Beam dynamics and expected performance of Sweden's new storage-ring light source: MAX IV

NASA Astrophysics Data System (ADS)

Leemann, S. C.; Andersson, Å.; Eriksson, M.; Lindgren, L.-J.; Wallén, E.; Bengtsson, J.; Streun, A.

2009-12-01

MAX IV will be Sweden’s next-generation high-performance synchrotron radiation source. The project has recently been granted funding and construction is scheduled to begin in 2010. User operation for a broad and international user community should commence in 2015. The facility is comprised of two storage rings optimized for different wavelength ranges, a linac-based short-pulse facility and a free-electron laser for the production of coherent radiation. The main radiation source of MAX IV will be a 528 m ultralow emittance storage ring operated at 3 GeV for the generation of high-brightness hard x rays. This storage ring was designed to meet the requirements of state-of-the-art insertion devices which will be installed in nineteen 5 m long dispersion-free straight sections. The storage ring is based on a novel multibend achromat design delivering an unprecedented horizontal bare lattice emittance of 0.33 nm rad and a vertical emittance below the 8 pm rad diffraction limit for 1 Å radiation. In this paper we present the beam dynamics considerations behind this storage-ring design and detail its expected unique performance.

Water, gravity and trees: Relationship of tree-ring widths and total water storage dynamics

NASA Astrophysics Data System (ADS)

Creutzfeldt, B.; Heinrich, I.; Merz, B.; Blume, T.; Güntner, A.

2012-04-01

Water stored in the subsurface as groundwater or soil moisture is the main fresh water source not only for drinking water and food production but also for the natural vegetation. In a changing environment water availability becomes a critical issue in many different regions. Long-term observations of the past are needed to improve the understanding of the hydrological system and the prediction of future developments. Tree ring data have repeatedly proved to be valuable sources for reconstructing long-term climate dynamics, e.g. temperature, precipitation and different hydrological variables. In water-limited environments, tree growth is primarily influenced by total water stored in the subsurface and hence, tree-ring records usually contain information about subsurface water storage. The challenge is to retrieve the information on total water storage from tree rings, because a training dataset of water stored in the sub-surface is required for calibration against the tree-ring series. However, measuring water stored in the subsurface is notoriously difficult. We here present high-precision temporal gravimeter measurements which allow for the depth-integrated quantification of total water storage dynamics at the field scale. In this study, we evaluate the relationship of total water storage change and tree ring growth also in the context of the complex interactions of other meteorological forcing factors. A tree-ring chronology was derived from a Norway spruce stand in the Bavarian Forest, Germany. Total water storage dynamics were measured directly by the superconducting gravimeter of the Geodetic Observatory Wettzell for a 9-years period. Time series were extended to 63-years period by a hydrological model using gravity data as the only calibration constrain. Finally, water storage changes were reconstructed based on the relationship between the hydrological model and the tree-ring chronology. Measurement results indicate that tree-ring growth is primarily controlled by total water storage in the subsurface. But high uncertainties intervals of the correlation coefficient urges for the extension of the measurement period. This multi-disciplinary study, combining hydrology, dendrochronology and geodesy shows that temporal gravimeter measurements may give us the unique opportunity to retrieve the information of total water storage contained in tree-ring records to reconstruct total water storage dynamics. Knowing the relationship of water storage and tree-ring growth can also support the reconstruction of other climate records based on tree-ring series, help with hydrological model testing and can improve our knowledge of long-term variations of water storage in the past.

A 1kW EUV source for lithography based on FEL emission in a compact storage ring

NASA Astrophysics Data System (ADS)

Feser, Michael; Ruth, Ron; Loewen, Rod

2017-10-01

EUV has long been hailed as the next generation lithography technology. Its adoption into high volume manufacturing (HVM), however, has been delayed several technology nodes due to technical issues, many of which can be attributed to the EUV source performance. Today's EUV lithography scanners are powered by laser produce plasma (LPP) sources. They have issues with power scaling beyond 300 W, reliability and contamination. Free Electron Lasers (FELs) have been considered as an alternative EUV source. Advantages of accelerator based sources are the maturity of the accelerator technology, lack of debris/contamination, and ability to provide high power. Industry turned away from this technology because of the requirement to feed up to 10 scanners from one linear FEL to make it economically feasible, the large footprint, and generation of radioactive byproducts. All of these issues are overcome in the presented concept using a compact storage ring with steady-state FEL lasing action. At 1 kW output power, comparable cost and footprint to an LPP source, this source is ideally suited for use on a single scanner and promises reliable, contamination free operation. FEL action in the storage ring is sustained by operating the FEL well below the saturation regime and preserving the equilibrium low emittance and energy distribution of the ring.

Intra-Beam Scattering, Impedance, and Instabilities in Ultimate Storage Rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bane, Karl; /SLAC

We have investigated collective effects in an ultimate storage ring, i.e. one with diffraction limited emittances in both planes, using PEP-X as an example. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, a 4.5 GeV ring running round beams at 200 mA in 3300 bunches, IBS doubles the emittances to 11.5 pm at the design current. The Touschek lifetime is 11 hours. Impedance driven collective effects tend not to be important since the beam current is relatively low. We have investigated collective effects in PEP-X, an ultimate storage ring, i.e.more » one with diffraction limited emittances (at one angstrom wavelength) in both planes. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, IBS doubles the emittances to 11.5 pm at the design current of 200 mA, assuming round beams. The Touschek lifetime is quite large in PEP-X, 11.6 hours, and - near the operating point - increases with decreasing emittance. It is, however, a very sensitive function of momentum acceptance. In an ultimate ring like PEP-X impedance driven collective effects tend not to be important since the beam current is relatively low. Before ultimate PEP-X can be realized, the question of how to run a machine with round beams needs serious study. For example, in this report we assumed that the vertical emittance is coupling dominated. It may turn out that using vertical dispersion is a preferable way to generate round beams. The choice will affect IBS and the Touschek effect.« less

A field-cancellation algorithm for constructing economical planar permanent magnet (PM) multipoles with large high-quality field apertures

NASA Astrophysics Data System (ADS)

Tatchyn, Roman

1997-05-01

In recent years studies have been initiated on a new class of multipole field generators consisting of cuboid planar permanent magnet (PM) pieces arranged in bi-planar arrays of 2-fold rotational symmetry(R. Tatchyn, "Planar Permanent Magnet Multipoles: for Particle Accelerator and Storage Ring Applications ," IEEE Trans. Mag. 30, 5050(1994).)(T. Cremer, R. Tatchyn, "Planar Permanent Magnet Multipoles: Measurements and Configurations," in Proceedings of the 1995 Particle Accelerator Conference, IEEE Catalog No. 95CH35843, paper FAQ-20.). These structures, first introduced for Free Electron Laser (FEL) applications(R. Tatchyn, "Selected applications of planar permanent magnet multipoles in FEL insertion device design," NIM A341, 449(1994).), are based on reducing the rotational symmetry of conventional N-pole field generators from N-fold to 2-fold. One consequence of this reduction is a large higher-multipole content in a planar PM multipole's field at distances relatively close to the structure's axis, making it generally unsuitable for applications requiring a large high-quality field aperture. In this paper we outline an economical field-cancellation algorithm that can substantially decrease the harmonic content of a planar PM's field without breaking its biplanar geometry or 2-fold rotational symmetry. This will enable planar PM multipoles to be employed in a broader range of applications than heretofore possible, in particular as distributed focusing elements installed in insertion device gaps on synchrotron storage rings. This accomplishment is expected to remove the conventional restriction of an insertion device's length to the scale of the local focusing beta, enabling short-period, small-gap undulators to be installed and operated as high-brightness sources on lower-energy storage rings(R. Tatchyn, P. Csonka, A. Toor, "Perspectives on micropole undulators in synchrotron radiation technology," Rev. Sci. Instrum. 60(7), 1796(1989).). Operation as ordinary focusing elements in storage ring magnetic lattices, as well as the performance of other high-quality multipole applications, should also becomes possible with the realization of the proposed structures.

Planning and Prototyping for a Storage Ring Measurement of the Proton Electric Dipole Moment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Talman, Richard

2015-07-01

Electron and proton EDM's can be measured in "frozen spin" (with the beam polarization always parallel to the orbit, for example) storage rings. For electrons the "magic" kinetic energy at which the beam can be frozen is 14.5 MeV. For protons the magic kinetic energy is 230 MeV. The currently measured upper limit for the electron EDM is much smaller than the proton EDM upper limit, which is very poorly known. Nevertheless, because the storage ring will be an order of magnitude cheaper, a sensible plan is to first build an all-electric electron storage ring as a prototype. Such anmore » electron ring was successfully built at Brookhaven, in 1954, as a prototype for their AGS ring. This leaves little uncertainty concerning the cost and performance of such a ring. (This is documentedin one of the Physical Review papers mentioned above.)« less

Storage-ring Electron Cooler for Relativistic Ion Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Fanglei; Derbenev, Yaroslav; Douglas, David R.

Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This papermore » reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the electron beam. The necessary energy difference is provided by an energy recovering SRF structure. A prototype linear optics of such storage-ring cooler is presented.« less

Physics issues in diffraction limited storage ring design

NASA Astrophysics Data System (ADS)

Fan, Wei; Bai, ZhengHe; Gao, WeiWei; Feng, GuangYao; Li, WeiMin; Wang, Lin; He, DuoHui

2012-05-01

Diffraction limited electron storage ring is considered a promising candidate for future light sources, whose main characteristics are higher brilliance, better transverse coherence and better stability. The challenge of diffraction limited storage ring design is how to achieve the ultra low beam emittance with acceptable nonlinear performance. Effective linear and nonlinear parameter optimization methods based on Artificial Intelligence were developed for the storage ring physical design. As an example of application, partial physical design of HALS (Hefei Advanced Light Source), which is a diffraction limited VUV and soft X-ray light source, was introduced. Severe emittance growth due to the Intra Beam Scattering effect, which is the main obstacle to achieve ultra low emittance, was estimated quantitatively and possible cures were discussed. It is inspiring that better performance of diffraction limited storage ring can be achieved in principle with careful parameter optimization.

CLEARING MAGNET DESIGN FOR APS-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abliz, M.; Grimmer, J.; Jaski, Y.

2017-06-25

The Advanced Photon Source is in the process of developing an upgrade (APS-U) of the storage ring. The upgrade will be converting the current double bend achromat (DBA) lattice to a multi-bend achromat (MBA) lattice. In addition, the storage ring will be operated at 6 GeV and 200 mA with regular swap-out injection to keep the stored beam current constant [1]. The swap-out injection will take place with beamline shutters open. For radiation safety to ensure that no electrons can exit the storage ring, a passive method of protecting the beamline and containing the electrons inside the storage ring ismore » proposed. A clearing magnet will be located in all beamline front ends inside the storage ring tunnel. This article will discuss the features and design of the clearing magnet scheme for APS-U.« less

National Synchrotron Light Source II storage ring vacuum systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hseuh, Hsiao-Chaun, E-mail: hseuh@bnl.gov; Hetzel, Charles; Leng, Shuwei

2016-05-15

The National Synchrotron Light Source II, completed in 2014, is a 3-GeV synchrotron radiation (SR) facility at Brookhaven National Laboratory and has been in steady operation since. With a design electron current of 500 mA and subnanometer radians horizontal emittance, this 792-m circumference storage ring is providing the highest flux and brightness x-ray beam for SR users. The majority of the storage ring vacuum chambers are made of extruded aluminium. Chamber sections are interconnected using low-impedance radiofrequency shielded bellows. SR from the bending magnets is intercepted by water-cooled compact photon absorbers resided in the storage ring chambers. This paper presents themore » design of the storage ring vacuum system, the fabrication of vacuum chambers and other hardware, the installation, the commissioning, and the continuing beam conditioning of the vacuum systems.« less

The phase slip factor of the electrostatic cryogenic storage ring CSR

NASA Astrophysics Data System (ADS)

Grieser, Manfred; von Hahn, Robert; Vogel, Stephen; Wolf, Andreas

2017-07-01

To determine the momentum spread of an ion beam from the measured revolution frequency distribution, the knowledge of the phase slip factor of the storage ring is necessary. The slip factor was measured for various working points of the cryogenic storage ring CSR at MPI for Nuclear Physics, Heidelberg and was compared with simulations. The predicted functional relationship of the slip factor and the horizontal tune depends on the different islands of stability, which has been experimentally verified. This behavior of the slip factor is in clear contrast to that of magnetic storage rings.

Online optimization of storage ring nonlinear beam dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Xiaobiao; Safranek, James

2015-08-01

We propose to optimize the nonlinear beam dynamics of existing and future storage rings with direct online optimization techniques. This approach may have crucial importance for the implementation of diffraction limited storage rings. In this paper considerations and algorithms for the online optimization approach are discussed. We have applied this approach to experimentally improve the dynamic aperture of the SPEAR3 storage ring with the robust conjugate direction search method and the particle swarm optimization method. The dynamic aperture was improved by more than 5 mm within a short period of time. Experimental setup and results are presented.

National Synchrotron Light Source II storage ring vacuum systems

DOE PAGES

Hseuh, Hsiao-Chaun; Hetzel, Charles; Leng, Shuwei; ...

2016-04-05

The National Synchrotron Light Source II, completed in 2014, is a 3-GeV synchrotron radiation (SR) facility at Brookhaven National Laboratory and has been in steady operation since. With a design electron current of 500 mA and subnanometer radians horizontal emittance, this 792-m circumference storage ring is providing the highest flux and brightness x-ray beam for SR users. Also, the majority of the storage ring vacuum chambers are made of extruded aluminium. Chamber sections are interconnected using low-impedance radiofrequency shielded bellows. SR from the bending magnets is intercepted by water-cooled compact photon absorbers resided in the storage ring chambers. Finally, thismore » paper presents the design of the storage ring vacuum system, the fabrication of vacuum chambers and other hardware, the installation, the commissioning, and the continuing beam conditioning of the vacuum systems.« less

Duke storage rink UV/VUV FEL: Status and prospects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Litvinenko, V.N.; Burnham, B.; Madey, J.M.J.

1995-12-31

The 1 GeV Duke storage ring was successfully commissioned with parameters exceeding initial specification. The OK-4 FEL has arrived at the Duke FEL laboratory from the Novosibirsk Institute of Nuclear Physics. The OK-4 installation and commissioning is in progress. In this paper we describe the up-to-date status of the Duke storage ring and the OK-4 FEL. The projected performance of the OK-4 UV/VUV FEL is presented based on the electron beam parameters achieved. Initial plans to operate the OK-4 UV/VUV FEL at the Duke 1 GeV storage ring are outlined. Future plans and prospects of both the OK-4 FEL andmore » the Duke storage ring are discussed.« less

A new storage-ring light source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Alex

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.

The design improvement of horizontal stripline kicker in TPS storage ring

NASA Astrophysics Data System (ADS)

Chou, P. J.; Chan, C. K.; Chang, C. C.; Hsu, K. T.; Hu, K. H.; Kuan, C. K.; Sheng, I. C.

2017-07-01

We plan to replace the existing horizontal stripline kicker of the transverse feedback system with an improved design. Large reflected power was observed at the downstream port of stripline kicker driven by the feedback amplifier. A rapid surge of vacuum pressure was observed when we tested the high current operation in TPS storage ring in April 2016. A burned feedthrough of the horizontal stripline kicker was discovered during a maintenance shutdown. The improved design is targeted to reduce the reflection of driving power from feedback system and to reduce beam induced RF heating. This major modification of the design is described. The results of RF simulation performed with the electromagnetic code GdfidL are reported as well.

Measurement of Tensor Analyzing Powers for Elastic Electron Scattering from a Polarized {sup 2}H Target Internal to a Storage Ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferro-Luzzi, M.; Bouwhuis, M.; Passchier, E.

1996-09-01

We report an absolute measurement of the tensor analyzing powers {ital T}{sub 20} and {ital T}{sub 22} in elastic electron-deuteron scattering at a momentum transfer of 1.6 fm{sup {minus}1}. The novel approach of this measurement is the use of a tensor polarized {sup 2}H target internal to an electron storage ring, with {ital in} {ital situ} measurement of the polarization of the target gas. Scattered electrons and recoil deuterons were detected in coincidence with two large acceptance nonmagnetic detectors. The techniques demonstrated have broad applicability to further measurements of spin-dependent electron scattering. {copyright} {ital 1996 The American Physical Society.}

Polarization Studies for the eRHIC Electron Storage Ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gianfelice-Wendt, Eliana; Tepikian, S.

A hadron/lepton collider with polarized beams has been under consideration by the scientific community since some years, in the U.S. and Europe. Among the various proposals, those by JLAB and BNL with polarized electron and proton beams are currently under closer study in the U.S. Experimenters call for the simultaneous storage of electron bunches with both spin helicity. In the BNL based Ring-Ring design, electrons are stored at top energy in a ring to be accommodated in the existing RHIC tunnel. The transversely polarized electron beam is injected into the storage ring at variable energies, between 5 and 18 GeV.more » Polarization is brought into the longitudinal direction at the IP by a couple of spin rotators. In this paper results of first studies of the attainable beam polarization level and lifetime in the storage ring at 18 GeV are presented.« less

Inertial energy storage device

DOEpatents

Knight, Jr., Charles E.; Kelly, James J.; Pollard, Roy E.

1978-01-01

The inertial energy storage device of the present invention comprises a composite ring formed of circumferentially wound resin-impregnated filament material, a flanged hollow metal hub concentrically disposed in the ring, and a plurality of discrete filament bandsets coupling the hub to the ring. Each bandset is formed of a pair of parallel bands affixed to the hub in a spaced apart relationship with the axis of rotation of the hub being disposed between the bands and with each band being in the configuration of a hoop extending about the ring along a chordal plane thereof. The bandsets are disposed in an angular relationship with one another so as to encircle the ring at spaced-apart circumferential locations while being disposed in an overlapping relationship on the flanges of the hub. The energy storage device of the present invention has the capability of substantial energy storage due to the relationship of the filament bands to the ring and the flanged hub.

Design of the transfer line from booster to storage ring at 3 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayar, C., E-mail: cafer.bayar@cern.ch; Ciftci, A. K., E-mail: abbas.kenan.ciftci@cern.ch

The Synchrotron Booster Ring accelerates the e-beam up to 3 GeV and particles are transported from booster to storage ring by transfer line. In this study, two options are considered, the first one is a long booster which shares the same tunnel with storage ring and the second one is a compact booster. As a result, two transfer line are designed based on booster options. The optical design is constrained by the e-beam Twiss parameters entering and leaving the transfer line. Twiss parameters in the extraction point of booster are used for the entrance of transfer line and are matchedmore » in the exit of transfer line to the injection point of the storage ring.« less

An Inside Look: NSLS-II Storage Ring

ScienceCinema

Fries, Gregory

2018-06-12

Look inside the storage ring of the National Synchrotron Light Source II, under construction at Brookhaven Lab. Exactly 843 magnets now encircle the ring. Their job will be to steer, stabilize, and store electrons racing around at near light speed.

Code comparison for accelerator design and analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parsa, Z.

1988-01-01

We present a comparison between results obtained from standard accelerator physics codes used for the design and analysis of synchrotrons and storage rings, with programs SYNCH, MAD, HARMON, PATRICIA, PATPET, BETA, DIMAD, MARYLIE and RACE-TRACK. In our analysis we have considered 5 (various size) lattices with large and small angles including AGS Booster (10/degree/ bend), RHIC (2.24/degree/), SXLS, XLS (XUV ring with 45/degree/ bend) and X-RAY rings. The differences in the integration methods used and the treatment of the fringe fields in these codes could lead to different results. The inclusion of nonlinear (e.g., dipole) terms may be necessary inmore » these calculations specially for a small ring. 12 refs., 6 figs., 10 tabs.« less

A FODO racetrack ring for nuSTORM: design and optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, A.; Bross, A.; Neuffer, D.

2017-07-01

The goal of nuSTORM is to provide well-defined neutrino beams for precise measurements of neutrino cross-sections and oscillations. The nuSTORM decay ring is a compact racetrack storage ring with a circumference of ~ 480 m that incorporates large aperture (60 cm diameter) magnets. There are many challenges in the design. In order to incorporate the Orbit Combination section (OCS), used for injecting the pion beam into the ring, a dispersion suppressor is needed adjacent to the OCS . Concurrently, in order to maximize the number of useful muon decays, strong bending dipoles are needed in the arcs to minimize the arcmore » length. These dipoles create strong chromatic effects, which need to be corrected by nonlinear sextupole elements in the ring. In this paper, a FODO racetrack ring design and its optimization using sextupolar fields via both a Genetic Algorithm (GA) and a Simulated Annealing (SA) algorithm will be discussed.« less

Diffraction-limited storage-ring vacuum technology

PubMed Central

Al-Dmour, Eshraq; Ahlback, Jonny; Einfeld, Dieter; Tavares, Pedro Fernandes; Grabski, Marek

2014-01-01

Some of the characteristics of recent ultralow-emittance storage-ring designs and possibly future diffraction-limited storage rings are a compact lattice combined with small magnet apertures. Such requirements present a challenge for the design and performance of the vacuum system. The vacuum system should provide the required vacuum pressure for machine operation and be able to handle the heat load from synchrotron radiation. Small magnet apertures result in the conductance of the chamber being low, and lumped pumps are ineffective. One way to provide the required vacuum level is by distributed pumping, which can be realised by the use of a non-evaporable getter (NEG) coating of the chamber walls. It may not be possible to use crotch absorbers to absorb the heat from the synchrotron radiation because an antechamber is difficult to realise with such a compact lattice. To solve this, the chamber walls can work as distributed absorbers if they are made of a material with good thermal conductivity, and distributed cooling is used at the location where the synchrotron radiation hits the wall. The vacuum system of the 3 GeV storage ring of MAX IV is used as an example of possible solutions for vacuum technologies for diffraction-limited storage rings. PMID:25177979

ONLINE MINIMIZATION OF VERTICAL BEAM SIZES AT APS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yipeng

In this paper, online minimization of vertical beam sizes along the APS (Advanced Photon Source) storage ring is presented. A genetic algorithm (GA) was developed and employed for the online optimization in the APS storage ring. A total of 59 families of skew quadrupole magnets were employed as knobs to adjust the coupling and the vertical dispersion in the APS storage ring. Starting from initially zero current skew quadrupoles, small vertical beam sizes along the APS storage ring were achieved in a short optimization time of one hour. The optimization results from this method are briefly compared with the onemore » from LOCO (Linear Optics from Closed Orbits) response matrix correction.« less

Pushing the MAX IV 3 GeV storage ring brightness and coherence towards the limit of its magnetic lattice

NASA Astrophysics Data System (ADS)

Leemann, S. C.; Wurtz, W. A.

2018-03-01

The MAX IV 3 GeV storage ring is presently being commissioned and crucial parameters such as machine functions, emittance, and stored current have either already been reached or are approaching their design specifications. Once the baseline performance has been achieved, a campaign will be launched to further improve the brightness and coherence of this storage ring for typical X-ray users. During recent years, several such improvements have been designed. Common to these approaches is that they attempt to improve the storage ring performance using existing hardware provided for the baseline design. Such improvements therefore present more short-term upgrades. In this paper, however, we investigate medium-term improvements assuming power supplies can be exchanged in an attempt to push the brightness and coherence of the storage ring to the limit of what can be achieved without exchanging the magnetic lattice itself. We outline optics requirements, the optics optimization process, and summarize achievable parameters and expected performance.

Cabling design of booster and storage ring construction progress of TPS

NASA Astrophysics Data System (ADS)

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

2017-06-01

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 mm2, 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 mm2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm2, 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.

Coupled beam motion in a storage ring with crab cavities

DOE PAGES

Huang, Xiaobiao

2016-02-16

We studied the coupled beam motion in a storage ring between the transverse and longitudinal directions introduced by crab cavities. Analytic form of the linear decoupling transformation is derived. Also, the equilibrium bunch distribution in an electron storage ring with a crab cavity is given, including contribution to the eigen-emittance induced by the crab cavity. Furthermore, application to the short pulse generation scheme using crab cavities [1] is considered.

A multiple-orbit time-of-flight mass spectrometer based on a low energy electrostatic storage ring

NASA Astrophysics Data System (ADS)

Sullivan, M. R.; Spanjers, T. L.; Thorn, P. A.; Reddish, T. J.; Hammond, P.

2012-11-01

The results are presented for an electrostatic storage ring, consisting of two hemispherical deflector analyzers (HDA) connected by two separate sets of cylindrical lenses, used as a time-of-flight mass spectrometer. Based on the results of charged particle simulations and formal matrix model, the Ion Storage Ring is capable of operating with multiple stable orbits, for both single and multiply charged ions simultaneously.

RF System Requirements for a Medium-Energy Electron-Ion Collider (MEIC) at JLab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimmer, Robert A; Hannon, Fay E; Guo, Jiquan

2015-09-01

JLab is studying options for a medium energy electron-ion collider that could fit on the JLab site and use CEBAF as a full-energy electron injector. A new ion source, linac and booster would be required, together with collider storage rings for the ions and electrons. In order to achieve the maximum luminosity these will be high-current storage rings with many bunches. We present the high-level RF system requirements for the storage rings, ion booster ring and high-energy ion beam cooling system, and describe the technology options under consideration to meet them. We also present options for staging that might reducemore » the initial capital cost while providing a smooth upgrade path to a higher final energy. The technologies under consideration may also be useful for other proposed storage ring colliders or ultimate light sources.« less

Effects of CSR Generated from Upstream Bends in a Laser Plasma Storage Ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, C.; Qiang, J.; Venturini, M.

The recent proposal [1] of a Laser Plasma Storage Ring (LPSR) envisions the use of a laser-plasma (LP) acceleration module to inject an electron beam into a compact 500 MeV storage ring. Electron bunches generated by LP methods are naturally very short (tens of femtoseconds), presenting peak currents on the order of 10 kA or higher. Of obvious concern is the impact of collective effects and in particular Coherent Synchrotron Radiation (CSR) on the beam dynamics in the storage ring. Available simulation codes (e.g. Elegant [2]) usually include transient CSR effects but neglect the contribution of radiation emitted from trailingmore » magnets. In a compact storage ring, with dipole magnets close to each other, cross talking between different magnets could in principle be important.In this note we investigate this effect for the proposed LPSR and show that, in fact, this effect is relatively small. However our analysis also indicates that CSR effects in general would be quite strong and deserve a a careful study.« less

Ring profiler: a new method for estimating tree-ring density for improved estimates of carbon storage

Treesearch

David W. Vahey; C. Tim Scott; J.Y. Zhu; Kenneth E. Skog

2012-01-01

Methods for estimating present and future carbon storage in trees and forests rely on measurements or estimates of tree volume or volume growth multiplied by specific gravity. Wood density can vary by tree ring and height in a tree. If data on density by tree ring could be obtained and linked to tree size and stand characteristics, it would be possible to more...

Storage rings, internal targets and PEP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spencer, J.E.

Storage rings with internal targets are described, using PEP as an example. The difference between electrons and heavier particles such as protons, antiprotons, and heavy ions is also discussed because it raises possibilities of bypass insertions for more exotic experiments. PEP is compared to other rings in various contexts to verify the assertion that it is an ideal ring for many fundamental and practical applications that can be carried on simultaneously. (LEW)

TRANSIENT BEAM LOADING EFFECTS IN RF SYSTEMS IN JLEIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Haipeng; Guo, Jiquan; Rimmer, Robert A.

2016-05-01

The pulsed electron bunch trains generated from the Continuous Electron Beam Accelerator Facility (CEBAF) linac to inject into the proposed Jefferson Lab Electron Ion Collider (JLEIC) e-ring will produce transient beam loading effects in the Superconducting Radio Frequency (SRF) systems that, if not mitigated, could cause unacceptably large beam energy deviation in the injection capture, or exceed the energy acceptance of CEBAF’s recirculating arcs. In the electron storage ring, the beam abort or ion clearing gaps or uneven bucket filling can cause large beam phase transients in the (S)RF cavity control systems and even beam loss due to Robinson instability.more » We have first analysed the beam stability criteria in steady state and estimated the transient effect in Feedforward and Feedback RF controls. Initial analytical models for these effects are shown for the design of the JLEIC e-ring from 3GeV to 12GeV.« less

ELISA - an electrostatic storage ring for low-energy ions

NASA Astrophysics Data System (ADS)

Pape Moeller, Soeren

1997-05-01

The design of a new type of storage ring for low-energy ions using electrostatic deflection and focusing devices is described. Electrostatic bends and quadrupoles are used since they are more efficient than magnetic ones for low-velocity heavy ions. Furthermore, electrostatic devices are more compact and easier to construct than magnetic devices. In comparison to an electromagnetic trap, one important advantage of the elecrostatic ring is the easy access to the circulating beam and its decay products. These and other features, e.g. no magnetic fields, makes such storage devices attractive for many atomic-physics experiments. Also neigboring fields as chemistry and biology might benefit from such an relatively inexpensive device. One important difference between an electrostatic and a magnetic ring is, that the longitudinal energy is not conserved for the electrostatic ring. The actual ring will have a race-track shape as defined by two straight sections each with two quadrupole doublets connected by 180-degrees bends. The bends will consist of 160-degrees spherical deflection plates surrounded by two parallel plate 10-degrees bends. The storage ring ELISA, currently being built, will have a circumference of 6 meters. The first beam tests will take place during summer 1996.

Beam diagnostics at high-intensity storage rings

NASA Astrophysics Data System (ADS)

Plum, Mike

1994-10-01

Beam diagnostics at high-intensity facilities feature their own special set of problems and characteristics, issues peculiar to high-intensity storage rings include beam loss, beam halos, extraction efficiency, beam in the gap, clearing electrodes, and beam-profile measurement. The Los Alamos Proton Storage Ring (PSR) is a nice example of a high-intensity storage ring. I will discuss in some detail three diagnostic systems currently in use at the PSR: the beam-loss-monitor system, the electron-clearing system, and the beam-in-the-gap monitor. Much of our discussion is inspired by the problems we have encountered and the useful things we have learned while commissioning and developing the PSR. Another inspiration is our work on the next-generation neutron-spallation source, also known as the National Center for Neutron Research (NCNR).

Model-independent and fast determination of optical functions in storage rings via multiturn and closed-orbit data

NASA Astrophysics Data System (ADS)

Riemann, Bernard; Grete, Patrick; Weis, Thomas

2011-06-01

Multiturn (or turn-by-turn) data acquisition has proven to be a new source of direct measurements for Twiss parameters in storage rings. On the other hand, closed-orbit measurements are a long-known tool for analyzing closed-orbit perturbations with conventional beam position monitor (BPM) systems and are necessarily available at every storage ring. This paper aims at combining the advantages of multiturn measurements and closed-orbit data. We show that only two multiturn BPMs and four correctors in one localized drift space in the storage ring (diagnostic drift) are sufficient for model-independent and absolute measuring of β and φ functions at all BPMs, including the conventional ones, instead of requiring all BPMs being equipped with multiturn electronics.

Single-pass BPM system of the Photon Factory storage ring.

PubMed

Honda, T; Katoh, M; Mitsuhashi, T; Ueda, A; Tadano, M; Kobayashi, Y

1998-05-01

At the 2.5 GeV ring of the Photon Factory, a single-pass beam-position monitor (BPM) system is being prepared for the storage ring and the beam transport line. In the storage ring, the injected beam position during the first several turns can be measured with a single injection pulse. The BPM system has an adequate performance, useful for the commissioning of the new low-emittance lattice. Several stripline BPMs are being installed in the beam transport line. The continuous monitoring of the orbit in the beam transport line will be useful for the stabilization of the injection energy as well as the injection beam orbit.

A FODO racetrack ring for nuSTORM: design and optimization

DOE PAGES

Liu, A.; Bross, A.; Neuffer, D.

2017-07-17

Here, the goal of nuSTORM is to provide well-defined neutrino beams for precise measurements of neutrino cross-sections and oscillations. The nuSTORM decay ring is a compact racetrack storage ring with a circumference of ~ 480 m that incorporates large aperture (60 cm diameter) magnets. There are many challenges in the design. In order to incorporate the Orbit Combination section (OCS), used for injecting the pion beam into the ring, a dispersion suppressor is needed adjacent to the OCS . Concurrently, in order to maximize the number of useful muon decays, strong bending dipoles are needed in the arcs to minimize themore » arc length. These dipoles create strong chromatic effects, which need to be corrected by nonlinear sextupole elements in the ring. In this paper, a FODO racetrack ring design and its optimization using sextupolar fields via both a Genetic Algorithm (GA) and a Simulated Annealing (SA) algorithm will be discussed.« less

REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B.

DOE Office of Scientific and Technical Information (OSTI.GOV)

FOERSTER,C.

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas aftermore » a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam line locations so that the monochromator, mirror box or sample chamber may be used in a helium atmosphere or rough vacuum. The window separates ring vacuum from the environment of the downstream beam line components. The stored beam lifetime in the storage rings and the maintenance of desirable reflection properties of optical surfaces depend upon hydrocarbon-free, ultra-high vacuum systems. Storage ring vacuum systems will operate at pressures of {approximately} 1 x 10{sup {minus}10} Torr without beam and {approximately} 1 x 10{sup {minus}9} Torr with beam. Systems are free of hydrocarbons in the sense that no pumps, valves, etc. containing organics are used. Components are all-metal, chemically cleaned and bakeable. To the extent that beam lines share a common vacuum with the storage ring, the same criteria will hold for beam line components. The design philosophy for NSLS beam lines is to use all-metal, hydrocarbon-free front end components and recommend that experimenters use this approach for common vacuum hardware downstream of front ends. O-ring-sealed valves, if used, are not permitted upstream of the monochromator exit aperture. It will be the responsibility of users to demonstrate that their experiment will not degrade the pressure or quality of the storage ring vacuum. As a matter of operating policy, all beam lines will be monitored for prescribed pressure and the contribution of high mass gases to this pressure each time a beam line has been opened to ring vacuum.« less

Fabrication and test of model superconducting inflector for g-2 at FNAL

DOE PAGES

Krave, Steven; Kashikhin, Vladimir S.; Strauss, Thomas

2017-03-01

The new FNAL g-2 experiment is based on the muon storage ring previously used at BNL. The 1.45 T dipole magnetic field in the storage ring is required to have very high (1 ppm) homogeneity. The muon beam injected into the ring must be transported through the magnet yoke and the main superconducting coil cryostat with minimal distortions. The old inflector magnet shielded the main dipole fringe field inside the muon transport beam pipe, with an outer NbTi superconducting screen, and did not disturb the field in the area of circulating beam. Nevertheless, this magnet had coils with closed endsmore » in which a large fraction of muon beam particles were lost. A new magnet is envisioned utilizing the same cross section as the original with open ends for improved beam transport. A model magnet has been wound utilizing 3d printed parts to verify the magnetic behavior of the magnet at room temperature and validate winding of the complicated geometry required for the magnet ends. Finally, room temperature magnetic measurements have been performed and confirm the magnetic design« less

Pseudo-single-bunch mode for a 100 MHz storage ring serving soft X-ray timing experiments

NASA Astrophysics Data System (ADS)

Olsson, T.; Leemann, S. C.; Georgiev, G.; Paraskaki, G.

2018-06-01

At many storage rings for synchrotron light production there is demand for serving both high-flux and timing users simultaneously. Today this is most commonly achieved by operating inhomogeneous fill patterns, but this is not preferable for rings that employ passive harmonic cavities to damp instabilities and increase Touschek lifetime. For these rings, inhomogeneous fill patterns could severely reduce the effect of the harmonic cavities. It is therefore of interest to develop methods to serve high-flux and timing users simultaneously without requiring gaps in the fill pattern. One such method is pseudo-single-bunch (PSB), where one bunch in the bunch train is kicked onto another orbit by a fast stripline kicker. The light emitted from the kicked bunch can then be separated by an aperture in the beamline. Due to recent developments in fast kicker design, PSB operation in multibunch mode is within reach for rings that operate with a 100 MHz RF system, such as the MAX IV and Solaris storage rings. This paper describes machine requirements and resulting performance for such a mode at the MAX IV 1.5 GeV storage ring. A solution for serving all beamlines is discussed as well as the consequences of beamline design and operation in the soft X-ray energy range.

Advances in large, transportable, highly spin-polarized, solid HD targets operable in the frozen-spin mode in a 1-4K temperature environment

NASA Astrophysics Data System (ADS)

Lewis, Aaron Paul

The development of large, portable highly spin-polarized solid HD targets has been in progress at Syracuse University for the past 5 years. These targets are scheduled for deployment at Brookhaven National Laboratory, bearing the acronym SPHICE (Spin-Polarized Hydrogen Ice), for studies of the electro-magnetic spin structure of the nucleus via scattering of polarized gammas from the HD polarized protons and deuterons. The target work has just reached the milestone demonstration of the complete system, including polarization of triple targets containing 4 moles of solid HD, aging of these targets so that they retain their polarization for months under storage at a temperature of 1.3K and in an 8 Tesla field, and for at least a week at operational conditions of 1.3K and 0.7 Tesla in an in-beam cryostat. Cold-transfers of the polarized targets to a storage cryostat have been successfully carried out, and the storage cryostat has been trucked from Syracuse to BNL with one polarized target, sufficient to test the in-beam operations there. The complete system is presented here, with emphasis on innovations for engagement and disengagement of multiple targets, a solution to the challenge of attaining sufficiently strong RF fields in the large volume probe coils at acceptable power dissipation in the cables, and the polarization production and monitoring in the highly inhomogeneous magnetic fields owing to the multiple targets and the large dimensions of the targets. In this first multiple target production and extraction-to-storage cycle, air-ice accumulation in the dilution refrigerator due to repetitive use of cold sliding o-ring seals resulted in a rupture of one of the inserted targets, and a consequent partial thermal short from a solid HD ice bridge. The o-ring fault was cured with double evacuatable o-ring seals, and the air-ice was successfully cleaned out. However, the refrigerator operating base temperature was substantially higher than that normally obtained and the proton polarizations were accordingly lower than the 48% previously obtained. Nevertheless, the targets passed all their production procedures and are still useful for a first experiment at BNL. We anticipate an era of important use of these now demonstrated specially advantageous polarized frozen-spin HD targets.

A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

NASA Astrophysics Data System (ADS)

Sannibale, F.; Byrd, J. M.; Loftsdóttir, Á.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wüstefeld, G.; Hübers, H.-W.; Warnock, R.

2004-08-01

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 BESSYII storage ring. We also use this model to optimize the performance of a source for stable CSR emission.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-06-01

Proposed action is to construct at BNL a 5,600-ft[sup 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.

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. Environmental assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-06-01

Proposed action is to construct at BNL a 5,600-ft{sup 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.

High resolution monochromator for the VUV radiation from the DORIS storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saile, V.; Gurtler, P.; Koch, E.E.

1976-10-01

The unique properties of the DORIS storage ring at DESY as a synchroton radiation source are exploited for high resolution spectroscopy in the vacuum ultraviolet. We describe a new experimental set up with a 3-m normal incidence monochromator for wavelengths between 3000 A and 300 A (4 < or = h..omega.. < or = 40 eV) using a vertical dispersion plane. The storage ring provides a light flux intense and stable enough for rapid photoelectrical scanning of the spectra with a resolution of 0.03 A in first order. (AIP)

ACCELERATORS: Preliminary application of turn-by-turn data analysis to the SSRF storage ring

NASA Astrophysics Data System (ADS)

Chen, Jian-Hui; Zhao, Zhen-Tang

2009-07-01

There is growing interest in utilizing the beam position monitor turn-by-turn (TBT) data to debug accelerators. TBT data can be used to determine the linear optics, coupled optics and nonlinear behaviors of the storage ring lattice. This is not only a useful complement to other methods of determining the linear optics such as LOCO, but also provides a possibility to uncover more hidden phenomena. In this paper, a preliminary application of a β function measurement to the SSRF storage ring is presented.

How to Reach a Thousand-Second in-Plane Polarization Lifetime with 0.97 - GeV / c Deuterons in a Storage Ring

DOE PAGES

Guidoboni, G.; Stephenson, E.; Andrianov, S.; ...

2016-07-28

Here, we observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of a magnetic storage ring (COSY). This long spin coherence time is maintained through a combination of beam bunching, electron cooling, sextupole field corrections, and the suppression of collective effects through beam current limits. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10 -29 $e$ cm.

Dielectronic recombination experiments at the storage rings: From the present CSR to the future HIAF

NASA Astrophysics Data System (ADS)

Huang, Z. K.; Wen, W. Q.; Xu, X.; Wang, H. B.; Dou, L. J.; Chuai, X. Y.; Zhu, X. L.; Zhao, D. M.; Li, J.; Ma, X. M.; Mao, L. J.; Yang, J. C.; Yuan, Y. J.; Xu, W. Q.; Xie, L. Y.; Xu, T. H.; Yao, K.; Dong, C. Z.; Zhu, L. F.; Ma, X.

2017-10-01

Dielectronic recombination (DR) experiments of highly charged ions at the storage rings have been developed as a precision spectroscopic tool to investigate the atomic structure as well as nuclear properties of stable and unstable nuclei. The DR experiment on lithium-like argon ions was successfully performed at main Cooler Storage Ring (CSRm) at Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex. The DR experiments on heavy highly charged ions and even radioactive ions are currently under preparation at the experimental Cooler Storage Ring (CSRe) at HIRFL. The current status of DR experiments at the CSRm and the preparation of the DR experiments at the CSRe are presented. In addition, an overview of DR experiments by employing an electron cooler and a separated ultra-cold electron target at the upcoming High Intensity heavy ion Accelerator Facility (HIAF) will be given.

Bruno Touschek: From Betatrons to Electron-Positron Colliders

NASA Astrophysics Data System (ADS)

Bernardini, Carlo; Pancheri, Giulia; Pellegrini, Claudio

Bruno Touschek's life as a physicist spanned the period from World War II to the 1970s. He was a key figure in the developments of electron-positron colliders and storage rings, and made important contributions to theoretical high energy physics. Storage rings, initially developed for high energy physics, are being widely used in many countries as synchrotron radiation sources and are a tool for research in physics, chemistry, biology, environmental sciences and cultural heritage studies. We describe Touschek's life in Austria, where he was born, in Germany, where he participated in the construction of a betatron during WWII, and in Italy, where he proposed and led to completion the first electron-positron storage ring in 1960, in Frascati. We highlight how his central European culture influenced his lifestyle and work, and his main contributions to physics, such as the discovery of the Touschek effect and beam instabilities in the larger storage ring ADONE.

Bruno Touschek: From Betatrons to Electron-Positron Colliders

NASA Astrophysics Data System (ADS)

Bernardini, Carlo; Pancheri, Giulia; Pellegrini, Claudio

Bruno Touschek’s life as a physicist spanned the period from World War II to the 1970s. He was a key figure in the developments of electron-positron colliders and storage rings, and made important contributions to theoretical high energy physics. Storage rings, initially developed for high energy physics, are being widely used in many countries as synchrotron radiation sources and are a tool for research in physics, chemistry, biology, environmental sciences and cultural heritage studies. We describe Touschek’s life in Austria, where he was born, in Germany, where he participated in the construction of a betatron during WWII, and in Italy, where he proposed and led to completion the first electron-positron storage ring in 1960, in Frascati. We highlight how his central European culture influenced his lifestyle and work, and his main contributions to physics, such as the discovery of the Touschek effect and beam instabilities in the larger storage ring ADONE.

High-energy accelerator for beams of heavy ions

DOEpatents

Martin, Ronald L.; Arnold, Richard C.

1978-01-01

An apparatus for accelerating heavy ions to high energies and directing the accelerated ions at a target comprises a source of singly ionized heavy ions of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy ions, a storage ring for accumulating the accelerated heavy ions and switching means for switching the heavy ions from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy ion that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular ions, the ions are dissociated to leave an accelerated singly ionized atomic ion in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic ion to switch the beam from the storage ring by bending it in magnetic field of the storage ring.

Injection envelope matching in storage rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minty, M.G.; Spence, W.L.

1995-05-01

The shape and size of the transverse phase space injected into a storage ring can be deduced from turn-by-turn measurements of the transient behavior of the beam envelope in the ring. Envelope oscillations at 2 x the {beta}-tron frequency indicate the presence of a {beta}-mismatch, while envelope oscillations at the {beta}-tron frequency are the signature of a dispersion function mismatch. Experiments in injection optimization using synchrotron radiation imaging of the beam and a fast-gated camera at the SLC damping rings are reported.

Injection envelope matching in storage rings

NASA Astrophysics Data System (ADS)

Minty, M. G.; Spence, W. L.

1995-05-01

The shape and size of the transverse phase space injected into a storage ring can be deduced from turn-by-turn measurements of the transient behavior of the beam envelope in the ring. Envelope oscillations at 2 x the beta-tron frequency indicate the presence of a beta-mismatch, while envelope oscillations at the beta-tron frequency are the signature of a dispersion function mismatch. Experiments in injection optimization using synchrotron radiation imaging of the beam and a fast-gated camera at the SLC damping rings are reported.

Software package for modeling spin-orbit motion in storage rings

NASA Astrophysics Data System (ADS)

Zyuzin, D. V.

2015-12-01

A software package providing a graphical user interface for computer experiments on the motion of charged particle beams in accelerators, as well as analysis of obtained data, is presented. The software package was tested in the framework of the international project on electric dipole moment measurement JEDI (Jülich Electric Dipole moment Investigations). The specific features of particle spin motion imply the requirement to use a cyclic accelerator (storage ring) consisting of electrostatic elements, which makes it possible to preserve horizontal polarization for a long time. Computer experiments study the dynamics of 106-109 particles in a beam during 109 turns in an accelerator (about 1012-1015 integration steps for the equations of motion). For designing an optimal accelerator structure, a large number of computer experiments on polarized beam dynamics are required. The numerical core of the package is COSY Infinity, a program for modeling spin-orbit dynamics.

Direct Observation of Spatiotemporal Dynamics of Short Electron Bunches in Storage Rings

NASA Astrophysics Data System (ADS)

Evain, C.; Roussel, E.; Le Parquier, M.; Szwaj, C.; Tordeux, M.-A.; Brubach, J.-B.; Manceron, L.; Roy, P.; Bielawski, S.

2017-02-01

In recent synchrotron radiation facilities, the use of short (picosecond) electron bunches is a powerful method for producing giant pulses of terahertz coherent synchrotron radiation. Here we report on the first direct observation of these pulse shapes with a few picoseconds resolution, and of their dynamics over a long time. We thus confirm in a very direct way the theories predicting an interplay between two physical processes. Below a critical bunch charge, we observe a train of identical THz pulses (a broadband Terahertz comb) stemming from the shortness of the electron bunches. Above this threshold, a large part of the emission is dominated by drifting structures, which appear through spontaneous self-organization. These challenging single-shot THz recordings are made possible by using a recently developed photonic time stretch detector with a high sensitivity. The experiment has been realized at the SOLEIL storage ring.

The trigger system for the external target experiment in the HIRFL cooling storage ring

NASA Astrophysics Data System (ADS)

Li, Min; Zhao, Lei; Liu, Jin-Xin; Lu, Yi-Ming; Liu, Shu-Bin; An, Qi

2016-08-01

A trigger system was designed for the external target experiment in the Cooling Storage Ring (CSR) of the Heavy Ion Research Facility in Lanzhou (HIRFL). Considering that different detectors are scattered over a large area, the trigger system is designed based on a master-slave structure and fiber-based serial data transmission technique. The trigger logic is organized in hierarchies, and flexible reconfiguration of the trigger function is achieved based on command register access or overall field-programmable gate array (FPGA) logic on-line reconfiguration controlled by remote computers. We also conducted tests to confirm the function of the trigger electronics, and the results indicate that this trigger system works well. Supported by the National Natural Science Foundation of China (11079003), the Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-N27), and the CAS Center for Excellence in Particle Physics (CCEPP).

Status and outlook of the CRYRING@ESR project

NASA Astrophysics Data System (ADS)

Geithner, W.; Andelkovic, Z.; Beck, D.; Bräuning, H.; Bräuning-Demian, A.; Danared, H.; Dimopoulou, C.; Engström, M.; Fedotova, S.; Gorda, O.; Herfurth, F.; Hess, R.; Källberg, A.; Kleffner, C.; Kotovskiy, N.; Kraus, I.; Lestinsky, M.; Litvinov, S.; Nolden, F.; Reiter, A.; Sieber, T.; Steck, M.; Vorobyev, G.

2017-11-01

Once operational, CRYRING@ESR will store and decelerate ions delivered by the experimental storage ring ESR at energies well below those of ESR. In addition to that, CRYRING@ESR has an electron cooler operating with an ultracold electron beam, allowing to provide cooled ion beams for precision experiments. These ions will be delivered to a broad range of experiments presently in preparation; either in-ring or extracted to a dedicated beamline for experiments. An overview and status report of the installation and commissioning of the CRYRING-@ESR storage ring for highly charged ions at the GSI Helmholtzzentrum für Schwerionenforschung is presented. The installation of this storage ring started in 2014 and was completing end of 2016, when this publication was written.

Status of the Frankfurt low energy electrostatic storage ring (FLSR)

NASA Astrophysics Data System (ADS)

King, F.; Kruppi, T.; Müller, J.; Dörner, R.; Schmidt, L. Ph H.; Schmidt-Böcking, H.; Stiebing, K. E.

2015-11-01

Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections.

Analysis and correction of linear optics errors, and operational improvements in the Indus-2 storage ring

NASA Astrophysics Data System (ADS)

Husain, Riyasat; Ghodke, A. D.

2017-08-01

Estimation and correction of the optics errors in an operational storage ring is always vital to achieve the design performance. To achieve this task, the most suitable and widely used technique, called linear optics from closed orbit (LOCO) is used in almost all storage ring based synchrotron radiation sources. In this technique, based on the response matrix fit, errors in the quadrupole strengths, beam position monitor (BPM) gains, orbit corrector calibration factors etc. can be obtained. For correction of the optics, suitable changes in the quadrupole strengths can be applied through the driving currents of the quadrupole power supplies to achieve the desired optics. The LOCO code has been used at the Indus-2 storage ring for the first time. The estimation of linear beam optics errors and their correction to minimize the distortion of linear beam dynamical parameters by using the installed number of quadrupole power supplies is discussed. After the optics correction, the performance of the storage ring is improved in terms of better beam injection/accumulation, reduced beam loss during energy ramping, and improvement in beam lifetime. It is also useful in controlling the leakage in the orbit bump required for machine studies or for commissioning of new beamlines.

Low emittance electron storage rings

NASA Astrophysics Data System (ADS)

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.

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abeyratne, S; Ahmed, S; Barber, D

2012-08-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectivelymore » utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF linac will serve as a full-energy injector, and, if needed, provide top-off refilling. The CEBAF fixed-target nuclear physics program can be simultaneously operated since the filling time of the electron ring is very short. The ion complex for MEIC consists of sources for polarized light ions and unpolarized light to heavy ions, an SRF ion linac with proton energy up to 280 MeV, a 3 GeV prebooster synchrotron, a large booster synchrotron for proton energy up to 20 GeV, and a medium-energy collider ring with energy up to 100 GeV. The ion complex can accelerate other species of ions with corresponding energies at each accelerating stage. There are three collision points planned for MEIC. Two of them are for collisions with medium-energy ions; the third is for low energy ion beams stored in a dedicated low-energy compact storage ring, as a possible follow-on project.« less

Facility for Antiproton and Ion Research, FAIR, at the GSI site

NASA Astrophysics Data System (ADS)

Rosner, Guenther

2006-11-01

FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

Picosecond, tunable, high-brightness hard x-ray inverse Compton source at Duke storage ring

NASA Astrophysics Data System (ADS)

Litvinenko, Vladimir N.; Wu, Ying; Burnham, Bentley; Barnett, Genevieve A.; Madey, John M. J.

1995-09-01

We suggest a state-of-the art x-ray source using a compact electron storage ring with modest energy (less than 1 GeV) and a high power mm-wave as an undulator. A source of this type has x-ray energies and brightness comparable with third generation synchrotron light sources while it can be very compact and fit in a small university or industrial laboratory or hospital. We propose to operate an isochronous mm-wave FEL and a hard x-ray inverse Compton source at the Duke storage ring to test this concept. Resonant FEL conditions for the mm- wave will be provided by the off-axis interaction with an electromagnetic wave. A special optical resonator with holes for the e-beam is proposed for pumping a hard x-ray inverse Compton source with very high brightness. Simulation results of mm-wave FEL operation of the Duke storage ring are discussed. Expected performance of mm-wave FEL and hard x-ray inverse Compton source are presented.

The Storage Ring Proton EDM Experiment

NASA Astrophysics Data System (ADS)

Semertzidis, Yannis; Storage Ring Proton EDM Collaboration

2014-09-01

The storage ring pEDM experiment utilizes an all-electric storage ring to store ~1011 longitudinally polarized protons simultaneously in clock-wise and counter-clock-wise directions for 103 seconds. The radial E-field acts on the proton EDM for the duration of the storage time to precess its spin in the vertical plane. The ring lattice is optimized to reduce intra-beam scattering, increase the statistical sensitivity and reduce the systematic errors of the method. The main systematic error is a net radial B-field integrated around the ring causing an EDM-like vertical spin precession. The counter-rotating beams sense this integrated field and are vertically shifted by an amount, which depends on the strength of the vertical focusing in the ring, thus creating a radial B-field. Modulating the vertical focusing at 10 kHz makes possible the detection of this radial B-field by a SQUID-magnetometer (SQUID-based BPM). For a total number of n SQUID-based BPMs distributed around the ring the effectiveness of the method is limited to the N = n /2 harmonic of the background radial B-field due to the Nyquist sampling theorem limit. This limitation establishes the requirement to reduce the maximum radial B-field to 0.1-1 nT everywhere around the ring by layers of mu-metal and aluminum vacuum tube. The metho's sensitivity is 10-29 e .cm , more than three orders of magnitude better than the present neutron EDM experimental limit, making it sensitive to SUSY-like new physics mass scale up to 300 TeV.

Dose estimates for the 1104 m APS storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moe, H.J.

1989-06-01

The estimated dose equivalent rates outside the shielded storage ring, and the estimated annual dose equivalent to members of the public due to direct radiation and skyshine from the ring, have been recalculated. The previous estimates found in LS-84 (MOE 87) and cited in the 1987 Conceptual Design Report of the APS (ANL 87) required revision because of changes in the ring circumference and in the proposed location of the ring with respect to the nearest site boundary. The values assumed for the neutron quality factors were also overestimated (by a factor of 2) in the previous computation, and themore » correct values have been used for this estimate. The methodology used to compute dose and dose rate from the storage ring is the same as that used in LS-90 (MOE 87a). The calculations assumed 80 cm thick walls of ordinary concrete (or the shielding equivalent of this) and a roof thickness of 1 meter of ordinary concrete. The circumference of the ring was increased to 1,104 m, and the closest distance to the boundary was taken as 140 m. The recalculation of the skyshine component used the same methodology as that used in LS-84.« less

Perspectives on micropole undulators in synchrotron radiation technology

NASA Astrophysics Data System (ADS)

Tatchyn, Roman; Csonka, Paul; Toor, Arthur

1989-07-01

Micropole undulators promise to advance synchrotron radiation (SR) technology in two distinct ways. The first is in the development of economical, low-energy storage rings, or linacs, as soft x-ray sources, and the second is in the opening up of gamma-ray spectral ranges on high-energy storage rings. In this paper the promise and current status of micropole undulator (MPU) technology are discussed, and a review of some practical obstacles to the implementation of MPU's on present-day storage rings is given. Some successful results of recent performance measurements of micropole undulators on the Lawrence Livermore National Laboratory linac are briefly summarized.

Data Access Based on a Guide Map of the Underwater Wireless Sensor Network

PubMed Central

Wei, Zhengxian; Song, Min; Yin, Guisheng; Wang, Hongbin; Cheng, Albert M. K.

2017-01-01

Underwater wireless sensor networks (UWSNs) represent an area of increasing research interest, as data storage, discovery, and query of UWSNs are always challenging issues. In this paper, a data access based on a guide map (DAGM) method is proposed for UWSNs. In DAGM, the metadata describes the abstracts of data content and the storage location. The center ring is composed of nodes according to the shortest average data query path in the network in order to store the metadata, and the data guide map organizes, diffuses and synchronizes the metadata in the center ring, providing the most time-saving and energy-efficient data query service for the user. For this method, firstly the data is stored in the UWSN. The storage node is determined, the data is transmitted from the sensor node (data generation source) to the storage node, and the metadata is generated for it. Then, the metadata is sent to the center ring node that is the nearest to the storage node and the data guide map organizes the metadata, diffusing and synchronizing it to the other center ring nodes. Finally, when there is query data in any user node, the data guide map will select a center ring node nearest to the user to process the query sentence, and based on the shortest transmission delay and lowest energy consumption, data transmission routing is generated according to the storage location abstract in the metadata. Hence, specific application data transmission from the storage node to the user is completed. The simulation results demonstrate that DAGM has advantages with respect to data access time and network energy consumption. PMID:29039757

Data Access Based on a Guide Map of the Underwater Wireless Sensor Network.

PubMed

Wei, Zhengxian; Song, Min; Yin, Guisheng; Song, Houbing; Wang, Hongbin; Ma, Xuefei; Cheng, Albert M K

2017-10-17

Underwater wireless sensor networks (UWSNs) represent an area of increasing research interest, as data storage, discovery, and query of UWSNs are always challenging issues. In this paper, a data access based on a guide map (DAGM) method is proposed for UWSNs. In DAGM, the metadata describes the abstracts of data content and the storage location. The center ring is composed of nodes according to the shortest average data query path in the network in order to store the metadata, and the data guide map organizes, diffuses and synchronizes the metadata in the center ring, providing the most time-saving and energy-efficient data query service for the user. For this method, firstly the data is stored in the UWSN. The storage node is determined, the data is transmitted from the sensor node (data generation source) to the storage node, and the metadata is generated for it. Then, the metadata is sent to the center ring node that is the nearest to the storage node and the data guide map organizes the metadata, diffusing and synchronizing it to the other center ring nodes. Finally, when there is query data in any user node, the data guide map will select a center ring node nearest to the user to process the query sentence, and based on the shortest transmission delay and lowest energy consumption, data transmission routing is generated according to the storage location abstract in the metadata. Hence, specific application data transmission from the storage node to the user is completed. The simulation results demonstrate that DAGM has advantages with respect to data access time and network energy consumption.

Compact Storage Ring for an X-Ray Source

NASA Astrophysics Data System (ADS)

Ovchinnikova, L.; Shvedunov, V.; Ivanov, K.

2017-12-01

We propose a new design of a compact storage ring for a source of X-ray radiation on the basis of reverse Thomson scattering of laser radiation by electrons with the energy of 35-50 MeV, which has small number of optical elements and a significant clear space for the placement of a beam injection-extraction system and a RF cavity. The original laser cavity layout has been considered. The ring dynamic aperture after correction of chromaticity and a second-order dispersion function is sufficient for the injection and stable circulation of an electron bunch in the ring.

Burton Richter, Storage Rings, and the J/psi Particle

Science.gov Websites

[SLAC's] Technical Director, [Richter] became Director ... from 1984 through 1999. During his tenure, SLAC Limits of Quantum Electro-dynamics, DOE Technical Report, June 1959 Design Considerations for High Energy Electron -- Positron Storage Rings, DOE Technical Report, November 1966 Inclusive Yields of pi+, pi-, K

Patterns of Storage, Synthesis and Changing Light Levels Revealed by Carbon Isotope Microsampling within Eocene Metasequoia Tree Rings

NASA Astrophysics Data System (ADS)

Jahren, H.; Sternberg, L.

2005-12-01

Fossil tree rings from Axel Heiberg Island were microanalyzed for δ13C value in order to assess patterns of tree growth and carbon storage within the Middle Eocene (~45 Ma) Arctic paleoenvironment. Wood from four Metasequoia-type individuals was subsampled for analysis: each individual fossil consisted of between 4 and 10 large (~1 cm thick) consecutive tree rings. One of the fossils displayed an obvious concentric pattern, allowing for the determination of the direction of growth with isotopic pattern. Each ring was divided into ~1 mm thick subsamples, resulting in 5-10 δ13C value determinations per period of ring growth (i.e., growing season). All rings revealed a distinct pattern that was characteristic across growing seasons and across individual fossils. Early in the season, δ13C was at its highest value but descended systematically and sharply to its lowest value at the end of the growing season. Total decrease ranged between 3 and 5 ‰ over the course of each growing season. Identical patterns were observed in the δ13C value of alpha-cellulose isolated from each subsample, indicating that the trends observed did not represent changing levels of secondary metabolites, but rather a seasonal adjustment in the bulk source of carbon used during biosynthesis. Our results are consistent with the following annual pattern of wood synthesis 1.) complete dependence on the mobilization of stored carbon compounds early in the growing season; 2.) systematically increasing use of actively-acquired photosynthate during the growing season; 3.) complete reliance on active photosynthate by the end of the growing season. An additional and significant source of 13C discrimination is declining light levels late in the growing season, and likely contributes to the extreme pattern of δ13C decrease seen across each ring. Our results mimic those seen from modern broadleaf deciduous trees (Helle & Schlesser 2004), but differ from those seen in modern conifers (Barbour et al 2002), underlining the important influence of dormancy, storage and changing light levels on carbon cycling within the Paleogene polar forests. Helle & Schleser 2004: Plant, Cell and Environment 27:367-380. Barbour, Walcroft & Farquhar 2002: Plant, Cell and Environment 25: 1483-1499.

Mechanical capacitor

NASA Technical Reports Server (NTRS)

Kirk, J. A.; Studer, P. A.; Evans, H. E.

1976-01-01

A new energy storage system (the mechanical capacitor), using a spokeless magnetically levitated composite ring rotor, is described and design formulas for sizing the components are presented. This new system is configured around a permanent magnet (flux biased) suspension which has active servo control in the radial direction and passive control in the axial direction. The storage ring is used as a moving rotor and electronic commutation of the stationary armature coils is proposed. There is no mechanical contact with the rotating spokeless ring; therefore, long life and near zero rundown losses are projected. A 7-kW h system is sized to demonstrate feasibility. A literature review of flywheel energy storage systems is also presented and general formulas are developed for comparing rotor geometries.

MULTI-OBJECTIVE ONLINE OPTIMIZATION OF BEAM LIFETIME AT APS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yipeng

In this paper, online optimization of beam lifetime at the APS (Advanced Photon Source) storage ring is presented. A general genetic algorithm (GA) is developed and employed for some online optimizations in the APS storage ring. Sextupole magnets in 40 sectors of the APS storage ring are employed as variables for the online nonlinear beam dynamics optimization. The algorithm employs several optimization objectives and is designed to run with topup mode or beam current decay mode. Up to 50\\% improvement of beam lifetime is demonstrated, without affecting the transverse beam sizes and other relevant parameters. In some cases, the top-upmore » injection efficiency is also improved.« less

National Synchrotron Light Source annual report 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Huang, Xiaobiao

2016-05-13

Here, we propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. Finally, the method has been successfully demonstrated on the NSLS-II storage ring.

A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Huang, Xiaobiao

2016-08-01

We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. Furthermore, the fitting results are used for lattice correction. Our method has been successfully demonstrated on the NSLS-II storage ring.

A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Huang, Xiaobiao

2016-08-01

We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. The method has been successfully demonstrated on the NSLS-II storage ring.

Facility for Antiproton and Ion Research, FAIR, at the GSI site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosner, Guenther

FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ionmore » and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.« less

Resonant beam behavior studies in the Proton Storage Ring

NASA Astrophysics Data System (ADS)

Cousineau, S.; Holmes, J.; Galambos, J.; Fedotov, A.; Wei, J.; Macek, R.

2003-07-01

We present studies of space-charge-induced beam profile broadening at high intensities in the Proton Storage Ring (PSR) at Los Alamos National Laboratory. We investigate the profile broadening through detailed particle-in-cell simulations of several experiments and obtain results in good agreement with the measurements. We interpret these results within the framework of coherent resonance theory. With increasing intensity, our simulations show strong evidence for the presence of a quadrupole-mode resonance of the beam envelope with the lattice in the vertical plane. Specifically, we observe incoherent tunes crossing integer values, and large amplitude, nearly periodic envelope oscillations. At the highest operating intensities, we observe a continuing relaxation of the beam through space charge forces leading to emittance growth. The increase of emittance commences when the beam parameters encounter an envelope stop band. Once the stop band is reached, the emittance growth balances the intensity increase to maintain the beam near the stop band edge. Additionally, we investigate the potential benefit of a stop band correction to the high intensity PSR beam.

Software package for modeling spin–orbit motion in storage rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zyuzin, D. V., E-mail: d.zyuzin@fz-juelich.de

2015-12-15

A software package providing a graphical user interface for computer experiments on the motion of charged particle beams in accelerators, as well as analysis of obtained data, is presented. The software package was tested in the framework of the international project on electric dipole moment measurement JEDI (Jülich Electric Dipole moment Investigations). The specific features of particle spin motion imply the requirement to use a cyclic accelerator (storage ring) consisting of electrostatic elements, which makes it possible to preserve horizontal polarization for a long time. Computer experiments study the dynamics of 10{sup 6}–10{sup 9} particles in a beam during 10{supmore » 9} turns in an accelerator (about 10{sup 12}–10{sup 15} integration steps for the equations of motion). For designing an optimal accelerator structure, a large number of computer experiments on polarized beam dynamics are required. The numerical core of the package is COSY Infinity, a program for modeling spin–orbit dynamics.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.

Experiments at storage ring light sources as well as at next-generation light sources increasingly require detectors capable of high dynamic range operation, combining low-noise detection of single photons with large pixel well depth. XFEL sources in particular provide pulse intensities sufficiently high that a purely photon-counting approach is impractical. The High Dynamic Range Pixel Array Detector (HDR-PAD) project aims to provide a dynamic range extending from single-photon sensitivity to 10{sup 6} photons/pixel in a single XFEL pulse while maintaining the ability to tolerate a sustained flux of 10{sup 11} ph/s/pixel at a storage ring source. Achieving these goals involves themore » development of fast pixel front-end electronics as well as, in the XFEL case, leveraging the delayed charge collection due to plasma effects in the sensor. A first prototype of essential electronic components of the HDR-PAD readout ASIC, exploring different options for the pixel front-end, has been fabricated. Here, the HDR-PAD concept and preliminary design will be described.« less

The GKSS beamlines at PETRA III and DORIS III

NASA Astrophysics Data System (ADS)

Haibel, A.; Beckmann, F.; Dose, T.; Herzen, J.; Utcke, S.; Lippmann, T.; Schell, N.; Schreyer, A.

2008-08-01

Due to the high brilliance of the new storage ring PETRA III at DESY in Hamburg, the low emittance of 1 nmrad and the high fraction of coherent photons also in the hard X-ray range extremely intense and sharply focused X-ray light will be provided. These advantages of the beam fulfill excellently the qualifications for the planned Imaging BeamLine IBL and the High Energy Materials Science Beamline (HEMS) at PETRA III, i.e. for absorption tomography, phase enhanced and phase contrast experiments, for diffraction, for nano focusing, for nano tomography, and for high speed or in-situ experiments with highest spatial resolution. The existing HARWI II beamline at the DORIS III storage ring at DESY completes the GKSS beamline concept with setups for high energy tomography (16-150 keV) and diffraction (16-250 keV), characterized by a large field of view and an excellent absorption contrast with spatial resolutions down to 2 μm.

NSLS-II storage ring insertion device and front-end commissioning and operation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G., E-mail: gwang@bnl.gov; Shaftan, T.; Amundsen, C.

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. During spring/ summer of 2014, the storage ring was commissioned up to 50 mA without insertion devices. In the fall of 2014, we began commissioning of the project beamlines, which included seven insertion devices on six ID ports. Beamlines IXS, HXN, CSX-1, CSX-2, CHX, SRX, and XPD-1 consist of elliptically polarized undulator (EPU), damping wigglers (DW) and in-vacuum undulators (IVU) covering from VUV to hard x-ray range. In this paper, experience with commissioning and operation is discussed.more » We focus on reaching storage ring performance with IDs, including injection, design emittance, compensation of orbit distortions caused by ID residual field, source point stability, beam alignment and tools for control, monitoring and protection of the ring chambers from ID radiation.« less

Fluorescence decay of naphthalene studied in an electrostatic storage ring, the Mini-Ring

NASA Astrophysics Data System (ADS)

Martin, S.; Matsumoto, J.; Kono, N.; Ji, M.-C.; Brédy, R.; Bernard, J.; Cassimi, A.; Chen, L.

2017-10-01

The cooling of naphthalene cations (C10H8)+ has been studied in a compact electrostatic ion storage ring, the Mini-Ring. A nano second laser pulse of 532 nm (2.33 eV) was used to probe the internal energy distribution every millisecond during the storage time up to 5 ms. The evolution of the internal energy distribution of the stored ions was simulated with a model taking into account the dissociation and the radiative decay processes. Calculated decay curves were fitted to the corresponding laser induced neutral decays. For a laser power of 200 μJ/pulse, a good agreement between experiment and modeling was found using an initial Gaussian energy distribution centered to 5.9 eV and a fluorescence decay rate varying from 200 to 300 s-1 in the energy range from 6 to 7 eV. This fast decay was attributed to the delayed Poincaré fluorescence process.

Colliding or co-rotating ion beams in storage rings for EDM search

NASA Astrophysics Data System (ADS)

Koop, I. A.

2015-11-01

A new approach to search for and measure the electric dipole moment (EDM) of the proton, deuteron and some other light nuclei is presented. The idea of the method is to store two ion beams, circulating with different velocities, in a storage ring with crossed electric and magnetic guiding fields. One beam is polarized and its EDM is measured using the so-called ‘frozen spin’ method. The second beam, which is unpolarized, is used as a co-magnetometer, sensitive to the radial component of the ring’s magnetic field. The particle’s magnetic dipole moment (MDM) couples to the radial magnetic field and mimics the EDM signal. Measuring the relative vertical orbit separation of the two beams, caused by the presence of the radial magnetic field, one can control the unwanted MDM spin precession. Examples of the parameters for EDM storage rings for protons and other species of ions are presented. The use of crossed electric and magnetic fields helps to reduce the size of the ring by a factor of 10-20. We show that the bending radius of such an EDM storage ring could be about 2-3 m. Finally, a new method of increasing the spin coherence time, the so-called ‘spin wheel’, is proposed and its applicability to the EDM search is discussed.

Tree- Rings Link Climate and Carbon Storage in a Northern Mixed Hardwood Forest

NASA Astrophysics Data System (ADS)

Chiriboga, A.

2007-12-01

The terrestrial biosphere is a variable sink for atmospheric carbon dioxide. It is important to understand how carbon storage in trees is affected by natural climate variability to better characterize the sink. Quantifying the sensitivity of forest carbon storage to climate will improve carbon budgets and have implications for forest management practices. Here we explore how climate variability affects the ability of a northern mixed hardwood forest in Michigan to sequester atmospheric carbon dioxide in woody tissues. This site is ideal for studies of carbon sequestration; The University of Michigan Biological Station is an Ameriflux site, and has detailed meteorological and biometric records, as well as CO2 flux data. We have produced an 82- year aspen (Populus grandidentata) tree-ring chronology for this site, and measured ring widths at several heights up the bole. These measurements were used to estimate annual wood volume, which represents carbon allocated to aboveground carbon stores. Standard dendroclimatological techniques are used to identify environmental factors (e.g. temperature or precipitation) that drive tree-ring increment variability in the past century, and therefore annual carbon storage in this forest. Preliminary results show that marker years within the tree- ring chronology correspond with years that have cold spring temperatures. This suggests that trees at this site are temperature sensitive.

Beam Loss Measurements at the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Spickermann, Thomas

2005-06-01

During normal operation the Los Alamos Proton Storage Ring (PSR) accumulates up to 4ṡ1013 protons over 625μs with a repetition rate of 20 Hz, corresponding to a current of 125μA to the Lujan Neutron Science Center. Beam losses in the ring as well as in the extraction beam line and the subsequent activation of material are a limiting factor at these currents. Careful tuning of injection, ring and extraction line is paramount to limiting losses to acceptable levels. Losses are typically not uniform around the ring, but occur in significantly higher levels in certain "hot spots". Here I will report on losses related to the stripper foil which are the dominant source of losses in the ring. First results of a comparison with simulations will also be presented.

Nitrile O-ring Cracking: A Case of Vacuum Flange O-ring Failures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dees, Craig

2016-07-01

A review of recent nitrile O-ring failures in ISO-KF vacuum flange connections in glovebox applications is presented. An investigation of a single “isolated” o-ring failure leads to the discovery of cracked nitrile o-rings in a glovebox atmospheric control unit. The initial cause of the o-ring failure is attributed to ozone degradation. However, additional investigation reveals nitrile o-ring cracking on multiple gloveboxes and general purpose piping, roughly 85% of the nitrile o-rings removed for inspection show evidence of visible cracking after being in service for 18 months or less. The results of material testing and ambient air testing is presented, elevatedmore » ozone levels are not found. The contributing factors of o-ring failure, including nitrile air sensitivity, inadequate storage practices, and poor installation techniques, are discussed. A discussion of nitrile o-ring material properties, the benefits and limitations, and alternate materials are discussed. Considerations for o-ring material selection, purchasing, storage, and installation are presented in the context of lessons learned from the nitrile o-ring cracking investigation. This paper can be presented in 20 minutes and does not require special accommodations or special audio visual devices.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horan, D.

1999-04-13

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 andmore » 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.« less

Analysis of Methods to Excite Head-Tail Motion Within the Cornell Electron Storage Ring

NASA Astrophysics Data System (ADS)

Gendler, Naomi; Billing, Mike; Shanks, Jim

The main accelerator complex at Cornell consists of two rings around which electrons and positrons move: the synchrotron, where the particles are accelerated to 5 GeV, and the Storage Ring, where the particles circulate a ta Þxed energy, guided by quadrupole and dipole magnets, with a steady energy due to a sinusoidal voltage source. Keeping the beam stable in the Storage Ring is crucial for its lifetime. A long-lasting, invariable beam means more accurate experiments, as well as brighter, more focused X-rays for use in the Cornell High Energy Synchrotron Source (CHESS). The stability of the electron and positron beams in the Cornell Electron Storage Ring (CESR) is important for the development of accelerators and for usage of the beam in X-ray science and accelerator physics. Bunch oscillations tend to enlarge the beam's cross section, making it less stable. We believe that one such oscillation is ``head-tail motion,'' where the bunch rocks back and forth on a pivot located at the central particle. In this project, we write a simulation of the bunch that induces head-tail motion with a vertical driver. We also excite this motion physically in the storage ring, and observe a deÞnite head-tail signal. In the experiment, we saw a deÞnite persistence of the drive-damp signal within a small band around the head-tail frequency, indicating that the head-tail frequency is a natural vertical mode of the bunch that was being excited. The signal seen in the experiment matched the signal seen in the simulation to within an order of magnitude.

Suppressing the Coffee-Ring Effect in Semitransparent MnO2 Film for a High-Performance Solar-Powered Energy Storage Window.

PubMed

Jin, Huanyu; Qian, Jiasheng; Zhou, Limin; Yuan, Jikang; Huang, Haitao; Wang, Yu; Tang, Wing Man; Chan, Helen Lai Wa

2016-04-13

We introduce a simple and effective method to deposit a highly uniform and semitransparent MnO2 film without coffee-ring effect (CRE) by adding ethanol into MnO2 ink for transparent capacitive energy storage devices. By carefully controlling the amount of ethanol added in the MnO2 droplet, we could significantly reduce the CRE and thus improve the film uniformity. The electrochemical properties of supercapacitor (SC) devices using semitransparent MnO2 film electrodes with or without CRE were measured and compared. The SC device without CRE shows a superior capacitance, high rate capability, and lower contact resistance. The CRE-free device could achieve a considerable volumetric capacitance of 112.2 F cm(-3), resulting in a high volumetric energy density and power density of 10 mWh cm(-3) and 8.6 W cm(-3), respectively. For practical consideration, both flexible SC and large-area rigid SC devices were fabricated to demonstrate their potential for flexible transparent electronic application and capacitive energy-storage window application. Moreover, a solar-powered energy storage window which consists of a commercial solar cell and our studied semitransparent MnO2-film-based SCs was assembled. These SCs could be charged by the solar cell and light up a light emitting diode (LED), demonstrating their potential for self-powered systems and energy-efficient buildings.

Beam vacuum system of Brookhaven`s muon storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hseuth, H.C.; Snydstrup, L.; Mapes, M.

1995-11-01

A storage ring with a circumference of 45 m is being built at Brookhaven to measure the g-2 value of the muons to an accuracy of 0.35 ppm.. The beam vacuum system of the storage ring will operate at 10{sup -7} Torr and has to be completely non-magnetic. It consists of twelve sector chambers. The chambers are constructed of aluminum and are approximately 3.5 m in length with a rectangular cross-section of 16.5 cm high by 45 cm at the widest point. The design features, fabrication techniques and cleaning methods for these chambers are described. The beam vacuum system willmore » be pumped by forty eight non-magnetic distributed ion pumps with a total pumping speed of over 2000 {ell}/sec. Monte Carlo simulations of the pressure distribution in the muon storage region are presented.« less

Corrections for a constant radial magnetic field in the muon \\varvec{g}-2 and electric-dipole-moment experiments in storage rings

NASA Astrophysics Data System (ADS)

Silenko, Alexander J.

2017-10-01

We calculate the corrections for constant radial magnetic field in muon {g}-2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of {g}-2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab.

Loss-free method of charging accumulator rings

DOEpatents

Maschke, Alfred W.

1979-01-01

A method for the production of high current pulses of heavy ions having an atomic weight greater than 100. Also a linear accelerator based apparatus for carrying out said method. Pulses formed by the method of the subject invention are suitable for storage in a storage ring. The accumulated pulses may be used in inertial fusion apparatus.

National Synchrotron Light Source annual report 1991. Volume 1, October 1, 1990--September 30, 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

Low emittance lattice for the storage ring of the Turkish Light Source Facility TURKAY

NASA Astrophysics Data System (ADS)

Nergiz, Z.; Aksoy, A.

2015-06-01

The TAC (Turkish Accelerator Center) project aims to build an accelerator center in Turkey. The first stage of the project is to construct an Infra-Red Free Electron Laser (IR-FEL) facility. The second stage is to build a synchrotron radiation facility named TURKAY, which is a third generation synchrotron radiation light source that aims to achieve a high brilliance photon beam from a low emittance electron beam at 3 GeV. The electron beam parameters are highly dependent on the magnetic lattice of the storage ring. In this paper a low emittance storage ring for TURKAY is proposed and the beam dynamic properties of the magnetic lattice are investigated. Supported by Turkish Republic Ministry of Development (DPT2006K120470)

PEGASYS---A proposed internal target facility for the PEP storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Biber, K.

A proposal for an integral gas-jet target and forward spectrometer for the PEP storage ring is described. The beam structure, allowable, luminosity (L = 10/sup 33/ cm/sup /minus/2/s/sup /minus/1/ for H/sub 2/, D/sub 2/) and energy (E/sub e/ less than or equal to 15 GeV) make the ring ideal for multiparticle coincidence studies in the scaling regime, and where perturbative QCD may be an apt description of some exclusive and semi-inclusive reactions. 14 refs., 7 figs.

Feasibility of maintaining in-plane polarization for a storage ring EDM search

NASA Astrophysics Data System (ADS)

Stephenson, Edward; Storage Ring EDM Collaboration

2014-09-01

A search for an electric dipole moment (EDM) on charged particles using a storage ring requires beam polarization lifetimes approaching 1000 s for in-plane polarization. A feasibility study using beam bunching and sextupole field adjustment is underway with a 0.97-GeV/c vector-polarized deuteron beam at COSY. The polarimeter consists of a thick carbon target positioned at the edge of the beam and the EDDA scintillation detectors. The DAQ system assigns a clock time to each polarimeter event. Once calibrated against the RF-cavity, the clock time is used to select events associated with a maximal sideways polarization (precessing at 120 kHz). With this tool, the in-plane polarization magnitude is tracked versus time. Electron cooling reduces the depolarization from finite emittance and second-order momentum spread acting through synchrotron oscillations. Further lifetime improvement to the level of hundreds of seconds is achieved by adjusting sextupole fields located in the COSY ring arcs at places of large transverse beta functions and dispersion. The dependence of the reciprocal of the lifetime on sextupole field strength is nearly linear, permitting an easy location of the best field values. These typically occur near loci of zero chromaticity. A search for an electric dipole moment (EDM) on charged particles using a storage ring requires beam polarization lifetimes approaching 1000 s for in-plane polarization. A feasibility study using beam bunching and sextupole field adjustment is underway with a 0.97-GeV/c vector-polarized deuteron beam at COSY. The polarimeter consists of a thick carbon target positioned at the edge of the beam and the EDDA scintillation detectors. The DAQ system assigns a clock time to each polarimeter event. Once calibrated against the RF-cavity, the clock time is used to select events associated with a maximal sideways polarization (precessing at 120 kHz). With this tool, the in-plane polarization magnitude is tracked versus time. Electron cooling reduces the depolarization from finite emittance and second-order momentum spread acting through synchrotron oscillations. Further lifetime improvement to the level of hundreds of seconds is achieved by adjusting sextupole fields located in the COSY ring arcs at places of large transverse beta functions and dispersion. The dependence of the reciprocal of the lifetime on sextupole field strength is nearly linear, permitting an easy location of the best field values. These typically occur near loci of zero chromaticity. Supported in part by the Forschungszentrum-Juelich and the European Union.

A fast and compact electromagnetic calorimeter for the PANDA detector at FAIR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilms, Andrea

2005-10-26

In this presentation we report on the electromagnetic calorimeter of the 4{pi} detector PANDA to be installed at the antiproton storage ring of the proposed Facility for Antiproton and Ion Research (FAIR). We present details of the R and D work with two scintillator materials, PbWO4 (PWO) and BGO, and the new developed large area avalanche photodiodes (LAAPDs) as detector readout.

The EUTERPE facility

NASA Astrophysics Data System (ADS)

Botman, J. I. M.; Xi, Boling; Timmermans, C. J.; Hagedoorn, H. L.

1992-01-01

The 400-MeV electron storage ring EUTERPE is a University project set up for studies of charged particle beam dynamics and applications of synchrotron radiation, and for the education of students in these fields. The ring has a relatively large circumference for the maximum beam energy contained, which is useful for accommodating insertion devices and diagnostic tools. The critical wavelength of the emitted photon spectrum is 8.3 nm for the regular dipole magnets and 1.2 nm corresponding to 1.03 keV for a 10-T wiggler. This provides useful radiation, e.g., for x-ray fluorescence up to 3.2 keV. An undulator with a periodicity distance of 2.5 cm is planned, to generate radiation of 40 nm. The major ring components are being constructed in the University workshop, including a 70-MeV injector microtron. The main characteristics of the machine and the present status are reported. Future options include a bypass system for microdevices.

Integrating CO₂ storage with geothermal resources for dispatchable renewable electricity

DOE PAGES

Buscheck, Thomas A.; Bielicki, Jeffrey M.; Chen, Mingjie; ...

2014-12-31

We present an approach that uses the huge fluid and thermal storage capacity of the subsurface, together with geologic CO₂ storage, to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources, as well as energy from electrical grids. Captured CO₂ is injected into saline aquifers to store pressure, generate artesian flow of brine, and provide an additional working fluid for efficient heat extraction and power conversion. Concentric rings of injection and production wells are used to create a hydraulic divide to store pressure, CO₂, and thermal energy. Such storage can take excess power frommore » the grid and excess/waste thermal energy, and dispatch that energy when it is demanded, enabling increased penetration of variable renewables. Stored CO₂ functions as a cushion gas to provide enormous pressure-storage capacity and displaces large quantities of brine, which can be desalinated and/or treated for a variety of beneficial uses.« less

BEAM DIAGNOSTICS USING BPM SIGNALS FROM INJECTED AND STORED BEAMS IN A STORAGE RING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G.M.; Shaftan; T.

2011-03-28

Many modern light sources are operating in top-off injection mode or are being upgraded to top-off injection mode. The storage ring always has the stored beam and injected beam for top-off injection mode. So the BPM data is the mixture of both beam positions and the injected beam position cannot be measured directly. We propose to use dedicated wide band BPM electronics in the NSLS II storage ring to retrieve the injected beam trajectory with the singular value decomposition (SVD) method. The beam position monitor (BPM) has the capability to measure bunch-by-bunch beam position. Similar electronics can be used tomore » measure the bunch-by-bunch beam current which is necessary to get the injection beam position. The measurement precision of current needs to be evaluated since button BPM sum signal has position dependence. The injected beam trajectory can be measured and monitored all the time without dumping the stored beam. We can adjust and optimize the injected beam trajectory to maximize the injection efficiency. We can also measure the storage ring acceptance by mapping the injected beam trajectory.« less

First storage of ion beams in the Double Electrostatic Ion-Ring Experiment: DESIREE.

PubMed

Schmidt, H T; Thomas, R D; Gatchell, M; Rosén, S; Reinhed, P; Löfgren, P; Brännholm, L; Blom, M; Björkhage, M; Bäckström, E; Alexander, J D; Leontein, S; Hanstorp, D; Zettergren, H; Liljeby, L; Källberg, A; Simonsson, A; Hellberg, F; Mannervik, S; Larsson, M; Geppert, W D; Rensfelt, K G; Danared, H; Paál, A; Masuda, M; Halldén, P; Andler, G; Stockett, M H; Chen, T; Källersjö, G; Weimer, J; Hansen, K; Hartman, H; Cederquist, H

2013-05-01

We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C(n)(-), n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2 (-) molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s ± 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10(-14) mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.

Beam position monitoring system at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Bergan, W. F.; Forster, M. J.; Meller, R. E.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Palmer, M. A.; Holtzapple, R. L.

2017-09-01

The Cornell Electron-positron Storage Ring (CESR) has been converted from a High Energy Physics electron-positron collider to operate as a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS) and to conduct accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Some of the specific topics that were targeted for the initial phase of operation of the storage ring in this mode, labeled CESRTA (CESR as a Test Accelerator), included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CESRTA occurred over a several year period and is described elsewhere. As a part of this conversion the CESR beam position monitoring (CBPM) system was completely upgraded to provide the needed instrumental capabilities for these studies. This paper describes the new CBPM system hardware, its function and representative measurements performed by the upgraded system.

The MAX IV storage ring project

PubMed Central

Tavares, Pedro F.; Leemann, Simon C.; Sjöström, Magnus; Andersson, Åke

2014-01-01

The MAX IV facility, currently under construction in Lund, Sweden, features two electron storage rings operated at 3 GeV and 1.5 GeV and optimized for the hard X-ray and soft X-ray/VUV spectral ranges, respectively. A 3 GeV linear accelerator serves as a full-energy injector into both rings as well as a driver for a short-pulse facility, in which undulators produce X-ray pulses as short as 100 fs. The 3 GeV ring employs a multibend achromat (MBA) lattice to achieve, in a relatively short circumference of 528 m, a bare lattice emittance of 0.33 nm rad, which reduces to 0.2 nm rad as insertion devices are added. The engineering implementation of the MBA lattice raises several technological problems. The large number of strong magnets per achromat calls for a compact design featuring small-gap combined-function magnets grouped into cells and sharing a common iron yoke. The small apertures lead to a low-conductance vacuum chamber design that relies on the chamber itself as a distributed copper absorber for the heat deposited by synchrotron radiation, while non-evaporable getter (NEG) coating provides for reduced photodesorption yields and distributed pumping. Finally, a low main frequency (100 MHz) is chosen for the RF system yielding long bunches, which are further elongated by passively operated third-harmonic Landau cavities, thus alleviating collective effects, both coherent (e.g. resistive wall instabilities) and incoherent (intrabeam scattering). In this paper, we focus on the MAX IV 3 GeV ring and present the lattice design as well as the engineering solutions to the challenges inherent to such a design. As the first realisation of a light source based on the MBA concept, the MAX IV 3 GeV ring offers an opportunity for validation of concepts that are likely to be essential ingredients of future diffraction-limited light sources. PMID:25177978

Preliminary study of injection transients in the TPS storage ring

NASA Astrophysics Data System (ADS)

Chen, C. H.; Liu, Y. C.; Y Chen, J.; Chiu, M. S.; Tseng, F. H.; Fann, S.; Liang, C. C.; Huang, C. S.; Y Lee, T.; Y Chen, B.; Tsai, H. J.; Luo, G. H.; Kuo, C. C.

2017-07-01

An optimized injection efficiency is related to a perfect match between the pulsed magnetic fields in the storage ring and transfer line extraction in the TPS. However, misalignment errors, hardware output errors and leakage fields are unavoidable. We study the influence of injection transients on the stored TPS beam and discuss solutions to compensate these. Related simulations and measurements will be presented.

Vacuum system for room temperature X-ray lithography source (XLS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schuchman, J.C.

1988-09-30

A prototype room-temperature X-Ray Lithography Source (XLS)was proposed to be built at Brookhaven National Laboratory as part of a technology-transfer- to-American-industry program. The overall machine comprises a full energy linac, a 170 meter long transport line, and a 39 meter circumference storage ring. The scope of this paper will be limited to describing the storage ring vacuum system. (AIP)

Vacuum system for room temperature X-ray lithography source (XLS)

NASA Astrophysics Data System (ADS)

Schuchman, J. C.

1988-09-01

A prototype room-temperature X-Ray Lithography Source (XLS)was proposed to be built at Brookhaven National Laboratory as part of a technology-transfer- to-American-industry program. The overall machine comprises a full energy linac, a 170 meter long transport line, and a 39 meter circumference storage ring. The scope of this paper will be limited to describing the storage ring vacuum system. (AIP)

Generalized Stability Conditions for an Ultra-Low Energy Electrostatic Charged Particle Storage Ring

NASA Astrophysics Data System (ADS)

Sullivan, Michael

A low energy (~50 eV) electrostatic storage ring has been constructed that can store a recirculating bunch of either electrons or ions. The charged particle bunch 'orbits' within an apparatus consisting of four lenses and two hemispherical deflector analysers, arranged in a 'race-track' configuration of length 64.1 cm. A theoretical study, using transfer matrices from charged particle optics for a 'symmetric' configuration of lens potentials, has been previously completed by Hammond et al. [New J. Phys. 11 (2009) 043033]. That approach was capable of predicting modes of storage which appeared as a resonant-like pattern. An 'asymmetric' configuration, new in this work and extending the previous study to apply to a more general case, has been completed and will be presented alongside experimental results. The level of agreement between the theoretical and experimental results is found to be excellent, and the robustness of the matrix formalism has eliminated the need to rely on computer simulation to achieve storage. This asymmetric arrangement of the lenses allows for greater flexibility in the operation of the ring, creating the potential for a more diverse range of applications and potentially aid in the design of future rings. Several spectra for both electrons and positive ions are presented to provide an indication as to how the charged particle bunch evolves as more orbits are completed. The number of counts inevitably decreases as a function of orbit number due to loss mechanisms. Enhanced measurement techniques, as well as the matrix theory, have made storage of the bunch for over a hundred orbits routine, corresponding to over 65 m travelled, and this is observed directly from the spectra. The application of the storage ring as a multi-pass time-of-flight mass spectrometer has been studied. The isotopes of krypton and xenon have been made to completely separate from one another out of a single pulse of ions. This is observed to occur after ~15 orbits of the ring, roughly 10 m of distance. Initial results have indicated that the mass resolution is approximately 5000. Limitations and potential improvements to the mass resolution are presented.

Measurement of Systematic Error Effects for a Sensitive Storage Ring EDM Polarimeter

NASA Astrophysics Data System (ADS)

Imig, Astrid; Stephenson, Edward

2009-10-01

The Storage Ring EDM Collaboration was using the Cooler Synchrotron (COSY) and the EDDA detector at the Forschungszentrum J"ulich to explore systematic errors in very sensitive storage-ring polarization measurements. Polarized deuterons of 235 MeV were used. The analyzer target was a block of 17 mm thick carbon placed close to the beam so that white noise applied to upstream electrostatic plates increases the vertical phase space of the beam, allowing deuterons to strike the front face of the block. For a detector acceptance that covers laboratory angles larger than 9 ^o, the efficiency for particles to scatter into the polarimeter detectors was about 0.1% (all directions) and the vector analyzing power was about 0.2. Measurements were made of the sensitivity of the polarization measurement to beam position and angle. Both vector and tensor asymmetries were measured using beams with both vector and tensor polarization. Effects were seen that depend upon both the beam geometry and the data rate in the detectors.

Feasibility of a ring FEL at low emittance storage rings

NASA Astrophysics Data System (ADS)

Agapov, I.

2015-09-01

A scheme for generating coherent radiation at latest generation low emittance storage rings such as PETRA III at DESY (Balewski et al., 2004 [1]) is proposed. The scheme is based on focusing and subsequent defocusing of the electron beam in the longitudinal phase space at the undulator location. The expected performance characteristics are estimated for radiation in the wavelength range of 500-1500 eV. It is shown that the average brightness is increased by several orders of magnitude compared to spontaneous undulator radiation, which can open new perspectives for photon-hungry soft X-ray spectroscopy techniques.

PEGASYS: A proposed internal target-spectrometer facility for the PEP storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Bibber, K.

A proposal for an internal gas-jet target and forward spectrometer for the PEP storage ring is described. The beam structure, allowable luminosity (L=10/sup 33/ cm/sup /minus/2/s/sup /minus/1/ for H/sub 2/, D/sub 2/ decreasing as Z/sup /minus/1.75/ for nuclear targets) and energy (E/sub e/less than or equal to 15 GeV) make the ring ideal for multiparticle coincidence studies in the scaling regime, and where perturbative QCD may be an apt description of some exclusive and semi-inclusive reactions. 17 refs., 5 figs.

Optimizing a synchrotron based x-ray lithography system for IC manufacturing

NASA Astrophysics Data System (ADS)

Kovacs, Stephen; Speiser, Kenneth; Thaw, Winston; Heese, Richard N.

1990-05-01

The electron storage ring is a realistic solution as a radiation source for production grade, industrial X-ray lithography system. Today several large scale plans are in motion to design and implement synchrotron storage rings of different types for this purpose in the USA and abroad. Most of the scientific and technological problems related to the physics, design and manufacturing engineering, and commissioning of these systems for microlithography have been resolved or are under extensive study. However, investigation on issues connected to application of Synchrotron Orbit Radiation (SOR ) in chip production environment has been somewhat neglected. In this paper we have filled this gap pointing out direct effects of some basic synchrotron design parameters and associated subsystems (injector, X-ray beam line) on the operation and cost of lithography in production. The following factors were considered: synchrotron configuration, injection energy, beam intensity variability, number of beam lines and wafer exposure concept. A cost model has been worked out and applied to three different X-ray Lithography Source (XLS) systems. The results of these applications are compared and conclusions drawn.

Coherent infrared radiation from the ALS generated via femtosecond laser modulation of the electron beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrd, J.M.; Hao, Z.; Martin, M.C.

2004-07-01

Interaction of an electron beam with a femtosecond laser pulse co-propagating through a wiggler at the ALS produces large modulation of the electron energies within a short {approx}100 fs slice of the electron bunch. Propagating around the storage ring, this bunch develops a longitudinal density perturbation due to the dispersion of electron trajectories. The length of the perturbation evolves with a distance from the wiggler but is much shorter than the electron bunch length. This perturbation causes the electron bunch to emit short pulses of temporally and spatially coherent infrared light which are automatically synchronized to the modulating laser. Themore » intensity and spectra of the infrared light were measured in two storage ring locations for a nominal ALS lattice and for an experimental lattice with the higher momentum compaction factor. The onset of instability stimulated by laser e-beam interaction had been discovered. The infrared signal is now routinely used as a sensitive monitor for a fine tuning of the laser beam alignment during data accumulation in the experiments with femtosecond x-ray pulses.« less

Future Facility: FAIR at GSI

NASA Astrophysics Data System (ADS)

Rosner, Guenther

2007-05-01

The Facility for Antiproton and Ion Research, FAIR, is a new particle accelerator facility to be built at the GSI site in Germany. The research at FAIR will cover a wide range of topics in nuclear and hadron physics, high density plasma and atomic physics, and applications in condensed matter physics and biology. A 1.1 km circumference double ring of rapidly cycling 100 and 300 Tm synchrotrons, will be FAIR's central accelerator system. It will be used to produce, inter alia, high intensity secondary beams of antiprotons and short-lived radioactive nuclei. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experiments are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mcwilliams, A. J.; Daugherty, W. L.; Skidmore, T. E.

The 9975 Type B shipping package is used within the DOE complex for shipping special nuclear materials. This package is re-certified annually in accordance with Safety Analysis Report for Packaging (SARP) requirements. The package is also used at the Savannah River Site as part of the long-term storage configuration of special nuclear materials. As such, the packages do not undergo annual recertification during storage, with uncertainty as to how long some of the package components will meet their functional requirements in the storage environment. The packages are currently approved for up to 15 years storage, and work continues to providemore » a technical basis to extend that period. This report describes efforts by the Savannah River National Laboratory (SRNL) to extend the service life estimate of Viton® GLT and GLT-S fluoroelastomer O-rings used in the 9975 shipping package. O-rings of both GLT and GLT-S compositions are undergoing accelerated aging at elevated temperature, and are periodically tested for compression stress relaxation (CSR) behavior. The CSR behavior of O-rings was evaluated at temperatures from 175 to 400 °F. These collective data were used to develop predictive models for extrapolation of CSR behavior to relevant service temperatures (< 156 °F). The predictive model developed from the CSR data conservatively indicates a service life of approximately 37 years for Viton GLT O-rings at the maximum effective service temperature of 156 °F. The estimated service life for Viton GLT-S O-rings is significantly longer.« less

Ringing in the new physics: The politics and technology of electron colliders in the United States, 1956--1972

NASA Astrophysics Data System (ADS)

Paris, Elizabeth

The ``November Revolution'' of 1974 and the experiments that followed consolidated the place of the Standard Model in modern particle physics. Much of the evidence on which these conclusions depended was generated by a new type of tool: colliding beam storage rings, which had been considered physically unfeasible twenty years earlier. In 1956 a young experimentalist named Gerry O'Neill dedicated himself to demonstrating that such an apparatus could do useful physics. The storage ring movement encountered numerous obstacles before generating one of the standard machines for high energy research. In fact, it wasn't until 1970 that the U.S. finally broke ground on its first electron-positron collider. Drawing extensively on archival sources and supplementing them with the personal accounts of many of the individuals who took part, Ringing in the New Physics examines this instance of post-World War II techno-science and the new social, political and scientific tensions that characterize it. The motivations are twofold: first, that the chronicle of storage rings may take its place beside mathematical group theory, computer simulations, magnetic spark chambers, and the like as an important contributor to a view of matter and energy which has been the dominant model for the last twenty-five years. In addition, the account provides a case study for the integration of the personal, professional, institutional, and material worlds when examining an episode in the history or sociology of twentieth century science. The story behind the technological development of storage rings holds fascinating insights into the relationship between theory and experiment, collaboration and competition in the physics community, the way scientists obtain funding and their responsibilities to it, and the very nature of what constitutes ``successful'' science in the post- World War II era.

Experimental Evidence for the Los Alamos Proton Storage Ring Beam Instability

NASA Astrophysics Data System (ADS)

Plum, M.; Fitzgerald, D. H.; Macek, R.; Sander, O.; Thiessen, H. A.; Wang, T. S.; Wilkinson, C.

1997-05-01

Although the exact instability mechanism at the Proton Storage Ring (PSR) has not yet been conclusively identified, the evidence gathered to date is consistent with an e-p instability. We have recently acquired new data which shows that clearing electrodes significantly affect the instability threshold. A set of comprehensive measurements is also planned for the first months of 1997. In this paper we will present our latest data.

Fundamentals of Coherent Synchrotron Radiation in Storage Rings

NASA Astrophysics Data System (ADS)

Sannibale, F.; Byrd, J. M.; Loftsdottir, A.; Martin, M. C.; Venturini, M.

2004-05-01

We present the fundamental concepts for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The analysis includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use these concepts to optimize the performance of a source for CSR emission.

Something old, something new: Why models need a multi-pool representation of storage reserves

NASA Astrophysics Data System (ADS)

Richardson, Andrew; Carbone, Mariah

2015-04-01

We know surprisingly little about processes regulating the allocation of photosynthetic assimilates to growth, storage, and other metabolic functions. Storage of nonstructural carbon (NSC, principally sugars and starch) is critically important for woody plants, because these reserves enable sessile, long-lived organisms to tolerate biotic and abiotic stress, including pests, disturbance, and drought. But, critical questions about the size and turnover of these reserves remain unanswered. Labeling studies have generally shown rapid use of new (labeled) NSC and inferred fast mixing between old and new NSC, both of which suggest quick turnover of storage reserves. However, recent studies have shown that some of the reserves stored in stem and root tissue are not only a decade old, but also still available to support new tissue growth following catastrophic disturbance. We characterized the distribution of NSC in the stemwood, branches, and roots of two temperate trees, and we used the continuous label offered by the radiocarbon (14C) bomb spike to estimate the mean age of NSC in different tissues of two temperate trees. NSC in branches and outermost stemwood growth rings had the 14C signature of the current growing season. However, NSC in older above- and below-ground tissues was enriched in 14C, indicating that it was produced from older assimilates. Radial patterns of 14C in stemwood NSC showed strong mixing of NSC across the youngest growth rings, with limited "mixing in" of younger NSC to older rings. Sugars in the outermost 5 growth rings, accounting for two-thirds of the stemwood pool, had a mean age < 1 y, whereas sugars in older growth rings had a mean age > 5 y. Thus, there is not a single, well-mixed "storage pool," and indeed "young" and "old" storage compounds appear to be physically isolated from each other. We will discuss the implications of these results for improving model representation of NSC storage and consumption by forest trees. We will suggest that there are conceptual similarities between modeling NSC pools and modeling soil C pools. We will propose future directions for modeling NSCs and also identify key questions that still need to be answered with new experimental work.

The Potential-Well Distortion Effect and Coherent Instabilities of Electron Bunches in Storage Rings

NASA Astrophysics Data System (ADS)

Korchuganov, V. N.; Smygacheva, A. S.; Fomin, E. A.

2018-05-01

The effect of electromagnetic interaction between electron bunches and the vacuum chamber of a storage ring on the longitudinal motion of bunches is studied. Specifically, the potential-well distortion effect and the so-called coherent instabilities of coupled bunches are considered. An approximate analytical solution for the frequencies of incoherent oscillations of bunches distributed arbitrarily within the ring is obtained for a distorted potential well. A new approach to determining frequencies of coherent oscillations and an approximate analytical relation for estimating the stability of a system of bunches as a function of their distribution in the accelerator orbit are presented.

First results from the AMY detector at Tristan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imlay, R.

1987-08-01

Bhabha scattering and multi-hadronic e/sup +/e/sup -/ annihilation events have been observed in the AMY detector at ..sqrt..s = 500 GeV at the TRISTAN e/sup +/e/sup -/ storage ring. Here the authors report the results of a preliminary analysis of the properties of these events. Of particular note is one event that contains a high energy, isolated gamma ray together with a large amount of missing momentum that penetrates the fiducial volume of the detector.

Unclassified Publications of Lincoln Laboratory, 1 January - 31 December 1995; Volume 21.

DTIC Science & Technology

1995-12-01

Air Defense Systems Weiner, S.D. Cebula , D.P. 27 Nov. 1995 ADA301812 1024 Temperature Dependence of Large Polaron Superconductivity Dionne, G.F...No. 2, April 1995, pp. 534-542 6853 Laser Physics Kelley, P.L. Chapter in Zayhowski, JJ . Encyclopedia of Applied Physics, Vol. 8, 1994, pp. 299...Diode Lasers Fabricated by ECR-JJ3AE 7127A Stability and Timing Maintenance in Soliton Transmission and Storage Rings Zayhowski, JJ

The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 1: overview

NASA Astrophysics Data System (ADS)

Billing, M. G.

2015-07-01

Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper outlines the motivation, design and conversion of CESR to a test accelerator, CESRTA, enhanced to study such subjects as low emittance tuning methods, electron cloud (EC) effects, intra-beam scattering, fast ion instabilities as well as general improvements to beam instrumentation. While the initial studies of CESRTA focussed on questions related to the International Linear Collider (ILC) damping ring design, CESRTA is a very flexible storage ring, capable of studying a wide range of accelerator physics and instrumentation questions. This paper contains the outline and the basis for a set of papers documenting the reconfiguration of the storage ring and the associated instrumentation required for the studies described above. Further details may be found in these papers.

Theoretical study of hydrogen storage in a truncated triangular pyramid molecule consisting of pyridine and benzene rings bridged by vinylene groups

NASA Astrophysics Data System (ADS)

Ishikawa, Shigeru; Nemoto, Tetsushi; Yamabe, Tokio

2018-06-01

Hydrogen storage in a truncated triangular pyramid molecule C33H21N3, which consists of three pyridine rings and one benzene ring bridged by six vinylene groups, is studied by quantum chemical methods. The molecule is derived by substituting three benzene rings in a truncated tetrahedron hydrocarbon C36H24 with pyridine rings. The optimized molecular structure under C 3v symmetry shows no imaginary vibrational modes at the B3LYP/cc-pVTZ level of theory. The hydrogen storage process is investigated based on the MP2/cc-pVTZ method. Like the structure before substitution, the C33H21N3 molecule has a cavity that stores a hydrogen molecule with a binding energy of - 140 meV. The Langmuir isotherm shows that this cavity can store hydrogen at higher temperatures and lower pressures than usual physisorption materials. The C33H21N3 molecule has a kinetic advantage over the C36H24 molecule because the former molecule has a lower barrier (+ 560 meV) for the hydrogen molecule entering the cavity compared with the latter molecule (+ 730 meV) owing to the lack of hydrogen atoms narrowing the opening.

Electron-cloud updated simulation results for the PSR, and recent results for the SNS

NASA Astrophysics Data System (ADS)

Pivi, M.; Furman, M. A.

2002-05-01

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 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.

BPM Breakdown Potential in the PEP-II B-factory Storage Ring Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weathersby, Stephen; Novokhatski, Alexander; /SLAC

2010-02-10

High current B-Factory BPM designs incorporate a button type electrode which introduces a small gap between the button and the beam chamber. For achievable currents and bunch lengths, simulations indicate that electric potentials can be induced in this gap which are comparable to the breakdown voltage. This study characterizes beam induced voltages in the existing PEP-II storage ring collider BPM as a function of bunch length and beam current.

Multi-objective dynamic aperture optimization for storage rings

DOE PAGES

Li, Yongjun; Yang, Lingyun

2016-11-30

We report an efficient dynamic aperture (DA) optimization approach using multiobjective genetic algorithm (MOGA), which is driven by nonlinear driving terms computation. It was found that having small low order driving terms is a necessary but insufficient condition of having a decent DA. Then direct DA tracking simulation is implemented among the last generation candidates to select the best solutions. The approach was demonstrated successfully in optimizing NSLS-II storage ring DA.

Towards a 4{sup th} generation storage ring at the Canadian Light Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dallin, Les; Wurtz, Ward

2016-07-27

Demands from beamline scientists for more brilliant sources of synchrotron radiation have resulted in the emergence of 4{sup th} generation (diffraction-limited) storage rings. The practical development of the multi-bend achromat (MBA) concept by MAX IV lab has spurred many synchrotron light sources around the world to develop similar machines. For existing facilities two options are available: upgrading existing machines or building a new structure. The Canadian Light Source (CLS) has explored both options. For a new low emittance source in the existing CLS tunnel a decrease in electron energy would be required. A machine similar to the ALS upgrade couldmore » be contemplated. To achieve low emittance at our present energy of 2.9 GeV a new storage ring is desirable. Several options have been investigated. These designs use extremely strong focusing magnets to achieve extremely low emittances in compact lattice achromats.« less

Preparing the MAX IV storage rings for timing-based experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stråhlman, C., E-mail: Christian.Strahlman@maxlab.lu.se; Olsson, T., E-mail: Teresia.Olsson@maxlab.lu.se; Leemann, S. C.

2016-07-27

Time-resolved experimental techniques are increasingly abundant at storage ring facilities. Recent developments in accelerator technology and beamline instrumentation allow for simultaneous operation of high-intensity and timing-based experiments. The MAX IV facility is a state-of-the-art synchrotron light source in Lund, Sweden, that will come into operation in 2016. As many storage ring facilities are pursuing upgrade programs employing strong-focusing multibend achromats and passive harmonic cavities (HCs) in high-current operation, it is of broad interest to study the accelerator and instrumentation developments required to enable timing-based experiments at such machines. In particular, the use of hybrid filling modes combined with pulse pickingmore » by resonant excitation or pseudo single bunch has shown promising results. These methods can be combined with novel beamline instrumentation, such as choppers and instrument gating. In this paper we discuss how these techniques can be implemented and employed at MAX IV.« less

Upgrading the Digital Electronics of the PEP-II Bunch Current Monitors at the Stanford Linear Accelerator Center

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kline, Josh; /SLAC

2006-08-28

The testing of the upgrade prototype for the bunch current monitors (BCMs) in the PEP-II storage rings at the Stanford Linear Accelerator Center (SLAC) is the topic of this paper. Bunch current monitors are used to measure the charge in the electron/positron bunches traveling in particle storage rings. The BCMs in the PEP-II storage rings need to be upgraded because components of the current system have failed and are known to be failure prone with age, and several of the integrated chips are no longer produced making repairs difficult if not impossible. The main upgrade is replacing twelve old (1995)more » field programmable gate arrays (FPGAs) with a single Virtex II FPGA. The prototype was tested using computer synthesis tools, a commercial signal generator, and a fast pulse generator.« less

X-ray nanoprobes and diffraction-limited storage rings: opportunities and challenges of fluorescence tomography of biological specimens

PubMed Central

de Jonge, Martin D.; Ryan, Christopher G.; Jacobsen, Chris J.

2014-01-01

X-ray nanoprobes require coherent illumination to achieve optic-limited resolution, and so will benefit directly from diffraction-limited storage rings. Here, the example of high-resolution X-ray fluorescence tomography is focused on as one of the most voracious demanders of coherent photons, since the detected signal is only a small fraction of the incident flux. Alternative schemes are considered for beam delivery, sample scanning and detectors. One must consider as well the steps before and after the X-ray experiment: sample preparation and examination conditions, and analysis complexity due to minimum dose requirements and self-absorption. By understanding the requirements and opportunities for nanoscale fluorescence tomography, one gains insight into the R&D challenges in optics and instrumentation needed to fully exploit the source advances that diffraction-limited storage rings offer. PMID:25177992

Collective electron driven linac for high energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seeman, J.T.

1983-08-01

A linac design is presented in which an intense ultrarelativistic electron bunch is used to excite fields in a series of cavities and accelerate charged particles. The intense electron bunch is generated in a simple storage ring to have the required transverse and longitudinal dimensions. The bunch is then transferred to the linac. The linac structure can be inexpensively constructed of spacers and washers. The fields in the cells resulting from the bunch passage are calculated using the program BCI. The results show that certain particles within the driving bunch and also trailing particles of any sign charge can bemore » accelerated. With existing electron storage rings, accelerating gradients greater than 16 MV/m are possible. Examples of two accelerators are given: a 30 GeV electron/positron accelerator useful as an injector for a high energy storage ring and 2) a 110 GeV per beam electron-positron collider.« less

Modeling Systematic Error Effects for a Sensitive Storage Ring EDM Polarimeter

NASA Astrophysics Data System (ADS)

Stephenson, Edward; Imig, Astrid

2009-10-01

The Storage Ring EDM Collaboration has obtained a set of measurements detailing the sensitivity of a storage ring polarimeter for deuterons to small geometrical and rate changes. Various schemes, such as the calculation of the cross ratio [1], can cancel effects due to detector acceptance differences and luminosity differences for states of opposite polarization. Such schemes fail at second-order in the errors, becoming sensitive to geometrical changes, polarization magnitude differences between opposite polarization states, and changes to the detector response with changing data rates. An expansion of the polarimeter response in a Taylor series based on small errors about the polarimeter operating point can parametrize such effects, primarily in terms of the logarithmic derivatives of the cross section and analyzing power. A comparison will be made to measurements obtained with the EDDA detector at COSY-J"ulich. [4pt] [1] G.G. Ohlsen and P.W. Keaton, Jr., NIM 109, 41 (1973).

Symplectic orbit and spin tracking code for all-electric storage rings

NASA Astrophysics Data System (ADS)

Talman, Richard M.; Talman, John D.

2015-07-01

Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring "trap." At the "magic" kinetic energy of 232.792 MeV, proton spins are "frozen," for example always parallel to the instantaneous particle momentum. Energy deviation from the magic value causes in-plane precession of the spin relative to the momentum. Any nonzero EDM value will cause out-of-plane precession—measuring this precession is the basis for the EDM determination. A proposed implementation of this measurement shows that a proton EDM value of 10-29e -cm or greater will produce a statistically significant, measurable precession after multiply repeated runs, assuming small beam depolarization during 1000 s runs, with high enough precision to test models of the early universe developed to account for the present day particle/antiparticle population imbalance. This paper describes an accelerator simulation code, eteapot, a new component of the Unified Accelerator Libraries (ual), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the nonconstant particle velocity in electric rings gives them significantly different properties, especially in weak focusing rings. Like the earlier code teapot (for magnetic ring simulation) this code performs exact tracking in an idealized (approximate) lattice rather than the more conventional approach, which is approximate tracking in a more nearly exact lattice. The Bargmann-Michel-Telegdi (BMT) equation describing the evolution of spin vectors through idealized bend elements is also solved exactly—original to this paper. Furthermore the idealization permits the code to be exactly symplectic (with no artificial "symplectification"). Any residual spurious damping or antidamping is sufficiently small to permit reliable tracking for the long times, such as the 1000 s assumed in estimating the achievable EDM precision. This paper documents in detail the theoretical formulation implemented in eteapot. An accompanying paper describes the practical application of the eteapot code in the Universal Accelerator Libraries (ual) environment to "resurrect," or reverse engineer, the "AGS-analog" all-electric ring built at Brookhaven National Laboratory in 1954. Of the (very few) all-electric rings ever commissioned, the AGS-analog ring is the only relativistic one and is the closest to what is needed for measuring proton (or, even more so, electron) EDM's. The companion paper also describes preliminary lattice studies for the planned proton EDM storage rings as well as testing the code for long time orbit and spin tracking.

Instrumentation for the study of low emittance tuning and beam dynamics at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Dobbins, J. A.; Forster, M. J.; Kreinick, D. L.; Meller, R. E.; Peterson, D. P.; Ramirez, G. A.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Williams, H. A.; Palmer, M. A.; Holtzapple, R. L.; Flanagan, J.

2017-11-01

The Cornell Electron-positron Storage Ring (CESR) has been converted from a High Energy Physics electron-positron collider to operate as a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS) and to conduct accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Some of the specific topics that were targeted for the initial phase of operation of the storage ring in this mode for CESR as a Test Accelerator (CesrTA) included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CesrTA occurred over a several year period, described elsewhere [1-3]. In addition to instrumentation for the storage ring, which was created for CesrTA, existing instrumentation was modified to facilitate the entire range of investigations to support these studies. Procedures were developed, often requiring coordinated measurements among different instruments [4]. This paper describes the instruments utilized for the study of beam dynamics during the operation of CesrTA. The treatment of these instruments will remain fairly general in this paper as it focusses on an overview of the instruments themselves. Their interaction and inter-relationships during sequences of observations is found in a companion paper describing the associated measurement techniques. More detailed descriptions and detailed operational performance for some of the instrumentation may be found elsewhere and these will be referenced in the related sections of this paper.

The EUTERPE facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Botman, J.I.M.; Xi, B.; Timmermans, C.J.

1992-01-01

The 400-MeV electron storage ring EUTERPE is a University project set up for studies of charged particle beam dynamics and applications of synchrotron radiation, and for the education of students in these fields. The ring has a relatively large circumference for the maximum beam energy contained, which is useful for accommodating insertion devices and diagnostic tools. The critical wavelength of the emitted photon spectrum is 8.3 nm for the regular dipole magnets and 1.2 nm corresponding to 1.03 keV for a 10-T wiggler. This provides useful radiation, e.g., for x-ray fluorescence up to 3.2 keV. An undulator with a periodicitymore » distance of 2.5 cm is planned, to generate radiation of 40 nm. The major ring components are being constructed in the University workshop, including a 70-MeV injector microtron. The main characteristics of the machine and the present status are reported. Future options include a bypass system for microdevices.« less

Capturing spiral radial growth of conifers using the superellipse to model tree-ring geometric shape

PubMed Central

Shi, Pei-Jian; Huang, Jian-Guo; Hui, Cang; Grissino-Mayer, Henri D.; Tardif, Jacques C.; Zhai, Li-Hong; Wang, Fu-Sheng; Li, Bai-Lian

2015-01-01

Tree-rings are often assumed to approximate a circular shape when estimating forest productivity and carbon dynamics. However, tree rings are rarely, if ever, circular, thereby possibly resulting in under- or over-estimation in forest productivity and carbon sequestration. Given the crucial role played by tree ring data in assessing forest productivity and carbon storage within a context of global change, it is particularly important that mathematical models adequately render cross-sectional area increment derived from tree rings. We modeled the geometric shape of tree rings using the superellipse equation and checked its validation based on the theoretical simulation and six actual cross sections collected from three conifers. We found that the superellipse better describes the geometric shape of tree rings than the circle commonly used. We showed that a spiral growth trend exists on the radial section over time, which might be closely related to spiral grain along the longitudinal axis. The superellipse generally had higher accuracy than the circle in predicting the basal area increment, resulting in an improved estimate for the basal area. The superellipse may allow better assessing forest productivity and carbon storage in terrestrial forest ecosystems. PMID:26528316

Capturing spiral radial growth of conifers using the superellipse to model tree-ring geometric shape.

PubMed

Shi, Pei-Jian; Huang, Jian-Guo; Hui, Cang; Grissino-Mayer, Henri D; Tardif, Jacques C; Zhai, Li-Hong; Wang, Fu-Sheng; Li, Bai-Lian

2015-01-01

Tree-rings are often assumed to approximate a circular shape when estimating forest productivity and carbon dynamics. However, tree rings are rarely, if ever, circular, thereby possibly resulting in under- or over-estimation in forest productivity and carbon sequestration. Given the crucial role played by tree ring data in assessing forest productivity and carbon storage within a context of global change, it is particularly important that mathematical models adequately render cross-sectional area increment derived from tree rings. We modeled the geometric shape of tree rings using the superellipse equation and checked its validation based on the theoretical simulation and six actual cross sections collected from three conifers. We found that the superellipse better describes the geometric shape of tree rings than the circle commonly used. We showed that a spiral growth trend exists on the radial section over time, which might be closely related to spiral grain along the longitudinal axis. The superellipse generally had higher accuracy than the circle in predicting the basal area increment, resulting in an improved estimate for the basal area. The superellipse may allow better assessing forest productivity and carbon storage in terrestrial forest ecosystems.

Storage Rings in the Sky: Gamma Ray Bursts and Galactic Gravitational Collapse Stored Energy

NASA Astrophysics Data System (ADS)

Greyber, H. D.

2004-05-01

The recent discovery of almost 100% polarization of the prompt gamma ray emission from GRB021206, (1), confirms my 44 year old ``Strong" Magnetic Field" model (SMF) for galactic dynamics. In SMF, Storage Ring particles were accelerated long ago during the original gravitational collapse of the pregalactic/prequasar plasma cloud that is permeated by an almost uniform primordial magnetic field (2,3) The enormous, intense, slender, relativistic, stable, completely coherent Storage Ring stores a very small fraction of the huge galactic gravitational collapse energy in an almost radiationless state, unless disturbed. The concept of an Astrophysical Storage Ring was introduced by me in l961. At first it was to explain galactic structure, but soon it proved useful to explain active galactic nuclei (AGN) and the dynamics of quasar/AGN jets. AGN and galactic morphology, energetics and dynamics vary as the ratio of magnetic energy to rotational energy in the particular object. Gamma ray bursts (GRB) are due simply to a ``rock". i.e. a white dwarf, ordinary star, neutron sstar, asteroid, planet, etc. falling rapidly through the Storage Ring and being almost instantly vaporized into a hot plasma fireball, causing an electromagnetic shower (2) Then the fireball speeds into the huge organized magnetic field surrounding the current ring, thus generating very highly polarized prompt gamma ray emission (as seen in GRB021206) from the synchrotron radiation process. The timing fits the GRB observations nicely. For instance, a ``rock" racing at 1000 kilometers per second across a 20,000 km. path in the beam would produce a twenty second burst. Other times, a target might track across a short chord for a short burst. Space missions have shown that often typical currents in space plasmas are made up of slender filaments. Thus the puzzling less than one millisecond spikes observed in some GRB are simply describing the structure of that particular ring current at that particular time. 1. W. Coburn and S.E. Boggs, Nature, 423, 415, (2003) 2. H. D. Greyber in a book, After the Dark Ages: When Galaxies Were Young, eds. S.S. Holt and E. P. Smith, AIP Conference Proceedings 470, 388-396. (1998) 3. H. D. Greyber in a Space Telescope Science Institute Report: Poster Papers from their 2001 Spring Symposium, ``The Dark Universe: Matter, Energy and Gravity," ed. Mario Livio, published March 2003, (34-39)

Beamline front end for in-vacuum short period undulator at the photon factory storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyauchi, Hiroshi, E-mail: hiroshi.miyauchi@kek.jp; Department of Accelerator Science, School of High Energy Accelerator Science, SOKENDAI; Tahara, Toshihiro, E-mail: ttahara@post.kek.jp

The straight-section upgrade project of the Photon Factory created four new short straight sections capable of housing in-vacuum short period undulators. The first to fourth short period undulators SGU#17, SGU#03, SGU#01 and SGU#15 were installed at the 2.5-GeV Photon Factory storage ring in 2005, 2006, 2009 and 2013, respectively. The beamline front end for SGU#15 is described in this paper.

A storage ring experiment to detect a proton electric dipole moment

DOE PAGES

Anastassopoulos, V.; Andrianov, S.; Baartman, R.; ...

2016-11-29

We describe a new experiment to detect a permanent electric dipole moment of the proton with a sensitivity of 10 $-$29e cm by using polarized “magic” momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the Standard Model at the scale of 3000 TeV.

A storage ring experiment to detect a proton electric dipole moment.

PubMed

Anastassopoulos, V; Andrianov, S; Baartman, R; Baessler, S; Bai, M; Benante, J; Berz, M; Blaskiewicz, M; Bowcock, T; Brown, K; Casey, B; Conte, M; Crnkovic, J D; D'Imperio, N; Fanourakis, G; Fedotov, A; Fierlinger, P; Fischer, W; Gaisser, M O; Giomataris, Y; Grosse-Perdekamp, M; Guidoboni, G; Hacıömeroğlu, S; Hoffstaetter, G; Huang, H; Incagli, M; Ivanov, A; Kawall, D; Kim, Y I; King, B; Koop, I A; Lazarus, D M; Lebedev, V; Lee, M J; Lee, S; Lee, Y H; Lehrach, A; Lenisa, P; Levi Sandri, P; Luccio, A U; Lyapin, A; MacKay, W; Maier, R; Makino, K; Malitsky, N; Marciano, W J; Meng, W; Meot, F; Metodiev, E M; Miceli, L; Moricciani, D; Morse, W M; Nagaitsev, S; Nayak, S K; Orlov, Y F; Ozben, C S; Park, S T; Pesce, A; Petrakou, E; Pile, P; Podobedov, B; Polychronakos, V; Pretz, J; Ptitsyn, V; Ramberg, E; Raparia, D; Rathmann, F; Rescia, S; Roser, T; Kamal Sayed, H; Semertzidis, Y K; Senichev, Y; Sidorin, A; Silenko, A; Simos, N; Stahl, A; Stephenson, E J; Ströher, H; Syphers, M J; Talman, J; Talman, R M; Tishchenko, V; Touramanis, C; Tsoupas, N; Venanzoni, G; Vetter, K; Vlassis, S; Won, E; Zavattini, G; Zelenski, A; Zioutas, K

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10 -29 e ⋅ cm by using polarized "magic" momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

A storage ring experiment to detect a proton electric dipole moment

NASA Astrophysics Data System (ADS)

Anastassopoulos, V.; Andrianov, S.; Baartman, R.; Baessler, S.; Bai, M.; Benante, J.; Berz, M.; Blaskiewicz, M.; Bowcock, T.; Brown, K.; Casey, B.; Conte, M.; Crnkovic, J. D.; D'Imperio, N.; Fanourakis, G.; Fedotov, A.; Fierlinger, P.; Fischer, W.; Gaisser, M. O.; Giomataris, Y.; Grosse-Perdekamp, M.; Guidoboni, G.; Hacıömeroǧlu, S.; Hoffstaetter, G.; Huang, H.; Incagli, M.; Ivanov, A.; Kawall, D.; Kim, Y. I.; King, B.; Koop, I. A.; Lazarus, D. M.; Lebedev, V.; Lee, M. J.; Lee, S.; Lee, Y. H.; Lehrach, A.; Lenisa, P.; Levi Sandri, P.; Luccio, A. U.; Lyapin, A.; MacKay, W.; Maier, R.; Makino, K.; Malitsky, N.; Marciano, W. J.; Meng, W.; Meot, F.; Metodiev, E. M.; Miceli, L.; Moricciani, D.; Morse, W. M.; Nagaitsev, S.; Nayak, S. K.; Orlov, Y. F.; Ozben, C. S.; Park, S. T.; Pesce, A.; Petrakou, E.; Pile, P.; Podobedov, B.; Polychronakos, V.; Pretz, J.; Ptitsyn, V.; Ramberg, E.; Raparia, D.; Rathmann, F.; Rescia, S.; Roser, T.; Kamal Sayed, H.; Semertzidis, Y. K.; Senichev, Y.; Sidorin, A.; Silenko, A.; Simos, N.; Stahl, A.; Stephenson, E. J.; Ströher, H.; Syphers, M. J.; Talman, J.; Talman, R. M.; Tishchenko, V.; Touramanis, C.; Tsoupas, N.; Venanzoni, G.; Vetter, K.; Vlassis, S.; Won, E.; Zavattini, G.; Zelenski, A.; Zioutas, K.

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10-29 e ṡ cm by using polarized "magic" momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

FLSR - The Frankfurt low energy storage ring

NASA Astrophysics Data System (ADS)

Stiebing, K. E.; Alexandrov, V.; Dörner, R.; Enz, S.; Kazarinov, N. Yu.; Kruppi, T.; Schempp, A.; Schmidt Böcking, H.; Völp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

2010-02-01

An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut für Kernphysik der Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

Conditioning of BPM pickup signals for operations of the Duke storage ring with a wide range of single-bunch current

NASA Astrophysics Data System (ADS)

Xu, Wei; Li, Jing-Yi; Huang, Sen-Lin; Z. Wu, W.; Hao, H.; P., Wang; K. Wu, Y.

2014-10-01

The Duke storage ring is a dedicated driver for the storage ring based oscillator free-electron lasers (FELs), and the High Intensity Gamma-ray Source (HIGS). It is operated with a beam current ranging from about 1 mA to 100 mA per bunch for various operations and accelerator physics studies. High performance operations of the FEL and γ-ray source require a stable electron beam orbit, which has been realized by the global orbit feedback system. As a critical part of the orbit feedback system, the electron beam position monitors (BPMs) are required to be able to precisely measure the electron beam orbit in a wide range of the single-bunch current. However, the high peak voltage of the BPM pickups associated with high single-bunch current degrades the performance of the BPM electronics, and can potentially damage the BPM electronics. A signal conditioning method using low pass filters is developed to reduce the peak voltage to protect the BPM electronics, and to make the BPMs capable of working with a wide range of single-bunch current. Simulations and electron beam based tests are performed. The results show that the Duke storage ring BPM system is capable of providing precise orbit measurements to ensure highly stable FEL and HIGS operations.

From J. J. Thomson to FAIR, what do we learn from Large-Scale Mass and Half-Life Measurements of Bare and Few-Electron Ions?

NASA Astrophysics Data System (ADS)

Münzenberg, Gottfried; Geissel, Hans; Litvinov, Yuri A.

2010-04-01

This contribution is based on the combination of the talks: "What can we learn from large-scale mass measurements," "Present and future experiments with stored exotic nuclei at relativistic energies," and "Beta decay of highly-charged ions." Studying the nuclear mass surface gives information on the evolution of nuclear structure such as nuclear shells, the onset of deformation and the drip-lines. Previously, most of the masses far-off stability has been obtained from decay data. Modern methods allow direct mass measurements. They are much more sensitive, down to single atoms, access short-lived species and have high accuracy. Large-scale explorations of the nuclear mass surface are ideally performed with the combination of the in-flight FRagment Separator FRS and the Experimental Storage Ring ESR. After a brief historic introduction selected examples such as the evolution of shell closures far-off stability and the proton-neutron interaction will be discussed in the framework of our data. Recently, the experiments have been extended and led to the discovery of new heavy neutron-rich isotopes along with their mass and lifetime measurements. Storage rings applied at relativistic energies are a unique tool to study the radioactive decay of bare or few-electron atomic nuclei. New features observed with the analysis of stored circulating mother and daughter ions including oscillations in the decay curves of hydrogen-like nuclei will be addressed. Future experiments with NUSTAR at FAIR will further extend our knowledge to the borderlines of nuclear existence.

Observations of a fast transverse instability in the PSR

NASA Astrophysics Data System (ADS)

Neuffer, D.; Colton, E.; Fitzgerald, D.; Hardek, T.; Hutson, R.; Macek, R.; Plum, M.; Thiessen, H.; Wang, T.-S.

1992-09-01

A fast instability with beam loss is observed in the Los Alamos Proton Storage Ring (PSR) when the injected beam current exceeds a threshold value, with both bunched and unbunched beams. Large coherent transverse oscillations occur prior to and during beam loss. The threshold depends strongly on rf voltage, beam-pulse shape, beam size, nonlinear fields, and beam environmental. Results of recent observations of the instability are reported; possible causes of the instability are discussed. Recent measurements and calculations indicate that the instability is an "e-p"-type instability, driven by coupled oscillations with electrons trapped within the proton beam. Future experiments toward further understanding of the instability are discussed, and methods of increasing PSR beam storage are suggested.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.; Mcwilliams, A.; Skidmore, E.

The 9975 Type B shipping package is used within the DOE complex for shipping special nuclear materials. This package is re-certified annually in accordance with Safety Analysis Report requirements. The package is also used at the Savannah River Site as part of the long-term storage configuration of special nuclear materials. As such, the packages do not undergo annual recertification during storage, with uncertainty as to how long some of the package components will meet their functional requirements in the storage environment. The packages are currently approved for up to 15 years storage, and work continues to provide a technical basismore » to extend that period. This paper describes efforts by the Savannah River National Laboratory (SRNL) to extend the service life estimate of Viton® GLT and GLT-S fluoroelastomer O-rings used in the 9975 shipping package. O-rings of both compositions are undergoing accelerated aging at elevated temperature, and are periodically tested for compression stress relaxation (CSR) behavior and leak performance. The CSR behavior of O-rings was evaluated at temperatures from 79 °C to 177 °C. These collective data were used to develop predictive models for extrapolation of CSR behavior to relevant service temperatures (< 75 °C). O-rings were also aged in Primary Containment Vessel (PCV) fixtures at temperatures ranging from 79 °C to 232 °C. The fixtures are helium leak tested periodically to determine if they remain leak-tight. The PCV fixture tests demonstrate that the 9975 O-rings will remain leak-tight at temperatures up to 149 °C for 3 years or more, and no leak failures have been observed with up to 8 years aging at 93 °C. Significantly longer periods of leak-tight service are expected at the lower temperatures actually experienced in the storage environment. The predictive model developed from the CSR data conservatively indicates a service life of more than 20 years at the bounding temperature of 75 °C. Although the relationship between CSR behavior and leak-tight performance has not been established for this design, the CSR predictions for this O-ring are conservative relative to leak-tight performance to date.« less

Design of 3 GeV booster ring lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Etisken, O., E-mail: ozgur.etisken@cern.ch; Ciftci, A. K., E-mail: abbas.kenan.ciftci@cern.ch

2016-03-25

The aim of this study is to design of a 3 GeV booster ring for the 3 GeV storage ring. Electrons are needed to be accelerated to 3.0 GeV from 0.15 GeV energy. In this frame, we studied on two options for booster ring; a compact booster and the booster that shares the same tunnel with the storage ring. The lattice type has been chosen FODO for both options, lattice parameters are calculated, sextupole magnets are used to decrease dynamic aperture problem and dynamic aperture calculations are also made with considering of the necessary conditions. After designing and calculating ofmore » the parameters, these designs have been compared with each other. In addition to this comparison, these booster design parameters have been compared with some world centers design parameters and the reliability of the booster design is seen. Beam optics, OPA and Elegant simulation programs have been used in the study calculations.« less

Properties of the electron cloud in a high-energy positron and electron storage ring

DOE PAGES

Harkay, K. C.; Rosenberg, R. A.

2003-03-20

Low-energy, background electrons are ubiquitous in high-energy particle accelerators. Under certain conditions, interactions between this electron cloud and the high-energy beam can give rise to numerous effects that can seriously degrade the accelerator performance. These effects range from vacuum degradation to collective beam instabilities and emittance blowup. Although electron-cloud effects were first observed two decades ago in a few proton storage rings, they have in recent years been widely observed and intensely studied in positron and proton rings. Electron-cloud diagnostics developed at the Advanced Photon Source enabled for the first time detailed, direct characterization of the electron-cloud properties in amore » positron and electron storage ring. From in situ measurements of the electron flux and energy distribution at the vacuum chamber wall, electron-cloud production mechanisms and details of the beam-cloud interaction can be inferred. A significant longitudinal variation of the electron cloud is also observed, due primarily to geometrical details of the vacuum chamber. Furthermore, such experimental data can be used to provide realistic limits on key input parameters in modeling efforts, leading ultimately to greater confidence in predicting electron-cloud effects in future accelerators.« less

Efficient Computation of Coherent Synchrotron Radiation Taking into Account 6D Phase Space Distribution of Emitting Electrons

NASA Astrophysics Data System (ADS)

Chubar, O.; Couprie, M.-E.

2007-01-01

CPU-efficient method for calculation of the frequency domain electric field of Coherent Synchrotron Radiation (CSR) taking into account 6D phase space distribution of electrons in a bunch is proposed. As an application example, calculation results of the CSR emitted by an electron bunch with small longitudinal and large transverse sizes are presented. Such situation can be realized in storage rings or ERLs by transverse deflection of the electron bunches in special crab-type RF cavities, i.e. using the technique proposed for the generation of femtosecond X-ray pulses (A. Zholents et. al., 1999). The computation, performed for the parameters of the SOLEIL storage ring, shows that if the transverse size of electron bunch is larger than the diffraction limit for single-electron SR at a given wavelength — this affects the angular distribution of the CSR at this wavelength and reduces the coherent flux. Nevertheless, for transverse bunch dimensions up to several millimeters and a longitudinal bunch size smaller than hundred micrometers, the resulting CSR flux in the far infrared spectral range is still many orders of magnitude higher than the flux of incoherent SR, and therefore can be considered for practical use.

Status of NSLS-II Storage Ring Vacuum Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doom,L.; Hseuh,H.; Ferreira, M.

2009-05-04

National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3-GeV, high-flux and high- brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system will have extruded aluminium chambers with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers will be used to intercept the un-used bending magnet radiation. In-situ bakeout will be implemented to achieve fast conditioning during initial commissioning and after interventions.

Saw-tooth instability in storage rings: simulations and dynamical model

NASA Astrophysics Data System (ADS)

Migliorati, M.; Palumbo, L.; Dattoli, G.; Mezi, L.

1999-11-01

The saw-tooth instability in storage rings is studied by means of a time-domain simulation code which takes into account the self-induced wake fields. The results are compared with those from a dynamical heuristic model exploiting two coupled non-linear differential equations, accounting for the time behavior of the instability growth rate and for the anomalous growth of the energy spread. This model is shown to reproduce the characteristic features of the instability in a fairly satisfactory way.

A storage ring experiment to detect a proton electric dipole moment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anastassopoulos, V.; Andrianov, S.; Baartman, R.

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity ofmore » $$10^{-29}e\\cdot$$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the Standard Model at the scale of 3000~TeV.« less

Storage rings for spin-polarized hydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, D.; Lovelace, R.V.E.; Lee, D.

1989-11-01

A strong-focusing storage ring is proposed for the long-term magnetic confinement of a collisional gas of neutral spin-polarized hydrogen atoms in the Za{l arrow} and Zb{l arrow} hyperfine states. The trap uses the interaction of the magnetic moments of the gas atoms with a static magnetic field. Laser cooling and evaporative cooling can be utilized to enhance the confinement and to offset the influence of viscous heating. An important application of the trap is to the attainment of Bose--Einstein condensation.

Photoswitchable Dihydroazulene Macrocycles for Solar Energy Storage: The Effects of Ring Strain.

PubMed

Vlasceanu, Alexandru; Frandsen, Benjamin N; Skov, Anders B; Hansen, Anne Schou; Rasmussen, Mads Georg; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

2017-10-06

Efficient energy storage and release are two major challenges of solar energy harvesting technologies. The development of molecular solar thermal systems presents one approach to address these issues by tuning the isomerization reactions of photo/thermoswitches. Here we show that the incorporation of photoswitches into macrocyclic structures is a particularly attractive solution for increasing the storage time. We present the synthesis and properties of a series of macrocycles incorporating two dihydroazulene (DHA) photoswitching subunits, bridged by linkers of varying chain length. Independent of ring size, all macrocycles exhibit stepwise, light-induced, ring-opening reactions (DHA-DHA to DHA-VHF to VHF-VHF; VHF = vinylheptafulvene) with the first DHA undergoing isomerization with a similar efficiency as the uncyclized parent system while the second (DHA-VHF to VHF-VHF) is significantly slower. The energy-releasing, VHF-to-DHA, ring closures also occur in a stepwise manner and are systematically found to proceed slower in the more strained (smaller) cycles, but in all cases with a remarkably slow conversion of the second VHF to DHA. We managed to increase the half-life of the second VHF-to-DHA conversion from 65 to 202 h at room temperature by simply decreasing the ring size. A computational study reveals the smallest macrocycle to have the most energetic VHF-VHF state and hence highest energy density.

Nitrile/Buna N Material Failure Assessment for an O-Ring used on the Gaseous Hydrogen Flow Control Valve (FCV) of the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Wingard, Doug

2006-01-01

After the rollout of Space Shuttle Discovery in April 2005 in preparation for return-to-flight, there was a failure of the Orbiter (OV-103) helium signature leak test in the gaseous hydrogen (GH2) system. Leakage was attributed to the Flow Control Valve (FCV) in Main Engine 3. The FCV determined to be the source of the leak for OV-103 is designated as LV-58. The nitrile/Buna N rubber O-ring seal was removed from LV-58, and failure analysis indicated radial cracks providing leak paths in one quadrant. Cracks were eventually found in 6 of 9 FCV O-rings among the three Shuttle Orbiters, though none were as severe as those for LV-58, OV-103. Testing by EM10 at MSFC on all 9 FCV O- rings included: laser dimensional, Shore A hardness and properties from a dynamic mechanical analyzer (DMA) and an Instron tensile machine. The following test data was obtained on the cracked quadrant of the LV-58, OV-103 O-ring: (1) the estimated compression set was only 9.5%, compared to none for the rest of the O-ring; (2) Shore A hardness for the O.D. was higher by almost 4 durometer points than for the rest of the O-ring; and (3) DMA data showed that the storage/elastic modulus E was almost 25% lower than for the rest of the O-ring. Of the 8 FCV O-rings tested on an Instron, 4 yielded tensile strengths that were below the MIL spec requirement of 1350 psi-a likely influence of rubber cracking. Comparisons were made between values of modulus determined by DNA (elastic) and Instron (Young s). Each nitrile/Buna N O-ring used in the FCV conforms to the MIL-P-25732C specification. A number of such O-rings taken from shelf storage at MSFC and Kennedy Space Center (KSC) were used to generate a reference curve of DMA glass transition temperature (Tg) vs. shelf storage time ranging from 8 to 26 years. A similar reference curve of TGA onset temperature (of rubber weight loss) vs. shelf storage time was also generated. The DMA and TGA data for the used FCV O-rings were compared to the reference curves. Correlations were also made between the DMA modulus (at 22 C) and Shore A hardness for all 9 of the FCV O-rings used among the three Shuttle Orbiters. The radial cracking in the FCV O-rings was determined to be due to ozone attack, as nitrile/Buna N rubber is susceptible to such attack. Nitrile/Buna N material under MIL-P25732C should be used in a hydraulic fluid environment to help protect it from cracking. However, the FCV O-rings were used in an air only environment. The FCV design has as much as a 9-mil gap that allows the O.D. of the O-ring to be directly exposed to ozone, pressurized air and some elevated temperatures, accelerating the weathering process that leads to O-ring cracking. Space Shuttle flights will likely not continue past 2010. Therefore, Shuttle management decided to continue using the nitrile/Buna N material for the FCVs, but have each O-ring replaced after 3 years to minimize any chances for crack initiation.

Flexible matrix composite laminated disk/ring flywheel

NASA Technical Reports Server (NTRS)

Gupta, B. P.; Hannibal, A. J.

1984-01-01

An energy storage flywheel consisting of a quasi-isotropic composite disk overwrapped by a circumferentially wound ring made of carbon fiber and a elastometric matrix is proposed. Through analysis it was demonstrated that with an elastomeric matrix to relieve the radial stresses, a laminated disk/ring flywheel can be designed to store a least 80.3 Wh/kg or about 68% more than previous disk/ring designs. at the same time the simple construction is preserved.

Electric dipole moment planning with a resurrected BNL Alternating Gradient Synchrotron electron analog ring

NASA Astrophysics Data System (ADS)

Talman, Richard M.; Talman, John D.

2015-07-01

There has been much recent interest in directly measuring the electric dipole moments (EDM) of the proton and the electron, because of their possible importance in the present day observed matter/antimatter imbalance in the Universe. Such a measurement will require storing a polarized beam of "frozen spin" particles, 15 MeV electrons or 230 MeV protons, in an all-electric storage ring. Only one such relativistic electric accelerator has ever been built—the 10 MeV "electron analog" ring at Brookhaven National Laboratory in 1954; it can also be referred to as the "AGS analog" ring to make clear it was a prototype for the Alternating Gradient Synchrotron (AGS) proton ring under construction at that time at BNL. (Its purpose was to investigate nonlinear resonances as well as passage through "transition" with the newly invented alternating gradient proton ring design.) By chance this electron ring, long since dismantled and its engineering drawings disappeared, would have been appropriate both for measuring the electron EDM and to serve as an inexpensive prototype for the arguably more promising, but 10 times more expensive, proton EDM measurement. Today it is cheaper yet to "resurrect" the electron analog ring by simulating its performance computationally. This is one purpose for the present paper. Most existing accelerator simulation codes cannot be used for this purpose because they implicitly assume magnetic bending. The new ual/eteapot code, described in detail in an accompanying paper, has been developed for modeling storage ring performance, including spin evolution, in electric rings. Illustrating its use, comparing its predictions with the old observations, and describing new expectations concerning spin evolution and code performance, are other goals of the paper. To set up some of these calculations has required a kind of "archeological physics" to reconstitute the detailed electron analog lattice design from a 1991 retrospective report by Plotkin as well as unpublished notes of Courant describing machine studies performed in 1954-1955. This paper describes the practical application of the eteapot code and provides sample results, with emphasis on emulating lattice optics in the AGS analog ring for comparison with the historical machine studies and to predict the electron spin evolution they would have measured if they had polarized electrons and electron polarimetry. Of greater present day interest is the performance to be expected for a proton storage ring experiment. To exhibit the eteapot code performance and confirm its symplecticity, results are also given for 30 million turn proton spin tracking in an all-electric lattice that would be appropriate for a present day measurement of the proton EDM. The accompanying paper "Symplectic orbit and spin tracking code for all-electric storage rings" documents in detail the theoretical formulation implemented in eteapot, which is a new module in the Unified Accelerator Libraries (ual) environment.

Phase measurement for driven spin oscillations in a storage ring

NASA Astrophysics Data System (ADS)

Hempelmann, N.; Hejny, V.; Pretz, J.; Soltner, H.; Augustyniak, W.; Bagdasarian, Z.; Bai, M.; Barion, L.; Berz, M.; Chekmenev, S.; Ciullo, G.; Dymov, S.; Eversmann, D.; Gaisser, M.; Gebel, R.; Grigoryev, K.; Grzonka, D.; Guidoboni, G.; Heberling, D.; Hetzel, J.; Hinder, F.; Kacharava, A.; Kamerdzhiev, V.; Keshelashvili, I.; Koop, I.; Kulikov, A.; Lehrach, A.; Lenisa, P.; Lomidze, N.; Lorentz, B.; Maanen, P.; Macharashvili, G.; Magiera, A.; Mchedlishvili, D.; Mey, S.; Müller, F.; Nass, A.; Nikolaev, N. N.; Nioradze, M.; Pesce, A.; Prasuhn, D.; Rathmann, F.; Rosenthal, M.; Saleev, A.; Schmidt, V.; Semertzidis, Y.; Senichev, Y.; Shmakova, V.; Silenko, A.; Slim, J.; Stahl, A.; Stassen, R.; Stephenson, E.; Stockhorst, H.; Ströher, H.; Tabidze, M.; Tagliente, G.; Talman, R.; Thörngren Engblom, P.; Trinkel, F.; Uzikov, Yu.; Valdau, Yu.; Valetov, E.; Vassiliev, A.; Weidemann, C.; Wrońska, A.; Wüstner, P.; Zuprański, P.; Żurek, M.; JEDI Collaboration

2018-04-01

This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV /c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles.

EUTERPE, a small electron storage ring for XRF

NASA Astrophysics Data System (ADS)

Botman, J. I. M.; Mutsaers, P. H. A.; Hagedoorn, H. L.; De Voigt, M. J. A.

1990-04-01

A small-sized electron storage ring is under construction at the Eindhoven University of Technology which will cover the energy range of 15 to 400 MeV. At top energy the characteristic wavelength of the synchrotron radiation spectrum is 8.3 nm for the regular dipole magnets and 1.2 nm corresponding to 1.06 keV for a 10 T wiggler magnet. This will provide useful radiation for X-ray fluorescence (XRF) up to 3.2 keV. Alternatively, photon conversion with a high power CO 2 laser beam of 0.124 eV photons will generate X-rays for XRF with energies ranging from 0.5 to 300 keV, depending on the operating energy of the storage ring. This facility will provide an important extension to the activities of the Eindhoven group on PIXE, RBS and microbeam analysis. A short description of the macnine will be given together with applications and specific examples of the XRF method.

Magnetic Measurements of Storage Ring Magnets for the APS Upgrade Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doose, C.; Dejus, R.; Jaski, M.

2017-06-01

Extensive prototyping of storage ring magnets is ongoing at the Advanced Photon Source (APS) in support of the APS Multi-Bend Achromat (MBA) upgrade project (APS-U) [1]. As part of the R&D activities four quadrupole magnets with slightly different geometries and pole tip materials, and one sextupole magnet with vanadium permendur (VP) pole tips were designed, built and tested. Magnets were measured individually using a rotating coil and a Hall probe for detailed mapping of the magnetic field. Magnets were then assembled and aligned relative to each other on a steel support plate and concrete plinth using precision machined surfaces tomore » gain experience with the alignment method chosen for the APS-U storage ring magnets. The required alignment of magnets on a common support structure is 30 μm rms. Measurements of magnetic field quality, strength and magnet alignment after subjecting the magnets and assemblies to different tests are presented.« less

ACCELERATORS: Beam based alignment of the SSRF storage ring

NASA Astrophysics Data System (ADS)

Zhang, Man-Zhou; Li, Hao-Hu; Jiang, Bo-Cheng; Liu, Gui-Min; Li, De-Ming

2009-04-01

There are 140 beam position monitors (BPMs) in the Shanghai Synchrotron Radiation Facility (SSRF) storage ring used for measuring the closed orbit. As the BPM pickup electrodes are assembled directly on the vacuum chamber, it is important to calibrate the electrical center offset of the BPM to an adjacent quadrupole magnetic center. A beam based alignment (BBA) method which varies individual quadrupole magnet strength and observes its effects on the orbit is used to measure the BPM offsets in both the horizontal and vertical planes. It is a completely automated technique with various data processing methods. There are several parameters such as the strength change of the correctors and the quadrupoles which should be chosen carefully in real measurement. After several rounds of BBA measurement and closed orbit correction, these offsets are set to an accuracy better than 10 μm. In this paper we present the method of beam based calibration of BPMs, the experimental results of the SSRF storage ring, and the error analysis.

Symplectic orbit and spin tracking code for all-electric storage rings

DOE PAGES

Talman, Richard M.; Talman, John D.

2015-07-22

Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring “trap.” At the “magic” kinetic energy of 232.792 MeV, proton spins are “frozen,” for example always parallel to the instantaneous particle momentum. Energy deviation from the magic value causes in-plane precession of the spin relative to the momentum. Any nonzero EDM value will cause out-of-plane precession—measuring this precession is the basis for the EDM determination. A proposed implementation of this measurement shows that a proton EDM value of 10 –29e–cm or greater will produce a statisticallymore » significant, measurable precession after multiply repeated runs, assuming small beam depolarization during 1000 s runs, with high enough precision to test models of the early universe developed to account for the present day particle/antiparticle population imbalance. This paper describes an accelerator simulation code, eteapot, a new component of the Unified Accelerator Libraries (ual), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the nonconstant particle velocity in electric rings gives them significantly different properties, especially in weak focusing rings. Like the earlier code teapot (for magnetic ring simulation) this code performs exact tracking in an idealized (approximate) lattice rather than the more conventional approach, which is approximate tracking in a more nearly exact lattice. The Bargmann-Michel-Telegdi (BMT) equation describing the evolution of spin vectors through idealized bend elements is also solved exactly—original to this paper. Furthermore the idealization permits the code to be exactly symplectic (with no artificial “symplectification”). Any residual spurious damping or antidamping is sufficiently small to permit reliable tracking for the long times, such as the 1000 s assumed in estimating the achievable EDM precision. This paper documents in detail the theoretical formulation implemented in eteapot. An accompanying paper describes the practical application of the eteapot code in the Universal Accelerator Libraries (ual) environment to “resurrect,” or reverse engineer, the “AGS-analog” all-electric ring built at Brookhaven National Laboratory in 1954. Of the (very few) all-electric rings ever commissioned, the AGS-analog ring is the only relativistic one and is the closest to what is needed for measuring proton (or, even more so, electron) EDM’s. As a result, the companion paper also describes preliminary lattice studies for the planned proton EDM storage rings as well as testing the code for long time orbit and spin tracking.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eriksson, Mikael

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)more » 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.« less

The Abort Kicker System for the PEP-II Storage Rings at SLAC.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delamare, Jeffrey E

2003-06-20

The PEP-II project has two storage rings. The HER (High Energy Ring) has up to 1.48 A of election beam at 9 GeV, and the LER (Low Energy Ring) has up to 2.14 A of positron beam at 3.1 GeV. To protect the HER and LER beam lines in the event of a ring component failure, each ring has an abort kicker system which directs the beam into a dump when a failure is detected. Due to the high current of the beams, the beam kick is tapered from 100% to 80% in 7.33 {micro}S (the beam transit time aroundmore » the ring). This taper distributes the energy evenly across the window which separates the ring from the beam dump such that the window is not damaged. The abort kicker trigger is synchronized with the ion clearing gap of the beam allowing for the kicker field to rise from 0-80% while there is no beam in the kicker magnet. Originally the kicker system was designed for a rise time of 370nS [1], but because the ion clearing gap was reduced in half, so was the rise time requirement for the kicker. This report discusses the design of the system interlocks, diagnostics, and modulator with the modifications necessary to accommodate an ion clearing gap of 185nS.« less

Present limits for the luminosity, the beam current and the beam lifetime in Doris II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nesemann, H.; Sarau, B.

1985-10-01

The e e storage ring DORIS II has been operating for high energy physics experiments in the region of the Y resonances around 2x5 GeV and as a source for synchrotron radiation near 3.7 GeV. A luminosity of nearly 3x10T cm Ssec or more than 1500 (nb) /day has been achieved. For synchrotron radiation e -currents of about 100 mA are stored in 4 bunches (out of 480 buckets). As long as the beam-beam interaction does not limit the luminosity the optimum performance of the ring is obtained for both modes of operation if the currents stored are large, themore » cross section of the beam is small and the lifetime is long. Thus we concentrate the discussion on these subjects.« less

Inferring biome-scale net primary productivity from tree-ring isotopes

NASA Astrophysics Data System (ADS)

Pederson, N.; Levesque, M.; Williams, A. P.; Hobi, M. L.; Smith, W. K.; Andreu-Hayles, L.

2017-12-01

Satellite estimates of vegetation growth (net primary productivity; NPP), tree-ring records, and forest inventories indicate that ongoing climate change and rising atmospheric CO2 concentration are altering productivity and carbon storage of forests worldwide. The impact of global change on the trends of NPP, however, remain unknown because of the lack of long-term high-resolution NPP data. For the first time, we tested if annually resolved carbon (δ13C) and oxygen (δ18O) stable isotopes from the cellulose of tree rings from trees in temperate regions could be used as a tool for inferring NPP across spatiotemporal scales. We compared satellite NPP estimates from the moderate-resolution imaging spectroradiometer sensor (MODIS, product MOD17A) and a newly developed global NPP dataset derived from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset to annually resolved tree-ring width and δ13C and δ18O records from four sites along a hydroclimatic gradient in Eastern and Central United States. We found strong correlations across large geographical regions between satellite-derived NPP and tree-ring isotopes that ranged from -0.40 to -0.91. Notably, tree-ring derived δ18O had the strongest relation to climate. The results were consistent among the studied tree species (Quercus rubra and Liriodendron tulipifera) and along the hydroclimatic conditions of our network. Our study indicates that tree-ring isotopes can potentially be used to reconstruct NPP in time and space. As such, our findings represent an important breakthrough for estimating long-term changes in vegetation productivity at the biome scale.

Development of a Bunched Beam Electron Cooler based on ERL and Circulator Ring Technology for the Jefferson Lab Electron-Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, Stephen V.; Derbenev, Yaroslav S.; Douglas, David R.

Jefferson Lab is in the process of designing an electron ion collider with unprecedented luminosity at a 45 GeV center-of-mass energy. This luminosity relies on ion cooling in both the booster and the storage ring of the accelerator complex. The cooling in the booster will use a conventional DC cooler similar to the one at COSY. The high-energy storage ring, operating at a momentum of up to 100 GeV/nucleon, requires novel use of bunched-beam cooling. There are two designs for such a cooler. The first uses a conventional Energy Recovery Linac (ERL) with a magnetized beam while the second usesmore » a circulating ring to enhance both peak and average currents experienced by the ion beam. This presentation will describe the design of both the Circulator Cooling Ring (CCR) design and that of the backup option using the stand-alone ERL operated at lower charge but higher repetition rate than the ERL injector required by the CCR-based design.« less

Characterizing near-surface CO2 conditions before injection - Perspectives from a CCS project in the Illinois Basin, USA

USGS Publications Warehouse

Locke, R.A.; Krapac, I.G.; Lewicki, J.L.; Curtis-Robinson, E.

2011-01-01

The Midwest Geological Sequestration Consortium is conducting a large-scale carbon capture and storage (CCS) project in Decatur, Illinois, USA to demonstrate the ability of a deep saline formation to store one million tonnes of carbon dioxide (CO2) from an ethanol facility. Beginning in early 2011, CO2 will be injected at a rate of 1,000 tonnes/day for three years into the Mount Simon Sandstone at a depth of approximately 2,100 meters. An extensive Monitoring, Verification, and Accounting (MVA) program has been undertaken for the Illinois Basin Decatur Project (IBDP) and is focused on the 0.65 km2 project site. Goals include establishing baseline conditions to evaluate potential impacts from CO2 injection, demonstrating that project activities are protective of human health and the environment, and providing an accurate accounting of stored CO2. MVA efforts are being conducted pre-, during, and post- CO2 injection. Soil and net CO2 flux monitoring has been conducted for more than one year to characterize near-surface CO2 conditions. More than 2,200 soil CO2 flux measurements have been manually collected from a network of 118 soil rings since June 2009. Three ring types have been evaluated to determine which type may be the most effective in detecting potential CO 2 leakage. Bare soil, shallow-depth rings were driven 8 cm into the ground and were prepared to minimize surface vegetation in and near the rings. Bare soil, deep-depth rings were prepared similarly, but were driven 46 cm. Natural-vegetation, shallow-depth rings were driven 8 cm and are most representative of typical vegetation conditions. Bare-soil, shallow-depth rings had the smallest observed mean flux (1.78 ??mol m-2 s-1) versus natural-vegetation, shallow-depth rings (3.38 ??mol m-2 s-1). Current data suggest bare ring types would be more sensitive to small CO2 leak signatures than natural ring types because of higher signal to noise ratios. An eddy covariance (EC) system has been in use since June 2009. Baseline data from EC monitoring is being used to characterize pre-injection conditions, and may then be used to detect changes in net exchange CO2 fluxes (Fc) that could be the result of CO2 leakage into the near-surface environment during or following injection. When injection at IBDP begins, soil and net CO2 monitoring efforts will have established a baseline of near-surface conditions that will be important to help demonstrate the effectiveness of storage activities. ?? 2011 Published by Elsevier Ltd.

Resonant neutral-particle emission in collisions of electrons with peptide ions in a storage ring.

PubMed

Tanabe, T; Noda, K; Saito, M; Lee, S; Ito, Y; Takagi, H

2003-05-16

Electron-biomolecular ion collisions were studied using an electrostatic storage ring with a merging beam technique for singly protonated peptides (angiotensin I, II, and III). A strong neutral-particle emission at around 6.5 eV was found in addition to neutrals from recombination at low energies. The rates of the high-energy peak greatly decreased with a slight decrease in the number of amino-acid residues from angiotensin I to III. These results suggest that some peptide bonds were selectively cleaved.

Commissioning and Early Operation Experience of the NSLS-II Storage Ring RF System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, F.; Rose, J.; Cupolo, J.

2015-05-03

The National Synchrotron Light Source II (NSLS-II) is a 3 GeV electron X-ray user facility commissioned in 2014. The storage ring RF system, essential for replenishing energy loss per turn of the electrons, consists of digital low level RF controllers, 310 kW CW klystron transmitters, CESR-B type superconducting cavities, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system for beam current up to 200mA.

Mass Measurements of Proton-rich Nuclides at the Cooler Storage Ring at IMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y. H.; Xu, H. S.; Wang, M.

2011-11-30

Recent results and progress of mass measurements of proton-rich nuclei using isochronous mass spectrometry (IMS) are reported. The nuclei under investigation were produced via fragmentation of relativistic energy heavy ions of {sup 78}Kr and {sup 58}Ni. After in-flight separation by the fragment separator RIBLL-2, the nuclei were injected and stored in the experimental storage ring CSRe, and their masses were determined from measurements of the revolution times. The impact of these measurements on the stellar nucleosynthesis in the rp-process is discussed.

Conditioning of the vacuum system of the TPS storage ring without baking in situ

NASA Astrophysics Data System (ADS)

Chan, C. K.; Chang, C. C.; Shueh, C.; Yang, I. C.; Wu, L. H.; Chen, B. Y.; Cheng, C. M.; Huang, Y. T.; Chuang, J. Y.; Cheng, Y. T.; Hsiao, Y. M.; Sheng, Albert

2017-04-01

To shorten the machine downtime, a maintenance procedure without baking in situ has been developed and applied to maintain and to upgrade the vacuum system of the TPS storage ring. The data of photon-stimulated desorption (PSD) reveal no obvious discrepancy between baking and not baking the vacuum system in situ. A beam-conditioning dose of extent only 11.8 A h is required to recover quickly the dynamic pressure of an unbaked vacuum system to its pre-intervention value according to the TPS maintenance experience.

Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root.

PubMed

Carvalho, Luiz Jcb; Agustini, Marco Av; Anderson, James V; Vieira, Eduardo A; de Souza, Claudia Rb; Chen, Songbi; Schaal, Barbara A; Silva, Joseane P

2016-06-10

Cassava (Manihot esculenta Crantz) storage root provides a staple food source for millions of people worldwide. Increasing the carotenoid content in storage root of cassava could provide improved nutritional and health benefits. Because carotenoid accumulation has been associated with storage root color, this study characterized carotenoid profiles, and abundance of key transcripts associated with carotenoid biosynthesis, from 23 landraces of cassava storage root ranging in color from white-to-yellow-to-pink. This study provides important information to plant breeding programs aimed at improving cassava storage root nutritional quality. Among the 23 landraces, five carotenoid types were detected in storage root with white color, while carotenoid types ranged from 1 to 21 in storage root with pink and yellow color. The majority of storage root in these landraces ranged in color from pale-to-intense yellow. In this color group, total β-carotene, containing all-E-, 9-Z-, and 13-Z-β-carotene isomers, was the major carotenoid type detected, varying from 26.13 to 76.72 %. Although no α-carotene was observed, variable amounts of a α-ring derived xanthophyll, lutein, was detected; with greater accumulation of α-ring xanthophylls than of β-ring xanthophyll. Lycopene was detected in a landrace (Cas51) with pink color storage root, but it was not detected in storage root with yellow color. Based on microarray and qRT-PCR analyses, abundance of transcripts coding for enzymes involved in carotenoid biosynthesis were consistent with carotenoid composition determined by contrasting HPLC-Diode Array profiles from storage root of landraces IAC12, Cas64, and Cas51. Abundance of transcripts encoding for proteins regulating plastid division were also consistent with the observed differences in total β-carotene accumulation. Among the 23 cassava landraces with varying storage root color and diverse carotenoid types and profiles, landrace Cas51 (pink color storage root) had low LYCb transcript abundance, whereas landrace Cas64 (intense yellow storage root) had decreased HYb transcript abundance. These results may explain the increased amounts of lycopene and total β-carotene observed in landraces Cas51 and Cas64, respectively. Overall, total carotenoid content in cassava storage root of color class representatives were associated with spatial patterns of secondary growth, color, and abundance of transcripts linked to plastid division. Finally, a partial carotenoid biosynthesis pathway is proposed.

The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 3: Electron cloud diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Billing, M. G.; Conway, J. V.; Crittenden, J. A.

Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper is the third in a series of four describing the conversion of CESR to themore » test accelerator, CESRTA. The first two papers discuss the overall plan for the conversion of the storage ring to an instrument capable of studying advanced accelerator physics issues [1] and the details of the vacuum system upgrades [2]. This paper focuses on the necessary development of new instrumentation, situated in four dedicated experimental regions, capable of studying such phenomena as electron clouds (ECs) and methods to mitigate EC effects. The fourth paper in this series describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of EC behavior within wigglers. Lastly, while the initial studies of CESRTA focused on questions related to the International Linear Collider damping ring design, CESRTA is a very versatile storage ring, capable of studying a wide range of accelerator physics and instrumentation questions.« less

The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 3: Electron cloud diagnostics

DOE PAGES

Billing, M. G.; Conway, J. V.; Crittenden, J. A.; ...

2016-04-28

Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper is the third in a series of four describing the conversion of CESR to themore » test accelerator, CESRTA. The first two papers discuss the overall plan for the conversion of the storage ring to an instrument capable of studying advanced accelerator physics issues [1] and the details of the vacuum system upgrades [2]. This paper focuses on the necessary development of new instrumentation, situated in four dedicated experimental regions, capable of studying such phenomena as electron clouds (ECs) and methods to mitigate EC effects. The fourth paper in this series describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of EC behavior within wigglers. Lastly, while the initial studies of CESRTA focused on questions related to the International Linear Collider damping ring design, CESRTA is a very versatile storage ring, capable of studying a wide range of accelerator physics and instrumentation questions.« less

Measurement techniques for low emittance tuning and beam dynamics at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Dobbins, J. A.; Forster, M. J.; Kreinick, D. L.; Meller, R. E.; Peterson, D. P.; Ramirez, G. A.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Williams, H. A.; Palmer, M. A.; Holtzapple, R. L.; Flanagan, J.

2018-03-01

After operating as a High Energy Physics electron-positron collider, the Cornell Electron-positron Storage Ring (CESR) has been converted to become a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS). Over the course of several years CESR was adapted for accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Initially some specific topics were targeted for accelerator physic research with the storage ring in this mode, labeled CesrTA. These topics included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud (EC) development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CesrTA occurred over a several year period, described elsewhere [1–3]. A number of specific instruments were developed for CesrTA. Much of the pre-existing instrumentation was modified to accommodate the scope of these studies and these are described in a companion paper [4]. To complete this research, a number of procedures were developed or modified, often requiring coordinated measurements among different instruments [5]. This paper provides an overview of types of measurements employed for the study of beam dynamics during the operation of CesrTA.

Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kafka, Gene

2015-05-01

The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with signi cant exibility in mind, but without compromising cost e ciency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of di erent variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state ofmore » the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of- ight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.« less

Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

NASA Astrophysics Data System (ADS)

Kafka, Gene

The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with significant flexibility in mind, but without compromising cost efficiency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of different variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of-flight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

Beam measurements using visible synchrotron light at NSLS2 storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Weixing, E-mail: chengwx@bnl.gov; Bacha, Bel; Singh, Om

2016-07-27

Visible Synchrotron Light Monitor (SLM) diagnostic beamline has been designed and constructed at NSLS2 storage ring, to characterize the electron beam profile at various machine conditions. Due to the excellent alignment, SLM beamline was able to see the first visible light when beam was circulating the ring for the first turn. The beamline has been commissioned for the past year. Besides a normal CCD camera to monitor the beam profile, streak camera and gated camera are used to measure the longitudinal and transverse profile to understand the beam dynamics. Measurement results from these cameras will be presented in this paper.more » A time correlated single photon counting system (TCSPC) has also been setup to measure the single bunch purity.« less

A compact high brightness laser synchrotron light source for medical applications

NASA Astrophysics Data System (ADS)

Nakajima, Kazuhisa

1999-07-01

The present high-brightness hard X-ray sources have been developed as third generation synchrotron light sources based on large high energy electron storage rings and magnetic undulators. Recently availability of compact terawatt lasers arouses a great interest in the use of lasers as undulators. The laser undulator concept makes it possible to construct an attractive compact synchrotron radiation source which has been proposed as a laser synchrotron light source. This paper proposes a compact laser synchrotron light source for mediacal applications, such as an intravenous coronary angiography and microbeam therapy.

Lithographically Patterned Nanoscale Electrodeposition of Plasmonic, Bimetallic, Semiconductor, Magnetic, and Polymer Nanoring Arrays

PubMed Central

2015-01-01

Large area arrays of magnetic, semiconducting, and insulating nanorings were created by coupling colloidal lithography with nanoscale electrodeposition. This versatile nanoscale fabrication process allows for the independent tuning of the spacing, diameter, and width of the nanorings with typical values of 1.0 μm, 750 nm, and 100 nm, respectively, and was used to form nanorings from a host of materials: Ni, Co, bimetallic Ni/Au, CdSe, and polydopamine. These nanoring arrays have potential applications in memory storage, optical materials, and biosensing. A modified version of this nanoscale electrodeposition process was also used to create arrays of split gold nanorings. The size of the split nanoring opening was controlled by the angle of photoresist exposure during the fabrication process and could be varied from 50% down to 10% of the ring circumference. The large area (cm2 scale) gold split nanoring array surfaces exhibited strong polarization-dependent plasmonic absorption bands for wavelengths from 1 to 5 μm. Plasmonic nanoscale split ring arrays are potentially useful as tunable dichroic materials throughout the infrared and near-infrared spectral regions. PMID:25553204

Multiparticle Simulation of Intrabeam Scattering for SuperB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biagini, M.; Boscolo, M.; Demma, T.

In this communication we present the structure of a multiparticle tracking code to investigate intrabeam scattering effects in low emittance colliders. Simulation results obtained with particular reference to the SuperB parameters are compared with those of conventional IBS theories.and with those of a novel semi-analythical model able to predict IBS effect in terms of emittance growths. Intrabeam scattering (IBS) is associated with multiple small angle scattering events leading to emittance growth. In most electron storage rings, the growth rates arising from IBS are usually much longer than damping times due to synchrotron radiation, and its effect is not observed. However,more » IBS growth rates increase with bunch charge density, and for machines such as SuperB, that operate with high bunch charges and very low emittances, the IBS growth rates can be large enough to observe significant emittance increase. Several formalisms have been developed for calculating IBS growth rates in storage rings, notably those by Piwinski, Bjorken and Mtingwa, and their high energy approximations. Calculations show that IBS should be manageable in both SuperB rings. However these analytical models, based on Gaussian bunch distributions, cannot investigate some interesting aspects of IBS such as its impact during the damping process and its effect on the beam distribution. We developed a multiparticle tracking code, based on the Zenkevich-Bolshakov algorithm, to investigate these effects. In this communication we present the structure of the code and some simulation results obtained with particular reference to the SuperB parameters. Simulation results are compared with those of conventional IBS theories.« less

Advanced Photon Source accelerator ultrahigh vacuum guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Emittance and lifetime measurement with damping wigglers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G. M.; Shaftan, T., E-mail: shaftan@bnl.gov; Cheng, W. X.

National Synchrotron Light Source II (NSLS-II) is a new third-generation storage ring light source at Brookhaven National Laboratory. The storage ring design calls for small horizontal emittance (<1 nm-rad) and diffraction-limited vertical emittance at 12 keV (8 pm-rad). Achieving low value of the beam size will enable novel user experiments with nm-range spatial and meV-energy resolution. The high-brightness NSLS-II lattice has been realized by implementing 30-cell double bend achromatic cells producing the horizontal emittance of 2 nm rad and then halving it further by using several Damping Wigglers (DWs). This paper is focused on characterization of the DW effects inmore » the storage ring performance, namely, on reduction of the beam emittance, and corresponding changes in the energy spread and beam lifetime. The relevant beam parameters have been measured by the X-ray pinhole camera, beam position monitors, beam filling pattern monitor, and current transformers. In this paper, we compare the measured results of the beam performance with analytic estimates for the complement of the 3 DWs installed at the NSLS-II.« less

Higher-Order Systematic Effects in the Muon Beam-Spin Dynamics for Muon g-2

NASA Astrophysics Data System (ADS)

Crnkovic, Jason; Brown, Hugh; Krouppa, Brandon; Metodiev, Eric; Morse, William; Semertzidis, Yannis; Tishchenko, Vladimir

2016-03-01

The BNL Muon g-2 Experiment (E821) produced a precision measurement of the muon anomalous magnetic moment, where as the Fermilab Muon g-2 Experiment (E989) is an upgraded version of E821 that has a goal of producing a measurement with approximately 4 times more precision. Improving the precision requires a more detailed understanding of the experimental systematic effects, and so three higher-order systematic effects in the muon beam-spin dynamics have recently been found and estimated for E821. The beamline systematic effect originates from muon production in beamline spectrometers, as well as from muons traversing beamline bending magnets. The kicker systematic effect comes from a combination of the variation in time spent inside the muon storage ring across a muon bunch and the temporal structure of the storage ring kicker waveform. Finally, the detector systematic effect arises from a combination of the energy dependent muon equilibrium orbit in the storage ring, muon decay electron drift time, and decay electron detector acceptance effects. Brookhaven Natl Lab.

Study of the longitudinal space charge compensation and longitudinal instability of the ferrite inductive inserts in the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Beltran, Chris

Future high intensity synchrotrons will have a large space charge effect. It has been demonstrated in the Proton Storage Ring (PSR) at the Los Alamos National Laboratory (LANL) that ferrite inductive inserts can be used to compensate for the longitudinal space charge effect. However, simply installing ferrite inductors in the PSR led to longitudinal instabilities that were not tolerable. It was proposed that heating the ferrite would change the material properties in such a way as to reduce the instability. This proposal was tested in the PSR, and found to be true. This dissertation investigates and describes the complex permeability of the ferrite at room temperature and at an elevated temperature. The derived complex permeability is then used to obtain an impedance at the two temperatures. The impedance is used to determine the amount of space charge compensation supplied by the inductors and predict the growth time and frequency range of the longitudinal instability. The impedance is verified by comparing the experimental growth time and frequency range of the longitudinal instability to theoretical and computer simulated growth times and frequency ranges of the longitudinal instability. Lastly, an approach to mitigating the longitudinal instability that does not involve heating the ferrite is explored.

Simulation of emission and propagation of coherent synchrotron radiation wave fronts using the methods of wave optics

NASA Astrophysics Data System (ADS)

Chubar, O.

2006-09-01

The paper describes methods of efficient calculation of spontaneous synchrotron radiation (SR) by relativistic electrons in storage rings, and propagation of this radiation through optical elements and drift spaces of beamlines, using the principles of wave optics. In addition to the SR from one electron, incoherent and coherent synchrotron radiation (CSR) emitted by electron bunches is treated. CPU-efficient CSR calculation method taking into account 6D phase space distribution of electrons in a bunch is proposed. The properties of CSR emitted by electron bunches with small longitudinal and large transverse size are studied numerically (such situation can be realized in storage rings e.g. by transverse deflection of the electron bunches in special RF cavities). It is shown that if the transverse size of a bunch is much larger than the diffraction limit for single-electron SR at a given wavelength - it affects the angular distribution of the CSR at this wavelength and reduces the coherent flux. Nevertheless, for transverse bunch dimensions up to several millimeters and the longitudinal bunch size smaller than hundred micrometers, the resulting CSR flux in the far infrared spectral range is still many orders of magnitude higher than the flux of incoherent SR.

The magnetic toroidal sector: a broad-band electron-positron pair spectrometer

NASA Astrophysics Data System (ADS)

Hagmann, Siegbert; Hillenbrand, Pierre-Michel; Litvinov, Yuri; Spillmann, Uwe

2016-05-01

At the future relativistic storage-ring HESR at FAIR the study of electron-positron pairs from non-nuclear, atomic processes will be one of the goals of the experimental program with kinematically complete experiments focusing on momentum spectroscopy of coincident emission of electrons and positrons from free-free pairs and corresponding recoil ions. The underlying production mechanisms belong to central topics of QED in strong fields. We present first results on the electron-optical properties of a magnetic toroidal sector configuration enabling coincident detection of free-free electron-positron pairs; this spectrometer is suitable for implementation into a storage ring with a supersonic jet target and covering a wide range of lepton emission into the forward hemisphere. The simulation calculations are performed using the OPERA code.

Safe operating conditions for NSLS-II Storage Ring Frontends commissioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seletskiy, S.; Amundsen, C.; Ha, K.

2015-04-02

The NSLS-II Storage Ring Frontends are designed to safely accept the synchrotron radiation fan produced by respective insertion device when the electron beam orbit through the ID is locked inside the predefined Active Interlock Envelope. The Active Interlock is getting enabled at a particular beam current known as AI safe current limit. Below such current the beam orbit can be anywhere within the limits of the SR beam acceptance. During the FE commissioning the beam orbit is getting intentionally disturbed in the particular ID. In this paper we explore safe operating conditions for the Frontends commissioning.

DESY II, a new injector for the DESY storage rings PETRA and DORIS II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemmie, G.

1983-08-01

There is a proposal to build a new 9 GeV electron synchrotron as a dedicated injector for the storage rings DORIS and PETRA. This machine will be housed in the old DESY-tunnel side-by-side with the original DESY-synchrotron. It is characterized by a separated function lattice, a 12.5 Hz repetition frequency, an all-metal vacuum chamber and a high shunt impedance rf-system. After commissioning of this new machine in 1984, the old DESY-synchrotron could be converted into a dedicated proton-accelerator as part of the injection chain for HERA.

Explicit symplectic orbit and spin tracking method for electric storage ring

DOE PAGES

Hwang, Kilean; Lee, S. Y.

2016-08-18

We develop a symplectic charged particle tracking method for phase space coordinates and polarization in all electric storage rings. Near the magic energy, the spin precession tune is proportional to the fractional momentum deviation δ m from the magic energy, and the amplitude of the radial and longitudinal spin precession is proportional to η/δ m, where η is the electric dipole moment for an initially vertically polarized beam. As a result, the method can be used to extract the electron electric dipole moment of a charged particle by employing narrow band frequency analysis of polarization around the magic energy.

Experience with Round Beam Operation at The Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, A.; Emery, L.; Sajaev, V.

2015-01-01

Very short Touschek lifetime becomes a common issue for next-generation ultra-low emittance storage ring light sources. In order to reach a longer beamlifetime, such amachine often requires operating with a vertical-to-horizontal emittance ratio close to an unity, i.e. a “round beam”. In tests at the APS storage ring, we determined how a round beam can be reached experimentally. Some general issues, such as beam injection, optics measurement and corrections, and orbit correction have been tested also. To demonstrate that a round beam was achieved, the beam size ratio is calibrated using beam lifetime measurement.

Three-dimensional ordering of cold ion beams in a storage ring: A molecular-dynamics simulation study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuri, Yosuke, E-mail: yuri.yosuke@jaea.go.jp

Three-dimensional (3D) ordering of a charged-particle beams circulating in a storage ring is systematically studied with a molecular-dynamics simulation code. An ion beam can exhibit a 3D ordered configuration at ultralow temperature as a result of powerful 3D laser cooling. Various unique characteristics of the ordered beams, different from those of crystalline beams, are revealed in detail, such as the single-particle motion in the transverse and longitudinal directions, and the dependence of the tune depression and the Coulomb coupling constant on the operating points.

Theory of the polarization of highly charged ions in storage rings: Production, preservation, observation and application to the search for a violation of the fundamental symmetries

NASA Astrophysics Data System (ADS)

Bondarevskaya, A.; Prozorov, A.; Labzowsky, L.; Plunien, G.; Liesen, D.; Bosch, F.

2011-10-01

Theoretical concepts for the production, preservation and control of polarized highly charged ion beams in storage rings are investigated. It is argued that hydrogen-like ions can be polarized efficiently by optical pumping of the Zeeman sublevels of ground state hyperfine levels and that the maximum achievable nuclear polarization exceeds 90%. In order to study the preservation of the polarization during the ion motion through the magnetic system of the ring, the concept of the instantaneous quantization axis is introduced. It is suggested that the employment of “Siberian snakes” may help to preserve the ion beam polarization in the ring. The control of the beam polarization can be achieved by different methods: by measuring the Stokes parameters for the emitted photons or by observing the angular dependence of the transition rates for polarized ions. The important motivation for the production of polarized ion beams is the possibility to observe parity nonconservation effects in the hyperfine-quenched transitions in helium-like highly charged ions, where these effects can reach an unprecedented high value for atomic physics. The possible observation of parity nonconservation effects connected with the nuclear anapole moment is also discussed. A method for the observation of the electric dipole moment of an electron in a storage ring with a polarized highly charged ion beam is proposed. This method allows, in principle, to improve the existing boundaries for the electric dipole moment of an electron. However, the requirements of the corresponding experiment are very stringent.

Coupling tree rings and eddy covariance to estimate long-term above and belowground carbon storage at the stand level

NASA Astrophysics Data System (ADS)

Dye, A.; Alexander, M. R.; Bishop, D.; Pederson, N.; Hessl, A. E.

2016-12-01

Storage of carbon in terrestrial plants and soils directly reduces atmospheric carbon concentration, and it is thereby imperative to improve our understanding of where carbon is being stored and released in an ecosystem and how storages and releases are changing over time. At data-rich sites, coupling alternative measurements of carbon flux can improve this understanding. Here, we present a methodology to inversely model stand-level net storage and release of above- and belowground carbon over a period of 1-2 decades using co-located tree-ring plots and eddy covariance towers at three eastern U.S. forests. We reconstructed annual aboveground wood production (aNPP) from tree rings collected near eddy covariance towers. We compared our aNPP reconstructions with annual tower NEE to address whether interannual variations are correlated. Despite modest correlation, we observed magnitude differences between both records that vary annually. We interpret these differences as indicative of changes in belowground carbon storage, i.e. an aNPP:NEE ratio > 1 indicates a net release of belowground carbon and a ratio < 1 a net storage of belowground carbon. For this interpretation, we assume the following: a) carbon not directed to above or belowground pools is insignificant, b) carbon not stored above ground is stored below ground, and c) mature trees do not add to a storage pool at a higher level every year. While the offset between biometric aNPP and tower NEE could partially be attributed to the diversion of assimilated carbon to nonstructural carbohydrates instead of growth, we argue that this becomes a less important factor over longer time scales in a mature tree. Our approach does not quantify belowground NPP or allocation, but we present a method for estimating belowground carbon storage and release at the stand level, an otherwise difficult task at this scale due to heterogeneity across the stand.

Maury Goodman

Science.gov Websites

the 29th International Cosmic Ray Conference, Pune India, August 10, 2005 Reactor Searches for Theta Rings, Bombay India, August 2, 2005 NOvA Presentation at the Workshop on Physics of Atmospheric Neutrinos and Neutrinos from Muon Storage Rings, Bombay India, August 2, 2005 The Double Chooz Double Fast

Sc-Decorated Porous Graphene for High-Capacity Hydrogen Storage: First-Principles Calculations.

PubMed

Chen, Yuhong; Wang, Jing; Yuan, Lihua; Zhang, Meiling; Zhang, Cairong

2017-08-02

The generalized gradient approximation (GGA) function based on density functional theory is adopted to investigate the optimized geometrical structure, electron structure and hydrogen storage performance of Sc modified porous graphene (PG). It is found that the carbon ring center is the most stable adsorbed position for a single Sc atom on PG, and the maximum number of adsorbed H₂ molecules is four with the average adsorption energy of -0.429 eV/H₂. By adding a second Sc atom on the other side of the system, the hydrogen storage capacity of the system can be improved effectively. Two Sc atoms located on opposite sides of the PG carbon ring center hole is the most suitable hydrogen storage structure, and the hydrogen storage capacity reach a maximum 9.09 wt % at the average adsorption energy of -0.296 eV/H₂. The adsorption of H₂ molecules in the PG system is mainly attributed to orbital hybridization among H, Sc, and C atoms, and Coulomb attraction between negatively charged H₂ molecules and positively charged Sc atoms.

Sc-Decorated Porous Graphene for High-Capacity Hydrogen Storage: First-Principles Calculations

PubMed Central

Chen, Yuhong; Wang, Jing; Yuan, Lihua; Zhang, Meiling

2017-01-01

The generalized gradient approximation (GGA) function based on density functional theory is adopted to investigate the optimized geometrical structure, electron structure and hydrogen storage performance of Sc modified porous graphene (PG). It is found that the carbon ring center is the most stable adsorbed position for a single Sc atom on PG, and the maximum number of adsorbed H2 molecules is four with the average adsorption energy of −0.429 eV/H2. By adding a second Sc atom on the other side of the system, the hydrogen storage capacity of the system can be improved effectively. Two Sc atoms located on opposite sides of the PG carbon ring center hole is the most suitable hydrogen storage structure, and the hydrogen storage capacity reach a maximum 9.09 wt % at the average adsorption energy of −0.296 eV/H2. The adsorption of H2 molecules in the PG system is mainly attributed to orbital hybridization among H, Sc, and C atoms, and Coulomb attraction between negatively charged H2 molecules and positively charged Sc atoms. PMID:28767084

Field Modeling, Symplectic Tracking, and Spin Decoherence for EDM and Muon $$g\\textrm{-}2$$ Lattices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valetov, Eremey Vladimirovich

2017-01-01

While the first particle accelerators were electrostatic machines, and several electrostatic storage rings were subsequently commissioned and operated, electrostatic storage rings pose a number of challenges. Unlike motion in the magnetic field, where particle energy remains constant, particle energy generally changes in electrostatic elements. Conservation of energy in an electrostatic element is, in practice, only approximate, and it requires careful and accurate design, manufacturing, installation, and operational use. Electrostatic deflectors require relatively high electrostatic fields, tend to introduce nonlinear aberrations of all orders, and are more challenging to manufacture than homogeneous magnetic dipoles. Accordingly, magnetic storage rings are overwhelmingly prevalent.more » The search for electric dipole moments (EDMs) of fundamental particles is of key importance in the study of C and CP violations and their sources. C and CP violations are part of the Sakharov conditions that explain the matter–antimatter asymmetry in the universe. Determining the source of CP violations would provide valuable empirical insight for beyond-Standard-Model physics. EDMs of fundamental particles have not to this date been experimentally observed. The search for fundamental particle EDMs has narrowed the target search region; however, an EDM signal is yet to be discovered. In 2008, Brookhaven National Laboratory (BNL) had proposed the frozen spin (FS) concept for the search of a deuteron EDM. The FS concept envisions launching deuterons through a storage ring with combined electrostatic and magnetic fields. The electrostatic and magnetic fields are in a proportion that would, without an EDM, freeze the deuteron’s spin along its momentum as the deuteron moves around the lattice. The radial electrostatic field would result in a torque on the spin vector, proportional to a deuteron EDM, rotating the spin vector out of the midplane.« less

Storing keV negative ions for an hour: the lifetime of the metastable ^(2)P((1/2)^(o)) level in ^(32)S^(-).

PubMed

Bäckström, E; Hanstorp, D; Hole, O M; Kaminska, M; Nascimento, R F; Blom, M; Björkhage, M; Källberg, A; Löfgren, P; Reinhed, P; Rosén, S; Simonsson, A; Thomas, R D; Mannervik, S; Schmidt, H T; Cederquist, H

2015-04-10

We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p^{5} ^{2}P_{1/2}^{o}→3p^{5} ^{2}P_{3/2}^{o} spontaneous radiative decay in ^{32}S^{-} to be 503±54  sec. This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10^{-14} mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ from the only available theoretical prediction [P. Andersson et al., Phys. Rev. A 73, 032705 (2006)].

Multipacting on the trailing edge of proton beam bunches in the PSR and SNS

NASA Astrophysics Data System (ADS)

Danilov, V.; Aleksandrov, A.; Galambos, J.; Jeon, D.; Holmes, J.; Olsen, D.

1999-12-01

The Proton Storage Ring (PSR) in Los Alamos has a fast intensity-limiting instability, which may result from an electron cloud interaction with the circulating proton beam leading to a transverse mode coupling instability. The most probable mechanism of the electron creation is multipacting. Though the effect depends on many parameters, a model is presented which predicts a large electron creation in the vacuum chamber. A comparison of this effect between the PSR in Los Alamos and the Spallation Neutron Source (SNS) in Oak Ridge is given. In addition, several possibilities to reduce multipactor are discussed.

CsI-Silicon Particle detector for Heavy ions Orbiting in Storage rings (CsISiPHOS)

NASA Astrophysics Data System (ADS)

Najafi, M. A.; Dillmann, I.; Bosch, F.; Faestermann, T.; Gao, B.; Gernhäuser, R.; Kozhuharov, C.; Litvinov, S. A.; Litvinov, Yu. A.; Maier, L.; Nolden, F.; Popp, U.; Sanjari, M. S.; Spillmann, U.; Steck, M.; Stöhlker, T.; Weick, H.

2016-11-01

A heavy-ion detector was developed for decay studies in the Experimental Storage Ring (ESR) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. This detector serves as a prototype for the in-pocket particle detectors for future experiments with the Collector Ring (CR) at FAIR (Facility for Antiproton and Ion Research). The detector includes a stack of six silicon pad sensors, a double-sided silicon strip detector (DSSD), and a CsI(Tl) scintillation detector. It was used successfully in a recent experiment for the detection of the β+-decay of highly charged 142Pm60+ ions. Based on the ΔE / E technique for particle identification and an energy resolution of 0.9% for ΔE and 0.5% for E (Full Width at Half Maximum (FWHM)), the detector is well-suited to distinguish neighbouring isobars in the region of interest.

Saturation of the laser-induced narrowband coherent synchrotron radiation process: Experimental observation at a storage ring

NASA Astrophysics Data System (ADS)

Hosaka, M.; Yamamoto, N.; Takashima, Y.; Szwaj, C.; Le Parquier, M.; Evain, C.; Bielawski, S.; Adachi, M.; Zen, H.; Tanikawa, T.; Kimura, S.; Katoh, M.; Shimada, M.; Takahashi, T.

2013-02-01

We study the efficiency limitation affecting laser-induced coherent synchrotron radiation (CSR) at high laser power. Experiments are made on the UVSOR-II storage ring in conditions of narrowband terahertz CSR emission. While, at moderate power, CSR power increases quadratically with laser power, a noticeable decrease in efficiency and eventually a decrease in CSR power is observed experimentally at high power. Details of the underlying process are analyzed numerically. As the saturation effect depends almost instantaneously on the laser intensity, the saturation occurs locally in longitudinal space. This has important consequences on the modulation pattern induced on the electron bunch.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stillwell, B.; Billett, B.; Brajuskovic, B.

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.

Development and operating experience of a short-period superconducting undulator at the Advanced Photon Source

DOE PAGES

Ivanyushenkov, Y.; Harkay, K.; Abliz, M.; ...

2015-04-01

In this study, a decade-long effort at the Advanced Photon Source (APS) of Argonne National Laboratory (ANL) on development of superconducting undulators culminated in December 2012 with the installation of the first superconducting undulator “SCU0” into Sector 6 of the APS storage ring. The device was commissioned in January 2013 and has been in user operation since. This paper presents the magnetic and cryogenic design of the SCU0 together with the results of stand-alone cold tests. The initial commissioning and characterization of SCU0 as well as its operating experience in the APS storage ring are described.

Broadband impedance calculations and single bunch instabilities estimations of of the HLS-II storage ring

NASA Astrophysics Data System (ADS)

Zhang, Qing-Kun; Wang, Lin; Li, Wei-Min; Gao, Wei-Wei

2015-12-01

The upgrade project of the Hefei Light Source storage ring is under way. In this paper, the broadband impedances of resistive wall and coated ceramic vacuum chamber are calculated using the analytic formula, and the wake fields and impedances of other designed vacuum chambers are simulated by CST code, and then a broadband impedance model is obtained. Using the theoretical formula, longitudinal and transverse single bunch instabilities are discussed. With the carefully-designed vacuum chamber, we find that the thresholds of the beam instabilities are higher than the beam current goal. Supported by Natural Science Foundation of China (11175182, 11175180)

Transparent lattice characterization with gated turn-by-turn data of diagnostic bunch train

NASA Astrophysics Data System (ADS)

Li, Yongjun; Cheng, Weixing; Ha, Kiman; Rainer, Robert

2017-11-01

Methods of characterization of a storage ring's lattice have traditionally been intrusive to routine operations. More importantly, the lattice seen by particles can drift with the beam current due to collective effects. To circumvent this, we have developed a novel approach for dynamically characterizing a storage ring's lattice that is transparent to operations. Our approach adopts a dedicated filling pattern which has a short, separate diagnostic bunch train (DBT). Through the use of a bunch-by-bunch feedback system, the DBT can be selectively excited on demand. Gated functionality of a beam position monitor system is capable of collecting turn-by-turn data of the DBT, from which the lattice can then be characterized after excitation. As the DBT comprises only about one percent of the total operational bunches, the effects of its excitation are negligible to users. This approach allows us to localize the distributed quadrupolar wakefields generated in the storage ring vacuum chamber during beam accumulation. While effectively transparent to operations, our approach enables us to dynamically control the beta beat and phase beat, and unobtrusively optimize performance of the National Synchrotron Light Source-II accelerator during routine operations.

Upgrade of BPM Electronics for the SPring-8 Storage Ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sasaki, Shigeki; Fujita, Takahiro; Shoji, Masazumi

2006-11-20

SPring-8, a 3rd generation synchrotron light source, has operated since 1997. Improvement of BPM performance is required as a part of upgrading activities of the storage ring as a light source. We have developed new electronics circuits for signal processing of the storage ring BPM, with target performance of sub-{mu}m range resolution with sufficiently fast measurement speed and good long-term stability. A set of the new circuits consists of multiplexers, an RF amplifier, a mixer, an IF amplifier, and a local oscillator for analog signal processing. The IF amplifier outputs are sampled with 16-bit 2-MSPS ADC on ADC boards andmore » the data are sent to a DSP board. The sampled data are processed and converted to position information in the DSP. A multiplexing method was employed to have a better stability of the performance by cancellation of variation common to each channel. Evaluation of the performance by using a prototype shows that position resolution well into the sub-{mu}m range has been achieved with a bandwidth of 1 kHz, and long-term stability of within 1 {mu}m has also been achieved.« less

Transparent lattice characterization with gated turn-by-turn data of diagnostic bunch train

DOE PAGES

Li, Yongjun; Cheng, Weixing; Ha, Kiman; ...

2017-11-21

Methods of characterization of a storage ring's lattice have traditionally been intrusive to routine operations. More importantly, the lattice seen by particles can drift with the beam current due to collective effects. To circumvent this, we have developed a novel approach for dynamically characterizing a storage ring's lattice that is transparent to operations. Our approach adopts a dedicated filling pattern which has a short, separate Diagnostic Bunch-Train (DBT). Through the use of a bunch-by-bunch feedback system, the DBT can be selectively excited on-demand. Gated functionality of a beam position monitor system is capable of collecting turn-by-turn data of the DBT,more » from which the lattice can then be characterized after excitation. As the DBT comprises only about one percent of the total operational bunches, the effects of its excitation are negligible to users. Therefore, this approach allows us to localize the distributed quadrupolar wake fields generated in the storage ring vacuum chamber during beam accumulation. While effectively transparent to operations, our approach enables us to dynamically control the beta-beat and phase-beat, and unobtrusively optimize performance of National Synchrotron Light Source-II accelerator during routine operations.« less

Electron cooling for the Fermilab recycler: Present concept and provisional parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagaitsev, S.

1997-09-01

In all scenarios of the possible Tevatron upgrades, luminosity is essentially proportional to the number of antiprotons. Thus, a tenfold increase in luminosity could be achieved by putting five times more protons on the antiproton production target and gaining an additional factor of two from recycling antiprotons left over from the previous store. Stacking and storing ten times more antiprotons puts an unbearable burden on the stochastic cooling system of the existing Accumulator Ring. Thus, one is led to consider an additional stage of antiproton storage the so called Recycler Ring. Electron cooling of the 8 GeV antiprotons in themore » Recycler could provide an attractive way around the problems of large stacks. Such a system would look much like the IUCF proposal to cool 12 GeV protons in the SSC Medium Energy Booster. Although electron cooling has now become a routine tool in many laboratories, its use has been restricted to lower energy accelerators (< 500 MeV/nucleon). An R&D program is currently underway at Fermilab to extend electron cooling technology to the GeV range. This paper describes the electron cooling system design as well as the Recycler ring parameters required to accommodate this system.« less

Delivery Ring Lattice Modifications for Transitionless Deceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnstone, J. A.; Syphers, M. J.

2016-10-09

A portion of the remnant Tevatron program infrastruc- ture at Fermilab is being reconfigured to be used for the generation and delivery of proton and muon beams for new high-precision particle physics experiments. With the 8 GeV Booster as its primary source, the Mu2e exper- iment will receive 8.9 GeV/c bunched beam on target, after being stored and slow spilled from the Delivery Ring (DR) -- a refurbished debuncher ring from Tevatron anti- proton production. For the Muon g-2 experiment, the DR will be tuned for 3.1 GeV/c to capture muons off of a target before sending them to thismore » experiment's Storage Ring. The apertures in the beam transport systems are optimized for the large muon beams of this lower-energy experiment. In order to provide further flexibility in the operation of the DR for future possible low-energy, high- intensity particle physics experiments (REDTOP[1], for example) and detector development, investigations are underway into the feasibility of decelerating beams from its maximum kinetic energy of 8 GeV level to lower en- ergies, down to 1-2 GeV. In this paper we look at possi- ble lattice modifications to the DR to avoid a transition crossing during the deceleration process. Hardware re- quirements and other operational implications of this scheme will also be discussed.« less

In-space inertial energy storage design

NASA Technical Reports Server (NTRS)

Studer, P. A.; Evans, H. E.

1981-01-01

Flywheel energy storage is a means of significantly improving the performance of space power systems. Two study contracts have been completed to investigate the merits of a magnetically suspended, ironless armature, ring rotor 'Mechanical Capacitor' design. The design of a suitable energy storage system is evaluated, taking into account baseline requirements, the motor generator, details regarding the suspension design, power conditioning, the rotor, and an example design. It appears on the basis of this evaluation that the inertial (flywheel) energy storage design is feasible.

Distributed trace using central performance counter memory

DOEpatents

Satterfield, David L; Sexton, James C

2013-10-22

A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

Distributed trace using central performance counter memory

DOEpatents

Satterfield, David L.; Sexton, James C.

2013-01-22

A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

15. DETAILED VIEW OF ENRICHED URANIUM STORAGE TANK. THE ADDITION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. DETAILED VIEW OF ENRICHED URANIUM STORAGE TANK. THE ADDITION OF THE GLASS RINGS SHOWN AT THE TOP OF THE TANK HELPS PREVENT THE URANIUM FROM REACHING CRITICALITY LIMITS. (4/12/62) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

A permanent-magnet rotor for a high-temperature superconducting bearing

NASA Astrophysics Data System (ADS)

Mulcahy, T. M.; Hull, J. R.; Uherka, K. L.; Abboud, R. G.; Wise, J. H.; Carnegie, D. W.

1995-06-01

Design, fabrication, and performance, of a 1/3-m dia., 10-kg flywheel rotor with only one bearing is discussed. To achieve low-loss energy storage, the rotor's segmented-ring permanent-magnet (PM) is optimized for levitation and circumferential homogeneity. The magnet's carbon composite bands enable practical energy storage.

Tuning the endothelial response: differential release of exocytic cargos from Weibel-Palade Bodies.

PubMed

Nightingale, Thomas D; McCormack, Jessica J; Grimes, William; Robinson, Christopher; Lopes da Silva, Mafalda; White, Ian J; Vaughan, Andrew; Cramer, Louise P; Cutler, Daniel F

2018-06-28

Endothelial cells harbour specialised storage organelles, Weibel-Palade Bodies (WPBs). Exocytosis of WPB content into the vascular lumen initiates primary haemostasis, mediated by Von Willebrands factor (VWF) and inflammation, mediated by several proteins including P-selectin. During full fusion, secretion of this large haemostatic protein and smaller pro-inflammatory proteins are thought to be inextricably linked. To determine if secretagogue-dependent differential release of WPB cargo occurs, and whether this is mediated by the formation of an actomyosin ring during exocytosis. We used VWF string analysis, leukocyte rolling assays, ELISA, spinning disk confocal microscopy, high-throughput confocal microscopy and inhibitor and siRNA treatments to demonstrate the existence of cellular machinery that allows differential release of WPB cargo proteins. Inhibition of the actomyosin ring differentially effects two processes regulated by WPB exocytosis; it perturbs VWF string formation but has no effect on leukocyte rolling. The efficiency of ring recruitment correlates with VWF release; the ratio of release of VWF to small cargoes decreases when ring recruitment is inhibited. The recruitment of the actin ring is time-dependent; fusion events occurring directly after stimulation are less likely to initiate haemostasis than later events, and is activated by PKC isoforms. Secretagogues differentially recruit the actomyosin ring, thus demonstrating one mechanism by which the pro-thrombotic effect of endothelial activation can be modulated. This potentially limits thrombosis whilst permitting a normal inflammatory response. These results have implications for the assessment of WPB fusion, cargo-content release and the treatment of patients with von Willebrand disease. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Energy storage apparatus

NASA Technical Reports Server (NTRS)

Studer, P. A.; Evans, H. E. (Inventor)

1978-01-01

A high efficiency, flywheel type energy storage device which comprises an electronically commutated d.c. motor/generator unit having a massive flywheel rotor magnetically suspended around a ring shaped stator is presented. During periods of low energy demand, the storage devices were operated as a motor, and the flywheel motor was brought up to operating speed. Energy was drawn from the device functioning as a generator as the flywheel rotor rotated during high energy demand periods.

Overview of a flywheel stack energy storage system

NASA Technical Reports Server (NTRS)

Kirk, James A.; Anand, Davinder K.

1988-01-01

The concept of storing electrical energy in rotating flywheels provides an attractive substitute to batteries. To realize these advantages the critical technologies of rotor design, composite materials, magnetic suspension, and high efficiency motor/generators are reviewed in this paper. The magnetically suspended flywheel energy storage system, currently under development at the University of Maryland, consisting of a family of interference assembled rings, is presented as an integrated solution for energy storage.

Nonlinear Delta-f Simulations of Collective Effects in Intense Charged Particle Beams

NASA Astrophysics Data System (ADS)

Qin, Hong

2002-11-01

A nonlinear delta-f particle simulation method based on the Vlasov-Maxwell equations has been recently developed to study collective processes in high-intensity beams, where space-charge and magnetic self-field effects play a critical role in determining the nonlinear beam dynamics. Implemented in the Beam Equilibrium, Stability and Transport (BEST) code, the nonlinear delta-f method provides a low-noise and self-consistent tool for simulating collective interactions and nonlinear dynamics of high-intensity beams in modern and next- generation accelerators and storage rings, such as the Spallation Neutron Source, and heavy ion fusion drivers. Simulation results for the electron-proton two-stream instability in the Proton Storage Ring (PSR) experiment at Los Alamos National Laboratory agree well with experimental observations. Large-scale parallel simulations have also been carried out for the ion-electron two-stream instability in the very high-intensity heavy ion beams envisioned for heavy ion fusion applications. In both cases, the simulation results indicate that the dominant two-stream instability has a dipole-mode (hose-like) structure and can be stabilized by a modest axial momentum spread of the beam particles of less than 0.25collective processes in high-intensity beams, such as anisotropy-driven instabilities, collective eigenmode excitations for perturbations about stable beam equilibria, and the Darwin model for fully electromagnetic perturbations will also be discussed.

Top-up operation at Pohang Light Source-II

NASA Astrophysics Data System (ADS)

Hwang, I.; Huang, J. Y.; Kim, M.; Lee, B.-J.; Kim, C.; Choi, J.-Y.; Kim, M.-H.; Lee, H. S.; Moon, D.; Lee, E. H.; Kim, D.-E.; Nam, S. H.; Shin, S.; Cho, Moohyun

2014-05-01

After three years of upgrading work, PLS-II (S. Shin, Commissioning of the PLS-II, JINST, January 2013) is now successfully operating. The top-up operation of the 3 GeV linear accelerator had to be delayed because of some challenges encountered, and PLS-II was run in decay mode at the beginning in March 2012. The main difficulties encountered in the top-up operation of PLS-II are different levels between the linear accelerator and the storage ring, the 14 narrow gap in-vacuum undulators in operation, and the full energy injection by 3 GeV linear accelerator. Large vertical emittance and energy jitter of the linac were the major obstacles that called for careful control of injected beam to reduce beam loss in the storage ring during injection. The following measures were taken to resolve these problems: (1) The high resolution Libera BPM (see http://www.i-tech.si) was implemented to measure the beam trajectory and energy. (2) Three slit systems were installed to filter the beam edge. (3) De-Qing circuit was applied to the modulator system to improve the energy stability of injected beam. As a result, the radiation by beam loss during injection is reduced drastically, and the top-up mode has been successfully operating since 19th March 2013. In this paper, we describe the experimental results of the PLS-II top-up operation and the improvement plan.

Space-charge-sustained microbunch structure in the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Cousineau, S.; Danilov, V.; Holmes, J.; Macek, R.

2004-09-01

We present experimental data from the Los Alamos Proton Storage Ring (PSR) showing long-lived linac microbunch structure during beam storage with no rf bunching. Analysis of the experimental data and particle-in-cell simulations of the experiments indicate that space charge, coupled with energy spread effects, is responsible for the sustained microbunch structure. The simulated longitudinal phase space of the beam reveals a well-defined separatrix in the phase space between linac microbunches, with particles executing unbounded motion outside of the separatrix. We show that the longitudinal phase space of the beam was near steady state during the PSR experiments, such that the separatrix persisted for long periods of time. Our simulations indicate that the steady state is very sensitive to the experimental conditions. Finally, we solve the steady-state problem in an analytic, self-consistent fashion for a set of periodic longitudinal space-charge potentials.

Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser

NASA Astrophysics Data System (ADS)

Adib, M. A. H. M.; Adnan, F.; Ismail, A. R.; Kardigama, K.; Salaam, H. A.; Ahmad, Z.; Johari, N. H.; Anuar, Z.; Azmi, N. S. N.

2012-09-01

Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ~ 60%) acceptable compared to diffuser with 6mm ~ 40% and 12mm ~ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).

Astrochemistry in TSR and CSR Ion Storage Rings

NASA Astrophysics Data System (ADS)

Novotny, Oldrich

2017-04-01

Dissociative recombination (DR) of molecular ions plays a key role in controlling the charge density and composition of the cold interstellar medium (ISM). Experimental data on DR are required in order to understand the chemical network in the ISM and related processes such as star formation from molecular clouds. Needed data include not only total reaction cross sections, but also the chemical composition and excitation states of the neutral products. Utilizing the TSR storage ring in Heidelberg, Germany, we have carried out DR measurements for astrophysically important molecular ions. We use a merged electron-ion beams technique combined with event-by-event fragment counting and fragment imaging. The count rate of detected neutral DR products yields the absolute DR rate coefficient. Imaging the distribution of fragment distances provides information on the kinetic energy released including the states of both the initial molecule and the final products. Additional kinetic energy sensitivity of the employed detector allows for identification of fragmentation channels by fragment-mass combination within each dissociation event. Such combined information is essential for studies on DR of polyatomic ions with multi-channel breakup. The recently commissioned Cryogenic Storage Ring (CSR) in Heidelberg, Germany, extends the experimental capabilities of TSR by operation at cryogenic temperatures down to 6 K. At these conditions residual gas densities down to 100 cm-3 can be reached resulting in beam storage times of several hours. Long storage in the cold environment allows the ions to relax down to their rotational ground state, thus mimicking well the conditions in the cold ISM. A variety of astrophysically relevant reactions will be investigated at these conditions, such as DR, electron impact excitation, ion-neutral collisions, etc. We report our TSR results on DR of HCl+ and D2Cl+. We also present first results from the CSR commissioning experiments.

Electric fields, electron production, and electron motion at the stripper foil in the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Plum, M.

The beam instability at the Los Alamos Proton Storage Ring (PSR) most likely involves coupled oscillations between electrons and protons. For this instability to occur, there must be a strong source of electrons. Investigation of the various sources of electrons in the PSR had begun. Copious electron production is expected in the injection section because this section contains the stripper foil. This foil is mounted near the center of the beam pipe, and both circulating and injected protons pass through it, thus allowing ample opportunity for electron production. This paper discusses various mechanisms for electron production, beam-induced electric fields, and electron motion in the vicinity of the foil.

Lifetimes of relativistic heavy-ion beams in the High Energy Storage Ring of FAIR

NASA Astrophysics Data System (ADS)

Shevelko, V. P.; Litvinov, Yu. A.; Stöhlker, Th.; Tolstikhina, I. Yu.

2018-04-01

The High Energy Storage Ring, HESR, will be constructed at the Facility for Antiproton and Ion Research, FAIR, Darmstadt. For the first time, it will be possible to perform experiments with cooled high-intensity stable and radioactive heavy ions at highly relativistic energies. To design experiments at the HESR, realistic estimations of beam lifetimes are indispensable. Here we report calculated cross sections and lifetimes for typical U88+ , U90+ , U92+ , Sn49+ and Sn50+ ions in the energy range E = 400 MeV/u-5 GeV/u, relevant for the HESR. Interactions with the residual gas and with internal gas-jet targets are also considered.

Benchmarking of Touschek Beam Lifetime Calculations for the Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, A.; Yang, B.

2017-06-25

Particle loss from Touschek scattering is one of the most significant issues faced by present and future synchrotron light source storage rings. For example, the predicted, Touschek-dominated beam lifetime for the Advanced Photon Source (APS) Upgrade lattice in 48-bunch, 200-mA timing mode is only ~ 2 h. In order to understand the reliability of the predicted lifetime, a series of measurements with various beam parameters was performed on the present APS storage ring. This paper first describes the entire process of beam lifetime measurement, then compares measured lifetime with the calculated one by applying the measured beam parameters. The resultsmore » show very good agreement.« less

Emittance measurements in low energy ion storage rings

NASA Astrophysics Data System (ADS)

Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

2018-07-01

The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

Development and operating experience of a 1.1-m-long superconducting undulator at the Advanced Photon Source

NASA Astrophysics Data System (ADS)

Ivanyushenkov, Y.; Harkay, K.; Borland, M.; Dejus, R.; Dooling, J.; Doose, C.; Emery, L.; Fuerst, J.; Gagliano, J.; Hasse, Q.; Kasa, M.; Kenesei, P.; Sajaev, V.; Schroeder, K.; Sereno, N.; Shastri, S.; Shiroyanagi, Y.; Skiadopoulos, D.; Smith, M.; Sun, X.; Trakhtenberg, E.; Xiao, A.; Zholents, A.; Gluskin, E.

2017-10-01

Development of superconducting undulators continues at the Advanced Photon Source (APS). Two years after successful installation and commissioning of the first relatively short superconducting undulator "SCU0" in Sector 6 of the APS storage ring, the second 1.1-m-long superconducting undulator "SCU1" was installed in Sector 1 of the APS. The device has been in user operation since its commissioning in May 2015. This paper describes the magnetic and cryogenic design of the SCU1 together with the results of stand-alone cold tests. The SCU1's magnetic and cryogenic performance as well as its operating experience in the APS storage ring are also presented.

The Effect of Gas Ion Bombardment on the Secondary Electron Yield of TiN, TiCN and TiZrV Coatings For Suppressing Collective Electron Effects in Storage Rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Pimpec, F.; /PSI, Villigen; Kirby, R.E.

In many accelerator storage rings running positively charged beams, ionization of residual gas and secondary electron emission (SEE) in the beam pipe will give rise to an electron cloud which can cause beam blow-up or loss of the circulating beam. A preventative measure that suppresses electron cloud formation is to ensure that the vacuum wall has a low secondary emission yield (SEY). The SEY of thin films of TiN, sputter deposited Non-Evaporable Getters and a novel TiCN alloy were measured under a variety of conditions, including the effect of re-contamination from residual gas.

Search for the 1P 1 charmonium state in overlinepp annihilations at the CERN intersecting storage rings

NASA Astrophysics Data System (ADS)

Baglin, C.; Baird, S.; Bassompierre, G.; Borreani, G.; Brient, J.-C.; Broll, C.; Brom, J.-M.; Bugge, L.; Buran, T.; Burq, J.-P.; Bussière, A.; Buzzo, A.; Cester, R.; Chemarin, M.; Chevallier, M.; Escoubes, B.; Fay, J.; Ferroni, S.; Gracco, V.; Guillaud, J.-P.; Khan-Aronsen, E.; Kirsebom, K.; Kylling, A.; Ille, B.; Lambert, M.; Leistam, L.; Lundby, A.; Macri, M.; Marchetto, F.; Menichetti, E.; Mörch, Ch.; Mouellic, B.; Olsen, D.; Pastrone, N.; Petrillo, L.; Pia, M. G.; Poole, J.; Poulet, M.; Rinaudo, G.; Santroni, A.; Severi, M.; Skjevling, G.; Stapnes, S.; Stugu, B.; R704 Collaboration

1986-04-01

This experiment has been performed at the CERN Intersecting Storage Rings to study the direct formation of charmonium states in antiproton-proton annihilations. The experimental program has partly been devoted to an inclusive scan for overlinepp → J/ψ + X in the range 3520-3530 MeV/ c2. A cluster of five events has been observed in a narrow energy band, centred on the centre of gravity of the 3P J states where the 1P 1 is expected to be. When interpreted as a new resonace, these data yield a mass m = 3525.4±0.8 MeV/ c2.

A long-lived relativistic electron storage ring embedded in Earth's Outer Van Allen belt

DOE PAGES

Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; ...

2013-02-28

Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts are thought to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is comprised predominantly of mega-electron volt (MeV) electrons that wax and wane in intensity on time scales ranging from hours to days depending primarily on external forcing by the solar wind. Thus, the spatially separated inner zone is comprised of commingled high-energy electrons and very energetic positive ions (mostly protons), the latter being stable in intensity levels over years to decades. In situ energy-specific and temporally resolved spacecraft observations revealmore » an isolated third ring, or torus, of high-energy (E > 2 MeV) electrons that formed on 2 September 2012 and persisted largely unchanged in the geocentric radial range of 3.0 to ~3.5 Earth radii for over four weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.« less

Fermilab Muon Campus g-2 Cryogenic Distribution Remote Control System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pei, L.; Theilacker, J.; Klebaner, A.

2015-11-05

The Muon Campus (MC) is able to measure Muon g-2 with high precision and comparing its value to the theoretical prediction. The MC has four 300 KW screw compressors and four liquid helium refrigerators. The centerpiece of the Muon g-2 experiment at Fermilab is a large, 50-foot-diameter superconducting muon storage ring. This one-of-a-kind ring, made of steel, aluminum and superconducting wire, was built for the previous g-2 experiment at Brookhaven. Due to each subsystem has to be far away from each other and be placed in the distant location, therefore, Siemens Process Control System PCS7-400, Automation Direct DL205 & DL05more » PLC, Synoptic and Fermilab ACNET HMI are the ideal choices as the MC g-2 cryogenic distribution real-time and on-Line remote control system. This paper presents a method which has been successfully used by many Fermilab distribution cryogenic real-time and On-Line remote control systems.« less

Refrigeration provides a simple means to synchronize in vitro cultures of Plasmodium falciparum.

PubMed

Yuan, Lili; Hao, Mingming; Wu, Lanou; Zhao, Zhen; Rosenthal, Benjamin M; Li, Xiaomei; He, Yongshu; Sun, Ling; Feng, Guohua; Xiang, Zheng; Cui, Liwang; Yang, Zhaoqing

2014-05-01

Plasmodium falciparum is usually asynchronous during in vitro culture. Highly synchronized cultures of P. falciparum are routinely used in malaria research. Here, we describe a simple synchronization procedure for P. falciparum asexual erythrocytic culture, which involves storage at 4°C for 8-24 h followed by routine culture. When cultures with 27-60% of ring stage were synchronized using this procedure, 70-93% ring stages were obtained after 48 h of culture and relative growth synchrony remained for at least two erythrocytic cycles. To test the suitability of this procedure for subsequent work, drug sensitivity assays were performed using four laboratory strains and four freshly adapted clinical P. falciparum isolates. Parasites synchronized by sorbitol treatment or refrigeration showed similar dose-response curves and comparable IC50 values to four antimalarial drugs. The refrigeration synchronization method is simple, inexpensive, time-saving, and should be especially useful when large numbers of P. falciparum culture are handled. Copyright © 2014 Elsevier Inc. All rights reserved.

Refrigeration provides a simple means to synchronize in vitro cultures of Plasmodium falciparum

PubMed Central

Yuan, Lili; Hao, Mingming; Wu, Lanou; Zhao, Zhen; Rosenthal, Benjamin M.; Li, Xiaomei; He, Yongshu; Sun, Ling; Feng, Guohua; Xiang, Zheng; Cui, Liwang; Yang, Zhaoqing

2014-01-01

Plasmodium falciparum is usually asynchronous during in vitro culture. Highly synchronized cultures of Plasmodium falciparum are routinely used in malaria research. Here, we describe a simple synchronization procedure for P. falciparum asexual erythrocytic culture, which involves storage at 4°C for 8–24 h followed by routine culture. When cultures with 27–60% of ring stage were synchronized using this procedure, 70–93% ring stages were obtained after 48 h of culture and relative growth synchrony remained for at least two erythrocytic cycles. To test the suitability of this procedure for subsequent work, drug sensitivity assays were performed using four laboratory strains and four freshly adapted clinical P. falciparum isolates. Parasites synchronized by sorbitol treatment or refrigeration showed similar dose-response curves and comparable IC50 values to four antimalarial drugs. The refrigeration synchronization method is simple, inexpensive, time-saving, and should be especially useful when large numbers of P. falciparum culture are handled. PMID:24632190

Modification of a liquid hydrogen tank for integrated refrigeration and storage

NASA Astrophysics Data System (ADS)

Swanger, A. M.; Jumper, K. M.; Fesmire, J. E.; Notardonato, W. U.

2015-12-01

The modification and outfitting of a 125,000-liter liquid hydrogen tank was performed to provide integrated refrigeration and storage capability. These functions include zero boil-off, liquefaction, and densification and therefore require provisions for sub-atmospheric tank pressures within the vacuum-jacketed, multilayer insulated tank. The primary structural modification was to add stiffening rings inside the inner vessel. The internal stiffening rings were designed, built, and installed per the ASME Boiler and Pressure Vessel Code, Section VIII, to prevent collapse in the case of vacuum jacket failure in combination with sub-atmospheric pressure within the tank. For the integrated refrigeration loop, a modular, skeleton-type heat exchanger, with refrigerant temperature instrumentation, was constructed using the stiffening rings as supports. To support the system thermal performance testing, three custom temperature rakes were designed and installed along the 21-meter length of the tank, once again using rings as supports. The temperature rakes included a total of 20 silicon diode temperature sensors mounted both vertically and radially to map the bulk liquid temperature within the tank. The tank modifications were successful and the system is now operational for the research and development of integrated refrigeration technology.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkel, L.; Dejus, R.; Maines, J.

This report is a description of the current status of the magnetic measurement facility and is a basic instructional manual for the operation of the facility and its components. Please refer to the appendices for more detailed information about specific components and procedures. The purpose of the magnetic measurement facility is to take accurate measurements of the magnetic field in the gay of the IDs in order to determine the effect of the ID on the stored particle beam and the emitted radiation. The facility will also play an important role when evaluating new ideas, novel devices, and inhouse prototypesmore » as part of the ongoing research and development program at the APS. The measurements will be performed with both moving search coils and moving Hall probes. The IDs will be evaluated by computer modeling of the emitted radiation for any given (measured) magnetic field map. The quality of the magnetic field will be described in terms of integrated multipoles for the effect on Storage Ring performance and in terms of the derived trajectories for the emitted radiation. Before being installed on the Storage Ring, every device will be measured and characterized to assure that it is compatible with Storage Ring requirements and radiation specifications. The accuracy that the APS needs to achieve for magnetic measurements will be based on these specifications.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huamg, C. W., E-mail: huang.zw@nsrrc.org.tw; Hwang, C. S., E-mail: cshwang@nsrrc.org.tw; Department of Electrophysics, National Chiao Tung University, Hsinchu 300, Taiwan

The Taiwan Photon Source (TPS) has been successfully commissioned. However, the minimum emittance in the TPS lattice is 1.6 nm rad. In the existing TPS storage ring lattice, it is imperative to reduce the emittance to below 1 nm rad. Therefore, a feasibility study for reducing the effective emittance of the TPS storage ring by using a Robinson wiggler was launched; the reduction is necessary to enhance the photon brilliance. In this study, a permanent-magnet multiperiod Robinson wiggler (MRW) was developed for use instead of the single-period Robinson wiggler. In general, the quadruple field of a combined function magnet inmore » the storage ring is approximately few tesla per meter. According to beam dynamic analysis, we found that it is necessary to adopt a high gradient (40 T/m) combined-function MRW magnet to reduce the emittance effectively. Therefore, a high gradient field strength is required in the combined function MRW magnet. In this study, the quadrupole field strength of the MRW magnet was allowed to be approximately 40 T/m at a magnet gap of 20 mm. The period length of the MRW magnet was 300 mm and the period number was 16. The of MRWs is discussed in regard to the possibility of increasing the photon brilliance from IU22.« less

Electron cooling of a bunched ion beam in a storage ring

NASA Astrophysics Data System (ADS)

Zhao, He; Mao, Lijun; Yang, Jiancheng; Xia, Jiawen; Yang, Xiaodong; Li, Jie; Tang, Meitang; Shen, Guodong; Ma, Xiaoming; Wu, Bo; Wang, Geng; Ruan, Shuang; Wang, Kedong; Dong, Ziqiang

2018-02-01

A combination of electron cooling and rf system is an effective method to compress the beam bunch length in storage rings. A simulation code based on multiparticle tracking was developed to calculate the bunched ion beam cooling process, in which the electron cooling, intrabeam scattering (IBS), ion beam space-charge field, transverse and synchrotron motion are considered. Meanwhile, bunched ion beam cooling experiments have been carried out in the main cooling storage ring (CSRm) of the Heavy Ion Research Facility in Lanzhou, to investigate the minimum bunch length obtained by the cooling method, and study the dependence of the minimum bunch length on beam and machine parameters. The experiments show comparable results to those from simulation. Based on these simulations and experiments, we established an analytical model to describe the limitation of the bunch length of the cooled ion beam. It is observed that the IBS effect is dominant for low intensity beams, and the space-charge effect is much more important for high intensity beams. Moreover, the particles will not be bunched for much higher intensity beam. The experimental results in CSRm show a good agreement with the analytical model in the IBS dominated regime. The simulation work offers us comparable results to those from the analytical model both in IBS dominated and space-charge dominated regimes.

Multi-MHz time-of-flight electronic bandstructure imaging of graphene on Ir(111)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tusche, C., E-mail: c.tusche@fz-juelich.de; Peter Grünberg Institut; Goslawski, P.

2016-06-27

In the quest for detailed spectroscopic insight into the electronic structure at solid surfaces in a large momentum range, we have developed an advanced experimental approach. It combines the 3D detection scheme of a time-of-flight momentum microscope with an optimized filling pattern of the BESSY II storage ring. Here, comprehensive data sets covering the full surface Brillouin zone have been used to study faint substrate-film hybridization effects in the electronic structure of graphene on Ir(111), revealed by a pronounced linear dichroism in angular distribution. The method paves the way to 3D electronic bandmapping with unprecedented data recording efficiency.

Fermilab Tevatron and Pbar source status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, H.

1986-08-01

The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently undermore » evaluation to accomplish these goals: luminosity increase to 5 x 10/sup 31/ cm/sup -2/sec/sup -1/, production rates up to 4 x 10/sup 11/ antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade. (LEW)« less

Kicker field simulation and measurement for the muon g-2 experiment at FNAL

NASA Astrophysics Data System (ADS)

Chang, Seung Pyo; Kim, Young Im; Choi, Jihoon; Semertzidis, Yannis; muon g-2 experiment Collaboration

2017-01-01

In the Muon g-2 experiment, muon beam is injected to the storage ring in a slightly tilted orbit whose center is 77 mm away from the center of the ring. The kicker is needed to send the muon beam to the central orbit. The magnetic kicker is designed for the experiment and about 0.1 Tm field integral is needed. The peak current pulse is 4200 A to make this field integral. This strong kicker pulse could make unwanted eddy current occur. This eddy current could spoil the main magnetic field of the storage ring. This could be a critical threat to the precision of experiment. The kicker field simulation has done using OPERA to estimate the effects. Also the kicker field should be measured based on Faraday effect. The measurement has tested in the lab before install the experiment area. In this presentation, the simulation and measurement results will be discussed. This work was supported by IBS-R017-D1-2016-a00.

Nuclear-matter radius studies from 58Ni(α ,α ) experiments at the GSI Experimental Storage Ring with the EXL facility

NASA Astrophysics Data System (ADS)

Zamora, J. C.; Aumann, T.; Bagchi, S.; Bönig, S.; Csatlós, M.; Dillmann, I.; Dimopoulou, C.; Egelhof, P.; Eremin, V.; Furuno, T.; Geissel, H.; Gernhäuser, R.; Harakeh, M. N.; Hartig, A.-L.; Ilieva, S.; Kalantar-Nayestanaki, N.; Kiselev, O.; Kollmus, H.; Kozhuharov, C.; Krasznahorkay, A.; Kröll, Th.; Kuilman, M.; Litvinov, S.; Litvinov, Yu. A.; Mahjour-Shafiei, M.; Mutterer, M.; Nagae, D.; Najafi, M. A.; Nociforo, C.; Nolden, F.; Popp, U.; Rigollet, C.; Roy, S.; Scheidenberger, C.; von Schmid, M.; Steck, M.; Streicher, B.; Stuhl, L.; Thürauf, M.; Uesaka, T.; Weick, H.; Winfield, J. S.; Winters, D.; Woods, P. J.; Yamaguchi, T.; Yue, K.; Zenihiro, J.

2017-09-01

A novel method for measuring nuclear reactions in inverse kinematics with stored ion beams was successfully used to extract the nuclear-matter radius of 58Ni. The experiment was performed at the experimental heavy-ion storage ring at the GSI facility using a stored 58Ni beam at energies of 100 and 150 MeV/u and an internal helium gas-jet target. Elastically scattered α -recoils at low momentum transfers were measured with an in-ring detector system compatible with ultrahigh vacuum. Experimental angular distributions were fitted using density-dependent optical model potentials within the eikonal approximation. This permitted the extraction of the point-matter root-mean-square radius of 58Ni with an average value of 3.70(7) fm. Results from this work are in good agreement with several experiments performed in the past in normal kinematics. This pioneering experiment demonstrates a major breakthrough towards future investigations with far-from-stability stored beams using the present technique.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Talman, Richard M.; Talman, John D.

Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring “trap.” At the “magic” kinetic energy of 232.792 MeV, proton spins are “frozen,” for example always parallel to the instantaneous particle momentum. Energy deviation from the magic value causes in-plane precession of the spin relative to the momentum. Any nonzero EDM value will cause out-of-plane precession—measuring this precession is the basis for the EDM determination. A proposed implementation of this measurement shows that a proton EDM value of 10 –29e–cm or greater will produce a statisticallymore » significant, measurable precession after multiply repeated runs, assuming small beam depolarization during 1000 s runs, with high enough precision to test models of the early universe developed to account for the present day particle/antiparticle population imbalance. This paper describes an accelerator simulation code, eteapot, a new component of the Unified Accelerator Libraries (ual), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the nonconstant particle velocity in electric rings gives them significantly different properties, especially in weak focusing rings. Like the earlier code teapot (for magnetic ring simulation) this code performs exact tracking in an idealized (approximate) lattice rather than the more conventional approach, which is approximate tracking in a more nearly exact lattice. The Bargmann-Michel-Telegdi (BMT) equation describing the evolution of spin vectors through idealized bend elements is also solved exactly—original to this paper. Furthermore the idealization permits the code to be exactly symplectic (with no artificial “symplectification”). Any residual spurious damping or antidamping is sufficiently small to permit reliable tracking for the long times, such as the 1000 s assumed in estimating the achievable EDM precision. This paper documents in detail the theoretical formulation implemented in eteapot. An accompanying paper describes the practical application of the eteapot code in the Universal Accelerator Libraries (ual) environment to “resurrect,” or reverse engineer, the “AGS-analog” all-electric ring built at Brookhaven National Laboratory in 1954. Of the (very few) all-electric rings ever commissioned, the AGS-analog ring is the only relativistic one and is the closest to what is needed for measuring proton (or, even more so, electron) EDM’s. As a result, the companion paper also describes preliminary lattice studies for the planned proton EDM storage rings as well as testing the code for long time orbit and spin tracking.« less

An undulator based soft x-ray source for microscopy on the Duke electron storage ring

NASA Astrophysics Data System (ADS)

Johnson, Lewis Elgin

1998-09-01

This dissertation describes the design, development, and installation of an undulator-based soft x-ray source on the Duke Free Electron Laser laboratory electron storage ring. Insertion device and soft x-ray beamline physics and technology are all discussed in detail. The Duke/NIST undulator is a 3.64-m long hybrid design constructed by the Brobeck Division of Maxwell Laboratories. Originally built for an FEL project at the National Institute of Standards and Technology, the undulator was acquired by Duke in 1992 for use as a soft x-ray source for the FEL laboratory. Initial Hall probe measurements on the magnetic field distribution of the undulator revealed field errors of more than 0.80%. Initial phase errors for the device were more than 11 degrees. Through a series of in situ and off-line measurements and modifications we have re-tuned the magnet field structure of the device to produce strong spectral characteristics through the 5th harmonic. A low operating K has served to reduce the effects of magnetic field errors on the harmonic spectral content. Although rms field errors remained at 0.75%, we succeeded in reducing phase errors to less than 5 degrees. Using trajectory simulations from magnetic field data, we have computed the spectral output given the interaction of the Duke storage ring electron beam and the NIST undulator. Driven by a series of concerns and constraints over maximum utility, personnel safety and funding, we have also constructed a unique front end beamline for the undulator. The front end has been designed for maximum throughput of the 1st harmonic around 40A in its standard mode of operation. The front end has an alternative mode of operation which transmits the 3rd and 5th harmonics. This compact system also allows for the extraction of some of the bend magnet produced synchrotron and transition radiation from the storage ring. As with any well designed front end system, it also provides excellent protection to personnel and to the storage ring. A diagnostic beamline consisting of a transmission grating spectrometer and scanning wire beam profile monitor was constructed to measure the spatial and spectral characteristics of the undulator radiation. Test of the system with a circulating electron beam has confirmed the magnetic and focusing properties of the undulator, and verified that it can be used without perturbing the orbit of the beam.

Multifluid geo-energy systems: Using geologic CO 2 storage for geothermal energy production and grid-scale energy storage in sedimentary basins

DOE PAGES

Buscheck, Thomas A.; Bielicki, Jeffrey M.; Edmunds, Thomas A.; ...

2016-05-05

We present an approach that uses the huge fluid and thermal storage capacity of the subsurface, together with geologic carbon dioxide (CO 2) storage, to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources, as well as excess energy on electric grids. Captured CO 2 is injected into saline aquifers to store pressure, generate artesian flow of brine, and provide a supplemental working fluid for efficient heat extraction and power conversion. Concentric rings of injection and production wells create a hydraulic mound to store pressure, CO 2, and thermal energy. This energy storage canmore » take excess power from the grid and excess/waste thermal energy, and dispatch that energy when it is demanded and thus enable higher penetration of variable renewable energy technologies (e.g., wind, solar). CO 2 stored in the subsurface functions as a cushion gas to provide enormous pressure-storage capacity and displace large quantities of brine, some of which can be treated for a variety of beneficial uses. Geothermal power and energy-storage applications may generate enough revenues to compensate for CO 2 capture costs. While our approach can use nitrogen (N 2), in addition to CO 2, as a supplemental fluid, and store thermal energy, this study focuses using CO 2 for geothermal energy production and grid-scale energy storage. We conduct a techno-economic assessment to determine the levelized cost of electricity of using this approach to generate geothermal power. We present a reservoir pressure-management strategy that diverts a small portion of the produced brine for beneficial consumptive use to reduce the pumping cost of fluid recirculation, while reducing the risk of seismicity, caprock fracture, and CO 2 leakage.« less

Sensory acceptability of squid rings gamma irradiated for shelf-life extension

NASA Astrophysics Data System (ADS)

Tomac, Alejandra; Cova, María C.; Narvaiz, Patricia; Yeannes, María I.

2017-01-01

The feasibility of extending the shelf-life of a squid product by gamma irradiation was analyzed. Illex argentinus rings were irradiated at 4 and 8 kGy; and stored at 4±1 °C during 77 days. No mesophilic bacteria, enterobacteriaceae and coliforms were detected in irradiated rings during storage. Psychrotrophic bacteria were significantly reduced by irradiation; their counts were fitted to a growth model which was further used for shelf-life estimations: 3 and 27 days for 0 and 4 kGy, respectively. Initially, non-irradiated as well as irradiated rings had very good sensory scores. The overall acceptability of 4 and 8 kGy rings did not decrease during 27 and 64 days, respectively, while control samples spoiled after 3 days. A radiation dose range for squid rings preservation was defined, which attained the technological shelf-life extension objective, without impairing sensory quality.

Correction to AD/RHIC-47, Beam Transfer From AGS to RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Claus, J.; Foelsche, H.

1988-12-12

RHIC an acronym for Relativistic Heavy Ion Collider, is a facility for colliding heavy ions with each other, proposed for construction at Brookhaven National Laboratory. This facility and the motivation for building it, have been described. It consists of two intersecting storage rings and the purpose of this note is to describe how these two rings are to be filled with beam.

Simulation of emittance dilution in electron storage ring from Compton backscattering

NASA Astrophysics Data System (ADS)

Blumberg, L. N.; Blum, E.

A Monte-Carlo simulation of Compton backscattered kappa(sub L) = 3.2-micron photons from an IR-FEL on 75-MeV electrons in a storage ring yields an RMS electron energy spread of delta(sub E) = 11.9-keV for a sample of 10(exp 7) single scattering events. Electrons are sampled from a beam of natural energy spread sigma(sub E) = 5.6-keV and damped transverse angle spreads sigma(sub x)(prime) = .041-mrad and sigma(sub y)(prime) = .052-mrad (100%) coupling, scaled from the 200-MeV BNL XLS compact storage ring. The Compton-scattered x-rays are generated from an integral of the CM Klein-Nishina cross-section transformed to the lab. A tracking calculation has also been performed in 6-dimensional phase space. Initial electron coordinates are selected randomly from a Gaussian distribution of RMS spreads sigma(sub xo) = .102-mm, sigma(sub x(prime)o) = .041-mrad, sigma(sub yo) = .018-mm, sigma(sub y(prime)o) = .052-mrad, sigma(sub (phi)o) = 22-mrad and sigma(sub Eo) = 6-keV. A sample of 10000 electrons were each following for 40000 turns around the ring through an RF cavity of f(sub RF) = 211.54-MHz and peak voltage V(sub m)=300-keV. Preliminary results indicate that the resulting energy distribution is quite broad with an RMS width of delta(sub E) = 124-keV. The transverse widths are only slightly increased from their original values, i.e. delta(sub x) = .106-mm and delta(sub x)(prime) = .043 mrad. The scaled energy spread of delta(sub E) approximately = 360-keV for approximately 350,000 turns desired in a 10-msec x-ray angiography exposure is well within the RF bucket used here; even V(sub m) less than 50-kV is adequate. Further, the electron energy spread adds a negligible RMS x-ray energy spread of delta(sub Ex) = .32-keV. The electron energy damping time of tau(sub E) = 379-msec at 75-MeV in an XLS-type ring allows for damping this induced spread and top-off of the ring between heart cycles.

Impact parameter sensitive study of inner-shell atomic processes in the experimental storage ring

NASA Astrophysics Data System (ADS)

Gumberidze, A.; Kozhuharov, C.; Zhang, R. T.; Trotsenko, S.; Kozhedub, Y. S.; DuBois, R. D.; Beyer, H. F.; Blumenhagen, K.-H.; Brandau, C.; Bräuning-Demian, A.; Chen, W.; Forstner, O.; Gao, B.; Gassner, T.; Grisenti, R. E.; Hagmann, S.; Hillenbrand, P.-M.; Indelicato, P.; Kumar, A.; Lestinsky, M.; Litvinov, Yu. A.; Petridis, N.; Schury, D.; Spillmann, U.; Trageser, C.; Trassinelli, M.; Tu, X.; Stöhlker, Th.

2017-10-01

In this work, we present a pilot experiment in the experimental storage ring (ESR) at GSI devoted to impact parameter sensitive studies of inner shell atomic processes for low-energy (heavy-) ion-atom collisions. The experiment was performed with bare and He-like xenon ions (Xe54+, Xe52+) colliding with neutral xenon gas atoms, resulting in a symmetric collision system. This choice of the projectile charge states was made in order to compare the effect of a filled K-shell with the empty one. The projectile and target X-rays have been measured at different observation angles for all impact parameters as well as for the impact parameter range of ∼35-70 fm.

Ultrashort high-brightness pulses from storage rings

NASA Astrophysics Data System (ADS)

Khan, Shaukat

2017-09-01

The brightness of short-wavelength radiation from accelerator-based sources can be increased by coherent emission in which the radiation intensity scales with the number of contributing electrons squared. This requires a microbunched longitudinal electron distribution, which is the case in free-electron lasers. The brightness of light sources based on electron storage rings was steadily improved, but could profit further from coherent emission. The modulation of the electron energy by a continuous-wave laser field may provide steady-state microbunching in the infrared regime. For shorter wavelengths, the energy modulation can be converted into a temporary density modulation by a dispersive chicane. One particular goal is coherent emission from a very short "slice" within an electron bunch in order to produce ultrashort radiation pulses with high brightness.

Astrochemistry at the Cryogenic Storage Ring

NASA Astrophysics Data System (ADS)

Kreckel, Holger; Becker, Arno; Blaum, Klaus; Breitenfeldt, Christian; George, Sebastian; Göck, Jürgen; Grieser, Manfred; Grussie, Florian; Guerin, Elisabeth; Heber, Oded; Karthein, Jonas; Krantz, Claude; Meyer, Christian; Mishra, Preeti; Novotny, Oldrich; O'Connor, Aodh; Saurabh, Sunny; Schippers, Stefan; Spruck, Kaija; Kumar, S. Sunil; Urbain, Xavier; Vogel, Stephen; von Hahn, Robert; Wilhelm, Patrick; Wolf, Andreas; Zajfman, Daniel

2017-01-01

Almost 200 different molecular species have been identified in space, and this number continues to grow steadily. This surprising molecular diversity bears witness to an active reaction network, in which molecular ions are the main drivers of chemistry in the gas phase. To study these reactions under controlled conditions in the laboratory is a major experimental challenge. The new Cryogenic Storage Ring (CSR) that has recently been commissioned at the Max Planck Institute for Nuclear Physics in Heidelberg will serve as an ideal testbed to study cold molecular ions in the gas phase. With residual gas densities of <140 cm-3 and temperatures below 10K, the CSR will allow for merged beams collision studies involving molecular ions, neutral atoms, free electrons and photons under true interstellar conditions.

Measurement of the Two-Photon Exchange Contribution to the Elastic e ± p Scattering Cross Sections at the VEPP-3 Storage Ring

DOE PAGES

Rachek, I. A.; Arrington, J.; Dmitriev, V. F.; ...

2015-02-12

The ratio of the elastic e +p to e –p scattering cross sections has been measured precisely, allowing the determination of the two-photon exchange contribution to these processes. This neglected contribution is believed to be the cause of the discrepancy between the Rosenbluth and polarization transfer methods of measuring the proton electromagnetic form factors. The experiment was performed at the VEPP-3 storage ring at beam energies of 1.6 and 1.0 GeV and at lepton scattering angles between 15° and 105°. The data obtained show evidence of a significant two-photon exchange effect. Furthermore, the results are compared with several theoretical predictions.

ALS superbend magnet performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, Steve; Zbasnik, John; Byrne, Warren

2001-12-10

The Lawrence Berkeley National Laboratory has been engaged in the design, construction and testing of four superconducting dipoles (Superbends) that are installed in three arcs of the Advanced Light Source (ALS), with the fourth magnet as a spare. This represents a major upgrade to the ALS providing an enhanced flux and brightness at photon energies above 10 keV. In preparation for installation, an extensive set of tests and measurements have been conducted to characterize the magnetic and cryogenic performance of the Superbends and to fiducialize them for accurate placement in the ALS storage ring. The magnets are currently installed, andmore » the storage ring is undergoing final commissioning. This paper will present the results of magnetic and cryogenic testing.« less

Research and Development on the Storage Ring Vacuum System for the APS Upgrade Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stillwell, B.; Brajuskovic, B.; Carter, J.

A number of research and development activities are underway at Argonne National Laboratory to build confidence in the designs for the storage ring vacuum system required for the Advanced Photon Source Up-grade project (APS-U) [1]. The predominant technical risks are: excessive residual gas pressures during operation; insufficient beam position monitor stability; excessive beam impedance; excessive heating by induced electrical surface currents; and insufficient operational reliability. Present efforts to mitigate these risks include: building and evaluating mockup assemblies; performing mechanical testing of chamber weld joints; developing computational tools; investigating design alternatives; and performing electrical bench measurements. Status of these activities andmore » some of what has been learned to date will be shared.« less

Prospects of high-resolution resonant X-ray inelastic scattering studies on solid materials, liquids and gases at diffraction-limited storage rings.

PubMed

Schmitt, Thorsten; de Groot, Frank M F; Rubensson, Jan Erik

2014-09-01

The spectroscopic technique of resonant inelastic X-ray scattering (RIXS) will particularly profit from immensely improved brilliance of diffraction-limited storage rings (DLSRs). In RIXS one measures the intensities of excitations as a function of energy and momentum transfer. DLSRs will allow for pushing the achievable energy resolution, signal intensity and the sampled spot size to new limits. With RIXS one nowadays probes a broad range of electronic systems reaching from simple molecules to complex materials displaying phenomena like peculiar magnetism, two-dimensional electron gases, superconductivity, photovoltaic energy conversion and heterogeneous catalysis. In this article the types of improved RIXS studies that will become possible with X-ray beams from DLSRs are envisioned.

FY2017 status report: Model 9975 O-ring fixture long-term leak performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W. L.

A series of experiments to monitor the aging performance of Viton® GLT and GLT-S O-rings used in the Model 9975 shipping package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups with GLT O-rings were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially andmore » have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, a smaller test matrix with fourteen additional tests was initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. Leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The 300 °F GLT O-ring fixtures failed after 2.8 to 5.7 years at temperature. The remaining GLT O-ring fixtures aging at 300 ºF were retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 9 to 10.5 years, or in GLT O-ring fixtures aging at 270 ºF for 5.7 years. These aging temperatures bound O-ring temperatures anticipated during normal storage in K-Area Complex (KAC). Leak test failures have been experienced in all of the GLT-S O-ring fixtures aging at 300 ºF and above. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 and 250 ºF for 6.9 to 7.5 years. Data from the O-ring fixtures are generally consistent with results from compression stress relaxation testing, and provide confidence in the predictive models based on those results. However, uncertainty still exists in extrapolating these elevated temperature results to the lower temperatures of interest for normal storage in KAC. Measurement of compression set in O-rings removed from failed fixtures, compared to that from KAC surveillance O-rings, indicates margin remains for O-rings still in service. Aging and periodic leak testing will continue for the remaining PCV fixtures.« less

Upgrades at the Duke Free Electron Laser Laboratory

NASA Astrophysics Data System (ADS)

Howell, Calvin R.

2004-11-01

Major upgrades to the storage-ring based photon sources at the Duke Free Electron Laser Laboratory (DFELL) are underway. The photon sources at the DFELL are well suited for research in the areas of medicine, biophysics, accelerator physics, nuclear physics and material science. These upgrades, which will be completed by the summer 2006, will significantly enhance the capabilities of the ultraviolet (UV) free-electron laser (FEL) and the high intensity gamma-ray source (HIGS). The HIGS is a relatively new research facility at the DFELL that is operated jointly by the DFELL and the Triangle Universities Nuclear Laboratory. The gamma-ray beam is produced by Compton back scattering of the UV photons inside the FEL optical cavity off the circulating electrons in the storage ring. The gamma-ray beam is 100% polarized and its energy resolution is selected by collimation. The capabilities of the upgraded facility will be described, the status of the upgrades will be summarized, and the proposed first-generation research program at HIGS will be presented.

Next Generation Muon g-2 Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hertzog, David W.

2015-12-02

I report on the progress of two new muon anomalous magnetic moment experiments, which are in advanced design and construction phases. The goal of Fermilab E989 is to reduce the experimental uncertainty ofmore » $$a_\\mu$$ from Brookhaven E821 by a factor of 4; that is, $$\\delta a_\\mu \\sim 16 \\times 10^{-11}$$, a relative uncertainty of 140~ppb. The method follows the same magic-momentum storage ring concept used at BNL, and pioneered previously at CERN, but muon beam preparation, storage ring internal hardware, field measuring equipment, and detector and electronics systems are all new or upgraded significantly. In contrast, J-PARC E34 will employ a novel approach based on injection of an ultra-cold, low-energy, muon beam injected into a small, but highly uniform magnet. Only a small magnetic focusing field is needed to maintain storage, which distinguishes it from CERN, BNL and Fermilab. E34 aims to roughly match the previous BNL precision in their Phase~1 installation.« less

AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar

PubMed Central

Patrut, Adrian; Patrut, Roxana T.; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A.; von Reden, Karl F.

2016-01-01

The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old. PMID:26760300

AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar.

PubMed

Patrut, Adrian; Patrut, Roxana T; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A; von Reden, Karl F

2016-01-01

The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old.

Top-up operation at Pohang Light Source-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, I.; Huang, J. Y.; Kim, M.

2014-05-15

After three years of upgrading work, PLS-II (S. Shin, Commissioning of the PLS-II, JINST, January 2013) is now successfully operating. The top-up operation of the 3 GeV linear accelerator had to be delayed because of some challenges encountered, and PLS-II was run in decay mode at the beginning in March 2012. The main difficulties encountered in the top-up operation of PLS-II are different levels between the linear accelerator and the storage ring, the 14 narrow gap in-vacuum undulators in operation, and the full energy injection by 3 GeV linear accelerator. Large vertical emittance and energy jitter of the linac weremore » the major obstacles that called for careful control of injected beam to reduce beam loss in the storage ring during injection. The following measures were taken to resolve these problems: (1) The high resolution Libera BPM (see http://www.i-tech.si ) was implemented to measure the beam trajectory and energy. (2) Three slit systems were installed to filter the beam edge. (3) De-Qing circuit was applied to the modulator system to improve the energy stability of injected beam. As a result, the radiation by beam loss during injection is reduced drastically, and the top-up mode has been successfully operating since 19th March 2013. In this paper, we describe the experimental results of the PLS-II top-up operation and the improvement plan.« less

Radiation energy conversion in space

NASA Technical Reports Server (NTRS)

Billman, K. W.

1979-01-01

Topics discussed at the third NASA conference on radiant energy conversion are reviewed. The unconcentrated-photovoltaic-generation version of a solar power satellite is described, noting that it will consist of a 21.3 x 5.3-sq-km silicon-solar-cell array expected to provide 17 Gw of electrical power, with 1 km in diam transmitters oriented to beam 2.45 GHz microwave power to two receiving/rectifying 'rectennas' on earth. The Solares space-energy-system concept, designed for providing a large fraction of the world's energy needs at costs comparable to those of future coal/nuclear alternative, is considered, as are subsystems for improving the economics of the solar power satellite. A concept proposing the use of relativistic-electron-storage rings for electron-beam energy transmission and storage, and a report on the production of a high temperature plasma with concentrated solar radiation are taken into account. Laser-conversion systems, including the direct-solar-pumped space laser, and the telec-powered spacecraft, are discussed.

Radiation energy conversion in space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Billman, K.W.

1979-03-01

Topics discussed at the third NASA conference on radiant energy conversion are reviewed. The unconcentrated-photovoltaic-generation version of a solar power satellite is described, noting that it will consist of a 21.3 x 5.3-sq-km silicon-solar-cell array expected to provide 17 Gw of electrical power, with 1 km in diam transmitters oriented to beam 2.45 GHz microwave power to two receiving/rectifying 'rectennas' on earth. The Solares space-energy-system concept, designed for providing a large fraction of the world's energy needs at costs comparable to those of future coal/nuclear alternative, is considered, as are subsystems for improving the economics of the solar power satellite.more » A concept proposing the use of relativistic-electron-storage rings for electron-beam energy transmission and storage, and a report on the production of a high temperature plasma with concentrated solar radiation are taken into account. Laser-conversion systems, including the direct-solar-pumped space laser, and the telec-powered spacecraft, are discussed.« less

Spin Pit Application of Image Derotated Holographic Interferometry.

DTIC Science & Technology

1980-09-01

temperatures resulting from induction heating of the test structuore through the interaction of the electromagnets and the magnetic ring. Subsequent...reference beam, and a Tektronix Model 7633 storage oscilloscope. When the laser is fired, a trigger signal from the laser power supply initiates the...rapid induction heating of the test structure due to the interaction of the electromagnets and the magnetic ring was evi(lent with the switch from dc to

Diagnostic Systems Plan for the Advanced Light Source Top-OffUpgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barry, Walter; Chin, Mike; Robin, David

2005-05-10

The Advanced Light Source (ALS) will soon be upgraded to enable top-off operations [1], in which electrons are quasi-continuously injected to produce constant stored beam current. The upgrade is structured in two phases. First, we will upgrade our injector from 1.5 GeV to 1.9 GeV to allow full energy injection and will start top-off operations. In the second phase, we will upgrade the Booster Ring (BR) with a bunch cleaning system to allow high bunch purity top-off injection. A diagnostics upgrade will be crucial for success in both phases of the top-off project, and our plan for it is describedmore » in this paper. New booster ring diagnostics will include updated beam position monitor (BPM) electronics, a tune monitoring system, and a new scraper. Two new synchrotron light monitors and a beam stop will be added to the booster-to-storage ring transfer line (BTS), and all the existing beam current monitors along the accelerator chain will be integrated into a single injection efficiency monitoring application. A dedicated bunch purity monitor will be installed in the storage ring (SR). Together, these diagnostic upgrades will enable smooth commissioning of the full energy injector and a quick transition to high quality top-off operation at the ALS.« less

The cryogenic storage ring CSR

NASA Astrophysics Data System (ADS)

von Hahn, R.; Becker, A.; Berg, F.; Blaum, K.; Breitenfeldt, C.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Heber, O.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; O'Connor, A. P.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Saurabh, S.; Schippers, S.; Schröter, C. D.; Schwalm, D.; Schweikhard, L.; Sieber, T.; Shornikov, A.; Spruck, K.; Sunil Kumar, S.; Ullrich, J.; Urbain, X.; Vogel, S.; Wilhelm, P.; Wolf, A.; Zajfman, D.

2016-06-01

An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm-3 is derived, equivalent to a room-temperature pressure below 10-14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

The cryogenic storage ring CSR.

PubMed

von Hahn, R; Becker, A; Berg, F; Blaum, K; Breitenfeldt, C; Fadil, H; Fellenberger, F; Froese, M; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; Heber, O; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lange, M; Laux, F; Lohmann, S; Menk, S; Meyer, C; Mishra, P M; Novotný, O; O'Connor, A P; Orlov, D A; Rappaport, M L; Repnow, R; Saurabh, S; Schippers, S; Schröter, C D; Schwalm, D; Schweikhard, L; Sieber, T; Shornikov, A; Spruck, K; Sunil Kumar, S; Ullrich, J; Urbain, X; Vogel, S; Wilhelm, P; Wolf, A; Zajfman, D

2016-06-01

An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

The insertion device magnetic measurement facility: Prototype and operational procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkel, L.; Dejus, R.; Maines, J.

1993-03-01

This report is a description of the current status of the magnetic measurement facility and is a basic instructional manual for the operation of the facility and its components. Please refer to the appendices for more detailed information about specific components and procedures. The purpose of the magnetic measurement facility is to take accurate measurements of the magnetic field in the gay of the IDs in order to determine the effect of the ID on the stored particle beam and the emitted radiation. The facility will also play an important role when evaluating new ideas, novel devices, and inhouse prototypesmore » as part of the ongoing research and development program at the APS. The measurements will be performed with both moving search coils and moving Hall probes. The IDs will be evaluated by computer modeling of the emitted radiation for any given (measured) magnetic field map. The quality of the magnetic field will be described in terms of integrated multipoles for the effect on Storage Ring performance and in terms of the derived trajectories for the emitted radiation. Before being installed on the Storage Ring, every device will be measured and characterized to assure that it is compatible with Storage Ring requirements and radiation specifications. The accuracy that the APS needs to achieve for magnetic measurements will be based on these specifications.« less

Magnet design for a low-emittance storage ring

PubMed Central

Johansson, Martin; Anderberg, Bengt; Lindgren, Lars-Johan

2014-01-01

The MAX IV 3 GeV storage ring, currently under construction, pursues the goal of low electron beam emittance by using a multi-bend achromat magnet lattice, which is realised by having several consecutive magnet elements precision-machined out of a common solid iron block, 2.3–3.4 m long. With this magnet design solution, instead of having 1320 individual magnets, the MAX IV 3 GeV storage ring is built up using 140 integrated ‘magnet block’ units, containing all these magnet elements. Major features of this magnet block design are compactness, vibration stability and that the alignment of magnet elements within each unit is given by the mechanical accuracy of the CNC machining rather than individual field measurement and adjustment. This article presents practical engineering details of implementing this magnet design solution, and mechanical + magnetic field measurement results from the magnet production series. At the time of writing (spring 2014), the production series, which is totally outsourced to industry, is roughly half way through, with mechanical/magnetic QA conforming to specifications. It is the conclusion of the authors that the MAX IV magnet block concept, which has sometimes been described as new or innovative, is from a manufacturing point of view simply a collection of known mature production methods and measurement procedures, which can be executed at fixed cost with a low level of risk. PMID:25177980

Engineering Sedimentary Geothermal Resources for Large-Scale Dispatchable Renewable Electricity

NASA Astrophysics Data System (ADS)

Bielicki, Jeffrey; Buscheck, Thomas; Chen, Mingjie; Sun, Yunwei; Hao, Yue; Saar, Martin; Randolph, Jimmy

2014-05-01

Mitigating climate change requires substantial penetration of renewable energy and economically viable options for CO2 capture and storage (CCS). We present an approach using CO2 and N2 in sedimentary basin geothermal resources that (1) generates baseload and dispatchable power, (2) efficiently stores large amounts of energy, and (3) enables seasonal storage of solar energy, all which (5) increase the value of CO2 and render CCS commercially viable. Unlike the variability of solar and wind resources, geothermal heat is a constant source of renewable energy. Using CO2 as a supplemental geothermal working fluid, in addition to brine, reduces the parasitic load necessary to recirculate fluids. Adding N2 is beneficial because it is cheaper, will not react with materials and subsurface formations, and enables bulk energy storage. The high coefficients of thermal expansion of CO2 and N2 (a) augment reservoir pressure, (b) generate artesian flow at the production wells, and (c) produce self-convecting thermosiphons that directly convert reservoir heat to mechanical energy for fluid recirculation. Stored pressure drives fluid production and responds faster than conventional brine-based geothermal systems. Our design uses concentric rings of horizontal wells to create a hydraulic divide that stores supplemental fluids and pressure. Production and injection wells are controlled to schedule power delivery and time-shift the parasitic power necessary to separate N2 from air and compress it for injection. The parasitic load can be scheduled during minimum power demand or when there is excess electricity from wind or solar. Net power output can nearly equal gross power output during peak demand, and energy storage is almost 100% efficient because it is achieved by the time-shift. Further, per-well production rates can take advantage of the large productivity of horizontal wells, with greater leveraging of well costs, which often constitute a major portion of capital costs for geothermal power systems.

TSR: A storage and cooling ring for HIE-ISOLDE

NASA Astrophysics Data System (ADS)

Butler, P. A.; Blaum, K.; Davinson, T.; Flanagan, K.; Freeman, S. J.; Grieser, M.; Lazarus, I. H.; Litvinov, Yu. A.; Lotay, G.; Page, R. D.; Raabe, R.; Siesling, E.; Wenander, F.; Woods, P. J.

2016-06-01

It is planned to install the heavy-ion, low-energy ring TSR, currently at the Max-Planck-Institute for Nuclear Physics in Heidelberg, at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored, cooled secondary beams that is rich and varied, spanning from studies of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. In addition to experiments performed using beams recirculating within the ring, the cooled beams can be extracted and exploited by external spectrometers for high-precision measurements. The capabilities of the ring facility as well as some physics cases will be presented, together with a brief report on the status of the project.

Variation in the concentration and age of nonstructural carbon stored in different tree tissues

NASA Astrophysics Data System (ADS)

Richardson, Andrew; Carbone, Mariah; Huggett, Brett; Furze, Morgan; Czimczik, Claudia I.; Xu, Xiaomei

2014-05-01

Trees store nonstructural carbon (NSC), in the form of sugars and starch, in the ray parenchyma cells of woody tissues. These reserves provide a carbon buffer when demand (growth, protection, or metabolism) exceeds supply (photosynthesis). This is particularly important in the context of resilience to stress and disturbance, such as might be associated with various global change factors. However, storage allocation processes and the availability of stored reserves remain poorly understood in woody plants. To better understand how NSC reserves are distributed throughout the tree, and the degree to which NSC reserves mix across ring boundaries and tissue types, we destructively sampled two 30-year-old trees (one red oak, Quercus rubra L., and one white pine, Pinus strobus L.) growing at Harvard Forest, an oak-dominated temperate forest in the northeastern United States. We analyzed stemwood samples (divided into individual rings, bark, and phloem), coarse and fine branches, and coarse (separated into three depths) and fine roots for concentrations of total sugars and starch. For a subset of samples we used the radiocarbon (14C) "bomb spike" method to estimate the mean age of extracted sugars and starch. In oak, stemwood sugar and starch concentrations were highest (50 mg/g) in the youngest (most recently-formed) rings, and dropped off rapidly (to 10 mg/g or less) across the 10 most recent rings. In oak phloem tissue, sugar concentrations were high (90 mg/g) compared to starch (10 mg/g). In pine, sugar concentrations dropped off rapidly across the three most recent rings (from 30 mg/g to 10 mg/g) whereas starch concentrations were low even for the youngest rings (10 mg/g or less). In pine, phloem concentrations of both sugar (190 mg/g) and starch (20 mg/g) were both substantially higher than in oak. Such strong radial trends must be accounted for when scaling up to whole-tree budgets, as whole increment cores cannot properly integrate (on a ring-area basis) across the depth profile. In oak, fine root concentrations of sugar and starch were similar (40 mg/g), and coarse roots had very high concentrations of starch (140 mg/g) compared to sugar (50 mg/g). In pine, fine root concentrations of both sugar and starch (60 mg/g) were higher than in coarse roots (10 mg/g). Coarse root NSC concentrations did not vary substantially along a radial gradient into the root. Even assuming a 1:5 root:shoot ratio, these data indicate that a large portion of the whole-tree NSC budget is stored belowground. For both sugars and starch, the 14C data indicated substantial mixing of new and older carbon across the youngest stemwood rings (up to 5 y), beyond which NSC age increased linearly with ring age. Coarse root NSC age also increased with radial depth and wood tissue age, and root NSC was consistently younger in pine than oak. The fact that NSC age is not constant with radial depth in the aboveground samples demonstrates that NSC reserves cannot be treated as a single, well-mixed pool. Rather, these results are consistent with previous observation suggesting last-in/first-out dynamics. From a modeling standpoint, these results support a simple two-pool structure where new photosynthate not used for current growth or metabolism enters a well-mixed and young "fast" pool, but over time storage in older rings is transferred to a distinct and older "slow" pool with which mixing no longer occurs.

Fast and accurate focusing analysis of large photon sieve using pinhole ring diffraction model.

PubMed

Liu, Tao; Zhang, Xin; Wang, Lingjie; Wu, Yanxiong; Zhang, Jizhen; Qu, Hemeng

2015-06-10

In this paper, we developed a pinhole ring diffraction model for the focusing analysis of a large photon sieve. Instead of analyzing individual pinholes, we discuss the focusing of all of the pinholes in a single ring. An explicit equation for the diffracted field of individual pinhole ring has been proposed. We investigated the validity range of this generalized model and analytically describe the sufficient conditions for the validity of this pinhole ring diffraction model. A practical example and investigation reveals the high accuracy of the pinhole ring diffraction model. This simulation method could be used for fast and accurate focusing analysis of a large photon sieve.

Development and operating experience of a 1.1-m-long superconducting undulator at the Advanced Photon Source

DOE PAGES

Ivanyushenkov, Y.; Harkay, K.; Borland, M.; ...

2017-10-03

Development of superconducting undulators continues at the Advanced Photon Source (APS). Two years after successful installation and commissioning of the first relatively short superconducting undulator “SCU0” in Sector 6 of the APS storage ring, the second 1.1-m long superconducting undulator “SCU1” was installed in Sector 1 of the APS. The device has been in user operation since its commissioning in May 2015. This paper describes the magnetic and cryogenic design of the SCU1 together with the results of stand-alone cold tests. The SCU1’s magnetic and cryogenic performance as well as its operating experience in the APS storage ring are alsomore » presented.« less

Coupling control and optimization at the Canadian Light Source

NASA Astrophysics Data System (ADS)

Wurtz, W. A.

2018-06-01

We present a detailed study using the skew quadrupoles in the Canadian Light Source storage ring lattice to control the parameters of a coupled lattice. We calculate the six-dimensional beam envelop matrix and use it to produce a variety of objective functions for optimization using the Multi-Objective Particle Swarm Optimization (MOPSO) algorithm. MOPSO produces a number of skew quadrupole configurations that we apply to the storage ring. We use the X-ray synchrotron radiation diagnostic beamline to image the beam and we make measurements of the vertical dispersion and beam lifetime. We observe satisfactory agreement between the measurements and simulations. These methods can be used to adjust phase space coupling in a rational way and have applications to fine-tuning the vertical emittance and Touschek lifetime and measuring the gas scattering lifetime.

The development of enabling technologies for producing active interrogation beams.

PubMed

Kwan, Thomas J T; Morgado, Richard E; Wang, Tai-Sen F; Vodolaga, B; Terekhin, V; Onischenko, L M; Vorozhtsov, S B; Samsonov, E V; Vorozhtsov, A S; Alenitsky, Yu G; Perpelkin, E E; Glazov, A A; Novikov, D L; Parkhomchuk, V; Reva, V; Vostrikov, V; Mashinin, V A; Fedotov, S N; Minayev, S A

2010-10-01

A U.S./Russian collaboration of accelerator scientists was directed to the development of high averaged-current (∼1 mA) and high-quality (emittance ∼15 πmm mrad; energy spread ∼0.1%) 1.75 MeV proton beams to produce active interrogation beams that could be applied to counterterrorism. Several accelerator technologies were investigated. These included an electrostatic tandem accelerator of novel design, a compact cyclotron, and a storage ring with energy compensation and electron cooling. Production targets capable of withstanding the beam power levels were designed, fabricated, and tested. The cyclotron/storage-ring system was theoretically studied and computationally designed, and the electrostatic vacuum tandem accelerator at BINP was demonstrated for its potential in active interrogation of explosives and special nuclear materials.

Prospects of high-resolution resonant X-ray inelastic scattering studies on solid materials, liquids and gases at diffraction-limited storage rings

PubMed Central

Schmitt, Thorsten; de Groot, Frank M. F.; Rubensson, Jan-Erik

2014-01-01

The spectroscopic technique of resonant inelastic X-ray scattering (RIXS) will particularly profit from immensely improved brilliance of diffraction-limited storage rings (DLSRs). In RIXS one measures the intensities of excitations as a function of energy and momentum transfer. DLSRs will allow for pushing the achievable energy resolution, signal intensity and the sampled spot size to new limits. With RIXS one nowadays probes a broad range of electronic systems reaching from simple molecules to complex materials displaying phenomena like peculiar magnetism, two-dimensional electron gases, superconductivity, photovoltaic energy conversion and heterogeneous catalysis. In this article the types of improved RIXS studies that will become possible with X-ray beams from DLSRs are envisioned. PMID:25177995

Development and operating experience of a 1.1-m-long superconducting undulator at the Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivanyushenkov, Y.; Harkay, K.; Borland, M.

Development of superconducting undulators continues at the Advanced Photon Source (APS). Two years after successful installation and commissioning of the first relatively short superconducting undulator “SCU0” in Sector 6 of the APS storage ring, the second 1.1-m long superconducting undulator “SCU1” was installed in Sector 1 of the APS. The device has been in user operation since its commissioning in May 2015. This paper describes the magnetic and cryogenic design of the SCU1 together with the results of stand-alone cold tests. The SCU1’s magnetic and cryogenic performance as well as its operating experience in the APS storage ring are alsomore » presented.« less

Time domain analysis of coherent terahertz synchrotron radiation

NASA Astrophysics Data System (ADS)

Hübers, H.-W.; Semenov, A.; Holldack, K.; Schade, U.; Wüstefeld, G.; Gol'tsman, G.

2005-10-01

The time structure of coherent terahertz synchrotron radiation at the electron storage ring of the Berliner Elektronensynchrotron und Speicherring Gesellschaft has been analyzed with a fast superconducting hot-electron bolometer. The emission from a single bunch of electrons was found to last ˜1500ps at frequencies around 0.4THz, which is much longer than the length of an electron bunch in the time domain (˜5ps). It is suggested that this is caused by multiple reflections at the walls of the beam line. The quadratic increase of the power with the number of electrons in the bunch as predicted for coherent synchrotron radiation and the transition from stable to bursting radiation were determined from a single storage ring fill pattern of bunches with different populations.

Calibration of space instruments at the Metrology Light Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klein, R., E-mail: roman.klein@ptb.de; Fliegauf, R.; Gottwald, A.

2016-07-27

PTB has more than 20 years of experience in the calibration of space-based instruments using synchrotron radiation to cover the UV, VUV and X-ray spectral range. New instrumentation at the electron storage ring Metrology Light Source (MLS) opens up extended calibration possibilities within this framework. In particular, the set-up of a large vacuum vessel that can accommodate entire space instruments opens up new prospects. Moreover, a new facility for the calibration of radiation transfer source standards with a considerably extended spectral range has been put into operation. Besides, characterization and calibration of single components like e.g. mirrors, filters, gratings, andmore » detectors is continued.« less

Simulation studies for the PANDA experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kopf, B.

2005-10-26

One main component of the planned Facility for Antiproton and Ion Research (FAIR) is the High Energy Storage Ring (HESR) at GSI, Darmstadt, which will provide cooled antiprotons with momenta between 1.5 and 15 GeV/c. The PANDA experiment will investigate p-barannihilations with internal hydrogen and nuclear targets. Due to the planned extensive physics program a multipurpose detector with nearly complete solid angle coverage, proper particle identification over a large momentum range, and high resolution calorimetry for neutral particles is required. For the optimization of the detector design simulation studies of several benchmark channels are in progress which are covering themore » most relevant physics topics. Some important simulation results are discussed here.« less

Design of barrier bucket kicker control system

NASA Astrophysics Data System (ADS)

Ni, Fa-Fu; Wang, Yan-Yu; Yin, Jun; Zhou, De-Tai; Shen, Guo-Dong; Zheng, Yang-De.; Zhang, Jian-Chuan; Yin, Jia; Bai, Xiao; Ma, Xiao-Li

2018-05-01

The Heavy-Ion Research Facility in Lanzhou (HIRFL) contains two synchrotrons: the main cooler storage ring (CSRm) and the experimental cooler storage ring (CSRe). Beams are extracted from CSRm, and injected into CSRe. To apply the Barrier Bucket (BB) method on the CSRe beam accumulation, a new BB technology based kicker control system was designed and implemented. The controller of the system is implemented using an Advanced Reduced Instruction Set Computer (RISC) Machine (ARM) chip and a field-programmable gate array (FPGA) chip. Within the architecture, ARM is responsible for data presetting and floating number arithmetic processing. The FPGA computes the RF phase point of the two rings and offers more accurate control of the time delay. An online preliminary experiment on HIRFL was also designed to verify the functionalities of the control system. The result shows that the reference trigger point of two different sinusoidal RF signals for an arbitrary phase point was acquired with a matched phase error below 1° (approximately 2.1 ns), and the step delay time better than 2 ns were realized.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plogmaker, Stefan; Johansson, Erik M. J.; Rensmo, Haakan

A novel light chopper system for fast timing experiments in the vacuum-ultraviolet (VUV) and x-ray spectral region has been developed. It can be phase-locked and synchronized with a synchrotron radiation storage ring, accommodating repetition rates in the range of {approx}8 to {approx}120 kHz by choosing different sets of apertures and subharmonics of the ring frequency (MHz range). Also the opening time of the system can be varied from some nanoseconds to several microseconds to meet the needs of a broad range of applications. Adjusting these parameters, the device can be used either for the generation of single light pulses ormore » pulse packages from a microwave driven, continuous He gas discharge lamp or from storage rings which are otherwise often considered as quasi-continuous light sources. This chopper can be utilized for many different kinds of experiments enabling, for example, unambiguous time-of-flight (TOF) multi-electron coincidence studies of atoms and molecules excited by a single light pulse as well as time-resolved visible laser pump x-ray probe electron spectroscopy of condensed matter in the valence and core level region.« less

Electron molecular ion recombination: product excitation and fragmentation.

PubMed

Adams, Nigel G; Poterya, Viktoriya; Babcock, Lucia M

2006-01-01

Electron-ion dissociative recombination is an important ionization loss process in any ionized gas containing molecular ions. This includes the interstellar medium, circumstellar shells, cometary comae, planetary ionospheres, fusion plasma boundaries, combustion flames, laser plasmas and chemical deposition and etching plasmas. In addition to controlling the ionization density, the process generates many radical species, which can contribute to a parallel neutral chemistry. Techniques used to obtain rate data and product information (flowing afterglows and storage rings) are discussed and recent data are reviewed including diatomic to polyatomic ions and cluster ions. The data are divided into rate coefficients and cross sections, including their temperature/energy dependencies, and quantitative identification of neutral reaction products. The latter involve both ground and electronically excited states and including vibrational excitation. The data from the different techniques are compared and trends in the data are examined. The reactions are considered in terms of the basic mechanisms (direct and indirect processes including tunneling) and recent theoretical developments are discussed. Finally, new techniques are mentioned (for product identification; electrostatic storage rings, including single and double rings; Coulomb explosion) and new ways forward are suggested.

The H{sub 60}Si{sub 6}C{sub 54} heterofullerene as high-capacity hydrogen storage medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yong, Yongliang, E-mail: ylyong@haust.edu.cn; Department of Physics, Zhejiang University, Hangzhou 310027; Zhou, Qingxiao

2016-07-15

With the great success in Si atoms doped C{sub 60} fullerene and the well-established methods for synthesis of hydrogenated carbon fullerenes, this leads naturally to wonder whether Si-doped fullerenes are possible for special applications such as hydrogen storage. Here by using first-principles calculations, we design a novel high-capacity hydrogen storage material, H{sub 60}Si{sub 6}C{sub 54} heterofullerene, and confirm its geometric stability. It is found that the H{sub 60}Si{sub 6}C{sub 54} heterofullerene has a large HOMO-LUMO gap and a high symmetry, indicating it is high chemically stable. Further, our finite temperature simulations indicate that the H{sub 60}Si{sub 6}C{sub 54} heterofullerene ismore » thermally stable at 300 K. H{sub 2} molecules would enter into the cage from the Si-hexagon ring because of lower energy barrier. Through our calculation, a maximum of 21 H{sub 2} molecules can be stored inside the H{sub 60}Si{sub 6}C{sub 54} cage in molecular form, leading to a gravimetric density of 11.11 wt% for 21H{sub 2}@H{sub 60}Si{sub 6}C{sub 54} system, which suggests that the hydrogenated Si{sub 6}C{sub 54} heterofullerene could be suitable as a high-capacity hydrogen storage material.« less

9975 Shipping package component long-term degradation rates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W. L.

Special nuclear materials are being stored in the K-Area Complex using 3013 containers that are held within Model 9975 shipping packages. The service life for these packages in storage was recently increased from 15 to 20 years, since some of these packages have been stored for nearly 15 years. A strategy is also being developed whereby such storage might be extended beyond 20 years. This strategy is based on recent calculations that support acceptable 9975 package performance for 20 years with internal heat loads up to 19 watts, and identifies a lower heat load limit for which the package componentsmore » should degrade at half the bounding rate or less, thus doubling the effective storage life for these lower wattage packages. The components of the 9975 package that are sensitive to aging under storage conditions are the fiberboard overpack and the O-ring seals, although some degradation of the lead shield and outer drum are also possible. This report summarizes degradation rates applicable to lower heat load storage conditions. In particular, the O-ring seals should provide leak-tight performance for more than 40 years in packages for which their maximum temperature is ≤135 °F. Similarly, the fiberboard should remain acceptable in performance of its required safety functions for up to 40 years in packages with a maximum fiberboard temperature ≤125 °F.« less

Hawaii Energy and Environmental Technologies Initiative 2010 (HEET10)

DTIC Science & Technology

2016-09-30

illustrated how local battery storage support of the lOMW Hawi wind farm can cause grid-wide issues. However, it was found that battery cycling can...capabilities pertaining to three different ex situ diagnostics were acquired and used under HEETlO. Focus was given to the catalyst (rotating ring ...cell. These capabilities are illustrated in Figure 9 1.1.1. Figure 1.1.1: (left) rotating ring /disc electrode; (middle) membrane conductivity cell

Design and development of a hybrid bioartificial water-induced shape memory polymeric material as an integral component for the anastomosis of human hollow organs.

PubMed

Paonessa, Siriana; Barbani, Niccoletta; Rocchietti, Elisa Cibrario; Giachino, Claudia; Cristallini, Caterina

2017-06-01

A large number of pathologies require the resection of the bowel and anastomoses to rejoin the two remaining stumps to regain lumen patency. Various materials have been used to rejoin one bowel end to the other such as catgut, stainless steel, and absorbable sutures. The present method for anastomosis surgery uses an entero-entero anastomosis (EEA) circular stapler with only a staple line. This method can have some drawbacks, such as intracellular fluid leakage and local inflammations. The aim of this study is to design and develop a novel bioartificial polymer with a ring shape made of polyvinyl alcohol (PVA) and gelatin (80/20 ratio (w/w)) loaded both directly with acetylsalicylic acid and with nanoparticles incorporating the same drug to reduce local inflammation even for a prolonged period of time. A physical method (8cycles freezing/thawing) was used to obtain a crosslinked bioartificial shape memory ring. Mechanical analysis showed a storage modulus having a comparable value with that of the human colon. HPLC analysis pointed out a sustained and prolonged release of the anti-inflammatory drug both immediately after anastomosis surgery and during healing period. Cell culture tests indicated the cytocompatibility of the bioartificial device. A shape memory of the hydrogel prepared in ring form was observed at 37°C after immersion in water. These bioartificial devices can represent a new approach to serve as a multifunctional anastomotic ring. Copyright © 2017. Published by Elsevier B.V.

High-latitude tree growth and satellite vegetation indices: Correlations and trends in Russia and Canada (1982-2008)

NASA Astrophysics Data System (ADS)

Berner, Logan T.; Beck, Pieter S. A.; Bunn, Andrew G.; Lloyd, Andrea H.; Goetz, Scott J.

2011-03-01

Vegetation in northern high latitudes affects regional and global climate through energy partitioning and carbon storage. Spaceborne observations of vegetation, largely based on the normalized difference vegetation index (NDVI), suggest decreased productivity during recent decades in many regions of the Eurasian and North American boreal forests. To improve interpretation of NDVI trends over forest regions, we examined the relationship between NDVI from the advanced very high resolution radiometers and tree ring width measurements, a proxy of tree productivity. We collected tree core samples from spruce, pine, and larch at 22 sites in northeast Russia and northwest Canada. Annual growth rings were measured and used to generate site-level ring width index (RWI) chronologies. Correlation analysis was used to assess the association between RWI and summer NDVI from 1982 to 2008, while linear regression was used to examine trends in both measurements. The correlation between NDVI and RWI was highly variable across sites, though consistently positive (r = 0.43, SD = 0.19, n = 27). We observed significant temporal autocorrelation in both NDVI and RWI measurements at sites with evergreen conifers (spruce and pine), though weak autocorrelation at sites with deciduous conifers (larch). No sites exhibited a positive trend in both NDVI and RWI, although five sites showed negative trends in both measurements. While there are technological and physiological limitations to this approach, these findings demonstrate a positive association between NDVI and tree ring measurements, as well as the importance of considering lagged effects when modeling vegetation productivity using satellite data.

Observations of stem water storage in trees of opposing hydraulic strategies

DOE PAGES

Matheny, Ashley M.; Bohrer, Gil; Garrity, Steven R.; ...

2015-09-29

Hydraulic capacitance and water storage form a critical buffer against cavitation and loss of conductivity within the xylem system. Withdrawal from water storage in leaves, branches, stems, and roots significantly impacts sap flow, stomatal conductance, and transpiration. Storage quantities differ based on soil water availability, tree size, wood anatomy and density, drought tolerance, and hydraulic strategy (anisohydric or isohydric). However, the majority of studies focus on the measurement of storage in conifers or tropical tree species. We demonstrate a novel methodology using frequency domain reflectometry (FDR) to make continuous, direct measurements of wood water content in two hardwood species inmore » a forest in Michigan. We present results of a two month study comparing the water storage dynamics between a mature red oak and red maple, two species with differing wood densities, hydraulic architecture, and hydraulic strategy. We also include results pertaining to the use of different probe lengths to sample water content only within the active sapwood and over the entire conductive sapwood and the outer portion of heartwood in red oak. Both species studied exhibited diurnal cycles of storage that aligned well with the dynamics of sap flux. Red maple, a diffuse porous, relatively isohydric species showed a strong dependence on stored water during both wet and dry periods. Red oak, a ring porous relatively anisohydric species, was less reliant on storage, and did not demonstrate a dependence on soil water potential. Comparison between long and short FDR probes in the oak revealed that oaks may utilize water stored in the innermost layers of the xylem when soil moisture conditions are limiting. We found the FDR probes to be a reliable, functional means for continuous automated measurement of wood water content in hardwoods at a fast time scale. Application of FDR technology for the measurement of tree water storage will benefit forest ecologists as well as the modeling community as we improve our understanding and simulations of plant hydrodynamic processes on a large scale.« less

ACCELERATORS: RF system design and measurement of HIRF-CSRe

NASA Astrophysics Data System (ADS)

Xu, Zhe; Zhao, Hong-Wei; Wang, Chun-Xiao; Xia, Jia-Wen; Zhan, Wen-Long; Bian, Zhi-Bin

2009-05-01

An RF system for the CSRe (cooling storage experimental ring) is designed and manufactured domestically. The present paper mainly describes the RF system design in five main sections: ferrite ring, RF cavity, RF generator, low level system and cavity cooling. The cavity is based on a type of coaxial resonator which is shorted at the end with one gap and loaded with domestic ferrite rings. The RF generator is designed in the push-pull mode and the low level control system is based on a DSP+FGPA+DDS+USB interface and has three feedback loops. Finally we give the results of the measurement on our system.

Tunable optical analog to electromagnetically induced transparency in graphene-ring resonators system.

PubMed

Wang, Yonghua; Xue, Chenyang; Zhang, Zengxing; Zheng, Hua; Zhang, Wendong; Yan, Shubin

2016-12-12

The analogue of electromagnetically induced transparency in optical ways has shown great potential in optical delay and quantum-information technology due to its flexible design and easy implementation. The chief drawback for these devices is the bad tunability. Here we demonstrate a tunable optical transparency system formed by graphene-silicon microrings which could control the transparent window by electro-optical means. The device consists of cascaded coupled ring resonators and a graphene/graphene capacitor which integrated on one of the rings. By tuning the Fermi level of the graphene sheets, we can modulate the round-trip ring loss so that the transparency window can be dynamically tuned. The results provide a new method for the manipulation and transmission of light in highly integrated optical circuits and quantum information storage devices.

DEVELOPMENT OF TITANIUM NITRIDE COATING FOR SNS RING VACUUM CHAMBERS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

HE,P.; HSEUH,H.C.; MAPES,M.

2001-06-18

The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with {approximately}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 resultsmore » were obtained with magnetron sputtering. The development of the parameters for the coating process and the surface analysis results are presented.« less

Design and performance of SiPM-based readout of PbF 2 crystals for high-rate, precision timing applications

DOE PAGES

Kaspar, J.; Fienberg, A. T.; Hertzog, D. W.; ...

2017-01-11

Here, we have developed a custom amplifier board coupled to a large-format 16-channel Hamamatsu silicon photomultiplier device for use as the light sensor for the electromagnetic calorimeters in the Muon g-2 experiment at Fermilab. The calorimeter absorber is an array of lead-fluoride crystals, which produces short-duration Cherenkov light. The detector sits in the high magnetic field of the muon storage ring. The SiPMs selected, and their accompanying custom electronics, must preserve the short pulse shape, have high quantum efficiency, be non-magnetic, exhibit gain stability under varying rate conditions, and cover a fairly large fraction of the crystal exit surface area.more » We describe an optimized design that employs the new-generation of thru-silicon via devices. As a result, the performance is documented in a series of bench and beam tests.« less

Synchrotron X-ray topography of electronic materials.

PubMed

Tuomi, T

2002-05-01

Large-area transmission, transmission section, large-area back-reflection, back-reflection section and grazing-incidence topography are the geometries used when recording high-resolution X-ray diffraction images with synchrotron radiation from a bending magnet, a wiggler or an undulator of an electron or a positron storage ring. Defect contrast can be kinematical, dynamical or orientational even in the topographs recorded on the same film at the same time. In this review article limited to static topography experiments, examples of defect studies on electronic materials cover the range from voids and precipitates in almost perfect float-zone and Czochralski silicon, dislocations in gallium arsenide grown by the liquid-encapsulated Czochralski technique, the vapour-pressure controlled Czochralski technique and the vertical-gradient freeze technique, stacking faults and micropipes in silicon carbide to misfit dislocations in epitaxic heterostructures. It is shown how synchrotron X-ray topographs of epitaxic laterally overgrown gallium arsenide layer structures are successfully explained by orientational contrast.

Nuclear stopping and collective flow in CSR/LanZhou energy region

NASA Astrophysics Data System (ADS)

Luo, X.-F.; Dong, X.; Shao, M.; Li, C.; Chen, H.-F.; Wu, K.-J.; Xu, H.-S.

2011-06-01

Nuclear stopping and collective flow for two pairs of symmetric colliding nuclei: 238U+238U and 129Xe+129Xe, which are proposed to be accelerated on Cooling Storage Ring (CSR), External Target Facility (ETF), LanZhou, China, are studied by a hadronic transport model ART1.0. The incident beam energy of Uranium and Xenon can be delivered up to 520 MeV/nucleon and 900MeV/nucleon, respectively. At this CSR energy region, the hot, dense nuclear matter are thought to be obtained in the lab, which is an idea circumstance to study the nuclear equation of state (EoS). As deformation of the Uranium nuclei, it is predicted that significant large baryon density in the tip-tip U+U collision patterns and the large elliptic flow in body-body collision pattern are both avail to study the nuclear EoS.

Inverse compton light source: a compact design proposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deitrick, Kirsten Elizabeth

In the last decade, there has been an increasing demand for a compact Inverse Compton Light Source (ICLS) which is capable of producing high-quality X-rays by colliding an electron beam and a high-quality laser. It is only in recent years when both SRF and laser technology have advanced enough that compact sources can approach the quality found at large installations such as the Advanced Photon Source at Argonne National Laboratory. Previously, X-ray sources were either high flux and brilliance at a large facility or many orders of magnitude lesser when produced by a bremsstrahlung source. A recent compact source wasmore » constructed by Lyncean Technologies using a storage ring to produce the electron beam used to scatter the incident laser beam. By instead using a linear accelerator system for the electron beam, a significant increase in X-ray beam quality is possible, though even subsequent designs also featuring a storage ring offer improvement. Preceding the linear accelerator with an SRF reentrant gun allows for an extremely small transverse emittance, increasing the brilliance of the resulting X-ray source. In order to achieve sufficiently small emittances, optimization was done regarding both the geometry of the gun and the initial electron bunch distribution produced off the cathode. Using double-spoke SRF cavities to comprise the linear accelerator allows for an electron beam of reasonable size to be focused at the interaction point, while preserving the low emittance that was generated by the gun. An aggressive final focusing section following the electron beam's exit from the accelerator produces the small spot size at the interaction point which results in an X-ray beam of high flux and brilliance. Taking all of these advancements together, a world class compact X-ray source has been designed. It is anticipated that this source would far outperform the conventional bremsstrahlung and many other compact ICLSs, while coming closer to performing at the levels found at large facilities than ever before. The design process, including the development between subsequent iterations, is presented here in detail, with the simulation results for this groundbreaking X-ray source.« less

Simulation of emittance dilution in electron storage ring from Compton backscattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blumberg, L.N.; Blum, E.

1993-07-01

A Monte-Carlo simulation of Compton backscattered {kappa}{sub L}=3.2-{mu}m photons from an IR-FEL on 75-MeV electrons in a storage ring yields an RMS electron energy spread of {Delta}{sub E}=11.9-keV for a sample of 10{sup 7} single scattering events. Electrons are sampled from a beam of natural energy spread {sigma}{sub E} = 5.6-keV and damped transverse angle spreads {sigma}{sub x}{prime}, = .041-mrad and {sigma}{sub y}{prime} = .052-mrad (100%) coupling, scaled from the 200-MeV BNL XLS compact storage ring. The Compton-scattered X-Rays are generated from an integral of the CM Klein-Nishina cross-section transformed to the lab. A tracking calculation has also been performedmore » in 6-dimensional phase space. Initial electron coordinates are selected randomly from a Gaussian distribution of RMS spreads {sigma}{sub xo}=.102-mm, {sigma}{sub x{prime}o}=.041-mrad, {sigma}{sub yo}=.018-mm, {sigma}{sub y{prime}o}=.052-mrad, {sigma}{sub {phi}o}=22-mrad and {sigma}{sub Eo}=6-keV. A sample of 10000 electrons were each following for 40000 turns around the ring through an RF cavity of f{sub rf}=211.54-MHz and peak voltage V{sub m}=300-keV. Preliminary results indicate that the resulting energy distribution is quite broad with an RMS width of {Delta}{sub E} = 124-keV. The transverse widths are only slightly increased from their original values, i.e. {Delta}{sub x} = .106-mm and {Delta}{sub x}{prime}=.043 mrad. The scaled energy spread of {Delta}{sub E} {approximately} 360-keV for {approximately} 350,000 turns desired in a 10-msec X-Ray angiography exposure is well within the RF bucket used here; even V{sub m} < 50-kV is adequate. Further, the electron energy spread adds a negligible RMS X-Ray energy spread of {Delta}{sub Ex}=.32-keV. The electron energy damping time of {tau}{sub E}=379-msec at 75-MeV in an XLS-type ring allows for damping this induced spread and top-off of the ring between heart cycles.« less

Construction of vacuum system for Tristan accumulation ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishimaru, H.; Horikoshi, G.; Kobayashi, M.

1983-08-01

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 andmore » 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.« less

Omnidirectional antenna having constant phase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sena, Matthew

Various technologies presented herein relate to constructing and/or operating an antenna having an omnidirectional electrical field of constant phase. The antenna comprises an upper plate made up of multiple conductive rings, a lower ground-plane plate, a plurality of grounding posts, a conical feed, and a radio frequency (RF) feed connector. The upper plate has a multi-ring configuration comprising a large outer ring and several smaller rings of equal size located within the outer ring. The large outer ring and the four smaller rings have the same cross-section. The grounding posts ground the upper plate to the lower plate while maintainingmore » a required spacing/parallelism therebetween.« less

Principles for timing at spallation neutron sources based on developments at LANSCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, R. O.; Merl, R. B.; Rose, C. R.

2001-01-01

Due to AC-power-grid frequency fluctuations, the designers for accelerator-based spallation-neutron facilities have worked to optimize the conflicting demands of accelerator and neutron chopper performance. For the first time, we are able to quantitatively access the tradeoffs between these two constraints and design or upgrade a facility to optimize total system performance using powerful new simulation techniques. We have modeled timing systems that integrate chopper controllers and chopper hardware and built new systems. Thus, at LANSCE, we now operate multiple chopper systems and the accelerator as simple slaves to a single master-timing-reference generator. Based on this experience we recommend that spallationmore » neutron sources adhere to three principles. First, timing for pulsed sources should be planned starting with extraction at a fixed phase and working backwards toward the leading edge of the beam pulse. Second, accelerator triggers and storage ring extraction commands from neutron choppers offer only marginal benefits to accelerator-based spallation sources. Third, the storage-ring RF should be phase synchronized with neutron choppers to provide extraction without the one orbit timing uncertainty.« less

Space charge tune shift, fast resonance traversal, and current limits in circular accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rees, G.H.

1996-06-01

Space charge tune shifts, fast resonance traversals, and current limits are important design issues for low energy, high power circular accelerators. Areas of interest are accumulator rings and fast cycling synchrotrons, and typical applications are for pulsed spallation neutron sources, heavy ion fusion storage ring drivers, and booster injectors for high energy proton and ion facilities. Aspects of the three topics are discussed in the paper. {copyright} {ital 1996 American Institute of Physics.}

Preparation, one- and two-photon properties of carbazole derivatives containing nitrogen heterocyclic ring

NASA Astrophysics Data System (ADS)

Zhang, Yichi; Wang, Ping; Li, Liang; Chen, Zhimin; He, Chunying; Wu, Yiqun

Preparation of recording materials with high two-photon absorption activities is one of the important issues to superhigh- density two-photon absorption (TPA) three-dimensional (3D) optical data storage. In this paper, three new carbazole derivatives containing nitrogen heterocyclic ring with symmetric and asymmetric structures are prepared using ethylene as the π bridge between the carbazole unit and nitrogen heterocyclic ring, namely, 9-butyl-3-(2-(1,8- naphthyridin)vinyl)-carbazole (material 1), 9-butyl-3,6-bis(2-(1,8-naphthyl)vinyl)-carbazole (material 2) and 9-butyl-3,6- bis(2-(quinolin)vinyl)-carbazole (material 3). Their one photon properties including linear absorption spectra, fluorescence emission spectra, and fluorescence quantum yields are studied. The fluorescence excited by 120 fs pulse at 800 nm Ti: sapphire laser operating at 1 kHz repetition rate with different incident powers of 9-butyl-3-(2-(quinolin) vinyl)-carbazole (material 3) was investigated, and two-photon absorption cross-sections has been obtained. It is shown that material 3 containing quinoline rings as electron acceptor with symmetric structure exhibit high two-photon absorption activity. The result implies that material 3 (9-butyl-3-(2-(quinolin) vinyl)-carbazole) is a good candidate as a promising recording material for super-high-density two-photon absorption (TPA) three-dimensional (3D) optical data storage. The influence of chemical structure of the materials on the optical properties is discussed.

FIRST BEAM TESTS OF THE APS MBA UPGRADE ORBIT FEEDBACK CONTROLLER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sereno, N. S.; Arnold, N.; Brill, A.

The new orbit feedback system required for the APS multi-bend acromat (MBA) ring must meet challenging beam stability requirements. The AC stability requirement is to correct rms beam motion to 10 % the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. In addition long term drift over a period of 7 days is required to be 1 micron or less at insertion de- vice BPMs and 2 microns formore » arc bpms. We present test re- sults of theMBA prototype orbit feedback controller (FBC) in the APS storage ring. In this test, four insertion device BPMs were configured to send data to the FBC for process- ing into four fast corrector setpoints. The configuration of four bpms and four fast correctors creates a 4-bump and the configuration of fast correctors is similar to what will be implemented in the MBA ring. We report on performance benefits of increasing the sampling rate by a factor of 15 to 22.6 kHz over the existing APS orbit feedback system, lim- itations due to existing storage ring hardware and extrapo- lation to theMBA orbit feedback design. FBC architecture, signal flow and processing design will also be discussed.« less

Calculations of the conditions for bunch leakage in the Los Alamos proton storage ring

NASA Astrophysics Data System (ADS)

Neuffer, D.; Ohmori, C.

1994-04-01

Observations are consistent with the possibility of an "ep" instability in the Los Alamos Proton Storage Ring (PSR) with both bunched and unbunched beam. The instability requires electrons to be trapped within the beam, and calculations have shown that such trapping requires leakage of beam into the interbunch gap. Observationally, leakage of beam into the gap appears necessary for the onset of the instability. In this paper we present results of studies of the longitudinal beam dynamics at PSR parameters. The studies indicate that the combined effects of the rf buncher, longitudinal space charge, and injection mismatch are sufficient to cause the observed bunch leakage. Simulation results are presented and compared with PSR observations. Variations of PSR performance parameters are considered, and methods of improving bunch confinement are suggested and studied.

STORAGE RING CROSS SECTION MEASUREMENTS FOR ELECTRON IMPACT IONIZATION OF Fe{sup 7+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahn, M.; Novotný, O.; Savin, D. W.

2015-11-01

We have measured electron impact ionization for Fe{sup 7+} from the ionization threshold up to 1200 eV. The measurements were performed using the TSR heavy ion storage ring. The ions were stored long enough prior to measurements to remove most metastables, resulting in a beam of 94% ground-level ions. Comparing with the previously recommended atomic data, we find that the Arnaud and Raymond cross section is up to about 40% larger than our measurement, with the largest discrepancies below about 400 eV. The cross section of Dere agrees to within 10%, which is about the magnitude of the experimental uncertainties.more » The remaining discrepancies between our measurement and the Dere calculations are likely due to shortcomings in the theoretical treatment of the excitation-autoionization contribution.« less

Installation of a second superconducting wiggler at SAGA-LS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaneyasu, T., E-mail: kaneyasu@saga-ls.jp; Takabayashi, Y.; Iwasaki, Y.

The SAGA Light Source is a synchrotron radiation facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring with a circumference of 75.6 m. A superconducting wiggler (SCW) with a peak magnetic field of 4 T has been routinely operating for generating hard X-rays since its installation in 2010. In light of this success, it was decided to install a second SCW as a part of the beamline construction by Sumitomo Electric Industries. To achieve this, machine modifications including installation of a new magnet power supply, improvement of the magnet control system, and replacement of themore » vacuum chambers in the storage ring were carried out. Along with beamline construction, installation and commissioning of the second SCW are scheduled to take place in 2015.« less

Electron-impact excitation and recombination of molecular cations in edge fusion plasma: application to H2+and BeD+

NASA Astrophysics Data System (ADS)

Pop, Nicolina; Iacob, Felix; Mezei, Zsolt; Motapon, Ousmanou; Niyonzima, Sebastien; Schneider, Ioan

2017-10-01

Dissociative recombination, ro-vibrational excitation and dissociative excitation of molecular cations with electrons are major elementary process in the kinetics and in the energy balance of astrophysically-relevant ionized media (supernovae, interstellar molecular clouds, planetary ionospheres, early Universe), in edge fusion and in many other cold media of technological interest. For the fusion plasma edge, extensive cross sections and rate coefficients have been produced for reactions induced on HD+, H2+ and BeD+ using the Multichannel Quantum Defect Theory (MQDT). Our calculations resulted in good agreement with the CRYRING (Stockholm) and TSR (Heidelberg) magnetic storage ring results, and our approach is permanently improved in order to face the new generation of electrostatic storage rings, as CSR (Heidelberg) and DESIREE (Stockholm). Member of APS Reciprocal Society: European Physics Society.

Non-exponential decoherence of radio-frequency resonance rotation of spin in storage rings

NASA Astrophysics Data System (ADS)

Saleev, A.; Nikolaev, N. N.; Rathmann, F.; Hinder, F.; Pretz, J.; Rosenthal, M.

2017-08-01

Precision experiments, such as the search for electric dipole moments of charged particles using radio-frequency spin rotators in storage rings, demand for maintaining the exact spin resonance condition for several thousand seconds. Synchrotron oscillations in the stored beam modulate the spin tune of off-central particles, moving it off the perfect resonance condition set for central particles on the reference orbit. Here, we report an analytic description of how synchrotron oscillations lead to non-exponential decoherence of the radio-frequency resonance driven up-down spin rotations. This non-exponential decoherence is shown to be accompanied by a nontrivial walk of the spin phase. We also comment on sensitivity of the decoherence rate to the harmonics of the radio-frequency spin rotator and a possibility to check predictions of decoherence-free magic energies.

Development of a bunch-by-bunch longitudinal feedback system with a wide dynamic range for the HIGS facility

NASA Astrophysics Data System (ADS)

Wu, W. Z.; Kim, Y.; Li, J. Y.; Teytelman, D.; Busch, M.; Wang, P.; Swift, G.; Park, I. S.; Ko, I. S.; Wu, Y. K.

2011-03-01

Electron beam coupled-bunch instabilities can limit and degrade the performance of storage ring based light sources. A longitudinal feedback system has been developed for the Duke storage ring to suppress multi-bunch beam instabilities which prevent stable, high-current operation of the storage ring based free-electron lasers (FELs) and an FEL driven Compton gamma source, the high intensity gamma-ray source (HIGS) at Duke University. In this work, we report the development of a state-of-the-art second generation longitudinal feedback system which employs a field programmable gate array (FPGA) based processor, and a broadband, high shunt-impedance kicker cavity. With two inputs and two outputs, the kicker cavity was designed with a resonant frequency of 937 MHz, a bandwidth of 97 MHz, and a shunt impedance of 1530 Ω. We also developed an S-matrix based technique to fully characterize the performance of the kicker cavity in the cold test. This longitudinal feedback system has been commissioned and optimized to stabilize high-current electron beams with a wide range of electron beam energies (250 MeV to 1.15 GeV) and a number of electron beam bunch modes, including the single-bunch mode and all possible symmetric bunch modes. This feedback system has become a critical instrument to ensure stable, high-flux operation of HIGS to produce nearly monochromatic, highly polarized Compton gamma-ray beams.

Analysis of coupled-bunch instabilities for the NSLS-II storage ring with a 500MHz 7-cell PETRA-III cavity

DOE PAGES

Bassi, G.; Blednykh, A.; Cheng, W.; ...

2015-12-11

We present the NSLS-II storage ring that is designed to operate with superconducting RF-cavities with the aim to store an average current of 500 mA distributed in 1080 bunches, with a gap in the uniform filling for ion clearing. At the early stage of the commissioning (phase 1), characterized by a bare lattice without damping wigglers and without Landau cavities, a normal conducting 7-cell PETRA-III RF-cavity structure has been installed with the goal to store an average current of 25 mA. In this paper we discuss our analysis of coupled-bunch instabilities driven by the Higher Order Modes (HOMs) of themore » 7-cell PETRA-III RF-cavity. As a cure of the instabilities, we apply a well-known scheme based on a proper detuning of the HOMs frequencies based upon cavity temperature change, and the use of the beneficial effect of the slow head–tail damping at positive chromaticity to increase the transverse coupled-bunch instability thresholds. In addition, we discuss measurements of coupled-bunch instabilities observed during the phase 1 commissioning of the NSLS-II storage ring. In our analysis we rely, in the longitudinal case, on the theory of coupled-bunch instability for uniform fillings, while in the transverse case we complement our studies with numerical simulations with OASIS, a novel parallel particle tracking code for self-consistent simulations of collective effects driven by short and long-range wakefields.« less

Sealing a Loosely Fitting Valve Assembly

NASA Technical Reports Server (NTRS)

Goff, L.; Tellier, G.

1986-01-01

Double-ring seal avoids expense of remachining or redesigning valve parts. Mating fittings on valve sealed by pair of rings - one O-ring and backup ring. Backup ring fills relatively large gap between parts. Prevents softer O-ring from being pushed into and through gap.

Planetary Rings

NASA Astrophysics Data System (ADS)

Esposito, Larry W.

2011-07-01

Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

NINTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.

2014-08-06

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperatures. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determinemore » if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The earliest 300 °F GLT O-ring fixture failure was observed at 34 months. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 72 - 96 months, which bounds O-ring temperatures anticipated during storage in K-Area Complex (KAC). Based on expectations that the 200 ºF fixtures will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures, thus providing additional time to failure data. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 54 - 57 months. No additional O-ring failures have been observed since the last interim report was issued. Aging and periodic leak testing will continue for the remaining PCV fixtures. Additional irradiation of several fixtures is recommended to maintain a balance between thermal and radiation exposures similar to that experienced in storage, and to show the degree of consistency of radiation response between GLT and GLT-S O-rings.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filhol, J. M.; Couprie, M. E.; Level, M. P.

SOLEIL is a third generation Synchrotron radiation Source, under construction in France at St Aubin, near Paris. The Storage Ring consists in a 357 m circumference ring, with 16 cells and 24 straight sections (4x12m, 12x7m, 8x3.6m), out of which up to 21 will house insertion devices. The optics, with distributed dispersion, features a low 3.7 nm.rad emittance at the 2.75 GeV operating energy, so as to provide high brilliance, from the VUV up to the hard X ray domain. In order to provide a long lifetime, and beam position stabilities in the micron range, significant attention was paid atmore » each design stage (optics, magnets, beam position monitors, vacuum and RF systems,..), including the design of the building and infrastructure, the construction of which is now complete. This resulted in some unprecedented approaches such as the intensive use of NEG coating Aluminium vessels, or the development of a dedicated superconducting RF cavity and of 190 kW solid state RF amplifiers. The construction, started in 2002, is now completed. The injector system (100 MeV Linac) and the 3 Hz full energy Booster synchrotron have reached nominal operating conditions by fall 2005. The installation of the Storage Ring was just completed and its commissioning started in May 2006. First 9 turns in the ring were achieved on May the 14th, and visible synchrotron radiation was also observed on a CCD camera. Innovative insertion devices were designed and built so as to provide the best possible performances in an energy range as large as 5 eV to 20 keV. These are helical electromagnetic devices with 640 mm and 256 mm periods, APPLE II type undulators with 80 mm period, and in-vacuum hybrid undulators with 20 mm period. Two infra-red beamlines providing both edge and constant dipole field emission are also under construction and a superconducting wiggler is currently being designed in order to provide high flux in the 10 to 50 keV range. A first set of 10 beamlines (out of 24 included in the project) is being built and will be tested from summer 2006 onwards, with the aim of starting Users operation by the beginning of 2007.« less

Status of the Commissioning of SOLEIL

NASA Astrophysics Data System (ADS)

Filhol, J. M.; Couprie, M. E.; Level, M. P.; Besson, J. C.; Brunelle, P.; Denard, J. C.; Godefroy, J. M.; Herbeaux, C.; Lebasque, P.; Le Roux, V.; Lestrade, A.; Loulergue, A.; Marchand, P.; Nadji, A.; Nadolski, L.; Nagaoka, R.; Pottin, B.; Tordeux, M. A.

2007-01-01

SOLEIL is a third generation Synchrotron radiation Source, under construction in France at St Aubin, near Paris. The Storage Ring consists in a 357 m circumference ring, with 16 cells and 24 straight sections (4×12m, 12×7m, 8×3.6m), out of which up to 21 will house insertion devices. The optics, with distributed dispersion, features a low 3.7 nm.rad emittance at the 2.75 GeV operating energy, so as to provide high brilliance, from the VUV up to the hard X ray domain. In order to provide a long lifetime, and beam position stabilities in the micron range, significant attention was paid at each design stage (optics, magnets, beam position monitors, vacuum and RF systems,..), including the design of the building and infrastructure, the construction of which is now complete. This resulted in some unprecedented approaches such as the intensive use of NEG coating Aluminium vessels, or the development of a dedicated superconducting RF cavity and of 190 kW solid state RF amplifiers. The construction, started in 2002, is now completed. The injector system (100 MeV Linac) and the 3 Hz full energy Booster synchrotron have reached nominal operating conditions by fall 2005. The installation of the Storage Ring was just completed and its commissioning started in May 2006. First 9 turns in the ring were achieved on May the 14th, and visible synchrotron radiation was also observed on a CCD camera. Innovative insertion devices were designed and built so as to provide the best possible performances in an energy range as large as 5 eV to 20 keV. These are helical electromagnetic devices with 640 mm and 256 mm periods, APPLE II type undulators with 80 mm period, and in-vacuum hybrid undulators with 20 mm period. Two infra-red beamlines providing both edge and constant dipole field emission are also under construction and a superconducting wiggler is currently being designed in order to provide high flux in the 10 to 50 keV range. A first set of 10 beamlines (out of 24 included in the project) is being built and will be tested from summer 2006 onwards, with the aim of starting Users operation by the beginning of 2007.

Planetary Rings

NASA Astrophysics Data System (ADS)

Esposito, Larry

2014-03-01

Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

A drift chamber constructed of aluminized mylar tubes

NASA Astrophysics Data System (ADS)

Baringer, P.; Jung, C.; Ogren, H. O.; Rust, D. R.

1987-03-01

A thin reliable drift chamber has been constructed to be used near the interaction point of the PEP storage ring in the HRS detector. It is composed of individual drift tubes with aluminized mylar walls.

Integration and initial operation of the multi-component large ring laser structure ROMY

NASA Astrophysics Data System (ADS)

Schreiber, Karl Ulrich; Igel, Heiner; Wassermann, Joachim; Gebauer, André; Simonelli, Andrea; Bernauer, Felix; Donner, Stefanie; Hadziioannou, Celine; Egdorf, Sven; Wells, Jon-Paul

2017-04-01

Rotation sensing for the geosciences requires a high sensor resolution of the order of 10 pico- radians per second or even less. An optical Sagnac interferometer offers this sensitivity, provided that the scale factor can be made very large. We have designed and built a multi- component ring laser system, consisting of 4 individual large ring lasers, each covering an area of more than 62 square m. The rings are orientated in the shape of a tetrahedron, so that all 3 spatial directions are covered, allowing also for some redundancy. We report on the initial operation of the free running gyroscopes in their underground facility in order to establish a performance estimate for the ROMY ring laser structure. Preliminary results suggest that the quantum noise limit is lower than that of the G ring laser.

The formation of peak rings in large impact craters.

PubMed

Morgan, Joanna V; Gulick, Sean P S; Bralower, Timothy; Chenot, Elise; Christeson, Gail; Claeys, Philippe; Cockell, Charles; Collins, Gareth S; Coolen, Marco J L; Ferrière, Ludovic; Gebhardt, Catalina; Goto, Kazuhisa; Jones, Heather; Kring, David A; Le Ber, Erwan; Lofi, Johanna; Long, Xiao; Lowery, Christopher; Mellett, Claire; Ocampo-Torres, Rubén; Osinski, Gordon R; Perez-Cruz, Ligia; Pickersgill, Annemarie; Poelchau, Michael; Rae, Auriol; Rasmussen, Cornelia; Rebolledo-Vieyra, Mario; Riller, Ulrich; Sato, Honami; Schmitt, Douglas R; Smit, Jan; Tikoo, Sonia; Tomioka, Naotaka; Urrutia-Fucugauchi, Jaime; Whalen, Michael; Wittmann, Axel; Yamaguchi, Kosei E; Zylberman, William

2016-11-18

Large impacts provide a mechanism for resurfacing planets through mixing near-surface rocks with deeper material. Central peaks are formed from the dynamic uplift of rocks during crater formation. As crater size increases, central peaks transition to peak rings. Without samples, debate surrounds the mechanics of peak-ring formation and their depth of origin. Chicxulub is the only known impact structure on Earth with an unequivocal peak ring, but it is buried and only accessible through drilling. Expedition 364 sampled the Chicxulub peak ring, which we found was formed from uplifted, fractured, shocked, felsic basement rocks. The peak-ring rocks are cross-cut by dikes and shear zones and have an unusually low density and seismic velocity. Large impacts therefore generate vertical fluxes and increase porosity in planetary crust. Copyright © 2016, American Association for the Advancement of Science.

Advanced photoelectric effect experiment beamline at Elettra: A surface science laboratory coupled with Synchrotron Radiation.

PubMed

Panaccione, G; Vobornik, I; Fujii, J; Krizmancic, D; Annese, E; Giovanelli, L; Maccherozzi, F; Salvador, F; De Luisa, A; Benedetti, D; Gruden, A; Bertoch, P; Polack, F; Cocco, D; Sostero, G; Diviacco, B; Hochstrasser, M; Maier, U; Pescia, D; Back, C H; Greber, T; Osterwalder, J; Galaktionov, M; Sancrotti, M; Rossi, G

2009-04-01

We report the main characteristics of the advanced photoelectric effect experiments beamline, operational at Elettra storage ring, featuring a fully independent double branch scheme obtained by the use of chicane undulators and able to keep polarization control in both linear and circular mode. The paper describes the novel technical solutions adopted, namely, (a) the design of a quasiperiodic undulator resulting in optimized suppression of higher harmonics over a large photon energy range (10-100 eV), (b) the thermal stability of optics under high heat load via cryocoolers, and (c) the end station interconnected setup allowing full access to off-beam and on-beam facilities and, at the same time, the integration of users' specialized sample growth chambers or modules.

Managing Systematic Errors in a Polarimeter for the Storage Ring EDM Experiment

NASA Astrophysics Data System (ADS)

Stephenson, Edward J.; Storage Ring EDM Collaboration

2011-05-01

The EDDA plastic scintillator detector system at the Cooler Synchrotron (COSY) has been used to demonstrate that it is possible using a thick target at the edge of the circulating beam to meet the requirements for a polarimeter to be used in the search for an electric dipole moment on the proton or deuteron. Emphasizing elastic and low Q-value reactions leads to large analyzing powers and, along with thick targets, to efficiencies near 1%. Using only information obtained comparing count rates for oppositely vector-polarized beam states and a calibration of the sensitivity of the polarimeter to rate and geometric changes, the contribution of systematic errors can be suppressed below the level of one part per million.

Tunable optical analog to electromagnetically induced transparency in graphene-ring resonators system

PubMed Central

Wang, Yonghua; Xue, Chenyang; Zhang, Zengxing; Zheng, Hua; Zhang, Wendong; Yan, Shubin

2016-01-01

The analogue of electromagnetically induced transparency in optical ways has shown great potential in optical delay and quantum-information technology due to its flexible design and easy implementation. The chief drawback for these devices is the bad tunability. Here we demonstrate a tunable optical transparency system formed by graphene-silicon microrings which could control the transparent window by electro-optical means. The device consists of cascaded coupled ring resonators and a graphene/graphene capacitor which integrated on one of the rings. By tuning the Fermi level of the graphene sheets, we can modulate the round-trip ring loss so that the transparency window can be dynamically tuned. The results provide a new method for the manipulation and transmission of light in highly integrated optical circuits and quantum information storage devices. PMID:27941895

Spin Transparent Siberian Snake And Spin Rotator With Solenoids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koop, I. A.; Otboyev, A. V.; Shatunov, P. Yu.

2007-06-13

For intermediate energies of electrons and protons it happens that it is more convenient to construct Siberian snakes and spin rotators using solenoidal fields. Strong coupling caused by the solenoids is suppressed by a number of skew and normal quadrupole magnets. More complicate problem of the spin transparency of such devices also can be solved. This paper gives two examples: spin rotator for electron ring in the eRHIC project and Siberian snake for proton (antiproton) storage ring HESR, which cover whole machines working energy region.

The NUSTAR project at FAIR

NASA Astrophysics Data System (ADS)

Nilsson, Thomas; the NUSTAR Collaboration

2015-11-01

The FAIR facility, under construction at the GSI site in Darmstadt, will be addressing a wealth of outstanding questions within the realm of subatomic, atomic, plasma, bio-physics and applications through a combination of novel accelerators, storage rings and innovative experimental set-ups. One of the key installations is the fragment separator Super-FRS that will be able to deliver an unprecedented range of radioactive ion beams in the energy range of 0-1.5 GeV u-1. These beams will be distributed to three branches, each with its unique domain with respect to beam energies and properties. The high-energy branch will permit reactions with radioactive beams at relativistic energies, whereas the low-energy branch will supply decelerated beams for high-resolution spectroscopy, traps and laser spectroscopy. Finally, the ring branch will uniquely permit stored and cooled exotic beams for a range of methods only possible in a storage ring. Thus, by developing experimental set-ups tailored for these beams, there are several complementary possibilities to gain information on key nuclei and reaction, to further our understanding on contemporary questions within nuclear structure and nuclear astrophysics. This ambitious programme is to be exploited within the nuclear structure, astrophysics and reactions collaboration.

An Orbit And Dispersion Correction Scheme for the PEP II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Y.; Donald, M.; Shoaee, H.

2011-09-01

To achieve optimum luminosity in a storage ring it is vital to control the residual vertical dispersion. In the original PEP storage ring, a scheme to control the residual dispersion function was implemented using the ring orbit as the controlling element. The 'best' orbit not necessarily giving the lowest vertical dispersion. A similar scheme has been implemented in both the on-line control code and in the simulation code LEGO. The method involves finding the response matrices (sensitivity of orbit/dispersion at each Beam-Position-Monitor (BPM) to each orbit corrector) and solving in a least squares sense for minimum orbit, dispersion function ormore » both. The optimum solution is usually a subset of the full least squares solution. A scheme of simultaneously correcting the orbits and dispersion has been implemented in the simulation code and on-line control system for PEP-II. The scheme is based on the eigenvector decomposition method. An important ingredient of the scheme is to choose the optimum eigenvectors that minimize the orbit, dispersion and corrector strength. Simulations indicate this to be a very effective way to control the vertical residual dispersion.« less

Kinoform optics applied to X-ray photon correlation spectroscopy.

PubMed

Sandy, A R; Narayanan, S; Sprung, M; Su, J-D; Evans-Lutterodt, K; Isakovic, A F; Stein, A

2010-05-01

Moderate-demagnification higher-order silicon kinoform focusing lenses have been fabricated to facilitate small-angle X-ray photon correlation spectroscopy (XPCS) experiments. The geometric properties of such lenses, their focusing performance and their applicability for XPCS measurements are described. It is concluded that one-dimensional vertical X-ray focusing via silicon kinoform lenses significantly increases the usable coherent flux from third-generation storage-ring light sources for small-angle XPCS experiments.

Formation, characterization, and dynamics of onion-like carbon structures for electrical energy storage from nanodiamonds using reactive force fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganesh, P.; Kent, P. R. C.; Mochalin, V.

We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbonnanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core of themore » nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a particular temperature is thereby determined by a delicate balance between the thermal energy, long-range interactions, and the entropic/enthalpic free energy gained by graphitization. Upon full graphitization, a multi-shell carbonnanostructure appears, with a shell-shell spacing of about ~3.4 Å for all sizes. The shells are highly defective with predominantly five- and seven-membered rings to curve space. Larger nanodiamonds with a diameter of 4 nm can graphitize into spiral structures with a large (~29-atom carbon ring) pore opening on the outermost shell. Such a large one-way channel is most attractive for a controlled insertion of molecules/ions such as Li ions, water, or ionic liquids, for increased electrochemical capacitor or battery electrode applications.« less

Formation, characterization and dynamics of onion like carbon structures from nanodiamonds using reactive force-fields for electrical energy storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kent, Paul R

We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbon nanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core ofmore » the nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a particular temperature is thereby determined by a delicate balance between the thermal energy, long-range interactions, and the entropic/enthalpic free energy gained by graphitization. Upon full graphitization, a multi-shell carbon nanostructure appears, with a shell-shell spacing of about {approx}3.4 {angstrom} for all sizes. The shells are highly defective with predominantly five- and seven-membered rings to curve space. Larger nanodiamonds with a diameter of 4 nm can graphitize into spiral structures with a large ({approx}29-atom carbon ring) pore opening on the outermost shell. Such a large one-way channel is most attractive for a controlled insertion of molecules/ions such as Li ions, water, or ionic liquids, for increased electrochemical capacitor or battery electrode applications.« less

Report of the New Rings Study Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holmes, S.D.; Dugan, G.; Marriner, J.

1987-10-19

We have taken the approach here of trying to understand both the feasibility and practicality of varied options for new rings at Fermilab, rather than trying to produce a single detailed design. In other words, this document is not a design report and should not be construed as such. Our perception of the potential needs for new rings (in order of priority) is as follows: Antiproton Storage and/or Recovery: A facility for storing up to 4 x 10/sup 12/ antiprotons is needed. Recovery of antiprotons from the collider becomes a viable option if the luminosity is indeed dominated by emittancemore » dilution rather than beam loss. New or Post-Booster: The goal here would be to inject into the existing Main Ring above transition. Improved performance of the Main Ring would be anticipated. New Main Ring: Advantages would include better emittance preservation, a faster cycle time for antiproton production, and the removal of interference/backgrounds at the B0 and D0 detectors. We discuss in this paper various scenarios based on one or more combinations of the above possibilities. 14 figs., 10 tabs.« less

Center for Electro Optics & Plasma Research

DTIC Science & Technology

1990-04-01

inversely proportional to the diameter of the plasma ring , the device had a large resistance and thus a large portion of the stored energy dissipated within...which produced an array of plasma rings concentric with the dye tube. These plasma rings emitted intense radiation over a wide range of the spectrum. The

Middle School Science Notes.

ERIC Educational Resources Information Center

School Science Review, 1980

1980-01-01

Outlines a variety of laboratory procedures, discussions, and demonstrations including Brownian motion, a synchronous motor, jet engine, atmospheric pressure vortex ring machines, solid chemical dispensing, testing household detergents, wallchart storage, pollution by industrial chemicals, an optical illusion, and buoyancy. (GS)

Spin Filtering in Storage Rings

NASA Astrophysics Data System (ADS)

Nikolaev, N. N.; Pavlov, F. F.

The spin filtering in storage rings is based on a multiple passage of a stored beam through a polarized internal gas target. Apart from the polarization by the spin-dependent transmission, a unique geometrical feature of interaction with the target in such a filtering process, pointed out by H.O. Meyer,1 is a scattering of stored particles within the beam. A rotation of the spin in the scattering process affects the polarization buildup. We derive here a quantum-mechanical evolution equation for the spin-density matrix of a stored beam which incorporates the scattering within the beam. We show how the interplay of the transmission and scattering within the beam changes from polarized electrons to polarized protons in the atomic target. After discussions of the FILTEX results on the filtering of stored protons,2 we comment on the strategy of spin filtering of antiprotons for the PAX experiment at GSI FAIR.3.

Single-particle detection of products from atomic and molecular reactions in a cryogenic ion storage ring

NASA Astrophysics Data System (ADS)

Krantz, C.; Novotný, O.; Becker, A.; George, S.; Grieser, M.; Hahn, R. von; Meyer, C.; Schippers, S.; Spruck, K.; Vogel, S.; Wolf, A.

2017-04-01

We have used a single-particle detector system, based on secondary electron emission, for counting low-energetic (∼keV/u) massive products originating from atomic and molecular ion reactions in the electrostatic Cryogenic Storage Ring (CSR). The detector is movable within the cryogenic vacuum chamber of CSR, and was used to measure production rates of a variety of charged and neutral daughter particles. In operation at a temperature of ∼ 6 K , the detector is characterised by a high dynamic range, combining a low dark event rate with good high-rate particle counting capability. On-line measurement of the pulse height distributions proved to be an important monitor of the detector response at low temperature. Statistical pulse-height analysis allows to infer the particle detection efficiency of the detector, which has been found to be close to unity also in cryogenic operation at 6 K.

Dissociative recombination measurements of NH{sup +} using an ion storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novotný, O.; Savin, D. W.; Berg, M.

We have investigated dissociative recombination (DR) of NH{sup +} with electrons using a merged beams configuration at the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We present our measured absolute merged-beams recombination rate coefficient for collision energies from 0 to 12 eV. From these data, we have extracted a cross section, which we have transformed to a plasma rate coefficient for the collisional plasma temperature range from T {sub pl} = 10 to 18,000 K. We show that the NH{sup +} DR rate coefficient data in current astrochemical models are underestimatedmore » by up to a factor of approximately nine. Our new data will result in predicted NH{sup +} abundances lower than those calculated by present models. This is in agreement with the sensitivity limits of all observations attempting to detect NH{sup +} in interstellar clouds.« less

Linear transformer driver for pulse generation

DOEpatents

Kim, Alexander A; Mazarakis, Michael G; Sinebryukhov, Vadim A; Volkov, Sergey N; Kondratiev, Sergey S; Alexeenko, Vitaly M; Bayol, Frederic; Demol, Gauthier; Stygar, William A

2015-04-07

A linear transformer driver includes at least one ferrite ring positioned to accept a load. The linear transformer driver also includes a first power delivery module that includes a first charge storage devices and a first switch. The first power delivery module sends a first energy in the form of a first pulse to the load. The linear transformer driver also includes a second power delivery module including a second charge storage device and a second switch. The second power delivery module sends a second energy in the form of a second pulse to the load. The second pulse has a frequency that is approximately three times the frequency of the first pulse. The at least one ferrite ring is positioned to force the first pulse and the second pulse to the load by temporarily isolating the first pulse and the second pulse from an electrical ground.

Note: Comparison of grazing incidence small angle x-ray scattering of a titania sponge structure at the beamlines BW4 (DORIS III) and P03 (PETRA III)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rawolle, M.; Koerstgens, V.; Ruderer, M. A.

2012-10-15

Grazing incidence small angle x-ray scattering (GISAXS) is a powerful technique for morphology investigation of nanostructured thin films. GISAXS measurements at the newly installed P03 beamline at the storage ring PETRA III in Hamburg, Germany, are compared to the GISAXS data from the beamline BW4 at the storage ring DORIS III, which had been used extensively for GISAXS investigations in the past. As an example, a titania thin film sponge structure is investigated. Compared to BW4, at beamline P03 the resolution of larger structures is slightly improved and a higher incident flux leads to a factor of 750 in scatteredmore » intensity. Therefore, the acquisition time in GISAXS geometry is reduced significantly at beamline P03.« less

A New Hard X-ray Wiggler for DORIS III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tischer, M.; Gumprecht, L.; Pflueger, J.

2007-01-19

A 4 m long hard X-ray wiggler has been built and installed in the DORIS III storage ring at DESY. The device replaces an old wiggler especially designed for angiography studies. Future use of this beamline at the HARWI straight section has been dedicated to hard X-ray scattering and diffraction experiments for material science and geological investigations. The required energy range is from 30 keV to about 200 keV with emphasis on the {approx}100 keV spectral range. The magnet configuration corresponds to a hybrid structure with additional side magnets to achieve a 2 T peak field for the specified periodmore » length of 110 mm. The wiggler position in the storage ring has been moved 8 m upstream into the next cell which allowed for reduction of the minimum magnetic wiggler gap to 14 mm.« less

Fluorescence dynamics of biological systems using synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gratton, E.; Mantulin, W.W.; Weber, G.

1996-09-01

A beamline for time-resolved fluorescence spectroscopy of biological systems is under construction at the Synchrotron Radiation Center. The fluorometer, operating in the frequency domain, will take advantage of the time structure of the synchrotron radiation light pulses to determine fluorescence lifetimes. Using frequency-domain techniques, the instrument can achieve an ultimate time resolution on the order of picoseconds. Preliminary experiments have shown that reducing the intensity of one of the fifteen electron bunches in the storage ring allows measurement of harmonic frequencies equivalent to the single-bunch mode. This mode of operation of the synchrotron significantly extends the range of lifetimes thatmore » can be measured. The wavelength range (encompassing the visible and ultraviolet), the range of measurable lifetimes, and the stability and reproducibility of the storage ring pulses should make this beamline a versatile tool for the investigation of the complex fluorescence decay of biological systems. {copyright} {ital 1996 American Institute of Physics.}« less

HIGH-ENERGY X-RAY PINHOLE CAMERA FOR HIGH-RESOLUTION ELECTRON BEAM SIZE MEASUREMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, B.; Morgan, J.; Lee, S.H.

The Advanced Photon Source (APS) is developing a multi-bend achromat (MBA) lattice based storage ring as the next major upgrade, featuring a 20-fold reduction in emittance. Combining the reduction of beta functions, the electron beam sizes at bend magnet sources may be reduced to reach 5 – 10 µm for 10% vertical coupling. The x-ray pinhole camera currently used for beam size monitoring will not be adequate for the new task. By increasing the operating photon energy to 120 – 200 keV, the pinhole camera’s resolution is expected to reach below 4 µm. The peak height of the pinhole imagemore » will be used to monitor relative changes of the beam sizes and enable the feedback control of the emittance. We present the simulation and the design of a beam size monitor for the APS storage ring.« less

The Muon g-2 Experiment overview and status as of June 2016

DOE PAGES

Holzbauer, J. L.

2016-12-09

The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion, which is a factor of four improvement over the previous E821 measurement at Brookhaven. The experiment will also extend the search for the electric dipole moment (EDM) of the muon by approximately two orders of magnitude, with a sensitivity down to 10 -21 e.cm. Both of these measurements are made by combining a precise measurement of the 1.45T storage ring magnetic field with an analysis of the modulation of the decay rate of higher-energy positrons (from anti-muons),more » recorded by 24 calorimeters and 3 straw tracking detectors. Furthermore, the recent progress in the alignment of the electrostatic quadrapole plates and the trolley rails inside the vacuum chambers, and in establishing the uniform storage ring magnetic field will be described.« less

Storage ring two-color free-electron laser

DOE PAGES

Yan, J.; Hao, H.; Li, J. Y.; ...

2016-07-05

We report a systematic experimental study of a storage ring two-color free-electron laser (FEL) operating simultaneously in the infrared (IR) and ultraviolet (UV) wavelength regions. The two-color FEL lasing has been realized using a pair of dual-band high-reflectivity FEL mirrors with two different undulator configurations. We have demonstrated independent wavelength tuning in a wide range for each lasing color, as well as harmonically locked wavelength tuning when the UV lasing occurs at the second harmonic of the IR lasing. Precise power control of two-color lasing with good power stability has also been achieved. In addition, the impact of the degradationmore » of FEL mirrors on the two-color FEL operation is reported. Moreover, we have investigated the temporal structures of the two-color FEL beams, showing simultaneous two-color micropulses with their intensity modulations displayed as FEL macropulses.« less

Introduction to the magnet and vacuum systems of an electron storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weng, W.T.

An accelerator or storage ring complex is a concerted interplay of various functional systems. For the convenience of discussion we can divide it into the following systems: injector, magnet, RF, vacuum, instrumentation and control. In addition, the conventional construction of the building and radiation safety consideration are also needed and finally the beam lines, detector, data acquisition and analysis set-ups for research programs. Dr. L. Teng has given a comprehensive review of the whole complex and the operation of such a facility. I concentrate on the description of magnet and vacuum systems. Only the general function of each system andmore » the basic design concepts will be introduced, no detailed engineering practice will be given which will be best done after a machine design is produced. For further understanding and references a table of bibliography is provided at the end of the paper.« less

Coulomb clusters in RETRAP

NASA Astrophysics Data System (ADS)

Steiger, J.; Beck, B. R.; Gruber, L.; Church, D. A.; Holder, J. P.; Schneider, D.

1999-01-01

Storage rings and Penning traps are being used to study ions in their highest charge states. Both devices must have the capability for ion cooling in order to perform high precision measurements such as mass spectrometry and laser spectroscopy. This is accomplished in storage rings in a merged beam arrangement where a cold electron beam moves at the speed of the ions. In RETRAP, a Penning trap located at Lawrence Livermore National Laboratory, a sympathetic laser/ion cooling scheme has been implemented. In a first step, singly charged beryllium ions are cooled electronically by a tuned circuit and optically by a laser. Then hot, highly charged ions are merged into the cold Be plasma. By collisions, their kinetic energy is reduced to the temperature of the Be plasma. First experiments indicate that the highly charged ions form a strongly coupled plasma with a Coulomb coupling parameter exceeding 1000.

Field Quality from Tolerance Stack-up In R&D Quadrupoles for the Advanced Photon Source Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J.; Jaski, M.; Dejus, R.

2016-10-01

The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is considering upgrading the current double-bend, 7-GeV, 3rd generation storage ring to a 6-GeV, 4th generation storage ring with a Multibend Achromat (MBA) lattice. In this study, a novel method is proposed to determine fabrication and assembly tolerances through a combination of magnetic and mechanical tolerance analyses. Mechanical tolerance stackup analyses using Teamcenter Variation Analysis are carried out to determine the part and assembly level fabrication tolerances. Finite element analyses using OPERA are conducted to estimate the effect of fabrication and assembly errors on the magnetic field of a quadrupolemore » magnet and to determine the allowable tolerances to achieve the desired magnetic performance. Finally, results of measurements in R&D quadrupole prototypes are compared with the analysis results.« less

Impedance computations and beam-based measurements: A problem of discrepancy

NASA Astrophysics Data System (ADS)

Smaluk, Victor

2018-04-01

High intensity of particle beams is crucial for high-performance operation of modern electron-positron storage rings, both colliders and light sources. The beam intensity is limited by the interaction of the beam with self-induced electromagnetic fields (wake fields) proportional to the vacuum chamber impedance. For a new accelerator project, the total broadband impedance is computed by element-wise wake-field simulations using computer codes. For a machine in operation, the impedance can be measured experimentally using beam-based techniques. In this article, a comparative analysis of impedance computations and beam-based measurements is presented for 15 electron-positron storage rings. The measured data and the predictions based on the computed impedance budgets show a significant discrepancy. Three possible reasons for the discrepancy are discussed: interference of the wake fields excited by a beam in adjacent components of the vacuum chamber, effect of computation mesh size, and effect of insufficient bandwidth of the computed impedance.

The Muon g-2 Experiment Overview and Status as of June 2016

NASA Astrophysics Data System (ADS)

Holzbauer, J.

2016-11-01

The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion, which is a factor of four improvement over the previous E821 measurement at Brookhaven. The experiment will also extend the search for the electric dipole moment (EDM) of the muon by approximately two orders of magnitude, with a sensitivity down to 10-21 e.cm. Both of these measurements are made by combining a precise measurement of the 1.45T storage ring magnetic field with an analysis of the modulation of the decay rate of higher-energy positrons (from anti-muons), recorded by 24 calorimeters and 3 straw tracking detectors. The recent progress in the alignment of the electrostatic quadrapole plates and the trolley rails inside the vacuum chambers, and in establishing the uniform storage ring magnetic field will be described.

New beam-position monitor system for upgraded Photon Factory storage ring.

PubMed

Haga, K; Honda, T; Tadano, M; Obina, T; Kasuga, T

1998-05-01

Accompanying the brilliance-upgrading project at the Photon Factory storage ring, the beam-position monitor (BPM) system has been renovated. The new system was designed to enable precise and fast measurements to correct the closed-orbit distortion (COD), as well as to feed back the orbit position during user runs. There are 42 BPMs newly installed, amounting to a total of 65 BPMs. All of the BPMs are calibrated on the test bench using a coaxially strung metallic wire. The measured electrical offsets are typically 200 micro m in both directions, which is 1/2-1/3 of those of the old-type BPMs. In the signal-processing system, PIN diode switches are employed in order to improve reliability. In the fastest mode, this system is capable of measuring COD within about 10 ms; this fast acquisition will allow fast suppression of the beam movement for frequencies up to 50 Hz using a global feedback system.

Large transient fault current test of an electrical roll ring

NASA Technical Reports Server (NTRS)

Yenni, Edward J.; Birchenough, Arthur G.

1992-01-01

The space station uses precision rotary gimbals to provide for sun tracking of its photoelectric arrays. Electrical power, command signals and data are transferred across the gimbals by roll rings. Roll rings have been shown to be capable of highly efficient electrical transmission and long life, through tests conducted at the NASA Lewis Research Center and Honeywell's Satellite and Space Systems Division in Phoenix, AZ. Large potential fault currents inherent to the power system's DC distribution architecture, have brought about the need to evaluate the effects of large transient fault currents on roll rings. A test recently conducted at Lewis subjected a roll ring to a simulated worst case space station electrical fault. The system model used to obtain the fault profile is described, along with details of the reduced order circuit that was used to simulate the fault. Test results comparing roll ring performance before and after the fault are also presented.

Planetary rings as relics of plasma pre-rings

NASA Astrophysics Data System (ADS)

Rabinovich, B. I.

2007-02-01

A possibility is discussed that the rings of large planets observed in the modern epoch are relics of some pre-rings consisting of magnetized plasma (according to a hypothesis by H. Alfven). The solution to a model problem published in [36, 37] is used. Its main result is a mechanism of stratification of an evolutionally mature plasma pre-ring into a large number of narrow elite rings separated by anti-rings (gaps). Another result is the theoretical substantiation of the presence in the near-planetary space of a region of existence and stability (in what follows it is referred to as ES-region) of plasma rings. The data obtained in the course of the Voyager, Galileo, and Cassini missions are used below for verification of the model on which the solutions presented in [36, 37] are based.

Groundwater storage inferred from earthquake activities around East Asia and West Pacific Ocean

NASA Astrophysics Data System (ADS)

Shih, David Ching-Fang

2017-01-01

Groundwater is a necessary and indispensable resource in the gradual depletion of the amount in the world. Groundwater storage is an important indicator to evaluate the capability of volume of water can be released from the aquifer. This research highlights a new assessment to infer the storage of aquifer using earthquakes activated around East Asia and the ring of fire at West Pacific Ocean. Ten significant seismic events are used to evaluate the groundwater storage at an observation station. By analyzing the spectra of groundwater level and seismogram, it is evident that the period varied in 7-25 s of Rayleigh waves significantly dominate propagation from the epicenter of earthquakes to the observation station. The storage coefficient is then shown in the order of 10-4-10-3. The major innovation of this study suggests that to concretely deduce the groundwater storage by earthquake activity has become feasible.

Cell-autonomous correction of ring chromosomes in human induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Bershteyn, Marina; Hayashi, Yohei; Desachy, Guillaume; Hsiao, Edward C.; Sami, Salma; Tsang, Kathryn M.; Weiss, Lauren A.; Kriegstein, Arnold R.; Yamanaka, Shinya; Wynshaw-Boris, Anthony

2014-03-01

Ring chromosomes are structural aberrations commonly associated with birth defects, mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome, and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes, no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division, ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations, enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of `chromosome therapy' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition, our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control, which is of critical relevance to human development and disease.

Magnetic bearing momentum wheels with magnetic gimballing capability for 3-axis active attitude control and energy storage

NASA Technical Reports Server (NTRS)

Sindlinger, R. S.

1977-01-01

A 3-axis active attitude control system with only one rotating part was developed using a momentum wheel with magnetic gimballing capability as a torque actuator for all three body axes. A brief description of magnetic bearing technology is given. It is concluded that based on this technology an integrated energy storage/attitude control system with one air of counterrotating rings could reduce the complexity and weight of conventional systems.

National Synchrotron Light Source II

ScienceCinema

Steve Dierker

2017-12-09

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

Portable convertible blast effects shield

DOEpatents

Pastrnak, John W [Livermore, CA; Hollaway, Rocky [Modesto, CA; Henning, Carl D [Livermore, CA; Deteresa, Steve [Livermore, CA; Grundler, Walter [Hayward, CA; Hagler, Lisle B [Berkeley, CA; Kokko, Edwin [Dublin, CA; Switzer, Vernon A [Livermore, CA

2011-03-15

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

Model-independent analysis of the Fermilab Tevatron turn-by-turn beam position monitor measurements

NASA Astrophysics Data System (ADS)

Petrenko, A. V.; Valishev, A. A.; Lebedev, V. A.

2011-09-01

Coherent transverse beam oscillations in the Tevatron were analyzed with the model-independent analysis (MIA) technique. This allowed one to obtain the model-independent values of coupled betatron amplitudes, phase advances, and dispersion function around the ring from a single dipole kick measurement. In order to solve the MIA mode mixing problem which limits the accuracy of determination of the optical functions, we have developed a new technique of rotational MIA mode untangling. The basic idea is to treat each beam position monitor (BPM) as two BPMs separated in a ring by exactly one turn. This leads to a simple criterion of MIA mode separation: the betatron phase advance between any BPM and its counterpart shifted by one turn should be equal to the betatron tune and therefore should not depend on the BPM position in the ring. Furthermore, we describe a MIA-based technique to locate vibrating magnets in a storage ring.

Investigation of the heavy-ion mode in the FAIR High Energy Storage Ring

NASA Astrophysics Data System (ADS)

Kovalenko, O.; Dolinskii, O.; Litvinov, Yu A.; Maier, R.; Prasuhn, D.; Stöhlker, T.

2015-11-01

High energy storage ring (HESR) as a part of the future accelerator facility FAIR (Facility for Antiproton and Ion Research) will serve for a variety of internal target experiments with high-energy stored heavy ions (SPARC collaboration). Bare uranium is planned to be used as a primary beam. Since a storage time in some cases may be significant—up to half an hour—it is important to examine the high-order effects in the long-term beam dynamics. A new ion optics specifically for the heavy ion mode of the HESR is developed and is discussed in this paper. The subjects of an optics design, tune working point and a dynamic aperture are addressed. For that purpose nonlinear beam dynamics simulations are carried out. Also a flexibility of the HESR ion optical lattice is verified with regard to various experimental setups. Specifically, due to charge exchange reactions in the internal target, secondary beams, such as hydrogen-like and helium-like uranium ions, will be produced. Thus the possibility of separation of these secondary ions and the primary {{{U}}}92+ beam is presented with different internal target locations.

Proton velocity ring-driven instabilities and their dependence on the ring speed: Linear theory

NASA Astrophysics Data System (ADS)

Min, Kyungguk; Liu, Kaijun; Gary, S. Peter

2017-08-01

Linear dispersion theory is used to study the Alfvén-cyclotron, mirror and ion Bernstein instabilities driven by a tenuous (1%) warm proton ring velocity distribution with a ring speed, vr, varying between 2vA and 10vA, where vA is the Alfvén speed. Relatively cool background protons and electrons are assumed. The modeled ring velocity distributions are unstable to both the Alfvén-cyclotron and ion Bernstein instabilities whose maximum growth rates are roughly a linear function of the ring speed. The mirror mode, which has real frequency ωr=0, becomes the fastest growing mode for sufficiently large vr/vA. The mirror and Bernstein instabilities have maximum growth at propagation oblique to the background magnetic field and become more field-aligned with an increasing ring speed. Considering its largest growth rate, the mirror mode, in addition to the Alfvén-cyclotron mode, can cause pitch angle diffusion of the ring protons when the ring speed becomes sufficiently large. Moreover, because the parallel phase speed, v∥ph, becomes sufficiently small relative to vr, the low-frequency Bernstein waves can also aid the pitch angle scattering of the ring protons for large vr. Potential implications of including these two instabilities at oblique propagation on heliospheric pickup ion dynamics are discussed.

Friction melt distribution in a multi-ring impact basin.

PubMed

Spray, J G; Thompson, L M

1995-01-12

It is generally accepted that multi-ring basins are the consequence of very large impacts, but the mechanism by which they form is still a matter of contention. Most of what is currently known about multi-ring basins is based on remote studies of the Moon and, to a lesser extent, Mars and Mercury. But at least two multi-ring impact basins have been recognized on Earth--the Sudbury (Canada) and Vredefort (South Africa) impact structures--providing an opportunity to study their properties directly. Here we describe the distribution of friction melt (pseudotachylyte) in the floor of the Sudbury impact basin. Although the veins and dykes of pseudotachylyte decrease in both thickness and frequency of occurrence towards the basin periphery, the greatest volumes of friction melt appear to define four rings around the central impact melt sheet. Field evidence indicates that the rings originated as zones of large displacement, which facilitated localized frictional melting of the basin floor during the modification (collapse) stage of the cratering process. By analogy, we argue that the rings of other multi-ring impact basins are also likely to be the remnants of such large-displacement fault zones.

Interaction of vortex rings with multiple permeable screens

NASA Astrophysics Data System (ADS)

Musta, Mustafa N.; Krueger, Paul S.

2014-11-01

Interaction of a vortex ring impinging on multiple permeable screens orthogonal to the ring axis was studied to experimentally investigate the persistence and decay of vortical structures inside the screen array using digital particle image velocimetry in a refractive index matched environment. The permeable screens had porosities (open area ratios) of 83.8%, 69.0%, and 55.7% and were held by a transparent frame that allowed the screen spacing to be changed. Vortex rings were generated using a piston-cylinder mechanism at nominal jet Reynolds numbers of 1000, 2000, and 3000 with piston stroke length-to-diameter ratios of 2 and 3. The interaction of vortex rings with the porous medium showed a strong dependence of the overall flow evolution on the screen porosity, with a central flow being preserved and vortex ring-like structures (with smaller diameter than the primary vortex ring) being generated near the centerline. Due to the large rod size used in the screens, immediate reformation of the transmitted vortex ring with size comparable to the primary ring (as has been observed with thin screens) was not observed in most cases. Since the screens have lower complexity and high open area ratios, centerline vortex ring-like flow structures formed with comparable size to the screen pore size and penetrated through the screens. In the case of low porosity screens (55.7%) with large screen spacing, re-emergence of large scale (large separation), weak vortical structures/pairs (analogous to a transmitted vortex ring) was observed downstream of the first screen. Additional smaller scale vortical structures were generated by the interaction of the vortex ring with subsequent screens. The size distribution of the generated vortical structures were shown to be strongly affected by porosity, with smaller vortical structures playing a stronger role as porosity decreased. Finally, porosity significantly affected the decay of total energy, but the effect of screen spacing decreased as porosity decreased.

Analytical approach to Eigen-emittance evolution in storage rings

NASA Astrophysics Data System (ADS)

Nash, Boaz

This dissertation develops the subject of beam evolution in storage rings with nearly uncoupled symplectic linear dynamics. Linear coupling and dissipative/diffusive processes are treated perturbatively. The beam distribution is assumed Gaussian and a function of the invariants. The development requires two pieces: the global invariants and the local stochastic processes which change the emittances, or averages of the invariants. A map based perturbation theory is described, providing explicit expressions for the invariants near each linear resonance, where small perturbations can have a large effect. Emittance evolution is determined by the damping and diffusion coefficients. The discussion is divided into the cases of uniform and non-uniform stochasticity, synchrotron radiation an example of the former and intrabeam scattering the latter. For the uniform case, the beam dynamics is captured by a global diffusion coefficent and damping decrement for each eigen-invariant. Explicit expressions for these quantities near coupling resonances are given. In many cases, they are simply related to the uncoupled values. Near a sum resonance, it is found that one of the damping decrements becomes negative, indicating an anti-damping instability. The formalism is applied to a number of examples, including synchrobetatron coupling caused by a crab cavity, a case of current interest where there is concern about operation near half integer betatron tune. In the non-uniform case, the moment evolution is computed directly, which is illustrated through the example of intrabeam scattering. Our approach to intrabeam scattering damping and diffusion has the advantage of not requiring a loosely-defined Coulomb Logarithm. It is found that in some situations there is a small difference between our results and the standard approaches such as Bjorken-Mtingwa, which is illustrated by comparison of the two approaches and with a measurement of Au evolution in RHIC. Finally, in combining IBS with the global invariants some general statements about IBS equilibrium can be made. Specifically, it is emphasized that no such equilibrium is possible in a non-smooth lattice, even below transition. Near enough to a synchrobetatron coupling resonance, it is found that even for a smooth ring, no IBS equilibrium occurs.

Large and small-scale structures in Saturn's rings

NASA Astrophysics Data System (ADS)

Albers, N.; Rehnberg, M. E.; Brown, Z. L.; Sremcevic, M.; Esposito, L. W.

2017-09-01

Observations made by the Cassini spacecraft have revealed both large and small scale structures in Saturn's rings in unprecedented detail. Analysis of high-resolution measurements by the Cassini Ultraviolet Spectrograph (UVIS) High Speed Photometer (HSP) and the Imaging Science Subsystem (ISS) show an abundance of intrinsic small-scale structures (or clumping) seen across the entire ring system. These include self-gravity wakes (50-100m), sub-km structure at the A and B ring edges, and "straw"/"ropy" structures (1-3km).

Metering Wheel-Wire Track Wire Boom Deployment Mechanism

NASA Technical Reports Server (NTRS)

Granoff, Mark S.

2014-01-01

The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

Force on a storage ring vacuum chamber after sudden turn-off of a magnet power supply

NASA Astrophysics Data System (ADS)

Sinha, Gautam; Prabhu, S. S.

2011-10-01

We are commissioning a 2.5 GeV synchrotron radiation source (SRS) where electrons travel in high vacuum inside the vacuum chambers made of aluminum alloys. These chambers are kept between the pole gaps of magnets and are made to facilitate the radiation coming out of the storage ring to the experimental station. These chambers are connected by metallic bellows. During the commissioning phase of the SRS, the metallic bellows became ruptured due to the frequent tripping of the dipole magnet power supply. The machine was down for quite some time. In the case of a power supply trip, the current in the magnets decays exponentially. It was observed experimentally that the fast B field decay generates a large eddy current in the chambers and consequently the chambers are subjected to a huge Lorentz force. This motivated us to develop a theoretical model to study the force acting on a metallic plate when exposed to an exponentially decaying field and then to extend it for a rectangular vacuum chamber. The problem is formulated using Maxwell’s equations and converted to the inhomogeneous Helmholtz equation. After taking the Laplace transform, the equation is solved with appropriate boundary conditions. Final results are obtained after taking the appropriate inverse Laplace transform. The expressions for eddy current contour and magnetic field produced by the eddy current are also derived. Variations of the force on chambers of different wall thickness due to spatially varying and exponentially time decaying field are presented. The result is a general theory which can be applied to different geometries and calculation of power loss as well. Comparisons are made with results obtained by simulation using a finite element based code, for quick verification of the theoretical model.

Mullite and Mullite Ceramics

DTIC Science & Technology

1994-01-01

possible. The here reported measurements were carried out with synchrotron radiation from the electron storage ring ELSA of the Bonn University. All...Physikalisches Institut der Universitdt Bonn , Bonn , Germany Measurements of X-ray absorption spectra near the absorption edge of a selected element (XANES

B factory plans at Cornell

NASA Astrophysics Data System (ADS)

Berkelman, Karl

1989-12-01

Recent upgrade project at the Cornell Electron Storage Ring is discussed. Modification was made to make B mesons factory design possible. The CLEO detector has been rebuilt with a new superconducting magnet and a high resolution electromagnetic calorimeter made of cesium iodide scintillators.(AIP)

Influence of the nuclear symmetry energy on the collective flows of charged pions

NASA Astrophysics Data System (ADS)

Gao, Yuan; Yong, Gao-Chan; Zhang, Lei; Zuo, Wei

2018-01-01

Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model, we studied charged pion transverse and elliptic flows in semicentral 197Au+197Au collisions at 600 MeV/nucleon. It is found that π+-π- differential transverse flow and the difference of π+ and π- transverse flows almost show no effects of the symmetry energy. Their corresponding elliptic flows are largely affected by the symmetry energy, especially at high transverse momenta. The isospin-dependent pion elliptic flow at high transverse momenta thus provides a promising way to probe the high-density behavior of the symmetry energy in heavy-ion collisions at the Facility for Antiproton and Ion Research (FAIR) at GSI, Darmstadt or at the Cooling Storage Ring (CSR) at HIRFL, Lanzhou.

Advanced photoelectric effect experiment beamline at Elettra: A surface science laboratory coupled with Synchrotron Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panaccione, G.; Vobornik, I.; Fujii, J.

2009-04-15

We report the main characteristics of the advanced photoelectric effect experiments beamline, operational at Elettra storage ring, featuring a fully independent double branch scheme obtained by the use of chicane undulators and able to keep polarization control in both linear and circular mode. The paper describes the novel technical solutions adopted, namely, (a) the design of a quasiperiodic undulator resulting in optimized suppression of higher harmonics over a large photon energy range (10-100 eV), (b) the thermal stability of optics under high heat load via cryocoolers, and (c) the end station interconnected setup allowing full access to off-beam and on-beammore » facilities and, at the same time, the integration of users' specialized sample growth chambers or modules.« less

Deuteron polarimetry at COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiladze, D.; High Energy Physics Institute, Tbilisi State University, 0186 Tbilisi; Grigoriev, K.

2007-06-13

The vector Pz and tensor Pzz polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions at the ANKE magnetic spetrometer. The overall precisions obtained were about 4% for both Pz and Pzz. One of the motivation for the experimental programme is the direct reconstruction of the spin-dependent amplitudes, including relative phases, of large angle neutron-proton elastic scattering, through the studymore » of the p(d,2p)n charge-exchange reaction up to the highest available deuteron energy at COSY (2.3 GeV)« less

FOKKER-PLANCK ANALYSIS OF TRANSVERSE COLLECTIVE INSTABILITIES IN ELECTRON STORAGE RINGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindberg, R. R.

We analyze single bunch transverse instabilities due to wakefields using a Fokker-Planck model. We expand on the work of Suzuki [1], writing out the linear matrix equation including chromaticity, both dipolar and quadrupolar transverse wakefields, and the effects of damping and diffusion due to the synchrotron radiation. The eigenvalues and eigenvectors determine the collective stability of the beam, and we show that the predicted threshold current for transverse instability and the profile of the unstable agree well with tracking simulations. In particular, we find that predicting collective stability for high energy electron beams at moderate to large values of chromaticitymore » requires the full Fokker-Planck analysis to properly account for the effects of damping and diffusion due to synchrotron radiation.« less

Capture, acceleration and bunching rf systems for the MEIC booster and storage rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shaoheng; Guo, Jiquan; Lin, Fanglei

2015-09-01

The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. The electron collider ring accepts electrons from CEBAF at energies from 3 to 12 GeV. Protons and ions are delivered to a booster and captured in a long bunch before being ramped and transferred to the ion collider ring. The ion collider ring accelerates a small number of long ion bunches to colliding energy before they are re-bunched into a high frequency train of very short bunches for colliding. Two sets of low frequency RF systems are needed for the long ion bunch energymore » ramping in the booster and ion collider ring. Another two sets of high frequency RF cavities are needed for re-bunching in the ion collider ring and compensating synchrotron radiation energy loss in the electron collider ring. The requirements from energy ramping, ion beam bunching, electron beam energy compensation, collective effects, beam loading and feedback capability, RF power capability, etc. are presented. The preliminary designs of these RF systems are presented. Concepts for the baseline cavity and RF station configurations are described, as well as some options that may allow more flexible injection and acceleration schemes.« less

Higher-order formulas of amplitude-dependent tune shift caused by a sextupole magnetic field distribution

NASA Astrophysics Data System (ADS)

Soutome, Kouichi; Tanaka, Hitoshi

2017-06-01

Nowadays, designs for ring-based light sources use multibend lattices for achieving a very small emittance of around 100 pmrad. In this type of storage ring, the chromaticity correcting sextupoles generally have greater strengths than those used in typical third-generation light sources. Therefore, controlling lattice nonlinearity such as amplitude-dependent tune shift (ADTS) is important for enabling stable operations and smooth beam commissioning. As the strength of the sextupoles increases, their higher-order terms contribute significantly to ADTS, rendering well-known lowest-order formulas inadequate for describing tune variations at large horizontal amplitudes. In response, we have derived explicit expressions of ADTS up to the fourth order in sextupole strength based on the canonical perturbation theory, assuming that the amplitude of a vertical betatron oscillation is smaller compared with the horizontal one. The new formulas express the horizontal and vertical betatron tune variations as functions of the action variables: Jx and Jy up to O (Jx2) and O (Jy) . The derived formulas were applied to a five-bend achromat lattice designed for the SPring-8 upgrade. By comparing the calculated results with the tracking simulations, we found that (1) the formulas accurately express ADTS around a horizontal amplitude of ˜10 mm and (2) the nonlinear terms of the fourth order in sextupole strength govern the behaviors of circulating electrons at large horizontal amplitudes. In this paper, we present explicit expressions of fourth-order formulas of ADTS and provide some examples to illustrate their effectiveness.

Electron cloud generation and trapping in a quadrupole magnet at the Los Alamos proton storage ring

NASA Astrophysics Data System (ADS)

Macek, Robert J.; Browman, Andrew A.; Ledford, John E.; Borden, Michael J.; O'Hara, James F.; McCrady, Rodney C.; Rybarcyk, Lawrence J.; Spickermann, Thomas; Zaugg, Thomas J.; Pivi, Mauro T. F.

2008-01-01

Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the “prompt” electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the “swept” electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100μs. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the quadrupole.

Sperm storage, sperm translocation and genitalia formation in females of the terrestrial isopod Armadillidium vulgare (Crustacea, Peracarida, Isopoda).

PubMed

Ziegler, Andreas; Suzuki, Sachiko

2011-01-01

We investigated sperm storage, sperm transfer from the oviduct to the seminal receptacle, and formation of the cuticular genitalia in female Armadillidium vulgare using light and electron microscopy. Apolysis of the genitalia within the oviduct forms a circum-genital lumen. During insemination this space is filled with immobile spermatozoa. Sperm transfer into the seminal receptacle takes place before oviposition. Within a peculiar proximal neck region of the oviduct spermatozoa are bundled and enveloped by a folded epicuticular layer. The envelope tightly surrounds the spermatozoa probably forming a seal against the main part of the circum-genital lumen. We propose that hydrostatic pressure produced by the muscle cells surrounding the oviduct leads to sperm transfer into the seminal receptacle. Within the seminal receptacle the sperm bundle forms a ring just around the orifice to the oviduct. At one side sheath-like extensions of epithelial cells surround the ring of spermatozoa holding it in place. At the other side oocytes would have access to the sperm during oviposition, probably allowing for fertilisation when they pass right through the ring of spermatozoa. After oviposition the new genitalia are formed from epicuticular folds, and cuticle secreted by the epithelial cells. Copyright © 2010 Elsevier Ltd. All rights reserved.

Results from a survey of the dynamics shaping Uranus' Mab/μ-ring system

NASA Astrophysics Data System (ADS)

Kumar, Kartik; de Pater, Imke; Showalter, Mark R.

2014-11-01

Based on Hubble Space Telescope (HST) data, Showalter and Lissauer (2006) reported the discovery of two faint rings beyond Uranus’ main rings: the ν- and μ- rings. They constitute Uranus' outer ring system and are located beyond the ɛ-ring but interior to the large classical moons. After co-adding a series of HST images, Showalter and Lissauer (2006) obtained radial profiles for both new rings. They discovered that the peak radial intensity of the μ-ring aligns closely with the orbit of Mab. Along with numerous other observations, this points to the fact that the Mab/μ-ring system is highly coupled.The discovery of the μ-ring has led to open questions about dust dynamics beyond Uranus' main rings. Like Saturn's E-ring, observations reveal that the μ-ring is blue, indicative of a pre-dominance of sub-micron-sized particles (de Pater et al., 2006). The E-ring results from plumes on Enceladus' south pole, however the origin of the μ-ring remains a mystery. The latter is likely fed by ejecta from micro-meteorite impacts with Mab, much like Jupiter's faint rings are regenerated by companion (small) moons (Burns et al., 1999). The μ-ring's steep size-distribution suggests that there is an unknown mechanism at play that hides or removes large dust particles. We present results from an investigation into the forces shaping the μ-ring. To simulate the motion of dust in the Mab/μ-ring system, we developed a numerical toolbox (Dustsim; Kumar et al., 2015) that uses Tudat (Kumar et al., 2012). We performed integrations using Dustsim that included the effects of Uranus' gravity field, titled magnetic moment, solar radiation pressure, and collisions with a putative suite of large μ-ring bodies, hypothesized as the cause of Mab's anomalous orbital motion (Kumar et al., 2014). Following on from previous studies (e.g., Sfair and Giuliatti Winter, 2009; Sfair and Giuliatti Winter, 2012), we present a survey of the expected lifetime of μ-ring dust, as a function of particle size. Our results lay the basis for further research into the hypothesis that the blueness of the μ-ring is a manifestation of size-based sorting, resulting from the natural environment.

Monte Carlo calculation of skyshine'' neutron dose from ALS (Advanced Light Source)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moin-Vasiri, M.

1990-06-01

This report discusses the following topics on skyshine'' neutron dose from ALS: Sources of radiation; ALS modeling for skyshine calculations; MORSE Monte-Carlo; Implementation of MORSE; Results of skyshine calculations from storage ring; and Comparison of MORSE shielding calculations.

Radiological considerations for the operation of the Advanced Photon Source storage ring (revised).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moe, H. J.

2002-05-02

This report deals with the radiological considerations of operations using 7700-MeV positron and electron beams in the storage ring (SR) tunnel. The radiological considerations addressed include the following: prompt secondary radiation (bremsstrahlung, giant resonance neutrons, medium and high energy neutrons, and muons) produced by electrons/positrons interacting in a beam stop or by particle losses in the component structures; skyshine radiation, which produces a radiation field in nearby areas and at the nearest off-site location; radioactive gases produced by neutron irradiation of air in the vicinity of a particle loss site; noxious gases (ozone and others) produced in air by themore » escaping bremsstrahlung radiation that results from absorbing particles in the components or by synchrotron radiation escaping into the tunnel; activation of the storage ring components that results in a residual radiation field in the vicinity of these materials following shutdown; potential activation of water used for cooling the magnets and other purposes in the SR tunnel; evaluation of the radiation fields due to escaping synchrotron radiation and gas bremsstrahlung. Estimated dose rates outside of the tunnel, in the early assembly area (EAA), and in the Experiment Hall for several modes of operation (including potential safety envelope beam power, normal beam power, and MCI (maximum credible incident) conditions) have been computed. Shielding in the first optics enclosure (FOE) and for the photon beamlines is discussed in ANL/APS/TB-7 (IPE 93), but additional radiological considerations for the ASD diagnostic beamlines are contained in Appendix C. Although the calculations refer to positrons, electron operation would produce essentially the same effects for the identical assumptions.« less

Floodplain ecohydrology: Climatic, anthropogenic, and local physical controls on partitioning of water sources to riparian trees.

PubMed

Singer, Michael Bliss; Sargeant, Christopher I; Piégay, Hervé; Riquier, Jérémie; Wilson, Rob J S; Evans, Cristina M

2014-05-01

Seasonal and annual partitioning of water within river floodplains has important implications for ecohydrologic links between the water cycle and tree growth. Climatic and hydrologic shifts alter water distribution between floodplain storage reservoirs (e.g., vadose, phreatic), affecting water availability to tree roots. Water partitioning is also dependent on the physical conditions that control tree rooting depth (e.g., gravel layers that impede root growth), the sources of contributing water, the rate of water drainage, and water residence times within particular storage reservoirs. We employ instrumental climate records alongside oxygen isotopes within tree rings and regional source waters, as well as topographic data and soil depth measurements, to infer the water sources used over several decades by two co-occurring tree species within a riparian floodplain along the Rhône River in France. We find that water partitioning to riparian trees is influenced by annual (wet versus dry years) and seasonal (spring snowmelt versus spring rainfall) fluctuations in climate. This influence depends strongly on local (tree level) conditions including floodplain surface elevation and subsurface gravel layer elevation. The latter represents the upper limit of the phreatic zone and therefore controls access to shallow groundwater. The difference between them, the thickness of the vadose zone, controls total soil moisture retention capacity. These factors thus modulate the climatic influence on tree ring isotopes. Additionally, we identified growth signatures and tree ring isotope changes associated with recent restoration of minimum streamflows in the Rhône, which made new phreatic water sources available to some trees in otherwise dry years. Water shifts due to climatic fluctuations between floodplain storage reservoirsAnthropogenic changes to hydrology directly impact water available to treesEcohydrologic approaches to integration of hydrology afford new possibilities.

The role of spin–rotation coupling in the non-exponential decay of hydrogen-like heavy ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambiase, Gaetano, E-mail: lambiase@sa.infn.it; INFN, Sezione di Napoli; International Institute for Advanced Scientific Studies, 89019 Vietri sul Mare

2013-05-15

Recent experiments carried out at the storage ring of GSI in Darmstadt reveal an unexpected oscillation in the orbital electron capture and subsequent decay of hydrogen-like {sup 140}Pr{sup 58+}, {sup 142}Pm{sup 60+} and {sup 122}I{sup 52+}. The modulations have periods of 7.069(8) s, 7.10(22) s and 6.1 s respectively in the laboratory frame and are superimposed on the expected exponential decays. In this paper we propose a semiclassical model in which the observed modulations arise from the coupling of rotation to the spins of electron and nucleus. We show that the modulations are connected to quantum beats and to themore » effect of the Thomas precession on the spins of bound electron and nucleus, the magnetic moment precessions of electron and nucleus and their cyclotron frequencies. We also show that the spin–spin coupling of electron and nucleus, though dominant relative to the magnetic moment coupling of electron and nucleus with the storage ring magnetic field, does not contribute to the modulation because these terms average out during the time of flight of the ions, or cancel out. The model also predicts that the anomaly cannot be observed if the motion of the ions is rectilinear, or if the ions are stopped in a target (decay of neutral atoms in solid environments). It also supports the notion that no modulation occurs for the β{sup +}-decay branch. -- Highlights: ► Spin precession of the spin of nucleus and electron in storage ring. ► Coupling of rotation to the spin of electron and nucleus. ► Modulation in the decay probability of the heavy ions induced by quantum beats. ► Comparison with experimental data.« less

Floodplain ecohydrology: Climatic, anthropogenic, and local physical controls on partitioning of water sources to riparian trees

PubMed Central

Singer, Michael Bliss; Sargeant, Christopher I; Piégay, Hervé; Riquier, Jérémie; Wilson, Rob J S; Evans, Cristina M

2014-01-01

Seasonal and annual partitioning of water within river floodplains has important implications for ecohydrologic links between the water cycle and tree growth. Climatic and hydrologic shifts alter water distribution between floodplain storage reservoirs (e.g., vadose, phreatic), affecting water availability to tree roots. Water partitioning is also dependent on the physical conditions that control tree rooting depth (e.g., gravel layers that impede root growth), the sources of contributing water, the rate of water drainage, and water residence times within particular storage reservoirs. We employ instrumental climate records alongside oxygen isotopes within tree rings and regional source waters, as well as topographic data and soil depth measurements, to infer the water sources used over several decades by two co-occurring tree species within a riparian floodplain along the Rhône River in France. We find that water partitioning to riparian trees is influenced by annual (wet versus dry years) and seasonal (spring snowmelt versus spring rainfall) fluctuations in climate. This influence depends strongly on local (tree level) conditions including floodplain surface elevation and subsurface gravel layer elevation. The latter represents the upper limit of the phreatic zone and therefore controls access to shallow groundwater. The difference between them, the thickness of the vadose zone, controls total soil moisture retention capacity. These factors thus modulate the climatic influence on tree ring isotopes. Additionally, we identified growth signatures and tree ring isotope changes associated with recent restoration of minimum streamflows in the Rhône, which made new phreatic water sources available to some trees in otherwise dry years. Key Points Water shifts due to climatic fluctuations between floodplain storage reservoirs Anthropogenic changes to hydrology directly impact water available to trees Ecohydrologic approaches to integration of hydrology afford new possibilities PMID:25506099

Large Double-ringed Basin

NASA Image and Video Library

2000-08-05

Taken about 40 minutes before NASA Mariner 10 made its close approach to Mercury on Sept. 21,1974, this picture shows a large double-ringed basin center of picture located in the planet south polar region

Multi-Fluid Geo-Energy Systems for Bulk and Thermal Energy Storage and Dispatchable Renewable and Low-Carbon Electricity

NASA Astrophysics Data System (ADS)

Buscheck, T. A.; Randolph, J.; Saar, M. O.; Hao, Y.; Sun, Y.; Bielicki, J. M.

2014-12-01

Integrating renewable energy sources into electricity grids requires advances in bulk and thermal energy storage technologies, which are currently expensive and have limited capacity. We present an approach that uses the huge fluid and thermal storage capacity of the subsurface to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources. CO2 captured from fossil-energy systems and N2 separated from air are injected into permeable formations to store pressure, generate artesian flow of brine, and provide additional working fluids. These enable efficient fluid recirculation, heat extraction, and power conversion, while adding operational flexibility. Our approach can also store and dispatch thermal energy, which can be used to levelize concentrating solar power and mitigate variability of wind and solar power. This may allow low-carbon, base-load power to operate at full capacity, with the stored excess energy being available to addresss diurnal and seasonal mismatches between supply and demand. Concentric rings of horizontal injection and production wells are used to create a hydraulic divide to store pressure, CO2, N2, and thermal energy. Such storage can take excess power from the grid and excess thermal energy, and dispatch that energy when it is demanded. The system is pressurized and/or heated when power supply exceeds demand and depressurized when demand exceeds supply. Supercritical CO2 and N2 function as cushion gases to provide enormous pressure-storage capacity. Injecting CO2 and N2 displaces large quantities of brine, reducing the use of fresh water. Geologic CO2 storage is a crucial option for reducing CO2 emissions, but valuable uses for CO2 are needed to justify capture costs. The initial "charging" of our system requires permanently isolating large volumes of CO2 from the atmosphere and thus creates a market for its disposal. Our approach is designed for locations where a permeable geologic formation is overlain by an impermeable formation that constrains migration of buoyant CO2 and/or N2, and heated brine. Such geologic conditions exist over nearly half of the contiguous United States. This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Portable convertible blast effects shield

DOEpatents

Pastrnak, John W.; Hollaway, Rocky; Henning, Carl D.; Deteresa, Steve; Grundler, Walter; Hagler,; Lisle B.; Kokko, Edwin; Switzer, Vernon A

2010-10-26

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

Portable convertible blast effects shield

DOEpatents

Pastrnak, John W [Livermore, CA; Hollaway, Rocky [Modesto, CA; Henning, Carl D [Livermore, CA; Deteresa, Steve [Livermore, CA; Grundler, Walter [Hayward, CA; Hagler, Lisle B [Berkeley, CA; Kokko, Edwin [Dublin, CA; Switzer, Vernon A [Livermore, CA

2007-05-22

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

Ring-Shaped Seismicity Structures in Southern California: Possible Preparation for Large Earthquake in the Los Angeles Basin

NASA Astrophysics Data System (ADS)

Kopnichev, Yu. F.; Sokolova, I. N.

2017-12-01

Some characteristics of seismicity in Southern California are studied. It is found that ring-shaped seismicity structures with threshold magnitudes M th of 4.1, 4.1, and 3.8 formed prior to three large ( M w > 7.0) earthquakes in 1992, 1999, and 2010, respectively. The sizes of these structures are several times smaller than for intracontinental strike-slip events with similar magnitudes. Two ring-shaped structures are identified in areas east of the city of Los Angeles, where relatively large earthquakes have not occurred for at least 150 years. The magnitudes of large events which can occur in the areas of these structures are estimated on the basis of the previously obtained correlation dependence of ring sizes on magnitudes of the strike-slip earthquakes. Large events with magnitudes of M w = 6.9 ± 0.2 and M w = 8.6 ± 0.2 can occur in the area to the east of the city of Los Angeles and in the rupture zone of the 1857 great Fort Tejon earthquake, respectively. We believe that ring-structure formation, similarly to the other regions, is connected with deep-seated fluid migration.

Search for exclusive multibody non- decays at the resonance.

PubMed

Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weaver, K M; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J

2006-01-27

Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e+e- storage ring, we present searches for 25 charmless decay modes of the psi(3770), mostly multibody final states. No evidence for charmless decays is found.

Diffraction-limited IR Microspectroscopy with IRENI

Treesearch

J. Sedlmair; B. Illman; M. Unger; C. Hirschmugl

2012-01-01

In a unique way, IRENI (Infrared environmental Imaging), operated at the Synchrotron Radiation Center in Madison, combines IR spectroscopy and IR imaging, revealing the chemical morphology of a sample. Most storage ring based IR confocal microscopes have to overcome a trade-off between spatial resolution versus...

Active damping of the e-p instability at the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Macek, R. J.; Assadi, S.; Byrd, J. M.; Deibele, C. E.; Henderson, S. D.; Lee, S. Y.; McCrady, R. C.; Pivi, M. F. T.; Plum, M. A.; Walbridge, S. B.; Zaugg, T. J.

2007-12-01

A prototype of an analog, transverse (vertical) feedback system for active damping of the two-stream (e-p) instability has been developed and successfully tested at the Los Alamos Proton Storage Ring (PSR). This system was able to improve the instability threshold by approximately 30% (as measured by the change in RF buncher voltage at instability threshold). The feedback system configuration, setup procedures, and optimization of performance are described. Results of several experimental tests of system performance are presented including observations of instability threshold improvement and grow-damp experiments, which yield estimates of instability growth and damping rates. A major effort was undertaken to identify and study several factors limiting system performance. Evidence obtained from these tests suggests that performance of the prototype was limited by higher instability growth rates arising from beam leakage into the gap at lower RF buncher voltage and the onset of instability in the horizontal plane, which had no feedback.

Completion of the LANSCE Proton Storage Ring Control System Upgrade -- A Successful Integration of EPICS Into a Running Control System

NASA Astrophysics Data System (ADS)

Schaller, S. C.; Bjorklund, E. A.; Carr, G. P.; Faucett, J. A.; Oothoudt, M. A.

1997-05-01

The Los Alamos Neutron Scattering Center (LANSCE) Proton Storage Ring (PSR) control system upgrade was completed in 1996. In previous work, much of a PDP-11-based control system was replaced with Experimental Physics and Industrial Control System (EPICS) controls. Several parts of the old control system which used a VAX for operator displays and direct access to a CAMAC serial highway still remained. The old system was preserved as a "fallback" if the new EPICS-based system had problems. The control system upgrade completion included conversion of several application programs to EPICS-based operator interfaces, moving some data acquisition hardware to EPICS Input-Output Controllers (IOCs), and the implementation of new gateway software to complete the overall control system interoperability. Many operator interface (OPI) screens, written by LANSCE operators, have been incorporated in the new system. The old PSR control system hardware was removed. The robustness and reliability of the new controls obviated the need for a fallback capability.

Impedance computations and beam-based measurements: A problem of discrepancy

DOE PAGES

Smaluk, Victor

2018-04-21

High intensity of particle beams is crucial for high-performance operation of modern electron-positron storage rings, both colliders and light sources. The beam intensity is limited by the interaction of the beam with self-induced electromagnetic fields (wake fields) proportional to the vacuum chamber impedance. For a new accelerator project, the total broadband impedance is computed by element-wise wake-field simulations using computer codes. For a machine in operation, the impedance can be measured experimentally using beam-based techniques. In this article, a comparative analysis of impedance computations and beam-based measurements is presented for 15 electron-positron storage rings. The measured data and the predictionsmore » based on the computed impedance budgets show a significant discrepancy. For this article, three possible reasons for the discrepancy are discussed: interference of the wake fields excited by a beam in adjacent components of the vacuum chamber, effect of computation mesh size, and effect of insufficient bandwidth of the computed impedance.« less

Impedance computations and beam-based measurements: A problem of discrepancy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smaluk, Victor

High intensity of particle beams is crucial for high-performance operation of modern electron-positron storage rings, both colliders and light sources. The beam intensity is limited by the interaction of the beam with self-induced electromagnetic fields (wake fields) proportional to the vacuum chamber impedance. For a new accelerator project, the total broadband impedance is computed by element-wise wake-field simulations using computer codes. For a machine in operation, the impedance can be measured experimentally using beam-based techniques. In this article, a comparative analysis of impedance computations and beam-based measurements is presented for 15 electron-positron storage rings. The measured data and the predictionsmore » based on the computed impedance budgets show a significant discrepancy. For this article, three possible reasons for the discrepancy are discussed: interference of the wake fields excited by a beam in adjacent components of the vacuum chamber, effect of computation mesh size, and effect of insufficient bandwidth of the computed impedance.« less

Millimeter wave coherent synchrotron radiation in a compact electron storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, J.B.; Blum, E.; Heese, R.

1998-01-01

Installation of a 2,856 MHz RF system into the XLS compact electron storage ring would allow the generation of millimeter wave coherent synchrotron radiation. Operating at 150 MeV, one could produce bunches containing on the order of 2 {times} 10{sup 7} electrons with a bunch length {sigma}{sub L0} = 0.3 mm, resulting in coherent emission at wavelengths above 0.8 mm. The characteristics of the source and the emitted radiation are discussed. In the case of 100 mrad horizontal collection angle, the average power radiated in the wavelength band 1 mm {le} {lambda} {le} 2 mm is 0.3 mW for singlemore » bunch operation and 24 mW for 80 bunch operation. The peak power in a single pulse of a few picosecond duration is on the order of one watt. By reducing the momentum compaction, the bunch length could be reduced to {sigma}{sub L0} = 0.15 mm, resulting in coherent synchrotron radiation down to 500 {micro}m.« less

Control of systematic uncertainties in the storage ring search for an electric dipole moment by measuring the electric quadrupole moment

NASA Astrophysics Data System (ADS)

Magiera, Andrzej

2017-09-01

Measurements of electric dipole moment (EDM) for light hadrons with use of a storage ring have been proposed. The expected effect is very small, therefore various subtle effects need to be considered. In particular, interaction of particle's magnetic dipole moment and electric quadrupole moment with electromagnetic field gradients can produce an effect of a similar order of magnitude as that expected for EDM. This paper describes a very promising method employing an rf Wien filter, allowing to disentangle that contribution from the genuine EDM effect. It is shown that both these effects could be separated by the proper setting of the rf Wien filter frequency and phase. In the EDM measurement the magnitude of systematic uncertainties plays a key role and they should be under strict control. It is shown that particles' interaction with field gradients offers also the possibility to estimate global systematic uncertainties with the precision necessary for an EDM measurement with the planned accuracy.

VERTICAL BEAM SIZE CONTROL IN TLS AND TPS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

KUO, C.C.; CHEN, J.R.; CHOU, P.J.

2006-06-26

Vertical beam size control is an important issue in the light source operations. The horizontal-vertical betatron coupling and vertical dispersion were measured and corrected to small values in the TLS 1.5 GeV storage ring. Estimated beam sizes are compared with the measured values. By employing an effective transverse damping system, the vertical beam blow-up due to transverse coherent instabilities, such as the fast-ion beam instability, was suppressed. As a result, the light source is very stable. In NSRRC we are designing an ultra low emittance 3-GeV storage ring and its designed vertical beam size could be as small as amore » few microns. The ground and mechanic vibration effects, and coherent instabilities could spoil the expected photon brightness due to blow-up of the vertical beam size if not well taken care of. The contributions of these effects to vertical beam size increase will be evaluated and the counter measures to minimize them will be proposed and reported in this paper.« less

Characterization and long term operation of a novel superconducting undulator with 15 mm period length in a synchrotron light source

NASA Astrophysics Data System (ADS)

Casalbuoni, S.; Cecilia, A.; Gerstl, S.; Glamann, N.; Grau, A. W.; Holubek, T.; Meuter, C.; de Jauregui, D. Saez; Voutta, R.; Boffo, C.; Gerhard, Th.; Turenne, M.; Walter, W.

2016-11-01

A new cryogen-free full scale (1.5 m long) superconducting undulator with a period length of 15 mm (SCU15) has been successfully tested in the ANKA storage ring. This represents a very important milestone in the development of superconducting undulators for third and fourth generation light sources carried on by the collaboration between the Karlsruhe Institute of Technology and the industrial partner Babcock Noell GmbH. SCU15 is the first full length device worldwide that with beam reaches a higher peak field than what expected with the same geometry (vacuum gap and period length) with an ideal cryogenic permanent magnet undulator built with the best material available PrFeB. After a summary on the design and main parameters of the device, we present here the characterization in terms of spectral properties and the long term operation of the SCU15 in the ANKA storage ring.

DISSOCIATIVE RECOMBINATION MEASUREMENTS OF HCl{sup +} USING AN ION STORAGE RING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novotný, O.; Stützel, J.; Savin, D. W.

We have measured dissociative recombination (DR) of HCl{sup +} with electrons using a merged beams configuration at the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We present the measured absolute merged beams recombination rate coefficient for collision energies from 0 to 4.5 eV. We have also developed a new method for deriving the cross section from the measurements. Our approach does not suffer from approximations made by previously used methods. The cross section was transformed to a plasma rate coefficient for the electron temperature range from T = 10 to 5000more » K. We show that the previously used HCl{sup +} DR data underestimate the plasma rate coefficient by a factor of 1.5 at T = 10 K and overestimate it by a factor of three at T = 300 K. We also find that the new data may partly explain existing discrepancies between observed abundances of chlorine-bearing molecules and their astrochemical models.« less

Performance Analysis for the New g-2 Experiment at Fermilab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stratakis, Diktys; Convery, Mary; Crmkovic, J.

2016-06-01

The new g-2 experiment at Fermilab aims to measure the muon anomalous magnetic moment to a precision of ±0.14 ppm - a fourfold improvement over the 0.54 ppm precision obtained in the g-2 BNL E821experiment. Achieving this goal requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we describe a muon capture and transport scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we describe its basic features. Then, we detail its performance numerically by simulating the pionmore » production in the (g-2) production target, the muon collection by the downstream beamline optics as well as the beam polarization and spin-momentum correlation up to the storage ring. The sensitivity in performance of our proposed channel against key parameters such as magnet apertures and magnet positioning errors is analyzed« less

The Muon g - 2 experiment at Fermilab

NASA Astrophysics Data System (ADS)

Mott, James; Muon g - 2 experiment

2017-06-01

The Muon g - 2 experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 ppb, reducing the experimental uncertainty by a factor of 4 compared to the previous measurement at BNL (E821). The measurement technique adopts the storage ring concept used for E821, with magic-momentum muons stored in a highly uniform 1.45 T magnetic dipole field. The spin precession frequency is extracted from an analysis of the modulation of the rate of higher-energy positrons from muon decays, detected by 24 calorimeters and 3 straw tracking detectors. Compared to the E821 experiment, muon beam preparation, storage ring internal hardware, field measuring equipment, and detector and electronics systems are all new or significantly upgraded. Herein, I report on the status of the experiment as of Sept. 2016, presenting the magnetic field uniformity results after the completion of the first round of shimming and outlining the construction progress of the main detector systems.

The Muon g $-$ 2 experiment at Fermilab

DOE PAGES

Mott, James

2017-06-21

Here, the Muon g-2 experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 ppb, reducing the experimental uncertainty by a factor of 4 compared to the previous measurement at BNL (E821). The measurement technique adopts the storage ring concept used for E821, with magic-momentum muons stored in a highly uniform 1.45 T magnetic dipole field. The spin precession frequency is extracted from an analysis of the modulation of the rate of higher-energy positrons from muon decays, detected by 24 calorimeters and 3 straw tracking detectors. Compared to the E821 experiment, muon beammore » preparation, storage ring internal hardware, field measuring equipment, and detector and electronics systems are all new or significantly upgraded. Herein, I report on the status of the experiment as of Sept. 2016, presenting the magnetic field uniformity results after the completion of the first round of shimming and outlining the construction progress of the main detector systems.« less

Initial application of a dual-sweep streak camera to the Duke storage ring OK-4 source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumpkin, A.H.; Yang, B.X.; Litvinenko, V.

1997-08-01

The visible and UV spontaneous emission radiation (SER) from the Duke OK-4 wiggler has been used with a Hamamatsu C5680 dual-sweep streak camera to characterize the stored electron beams. Particle beam energies of 270 and 500 MeV in the Duke storage ring were used in this initial application with the OK-4 adjusted to generate wavelengths from 500 nm to near 200 nm. The OK-4 magnetic system with its 68 periods provided a much stronger radiation source than a nearby bending magnet source point. Sensitivity to single-bunch, single-turn SER was shown down to 4 {mu}A beam current at {lambda} = 450more » nm. The capability of seeing second passes in the FEL resonator at a wavelength near 200 nm was used to assess the cavity length versus orbit length. These tests (besides supporting preparation for UV-visible SR FEL startups) are also relevant to possible diagnostics techniques for single-pass FEL prototype facilities.« less

Top-Off Injection and Higher Currents at the Stanford Synchrotron Radiation Lightsource

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, Johannes M.; Liu, James C.; Prinz, Alyssa A.

2011-04-05

The Stanford Synchrotron Radiation Lightsource (SSRL) at the SLAC National Accelerator Laboratory is a 234 m circumference storage ring for 3 GeV electrons with its synchrotron radiation serving currently 13 beamlines with about 27 experimental stations. It operated for long time with 100 mA peak current provided by usually three injections per day. In July 2009, the maximum beam current was raised to 200 mA. Over the period from June 2009 to March 2010, Top-Off operation started at every beamline. Top-Off, i.e., the injection of electrons into the storage ring with injection stoppers open, is necessary for SSRL to reachmore » its design current of 500 mA. In the future, the maximal power of the injection current will also soon be raised from currently 1.5 W to 5 W. The Radiation Protection Department at SLAC worked with SSRL on the specifications for the safety systems for operation with Top-Off injection and higher beam currents.« less

In-situ calibration: migrating control system IP module calibration from the bench to the storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, Jonah M.; Chin, Michael

2002-04-30

The Control System for the Advanced Light Source (ALS) at Lawrence Berkeley National Lab (LBNL) uses in-house designed IndustryPack(registered trademark) (IP) modules contained in compact PCI (cPCI) crates with 16-bit analog I/O to control instrumentation. To make the IP modules interchangeable, each module is calibrated for gain and offset compensation. We initially developed a method of verifying and calibrating the IP modules in a lab bench test environment using a PC with LabVIEW. The subsequent discovery that the ADCs have significant drift characteristics over periods of days of installed operation prompted development of an ''in-situ'' calibration process--one in which themore » IP modules can be calibrated without removing them from the cPCI crates in the storage ring. This paper discusses the original LabVIEW PC calibration and the migration to the proposed in-situ EPICS control system calibration.« less

Photon-induced positron annihilation lifetime spectroscopy using ultrashort laser-Compton-scattered gamma-ray pulses

NASA Astrophysics Data System (ADS)

Taira, Y.; Toyokawa, H.; Kuroda, R.; Yamamoto, N.; Adachi, M.; Tanaka, S.; Katoh, M.

2013-05-01

High-energy ultrashort gamma-ray pulses can be generated via laser Compton scattering with 90° collisions at the UVSOR-II electron storage ring. As an applied study of ultrashort gamma-ray pulses, a new photon-induced positron annihilation lifetime spectroscopy approach has been developed. Ultrashort gamma-ray pulses with a maximum energy of 6.6 MeV and pulse width of 2.2 ps created positrons throughout bulk lead via pair production. Annihilation gamma rays were detected by a BaF2 scintillator mounted on a photomultiplier tube. A positron lifetime spectrum was obtained by measuring the time difference between the RF frequency of the electron storage ring and the detection time of the annihilation gamma rays. We calculated the response of the BaF2 scintillator and the time jitter caused by the variation in the total path length of the ultrashort gamma-ray pulses, annihilation gamma rays, and scintillation light using a Monte Carlo simulation code. The positron lifetime for bulk lead was successfully measured.

Dielectronic Recombination In Active Galactic Nuclei

NASA Technical Reports Server (NTRS)

Lukic, D. V.; Schnell, M.; Savin, D. W.; Altun, Z.; Badnell, N.; Brandau, C.; Schmidt, E. W.; Mueller, A.; Schippers, S.; Sprenger, F.;

Compton backscattered collimated x-ray source

DOEpatents

Ruth, R.D.; Huang, Z.

1998-10-20

A high-intensity, inexpensive and collimated x-ray source is disclosed for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications. 4 figs.

Compton backscattered collimated x-ray source

DOEpatents

Ruth, Ronald D.; Huang, Zhirong

1998-01-01

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Compton backscattered collmated X-ray source

DOEpatents

Ruth, Ronald D.; Huang, Zhirong

2000-01-01

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

The Muon g $-$ 2 experiment at Fermilab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mott, James

Here, the Muon g-2 experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 ppb, reducing the experimental uncertainty by a factor of 4 compared to the previous measurement at BNL (E821). The measurement technique adopts the storage ring concept used for E821, with magic-momentum muons stored in a highly uniform 1.45 T magnetic dipole field. The spin precession frequency is extracted from an analysis of the modulation of the rate of higher-energy positrons from muon decays, detected by 24 calorimeters and 3 straw tracking detectors. Compared to the E821 experiment, muon beammore » preparation, storage ring internal hardware, field measuring equipment, and detector and electronics systems are all new or significantly upgraded. Herein, I report on the status of the experiment as of Sept. 2016, presenting the magnetic field uniformity results after the completion of the first round of shimming and outlining the construction progress of the main detector systems.« less

APS Storage Ring Monopulse RF BPM Upgrade

NASA Astrophysics Data System (ADS)

Lill, R.; Pietryla, A.; Norum, E.; Lenkszus, F.

2004-11-01

The Advanced Photon Source (APS) is a third-generation synchrotron light source in its ninth year of operation. The storage ring monopulse radio frequency (rf) beam position monitor (BPM) was designed to measure single-turn and multi-turn beam positions for operations and machine physics studies. Many of the components used in the original design are obsolete and costly to replace. In this paper we present a proposal to upgrade the monopulse rf BPMs in which the existing system hardware is repartitioned and the aging data acquisition system is replaced. By replacing only the data acquisition system, we will demonstrate a cost-effective approach to improved beam stability, reliability, and enhanced postmortem capabilities. An eight-channel ADC/digitizer VXI board with sampling rate of up to 105 MHz (per channel) and 14-bit resolution coupled with a field-programmable gate array and embedded central processing will provide the flexibility to revitalize this system for another decade of operation. We will discuss the upgrade system specifications, design, and prototype test results.

Carbon Allocation of 13CO2-labeled Photoassimilate in Larix gmelinii Saplings - A Physiological Basis for Isotope Dendroclimatology in Eastern Siberia.

NASA Astrophysics Data System (ADS)

Kagawa, A.; Sugimoto, A.; Maximov, T. C.

2006-12-01

Tree-ring density and widths have been successfully used to reconstruct summer temperatures in high- northern latitudes, although a discrepancy between tree-growth and temperature has been found for recent decades. The so-called "reduced sensitivity" of tree rings to summer temperatures has been observed especially strongly in northern Siberia (Briffa et al., 1998) and drought stress (increased water use efficiency) arose from global warming and/or increasing CO2 are suggested as causes (Barber et al. 2000, Saurer et al. 2004). By using carbon isotope ratio as an indicator of drought stress and ring-width/density as indicators of growth, we can clarify how drought stress caused by recent global warming affects wood formation of Siberian trees. However, isotope dendroclimatology is still in its infancy and our understanding of basic physiological processes of isotope signal transfer from leaves to tree rings is insufficient. In order to understand translocation, storage, and allocation of photoassimilate to different organs of trees, we pulse- labeled ten L. gmelinii growing in a continuous permafrost zone with stable 13CO2. We studied seasonal course of carbon allocation patterns of photoassimilate among needles, branches, stem and roots and also how spring, summer, and autumn photoassimilate is later used for both earlywood and latewood formation. About half of the carbon in new needles was derived from stored material. The starch pool in non- needle parts, which can be used for xylem formation, drew about 43 percent of its carbon from previous year's photoassimilate, suggesting that carbon storage is the key mechanism behind autocorrelation in (isotope) dendroclimatology. Analysis of intra-annual 13C of the tree rings formed after the labeling revealed that earlywood contained photoassimilate from the previous summer and autumn as well as from the current spring. Latewood was mainly composed of photoassimilate from the current year's summer/autumn, although it also relied on stored material in some cases. Carbon isotope chronology of recent 100 years shows that the latewood 13C contains stronger climate signal than the earlywood and is significantly correlated to July temperature and July precipitation, corresponding to the timing of carbon incorporation that constitutes latewood. The results suggest the need for separating earlywood and latewood for isotope dendroclimatological study in Siberia. References: 1) Kagawa A., Sugimoto A., & Maximov, T.C. (2006) 13CO2 pulse-labelling of photoassimilates reveals carbon allocation within and between tree rings. Plant, Cell and Environment 29, 1571-1584. 2) Kagawa A., Sugimoto A., & Maximov, T. C. (2006) Seasonal course of translocation, storage, and remobilization of 13C pulse-labeled photoassimilate in naturally growing Larix gmelinii saplings. New Phytologist 171, 793-804. 3) Kagawa A., Naito D., Sugimoto A. & Maximov T. C. (2003) Effects of spatial and temporal variability in soil moisture on widths and 13C values of eastern Siberian tree rings. Journal of Geophysical Research 108 (D16), 4500, doi:10.1029/2002JD003019.

Paracyclophane functionalized with Sc and Li for hydrogen storage

NASA Astrophysics Data System (ADS)

Sathe, Rohit Y.; Dhilip Kumar, T. J.

2018-01-01

Li and Sc metals functionalized on the delocalized π -electrons of benzene rings in [2,2]paracyclophane structure are studied for hydrogen storage efficiency by using the M06 DFT functional with 6-311G(d,p) basis set. It is found that Sc and Li functionalized [2,2]paracyclophane complexes can hold up to 10 H2 molecules and 8 H2 molecules by Kubas-Niu-Jena interaction and charge polarization mechanism with hydrogen weight percentage of 11.4 and 13.5, respectively. Molecular dynamics simulation at various temperatures showed appreciable thermal stability while the chemical potential calculation at room temperature reveals that Sc functionalized [2,2]paracyclophane system will be a promising hydrogen storage material.

Experiments with a New, Unique Large-Scale Rig Investigating the Effects of Background System Rotation on Vortex Rings in Water

NASA Astrophysics Data System (ADS)

Brend, Mark A.; Verzicco, Roberto

2005-11-01

We introduce our unique, new large-scale experimental facility [1] designed for our long-term research program investigating the effects of background system rotation on the stability and the dynamics of vortex rings. The new rig constitutes a large water-filled tank positioned on a rotating turntable and its overall height and diameter are 5.7m and 1.4 m, respectively. First experimental and computational results of our program are summarized. We will show various videos of flow visualizations that illustrate some major, qualitative differences between rings propagating in rotating and non-rotating flows. Some of the investigated characteristics of the vortex rings include their translation velocity, the velocity field inside and surrounding the rings, and, in particular, their stability. We will briefly outline experiments employing the relatively new Ultrasonic-Velocity-Profiler technique (UVP). This technique appears to be particularly suited for some of our measurements and it was, as far as we are aware, not previously used in the context of vortex-ring studies. [1] http://www.eng.warwick.ac.uk/staff/pjt/turntabpics/voriskt.html

Applications of Cavity Ring-Down Spectroscopy (CRDS) to Analysis of Carbon Stable Isotope Composition of Groundwater

NASA Astrophysics Data System (ADS)

Jeong, T.; Woo, N. C.; Choi, H.

2014-12-01

Carbon Capture and Storage (CCS) has been considered as an effective strategy to reduce atmospheric carbon dioxide (CO2) concentration. However, unintended leakage of CO2 leakage from storage sites could occur through highly permeable conduits such as fractures in low-K formations during the injection and storage of SCCO2 (supercritical phase CO2). Therefore, prediction and detection of CO2 leakage and relevant analysis of carbon isotope are crucial to assure environmental and public safety. Until recently, Isotope Ratio Mass Spectrometry (IRMS) has been utilized to measure the stable isotope ratio of water. However, IRMS is time-consuming operation due to complicated pretreatment, and thus not a practical methodology under field conditions. Carbon Isotope Analyzer (CCIA), which is a kind of Cavity Ring-Down Spectroscopy (CRDS) and has a wide measurement range from 300 to 25000 ppmv, can facilitate the rate of measurements up to 1 Hz by using continuous flow method so that it can be readily applied to field. In this study, carbon stable isotope ratio of groundwater will be analyzed using CCIA. Then, the CCIA results will be compared with IRMS to validate its accuracy and stability. This research will provide an appropriate method for analyzing carbon stable isotope in groundwater, using a continuous flow mode.

Rolling up of Large-scale Laminar Vortex Ring from Synthetic Jet Impinging onto a Wall

NASA Astrophysics Data System (ADS)

Xu, Yang; Pan, Chong; Wang, Jinjun; Flow Control Lab Team

2015-11-01

Vortex ring impinging onto a wall exhibits a wide range of interesting behaviors. The present work devotes to an experimental investigation of a series of small-scale vortex rings impinging onto a wall. These laminar vortex rings were generated by a piston-cylinder driven synthetic jet in a water tank. Laser Induced Fluorescence (LIF) and Particle Image Velocimetry (PIV) were used for flow visualization/quantification. A special scenario of vortical dynamic was found for the first time: a large-scale laminar vortex ring is formed above the wall, on the outboard side of the jet. This large-scale structure is stable in topology pattern, and continuously grows in strength and size along time, thus dominating dynamics of near wall flow. To quantify its spatial/temporal characteristics, Finite-Time Lyapunov Exponent (FTLE) fields were calculated from PIV velocity fields. It is shown that the flow pattern revealed by FTLE fields is similar to the visualization. The size of this large-scale vortex ring can be up to one-order larger than the jet vortices, and its rolling-up speed and entrainment strength was correlated to constant vorticity flux issued from the jet. This work was supported by the National Natural Science Foundation of China (Grants No.11202015 and 11327202).

Archaea S-layer nanotube from a "black smoker" in complex with cyclo-octasulfur (S8 ) rings.

PubMed

McDougall, Matthew; Francisco, Olga; Harder-Viddal, Candice; Roshko, Roy; Meier, Markus; Stetefeld, Jörg

2017-12-01

Elemental sulfur exists primarily as an S80 ring and serves as terminal electron acceptor for a variety of sulfur-fermenting bacteria. Hyperthermophilic archaea from black smoker vents are an exciting research tool to advance our knowledge of sulfur respiration under extreme conditions. Here, we use a hybrid method approach to demonstrate that the proteinaceous cavities of the S-layer nanotube of the hyperthermophilic archaeon Staphylothermus marinus act as a storage reservoir for cyclo-octasulfur S8. Fully atomistic molecular dynamics (MD) simulations were performed and the method of multiconfigurational thermodynamic integration was employed to compute the absolute free energy for transferring a ring of elemental sulfur S8 from an aqueous bath into the largest hydrophobic cavity of a fragment of archaeal tetrabrachion. Comparisons with earlier MD studies of the free energy of hydration as a function of water occupancy in the same cavity of archaeal tetrabrachion show that the sulfur ring is energetically favored over water. © 2017 Wiley Periodicals, Inc.

Characterization of the International Linear Collider damping ring optics

NASA Astrophysics Data System (ADS)

Shanks, J.; Rubin, D. L.; Sagan, D.

2014-10-01

A method is presented for characterizing the emittance dilution and dynamic aperture for an arbitrary closed lattice that includes guide field magnet errors, multipole errors and misalignments. This method, developed and tested at the Cornell Electron Storage Ring Test Accelerator (CesrTA), has been applied to the damping ring lattice for the International Linear Collider (ILC). The effectiveness of beam based emittance tuning is limited by beam position monitor (BPM) measurement errors, number of corrector magnets and their placement, and correction algorithm. The specifications for damping ring magnet alignment, multipole errors, number of BPMs, and precision in BPM measurements are shown to be consistent with the required emittances and dynamic aperture. The methodology is then used to determine the minimum number of position monitors that is required to achieve the emittance targets, and how that minimum depends on the location of the BPMs. Similarly, the maximum tolerable multipole errors are evaluated. Finally, the robustness of each BPM configuration with respect to random failures is explored.

Multi-Pulse Extraction from Los Alamos Proton Storage Ring for Radiographic Applications

NASA Astrophysics Data System (ADS)

Thiessen, Henry A.; Neri, Filippo; Rust, Kenneth R.; Redd, Dale B.

1997-05-01

For radiography of moving objects, two or more pulses with adjustable time spacing are required. The existing Proton Stotage Ring (PSR) extraction system is configured to extract the entire beam in a single turn. Two kickers and two kicker modulators fired at the same time perform the normal extraction function. By reconfiguring the two kickers and two modulators, it is possible to obtain two half-sized extraction kicks with adjustable time spacing. In this way, we have extracted two pulses with adjustable relative timing. The setup will be described and experimental results will be presented.

Design of all-optical memory cell using EIT and lasing without inversion phenomena in optical micro ring resonators

NASA Astrophysics Data System (ADS)

Pasyar, N.; Yadipour, R.; Baghban, H.

2017-07-01

The proposed design of the optical memory unit cell contains dual micro ring resonators in which the effect of lasing without inversion (LWI) in three-level nano particles doped over the optical resonators or integrators as the gain segment is used for loss compensation. Also, an on/off phase shifter based on electromagnetically induced transparency (EIT) in three-level quantum dots (QDs) has been used for data reading at requested time. Device minimizing for integrated purposes and high speed data storage are the main advantages of the optical integrator based memory.

Multifractal Approaches of the Ring Tensile Rupture Patterns of Dried Laver (Porphyra) as Affected by the Relative Humidity.

PubMed

Jung, Hwabin; Yoon, Won Byong

2017-12-01

The effect of water activity (a w ) or the relative humidity (RH) on the tensile rupture properties of dried laver (DL) associated with structures formed with phycocolloids was investigated. The morphological characteristics of tensile ruptured DL samples at various relative humidities were evaluated by multifractal analysis. The RH of the microclimate was controlled from 10% to 90% at 25 °C using supersaturated salt solutions. The sorption isotherm of DL was experimentally obtained and quantitatively analyzed using mathematical models. The monolayer moisture contents from the Guggenheim-Anderson-de Boer (GAB) model was 5.92% (w.b.). An increase in the RH resulted in increasing ring tensile stress and maintaining constant ring tensile strain up to 58% to 75% RH, whereas the ring tensile stress and the ring tensile strain rapidly decreased and increased, respectively, when the RH was higher than 75%. The general fractal dimensions and the multifractal spectra f(α) manifested that the patterns of the lowest and the highest moisture content of dried laver showed high irregularity. The different multifractal parameters obtained from the DL at various RHs well-represented the transient moment of the structures from the monolayer moisture to texture changes associated with RH. Overall, the ring tensile test and the multifractal analysis were useful tools to analyze the change of crispness of DL from its structural characteristics. In addition, the results of this study revealed that the integration and disintegration properties of DL occurred through the networks of phycocolloids at various moisture contents. Texture properties are the most important quality attributes for commercial dried laver (DL) products. The relative humidity influences the texture properties of DL during production, storage, shipping, and consuming. This study well characterized the effect of the relative humidity on the texture properties of DL using the tensile tests under microclimate conditions. This information is very practical and can be immediately applied to control the relative humidity of the packaging and the storage room for DL. © 2017 Institute of Food Technologists®.

Origin of Saturn's rings and inner moons by mass removal from a lost Titan-sized satellite.

PubMed

Canup, Robin M

2010-12-16

The origin of Saturn's rings has not been adequately explained. The current rings are more than 90 to 95 per cent water ice, which implies that initially they were almost pure ice because they are continually polluted by rocky meteoroids. In contrast, a half-rock, half-ice mixture (similar to the composition of many of the satellites in the outer Solar System) would generally be expected. Previous ring origin theories invoke the collisional disruption of a small moon, or the tidal disruption of a comet during a close passage by Saturn. These models are improbable and/or struggle to account for basic properties of the rings, including their icy composition. Saturn has only one large satellite, Titan, whereas Jupiter has four large satellites; additional large satellites probably existed originally but were lost as they spiralled into Saturn. Here I report numerical simulations of the tidal removal of mass from a differentiated, Titan-sized satellite as it migrates inward towards Saturn. Planetary tidal forces preferentially strip material from the satellite's outer icy layers, while its rocky core remains intact and is lost to collision with the planet. The result is a pure ice ring much more massive than Saturn's current rings. As the ring evolves, its mass decreases and icy moons are spawned from its outer edge with estimated masses consistent with Saturn's ice-rich moons interior to and including Tethys.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bagley, G. P.

An SCR DC to DC converter is described which will operate at an output of 275 kW and will supply current to electron storage ring magnets requiring 5 h stability of 50 ppM. The operation of this modified chopper is described and design equations are presented, along with the system control loop description.

From Macrocrystals to Microcrystals: A Strategy for Membrane Protein Serial Crystallography.

PubMed

Dods, Robert; Båth, Petra; Arnlund, David; Beyerlein, Kenneth R; Nelson, Garrett; Liang, Mengling; Harimoorthy, Rajiv; Berntsen, Peter; Malmerberg, Erik; Johansson, Linda; Andersson, Rebecka; Bosman, Robert; Carbajo, Sergio; Claesson, Elin; Conrad, Chelsie E; Dahl, Peter; Hammarin, Greger; Hunter, Mark S; Li, Chufeng; Lisova, Stella; Milathianaki, Despina; Robinson, Joseph; Safari, Cecilia; Sharma, Amit; Williams, Garth; Wickstrand, Cecilia; Yefanov, Oleksandr; Davidsson, Jan; DePonte, Daniel P; Barty, Anton; Brändén, Gisela; Neutze, Richard

2017-09-05

Serial protein crystallography was developed at X-ray free-electron lasers (XFELs) and is now also being applied at storage ring facilities. Robust strategies for the growth and optimization of microcrystals are needed to advance the field. Here we illustrate a generic strategy for recovering high-density homogeneous samples of microcrystals starting from conditions known to yield large (macro) crystals of the photosynthetic reaction center of Blastochloris viridis (RC vir ). We first crushed these crystals prior to multiple rounds of microseeding. Each cycle of microseeding facilitated improvements in the RC vir serial femtosecond crystallography (SFX) structure from 3.3-Å to 2.4-Å resolution. This approach may allow known crystallization conditions for other proteins to be adapted to exploit novel scientific opportunities created by serial crystallography. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of large volume double ring penning plasma discharge source for efficient light emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakash, Ram; Vyas, Gheesa Lal; Jain, Jalaj

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd{sub 2}Fe{sub 14}B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic fieldmore » of {approx}0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is {approx}2 Multiplication-Sign 10{sup 11} cm{sup -3}, which is around one order of magnitude larger than that of single ring arrangement.« less

Development of large volume double ring penning plasma discharge source for efficient light emissions.

PubMed

Prakash, Ram; Vyas, Gheesa Lal; Jain, Jalaj; Prajapati, Jitendra; Pal, Udit Narayan; Chowdhuri, Malay Bikas; Manchanda, Ranjana

2012-12-01

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd(2)Fe(14)B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ~0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is ~2 × 10(11) cm(-3), which is around one order of magnitude larger than that of single ring arrangement.

New Morphometric Measurements of Peak-Ring Basins on Mercury and the Moon: Results from the Mercury Laser Altimeter and Lunar Orbiter Laser Altimeter

NASA Technical Reports Server (NTRS)

Baker, David M. H.; Head, James W.; Prockter, Louise M.; Fassett, Caleb I.; Neumann, Gregory A.; Smith, David E.; Solomon, Sean C.; Zuber, Maria T.; Oberst, Juergen; Preusker, Frank;

A numerical investigation into the dynamics of Uranus' mu-ring

NASA Astrophysics Data System (ADS)

Kumar, K.; De Pater, I.; Showalter, M.

2017-12-01

Showalter and Lissauer (2006) reported the discovery of the nu-ring and mu-ring, located beyond Uranus' main ring system. Both faint, dusty rings are located interior to the large classical moons and were observed by co-adding Hubble Space Telescope (HST) images. The peak radial brightness of the mu-ring coincides with the orbit of Mab, a small moon discovered in 2003 by Showalter and Lissauer. Observations of the Mab/mu-ring system indicate a highly dynamic environment. The motion of Mab was determined to be anomalous over short time scales, with large position deviations computed with respect to a fitted precessing Keplerian ellipse. Numerical simulations to survey the possible cause of this anomalous motion hint at the possibility of interactions with a distribution of tens of bodies, below the HST detection threshold, in the neighborhood of Mab (Kumar, et al., 2016). Analysis of the mu-ring data has led to the discovery of peculiar features, leading to open questions about dust dynamics in the associated region around Uranus. Observations obtained using the HST and Keck telescopes reveal that the μ-ring is blue, indicative of a pre-dominance of sub-micron-sized particles (de Pater, et al., 2006). The only other blue ring detected in the Solar System is Saturn's E-ring, generated by plumes on Enceladus' south pole. The origin of the mu-ring however remains an open area of research. Mab is thought to be the likely source of the material in the mu-ring, with micrometeoroid impacts releasing material into orbit around Uranus, much like Jupiter's faint rings are regenerated by companion (small) moons (Burns et al. 1999). The mu-ring's blue color suggests however that there is an unknown mechanism at play that hides or removes large particles from the expected size distribution. We present results from a numerical investigation into the effects of gravitational and non-gravitational forces on the evolution of mu-ring dust particles. Following on from previous studies (Sfair and Giuliatti Winter, 2009; Sfair and Giuliatti Winter, 2012; Sfair, 2013; Hsu, et al., 2014), we generate statistics to provide insight into the lifetime of mu-ring dust. We utilize these results to analyze the possibility that the steep size distribution results from size-based sorting effects due to the natural environment.

Review of third and next generation synchrotron light sources

NASA Astrophysics Data System (ADS)

Bilderback, Donald H.; Elleaume, Pascal; Weckert, Edgar

2005-05-01

Synchrotron radiation (SR) is having a very large impact on interdisciplinary science and has been tremendously successful with the arrival of third generation synchrotron x-ray sources. But the revolution in x-ray science is still gaining momentum. Even though new storage rings are currently under construction, even more advanced rings are under design (PETRA III and the ultra high energy x-ray source) and the uses of linacs (energy recovery linac, x-ray free electron laser) can take us further into the future, to provide the unique synchrotron light that is so highly prized for today's studies in science in such fields as materials science, physics, chemistry and biology, for example. All these machines are highly reliant upon the consequences of Einstein's special theory of relativity. The consequences of relativity account for the small opening angle of synchrotron radiation in the forward direction and the increasing mass an electron gains as it is accelerated to high energy. These are familiar results to every synchrotron scientist. In this paper we outline not only the origins of SR but discuss how Einstein's strong character and his intuition and excellence have not only marked the physics of the 20th century but provide the foundation for continuing accelerator developments into the 21st century.

Colliders Come of Age in Europe: PETRA and LEP

NASA Astrophysics Data System (ADS)

Hofmann, Albert

2003-04-01

Based on the success with early electron positron rings a new generation of facilities was constructed, optimized in cost and performance. In Europe PETRA was built at DESY with many innovations: smooth vacuum chamber with small impedance, efficient multi-cell RF-cavities, an optics giving an emittance optimized for luminosity, few bunches in head-on collision, a mini-beta scheme, accurate energy calibration based on depolarization resonances. From 1978 to 1986 PETRA provided high luminosity with over 22 GeV beam energy for particle physics experiments. The next ring, LEP at CERN, was optimized for two beam energy ranges, 46 and 93 - 105 GeV for Z0 and W production and particle search. This resulted in a large circumference of 27 km and low field bending magnets which had widely spaced laminations filled with concrete. The RF-voltage was produced in Cu cavities being coupled to low loss storage cavities at the lower, and with a superconducting RF-system, exceeding 3.6 GV, at the higher energy. Superconducting low beta insertions helped to obtain a high luminosity which reached integrated values of over 2000 1/nb per day at high energy. Very important for LEP was a precise energy calibration using depolarizing resonaces and careful control of all relevant parameters. LEP operated with four experiments from 1989 to 2000.

Beam On Target (BOT) Produces Gamma Ray Burst (GRB) Fireballs and Afterglows

NASA Astrophysics Data System (ADS)

Greyber, H. D.

1997-12-01

Unlike the myriads of ad hoc models that have been offered to explain GRB, the BOT process is simply the very common process used worldwide in accelerator laboratories to produce gamma rays. The Strong Magnetic Field (SMF) model postulates an extremely intense, highly relativistic current ring formed during the original gravitational collapse of a distant galaxy when the plasma cloud was permeated by a primordial magnetic field. GRB occur when solid matter (asteroid, white dwarf, neutron star, planet) falls rapidly through the Storage Ring beam producing a very strongly collimated electromagnetic shower, and a huge amount of matter from the target, in the form of a giant, hot, expanding plasma cloud, or ``Fireball,'' is blown off. BOT satisfies all the ``severe constraints imposed on the source of this burst --'' concluded by the CGRO team (Sommer et al, Astrophys. J. 422 L63 (1994)) for the huge intense burst GRB930131, whereas neutron star merger models are ``difficult to reconcile.'' BOT expects the lowest energy gamma photons to arrive very slightly later than higher energy photons due to the time for the shower to penetrate the target. The millisecond spikes in bursts are due to the slender filaments of current that make up the Storage Ring beam. Delayed photons can be explained by a broken target ``rock.'' See H. Greyber in the book ``Compton Gamma Ray Observatory,'' AIP Conf. Proc. 280, 569 (1993).

Quantum mechanical design of efficient second-order nonlinear optical materials based on heteroaromatic imido-substituted hexamolybdates: first theoretical framework of POM-based heterocyclic aromatic rings.

PubMed

Janjua, Muhammad Ramzan Saeed Ashraf

2012-11-05

This work was inspired by a previous report (Janjua et al. J. Phys. Chem. A 2009, 113, 3576-3587) in which the nonlinear-optical (NLO) response strikingly improved with an increase in the conjugation path of the ligand and the nature of hexamolybdates (polyoxometalates, POMs) was changed into a donor by altering the direction of charge transfer with a second aromatic ring. Herein, the first theoretical framework of POM-based heteroaromatic rings is found to be another class of excellent NLO materials having double heteroaromatic rings. First hyperpolarizabilities of a large number of push-pull-substituted conjugated systems with heteroaromatic rings have been calculated. The β components were computed at the density functional theory (DFT) level (BP86 geometry optimizations and LB94 time-dependent DFT). The largest β values are obtained with a donor (hexamolybdates) on the benzene ring and an acceptor (-NO(2)) on pyrrole, thiophene, and furan rings. The pyrrole imido-substituted hexamolybdate (system 1c) has a considerably large first hyperpolarizability, 339.00 × 10(-30) esu, and it is larger than that of (arylimido)hexamolybdate, calculated as 0.302 × 10(-30) esu (reference system 1), because of the double aromatic rings in the heteroaromatic imido-substituted hexamolybdates. The heteroaromatic rings act as a conjugation bridge between the electron acceptor (-NO(2)) and donor (polyanion). The introduction of an electron donor into heteroaromatic rings significantly enhances the first hyperpolarizabilities because the electron-donating ability is substantially enhanced when the electron donor is attached to the heterocyclic aromatic rings. Interposing five-membered auxiliary fragments between strong donor (polyanion) or acceptor (-NO(2)) groups results in a large computed second-order NLO response. The present investigation provides important insight into the NLO properties of (heteroaromatic) imido-substituted hexamolybdate derivatives because these compounds exhibit enhanced hyperpolarizabilities compared to typical NLO arylimido hexamolybdates and heterocyclic aromatic rings reported in the literature.

Results from DORIS, DASP. [Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pretzl, K.P.

1976-01-01

An updated report is given on the results of the DASP-Collaboration obtained at the e/sup +/e/sup -/ storage rings DORIS at DESY (Hamburg) on inclusive distributions, particle ratios, mass searches in J/psi and psi' decays, hadronic two body decays of J/psi and psi', radiative decays of J/psi and psi'.

Rare B Decays with the BaBar Detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spanier, Stefane

2001-09-07

The BABAR detector at SLAC's PEP-II storage ring collected a luminosity equivalent data of about 22 fb{sup -1} at the {Upsilon}(4S) resonance during 1999 and 2000. Results on branching fractions of rare and charmless B$-meson decays and first fits for direct CP violation are presented.

Computer Applications for Alternative Assessment: An Instructional and Organization Dilemma.

ERIC Educational Resources Information Center

Mills, Ed; Brown, John A.

1997-01-01

Describes the possibilities and problems that computer-generated portfolios will soon present to instructors across America. Highlights include the history of portfolio assessment, logistical problems of handling portfolios in the traditional three-ring binder format, use of the zip drive for storage, and software/hardware compatibility problems.…

Effect of end-ring stiffness on buckling of pressure-loaded stiffened conical shells

NASA Technical Reports Server (NTRS)

Davis, R. C.; Williams, J. G.

1977-01-01

Buckling studies were conducted on truncated 120 deg conical shells having large end rings and many interior reinforcing rings that are typical of aeroshells used as spacecraft decelerators. Changes in base-end-ring stiffness were accomplished by simply machining away a portion of the base ring between successive buckling tests. Initial imperfection measurements from the test cones were included in the analytical model.

Interaction of Vortex Rings and Steady Jets with Permeable Screens of Varied Porosity

NASA Astrophysics Data System (ADS)

Musta, Mustafa

2013-11-01

Vortex ring and steady jet interaction with a porous matrix formed from several parallel, transparent permeable screens with the same grid geometry for open area ratios (φ) 49.5% - 83.8% was studied previously using digital particle image velocimetry (DPIV) at jet Reynolds number (Re) of 1000-3000. Vortex ring results showed that unlike the experiments with thin screens, a transmitted vortex ring, which has a similar diameter to the primary one, wasn't formed. Instead a centerline vortex ring like structure formed and its diameter, circulation, and dissipation time decreased as φ decreased. However, for the case of screens φ = 55.7% with large screen spacing, reformation of large scale weak vortex rings was observed downstream of the first screen. The present work experimentally investigates the interaction of vortex rings and steady jets with screens of decreasing φ (83.8%-49.5%) in the flow direction. A piston type vortex ring generator was used and measurements were made using DPIV. The vortex ring results show that the size and circulation of the vortex ring like flow structure was changed based on the screen φ within the permeable screen matrix. Similarly, steady jet flow structure and the local turbulent kinetic energy was changed based on the local screen φ.

Design study of the storage ring EUTERPE

NASA Astrophysics Data System (ADS)

Xi, Boling; Botman, J. I. M.; Timmermans, C. J.; Hagedoorn, H. L.

1992-05-01

At present the 400 MeV electron storage ring EUTERPE is being constructed at the Eindhoven University of Technology. It is a university project set up for studies of charged particle beam dynamics and applications of synchroton radiation, and for the education of students in these fields. The design of the ring is described in this paper. Considering the requirements of users in different fields, a lattice based on a so-called triple bend achromat structure with a high flexibility has been chosen. With this lattice, different optical options, including the HBSB (high brightness, small beam), the SBL (short bunch length) and the HLF (high light flux) modes can be realized. A small emittance of 7 nm rad and a short bunch length of the order of several mm can be achieved. In the first phase the synchrotron radiation in the UV and XUV region (the critical wavelength is 8.3 nm) will be provided from the regular dipole magnets. Later on, a 10 T wiggler magnet and other special inserters will be added, and other applications and beam dynamics studies will be feasible. Bending magnets are of the parallel faced C configuration. The effective aperture of the vacuum chamber is 2.3 cm (vertical) in the bending magnets and 4.7 cm elsewhere with a working vacuum condition of 10-9 Torr. Collective effects have been studied initially. First calculations indicate that a lifetime of several hours, influenced by the Touschek effect and residual gas scattering will be achievable for a 200 mA beam in the HLF mode for the standard rf parameters. A 70 MeV racetrack microtron will serve as injector for the ring.

Annular array and method of manufacturing same

DOEpatents

Day, Robert A.

1989-01-01

A method for manufacturing an annular acoustic transducer array from a plate of transducer material, which enables production of precision aligned arrays at low cost. The circular plate is sawed along at least two lines that are radial to the axis of the plate. At steps along each radial cut, the plate is rotated first in one direction and then in an opposite direction by a predetermined angle such as slightly less than 90.degree.. The cuts result in the forming of several largely ring-shaped lands, each largely ring-shaped land being joined to the other rings of different radii by thin portions of the plate, and each ring being cut into segments. The bridges that join different rings, hold the transducer together until it can be mounted on a lens.

Means of manufacturing annular arrays

DOEpatents

Day, R.A.

1985-10-10

A method is described for manufacturing an annular acoustic transducer array from a plate of transducer material, which enables production of precision aligned arrays at low cost. The circular plate is sawed along at least two lines that are radial to the axis of the plate. At steps along each radial cut, the plate is rotated first in one direction and then in an opposite direction by a predetermined angle such as slightly less than 90/sup 0/. The cuts result in the forming of several largely ring-shaped lands, each largely ring-shaped land being joined to the other rings of different radii by thin portions of the plate, and each ring being cut into segments. The bridges that join different rings hold the transducer together until it can be mounted on a lens.

Earth Battery: An Approach for Reducing the Carbon and Water Intensity of Energy

NASA Astrophysics Data System (ADS)

Buscheck, T. A.; Bielicki, J. M.; Randolph, J.

2016-12-01

Mitigating climate change requires a range of measures, including increased use of renewable and low-carbon energy and reducing the CO2 intensity of fossil energy use. Our approach, called the Earth Battery, uses the storage of supercritical CO2, N2, or pressurized air to enable utility-scale energy storage needed for increased use of variable renewable energy and low-carbon baseload power. When deployed with CO2, the Earth Battery is designed to address the major deployment barriers to CO2 capture, utilization, and storage (CCUS) by managing overpressure and creating a business case for CO2 storage. We use the huge fluid and thermal storage capacity of the earth, together with overpressure driven by CO2, N2, or pressurized air storage, to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, fossil) thermal resources, as well as excess energy from electric grids. The storage of CO2, N2, or air enables the earth to function as a low-carbon energy-system hub. Stored CO2, N2, or air plays three key roles: (1) as a supplemental fluid that creates pressure to efficiently recirculate working fluids that store and recover energy, (2) as a working fluid for efficient, low-water-intensity electricity conversion, and (3) as a shock absorber to allow diurnal and seasonal recharge/discharge cycles with minimal pressure oscillations, providing large pressure-storage capacity, with reduced risk of induced seismicity or leakage of stored CO2. To keep reservoir pressures in a safe range, a portion of the produced brine is diverted to generate water. Concentric rings of injection and production wells create a hydraulic divide to store pressure, CO2, N2/air, and thermal energy. Such storage can take excess power from the grid and excess thermal energy, and dispatch that energy when it is demanded. The system is pressurized and heated when power supply exceeds demand and depressurized when demand exceeds supply. The Earth Battery is designed for locations where a permeable geologic formation is overlain by an impermeable formation that constrains migration of buoyant CO2, N2/air, and heated brine. Such geologic conditions exist over half of the contiguous United States. This work was performed under the auspices of the USDOE by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Self-Alining Quick-Connect Joint

NASA Technical Reports Server (NTRS)

Lucy, M. H.

1983-01-01

Quick connect tapered joint used with minimum manipulation and force. Split ring retainer holds locking ring in place. Minimal force required to position male in female joint, at which time split-ring retainers are triggered to release split locking rings. Originally developed to assemble large space structures, joint is simple, compact, strong, lightweight, self alining, and has no loose parts.

Charged black rings at large D

NASA Astrophysics Data System (ADS)

Chen, Bin; Li, Peng-Cheng; Wang, Zi-zhi

2017-04-01

We study the charged slowly rotating black holes in the Einstein-Maxwell theory in the large dimensions ( D). By using the 1 /D expansion in the near regions of the black holes we obtain the effective equations for the charged slowly rotating black holes. The effective equations capture the dynamics of various stationary solutions, including the charged black ring, the charged slowly rotating Myers-Perry black hole and the charged slowly boosted black string. Via different embeddings we construct these stationary solutions explicitly. For the charged black ring at large D, we find that the charge lowers the angular momentum due to the regularity condition on the solution. By performing the perturbation analysis of the effective equations, we obtain the quasinormal modes of the charge perturbation and the gravitational perturbation analytically. Like the neutral case the charged thin black ring suffers from the Gregory-Laflamme-like instability under the non-axisymmetric perturbations, but the charge weakens the instability. Besides, we find that the large D analysis always respects the cosmic censorship.

Operating characteristics of a three-piece-inner-ring large-bore roller bearing to speeds of 3 million DN

NASA Technical Reports Server (NTRS)

Schuller, F. T.

1984-01-01

A 118 mm bore roller bearing with a three piece inner ring ran successfully at 300,000 DN for 20 hr. Provisions were made for lubrication and cooling through the inner ring. In some tests the outer ring was also cooled. Power loss within the bearing increased with both speed and total oil flow rate to the inner ring. Outer ring temperature decreased by as much as 22 K (40 F) when outer ring cooling was employed whereas inner ring temperature remained essentially constant. Cage slip was greatly reduced or even eliminated by using a bearing with a very tight clearance at operating speed. A three piece inner ring bearing had higher inner ring temperatures and less temperature difference between the inner and outer rings than a conventional one piece inner ring bearing.

Improving the hydrogen storage properties of metal-organic framework by functionalization.

PubMed

Xia, Liangzhi; Liu, Qing; Wang, Fengling; Lu, Jinming

2016-10-01

Based on the structure of MOF-808, different substituents were introduced to replace hydrogen atom on the phenyl ring of MOF-808. The GCMC method was used to study the effect of functional groups on the hydrogen storage properties of MOF-808-X (X = -OH, -NO 2 , -CH 3 , -CN, -I). The H 2 uptakes and isosteric heat of adsorption were simulated at 77 K. The results indicate that all these substituents have favorable impact on the hydrogen storage capacity, and -CN is found to be the most promising substituent to improve H 2 uptake. These results may be helpful for the design of MOFs with higher hydrogen storage capacity. Graphical abstract Atomistic structures of MOFs. (a) The structures of MOF-808-X. (b) Model of organic linker. Atom color scheme: C, gray; H, white; O, red; X, palegreen (X = -OH, -NO 2 , -CH 3 , -CN, -I).

The Crossings of Saturn Ring Plane by the Earth in 1995: Ring Thickness

NASA Astrophysics Data System (ADS)

Poulet, François; Sicardy, Bruno; Dumas, Christophe; Jorda, Laurent; Tiphène, Didier

2000-05-01

The crossings of Saturn's ring plane by Earth were observed in the near infrared on May 22 and August 10, 1995, from the 2.2-m telescope of the University of Hawaii, the 2-m telescope at Pic du Midi, France, and with the Adonis adaptive optics camera at the 3.6-m telescope of the European Southern Observatory in Chile. Images from the Hubble Space Telescope, obtained in August 1995, are also reanalyzed. The radial brightness profiles of the rings indicate that the outer and usually faint F ring dominates the edge-on brightness of the system, thus hiding the vertical structure of the main rings within a few hours around the ring plane crossing. The photometric behaviors of the A, B, and C rings and of the Cassini Division are analyzed, using a radiative transfer code which includes the illuminations by the Sun and by the planet. The F ring is modeled as a physically thick ribbon of height H, composed of large particles embedded in dust of fractional optical depth f. The observed profiles, combined with previous results, can be explained if the F ring is both optically thick ( radial optical depth ˜0.20) and physically thick ( H=21±4 km). We suggest that this vertical distribution results from the interactions between ring particles and shepherding satellites and/or from gravitational stirring by large bodies. The dust particles dominate the F ring's photometric behavior even in backscattered light ( f>0.80). Constraints on the particle properties of the other rings are also derived.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuchiya, Kimichika, E-mail: kimichika.tsuchiya@kek.jp; Adachi, Masahiro; Shioya, Tatsuro

At the 2.5-GeV Photon Factory (PF) storage ring, we recently constructed four new undulators known as U#02-2, U#13, SGU#15, and U#28 for BL02, BL13, BL15, and BL28, respectively. SGU#15 is an in-vacuum undulator with a period length of 17.6 mm. The other three undulators are elliptically polarizing undulators (EPUs) for the vacuum ultraviolet and soft X-ray (VUV-SX) light sources to obtain various polarization states. We constructed these new undulators by fiscal 2013 and step by step installed them in the PF ring. We describe the details of the construction of these new undulators in this report.

Accelerator structure and beam transport system for the KEK photon factory injector

NASA Astrophysics Data System (ADS)

Sato, Isamu

1980-11-01

The injector is a 2.5 GeV electron linac which serves multiple purposes, being not only the injector for the various storage rings of the Photon Factory but also for the next planned project, the TRISTAN RING, and also as an intense electron or γ-ray source for research on phenomena in widely diverse scientific fields. The accelerator structure and beam transport system for the linac were designed with the greatest care in order to avoid beam blow-up difficulties, and also to be as suitable as possible to enable the economical mass production of the accelerator guides and focusing magnets.

Estimation of neutron dose equivalent at the mezzanine of the Advanced Light Source and the laboratory boundary using the ORNL program MORSE.

PubMed

Sun, R K

1990-12-01

To investigate the radiation effect of neutrons near the Advanced Light Source (ALS) at Lawrence Berkeley Laboratory (LBL) with respect to the neutron dose equivalents in nearby occupied areas and at the site boundary, the neutron transport code MORSE, from Oak Ridge National Laboratory (ORNL), was used. These dose equivalents result from both skyshine neutrons transported by air scattering and direct neutrons penetrating the shielding. The ALS neutron sources are a 50-MeV linear accelerator and its transfer line, a 1.5-GeV booster, a beam extraction line, and a 1.9-GeV storage ring. The most conservative total occupational-dose-equivalent rate in the center of the ALS mezzanine, 39 m from the ALS center, was found to be 1.14 X 10(-3) Sv y-1 per 2000-h "occupational" year, and the total environmental-dose-equivalent rate at the ALS boundary, 125 m from the ALS center, was found to be 3.02 X 10(-4) Sv y-1 per 8760-h calendar year. More realistic dose-equivalent rates, using the nominal (expected) storage-ring current, were calculated to be 1.0 X 10(-4) Sv y-1 and 2.65 X 10(-5) Sv y-1 occupational year and calendar year, respectively, which are much lower than the DOE reporting levels.

Noise reduction as affected by the extent and distribution of acoustic treatment in a turbofan engine inlet

NASA Technical Reports Server (NTRS)

Minner, G. L.; Homyak, L.

1976-01-01

An inlet noise suppressor for a TF-34 engine designed to have three acoustically treated rings was tested with several different ring arrangements. The configurations included: all three rings; two outer rings; single outer ring; single intermediate ring, and finally no rings. It was expected that as rings were removed, the acoustic performance would be degraded considerably. While a degradation occurred, it was not as large as predictions indicated. The prediction showed good agreement with the data only for the full-ring inlet configuration. The underpredictions which occurred with ring removal were believed a result of ignoring the presence of spinning modes which are known to damp more rapidly in cylindrical ducts than would be predicted by least attenuated mode or plane wave analysis.

Search for the rare decay D + → D 0 e + ν e

DOE PAGES

Ablikim, M.; Achasov, M. N.; Ahmed, S.; ...

2017-11-13

Using a data set with an integrated luminosity ofmore » $$2.93\\text{ }\\text{ }{\\mathrm{fb}}^{{-}1}$$ collected at $$\\sqrt{s}=3.773\\text{ }\\mathrm{GeV}$$ with the BESIII detector operating at the BEPCII storage rings, we search for the rare decay $${D}^{+}{\\rightarrow}{D}^{0}{e}^{+}{{\

Search for the rare decay D + → D 0 e + ν e

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ablikim, M.; Achasov, M. N.; Ahmed, S.

Using a data set with an integrated luminosity ofmore » $$2.93\\text{ }\\text{ }{\\mathrm{fb}}^{{-}1}$$ collected at $$\\sqrt{s}=3.773\\text{ }\\mathrm{GeV}$$ with the BESIII detector operating at the BEPCII storage rings, we search for the rare decay $${D}^{+}{\\rightarrow}{D}^{0}{e}^{+}{{\

Review of Physics Research Programs at LAMPF. Progress report, January-December 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allred, J.C.

1984-04-01

Research and development summaries are presented under the main headings: research, proton storage ring construction and research program development, status of LAMPF II, facility and experimental development, and accelerator operations. Complete lists are given for experiments run in 1983, new prospects, and active and complete experiments by channel. (WHK)

Overview and Status of the Los Alamos PSR Injection Upgrade Project

NASA Astrophysics Data System (ADS)

Fitzgerald, D. H.; Ahn, H.; Blind, B.; Borden, M. J.; Macek, R. J.; Neri, F.; Rose, C. R.; Thiessen, H. A.; Wilkinson, C. A.; Zumbro, M. V.

1997-05-01

An upgrade is in progress to the Los Alamos Proton Storage Ring (PSR) to allow direct injection of the H^- beam into the ring and provide a beam bump system to move the circulating beam off the stripper foil. The primary benefits of this upgrade are matching the transverse phase space of the injected beam to the PSR acceptance and reduction of foil hits by the circulating beam by a factor of ten. Foil thickness is optimized to minimize the combination of circulating-beam losses plus losses due to excited H^0 states produced at injection. An overall factor of four reduction in losses is expected. The project comprises extensive modifications of the injection line, the injection section of the ring, and the waste-beam transport line. We will discuss the goals of the project, present an overview of the technical design, and describe the status of the implementation plan.

Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

PubMed

Durgun, E; Grossman, Jeffrey C

2013-03-21

Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

Measurements of Discrete Symmetries in the Neutral Kaon System with the CPLEAR (PS195) Experiment

NASA Astrophysics Data System (ADS)

Ruf, Thomas

2015-07-01

The antiproton storage ring LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of T, \\{CPT} and \\{CP} symmetries in the neutral kaon system. It measured with high precision the time evolution of initially strangeness-tagged K0 and overline K ^0 states to determine the size of violations with respect to these symmetries in the context of a systematic study. In parallel, limits concerning quantum-mechanical predictions (EPR paradox, coherence of the wave function) or the equivalence principle of general relativity have been obtained. This article will first discuss briefly the unique low energy antiproton storage ring LEAR followed by a description of the CPLEAR experiment, including the basic formalism necessary to understand the time evolution of a neutral kaon state and the main results related to measurements of discrete symmetries in the neutral kaon system. An excellent and exhaustive review of the CPLEAR experiment and all its measurements is given in Ref. 1.

Manifestations of geometric phases in a proton electric-dipole-moment experiment in an all-electric storage ring

NASA Astrophysics Data System (ADS)

Silenko, Alexander J.

2017-12-01

We consider a proton electric-dipole-moment experiment in an all-electric storage ring when the spin is frozen and local longitudinal and vertical electric fields alternate. In this experiment, the geometric (Berry) phases are very important. Due to the these phases, the spin rotates about the radial axis. The corresponding systematic error is rather important while it can be canceled with clockwise and counterclockwise beams. The geometric phases also lead to the spin rotation about the radial axis. This effect can be canceled with clockwise and counterclockwise beams as well. The sign of the azimuthal component of the angular velocity of the spin precession depends on the starting point where the spin orientation is perfect. The radial component of this quantity keeps its value and sign for each starting point. When the longitudinal and vertical electric fields are joined in the same sections without any alternation, the systematic error due to the geometric phases does not appear but another systematic effect of the spin rotation about the azimuthal axis takes place. It has opposite signs for clockwise and counterclockwise beams.

Analysis of closed orbit deviations for a first direct deuteron electric dipole moment measurement at the cooler synchrotron COSY

NASA Astrophysics Data System (ADS)

Schmidt, V.; Lehrach, A.

2017-07-01

The Jülich Electric Dipole moment Investigations (JEDI) collaboration in Julich is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. Ensuring a precise measurement, various beam and spin manipulating effects have to be considered and investigated. A distortion of the closed orbit is one of the major sources for systematic uncertainties. Therefore misalignments of magnets and residual power supply oscillations are simulated using the MAD-X code in order to analyse their effect on the orbit. The underlying model for all simulations includes the dipoles, quadrupoles and sextupoles at COSY as well as the corrector magnets and BPMs (Beam Position Monitors). Since most sextupoles are only used during beam extraction, the sextupole strengths are set to zero resulting in a linear machine. The optics is adjusted in a way that the dispersion is zero in the straight sections. The closed orbit studies are performed for deuterons with a momentum of 970 MeV/c.

Improving the precision of linear optics measurements based on turn-by-turn beam position monitor data after a pulsed excitation in lepton storage rings

NASA Astrophysics Data System (ADS)

Malina, L.; Coello de Portugal, J.; Persson, T.; Skowroński, P. K.; Tomás, R.; Franchi, A.; Liuzzo, S.

2017-08-01

Beam optics control is of critical importance for machine performance and protection. Nowadays, turn-by-turn (TbT) beam position monitor (BPM) data are increasingly exploited as they allow for fast and simultaneous measurement of various optics quantities. Nevertheless, so far the best documented uncertainty of measured β -functions is of about 10‰ rms. In this paper we compare the β -functions of the ESRF storage ring measured from two different TbT techniques—the N-BPM and the Amplitude methods—with the ones inferred from a measurement of the orbit response matrix (ORM). We show how to improve the precision of TbT techniques by refining the Fourier transform of TbT data with properly chosen excitation amplitude. The precision of the N-BPM method is further improved by refining the phase advance measurement. This represents a step forward compared to standard TbT measurements. First experimental results showing the precision of β -functions pushed down to 4‰ both in TbT and ORM techniques are reported and commented.

First application of combined isochronous and Schottky mass spectrometry: Half-lives of fully ionized Cr 24 + 49 and Fe 26 + 53 atoms

NASA Astrophysics Data System (ADS)

Tu, X. L.; Chen, X. C.; Zhang, J. T.; Shuai, P.; Yue, K.; Xu, X.; Fu, C. Y.; Zeng, Q.; Zhou, X.; Xing, Y. M.; Wu, J. X.; Mao, R. S.; Mao, L. J.; Fang, K. H.; Sun, Z. Y.; Wang, M.; Yang, J. C.; Litvinov, Yu. A.; Blaum, K.; Zhang, Y. H.; Yuan, Y. J.; Ma, X. W.; Zhou, X. H.; Xu, H. S.

2018-01-01

Lifetime measurements of β -decaying highly charged ions have been performed in the experimental storage ring (CSRe) by applying the isochronous Schottky mass spectrometry. The fully ionized 49Cr and 53Fe ions were produced in projectile fragmentation of 58Ni primary beam and were stored in the CSRe tuned into the isochronous ion-optical mode. The new resonant Schottky detector was applied to monitor the intensities of stored uncooled Cr 24 + 49 and Fe 26 + 53 ions. The extracted half-lives T1 /2(Cr 24 + 49 ) =44.0 (27 ) min and T1 /2(Fe 26 + 53 ) =8.47 (19 ) min are in excellent agreement with the literature half-life values corrected for the disabled electron capture branchings. This is an important proof-of-principle step towards realizing the simultaneous mass and lifetime measurements on exotic nuclei at the future storage ring facilities.

Study of Uneven Fills to Cure the Coupled-Bunch Instability in SRRC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Alex W.

2002-08-12

The performance of the 1.5-GeV storage ring light source TLS in SRRC has been limited by a longitudinal coupled-bunch beam instability. To improve the performance of the TLS, the beam instability has to be suppressed. One possible way considered for the TLS to suppress its coupled-bunch instability uses uneven filling patterns according to the theory of Prabhakar[1]. By knowing the harmful high-order-modes (HOMs), a special filling pattern can be designed to utilize either mode coupling or Landau damping to cure beam instability. In TLS the HOMs are contributed from the Doris RF cavity installed in the storage ring. The HOMsmore » of a 3-D Doris cavity was numerically analyzed. Filling patterns with equal bunch current according to theory had been calculated to cure the most harmful HOM. A longitudinal particle tracking program was used to simulate the coupled-bunch beam instability with both the uniform filling and the special designed filling. Filling pattern with unequal bunch current was also studied. The results of the simulation were discussed and compared to the theory.« less

Negative ion source development at the cooler synchrotron COSY/Jülich

NASA Astrophysics Data System (ADS)

Felden, O.; Gebel, R.; Maier, R.; Prasuhn, D.

2013-02-01

The Nuclear Physics Institute at the Forschungszentrum Jülich, a member of the Helmholtz Association, conducts experimental and theoretical basic research in the field of hadron, particle, and nuclear physics. It operates the cooler synchrotron COSY, an accelerator and storage ring, which provides unpolarized and polarized proton and deuteron beams with beam momenta of up to 3.7 GeV/c. Main activities of the accelerator division are the design and construction of the high energy storage ring HESR, a synchrotron and part of the international FAIR project, and the operation and development of COSY with injector cyclotron and ion sources. Filament driven volume sources and a charge exchange colliding beams source, based on a nuclear polarized atomic beam source, provide unpolarized and polarized H- or D- routinely for more than 6500 hours/year. Within the Helmholtz Association's initiative Accelerator Research and Development, ARD, the existing sources at COSY, as well as new sources for future programs, are investigated and developed. The paper reports about these plans, improved pulsed beams from the volume sources and the preparation of a source for the ELENA project at CERN.

Component Database for the APS Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veseli, S.; Arnold, N. D.; Jarosz, D. P.

The Advanced Photon Source Upgrade (APS-U) project will replace the existing APS storage ring with a multi-bend achromat (MBA) lattice to provide extreme transverse coherence and extreme brightness x-rays to its users. As the time to replace the existing storage ring accelerator is of critical concern, an aggressive one-year removal/installation/testing period is being planned. To aid in the management of the thousands of components to be installed in such a short time, the Component Database (CDB) application is being developed with the purpose to identify, document, track, locate, and organize components in a central database. Three major domains are beingmore » addressed: Component definitions (which together make up an exhaustive "Component Catalog"), Designs (groupings of components to create subsystems), and Component Instances (“Inventory”). Relationships between the major domains offer additional "system knowledge" to be captured that will be leveraged with future tools and applications. It is imperative to provide sub-system engineers with a functional application early in the machine design cycle. Topics discussed in this paper include the initial design and deployment of CDB, as well as future development plans.« less

Independent component analysis applied to long bunch beams in the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Kolski, Jeffrey S.; Macek, Robert J.; McCrady, Rodney C.; Pang, Xiaoying

2012-11-01

Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis, ICA is more robust to noise, coupling, and nonlinearity. The conventional ICA application to turn-by-turn position data from multiple beam position monitors (BPMs) yields information about cross-BPM correlations. With this scheme, multi-BPM ICA has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch revealing correlations of particle motion within the beam bunch. We digitize beam signals of the long bunch at the Los Alamos Proton Storage Ring with a single device (BPM or fast current monitor) for an entire injection-extraction cycle. ICA of the digitized beam signals results in source signals, which we identify to describe varying betatron motion along the bunch, locations of transverse resonances along the bunch, measurement noise, characteristic frequencies of the digitizing oscilloscopes, and longitudinal beam structure.

Improved test of time dilation in special relativity.

PubMed

Saathoff, G; Karpuk, S; Eisenbarth, U; Huber, G; Krohn, S; Muñoz Horta, R; Reinhardt, S; Schwalm, D; Wolf, A; Gwinner, G

2003-11-07

An improved test of time dilation in special relativity has been performed using laser spectroscopy on fast ions at the heavy-ion storage-ring TSR in Heidelberg. The Doppler-shifted frequencies of a two-level transition in 7Li+ ions at v=0.064c have been measured in the forward and backward direction to an accuracy of Deltanu/nu=1 x 10(-9) using collinear saturation spectroscopy. The result confirms the relativistic Doppler formula and sets a new limit of 2.2 x 10(-7) for deviations from the time dilation factor gamma(SR)=(1-v2/c2)(-1/2).

Invited review article: Large ring lasers for rotation sensing.

PubMed

Schreiber, Karl Ulrich; Wells, Jon-Paul R

2013-04-01

Over the last two decades a series of large ring laser gyroscopes have been built having an unparalleled scale factor. These upscaled devices have improved the sensitivity and stability for rotation rate measurements by six orders of magnitude when compared to previous commercial developments. This progress has made possible entirely new applications of ring laser gyroscopes in the fields of geophysics, geodesy, and seismology. Ring lasers are currently the only viable measurement technology, which is directly referenced to the instantaneous rotation axis of the Earth. The sensor technology is rapidly developing. This is evidenced by the first experimentally viable proposals to make terrestrial tests of general relativistic effects such as the frame dragging of the rotating Earth.

Present status and future prospects of heavy ion beams as drivers for ICF

NASA Astrophysics Data System (ADS)

Godlove, Terry F.

1986-01-01

A candidate driver for a practical inertial fusion reactor system must, among other characteristics, be cost effective and reliable for the parameters required by the fusion target and the remainder of the system. Although the history of large particle accelerators provides abundant evidence of their reliability at high repetition rates, their capital cost for the fusion application has been open to question. Attempts to design cost effective systems began with accelerators based on currently available technology such as RF linacs and storage rings. The West German HIBALL and the Japanese HIBLIC are examples of this initial effort. These designs are sufficiently credible that a strong argument can be made for the heavy ion method in general, but to reduce the cost per unit power it was found necessary to design for large scale, hence high capital cost. Emphasis in the U.S. shifted to newer technologies which offer hope of significant improvement in cost. In this paper the status of various heavy ion driver designs are compared with currently perceived requirements in order to illustrate their potential and assess their development needs.

Reconstructing three-dimensional protein crystal intensities from sparse unoriented two-axis X-ray diffraction patterns

PubMed Central

Lan, Ti-Yen; Wierman, Jennifer L.; Tate, Mark W.; Philipp, Hugh T.; Elser, Veit

2017-01-01

Recently, there has been a growing interest in adapting serial microcrystallography (SMX) experiments to existing storage ring (SR) sources. For very small crystals, however, radiation damage occurs before sufficient numbers of photons are diffracted to determine the orientation of the crystal. The challenge is to merge data from a large number of such ‘sparse’ frames in order to measure the full reciprocal space intensity. To simulate sparse frames, a dataset was collected from a large lysozyme crystal illuminated by a dim X-ray source. The crystal was continuously rotated about two orthogonal axes to sample a subset of the rotation space. With the EMC algorithm [expand–maximize–compress; Loh & Elser (2009). Phys. Rev. E, 80, 026705], it is shown that the diffracted intensity of the crystal can still be reconstructed even without knowledge of the orientation of the crystal in any sparse frame. Moreover, parallel computation implementations were designed to considerably improve the time and memory scaling of the algorithm. The results show that EMC-based SMX experiments should be feasible at SR sources. PMID:28808431

I12: the Joint Engineering, Environment and Processing (JEEP) beamline at Diamond Light Source.

PubMed

Drakopoulos, Michael; Connolley, Thomas; Reinhard, Christina; Atwood, Robert; Magdysyuk, Oxana; Vo, Nghia; Hart, Michael; Connor, Leigh; Humphreys, Bob; Howell, George; Davies, Steve; Hill, Tim; Wilkin, Guy; Pedersen, Ulrik; Foster, Andrew; De Maio, Nicoletta; Basham, Mark; Yuan, Fajin; Wanelik, Kaz

2015-05-01

I12 is the Joint Engineering, Environmental and Processing (JEEP) beamline, constructed during Phase II of the Diamond Light Source. I12 is located on a short (5 m) straight section of the Diamond storage ring and uses a 4.2 T superconducting wiggler to provide polychromatic and monochromatic X-rays in the energy range 50-150 keV. The beam energy enables good penetration through large or dense samples, combined with a large beam size (1 mrad horizontally × 0.3 mrad vertically). The beam characteristics permit the study of materials and processes inside environmental chambers without unacceptable attenuation of the beam and without the need to use sample sizes which are atypically small for the process under study. X-ray techniques available to users are radiography, tomography, energy-dispersive diffraction, monochromatic and white-beam two-dimensional diffraction/scattering and small-angle X-ray scattering. Since commencing operations in November 2009, I12 has established a broad user community in materials science and processing, chemical processing, biomedical engineering, civil engineering, environmental science, palaeontology and physics.

I12: the Joint Engineering, Environment and Processing (JEEP) beamline at Diamond Light Source

PubMed Central

Drakopoulos, Michael; Connolley, Thomas; Reinhard, Christina; Atwood, Robert; Magdysyuk, Oxana; Vo, Nghia; Hart, Michael; Connor, Leigh; Humphreys, Bob; Howell, George; Davies, Steve; Hill, Tim; Wilkin, Guy; Pedersen, Ulrik; Foster, Andrew; De Maio, Nicoletta; Basham, Mark; Yuan, Fajin; Wanelik, Kaz

2015-01-01

I12 is the Joint Engineering, Environmental and Processing (JEEP) beamline, constructed during Phase II of the Diamond Light Source. I12 is located on a short (5 m) straight section of the Diamond storage ring and uses a 4.2 T superconducting wiggler to provide polychromatic and monochromatic X-rays in the energy range 50–150 keV. The beam energy enables good penetration through large or dense samples, combined with a large beam size (1 mrad horizontally × 0.3 mrad vertically). The beam characteristics permit the study of materials and processes inside environmental chambers without unacceptable attenuation of the beam and without the need to use sample sizes which are atypically small for the process under study. X-ray techniques available to users are radiography, tomography, energy-dispersive diffraction, monochromatic and white-beam two-dimensional diffraction/scattering and small-angle X-ray scattering. Since commencing operations in November 2009, I12 has established a broad user community in materials science and processing, chemical processing, biomedical engineering, civil engineering, environmental science, palaeontology and physics. PMID:25931103

Modal ring method for the scattering of sound

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.; Kreider, Kevin L.

1993-01-01

The modal element method for acoustic scattering can be simplified when the scattering body is rigid. In this simplified method, called the modal ring method, the scattering body is represented by a ring of triangular finite elements forming the outer surface. The acoustic pressure is calculated at the element nodes. The pressure in the infinite computational region surrounding the body is represented analytically by an eigenfunction expansion. The two solution forms are coupled by the continuity of pressure and velocity on the body surface. The modal ring method effectively reduces the two-dimensional scattering problem to a one-dimensional problem capable of handling very high frequency scattering. In contrast to the boundary element method or the method of moments, which perform a similar reduction in problem dimension, the model line method has the added advantage of having a highly banded solution matrix requiring considerably less computer storage. The method shows excellent agreement with analytic results for scattering from rigid circular cylinders over a wide frequency range (1 is equal to or less than ka is less than or equal to 100) in the near and far fields.

Electrochemical Studies of Redox Systems for Energy Storage

NASA Technical Reports Server (NTRS)

Wu, C. D.; Calvo, E. J.; Yeager, E.

1983-01-01

Particular attention was paid to the Cr(II)/Cr(III) redox couple in aqueous solutions in the presence of Cl(-) ions. The aim of this research has been to unravel the electrode kinetics of this redox couple and the effect of Cl(1) and electrode substrate. Gold and silver were studied as electrodes and the results show distinctive differences; this is probably due to the role Cl(-) ion may play as a mediator in the reaction and the difference in state of electrical charge on these two metals (difference in the potential of zero charge, pzc). The competition of hydrogen evolution with CrCl3 reduction on these surfaces was studied by means of the rotating ring disk electrode (RRDE). The ring downstream measures the flux of chromous ions from the disk and therefore separation of both Cr(III) and H2 generation can be achieved by analyzing ring and disk currents. The conditions for the quantitative detection of Cr(2+) at the ring electrode were established. Underpotential deposition of Pb on Ag and its effect on the electrokinetics of Cr(II)/Cr(III) reaction was studied.

Statistical analysis of the limitation of half integer resonances on the available momentum acceptance of the High Energy Photon Source

NASA Astrophysics Data System (ADS)

Jiao, Yi; Duan, Zhe

2017-01-01

In a diffraction-limited storage ring, half integer resonances can have strong effects on the beam dynamics, associated with the large detuning terms from the strong focusing and strong sextupoles as required for an ultralow emittance. In this study, the limitation of half integer resonances on the available momentum acceptance (MA) was statistically analyzed based on one design of the High Energy Photon Source (HEPS). It was found that the probability of MA reduction due to crossing of half integer resonances is closely correlated with the level of beta beats at the nominal tunes, but independent of the error sources. The analysis indicated that for the presented HEPS lattice design, the rms amplitude of beta beats should be kept below 1.5% horizontally and 2.5% vertically to reach a small MA reduction probability of about 1%.

3D theory of a high-gain free-electron laser based on a transverse gradient undulator

NASA Astrophysics Data System (ADS)

Baxevanis, Panagiotis; Ding, Yuantao; Huang, Zhirong; Ruth, Ronald

2014-02-01

The performance of a free-electron laser (FEL) depends significantly on the various parameters of the driving electron beam. In particular, a large energy spread in the beam results in a substantial reduction of the FEL gain, an effect which is especially relevant when one considers FELs driven by plasma accelerators or ultimate storage rings. For such cases, one possible solution is to use a transverse gradient undulator (TGU). In this concept, the energy spread problem is mitigated by properly dispersing the electron beam and introducing a linear, transverse field dependence in the undulator. This paper presents a self-consistent theoretical analysis of a TGU-based, high-gain FEL which takes into account three-dimensional (3D) effects, including beam size variations along the undulator. The results of our theory compare favorably with simulation and are used in fast optimization studies of various x-ray FEL configurations.

Fokker-Planck analysis of transverse collective instabilities in electron storage rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindberg, Ryan R.

We analyze single bunch transverse instabilities due to wakefields using a Fokker-Planck model. We first expand on the work of T. Suzuki, Part. Accel. 12, 237 (1982) to derive the theoretical model including chromaticity, both dipolar and quadrupolar transverse wakefields, and the effects of damping and diffusion due to the synchrotron radiation. We reduce the problem to a linear matrix equation, whose eigenvalues and eigenvectors determine the collective stability of the beam. We then show that various predictions of the theory agree quite well with results from particle tracking simulations, including the threshold current for transverse instability and the profilemore » of the unstable mode. In particular, we find that predicting collective stability for high energy electron beams at moderate to large values of chromaticity requires the full Fokker-Planck analysis to properly account for the effects of damping and diffusion due to synchrotron radiation.« less

Correcting systematic errors in high-sensitivity deuteron polarization measurements

NASA Astrophysics Data System (ADS)

Brantjes, N. P. M.; Dzordzhadze, V.; Gebel, R.; Gonnella, F.; Gray, F. E.; van der Hoek, D. J.; Imig, A.; Kruithof, W. L.; Lazarus, D. M.; Lehrach, A.; Lorentz, B.; Messi, R.; Moricciani, D.; Morse, W. M.; Noid, G. A.; Onderwater, C. J. G.; Özben, C. S.; Prasuhn, D.; Levi Sandri, P.; Semertzidis, Y. K.; da Silva e Silva, M.; Stephenson, E. J.; Stockhorst, H.; Venanzoni, G.; Versolato, O. O.

2012-02-01

This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY at Jülich. By measuring with very high statistical precision, the contributions that are second-order in the systematic errors become apparent. By calibrating the sensitivity of the polarimeter to such errors, it becomes possible to obtain information from the raw count rate values on the size of the errors and to use this information to correct the polarization measurements. During the experiment, it was possible to demonstrate that corrections were satisfactory at the level of 10 -5 for deliberately large errors. This may facilitate the real time observation of vector polarization changes smaller than 10 -6 in a search for an electric dipole moment using a storage ring.