the Photon Factory, we have been pursuing the various sources of the beam instabilities which deteriorated the SR beam quality in the wide frequency range. Some of the sources were the vibrations of magnets and floor of the ring tunnel, temperature change of the cooling water and the elongation of the storage ring building roof due to sunshine that induced the diurnal motion of the SR beam axis. This article presents the results of the vibration measurements that have been performed at the Photon Factory storage ring building. (1) The vibrations of the ring tunnel floor and the experimental hall floor, comparing with the vibration of the ground surrounding the storage ring building, are same order in the 1 ∼ 5 Hz range, and 1/3 ∼ 1/5 in the 5 ∼ 100 Hz range, in the vertical and the horizontal direction. (2) The effects of the vibration arising from the operating eight air-conditioners can be seen in the Fourier spectrum of the vibration of the ring tunnel floor, experimental floor, Q-magnets and BPM vacuum duct. (3) The vibrations of the Q-magnet and girder at frequencies near their fundamental resonant frequencies have been amplified 100 limes in the lateral direction comparing to the floor vibration. (4) Correlation between the vibration of the BPM vacuum duct and the vibration of the electron beam motion is unknown for the lack of the precise data. (authors)

Quantum interference of ballistic carriers in one-dimensional semiconductor rings

International Nuclear Information System (INIS)

Bagraev, N.T.; Buravlev, A.D.; Klyachkin, L.E.; Malyarenko, A.M.; Ivanov, V.K.; Rykov, S.A.; Shelykh, I.A.

2000-01-01

Quantum interference of ballistic carriers has been studied for the first time, using one-dimensional rings formed by quantum wire pairs in self-assembled silicon quantum wells. Energy dependencies of the transmission coefficient is calculated as a function of the length and modulation of the quantum wire pairs separated by a unified drain-source system or the quantum point contacts. The quantum conductance is predicted to be increased by a factor of four using the unified drain-source system as a result of the quantum interference. Theoretical dependencies are revealed by the quantum conductance oscillations created by the deviations of both the drain-source voltage and external magnetic field inside the silicon one-dimensional rings. The results obtained put forward a basis to create the Aharonov-Bohm interferometer using the silicon one-dimensional ring [ru

Ring cavity surface emitting semiconductor lasers

International Nuclear Information System (INIS)

Mujagic, E.

2010-01-01

Quantum cascade lasers (QCLs) are electrically driven semiconductor lasers, which have undergone a steady improvement since the first demonstration in 1994. These are now well established as reliable sources of coherent light in the mid-infrared (MIR) and terahertz (THz)range of the electromagnetic spectrum (3-300 μm). The rapid progress of this type of lasers is based on a high degree of freedom in tailoring the emission wavelength within a large variety of semiconductor heterostructure designs and materials. These properties have attracted the attention of various applications such as gas analysis, chemical sensing, spectral imaging and free-space telecommunication. In order to improve the selectivity, sensitivity and efficiency of today's sensor systems, high optical power, continuous wave and room temperature performance, single-mode operation and low divergence optical beams, are highly desirable qualities of a compact laser source in this field of research. Since all of these features cannot be provided by a conventional edge-emitting device at the same time, research has put focus on the development of surface emitting devices. Nowadays, the vertical cavity surface emitting lasers (VCSELs) are the most prominent representative for this type of light emitters. With its capability of producing narrow circular beams, the feasibility of two-dimensional arrays and on-wafer testing, such a coherent light source results in a reduction of the fabrication effort and production costs. Since the radiation in QCLs is strictly polarized normal to the epitaxial layer plane, fabrication of VCSELs based on QC structures is not viable. The subject of this work is the design and realization of 'ring cavity surface emitting lasers' (ring-CSELs). This type of lasers employs a circular ring cavity and a resonant distributed feedback (DFB) surface grating. Ring-CSELs were fabricated on the basis of MIR and THz QC structures, which cover a wavelength range from 4 μm to 93 �

Advanced photon source low-energy undulator test line

International Nuclear Information System (INIS)

Milton, S.V.

1997-01-01

The injector system of the Advanced Photon Source (APS) consists of a linac capable of producing 450-MeV positrons or > 650-MeV electrons, a positron accumulator ring (PAR), and a booster synchrotron designed to accelerate particles to 7 GeV. There are long periods of time when these machines are not required for filling the main storage ring and instead can be used for synchrotron radiation research. We describe here an extension of the linac beam transport called the Low-Energy Undulator Test Line (LEUTL). The LEUTL will have a twofold purpose. The first is to fully characterize innovative, future generation undulators, some of which may prove difficult or impossible to measure by traditional techniques. These might include small-gap and superconducting undulators, very long undulators, undulators with designed-in internal focusing, and helical undulators. This technique also holds the promise of extending the magnetic measurement sensitivity beyond that presently attainable. This line will provide the capability to directly test undulators before their possible insertion into operating storage rings. A second use for the test line will be to investigate the generation of coherent radiation at wavelengths down to a few tens of nanometers

The impact of tree age on biomass growth and carbon accumulation capacity: A retrospective analysis using tree ring data of three tropical tree species grown in natural forests of Suriname.

Science.gov (United States)

Köhl, Michael; Neupane, Prem R; Lotfiomran, Neda

2017-01-01

The world's forests play a pivotal role in the mitigation of global climate change. By photosynthesis they remove CO2 from the atmosphere and store carbon in their biomass. While old trees are generally acknowledged for a long carbon residence time, there is no consensus on their contribution to carbon accumulation due to a lack of long-term individual tree data. Tree ring analyses, which use anatomical differences in the annual formation of wood for dating growth zones, are a retrospective approach that provides growth patterns of individual trees over their entire lifetime. We developed time series of diameter growth and related annual carbon accumulation for 61 trees of the species Cedrela odorata L. (Meliacea), Hymenaea courbaril L. (Fabacea) and Goupia glabra Aubl. (Goupiacea). The trees grew in unmanaged tropical wet-forests of Suriname and reached ages from 84 to 255 years. Most of the trees show positive trends of diameter growth and carbon accumulation over time. For some trees we observed fluctuating growth-periods of lower growth alternate with periods of increased growth. In the last quarter of their lifetime trees accumulate on average between 39 percent (C. odorata) and 50 percent (G. glabra) of their final carbon stock. This suggests that old-growth trees in tropical forests do not only contribute to carbon stocks by long carbon resistance times, but maintain high rates of carbon accumulation at later stages of their life time.

Saturn’s ring temperatures at equinox

Science.gov (United States)

Spilker, Linda J.; Ferrari, C.; Morishima, R.

2013-10-01

Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.

APS storage ring vacuum system performance

International Nuclear Information System (INIS)

Noonan, J.R.; Gagliano, J.; Goeppner, G.A.

1997-01-01

The Advanced Photon Source (APS) storage ring was designed to operated with 7-GeV, 100-mA positron beam with lifetimes > 20 hours. The lifetime is limited by residual gas scattering and Touschek scattering at this time. Photon-stimulated desorption and microwave power in the rf cavities are the main gas loads. Comparison of actual system gas loads and design calculations will be given. In addition, several special features of the storage ring vacuum system will be presented

Effect of the sextupole distribution on the momentum aperture in the small cooling ring lattice at Fermilab

International Nuclear Information System (INIS)

Month, M.; Wiedemann, H.

1978-01-01

In the process of cooling and accumulating antiprotons for use in p-anti p collisions, rings must be designed with a large usable momentum aperture, on the order of 3% or larger. Since long straight sections and dispersionless regions are generally required, the sextupole field correction system for ''chromatic aberration'' is an important aspect of the overall lattice design. The Fermilab small cooling ring, whose purpose is to demonstrate the feasibility of cooling and accumulating protons (and antiprotons) with electrons, is a particularly simple system. This lattice is used to show the sensitivity of the momentum aperture to the sextupole correction system distribution

Einstein Ring in Distant Universe

Science.gov (United States)

2005-06-01

Using ESO's Very Large Telescope, Rémi Cabanac and his European colleagues have discovered an amazing cosmic mirage, known to scientists as an Einstein Ring. This cosmic mirage, dubbed FOR J0332-3557, is seen towards the southern constellation Fornax (the Furnace), and is remarkable on at least two counts. First, it is a bright, almost complete Einstein ring. Second, it is the farthest ever found. ESO PR Photo 20a/05 ESO PR Photo 20a/05 Deep Image of a Region in Fornax (FORS/VLT) [Preview - JPEG: 400 x 434 pix - 60k] [Normal - JPEG: 800 x 867 pix - 276k] [Full Res - JPEG: 1859 x 2015 pix - 3.8M] ESO PR Photo 20b/05 ESO PR Photo 20b/05 Zoom-in on the Newly Found Einstein Ring (FORS/VLT) [Preview - JPEG: 400 x 575 pix - 168k] [Normal - JPEG: 630 x 906 pix - 880k] Caption: ESO PR Photo 20a/05 is a composite image taken in two bands (B and R) with VLT/FORS1 of a small portion of the sky (field-of-view 7x7' or 1/15th of the area of the full moon). The faintest object seen in the image has a magnitude 26, that is, it is 100 million times fainter than what can be observed with the unaided eye. The bright elliptical galaxy on the lower-left quadrant is a dwarf galaxy part of a large nearby cluster in the Fornax constellation. As for all deep images of the sky, this field shows a variety of objects, the brightest ponctual sources being stars from our Galaxy. By far the field is dominated by thousands of faint background galaxies the colours of which are related to the age of their dominant stellar population, their dust content and their distance. The newly found Einstein ring is visible in the top right part of the image. ESO PR Photo 20b/05 zooms-in on the position of the newly found cosmic mirage. ESO PR Photo 20c/05 ESO PR Photo 20c/05 Einstein Ring in Distant Universe (FORS/VLT) [Preview - JPEG: 400 x 584 pix - 104k] [Normal - JPEG: 800 x 1168 pix - 292k] [Full Res - JPEG: 1502 x 2192 pix - 684k] Caption of ESO PR Photo 20c/05: The left image is magnified and centred

SOR-ring failure

International Nuclear Information System (INIS)

Kitamura, Hideo

1981-01-01

It was in the autumn of 1976 that the SOR-ring (synchrotron radiation storage ring) has commenced the regular operation. Since then, the period when the operation was interrupted due to the failures of SOR-ring itself is in total about 8 weeks. Failures and accidents have occurred most in the vacuum system. Those failure experiences are described on the vacuum, electromagnet, radio-frequency acceleration and beam transport systems with their interrupted periods. The eleven failures in the vacuum system have been reported, such as bellows breakage in a heating-evacuating period, leakage from the bellows of straight-through valves (made in U.S.A. and Japan), and leakage from the joint flange of the vacuum system. The longest interruption was 5 weeks due to the failure of a domestically manufactured straight-through valve. The failures of the electromagnet system involve the breakage in a cooling water system, short circuit of a winding in the Q magnet power transformer, blow of a fuse protecting the deflection magnet power source by the current less than the rating, and others. The failures of the RF acceleration system include the breakage of an output electronic tube the breakage of a cavity ceramic, RF voltage fluctuation due to the contact deterioration at a cavity electrode, and the failure of grid bias power source. It is necessary to select the highly reliable components for the vacuum system because the vacuum system failures require longer time for recovery, and very likely to induce secondary and tertiary failures. (Wakatsuki, Y.)

Undulator tunability and synchrotron ring-energy

International Nuclear Information System (INIS)

Viccaro, P.J.; Sheony, G.K.

1992-01-01

An undulator has two properties which make it an extremely attractive source of electromagnetic radiation. The first is that the radiation is concentrated in a number of narrow energy bands known as harmonics of the device. The second characteristic is that under favorable operating conditions, the energy of these harmonics can be shifted or open-quote tunedclose quotes over an energy interval which can be as large as two or three times the value of the lowest energy harmonic. Both the photon energy of an undulator as well as its tunability are determined by the period, λ, of the device, the magnetic gap, G (which is larger than the minimum aperture required for injection and operation of the storage ring) and the storage ring energy E R . Given the photon energy, E p , the above parameters ultimately define the limits of operation or tunability of the undulator. In general, the larger the tunability range, the more useful the device. Therefore, for a given required maximum photon energy, it is desirable to find the operating conditions and device parameters which result in the largest tunability interval possible. With this in mind, we have investigated the question of undulator tunability with emphasis on the role of the ring energy in order to find the smallest E R consistent with the desired tunability interval and photon energy. As a guideline, we have included a preliminary criteria, concerning the tunability requirements for the Advanced Photon Source (APS) to be built at Argonne. The analysis is aimed at X-ray undulator sources on the APS but is applicable to any storage ring

Compact X-ray source based on Compton backscattering

CERN Document Server

Bulyak, E V; Zelinsky, A; Karnaukhov, I; Kononenko, S; Lapshin, V G; Mytsykov, A; Telegin, Yu P; Khodyachikh, A; Shcherbakov, A; Molodkin, V; Nemoshkalenko, V; Shpak, A

2002-01-01

The feasibility study of an intense X-ray source based on the interaction between the electron beam in a compact storage ring and the laser pulse accumulated in an optical resonator is carried out. We propose to reconstruct the 160 MeV electron storage ring N-100, which was shutdown several years ago. A new magnetic lattice will provide a transverse of electron beam size of approx 35 mu m at the point of electron beam-laser beam interaction. The proposed facility is to generate X-ray beams of intensity approx 2.6x10 sup 1 sup 4 s sup - sup 1 and spectral brightness approx 10 sup 1 sup 2 phot/0.1%bw/s/mm sup 2 /mrad sup 2 in the energy range from 10 keV up to 0.5 MeV. These X-ray beam parameters meet the requirements for most of technological and scientific applications. Besides, we plan to use the new facility for studying the laser cooling effect.

Compact X-ray source based on Compton backscattering

Energy Technology Data Exchange (ETDEWEB)

Bulyak, E.; Gladkikh, P.; Zelinsky, A. E-mail: zelinsky@kipt.kharkov.ua; Karnaukhov, I.; Kononenko, S.; Lapshin, V.; Mytsykov, A.; Telegin, Yu.; Khodyachikh, A.; Shcherbakov, A.; Molodkin, V.; Nemoshkalenko, V.; Shpak, A

2002-07-21

The feasibility study of an intense X-ray source based on the interaction between the electron beam in a compact storage ring and the laser pulse accumulated in an optical resonator is carried out. We propose to reconstruct the 160 MeV electron storage ring N-100, which was shutdown several years ago. A new magnetic lattice will provide a transverse of electron beam size of {approx}35 {mu}m at the point of electron beam-laser beam interaction. The proposed facility is to generate X-ray beams of intensity {approx}2.6x10{sup 14} s{sup -1} and spectral brightness {approx}10{sup 12} phot/0.1%bw/s/mm{sup 2}/mrad{sup 2} in the energy range from 10 keV up to 0.5 MeV. These X-ray beam parameters meet the requirements for most of technological and scientific applications. Besides, we plan to use the new facility for studying the laser cooling effect.

A Bell inequality for a class of multilocal ring networks

Science.gov (United States)

Frey, Michael

2017-11-01

Quantum networks with independent sources of entanglement (hidden variables) and nodes that execute joint quantum measurements can create strong quantum correlations spanning the breadth of the network. Understanding of these correlations has to the present been limited to standard Bell experiments with one source of shared randomness, bilocal arrangements having two local sources of shared randomness, and multilocal networks with tree topologies. We introduce here a class of quantum networks with ring topologies comprised of subsystems each with its own internally shared source of randomness. We prove a Bell inequality for these networks, and to demonstrate violations of this inequality, we focus on ring networks with three-qubit subsystems. Three qubits are capable of two non-equivalent types of entanglement, GHZ and W-type. For rings of any number N of three-qubit subsystems, our inequality is violated when the subsystems are each internally GHZ-entangled. This violation is consistently stronger when N is even. This quantitative even-odd difference for GHZ entanglement becomes extreme in the case of W-type entanglement. When the ring size N is even, the presence of W-type entanglement is successfully detected; when N is odd, the inequality consistently fails to detect its presence.

Femtosecond laser-induced concentric ring microstructures on Zr-based metallic glass

International Nuclear Information System (INIS)

Ma Fengxu; Yang Jianjun; Xiaonong Zhu; Liang Chunyong; Wang Hongshui

2010-01-01

Surface morphological evolution of Zr-based metallic glass ablated by femtosecond lasers is investigated in atmosphere condition. Three types of permanent ring structures with micro-level spacing are observed for different laser shots and fluences. In the case of low laser fluences, the generation of annular patterns with nonthermal features is observed on the rippled structure with the subwavelength scale, and the ring spacing shows a decrease tendency from the center to the margin. While in the case of high laser fluences, the concentric rings formation within the laser spot is found to have evident molten traces and display the increasing ring spacing along the radial direction. Moreover, when the laser shots accumulation becomes large, the above two types of ring microstructures begin to develop into the common ablation craters. Analysis and discussion suggests that the stress-induced condensation of ablation vapors and the frozen thermocapillary waves on the molten surfaces should be responsible for the formation of two different types of concentric ring structures, respectively. Eventually, a processing window for each resulting surface microstructure type is obtained experimentally and indicates the possibility to control the morphological transitions among different types.

The earth's ring current - Present situation and future thrusts

Science.gov (United States)

Williams, D. J.

1987-01-01

Particle distributions, currents, and the ring current situation prior to the August 1984 launch of the AMPTE Charge Composition Explorer (CCE) are discussed. CCE results which demonstrate the capability of these new measurements to pursue questions of ring current sources, energization, and transport are presented. Consideration is given to various ring current generation mechanisms which have been discussed in the literature, and a two-step generation process which to a certain extent unifies the previous mechanisms is presented. The first in-situ global observations of ring current decay as obtained through the detection of energetic neutral atoms generated by charge exchange interactions between the ring current and hydrogen geocorona are discussed, as well as the possibility of using the detection of energetic neutral atoms to obtain global images of the earth's ring current.

Examining the Combined Saturn and Ring Exosphere/Ionosphere using Cassini's Proximal orbits

Science.gov (United States)

Tucker, O. J.; Tseng, W. L.; Johnson, R. E.; Perry, M. E.

2017-12-01

Neutral molecules that are emitted from Saturn's exobase (i.e., H2) and the main rings (i.e., H2, O2, H) are a source of material for both the Saturn and ring ionospheres as well as Saturn's magnetosphere (Tseng et al., 2013 [PSS 85 164 - 167]). However, the density gradient of H2 produced from the main rings is very different than that produced by Saturn's exospheric flux due to its emission from the ring plane and distance from Saturn. Cassini measurements obtained during the proximal orbits can likely be used to identify contributions from Saturn and the rings. Here we present results obtained from Monte Carlo models of the Saturn and ring exosphere used to analyze INMS data of neutrals and ions measured along the trajectories of the Proximal orbits. Understanding the sources of neutrals and the concomitant ions can help provide insight about the dynamics occurring in the Saturn system.

Recent results on lead-ion accumulation in LEAR for the LHC

International Nuclear Information System (INIS)

Baird, S.; Bosser, J.; Broere, J.; Carli, C.; Chanel, M.; Hill, C.; Ley, R.; Lombardi, A.; Maccaferri, R.; Maury, S.; Meshkov, I.; Moehl, D.; Molinari, G.; Mulder, H.; Syresin, E.; Tanke, E.; Tranquille, G.; Varenne, F.; Vretenar, M.

1997-01-01

To prepare dense bunches of lead ions for the LHC it has been proposed to accumulate the 4.2 MeV/u linac beam in a storage ring with electron cooling. A series of experiments is being performed in the low-energy ring LEAR to test this technique. First results were already reported at the Beam Crystallisation Workshop in Erice in November 1995. Two more recent runs to complement these investigations were concerned with: further study of the beam lifetime; the dependence of the cooling time on optical settings of the storage ring and on neutralization of the electron beam: and tests in view of multiturn injection. New results obtained in these two runs in December 1995 and in April 1996 are discussed in this contribution. (orig.)

The Advanced Photon Source injection timing system

International Nuclear Information System (INIS)

Lenkszus, F.R.; Laird, R.

1995-01-01

The Advanced Photon Source consists of five accelerators. The injection timing system provides the signals required to cause a bunch emitted from the electron gun to navigate through intermediate accelerators to a specific bucket (1 out of 1296) within the storage ring. Two linacs and a positron accumulator ring operate at 60Hz while a booster synchrotron ramps and injects into the storage ring at 2Hz. The distributed, modular VME/VXI-based injection timing system is controlled by two EPICS-based input/output controllers (IOCs). Over 40 VME/VXI cards have been developed to implement the system. Card types range from 352MHz VXI timing modules to VME-based fiber optic fanouts and logic translators/drivers. All timing is distributed with fiber optics. Timing references are derived directly from machine low-level rf of 9.77MHz and 352MHz. The timing references provide triggers to programmable delay generators. Three grades of timing are provided. Precision timing is derived from commercial digital delay generators, intermediate precision timing is obtained from VXI 8-channel digital delay generators which provide timing with 25ns peak-to-peak jitter, and modest precision timing is provided by the APS event system. The timing system is fully integrated into the APS EPICS-based control system

Properties of tree rings in LSST sensors

International Nuclear Information System (INIS)

Park, H.Y.; Tsybychev, D.; Nomerotski, A.

2017-01-01

Images of uniformly illuminated sensors for the Large Synoptic Survey Telescope have circular periodic patterns with an appearance similar to tree rings. These patterns are caused by circularly symmetric variations of the dopant concentration in the monocrystal silicon boule induced by the manufacturing process. Non-uniform charge density results in the parasitic electric field inside the silicon sensor, which may distort shapes of astronomical sources. In this study we analyzed data from fifteen LSST sensors produced by ITL to determine the main parameters of the tree rings: amplitude and period, and also variability across the sensors tested at Brookhaven National Laboratory. Tree ring pattern has a weak dependence on the wavelength. However the ring amplitude gets smaller as wavelength gets longer, since longer wavelengths penetrate deeper into the silicon. Tree ring amplitude gets larger as it gets closer to the outer part of the wafer, from 0.1 to 1.0%, indicating that the resistivity variation is larger for larger radii.

CESAR, 2 MeV electron storage ring; general view from above.

CERN Multimedia

Service Photo; CERN PhotoLab

1967-01-01

CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

National Synchrotron Light Source

International Nuclear Information System (INIS)

van Steenbergen, A.

1979-01-01

The National Synchrotron Light Source comprises two high intensity electron storage rings for the generation of intense fluxes of synchrotron radiation in the vuv wavelength domain (700 MeV e - ring) and in the x-ray wavelength domain (2.5 GeV e - ring). A description is presented of the basic facility and the characteristics of the synchrotron radiation sources. The present plans for specific beam lines will be enumerated and the planned use of beam wigglers and undulators will be discussed

Ring Theory

CERN Document Server

Jara, Pascual; Torrecillas, Blas

1988-01-01

The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

Renormalized second post-Newtonian spin contributions to the accumulated orbital phase for LISA sources

International Nuclear Information System (INIS)

Gergely, Laszlo Arpad; Mikoczi, Balazs

2009-01-01

We give here a new third post-Newtonian (3PN) spin-spin contribution (in the PN parameter ε) to the accumulated orbital phase of a compact binary, arising from the spin-orbit precessional motion of the spins. In the equal mass case, this contribution vanishes, but Laser Interferometer Space Antenna (LISA) sources of merging supermassive binary black holes have typically a mass ratio of 1:10. For such nonequal masses, this 3PN correction is periodic in time, with a period approximately ε -1 times larger than the period of gravitational waves. We derive a renormalized and simpler expression of the spin-spin coefficient at 2PN, as an average over the time scale of this period of the combined 2PN and 3PN contribution. We also find that for LISA sources the quadrupole-monopole contribution to the phase dominates over the spin-spin contribution, while the self-spin contribution is negligible even for the dominant spin. Finally, we define a renormalized total spin coefficient σ to be employed in the search for gravitational waves emitted by LISA sources.

SXLS storage ring design

International Nuclear Information System (INIS)

Anon.

1991-01-01

X-ray lithography has emerged as a strong candidate to meet the demands of ever finer linewidths on integrated circuits, particularly for linewidths less than .25 microns. Proximity printing X-ray lithography makes use of soft X-rays to shadow print an image of a mask onto a semiconductor wafer to produce integrated circuits. To generate the required X-rays in sufficient quantities to make commercial production viable, electron storage rings have been proposed as the soft X-ray sources. Existing storage rings have been used to do the initial development work and the success of these efforts has led the lithographers to request that new rings be constructed that are dedicated to X-ray lithography. As a result of a series of workshops held at BNL [10.3] which were attended by both semiconductor and accelerator scientists, the following set of zeroth order specifications' on the light and electron beam of a storage ring for X-ray lithography were developed: critical wavelength of light: λ c = 6 to 10 angstroms, white light power: P = 0.25 to 2.5 watts/mrad, horizontal collection angle per port: θ = 10 to 50 mrad, electron beam sizes: σ x ∼ σ y y ' < 1 mrad

Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings

Energy Technology Data Exchange (ETDEWEB)

Wagener, M. C.; Botha, J. R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Carrington, P. J. [Department of Electronic and Electrical Engineering, University College London, London (United Kingdom); Krier, A. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

2014-07-28

The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudo-monochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo- and thermal-emission characteristics of the quantum rings.

Waves in Saturn's rings probed by radio occultation

International Nuclear Information System (INIS)

Rosen, P.A.

1989-01-01

Thirty wave features, observed in 3.6 and 13 cm-wavelength optical depth profiles of Saturn's rings obtained by Voyager 1 radio occultation, are analyzed individually and comparatively. Many are the signature of spiral density waves and bending waves excited by gravitational resonances with Saturn's satellites. A new technique for locating waveform extrema, which fits a sinusoid to each half cycle of wave data, quantifies the wavelength variation across a feature. Fitting dispersion models to the derived wavelengths provides new estimates of ambient surface mass density σ in each wave region. For fourteen weak density waves in Ring A, modelling of the waveform near resonance with linear density wave theory gives independent estimates of σ, as well as reliable estimates of resonance location. Measurements of wave amplitude damping give an upper bound for ring thickness 2H, where H is the ring scale height. In the wave regions studied, Rings A, B, and C have 30 approx-lt σ approx-lt 70, σ approx-gt 65, and σ ∼ 1 g/cm 2 , respectively. Mass loading estimates from waveform modelling are 20 to 40% larger than dispersion-derived values, suggesting accumulation of mass in the wave regions. The average offset of derived wave location from theoretical resonance is about 1 km. Model waveforms of overlapping waves excited by the satellites Janus and Epimethenus agree well with observed morphologies in the linear region near resonance. In Ring C, dispersion analysis indicates that the most prominent wave feature, previously unidentified, is a one-armed spiral wave

Neutron activation studies of trace elements in tree rings

International Nuclear Information System (INIS)

Tout, R.E.; Gilboy, W.B.; Spyrou, N.M.

1977-01-01

The levels of twelve elements most of which are either considered essential to plant growth or have been detected in air filter samples in an air pollution survey have been monitored in three transverse sections of trees, two elms (ring-porous trees) and one cedar (a conifer). An irradiation time of 10 minutes and a waiting time of 1 minute were selected followed by a 10-minute count. The activated samples were placed on a specially shaped perspex disc situated on a 45-cm 3 Ge(Li) detector. The gamma-ray spectra were subsequently analysed on a 6600 computer, using the library program 'SAMPO' to which subroutines have been added for peak identification and for calculating the mass of elements present. All irradiations were carried out using a thermal neutron flux of 1.5x10 12 ncm -2 sec -1 . Two dimensional distributions of the elements around the tree rings of the section and radially from ring to ring, have been obtained to see if tree rings can be analysed for use as a record of historical pollution. Definite movement of most of these elements between the two main parts of the xylem has occured in all three trees. This makes it seem unlikely that any pollution products taken up from the atmosphere would be retained in the same ring in which they were originally accumulated. Exceptions may occur in the sapwood rings, where a few elements, especially Cl, show directional peaks which do not persist in the heartwood. (T.G.)

Characterization of distinct Arctic aerosol accumulation modes and their sources

DEFF Research Database (Denmark)

Lange, R.; Dall'Osto, M.; Skov, H.

2018-01-01

-August). By association to chemical composition, cloud condensation nuclei properties, and meteorological variables, three typical accumulation mode aerosol clusters were identified: Haze (32% of the time), Bimodal (14%) and Aged (6%). In brief: (1) Haze accumulation mode aerosol shows a single mode at 150 nm, peaking...

The CERN Antiproton Collider Programme Accelerators and Accumulation Rings

CERN Document Server

Koziol, Heribert

2004-01-01

One of CERN's most daring and successful undertakings was the quest for the intermediate bosons, W and Z. In this paper, we describe the accelerator part of the venture which relied on a number of innovations: an extension of the budding method of stochastic cooling by many orders of magnitude; the construction of the Antiproton Accumulator, depending on several novel accelerator methods and technologies; major modifications to the 26 GeV PS Complex; and the radical conversion of the 300 GeV SPS, which just had started up as an accelerator, to a protonâ€"antiproton collider. The SPS Collider had to master the beamâ€"beam effect far beyond limits reached ever before and had to function in a tight symbiosis with the huge detectors UA1 and UA2.

Progress on the Design of the Storage Ring Vacuum System for the Advanced Photon Source Upgrade Project

Energy Technology Data Exchange (ETDEWEB)

Stillwell, B.; Billett, B.; Brajuskovic, B.; Carter, J.; Kirkus, E.; Lale, M.; Lerch, J.; Noonan, J.; O' Neill, M.; Rocke, B.; Suthar, K.; Walters, D.; Wiemerslage, G.; Zientek, J.

2017-06-20

Recent work on the design of the storage ring vacuum system for the Advanced Photon Source Upgrade project (APS-U) includes: revising the vacuum system design to accommodate a new lattice with reverse bend magnets, modifying the designs of vacuum chambers in the FODO sections for more intense incident synchrotron radiation power, modifying the design of rf-shielding bellows liners for better performance and reliability, modifying photon absorber designs to make better use of available space, and integrated planning of components needed in the injection, extraction and rf cavity straight sections. An overview of progress in these areas is presented.

Magnon Accumulation by Clocked Laser Excitation as Source of Long-Range Spin Waves in Transparent Magnetic Films

Directory of Open Access Journals (Sweden)

M. Jäckl

2017-04-01

Full Text Available Optical tools are promising for spin-wave generation because of the possibilities of ultrafast manipulation and local excitation. However, a single laser pulse can inject spin waves (SWs only with a broad frequency spectrum, resulting in short propagation distances and low wave amplitudes. Here, we excite a magnetic garnet film by a train of fs-laser pulses with a 1-GHz repetition rate so that the pulse separation is shorter than the decay time of magnetic modes, which allows us to achieve a collective impact on the magnetization and establish a quasistationary source of spin waves, namely, a coherent accumulation of magnons (“magnon cloud”. This approach has several appealing features: (i The magnon source is tunable, (ii the SW amplitude can be significantly enhanced, (iii the SW spectrum is quite narrow, providing long-distance propagation, (iv the periodic pumping results in an almost constant-in-time SW amplitude for the distances larger than 20  μm away from the source, and (v the SW emission shows pronounced directionality. These results expand the capabilities of ultrafast coherent optical control of magnetization and pave the way for applications in data processing, including the quantum regime. The quasistationary magnon accumulation might also be of interest for applications in magnon Bose-Einstein condensates.

Report of the eRHIC Ring-Ring Working Group

Energy Technology Data Exchange (ETDEWEB)

Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-10-13

This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

Tribological Performance of Different Geometries of Piston Rings in Marine Diesel Engines

DEFF Research Database (Denmark)

Imran, Tajammal; Klit, Peder; Felter, Christian

Friction in the piston ring package (piston, piston rings and liner) is a major source of power consumption in two stroke marine diesel engines. It is well-known that a typical piston ring operates under full separation in the mid-part of the stroke, and in the mixed lubrication regime at the dead...

SOR-RING: an electron storage ring dedicated to spectroscopy, 2

International Nuclear Information System (INIS)

Kitamura, H.; Miyahara, T.; Sato, S.; Watanabe, M.; Mitani, S.

1976-01-01

A 300 MeV electron storage ring to be used exclusively as a synchrotron radiation source for spectroscopy has been constructed in Institute for Nuclear Study (INS), University of Tokyo, Tanashi. Its useful spectral range lies between 40 and 2200 A. The 1.3 GeV electron synchrotron of INS currently being operated for high energy particle experiments serves as an injector. Electron beams are extracted from the synchrotron at 300 MeV, transported about twenty meters, and injected to the ring one pulse per second. In the test operation a current of 10 mA was stored with a lifetime of one hour, while the design goal determined by the Touschek effect is 100 mA with one hour, for operation in 300 MeV. Increase of operating energy up to 375 MeV is feasible with a minor modification of the present design. (auth.)

Effects of errors on the dynamic aperture of the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Bizek, H.; Crosbie, E.; Lessner, E.; Teng, L.; Wirsbinski, J.

1991-01-01

The individual tolerance limits for alignment errors and magnet fabrication errors in the 7-GeV Advanced Photon Source storage ring are determined by computer-simulated tracking. Limits are established for dipole strength and roll errors, quadrupole strength and alignment errors, sextupole strength and alignment errors, as well as higher order multipole strengths in dipole and quadrupole magnets. The effects of girder misalignments on the dynamic aperture are also studied. Computer simulations are obtained with the tracking program RACETRACK, with errors introduced from a user-defined Gaussian distribution, truncated at ±5 standard deviation units. For each error, the average and rms spread of the stable amplitudes are determined for ten distinct machines, defined as ten different seeds to the random distribution, and for five distinct initial directions of the tracking particle. 4 refs., 4 figs., 1 tab

Pulsed Power Applications in High Intensity Proton Rings

CERN Document Server

Zhang, Wu; Ducimetière, Laurent; Fowler, Tony; Kawakubo, Tadamichi; Mertens, Volker; Sandberg, Jon; Shirakabe, Yoshihisa

2005-01-01

The pulsed power technology has been applied in particle accelerators and storage rings for over four decades. It is most commonly used in injection, extraction, beam manipulation, source, and focusing systems. These systems belong to the class of repetitive pulsed power. In this presentation, we review and discuss the history, present status, and future challenge of pulsed power applications in high intensity proton accelerators and storage rings.

Cooler Storage Ring at China Institute of Modern Physics

CERN Document Server

Wen-Xia, Jia; Zhan, W

2005-01-01

CSR, a new ion cooler-storage-ring project in China IMP, is a double ring system, and consists of a main ring (CSRm) and an experimental ring (CSRe). The two existing cyclotrons SFC (K=69) and SSC (K=450) of the Heavy Ion Research Facility in Lanzhou (HIRFL) will be used as its injector system. The heavy ion beams with the energy range of 7-30 MeV/nucleus from the HIRFL will be accumulated, cooled and accelerated to the higher energy range of 100-500 MeV/ nucleus in CSRm, and then extracted fast to produce radioactive ion beams or highly charged heavy ions. Those secondary beams will be accepted and stored or decelerated by CSRe for many internal-target experiments or high precision spectroscopy with beam cooling. On the other hand, the beams with the energy range of 100-1000MeV/ nucleus will also be extracted from CSRm by using slow extraction or fast extraction for many external-target experiments. CSR project was started in the end of 1999 and will be finished in 2006. In this paper the outline and the act...

ANL stochastic-cooling experiments using the FNAL 200-MeV cooling ring

International Nuclear Information System (INIS)

Hogrefe, R.L.; Kellogg, K.D.; Konecny, R.S.; Kramer, S.L.; Simpson, J.D.; Suddeth, D.E.; Hardek, T.W.

1981-01-01

Studies of stochastic momentum cooling are being conducted on the FNAL 200-MeV Storage Ring. The specific goal of the activity is to establish confidence in the theory and simulation methods used to describe the cooling process, and to develop techniques and devices suitable for use in the antiproton-accumulation scheme now planned for construction at FNAL. A summary of the activity, including hardware design, results of experiments, comparison with theory, and implications for the antiproton accumulator are presented

Ring current proton decay by charge exchange

Science.gov (United States)

Smith, P. H.; Hoffman, R. A.; Fritz, T.

1975-01-01

Explorer 45 measurements during the recovery phase of a moderate magnetic storm have confirmed that the charge exchange decay mechanism can account for the decay of the storm-time proton ring current. Data from the moderate magnetic storm of 24 February 1972 was selected for study since a symmetrical ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, the equatorially mirroring protons in the energy range 5 to 30 keV decayed throughout the L-value range of 3.5 to 5.0 at the charge exchange decay rate calculated by Liemohn. After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange can entirely account for the storm-time proton ring current decay, and that this mechanism must be considered in all studies involving the loss of proton ring current particles.

Femtoslicing in Storage Rings

CERN Document Server

Khan, Shaukat

2005-01-01

The generation of ultrashort synchrotron radiation pulses by laser-induced energy modulation of electrons and their subsequent transverse displacement, now dubbed "femtoslicing," was demonstrated at the Advanced Light Source in Berkeley. More recently, a femtoslicing user facility was commissioned at the BESSY storage ring in Berlin, and another project is in progress at the Swiss Light Source. The paper reviews the principle of femtoslicing, its merits and shortcomings, as well as the variations of its technical implementation. Various diagnostics techniques to detect successful laser-electron interaction are discussed and experimental results are presented.

A model of ATL ground motion for storage rings

International Nuclear Information System (INIS)

Wolski, Andrzej; Walker, Nicholas J.

2003-01-01

Low emittance electron storage rings, such as those used in third generation light sources or linear collider damping rings, rely for their performance on highly stable alignment of the lattice components. Even if all vibration and environmental noise sources could be suppressed, diffusive ground motion will lead to orbit drift and emittance growth. Understanding such motion is important for predicting the performance of a planned accelerator and designing a correction system. A description (known as the ATL model) of ground motion over relatively long time scales has been developed and has become the standard for studies of the long straight beamlines in linear colliders. Here, we show how the model may be developed to include beamlines of any geometry. We apply the model to the NLC and TESLA damping rings, to compare their relative stability under different conditions

Neutronic Design Calculations on Moderators for the Spallation Neutron Source (SNS)

International Nuclear Information System (INIS)

Murphy, D.B.

1999-01-01

The Spallation Neutron Source (SNS) to be built at the Oak Ridge National Laboratory will provide an intense source of neutrons for a large variety of experiments. It consists of a high-energy (1-GeV) and high-power (∼1-MW) proton accelerator, an accumulator ring, together with a target station and an experimental area. In the target itself, the proton beam will produce neutrons via the spallation process and these will be converted to low-energy ( 2 O moderators. Extensive engineering design work has been conducted on the moderator vessels. For our studies we have produced realistic neutronic representations of these moderators. We report on neutronic studies conducted on these representations of the moderators using Monte Carlo simulation techniques

Some notes on the rings with sacred inscriptions from Pannonia

Directory of Open Access Journals (Sweden)

András Szabó

2015-02-01

Full Text Available More than a hundred rings bearing inscriptions are known from the territory of Roman Pannonia. Among these close to 30 artefacts can be regarded as rings displaying inscriptions of religious significance. Besides the Silvanus-rings, well-known to the archaeological research, some new groups of rings featuring sacred inscriptions can be distinguished according to the dedications. The aim of this paper is to analyse these objects and their religious backgrounds with the help of some archaeological, epigraphical and literary sources and to point out some of the questionable observations of the earlier research.

Coulomb collisions of ring current particles: Indirect source of heat for the ionosphere

Science.gov (United States)

Cole, K. D.

1975-01-01

The additional energy requirements of the topside ionosphere during a magnetic storm are less than one quarter of the ring current energy. This energy is supplied largely by Coulomb collisions of ring current protons of energy less than about 20 keV with background thermal electrons which conduct the heat to the ionosphere. Past criticisms are discussed of this mechanism for the supply of energy to the SAR-arc and neighboring regions of the ionosphere.

Compact electron storage ring JESCOS with normalconducting or superconducting magnets for X-ray lithography

International Nuclear Information System (INIS)

Anton, F.; Klein, U.; Krischel, D.; Anderberg, B.

1992-01-01

The layouts of a normal conducting electron storage ring and a storage ring with superconducting bending magnets are presented. The storage rings have a critical wavelength of 1 nm and are designed as compact sources for X-ray lithography. Each ring fits into a shielded room with a diameter of 14 m. (author) 3 refs.; 5 figs.; 1 tab

Future Synchrotron Radiation Sources

CERN Document Server

Winick, Herman

2003-01-01

Sources of synchrotron radiation (also called synchrotron light) and their associated research facilities have experienced a spectacular growth in number, performance, and breadth of application in the past two to three decades. In 1978 there were eleven electron storage rings used as light sources. Three of these were small rings, all below 500 mega-electron volts (MeV), dedicated to this purpose; the others, with energy up to 5 giga-electron volts (GeV), were used parasitically during the operation of the ring for high energy physics research. In addition, at that time synchrotron radiation from nine cyclic electron synchrotrons, with energy up to 5 GeV, was also used parasitically. At present no cyclic synchrotrons are used, while about 50 electron storage rings are in operation around the world as fully dedicated light sources for basic and applied research in a wide variety of fields. Among these fields are structural molecular biology, molecular environmental science, materials, analytic chemistry, micr...

Injection, compression and stability of intense ion-rings

International Nuclear Information System (INIS)

Sudan, R.N.

1975-01-01

Recent advances in pulsed high power ion beam technology make possible the creation of intense ion-rings with strong self-magnetic fields by single pulse injection. Such ion rings have several uses in controlled fusion e.g., to produce a min parallel B parallel magnetic geometry with a mirror ratio much higher than is possible with external conductors. For even stronger ion rings a min parallel B parallel with closed lines of force (ASTRON type) can be created. For this purpose, since the ion energies required are much higher than are available from high power sources, magnetic compression can be utilized to increase the ion energy. The success of this scheme depends critically on the stability of the ion ring. The low frequency perturbations of the ring-plasma system is examined by means of a generalization of the energy principle which established sufficient conditions for stability. The high-frequency micro-instabilities and their nonlinear consequences are discussed in terms of conventional techniques

Storage ring design of the 8 GeV synchrotron radiation facility (SPring-8)

International Nuclear Information System (INIS)

Hara, M.; Bc, S.H.; Motonaga, S.

1990-01-01

In Japan, RIKEN (Institute of Physical and Chemical Research) and JAERI (Japan Atomic Energy Research Institute) have organized a joint design team and started a design study for an 8 GeV synchrotron radiation X-ray source. This paper outlines the status of the design study for the 8 GeV highly brilliant synchrotron radiation X-ray source ring named Super Photon Ring (SPring-8). The facility consists of a main storage ring, a full-energy injector booster synchrotron and a pre-injector 1 GeV linac. The injector linac and synchrotron are laid outside the storage ring because to permit the use of the linac and synchrotron not only as an injector but also as an electron or positron beam source. The purpose of the facility is to provide stable photon beams with high brilliance in the X-ray region. The energy of the stored electrons (positrons) is fixed at 8 GeV to fulfill the required condition using conventional type insertion devices. (N.K.)

ASSOCIATIVE RINGS SOLVED AS LIE RINGS

Directory of Open Access Journals (Sweden)

M. B. Smirnov

2011-01-01

Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

A simple scheme for injection and extraction in compact rings

International Nuclear Information System (INIS)

Xu, H. S.; Huang, W. H.; Tang, C. X.

2014-01-01

There has been great interest in building compact synchrotrons for various applications, for example, inverse Compton scattering X-ray sources. However, the beam injection and extraction in compact rings require careful design for the lack of space. In this paper, we propose a simple combined injection-extraction scheme exploiting the fringe field of existing dipole magnets instead of additional septum magnets. This scheme is illustrated by using the 4.8 m ring proposed for Tsinghua Thomson scattering X-ray source as an example. Particle tracking is applied to demonstrate the validity of this scheme

Bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from East Greenland.

Science.gov (United States)

Letcher, Robert J; Gebbink, Wouter A; Sonne, Christian; Born, Erik W; McKinney, Melissa A; Dietz, Rune

2009-11-01

We report on the comparative bioaccumulation, biotransformation and/or biomagnification from East Greenland ringed seal (Pusa hispida) blubber to polar bear (Ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (PCBs), chlordanes (CHLs), hydroxyl (OH-) and methylsulfonyl (MeSO(2)-) PCBs, polybrominated biphenyls (PBBs), OH-PBBs, polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants and OH- and methoxyl (MeO-) PBDEs, 2,2-dichloro-bis(4-chlorophenyl)ethene (p,p'-DDE), 3-MeSO(2)-p,p'-DDE, pentachlorophenol (PCP) and 4-OH-heptachlorostyrene (4-OH-HpCS). We detected all of the investigated contaminants in ringed seal blubber with high frequency, the main diet of East Greenland bears, with the exception of OH-PCBs and 4-OH-HpCS, which indicated that these phenolic contaminants were likely of metabolic origin and formed in the bears from accumulated PCBs and octachlorostyrene (OCS), respectively, rather than being bioaccumulated from a seal blubber diet. For all of the detectable sum of classes or individual organohalogens, in general, the ringed seal to polar bear mean BMFs for SigmaPCBs, p,p'-DDE, SigmaCHLs, SigmaMeSO(2)-PCBs, 3-MeSO(2)-p,p'-DDE, PCP, SigmaPBDEs, total-(alpha)-HBCD, SigmaOH-PBDEs, SigmaMeO-PBDEs and SigmaOH-PBBs indicated that these organohalogens bioaccumulate, and in some cases there was tissue-specific biomagnification, e.g., BMFs for bear adipose and liver ranged from 2 to 570. The blood-brain barrier appeared to be effective in minimizing brain accumulation as BMFs were bear tissues appeared to be mainly accumulated from the seal blubber rather than being metabolic formed from PBDEs in the bears. In vitro PBDE depletion assays using polar bear hepatic microsomes, wherein the rate of oxidative metabolism of PBDE congeners was very slow, supported the probability that accumulation

Lattice Study for the Taiwan Photon Source

CERN Document Server

Kuo, Chin-Cheng; Chen Chien Te; Luo, Gwo-Huei; Tsai, Hung-Jen; Wang, Min-Huey

2005-01-01

The feasibility study for the new 3.0~3.3 GeV Taiwan synchrotron light source, dubbed Taiwan Photon Source, was initiated in July, 2004. The goal is to construct a high performance light source with extremely bright X-ray in complementary to the existing 1.5 GeV light source in Taiwan. The ring circumference is 518.4 m and a 24-cell DBA lattice structure is chosen. The natural emittance with distributed dispersion is less than 2 nm-rad. A large booster ring of 499.2 m sharing the storage ring tunnel will be adopted.

Combining tree-ring metal concentrations and lead, carbon and oxygen isotopes to reconstruct peri-urban atmospheric pollution

Directory of Open Access Journals (Sweden)

Annick Doucet

2012-08-01

Full Text Available In this study, we analysed the tree-ring metal concentrations and isotope ratios of five stands located in three contrasted settings to infer the diffuse air pollution history of the northern part of the Windsor–Québec City Corridor in eastern Canada. Tree-ring series show that the Cd and Zn accumulation rates were higher between 1960 and 1986 and that the long-term acidification of the soil (Ca/Al series was likely induced by NOx and SOx deposition (δ15N and δ13C trends as proxy. The Pb concentrations and 206Pb/207Pb ratios indicate that the dominant source of lead from 1880 to the 1920s was the combustion of north-eastern American coal, which was succeeded by the combustion of leaded gasoline from the 1920s to the end of the 1980s. Our modelling approach allows separating the climatic and anthropogenic effects on the tree-ring δ13C and δ18O responses. Diffuse air pollution caused an enrichment in 13C in all stands and a decrease of the δ18O values only in three of the stands. This study indicates that dendrogeochemistry can show contrasted responses to environmental changes and that the combination of several independent indicators constitutes a powerful tool to reconstruct the air pollution history in the complex context of peri-urban regions.

Ground Deformation Related to Caldera Collapse and Ring-Fault Activity

KAUST Repository

Liu, Yuan-Kai

2018-05-01

Volcanic subsidence, caused by partial emptying of magma in the subsurface reservoir has long been observed by spaceborne radar interferometry. Monitoring long-term crustal deformation at the most notable type of volcanic subsidence, caldera, gives us insights of the spatial and hazard-related information of subsurface reservoir. Several subsiding calderas, such as volcanoes on the Galapagos islands have shown a complex ground deformation pattern, which is often composed of a broad deflation signal affecting the entire edifice and a localized subsidence signal focused within the caldera floor. Although numerical or analytical models with multiple reservoirs are proposed as the interpretation, geologically and geophysically evidenced ring structures in the subsurface are often ignored. Therefore, it is still debatable how deep mechanisms relate to the observed deformation patterns near the surface. We aim to understand what kind of activities can lead to the complex deformation. Using two complementary approaches, we study the three-dimensional geometry and kinematics of deflation processes evolving from initial subsidence to later collapse of calderas. Firstly, the analog experiments analyzed by structure-from-motion photogrammetry (SfM) and particle image velocimetry (PIV) helps us to relate the surface deformation to the in-depth structures. Secondly, the numerical modeling using boundary element method (BEM) simulates the characteristic deformation patterns caused by a sill-like source and a ring-fault. Our results show that the volcano-wide broad deflation is primarily caused by the emptying of the deep magma reservoir, whereas the localized deformation on the caldera floor is related to ring-faulting at a shallower depth. The architecture of the ring-fault to a large extent determines the deformation localization on the surface. Since series evidence for ring-faulting at several volcanoes are provided, we highlight that it is vital to include ring

Ground Deformation Related to Caldera Collapse and Ring-Fault Activity

KAUST Repository

Liu, Yuan-Kai

2018-01-01

Volcanic subsidence, caused by partial emptying of magma in the subsurface reservoir has long been observed by spaceborne radar interferometry. Monitoring long-term crustal deformation at the most notable type of volcanic subsidence, caldera, gives us insights of the spatial and hazard-related information of subsurface reservoir. Several subsiding calderas, such as volcanoes on the Galapagos islands have shown a complex ground deformation pattern, which is often composed of a broad deflation signal affecting the entire edifice and a localized subsidence signal focused within the caldera floor. Although numerical or analytical models with multiple reservoirs are proposed as the interpretation, geologically and geophysically evidenced ring structures in the subsurface are often ignored. Therefore, it is still debatable how deep mechanisms relate to the observed deformation patterns near the surface. We aim to understand what kind of activities can lead to the complex deformation. Using two complementary approaches, we study the three-dimensional geometry and kinematics of deflation processes evolving from initial subsidence to later collapse of calderas. Firstly, the analog experiments analyzed by structure-from-motion photogrammetry (SfM) and particle image velocimetry (PIV) helps us to relate the surface deformation to the in-depth structures. Secondly, the numerical modeling using boundary element method (BEM) simulates the characteristic deformation patterns caused by a sill-like source and a ring-fault. Our results show that the volcano-wide broad deflation is primarily caused by the emptying of the deep magma reservoir, whereas the localized deformation on the caldera floor is related to ring-faulting at a shallower depth. The architecture of the ring-fault to a large extent determines the deformation localization on the surface. Since series evidence for ring-faulting at several volcanoes are provided, we highlight that it is vital to include ring

Ring Current Response to Different Storm Drivers. Van Allen Probes and Cluster Observations.

Science.gov (United States)

Bingham, S.; Mouikis, C.; Kistler, L. M.; Spence, H. E.; Gkioulidou, M.; Claudepierre, S. G.; Farrugia, C. J.

2015-12-01

The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), co-rotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure change the global magnetic field, which affects the transport of the radiation belts. In order to determine the field changes during a storm it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. The source population of the storm time ring current is the night side plasma sheet. However, it is not clear how these convecting particles affect the storm time ring current pressure development. We use Van Allen Probes and Cluster observations together with the Volland-Stern and dipole magnetic field models to determine the contribution in the ring current pressure of the plasma sheet particles convecting from the night side that are on open drift paths, during the storm evolution. We compare storms that are related to different interplanetary drivers, CME and CIR, as observed at different local times.

Missing Rings, Synchronous Growth, and Ecological Disturbance in a 36-Year Pitch Pine (Pinus rigida Provenance Study.

Directory of Open Access Journals (Sweden)

Caroline Leland

Full Text Available Provenance studies are an increasingly important analog for understanding how trees adapted to particular climatic conditions might respond to climate change. Dendrochronological analysis can illuminate differences among trees from different seed sources in terms of absolute annual growth and sensitivity to external growth factors. We analyzed annual radial growth of 567 36-year-old pitch pine (Pinus rigida Mill. trees from 27 seed sources to evaluate their performance in a New Jersey Pine Barrens provenance experiment. Unexpectedly, missing rings were prevalent in most trees, and some years-1992, 1999, and 2006-had a particularly high frequency of missing rings across the plantation. Trees from local seed sources (<55 km away from the plantation had a significantly smaller percentage of missing rings from 1980-2009 (mean: 5.0%, relative to northernmost and southernmost sources (mean: 9.3% and 7.9%, respectively. Some years with a high frequency of missing rings coincide with outbreaks of defoliating insects or dry growing season conditions. The propensity for missing rings synchronized annual variations in growth across all trees and might have complicated the detection of potential differences in interannual variability among seed sources. Average ring width was significantly larger in seed sources from both the southernmost and warmest origins compared to the northernmost and coldest seed sources in most years. Local seed sources had the highest average radial growth. Adaptation to local environmental conditions and disturbances might have influenced the higher growth rate found in local seed sources. These findings underscore the need to understand the integrative impact of multiple environmental drivers, such as disturbance agents and climate change, on tree growth, forest dynamics, and the carbon cycle.

Impedance calculations for 2-D and 3-D structures and the impedance budget of 7-GeV APS [Advanced Photon Source] storage ring

International Nuclear Information System (INIS)

Chou, W.; Jin, Y.

1989-01-01

For the storage ring of the 7-GeV Advanced Photon Source (APS), we numerically calculate the longitudinal and the transverse coupling impedances of various kinds of two- and three-dimensional structures. It is shown that the RF cavities are the main contributors to the longitudinal impedance, whereas the transitions between the chamber and the insertion device section dominate the transverse one. Several different numerical approaches are adopted. It is argued that the broadband resonator model may not be appropriate to model the longitudinal impedance. Several interesting phenomena of general interest, including a composition rule and the negative transverse impedance, are discussed. Based on our numerical results and other results available, the impedance budget of the storage ring is established. 9 refs., 8 figs., 1 tab

DEGRADATION OF MAGNET EPOXY AT NSLS X-RAY RING.

Energy Technology Data Exchange (ETDEWEB)

HU,J.P.; ZHONG,Z.; HAAS,E.; HULBERT,S.; HUBBARD,R.

2004-05-24

Epoxy resin degradation was analyzed for NSLS X-ring magnets after two decades of 2.58-2.8 GeV continuous electron-beam operation, based on results obtained from thermoluminescent dosimeters irradiated along the NSLS ring and epoxy samples irradiated at the beamline target location. A Monte Carlo-based particle transport code, MCNP, was utilized to verify the dose from synchrotron radiation distributed along the axial- and transverse-direction in a ring model, which simulates the geometry of a ring quadrupole magnet and its central vacuum chamber downstream of the bending-magnet photon ports. The actual life expectancy of thoroughly vacuum baked-and-cured epoxy resin was estimated from radiation tests on similar polymeric materials using a radiation source developed for electrical insulation and mechanical structure studies.

Revisit the modeling of the Saturnian ring atmosphere and ionosphere from the "Cassini Grand Finale" results

Science.gov (United States)

Tseng, W. L.; Johnson, R. E.; Tucker, O. J.; Perry, M. E.; Ip, W. H.

2017-12-01

During the Cassini Grand Finale mission, this spacecraft, for the first time, has done the in-situ measurements of Saturn's upper atmosphere and its rings and provides critical information for understanding the coupling dynamics between the main rings and the Saturnian system. The ring atmosphere is the source of neutrals (i.e., O2, H2, H; Tseng et al., 2010; 2013a), which is primarily generated by photolytic decomposition of water ice (Johnson et al., 2006), and plasma (i.e., O2+ and H2+; Tseng et al., 2011) in the Saturnian magnetosphere. In addition, the main rings have strong interaction with Saturn's atmosphere and ionosphere (i.e., a source of oxygen into Saturn's upper atmosphere and/or the "ring rain" in O'Donoghue et al., 2013). Furthermore, the near-ring plasma environment is complicated by the neutrals from both the seasonally dependent ring atmosphere and Enceladus torus (Tseng et al., 2013b), and, possibly, from small grains from the main and tenuous F and G rings (Johnson et al.2017). The data now coming from Cassini Grand Finale mission already shed light on the dominant physics and chemistry in this region of Saturn's magnetosphere, for example, the presence of carbonaceous material from meteorite impacts in the main rings and each gas species have similar distribution in the ring atmosphere. We will revisit the details in our ring atmosphere/ionosphere model to study, such as the source mechanism for the organic material and the neutral-grain-plasma interaction processes.

The Antiproton Accumulator and Collector and the discovery of the W & Z intermediate vector bosons

CERN Document Server

Chohan, Vinod

2016-01-01

The following sections are included: Preface ; Brief outline of the overall scheme for antiprotons of the SPS as a collider ; Antiproton production and accumulation ; The AA and AC storage rings ; Stochastic cooling and stacking ; Post-acceleration of antiprotons and beams for SPS Collider ; Proton test beams for the AA and AC from the PS ; The W and Z discoveries and the Nobel Prize ; Accumulator performance ; Acknowledgements and conclusions ; References

Experience with a high-brightness storage ring: the NSLS 750 MeV vuv ring

International Nuclear Information System (INIS)

Galayda, J.

1984-01-01

The NSLS vuv ring is the first implementation of the proposals of R. Chasman and G.K. Green for a synchrotron radiation source with enhanced brightness: its lattice is a series of achromatic bends with two zero-gradient dipoles each, giving small damped emittance; and these bends are connected by straight sections with zero dispersion to accommodate wigglers and undulators without degrading the radiation damping properties of the ring. The virtues of the Chasman-Green lattice, its small betatron and synchrotron emittances, may be understood with some generality; e.g. the electron γm 0 c 2 energy and the number of achromatic bends M sets a lower limit on the betatron emittance of e/sub x/ > 7.7 x 10 -13 γ 2 /M meter-radians. There is strong interest in extrapolation of this type of lattice to 6 GeV and to 32 achromatic bends. The subject of this report is the progress toward achieving performance in the vuv ring limited by the radiation damping parameters optimized in its design. 14 refs., 4 figs., 1 tab

Causes of ring-related leg injuries in birds - evidence and recommendations from four field studies.

Directory of Open Access Journals (Sweden)

Michael Griesser

Full Text Available One of the main techniques for recognizing individuals in avian field research is marking birds with plastic and metal leg rings. However, in some species individuals may react negatively to rings, causing leg injuries and, in extreme cases, the loss of a foot or limb. Here, we report problems that arise from ringing and illustrate solutions based on field data from Brown Thornbills (Acanthiza pusilla (2 populations, Siberian Jays (Perisoreus infaustus and Purple-crowned Fairy-wrens (Malurus coronatus. We encountered three problems caused by plastic rings: inflammations triggered by material accumulating under the ring (Purple-crowned Fairy-wrens, contact inflammations as a consequence of plastic rings touching the foot or tibio-tarsal joint (Brown Thornbills, and toes or the foot getting trapped in partly unwrapped flat-band colour rings (Siberian Jays. Metal rings caused two problems: the edges of aluminium rings bent inwards if mounted on top of each other (Brown Thornbills, and too small a ring size led to inflammation (Purple-crowned Fairy-wrens. We overcame these problems by changing the ringing technique (using different ring types or larger rings, or using different adhesive. Additionally, we developed and tested a novel, simple technique of gluing plastic rings onto metal rings in Brown Thornbills. A review of studies reporting ring injuries (N = 23 showed that small birds (35 g tend to get rings stuck over their feet. We give methodological advice on how these problems can be avoided, and suggest a ringing hazard index to compare the impact of ringing in terms of injury on different bird species. Finally, to facilitate improvements in ringing techniques, we encourage online deposition of information regarding ringing injuries of birds at a website hosted by the European Union for Bird Ringing (EURING.

Ring magnets for the synchrotron x-ray source at ANL

International Nuclear Information System (INIS)

Praeg, W.F.; Thompson, K.M.; Kim, S.H.

1987-03-01

The designs of the bending, focusing, and correction magnetic for the storage ring are described. The computer-optimized pole-tip contours of the dipole, quadrupole, and sextupole magnets and the construction and assembly techniques keep the field errors within the specified limits. Horizontal and vertical steering corrections are provided by separate magnets in addition to a steering capability included in the sextupole magnets

Alignment for new Subaru ring

International Nuclear Information System (INIS)

Zhang, Ch.; Matsui, S.; Hashimoto, S.

1999-01-01

The New SUBARU is a synchrotron light source being constructed at the SPring-8 site. The main facility is a 1.5 GeV electron storage ring that provides light beam in the region from VUV to soft X-ray using SPring-8's 1 GeV linac as an injector. The ring, with a circumference of about 119 meters, is composed of six bending cells. Each bending cell has two normal dipoles of 34 degree and one inverse dipole of -8 degree. The ring has six straight sections: two very long straight sections for a 11-m long undulator and an optical klystron, four short straight sections for a 2.3-m undulator, a super-conducting wiggler, rf cavity and injection, etc. The magnets of the storage ring are composed of 12 dipoles (BMs), 6 invert dipoles (BIs), 56 quadrupoles and 44 sextupoles, etc. For the magnet alignment, positions of the dipoles (the BMs and BIs) are determined by network survey method. The multipoles, which are mounted on girders between the dipoles, are aligned with a laser-CCD camera system. This article presents the methodology used to position the different components and particularly to assure the precise alignment of the multipoles. (authors)

Stable Ca Isotopes in Tamarix aphylla Tree Rings, Death Valley, California

Science.gov (United States)

Yang, W.; Depaolo, D. J.; Ingram, B. L.; Owens, T. L.

2008-12-01

As a dune stabilizer and windbreak, Tamarix aphylla is an exotic perennial and evergreen tree in Death Valley. Its tap roots can reach down to 30 m depth and sub-superficial side roots may reach 50 m horizontally. The species can store large amounts of water in its roots and undergoes high evapotranspiration. Since Tamarix aphylla is a perennial tree growing in desert environments and its roots reach deep to the water table, it could be a proxy for desert ecological and hydrologic systems through time. We measured Ca isotopes in the soluble fraction of 8 tree ring samples from a 50-year-old specimen growing on an alluvial fan in Death Valley near Furnace Creek. Previous studies (Yang et al, GCA 60, 1996) indicate that this tree's rings contain high sulfur concentrations (4-6% expressed as sulfate) with chemical composition of CaSO4 (0.15-0.62 H2O). The δ34S values of soluble sulfate increase from +13.5 to +18 permil VCDT from the core to the bark, which are interpreted as reflecting deeper sulfate sources as the tree grew. The δ13C variations of the tree-ring cellulose (-27.6 to -24.0 permil VPDB) reflect changes in the local precipitation and show that Tamarix aphylla undergoes C3 photosynthesis. The δ44Ca for the soluble sulfate Ca through the tree-ring section, which covers a time period from 1945 to 1993, have an average value -2.52 permil (-3.4 permil relative to seawater). Only small variations are observed, from -2.69 to -2.28; the highest value (for 1990) occurs near the end of an extended drought. These are the first measurements of tree rings, but the low δ44Ca values are consistent with previous measurements of beech roots and stems from a temperate forest (Page et al., Biogeochem. 88, 2008). In our case, the tree has only one Ca source, which is expected to be isotopically uniform and similar to both local rainfall and limestones (δ44Ca ~ -0.6 permil), and with the minimal vegetation and extensive deep root system it is unlikely that there is a

The search for a source rock for the giant Tar Sand triangle accumulation, southeastern Utah

Science.gov (United States)

Huntoon, J.E.; Hansley, P.L.; Naeser, N.D.

1999-01-01

A large proportion (about 36%) of the world's oil resource is contained in accumulations of heavy oil or tar. In these large deposits of degraded oil, the oil in place represents only a fraction of what was present at the time of accumulation. In many of these deposits, the source of the oil is unknown, and the oil is thought to have migrated over long distances to the reservoirs. The Tar Sand triangle in southeastern Utah contains the largest tar sand accumulation in the United States, with 6.3 billion bbl of heavy oil estimated to be in place. The deposit is thought to have originally contained 13-16 billion bbl prior to the biodegradation, water washing, and erosion that have taken place since the middle - late Tertiary. The source of the oil is unknown. The tar is primarily contained within the Lower Permian White Rim Sandstone, but extends into permeable parts of overlying and underlying beds. Oil is interpreted to have migrated into the White Rim sometime during the Tertiary when the formation was at a depth of approximately 3500 m. This conclusion is based on integration of fluid inclusion analysis, time-temperature reconstruction, and apatite fission-track modeling for the White Rim Sandstone. Homogenization temperatures cluster around 85-90??C for primary fluid inclusions in authigenic, nonferroan dolomite in the White Rim. The fluid inclusions are associated with fluorescent oil-bearing inclusions, indicating that dolomite precipitation was coeval with oil migration. Burial reconstruction suggests that the White Rim Sandstone reached its maximum burial depth from 60 to 24 Ma, and that maximum burial was followed by unroofing from 24 to 0 Ma. Time-temperature modeling indicates that the formation experienced temperatures of 85-90??C from about 35 to 40 Ma during maximum burial. Maximum formation temperatures of about 105-110??C were reached at about 24 Ma, just prior to unroofing. Thermal modeling is used to examine the history of potential source rocks

Use of Tritium Accelerator Mass Spectrometry for Tree Ring Analysis

Science.gov (United States)

LOVE, ADAM H.; HUNT, JAMES R.; ROBERTS, MARK L.; SOUTHON, JOHN R.; CHIARAPPA - ZUCCA, MARINA L.; DINGLEY, KAREN H.

2010-01-01

Public concerns over the health effects associated with low-level and long-term exposure to tritium released from industrial point sources have generated the demand for better methods to evaluate historical tritium exposure levels for these communities. The cellulose of trees accurately reflects the tritium concentration in the source water and may contain the only historical record of tritium exposure. The tritium activity in the annual rings of a tree was measured using accelerator mass spectrometry to reconstruct historical annual averages of tritium exposure. Milligram-sized samples of the annual tree rings from a Tamarix located at the Nevada Test Site are used for validation of this methodology. The salt cedar was chosen since it had a single source of tritiated water that was well-characterized as it varied over time. The decay-corrected tritium activity of the water in which the salt cedar grew closely agrees with the organically bound tritium activity in its annual rings. This demonstrates that the milligram-sized samples used in tritium accelerator mass spectrometry are suited for reconstructing anthropogenic tritium levels in the environment. PMID:12144257

Design and development of a ring cathode electron gun as an evaporation source

Energy Technology Data Exchange (ETDEWEB)

Poyner, G T [Craswell Scientific Ltd., Cheltenham (UK)

1976-11-01

The RG2 ring cathode gun is a simple application of electron beam heating. The gun described was developed to provide a relatively inexpensive source for evaporating a range of metals and oxides which were otherwise difficult or impossible to evaporate by conventional resistance heating. Following several stages of improvement the gun was progressively reduced in size and the 'optics', or focusing, improved so that in its existing state an area of approximately 2mm diameter is heated. It was decided to limit the accelerating voltage as far as possible to minimize the practical problems associated with its operation and also the manufacture of the power supply. As development proceeded it became apparent that the relatively low accelerating voltage chosen improved the flexibility of the gun. Two versions are manufactured, the first, equipped with a six position rotary hearth, and the second, utilising a single hearth, is intended to be used as one of a pair. The latter design was reduced in size even further in order to minimize the distance between two adjacent guns.

Revisiting the Fully Automated Double-Ring Infiltrometer Using Open-Source Electronics

Science.gov (United States)

The double-ring infiltrometer (DRI) is commonly used for measuring soil hydraulic conductivity. However, constant-head DRI tests typically involve the use of Mariotte tubes, which can be problematic to set-up, and time-consuming to maintain and monitor during infiltration tests....

Fecal sterols, seasonal variability, and probable sources along the ring of cenotes, Yucatan, Mexico

Science.gov (United States)

Arcega-Cabrera, F.; Velázquez-Tavera, N.; Fargher, L.; Derrien, M.; Noreña-Barroso, E.

2014-11-01

Rapid development in Yucatan has had a dramatic impact on the environment, especially the water supply. Groundwater is the only source of water in Yucatan, since surface water is virtually absent due to the karstic nature of the soil. The ring of cenotes (RC) is a geological feature which functions as a source of water and as nodes in the underground river system that canalizes water towards the coast. Numerous productive and domestic activities take place around the RC in the absence of wastewater treatment or sewage systems. Consequently, a number of researchers have hypothesized that pollutants could migrate from the land surface to the underlying aquifer and, eventually, to the coast. Therefore, the present study investigates the relationship among sources of fecal sterols and their levels in cenotes, using the expected levels of fecal sterols obtained by a spatial analysis of the sources and a Pollution Source Index. Accordingly, expected levels are compared with the detected levels of fecal sterols in 5 areas around the RC. Regarding levels, observed during a sampling campaign carried out along the RC during September 2011 (rainy season) and May 2012 (dry season), varied from low to high concentrations of sterols (0.5-2396.42 μg g- 1) and fecal sterols (0.3-1690.18 μg g- 1). These concentrations showed no relationship between neighboring cenotes, where similar fecal sterol concentrations or gradients were expected. When comparing expected fecal sterols levels with the detected ones, only two of the five analyzed areas concur, suggesting that no clear relationship exists among sources and fecal sterols levels at the regional scale. Multivariate analysis showed that fecal sterols were associated with sterols and fine grain particulates during the rainy season, which suggests co-transport. During the dry season, fecal sterols associated with fine grain particulate and organic matter, which indicates a change to a deposition phenomenon. These findings indicate

Effects of potassium application on the accumulated nitrogen source and yield of peanut

International Nuclear Information System (INIS)

Wang Yuefu; Kang Yujie; Wang Minglun; Zhao Changxing

2013-01-01

Pot experiments and were carried out respectively to study the effects of different potassium application on soil nitrogen uptake, fertilizer nitrogen uptake, nodule nitrogen fixation and their proportion and yield of peanut (Arachis Hypogaea L.) by "1"5N tracer technique, and explore the reasons, which may provide a theoretical basis and technical guidance for peanut production in the scientific fertilizer application. Results showed that nitrogen in peanut all mainly accumulated in the kernel for different treatments of potassium fertilizer application. However, with increasing of potassium application, the increasing extent of nitrogen content of stems was the biggest during all the peanut organs, with nut shells the smallest. Properly increasing the amount of potassium can improve nitrogen content, "1"5N abundance, nitrogen and "1"5N accumulation of every organ, and promote absorption and utilization three nitrogen-source especially with the most effect for the kernel biomass (economic output). The ratio of fertilizer nitrogen, soil nitrogen and atmospheric nitrogen absorbed by peanut was respectively between 12.37%-13.10%, 38.29%-45.10%, and 42.53%-48.31% respectively. Properly increasing potassium fertilizer application improved the absorption ratio of fertilizer nitrogen and nodule nitrogen fixation, reduced the proportion of soil uptake and enhanced fertilizer nitrogen use efficiency. However, the influences of excessive application of potassium fertilizer decreased. (authors)

A status update on the Advanced Photon Source Project--Summer 1993

International Nuclear Information System (INIS)

Moncton, D.E.; Fenner, R.B.

1993-01-01

The Advanced Photon Source Project has passed the mid-point in its construction. The linac and synchrotron booster enclosures are complete. A portion of the experiment hall has been completed and put into use to support accelerator component assembly, test, and installation. Plans for the user lab/office modules and the central laboratory/office complex are well advanced. Installation of the linac injection system has been completed and commissioning is beginning. Installation and commissioning of the positron accumulator ring, the booster synchrotron, the storage ring, and the rf power systems will follow. Accelerator operations capable of supporting the commissioning of the experimental beamlines is planned for the summer of 1995. A strong research program is continuing to produce results supportive of both accelerator and beamline construction and operations. Collaborative Access Teams have been formed to conduct research with the initial set of 32 beamlines that will be available at the completion of the first phase of construction

Carbon, hydrogen oxygen isotope studies on imbedded old tree ring and paleoclimate reconstruction

International Nuclear Information System (INIS)

Sun Yanrong; Mu Zhiguo; Cui Haiting

2002-01-01

Tree ring is a kind of natural archives, on which the isotopic analysis is important to study global climate and environmental change. The authors mainly provide a comprehensive introduction to the fractionation models of carbon, hydrogen and oxygen isotope in plants, their research technique and the extract methods from cellulose. That results show isotopic tracer can record the message of climatic variation and has become a powerful tool for paleoclimate reconstruction and for the modern environment changing research. Especially studying on PAGES. the cellulose isotopic analyses of imbedded old tree ring have become the mainly quantitative means of environmental evolvement. In addition, China is a typical monsoon country, research in tree ring stable isotope seasonal variation can give a lot of important information on that. Up to now, the research techniques and works on tree ring in China are still in its earlier stage, and remain many limitations. It needs further accumulate basic research materials, intensity regional contrast and intercross studies on relative subjects

Characterization of distinct Arctic aerosol accumulation modes and their sources

Science.gov (United States)

Lange, R.; Dall'Osto, M.; Skov, H.; Nøjgaard, J. K.; Nielsen, I. E.; Beddows, D. C. S.; Simo, R.; Harrison, R. M.; Massling, A.

2018-06-01

In this work we use cluster analysis of long term particle size distribution data to expand an array of different shorter term atmospheric measurements, thereby gaining insights into longer term patterns and properties of Arctic aerosol. Measurements of aerosol number size distributions (9-915 nm) were conducted at Villum Research Station (VRS), Station Nord in North Greenland during a 5 year record (2012-2016). Alongside this, measurements of aerosol composition, meteorological parameters, gaseous compounds and cloud condensation nuclei (CCN) activity were performed during different shorter occasions. K-means clustering analysis of particle number size distributions on daily basis identified several clusters. Clusters of accumulation mode aerosols (main size modes > 100 nm) accounted for 56% of the total aerosol during the sampling period (89-91% during February-April, 1-3% during June-August). By association to chemical composition, cloud condensation nuclei properties, and meteorological variables, three typical accumulation mode aerosol clusters were identified: Haze (32% of the time), Bimodal (14%) and Aged (6%). In brief: (1) Haze accumulation mode aerosol shows a single mode at 150 nm, peaking in February-April, with highest loadings of sulfate and black carbon concentrations. (2) Accumulation mode Bimodal aerosol shows two modes, at 38 nm and 150 nm, peaking in June-August, with the highest ratio of organics to sulfate concentrations. (3) Aged accumulation mode aerosol shows a single mode at 213 nm, peaking in September-October and is associated with cloudy and humid weather conditions during autumn. The three aerosol clusters were considered alongside CCN concentrations. We suggest that organic compounds, that are likely marine biogenic in nature, greatly influence the Bimodal cluster and contribute significantly to its CCN activity. This stresses the importance of better characterizing the marine ecosystem and the aerosol-mediated climate effects in the

Geochemistry Model Validation Report: External Accumulation Model

International Nuclear Information System (INIS)

Zarrabi, K.

2001-01-01

The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

Shoreline erosion and decadal sediment accumulation in the Tar-Pamlico estuary, North Carolina, USA: A source-to-sink analysis

Science.gov (United States)

Eulie, Devon O.; Corbett, D. Reide; Walsh, J. P.

2018-03-01

Estuaries contain vital habitats and it is important to understand how these areas respond to human activities and natural processes such as sea-level rise and wave attack. As estuarine shorelines erode or become modified with hard structures, there is potential for significantly altering the availability of sediment and the filling of coastal systems. This study used a source-to-sink approach and quantified rates of shoreline erosion in the Tar-Pamlico sub-estuary, a tributary of the larger Albemarle-Pamlico Estuarine System (APES). The average shoreline change rate (SCR) determined using an end-point method was -0.5 ± 0.9 m yr-1 for the Tar-Pamlico. Incorporating bulk density estimates, this contributes 0.6 × 105 tons of fine sediment to the system annually, or after accounting for fluvial input, about 40% of the total sediment supply to the sub-estuary. The role of the Tar-Pamlico as a sink for these sediments was addressed using the radionuclide tracers 210Pb and 137Cs. Radionuclide activities and sediment accumulation rates identified several depositional regions, in particular in the middle of the estuary. Linear sediment accumulation rates ranged from 0.10 ± 0.02 to 0.38 ± 0.02 g cm-2 yr-1, and total storage of fine sediment in the system was 1.6 × 105 t yr-1. It was not possible to confidently discern a change in the rate of shoreline erosion or seabed accumulation. A preliminary budget for fine sediments (grain-size <63 μm) was then calculated to compare erosional sources with sedimentary sinks. Almost all (∼93.0%) of the fine sediment entering the system was accumulated and stored, while only about 7.0% was exported to Pamlico Sound.

A compact electron storage ring design

International Nuclear Information System (INIS)

Swenson, C.A.

1992-01-01

Electron storage rings are sources of synchrotron radiation in the soft and hard parts of the x-ray spectrum. X-ray lithography is an ideal candidate technology for the production of microelectronic devices with sizes between 0.3-0.5 microns. Industrial x-ray lithography requires the x-ray source, which is the electron storage ring, to be as compact and reliable as possible. In this thesis the author reviews and develops the basic physical principles governing the design of compact electron synchrotrons for x-ray lithography. He explores the various aspects of lattice design for this application. He argues that the optimal storage ring design consists of a four fold symmetric cell lattice with two quadrupole families and 90 degrees zero gradient dipole magnets. It is demonstrated that radiation requirements for lithography and the use of zero gradient magnetic dipole fields constrains the lattice to four or more dipole magnets. The author develops a lattice design for x-ray lithography following this logic. He then develops a dipole magnet design for a machine using this lattice. Particle tracking data is integrated into the magnet design and used to optimize the end coil configurations of the magnets. The author then reviews the magnet's physical construction and measurement. He develops a cryogenic Hall probe mapping apparatus for this magnet and measure its excitation curves

Historical overview of the synchrotron radiation research in Japan. From the view point of creative works in the development of light sources and related technology

International Nuclear Information System (INIS)

Kamitsubo, Hiromichi

2007-01-01

Synchrotron radiation research in Japan started in early 1960's when the first electron synchrotron was commissioned at the Institute of Nuclear Study (INS), University of Tokyo (UT). This review covers the parasite use of the INS electron synchrotron and research works done at the light sources in Japan such as SOR-RING, Photon Factory (KEK-PF) Accumulator Ring (KEK-AR), and SPring-8. History of synchrotron radiation research in Japan was overviewed by paying attention to the creative works in the development of light sources and related technology, as well as the pioneering works on the development of experimental techniques and methods. At present there are more than ten synchrotron radiation sources are in operation and the number of their users, especially users from industries in Japan is increasing very rapidly and the research fields of users are also developing. Accordingly the synchrotron radiation facility becomes more and more indispensable facility in the society in Japan. (author)

Acceptability of the vaginal contraceptive ring among adolescent women.

Science.gov (United States)

Terrell, Lekeisha R; Tanner, Amanda E; Hensel, Devon J; Blythe, Margaret J; Fortenberry, J Dennis

2011-08-01

Although underutilized, the vaginal contraceptive ring has several advantages over other contraceptive methods that could benefit adolescents. We examined factors that may influence willingness to try the vaginal ring including: sexual and contraceptive history, genital comfort, and vaginal ring characteristics. Cross sectional Midwestern adolescent health clinics Adolescent women (N = 200; 14-18 years; 89% African-American) INTERVENTIONS/MAIN OUTCOME MEASURES: All participants received education about the vaginal ring and viewed pictures demonstrating insertion; they then completed a visual/audio computer-assisted self interview. The primary outcome variable, willingness to try the vaginal ring, was a single Likert-scale item. Over half the participants reported knowledge of the vaginal ring with healthcare providers identified as the most important source of contraceptive information. Comfort with one's genitals, insertion and removal, using alternative methods of insertion, and knowing positive method characteristics were significantly associated with willingness to try the vaginal ring. A decreased willingness to try the vaginal ring was related to concerns of the ring getting lost inside or falling out of the vagina. Willingness to try the ring was associated with positive feelings about genitals (e.g., comfort with appearance, hygiene, function). Thus, to increase willingness to try the vaginal ring among adolescents, providers should make it common practice to discuss basic female reproductive anatomy, raise awareness about female genital health and address concerns about their genitals. Providers can offer alternative insertion techniques (e.g., gloves) to make use more accessible. These strategies may increase vaginal ring use among adolescents. 2011 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Photon-induced tunability of the thermospin current in a Rashba ring

Science.gov (United States)

Abdullah, Nzar Rauf; Arnold, Thorsten; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar

2018-04-01

The goal of this work is to show how the thermospin polarization current in a quantum ring changes in the presence of Rashba spin-orbit coupling and a quantized single photon mode of a cavity the ring is placed in. Employing the reduced density operator and a general master equation formalism, we find that both the Rashba interaction and the photon field can significantly modulate the spin polarization and the thermospin polarization current. Tuning the Rashba coupling constant, degenerate energy levels are formed corresponding to the Aharonov-Casher destructive phase interference in the quantum ring system. Our analysis indicates that the maximum spin polarization can be observed at the points of degenerate energy levels due to spin accumulation in the system without the photon field. The thermospin current is thus suppressed. In the presence of the cavity, the photon field leads to an additional kinetic momentum of the electron. As a result the spin polarization can be enhanced by the photon field.

Activity distribution of a cobalt-60 teletherapy source

International Nuclear Information System (INIS)

Jaffray, D.A.; Munro, P.; Battista, J.J.; Fenster, A.

1991-01-01

In the course of quantifying the effect of radiation source size on the spatial resolution of portal images, a concentric ring structure in the activity distribution of a Cobalt-60 teletherapy source has been observed. The activity distribution was measured using a strip integral technique and confirmed independently by a contact radiograph of an identical but inactive source replica. These two techniques suggested that this concentric ring structure is due to the packing configuration of the small 60Co pellets that constitute the source. The source modulation transfer function (MTF) showed that this ring structure has a negligible influence on the spatial resolution of therapy images when compared to the effect of the large size of the 60Co source

Black rings

International Nuclear Information System (INIS)

Emparan, Roberto; Reall, Harvey S

2006-01-01

A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

Commissioning software tools at the Advanced Photon Source

International Nuclear Information System (INIS)

Emery, L.

1995-01-01

A software tool-oriented approach has been adopted in the commissioning of the Advanced Photon Source (APS) at Argonne National Laboratory, particularly in the commissioning of the Positron Accumulator Ring (PAR). The general philosophy is to decompose a complicated procedure involving measurement, data processing, and control into a series of simpler steps, each accomplished by a generic toolkit program. The implementation is greatly facilitated by adopting the SDDS (self-describing data set protocol), which comes with its own toolkit. The combined toolkit has made accelerator physics measurements easier. For instance, the measurement of the optical functions of the PAR and the beamlines connected to it have been largely automated. Complicated measurements are feasible with a combination of tools running independently

Single-Particle Dynamics in Electron Storage Rings with Extremely Low Emittance

Energy Technology Data Exchange (ETDEWEB)

Cai, Yunhai; /SLAC

2011-05-31

Electron storage rings are widely used for high luminosity colliders, damping rings in high-energy linear colliders, and synchrotron light sources. They have become essential facilities to study high-energy physics and material and medical sciences. To further increase the luminosity of colliders or the brightness of synchrotron light sources, the beam emittance is being continually pushed downward, recently to the nanometer region. In the next decade, another order of reduction is expected. This requirement of ultra-low emittance presents many design challenges in beam dynamics, including better analysis of maps and improvement of dynamic apertures. To meet these challenges, we have refined transfer maps of common elements in storage rings and developed a new method to compute the resonance driving terms as they are built up along a beamline. The method is successfully applied to a design of PEP-X as a future light source with 100-pm emittance. As a result, we discovered many unexpected cancelations of the fourth-order resonance terms driven by sextupoles within an achromat.

Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

2010-12-01

Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

Experimental and histological studies on appearance mechanism of ring enhancement

International Nuclear Information System (INIS)

Takasugi, Shinsuke; Kageyama, Takefumi; Yamashita, Shigeru; Kusaka, Kazumasa; Ueda, Shin

1980-01-01

Intracerebral hematoma was experimentally induced in 26 adult dogs of mixed breed by injecting autologous venous blood into the internal capsule of dogs. CT images and histological findings of these dogs with intracerebral hematoma were compared with time, and causes of changes in contrast enhancement (CE) CT images and CE positive images were discussed pathologically. It was thought that CE-CT positive images of intracerebral hematoma did not show special phenomena which occurred variously according to causes of hematoma, but general phenomena observed in the process of recovery of general intracerebral hematoma. Ring enhancement appeared mostly about 9 days after hematoma formation. There was a close relationship between appearance of ring enhancement and new vascularization which appeared in the process of recovery of hematoma. It was also thought that blood-brain barrier (B.B.B.) such as normal cerebral capillary vessels did not exist because new vascularization had the fine structure similar to muscle type capillary vessels. Ring enhancement might be seen probably because of the accumulation of contrast medium in regions where new vascularization without B.B.B. appeared. (Tsunoda, M.)

Synchrotron based spallation neutron source concepts

International Nuclear Information System (INIS)

Cho, Y.

1998-01-01

During the past 20 years, rapid-cycling synchrotrons (RCS) have been used very productively to generate short-pulse thermal neutron beams for neutron scattering research by materials science communities in Japan (KENS), the UK (ISIS) and the US (IPNS). The most powerful source in existence, ISIS in the UK, delivers a 160-kW proton beam to a neutron-generating target. Several recently proposed facilities require proton beams in the MW range to produce intense short-pulse neutron beams. In some proposals, a linear accelerator provides the beam power and an accumulator ring compresses the pulse length to the required ∼ 1 micros. In others, RCS technology provides the bulk of the beam power and compresses the pulse length. Some synchrotron-based proposals achieve the desired beam power by combining two or more synchrotrons of the same energy, and others propose a combination of lower and higher energy synchrotrons. This paper presents the rationale for using RCS technology, and a discussion of the advantages and disadvantages of synchrotron-based spallation sources

Resting state networks' corticotopy: the dual intertwined rings architecture.

Directory of Open Access Journals (Sweden)

Salma Mesmoudi

Full Text Available How does the brain integrate multiple sources of information to support normal sensorimotor and cognitive functions? To investigate this question we present an overall brain architecture (called "the dual intertwined rings architecture" that relates the functional specialization of cortical networks to their spatial distribution over the cerebral cortex (or "corticotopy". Recent results suggest that the resting state networks (RSNs are organized into two large families: 1 a sensorimotor family that includes visual, somatic, and auditory areas and 2 a large association family that comprises parietal, temporal, and frontal regions and also includes the default mode network. We used two large databases of resting state fMRI data, from which we extracted 32 robust RSNs. We estimated: (1 the RSN functional roles by using a projection of the results on task based networks (TBNs as referenced in large databases of fMRI activation studies; and (2 relationship of the RSNs with the Brodmann Areas. In both classifications, the 32 RSNs are organized into a remarkable architecture of two intertwined rings per hemisphere and so four rings linked by homotopic connections. The first ring forms a continuous ensemble and includes visual, somatic, and auditory cortices, with interspersed bimodal cortices (auditory-visual, visual-somatic and auditory-somatic, abbreviated as VSA ring. The second ring integrates distant parietal, temporal and frontal regions (PTF ring through a network of association fiber tracts which closes the ring anatomically and ensures a functional continuity within the ring. The PTF ring relates association cortices specialized in attention, language and working memory, to the networks involved in motivation and biological regulation and rhythms. This "dual intertwined architecture" suggests a dual integrative process: the VSA ring performs fast real-time multimodal integration of sensorimotor information whereas the PTF ring performs multi

Resting State Networks' Corticotopy: The Dual Intertwined Rings Architecture

Science.gov (United States)

Mesmoudi, Salma; Perlbarg, Vincent; Rudrauf, David; Messe, Arnaud; Pinsard, Basile; Hasboun, Dominique; Cioli, Claudia; Marrelec, Guillaume; Toro, Roberto; Benali, Habib; Burnod, Yves

2013-01-01

How does the brain integrate multiple sources of information to support normal sensorimotor and cognitive functions? To investigate this question we present an overall brain architecture (called “the dual intertwined rings architecture”) that relates the functional specialization of cortical networks to their spatial distribution over the cerebral cortex (or “corticotopy”). Recent results suggest that the resting state networks (RSNs) are organized into two large families: 1) a sensorimotor family that includes visual, somatic, and auditory areas and 2) a large association family that comprises parietal, temporal, and frontal regions and also includes the default mode network. We used two large databases of resting state fMRI data, from which we extracted 32 robust RSNs. We estimated: (1) the RSN functional roles by using a projection of the results on task based networks (TBNs) as referenced in large databases of fMRI activation studies; and (2) relationship of the RSNs with the Brodmann Areas. In both classifications, the 32 RSNs are organized into a remarkable architecture of two intertwined rings per hemisphere and so four rings linked by homotopic connections. The first ring forms a continuous ensemble and includes visual, somatic, and auditory cortices, with interspersed bimodal cortices (auditory-visual, visual-somatic and auditory-somatic, abbreviated as VSA ring). The second ring integrates distant parietal, temporal and frontal regions (PTF ring) through a network of association fiber tracts which closes the ring anatomically and ensures a functional continuity within the ring. The PTF ring relates association cortices specialized in attention, language and working memory, to the networks involved in motivation and biological regulation and rhythms. This “dual intertwined architecture” suggests a dual integrative process: the VSA ring performs fast real-time multimodal integration of sensorimotor information whereas the PTF ring performs multi

A potpourri of impedance measurements at the advanced photon source storage ring

International Nuclear Information System (INIS)

Sereno, N.S.; Chae, Y.C.; Harkay, K.C.; Lumpkin, A.H.; Milton, S.V.; Yang, B.X.

1997-01-01

Machine coupling impedances were determined in the APS storage ring from measurements of the bunch length, synchronous phase, and synchrotron and betatron tunes vs single-bunch current. The transverse measurements were performed for various numbers of small gap insertion device (ID) chambers installed in the ring. The transverse impedance is determined from measurements of the transverse tunes and bunch length as a function of single-bunch current. The shift in the synchrotron tune was measured as a function of bunch current from which the total cavity impedance was extracted. The loss factor was determined by measuring the relative synchronous phase as a function of bunch current. The longitudinal resistive impedance is calculated using the loss factor dependence on the bunch length. From these results, the authors can estimate what the impedance would be for a full set of ID chambers

The exotic exchange of smoke rings

International Nuclear Information System (INIS)

Niemi, Antti J.

2006-01-01

Smoke rings are fascinating, to humans and animals alike. Experienced cigarette smokers blow them for entertainment while dolphins play with air-filled underwater rings that know how to puff. Smoke ring machines can be bought from science gadget shops and Lord Kelvin explains in a paper [Lord Kelvin, Proceedings of the Royal Society of Edinburgh, Vol. VI (1867), p. 94; reprinted in Philos. Mag. Vol. XXXIV (1867), p. 15] how one can be constructed from a cardboard box. Even Mount Etna [http://news.bbc.co.uk/1/hi/sci/tech/696953.stm] and our Sun [http://spacescience.com/headlines/y2000/ast03feb 1 .htm] are known to be sources of huge smoke rings. But a smoke ring is not only fun to watch. It is also an organized structure with the ability to engage in complex acts, best exemplified by the leapfrogging motion of two smoke rings. Here we propose that the leapfrogging actually encodes very important Physics: It is a direct three dimensional generalization of the motion that in the two dimensional context is responsible for exotic exchange statistics which rules the properties of structures and materials such as quantum Hall systems and high-temperature superconductors. By employing very simple and universal concepts with roots in the hydrodynamical Euler equation, the universal law that describes the properties of fluids and gases, we argue that three dimensional exotic exchange statistics is commonplace. Our observations could have far reaching consequences in fluids and gases which are subject to the laws of quantum mechanics, from helium superfluids to Bose-Einstein condensed alkali gases and even metallic hydrogen in its liquid phases. (author)

Performance characteristics of CdTe drift ring detector

Science.gov (United States)

Alruhaili, A.; Sellin, P. J.; Lohstroh, A.; Veeramani, P.; Kazemi, S.; Veale, M. C.; Sawhney, K. J. S.; Kachkanov, V.

2014-03-01

CdTe and CdZnTe material is an excellent candidate for the fabrication of high energy X-ray spectroscopic detectors due to their good quantum efficiency and room temperature operation. The main material limitation is associated with the poor charge transport properties of holes. The motivation of this work is to investigate the performance characteristics of a detector fabricated with a drift ring geometry that is insensitive to the transport of holes. The performance of a prototype Ohmic CdTe drift ring detector fabricated by Acrorad with 3 drift rings is reported; measurements include room temperature current voltage characteristics (IV) and spectroscopic performance. The data shows that the energy resolution of the detector is limited by leakage current which is a combination of bulk and surface leakage currents. The energy resolution was studied as a function of incident X-ray position with an X-ray microbeam at the Diamond Light Source. Different ring biasing schemes were investigated and the results show that by increasing the lateral field (i.e. the bias gradient across the rings) the active area, evaluated by the detected count rate, increased significantly.

Alternative loop rings

CERN Document Server

Goodaire, EG; Polcino Milies, C

1996-01-01

For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

Primitivity and weak distributivity in near rings and matrix near rings

International Nuclear Information System (INIS)

Abbasi, S.J.

1993-08-01

This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

Expected first-order effects of a notional equatorial ring on Earth's night sky: a geometric consideration

Science.gov (United States)

Hancock, L. O.

2013-12-01

G. Jones (1856) was first to suggest that the Earth might have its own ring, noting that an Earth ring in the ecliptic plane would account for the latitude dependence of the zodiacal light. Jones's proposal was not accepted: it is difficult to see why the ecliptic would accumulate mass within the Earth-Moon system. Very recently, however, this objection has been mitigated by the discovery of Saturn's Phoebe ring: evidently, the plane of a planetary moon's orbit has now been observed as the site of mass accumulation. An adjustment of just a few degrees from ecliptic to the plane of the lunar orbit gives Jones's proposal the boost of an existing Solar System analogue, mysterious though the analogue is. J. O'Keefe (1980) was first to suggest that an Earth ring system could drive climate: a ring in the equatorial plane, waxing and waning in optical depth, could drive the alternation of Ice Age and interglacial climates. This driver would account for the observation that the Ice Age climate was mainly a difference in winter only. Could Earth have a ring system with one or both elements? Even if light and unstable, it would be important to assess, as it could drive climate change. Dust assessments have not discovered a ring system, but they do not cover low orbits well, nor rule out very small particles stringently. Yet tiny particles can be optically important. There are many difficulties with this hypothesis: Why have ground-based observers never identified an equatorial ring, which after all should be the brightest element of a ring system? Why should a ring system be made of very small particles only? The material must be constantly falling to Earth - where is it? Finally, can we believe in the level of lunar geological activity needed to sustain an Earth ring system? This presentation addresses only one issue: Could ground-based observers have seen but misidentified an equatorial ring? To support consideration of that question, herewith a simple geometric exercise

The design and development of a ring cathode electron gun as an evaporation source

International Nuclear Information System (INIS)

Poyner, G.T.

1976-01-01

The RG2 ring cathode gun is a simple application of electron beam heating. The gun described was developed to provide a relatively inexpensive source for evaporating a range of metals and oxides which were otherwise difficult or impossible to evaporate by conventional resistance heating. Following several stages of improvement the gun was progressively reduced in size and the 'optics', or focusing, improved so that in its existing state an area of approximately 2mm diameter is heated. It was decided to limit the accelerating voltage as far as possible to minimize the practical problems associated with its operation and also the manufacture of the power supply. As development proceeded it became apparent that the relatively low accelerating voltage chosen improved the flexibility of the gun. Two versions are manufactured, the first, equipped with a six position rotary hearth, and the second, utilising a single hearth, is intended to be used as one of a pair. The latter design was reduced in size even further in order to minimize the distance between two adjacent guns. (author)

An analog RF gap voltage regulation system for the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Horan, D.

1999-01-01

An analog rf gap voltage regulation system has been designed and built at Argonne National Laboratory to maintain constant total storage ring rf gap voltage, independent of beam loading and cavity tuning effects. The design uses feedback control of the klystron mod-anode voltage to vary the amount of rf power fed to the storage ring cavities. The system consists of two independent feedback loops, each regulating the combined rf gap voltages of eight storage ring cavities by varying the output power of either one or two rf stations, depending on the mode of operation. It provides full operator control and permissive logic to permit feedback control of the rf system output power only if proper conditions are met. The feedback system uses envelope-detected cavity field probe outputs as the feedback signal. Two different methods of combining the individual field probe signals were used to generate a relative DC level representing one-half of the total storage ring rf voltage, an envelope-detected vector sum of the field probe rf signals, and the DC sum of individual field probe envelope detector outputs. The merits of both methods are discussed. The klystron high-voltage power supply (HVPS) units are fitted with an analog interface for external control of the mod-anode voltage level, using a four-quadrant analog multiplier to modulate the HVPS mod-anode voltage regulator set-point in response to feedback system commands

An Automatic Assembling System for Sealing Rings Based on Machine Vision

Directory of Open Access Journals (Sweden)

Mingyu Gao

2017-01-01

Full Text Available In order to grab and place the sealing rings of battery lid quickly and accurately, an automatic assembling system for sealing rings based on machine vision is developed in this paper. The whole system is composed of the light sources, cameras, industrial control units, and a 4-degree-of-freedom industrial robot. Specifically, the sealing rings are recognized and located automatically with the machine vision module. Then industrial robot is controlled for grabbing the sealing rings dynamically under the joint work of multiple control units and visual feedback. Furthermore, the coordinates of the fast-moving battery lid are tracked by the machine vision module. Finally the sealing rings are placed on the sealing ports of battery lid accurately and automatically. Experimental results demonstrate that the proposed system can grab the sealing rings and place them on the sealing port of the fast-moving battery lid successfully. More importantly, the proposed system can improve the efficiency of the battery production line obviously.

Statistical analyses of the magnet data for the advanced photon source storage ring magnets

International Nuclear Information System (INIS)

Kim, S.H.; Carnegie, D.W.; Doose, C.; Hogrefe, R.; Kim, K.; Merl, R.

1995-01-01

The statistics of the measured magnetic data of 80 dipole, 400 quadrupole, and 280 sextupole magnets of conventional resistive designs for the APS storage ring is summarized. In order to accommodate the vacuum chamber, the curved dipole has a C-type cross section and the quadrupole and sextupole cross sections have 180 degrees and 120 degrees symmetries, respectively. The data statistics include the integrated main fields, multipole coefficients, magnetic and mechanical axes, and roll angles of the main fields. The average and rms values of the measured magnet data meet the storage ring requirements

Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates

International Nuclear Information System (INIS)

Xue Jukui

2005-01-01

The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity

Accumulation status, sources and phytoavailability of metals in greenhouse vegetable production systems in Beijing, China.

Science.gov (United States)

Xu, Li; Lu, Anxiang; Wang, Jihua; Ma, Zhihong; Pan, Ligang; Feng, Xiaoyuan; Luan, Yunxia

2015-12-01

The accumulation status, sources and phytoavailability of selected metals in greenhouse vegetable production systems in peri-urban areas of Beijing were investigated. The mean concentrations of As, Cd, Cr, Hg and Pb in greenhouse soils were 8.44, 0.25, 69.0, 0.09 and 22.0 mg kg(-1), dw, respectively. According to principal component analysis, As, Cd, Cr and Hg are mainly from anthropogenic source, but Pb is likely from natural source. Metal concentrations in all vegetable samples were decreased in the order of Cr>As>Pb>Cd>Hg. Compared with root and fruit vegetables, leaf vegetables had relatively high concentrations and transfer factors of heavy metals, except for Cd. By including soil pH, OM and greenhouse soil metals, 10 empirical models were derived using stepwise multiple linear regression analysis to predict heavy metal concentrations in the edible parts of different vegetables. Among the different vegetable groups, the highest intakes of metals occurred through consumption of leaf vegetables for the two age groups, except for Cd. The HI value of the studied metals were all below 1, indicating that consumption of vegetables grown in greenhouse soils was of low risk to consumers in our study area. Copyright © 2015 Elsevier Inc. All rights reserved.

Experimental investigation of electron cooling and stacking of lead ions in a low energy accumulation ring

CERN Document Server

Bosser, Jacques; Chanel, M; Hill, C; Lombardi, A M; MacCaferri, R; Maury, S; Möhl, D; Molinari, G; Rossi, S; Tanke, E; Tranquille, G; Vretenar, Maurizio

1999-01-01

This report gives the results of a programme of experimental investigations, which were carried out to test stacking of lead ions in a storage ring (the former Low Energy Antiproton Ring, LEAR) at 4.2 MeV per nucleon. The motivation was to demonstrate the feasibility of gaining the large factor in the phase-space density required for injection into the LHC. In the first part of the report, the layout of the experiments is described, the choice of the parameters of the electron cooling system used for stacking is reported and the multi-turn injection using horizontal- and longitudinal- (and in the final project also vertical-) phase space is discussed. In the second part the experimental results are presented. Factors of vital importance are the stacking efficiency, the beam life-time and the cooling time of the ions. The beam decay owing to charge exchange with the residual gas and to recombination by the capture of cooling electrons was intensively studied. Beam instabilities and space-charge effects in the ...

Microcontroller based motion control interface unit for double slit type beam emittance monitor for H- ion source

International Nuclear Information System (INIS)

Holikatti, A.C.; Jain, Rahul; Karnewar, A.K.; Sonawane, B.B.; Maurya, N.K.; Puntambekar, T.A.

2015-01-01

The Indian Spallation Neutron Source (ISNS), proposed to be developed at RRCAT, will use a 1 GeV H - linac and an accumulator ring to produce high flux of pulsed neutrons via spallation process. The development activity of front end of 1H - linac for ISNS is under progress at RRCAT, for which a pulsed H - ion source of 50 keV energy, 30 mA current with pulse width of 500 μs has been developed at RRCAT. In this paper, we present the design and development of a microcontroller based motion control interface unit for double slit type beam emittance monitor for the H - ion source. This is an interceptive type of beam diagnostic device, which is used for the quantitative measurement of transverse emittance and beam intensity profile

Overview of collective effects in the NLC main damping rings

International Nuclear Information System (INIS)

Wolski, A.; Santis, S. de

2002-01-01

The present design for the NLC Main Damping Rings (MDRs) meets the specifications for acceptance and extracted emittance, in the limit of zero current. However, the relatively large bunch charge and moderate energy mean that a variety of collective effects can impact the beam dynamics, leading to loss of stability or increase of equilibrium emittance. These effects include intrabeam scattering, impedance from numerous sources, fast ion instability, and (in the positron ring) electron cloud. In this note, we survey the expected impact on damping ring performance from each of a number of collective effects, and discuss the priorities for future studies in this area

Simulated microbe removal around finger rings using different hand sanitation methods.

Science.gov (United States)

Alur, Archana A; Rane, Madhavi J; Scheetz, James P; Lorenz, Douglas J; Gettleman, Lawrence

2009-09-01

It is our opinion that the CDC and the WHO have underestimated cross-contamination under examination gloves in dental clinics while wearing jewelry, such as finger rings. These agencies only "recommend" removing jewelry, and only washing hands for 15 seconds with soap and warm water before donning gloves. This study examined several washing procedures and finger rings using simulated microbes. A gloved rubber hand manikin was made and fitted with a fresh disposable vinyl glove. Four fingers were fitted with rings or no ring, dusted with simulated microbes, and washed with a scrub brush for 5, 15, and 25 seconds under 20 degrees C and 40 degrees C water alone, or with liquid hand soap. Light levels (in lux) of fluorescent powder before and after washing were measured and delta scores calculated for changes in light levels, equivalent to effectiveness of hand washing procedures. A full-factorial, 3-factor analysis of variance (ANOVA) was used to test for differences among levels of the three study factors-time, temperature, and soap use. Tukey's post hoc honestly significant difference (HSD) test was applied to significant factors to examine pair-wise differences between factor levels. It was found that the longer the hands with rings were washed with a scrub brush under flowing water, the more simulated microbes were removed. By 25 seconds, all methods were essentially the same. Simulated microbes were more difficult to remove from the palm compared to the back of the hand. The liquid hand soap used in this study was more effective with warm water than cold. When given a choice of washing with cold water up to 15 seconds, it would be preferable not to use soap to remove simulated microbes. Qualitatively, the outer surface of finger rings were more effectively cleaned than the crevice below the ring, and the ring with a stone setting appeared to accumulate and retain simulated microbes more than other rings. The most effective treatment was washing with warm water

Plutonium in tree rings from France and Japan

International Nuclear Information System (INIS)

Garrec, J.-P.; Suzuki, T.; Mahara, Y.; Santry, D.C.; Miyahara, S.; Sugahara, M.; Zheng, J.; Kudo, A.

1995-01-01

Plutonium, along with other radionuclide concentrations, was measured in evergreen tree rings from two different locations. This was used as an information source for the past two centuries. Tree rings are a product of annual layers and thus chronological information is clearly visible. Three trees were harvested in 1988-1990: a French white fir (137 years old) and a spruce tree (177 years old) from the France-Germany border near Nancy, France and a sugi (78 years old) from Nagasaki, Japan. The highest 239 + 240 Pu concentration of 30.0 mBq/kg of dry wood was obtained from the tree rings from Nagasaki, located at the centre of the local fallout of the Pu A-bomb detonated in 1945. This concentration peak was, however, observed in tree rings of 1965-67. The concentration was only 2.9 mBq/kg for the tree rings of 1944-46. The contribution of the local fallout on the surface soils from the A-bomb was 181 mBq/cm 2 at the harvested area of the tree, while the contribution of global fallout by many weapons testing was 5.9 mBq/cm 2 (or 3.3% total fallout in the region). The reason for the over 20 year time lag of 239 + 240 Pu uptake by the tree rings is unknown because many factors influence the routes of Pu into the tree rings. Also the chemical form of Pu in surface soils may have been changed by the surrounding environment. The highest concentration in the tree rings from France was 9.4 mBq/kg which is about 31% of Nagasaki 239 + 240 Pu concentration. (author)

A feasibility study for a one-megawatt pulsed spallation source at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Pynn, R.

1994-01-01

Over the past two decades, high-intensity proton accelerators have been designed and developed to support nuclear physics research and defense applications. This technology has now matured to the point where it can support simultaneous and cost-effective exploitation of a number of important areas of both basic and applied science. Examples include neutron scattering, the production of radioisotopes, tests of technologies to transmute nuclear waste, radiation damage studies, nuclear physics, and muon spin research. As part of a larger program involving these and other areas, a team at Los Alamos National Laboratory has undertaken a feasibility study for a 1-MW pulsed spallation neutron source (PSS) based on the use of an 800-MeV proton linac and an accumulator ring. In January 1994, the feasibility study was reviewed by a large, international group of experts in the design of accelerators and neutron spallation targets. This group confirmed the viability of the proposed neutron source. In this paper, I describe the approach Los Alamos has taken to the feasibility study, which has involved a synergistic application of the Laboratory's expertise in nuclear science and technology, computation, and particle-beam technologies. Several examples of problems resolved by the study are described, including chopping of low-energy proton beam, interactions between H - particles and the stripper foil used to produce protons for injection into an accumulator ring, and the inclusion of engineering realities into the design of a neutron production target. These examples are chosen to illustrate the breadth of the expertise that has been brought to bear on the feasibility study and to demonstrate that there are real R ampersand D issues that need to be resolved before a next-generation spoliation source can be built

Compact 6 dB Two-Color Continuous Variable Entangled Source Based on a Single Ring Optical Resonator

Directory of Open Access Journals (Sweden)

Ning Wang

2018-02-01

Full Text Available Continuous-variable entangled optical beams at the degenerate wavelength of 0.8 μm or 1.5 μm have been investigated extensively, but separately. The two-color entangled states of these two useful wavelengths, with sufficiently high degrees of entanglement, still lag behind. In this work, we analyze the various limiting factors that affect the entanglement degree. On the basis of this, we successfully achieve 6 dB of two-color quadrature entangled light beams by improving the escape efficiency of the nondegenerate optical amplifier, the stability of the phase-locking servo system, and the detection efficiency. Our entangled source is constructed only from a single ring optical resonator, and thus is highly compact, which is suitable for applications in long-distance quantum communication networks.

Flux and brightness calculations for various synchrotron radiation sources

International Nuclear Information System (INIS)

Weber, J.M.; Hulbert, S.L.

1991-11-01

Synchrotron radiation (SR) storage rings are powerful scientific and technological tools. The first generation of storage rings in the US., e.g., SURF (Washington, D.C.), Tantalus (Wisconsin), SSRL (Stanford), and CHESS (Cornell), revolutionized VUV, soft X-ray, and hard X-ray science. The second (present) generation of storage rings, e.g. the NSLS VUV and XRAY rings and Aladdin (Wisconsin), have sustained the revolution by providing higher stored currents and up to a factor of ten smaller electron beam sizes than the first generation sources. This has made possible a large number of experiments that could not performed using first generation sources. In addition, the NSLS XRAY ring design optimizes the performance of wigglers (high field periodic magnetic insertion devices). The third generation storage rings, e.g. ALS (Berkeley) and APS (Argonne), are being designed to optimize the performance of undulators (low field periodic magnetic insertion devices). These extremely high brightness sources will further revolutionize x-ray science by providing diffraction-limited x-ray beams. The output of undulators and wigglers is distinct from that of bending magnets in magnitude, spectral shape, and in spatial and angular size. Using published equations, we have developed computer programs to calculate the flux, central intensity, and brightness output bending magnets and selected wigglers and undulators of the NSLS VUV and XRAY rings, the Advanced Light Source (ALS), and the Advanced Photon Source (APS). Following is a summary of the equations used, the graphs and data produced, and the computer codes written. These codes, written in the C programming language, can be used to calculate the flux, central intensity, and brightness curves for bending magnets and insertion devices on any storage ring

Photocapacitance study of type-II GaSb/GaAs quantum ring solar cells

Energy Technology Data Exchange (ETDEWEB)

Wagener, M. C.; Botha, J. R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Carrington, P. J.; Krier, A. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

2014-01-07

In this study, the density of states associated with the localization of holes in GaSb/GaAs quantum rings are determined by the energy selective charging of the quantum ring distribution. The authors show, using conventional photocapacitance measurements, that the excess charge accumulated within the type-II nanostructures increases with increasing excitation energies for photon energies above 0.9 eV. Optical excitation between the localized hole states and the conduction band is therefore not limited to the Γ(k = 0) point, with pseudo-monochromatic light charging all states lying within the photon energy selected. The energy distribution of the quantum ring states could consequently be accurately related from the excitation dependence of the integrated photocapacitance. The resulting band of localized hole states is shown to be well described by a narrow distribution centered 407 meV above the GaAs valence band maximum.

Construction and operation of a support facilities (Building 729) for operation/testing of a prototype accelerator/storage ring (XLS) and machine shop for the National Synchrotron Light Source at Brookhaven National Laboratory, Upton, New York

International Nuclear Information System (INIS)

1992-06-01

Proposed action is to construct at BNL a 5,600-ft 2 support building, install and operate a prototypic 200 MeV accelerator and a prototypic 700 MeV storage ring within, and to construct and operate a 15 kV substation to power the building. The accelerator and storage ring would comprise the x-ray lithography source or XLS

Rings in drugs.

Science.gov (United States)

Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

2014-07-24

We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

Summary test results of the particle-beam diagnostics for the Advanced Photon Source (APS) subsystems

International Nuclear Information System (INIS)

Lumpkin, A.; Wang, X.; Sellyey, W.; Patterson, D.; Kahana, E.

1994-01-01

During the first half of 1994, a number of the diagnostic systems for measurement of the charged-particle beam parameters throughout the subsystems of the Advanced Photon Source (APS) have been installed and tested. The particle beams eventually will involve 450-MeV to 7-GeV positrons and with different pulse formats. The first test and commissionin results for beam profiles, beam position monitors, loss rate monitors, current monitors, and synchrotron radiation photon monitors hve been obtained using 200- to 350-MeV electron beams injected into the subsystems. Data presented are principally from the transport lines and the positron accumulator ring

Development of a model capable of predicting the performance of piston ring-cylinder liner-like tribological interfaces

DEFF Research Database (Denmark)

Felter, C.L.; Vølund, A.; Imran, Tajammal

2010-01-01

Friction in the piston ring package (piston, piston rings, and liner) is a major source of power consumption in large two-stroke marine diesel engines. In order to improve the frictional and wear performance, knowledge about the tribological interface between piston rings and liner is needed...

Positron Options for the Linac-Ring LHeC

CERN Document Server

Zimmermann, F; Papaphilippou, Y; Schulte, D; Sievers, P; Rinolfi, L; Variola, A; Zomer, F; Braun, H H; Yakimenko, V; Bulyak, E V; Klein, M

2012-01-01

The full physics program of a future Large Hadron electron Collider (LHeC) [1] requires both pe+ and pe− collisions. For a pulsed 140-GeV or an ERL-based 60-GeV Linac-Ring LHeC this implies a challenging rate of, respectively, about 1.8 × 1015 or 4.4 × 1016 e+/s at the collision point, which is about 300 or 7000 times the rate previously obtained, at the SLAC Linear Collider (SLC). We consider providing this e+ rate through a combination of measures: (1) Reducing the required production rate from the e+ target through colliding e+ (and the LHC protons) several times before deceleration, by reusing the e+ over several acceleration/deceleration cycles, and by cooling them, e.g., with a compact tri-ring scheme or a conventional damping ring in the SPS tunnel. (2) Using an advanced target, e.g., W-granules, rotating wheel, slicedrod converter, or liquid metal jet, for converting gamma rays to e+. (3) Selecting the most powerful of several proposed gamma sources, namely Compton ERL, Compton storage ring, coher...

Aflatoxin Accumulation in a Maize Diallel Cross

Directory of Open Access Journals (Sweden)

W. Paul Williams

2015-06-01

Full Text Available Aflatoxins, produced by the fungus Aspergillus flavus, occur naturally in maize. Contamination of maize grain with aflatoxin is a major food and feed safety problem and greatly reduces the value of the grain. Plant resistance is generally considered a highly desirable approach to reduction or elimination of aflatoxin in maize grain. In this investigation, a diallel cross was produced by crossing 10 inbred lines with varying degrees of resistance to aflatoxin accumulation in all possible combinations. Three lines that previously developed and released as sources of resistance to aflatoxin accumulation were included as parents. The 10 parental inbred lines and the 45 single crosses making up the diallel cross were evaluated for aflatoxin accumulation in field tests conducted in 2013 and 2014. Plants were inoculated with an A. flavus spore suspension seven days after silk emergence. Ears were harvested approximately 60 days later and concentration of aflatoxin in the grain determined. Parental inbred lines Mp717, Mp313E, and Mp719 exhibited low levels (3–12 ng/g of aflatoxin accumulation. In the diallel analysis, both general and specific combining ability were significant sources of variation in the inheritance of resistance to aflatoxin accumulation. General combining ability effects for reduced aflatoxin accumulation were greatest for Mp494, Mp719, and Mp717. These lines should be especially useful in breeding for resistance to aflatoxin accumulation. Breeding strategies, such as reciprocal recurrent selection, would be appropriate.

The advanced photon source

International Nuclear Information System (INIS)

Galayda, J.N.

1995-01-01

The Advanced Photon Source (APS) is a 7-GeV third-generation synchrotron radiation storage ring and full-energy positron injector. Construction project funding began in 1989, and ground breaking took place on 5 May 1990. Construction of all accelerator facilities was completed in January 1995 and storage ring commissioning is underway. First observation of x-rays from a bending magnet source took place on 26 March 1995. Nearly all performance specifications of the injector have been reached, and first observations indicate that the reliability, dynamic aperture, emittance, and orbit stability in the storage ring are satisfactory. Observation of radiation from the first of 20 insertion device beamlines is scheduled for October 1995. Start of regular operations is expected to take place well before the APS Project target date of December 1996

Retention of Plasmodium falciparum ring-infected erythrocytes in the slow, open microcirculation of the human spleen.

Science.gov (United States)

Safeukui, Innocent; Correas, Jean-Michel; Brousse, Valentine; Hirt, Déborah; Deplaine, Guillaume; Mulé, Sébastien; Lesurtel, Mickael; Goasguen, Nicolas; Sauvanet, Alain; Couvelard, Anne; Kerneis, Sophie; Khun, Huot; Vigan-Womas, Inès; Ottone, Catherine; Molina, Thierry Jo; Tréluyer, Jean-Marc; Mercereau-Puijalon, Odile; Milon, Geneviève; David, Peter H; Buffet, Pierre A

2008-09-15

The current paradigm in Plasmodium falciparum malaria pathogenesis states that young, ring-infected erythrocytes (rings) circulate in peripheral blood and that mature stages are sequestered in the vasculature, avoiding clearance by the spleen. Through ex vivo perfusion of human spleens, we examined the interaction of this unique blood-filtering organ with P falciparum-infected erythrocytes. As predicted, mature stages were retained. However, more than 50% of rings were also retained and accumulated upstream from endothelial sinus wall slits of the open, slow red pulp microcirculation. Ten percent of rings were retained at each spleen passage, a rate matching the proportion of blood flowing through the slow circulatory compartment established in parallel using spleen contrast-enhanced ultrasonography in healthy volunteers. Rings displayed a mildly but significantly reduced elongation index, consistent with a retention process, due to their altered mechanical properties. This raises the new paradigm of a heterogeneous ring population, the less deformable subset being retained in the spleen, thereby reducing the parasite biomass that will sequester in vital organs, influencing the risk of severe complications, such as cerebral malaria or severe anemia. Cryptic ring retention uncovers a new role for the spleen in the control of parasite density, opening novel intervention opportunities.

The US spallation neutron source (SNS) project

International Nuclear Information System (INIS)

Alonso, J.R.

1999-01-01

The SNS is a 1 MW pulsed spallation neutron source that will be sited at Oak Ridge. It will consist of a high-current, normal-conducting linac accelerating an H - beam to 1 GeV, an accumulator ring which compresses each 1 ms linac pulse into a 600 ns bunch which is then extracted in a single turn onto a liquid mercury target. Neutron pulses emerge at a 60 Hz rate from the two ambient, and two cryogenic moderators. Eighteen beam ports surrounding the target station are available for neutron-scattering instrumentation. Funds for ten instruments are included in the construction project; these instruments will provide basic measurement capability for the many and varied research activities at the SNS facility. The new spallation source is being built by a consortium of laboratories; the partners are LBNL, LANL, BNL, ANL and ORNL. The breadth and depth of experience and resources brought by such a wide-spread team offers very significant advantages. Construction will start in October of 1998, operation will begin in October, 2005. (J.P.N.)

Using the circulating beam in the Fermilab antiproton accumulator for experiments

International Nuclear Information System (INIS)

MacLachlan, J.A.

1988-01-01

The Fermilab Accumulator is a storage ring optimized for stacking and stochastic cooling 8 GeV antiprotons for the Tevatron collider. Minor modifications have been made to provide for beam in the energy range 8.0-2.9 GeV of luminosity /approximately/10 31 cm -2 s/sup - 1/ with a hydrogen jet internal target. Experience to date consists of machine studies and detector engineering run with protons. 7 refs

Years of annual ring formation of trees and elements of minute amount

International Nuclear Information System (INIS)

Katayama, Yukio

1988-01-01

The structure of the trunks of trees is briefly explained, and the effect of environmental factors such as light, rain, soil, temperature and so on and the effect of environmental pollution are conceivable. The examples of the research on the quantitative determination of the elements of minute amount contained in the annual rings of trees and their use as the living things for environmental pollution index are shown, and the problems are considered. The concentration of manganese contained in annual rings may be used as environmental pollution index. It was pointed out that cadmium accumulated in annual rings had a strong correlation with the decrease of annual ring width. K-40 once taken in annual rings moved radially in connection with physical and physiological actions. The authors have examined the distribution of the elements of minute amount in the trunks, using Japanese cedar, white fir and oak as the specimens. For the quantitative analysis of the elements of minute amount, thermal neutron radioactivation analysis was used, which can analyze many elements simultaneously by nondestructive method. The elements of minute amount in the trunks of Japanese cedar, the difference of the distribution according to the kinds of trees, and the movement of elements within trunks are reported. The application of PIXE method to this analysis is considered. (Kako, I.)

Accumulation, sources and health risks of trace metals in elevated geochemical background soils used for greenhouse vegetable production in southwestern China.

Science.gov (United States)

Zhang, Haidong; Huang, Biao; Dong, Linlin; Hu, Wenyou; Akhtar, Mohammad Saleem; Qu, Mingkai

2017-03-01

Greenhouse vegetable cultivation with substantive manure and fertilizer input on soils with an elevated geochemical background can accumulate trace metals in soils and plants leading to human health risks. Studies on trace metal accumulation over a land use shift duration in an elevated geochemical background scenario are lacking. Accumulation characteristics of seven trace metals in greenhouse soil and edible plants were evaluated along with an assessment of the health risk to the consumers. A total of 118 greenhouse surface soils (0-20cm) and 30 vegetables were collected from Kunming City, Yunnan Province, southwestern China, and analyzed for total Cd, Pb, Cu, Zn, As, Hg, and Cr content by ICP-MS and AFS. The trace metals were ordered Cu>Cd>Hg>Zn>Pb>As>Cr in greenhouse soils accumulation level, and the geo-accumulation index suggested the soil more severely polluted with Cd, Cu, Hg and Zn. The greenhouse and open-field soils had significant difference in Cd, Cr and Zn. The duration of shift from paddy to greenhouse land-use significantly influenced trace metal accumulation with a dramatic change during five to ten year greenhouse land-use, and continuous increase of Cd and Hg. A spatial pattern from north to south for Cd and Hg and a zonal pattern for Cu and Zn were found. An anthropogenic source primarily caused trace metal accumulation, where the principal component analysis/multiple linear regression indicated a contribution 61.2%. While the assessment showed no potential risk for children and adults, the hazard health risks index was greater than one for adolescents. The extended duration of land use as greenhouses caused the trace metal accumulation, rotation in land use should be promoted to reduce the health risks. Copyright © 2016. Published by Elsevier Inc.

Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina

International Nuclear Information System (INIS)

Wannaz, Eduardo D.; Carreras, Hebe A.; Perez, Carlos A.; Pignata, Maria L.

2006-01-01

The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n = 38) were chosen in the province of Cordoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies

Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina

Energy Technology Data Exchange (ETDEWEB)

Wannaz, Eduardo D. [Departamento de Quimica, Instituto Multidisciplinario de Biologia Vegetal - IMBIV/CONICET-UNC, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, Ciudad Universitaria (X5016GCA) Cordoba (Argentina); Carreras, Hebe A. [Departamento de Quimica, Instituto Multidisciplinario de Biologia Vegetal - IMBIV/CONICET-UNC, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, Ciudad Universitaria (X5016GCA) Cordoba (Argentina); Perez, Carlos A. [Laboratorio Nacional de Luz Sincrotron - LNLS/CNPq, Caixa Postal 6192, 13038-970 Campinas (Brazil); Pignata, Maria L. [Departamento de Quimica, Instituto Multidisciplinario de Biologia Vegetal - IMBIV/CONICET-UNC, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, Ciudad Universitaria (X5016GCA) Cordoba (Argentina)]. E-mail: pignata@com.uncor.edu

2006-05-15

The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n = 38) were chosen in the province of Cordoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies.

Suppression of propagating TE modes in the FNAL antiproton source stochastic beam cooling system

International Nuclear Information System (INIS)

Barry, W.C.

1985-05-01

A method of attenuating the propagation of waveguide modes in the stochastic cooling array beam pipes to be utilized in the accumulator and debuncher rings of the Fermilab antiproton source is described. The attenuation method treated involves lining the vertical walls of the beam pipes with a ferrimagnetic material. The general solution for propagation in a nonhomogeneously loaded waveguide is presented along with numerical results specific to the antiproton source beam cooling system. Also described is a broadband, automated technique for the simultaneous measurement of complex μ and epsilon developed to aid in the characterization of different ferrite materials. Permittivity and permeability data for a typical ferrite are presented along with a discussion of the effects of these parameters on waveguide mode attenuation in the ferrite lined beam pipes

Evaluation of Maize Germplasm for Resistance to Aflatoxin Accumulation

Directory of Open Access Journals (Sweden)

Michael H. Blanco

2012-03-01

Full Text Available Aflatoxin contamination of maize grain threatens human food and animal feed safety. Breeding for reduced grain aflatoxin accumulation is one of the best strategies presently available to lower grain aflatoxin accumulation. Previously identified sources of germplasm with reduced grain aflatoxin accumulation are excessively tall and late maturing. The objective of this research was to screen germplasm and identify potential sources of aflatoxin resistance. KO679Y and CUBA117:S15-101-001-B-B-B-B inbreds were evaluated for aflatoxin accumulation alongside resistant and susceptible checks with both performing well. These two lines were also evaluated in various crosses. KO679Y performed especially well in crosses with Mp494 and Mp717, resulting in low ear rot and very low aflatoxin levels, but not well in other crosses. A breeding cross including CUBA117:S15-101-001-B-B-B-B as a parent accumulated low levels of aflatoxin both years it was evaluated. Lines resulting from these crosses are being advanced for further evaluation and improvement. KO679Y and CUBA117:S15-101-001-B-B-B-B may prove useful for breeders seeking germplasm sources for ear rot and mycotoxin reduction, especially KO679Y which matures a week earlier and is approximately 25% shorter than current lines resistant to grain aflatoxin accumulation.

CIRCE: A dedicated storage ring for coherent THz synchrotron radiation

International Nuclear Information System (INIS)

Byrd, J.M.; Martin, Michael C.; McKinney, W.R.; Munson, D.V.; Nishimura, H.; Robin, D.S.; Sannibale, F.; Schlueter, R.D.; Thur, W.G.; Jung, J.Y.; Wan, W.

2003-01-01

We present the concepts for an electron storage ring dedicated to and optimized for the production of stable coherent synchrotron radiation (CSR) over the far-infrared terahertz wavelength range from 200 mm to about one cm. CIRCE (Coherent InfraRed CEnter) will be a 66 m circumference ring located on top of the ALS booster synchrotron shielding tunnel and using the existing ALS injector. This location provides enough floor space for both the CIRCE ring, its required shielding, and numerous beamlines. We briefly outline a model for CSR emission in which a static bunch distortion induced by the synchrotron radiation field is used to significantly extend the stable CSR emission towards higher frequencies. This model has been verified with experimental CSR results. We present the calculated CIRCE photon flux where a gain of 6-9 orders of magnitude is shown compared to existing far-IR sources. Additionally, the particular design of the dipole vacuum chamber has been optimized to allow an excellent transmission of these far-infrared wavelengths. We believe that the CIRCE source can be constructed for a modest cost

A review of methods for experimentally determining linear optics in storage rings

International Nuclear Information System (INIS)

Safranek, J.

1995-01-01

In order to maximize the brightness and provide sufficient dynamic aperture in synchrotron radiation storage rings, one must understand and control the linear optics. Control of the horizontal beta function and dispersion is important for minimizing the horizontal beam size. Control of the skew gradient distribution is important for minimizing the vertical size. In this paper, various methods for experimentally determining the optics in a storage ring will be reviewed. Recent work at the National Synchrotron Light Source X-Ray Ring will be presented as well as work done at laboratories worldwide

Forward modeling of tree-ring data: a case study with a global network

Science.gov (United States)

Breitenmoser, P. D.; Frank, D.; Brönnimann, S.

2012-04-01

Information derived from tree-rings is one of the most powerful tools presently available for studying past climatic variability as well as identifying fundamental relationships between tree-growth and climate. Climate reconstructions are typically performed by extending linear relationships, established during the overlapping period of instrumental and climate proxy archives into the past. Such analyses, however, are limited by methodological assumptions, including stationarity and linearity of the climate-proxy relationship. We investigate climate and tree-ring data using the Vaganov-Shashkin-Lite (VS-Lite) forward model of tree-ring width formation to examine the relations among actual tree growth and climate (as inferred from the simulated chronologies) to reconstruct past climate variability. The VS-lite model has been shown to produce skill comparable to that achieved using classical dendrochronological statistical modeling techniques when applied on simulations of a network of North American tree-ring chronologies. Although the detailed mechanistic processes such as photosynthesis, storage, or cell processes are not modeled directly, the net effect of the dominating nonlinear climatic controls on tree-growth are implemented into the model by the principle of limiting factors and threshold growth response functions. The VS-lite model requires as inputs only latitude, monthly mean temperature and monthly accumulated precipitation. Hence, this simple, process-based model enables ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated tree-rings to monthly climate conditions obtained from the 20th century reanalysis project back to 1871. These simulated tree-ring chronologies are compared to the climate-driven variability in worldwide observed tree-ring chronologies from the International Tree Ring Database. Results point toward the suitability of the relationship among actual tree

Design and jump phenomenon analysis of an eccentric ring energy harvester

International Nuclear Information System (INIS)

Wang, Yu-Jen; Chen, Chung-De

2013-01-01

This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318–442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers. (paper)

Design and jump phenomenon analysis of an eccentric ring energy harvester

Science.gov (United States)

Wang, Yu-Jen; Chen, Chung-De

2013-10-01

This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318-442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers.

Beam monitors and transverse feedback system of TRISTAN Main Ring

International Nuclear Information System (INIS)

Ieiri, T.; Ishii, H.; Kishiro, J.; Mizumachi, Y.; Mori, K.; Nakajima, K.; Ogata, A.; Shintake, T.; Tejima, M.

1987-01-01

The construction of 30 GeV TRISTAN Main Ring (MR) started in 1983 soon after the commissioning of 8 GeV Accumulation Ring (AR). The authors prepared 392 position monitors, 6 synchrotron radiation monitors, 9 screen monitors, 2 DCCT's, 3 scrapers, 12 bunch monitors, transverse feedback systems for two beams and DC separators. Since the required monitoring devices of AR and MR are almost the same, the experiences in AR were very useful in the design of MR monitors. However, machine parameters of two rings are very different and the authors had to review the performance of each item. From the monitor point of view the most important is the difference of revolution frequency; 794.6 kHz for AR and 99.33 kHz for MR. This means that average beam current of MR is 1/8 as small as AR current with the same bunch number and intensity. Therefore, the sensitivity of each monitor must be better in MR. The second difference is that MR should be used as a collider from the beginning. Therefore they must prepare for multi-beam and multi-bunch operation

Survey of Digital Feedback Systems in High Current Storage Rings

International Nuclear Information System (INIS)

Teytelman, Dmitry

2003-01-01

In the last decade demand for brightness in synchrotron light sources and luminosity in circular colliders led to construction of multiple high current storage rings. Many of these new machines require feedback systems to achieve design stored beam currents. In the same time frame the rapid advances in the technology of digital signal processing allowed the implementation of these complex feedback systems. In this paper I concentrate on three applications of feedback to storage rings: orbit control in light sources, coupled-bunch instability control, and low-level RF control. Each of these applications is challenging in areas of processing bandwidth, algorithm complexity, and control of time-varying beam and system dynamics. I will review existing implementations as well as comment on promising future directions

White Ring; White ring

Energy Technology Data Exchange (ETDEWEB)

Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

1998-01-05

White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

Design of the WNR proton storage ring lattice

International Nuclear Information System (INIS)

Cooper, R.K.; Lawrence, G.P.

1977-01-01

The Weapons Neutron Research Facility, now approaching operational status, is a pulsed neutron time-of-flight facility utilizing bursts of 800 MeV protons from the LAMPF linac. The protons strike a heavy metal target and produce a broad energy spectrum of neutrons via spallation reactions. Ideally the width of the proton pulse should approach a delta function in order to achieve good neutron energy resolution. Practically, the shortest pulse that can be employed in the facility is that produced by a single LAMPF micropulse, which, at design current, contains approximately 5 x 10 8 protons. With the addition of a storage ring capable of accumulating many micropulses, this intensity can be increased, as can the repetition rate. Moreover, by storing an unbunched beam, a low repetition rate, very intense proton burst can be generated. This latter mode of usage allows neutron time-of-flight studies using large neutron targets, for which pulse lengths of the order of several hundred nanoseconds are suitable. The primary goals of the ring are reported: (i) to increase the intensity of the burst to 10 11 protons while retaining a short pulse length; (ii) to increase the repetition rate of the bursts by at least a factor of six; and (iii) to store as many particles as possible, uniformly distributed around the ring

Token Ring Project

Directory of Open Access Journals (Sweden)

Adela Ionescu

2007-01-01

Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

Semi-algebraic function rings and reflectors of partially ordered rings

CERN Document Server

Schwartz, Niels

1999-01-01

The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.

A Catalog of MIPSGAL Disk and Ring Sources

Science.gov (United States)

2010-04-01

remaining 11 are identified only as IRAS sources with no additional information available, except perhaps Two Micron All Sky Survey ( 2MASS )9 data...correspondence to the 24/xm emission, and a negative result means either no 9 Most of the catalog sources have at least one 2MASS source within 5", often

Rotating ring-ring electrode theory and experiment

NARCIS (Netherlands)

Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

2000-01-01

A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

HISTRAP proposal: heavy-ion storage ring for atomic physics

Energy Technology Data Exchange (ETDEWEB)

Olsen, D K; Alton, G D; Datz, S; Dittner, P F; Dowling, D T; Haynes, D L; Hudson, E D; Johnson, J W; Lee, I Y; Lord, R S

1987-04-01

HISTRAP, Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charge very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will have a maximum bending power of 2.0 T m and will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac.

Ring artifacts removal from synchrotron CT image slices

International Nuclear Information System (INIS)

Wei Zhouping; Chapman, Dean; Wiebe, Sheldon

2013-01-01

Ring artifacts can occur in reconstructed images from x-ray Computerized Tomography (CT) as full or partial concentric rings superimposed on the scanned structures. Due to the data corruption by those ring artifacts in CT images, qualitative and quantitative analysis of these images are compromised. In this paper, we propose to correct the ring artifacts on the reconstructed synchrotron radiation (SR) CT image slices. The proposed correction procedure includes the following steps: (1). transform the reconstructed CT images into polar coordinates; (2) apply discrete two-dimensional (2D) wavelet transform to the polar image to decompose it into four image components: low pass band image component, as well as the components from horizontal, vertical and diagonal details bands; (3). apply 2D Fourier transform to the vertical details band image component only, since the ring artifacts become vertical lines in the polar coordinates; (4). apply Gaussian filtering in Fourier domain along the abscissa direction to suppress the vertical lines, since the information of the vertical lines in Fourier domain is completely condensed to that direction; (5). perform inverse Fourier transform to get the corrected vertical details band image component; (6). perform inverse wavelet transform to get the corrected polar image; (7). transform the corrected polar image back to Cartesian coordinates to get the CT image slice with reduced ring artifacts. This approach has been successfully used on CT data acquired from the Biomedical Imaging and Therapy (BMIT) beamline in Canadian Light Source (CLS), and the results show that the ring artifacts in original SR CT images have been effectively suppressed with all the structure information in the image preserved.

Conceptual design for an accelerator system for a very high-intensity pulsed neutron source using a linear-induction accelerator

International Nuclear Information System (INIS)

Foss, M.H.

1981-01-01

Several accelerator-based intense neutron sources have been constructed or designed by various laboratories around the world. All of these facilities have a common scheme of a linac and synchrotron or accumulator ring, and the system produces the proton energy of 500 to 1000 MeV. The average beam currents range from a few mA to a few hundred mA. The protons are then used to generate high-flux neutrons by spallation out of heavy-metal targets. In a synchrotron system, the protons are already bunched, and thus the pulse rate of the neutron beam is that of the repetition rate of the synchrotron. For an accumulator system, the pulse rate is determined by the extraction repetition rate of the accumulator. We have conceptually designed a new system that uses a linear-induction accelerator which can be operated for an average beam current up to a few mA with a repetition rate up to 100 Hz. The details of the design will be given

Topological ring currents in the "empty" ring of benzo-annelated perylenes.

Science.gov (United States)

Dickens, Timothy K; Mallion, Roger B

2011-01-27

Cyclic conjugation in benzo-annelated perylenes is examined by means of the topological π-electron ring currents calculated for each of their constituent rings, in a study that is an exact analogy of a recent investigation by Gutman et al. based on energy-effect values for the corresponding rings in each of these structures. "Classical" approaches, such as Kekulé structures, Clar "sextet" formulas, and circuits of conjugation, predict that the central ring in perylene is "empty" and thus contributes negligibly to cyclic conjugation. However, conclusions from the present calculations of topological ring currents agree remarkably with those arising from the earlier study involving energy-effect values in that, contrary to what would be predicted from the classical approaches, rings annelated in an angular fashion relative to the central ring of these perylene structures materially increase the extent of that ring's involvement in cyclic conjugation. It is suggested that such close quantitative agreement between the predictions of these two superficially very different indices (energy effect and topological ring current) might be due to the fact that, ultimately, both depend, albeit in ostensibly quite different ways, only on an adjacency matrix that contains information about the carbon-carbon connectivity of the conjugated system in question.

Automated tune measurements in the Advanced Light Source storage ring using a LabVIEW application

International Nuclear Information System (INIS)

Hinkson, J.A.; Chin, M.; Kim, C.H.; Nishimura, H.

1994-06-01

Horizontal and vertical betatron tunes and the synchrotron tune are measured frequently during storage ring commissioning. The measurements are tedious and subject to human errors. Automating this kind of repetitive measurement is underway using LabVIEW for Windows, a software application supplied by National Instruments Corporation, that provides acquisition, graphing, and analysis of data as well as instrument control through the General Purpose Interface Bus (GPIB). We have added LabVIEW access to the Advanced Light Source (ALS) data base and control system. LabVIEW is a fast and efficient tool for accelerator commissioning and beam physics studies. Hardware used to perform tune measurements include a tracking generator (or a white noise generator), strip line electrodes for external ''citation of the beam, button monitors, and a spectrum analyzer. All three tunes are displayed simultaneously on the spectrum analyzer. Our program automatically identifies three tunes by applying and analyzing small variations and reports the results. This routine can be encapsulated in other applications, for instance, in a chromaticity measurement and correction program

Application of quantum-dot multi-wavelength lasers and silicon photonic ring resonators to data-center optical interconnects

Science.gov (United States)

Beckett, Douglas J. S.; Hickey, Ryan; Logan, Dylan F.; Knights, Andrew P.; Chen, Rong; Cao, Bin; Wheeldon, Jeffery F.

2018-02-01

Quantum dot comb sources integrated with silicon photonic ring-resonator filters and modulators enable the realization of optical sub-components and modules for both inter- and intra-data-center applications. Low-noise, multi-wavelength, single-chip, laser sources, PAM4 modulation and direct detection allow a practical, scalable, architecture for applications beyond 400 Gb/s. Multi-wavelength, single-chip light sources are essential for reducing power dissipation, space and cost, while silicon photonic ring resonators offer high-performance with space and power efficiency.

General overview and a review of storage rings, research facilities, and insertion devices

International Nuclear Information System (INIS)

Winick, H.

1989-01-01

Synchrotron radiation, the electromagnetic radiation given off by electrons in circular motion, is revolutionizing many branches of science and technology by offering beams of vacuum ultraviolet light and x rays of immense flux and brightness. In the past decade there has been an explosion of interest in these applications leading to increased exploitation of existing rings and activity to construct new research facilities based on advanced storage rings and insertion device sources. Applications include basic and applied research in biology, chemistry, medicine, and physics plus many areas of technology. In this article they present a general overview of the field of synchrotron radiation research, its history, the present status and future prospects of storage rings and research facilities, and the development of wiggler and undulator insertion devices as sources of synchrotron radiation. 66 references, 20 figures, 1 table

Muon sources

International Nuclear Information System (INIS)

Parsa, Z.

2001-01-01

A full high energy muon collider may take considerable time to realize. However, intermediate steps in its direction are possible and could help facilitate the process. Employing an intense muon source to carry out forefront low energy research, such as the search for muon-number non-conservation, represents one interesting possibility. For example, the MECO proposal at BNL aims for 2 x 10 -17 sensitivity in their search for coherent muon-electron conversion in the field of a nucleus. To reach that goal requires the production, capture and stopping of muons at an unprecedented 10 11 μ/sec. If successful, such an effort would significantly advance the state of muon technology. More ambitious ideas for utilizing high intensity muon sources are also being explored. Building a muon storage ring for the purpose of providing intense high energy neutrino beams is particularly exciting.We present an overview of muon sources and example of a muon storage ring based Neutrino Factory at BNL with various detector location possibilities

Kayser-Fleischer Rings

Science.gov (United States)

... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

Planetary Rings

Science.gov (United States)

Nicholson, P. D.

2001-11-01

A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

Study of 1 MW neutron source synchrotron dual frequency power circuit for the main ring magnets

International Nuclear Information System (INIS)

McGhee, D.G.

1993-01-01

This paper describes the proposed design of the resonant power circuits for the 1-MW neutron source synchrotron's main ring magnets. The synchrotron is to have a duty cycle of 30 Hz with a maximum upper limit of operation corresponding to 2.0 GeV and a maximum design value of 2.2 GeV. A stability of 30 ppM is the design goal for the main bending and focusing magnets (dipoles and quadruples), in order to achieve an overall stabffity of 100 ppm when random field and position errors of the magnets are included. The power circuits of this design are similar to those used in Argonne's Intense Pulsed Neutron Source (IPNS) where the energy losses during each cycle are supplied by continuous excitation from modulated multiphase DC power supplies. Since only 50% of the 30-Hz sinewave is used for acceleration, a dual-frequency resonant magnet circuit is used in this design. The 30-Hz repetition rate is maintained with a 20-Hz magnet guide field during acceleration and a 60-Hz reset field when no beam is present. This lengthens the guide-field rise time and shortens the fall time, improving the duty factor for acceleration. The maximum B dot is reduced by 33% during acceleration and hence, the maximum rf voltage/turn is reduced by 56%

DEVELOPMENT OF TITANIUM NITRIDE COATING FOR SNS RING VACUUM CHAMBERS

International Nuclear Information System (INIS)

HE, P.; HSEUH, H.C.; MAPES, M.; TODD, R.; WEISS, D.

2001-01-01

The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with ∼100 nm of Titanium Nitride (TiN). This is to minimize the secondary electron yield (SEY) from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Both DC sputtering and DC-magnetron sputtering were conducted in a test chamber of relevant geometry to SNS ring vacuum chambers. Auger Electron Spectroscopy (AES) and Rutherford Back Scattering (RBS) were used to analyze the coatings for thickness, stoichiometry and impurity. Excellent results were obtained with magnetron sputtering. The development of the parameters for the coating process and the surface analysis results are presented

Preliminary Design Study of a Pre-booster Damping Ring for the FCC e+e− Injector

CERN Document Server

Etisken, O; Papaphilippou, Y

2017-01-01

The aim of the FCC e+e− lepton collider is to collide particles in the energy range 40–175 GeV. The FCC e+e− injector complex needs to produce and transport high-intensity e+e− beams at a fast repetition rate of about 0.1 Hz to top up the collider at its collision energy. A basic parameter set exists for all collider energies, assuming a 10 GeV linac operating with a large number of bunches accumulating in the existing SPS, which serves as pre-accelerator and damping ring before the bunches are transferred to the high-energy booster. The purpose of this study is to provide the conceptual design of an alternative damping and accelerator ring, replacing the SPS in the current scheme. This ring will have an injection energy of around 6 GeV and an extraction energy of around 20 GeV. Apart from establishing the basic ring parameters, the final study will include the optics design and layout, and single particle linear and non-linear dynamics optimization, including magnetic and alignment error tolerances. ...

Further comprehension of natural gas accumulation, distribution, and prediction prospects in China

Directory of Open Access Journals (Sweden)

Jun Li

2017-06-01

Full Text Available In-depth research reveals that the natural gas accumulation and distribution are characterized by cycle, sequence, equilibrium, traceability, and multi-stage. To be specific, every geotectonic cycle represents a gas reservoir forming system where natural gas is generated, migrated, accumulated, and formed into a reservoir in a certain play. Essentially, hydrocarbon accumulation occurs when migration force and resistance reach an equilibrium. In this situation, the closer to the source rock, the higher the accumulation efficiency is. Historically, reservoirs were formed in multiple phases. Moreover, zones in source rocks and adjacent to source rocks, unconformity belts, and faulted anticline belts are favorable areas to finding large gas fields. Apart from the common unconformity belts and faulted anticline belts, in-source and near-source zones should be considered as critical targets for future exploration. Subsequent exploration should focus on Upper Palaeozoic in the southeastern Ordos Basin, Triassic in southwestern Sichuan Basin, Jurassic in the northern section of the Kuqa Depression and other zones where no great breakthroughs have been made. Keywords: Large gas field, Distribution characteristics, Potential zone, Prospect

Plume residence and toxic material accumulation

International Nuclear Information System (INIS)

Spigarelli, S.A.; Holpuch, R.

1975-01-01

Increased growth rates and 137 Cs concentrations in plume resident trout are thought to be the result of increased metabolism, food consumption, and activity caused by exposure to increased water temperature and flow in thermal discharges. These exposure conditions could contribute to increased accumulation of biologically active, toxic substances by primary forage and predator fish species in the Great Lakes. Uptake and retention of various toxic substances by predators depend on concentrations in forage species (trophic transfer), ambient water, and point source effluents (direct uptake). Contaminants of immediate concern in Great Lakes systems (e.g., chlorinated hydrocarbons) accumulate in adipose tissue, and body concentrations have been correlated with total lipid content in fish. In addition to direct toxic effects on fish, many lipophilic contaminants are known to cause severe human health problems when ingested at concentrations commonly found in Lake Michigan salmonids. Although power plants may or may not be the direct source of a toxic substance, the thermal discharge environment may contribute to the accumulation of toxic substances in fish and the transfer of these materials to man

Fugitive Methane Emission Identification and Source Attribution: Ethane-to-Methane Analysis Using a Portable Cavity Ring-Down Spectroscopy Analyzer

Science.gov (United States)

Kim-Hak, D.; Fleck, D.

2017-12-01

Natural gas analysis and methane specifically have become increasingly important by virtue of methane's 28-36x greenhouse warming potential compared to CO2 and accounting for 10% of total greenhouse gas emissions in the US alone. Additionally, large uncontrolled leaks, such as the recent one from Aliso Canyon in Southern California, originating from uncapped wells, storage facilities and coal mines have increased the total global contribution of methane missions even further. Determining the specific fingerprint of methane sources by quantifying the ethane to methane (C2:C1) ratios provides us with means to understand processes yielding methane and allows for sources of methane to be mapped and classified through these processes; i.e. biogenic or thermogenic, oil vs. gas vs. coal gas-related. Here we present data obtained using a portable cavity ring-down spectrometry analyzer weighing less than 25 lbs and consuming less than 35W that simultaneously measures methane and ethane in real-time with a raw 1-σ precision of plane gas propagation.

Mid-Infrared Observations of Possible Intergalactic Star Forming Regions in the Leo Ring

Science.gov (United States)

Giroux, Mark; Smith, B.; Struck, C.

2011-05-01

Within the Leo group of galaxies lies a gigantic loop of intergalactic gas known as the Leo Ring. Not clearly associated with any particular galaxy, its origin remains uncertain. It may be a primordial intergalactic cloud alternatively, it may be a collision ring, or have a tidal origin. Combining archival Spitzer images of this structure with published UV and optical data, we investigate the mid-infrared properties of possible knots of star formation in the ring. These sources are very faint in the mid-infrared compared to star forming regions in the tidal features of interacting galaxies. This suggests they are either deficient in dust, or they may not be associated with the ring.

Orbit stability of the ALS storage ring

International Nuclear Information System (INIS)

Keller, R.; Nishimura, H.; Biocca, A.

1997-05-01

The Advanced Light Source (ALS) storage ring, a synchrotron light source of the third generation, is specified to maintain its electron orbit stable within one tenth of the rms beam size. In the absence of a dedicated orbit feed-back system, several orbit-distorting effects were investigated, aided by a new interactive simulation tool, the code TRACY V. The effort has led to a better understanding of the behavior of a variety of accelerator subsystems and in consequence produced a substantial improvement in day-to-day orbit stability

Design for ANL 7 GeV storage ring vacuum system

International Nuclear Information System (INIS)

Wehrle, R.B.; Nielsen, R.W.

1988-01-01

The 7-GeV Advanced Photon Source (APS) design includes a storage ring having a 1060-m circumference with the capability of accommodating 34 insertion devices (ID) and their associated photon beam lines. An additional 35 photon lines can be provided from bending magnets. The vacuum system for the storage ring is designed to maintain a beam-on operating pressure of 1n Torr or less to achieve a positron beam lifetime of approximately 20 hours. The vacuum system and it's current developmental status are described

The suitability of annual tree growth rings as environmental archives: Evidence from Sr, Nd, Pb and Ca isotopes in spruce growth rings from the Strengbach watershed

Science.gov (United States)

Stille, Peter; Schmitt, Anne-Désirée; Labolle, François; Pierret, Marie-Claire; Gangloff, Sophie; Cobert, Florian; Lucot, Eric; Guéguen, Florence; Brioschi, Laure; Steinmann, Marc; Chabaux, François

2012-05-01

The combination of the Sr, Nd and Pb isotope systems, recognized as tracers of sources, with the Ca isotope system, known to reveal biology-related fractionations, allowed us to test the reliability of spruce (Picea abies) growth rings as environmental archives through time (from 1916 to 1983) in a forest ecosystem affected by acid atmospheric deposition. Sr and Pb isotopes have already been applied in former tree-ring studies, whereas the suitability of Nd and Ca isotope systems is checked in the present article. Our Sr and Nd isotope data indicate an evolution in the cation origin with a geogenic origin for the oldest rings and an atmospheric origin for the youngest rings. Ca isotopes show, for their part, an isotopic homogeneity which could be linked to the very low weathering flux of Ca. Since this flux is weak the spruces' root systems have pumped the Ca mainly from the organic matter-rich top-soil over the past century. In contrast, the annual growth rings studied are not reliable and suitable archives of past Pb pollution.

Are the Dyson rings around pulsars detectable?

Science.gov (United States)

Osmanov, Z.

2018-04-01

In the previous paper ring (Osmanov 2016) (henceforth Paper-I) we have extended the idea of Freeman Dyson and have shown that a supercivilization has to use ring-like megastructures around pulsars instead of a spherical shell. In this work we reexamine the same problem in the observational context and we show that facilities of modern infrared (IR) telescopes (Very Large Telescope Interferometer and Wide-field Infrared Survey Explorer (WISE)) might efficiently monitor the nearby zone of the solar system and search for the IR Dyson-rings up to distances of the order of 0.2 kpc, corresponding to the current highest achievable angular resolution, 0.001 mas. In this case the total number of pulsars in the observationally reachable area is about 64 +/- 21. We show that pulsars from the distance of the order of ~ 1 kpc are still visible for WISE as point-like sources but in order to confirm that the object is the neutron star, one has to use the ultraviolet telescopes, which at this moment cannot provide enough sensitivity.

Sources and accumulation of plutonium in a large Western Pacific marginal sea: The South China Sea.

Science.gov (United States)

Wu, Junwen; Dai, Minhan; Xu, Yi; Zheng, Jian

2018-01-01

In order to examine the sources of plutonium (Pu) and elaborate its scavenging and accumulation processes, 240 Pu/ 239 Pu atom ratios and 239+240 Pu activities in the water column of the South China Sea (SCS) were determined and compared with our previously reported data for the sediments. Consistently high 240 Pu/ 239 Pu atom ratios that ranged from 0.184-0.250 (average=0.228±0.015), indicative of non-global fallout Pu sources were observed both in the surface water and at depth during 2012-2014. The spatial distribution of the 240 Pu/ 239 Pu atom ratio in the SCS showed a decreasing trend away from the Luzon Strait, which was very consistent with the introduction pathway of the Kuroshio Current. The Kuroshio had an even heavier Pu isotopic ratio ranging from 0.250-0.263 (average=0.255±0.006), traceable to the non-global fallout Pu signature from the Pacific Proving Grounds (PPG). Using a simple two end-member mixing model, we further revealed that this PPG source contributed 41±17% of the Pu in the SCS water column. The 239+240 Pu activities in the SCS surface seawater varied from 1.59 to 2.94mBqm -3 , with an average of 2.34±0.38mBqm -3 . Such an activity level was ~40% higher than that in the Kuroshio. The distribution of 239+240 Pu in the surface seawater further showed a general trend of increase from the Kuroshio to the SCS basin, suggesting significant accumulation of Pu within the SCS. The 239+240 Pu inventory of the water column in the SCS basin at the SEATS station with a total depth of ~3840m was estimated to be ~29Bqm -2 , which was substantially higher than the sediment core estimates made for the SCS basin (3.75Bqm -2 ) but much lower than the sediment core estimates made for the shelf of the northern SCS (365.6Bqm -2 ). Such differences were determined by the lower scavenging efficiency of Pu in the SCS basin compared to the northern SCS shelf. Copyright © 2017 Elsevier B.V. All rights reserved.

Physiology and biochemistry of source-regulated protein accumulation in the wheat grain.

Science.gov (United States)

Barneix, Atilio J

2007-05-01

Wheat is unique among cereals for the baking qualities of its flour, which are dependent upon the type and concentration of its proteins. As a consequence, the grain protein concentration (GPC) is one of the main determinants of wheat international market price. More than 50-70% of the final grain N is accumulated before flowering and later remobilized to the grain, N fertilization being the common practice used to produce high GPC. However, after incremental additions of N fertilizer, GPC reaches a maximum and then remains constant, without any increase in N uptake or remobilization by the crop, thus decreasing the efficiency of N fertilizer. Although, the genetic and molecular mechanisms that regulate N uptake by the roots are being clarified quickly, the regulation and physiology of N transport from the leaves to the grain remains less clear. In this review, the possible regulatory points involved in N transport to the grain and the difficulties for increasing GPC are discussed. It has been demonstrated that protein synthesis in the grain is source-limited, and that the grain can accumulate protein limited only by the amino acids provided by the phloem. It has also been shown that there is no limitation in the amino acid/sugar ratios that can be exported to the phloem. On the other hand, NO(3)(-) uptake transporters are depressed when the plant concentration of some amino acids, such as glutamine, is high. It has also been shown that a high N supply increases cytokinins concentration, preventing leaf senescence and proteolysis. Based on this information, it is postulated that there are two main regulatory points during grain filling when plant N status is ample. On the one hand, the N uptake transporters in the roots are depressed due to the high amino acids concentration in the tissues, and N uptake is low. On the other, a high amino acids concentration keeps the cytokinins level high, repressing leaf protein degradation and decreasing amino acid export to the

Catch history of ringed seals (Phoca hispida in Canada

Directory of Open Access Journals (Sweden)

Randall R Reeves

1998-06-01

Full Text Available The ringed seal (Phoca hispida has always been a staple in the diet and household economy of Inuit in Canada. The present paper was prepared at the request of the NAMMCO Scientific Committee to support their assessment of ringed seal stocks in the North Atlantic Basin and adjacent arctic and subarctic waters. Specifically, our objective was to evaluate recent and current levels of use of ringed seals by Canadian Inuit. Annual removals probably were highest (possibly greater than 100,000 in the 1960s and 1970s, a period when sealskin prices were particularly strong. Catches declined substantially in the 1980s following a collapse in sealskin prices, presumably related to the European trade ban on skins from newborn harp and hooded seals (Phoca groenlandica and Cystophora cristata, respectively. Recent catch levels throughout Canada (1980s and early 1990s are believed to be in the order of 50,000 to 65,000 ringed seals, with a total average annual kill (including hunting loss in the high tens of thousands. No reliable system is in place to monitor catches of ringed seals, so any estimate must be derived from a heterogeneous array of sources.

Synchrotron radiation sources: general features and vacuum system

International Nuclear Information System (INIS)

Craievich, A.F.

1985-01-01

In the last years the electron or positron storage rings, which were until 1970 only used for high energy physics experiments, begun to be built in several countries exclusively as electromagnetic radiation source (synchrotron radiation). The sources are generally made up by injector (linear accelerator or microtron), 'booster' (synchrotron), storage ring, insertions ('Wigglers' and ondulators) and light lines. The interest by these sources are due to the high intensity, large spectrum (from infrared to the X-rays), polarization and pulsed structure of the produced radiation. For the ultra-vacuum obtainement, necessary for the functioning storage rings (p=10 -9 Torr), several special procedures are used. In Brazil the Synchrotron Radiation National Laboratory of the CNPq worked out a conceptual project of synchrotron radiation source, whose execution should begin by the construction of the several components prototypes. (L.C.) [pt

Effect of minerals on accumulation of Cs by fungus Saccaromyces cerevisiae.

Science.gov (United States)

Ohnuki, Toshihiko; Sakamoto, Fuminori; Yamasaki, Shinya; Kozai, Naofumi; Shiotsu, Hiroyuki; Utsunomiya, Satoshi; Watanabe, Naoko; Kozaki, Tamotsu

2015-06-01

The accumulation of Cs by unicellular fungus of Saccharomyces cerevisiae in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. Two different types of experiments were employed: experiments using stable Cs to examine the effect of a carbon source on the accumulation of Cs, and accumulation experiments of radioactive Cs from agar medium containing (137)Cs and zeolite, vermiculite, phlogopite, smectite, mica, or illite as mineral supplements. In the former type of experiments, the Cs-accumulated cells were analyzed by scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDS). In the latter type, the radioactivity in the yeast cells was measured by an autoradiography technique. When a carbon source was present, higher amounts of Cs accumulated in the cells than in the resting condition without a carbon source. Analyses with SEM-EDS showed that no mineral formed on the cell surface. These results indicate that the yeast cells accumulate Cs by adsorption on the cell surface and intracellular accumulation. In the presence of minerals in the agar medium, the radioactivity in the yeast cells was in the order of mica > smectite, illite > vermiculite, phlogopite, zeolite. This order is inversely correlated to the ratio of the concentration of radioactive Cs between the minerals and the medium solution. These results strongly suggest that the yeast accumulates radioactive Cs competitively with minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Plasma density measurement with ring-type cutoff probe

International Nuclear Information System (INIS)

Kim, D.W.; You, S.J.; Na, B.K.; Kim, J.H.; Shin, Y.H.; Chang, H.Y.; Oh, W.Y.

2013-01-01

We proposed a cutoff probe with a ring-type detection tip enclosing a bar-type radiation tip. A comparative study between a proposed ring-type cutoff (RTC) probe and a conventional bar-type cutoff (BTC) probe showed that the RTC probe solved the problem of the BTC probe, the large measurement uncertainty of the electron density in a capacitively coupled plasma source. This improved characteristics of the RTC probe might have originated from the geometrical structure of the RTC probe concerning the monopole antennae radiation. This proposed cutoff probe can be expected to expand the applicable diagnostic range and to enhance the sensitivity of the cutoff probe. - Highlights: ► A cutoff probe with a ring type detection tip is proposed. ► Comparative experiment and simulation were conducted. ► The proposed probe showed a small uncertainty of measured plasma density. ► Improved characteristics might be originated from the geometrical structure

Workshop on compact storage ring technology: applications to lithography

International Nuclear Information System (INIS)

1986-01-01

Project planning in the area of x-ray lithography is discussed. Three technologies that are emphasized are the light source, the lithographic technology, and masking technology. The needs of the semiconductor industry in the lithography area during the next decade are discussed, particularly as regards large scale production of high density dynamic random access memory devices. Storage ring parameters and an overall exposure tool for x-ray lithography are addressed. Competition in this area of technology from Germany and Japan is discussed briefly. The design of a storage ring is considered, including lattice design, magnets, and beam injection systems

First turn beam correction for the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Qian, Y.; Crosbie, E.; Teng, L.

1991-01-01

A procedure was developed for precise realignment of the quadrupoles in a synchrotron radiation storage ring which can substantially ease the required precision of the initial survey. The procedure consists of first using the injected beam to obtain a closed orbit which is centered on the beam position monitors by the correction dipoles. The strengths of the correction dipoles then give the required fine-adjustment of the quadrupole positions. In this paper the authors discuss only the algorithm for obtaining the closed orbit

The role of ring current O+ in the formation of stable auroral red arcs

International Nuclear Information System (INIS)

Kozyra, J.U.; Cravens, T.E.; Nagy, A.F.; Shelley, E.G.; Comfort, R.H.; Brace, L.H.

1987-01-01

Coulomb collisions between ring current protons and thermal electrons were first proposed by Cole (1965) as the energy source for stable auroral red (SAR) arcs. Recent observations have shown that the ring current and magnetospheric plasma contain significant amounts of heavy ions (Johnson et al., 1977; Young et al., 1977; Geiss et al., 1978; and others). In fact, the ring current is often dominated by heavy ions at those energies (E ≤ 17 keV) important for Coulomb collisions on SAR arc field lines (Kozyra et al., 1986a). Observations (during four SAR arcs in 1981) of thermal and energetic ion populations by the Dynamics Explorer 1 satellite in the magnetospheric energy source region and nearly simultaneous Langmuir probe measurements of enhanced electron temperatures by Dynamics Explorer 2 within the SAR arc at F region heights have allowed the authors to examine the role of heavy ions in the formation of SAR arcs. They find that (1) sufficient energy is transferred to the electron gas at high altitudes via Coulomb collisions between the observed ring current ions and thermal electrons to support the enhanced (SAR arc) F region electron temperatures measured on these field lines, (2) the latitudinal variation in the electron heating rates calculated using observed ion populations is consistent with the observed variation in electron temperature across the SAR arc, and (3) in all cases, ring current O + is the major source of energy for the SAR arcs. This implies a relationship between the heavy ion content of the magnetospheric plasma and the occurrence frequency and intensity of SAR arcs

Ring faults and ring dikes around the Orientale basin on the Moon.

Science.gov (United States)

Andrews-Hanna, Jeffrey C; Head, James W; Johnson, Brandon; Keane, James T; Kiefer, Walter S; McGovern, Patrick J; Neumann, Gregory A; Wieczorek, Mark A; Zuber, Maria T

2018-08-01

The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.

Groups, rings, modules

CERN Document Server

Auslander, Maurice

2014-01-01

This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

Rotating anode X-ray source

International Nuclear Information System (INIS)

Wittry, D.B.

1979-01-01

A rotating anode x-ray source is described which consists of a rotary anode disc including a target ring and a chamber within the anode disc. Liquid is evaporated into the chamber from the target ring to cool the target and a method is provided of removing the latent heat of the vapor. (U.K.)

Saturn's Rings Edge-on

Science.gov (United States)

1995-01-01

In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

The Ring Current Response to Solar and Interplanetary Storm Drivers

Science.gov (United States)

Mouikis, C.; Kistler, L. M.; Bingham, S.; Kronberg, E. A.; Gkioulidou, M.; Huang, C. L.; Farrugia, C. J.

2014-12-01

The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), corotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure, in turn, change the global magnetic field, controlling the transport of the radiation belts. To quantitatively determine the field changes during a storm throughout the magnetosphere, it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. Because the measured ring current energy spectra depend not only on local processes, but also on the history of the ions along their entire drift path, measurements of ring current energy spectra at two or more locations can be used to strongly constrain the time dependent magnetic and electric fields. In this study we use data predominantly from the Cluster and the Van Allen Probes, covering more than a full solar cycle (from 2001 to 2014). For the period 2001-2012, the Cluster CODIF and RAPID measurements of the inner magnetosphere are the primary data set used to monitor the storm time ring current variability. After 2012, the Cluster data set complements the data from the Van Allen Probes HOPE and RBSPICE instruments, providing additional measurements from different MLT and L shells. Selected storms from this periods, allow us to study the ring current dynamics and pressure changes, as a function of L shell, magnetic local time, and the type of interplanetary disturbances.

A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

International Nuclear Information System (INIS)

Sannibale, F.

2004-01-01

We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

A model describing stable coherent synchrotron radiation in storage rings

International Nuclear Information System (INIS)

Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wuestefeld, G.; Huebers, H.-W.; Warnock, R.

2004-01-01

We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

The Rotating Ring-Ring Electrode. Theory and Experiment

NARCIS (Netherlands)

Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

2000-01-01

A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

Experimental Investigation and Analysis of an Annular Pogo Accumulator

Science.gov (United States)

Peugeot, John; Schwarz, Jordan; Yang, H. Q.; Zoladz, Tom

2011-01-01

An experimental investigation was conducted on a scaled annular pogo accumulator for the Ares I Upper Stage. The test article was representative of the LO2 feedline and preliminary accumulator design, and included multiple designs of a perforated ring connecting the accumulator to the core feedline flow. The system was pulse tested in water over a range of pulse frequency and flow rates. Time dependent measurements of pressure at various locations in the test article were used to extract system compliance, inertance, and resistance. Preliminary results indicated a significant deviation from standard orifice flow theory and suggest a strong dependence on feedline average velocity. In addition, several CFD analyses were conducted to investigate the details of the time variant flow field. Both two-dimensional and three-dimensional simulations were performed with time varying boundary conditions used to represent system pulsing. The CFD results compared well with the sub-scale results and demonstrated the influence of feedline average velocity on the flow into and out of the accumulator. This paper presents updated results of the investigation including a parametric design space for determining resistance characteristics. Using the updated experimental results a new scaling relationship has been defined for shear flow over a cavity. A comparison of sub-scale and full scale CFD simulations provided early verification of the scaling of the fluid flowfield and resistance characteristics.

Operational Status of PF-Ring and PF-AR after the Earthquake

International Nuclear Information System (INIS)

Honda, T; Asaoka, S; Haga, K; Harada, K; Honda, Y; Izawa, M; Kamiya, Y; Kobayashi, Y; Miyajima, T; Miyauchi, H; Nagahashi, S; Nakamura, N; Nogami, T; Obina, T; Ozaki, T; Sagehashi, H; Sakai, H; Sakanaka, S; Sasaki, H; Sato, Y

2013-01-01

In 2011, two SR sources of KEK, PF-ring and PF-AR, needed to change the operation schedule because of the unprecedented earthquake on March 11. Though the injector linac and the storage rings suffered a serious damage, temporary recovery was accomplished quickly and the trial operation started in May. The regular user operation could be resumed in October 2011. In the restoration work after the earthquake, some old vacuum components were removed from PF-ring. This work fortunately brought an effect of settling the quadrupole-mode longitudinal instability. For the top-up injection of PF-ring, the pulsed sextupole magnet has been used instead of the conventional kicker magnets since 2011. The hybrid-fill mode in place of the single-bunch mode has become available. Recently, the 10-Hz orbit switching for the tandem circularly polarized undulators has been developed for the user operation.

Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear

Directory of Open Access Journals (Sweden)

P. Ilanthirayan

2017-12-01

Full Text Available The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC and Bottom dead centre (BDC of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.

PREFACE: Special section on vortex rings Special section on vortex rings

Science.gov (United States)

Fukumoto, Yasuhide

2009-10-01

This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill

The superconducting x-ray lithography source program at Brookhaven

Energy Technology Data Exchange (ETDEWEB)

Williams, G. P.; Heese, R. N.; Vignola, G.; Murphy, J. B.; Godel, J. B.; Hsieh, H.; Galayda, J.; Seifert, A.; Knotek, M. L.

1989-07-01

A compact electron storage ring with superconducting dipole magnets, is being developed at the National Synchrotron Light Source at Brookhaven. The parameters of the source have been optimized for its future use as an x-ray source for lithography. This first ring is a prototype which will be used to study the operating characteristics of machines of this type with particular attention being paid to low-energy injection and long beam lifetime.

Status report on the Los Alamos proton storage ring

International Nuclear Information System (INIS)

Colton, E.; Neuffer, D.; Thiessen, H.A.

1988-01-01

The proton storage ring currently operates at an average current of 30 μA corresponding to 1.25 /times/ 10 13 protons per pulse (ppp) at a repetition rate of 15 Hz. The design operating current for the machine is 100 μA. We are limited to running at the reduced yield because of beam losses during the accumulation period. These losses are understood and arise mainly from emittance growths during the injection and multiple scattering in the stripping foil during the storage. During beam studies we have succeeded in accumulating in excess of 3.7 /times/ 10 13 ppp. We have also observed a coherent transverse instability at high charge levels. The signature for the instability is rapid coherent growth of the transverse beam size followed by a loss of beam in the machine. The threshold for the instability depends most strongly upon rf voltage and beam size. 3 refs., 1 fig., 1 tab

Vortex rings

CERN Document Server

Akhmetov, D G

2009-01-01

This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

Ring-fault activity at subsiding calderas studied from analogue experiments and numerical modeling

Science.gov (United States)

Liu, Y. K.; Ruch, J.; Vasyura-Bathke, H.; Jonsson, S.

2017-12-01

Several subsiding calderas, such as the ones in the Galápagos archipelago and the Axial seamount in the Pacific Ocean have shown a complex but similar ground deformation pattern, composed of a broad deflation signal affecting the entire volcanic edifice and of a localized subsidence signal focused within the caldera. However, it is still debated how deep processes at subsiding calderas, including magmatic pressure changes, source locations and ring-faulting, relate to this observed surface deformation pattern. We combine analogue sandbox experiments with numerical modeling to study processes involved from initial subsidence to later collapse of calderas. The sandbox apparatus is composed of a motor driven subsiding half-piston connected to the bottom of a glass box. During the experiments the observation is done by five digital cameras photographing from various perspectives. We use Photoscan, a photogrammetry software and PIVLab, a time-resolved digital image correlation tool, to retrieve time-series of digital elevation models and velocity fields from acquired photographs. This setup allows tracking the processes acting both at depth and at the surface, and to assess their relative importance as the subsidence evolves to a collapse. We also use the Boundary Element Method to build a numerical model of the experiment setup, which comprises contracting sill-like source in interaction with a ring-fault in elastic half-space. We then compare our results from these two approaches with the examples observed in nature. Our preliminary experimental and numerical results show that at the initial stage of magmatic withdrawal, when the ring-fault is not yet well formed, broad and smooth deflation dominates at the surface. As the withdrawal increases, narrower subsidence bowl develops accompanied by the upward propagation of the ring-faulting. This indicates that the broad deflation, affecting the entire volcano edifice, is primarily driven by the contraction of the

Mapping the Thermal Inertia of Saturn’s Rings with Cassini CIRS

Science.gov (United States)

Brooks, Shawn M.; Spilker, L. J.; PIlorz, S. H.; Showalter, M. R.

2013-10-01

We use data from Cassini's Composite Infrared Spectrometer to map out the thermal response of Saturn's ring particles passing through Saturn's shadow and to determine variations in ring thermal inertia. CIRS records far infrared radiation in three separate detectors, each of which covers a distinct wavelength range. In this work, we analyze rings spectra recorded at focal plane 1 (FP1), as its wavelength response (16.7-1000 microns) is well suited to detecting direct thermal emission from Saturn's rings. The thermal budget of the rings is typically dominated by solar radiation. When ring particles enter Saturn’s shadow this source of energy is abruptly cut off with a consequential drop in ring temperature. Likewise, temperatures rebound when particles exit the shadow. To characterize these heating and cooling events, FP1 was repeatedly scanned across the main rings. Each scan was offset from either the ingress or egress shadow boundary by an amount corresponding to a fraction of a Keplerian orbit. By resampling these scans onto a common radial grid, we can map out the rings’ response to the abrupt changes in insolation at shadow ingress and egress. Periods near equinox represent a unique situation. During this time the Sun's disk crosses the ring plane and its rays strike the rings at zero incidence. Solar heating is virtually absent, and thermal radiation from Saturn and sunlight reflected by Saturn dominate the thermal environment. While ring temperature variations at equinox are much more subtle, they represent temperature contrasts that vary at the unique timescale corresponding to variations in Saturn contributions to the rings’ thermal budget. By analyzing CIRS data at a variety of locations and epochs, we will map out thermal inertia across the rings and attempt to tease out structural information about the particles which comprise Saturn’s rings. This presentation will report upon our progress towards these ends. This research was carried out at the

FUZZY RINGS AND ITS PROPERTIES

Directory of Open Access Journals (Sweden)

Karyati Karyati

2017-01-01

  One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

Tectonic Characteristics and its Effects on the Control of the Oil and Gas Accumulation in Bayanhushu Depression

Directory of Open Access Journals (Sweden)

Tan Zhaobin

2015-01-01

Full Text Available In this paper, it makes full use of seismic and Wells in the single well data on the basis of predecessors’ research. On the basis of structural geology theory as the instruction, the detailed characteristics of structure and fracture were studied in this paper. Based on the fracture characteristics, the authors studied the basement depth and the development of hydrocarbon source rocks characteristics, and the restoration method of sag tectonic evolution characteristics are analyzed as well. The authors also discussed the construction control of the oil and gas distribution rules. Through this research, the authors found out the regional tectonic framework, the fault distribution and the tectonic evolution stage, illustrated the structure of oil and gas accumulation conditions, the accumulation mode, and the distribution rule of control law. Through prototype basin restoration, the authors given concerns about the early depression and tectonic background of stuck faults control source, the distribution of sand body, the western steep slope fan delta and gentle slope belt of eastern braided river delta front sand body is favorable reservoir. Depression after Nantun group and the end of the Yimin group at the end of the reversal of the two big changes, ring between the concave structure development, favorable traps formed early reverse changes, late reverse change on the early formation of trap destruction; reservoir by the late Nantun group is formed by the reverse change control in the construction of the steep slope belt wing structure oil and gas enrichment.

Effect of minerals on accumulation of Cs by fungus Saccaromyces cerevisiae

International Nuclear Information System (INIS)

Ohnuki, Toshihiko; Sakamoto, Fuminori; Yamasaki, Shinya; Kozai, Naofumi; Shiotsu, Hiroyuki; Utsunomiya, Satoshi; Watanabe, Naoko; Kozaki, Tamotsu

2015-01-01

The accumulation of Cs by unicellular fungus of Saccharomyces cerevisiae in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. Two different types of experiments were employed: experiments using stable Cs to examine the effect of a carbon source on the accumulation of Cs, and accumulation experiments of radioactive Cs from agar medium containing 137 Cs and zeolite, vermiculite, phlogopite, smectite, mica, or illite as mineral supplements. In the former type of experiments, the Cs-accumulated cells were analyzed by scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDS). In the latter type, the radioactivity in the yeast cells was measured by an autoradiography technique. When a carbon source was present, higher amounts of Cs accumulated in the cells than in the resting condition without a carbon source. Analyses with SEM-EDS showed that no mineral formed on the cell surface. These results indicate that the yeast cells accumulate Cs by adsorption on the cell surface and intracellular accumulation. In the presence of minerals in the agar medium, the radioactivity in the yeast cells was in the order of mica > smectite, illite >> vermiculite, phlogopite, zeolite. This order is inversely correlated to the ratio of the concentration of radioactive Cs between the minerals and the medium solution. These results strongly suggest that the yeast accumulates radioactive Cs competitively with minerals. - Graphical abstract: Autoradiography analysis showed that presence of larger amounts of mineral of vermiculite collected in South Africa induced less accumulation of radioactive Cs in yeast cells from the medium. - Highlights: • Effect of minerals on the accumulation of radioactive Cs by yeast was studied. • Presence of minerals reduced accumulation of radioactive Cs by yeast. • The order of reduction is mica>smectite, illite>>vermiculite, phlogopite

Polarization Insensitivity in Double-Split Ring and Triple-Split Ring Terahertz Resonators

International Nuclear Information System (INIS)

Wu Qian-Nan; Lan Feng; Tang Xiao-Pin; Yang Zi-Qiang

2015-01-01

A modified double-split ring resonator and a modified triple-split ring resonator, which offer polarization-insensitive performance, are investigated, designed and fabricated. By displacing the two gaps of the conventional double-split ring resonator away from the center, the second resonant frequency for the 0° polarized wave and the resonant frequency for the 90° polarized wave become increasingly close to each other until they are finally identical. Theoretical and experimental results show that the modified double-split ring resonator and the modified triple-split ring resonator are insensitive to different polarized waves and show strong resonant frequency dips near 433 and 444 GHz, respectively. The results of this work suggest new opportunities for the investigation and design of polarization-dependent terahertz devices based on split ring resonators. (paper)

Comparative hepatic in vitro depletion and metabolite formation of major perfluorooctane sulfonate precursors in Arctic polar bear, beluga whale, and ringed seal.

Science.gov (United States)

Letcher, Robert J; Chu, Shaogang; McKinney, Melissa A; Tomy, Gregg T; Sonne, Christian; Dietz, Rune

2014-10-01

Perfluorooctane sulfonate (PFOS) has been reported to be among the most concentrated persistent organic pollutants in Arctic marine wildlife. The present study examined the in vitro depletion of major PFOS precursors, N-ethyl-perfluorooctane sulfonamide (N-EtFOSA) and perfluorooctane sulfonamide (FOSA), as well as metabolite formation using an assay based on enzymatically viable liver microsomes for three top Arctic marine mammalian predators, polar bear (Ursus maritimus), beluga whale (Delphinapterus leucas), and ringed seal (Pusa hispida), and in laboratory rat (Rattus rattus) serving as a general mammalian model and positive control. Rat assays showed that N-EtFOSA (38 nM or 150 ng mL(-1)) to FOSA metabolism was >90% complete after 10 min, and at a rate of 23 pmol min(-1) mg(-1) protein. Examining all species in a full 90 min incubation assay, there was >95% N-EtFOSA depletion for the rat active control and polar bear microsomes, ∼65% for ringed seals, and negligible depletion of N-EtFOSA for beluga whale. Concomitantly, the corresponding in vitro formation of FOSA from N-EtFOSA was also quantitatively rat≈polar bear>ringed seal>beluga whale. A lack of enzymatic ability and/or a rate too slow to be detected likely explains the lack of N-EtFOSA to FOSA transformation for beluga whale. In the same assays, the depletion of the FOSA metabolite was insignificant (p>0.01) and with no concomitant formation of PFOS metabolite. This suggests that, in part, a source of FOSA is the biotransformation of accumulated N-EtFOSA in free-ranging Arctic ringed seal and polar bear. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Sources and sinks of Earth's ring current populations

Science.gov (United States)

Mauk, B.

2017-12-01

Processes that modify and transport current-carrying particles into and out of Earth's ring current regions are overviewed and discussed here with a focus on outstanding mysteries and uncertainties. Examples of such mysteries include the following. Some modeling and observational approaches point to a need for storm-time enhancements in the global electric field configuration to help bring magnetotail populations into the inner magnetosphere. And yet, electric field measurements from several missions, most recently the Van Allen Probes, suggest that only highly transient enhancements occur in critical regions that connect the outer and inner regions. Global enhancements appear to be internally generated rather than necessarily being driven from the outside. Another sample mystery involves the processes that give rise to the sometimes initial prompt recovery of the magnetic storm indice DST, given that loss processes traditionally invoked are likely too slow. Wave losses, such as those engendered by Electromagnetic Ion Cyclotron (EMIC) waves, may be responsible, but observational support for such a solution is lacking. These and other uncertainties are discussed with a goal of addressing how they might be addressed with the present great constellation of Earth-orbiting spacecraft, most recently joined by MMS and Arase (ERG).

Impedances and beam stability issues of the Fermilab recycler ring

International Nuclear Information System (INIS)

Ng, King-Yuen.

1996-04-01

The Fermilab Recycler Ring (permanent magnets) will be built on top of the Fermilab Main Injector sharing the same tunnel; its main function is to recycle the anti-protons after a store in the Tevatron and to provide storage for them after after accumulation and cooling in the Accumulator. Estimates of coupling impedances show domination by space charge. Examination of longitudinal instabilities shows that microwave instability will not occur if there are only N = 2.53 x 10 12 anti-protons in the beam. Longitudinal coupling-bunch instability during injection stacking does not appear possible because of long bunch lengths/short bunch gaps and lack of sharp resonances. Transverse instability, on the other hand, cannot be Landau damped by the momentum spread in the beam, but it can be cured by a small spread in the betatron tunes (either from space charge or an octupole)

Electron density enhancement in a quasi isochronous storage ring

International Nuclear Information System (INIS)

Pellegrini, C.; Robin, D.

1991-01-01

The six dimensional phase-space density of an electron beam in a storage ring is determined by the emission of synchrotron radiation, and by the transverse and longitudinal focusing forces determining the particle trajectories. In the simplest case of uncoupled horizontal, vertical and longitudinal motion, the phase space volume occupied by the beam can be characterized by the product of its three projections on the single degree of freedom planes, the horizontal, vertical, and longitudinal emittances. To minimize the beam phase space volume the authors can minimize the transverse and longitudinal emittances. In the case of transverse emittances this problem is very important for synchrotron radiation sources, and has been studied by several authors. A method to minimize the longitudinal emittance, and produce electron bunches with a short pulse length, small energy spread and large peak current has been proposed and discussed recently by C. Pellegrini and D. Robin. This method uses a ring in which the revolution period is weakly dependent on the particle energy, Quasi Isochronous Ring (QIR), in other words a ring with a momentum compaction nearly zero. In this paper they will extend the previous analysis of the conditions for stable single particle motion in such a ring, and give simple criteria for the estimate of the energy spread and phase acceptance of a QIR

Project of the compact superconducting storage ring Siberia-SM

Energy Technology Data Exchange (ETDEWEB)

Anashin, V V; Arbuzov, V S; Blinov, G A; Veshcherevich, V G; Vobly, P D; Gorniker, E I; Zinevich, N I; Zinin, E I; Zubkov, N I; Kiselev, V A; Kollerov, E P; Kulipanov, G N; Matveev, Yu G; Medvedko, A S; Mezentsev, N A; Morgunov, L G; Petrov, V M; Petrov, S P; Repkov, V V; Roenko, V A; Skrinsky, A N; Sukhanov, S V; Tokarev, Yu I; Trakhtenberg, E M [AN SSSR, Novosibirsk. Inst. Yadernoj Fiziki

1989-10-10

In the last decade researches dealing with the creation of technology for X-ray lithography and for appropriate production equipment have been performed in many countries. The basic aim of these works is to provide a mass production of inexpensive devices with submicron structures (0.7-0.1 {mu}m). Bringing X-ray lithographic technology into commercial practice necessitates to design and build a dedicated SR source for the electronic industry. The use of superconducting bending magnets with 40-70 kG field strength enables the storage ring circumference to be reduced by a factor of 2-5 and the injection energy by a factor of 3-4 as compared to the conventional designs of storage rings. In the present paper we consider a storage ring which was designed for a maximum energy of 600 MeV, with 60 kG field strength in its bending magnets and 10 m circumference. The critical SR wavelength is 8.6 A. The electrons are injected into the storage ring at 50-60 MeV and the maximum stored current is assumed to be equal to 0.3 A. (orig.).

HISTRAP [Heavy Ion Storage Ring for Atomic Physics] prototype hardware studies

International Nuclear Information System (INIS)

Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.

1989-01-01

HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs

RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

Energy Technology Data Exchange (ETDEWEB)

Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

2015-12-15

We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

Wave-Kinetic Simulations of the Nonlinear Generation of Electromagnetic VLF Waves through Velocity Ring Instabilities

Science.gov (United States)

Ganguli, G.; Crabtree, C. E.; Rudakov, L.; Mithaiwala, M.

2014-12-01

Velocity ring instabilities are a common naturally occuring magnetospheric phenomenon that can also be generated by man made ionospheric experiments. These instabilities are known to generate lower-hybrid waves, which generally cannot propagte out of the source region. However, nonlinear wave physics can convert these linearly driven electrostatic lower-hybrid waves into electromagnetic waves that can escape the source region. These nonlinearly generated waves can be an important source of VLF turbulence that controls the trapped electron lifetime in the radiation belts. We develop numerical solutions to the wave-kinetic equation in a periodic box including the effects of nonlinear (NL) scattering (nonlinear Landau damping) of Lower-hybrid waves giving the evolution of the wave-spectra in wavenumber space. Simultaneously we solve the particle diffusion equation of both the background plasma particles and the ring ions, due to both linear and nonlinear Landau resonances. At initial times for cold ring ions, an electrostatic beam mode is excited, while the kinetic mode is stable. As the instability progresses the ring ions heat, the beam mode is stabilized, and the kinetic mode destabilizes. When the amplitude of the waves becomes sufficient the lower-hybrid waves are scattered (by either nearly unmagnetized ions or magnetized electrons) into electromagnetic magnetosonic waves [Ganguli et al 2010]. The effect of NL scattering is to limit the amplitude of the waves, slowing down the quasilinear relaxation time and ultimately allowing more energy from the ring to be liberated into waves [Mithaiwala et al. 2011]. The effects of convection out of the instability region are modeled, additionally limiting the amplitude of the waves, allowing further energy to be liberated from the ring [Scales et al., 2012]. Results are compared to recent 3D PIC simulations [Winske and Duaghton 2012].

Stirling engine piston ring

Science.gov (United States)

Howarth, Roy B.

1983-01-01

A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

Physics of quantum rings

International Nuclear Information System (INIS)

Fomin, Vladimir M.

2014-01-01

Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

Improved performance of inkjet-printed Ag source/drain electrodes for organic thin-film transistors by overcoming the coffee ring effects

Science.gov (United States)

Liu, Cheng-Fang; Lin, Yan; Lai, Wen-Yong; Huang, Wei

2017-11-01

Inkjet printing is a promising technology for the scalable fabrication of organic electronics because of the material conservation and facile patterning as compared with other solution processing techniques. In this study, we have systematically investigated the cross-sectional profile control of silver (Ag) electrode via inkjet printing. A facile methodology for achieving inkjet-printed Ag source/drain with improved profiles is developed. It is demonstrated that the printing conditions such as substrate temperature, drop spacing and printing layers affect the magnitude of the droplet deposition and the rate of evaporation, which can be optimized to greatly reduce the coffee ring effects for improving the inkjet-printed electrode profiles. Ag source/drain electrodes with uniform profiles were successfully inkjet-printed and incorporated into organic thin-film transistors (OTFTs). The resulting devices showed superior electrical performance than those without special treatments. It is noted to mention that the strategy for modulating the inkjet-printed Ag electrodes in this work does not demand the ink formulation or complicated steps, which is beneficial for scaling up the printing techniques for potential large-area/mass manufacturing.

Biomarkers and biometric measures of adherence to use of ARV-based vaginal rings.

Science.gov (United States)

Stalter, Randy M; Moench, Thomas R; MacQueen, Kathleen M; Tolley, Elizabeth E; Owen, Derek H

2016-01-01

: intracellular drug levels, drug levels in hair, the accumulation of a vaginal analyte that diffuses into the ring, and the depletion of an intrinsic ring constituent. While some approaches show significant promise over others, it is recommended that a strategy of using complementary biometric and behavioural approaches be adopted to best understand participants' adherence to ARV-based ring products in clinical trials.

How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

Science.gov (United States)

Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

2012-11-01

The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.

Manipulating the Coffee-Ring Effect: Interactions at Work.

Science.gov (United States)

Anyfantakis, Manos; Baigl, Damien

2015-07-31

The evaporation of a drop of colloidal suspension pinned on a substrate usually results in a ring of particles accumulated at the periphery of the initial drop. Intense research has been devoted to understanding, suppressing and ultimately controlling this so-called coffee-ring effect (CRE). Although the crucial role of flow patterns in the CRE has been thoroughly investigated, the effect of interactions on this phenomenon has been largely neglected. This Concept paper reviews recent works in this field and shows that the interactions of colloids with (and at) liquid-solid and liquid-gas interfaces as well as bulk particle-particle interactions drastically affect the morphology of the deposit. General rules are established to control the CRE by tuning these interactions, and guidelines for the rational physicochemical formulation of colloidal suspensions capable of depositing particles in desirable patterns are provided. This opens perspectives for the reliable control of the CRE in real-world formulations and creates new paradigms for flexible particle patterning at all kinds of interfaces as well for the exploitation of the CRE as a robust and inexpensive diagnostic tool. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

α-Skew π-McCoy Rings

Directory of Open Access Journals (Sweden)

Areej M. Abduldaim

2013-01-01

Full Text Available As a generalization of α-skew McCoy rings, we introduce the concept of α-skew π-McCoy rings, and we study the relationships with another two new generalizations, α-skew π1-McCoy rings and α-skew π2-McCoy rings, observing the relations with α-skew McCoy rings, π-McCoy rings, α-skew Armendariz rings, π-regular rings, and other kinds of rings. Also, we investigate conditions such that α-skew π1-McCoy rings imply α-skew π-McCoy rings and α-skew π2-McCoy rings. We show that in the case where R is a nonreduced ring, if R is 2-primal, then R is an α-skew π-McCoy ring. And, let R be a weak (α,δ-compatible ring; if R is an α-skew π1-McCoy ring, then R is α-skew π2-McCoy.

Cabling design of booster and storage ring construction progress of TPS

International Nuclear Information System (INIS)

Wong, Y.-S.; Liu, K.-B.; Liu, C.-Y.; Wang, B.-S.

2017-01-01

The 2012 Taiwan Photon Source (TPS) cable construction project started after 10 months to complete the cable laying and installation of power supply. The circumference of the booster ring (BR) is 496.8 m, whereas that of the storage ring (SR) is 518.4 m. Beam current is set to 500 mA at 3.3 GeV. The paper on grounding systems discusses the design of the ground wire (< 0.2 Ω) with low impedance, power supply of the accelerator and cabling tray. The flow and size of the ground current are carefully evaluated to avoid grounded current from flowing everywhere, which causes interference problems. In the design of the TPS, special shielding will be established to isolate the effects of electromagnetic interference on the magnet and ground current. Booster ring dipoles are connected by a series of 54-magnet bending dipole; the cable size of its stranded wire measures 250 mm"2, with a total length of 5000 m. Booster ring and storage ring quadrupoles have 150 magnets; the cable size of their stranded wire is 250 mm"2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm"2, with a total length of 6000 m. This study discusses the power supply cabling design of the storage ring and booster ring construction progress of TPS. The sections of this paper are divided into discussions of the construction of the control and instrument area, cabling layout of booster ring and storage ring, as well as the installation and commission machine. This study also discusses the use of a high-impedance meter to determine the effect of cabling insulation and TPS power supply machine on energy transfer to ensure the use of safe and correct magnet.

Development and status of superconducting SR-ring

International Nuclear Information System (INIS)

Toyota, Eijiro; Tomimasu, Takio.

1991-01-01

Recently, attention has been paid to synchrotron radiation as a powerful tool for material science research, and for the most advanced research, stronger beam is sought for, therefore, large scale synchrotron radiation source facilities are going to be constructed. In contrast with the move toward large scale like this, effort is exerted to reduce the size by using superconductivity and to utilize for industries. Especially Japan precedes most in this field, and has already succeeded in the beam generation. This move to reduce size and pursue economic efficiency is noteworthy as that of supplementing the trend to large scale on the other hand, and its outline is explained. Synchrotron radiation means the strong beam emitted in tangential direction when the electrons or positrons moving at the velocity close to the velocity of light are bent in a magnetic field. The device which stably generates synchrotron radiation is an electron storage ring. The features of synchrotron radiation are explained. The history of synchrotron radiation research, the trend of development of superconducting synchrotron radiation ring, the actual examples of superconducting SR rings and their problems are described. (K.I.)

Photon Factory Activity Report, 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

Photon Factory Activity Report no.12 deals with our activities in the period from October 1993 through September 1994. We operate two light sources at the Photon Factory; the 2.5-GeV Photon Factory storage ring, which is a dedicated light source, and the 6.5-GeV TRISTAN Accumulation Ring, which is parasitically used as a light source. We keep more than seventy experimental stations at two facilities, and accept experiments primarily according to approval by the Program Advisory Committee. The number of proposals to the Photon Factory has been still growing. Three-hundred eighty two proposals were approved by the PAC in FY1994, which is an increase by thirteen percent compared to the previous year. Remarkable was growth in biology proposals, particularly proposals in protein crystallography. In FY 1994, we accepted approximately 20,000 man-days as general users, and almost ten percent of them were from abroad. We always open the facility to users, not only domestic but also international. Recently we have been concentrating our effort to upgrading of the light sources and reconstruction of the experimental stations to keep the Photon Factory an attractive research facility in the forthcoming years. We have already started a program of reducing the emittance of the 2.5-GeV storage ring, which now operates with an emittance of 110 nm-rad, to 27 nm-rad by modifying the lattice, with the goal of operation at the reduced emittance in the fall of 1997. We also have conceived of a conversion of the TRISTAN Accumulation Ring to a dedicated light source of high energies. The on-going TRISTAN project will terminate by the end of 1995, and the TRISTAN Main Ring will be converted to a new B-Factory. At this moment, the TRISTAN Accumulation Ring will be disused as the injector to the Main Ring, and conversion of the AR to a dedicated light source becomes possible. (J.P.N.)

Photon Factory Activity Report, 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Photon Factory Activity Report no.12 deals with our activities in the period from October 1993 through September 1994. We operate two light sources at the Photon Factory; the 2.5-GeV Photon Factory storage ring, which is a dedicated light source, and the 6.5-GeV TRISTAN Accumulation Ring, which is parasitically used as a light source. We keep more than seventy experimental stations at two facilities, and accept experiments primarily according to approval by the Program Advisory Committee. The number of proposals to the Photon Factory has been still growing. Three-hundred eighty two proposals were approved by the PAC in FY1994, which is an increase by thirteen percent compared to the previous year. Remarkable was growth in biology proposals, particularly proposals in protein crystallography. In FY 1994, we accepted approximately 20,000 man-days as general users, and almost ten percent of them were from abroad. We always open the facility to users, not only domestic but also international. Recently we have been concentrating our effort to upgrading of the light sources and reconstruction of the experimental stations to keep the Photon Factory an attractive research facility in the forthcoming years. We have already started a program of reducing the emittance of the 2.5-GeV storage ring, which now operates with an emittance of 110 nm-rad, to 27 nm-rad by modifying the lattice, with the goal of operation at the reduced emittance in the fall of 1997. We also have conceived of a conversion of the TRISTAN Accumulation Ring to a dedicated light source of high energies. The on-going TRISTAN project will terminate by the end of 1995, and the TRISTAN Main Ring will be converted to a new B-Factory. At this moment, the TRISTAN Accumulation Ring will be disused as the injector to the Main Ring, and conversion of the AR to a dedicated light source becomes possible. (J.P.N.)

Photon Factory Activity Report, 1994

International Nuclear Information System (INIS)

1995-01-01

Photon Factory Activity Report no.12 deals with our activities in the period from October 1993 through September 1994. We operate two light sources at the Photon Factory; the 2.5-GeV Photon Factory storage ring, which is a dedicated light source, and the 6.5-GeV TRISTAN Accumulation Ring, which is parasitically used as a light source. We keep more than seventy experimental stations at two facilities, and accept experiments primarily according to approval by the Program Advisory Committee. The number of proposals to the Photon Factory has been still growing. Three-hundred eighty two proposals were approved by the PAC in FY1994, which is an increase by thirteen percent compared to the previous year. Remarkable was growth in biology proposals, particularly proposals in protein crystallography. In FY 1994, we accepted approximately 20,000 man-days as general users, and almost ten percent of them were from abroad. We always open the facility to users, not only domestic but also international. Recently we have been concentrating our effort to upgrading of the light sources and reconstruction of the experimental stations to keep the Photon Factory an attractive research facility in the forthcoming years. We have already started a program of reducing the emittance of the 2.5-GeV storage ring, which now operates with an emittance of 110 nm-rad, to 27 nm-rad by modifying the lattice, with the goal of operation at the reduced emittance in the fall of 1997. We also have conceived of a conversion of the TRISTAN Accumulation Ring to a dedicated light source of high energies. The on-going TRISTAN project will terminate by the end of 1995, and the TRISTAN Main Ring will be converted to a new B-Factory. At this moment, the TRISTAN Accumulation Ring will be disused as the injector to the Main Ring, and conversion of the AR to a dedicated light source becomes possible. (J.P.N.)

Effects of age on muscarinic agonist-induced contraction an IP accumulation in airway smooth muscle

International Nuclear Information System (INIS)

Wills-Karp, M.

1991-01-01

The effects of age on carbachol-stimulated force development and [ 3 H]inositol phosphate production was studied in tracheal rings from guinea pigs aged 1 month and 25 months of age. The pD 2 for the contractile response to carbachol was significantly reduced in tracheal tissues from old animals as compared to that of the young tissues, respectively. In contrast, inositol phosphate formation was not altered with increasing age when stimulated by carbachol or NaF, a direct activator of G proteins. Carbachol-induced inositol phosphate accumulation was inhibited by treatment with 1μg/ml pertussis toxin, suggesting that IP1 accumulation is coupled to a pertussis-toxin-sensitive protein. The pD 2 values for contraction were significantly different from the pD 2 values for IP1 accumulation, in both young and old tissues, respectively. These data suggest that IP1 accumulation is not responsible for the decreased contractile ability in tracheal smooth muscle during aging

Effects of age on muscarinic agonist-induced contraction an IP accumulation in airway smooth muscle

Energy Technology Data Exchange (ETDEWEB)

Wills-Karp, M. (Johns Hopkins Univ., Baltimore, MD (United States))

1991-01-01

The effects of age on carbachol-stimulated force development and ({sup 3}H)inositol phosphate production was studied in tracheal rings from guinea pigs aged 1 month and 25 months of age. The pD{sub 2} for the contractile response to carbachol was significantly reduced in tracheal tissues from old animals as compared to that of the young tissues, respectively. In contrast, inositol phosphate formation was not altered with increasing age when stimulated by carbachol or NaF, a direct activator of G proteins. Carbachol-induced inositol phosphate accumulation was inhibited by treatment with 1{mu}g/ml pertussis toxin, suggesting that IP1 accumulation is coupled to a pertussis-toxin-sensitive protein. The pD{sub 2} values for contraction were significantly different from the pD{sub 2} values for IP1 accumulation, in both young and old tissues, respectively. These data suggest that IP1 accumulation is not responsible for the decreased contractile ability in tracheal smooth muscle during aging.

Induced Plant Accumulation of Lithium

Directory of Open Access Journals (Sweden)

Laurence Kavanagh

2018-02-01

Full Text Available Lithium’s (Li value has grown exponentially since the development of Li-ion batteries. It is usually accessed in one of two ways: hard rock mineral mining or extraction from mineral-rich brines. Both methods are expensive and require a rich source of Li. This paper examines the potential of agro-mining as an environmentally friendly, economically viable process for extracting Li from low grade ore. Agro-mining exploits an ability found in few plant species, to accumulate substantial amounts of metals in the above ground parts of the plant. Phyto-mined metals are then retrieved from the incinerated plants. Although the actual amount of metal collected from a crop may be low, the process has been shown to be profitable. We have investigated the suitability of several plant species including: Brassica napus and Helianthus annuus, as Li-accumulators under controlled conditions. Large plant trials were carried out with/without chelating agents to encourage Li accumulation. The question we sought to answer was, can any of the plant species investigated accumulate Li at levels high enough to justify using them to agro-mine Li. Results show maximum accumulated levels of >4000 mg/kg Li in some species. Our data suggests that agro-mining of Li is a potentially viable process.

VUV optical ring resonator for Duke storage ring free electron laser

Energy Technology Data Exchange (ETDEWEB)

Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

1995-12-31

The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

Integrated photon sources for quantum information science applications

Science.gov (United States)

Fanto, M. L.; Tison, C. C.; Steidle, J. A.; Lu, T.; Wang, Z.; Mogent, N. A.; Rizzo, A.; Thomas, P. M.; Preble, S. F.; Alsing, P. M.; Englund, D. R.

2017-10-01

Ring resonators are used as photon pair sources by taking advantage of the materials second or third order non- linearities through the processes of spontaneous parametric downconversion and spontaneous four wave mixing respectively. Two materials of interest for these applications are silicon for the infrared and aluminum nitride for the ultraviolet through the infrared. When fabricated into ring type sources they are capable of producing pairs of indistinguishable photons but typically suffer from an effective 50% loss. By slightly decoupling the input waveguide from the ring, the drop port coincidence ratio can be significantly increased with the trade-off being that the pump is less efficiently coupled into the ring. Ring resonators with this design have been demonstrated having coincidence ratios of 96% but requiring a factor of 10 increase in the pump power. Through the modification of the coupling design that relies on additional spectral dependence, it is possible to achieve similar coincidence ratios without the increased pumping requirement. This can be achieved by coupling the input waveguide to the ring multiple times, thus creating a Mach-Zehnder interferometer. This coupler design can be used on both sides of the ring resonator so that resonances supported by one of the couplers are suppressed by the other. This is the ideal configuration for a photon-pair source as it can only support the pump photons at the input side while only allowing the generated photons to leave through the output side. Recently, this device has been realized with preliminary results exhibiting the desired spectral dependence and with a coincidence ratio as high as 97% while allowing the pump to be nearly critically coupled to the ring. The demonstrated near unity coincidence ratio infers a near maximal heralding efficiency from the fabricated device. This device has the potential to greatly improve the scalability and performance of quantum computing and communication systems.

Ion rings for magnetic fusion. Technical progress report, August 1, 1993--June 1, 1994

International Nuclear Information System (INIS)

Sudan, R.N.

1994-01-01

In Our Proposal ''Ion Rings for Magnetic Fusion'' of January 6, 1993, Stage I of our Proposed Program plan (the 12 months) consisted of the following tasks: Experiments on the existing ion ring experimental system IREX to test a new magnetically-controlled anode plasma source (MAP) for the ion beam diode injector; numerical simulations of ion ring formation to optimize design parameters for the field reversed ion ring experiment (FIREX) to be built and operated in Stage II; and designing the power supply for the FIREX injector and the magnetic field system using results for A and B. During the past 7 1/2 months our work has progressed according to the above plan. In addition to testing the MAP diode on IREX we have tested the EMFAPS (evaporating metal film anode plasma source) anode on the Sandia National Laboratories funded LION pulsed power generator. As a result of these experiments, described this paper, we have arrived at the conclusion that EMFAPS anode for the ion at present because the MAP diode beam diode injector is our preferred choice for is still in an early stage of development

Guide to the Main Ring DO overpass

International Nuclear Information System (INIS)

Turkot, F.

1985-01-01

The DO overpass is a modification of the beam orbit in Main Ring in order to better accommodate a Tevatron collider detector at DO. The orbit is moved up approx. 51 inches over most of the long straight section at DO, thus making the Main Ring the world's first non-planar proton synchrotron. A similar overpass, but with four times the displacement, is planned for the CDF detector at the BO straight section. The nominal separation between the beam orbit in the Main Ring and the orbit in the Tevatron is 25.5 inches. Early in the design study of a detector that would utilize the Tevatron is a anti pp collider, it was apparent that a larger separation at the detector was highly desirable. In 1981, Tom Collins proposed a specific lattice geometry in the Main Ring for achieving larger separation, called ''the screw beam''. His proposal has served as the basis for the design of both the BO and DO overpasses. The main purpose of this report is to describe in some detail the implementation of the DO overpass. Topics to be covered include: (a) geometry of the overpass orbit, (b) the new hardware in the tunnel, (c) the power supply system, (d) the control facility, (e) accelerator beam dynamics ramifications, and (f) commissioning experience. A secondary purpose is to provide a fairly complete ''bibliography'' to the sources of information on the overpass. 17 refs., 17 figs

Optics design of Intrabeam Scattering dominated damping rings

CERN Document Server

Antoniou, Fanouria; Papaphilippou, Ioannis

A e+/e- linear collider, the Compact Linear Collider (CLIC) is under design at CERN, aiming to explore the terascale particle physics regime. The collider has been optimized at 3 TeV center of mass energy and targets a luminosity of 1034 cm-2 s-1. In order to achieve this high luminosity, high intensity bunches with ultra low emittances, in all three planes, are required. The generation of ultra low emittance is achieved in the Damping Rings (DR) complex of the collider. The large input beam emittances, especially the ones coming from the positron source, and the requirement of ultra low emittance production in a fast repetition time of 20 ms, imply that the beam damping is done in two stages. Thus, a main-damping ring (DR) and a predamping ring (PDR) are needed, for each particle species. The high bunch brightness gives rise to several collective effects, with Intra-beam scattering (IBS) being the main limitation to the ultra-low emittance. This thesis elaborates the lattice design and non-linear optimizatio...

Interaction Region Design for a Ring-Ring LHeC

CERN Document Server

Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

2011-01-01

tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

Transverse Periodic Beam Loading Effects in a Storage Ring

International Nuclear Information System (INIS)

Thompson, J.R.; Byrd, J.M.

2009-01-01

Uneven beam fill patterns in storage rings, such as gaps in the fill patterns, leads to periodic, or transient loading of the modes of the RF cavities. We show that an analogous effect can occur in the loading of a dipole cavity mode when the beam passes off the electrical center of the cavity mode. Although this effect is small, it results in a variation of the transverse offset of the beam along the bunch train. For ultralow emittance beams, such as optimized third generation light sources and damping rings, this effect results in a larger projected emittance of the beam compared with the single bunch emittance. The effect is particularly strong for the case when a strong dipole mode has been purposely added to the ring, such as a deflecting, or 'crab' cavity. We derive an approximate analytic solution for the variation of the beam-induced deflecting voltage along the bunch train.

Retrospective evaluation of tritium fallout by tree-ring analysis

International Nuclear Information System (INIS)

Kozak, K.; Biro, T.; Golder, F.; Rank, D.; Rajner, V.; Staudner, F.

1993-01-01

Tritium analyses of tree-ring cellulose were made to test its suitability for retrospective evaluation of a local tritium fallout. Several spruce trees were taken from an Austrian alpine area where tritium contamination of May 1974 precipitation had been detected. Wood from the annual growth rings of 1973, 1974 and 1975 was separated and the cellulose extracted. After isotopic equilibration with dead water, cellulose was combusted to yield water, whose tritium concentration was measured by liquid scintillation counting. Rigorous statistical treatment proved the significance of the increased tritium concentration caused by the tritium anomaly, which occurred during the growing season. The long-term trends of local atmospheric tritium, including the 1974 peak, were also well reflected by analysis of a 24-year ring sequence from a single tree in the contaminated area. The tritium data gained by the given method can be used at present qualitatively and a better understanding of the possible sources of contamination is required in order that the quantitative criteria be satisfied. (Author)

INMS measures an influx of molecules from Saturn's rings

Science.gov (United States)

Perry, M. E.

2017-12-01

In 1984, Connerney and Waite proposed water influx from Saturn's rings to explain the low electron densities measured during Pioneer and Voyager radio occultation experiments. Charge exchange with this minor species depleted the H+ ions and provided a faster path to electron recombination. With ice the primary constituent of the rings, water was the most likely in-falling molecule. During the Grand Finale orbits, Cassini's Ion and Neutral Mass Spectrometer (INMS) detected and quantified an influx from the rings. Unexpectedly, the primary influx molecules are CH4 and a heavier carbon-bearing species. Water was detected, but quantities were factors of ten lower than these other species. Distribution in both altitude and latitude are consistent with a ring influx. The concentration of the minor species in Saturn's atmosphere shows that they enter Saturn's atmosphere from the top. Both molecules have their highest concentrations at the highest altitudes, with concentrations >0.4% at 3,500 km altitude and only 0.02% at 2,700 km. Molecules from the rings deorbit to Saturn's atmosphere at altitudes near 4,000 km, consistent with the INMS measurements. The latitudinal dependence of the minor species indicates that their source is near the equatorial plane. At high altitudes, the minor species were observed primarily at zero latitude, where the 28u species was six times more concentrated than at 5° latitude. At lower altitudes, the peaking ratio was 1, indicating that the species had diffused and was fully mixed into Saturn's H2 atmosphere. The lighter molecule, CH4, diffuses more rapidly than the 28u species. INMS also detected both of these species during the earlier F-ring passes, finding that the neutrals were centered at the ring plane and extended 3,000 km (half width, half max) north and south.

Implementation status of the global and local beam position feedback systems for the Advanced Photon Source storage ring

International Nuclear Information System (INIS)

Chung, Y.; Barr, D.; Decker, G.; Galayda, J.; Kirchman, J.; Lenkszus, F.; Lumpkin, A.; Votaw, A.J.

1995-01-01

The Advanced Photon Source (APS) is implementing an extensive beam position feedback system for both global and local stabilization of particle and photon beams based on digital signal processing. The description and operational experience of the system will be given in this paper. In particular, we will discuss the underlying fundamental principles, hardware layout, controls interface, and automatic software generation for multiple digital signal processors (DSPS) distributed in 20 VME crates around the ring. The feedback system runs at 4-kHz sampling frequency in order to achieve the correction bandwidth of approximately 100 Hz. For the maximum correction efficiency and resolution of conflicts among multiple local feedback systems due to the local bump closure error, the global and local feedback systems are combined into a single unified system. This novel approach is made possible through data sharing among the global and local systems via the fiber-optically networked reflective memories

Meiotic and mitotic behaviour of a ring/deleted chromosome 22 in human embryos determined by preimplantation genetic diagnosis for a maternal carrier

Directory of Open Access Journals (Sweden)

Laver Sarah

2009-01-01

Full Text Available Abstract Background Ring chromosomes are normally associated with developmental anomalies and are rarely inherited. An exception to this rule is provided by deletion/ring cases. We were provided with a unique opportunity to investigate the meiotic segregation at oogenesis in a woman who is a carrier of a deleted/ring 22 chromosome. The couple requested preimplantation genetic diagnosis (PGD following the birth of a son with a mosaic karyotype. The couple underwent two cycles of PGD. Studies were performed on lymphocytes, single embryonic cells removed from 3 day-old embryos and un-transferred embryos. Analysis was carried out using fluorescence in situ hybridisation (FISH with specific probe sets in two rounds of hybridization. Results In total, 12 embryos were biopsied, and follow up information was obtained for 10 embryos. No embryos were completely normal or balanced for chromosome 22 by day 5. There was only one embryo diagnosed as balanced of 12 biopsied but that accumulated postzygotic errors by day 5. Three oocytes apparently had a balanced chromosome 22 complement but all had the deleted and the ring 22 and not the intact chromosome 22. After fertilisation all the embryos accumulated postzygotic errors for chromosome 22. Conclusion The study of the preimplantation embryos in this case provided a rare and significant chance to study and understand the phenomena associated with this unusual type of anomaly during meiosis and in the earliest stages of development. It is the first reported PGD attempt for a ring chromosome abnormality.

Uniquely Strongly Clean Group Rings

Institute of Scientific and Technical Information of China (English)

WANG XIU-LAN

2012-01-01

A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

Mercury and cadmium in ringed seals in the Canadian Arctic: Influence of location and diet

Energy Technology Data Exchange (ETDEWEB)

Brown, Tanya M., E-mail: tanya.brown@mun.ca [Memorial University of Newfoundland, St. John' s, Newfoundland A1B 3X9 (Canada); Fisk, Aaron T. [Great Lakes Institute of Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, Ontario N9B 3P4 (Canada); Wang, Xiaowa [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada); Ferguson, Steven H. [Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba R3T 2N6 (Canada); Young, Brent G. [University of Manitoba, 500 University Crescent, Winnipeg, Manitoba R3T 2N2 (Canada); Reimer, Ken J. [Environmental Sciences Group, Royal Military College of Canada, PO Box 17000, Stn Forces, Kingston, Ontario K7K 7B4 (Canada); Muir, Derek C.G. [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada)

2016-03-01

Concentrations of total mercury (THg) and total cadmium (TCd) were determined in muscle and liver of ringed seals (Pusa hispida) from up to 14 locations across the Canadian Arctic. Location, trophic position (TP) and relative carbon source best predicted the THg and TCd concentrations in ringed seals. THg concentrations in ringed seals were highest in the western Canadian Arctic (Beaufort Sea), whereas TCd was highest in the eastern Canadian Arctic (Hudson Bay and Labrador). A positive relationship between THg and TP and a negative relationship between THg and relative carbon source contributed to the geographical patterns observed and elevated THg levels at certain sites. In contrast, a negative relationship between TCd and TP was found, indicating that high TCd concentrations are related to seals feeding more on invertebrates than fish. Feeding ecology appears to play an important role in THg and TCd levels in ringed seals, with biomagnification driving elevated THg levels and a dependence on low-trophic position prey resulting in high TCd concentrations. The present study shows that both natural geological differences and diet variability among regions explain the spatial patterns for THg and TCd concentrations in ringed seals. - Highlights: • Diet and location influenced THg and Cd in ringed seals across the Canadian Arctic. • Biomagnification processes contribute to elevated THg levels in the western Arctic. • Consuming low-trophic position prey explains high Cd levels in the eastern Arctic.

Mercury and cadmium in ringed seals in the Canadian Arctic: Influence of location and diet

International Nuclear Information System (INIS)

Brown, Tanya M.; Fisk, Aaron T.; Wang, Xiaowa; Ferguson, Steven H.; Young, Brent G.; Reimer, Ken J.; Muir, Derek C.G.

2016-01-01

Concentrations of total mercury (THg) and total cadmium (TCd) were determined in muscle and liver of ringed seals (Pusa hispida) from up to 14 locations across the Canadian Arctic. Location, trophic position (TP) and relative carbon source best predicted the THg and TCd concentrations in ringed seals. THg concentrations in ringed seals were highest in the western Canadian Arctic (Beaufort Sea), whereas TCd was highest in the eastern Canadian Arctic (Hudson Bay and Labrador). A positive relationship between THg and TP and a negative relationship between THg and relative carbon source contributed to the geographical patterns observed and elevated THg levels at certain sites. In contrast, a negative relationship between TCd and TP was found, indicating that high TCd concentrations are related to seals feeding more on invertebrates than fish. Feeding ecology appears to play an important role in THg and TCd levels in ringed seals, with biomagnification driving elevated THg levels and a dependence on low-trophic position prey resulting in high TCd concentrations. The present study shows that both natural geological differences and diet variability among regions explain the spatial patterns for THg and TCd concentrations in ringed seals. - Highlights: • Diet and location influenced THg and Cd in ringed seals across the Canadian Arctic. • Biomagnification processes contribute to elevated THg levels in the western Arctic. • Consuming low-trophic position prey explains high Cd levels in the eastern Arctic.

CHESS-the Cornell High Energy Synchrotron Source

International Nuclear Information System (INIS)

Batterman, B.W.; Cornell Univ., Ithaca, NY

1980-01-01

The Wilson Laboratory at Cornell University has done pioneering work on development of high energy synchrotrons. In the last decade, the 12 GeV synchrotron has been the most energetic electron synchrotron in the world. In 1975 plans were formulated to build a 4-8 GeV storage ring in the same tunnel as the synchrotron and to use the latter as the injector for the storage ring. This small radius (the normal bend magnets have R = 87 m), coupled with the relatively high electron energy of the storage ring, makes these magnets potent sources of synchrotron radiation. In June of 1978 the National Science Foundation funded a project to create CHESS, the Cornell High Energy Synchrotron Source. (orig./FKS)

Mechanical Engineering of the Linac for the Spallation Neutron Source

International Nuclear Information System (INIS)

Bultman, N.K.; Chen, Z.; Collier, M.; Erickson, J.L.; Guthrie, A.; Hunter, W.T.; Ilg, T.; Meyer, R.K.; Snodgrass, N.L.

1999-01-01

The linac for the Spallation Neutron Source (SNS) Project will accelerate an average current of 1 mA of H - ions from 20 MeV to 1GeV for injection into an accumulator ring. The linac will be an intense source of H - ions and as such requires advanced design techniques to meet project technical goals as well as to minimize costs. The DTL, CCDTL and CCL are 466m long and operate at 805 MHz with a maximum H - input current of 28 mA and 7% rf duty factor. The Drift Tube Linac is a copper-plated steel structure using permanent magnetic quadrupoles. The Coupled-Cavity portions are brazed copper structures and use electromagnetic quads. RF losses in the copper are 80 MW, with total rf power supplied by 52 klystrons. Additionally, the linac is to be upgraded to the 2- and 4-MW beam power levels with no increase in duty factor. The authors give an overview of the linac mechanical engineering effort and discuss the special challenges and status of the effort

Influence of ring growth rate on damage development in hot ring rolling

NARCIS (Netherlands)

Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

2015-01-01

As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For