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Sample records for 7-gev storage ring

  1. Heavy ion storage rings

    SciTech Connect

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented.

  2. Storage ring injection

    SciTech Connect

    Burke, R.J.

    1980-01-01

    Some basic issues involved in injecting the beam into storage rings with the principal parameters of those studied at the workshop have been considered. The main conclusion is that straightforward adjustments of the storage ring parameters makes injection easy. The largest number of injected turns is fourteen, and the phase space dilution allowance seems adequate to ensure very small beam loss during injection. The adjustments also result in lower bending magnet fields, and high field superconducting magnets (e.g., 5 Tesla) are not necessary. The design changes do not necessarily affect the Keil-Schnell criterion for stability of the longitudinal microwave instability, although that criterion appears to be irrelevant. Because the beams are expected to be unstable, but with slow growth rates, the vacuum chamber impedances required to give equal risetimes for the various designs are compared for systems posing various degrees of difficulty for injection. Finally, the impact of the parameters on cost is noted, and a system is considered that cuts the length of the linac in half by using doubly charged ions.

  3. Reversible Seeding in Storage Rings

    SciTech Connect

    Ratner, Daniel; Chao, Alex; /SLAC

    2011-12-14

    We propose to generate steady-state microbunching in a storage ring with a reversible seeding scheme. High gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) are two promising methods for microbunching linac electron beams. Because both schemes increase the energy spread of the seeded beam, they cannot drive a coherent radiator turn-by-turn in a storage ring. However, reversing the seeding process following the radiator minimizes the impact on the electron beam and may allow coherent radiation at or near the storage ring repetition rate. In this paper we describe the general idea and outline a proof-of-principle experiment. Electron storage rings can drive high average power light sources, and free-electron lasers (FELs) are now producing coherent light sources of unprecedented peak brightness While there is active research towards high repetition rate FELs (for example, using energy recovery linacs), at present there are still no convenient accelerator-based sources of high repetition rate, coherent radiation. As an alternative avenue, we recently proposed to establish steady-state microbunching (SSMB) in a storage ring. By maintaining steady-state coherent microbunching at one point in the storage ring, the beam generates coherent radiation at or close to the repetition rate of the storage ring. In this paper, we propose a method of generating a microbunched beam in a storage ring by using reversible versions of linac seeding schemes.

  4. A new storage-ring light source

    SciTech Connect

    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.

  5. Storage ring working group report

    SciTech Connect

    Krinsky, S.

    1997-01-01

    Over the last two decades great progress has been made in the development of storage rings with small transverse emittance. It is now a good time to consider the possibility of achieving very short bunches m storage rings. From the perspective of synchrotron radiation source development, there are at least two motivations for obtaining short electron bunches: (1) the generation of sub- picosecond x-ray pulses and (2) the coherent emission of sub- picosecond pulses of far infrared radiation. A useful short-term goal is the experimental study of bunches with 1 ps rms length both at high ({approx_gt} 1 GeV) and low ({approx_lt} 150 MeV) electron energies. Experiments on 1 ps bunches are now feasible and can yield new insight into the high frequency impedance of storage rings and the associated phenomena which can result in bunch lengthening. Achievement of 1 ps bunches can also be expected to allow the first observation of coherent synchrotron radiation in a storage ring, in the millimeter wavelength regime. A longer-term objective is the realization of 100 fs bunches. Achievement of this goal not only will advance understanding of storage rings but will open up new opportunities in synchrotron radiation based research at both x-ray and far infrared wavelengths. It is now an appropriate time to carry forward theoretical investigations clarifying the fundamental limitations on bunch length, and to devise schemes to minimize it.

  6. APS storage ring vacuum system

    SciTech Connect

    Niemann, R.C.; Benaroya, R.; Choi, M.; Dortwegt, R.J.; Goeppner, G.A.; Gonczy, J.; Krieger, C.; Howell, J.; Nielsen, R.W.; Roop, B.; Wehrle, R.B.

    1990-01-01

    The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7 GeV positrons for the generation of photon beams for the facility's experimental program. The Storage Ring's 1104 m circumference is divided into 40 functional sectors. The sectors include vacuum, beam transport, control, acceleration and insertion device components. The vacuum system, which is designed to operate at a pressure of 1 n Torr, consists of 240 connected sections, the majority of which are fabricated from an aluminum alloy extrusion. The sections are equipped with distributed NeG pumping, photon absorbers with lumped pumping, beam position monitors, vacuum diagnostics and valving. The details of the vacuum system design, selected results of the development program and general construction plans are presented. 11 refs., 6 figs., 3 tabs.

  7. Fourth-generation storage rings

    SciTech Connect

    Galayda, J. N.

    1999-11-16

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

  8. Longitudinal dynamics in storage rings

    SciTech Connect

    Colton, E.P.

    1986-01-01

    The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and ''matched'' bunches. A brief analysis including second-harmonic rf contributions is also given. The final sections supply calculations of dynamical quantities and particle simulations with the space-charge effects neglected.

  9. 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.

  10. 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.

  11. 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.

  12. Features of the compact photon storage ring

    NASA Astrophysics Data System (ADS)

    Yamada, Hironari; Tsutsui, Hiroshi; Shimoda, Koichi; Mima, Kunioki

    1993-07-01

    The compact photon storage ring (PhSR) is a hybrid machine that features both linac driven FEL and storage ring driven FEL. The lasing condition is determined by the exactly circular electron storage ring, but a continuous electron injection is possible without disturbing the lasing. An effect of coherent synchrotron radiation takes an important role in the lasing. It is found that the compact PhSR is promising in lasing up to a wavelength of less than 10 μm with 10 A accumulated current.

  13. INSTABILITY ISSUES AT THE SNS STORAGE RING

    SciTech Connect

    ZHANG,S.Y.

    1999-06-28

    The impedance and beam instability issues of the SNS storage ring is reviewed, and the effort toward solutions at the BNL is reported. Some unsettled issues are raised, indicating the direction of planned works.

  14. APS storage ring vacuum system performance

    SciTech Connect

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

    1997-06-01

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

  15. Storage rings, internal targets and PEP

    SciTech Connect

    Spencer, J.E.

    1986-11-01

    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)

  16. Stable CSR in storage rings: A model

    SciTech Connect

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

    2005-01-03

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

  17. Storage-ring Electron Cooler for Relativistic Ion Beams

    SciTech Connect

    Lin, Fanglei; Derbenev, Yaroslav; Douglas, David R.; Guo, Jiquan; Johnson, Rolland P.; Krafft, Geoffrey A.; Morozov, Vasiliy; Zhang, Yuhong

    2016-05-01

    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 paper 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.

  18. Dedicated storage rings for nuclear physics

    SciTech Connect

    Jackson, H.E.

    1984-01-01

    The use of internal targets in circulating beams of electron storage and stretcher rings has been widely discussed recently as a method of achieving high luminosity under conditions of low background, and good energy resolution, with minimal demands for beam from an injecting accelerator. In the two critical areas of the technology, ring design and target development, research is very active, and the prospects for major advances are very bright. Reasonable extrapolations of the current state of the art suggest for many problems in nuclear physics, particularly polarization physics of the nucleon and few body nuclei, internal target measurement may be the optimum experimental technique. This paper, discusses the comparative merit of internal target rings and external beam experiments, reviews briefly current research efforts in the critical areas of the technology, and establishes one goal for the discussions at the workshop. It appears that storage rings dedicated to internal target physics may offer a powerful option for future advances in nuclear physics.

  19. Nonlinear dynamics aspects of modern storage rings

    SciTech Connect

    Helleman, R.H.G.; Kheifets, S.A.

    1986-01-01

    It is argued that the nonlinearity of storage rings becomes an essential problem as the design parameters of each new machine are pushed further and further. Yet the familiar methods of classical mechanics do not allow determination of single particle orbits over reasonable lengths of time. It is also argued that the single particle dynamics of a storage ring is possibly one of the cleanest and simplest nonlinear dynamical systems available with very few degrees of freedom. Hence, reasons are found for accelerator physicists to be interested in nonlinear dynamics and for researchers in nonlinear dynamics to be interested in modern storage rings. The more familiar methods of treating nonlinear systems routinely used in acclerator theory are discussed, pointing out some of their limitations and pitfalls. 39 refs., 1 fig. (LEW)

  20. Latest on polarization in electron storage rings

    SciTech Connect

    Chao, A.W.

    1983-01-01

    The field of beam polarization in electron storage rings is making rapid progress in recent several years. This report is an attempt to summarize some of these developments concerning how to produce and maintain a high level of beam polarization. Emphasized will be the ideas and current thoughts people have on what should and could be done on electron rings being designed at present such as HERA, LEP and TRISTAN. 23 references.

  1. Electron Storage Ring Development for ICS Sources

    SciTech Connect

    Loewen, Roderick

    2015-09-30

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

  2. Dissociative recombination: Results from storage rings

    SciTech Connect

    Larsson, Mats

    2005-05-27

    The focus of this article is on the measurement of product branching ratios in the dissociative recombination of polyatomic molecular ions with electrons by means of ion storage rings. Recombination of ions of interest in astrophysics, plasma-assisted combustion, thermonuclear fusion, protein fragmentation, and atmospheric physics are reviewed and discussed.

  3. The CERN intersecting storage rings (ISR)

    NASA Astrophysics Data System (ADS)

    Hübner, Kurt

    2012-03-01

    The CERN Intersecting Storage Rings (ISR) was the first facility ever built providing colliding hadron beams. It mainly operated with protons with beam energies of 15 to 31 GeV. The ISR was conceived in the years 1960 to 1964 and was approved in 1965. It came into operation at the beginning of 1971 and was decommissioned as a collider in 1983. A number of accelerator technologies have been either much improved or developed at the ISR which subsequently have become enabling technologies for a number of hadron storage rings and large colliders. Prominent examples of such technologies are ultra-high vacuum technology, beam diagnostics based on Schottky signals and stochastic cooling. The experiences obtained with the ISR were later exploited at the proton-antiproton facility in the CERN SPS, the Tevatron at Fermilab, the RHIC at Brookhaven and, finally, by the LHC at CERN.

  4. Mass and Lifetime Measurements in Storage Rings

    SciTech Connect

    Weick, H.; Beckert, K.; Beller, P.; Bosch, F.; Dimopoulou, C.; Kozhuharov, C.; Kurcewicz, J.; Mazzocco, M.; Nociforo, C.; Nolden, F.; Steck, M.; Sun, B.; Winkler, M.; Brandau, C.; Chen, L.; Geissel, H.; Knoebel, R.; Litvinov, S. A.; Litvinov, Yu. A.; Scheidenberger, C.

    2007-05-22

    Masses of nuclides covering a large area of the chart of nuclides can be measured in storage rings where many ions circulate at the same time. In this paper the recent progress in the analysis of Schottky mass spectrometry data is presented as well as the technical improvements leading to higher accuracy for isochronous mass measurements with a time-of-flight detector. The high sensitivity of the Schottky method down to single ions allows to measure lifetimes of nuclides by observing mother and daughter nucleus simultaneously. In this way we investigated the decay of bare and H-like 140Pr. As we could show the lifetime can be even shortened compared to those of atomic nuclei despite of a lower number of electrons available for internal conversion or electron capture.All these techniques will be implemented with further improvements at the storage rings of the new FAIR facility at GSI in the future.

  5. 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.

  6. Radiation Safety Design for SSRL Storage Ring

    SciTech Connect

    Khater, Hesham; Liu, James; Fasso, Alberto; Prinz, Alyssa; Rokni, Sayed; /SLAC

    2007-02-12

    In 2003, the Stanford Synchrotron Radiation Laboratory (SSRL) has upgraded its storage ring to a 3rd generation storage ring (SPEAR3). SPEAR3 is deigned to operate at 500 mA stored beam current and 3 GeV energy. The 234-meter circumference SPEAR3 ring utilizes 60-cm-thick concrete lateral walls, 30-cm-thick concrete roof, as well as 60-cm or 90-cm-thick concrete ratchet walls. A total of 3.5 x 10{sup 15} e{sup -}/y will be injected into the ring with an injection power of 4 W and an injection efficiency of 75%. Normal beam losses occur due to both injection and stored beam operations in the total of 20 low loss as well as 3 high loss limiting apertures. During the 6-minutes injection period, an instantaneous power loss of 0.05 W occurs at each low loss aperture. When averaged over the operational year, the loss of both the injection and stored beams is equivalent to an average loss of 2 mW at each low loss aperture. On the other hand, the average losses in the high loss apertures are 16 mW for the injection septum, 47 mW for the beam abort dump, and 13 mW for the ring stoppers. The shielding requirements for losses in the new ring were based on a generic approach that used both FLUKA Monte Carlo particle generation and transport code and empirical computer codes and formulae.

  7. Lattice design of a quasi-isochronous ring for a storage-ring FEL

    SciTech Connect

    Ohgaki, H.; Robin, D.; Yamazaki, T.

    1995-12-31

    Design work for a Quasi-Isochronous Ring (QI-Ring) dedicated to Storage Ring FELs in Electrotechnical Laboratory has been completed. The motivation for this work is to shorten the electron bunch length in order to get a high peak current in a compact Storage-Ring (SR). By placing an inverted dipole field in a location where the energy dispersion function is relatively large, one can reduce the momentum compaction factor ({alpha}) and shorten a bunch length in a SR. The main requirements for the QI-Ring are: 1.5GeV maximum beam energy; 80m circumference; two 10m-long dispersion free straight sections for insertion devices. A few meters dispersion free straight sections for RF cavities and injection bumpers; and a wide tune ability in betatron functions and momentum compaction factor ({alpha}). As shown in figure 1, the lattice includes two 49 degree, 3 T superconducting bending magnets to reduce the circumference of the ring, a -8 degree normal inverted dipole magnet (ID), 4 families quadrupole magnets (QF, QD, QFA, QDA), and 3 families sextupole magnets. Each quadrupole family has a specific function: QF & QD control the betatron tunes, and QFA & QDA control the {alpha} and suppress the energy dispersion in a straight section. In this type of ring it is important to compensate the second order momentum compaction factor ({alpha}{sub 2}), so at least three families of sextupoles are required.

  8. A storage ring for the JULIC cyclotron

    NASA Astrophysics Data System (ADS)

    Martin, S. A.; Prasuhn, D.; Schott, W.; Wiedner, C. A.

    1985-05-01

    The storage ring COSY is planned to provide higher intensity and resolution for nuclear structure experiments using the light heavy ion beams (p, d, τ, α) of the JULIC cyclotron and the magnet spectrograph BIG KARL. The ring contains the measuring target of BIG KARL as an internal target, two rf cavities for compensating the mean energy loss in the target and providing additional acceleration of the stored beam and an e --cooling section. In the recirculator mode, i.e., without e --cooling, a luminosity of L = 3.64 × 10 30 particles/(cm 2 s) is obtained for an experiment with 41 MeV protons and a 50 μg/cm 212C target at a spectrograph resolution p/d p = 10 4 and 100% duty factor. This corresponds to a gain in L of 546.5 in comparison with the same experiment without a storage ring. In the recirculator mode with acceleration L = 1.17 × 10 32 p/(cm 2 s) and 98.8% duty factor results for 1500 MeV protons on the same target at the same resolution. Using e --cooling L and the feasible p/d p can be enhanced, however, at a reduced duty factor.

  9. Beam properties of UVSOR storage ring

    SciTech Connect

    Kasuga, T.; Hasumoto, M.; Kinoshita, T.; Yonehara, H.

    1985-10-01

    UVSOR constructed at the IMS (Institute for Molecular Science) is an electron storage ring dedicated to synchrotron radiation research in molecular science and its related fields. The first beam was stored on 10th Nov. in 1983. From that time on, efforts have been devoted to improvement of the performance of the ring. During the accelerator studies, some inconvenient phenomena were found. One of the big problems is ion trapping effect. Trapped ions change the operating point and enhance the coupling between horizontal and vertical oscillations. As a result, the beam height is enlarged considerably at high beam current. The beam is shaken slightly in the vertical plane and the electrostatic clearing field is applied to solve this problem. The bunch length is somewhat longer than the expected value. This effect is also a problem to be solved.

  10. APS Storage Ring vacuum chamber fabrication

    SciTech Connect

    Goeppner, G.A.

    1990-01-01

    The 1104-m circumference Advanced Photon Source Storage Ring Vacuum System is composed of 240 individual sections, which are fabricated from a combination of aluminum extrusions and machined components. The vacuum chambers will have 3800 weld joints, each subject to strict vacuum requirements, as well as a variety of related design criteria. The vacuum criteria and chamber design are reviewed, including a discussion of the weld joint geometries. The critical fabrication process parameters for meeting the design requirements are discussed. The experiences of the prototype chamber fabrication program are presented. Finally, the required facilities preparation for construction activity is briefly described. 6 refs., 6 figs., 1 tab.

  11. Smoothing analysis of HLSII storage ring magnets

    NASA Astrophysics Data System (ADS)

    Wang, Wei; He, Xiao-Ye; Tang, Zheng; Yao, Qiu-Yang

    2016-12-01

    Hefei Light Source (HLS) has been upgraded to improve the quality and stability of the synchrotron light, and the new facility is named HLSII. However, a final accurate adjustment is required to smooth the beam orbit after the initial instalment and alignment of the magnets. We implement a reliable smoothing method for the beam orbit of the HLSII storage ring. In addition to greatly smoothing and stabilizing the beam orbit, this method also doubles the work efficiency and significantly reduces the number of magnets adjusted and the range of the adjustments. Supported by National Natural Science Foundation of China (11275192) and the Upgrade Project of Hefei Light Source

  12. Introductory statistical mechanics for electron storage rings

    NASA Astrophysics Data System (ADS)

    Jowett, John M.

    1987-02-01

    These lectures concentrate on statistical phenomena in electron storage rings. A stored electron beam is a dissipative, fluctuating system far from equilibrium whose mathematical description can be based upon non-equilibrium statistical mechanics. Stochastic differential equations are used to describe the quantum fluctuations of synchrotron radiation which is the main cause of randomness in electron dynamics. Fluctuating radiation reaction forces can be described via stochastic terms in Hamilton's equations of motion. Normal modes of particle motion, radiation damping effects, quantum diffusion in single-particle phase space are all discussed in this statistical formalism. (AIP)

  13. An Inside Look: NSLS-II Storage Ring

    SciTech Connect

    Fries, Gregory

    2013-10-21

    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.

  14. An Inside Look: NSLS-II Storage Ring

    ScienceCinema

    Fries, Gregory

    2016-10-19

    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.

  15. Design Considerations for High Energy Electron -- Positron Storage Rings

    DOE R&D Accomplishments Database

    Richter, B.

    1966-11-01

    High energy electron-positron storage rings give a way of making a new attack on the most important problems of elementary particle physics. All of us who have worked in the storage ring field designing, building, or using storage rings know this. The importance of that part of storage ring work concerning tests of quantum electrodynamics and mu meson physics is also generally appreciated by the larger physics community. However, I do not think that most of the physicists working tin the elementary particle physics field realize the importance of the contribution that storage ring experiments can make to our understanding of the strongly interacting particles. I would therefore like to spend the next few minutes discussing the sort of things that one can do with storage rings in the strongly interacting particle field.

  16. Storage ring development at the National Synchrotron Light Source

    SciTech Connect

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

    1991-09-01

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

  17. 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

  18. Introductory statistical mechanics for electron storage rings

    SciTech Connect

    Jowett, J.M.

    1986-07-01

    These lectures introduce the beam dynamics of electron-positron storage rings with particular emphasis on the effects due to synchrotron radiation. They differ from most other introductions in their systematic use of the physical principles and mathematical techniques of the non-equilibrium statistical mechanics of fluctuating dynamical systems. A self-contained exposition of the necessary topics from this field is included. Throughout the development, a Hamiltonian description of the effects of the externally applied fields is maintained in order to preserve the links with other lectures on beam dynamics and to show clearly the extent to which electron dynamics in non-Hamiltonian. The statistical mechanical framework is extended to a discussion of the conceptual foundations of the treatment of collective effects through the Vlasov equation.

  19. 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.

  20. Unicell structure for superconducting storage rings

    SciTech Connect

    Danby, G.; DeVito, B.; Jackson, J.; Keohane, G.; Lee, Y.Y.; Phillips, R.; Plate, S.; Repeta, L.; Skaritka, J.; Smith, L.

    1985-01-01

    Mechanically integrated, magnetically decoupled storage rings were designed for a heavy ion collider for 100 GeV/amu Au, at B = 2.7T. New concepts were developed, including detailed engineering design and cost estimates. A ''unicell'' contains a half-cell of both rings within a single He vessel. The unicell design is optimized for economical mass production. Survey pads welded to the laminations provide external fiducials to locate the magnet cores. Roller bearing self aligning supports accommodate cool-down shrinkage. The design tolerates relative motion of components resulting from longitudinal shrinkage in the approx.15 m long unicell without affecting performance. Magnetic and physical lengths are the same, eliminating waste space. ''Achromatic'' quadrupoles with sextupoles at both ends are located on a common precision beam tube which aligns and supports a pick-up electrode. The unicell accommodates longer dipoles compared to conventional designs, reducing B/sub max/, stored energy, and the volume of iron and superconductor. Applications to future machines will be discussed.

  1. 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.

  2. Measurement of storage ring motion at the advanced light source

    SciTech Connect

    Krebs, G.F.

    1997-05-01

    The mechanical stability of the Advanced Light Source storage ring is examined over a period of 1.5 years from the point of view of floor motion. The storage ring beam position monitor stability is examined under various operating conditions.

  3. A design of a quasi-isochronous storage ring

    SciTech Connect

    Lee, S.Y.; Ng, K.Y.; Trbojevic, D.

    1993-07-01

    Isochronous electron storage rings may offer advantages for future high luminosity meson factories. A Quasi-isochronous lattice based on the design principle of flexible {gamma}{tau} lattice is studied. The emittance and chromatic properties of such a lattice are studied. Applications of this design techniques for electron storage rings will be discussed.

  4. VUV optical ring resonator for Duke storage ring free electron laser

    SciTech Connect

    Park, S.H.; Litvinenko, V.N.; Madey, J.M.J.

    1995-12-31

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

  5. Storage ring mass spectrometry for nuclear structure and astrophysics research

    NASA Astrophysics Data System (ADS)

    Zhang, Y. H.; Litvinov, Yu A.; Uesaka, T.; Xu, H. S.

    2016-07-01

    In the last two and a half decades ion storage rings have proven to be powerful tools for precision experiments with unstable nuclides in the realm of nuclear structure and astrophysics. There are presently three storage ring facilities in the world at which experiments with stored radioactive ions are possible. These are the ESR in GSI, Darmstadt/Germany, the CSRe in IMP, Lanzhou/China, and the R3 storage ring in RIKEN, Saitama/Japan. In this work, an introduction to the facilities is given. Selected characteristic experimental results and their impact in nuclear physics and astrophysics are presented. Planned technical developments and the envisioned future experiments are outlined.

  6. National Synchrotron Light Source II storage ring vacuum systems

    SciTech Connect

    Hseuh, Hsiao-Chaun; Hetzel, Charles; Leng, Shuwei; Wilson, King; Xu, Huijuan; Zigrosser, Douglas

    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, this 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.

  7. 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.

  8. 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

  9. Progress Report on the g-2 Storage Ring Magnet System

    SciTech Connect

    Bunce, G.A.; Cullen, J.; Danby, G.; Green, M.A.; Jackson, J.; Jia, L.; Krienen, F.; Meier, R.; Meng, W.; Morse, W.; Pai, C.; Polk, I.; Prodell, A.; Shutt, R.; Snydstrup, L.; Yamamoto, A.

    1995-06-01

    The 3.1 GeV muon storage ring for the g-2 experiment at Brookhaven National Laboratory has three large solenoid magnets that form a continuous 1.451 tesla storage ring dipole with an average beam bend radius of 7.1 meters. In addition to the three storage ring solenoids, there is an inflector dipole with nested dipole coils that create very little stray magnetic field. A superconducting shield on the inflector gets rid of most of the remaining stray flux. This paper reports on the progress made on the storage ring solenoid magnet system and the inflector as of June 1995. The results of cryogenic system tests are briefly reported.

  10. The performance of the Duke FEL storage ring

    SciTech Connect

    Wu, Y.; Burnham, B.; Litvinenko, V.N.

    1995-12-31

    The commissioning of the Duke FEL storage ring has been completed. During commissioning, we have conducted a series of performance measurements on the storage ring lattice and the electron beam parameters. In this paper, we will discuss the techniques used in the measurements, present measurement results, and compare the measured parameters with the design specifications. In addition, we will present the expected OK-4 FEL performance based on the measured beam parameters.

  11. Storage rings for investigation of ion-atom collisions

    SciTech Connect

    Schuch, R.

    1987-08-01

    In this survey, we give a brief description of synchrotron storage rings for heavy ions, and examples for their use in ion-atom collision physics. The compression of the phase space distribution of the ions by electron cooling, and the gain factors of in-ring experiments compared to single-pass experiments are explained. Some examples of a new generation of ion-atom collision experiments which may become feasible with storage rings are given. These include the studies of angular differential single- and double-electron capture cross sections, the production of slow highly charged recoil ions, and atomic collision processes using decelerated and crossed beam. 30 refs.

  12. Design of a novel electrostatic ion storage ring at KACST

    NASA Astrophysics Data System (ADS)

    El Ghazaly, M. O. A.; Alshammari, S. M.; Welsch, C. P.; Alharbi, H. H.

    2013-05-01

    A new electrostatic storage ring for beams at energies up to 30 keV·q is currently under development at the National Centre for Mathematics and Physics (NCMP), King Abdulaziz City for Science and Technology (KACST). The ring design is based on the existing electrostatic storage rings, but stretches significantly beyond them in that it shall form the core of a unique flexible experimental facility at KACST. The lattice of this ring has been designed in a way that enables the use of state-of-the-art experimental methods to study electron-ion, laser-ion, and ion-neutral beams interactions. The lattice design also allows for a future upgrade of the ring to a double storage ring structure that would enable ion-ion beam interactions to be performed. In this paper, we present the design of this ring with a focus on beam dynamics calculations for the 7° single-bend racetrack layout. The study is principally based on the SIMION8 program. We complemented this study further by using purpose-written routine and MAD-X simulation code. An in-depth investigation into beam stability under consideration of non-linear field components in the electrostatic optical elements, is presented. Finally, different working points and stability regions are discussed.

  13. Status of the Mini-Ring project: a compact electrostatic storage ring

    SciTech Connect

    Bernard, J.; Montagne, G.; Ales, J.; Bredy, R.; Chen, L.; Martin, S.; Cederquist, H.; Schmidt, H.

    2008-12-08

    The idea of building a small, cheap and transportable electrostatic storage ring emerged in the Lyon and Stockholm groups as a collaborative work in the framework of the ITS-LEIF European network. Such a ring could be devoted to experiments where the ring needs to be transported to different facilities that can deliver exotic particles or means of excitation (e.-g. highly charged ions, X--ray synchrotron...). The design of the so-called Mini-Ring and ion trajectory simulations will be presented. First preliminary results have demonstrated the storage of stable Ar{sup +} ion beams in the millisecond time range. The storage time is presently limited by the poor vacuum conditions (P = 2x10{sup -7} mbar) in the chamber, a feature that is going to be improved in the future.

  14. An electrostatic storage ring for atomic and molecular science

    NASA Astrophysics Data System (ADS)

    Tanabe, T.; Chida, K.; Noda, K.; Watanabe, I.

    2002-04-01

    An electrostatic storage ring with a circumference of 8.1 m was designed for the research of atomic and molecular science. The race-track ring consists of two 160° deflectors, four 10° deflectors and four quadrupole doublets. For the 160° deflectors, a cylindrical shape has been adopted. In this ring, there are four types of stable regions with and without waists of the beam envelope in the middle of the deflectors. A beam test was performed with 20-keV ion beams from an ECR ion source. The observed lifetimes of beams stored in each stable region were different under the same conditions, except for the tune values. The lifetimes did not depend much on the injected beam intensity for a current of less than about 100 nA. The design and performance of the electrostatic storage ring are presented.

  15. Beam diagnostics at high-intensity storage rings

    SciTech Connect

    Plum, M. )

    1994-10-10

    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).

  16. Beam diagnostics at high-intensity storage rings

    SciTech Connect

    Plum, M.

    1993-11-01

    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. The author discusses 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 the discussion is inspired by the problems that were encountered and the useful things learned while commissioning and developing the PSR. Another inspiration is the work on the next-generation neutron-spallation source, also known as the National Center for Neutron Research (NCNR).

  17. Higher-order modes in the APS storage ring waveguides

    SciTech Connect

    Brauer, S.O.; Kustom, R.L.

    1993-07-01

    Twelve higher-order modes (HOMs) in the single-cell accelerating cavities for the Advanced Photon Source (APS) storage ring were calculated to have complex impedances that will cause coupled-bunched instabilities near or below the 300mA positron current which is the design goal. Some of these modes couple, through the coupling loop, from the storage ring cavity into the waveguide. This study investigates the transmission of these modes from the cavity into the waveguide. The standing wave ratio (VSWR) of a WR2300 hybrid waveguide component has been measured at each HOM frequency, and its effect on the transmitted modes in the waveguide is studied.

  18. Lattice optimization for the HLS-II storage ring

    NASA Astrophysics Data System (ADS)

    Bai, Zheng-He; Wang, Lin; Jia, Qi-Ka; Li, Wei-Min

    2013-01-01

    The upgrade project of the Hefei Light Source (HLS), named HLS-II, is under way, which includes the reconstruction of its storage ring. The HLS-II storage ring has lower emittance and more straight sections available for insertion devices as compared with the present HLS storage ring. The scan method is applied to the linear lattice optimization for the HLS-II storage ring to get thorough information about the lattice. To reduce the amount of computation, several scans with different grid spacing values are conducted. In addition, the calculation of the chromatic sextupole strength for the achromatic mode is included in the scan, which is useful for nonlinear lattice optimization. To better analyze the obtained solutions in the scan, the lattice properties and the variables of quadrupole strengths are statistically analyzed. The process of selecting solutions is described in detail, including the choice of the working point, the settings for the emittance and optical functions, and the restriction of maximum magnet strength. Two obtained lattices, one for the achromatic mode and the other for the non-achromatic mode, are presented, including their optical functions and optimized dynamic apertures.

  19. DESIGN OF VISIBLE DIAGNOSTIC BEAMLINE FOR NSLS2 STORAGE RING

    SciTech Connect

    Cheng, W.; Fernandes, H.; Hseuh, H.; Kosciuk, B.; Krinsky, S.; Singh, O.

    2011-03-28

    A visible synchrotron light monitor (SLM) beam line has been designed at the NSLS2 storage ring, using the bending magnet radiation. A retractable thin absorber will be placed in front of the first mirror to block the central x-rays. The first mirror will reflect the visible light through a vacuum window. The light is guided by three 6-inch diameter mirrors into the experiment hutch. In this paper, we will describe design work on various optical components in the beamline. The ultra high brightness NSLS-II storage ring is under construction at Brookhaven National Laboratory. It will have 3GeV, 500mA electron beam circulating in the 792m ring, with very low emittance (0.9nm.rad horizontal and 8pm.rad vertical). The ring is composed of 30 DBA cells with 15 fold symmetry. Three damping wigglers will be installed in long straight sections 8, 18 and 28 to lower the emittance. While electrons pass through the bending magnet, synchrotron radiation will be generated covering a wide spectrum. There are other insertion devices in the storage ring which will generate shorter wavelength radiation as well. Synchrotron radiation has been widely used as diagnostic tool to measure the transverse and longitudinal profile. Three synchrotron light beam lines dedicated for diagnostics are under design and construction for the NSLS-II storage ring: two x-ray beam lines (pinhole and CRL) with the source points from Cell 22 BM{_}A (first bending in the DBA cell) and Cell22 three-pole wiggler; the third beam line is using visible part of radiation from Cell 30 BM{_}B (second bending magnet from the cell). Our paper focuses on the design of the visible beam line - SLM.

  20. Development of a longitudinal density monitor for storage rings

    SciTech Connect

    Zolotorev, M.; Beche, J.-F.; Byrd, J.; Datte, P.; De Santis, S.; Denes, P.; Placidi, M.; Ratti, A.; Riot, V.; Schoenlein, R.; Turner, W.

    2003-05-28

    We report on development of a new storage ring operations tool for measurement of longitudinal beam density profile. The technique mixes synchrotron light with light from a mode locked solid-state laser oscillator in a non-linear crystal and detects the up-converted radiation with a photo-multiplier. The laser is phase locked to the storage ring RF system. The laser choices available for repetition frequency, pulse length and phase modulation give a very wide range of options for matching the bunch configuration of particular storage rings. Progress in the technology of solid-state lasers ensures this system can be made robust for routine use in storage ring operations. A very large number of important applications are possible including measurement of the fraction of untrapped particles prior to acceleration, the population of particles in the nominally unfilled RF buckets in a bunch train (''ghost bunches''), longitudinal tails, the diffusion of particles into the beam abort gap and th e normal bunch parameters of longitudinal shape and intensity. We are currently investigating application to two devices: (1) the 1.9 GeV ALS electron storage ring at LBNL with 328 RF buckets, 2ns bucket spacing, 276 nominally filled bunches, 15-30ps rms bunch length and (2) the 7 TeV LHC proton collider under construction at CERN with 35,640 RF buckets, 2.5 ns bucket spacing, 2,808 nominally filled bunches, 280-620 ps rms bunch length. A proof of principle experiment is being conducted on ALS. The results of the ALS experiment and detailed analyses of the application to LHC and its requirements are described.

  1. Experimental determination of storage ring optics using orbit response measurements

    NASA Astrophysics Data System (ADS)

    Safranek, J.

    1997-02-01

    The measured response matrix giving the change in orbit at beam position monitors (BPMs) with changes in steering magnet excitation can be used to accurately calibrate the linear optics in an electron storage ring [1-8]. A computer code called LOCO (Linear Optics from Closed Orbits) was developed to analyze the NSLS X-Ray Ring measured response matrix to determine: the gradients in all 56 quadrupole magnets; the calibration of the steering magnets and BPMs; the roll of the quadrupoles, steering magnets, and BPMs about the electron beam direction; the longitudinal magnetic centers of the orbit steering magnets; the horizontal dispersion at the orbit steering magnets; and the transverse mis-alignment of the electron orbit in each of the sextupoles. Random orbit measurement error from the BPMs propagated to give only 0.04% rms error in the determination of individual quadrupole gradients and 0.4 mrad rms error in the determination of individual quadrupole rolls. Small variations of a few parts in a thousand in the quadrupole gradients within an individual family were resolved. The optics derived by LOCO gave accurate predictions of the horizontal dispersion, the beta functions, and the horizontal and vertical emittances, and it gave good qualitative agreement with the measured vertical dispersion. The improved understanding of the X-Ray Ring has enabled us to increase the synchrotron radiation brightness. The LOCO code can also be used to find the quadrupole family gradients that best correct for gradient errors in quadrupoles, in sextupoles, and from synchrotron radiation insertion devices. In this way the design periodicity of a storage ring's optics can be restored. An example of periodicity restoration will be presented for the NSLS VUV Ring. LOCO has also produced useful results when applied to the ALS storage ring [8].

  2. SECONDARY ELECTRON PRODUCTION AT THE SNS STORAGE RING COLLIMATOR.

    SciTech Connect

    ZHANG,S.Y.

    1999-03-29

    Secondary electron (SE) production is briefly reviewed. If the collimator of the SNS storage ring allows proton beam scraping to take place, the electron yield might be quite large. At the AGS Booster, by steering the Au{sup 31+} ion beam into the electrostatic inflector, beam scraping effect on SE production is studied. The results of this experiment can be translated into the situation of proton beam scraping at the SNS collimator. It seems sufficient to support a new look of the SNS ring collimator design.

  3. Evidences for isochronous behavior in electron and ion storage for a low energy electrostatic storage ring

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    The temporal width of a stored bunch of low energy (~30 eV) electrons circulating in desk-top sized passive electrostatic storage ring has been observed to be unchanging with orbit number. The storage ring has been operated with a range of asymmetric voltages for both stored electron and ion bunches with a particular focus on controllably probing the edges of stable storage regions to explore variations in the temporal widths as a function of storage time. For electron storage an operating condition is identified in which the temporal width approaches a constant value after a period of increase - isochronous behavior. Measurements using stored ions indicate similar behavior can be achieved. Possible mechanisms for the observed behavior are discussed.

  4. The KACST Heavy-Ion Electrostatic Storage Ring

    NASA Astrophysics Data System (ADS)

    Almuqhim, A. A.; Alshammari, S. M.; El Ghazaly, M. O. A.; Papash, A. I.; Welsch, C. P.

    2011-10-01

    A novel Electrostatic Storage Ring (ESR) for beams at energies up to 30keV/q is now being constructed at the National Centre for Mathematics and Physics (NCMP), King Abdul-Aziz City for Science and Technology (KACST). The ring is designed to be the core of a highly flexible experimental platform that will combine a large package of complementary beam techniques for atomic and molecular physics and related fields. The lattice design had to cover the different experimental techniques that the ring will be equipped with, such as e.g. Electron-Ion, Laser-Ion, Ion-Ion or Ion-Neutral beams, in both crossed and merged-beam configurations. The development of such an ESR is realized in a staged approach, in which a simple and early-run adaptation of the ring is built first, and then this basic version is upgraded to a higher symmetry of the ultimate version of the ring. Here, we report a general overview of this technical development with a focus on the layout of the first built stage of the ring.

  5. The KACST Heavy-Ion Electrostatic Storage Ring

    SciTech Connect

    Almuqhim, A. A.; Alshammari, S. M.; El Ghazaly, M. O. A.; Papash, A. I.; Welsch, C. P.

    2011-10-27

    A novel Electrostatic Storage Ring (ESR) for beams at energies up to 30keV/q is now being constructed at the National Centre for Mathematics and Physics (NCMP), King Abdul-Aziz City for Science and Technology (KACST). The ring is designed to be the core of a highly flexible experimental platform that will combine a large package of complementary beam techniques for atomic and molecular physics and related fields. The lattice design had to cover the different experimental techniques that the ring will be equipped with, such as e.g. Electron-Ion, Laser-Ion, Ion-Ion or Ion-Neutral beams, in both crossed and merged-beam configurations. The development of such an ESR is realized in a staged approach, in which a simple and early-run adaptation of the ring is built first, and then this basic version is upgraded to a higher symmetry of the ultimate version of the ring. Here, we report a general overview of this technical development with a focus on the layout of the first built stage of the ring.

  6. Storage Ring Measurements of Electron Impact Ionization for Solar Physics

    NASA Astrophysics Data System (ADS)

    Hahn, Michael; Becker, A.; Bernhardt, D.; Grieser, M.; Krantz, C.; Lestinsky, M.; Müller, A.; Novotný, O.; Repnow, R.; Schippers, S.; Spruck, K.; Wolf, A.; Savin, D. W.

    2013-07-01

    The interpretation of astrophysical spectra requires knowledge of the charge state distribution (CSD) of the plasma. The CSD is determined by the rates of ionization and recombination. Thus, accurate electron impact ionization (EII) data are needed to calculate the CSD of the solar atmosphere as well as for other electron-ionized astrophysical objects, such as stars, supernovae, galaxies, and clusters of galaxies. We are studying EII for astrophysically important ions using the TSR storage ring located at the Max Plank Institute for Nuclear Physics in Heidelberg, Germany. Storage ring measurements are largely free of the metastable contamination found in other experimental geometries, resulting in unambiguous EII data. We have found discrepancies of about 10% - 30% between our measured cross sections and those commonly used in CSD models. Because it is impractical to perform experimental measurements for every astrophysically relevant ion, theory must provide the bulk of the necessary EII data. These experimental results provide an essential benchmark for such EII calculations.

  7. Lattice study for the HLS-II storage ring

    NASA Astrophysics Data System (ADS)

    Bai, Zheng-He; Wang, Lin; Jia, Qi-Ka; Li, Wei-Min

    2013-04-01

    The Hefei Light Source (HLS) is undergoing a major upgrade project, named HLS- II, in order to obtain lower emittance and more insertion device straight sections. Undulators are the main insertion devices in the HLS- II storage ring. In this paper, based on the database of lattice parameters built for the HLS- II storage ring obtained by the global scan method, we use the quantity related to the undulator radiation brightness to more directly search for high brightness lattices. Lattice solutions for achromatic and non-achromatic modes are easily found with lower emittance, smaller beta functions at the center of the insertion device straight sections and lower dispersion in nonzero dispersion straight sections compared with the previous lattice solutions. In this paper, the superperiod lattice with alternating high and low horizontal beta functions in long straight sections for the achromatic mode is studied using the multiobjective particle swarm optimization algorithm.

  8. Global coupling and decoupling of the APS storage ring

    SciTech Connect

    Chae, Y.C.; Liu, J.; Teng, L.C.

    1993-07-01

    This paper describes a study of controlling the coupling between the horizontal and the vertical betatron oscillations in the 7-GeV Advanced Photon Source (APS) storage ring. First, we investigate the strengthening of coupling using two families of skew quadrupoles. Twenty skew quadrupoles are arranged in the 40 sectors of the storage ring and powered in such a way so as to generate both quadrature components of the required 21st harmonic. The numerical results from tracking a single particle are presented for the various configurations of skew quadrupoles. Second, we describe the global decoupling procedure to minimize the unwanted coupling effects. These are mainly due to the random roll errors of normal quadruples. It is shown that even with the rather large rms roll error of 2 mrad, the coupling effects can be compensated for with 20 skew quadrupoles each having maximum strength one order of magnitude lower than the typical normal quadrupole strength.

  9. 40-{angstrom} FEL designs for the PEP storage ring

    SciTech Connect

    Fisher, A.S.; Gallardo, J.C.; Nuhn, H.D.; Tatchyn, R.; Winick, H.; Pellegrini, C.

    1991-12-31

    We explore the use of the 2.2-km PEP storage ring at SLAC to drive a 40-{Angstrom} free-electron laser in the self-amplified spontaneous emission configuration. Various combinations for electron-beam and undulator parameters, as well as special undulator designs, are discussed. Saturation and high peak, in-band, coherent power (460 MW) are possible with a 67-m, hybrid permanent-magnet undulator in a ring bypass. A 100-m, cusp-field undulator can achieve high average, in-band, coherent power (0.25 W) in the main ring. The existing, 25.6-m, Paladin undulator at LLNL, with the addition of optical-klystron dispersive sections, is considered for both peak and average power. 35 refs., 4 figs., 1 tab.

  10. 40- angstrom FEL designs for the PEP storage ring

    SciTech Connect

    Fisher, A.S.; Gallardo, J.C. ); Nuhn, H.D.; Tatchyn, R.; Winick, H. . Stanford Synchrotron Radiation Lab.); Pellegrini, C. . Dept. of Physics)

    1991-01-01

    We explore the use of the 2.2-km PEP storage ring at SLAC to drive a 40-{Angstrom} free-electron laser in the self-amplified spontaneous emission configuration. Various combinations for electron-beam and undulator parameters, as well as special undulator designs, are discussed. Saturation and high peak, in-band, coherent power (460 MW) are possible with a 67-m, hybrid permanent-magnet undulator in a ring bypass. A 100-m, cusp-field undulator can achieve high average, in-band, coherent power (0.25 W) in the main ring. The existing, 25.6-m, Paladin undulator at LLNL, with the addition of optical-klystron dispersive sections, is considered for both peak and average power. 35 refs., 4 figs., 1 tab.

  11. Sub-nm emittance lattice design for CANDLE storage ring

    NASA Astrophysics Data System (ADS)

    Sargsyan, A.; Zanyan, G.; Sahakyan, V.; Tsakanov, V.

    2016-10-01

    The most effective way to increase the brilliance of synchrotron light sources is the reduction of beam emittance. Following the recent developments in low emittance lattice design, a new sub-nm emittance lattice based on implementation of multi-band achromat concept and application of longitudinal gradient bending magnets was developed for CANDLE storage ring. The paper presents the main design considerations, linear and non-linear beam dynamics aspects of the new lattice proposed.

  12. A new method for beam stacking in storage rings

    SciTech Connect

    Bhat, C.M.; /Fermilab

    2008-06-01

    Recently, I developed a new beam stacking scheme for synchrotron storage rings called 'longitudinal phase-space coating' (LPSC). This scheme has been convincingly validated by multi-particle beam dynamics simulations and has been demonstrated with beam experiments at the Fermilab Recycler. Here, I present the results from both simulations and experiments. The beam stacking scheme presented here is the first of its kind.

  13. Multi-objective dynamic aperture optimization for storage rings

    NASA Astrophysics Data System (ADS)

    Li, Yongjun; Yang, Lingyun

    2016-11-01

    We report an efficient dynamic aperture (DA) optimization approach using multi-objective 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.

  14. A transverse electron target for heavy ion storage rings

    SciTech Connect

    Geyer, Sabrina Meusel, Oliver; Kester, Oliver

    2015-01-09

    Electron-ion interaction processes are of fundamental interest for several research fields like atomic and astrophysics as well as plasma applications. To address this topic, a transverse electron target based on the crossed beam technique was designed and constructed for the application in storage rings. Using a sheet beam of free electrons in crossed beam geometry promises a good energy resolution and gives access to the interaction region for spectroscopy. The produced electron beam has a length of 10 cm in ion beam direction and a width in the transverse plane of 5 mm. Therewith, electron densities of up to 10{sup 9} electrons/cm{sup 3} are reachable in the interaction region. The target allows the adjustment of the electron beam current and energy in the region of several 10 eV to a few keV. Simulations have been performed regarding the energy resolution for electron-ion collisions and its influence on spectroscopic measurements. Also, the effect on ion-beam optics due to the space charge of the electron beam was investigated. Presently the electron target is integrated into a test bench to evaluate its performance for its dedicated installation at the storage rings of the FAIR facility. Therefore, optical diagnostics of the interaction region and charge state analysis with a magnetic spectrometer is used. Subsequently, the target will be installed temporarily at the Frankfurt Low-Energy Storage Ring (FLSR) for further test measurements.

  15. RF stations of the SPring-8 storage ring

    NASA Astrophysics Data System (ADS)

    Hara, M.; Ego, H.; Kawashima, Y.; Ohashi, Y.; Ohshima, T.; Takashima, T.

    1997-05-01

    Construction of three RF stations in the storage ring of SPring-8 has been completed. Twenty four single-cell cavities of which inside dimensions are trimmed completely systematically were installed in the storage ring. A group of eight single-cell cavities as a component of the storage ring is occupied in an RF station. A series of processes such as installation of couplers, evacuation, baking and connection of waveguides were carried out. Three klystrons and their power equipments were also installed. Low power control system which includes tuner control, feedback such as phase lock loop and keeping voltage in a cavity constant was constructed and tuned. From August to December in 1996, high power test up to 800 kW were carried out in each RF station without serious trouble and particularly it was verified that water cooling system for cavity could keep the water temperature in the range of 29.89 to 30.15 degrees. But some bugs on klystron power equipments were found. We report on the construction processes and the results of high power test.

  16. Compensation for booster leakage field in the Duke storage ring

    NASA Astrophysics Data System (ADS)

    Li, Wei; Hao, Hao; Mikhailov, Stepan F.; Popov, Victor; Li, Wei-Min; Wu, Ying. K.

    2017-01-01

    The High Intensity Gamma-ray Source (HIGS) at Duke University is an accelerator-driven Compton gamma-ray source, providing high flux gamma-ray beam from 1 MeV to 100 MeV for photo-nuclear physics research. The HIGS facility operates three accelerators, a linac pre-injector (0.16 GeV), a booster injector (0.16—1.2 GeV), and an electron storage ring (0.24—1.2 GeV). Because of the proximity of the booster injector to the storage ring, the magnetic field of the booster dipoles close to the ring can significantly alter the closed orbit in the storage ring being operated in the low energy region. This type of orbit distortion can be a problem for certain precision experiments which demand a high degree of energy consistency of the gamma-ray beam. This energy consistency can be achieved by maintaining consistent aiming of the gamma-ray beam, and therefore a steady electron beam orbit and angle at the Compton collision point. To overcome the booster leakage field problem, we have developed an orbit compensation scheme. This scheme is developed using two fast orbit correctors and implemented as a feedforward which is operated transparently together with the slow orbit feedback system. In this paper, we will describe the development of this leakage field compensation scheme, and report the measurement results, which demonstrate the effectiveness of the scheme. Supported by National Natural Science Foundation of China (11175180, 11475167) and US DOE (DE-FG02-97ER41033)

  17. Future Synchrotron Light Sources Based on Ultimate Storage Rings

    SciTech Connect

    Cai, Yunhai; /SLAC

    2012-04-09

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

  18. Measurements of the electron cloud in the APS storage ring.

    SciTech Connect

    Harkey, K. C.

    1999-04-16

    Synchrotron radiation interacting with the vacuum chamber walls in a storage ring produce photoelectrons that can be accelerated by the beam, acquiring sufficient energy to produce secondary electrons in collisions with the walls. If the secondary-electron yield (SEY) coefficient of the wall material is greater than one, as is the case with the aluminum chambers in the Advanced Photon Source (APS) storage ring, a runaway condition can develop. As the electron cloud builds up along a train of stored positron or electron bunches, the possibility exists that a transverse perturbation of the head bunch will be communicated to trailing bunches due to interaction with the cloud. In order to characterize the electron cloud, a special vacuum chamber was built and inserted into the ring. The chamber contains 10 rudimentary electron-energy analyzers, as well as three targets coated with different materials. Measurements show that the intensity and electron energy distribution are highly dependent on the temporal spacing between adjacent bunches and the amount of current contained in each bunch. Furthermore, measurements using the different targets are consistent with what would be expected based on the SEY of the coatings. Data for both positron and electron beams are presented.

  19. Los Alamos high-current proton storage ring

    NASA Astrophysics Data System (ADS)

    Lawrence, G. P.; Hardekopf, R. A.; Jason, A. J.; Clout, P. N.; Sawyer, G. A.

    1985-05-01

    The Proton Storage Ring (PSR), whose installation was recently completed at Los Alamos, is a fast-cycling high-current accumulator designed to produce intense 800 MeV proton pulses for driving a spallation neutron source. The ring converts long beam pulses from the LAMPF linear accelerator into short bunches well matched to requirements of a high-resolution neutron-scattering materials science program. The initial performance goal for this program is to provide 100-(MU)A average current at the neutron production target within a 12-Hz pulse rate. Operation at 20 (MU)A is scheduled for September 1985, with full intensity within the next year. The storage ring was originally designed to function in a second mode in which six 1-ns bunches are accumulated and separately extracted every LAMPF macropulse. Implementation of this mode, which would serve a fast-neutron nuclear-physics program, was deferred in favor of initial concentration on the neutron-scattering program. The PSR design and status is summarized. Unique machine features include high peak current, two-step charge-stripping injection, a low-impedance buncher amplifier to counter beam-loading, and a high-repetition-rate strip-line extraction kicker.

  20. Beam Loss Monitors for NSLS-II Storage Ring

    SciTech Connect

    Kramer, S.L.; Cameron, P.

    2011-03-28

    The shielding for the NSLS-II storage ring will provide adequate protection for the full injected beam losses in two cells of the ring around the injection point, but the remainder of the ring is shielded for lower losses of <10% top-off injection beam current. This will require a system to insure that beam losses do not exceed levels for a period of time that could cause excessive radiation exposure outside the shield walls. This beam Loss Control and Monitoring system will have beam loss monitors that will measure where the beam charge is lost around the ring, to warn operators if losses approach the design limits. To measure the charge loss quantitatively, we propose measuring the electron component of the shower as beam electrons hit the vacuum chamber (VC) wall. This will be done using the Cerenkov light as electrons transit ultra-pure fused silica rods placed close to the inner edge of the VC. The entire length of the rod will collect light from the electrons of the spread out shower resulting from the small glancing angle of the lost beam particles to the VC wall. The design and measurements results of the prototype Cerenkov BLM will be presented.

  1. Ionization cooling in a low-energy proton storage ring

    SciTech Connect

    Neuffer, David V.; /Fermilab

    2006-03-01

    At the FFAG05 meeting, Mori and Okabe presented a scenario in which the lifetime of protons in a low-energy storage ring ({approx}10 MeV) is extended by energy-loss in a wedge foil, and this enables greater neutron production from the foil. The lifetime extension is due to the cooling effect of this energy loss. We have previously analyzed ionization cooling for muons at optimal cooling energies. The same equations, with appropriate adaptations, can be used to analyze the dynamic situation for proton-material interactions at low energies. In this note we discuss this extension and calculate cooling and heating effects at these very different parameters. The ring could provide a practical application of ionization cooling methods.

  2. Nomenclature and name assignment rules for the APS storage ring

    SciTech Connect

    Decker, G.

    1992-03-16

    Because the APS accelerators are moving into the fabrication/assembly/installation stage, it is important for consistent naming conventions to be used throughout the project. The intent of this note is to dictate the rules to be adhered to when naming devices in the storage ring. These rules are generic in nature, and shall be applied in principle to the other machines as well. It is essential that every component have a unique and, hopefully, easily recognizable name. Every ASD and XFD group, except for magnets, must interface with the control system. For this reason all device names were developed keeping in mind their actual function, such as controlling or monitoring some device in the ring. Even though magnets are not directly interfaced to the control system, their power supplies are; therefore, a magnet will have the same name as its associated power supply.

  3. ELASR - An electrostatic storage ring for atomic and molecular physics at KACST

    NASA Astrophysics Data System (ADS)

    El Ghazaly, Mohamed O. A.

    A new ELectrostAtic Storage Ring (ELASR) has been designed and built at the King Abdulaziz City for Science and Technology (KACST), in Riyadh, Saudi Arabia. It was developed to be the core of a new storage ring laboratory for atomic and molecular physics at KACST. ELASR follows the standard design of the pioneering storage ring ELISA and it thereby features a racetrack single-bend shaped ring. Complementary simulation code packages were used to work out the design under the requirements of the projected experiments. This paper reports a short description of the ELASR storage ring through an overview of its design and construction.

  4. Ultra Cold Photoelectron Beams for Ion Storage Rings

    SciTech Connect

    Orlov, D. A.; Krantz, C.; Shornikov, A.; Lestinsky, M.; Hoffmann, J.; Wolf, A.; Jaroshevich, A. S.; Kosolobov, S. N.; Terekhov, A. S.

    2009-08-04

    An ultra cold electron target with a cryogenic GaAs photocathode source, developed for the Heidelberg TSR, delivers electron currents up to a few mA with typical kinetic energies of few keV and provides unprecedented energy resolution below 1 meV for electron-ion recombination merged-beam experiments. For the new generation of low-energy electrostatic storage rings, cold electron beams from a photocathode source can bring additional benefits, improving the cooling efficiency of stored ions and making it possible to cool even heavy, slow molecules by electron beams of energies of only a few eV or even below.

  5. Analysis ob beam losses at PSR (Proton Storage Ring)

    SciTech Connect

    Macek, R.J.; Fitzgerald, D.H.; Hutson, R.L.; Plum, M.A.; Thiessen, H.A.

    1988-01-01

    Beam losses and the resulting component activation at the Los Alamos Proton Storage Ring (PSR) have limited operating currents to about 30..mu..A average at a repetition rate of 15 Hz. Loss rates were found to be approximately proportional to the circulating current and can be understood by a detailed accounting of emittance growth in the two step injection process along with Coulomb scattering of the stored beam during multiple traversals of the injection foil. Calculations and simulations of the losses are in reasonable agreement with measurements.

  6. Manufacture of the ALS storage ring vacuum system

    NASA Astrophysics Data System (ADS)

    Kennedy, Kurt

    1991-08-01

    The Advanced Light Source (ALS) storage ring has a 4.9 meter magnetic radius and an antechamber type vacuum chamber. These two requirements makes conventional bent tube manufacturing techniques difficult. The ALS sector vacuum chambers have been made by machining two halves out of aluminum plate and welding at the mid plane. Each of these chambers have over 50 penetrations with metal sealed flanges and seven metal sealed poppet valves which use the chamber wall as the valve seat. The sector chambers are 10 meters long and some features in the chambers must be located to .25 mm. This paper describes how and how successfully these features have been achieved.

  7. Application of permanent magnets in accelerators and electron storage rings

    NASA Astrophysics Data System (ADS)

    Halbach, K.

    1985-04-01

    The use of permanent-magnet systems in high-energy accelerators and as sources of synchrotron radiation in electron-storage rings is discussed in a review of recent experimental investigations. Consideration is given to the generic advantages of permanent magnets over electromagnets (higher field strength per magnet size) in small-scale configurations; the magnetic properties of some charge-sheet-equivalent-permanent-magnet materials (CSEMs); and the design of pure-CSEM and CSEM-Fe-hybrid multipole magnetic lenses, dipoles, and undulator/wiggler systems for use in free-electron lasers and the production of elliptically polarized synchrotron light. Drawings and diagrams are provided.

  8. Geometric phase of atoms in a magnetic storage ring

    SciTech Connect

    Zhang, P.; You, L.

    2006-12-15

    A magnetically trapped atom experiences an adiabatic geometric (Berry's) phase due to changing field direction. We investigate theoretically such an Aharonov-Bohm-like geometric phase for atoms adiabatically moving inside a storage ring as demonstrated in several recent experiments. Our result shows that this phase shift is easily observable in a closed-loop interference experiment, and thus the shift has to be accounted for in the proposed inertial sensing applications. The spread in phase shift due to the atom transverse distribution is quantified through numerical simulations.

  9. Optical distortions in electron/positron storage rings

    SciTech Connect

    Brown, K.L.; Donald, M.; Servranckx, R.

    1983-01-01

    We have studied the optical distortions in the PEP electron/positron storage ring for various optical configurations using the computer programs DIMAT, HARMON, PATRICIA, and TURTLE. The results are shown graphically by tracing several thousand trajectories from one interaction region to the next using TURTLE and by tracing a few selected rays several hundred turns using the programs DIMAT and PATRICIA. The results show an interesting correlation between the calculated optical cleanliness of a particular lattice configuration and the observed operating characteristics of the machine.

  10. 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

  11. Beam-based modeling and control of storage rings

    NASA Astrophysics Data System (ADS)

    Safranek, J.

    1997-05-01

    Analysis of the measured orbit response matrix is a powerful technique for debugging the linear optics of storage rings. The orbit response matrix is the change in orbit at the beam position monitors (BPMs) with changes in steering magnet excitation. Results will be presented from a computer code called LOCO (Linear Optics from Closed Orbits) that has been used to analyze the response matrices from several synchrotron light sources including the ALS, APS, NSLS VUV, NSLS X-Ray, and SRRC storage rings. The analysis accurately determines the individual quadrupole magnet gradients as well as the gains of BPMs and the calibrations of the steering magnets. The coupling terms of the response matrix such as the shift in vertical orbit from horizontal steering magnets can be included in the analysis to give the role of the quadrupoles, BPMs and steering magnets. The LOCO code can also be used to find the changes in quadrupole gradient that best compensate for gradient errors from insertion devices and sextupoles. In this way the design periodicity of the linear optics can be restored.

  12. Upgrade of BPM Electronics for the SPring-8 Storage Ring

    SciTech Connect

    Sasaki, Shigeki; Fujita, Takahiro; Shoji, Masazumi; Takashima, Takeo

    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 and 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.

  13. CIRCE: A dedicated storage ring for coherent THz synchrotron radiation

    SciTech Connect

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

    2003-08-12

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

  14. Beam Loss Control for the NSLS-II Storage Ring

    SciTech Connect

    Kramer, S.L.; Choi, J.

    2011-03-28

    The shielding design for the NSLS-II storage ring is designed for the full injected beam losses in two periods of the ring around the injection point, but for the remainder of the ring its shielded for {le} 10% top-off injection beam. This will require a system to insure that beam losses do not exceed these levels for time sufficient to cause excessive radiation exposure outside the shield walls. This beam Loss Control and Monitoring (LCM) system will control the beam losses to the more heavily shielded injection region while monitoring the losses outside this region. To achieve this scrapers are installed in the injection region to intercept beam particles that might be lost outside this region. The scrapers will be thin (< 1Xrad) that will allow low energy electrons to penetrate and the subsequent dipole will separate them from the stored beam. These thin scrapers will reduce the radiation from the scraper compared to thicker scrapers. The dipole will provide significant local shielding for particles that hit inside the gap and a source for the loss monitor system that will measure the amount of beam lost in the injection region.

  15. An electrostatic storage ring for atomic and molecular physics, at KACST - a status report

    NASA Astrophysics Data System (ADS)

    El Ghazaly, Mohamed O. A.

    2015-01-01

    An electrostatic storage ring has been designed following the pioneering storage ring ELISA [1], and it is currently being built as a new core laboratory for atomic and molecular collisions at the King Abdulaziz City for Science and Technology (KACST), in Riyadh, Saudi Arabia. In this paper, the design of the electrostatic storage ring together with an outline on the status of the construction are given.

  16. Status and upgrade of the VEPP-4 storage-ring facility

    NASA Astrophysics Data System (ADS)

    Levichev, E. B.

    2016-12-01

    The VEPP-4 facility is an e + e - collider with a beam energy up to 2 GeV. The scientific program includes topics in high-energy and nuclear physics, as well as various investigations using synchrotron radiation and polarized or unpolarized charged-particle beams. An energy upgrade to 5 GeV is planned, and reliable and efficient operation of the storage-ring complex upon increased energy must be provided. We discuss the recent experimental results and the opportunities to be created by the energy upgrade.

  17. A Linear Theory of Microwave Instability in Electron Storage Rings

    SciTech Connect

    Cai, Yunhai; /SLAC

    2011-07-06

    The well-known Haissinski distribution provides a stable equilibrium of longitudinal beam distribution in electron storage rings below a threshold current. Yet, how to accurately determine this threshold, above which the Haissinski distribution becomes unstable, is not firmly established in theory. In this paper, we will show how to apply the Laguerre polynomials in an analysis of this stability that are associated with the potential-well distortion. Our approach provides an alternative to the discretization method proposed by Oide and Yokoya. Moreover, it reestablishes an essential connection to the theory of mode coupling originated by Sacherer. Our new and self-consistent method is applied to study the microwave instability driven by commonly known impedances, including coherent synchrotron radiation in free space.

  18. Coupling measurement and correction at the SSRF storage ring

    NASA Astrophysics Data System (ADS)

    Zhang, ManZhou; Hou, Jie; Li, HaoHu

    2011-12-01

    Brightness is an important parameter for 3rd generation light source. Correcting the emittance coupling is a realistic way to increase brightness without any additional equipment in a machine under operation. The main sources of emittance coupling are betatron coupling and vertical dispersion. At the SSRF storage ring, tune split and LOCO are used to measure the respective betatron and emittance coupling. Both of these sources can be corrected by skew quadrupoles. By measuring the skew quadrupole-coupling response matrix, betatron coupling can be changed from 0.014% to 2%. But the vertical dispersion changes at the same time. LOCO can find the suitable setting to correct simultaneously the betatron coupling and vertical dispersion. The emittance coupling can be reduced to 0.17% by this method. More simulations show the potential for smaller emittance coupling if more skew quadrupoles are employed.

  19. The magnet design for the HLS storage ring upgrade project

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Li, Wei-Min; Feng, Guang-Yao; Wang, Lin; Zhang, Shan-Cai; Li, Wei; Liang, Jun-Jun

    2012-01-01

    In order to improve the performance of the Hefei Light Source (HLS), in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices, an upgrade project called HLSII will be launched soon. The storage ring lattice, which has a double bend achromatic structure with four periods, comprises eight dipoles, 32 quadrupoles and 32 combined function sextupoles. The design and analysis of the magnets are shown in this paper, along with the optimization of the multipurpose combined function magnet, which consists of three magnets: skew quadrupole, horizontal dipole and vertical dipole, with the main sextupole magnet. This type of magnet is the first one that has been designed and used in China. The mechanical design and fabrication procedures for the magnets are also presented.

  20. Impedance Calculations for the NSLS-II Storage Rings

    SciTech Connect

    Blednykh,A.; Ferreira, M.; Krinsky, S.

    2009-05-04

    Impedance of two vacuum chamber components, Bellows and BPM, is considered in some detail. In order to avoid generation of Higher-Order Modes (HOM's) in the NSLS-II bellows, we designed a new low-impedance RF shielding consisting of 6 wide and 2 narrow metal plates without opening slots between them. The short-range wakepotential has been optimized taking into account vertical offset of RF fingers from their nominal position. The results were compared with data of bellows designed at other laboratories. Narrow-band impedance of the BPM Button has been studied. TE-modes in the BPM button were suppressed by a factor of 8 by modification of existing housings. Two new types of housings are shown. The total impedance of the NSLS-II storage ring is discussed in terms of the loss factor and the vertical kick factor for a 3mm-Gaussian bunch.

  1. Proceedings of the workshop on polarized targets in storage rings

    SciTech Connect

    Holt, R.J.

    1984-08-01

    Polarization phenomena have played an increasingly important part in the study of nuclei and nucleons in recent years. Polarization studies have been hampered by the relatively few and rather fragile polarized targets which are presently available. The concept of polarized gas targets in storage rings opens a much wider range of possibilities than is available in the external target geometry. This novel method will represent a considerable advance in nuclear physics and will continue to receive much attention in plans for future facilities. An internal, polarized-target station is being planned for the cooler ring at the Indiana University Cyclotron Facility. Internal targets are compatible with recent designs of electron accelerators proposed by the Massachusetts Institute of Technology and the Southeastern Universities Research Association. The key to nuclear-science programs based on internal targets pivots on recent developments in polarized atomic beam methods, which include the more recent laser-driven polarized targets. The workshop drew together a unique group of physicists in the fields of high-energy, nuclear and atomic physics. The meeting was organized in a manner that stimulated discussion among the 58 participants and focused on developments in polarized target technology and the underlying atomic physics. An impressive array of future possibilities for polarized targets as well as current developments in polarized target technology were discussed at the workshop. Abstracts of individual items from the workshop were prepared separately for the data base.

  2. Electron clearing in the Los Alamos Proton Storage Ring

    SciTech Connect

    Plum, M.A.; Allen, J.; Borden, M.J.; Fitzgerald, D.H.; Macek, R.J.; Wang, T.S.

    1995-05-01

    The instability observed in the Los Alamos Proton Storage Ring (PSR) has been tentatively identified as an electron-proton instability. A source of electrons must exist for this instability to occur. The PSR injection section contains the stripper foil, and therefore provides several strong sources of electrons. An electron clearing system was installed in the injection section to clear out these electrons. The system comprised: (1) a foil biasing system to clear the SEM and thermionic electrons, (2) a pair of low-field bending magnets with a Faraday cup to clear the convoy electrons, and (3) two pairs of clearing electrodes, one upstream and one downstream of the stripper foil, to clear the remaining electrons. This paper discusses the design and performance of the Electron Clearing System, and its effect on the instability. Also presented are some results from other charge-collection experiments that suggest there is also substantial electron production in parts of the ring other than the injection section.

  3. Compton backscattering of intracavity storage ring free-electron laser radiation

    SciTech Connect

    Dattoli, G.; Giannessi, L.; Torre, A.

    1995-12-31

    We discuss the{gamma}-ray production by Compton backscattering of intracavity storage ring Free-Electron Laser radiation. We use a semi-analytical model which provides the build up of the signal combined with the storage ring damping mechanism and derive simple relations yielding the connection between backscattered. Photons brightness and the intercavity laser equilibrium intensity.

  4. Mass and lifetime measurements of exotic nuclei in storage rings.

    PubMed

    Franzke, Bernhard; Geissel, Hans; Münzenberg, Gottfried

    2008-01-01

    Mass and lifetime measurements lead to the discovery and understanding of basic properties of matter. The isotopic nature of the chemical elements, nuclear binding, and the location and strength of nuclear shells are the most outstanding examples leading to the development of the first nuclear models. More recent are the discoveries of new structures of nuclides far from the valley of stability. A new generation of direct mass measurements which allows the exploration of extended areas of the nuclear mass surface with high accuracy has been opened up with the combination of the Experimental Storage Ring ESR and the FRragment Separator FRS at GSI Darmstadt. In-flight separated nuclei are stored in the ring. Their masses are directly determined from the revolution frequency. Dependent on the half-life two complementary methods are applied. Schottky Mass Spectrometry SMS relies on the measurement of the revolution frequency of electron cooled stored ions. The cooling time determines the lower half-life limit to the order of seconds. For Isochronous Mass Spectrometry IMS the ring is operated in an isochronous ion-optical mode. The revolution frequency of the individual ions coasting in the ring is measured using a time-of-flight method. Nuclides with lifetimes down to microseconds become accessible. With SMS masses of several hundreds nuclides have been measured simultaneously with an accuracy in the 2 x 10(-7)-range. This high accuracy and the ability to study large areas of the mass surface are ideal tools to discover new nuclear structure properties and to guide improvements for theoretical mass models. In addition, nuclear half-lives of stored bare and highly charged ions have been measured. This new experimental development is a significant progress since nuclear decay characteristics are mostly known for neutral atoms. For bare and highly charged ions new nuclear decay modes become possible, such as bound-state beta decay. Dramatic changes in the nuclear lifetime

  5. Steady State Analysis of Short-wavelength, High-gainFELs in a Large Storage Ring

    SciTech Connect

    Huang, Z.; Bane, K.; Cai, Y.; Chao, A.; Hettel, R.; Pellegrini, C.; /UCLA

    2007-10-15

    Storage ring FELs have operated successfully in the low-gain regime using optical cavities. Discussions of a high-gain FEL in a storage ring typically involve a special bypass to decouple the FEL interaction from the storage ring dynamics. In this paper, we investigate the coupled dynamics of a high-gain FEL in a large storage ring such as PEP and analyze the equilibrium solution. We show that an FEL in the EUV and soft x-ray regimes can be integrated into a very bright storage ring and potentially provides three orders of magnitude improvement in the average brightness at these radiation wavelengths. We also discuss possibilities of seeding with HHG sources to obtain ultra-short, high-peak power EUV and soft x-ray pulses.

  6. Central RF frequency measurement of the HLS-II storage ring

    NASA Astrophysics Data System (ADS)

    Zheng, Jia-Jun; Yang, Yong-Liang; Sun, Bao-Gen; Wu, Fang-Fang; Cheng, Chao-Cai; Tang, Kai; Wei, Jun-Hao

    2016-04-01

    Central RF frequency is a key parameter of storage rings. This paper presents the measurement of central RF frequency of the HLS-II storage ring with the sextupole modulation method. Firstly, the basis of central RF frequency measurement of the electron storage ring is briefly introduced. Then, the error sources and the optimized measurement method for the HLS-II storage ring are discussed. The workflow of a self-compiled Matlab script used in central RF frequency measurement is also described. Finally, the results achieved by using two data processing methods to cross-check each other are shown. The measured value of the central RF frequency demonstrates that the circumference deviation of the HLS-II storage ring is less than 1 mm. Supported by National Natural Science Foundation of China (11105141, 11175173) and the upgrade project of Hefei Light Source

  7. Initial scientific uses of coherent synchrotron radiation inelectron storage rings

    SciTech Connect

    Basov, D.N.; Feikes, J.; Fried, D.; Holldack, K.; Hubers, H.W.; Kuske, P.; Martin, M.C.; Pavlov, S.G.; Schade, U.; Singley, E.J.; Wustefeld, G.

    2004-11-23

    The production of stable, high power, coherent synchrotron radiation at sub-terahertz frequency at the electron storage ring BESSY opens a new region in the electromagnetic spectrum to explore physical properties of materials. Just as conventional synchrotron radiation has been a boon to x-ray science, coherent synchrotron radiation may lead to many new innovations and discoveries in THz physics. With this new accelerator-based radiation source we have been able to extend traditional infrared measurements down into the experimentally poorly accessible sub-THz frequency range. The feasibility of using the coherent synchrotron radiation in scientific applications was demonstrated in a series of experiments: We investigated shallow single acceptor transitions in stressed and unstressed Ge:Ga by means of photoconductance measurements below 1 THz. We have directly measured the Josephson plasma resonance in optimally doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} for the first time and finally we succeeded to confine the sub-THz radiation for spectral near-field imaging on biological samples such as leaves and human teeth.

  8. Design of the muon collider isochronous storage ring lattice

    NASA Astrophysics Data System (ADS)

    Trbojevic, D.; Ng, K. Y.; Courant, E. D.; Lee, S. Y.; Johnstone, C.; Gallardo, J.; Palmer, R.; Tepikian, S.

    1996-04-01

    The muon collider would extend the limitations of e+ e- colliders and provide new physics potentials, with possible discovery of the heavy Higgs bosons. At the maximum energy of 2 TeV the projected luminosity is of the order of 1035 cm-2 s-1. The colliding μ+ μ- bunches have to be focused to a very small transverse size of 2.8 μm, which is accomplished by the betatron functions at the crossing point of β*=3 mm. This requires a longitudinal space of the same length, 3 mm. These very short bunches at 2 TeV could circulate only in a quasi-isochronous storage ring where the momentum compaction is very close to zero. We report on a design of a muon collider isochronous lattice. The momentum compaction is brought to zero by having the average value of the dispersion function through dipoles equal to zero. This is accomplished by a combination of FODO cells with a low-beta insertion. The dispersion function oscillates between negative and positive values.

  9. Variable input coupler design for storage ring cavities

    SciTech Connect

    Kang, Y.W.; Kustom, R.L.

    1995-08-18

    Magnetic loop type input couplers are used for coupling rf power from waveguides to the storage ring cavities: In a high rf power and high beam current accelerating cavity, the change in beam loading results in high reflected power due to input rf mismatch. The coupler can be matched for a specific loading condition, but cannot be matched in other conditions. The input mismatch results in poor rf power efficiency and overheating of the ceramic window in the coupler. Therefore, coupling through the coupling loop must be adjustable for maximum operating power efficiency and coupler reliability. The adjustment of coupling can be made by changing the magnetic flux linkage through the loop area. This can be done either mechanically by moving the coupling loop position or electronically by using impedance matching to change the properties of low loss material such as ferrite. In the existing coupler design, to change the coupling the coupler loop is turned physically for matching. The cavity vacuum must be broken and pumped down again; this can cause long system down time.

  10. Collective Effects in a Diffraction Limited Storage Ring

    SciTech Connect

    Nagaoka, Ryutaro; Bane, Karl L.F.

    2015-10-20

    Our paper gives an overview of collective effects that are likely to appear and possibly limit the performance in a diffraction-limited storage ring (DLSR) that stores a high-intensity ultra-low-emittance beam. Beam instabilities and other intensity-dependent effects that may significantly impact the machine performance are covered. The latter include beam-induced machine heating, Touschek scattering, intra-beam scattering, as well as incoherent tune shifts. The general trend that the efforts to achieve ultra-low emittance result in increasing the machine coupling impedance and the beam sensitivity to instability is reviewed. The nature of coupling impedance in a DLSR is described, followed by a series of potentially dangerous beam instabilities driven by the former, such as resistive-wall, TMCI (transverse mode coupling instability), head-tail and microwave instabilities. Additionally, beam-ion and CSR (coherent synchrotron radiation) instabilities are also treated. Means to fight against collective effects such as lengthening of the bunch with passive harmonic cavities and bunch-by-bunch transverse feedback are introduced. Numerical codes developed and used to evaluate the machine coupling impedance, as well as to simulate beam instability using the former as inputs are described.

  11. The electrostatic Cryogenic Storage Ring CSR - Mechanical concept and realization

    NASA Astrophysics Data System (ADS)

    von Hahn, R.; Berg, F.; Blaum, K.; Crespo Lopez-Urrutia, J. R.; Fellenberger, F.; Froese, M.; Grieser, M.; Krantz, C.; Kühnel, K.-U.; Lange, M.; Menk, S.; Laux, F.; Orlov, D. A.; Repnow, R.; Schröter, C. D.; Shornikov, A.; Sieber, T.; Ullrich, J.; Wolf, A.; Rappaport, M.; Zajfman, D.

    2011-12-01

    A new and technologically challenging project, the electrostatic Cryogenic Storage Ring CSR, is presently under construction at the Max-Planck-Institute for Nuclear Physics in Heidelberg. Applying liquid helium cooling, the CSR, with 35 m circumference, will provide a low temperature environment of only a few Kelvin and an extremely high vacuum of better than 10 -13 mbar. To realize these conditions the mechanical design has been completed and now the first quarter section is in the construction phase. For the onion skin structure of the cryogenic system we have at the outer shell the cryostat chambers, realized by welded rectangular stainless steel frames with aluminum plates. The next two shells are fabricated as aluminum shields kept at 80 and 40 K. The inner vacuum chambers for the experimental vacuum consist of stainless steel chambers cladded with external copper sheets connected to the LHe lines for optimized thermal equilibration and cryopumping. Additional large surface 2 K units are installed for cryogenic pumping of H 2. The mechanical concepts and the realization will be presented in detail.

  12. A pinger system for the Los Alamos Proton Storage Ring

    SciTech Connect

    Hardek, T.W.; Thiessen, H.A.

    1991-01-01

    Developers at the Proton Storage Ring have long desired a modulator and electrode combination capable of kicking the 800-MeV proton beam enough to conduct tune measurements with full intensity beams. At present this has been accomplished by reducing the voltage on one extraction kicker modulator and turning the other off. This method requires that all of the accumulated beam be lost on the walls of the vacuum chamber. In addition to tune measurements a more recent desire is to sweep out beam that may have leaked into the area between bunches. A four-meter electrode has been designed and constructed for the purpose. The design is flexible in that the electrode may be split in the center and rotated in order to provide vertical and horizontal electrodes each 2 meters long. In addition two solid-state pulse modulators that can provide 10kV in burst mode at up to 700 KHz have been purchased. This hardware and its intended use are described. 3 refs., 2 figs., 1 tab.

  13. Collective Effects in a Diffraction Limited Storage Ring

    DOE PAGES

    Nagaoka, Ryutaro; Bane, Karl L.F.

    2015-10-20

    Our paper gives an overview of collective effects that are likely to appear and possibly limit the performance in a diffraction-limited storage ring (DLSR) that stores a high-intensity ultra-low-emittance beam. Beam instabilities and other intensity-dependent effects that may significantly impact the machine performance are covered. The latter include beam-induced machine heating, Touschek scattering, intra-beam scattering, as well as incoherent tune shifts. The general trend that the efforts to achieve ultra-low emittance result in increasing the machine coupling impedance and the beam sensitivity to instability is reviewed. The nature of coupling impedance in a DLSR is described, followed by a seriesmore » of potentially dangerous beam instabilities driven by the former, such as resistive-wall, TMCI (transverse mode coupling instability), head-tail and microwave instabilities. Additionally, beam-ion and CSR (coherent synchrotron radiation) instabilities are also treated. Means to fight against collective effects such as lengthening of the bunch with passive harmonic cavities and bunch-by-bunch transverse feedback are introduced. Numerical codes developed and used to evaluate the machine coupling impedance, as well as to simulate beam instability using the former as inputs are described.« less

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

    SciTech Connect

    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 an 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.)

  15. Beam Loss Monitors in the NSLS Storage Rings

    SciTech Connect

    Kramer,S.L.; Fedurin, M.

    2009-05-04

    Beam loss monitors (BLM) have been used for more than two decades in the VUV ring at the NSLS. These have proved useful for optimizing injection and operation of the ring. Recently similar monitors have been installed in the X-ray ring and are being used to better understand injection, as well as operation of the ring. These units have been compared with the Bergoz BLMs, which have been mostly useful for understanding operating beam losses.

  16. Comparison of beam transport simulations to measurements at the Los Alamos Proton Storage Ring

    SciTech Connect

    Wilkinson, C.; Neri, F.; Fitzgerald, D.H.; Blind, B.; Macek, R.; Plum, M.; Sander, O.; Thiessen, H.A.

    1997-10-01

    The ability to model and simulate beam behavior in the Proton Storage Ring (PSR) of the Los Alamos Neutron Science Center (LANSCE) is an important diagnostic and predictive tool. This paper gives the results of an effort to model the ring apertures and lattice and use beam simulation programs to track the beam. The results are then compared to measured activation levels from beam loss in the ring. The success of the method determines its usefulness in evaluating the effects of planned upgrades to the Proton Storage Ring.

  17. Electron cloud development in the Proton Storage Ring and in theSpallation Neutron Source

    SciTech Connect

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

    2002-10-08

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

  18. Users program for storage-ring based FEL and synchrotron sources of the Duke FEL Laboratory

    SciTech Connect

    Straub, K.D.; Barnett, G.; Burnham, B.

    1995-12-31

    The storage ring at the Duke FEL Laboratory was first operated with a stored e-beam in November, 1994. It has now achieved operation energies in excess 1 GeV with more than 100 mA current at 280 MeV. The ring has several ports for FEL and synchrotron light source research. The circulating ring current can be synchronized with the seperate Mark III FEL operating in the 2-9.5 {mu}m IR region. This allows low optical jitter (10-20 ps) between the two sources and thus pump-probe operation. The ring has been configured to drive a number of light sources including the OK-4 FEL system capable of FEL operation between 400 and 65 nm, an inverse Compton scattering source using this undulator which will yield 4-200 MeV gammas, an undulator source at approximately 40 {angstrom} (not an FEL), a mm FEL with inverse compton scattering providing 1-100 keV x-rays and two synchrotron ports from the bend magnets for which the {lambda}{sub c} = 11-12 {angstrom} for 1 GeV. The broadly tunable FEL sources and their associated inverse compton scattering are extremely bright. The initial research proposals, submitted to the Laboratory emphasizes photoelectron spectroscopy, PEEM, high resolution vacuum UV of gases, solid spectroscopy and photochemistry in the UV, X-ray microprobe studies, X-ray microscopy, X-ray holography, X-ray crystallography, Mossbauer spectroscopy, nuclear spectroscopy, neutron production, photon activation therapy and broadband synchrotron as a probe of fast reaction in the IR and near IR.

  19. Analytical Approach to Eigen-Emittance Evolution in Storage Rings

    SciTech Connect

    Nash, Boaz; /SLAC

    2006-05-16

    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 coefficient 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 {nu}{sub x}. 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

  20. Measurement of the thermal noise of a proton beam in the NAP-M storage ring

    SciTech Connect

    Dement'ev, E.M.; Dikanskii, N.S.; Medvedko, A.S.; Parkhomchuk, V.V.; Pestrikov, D.V.

    1980-08-01

    Measurements of the spectra and power of the noise of uncooled and cooled proton beams in the NAP-M storage ring are reported. Features of the noise of the cooled beam due to particle interaction are analyzed.

  1. Theories of statistical equilibrium in electron-positron colliding-beam storage rings

    SciTech Connect

    Schonfeld, J.F.

    1985-01-01

    In this lecture I introduce you to some recent theoretical work that represents a significant and long overdue departure from the mainstream of ideas on the physics of colliding- beam storage rings. The goal of the work in question is to understand analytically - without recourse to computer simulation - the role that dissipation and noise play in the observed colliding-beam behavior of electron-positron storage rings.

  2. A practical method to generate brilliant hard x-rays with a tabletop electron storage ring

    SciTech Connect

    Yamada, H.; Amano, D.; Miyade, H.

    1995-12-31

    With electron storage rings not only synchrotron radiation(SR) but also bremsstrahlung(BS) from a thin target placed in the electron orbit are mechanisms to generate brilliant x-ray beams. The calculated brilliance of BS with a 50 MeV storage ring, which is nearly 10{sup 13} photons/s, mrad{sup 2}, mm{sup 2}, 0.1% band width for 100 keV x-rays, exceeds that of SR from a 1 GeV storage ring. This photon energy spectrum is almost constant and extend up to the electron energy. The reasons for this high brilliance with this new radiation scheme is that the electron beams penetrating the thin target are utilized repeatedly, the narrow angular divergence of BS is determined by the kinematics of relativistic electron as same as SR, and the x-ray source size of the order of 1 {mu}m is determined by the size of thin target instead of electron beam sizes. Continuous injection of electron beam to the storage ring at full energy is the way to keep high and constant beam current. Peak current and repetition rate determine x-ray out put power. Note that the power of x-ray beam is also provided from a RF cavity of the storage ring. In this paper we will report some experimental results and discuss further application on a coherent bremsstrahlung generated from a set of stacked foils placed in the electron orbit of the ring. Resulting from these investigations the photon storage ring which is based on a 50 MeV exact circular electron storage ring could provide wide range of coherent and incoherent radiations from far infrared to hard x-ray in a practical amount of radiation power.

  3. Total water storage dynamics derived from tree-ring records and terrestrial gravity observations

    NASA Astrophysics Data System (ADS)

    Creutzfeldt, Benjamin; Heinrich, Ingo; Merz, Bruno

    2015-10-01

    For both societal and ecological reasons, it is important to understand past and future subsurface water dynamics but estimating subsurface water storage is notoriously difficult. In this pilot study, we suggest the reconstruction of subsurface water dynamics by a multi-disciplinary approach combining hydrology, dendrochronology and geodesy. In a first step, nine complete years of high-precision gravimeter observations are used to estimate water storage changes in the subsurface at the Geodetic Observatory Wettzell in the Bavarian Forest, Germany. The record is extended to 63 years by calibrating a hydrological model against the 9 years of gravimeter observations. The relationship between tree-ring growth and water storage changes is evaluated as well as that between tree-ring growth and supplementary hydro-meteorological data. Results suggest that tree-ring growth is influenced primarily by subsurface water storage. Other variables related to the overall moisture status (e.g., Standardized Precipitation Index, Palmer Drought Severity Index, streamflow) are also strongly correlated with tree-ring width. While these indices are all indicators of water stored in the landscape, water storage changes of the subsurface estimated by depth-integral measurements give us the unique opportunity to directly reconstruct subsurface water storage dynamics from records of tree-ring width. Such long reconstructions will improve our knowledge of past water storage variations and our ability to predict future developments. Finally, knowing the relationship between subsurface storage dynamics and tree-ring growth improves the understanding of the different signal components contained in tree-ring chronologies.

  4. Ring-toric lens for focus-error sensing in optical data storage.

    PubMed

    Descour, M R; Simon, D I; Yeh, W H

    1999-03-10

    We discuss the design and performance of diffractive ring-toric lenses for focus-error sensing in optical data storage. A ring-toric lens images a point source of light to a ring-shaped image. Focus-error sensing is accomplished by means of monitoring the change in ring radius: The ring expands in response to a diverging wave front, and the ring contracts in response to a converging wave front. We describe the use of a segmented phi detector to generate a focus-error signal (FES). We found that the FES slope, a measure of sensitivity to disk defocus, is higher for the ring-toric lenses described in this paper than for other techniques such as the astigmatic and the obscuration methods. We measured an FES slope of 0.7 per micrometer of disk defocus (microm(-1)). The corresponding theoretical FES slope is 0.96 microm(-1).

  5. 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.

  6. The new 1.5 GeV storage ring for synchrotron radiation: MAX II

    NASA Astrophysics Data System (ADS)

    Andersson, Å.; Eriksson, M.; Lindgren, L.-J.; Röjsel, P.; Werin, S.

    1995-02-01

    The MAX laboratory at Lund University, Sweden, today operates an accelerator system consisting of a 100 MeV racetrack microtron and a 550 MeV storage ring (MAX I). At the moment (July 1994) a new storage ring MAX II is near completion and will start first injections within 2 months. This work gives an overview of the MAX II project including the first beamlines and a description of the accelerator system. MAX II is a 1.5 GeV third generation light source optimized for the VUV and soft-x-ray region. It consists of a ten cell double bend achromat lattice forming the 90 m circumference ring. Injection is done at 500 MeV from the existing storage ring MAX I, and ramping up to full energy will take place in MAX II. The straight sections have a length of 3.2 m and eight sections are free to house insertion devices. At start up the ring will be equipped with one 7.5 T superconducting wiggler and one 1.8 T multipole wiggler. Two more undulators are ordered and under construction. To be able to achieve the project a few shortcuts have been made in the design of the storage ring: (1) Nonzero dispersion is allowed in the straight sections, (2) chromaticity correction is built into the quadrupole magnets, and (3) the length of the straight sections is limited to 3.2 m. The project is progressing on time. Extraction of an electron beam from the MAX I storage ring has been achieved and has successfully been transported into the MAX II building. The MAX II ring is under assembly with most of the sections already mounted. First injection is planned to take place in August 1994.

  7. Low Energy Storage Rings: Opening Routes for Beyond State-of-the-art Research

    SciTech Connect

    Welsch, Carsten P.

    2011-10-27

    Electrostatic storage rings have proven to be invaluable tools for atomic and molecular physics at the ultra-low energy range from 1 to 100 keV/A. Due to the mass independence of the electrostatic rigidity these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio-molecules. Their beam dynamics is, however, fundamentally different to magnetic storage rings and therefore needs to be investigated in detail to optimize storage ring performance and experimental output. This paper first gives an overview of existing electrostatic storage rings and their experimental programs. Second, future machines in Heidelberg, Stockholm and the Facility for Antiproton and Ion Research (FAIR) are described and the main challenges are summarized. Finally, the focus is set on a flexible storage ring facility presently being built up at the King Abdulaziz Center for Science and Technology (KACST) in Riyadh, Saudi Arabia, that addresses a broad user community and will allow for a next-generation experimental program in the low energy regime.

  8. Low Energy Storage Rings: Opening Routes for Beyond State-of-the-art Research

    NASA Astrophysics Data System (ADS)

    Welsch, Carsten P.

    2011-10-01

    Electrostatic storage rings have proven to be invaluable tools for atomic and molecular physics at the ultra-low energy range from 1 to 100 keV/A. Due to the mass independence of the electrostatic rigidity these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio-molecules. Their beam dynamics is, however, fundamentally different to magnetic storage rings and therefore needs to be investigated in detail to optimize storage ring performance and experimental output. This paper first gives an overview of existing electrostatic storage rings and their experimental programs. Second, future machines in Heidelberg, Stockholm and the Facility for Antiproton and Ion Research (FAIR) are described and the main challenges are summarized. Finally, the focus is set on a flexible storage ring facility presently being built up at the King Abdulaziz Center for Science and Technology (KACST) in Riyadh, Saudi Arabia, that addresses a broad user community and will allow for a next-generation experimental program in the low energy regime.

  9. Resonant condition for storage ring short wavelength FEL with power exceeding Renieri limit

    SciTech Connect

    Litvinenko, V.N.; Burnham, B.; Wu, Y.

    1995-12-31

    In this paper we discuss the possibility of operating a storage ring FEL with resonant conditions providing for preservation of electron beam structure on an optical wave scale. We suggest tuning the storage ring betatron and synchrotron tunes on one of the high (N-th) order resonances to compensate dynamic diffusion of optical phase. This mode of operation does not require isochronicity of the ring lattice. In these conditions optical phase will be restored after N turns around the ring and stochastic conditions used in the derivation of Renieri limit are no longer applicable. We discuss the influence of high order terms in electron motion, RF frequency stability, and synchrotron radiation effects on preservation of optical phase.

  10. NEUTRINO FACTORY BASED ON MUON-STORAGE-RINGS TO MUON COLLIDERS: PHYSICS AND FACILITIES.

    SciTech Connect

    PARSA,Z.

    2001-06-18

    Intense muon sources for the purpose of providing intense high energy neutrino beams ({nu} factory) represents very interesting possibilities. If successful, such efforts would significantly advance the state of muon technology and provides intermediate steps in technologies required for a future high energy muon collider complex. High intensity muon: production, capture, cooling, acceleration and multi-turn muon storage rings are some of the key technology issues that needs more studies and developments, and will briefly be discussed here. A muon collider requires basically the same number of muons as for the muon storage ring neutrino factory, but would require more cooling, and simultaneous capture of both {+-} {mu}. We present some physics possibilities, muon storage ring based neutrino facility concept, site specific examples including collaboration feasibility studies, and upgrades to a full collider.

  11. Storage ring cross section measurements for electron impact ionization of Fe8+

    NASA Astrophysics Data System (ADS)

    Hahn, M.; Becker, A.; Bernhardt, D.; Grieser, M.; Krantz, C.; Lestinsky, M.; Müller, A.; Novotný, O.; Pindzola, M. S.; Repnow, R.; Schippers, S.; Spruck, K.; Wolf, A.; Savin, D. W.

    2016-04-01

    We have measured electron impact ionization (EII) for Fe8+ forming Fe9+ from below the ionization threshold to 1200 eV. These measurements were carried out at the TSR heavy ion storage ring. The objective of using a storage ring is to store the ion beam initially so that metastable levels decay, thereby allowing for measurements on a well-defined ground-level ion beam. In this case, however, some metastable levels were too long lived to be removed. We discuss several methods for quantifying the metastable fraction, which we estimate to be ˜30%-40%. Although metastables remain problematic, the present storage ring work improves upon other experimental geometries by limiting the metastable contamination to only a few long-lived excited levels. We discuss some future prospects for obtaining improved measurements of Fe8+ and other ions with long-lived metastable levels.

  12. 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.

  13. Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources

    SciTech Connect

    Chao, Alex; Ratner, Daniel; Jiao, Yi; /Beijing, Inst. High Energy Phys.

    2012-09-06

    Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original references. Once the stored beam is steady-state microbunched in a storage ring, it passes through a radiator repeatedly every turn (or few turns). The radiator extracts a small fraction of the beam energy as coherent radiation with a wavelength corresponding to the microbunched period of the beam. In contrast to an FEL, this radiator is not needed to generate the microbunching (as required e.g. by SASE FELs or seeded FELs), so the radiator can be comparatively simple and short.

  14. 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.

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

    SciTech Connect

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

    1995-05-01

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

  16. The low energy kaon program at the celsius storage ring

    NASA Astrophysics Data System (ADS)

    Badalà, A.; Barbera, R.; Gulino, M.; Librizzi, F.; Mascali, A.; Nicotra, D.; Palmeri, A.; Pappalardo, G. S.; Riggi, F.; Russo, A. C.; Russo, G.; Santoro, A.; Turrisi, R.; Dunin, V.; Ekström, C.; Ericsson, G.; Höistad, B.; Johansson, J.; Johansson, T.; Westerberg, L.; Zlomaczhuk, J.

    1997-02-01

    The CLAMSUD spectrometer has been recently installed at the jet-target position of the CELSIUS ring at "THE SVEDBERG LABORATORY." The physical purpose is the study of kaon production at energies below the N-N threshold. Due to the low cross-section and short lifetime of kaons we increased the solid angle by means of two quadrupoles positioned at the entrance of the dipole. The experimental quality of the measurements due both to the beam characteristics and to the CLAMSUD detector will be shown.

  17. Large magnetic storage ring for Bose-Einstein condensates

    SciTech Connect

    Arnold, A. S.; Garvie, C. S.; Riis, E.

    2006-04-15

    Cold atomic clouds and Bose-Einstein condensates have been stored in a 10 cm diameter vertically oriented magnetic ring. An azimuthal magnetic field enables low-loss propagation of atomic clouds over a total distance of 2 m, with a heating rate of less than 50 nK/s. The vertical geometry was used to split an atomic cloud into two counter-rotating clouds which were recombined after one revolution. The system will be ideal for studying condensate collisions and ultimately Sagnac interferometry.

  18. Multi-pulse extraction from Los Alamos Proton Storage Ring for radiographic applications

    SciTech Connect

    Thiessen, H.A.; Neri, F.; Rust, K.; Redd, D.B.

    1997-08-01

    In Proton Radiography, one of the goals is a motion picture of a rapidly moving object. The Los Alamos Proton Storage Ring (PSR) in its normal operating mode, delivers a single pulse approximately 120 ns wide (fwhm). In development runs at the PSR, the authors successfully demonstrated operation of a technique to deliver two pulses, each 40 nsec wide, with adjustable spacing.

  19. Evaluation of Pinhole Camera Resolution for NSLS-II Storage Ring

    SciTech Connect

    Pinayev,I.

    2008-05-04

    The NSLS-II Storage Ring provides ultrabright radiation sources with extra-small sizes of the circulating electron beam. The beam dimensions will be monitored with a pinhole camera. In this paper they discuss the possible design and ultimate achievable resolution of the system. Modeling is based on the SRW code as well as numerical calculations using MATLAB.

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

    SciTech Connect

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

    2013-08-28

    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 trailing 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.

  1. Design and optimization of a longitudinal feedback kicker cavity for the HLS-II storage ring

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Z. Wu, W.; He, Duo-Hui; K. Wu, Y.

    2013-03-01

    In the Hefei Light Source (HLS) storage ring, multibunch operation is used to obtain a high luminosity. Multibunch instabilities can severely limit light source performance with a variety of negative impacts, including beam loss, low injection efficiency, and overall degradation of the beam quality. Instabilities of a multibunch beam can be mitigated using certain techniques including increasing natural damping (operating at a higher energy), lowering the beam current, and increasing Landau damping. However, these methods are not adequate to stabilize a multibunch electron beam at a low energy and with a high current. In order to combat beam instabilities in the HLS storage ring, active feedback systems including a longitudinal feedback system (LFB) and a transverse feedback system (TFB) will be developed as part of the HLS upgrade project, the HLS- II storage ring project. As a key component of the longitudinal bunch-by-bunch feedback system, an LFB kicker cavity with a wide bandwidth and high shunt impedance is required. In this paper we report our work on the design of the LFB kicker cavity for the HLS- II storage ring and present the new tuning and optimization techniques developed in designing this high performance LFB kicker.

  2. Exciton storage in a nanoscale Aharonov-Bohm ring with electric field tuning.

    PubMed

    Fischer, Andrea M; Campo, Vivaldo L; Portnoi, Mikhail E; Römer, Rudolf A

    2009-03-06

    We study analytically the optical properties of a simple model for an electron-hole pair on a ring subjected to perpendicular magnetic flux and in-plane electric field. We show how to tune this excitonic system from optically active to optically dark as a function of these external fields. Our results offer a simple mechanism for exciton storage and readout.

  3. Exciton Storage in a Nanoscale Aharonov-Bohm Ring with Electric Field Tuning

    SciTech Connect

    Fischer, Andrea M.; Roemer, Rudolf A.; Campo, Vivaldo L. Jr.; Portnoi, Mikhail E.

    2009-03-06

    We study analytically the optical properties of a simple model for an electron-hole pair on a ring subjected to perpendicular magnetic flux and in-plane electric field. We show how to tune this excitonic system from optically active to optically dark as a function of these external fields. Our results offer a simple mechanism for exciton storage and readout.

  4. Polarization fields and phase space densities in storage rings: Stroboscopic averaging and the ergodic theorem

    NASA Astrophysics Data System (ADS)

    Ellison, James A.; Heinemann, Klaus

    2007-10-01

    A class of orbital motions with volume preserving flows and with vector fields periodic in the “time” parameter θ is defined. Spin motion coupled to the orbital dynamics is then defined, resulting in a class of spin-orbit motions which are important for storage rings. Phase space densities and polarization fields are introduced. It is important, in the context of storage rings, to understand the behavior of periodic polarization fields and phase space densities. Due to the 2π time periodicity of the spin-orbit equations of motion the polarization field, taken at a sequence of increasing time values θ,θ+2π,θ+4π,…, gives a sequence of polarization fields, called the stroboscopic sequence. We show, by using the Birkhoff ergodic theorem, that under very general conditions the Cesàro averages of that sequence converge almost everywhere on phase space to a polarization field which is 2π-periodic in time. This fulfills the main aim of this paper in that it demonstrates that the tracking algorithm for stroboscopic averaging, encoded in the program SPRINT and used in the study of spin motion in storage rings, is mathematically well-founded. The machinery developed is also shown to work for the stroboscopic average of phase space densities associated with the orbital dynamics. This yields a large family of periodic phase space densities and, as an example, a quite detailed analysis of the so-called betatron motion in a storage ring is presented.

  5. Statistical properties of wiggler and bending-magnet radiation from the Brookhaven vacuum-ultraviolet electron storage ring

    SciTech Connect

    Teich, M.C. ); Tanabe, T.; Marshall, T.C. ); Galayda, J. )

    1990-12-31

    The photoelectron counts of spontaneous light from the wiggler in the Brookhaven electron storage ring obey the negative-binomial distribution, in accord with the predictions of a multielectron, multimode theory. The bending-magnet light emerging from the Pyrex exit port of the storage ring obeys the Neyman type-A distribution.

  6. Statistical properties of Wiggler and bending-magnet radiation from the Brookhaven vacuum-ultraviolet electron storage ring

    NASA Astrophysics Data System (ADS)

    Teich, Malvin C.; Tanabe, Toshiya; Marshall, Thomas C.; Galayda, John

    1990-12-01

    The photoelectron counts of spontaneous light from the wiggler in the Brookhaven electron storage ring obey the negative-binomial distribution, in accord with the predictions of a multielectron, multimode theory. The bending-magnet light emerging from the Pyrex exit port of the storage ring obeys the Neyman type-A distribution.

  7. Intrabeam scattering studies at the Cornell Electron Storage Ring Test Accelerator

    NASA Astrophysics Data System (ADS)

    Ehrlichman, M. P.; Hartung, W.; Heltsley, B.; Peterson, D. P.; Rider, N.; Rubin, D.; Sagan, D.; Shanks, J.; Wang, S. T.; Campbell, R.; Holtzapple, R.

    2013-10-01

    Intrabeam scattering (IBS) limits the emittance and single-bunch current that can be achieved in electron or positron storage ring colliders, damping rings, and light sources. Much theoretical work on IBS exists, and while the theories have been validated in hadron and ion machines, the presence of strong damping makes IBS in lepton machines a different phenomenon. We present the results of measurements at CesrTA of IBS-dominated beams, and compare the data with theory. The beams we study have parameters typical of those specified for the next generation of wiggler-dominated storage rings: low emittance, small bunch length, and an energy of a few GeV. Our measurements are in good agreement with IBS theory, provided a tail-cut procedure is applied.

  8. A super-bright storage ring alternative to an energy recovery linac

    NASA Astrophysics Data System (ADS)

    Borland, Michael

    2006-02-01

    One of the promised characteristics of an energy recovery linac (ERL) as a synchrotron light source is the very low emittance of the electron beam. A difficulty with ERLs is that, as yet, no one has demonstrated a gun that delivers average currents comparable to what has been demonstrated in storage rings, i.e., 0.1-1 A, with the required emittance and for the long periods of time necessary for a user facility. As an alternative to an ERL, one might consider a super-bright storage ring with short lifetime, requiring fast top-up. We present a possible replacement ring for the Advanced Photon Source with 0.5-micron normalized emittance at 7 GeV, along with a discussion of design challenges and operating considerations.

  9. Nonlinear and long-term beam dynamics in low energy storage rings

    NASA Astrophysics Data System (ADS)

    Papash, A. I.; Smirnov, A. V.; Welsch, C. P.

    2013-06-01

    Electrostatic storage rings operate at very low energies in the keV range and have proven to be invaluable tools for atomic and molecular physics. Because of the mass independence of electric rigidity, these machines are able to store a wide range of different particles, from light ions to heavy singly charged biomolecules, opening up unique research opportunities. However, earlier measurements have shown strong limitations in maximum beam intensity, fast decay of the stored ion current, and reduced beam lifetime. The nature of these effects has not been fully understood and an improved understanding of the physical processes influencing beam motion and stability in such rings is needed. In this paper, a comprehensive study into nonlinear and long-term beam dynamics studies is presented on the examples of a number of existing and planned electrostatic storage rings using the BETACOOL, OPERA-3D, and MAD-X simulation software. A detailed investigation into ion kinetics, under consideration of effects from electron cooling and multiple scattering of the beam on a supersonic gas jet target, is carried out and yields a consistent explanation of the physical effects in a whole class of storage rings. The lifetime, equilibrium momentum spread, and equilibrium lateral spread during collisions with the target are estimated. In addition, the results from experiments at the Test Storage Ring, where a low-intensity beam of CF+ ions at 93keV/u has been shrunk to extremely small dimensions, are reproduced. Based on these simulations, the conditions for stable ring operation with an extremely low-emittance beam are presented. Finally, results from studies into the interaction of 3-30 keV ions with a gas jet target are summarized.

  10. Progress of the commissioning of the DELTA storage ring FEL facility

    SciTech Connect

    Noelle, D.; Geisler, A.; Ridder, M.

    1995-12-31

    This paper will present the status of the ongoing commissioning of the DELTA storage-ring FEL facility. The commissioning of the LINAC started in autumn `94. The operation of the booster started in spring `95, the first stored beam was achieved end of march `95. During the summer of `95 the commissioning of the main storage ring will be started. Simultaneously, the first FEL FELICTA I was built. All FEL hardware is in house, the undulator is already mounted in the storage-ring. Thus first operation of the undulator with electron beam, will take place immediately after the first stored beam in DELTA. Therefore, first spontanous photons are to be expected in late summer `95. As soon as DELTA provides stable and rather reliable operation the experiments on FELICITA I will start. 16 mA total average current in DELTA at 500 MeV should be sufficient to reach the laser threshold in the FEL mode of FELICITA I. Operating the device as an optical klystron should result in lasing at substantial less currents.

  11. Radiation Belts Storage Ring : What the Cluster-CIS data can tell us

    NASA Astrophysics Data System (ADS)

    Dandouras, I. S.; Ganushkina, N.; Amariutei, O. A.; Reme, H.

    2013-12-01

    Following the launch by NASA of the Radiation Belt Storm Probes (RBSP) twin spacecraft, now named the Van Allen Probes, the discovery of a storage ring was announced: Baker et al., Science, 2013. This transient feature was observed during September 2012, following the arrival of an interplanetary shock, was located between L=3.0 and L=3.5 and consisted of about 4 to 6 MeV electrons. During that period the Cluster spacecraft had a high-inclination orbit, with a perigee just above 2 Re. The CIS experiment onboard Cluster is sensitive to penetrating energetic electrons (E > 2 MeV), which produce background counts and thus allow to localize the boundaries of the outer and inner radiation belts (Ganushkina et al., JGR, 2011). A search was undertaken in the September 2012 CIS data for eventual signatures of the storage ring, and indeed a small increase of the instrument background was observed between L=3.0 and L=3.5. This is clearly separated from the main outer radiation belt, which presents a much stronger background due to higher fluxes of relativistic electrons. A mono-energetic ion drift band was also observed by CIS inside the storage ring, at about 5 keV for He+ and O+ ions. This result provides an independent confirmation for the storage ring. In addition, it allows also to examine Cluster and Double Star data from earlier years, covering a full solar cycle, for other such signatures of a transient storage ring. It results that this 3-belt structure is seen several times.

  12. High intensity polarized atomic beam source for polarized internal storage ring targets

    NASA Astrophysics Data System (ADS)

    Schiemenz, P.

    1989-05-01

    In collaboration with the Max-Planck-Institut (MPI) für Kernphysik in Heidelberg and the University of Marburg we presently design and construct a high intensity polarized atomic beam source. It is intended to deliver 1*1017 atoms/sec in one hyperfine state into a storage cell for FILTEX. FILTEX is an abbreviation for FILTer EXperiment aiming to polarize storage ring beams. The structure and the vacuum chambers of this source are completed and installed at the Heidelberg Test Storage Ring (TSR). Vacuum pumps, gauges etc. are mounted and partly connected to a logical operation system. When atomic beam nozzle and skimmer geometries and distances as well as the nozzle temperature are optimized, the final geometrical arrangement or our new hybrid sixpole magnets will be decided and the whole source should be completed by the end of 1989.

  13. 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

  14. Crystalline beam in a storage ring: How long can it last?

    SciTech Connect

    Li, Xiao-Ping; Sessler, A.M.; Wei, Jie

    1994-08-01

    The ground state of a crystalline beam in a realistic storage ring is well understood by now. No crystalline beam exists in a constant gradient storage ring, but in an alternating gradient (AG) ring crystalline beams exist at all density as long as the beam energy is smaller than the transition energy. However, since the Hamiltonian is time dependent, the total energy of the beam is not a constant of motion. As a result, the crystalline beam will gradually heat up and eventually melt if not refrigerated. Here, we show that if the frequency due to the AG lattice is lower than twice the betatron frequency, heat will transfer into the system extremely fast so that a crystalline beam can not last a meaningful period of time (except at very low density). On the other hand, if the AG lattice frequency is higher than twice the betatron frequency, the heat transfer is slow, and the -crystalline beam can last for a long time. We therefore arrive at the conclusion that in order for a crystalline beam to be conveniently observed, the storage ring should be designed such that the AG lattice frequency is as high as possible while the betatron frequency is kept as low as possible.

  15. Effectiveness of rf phase modulation for increasing bunch length in electron storage rings

    PubMed

    Orsini; Mosnier

    2000-04-01

    Aiming at increasing the apparent bunch length and hence the beam lifetime in electron storage rings, rf phase modulation near one parametric resonance has been experimentally investigated. Since the possible benefit of this technique depends greatly on the ring parameters, we studied the effect of such a modulation for different rf parameters on the longitudinal emittance. Theoretical predictions and results of simulations are compared and discussed. It is shown that synchrotron radiation tends to spoil the parametric resonance. In particular, a criterion for island survival has been found.

  16. STUDY OF THE STABILITY OF PARTICLE MOTION IN STORAGE RINGS. Final Report

    SciTech Connect

    Jack J. Shi

    2012-09-07

    During this period, our research was concentrated on the study of beam-beam effects in large storage-ring colliders and coherent synchrotron radiation (CSR) effect in light sources. Our group was involved in and made significant contribution to several international accelerator projects such as the US-LHC project for the design of the LHC interaction regions, the luminosity upgrade of Tevatron and HERA, the design of eRHIC, and the U.S. LHC Accelerator Research Program (LARP) for the future LHC luminosity upgrade.

  17. 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).

  18. Steady-State Microbunching in a Storage Ring for Generating Coherent Radiation

    SciTech Connect

    Ratner, Daniel F.; Chao, Alexander W.; /SLAC

    2011-05-19

    Synchrotrons and storage rings deliver radiation across the electromagnetic spectrum at high repetition rates, and free electron lasers (FELs) produce radiation pulses with high peak brightness. However, at present few light sources can generate both high repetition rate and high brightness outside the optical range. We propose to create steady-state microbunching (SSMB) in a storage ring to produce coherent radiation at a high repetition rate or in continuous wave (CW) mode. In this paper we describe a general mechanism for producing SSMB and give sample parameters for EUV lithography and sub-millimeter sources. We also describe a similar arrangement to produce two pulses with variable spacing for pump-probe experiments. With technological advances, SSMB could reach the soft X-ray range (< 10 nm).

  19. 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)

  20. Recombination and Ionization Measurements at the Heidelberg Heavy Ion Storage Ring TSR

    NASA Astrophysics Data System (ADS)

    Hahn, M.; Lestinsky, M.; Novotný, O.; Savin, D. W.; Bernhardt, D.; Müller, A.; Schippers, S.; Krantz, C.; Grieser, M.; Repnow, R.; Wolf, A.

    2011-05-01

    Knowledge of the charge state distribution (CSD) of astrophysical plasmas is important for the interpretation of spectroscopic data. To accurately calculate CSDs, reliable rate coefficients are needed for dielectronic recombination (DR), which is the dominant electron-ion recombination mechanism for most ions, and for electron impact ionization (EII). We are carrying out DR and EII measurements of astrophysically important ions using the TSR storage ring at the Max-Plank-Institute for Nuclear Physics in Heidelberg, Germany. Storage ring measurements are largely free of the metastable contamination found in other experimental geometries, resulting in more unambiguous DR and EII reaction rate measurements. The measured data can be used in plasma modelling as well as for benchmarking theoretical atomic calculations.

  1. Intense inverse compton {gamma}-ray source from Duke storage ring FEL

    SciTech Connect

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

    1995-12-31

    We suggest using FEL intracavity power in the Duke storage ring fortrays production via Inverse Compton Backscattering (ICB). The OK-4 FEL driven by the Duke storage ring will tens of watts of average lasing power in the UV/VUV range. Average intracavity power will be in kilowatt range and can be used to pump ICB source. The {gamma}-rays with maximum energy from 40 MeV to 200 MeV with intensity of 0.1-5 10{sup 10}{gamma} per second can be generated. In this paper we present expected parameters of {gamma}-ray beam parameters including its intensity and distribution. We discuss influence of e-beam parameters on collimated {gamma}-rays spectrum and optimization of photon-electron interaction point.

  2. Measurement of the beam longitudinal profile in a storage ring bynon-linear laser mixing

    SciTech Connect

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

    2004-05-03

    We report on the development of a new technique for the measurement of the longitudinal beam profile in storage rings. This technique, which has been successfully demonstrated at the Advanced Light Source, mixes the synchrotron radiation with the light from a mode-locked solid state laser oscillator in a non-linear crystal. The up-converted radiation is then detected with a photomultiplier and processed to extract, store, and display the required information. The available choices of laser repetition frequency, pulse width, and phase modulation give a wide range of options for matching the bunch configuration of a particular storage ring. Besides the dynamic measurement of the longitudinal profile of each bunch, the instrument can monitor the evolution of the bunch tails, the presence of untrapped particles and their diffusion into nominally empty RF buckets (''ghostbunches'').

  3. Applications of differential algebra to single-particle dynamics in storage rings

    SciTech Connect

    Yan, Y.

    1991-09-01

    Recent developments in the use of differential algebra to study single-particle beam dynamics in charged-particle storage rings are the subject of this paper. Chapter 2 gives a brief review of storage rings. The concepts of betatron motion and synchrotron motion, and their associated resonances, are introduced. Also introduced are the concepts of imperfections, such as off-momentum, misalignment, and random and systematic errors, and their associated corrections. The chapter concludes with a discussion of numerical simulation principles and the concept of one-turn periodic maps. In Chapter 3, the discussion becomes more focused with the introduction of differential algebras. The most critical test for differential algebraic mapping techniques -- their application to long-term stability studies -- is discussed in Chapter 4. Chapter 5 presents a discussion of differential algebraic treatment of dispersed betatron motion. The paper concludes in Chapter 6 with a discussion of parameterization of high-order maps.

  4. Analysis of sextupole effects on β function beating in the SSRF storage ring

    NASA Astrophysics Data System (ADS)

    Tian, Shun-Qiang; Hou, Jie; Chen, Guang-Ling; Liu, Gui-Min

    2008-07-01

    In a storage ring, asymmetry of the β function with momentum deviation is the main reason for asymmetry of the dynamic aperture. This paper applies simulation method based on AT code in Matlab to investigate sensitivity of the β function beating and the tune shift to quadrupole field error with the presence of bending field error in the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. Sextupole effect on the variation trend is analyzed. Dynamics of the lattice for working points close to and away from the second order structural resonance stop-band are compared. These results show that the β function beating with momentum deviation doesn't lie in the influence of the second order structural resonance stop-bands completely, but it is relevant to lattice structure. Supported by SSRF Project

  5. An ion-beam injection line for the ELASR storage ring at KACST

    NASA Astrophysics Data System (ADS)

    El Ghazaly, M. O. A.; Behery, S. A.; Almuqhim, A. A.; Almalki, M. H.; Alshammari, S. M.; Alrashdi, A. O.; Alamer, H. S.; Jabr, A. S.; Lanazi, A. Z.

    2016-01-01

    A versatile ion injector beam-line has been developed for the specific use in the multi-purpose low-energy, storage ring facility at the King Abdulaziz City for Sciences and Technology (KACST) in Riyadh, Saudi Arabia. It incorporates a purpose-developed, high-resolution mass analyzing magnet and it is thereby dedicated to provide the ELASR storage ring with beams of ions of specific mass. It is also intended to operate independently as a single-pass experiment. This versatile ion-injection line was constructed in a staged approach, in which an axial injection version was built first, commissioned and is currently operating. The injection line in its final design is now being assembled and commissioned at KACST.

  6. CRYOGENIC AND VACUUM TECHNOLOGICAL ASPECTS OF THE LOW-ENERGY ELECTROSTATIC CRYOGENIC STORAGE RING

    SciTech Connect

    Orlov, D. A.; Lange, M.; Froese, M.; Hahn, R. von; Grieser, M.; Mallinger, V.; Sieber, T.; Weber, T.; Wolf, A.; Rappaport, M.

    2008-03-16

    The cryogenic and vacuum concepts for the electrostatic Cryogenic ion Storage Ring (CSR), under construction at the Max-Planck-Institut fuer Kernphysik in Heidelberg, is presented. The ring will operate in a broad temperature range from 2 to 300 K and is required to be bakeable up to 600 K. Extremely high vacuum and low temperatures are necessary to achieve long lifetimes of the molecular ions stored in the ring so that the ions will have enough time to cool by radiation to their vibrational and rotational ground states. To test cryogenic and vacuum technological aspects of the CSR, a prototype is being built and will be connected to the commercial cryogenic refrigerator recently installed, including a specialized 2-K connection system. The first results and the status of current work with the prototype are also presented.

  7. Overall design concepts for the APS storage ring machine protection system

    SciTech Connect

    Lumpkin, A.; Fuja, R.; Votaw, A.; Wang, X.; Shu, D.; Stepp, J.; Arnold, N.; Nawrocki, G.; Decker, G.; Chung, Y.

    1995-07-01

    The basic design and status of the machine protection system for the Advanced Photon Source (APS) storage ring are discussed. The machine is passively safe to the bending magnet sources, but the high power of the insertion devices requires missteering conditions to be identified and the beam aborted in less than one millisecond. The basic aspects of waterflow, temperature, beam position, etc. monitoring are addressed. Initial commissioning of subsystems and sensors is statused.

  8. 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.

  9. Magnet power supply control of the NSLS VUV and x-ray storage rings transfer lines

    SciTech Connect

    Klein, J.D.; Ramamoorthy, S.; Singh, O.; Smith, J.D.

    1985-01-01

    The transfer lines for NSLS VUV and x-ray storage rings have been split. New power supplies have been incorporated with existing ones. The existing microprocessor system has been upgraded in order to control the additional functions. This system expands the input/output port of the microprocessor to an addressable serial/parallel link to each magnet power supply. The implementation of this system will be discussed.

  10. Studies of Electron-Ion Interactions Using the CRYRING Heavy-Ion Storage Ring Facility

    DTIC Science & Technology

    2005-06-01

    were measured at CRYRING but not ASTRID, and relative cross sections were measured over a broader energy range in ASTRID as compared with CRYRING. We...storage ring facility, has proved to be a powerful tool for measurements of branching ratios in recombination of polyatomic molecular ions. However...because well-resolved mass peaks facilitate the measurement of product branching ratios. Deuterated molecules and peak fitting procedures will be applied to

  11. Dynamical aspects on FEL interaction in single passage and storage ring devices

    SciTech Connect

    Dattoli, G.; Renieri, A.

    1995-12-31

    The dynamical behaviour of the free-electron lasers is investigated using appropriate scaling relations valid for devices operating in the low and high gain regimes, including saturation. The analysis is applied to both single passage and storage ring configurations. In the latter case the interplay between the interaction of the electron bean with the laser field and with the accelerator environment is investigated. In particular we discuss the effect of FEL interaction on the microwave instability.

  12. 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.

  13. Harmonics suppression in electromagnets with application to the ALS storage ring corrector magnet design

    SciTech Connect

    Schlueter, R.D.

    1991-01-28

    This memo presents an analytical development for prediction of skew harmonics in a iron core C-magnet to due arbitrarily positioned electromagnet coils. A structured approach is presented for the suppression of an arbitrary number of harmonic components to arbitrarily low values. Application of the analytical harmonic strength calculations coupled to the structured harmonic suppression approach is presented in the context of the design of the ALS storage ring corrector magnets.

  14. A possible approach to reduce the emittance of HLS- II storage ring using a Robinson wiggler

    NASA Astrophysics Data System (ADS)

    Li, Jing-Yi; Liu, Gong-Fa; Xu, Wei; Li, Wei-Min; Li, Yong-Jun

    2013-10-01

    In this paper, we present some preliminary studies on using a Robinson wiggler to reduce the horizontal beam emittance in the Hefei Light Source II (HLS- II) storage ring. A proof-of-principle lattice demonstrates that it is possible to reduce its emittance by 50% with a 2-meter long wiggler. This encouraging result suggests a feasible option to significantly improve the machine performance at a relatively low cost.

  15. 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.

  16. Observation of Magnetic Resonances in Electron Clouds in a Positron Storage Ring

    SciTech Connect

    Pivi, M.T.F.; Ng, J.S.T.; Cooper, F.; Kharakh, D.; King, F.; Kirby, R.E.; Kuekan, B.; Spencer, Cherrill M.; Raubenheimer, T.O.; Wang, L.F.; /SLAC

    2011-08-24

    The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.

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

    SciTech Connect

    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.; 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.

    2016-11-29

    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.

  18. Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring

    SciTech Connect

    Trabert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

    2008-10-09

    Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

  19. elegantRingAnalysis : an interface for high-throughput analysis of storage ring lattices using elegant.

    SciTech Connect

    Borland, M. D.; APS Operations Division

    2005-05-01

    The code elegant is widely used for simulation of linacs for drivers for free-electron lasers. Less well known is that elegant is also a very capable code for simulation of storage rings. In this paper, we show a newly developed graphical user interface that allows the user to easily take advantage of these capabilities. The interface is designed for use on a Linux cluster, providing very high throughput. It can also be used on a single computer. Among the features it gives access to are basic calculations (Twiss parameters, radiation integrals), phase-space tracking, nonlinear dispersion, dynamic aperture (on-and off-momentum), frequency map analysis, and collective effects (IBS, bunch-lengthening). Using a cluster, it is easy to get highly detailed dynamic aperture and frequency map results in a surprisingly short time.

  20. The double electrostatic ion ring experiment: a unique cryogenic electrostatic storage ring for merged ion-beams studies.

    PubMed

    Thomas, R D; Schmidt, H T; Andler, G; Björkhage, M; Blom, M; Brännholm, L; Bäckström, E; Danared, H; Das, S; Haag, N; Halldén, P; Hellberg, F; Holm, A I S; Johansson, H A B; Källberg, A; Källersjö, G; Larsson, M; Leontein, S; Liljeby, L; Löfgren, P; Malm, B; Mannervik, S; Masuda, M; Misra, D; Orbán, A; Paál, A; Reinhed, P; Rensfelt, K-G; Rosén, S; Schmidt, K; Seitz, F; Simonsson, A; Weimer, J; Zettergren, H; Cederquist, H

    2011-06-01

    We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.

  1. Single bunch injection system for storage ring FEL using an rf photoinjector

    NASA Astrophysics Data System (ADS)

    O'Shea, P. G.; Lancaster, J. A.; Madey, J. M. J.; Sachtschale, R.; Jones, R.

    1997-05-01

    RF photoinjectors have gained acceptance as the source of choice for high-brightness electron accelerators, but have been quite expensive to build and difficult to operate. In this paper we describe the successful operation of an inexpensive, simple and reliable rf photoinjector suitable for single bunch injection into storage rings. For optimum storage ring FEL and Compton Backscatter performance, we require that the electrons be injected to specified ring rf buckets and no others. The injector-linac electron gun is a single-cell s-band rf gun with a LaB6 cathode. The gun is followed by an a-magnet momentum filter and buncher. The LaB6 cathode can be operated in a pure thermionic mode, a laser switched photoemission mode, or in a combined mode. The laser is a near-UV TEA nitrogen laser with a 600 ps pulse, and 0-50 Hz repetition rate. We routinely inject 0.1 nC bunches at 270 MeV. The ratio of charge in the primary ring bucket to that in the other buckets is better than 1000.

  2. Radiation Safety Considerations for Design of the SPEAR3 Storage Ring

    SciTech Connect

    Rokni, Sayed H.

    2003-03-17

    The SPEAR3 storage ring at the Stanford Synchrotron Radiation Laboratory (SSRL) is an upgrade of the existing SPEAR2 ring to a 3rd-generation storage ring with beam parameters of 3 GeV of electron beam energy, 18 nm-radian emittance and up to 500 mA of circulating current. While the existing injector will not be changed, the 234-m-circumference SPEAR2 ring components will be completely replaced with new components including C-shaped dipoles. The concrete shielding walls are to remain unchanged. This restriction, when considered in conjunction with the significant increase in the current and loss of self-shielding in the dipole magnets, requires careful study of the SPEAR3 shielding. This paper describes the methodology used for calculating the required shielding in a generic method. The criteria used for the design of shielding and beam loss estimates for various modes of beam operation are also presented. FLUKA Monte Carlo code was used extensively in generating source term data (dose rate as a function of angle for photons and neutrons) for both thin and thick targets. Attenuation profiles of neutrons and photons in concrete and lead shield materials are also presented. These data are being used to evaluate the shielding requirements for the lateral and ratchet walls. The current status of this approach will be discussed. Other issues presented include the use of active devices that are part of the radiation safety systems for the SPEAR3.

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

    SciTech Connect

    Bane, Karl; /SLAC

    2012-03-28

    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. 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.

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

    SciTech Connect

    Wang, G.M.; Shaftan; T.; Cheng; W.X.; Fliller; R.; Heese; R.; Singh; O.; Willeke; F.

    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 to 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.

  5. Ionization and Recombination Measurements at the Heidelberg Heavy Ion Storage Ring TSR

    NASA Astrophysics Data System (ADS)

    Savin, D. W.; Hahn, M.; Lestinsky, M.; Novonty, O.; Bernhardt, D.; Mueller, A.; Schippers, S.; Krantz, C.; Wolf, A.

    2011-05-01

    Reliable ionization balance calculations are needed to analyze spectra from a wide range of cosmic sources including photoionized objects such as AGNs and X-ray binaries and electron ionized objects such as as stars, supernovae, galaxies, and clusters of galaxies. These theoretical charge state distributions (CSD) depend in turn upon the underlying atomic data. Of particular importance are reliable rate coefficients for dielectronic recombination (DR), which is the dominant electron-ion recombination recombination mechanism for most ions, and for electron impact ionization (EII). We are carrying out DR and EII measurements of astrophysically important ions using the heavy ion Test Storage Ring (TSR) at the Max-Plank-Institute for Nuclear Physics in Heidelberg, Germany. The storage ring measurements are largely free of the metastable contamination found in other experimental geometries. Storage ring measurements therefore result in more precise DR and EII reaction rate measurements. The measured rate coefficients can be used in modeling cosmic and laboratory plasmas as well as in the benchmarking of theoretical atomic calculations. Here we report results for selected recent DR and EII measurements.

  6. Recombination and Ionization Measurements at the Heidelberg Heavy Ion Storage Ring TSR

    NASA Astrophysics Data System (ADS)

    Hahn, Michael; Bernhardt, D.; Krantz, C.; Lestinsky, M.; Mueller, A.; Novotny, O.; Schippers, S.; Wolf, A.; Savin, D. W.

    2010-03-01

    Reliable ionization balance calculations are needed to analyze spectra from a wide range of cosmic sources including photoionized objects such as AGNs and X-ray binaries and electron ionized objects such as as stars, supernovae, galaxies, and clusters of galaxies. These theoretical charge state distributions (CSD) depend in turn upon the underlying atomic data. Of particular importance are reliable rate coefficients for dielectronic recombination (DR), which is the dominant electron-ion recombination recombination mechanism for most ions, and for electron impact ionzation (EII). We are carrying out DR and EII measurements of astrophysically important ions using the heavy ion Test Storage Ring (TSR) at the Max-Plank-Insitute for Nuclear Physics in Heidelberg, Germany. The storage ring measurements are largely free of the metastable contamination found in other experimental geometries. Storage ring measurements therefore result in more precise DR and EII reaction rate measurements. The measured rate coefficients can be used in plasma modelling as well as in the benchmarking of theoretical atomic calculations. Here we report recent DR and EII measurements of Mg VIII and Fe XII.

  7. TIG welding of aluminum alloys for the APS storage ring - a UHV application

    SciTech Connect

    Goeppner, G.A.

    1996-05-29

    The Advanced Photon Source (APS) incorporates a 7-GeV positron storage ring 1104 meters in circumference. The storage ring vacuum system is designed to maintain a pressure of 1 nTorr or less with a circulating current of 300 mA to enable beam lifetimes of greater than 10 hours. The vacuum chamber is an aluminum extrusion of 6063T5 alloy. There are 235 separate aluminum vacuum chambers in the storage ring connected by stainless steel bellows assemblies. Aluminum was chosen for the vacuum chamber because it can be economically extruded and machined, has good thermal conductivity, low thermal emissivity, a low outgassing rate, low residual radioactivity, and is non-magnetic. The 6063 aluminum-silicon-magnesium alloy provides high strength combined with good machining and weldability characteristics. The extrusion process provides the interior surface finish needed for the ultrahigh vacuum (UHV) environments There are six different vacuum chambers with the same extrusion cross section. The average vacuum chamber length is 171.6 inches. The extruded vacuum chambers are welded to flange assemblies made up of machined 2219 aluminum alloy pieces and 2219 aluminum vacuum flanges from a commercial source.

  8. A new data acquisition system for Schottky signals in atomic physics experiments at GSI's and FAIR's storage rings

    NASA Astrophysics Data System (ADS)

    Trageser, C.; Brandau, C.; Kozhuharov, C.; Litvinov, Yu A.; Müller, A.; Nolden, F.; Sanjari, S.; Stöhlker, T.

    2015-11-01

    A new continuous and broadband data acquisition system for measurements of Schottky-signals of ions revolving in a storage ring has been implemented. This set-up is capable of recording the radio frequency (RF) signal of the ions that circulate in the storage ring with a sustained acquisition rate of more than 3.5× {10}7 IQ-samples per second. This allows several harmonics of the full momentum acceptance of a storage ring to be measured at the same time. The RF signal analyzer modules are complemented by further electronic modules such as counters, precision clocks and synchronization modules that facilitate a seamless integration with main experimental data acquisitions for atomic and nuclear physics. In this contribution, the setup and first results from a test run at the experimental storage ring at GSI, Darmstadt, Germany, are presented.

  9. Present status of the NIJI-IV storage-ring free-electron lasers

    SciTech Connect

    Yamazaki, T.; Yamada, K.; Sei, N.

    1995-12-31

    The tunable region of the free-electron-laser (FEL) wavelength with the NIJI-IV system is now 348{approximately}595 nm. After the lasing at 352 nm in 1994, the quality of the electron beam stored in the ring has been improved further, and the highest peak intensity of the laser obtained so far is more than 300 times as high as that of the resonated spontaneous emission. The macro-temporal structure of the lasing has been greatly improved. Recently, a single-bunch injection system was completed, and the system has been installed in the injector linac, which is expected to increase the peak stored-beam current. The commissioning and the test of the new system is under way. The beam transporting system from the linac to the ring is also being modified by increasing the number of quadrupole magnets. The experiments related to the FEL in the ultraviolet wavelength region will be begun in this coming May. The results and the status of the FEL experiments will be presented at the Conference.

  10. 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

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

    SciTech Connect

    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 a 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.

  12. Diffraction-limited storage rings - a window to the science of tomorrow.

    PubMed

    Eriksson, Mikael; van der Veen, J Friso; Quitmann, Christoph

    2014-09-01

    This article summarizes the contributions in this special issue on Diffraction-Limited Storage Rings. It analyses the progress in accelerator technology enabling a significant increase in brightness and coherent fraction of the X-ray light provided by storage rings. With MAX IV and Sirius there are two facilities under construction that already exploit these advantages. Several other projects are in the design stage and these will probably enhance the performance further. To translate the progress in light source quality into new science requires similar progress in aspects such as optics, beamline technology, detectors and data analysis. The quality of new science will be limited by the weakest component in this value chain. Breakthroughs can be expected in high-resolution imaging, microscopy and spectroscopy. These techniques are relevant for many fields of science; for example, for the fundamental understanding of the properties of correlated electron materials, the development and characterization of materials for data and energy storage, environmental applications and bio-medicine.

  13. Storage Ring Section for a Polarized Gas Target with High Angular Acceptance

    NASA Astrophysics Data System (ADS)

    Garishvili, A.; Lorentz, B.; Nass, A.; Lehrach, A.; Lenisa, P.; Maier, R.; Martin, S.; Rathmann, F.; Statera, M.; Steffens, E.; Ströher, H.

    2008-02-01

    In the framework of the FAIR project [1], the PAX collaboration [2] has suggested new experiments using polarized protons and antiprotons. In order to provide polarized antiprotons, the polarization buildup by spin-dependent attenuation due to nuclear interaction (spin-filtering) must be studied. The goal of these investigations is to understand the physics of the spin-filtering process with stored protons at COSY, and to shed light on the role of polarized electrons for the polarization buildup. Later on, the spin-dependence of the proton-antiproton interaction will be investigated at the Antiproton Decelerator ring (AD) of CERN. In order to carry out these investigations, a storage ring section has to be developed which minimizes the spin-independent losses due to single Coulomb scattering.

  14. THE POTENTIAL FOR NEUTRINO PHYSICS AT MUON COLLIDERS AND DEDICATED HIGH CURRENT MUON STORAGE RINGS

    SciTech Connect

    BIGI,I.; BOLTON,T.; FORMAGGIO,J.; HARRIS,D.; MORFIN,J.; SPENTZOURIS,P.; YU,J.; KAYSER,B.; KING,B.J.; MCFARLAND,K.; PETROV,A.; SCHELLMAN,H.; VELASCO,M.; SHROCK,R.

    2000-05-11

    Conceptual design studies are underway for both muon colliders and high-current non-colliding muon storage rings that have the potential to become the first true neutrino factories. Muon decays in long straight sections of the storage rings would produce uniquely intense and precisely characterized two-component neutrino beams--muon neutrinos plus electron antineutrinos from negative muon decays and electron neutrinos plus muon antineutrinos from positive muons. This article presents a long-term overview of the prospects for these facilities to greatly extend the capabilities for accelerator-based neutrino physics studies for both high rate and long baseline neutrino experiments. As the first major physics topic, recent experimental results involving neutrino oscillations have motivated a vigorous design effort towards dedicated neutrino factories that would store muon beams of energies 50 GeV or below. These facilities hold the promise of neutrino oscillation experiments with baselines up to intercontinental distances and utilizing well understood beams that contain, for the first time, a substantial component of multi-GeV electron-flavored neutrinos. In deference to the active and fast-moving nature of neutrino oscillation studies, the discussion of long baseline physics at neutrino factories has been limited to a concise general overview of the relevant theory, detector technologies, beam properties, experimental goals and potential physics capabilities. The remainder of the article is devoted to the complementary high rate neutrino experiments that would study neutrino-nucleon and neutrino-electron scattering and would be performed at high performance detectors placed as close as is practical to the neutrino production straight section of muon storage rings in order to exploit beams with transverse dimensions as small as a few tens of centimeters.

  15. COUPLING IMPEDANCE OF CESR-B RF CAVITY FOR THE NSLS-II STORAGE RING.

    SciTech Connect

    BLEDNYKH,A.; KRINSKY, S.; ROSE, J.

    2007-06-25

    CESR-B type superconducting cavities are under consideration for acceleration of the electron beam in the 3GeV NSLS-II storage ring. In this paper we present detailed investigation of longitudinal and transverse impedance of CESR-B cavity and transitions. Ferrite material is included in impedance analysis. Its effect on short range wake potential has been studied using GdfidL code. The summary results of loss factors and kick factors are presented for a 3mm rms bunch length.

  16. IMPEDANCE OF ELECTRON BEAM VACUUM CHAMBERS FOR THE NSLS-II STORAGE RING.

    SciTech Connect

    BLEDNYKH,A.; KRINSKY, S.

    2007-06-25

    In this paper we discuss computation of the coupling impedance of the vacuum chambers for the NSLS-II storage ring using the electromagnetic simulator GdfidL [1]. The impedance of the vacuum chambers depends on the geometric dimensions of the cross-section and height of the slot in the chamber wall. Of particular concern is the complex geometry of the infrared extraction chambers to be installed in special large-gap dipole magnets. In this case, wakefields are generated due to tapered transitions and large vertical-aperture ports with mirrors near the electron beam.

  17. Minimum emittance in electron storage rings with uniform or nonuniform dipoles.

    SciTech Connect

    Wang, C.-x.; Accelerator Systems Division

    2009-06-01

    A simple treatment of minimum emittance theory in storage rings is presented, favoring vector and matrix forms for a more concise picture. Both conventional uniform dipoles and nonuniform dipoles with bending radius variation are treated. Simple formulas are given for computing the minimum emittance, optimal lattice parameters, as well as effects of nonoptimal parameters. For nonuniform dipoles, analytical results are obtained for a three-piece sandwich dipole model. Minimization of the effective emittance for light sources is given in detail. Usefulness of gradient and/or nonuniform dipoles for reducing the effective emittance is addressed.

  18. 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.

  19. A statistical analysis of the beam position measurement in the Los Alamos proton storage ring

    SciTech Connect

    Kolski, Jeff S; Macek, Robert J; Mc Crady, Rodney C

    2010-01-01

    The beam position monitors (BPMs) are the main diagnostic in the Los Alamos Proton Storage Ring (PSR). They are used in several applications during operations and tuning including orbit bumps and measurements of the tune, closed orbit (CO), and injection offset. However the BPM data acquisition system makes use of older technologies, such as matrix switches, that could lead to faulty measurements. This is the first statistical study of the PSR BPM perfonnance using BPM measurements. In this study, 101 consecutive CO measurements are analyzed. Reported here are the results of the statistical analysis, tune and CO measurement spreads, the BPM single turn measurement error, and examples of the observed data acquisition errors.

  20. The amplitude and phase control of the ALS Storage Ring RF System

    SciTech Connect

    Lo, C.C.; Taylor, B.; Baptiste, K.

    1995-03-01

    A 500MHz, 300KW Klystron power amplifier provides RF power to the ALS Storage Ring. In order to accommodate the amplitude and phase changes during beam stacking and decay, which demand continuously varying power levels from the Klystron, four loops are used to keep the system operating properly, with two of those loops dedicated to keeping the two cavity tuners on tune. Description of the control loops and their performance data will be given. Using the modulation anode of the Klystron in the amplitude loop will be discussed.

  1. Control of coupled-bunch instabilities in high current storage rings

    SciTech Connect

    Lambertson, G.

    1991-04-01

    Intense particle beams may be subject to coupled-bunch instabilities that would grow at rates greater than the bunch oscillation frequencies. The suppression of the growth requires both reduction of the driving impedances and active feedback of bunch motions. The shunt impedances of higher-order cavity resonances can be reduced by passive dampers and the beam impedance within the band of the fundamental resonance can be reduced by rf feedback around the cavity and power amplifier. The feedback of bunch motions composed of numerous coupled-bunch modes requires broad-band systems for which the amplifiers are costly. Examples proposed for electron storage rings are presented. 10 refs, 5 figs.

  2. Electric field detection of coherent synchrotron radiation in a storage ring generated using laser bunch slicing

    SciTech Connect

    Katayama, I.; Shimosato, H.; Bito, M.; Furusawa, K.; Adachi, M.; Zen, H.; Kimura, S.; Katoh, M.; Shimada, M.; Yamamoto, N.; Hosaka, M.; Ashida, M.

    2012-03-12

    The electric field of coherent synchrotron radiation (CSR) generated by laser bunch slicing in a storage ring has been detected by an electro-optic sampling method. The gate pulses for sampling are sent through a large-mode-area photonic-crystal fiber. The observed electric field profile of the CSR is in good agreement with the spectrum of the CSR observed using Fourier transform far-infrared spectrometry, indicating good phase stability in the CSR. The longitudinal density profiles of electrons modulated by laser pulses were evaluated from the electric field profile.

  3. 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)

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

    SciTech Connect

    Gao, F.; Rose, J.; Cupolo, J.; Dilgen, T.; Rose, B.; Gash, W.; Ravindranath, V.; Yeddulla, M.; Papu, J.; Davila, P.; Holub, B.; Tagger, J.; Sikora, R.; Ramirez, G.; Kulpin, 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.

  5. Measurement of photon statistics of wiggler radiation from an electron storage ring

    NASA Astrophysics Data System (ADS)

    Tanabe, Toshiya; Teich, Malvin C.; Marshall, T. C.; Galayda, John

    1991-07-01

    The number of visible photons emitted by an electron bunch moving through a wiggler in the Brookhaven Synchrotron Light Source storage ring was repetitively measured using an analog photon counting technique, and the photon counting distribution, which is the probability of finding n photons versus n, was obtained. The photoelectron-counting distribution of detected spontaneous light from the wiggler obeys a negative-binomial distribution consistent with a multi-electron, multimode description of the light generation process. In the absence of the wiggler, the bending-magnet light emerging from the pyrex exit port obeys the Neyman type-A distribution.

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

    SciTech Connect

    Zhang, Y. H.; Xu, H. S.; Wang, M.; Zhou, X. H.; Yuan, Y. J.; Xia, J. W.; Hu, Z. G.; Huang, W. X.; Liu, Y.; Ma, X.; Mao, R. S.; Mei, B.; Sun, Z. Y.; Wang, J. S.; Xiao, G. Q.; Yan, X. L.; Yang, J. C.; Zhao, H. W.; Zhao, T. C.; Zhang, X. Y.; and others

    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.

  7. Rf stability, control and bunch lengthening in electron synchrotron storage rings

    SciTech Connect

    Wachtel, J.M.

    1989-09-01

    A self-consistent theory for nonlinear longitudinal particle motion and rf cavity excitation in a high energy electron storage ring is developed. Coupled first order equations for the motion of an arbitrary number of particles and for the field in several rf cavities are given in the form used in control system theory. Stochastic quantum excitation of synchrotron motion is included, as are the effects of rf control system corrections. Results of computations for double cavity bunch lengthening are given. 11 refs., 4 figs., 1 tab.

  8. On the Absorber Thickness of Microcalorimetric Detectors in Experiments at Nuclear Storage Rings

    NASA Astrophysics Data System (ADS)

    Andrianov, V. A.; Kraft-Bermuth, S.; Scholz, P.

    2016-07-01

    Low-temperature calorimetric detectors are now successfully used in experiments on Lamb-Shift measurements at experimental storage rings. Strong Doppler broadening of the detected X-ray lines is a prominent feature of these experiments. Accordingly, an optimization procedure for the absorber thickness is proposed that considers the self-width of the X-ray detector line, the Doppler broadening, and the absorption efficiency, taking into account the possibility of the escape of secondary radiation. The optimum thickness for Sn-absorbers in this type of experiments is determined as 0.17 mm.

  9. Safe operating conditions for NSLS-II Storage Ring Frontends commissioning

    SciTech Connect

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

    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.

  10. Laser cooling of {sup 24}Mg{sup +} in the ASTRID storage ring

    SciTech Connect

    Nielsen, J.S.; Hangst, J.S.; Poulsen, O.; Shi, P. |; Schiffer, J.P. |; Wanner, B.

    1994-05-01

    Laser cooling of {sup 24}Mg{sup +} has now begun at the ASTRID storage ring. In contrast to {sup 7}Li{sup +}, which has been used up to now, it is now possible for the laser to interact with all of the beam. In this paper some of the results from the first beam time with {sup 24}Mg{sup +} are described. By frequency chirping a single laser, laser cooling has been performed on a coasting beam, and first evidence of sympathetic transverse cooling has been observed.

  11. Calculation of the intensity of Touschek electrons in the VEPP-4M storage ring

    SciTech Connect

    Nikitin, S. A. Nikolaev, I. B.

    2012-07-15

    Formulas for calculating the intensity of intrabeam scattering of electrons in the Born approximation for the one- and two-dimensional collision models have been obtained for the nonrelativistic and relativistic cases. The Baier-Katkov-Strakhovenko two-dimensional relativistic model with Coulomb corrections has been analyzed. Formulas in the ultrarelativistic limit have been obtained using this model. Different models have been compared. The intensities of Touschek electrons and the polarization contribution have been calculated under the conditions of the detection of scattered particles at the VEPP-4M storage ring. The calculations have been compared to experimental data.

  12. Development of a hydrogen and deuterium polarized gas target for application in storage rings

    SciTech Connect

    Haeberli, W.

    1992-02-01

    Polarized gas targets of atomic hydrogen and deuterium have significant advantages over conventional polarized targets, e.g. chemical and isotopic purity, large polarization including deuteron tensor polarization, absence of strong magnetic fields, rapid polarization reversal. While in principle the beam of polarized atoms from an atomic beam source (Stern-Gerlach spin separation) can be used as a polarized target, the target thickness achieved is too small for most applications. We propose to increase the target thickness by injecting the polarized atoms into a storage cell. Provided the atoms survive several hundred wall collisions without losing their polarization, it will be possible to achieve a target thickness of 10{sup 13} to 10{sup 14} atoms/cm{sup 2} by injection of polarized atoms from an atomic-beam source into suitable cells. Such targets are very attractive as internal targets in storage rings.

  13. Development of a hydrogen and deuterium polarized gas target for application in storage rings. Progress report

    SciTech Connect

    Haeberli, W.

    1992-02-01

    Polarized gas targets of atomic hydrogen and deuterium have significant advantages over conventional polarized targets, e.g. chemical and isotopic purity, large polarization including deuteron tensor polarization, absence of strong magnetic fields, rapid polarization reversal. While in principle the beam of polarized atoms from an atomic beam source (Stern-Gerlach spin separation) can be used as a polarized target, the target thickness achieved is too small for most applications. We propose to increase the target thickness by injecting the polarized atoms into a storage cell. Provided the atoms survive several hundred wall collisions without losing their polarization, it will be possible to achieve a target thickness of 10{sup 13} to 10{sup 14} atoms/cm{sup 2} by injection of polarized atoms from an atomic-beam source into suitable cells. Such targets are very attractive as internal targets in storage rings.

  14. A Pulsed Modulator Power Supply for the g-2 Muon Storage Ring Injection Kicker

    SciTech Connect

    Mi,J.; Lee, Y.Y.; Morse, W. M.; Pai, C.; Pappas, G.; Sanders, R.; Semertzidis, Y.

    1999-03-29

    This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the g-2 storage ring that has been built at Brookhaven. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95 kV. the damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. this paper discusses the modulator design, construction and operation.

  15. A PULSED MODULATOR POWER SUPPLY FOR THE G-2 MUON STORAGE RING INJECTION KICKER.

    SciTech Connect

    MI,J.LEE,Y.Y.MORSE,W.M.PAI,C.I.PAPPAS,G.C.SANDERS,Y.SEMERTIZIDIS,Y.,ET AL.

    2003-03-01

    This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the 8-2 storage ring that has been built at Brookhaven National Laboratory. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, a damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95kV. The damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. This paper discusses the modulator design, construction and operation.

  16. Improvement of current limitation in the storage ring NIJI-IV

    SciTech Connect

    Yokoyama, M.; Kawai, M.; Hamada, S.

    1995-12-31

    The storage ring NIJI-IV dedicated to free-electron lasers was completed in December 1990. Lasing at 595-352 nm by using the NIJI-IV was accomplished by April 1994. The NIJI-IV has 16 rf-buckets. The electron bunch contributed to FEL gain of the NIJI-IV is only one of 16. In order to get the redundant bunch, make beam quality better, and make the FEL operation easier, a single bunch injection (SBI) system by using a short pulse beam from an electron gun was prepared. The quality of the beam accelerated and bunched by a buncher section has already been investigated. It was convinced that the accelerated short pulse beam satisfies the performance required on the SBI of the NIJI-IV. At present, the operation of the SBI system is being tested. Storage efficiency (the ratio of storage current to injection current) and limitation of storage current by using the SBI system will be reported in this conference. We expect lasing at below 352nm by the SBI.

  17. Exact transfer functions for the PEP storage ring magnets and some general characteristics and techniques

    SciTech Connect

    Spencer, J.E.

    1982-05-01

    The exact, ion-optical transfer functions for the dipoles, quadrupoles and sextupoles of the PEP standard PODC cell are calculated for any single particle with initial coordinates (r, p, s). Modifications resulting from radiative energy loss are also calculated and discussed. These functions allow one to characterize individual magnets or classes of magnets by their aberrations and thereby simplify their study and correction. In contrast to high-energy spectrometers where aberrations are often analyzed away, those in storage rings drive series of high order resonances, even for perfect magnets (2), that can produce stop bands and other effects which can seriously limit performance. Thus, one would like to eliminate them altogether or failing this to develop local and global correction schemes. Even then, one should expect higher order effects to influence injection, extraction or single-pass systems either because of orbit distortions or overly large phase spece distortions such as may occur in low-beta insertions or any final-focus optics. The term exact means that the results here are based on solving the relativistic Lorentz force equation with accurate representations of measured magnetostatic fields. Such fields satisfy Maxwell's equations and are the actual fields seen by a particle as it propagates around a real storage ring. This is discussed in detail and illustrated with examples that show that this is possible, practical and may even be useful.

  18. Gas bremsstrahlung studies for medium energy electron storage rings using FLUKA Monte Carlo code

    NASA Astrophysics Data System (ADS)

    Sahani, Prasanta Kumar; Haridas, G.; Sinha, Anil K.; Hannurkar, P. R.

    2016-02-01

    Gas bremsstrahlung is generated due to the interaction of the stored electron beam with residual gas molecules of the vacuum chamber in a storage ring. As the opening angle of the bremsstrahlung is very small, the scoring area used in Monte Carlo simulation plays a dominant role in evaluating the absorbed dose. In the present work gas bremsstrahlung angular distribution and absorbed dose for the energies ranging from 1 to 5 GeV electron storage rings are studied using the Monte Carlo code, FLUKA. From the study, an empirical formula for gas bremsstrahlung dose estimation was deduced. The results were compared with the data obtained from reported experimental values. The results obtained from simulations are found to be in very good agreement with the reported experimental data. The results obtained are applied in estimating the gas bremsstrahlung dose for 2.5 GeV synchrotron radiation source, Indus-2 at Raja Ramanna Centre for Advanced Technology, India. The paper discusses the details of the simulation and the results obtained.

  19. Study of magnetic hysteresis effects in a storage ring using precision tune measurement

    NASA Astrophysics Data System (ADS)

    Li, Wei; Hao, Hao; Mikhailov, Stepan F.; Xu, Wei; Li, Jing-Yi; Li, Wei-Min; Wu, Ying. K.

    2016-12-01

    With the advances in accelerator science and technology in recent decades, the accelerator community has focused on the development of next-generation light sources, for example diffraction-limited storage rings (DLSRs), which require precision control of the electron beam energy and betatron tunes. This work is aimed at understanding magnet hysteresis effects on the electron beam energy and lattice focusing in circular accelerators, and developing new methods to gain better control of these effects. In this paper, we will report our recent experimental study of the magnetic hysteresis effects and their impacts on the Duke storage ring lattice using the transverse feedback based precision tune measurement system. The major magnet hysteresis effects associated with magnet normalization and lattice ramping are carefully studied to determine an effective procedure for lattice preparation while maintaining a high degree of reproducibility of lattice focusing. The local hysteresis effects are also studied by measuring the betatron tune shifts which result from adjusting the setting of a quadrupole. A new technique has been developed to precisely recover the focusing strength of the quadrupole by returning it to a proper setting to overcome the local hysteresis effect. Supported by National Natural Science Foundation of China (11175180, 11475167) and US DOE (DE-FG02-97ER41033)

  20. Recombination and Ionization Measurements at the Heidelberg Heavy Ion Storage Ring TSR

    NASA Astrophysics Data System (ADS)

    Lestinsky, Michael; Lukic, D.; Savin, D. W.; Hoffmann, J.; Krantz, C.; Orlov, D. A.; Wolf, A.; Bernhardt, D.; Borovyk, O.; Schmidt, E. W.; Yu, D.; Schippers, S.; Müller, A.; Badnell, N. R.

    2008-05-01

    Much of our knowledge of the universe rests on our ability to interpret spectra collected from various cosmic sources. This analysis requires reliably understanding the underlying charge state distribution (CSD) for the observed gas. In turn, this depends on accurate rate coefficients for dielectronic recombination (DR) and electron impact ionization (EII), which play important roles in determining the CSD for a wide range of cosmic objects. To address these needs we have an ongoing experimental program carrying out DR and EII measurements for astrophysically important ions of cosmically abundant elements. Measurements are performed using the heavy-ion Test Storage Ring (TSR) at the Max-Plank-Institute for Nuclear Physics in Heidelberg, Germany. Storage rings are currently the only laboratory method capable of studying the astrophysically relevant DR channels for the majority of cosmically important ions. They are also the only method capable of studying EII using beams of ions with multiple electrons in the valence shell which are free of metastable contamination, allowing for unambiguous EII laboratory data. We use our results to produce rate coefficients for plasma modelling. We are also providing our data to atomic theorist to benchmark their calculations. Here we report our recent results for DR measurements of Fe XI and Fe X and show an early status report on the analysis of recent EII measurements of C IV, C V and O IV. This work has been supported in part by NASA, the German Federal Ministry for Education and Research, and the German Research Council.

  1. Waveguide Structures for RF Undulators with Applications to FELs and Storage Rings

    SciTech Connect

    Yeddulla, M.; Geng, H.G.; Huang, Z.; Ma, Z.; Tantawi, S.G.; /SLAC

    2011-11-02

    RF undulators, suggested a long time ago, have the advantage of fast dynamic control of polarization, undulator strength and wavelength. However, RF undulators require very strong RF fields in order to produce radiation of the same order as conventional static devices. Very high power RF energy confined inside a waveguide or a cavity can provide the necessary RF fields to undulate the electron beam. However, the wall losses in the waveguide should be low enough to make it practically feasible as a CW or quasi CW undulator and, hence, competitive with static devices for applications to storage rings and FELs. Here we present various waveguide structures such as smooth walled and corrugated walled waveguides and various RF modes. We will show that there are some advantages in operating with higher order modes and also with hybrid modes in the corrugated guide. We will show that the RF power requirement for some of these modes will permit a quasi CW operation of the undulator, thus permitting its operation in a storage ring.

  2. Use of the Halbach perturbation theory for the multipole design of the ALS storage ring sextupole

    SciTech Connect

    Marks, S.

    1995-02-01

    The Advanced Light Source (ALS) storage ring sextupole is a unique multi-purpose magnet. It is designed to operate in the primary or sextupole mode and in three auxiliary trim modes: horizontal steering, vertical steering, and skew quadrupole. Klaus Halbach developed a perturbation theory for iron-dominated magnets which provides the basis for this design. Many magnet designers, certainly those who have been exposed to Klaus, are familiar with this theory and have used it for such things as evaluating the effect of assembly alignment errors. The ALS sextupole design process was somewhat novel in its use of the perturbation theory to design essential features of the magnet. In particular, the steering and skew quadrupole functions are produced by violating sextupole symmetry and are thus perturbations of the normal sextupole excitation. The magnet was designed such that all four modes are decoupled and can be excited independently. This paper discusses the use of Halbach`s perturbation theory to design the trim functions and to evaluate the primary asymmetry in the sextupole mode, namely, a gap in the return yoke to accommodate the vacuum chamber. Prototype testing verified all operating modes of the magnet and confirmed the expected performance from calculations based upon the Halbach perturbation theory. A total of 48 sextupole magnets of this design are now installed and operating successfully in the ALS storage ring.

  3. The large superconducting solenoids for the g-2 muon storage ring

    SciTech Connect

    Bunce, G.; Cullen, J.; Danby, G.

    1994-12-01

    The g-2 muon storage ring at Brookhaven National Laboratory consists of four large superconducting solenoids. The two outer solenoids, which are 15.1 meters in diameter, share a common cryostat. The two inner solenoids, which are 13.4 meters in diameter, are in separate cryostats. The two 24 turn inner solenoids are operated at an opposite polarity from the two 24 turn outer solenoids. This generates a dipole field between the inner and outer solenoids. The flux between the solenoids is returned through a C shaped iron return yoke that also shapes the dipole field. The integrated field around the 14 meter diameter storage ring must be good to about 1 part in one million over the 90 mm dia. circular cross section where the muons are stored, averaged over the azimuth. When the four solenoids carry their 5300 A design current, the field in the 18 centimeter gap between the poles is 1.45 T. When the solenoid operates at its design current 5.5 MJ is stored between the poles. The solenoids were wound on site at Brookhaven National Laboratory. The cryostats were built around the solenoid windings which are indirectly cooled using two-phase helium.

  4. Improved temperature regulation of process water systems for the APS storage ring.

    SciTech Connect

    Putnam, C.; Dortwegt, R.

    2002-10-10

    Beam stability and operational reliability of critical mechanical systems are key performance issues for synchrotron accelerators such as the Advanced Photon Source (APS). Stability is influenced by temperature fluctuations of the process water (PW) used for cooling and/or temperature conditioning storage ring (SR) components such as vacuum chambers, magnets, absorbers, etc. Operational reliability is crucial in maintaining facility beam operations and remaining within downtime ''budgets.'' Water systems for the APS storage ring were originally provided with a distributive control system (DCS) capable of regulation to {+-}1.0 F, as specified by facility design requirements. After several years of operation, a particular mode of component mortality indicated a need for upgrade of the temperature control system. The upgrade that was implemented was chosen for both improved component reliability and temperature stability (now on the order of {+-}0.2 F for copper components and {+-}0.05 F for aluminum components). The design employs a network of programmable logic controllers (PLCs) for temperature control that functions under supervision of the existing DCS. The human-machine interface (HMI) of the PLC system employs RSView32 software. The PLC system also interfaces with the EPICS accelerator control system to provide monitoring of temperature control parameters. Eventual supervision of the PLC system by EPICS is possible with this design.

  5. The Conversion and operation of the Cornell electron storage ring as a test accelerator (cesrta) for damping rings research and development

    SciTech Connect

    Palmer, M.A.; Alexander, J.; Byrd, J.; Celata, C.M.; Corlett, J.; De Santis, S.; Furman, M.; Jackson, A.; Kraft, R.; Munson, D.; Penn, G.; Plate, D.; Rawlins, A.; Venturini, M.; Zisman, M.; Billing, M.; Calvey, J.; Chapman, S.; Codner, G.; Conolly, C.; Crittenden, J.; Dobbins, J.; Dugan, G.; Fontes, E.; Forster, M.; Gallagher, R.; Gray, S.; Greenwald, S.; Hartill, D.; Hopkins, W.; Kandaswamy, J.; Kreinick, D.; Li, Y.; Liu, X.; Livezey, J.; Lyndaker, A.; Medjidzade, V.; Meller, R.; Peck, S.; Peterson, D.; Rendina, M.; Revesz, P.; Rice, D.; Rider, N.; Rubin, D.; Sagan, D.; Savino, J.; Seeley, R.; Sexton, J.; Shanks, J.; Sikora, J.; Smolenski, K.; Strohman, C.; Temnykh, A.; tigner, M.; Whitney, W.; Williams, H.; Vishniakou, S.; Wilkens, T.; Harkay, K.; Holtzapple, R.; Smith, E.; Jones, J.; Wolski, A.; He, Y.; Ross, M.; Tan, C.Y.; Zwaska, R.; Flanagan, J.; Jain, P.; Kanazawa, K.; Ohmi, K.; Sakai, H.; Shibata, K.; Suetsugu, Y.; Kharakh, D.; Pivi, M.; Wang, L.

    2009-05-01

    In March of 2008, the Cornell Electron Storage Ring (CESR) concluded twenty eight years of colliding beam operations for the CLEO high energy physics experiment. We have reconfigured CESR as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R&D. The primary goals of the CesrTA program are to achieve a beam emittance approaching that of the ILC Damping Rings with a positron beam, to investigate the interaction of the electron cloud with both low emittance positron and electron beams, to explore methods to suppress the electron cloud, and to develop suitable advanced instrumentation required for these experimental studies (in particular a fast x-ray beam size monitor capable of single pass measurements of individual bunches). We report on progress with the CESR conversion activities, the status and schedule for the experimental program, and the first experimental results that have been obtained.

  6. Localized Chromaticity Correction of Low-Beta Insertions in Storage Rings

    SciTech Connect

    Donald, M.; Helm, R.; Moshammer, I.H.; Forest, E.; Robin, David; Zholents, A.A.; Sullivan, M.; Irwin, J.

    1993-05-01

    The correction of the chromaticity of low-beta insertions in the storage rings is usually made with sextupole lenses in the ring's arcs. When decreasing the beta functions at the insertion point (IP), this technique becomes fairly ineffective, since it fails to properly correct the higher order chromatic aberrations. Here we consider the approach where the chromatic effects of the quadrupole lenses generating low beta functions at the IP are corrected locally with two families of sextupoles, one family for each plane. Each family has two pairs of sextupoles which are located symmetrically on both sides of the IP. The sextupole-like aberrations of individual sextupoles are eliminated by utilizing optics forming a -I transformation between sextupoles in the pair. The optics also includes bending magnets which preserve equal dispersion functions at the two sextupoles in each pair. At sextupoles in one family, the vertical beta function is made large and the horizontal is made small. The situation is reversed in the sextupoles of the other family. The betatron phase advances from the IP to the sextupoles are chosen to eliminate a second order chromatic aberration. The application of the localized chromatic correction is demonstrated using as an example the lattice design for the Low Energy Ring of the SLAC/LBL/LLNL PEP-II B Factory.

  7. Lattice Design for PEP-X Ultimate Storage Ring Light Source

    SciTech Connect

    Bane, K.L.F.; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; Hettel, R.O.; /SLAC

    2011-12-13

    SLAC expertise in designing and operating high current storage rings and the availability of the 2.2-km PEP-II tunnel present an opportunity for building a next generation light source - PEP-X - that would replace the SPEAR3 storage ring in the future. The PEP-X 'baseline' design, with 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. As a next step, a so-called 'ultimate' PEP-X lattice, reducing the emittance to 11 pm-rad at zero current, has been designed. This emittance approaches the diffraction limited photon emittance for multi-keV photons, providing near maximum photon brightness and high coherence. It is achieved by using 7-bend achromat cells in the ring arcs and a 90-m damping wiggler in one of the 6 long straight sections. Details of the lattice design, dynamic aperture, and calculations of the intra-beam scattering effect and Touschek lifetime at a nominal 0.2 A current are presented. Accelerator-based light sources are in high demand for many experimental applications. The availability of the 2.2-km PEP-II tunnel at SLAC presents an opportunity for building a next generation light source - PEP-X - that would replace the existing SPEAR3 light source in the future. The PEP-X study started in 2008, and the 'baseline' design, yielding 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. This relatively conservative design can be built using existing technology. However, for a long term future, it is natural to investigate a more aggressive, so-called 'ultimate' ring design. The goal is to reduce the electron emittance in both x and y planes to near the diffraction limited photon emittance of 8 pm-rad at hard X-ray photon wavelength of 0.1 nm. This would provide a near maximum photon brightness and significant increase in photon coherence. This study was motivated by the advances in low emittance design at MAX-IV. The latter was used as a starting point for the PEP-X arc lattice

  8. LIGHT SOURCE: Optics for the lattice of the compact storage ring for a Compton X-ray source

    NASA Astrophysics Data System (ADS)

    Yu, Pei-Cheng; Wang, Yu; Shen, Xiao-Zhe; Huang, Wen-Hui; Yan, Li-Xin; Du, Ying-Chao; Li, Ren-Kai; Tang, Chuan-Xiang

    2009-06-01

    We present two types of optics for the lattice of a compact storage ring for a Compton X-ray source. The optics design for different operation modes of the storage ring are discussed in detail. For the pulse mode optics, an IBS-suppression scheme is applied to optimize the optics for lower IBS emittance growth rate; as for the steady mode, the method to control momentum compact factor is adopted [Gladkikh P, Phys. Rev. ST Accel. Beams 8, 050702] to obtain stability of the electron beam.

  9. Effects of construction and alignment errors on the orbit functions of the advanced photon source storage ring

    SciTech Connect

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

    1991-01-01

    The orbit functions for the Advanced Photon Source Storage Ring have been studied using the simulation code RACETRACK. Non-linear elements are substituted into the storage ring lattice to simulate the effects of construction and alignment errors in the quadrupole, dipole, and sextupole magnets. The effects of these errors on the orbit distortion, dispersion, and beta functions are then graphically analyzed to show the rms spread of the functions across several machines. The studies show that the most significant error is displacement of the quadrupole magnets. Further studies using a 3 bump correction routine show that these errors can be corrected to acceptable levels. 1 ref., 10 figs., 1 tab.

  10. Mitigation of the electron-cloud effect in the PSR and SNS proton storage rings by tailoring the bunch profile

    SciTech Connect

    Pivi, M.; Furman, M.A.

    2003-05-20

    For the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electroncloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal bunch profile at fixed bunch charge, resulting in a significant decrease in the electron-cloud effect. We briefly discuss the experimental difficulties expected in the implementation of this cure.

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

    SciTech Connect

    Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N.

    1995-12-31

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

  12. Beam dynamics in an ultra-low energy storage rings (review of existing facilities and feasibility studies for future experiments)

    NASA Astrophysics Data System (ADS)

    Papash, A. I.; Smirnov, A. V.; Welsch, C. P.

    2014-03-01

    Storage rings operating at ultra-low energies and in particular electrostatic storage rings have proven to be invaluable tools for atomic and molecular physics. Due to the mass independence of the electrostatic rigidity, these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio-molecules. However, earlier measurements showed strong limitations on beam intensity, fast decay of ion current, reduced life time etc. The nature of these effects was not fully understood. Also a large variety of experiments in future generation ultra-low energy storage and decelerator facilities including in-ring collision studies with a reaction microscope require a comprehensive investigation of the physical processes involved into the operation of such rings. In this paper, we present review of non-linear and long term beam dynamics studies on example of the ELISA, AD Recycler, TSR and USR rings using the computer codes BETACOOL, OPERA-3D and MAD-X. The results from simulations were benchmarked against experimental data of beam losses in the ELISA storage ring. We showed that decay of beam intensity in ultra-low energy rings is mainly caused by ion losses on ring aperture due to multiple scattering on residual gas. Beam is lost on ring aperture due to small ring acceptance. Rate of beam losses increases at high intensities because of the intra-beam scattering effect adds to vacuum losses. Detailed investigations into the ion kinetics under consideration of the effects from electron cooling and multiple scattering of the beam on a supersonic gas jet target have been carried out as well. The life time, equilibrium momentum spread and equilibrium lateral spread during collisions with this internal gas jet target were estimated. In addition, the results from experiments at the TSR ring, where low intensity beam of CF+ ions at 93 keV/u has been shrunk to extremely small dimensions have been reproduced. Based on these simulations

  13. Mechanical design upgrade of the APS storage ring rf cavity tuner

    SciTech Connect

    Jones, J.; Bromberek, D.; Kang, Y.

    1997-08-01

    The Advanced Photon Source (APS) storage ring (SR) rf system employs four banks of four spherical, single-cell resonant cavities. Each cavity is tuned by varying the cavity volume through insertion/retraction of a copper piston located at the circumference of the cavity and oriented perpendicular to the accelerator beam. During the commissioning of the APS SR, the tuners and cavity tuner ports were prone to extensive arcing and overheating. The existing tuners were modified to eliminate the problems, and two new, redesigned tuners were installed. In both cases marked improvements were obtained in the tuner mechanical performance. As measured by tuner piston and flange surface temperatures, tuner heating has been reduced by a factor of five in the new version. Redesign considerations discussed include tuner piston-to-housing alignment, tuner piston and housing materials and cooling configurations, and tuner piston sliding electrical contacts. The tuner redesign is also distinguished by a modular, more maintainable assembly.

  14. Schottky Mass Measurements of Cooled Proton-Rich Nuclei at the GSI Experimental Storage Ring

    SciTech Connect

    Radon, T.; Schlitt, B.; Beckert, K.; Bosch, F.; Eickhoff, H.; Franzke, B.; Geissel, H.; Hausmann, M.; Irnich, H.; Klepper, O.; Kluge, H.; Kozhuharov, C.; Kraus, G.; Muenzenberg, G.; Nickel, F.; Nolden, F.; Patyk, Z.; Reich, H.; Scheidenberger, C.; Schwab, W.; Steck, M.; Suemmerer, K.; Kerscher, T.; Beha, T.; Loebner, K.E.; Fujita, Y.; Jung, H.C.; Wollnik, H.; Novikov, Y.

    1997-06-01

    High-precision mass measurements of proton-rich isotopes in the range of 60{le}Z{le}84 were performed using the novel technique of Schottky spectrometry. Projectile fragments produced by {sup 209}Bi ions at 930{ital A} MeV were separated with the magnetic spectrometer FRS and stored and cooled in the experimental storage ring (ESR). A typical mass resolving power of 350000 and a precision of 100keV were achieved in the region A{approx}200 . Masses of members of {alpha} chains linked by precise Q{sub {alpha}} values but not yet connected to the known masses were determined. In this way it is concluded that {sup 201}Fr and {sup 197}At are proton unbound. {copyright} {ital 1997} {ital The American Physical Society}

  15. Recombination of simple molecular ions studied in storage ring: dissociative recombination of H2O+

    PubMed

    Rosen; Derkatch; Semaniak; Neau; al-Khalili; Le Padellec A; Vikor; Thomas; Danared; af Ugglas M; Larsson

    2000-01-01

    Dissociative recombination of vibrationally relaxed H2O+ ions with electrons has been studied in the heavy-ion storage ring CRYRING. Absolute cross-sections have been measured for collision energies between 0 eV and 30 eV. The energy dependence of the cross-section below 0.1 eV is found to be much steeper than the E-1 behaviour associated with the dominance of the direct recombination mechanism. Resonant structures found at 4 eV and 11 eV have been attributed to the electron capture to Rydberg states converging to electronically excited ionic states. Complete branching fractions for all dissociation channels have been measured at a collision energy of 0 eV. The dissociation process is dominated by three-body H + H + O breakup that occurs with a branching ratio of 0.71.

  16. Electron Spectroscopy In Heavy-Ion Storage Rings: Resonant and Non-Resonant Electron Transfer Processes

    SciTech Connect

    Hagmann, S.; Stoehlker, Th.; Trotsenko, S.; Kozhuharov, Ch.; Spillmann, U.; Bosch, F.; Liesen, D.; Winters, D.; Hillenbrand, P.-M.; Shabaev, V.; Tupitsyn, I.; Kozhedub, Y.; Rothard, H.; Reuschl, R.; Ullrich, J.; Moshammer, R.; Voitkiv, A.; Surzhykov, A.; Fischer, D.; Doerner, R.

    2011-06-01

    Whereas our understanding of total cross sections for ionization and capture processes in ion-atom collisions is widely viewed as having arrived at a state of adequate maturity, the same cannot be said at all about the dynamics of collisions, multi-electron processes or the electron continua (in target and projectile) which are at the origin of total cross sections. We depict how these processes can be studied favourably in storage ring environments. We present examples of resonant and non-resonant electron transfer processes, radiative and non-radiative. This is elucidated via the relation of the electron nucleus bremsstrahlung at the high energy tip of the bremsstrahlung spectrum to the radiative electron capture cusp (RECC) and a new approach to determining molecular orbital binding energies in superheavy quasi-molecules in resonant KK charge transfer.

  17. The Heidelberg test storage ring for heavy ions and its use for atomic physics

    SciTech Connect

    Schuch, R.

    1986-11-01

    A brief description of the Heavy-Ion Test Storage Ring (TSR) presently being built at the Max-Planck Institut in Heidelberg is given. It will be able to store ions injected from the tandem postaccelerator combination up to about 30 MeV/nucleon for a charge to mass ratio of 0.5. One of the main purposes of the TSR will be the study of electron cooling. Some atomic physics experiments are discussed using the electron cooling device which provides an electron-ion collision facility with good energy resolution and ion beams of high currents and low emittances. Here the possibilities for measurements of spontaneous and laser-induced radiative recombination and dielectronic recombination in the electron cooling section are discussed.

  18. Dissociative recombination measurements of NH{sup +} using an ion storage ring

    SciTech Connect

    Novotný, O.; Savin, D. W.; Berg, M.; Bing, D.; Buhr, H.; Grieser, M.; Grussie, F.; Krantz, C.; Mendes, M. B.; Nordhorn, C.; Repnow, R.; Schwalm, D.; Yang, B.; Wolf, A.; Geppert, W.

    2014-09-10

    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 underestimated 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.

  19. Photodissociation of an Internally Cold Beam of CH+ Ions in a Cryogenic Storage Ring

    NASA Astrophysics Data System (ADS)

    O'Connor, A. P.; Becker, A.; Blaum, K.; Breitenfeldt, C.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; von Hahn, R.; Hechtfischer, U.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lohmann, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; Repnow, R.; Saurabh, S.; Schwalm, D.; Spruck, K.; Sunil Kumar, S.; Vogel, S.; Wolf, A.

    2016-03-01

    We have studied the photodissociation of CH+ in the Cryogenic Storage Ring at ambient temperatures below 10 K. Owing to the extremely high vacuum of the cryogenic environment, we were able to store CH+ beams with a kinetic energy of ˜60 keV for several minutes. Using a pulsed laser, we observed Feshbach-type near-threshold photodissociation resonances for the rotational levels J =0 - 2 of CH+, exclusively. In comparison to updated, state-of-the-art calculations, we find excellent agreement in the relative intensities of the resonances for a given J , and we can extract time-dependent level populations. Thus, we can monitor the spontaneous relaxation of CH+ to its lowest rotational states and demonstrate the preparation of an internally cold beam of molecular ions.

  20. Beam pinging, sweeping, shaking, and electron/ion collecting, at the Proton Storage Ring

    SciTech Connect

    Hardek, T.W.; Macek, R.J.; Plum, M.A.; Wang, T.S.F.

    1993-06-01

    We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results.

  1. NEW DEVELOPMENTS ON THE E-P INSTABILITY AT THE PROTON STORAGE RING (PSR)

    SciTech Connect

    R. MACEK

    2001-01-01

    New results are reported from an R and D program aimed at greater understanding and control of the e-p instability observed at the Los Alamos Proton Storage Ring (PSR). Numerous characteristics of the electron cloud for both stable and unstable beams in PSR were measured with ANL electron analyzers and various collection plates. Strong suppression of the electron flux density by TiN coating of the vacuum chamber in a straight section was also observed, thereby confirming an essential role for secondary emission at the walls. Landau Damping by a variety of techniques including higher rf voltage, transverse coupling, multipole fields in the lattice, and the use of inductive inserts has been effective in controlling the e-p instability. By these methods, the instability threshold has been raised significantly to 9.7 micro Coulombs per stored pulse.

  2. Recent experience with inductive insert at the proton storage ring (PSR)

    SciTech Connect

    Ng, K.-Y; Griffin, J. E.; Wildman, D.; Popovic, M.; Browman, A. A.; Fitzgerald, D. H.; Macek, R. J.; Plum, M. A.; Spickermann, T. J.

    2001-01-01

    In a Fermilab-Los Alamos collaboration, inductances constructed of ferrite cores sufficient to cancel a large fraction of the space charge potential-well distortion were installed in the Los Alamos Proton Storage Ring (PSR) as one means of raising the threshold for the two-stream e-p instability. When operating at higher intensities and with sufficient inductance added for full space-charge compensation, an unacceptable longitudinal self-bunching, microwavelike, instability was encountered. Heating the cores to N 130 C proved to be an effective cure, and was found to be a means for tuning the inductance over a limited but useful range. The heated inductors were an essential ingredient in achieving a record accumulation of 9.7 pC/pulse. An engineered version of the inductors is now installed for routine operation of the PSR. A summary of the inductor characteristics, theory of operation, experimental results, and interpretation will be presented.

  3. Beam pinging, sweeping, shaking, and electron/ion collecting, at the Proton Storage Ring

    SciTech Connect

    Hardek, T.W.; Macek, R.J.; Plum, M.A.; Wang, T.S.F.

    1993-01-01

    We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results.

  4. Active Damping of the E-P Instability at the Los Alamos Proton Storage Ring

    SciTech Connect

    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.; /Los Alamos

    2008-03-17

    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.

  5. Active damping of the e-p instability at the Los Alamos Proton Storage Ring

    SciTech Connect

    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.

    2007-12-15

    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.

  6. Theory of a modified Wadsworth monochromator matched to a low energy storage ring source

    SciTech Connect

    Howells, M.R.

    1981-01-01

    The concave diffraction grating in the Wadsworth mounting has been popular with synchrotron radiation spectroscopists because of its use of parallel light. This is well matched to experimental stations which are a great distance away from the source as would be the case in using a high energy synchrotron. For low energy storage rings the working distance is quite small and in this case it is appropriate to use a collimating mirror. Large collection angles are possible with this arrangement and reasonable resolution can be obtained using spherical surfaces. Astigmatism is much lower than for Rowland circle mountings. These questions are analyzed using an optical path function development and calculations are presented which include the aberrations both in the two optics and those caused by the large extension of the source in the direction of the radiation emission.

  7. Introduction to the magnet and vacuum systems of an electron storage ring

    SciTech Connect

    Weng, W.T.

    1982-08-15

    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 and 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.

  8. Lasing of middle-infrared free-election lasers using the storage ring NIJI-IV.

    PubMed

    Sei, Norihiro; Ogawa, Hiroshi; Yamada, Kawakatsu

    2011-09-15

    We report for the first time to our knowledge the experimental realization of a storage ring free-electron laser (FEL) in the middle-infrared (MIR) region. A technique to adjust the optical cavity using higher harmonic FELs was developed for a fundamental FEL in the MIR region. The MIR FELs were oscillated in the wavelength region of 2475 to 2673 nm, and the relative linewidth was 5×10⁻⁴. A quasi-monochromatic x-ray beam with an energy of 700 keV was generated using FEL Compton backscattering. We were able to realize a quasi-monochromatic x-ray beam, whose energy is difficult to generate even in advanced synchrotron radiation facilities.

  9. Lasing of infrared free-election lasers using the storage ring NIJI-IV.

    PubMed

    Sei, Norihiro; Ogawa, Hiroshi; Yamada, Kawakatsu

    2009-06-15

    We report for the first time to our knowledge the experimental achievement of a storage ring free-electron laser (FEL) device dedicated to applications in the IR region. IR FELs were oscillated in the wavelength region of 1392-1502 nm, and the relative linewidth was 3 x 10(-4). The maximum power of the IR FEL transmitted through a vacuum window was approximately 0.3 mW, and the intracavity power was approximately 2 W. We have already observed an intensive quasi-monochromatic x ray by using FEL Compton backscattering. The results of our study are expected to lead to applications in which an IR FEL and a quasi-monochromatic x ray will be used simultaneously.

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

    SciTech Connect

    Hahn, M.; Novotný, O.; Savin, D. W.; Becker, A.; Grieser, M.; Krantz, C.; Repnow, R.; Wolf, A.; Bernhardt, D.; Müller, A.; Schippers, S.; Spruck, K.; Lestinsky, M.

    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. The remaining discrepancies between our measurement and the Dere calculations are likely due to shortcomings in the theoretical treatment of the excitation-autoionization contribution.

  11. Software package for modeling spin–orbit motion in storage rings

    SciTech Connect

    Zyuzin, D. V.

    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{sup 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.

  12. Vacuum system development status for the APS (Advanced Photon Source) storage ring

    SciTech Connect

    Wherle, R.; Nielson, R.; Kim, S.

    1989-01-01

    The status of the design and fabrication of a prototype sector of the storage ring vacuum system for the Advanced Photon Source is described. The 26.5-m-long prototype sector will be assembled within a full-scale magnet and tunnel mockup to study interspacial component relationships for maintenance, as well as the vacuum system operational performance. Each completed vacuum section is mounted as an integral part of the modular structure that contains the magnets and magnet power supplies on a common base. Unique automatic machine welding designs and techniques are employed in the fabrication of the aluminium vacuum chambers from extrusions. Special chamber bending procedures and measurements checks are used to maintain the required flatness of the insider chamber light gap surfaces. Photo-electron yields due to low-energy photons in the narrow channel gap of the vacuum chamber and their potential effects on the overall outgassing rate are found to be negligible. 9 refs., 5 figs.

  13. Magnetic design of trim excitations for the advanced light source storage ring sextupole

    SciTech Connect

    Marks, S.

    1995-06-01

    The Advanced Light Source (ALS) storage ring sextupole is a unique multi-purpose magnet. It is designed to operate as a sextupole with three auxiliary trim modes: horizontal steering, vertical steering, and skew quadrupole. A perturbation theory for iron-dominated magnets developed by Klaus Halbach provides the basis for this design. The three trim excitations are produced by violating sextupole symmetry and are thus perturbations of the normal sextupole excitation. The magnet was designed such that all four modes are decoupled and can be excited independently. This paper discusses the use of Halbach`s perturbation theory to design the trim functions and to evaluate the primary asymmetry in the sextupole mode, namely, a gap in the return yoke to accommodate the vacuum chamber.

  14. Magnetic design of trim excitations for the Advanced Light Source storage ring sextupole

    SciTech Connect

    Marks, S.

    1996-07-01

    The Advanced Light Source (ALS) storage ring sextupole is a unique multi-purpose magnet. It is designed to operate as a sextupole with three auxiliary trim modes: horizontal steering, vertical steering, and skew quadrupole. A perturbation theory for iron-dominated magnets developed by Klaus Halbach provides the basis for this design. The three trim excitations are produced by violating sextupole symmetry and are thus perturbations of the normal sextupole excitation. The magnet was designed such that all four modes are decoupled and can be excited independently. This paper discusses the use of Halbach`s perturbation theory to design the trim functions and to evaluate the primary asymmetry in the sextupole mode, namely, a gap in the return yoke to accommodate the vacuum chamber.

  15. Photodissociation of an Internally Cold Beam of CH^{+} Ions in a Cryogenic Storage Ring.

    PubMed

    O'Connor, A P; Becker, A; Blaum, K; Breitenfeldt, C; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; von Hahn, R; Hechtfischer, U; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lohmann, S; Meyer, C; Mishra, P M; Novotný, O; Repnow, R; Saurabh, S; Schwalm, D; Spruck, K; Sunil Kumar, S; Vogel, S; Wolf, A

    2016-03-18

    We have studied the photodissociation of CH^{+} in the Cryogenic Storage Ring at ambient temperatures below 10 K. Owing to the extremely high vacuum of the cryogenic environment, we were able to store CH^{+} beams with a kinetic energy of ∼60  keV for several minutes. Using a pulsed laser, we observed Feshbach-type near-threshold photodissociation resonances for the rotational levels J=0-2 of CH^{+}, exclusively. In comparison to updated, state-of-the-art calculations, we find excellent agreement in the relative intensities of the resonances for a given J, and we can extract time-dependent level populations. Thus, we can monitor the spontaneous relaxation of CH^{+} to its lowest rotational states and demonstrate the preparation of an internally cold beam of molecular ions.

  16. Lattice design and optimization for the PEP-X ultra low emittance storage ring at SLAC

    SciTech Connect

    Wang, Min-Huey; Nosochkov, Yuri; Bane, Karl; Cai, Yunhai; Hettel, Robert; Huang, Xiaobiao; /SLAC

    2011-08-12

    SLAC is developing a long-range plan to transfer the evolving scientific programs at SSRL from the SPEAR3 light source to a much higher performing photon source. One of the possibilities is a new PEP-X 4.5 GeV storage ring that would be housed in the 2.2 km PEP-II tunnel. The PEP-X is designed to produce photon beams having brightness near 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV with 3.5 m undulator at beam current of 1.5 A. This report presents an overview of the PEP-X baseline lattice design and describes the lattice optimization procedures in order to maximize the beam dynamic aperture. The complete report of PEP-X baseline design is published in SLAC report.

  17. Calculations for shortening the bunch length in storage rings using a harmonic cavity

    NASA Astrophysics Data System (ADS)

    Fan, Hao; Wu, Cong-Feng; He, Duo-Hui

    2014-08-01

    Using the Hefei Light Source phase II project (HLS- II) as an example, a theoretical analysis of shortening the bunch lengths using a higher harmonic cavity (HHC) is given. The threshold voltage of an active HHC and the threshold tuning angle of a passive HHC are first analysed. The optimum tuning angle for the constant detuning scenario and the optimum harmonic voltage for the constant voltage scenario are presented. The calculated results show that the reduced bunch length is about half that of the nominal bunch. The bunch lengths vary from 11 mm at 0.1 A to 7 mm at 0.4 A for the constant detuning scenario, while the bunch lengths are around 7 mm over the beam current range for the constant voltage scenario. In addition, the synchrotron frequency spread is increased. It indicates that HHC may be used to reduce the bunch length and increase the Landau damping of synchrotron oscillations in a storage ring.

  18. 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).

  19. Distributed Non-evaporable Getter pumps for the storage ring of the APS

    SciTech Connect

    Dortwegt, R.; Benaroya, R.

    1993-07-01

    A pair of distributed Non-evaporable Getter (NeG) strip assemblies is installed in each of 236 aluminum vacuum chambers of the 1104-m storage ring of the Advanced Photon Source. Distributed pumping is provided to remove most of the gas resulting from photon-stimulated desorption occurring along the outer walls of the chambers. This is an efficient way of pumping because conductance is limited along the beam axis. The St-707 NeG strips are conditioned at 450{degree}C for 45 min. with 42 A. Base pressures obtained are also as low as 4 {times} 10{sup 11} Torr. The NeG strip assemblies are supported by a series of electrically isolated, 125-mm-long, interlocking stainless steel carriers. These unique interlocking carrier elements provide flexibility along the vacuum chamber curvature (r=38.96 m) and permit removal and installation of assemblies with as little as 150 mm external clearance between adjacent chambers.

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

    PubMed

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

    2017-02-03

    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.

  1. Scientific potential and design considerations for an undulator beam line on Aladdin storage ring

    SciTech Connect

    Arko, A. J.; Bader, S. D.; Dehmer, Joseph L.; Kim, S. H.; Knapp, G. S.; Shenoy, G. K.; Veal, B. W.; Young, C. E.; Brown, F. C.; Weaver, J. W.

    1985-04-08

    The unique features of undulator radiation, i.e., high photon flux and brightness, partial coherence, small beam divergence, spectral tunability, etc., mandate that undulators be included in the future plans for Aladdin. This will make it possible to perform the next generation of experiments in photon-stimulated spectroscopies. A team of scientists (see Appendix) has now been assembled to build an insertion device (ID) and the associated beam line at Aladdin. In considering the specifications for the ID, it was assumed that the ID beamline will be an SRC user facility. Consequently, design parameters were chosen with the intent of maximizing experimental flexibility consistent with a conservative design approach. A tunable ''clamshell'' undulator device was Chosen with a first harmonic tunable from 35 to 110 eV to operate on a 1 GeV storage ring. Higher harmonics will be utilized for experiments needing higher photon energies.

  2. An ultimate storage ring lattice with vertical emittance generated by damping wigglers

    SciTech Connect

    Huang, Xiaobiao

    2015-01-06

    We discuss the approach of generating round beams for ultimate storage rings using vertical damping wigglers (with horizontal magnetic field). The vertical damping wigglers provide damping and excite vertical emittance. This eliminates the need to generate large linear coupling that is impractical with traditional off-axis injection. We use a PEP-X compatible lattice to demonstrate the approach. This lattice uses separate quadrupole and sextupole magnets with realistic gradient strengths. Intrabeam scattering effects are calculated. As a result, the horizontal and vertical emittances are 22.3 pm and 10.3 pm, respectively, for a 200 mA, 4.5 GeV beam, with a vertical damping wiggler of a total length of 90 m, a peak field of 1.5 T and a wiggler period of 100 mm.

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

    SciTech Connect

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

    1991-01-01

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

  4. 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.

  5. Electron Cloud Generation and Trapping in a Quadrupole Magnet at the Los Alamos Proton Storage Ring

    SciTech Connect

    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.; /SLAC

    2008-03-17

    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 100 {micro}s. 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.

  6. PEP-X: An Ultimate Storage Ring Based on Fourth-Order Geometric Achromats

    SciTech Connect

    Cai, Yunhai; Bane, Karl; Hettel, Robert; Nosochkov, Yuri; Wang, Min-Huey; /SLAC

    2012-04-06

    We have designed an 'ultimate' storage ring for the PEP-X light source that achieves the diffraction limited emittances (at 1.5 {angstrom}) of 12 pm-rad in both horizontal and vertical planes with a 4.5-GeV beam. These emittances include the contribution of intrabeam scattering at a nominal current of 200 mA in 3300 bunches. This quality beam in conjunction with a conventional 4-m undulator in a straight section can generate synchrotron radiation having a spectral brightness above 10{sup 22} [photons/s/mm{sup 2}/mrad{sup 2}/0.1% BW] at a 10 keV photon energy. The high coherence at the diffraction limit makes PEP-X competitive with 4th generation light sources based on an energy recovery linac. In addition, the beam lifetime is several hours and the dynamic aperture is large enough to allow off-axis injection. The alignment and stability tolerances, though challenging, are achievable. A ring with all these properties is only possible because of several major advances in mitigating the effects of nonlinear resonances.

  7. Precision analog signal processor for beam position measurements in electron storage rings

    SciTech Connect

    Hinkson, J.A.; Unser, K.B.

    1995-05-01

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y posit ion entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM.

  8. Achieving a precision field in the muon g-2 storage ring magnet at Fermilab

    NASA Astrophysics Data System (ADS)

    Swanson, H. Erik; Muon g-2 Collaboration Collaboration

    2016-09-01

    The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic moment aμ of the muon. The target precision is 140 parts per billion (ppb), a four-fold improvement over the previous Brookhaven E821 measurement which found a 3.5 standard deviation discrepancy from the Standard Model prediction. This precision requires knowing the magnetic field strength in the muon storage ring with an uncertainty of 70 ppb. The magnet is first shimmed to achieve an average uniformity of one part per million (ppm). The field in the muon storage volume will be periodically measured and continuously monitored using proton NMR with single shot precision of 10 ppb. This magnet was successfully commissioned in October, 2015 and the shimming of the field to achieve the ultimate uniformity has been ongoing since that time. We will present the final results of this year-long process, describing some of the unique instrumentation and analysis routines we have developed along the way. DOE Grant DE-FG02-97ER41020.

  9. Performance of a hydrogen/deuterium polarized gas target in a storage ring

    NASA Astrophysics Data System (ADS)

    van Buuren, L. D.; Szczerba, D.; van den Brand, J. F. J.; Bulten, H. J.; Ferro-Luzzi, M.; Klous, S.; Kolster, H.; Lang, J.; Mul, F. A.; Poolman, H. R.; Simani, M. C.

    2001-12-01

    The performance of a high-density polarized hydrogen/deuterium gas target internal to a medium-energy electron storage ring is presented. Compared to our previous electron scattering experiments with tensor-polarized deuterium at NIKHEF (Zhou et al., Nucl. Instr. and Meth. A 378 (1996) 40; Ferro-Luzzi et al., Phys. Rev. Lett. 77 (1996) 2630; Van den Brand et al., Phys. Rev. Lett. 78 (1997) 1235; Bouwhuis et al., Phys. Rev. Lett. 82 (1999) 687; Zhou et al., Phys. Rev. Lett. 82 (1999) 687) the target figure of merit, ( polarization) 2× luminosity, was improved by more than an order of magnitude. The target density was increased by upgrading the flux of nuclear-polarized atoms injected into the storage cell and by using a longer (60 cm) and colder (˜70 K) storage cell. A maximal target thickness of 1.2 (1.1)±0.1×10 14 nuclei/ cm2 was achieved with deuterium (hydrogen). With typical beam currents of 110 mA, this corresponds to a luminosity of about 8.4 (7.8)±0.8×10 31e- nuclei cm -2 s-1. By reducing the molecular background and using a stronger target guide field, a higher polarization was achieved. The target was used in combination with a 720 MeV polarized electron beam stored in the AmPS ring (NIKHEF) to measure spin observables in electron-proton and electron-deuteron scattering. Scattered electrons were detected in a large acceptance magnetic spectrometer. Ejected hadrons were detected in a single time-of-flight scintillator array. The product of beam and target vector polarization, PePt, was determined from the known spin-correlation parameters of e' p quasi-elastic (or elastic) scattering. With the deuterium (hydrogen) target, values up to PePt=0.49±0.03 (0.32±0.03) were obtained with an electron beam polarization of Pe=0.62±0.04 (0.56±0.03) as measured with a Compton backscattering polarimeter (Passchier et al., Nucl. Instr. and Meth. A 414 (1998) 4988). From this, we deduce a cell-averaged target polarization of Pt=0.78±0.07 (0.58±0.07), including

  10. 1000-TeV in the Center-Of-Mass: Introduction to High-Energy Storage Rings

    SciTech Connect

    Bjorken, J D

    1982-09-01

    The lecture discusses, in a pedagogic way, a hypothetical 500 TeV proton storage ring accelerator. It gives machine parameters, discusses linear optics and betatron motions, surveys questions of errors, tolerances and nonlinear resonances, and discusses some of the demands on the detection apparatus, especially the apparent inevitability of multiple interactions per bunch crossing. (GHT)

  11. Microscopic study on lasing characteristics of the UVSOR storage ring free electron laser

    SciTech Connect

    Hama, H. |; Yamazaki, J.; Kinoshita, T.

    1995-12-31

    Characteristics of storage ring free electron laser (SRFEL) at a short wavelength region (UV and visible) has been studied at the UVSOR facility, Institute for Molecular Science. We have measured the laser power evolution by using a biplanar photodiode, and the micro-macro temporal structure of both the laser and the electron bunch with a dualsweep streak camera. The saturated energy of the laser micropulse in the gain-switching (Q-switching) mode has been measured as a function of the ring current. We have not observed a limitation of the output power yet within the beam current can be stored. We have analyzed the saturated micropulse energy based on a model of gain reduction due to the bunch-heating. The bunch-heating process seems to be very complicate. We derived time dependent gain variations from the shape of macropulse and the bunch length. Those two gain variations are almost consistent with each other but slightly different in detail. The gain may be not only simply reduced by the energy spread but also affected by the phase space rotation due to synchrotron oscillation of the electron bunch. As reported in previous issue, the lasing macropulse consists of a couple of micropulses that are simultaneously evolved. From high resolution two-dimensional spectra taken by the dual-sweep streak camera, we noticed considerable internal substructures of the laser micropulse in both the time distribution and the spectral shape. There are a couple of peaks separated with almost same distance in a optical bunch. Such substructure does not seem to result from statistical fluctuations of laser seeds. Although the origin of the substructure of macropulse is not dear at the present, we are going to discuss about SRFEL properties.

  12. An injection system for PEP-based asymmetric storage ring collider for the copious production of B mesons

    SciTech Connect

    Barletta, W.A.

    1989-09-18

    The proposed asymmetric energy B-factory utilizing PEP will require high energy, low emittance sources of positrons and electrons suitable for filling the storage rings. Proposed characteristics of this collider operating at a luminosity of 10{sup 34} cm{sup -2}s{sup -1} have been studied by LBL (Apiary-III). The design consists of two rings, a large 9 GeV ring (PEP or a modification thereof) plus a smaller 3.1 GeV ring, each with a circulating current of 3 Amperes. Ideally the fill time should be much shorter than the luminosity life-time of the rings (set by the size of the low energy ring). As the luminosity lifetime of the collider is not expected to be very high, the PEP-based B-factory should have a powerful, dedicated injector. For the purpose of estimating the characteristics of the injection system the maximum time for a complete fill of the positron ring is taken to be {approx}100 seconds. The design of the injection system is discussed in this paper. 1 ref., 9 figs., 4 tabs.

  13. Longitudinal instability studies at the SURF II storage ring at NIST.

    SciTech Connect

    Harkay, K.C.; Sereno, N.S.

    1998-08-27

    Measurements of the longitudinal instability observed in the storage ring at the Synchrotrons Ultraviolet Radiation Facility (SURF II) at the National Institute of Standards and Technology (NET) were performed to understand the mechanism driving the instability. The instability, studied in depth by Ralcowsky and others, manifests itself in broad resonance features in the horizontal and vertical motion spectrum of the synchrotrons light from DC to a few kHz. Also observed are multiple synchrotrons harmonics that modulate the revolution harmonics; these are characteristic of longitudinal phase oscillations. These spectral features of the motion are found to be correlated with the periodic lengthening and shortening of the bunch length on time scales from {approximately}0.1 ms to 20 ms, depending on machine and radio-frequency (rf) system parameters. In this report, the growth rate of the instability is determined from measurements using an rf pickup electrode. The measured growth rates are compared to computed growth rates from an analytical model. Recommendations are made regarding options to control or mitigate the instability. In light of upgrade plans for SURF III, a few comments are presented about the beam lifetime.

  14. Initial test results of the Los Alamos proton-storage-ring bump-magnet system

    SciTech Connect

    Rose, C.R.; Barlow, D.B.; Redd, D.B.

    1997-09-01

    An upgrade program for increasing the stored beam current in the LANSCE Proton Storage is presently under way. Part of the upgrade effort has been to design, specify, and add four bump-magnet/modulator systems to the ring. This paper describes the initial test results of the first bump-magnet/modulator system. The paper begins with an overview of the pulsed-power system including important specifications of the modulator, magnet, cabling, and control system. In the main portion of the paper, waveforms and test data are included showing the accuracy, repeatability, and stability of the magnet-current pulses. These magnet pulses are programmable both in rise and fall time as well as in amplitude. The amplitude can be set between 50 and 300 A, the rise-time is fixed at 1 ms, and the linear fall-time can be varied between 500 {mu}s and 1500 {mu}s. Other issues such as loading effects and power dissipation in the magnet-bore beamtube are examined and reported.

  15. Ion storage ring measurements of dielectronic recombination for astrophysically relevant Feq+ ions

    SciTech Connect

    Savin, D W; Badnell, N R; Bartsch, T; Brandau, C; Chen, M H; Grieser, M; Gwinner, G; Hoffknecht, A; Kahn, S M; Linkemann, J; Muller, A; Repnow, R; Saghiri, A A; Schippers, S; Schmitt, M; Schwalm, D; Wolf, A

    2000-06-06

    Iron ions provide many valuable plasma diagnostics for cosmic plasmas. The accuracy of these diagnostics, however, often depends on an accurate understanding of the ionization structure of the emitting gas. Dielectronic recombination (DR) is the dominant electron-ion recombination mechanism for most iron ions in cosmic plasmas. Using the heavy-ion storage ring at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany, we have measured the low temperature DR rates for Fe{sup q+} where q = 15, 17, 18, and 19. These rates are important for photoionized gases which form in the media surrounding active galactic nuclei, X-ray binaries, and cataclysmic variables. Our results demonstrate that commonly used theoretical approximations for calculating low temperature DR rates can easily under- or over-estimate the DR rate by a factor of {approx} 2 or more. As essentially all DR rates used for modeling photoionized gases are calculated using these approximations, our results indicate that new DR rates are needed for almost all charge states of cosmically abundant elements. Measurements are underway for other charge states of iron.

  16. HISTRAP: Proposal for a Heavy Ion Storage Ring for Atomic Physics

    SciTech Connect

    Not Available

    1988-11-01

    This paper presents an overview of the physics capabilities of HISTRAP together with a brief description of the facility and a sampling of the beams which will be available for experimentation, and surveys some of the lines of investigation in the physics of multicharged ions, molecular ion spectroscopy, condensed beams, and nuclear physics that will become possible with the advent of HISTRAP. Details of the accelerator design are discussed, including computer studies of beam tracking in the HISTRAP lattice, a discussion of the HHIRF tandem and ECR/RFQ injectors, and a description of the electron beam cooling system. In the past three years, HISTRAP has received substantial support from Oak Ridge National Laboratory management and staff. The project has used discretionary funds to develop hardware prototypes and carry out design studies. Construction has been completed on a vacuum test stand which models 1/16 of the storage ring and has attained a pressure of 4 x 10/sup -12/ Torr; a prototype rf cavity capable of accelerating beams up to 90 MeV/nucleon and decelerating to 20 keV/nucleon; and a prototype dipole magnet, one of the eight required for the HISTRAP lattice. This paper also contains a summary of the work on electron cooling carried out by one of our staff members at CERN. Building structures and services are described. Details of cost and schedule are also discussed. 77 refs.

  17. DISSOCIATIVE RECOMBINATION MEASUREMENTS OF HCl{sup +} USING AN ION STORAGE RING

    SciTech Connect

    Novotný, O.; Stützel, J.; Savin, D. W.; Becker, A.; Buhr, H.; Domesle, C.; Grieser, M.; Krantz, C.; Kreckel, H.; Repnow, R.; Schwalm, D.; Yang, B.; Wolf, A.; Geppert, W.; Spruck, K.

    2013-11-01

    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 5000 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.

  18. The Darmstadt Antiproton Project (PANDA) at the High Energy Storage Ring at GSI

    SciTech Connect

    Peters, Klaus J.

    2002-11-20

    Recently GSI presented the plans for a major new international research facility. A key feature of this new facility will be the delivery of intense, high-quality secondary beams which embody the production of antiprotons. For the antiproton beams a 50 Tm storage ring is planned, including electron and stochastic cooling, will be able to handle antiproton beams in the momentum range from 1.5 up to 15 GeV/c. The design luminosity is 2 x 10{sup 32} cm{sup -2} s{sup -1}. The PANDA Experiment will take place at an internal target and will cover the aspects of the structure of hadrons and the properties of hadronic matter in the corresponding energy range. The main topics to be addressed are: Spectroscopy of charmonium; Search for charmed hybrids and glueballs; Interaction of open and hidden charm with nucleons and nuclei; Single and double hypernuclei; Open charm spectroscopy; CP-Violation in the charm sector; Deeply Virtual Comptom Scattering, etc. The major part of the experimental program will make use of a general purpose detector PANDA. The concept of this detector is presented.

  19. A new current regulator for the APS storage ring correction magnet bipolar switching mode converters.

    SciTech Connect

    Wang, J.; Accelerator Systems Division

    2004-01-01

    The correction magnets in the Advanced Photon Source's storage ring are powered by PWM-controlled bipolar switching-mode converters. These converters are designed to operate at up to {+-}150 A. The original control circuit used a polarity detection circuit with a hysteresis to determine which IGBT was needed to regulate the current with a given polarity. Only the required IGBT was switched with PWM pulses while others were held on or off continuously. The overall IGBT switching losses were minimized by the design. The shortcoming of the design was that the converter's output was unstable near zero current because of the hysteresis. To improve the stability, a new current regulator using a different PWM method has been developed to eliminate the requirement of the polarity detection. With the new design, converters can operate smoothly in the full range of {+-}150 A. The new design also meets tighter specs in terms of the ripple current and dynamic response. This paper describes the design of the new regulator and the test results.

  20. New waveguide-type HOM damper for ALS storage ring cavities.

    SciTech Connect

    Kwiatkowski, Slawomir; Baptiste, Kenneth; Julian, James

    2004-06-28

    The ALS storage ring 500 MHz RF system uses two re-entrant accelerating cavities powered by a single 320kW PHILLIPS YK1305 klystron. During several years of initial operation, the RF cavities were not equipped with effective passive HOM damper systems. Longitudinal beam stability was achieved through cavity temperature control and the longitudinal feedback system (LFB), which was often operating at the edge of its capabilities. As a result, longitudinal beam stability was a significant operations issue at the ALS. During two consecutive shutdown periods (April 2002 and 2003) we installed E-type HOM dampers on the main and third harmonic cavities. These devices dramatically decreased the Q-values of the longitudinal anti-symmetric HOM modes. The next step is to damp the rest of the longitudinal HOM modes in the main cavities below the synchrotron radiation damping level. This will hopefully eliminate the need for the LFB and set the stage for a possible increase in beam current. The ''waveguide'' type of HOM damper was the only option that didn't significantly compromise the vacuum performance of the RF cavity. The design process and the results of the low level measurements of the new waveguide dampers are presented in this paper.

  1. A multi-length bunch design for electron storage rings with odd buckets

    NASA Astrophysics Data System (ADS)

    Zhu, Liang-Jing; Li, Wei-Min; Wang, Lin; Xiang, Dao; Huang, Xiao-Biao

    2015-07-01

    A scheme with two superconducting RF cavities is designed to upgrade electron storage rings with odd buckets to multi-length bunches. In this paper, the Hefei Light Source II (HLS II) is given as an example for odd buckets. As it is designed for 45 buckets, which is a multiple of 3, simultaneous generation of three different lengths of bunches is proposed with the presently applied user optics. The final result, without low-α optics, is to fill HLS II with long bunches of length 50 ps, medium bunches of 23 ps and short bunches of 6 ps. Every third bucket can be filled with short bunches, of which the current limit is up to 6.6 mA, more than 60 times the limit for low-α mode. Moreover, particle tracking simulations to examine the beam dynamics, performed by ELEGANT, and calculations of the beam instabilities are presented in this paper. Supported by National Natural Science Foundation of China (11327902, 11175180, 11175182) and U.S. DOE (DE-AC02-76SF00515)

  2. X-ray BPM-based feedback system at the APS storage ring

    SciTech Connect

    Singh, O.; Erwin, L.; Decker, G.; Laird, R.; Lenkszus, F.

    2000-05-17

    At the Advanced Photon Source (APS) storage ring, the X-ray beam position monitors (X-BPMs) measure accurate photon position down to the submicron level. This level of stable measurement has been possible due to (1) superior thermal insulation and vibration damping of the X-ray BPM support structure, (2) minimal dependence on the bunch pattern and intensity variations, and (3) use of ultrastable preamplifiers and processing electronics. A new X-BPM interface is under development and will be discussed here. This interface will be integrated into the existing rf-based orbit feedback systems. To study preliminary results, an experimental X-BPM orbit feedback set-up was developed and implemented in one of the bending magnet beamlines. The results from this set-up are encouraging. For an operational fill, a typical orbit drift of 30 microns (at X-ray BPMs) has been reduced to less than 5 microns. The fill-to-fill photon orbit reproducibility has been improved from 75 microns to less than 10 microns.

  3. Dynamic Aperture and Tolerances for PEP-X Ultimate Storage Ring Design

    SciTech Connect

    Borland, M.; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; Hettel, R.O.; /SLAC

    2011-12-13

    A lattice for the PEP-X ultimate storage ring light source, having 11 pm-rad natural emittance at a beam energy of 4.5 GeV at zero current, using 90 m of damping wiggler and fitting into the existing 2.2-km PEP-II tunnel, has been recently designed. Such a low emittance lattice requires very strong sextupoles for chromaticity correction, which in turn introduce strong non-linear field effects that limit the beam dynamic aperture. In order to maximize the dynamic aperture we choose the cell phases to cancel the third and fourth order geometric resonances in each 8-cell arc. Four families of chromatic sextupoles and six families of geometric (or harmonic) sextupoles are added to correct the chromatic and amplitude-dependent tunes. To find the best settings of the ten sextupole families, we use a Multi-Objective Genetic Optimizer employing elegant to optimize the beam lifetime and dynamic aperture simultaneously. Then we evaluate dynamic aperture reduction caused by magnetic field multipole errors, magnet fabrication errors and misalignments. A sufficient dynamic aperture is obtained for injection, as well as workable beam lifetime.

  4. Characterization of electron clouds in the Cornell Electron Storage Ring Test Accelerator using TE-wave transmission

    SciTech Connect

    De Santis, S.; Byrd, J. M.; Billing, M.; Palmer, M.; Sikora, J.; Carlson, B.

    2010-01-02

    A relatively new technique for measuring the electron cloud density in storage rings has been developed and successfully demonstrated [S. De Santis, J.M. Byrd, F. Caspers, A. Krasnykh, T. Kroyer, M.T.F. Pivi, and K.G. Sonnad, Phys. Rev. Lett. 100, 094801 (2008).]. We present the experimental results of a systematic application of this technique at the Cornell Electron Storage Ring Test Accelerator. The technique is based on the phase modulation of the TE mode transmitted in a synchrotron beam pipe caused by the periodic variation of the density of electron plasma. Because of the relatively simple hardware requirements, this method has become increasingly popular and has been since successfully implemented in several machines. While the principles of this technique are straightforward, quantitative derivation of the electron cloud density from the measurement requires consideration of several effects, which we address in detail.

  5. 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

  6. Generation of ultrashort coherent vacuum ultraviolet pulses using electron storage rings: a new bright light source for experiments.

    PubMed

    De Ninno, G; Allaria, E; Coreno, M; Curbis, F; Danailov, M B; Karantzoulis, E; Locatelli, A; Menteş, T O; Nino, M A; Spezzani, C; Trovò, M

    2008-08-01

    We demonstrate for the first time that seeded harmonic generation on electron storage rings can produce coherent optical pulses in the vacuum ultraviolet spectral range. The experiment is performed at Elettra, where coherent pulses are generated at 132 nm, with a duration of about 100 fs. The light source has a repetition rate of 1 kHz and adjustable polarization; it is very bright, with a peak power several orders of magnitude above that of spontaneous synchrotron radiation. Owing to high stability, the source is used in a test photoemission electron microscopy experiment. We anticipate that seeded harmonic generation on storage rings can lead to unprecedented developments in time-resolved femtosecond spectroscopy and microscopy.

  7. Continuously tunable narrowband pulses in the THz gap from laser-modulated electron bunches in a storage ring

    NASA Astrophysics Data System (ADS)

    Ungelenk, P.; Höner, M.; Huck, H.; Khan, S.; Mai, C.; Meyer auf der Heide, A.; Evain, C.; Szwaj, C.; Bielawski, S.

    2017-02-01

    This article reports on the generation of narrowband coherent synchrotron radiation from an electron storage ring. For the first time, this kind of radiation was now produced with continuously tunable frequencies in the so-called "THz gap" (between 1.2 and 5.6 THz), whereas previous experiments were limited to below 750 GHz. The experiment was performed at the DELTA storage ring in Dortmund, Germany, employing the interaction of external intensity-modulated laser pulses with an electron bunch, which causes a periodic longitudinal modulation of the charge density on a sub-millimeter scale. Furthermore, a strong influence of third-order dispersion in the laser pulses on the bandwidth and peak intensity of the THz radiation was observed. This effect is discussed in detail based on numerical simulations of the laser pulse generation and laser-electron interaction, and a modification of the laser system for compensating third-order dispersion is proposed.

  8. Mini-proceedings of the workshop on heavy ion physics and instrumentation for a 15-Tm booster and storage ring

    SciTech Connect

    Not Available

    1986-11-01

    The goal of this workshop was to probe in depth a few of the areas of possible physics made possible by the availability of an intermediate energy heavy-ion physics facility. There was a special emphasis on physics that would be possible only with a storage/cooler ring. Topics discussed were nuclei far from stability, quantum electrodynamics, giant resonances and photonuclear reactions, and high energy gamma-ray production. Individual papers in this meeting were abstracted separately.

  9. High-resolution storage-ring measurements of the dissociative recombination of H{sub 3}{sup +} using a supersonic expansion ion source

    SciTech Connect

    Kreckel, Holger; Crabtree, Kyle N.; Tom, Brian A.; Novotny, Oldrich; Lestinsky, Michael; Buhr, Henrik; Petrignani, Annemieke; Berg, Max H.; Bing, Dennis; Grieser, Manfred; Krantz, Claude; Mendes, Mario B.; Nordhorn, Christian; Repnow, Roland; Stuetzel, Julia; Wolf, Andreas; Thomas, Richard D.; McCall, Benjamin J.

    2010-10-15

    We have performed measurements of the dissociative electron recombination (DR) of H{sub 3}{sup +} at the ion storage ring TSR utilizing a supersonic expansion ion source. The ion source has been characterized by continuous wave cavity ring-down spectroscopy. We present high-resolution DR rate coefficients for different nuclear spin modifications of H{sub 3}{sup +} combined with precise fragment imaging studies of the internal excitation of the H{sub 3}{sup +} ions inside the storage ring. The measurements resolve changes in the energy dependence between the ortho-H{sub 3}{sup +} and para-H{sub 3}{sup +} rate coefficients at low center-of-mass collision energies. Analysis of the imaging data indicates that the stored H{sub 3}{sup +} ions may have higher rotational temperatures than previously assumed, most likely due to collisional heating during the extraction of the ions from the ion source. Simulations of the ion extraction shed light on possible origins of the heating process and how to avoid it in future experiments.

  10. Damping higher order modes in the PEP-II B-Factory storage ring collider

    NASA Astrophysics Data System (ADS)

    Weathersby, Stephen

    2007-05-01

    The PEP-II B-Factory storage ring collider at SLAC provides crucial experimental evidence for the physics of CP violation. To investigate rare B-meson decays requires high luminosity which comes mainly from increasing bunch currents and reducing bunch sizes. Electromagnetic effects of intense bunch fields in the form of wake fields couple into accelerator components, inducing Joule heating at levels detrimental to vacuum chamber components. Additionally, wake fields contribute to beam instability, decreasing luminosity. These effects are limiting B-factory performance. Computer simulations and experimental evidence indicate that beam collimators produce wake fields in the form of dipole and quadrupole waveguide modes which can propagate tens of meters from their source before depositing energy at remote locations. Simulations confirm that coupling through narrow slots into bellows cavities occurs for beam pipe modes. Two proposals are set forth to mitigate wake field effects. The first proposal is to reduce the quality factor of resonant structures with a water cooled dielectric lossy material. Electromagnetic energy coupling into resonant structures can be isolated and safely dissipated. Prototype devices have been built and have been shown to reduce resistive heating in large pumping chambers coupled to the beam chamber. Designs and simulations which incorporate such techiques into bellows devices are presented. The second proposal incorporates novel devices introduced in the accelerator vacuum chamber which selectively traps dipole and quadrupole propagating wake fields before they can couple into sensitive beam line components without introducing impedance to the beam. Scattering parameter analysis is used to tailor device response to specific modes. Dangerous modes are extracted from the beam chamber, trapped and dissipated in a water cooled lossy material. Modes which represent an impedance to the beam are not affected. After design optimization, production

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

    SciTech Connect

    Cossairt, J.Donald; /Fermilab

    2010-12-01

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

  12. 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.

  13. Commissioning results of the narrow-band beam position monitor system upgrade in the APS storage ring.

    SciTech Connect

    Singh, O.

    1999-04-20

    When using a low emittance storage ring as a high brightness synchrotron radiation source, it is critical to maintain a very high degree of orbit stability, both for the short term and for the duration of an operational fill. A fill-to-fill reproducibility is an additional important requirement. Recent developments in orbit correction algorithms have provided tools that are capable of achieving a high degree of orbit stability. However, the performance of these feedback systems can be severely limited if there are errors in the beam position monitors (BPMs). The present orbit measurement and correction system at the APS storage ring utilizes 360 broad-band-type BPMs that provide turn-by-turn diagnostics and an ultra-stable orbit: < 1.8 micron rms vertically and 4.5 microns rms horizontally in a frequency band of 0.017 to 30 Hz. The effects of beam intensity and bunch pattern dependency on these BPMs have been significantly reduced by employing offset compensation correction. Recently, 40 narrow-band switching-type BPMs have been installed in the APS storage ring, two in each of 20 operational insertion device straight sections, bringing the total number of beam position monitors to 400. The use of narrow-band BPM electronics is expected to reduce sensitivity to beam intensity, bunch pattern dependence, and long-term drift. These beam position monitors are used for orbit correction/feedback and machine protection interlocks for the insertion device beamlines. The commissioning results and overall performance for orbit stability are provided.

  14. Capture, acceleration and bunching rf systems for the MEIC booster and storage rings

    SciTech Connect

    Wang, Shaoheng; Guo, Jiquan; Lin, Fanglei; Morozov, Vasiliy; Rimmer, Robert A.; Wang, Haipeng; Zhang, Yuhong

    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 energy 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.

  15. LEPTON ACCELERATORS AND COLLIDERS: Linear optics calibration and nonlinear optimization during the commissioning of the SSRF storage ring

    NASA Astrophysics Data System (ADS)

    Tian, Shun-Qiang; Zhang, Wen-Zhi; Li, Hao-Hu; Zhang, Man-Zhou; Hou, Jie; Zhou, Xue-Mei; Liu, Gui-Min

    2009-06-01

    Phase I commissioning of the SSRF storage ring on 3.0 GeV beam energy was started at the end of December 2007. A lot of encouraging results have been obtained so far. In this paper, calibrations of the linear optics during the commissioning are discussed, and some measured results about the nonlinearity given. Calibration procedure emphasizes correcting quadrupole magnetic coefficients with the Linear Optics from Closed Orbit (LOCO) technique. After fitting the closed orbit response matrix, the linear optics of the four test modes is substantially corrected, and the measured physical parameters agree well with the designed ones.

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

    SciTech Connect

    Yuri, Yosuke

    2015-06-29

    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.

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

    SciTech Connect

    Plum, M.

    1995-05-01

    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.

  18. STORAGE RING MEASUREMENT OF ELECTRON IMPACT IONIZATION FOR Mg{sup 7+} FORMING Mg{sup 8+}

    SciTech Connect

    Hahn, M.; Lestinsky, M.; Novotny, O.; Savin, D. W.; Bernhardt, D.; Mueller, A.; Schippers, S.; Wolf, A.

    2010-04-01

    We report electron impact ionization cross section measurements for Mg{sup 7+} forming Mg{sup 8+} at center of mass energies from approximately 200 eV to 2000 eV. The experimental work was performed using the heavy-ion storage ring TSR located at the Max-Planck-Institut fuer Kernphysik in Heidelberg, Germany. We find good agreement with distorted wave calculations using both the GIPPER code of the Los Alamos Atomic Physics Code suite and using the Flexible Atomic Code.

  19. Predicted performance of a multi-section VUV FEL with the Amsterdam pulse stretcher and storage ring AmPS

    SciTech Connect

    Bazylev, V.A.; Pitatelev, M.I.; Tulupov, A.V.

    1995-12-31

    A design is proposed to realize a VUV FEL with the Amsterdam Pulse Stretcher and Storage Ring (AmPS). The FEL is based on 4 identical undulator sections and 3 dispersive sections. The total magnetic system has a length of 12 m. 3 D simulations with the actual electron beam parameters of AmPS have been done with a version of TDA code modified for multi-sectional FELs. The spectral range between 50 and 100 nm has been considered. The simulations show that an amplification as large as 1*E5 - 1*E7 can be achieved. The amplification can be enhanced by a further optimisation procedure.

  20. Electron beam stability and beam peak to peak motion data for NSLS X-Ray storage ring

    SciTech Connect

    Singh, O.

    1993-07-01

    In the past two years, a significant reduction in electron beam motion has been achieved at the NSLS X-Ray storage ring. The implementation of global analog orbit feedbacks, based on a harmonics correction scheme, has reduced the beam motion globally. Implementation of six local analog feedback systems has reduced the beam motion even further at the corresponding beam line straight sections. This paper presents beam motion measurements, showing the improvement due to the feedback systems. Beam motion is measured using a spectrum analyzer and data is presented at various frequencies, where peaks were observed. Finally, some of the beam motion sources are discussed.

  1. An Electron Target/cooler for Extremely Low-Energy Ion Beams at the Electrostatic Storage Ring

    NASA Astrophysics Data System (ADS)

    Tanabe, Tetsumi; Noda, Koji; Watanabe, Ikuo

    2002-12-01

    An electrostatic storage ring for studying atomic and molecular science has been operational at KEK since May, 2000. The ring has a circumference of 8 m and can store light-to-heavy ions with an E/q of up to 30 keV. Light ions are produced with an electron cyclotron resonance ion source, while bio-molecular ions are produced with an electrospray ion source The measured 1/e-lifetimes of stored single-charge ions injected from the electron cyclotron resonance ion source are from 10 to 50 s. On the other hand, ions from the electrospray ion source have lifetimes from 12 to 20 s. These lifetimes are long enough to cool vibrationally excited molecular ions, and their intensities are tolerable for practical use, like atomic collision experiments. In order to study electron-ion collisions, an electron beam target has been designed, which will be installed in a straight section of the ring. The structure of the target is almost the same as an electron cooler consisting of an adiabatically expanded electron beam; the target can also function as an electron cooler for light-mass ions.

  2. Measurement of Photon Statistics of Wiggler Radiation from AN Electron Storage Ring at the National Synchrotron Light Source.

    NASA Astrophysics Data System (ADS)

    Tanabe, Toshiya

    1990-01-01

    The photon statistics of wiggler light from the vacuum ultraviolet (VUV) storage ring at the National Synchrotron Light Source (NSLS) in Brookhaven National Laboratory (BNL) have been measured using an analog photon-counting technique. The linear wiggler produces fundamental wavelength light and the third harmonic light at 532 nm for ring energies ~650 MeV and 375 MeV, respectively. The average ring current was ~50 mA for one-electron-bunch operation. The bunch was ~480 psec long and the wiggler light was emitted every 170.2 nsec. The number of photons emitted by an electron bunch was repetitively measured for a given coherence volume. The photon counting distribution, which is the probability of finding n photons versus n, was obtained. The experimental results show that the wiggler radiation is consistent with multi-mode thermal radiation, whereas the bending magnet light gives rise to a distribution consistent with a Neyman Type-A distribution instead of Poisson when the light of large bandwith through a Pyrex window is collected. Near field and electron beam emittance effects have proven to have an important influence on the transverse coherence of the emitted radiation.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  6. Precision Mass Measurements of Short-Lived Nuclides at The Heavy-Ion Storage Ring in Lanzhou

    NASA Astrophysics Data System (ADS)

    Zhang, Yuhu; Xu, Hushan; Litvinov, Yuri A.

    Recent commissioning of the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou enabled us to conduct high-precision mass measurements at the Institute of Modern Physics in Lanzhou (IMP). In the past few years, mass measurements were performed using the CSRe-based isochronous mass spectrometry employing the fragmentation of the energetic beams of 58Ni, 78Kr, 86Kr, and 112Sn projectiles. Masses of short-lived nuclides of on both sides of the stability valley were addressed. Relative mass precision of down to 10-6-10-7 is routinely achieved. The mass values were used as an input for dedicated nuclear structure and astrophysics studies, providing for instance new insights into the rp-process of nucleosynthesis in X-ray bursts. In this contribution, we briefly review the so far conducted experiments and the main achieved results, as well as outline the plans for future experiments.

  7. In-situ calibration: migrating control system IP module calibration from the bench to the storage ring

    SciTech Connect

    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 the 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.

  8. Stripper-foil scan studies of the first-turn beam loss mechanism in the LAMPF proton storage ring (PSR)

    SciTech Connect

    Hutson, R.: Fitzgerald, D.; Frankle, S.; Macek, R.; Plum, M.; Wilkinson, C.

    1993-01-01

    First-turn beam losses in the LAMPF Proton Storage Ring were measured as a function of the left-right position of the carbon foil used to strip neutral hydrogen atoms to H[sup +] for proton injection into the PSR. Two foil thicknesses, 200 and 300 [mu]g/cm[sup 2], were tested. Results indicated that first-turn loss is caused predominately by magnetic field stripping of a small fraction of the H[sub 0] atoms that pass through the stripper foil without being stripped to protons, and the results were not consistent with a mechanism involving protons originating from atoms in the halo of the neutral beam incident on the stripper foil.

  9. Stripper-foil scan studies of the first-turn beam loss mechanism in the LAMPF proton storage ring (PSR)

    SciTech Connect

    Hutson, R.: Fitzgerald, D.; Frankle, S.; Macek, R.; Plum, M.; Wilkinson, C.

    1993-06-01

    First-turn beam losses in the LAMPF Proton Storage Ring were measured as a function of the left-right position of the carbon foil used to strip neutral hydrogen atoms to H{sup +} for proton injection into the PSR. Two foil thicknesses, 200 and 300 {mu}g/cm{sup 2}, were tested. Results indicated that first-turn loss is caused predominately by magnetic field stripping of a small fraction of the H{sub 0} atoms that pass through the stripper foil without being stripped to protons, and the results were not consistent with a mechanism involving protons originating from atoms in the halo of the neutral beam incident on the stripper foil.

  10. 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.

  11. Effects of magnetic non-linearities on a stored proton beam and their implications for superconducting storage rings

    SciTech Connect

    Cornacchia, M.; Evans, L.

    1985-06-01

    A nonlinear lens may be used to study the effect of high-order multipolar field imperfections on a stored proton beam. Such a nonlinear lens is particulary suitable to simulate field imperfections of the types encountered in coil dominated superconducting magnets. We have studied experimentally at the SPS the effect of high order (5th and 8th) single isolated resonances driven by the nonlinear lens. The width of these resonances is of the order one expects to be caused by field errors in superconducting magnets of the SSC type. The experiment shows that, in absence of tune modulation, these resonances are harmless. Slow crossings of the resonance, on the other hand, have destructive effects on the beam, much more so than fast crossings caused by synchrotron oscillations. In the design of future storage rings, sources of low-frequency tune modulation should be avoided as a way to reduce the harmful effects of high order multipolar field imperfection.

  12. Multiple-bunch-length operating mode design for a storage ring using hybrid low alpha and harmonic cavity method

    NASA Astrophysics Data System (ADS)

    Gao, Weiwei; Wang, Lin; Li, Heting

    2017-03-01

    In this paper we design a simultaneous three bunch length operating mode at the HLS-II (Hefei Light Source II) storage ring by installing two harmonic cavities and minimizing the momentum compaction factor. The short bunches (2.6 mm) presented in this work will meet the requirement of coherent millimeter-wave and sub-THz radiation experiments, while the long bunches (20 mm) will efficiently increase the total beam current. Therefore, this multiple-bunch-length operating mode allows present synchrotron users and coherent millimeter-wave users (or sub THz users) to carry out their experiments simultaneously. Since the relatively low energy characteristic of HLS-II we achieve the multiple-bunch-length operating mode without multicell superconducting RF cavities, which is technically feasible.

  13. Resonance method to produce a polarisation asymmetry in electron-positron storage rings

    SciTech Connect

    Toner, W.T.

    1988-01-01

    Pulsed solenoids of a few tens of ampere turns, operated in synchronism with the ..gamma..(g-2/2) 'th harmonic of the orbit period, can be used to prevent a stored electron beam from becoming polarised through the emission of synchrotron radiation. With such low fields it is easy to arrange that only some of the stored bunches are affected. This makes it possible to produce collisions between counter-rotating electrons and positrons stored in a single ring in which the electron and positron polarisations are not equal and opposite. 8 refs.

  14. Experiments with Longitudinally Polarized Electrons in a Storage Ring Using a Siberian Snake

    SciTech Connect

    H. R. Poolman; D. J. Boersma; M. Harvey; Douglas W. Higinbotham; I. Passchier; E. Six; Ricardo Alarcon; P. W. van Amersfoort; Th. S. Bauer; H. Boer Rookhuizen; J. F. J. van den Brand; L. D. van Buuren; H. J. Bulten; Rolf Ent; M. Ferro-Luzzi; D. G. Geurts; Peter Heimberg; Kees de Jager; P. Klimin; I. Koop; F. Kroes; J. van der Laan; G. Luijckx; A. Lysenko; B. Militsyn; I. Nesterenko; J. Noomen; Blaine Norum; M. J. J. van den Putte; Yu. Shatunov; J. J. M. Steijger; D. Szczerba; H. de Vries

    2000-04-24

    We report on first measurements with polarized electrons stored in a medium-energy ring and with a polarized internal target. Polarized electrons were injected at 442 MeV (653 MeV), and a partial (full) Siberian snake was employed to preserve the polarization. Longitudinal polarization at the interaction point and polarization lifetime of the stored electrons were determined with laser backscattering. Spin observables were measured for electrodisintegration of polarized {sup 3}He, with simultaneous detection of scattered electrons, protons, neutrons, deuterons, and {sup 3}He nuclei, over a large phase space.

  15. High-Current Effects in The PEP-II Storage Rings

    SciTech Connect

    Wienands, U.; Sullivan, M.K.; Akre, R.; Cheng, W.; Colocho, W.; DeBarger, S.; Decker, F.-J.; Ecklund, S.; Fisher, A.; Kharakh, D.; Krasnykh, A.; Novokhatski, A.; /SLAC

    2009-06-19

    High beam currents in PEP-II have been a challenge for vacuum system and ring components. For the {approx} 1 cm long bunches peak currents exceed 100 A and modest impedance can give rise to voltage spikes and discharges. During the last two runs, difficulties arose from rf seals at the 'flex flanges' in the HER. High temperatures were seen and the seals turned out to be severely damaged by discharges. In the LER, the horizontal stripline kickers of the bunch-by-bunch feedback system experiences breakdown at high bunch current-Macor pins installed for mechanical stability turned out to be a weak spot causing discharges. Finally, in the HER an experiment to shorten the ion-clearing gap in the beam revealed signs of ion-induced instability indicating that the HER has been operating quite close to the stability limit. The effects shown here are relevant to future high-intensity electron and positron rings like SuperB and PEP-X.

  16. Non-Gaussian beam dynamics in low energy antiproton storage rings

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    In low energy antiproton facilities, where electron cooling is fundamental, the cooling forces together with heating phenomena causing emittance blow-up, such as Intra Beam Scattering (IBS), result in highly non-Gaussian beam distributions. In these cases, a precise simulation of IBS effects is essential to realistically evaluate the long term beam evolution, taking into account the non-Gaussian characteristics of the beam. Here, we analyse the beam dynamics in the Extra Low ENergy Antiproton ring (ELENA), which is a new small synchrotron currently being constructed at CERN to decelerate antiprotons to energies as low as 100 keV. Simulations are performed using the code BETACOOL, comparing different models of IBS.

  17. Operational Studies of the 10 keV Electron Storage Ring UMER

    SciTech Connect

    Bernal, S.; Sutter, D.; Cornacchia, M.; Beaudoin, B.; Haber, I.; Kishek, R. A.; Reiser, M.; Wu, C.; O'Shea, P. G.

    2009-01-22

    The University of Maryland Electron Ring (UMER) is now operational. UMER can operate with currents from 0.6 mA to 100 mA, ranging from the emittance dominated to the heavily space charge dominated regimes. Multiple turns have been achieved at all operating currents, from 250 turns at 0.6 mA to about 12 turns at 100 mA, but not yet optimized for operation above 25 mA. Machine development in the past year has been on understanding the single particle behavior in order to establish a strong basis for studying the effects of space charge. The effect of the earth's field has been studied and compensation implemented. Basic machine parameters such as the tune, equilibrium orbit, chromaticity and dispersion have been measured over a range of currents. We report here on these measurements and corresponding simulations.

  18. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    SciTech Connect

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G.; Singh, P.

    2013-12-15

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

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

    PubMed

    Baker, D N; Kanekal, S G; Hoxie, V C; Henderson, M G; Li, X; Spence, H E; Elkington, S R; Friedel, R H W; Goldstein, J; Hudson, M K; Reeves, G D; Thorne, R M; Kletzing, C A; Claudepierre, S G

    2013-04-12

    Since their discovery more than 50 years ago, Earth's Van Allen radiation belts have been considered to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is composed predominantly of megaelectron 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. The spatially separated inner zone is composed 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 reveal an isolated third ring, or torus, of high-energy (>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 more than 4 weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.

  20. 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

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

    SciTech Connect

    Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Henderson, M. G.; Li, X.; Spence, H. E.; Elkington, S. R.; Friedel, R. H. W.; Goldstein, J.; Hudson, M. K.; Reeves, G. D.; Thorne, R. M.; Kletzing, C. A.; Claudepierre, S. G.

    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 reveal 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.

  2. Lifetimes of C602- and C702- dianions in a storage ring

    NASA Astrophysics Data System (ADS)

    Tomita, S.; Andersen, J. U.; Cederquist, H.; Concina, B.; Echt, O.; Forster, J. S.; Hansen, K.; Huber, B. A.; Hvelplund, P.; Jensen, J.; Liu, B.; Manil, B.; Maunoury, L.; Brøndsted Nielsen, S.; Rangama, J.; Schmidt, H. T.; Zettergren, H.

    2006-01-01

    C602- and C702- dianions have been produced by electrospray of the monoanions and subsequent electron pickup in a Na vapor cell. The dianions were stored in an electrostatic ring and their decay by electron emission was measured up to 1 s after injection. While C702- ions are stable on this time scale, except for a small fraction of the ions which have been excited by gas collisions, most of the C602- ions decay on a millisecond time scale, with a lifetime depending strongly on their internal temperature. The results can be modeled as decay by electron tunneling through a Coulomb barrier, mainly from thermally populated triplet states about 120 meV above a singlet ground state. At times longer than about 100 ms, the absorption of blackbody radiation plays an important role for the decay of initially cold ions. The tunneling rates obtained from the modeling, combined with WKB estimates of the barrier penetration, give a ground-state energy 200±30meV above the energy of the monoanion plus a free electron and a ground-state lifetime of the order of 20 s.

  3. Observation of Electron Cloud Instabilities and Emittance Dilution at the Cornell Electron-Positron Storage Ring Test Accelerator

    NASA Astrophysics Data System (ADS)

    Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; Dugan, G. F.; Flanagan, J.; McArdle, K. E.; Miller, M. I.; Palmer, M. A.; Ramirez, G. A.; Sonnad, K. G.; Totten, M. M.; Tucker, S. L.; Williams, H. A.

    2016-04-01

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnotics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.

  4. Calibration of Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators

    SciTech Connect

    Dooling, J.; Harkay, K.; Ivanyushenkov, Y.; Sajaev, V.; Xiao, A.; Vella, Andrea K.

    2015-01-01

    We report on the calibration and use of fast fiber-optic (FO) beam loss monitors (BLMs) in the Advanced Photon Source storage ring (SR). A superconducting undulator prototype (SCU0) has been operating in SR Sector 6 (“ID6”) since the beginning of CY2013, and another undulator SCU1 (a 1.1-m length undulator that is three times the length of SCU0) is scheduled for installation in Sector 1 (“ID1”) in 2015. The SCU0 main coil often quenches during beam dumps. MARS simulations have shown that relatively small beam loss (<1 nC) can lead to temperature excursions sufficient to cause quenchingwhen the SCU0windings are near critical current. To characterize local beam losses, high-purity fused-silica FO cables were installed in ID6 on the SCU0 chamber transitions and in ID1 where SCU1 will be installed. These BLMs aid in the search for operating modes that protect the SCU structures from beam-loss-induced quenching. In this paper, we describe the BLM calibration process that included deliberate beam dumps at locations of BLMs. We also compare beam dump events where SCU0 did and did not quench.

  5. High flux circularly polarized gamma beam factory: coupling a Fabry-Perot optical cavity with an electron storage ring

    NASA Astrophysics Data System (ADS)

    Chaikovska, I.; Cassou, K.; Chiche, R.; Cizeron, R.; Cornebise, P.; Delerue, N.; Jehanno, D.; Labaye, F.; Marie, R.; Martens, A.; Peinaud, Y.; Soskov, V.; Variola, A.; Zomer, F.; Cormier, E.; Lhermite, J.; Dolique, V.; Flaminio, R.; Michel, C.; Pinard, L.; Sassolas, B.; Akagi, T.; Araki, S.; Honda, Y.; Omori, T.; Terunuma, N.; Urakawa, J.; Miyoshi, S.; Takahashi, T.; Yoshitama, H.

    2016-11-01

    We report and discuss high-flux generation of circularly polarized γ-rays by means of Compton scattering. The γ-ray beam results from the collision of an external-cavity-enhanced infrared laser beam and a low emittance relativistic electron beam. By operating a non-planar bow-tie high-finesse optical Fabry-Perot cavity coupled to a storage ring, we have recorded a flux of up to (3.5 ± 0.3) × 108 photons per second with a mean measured energy of 24 MeV. The γ-ray flux has been sustained for several hours. In particular, we were able to measure a record value of up to 400 γ-rays per collision in a full bandwidth. Moreover, the impact of Compton scattering on the electron beam dynamics could be observed resulting in a reduction of the electron beam lifetime correlated to the laser power stored in the Fabry-Perot cavity. We demonstrate that the electron beam lifetime provides an independent and consistent determination of the γ-ray flux. Furthermore, a reduction of the γ-ray flux due to intrabeam scattering has clearly been identified. These results, obtained on an accelerator test facility, warrant potential scaling and revealed both expected and yet unobserved effects. They set the baseline for further scaling of the future Compton sources under development around the world.

  6. Harmonic generation in VUV/x-ray range at the Duke storage ring FEL using electron beam outcoupling

    SciTech Connect

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

    1995-12-31

    We suggest using the OK-4 FEL operating in giant pulse mode to generate intracavity optical power at a level of hundreds of megawatts. These levels of power are sufficient to generate harmonics in the electron beam density. The prebunched electron beam then radiates coherently in an additional wiggler which is tuned on a harmonic of the OK-4 wavelength. The electron beam is turned by an achromatic bend into this wiggler, and harmonic radiation propagates with a small angle with respect to the OK-4 optical axis. This radiation will pass around the mirror of the OK-4 optical cavity and can then be utilized. This electron outcoupling scheme was suggested by N.A. Vinokurov as a method of optics independent outcoupling for high power FELs where electron beam bunching is provided in the master oscillator. This scheme is perfectly suited for optics independent harmonic generation. We suggest to operate the OK-4 FEL as a master oscillator in the UV range of 100 to 250 nm where conventional optics are available. This harmonic generation scheme would allow us to cover the VUV and soft X-Ray range with tunable coherent radiation. In this paper we present the possible layout of this system at the Duke storage ring and its expected operating parameters.

  7. PEGASYS/Mark II: A program of internal target physics using the Mark II detector at the PEP storage ring

    SciTech Connect

    Not Available

    1990-11-01

    This document is a proposal to SLAC on behalf of the PEGASYS Collaboration for a program of internal target physics at PEP utilizing the Mark A detector. Having completed its tour of duty at SLC in November 1990, we propose that the Mark A detector be returned to the PEP storage ring, where it will be used in conjunction with a long gas target for studies of QCD with nucleon and nuclear targets, as well as tests of QED in lepton pair production, and a search for new neutral bosons. We expect that the detector in its new configuration could be commissioned by late 1991 and begin taking data by 1992. This document presents the physics to be accomplished with the Mark A, and describes the minimal changes to the detector that we will need to make it function for internal target experiments. We also show a possible timeline for the project, and indicate the makeup of the collaboration that will carry out the work.

  8. Observation of electron cloud instabilities and emittance dilution at the Cornell electron-positron Storage ring Test Accelerator

    SciTech Connect

    Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; Dugan, G. F.; Flanagan, J.; McArdle, K. E.; Miller, M. I.; Palmer, M. A.; Ramirez, G. A.; Sonnad, K. G.; Totten, M. M.; Tucker, S. L.; Williams, H. A.

    2016-04-11

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnostics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains, 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this study we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.

  9. A Design Report of the Baseline for PEP-X: an Ultra-Low Emittance Storage Ring

    SciTech Connect

    Bane, Karl; Bertsche, Kirk; Cai, Yunhai; Chao, Alex; Corbett, Willian; Fox, John; Hettel, Robert; Huang, Xiaobiao; Huang, Zhirong; Ng, Cho-Kuen; Nosochkov, Yuri; Novokhatski, Sasha; Radedeau, Thomas; Raubenheimer, Tor; Rivetta, Claudio; Safranek, James; Seeman, John; Stohr, Joachim; Stupakov, Gennady; Wang, Lanfa; Wang, Min-Huey; /SLAC

    2010-06-02

    Over the past year, we have worked out a baseline design for PEP-X, as an ultra-low emittance storage ring that could reside in the existing 2.2-km PEPII tunnel. The design features a hybrid lattice with double bend achromat (DBA) cells in two arcs and theoretical minimum emittance (TME) cells in the remaining four arcs. Damping wigglers are used to reduce the horizontal emittance to 86 pm-rad at zero current for a 4.5 GeV electron beam. At a design current of 1.5 A, the horizontal emittance increases, due to intrabeam scattering, to 164 pm-rad when the vertical emittance is maintained at a diffraction limited 8 pm-rad. The baseline design will produce photon beams achieving a brightness of 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV in a 3.5-m conventional planar undulator. Our study shows that an optimized lattice has adequate dynamic aperture, while accommodating a conventional off-axis injection system. In this report, we present the results of study, including the lattice properties, nonlinear dynamics, intra-beam scattering and Touschek lifetime, RF system, and collective instabilities. Finally, we discuss the possibility of partial lasing at soft X-ray wavelengths using a long undulator in a straight section.

  10. Observation of electron cloud instabilities and emittance dilution at the Cornell electron-positron Storage ring Test Accelerator

    DOE PAGES

    Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; ...

    2016-04-11

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnostics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud withmore » stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains, 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this study we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.« less

  11. High flux circularly polarized gamma beam factory: coupling a Fabry-Perot optical cavity with an electron storage ring

    PubMed Central

    Chaikovska, I.; Cassou, K.; Chiche, R.; Cizeron, R.; Cornebise, P.; Delerue, N.; Jehanno, D.; Labaye, F.; Marie, R.; Martens, A.; Peinaud, Y.; Soskov, V.; Variola, A.; Zomer, F.; Cormier, E.; Lhermite, J.; Dolique, V.; Flaminio, R.; Michel, C.; Pinard, L.; Sassolas, B.; Akagi, T.; Araki, S.; Honda, Y.; Omori, T.; Terunuma, N.; Urakawa, J.; Miyoshi, S.; Takahashi, T.; Yoshitama, H.

    2016-01-01

    We report and discuss high-flux generation of circularly polarized γ-rays by means of Compton scattering. The γ-ray beam results from the collision of an external-cavity-enhanced infrared laser beam and a low emittance relativistic electron beam. By operating a non-planar bow-tie high-finesse optical Fabry-Perot cavity coupled to a storage ring, we have recorded a flux of up to (3.5 ± 0.3) × 108 photons per second with a mean measured energy of 24 MeV. The γ-ray flux has been sustained for several hours. In particular, we were able to measure a record value of up to 400 γ-rays per collision in a full bandwidth. Moreover, the impact of Compton scattering on the electron beam dynamics could be observed resulting in a reduction of the electron beam lifetime correlated to the laser power stored in the Fabry-Perot cavity. We demonstrate that the electron beam lifetime provides an independent and consistent determination of the γ-ray flux. Furthermore, a reduction of the γ-ray flux due to intrabeam scattering has clearly been identified. These results, obtained on an accelerator test facility, warrant potential scaling and revealed both expected and yet unobserved effects. They set the baseline for further scaling of the future Compton sources under development around the world. PMID:27857146

  12. Analysis and design of a high-current, high-voltage accurate power supply for the APS storage ring

    SciTech Connect

    Fathizadeh, M.

    1993-08-01

    There are 81 dipole magnets contained in the storage ring at the Advanced Photon Source (APS). These magnets are connected in series and are energized by only one 12-phase power supply. The eighty-first magnet is located in a temperature-controlled room with an NMR probe to monitor the magnetic field in the magnet and provide a reference signal for correction of the field drift due to aging of the components. The current in the magnets will be held at 497 A. The required current stability of the power supply is {plus_minus}30 ppM, the current reproducibility is {plus_minus}50 ppM, and the current ripple is {plus_minus}400 ppM. The voltage required to maintain such a current in the magnets is about 1700 V. Different schemes for regulating current in the magnets are studied. Pspice software is used to simulate the behavior and the design of such a power supply under different conditions. The pros and cons of each scheme will be given and the proper power and regulating scheme will be selected.

  13. Design and project status of the National Synchrotron Light Source; storage rings (2. 5 GeV, 0. 7 GeV) for the generation of bright synchrotron radiation sources

    SciTech Connect

    van Steenbergen, A

    1980-01-01

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

  14. Systematic Vibration Studies on a Cryogen-Free ^3He/^4He Dilution Refrigerator for X-ray Spectroscopy at Storage Rings

    NASA Astrophysics Data System (ADS)

    Scholz, P. A.; Kraft-Bermuth, S.; Andrianov, V.

    2016-08-01

    High-precision X-ray spectroscopy of highly charged ions at storage rings provides a sensitive test of quantum electrodynamics in strong Coulomb fields. To increase the precision of such experiments, silicon microcalorimeters have already been applied successfully. To minimize the interruption of beam times due to maintenance, a new cryogen-free ^3He/^4He dilution refrigerator has been designed and is under commissioning. However, in cryogen-free systems microphonic noise due to vibrations contributes considerably to the overall noise and may limit the detector energy resolution. Therefore, we report on systematic vibration studies on a cryogen-free ^3He/^4He dilution refrigerator which is specially adapted for experiments at storage rings.

  15. Source challenges resulting of the first applications of a UV storage ring FEL on Super-ACO

    SciTech Connect

    Couprie, M.E.; Bakker, R.; Nahon, L. |

    1995-12-31

    Since 1992, significant progresses were achieved on the Super-ACO (S-ACO) storage ring Free Electron Laser (FEL) in the UV. The operation at the nominal energy 800 MeV has several consequences: higher average power in the UV (25 mW at 60 mA and more recently 100 mW at 100 mA available for the users), 10 hours of lasing for the same injection of positrons, providing enough time for performing an user experiment, compatibility with the users of synchrotron radiation (SR) in the temporal structure mode for 120 mA with the possibility of closing the four insertion devices of S-ACO. The main difficulties to extend the FEL optical performances come from the small gain (2%), limiting a rapid extention of the spectral range (either in the laser mode or by coherent harmonic generation from the FEL itself in the undulator) or linewidth narrowing. The installation of a 500 MHz harmonic cavity for bunch length reduction and gain increase is under consideration{hor_ellipsis} The stability of the FEL temporal and spectral was systematically followed versus time, for various scales (from ns to half an hour) with different detectors. The stability of the laser source has been significantly improved with a longitudinal feedback system allowing the jitter of the 25 ps RMS laser micropulse to be reduced from 150-200 ps down to 10-20 ps. the intensity fluctuations to be damped down 1% and the spectral drift to be smaller than the resolution of the scanning Fabry-Perot (0.01{angstrom}) at perfect synchronism. The laser can work during more than 3 consecutive hours without readjustments. In addition, according to the ring current, the positron beam is submitted to coherent modes of synchrotron oscillations. Right now, a Pedersen type longitudinal feedback damps the dipolar modes of such oscillation. The quadrupolar modes in the 120-60 mA range leading to a rather unstable FEL are on the way to be damped with an additional feedback.

  16. Five-membered rings as diazo components in optical data storage devices: an ab initio investigation of the lowest singlet excitation energies

    NASA Astrophysics Data System (ADS)

    Åstrand, Per-Olof; Sommer-Larsen, Peter; Hvilsted, Søren; Ramanujam, P. S.; Bak, Keld L.; Sauer, Stephan P. A.

    2000-07-01

    The two lowest singlet excitation energies of 18 azo dyes have been studied by ab initio quantum-chemical methods within the second-order polarization propagator approximation (SOPPA). Various combinations of five-membered rings (furan, thiophene, pyrrole, oxazole, thiazole, and imidazole) have been investigated as diazo components for a potential use in optical data storage materials. It is found that the diazo compounds with two heterocyclic five-membered rings have π→π ∗ excitation energies corresponding to laser wavelengths in the region 450-500 nm whereas one five-membered ring and a phenyl group as diazo components results in wavelengths in the region 400-435 nm.

  17. Application of the Green's function method to some nonlinear problems of an electron storage ring. Part III. Beam-size enhancement due to the presence of nonlinear magnets in a ring

    SciTech Connect

    Kheifets, S.

    1983-01-01

    A perturbation method which allows one to find the distribution function and the beam size for a broad class of storage ring nonlinear problems is described in Part I of this work. In present note I apply this method to a particular problem. Namely, I want to evaluate an enhancement of the vertical beam size of a bunch due to the presence of the ring of nonlinear magnetic fields. The main part of the work deals with sextupole magnets. Formula for the beam size in the presence of octupole fields are also developed to the first order in the octupole strength, although octupole magnets are not widely used in present storage ring designs. This calculation is done mainly because the octupole field has the same symmetry as the beam-beam force for the head-on collision. This will give us the opportunity to compare the conduct of the bunch due to this two types of nonlinear kicks. The general terms of the applicability of the Green's function method is discussed in the first part of this work.

  18. Calculations of neutron and photon source terms and attenuation profiles for the generic design of the SPEAR3 storage ring shield.

    PubMed

    Rokni, S H; Khater, H; Liu, J C; Mao, S; Vincke, H

    2005-01-01

    The FLUKA Monte Carlo particle generation and transport code was used to calculate shielding requirements for the 3 GeV, 500 mA SPEAR3 storage ring at the Stanford Synchrotron Radiation Laboratory. The photon and neutron dose equivalent source term data were simulated for a 3 GeV electron beam interacting with two typical target/shielding geometries in the ring. The targets simulated are a rectangular block of 0.7 cm thick copper and a 5 cm thick iron block, both tilted at 1 degree relative to the beam direction. Attenuation profiles for neutrons and photons in concrete and lead as a function of angle at different shield thicknesses were calculated. The first, second and equilibrium attenuation lengths of photons and neutrons in the shield materials are derived from the attenuation profiles. The source term data and the attenuation lengths were then used to evaluate the shielding requirements for the ratchet walls of all front-ends of the SPEAR3 storage ring.

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

    NASA Astrophysics Data System (ADS)

    Bassi, G.; Blednykh, A.; Cheng, W.; Gao, F.; Rose, J.; Teytelman, D.

    2016-02-01

    The NSLS-II storage ring 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 the 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.

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

    SciTech Connect

    Bassi, G.; Blednykh, A.; Cheng, W.; Gao, F.; Rose, J.; Teytelman, D.

    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 the 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.

  1. 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.

  2. 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

  3. 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

  4. Electron-deuteron scattering with a polarized deuterium gas target in the VEPP-3 electron storage ring

    SciTech Connect

    Jones, C.E.; Fedchak, J.A.; Kowalczyk, R.S.

    1995-08-01

    The collaborative effort between Argonne and the Budker Institute for Nuclear Physics in Novosibirsk to measure the tensor analyzing power of the deuteron at high momentum transfer continues. This measurement allows the experimental separation of the deuteron charge and quadrupole form factors, which cannot be obtained from unpolarized scattering alone. Phase 2 of the experiment, which used a storage cell fed by an atomic beam source as the internal target, was completed. The limited statistics collected in this phase of the experiment are insufficient to confirm the existing data from MIT-Bates in the kinematic region up to q = 5 fm{sup -1}. It was decided to change to Phase 3 of the experiment, which uses a laser-driven polarized deuterium source and a passive storage cell as the target. All necessary parts of the Argonne source were delivered to Novosibirsk and work is underway to construct and test the target.

  5. Optimizing the lattice design of a diffraction-limited storage ring with a rational combination of particle swarm and genetic algorithms

    NASA Astrophysics Data System (ADS)

    Jiao, Yi; Xu, Gang

    2017-02-01

    In the lattice design of a diffraction-limited storage ring (DLSR) consisting of compact multi-bend achromats (MBAs), it is challenging to simultaneously achieve an ultralow emittance and a satisfactory nonlinear performance, due to extremely large nonlinearities and limited tuning ranges of the element parameters. Nevertheless, in this paper we show that the potential of a DLSR design can be explored with a successive and iterative implementation of the multi-objective particle swarm optimization (MOPSO) and multi-objective genetic algorithm (MOGA). For the High Energy Photon Source, a planned kilometer-scale DLSR, optimizations indicate that it is feasible to attain a natural emittance of about 50 pm·rad, and simultaneously realize a sufficient ring acceptance for on-axis longitudinal injection, by using a hybrid MBA lattice. In particular, this study demonstrates that a rational combination of the MOPSO and MOGA is more effective than either of them alone, in approaching the true global optima of an explorative multi-objective problem with many optimizing variables and local optima. Supported by NSFC (11475202, 11405187) and Youth Innovation Promotion Association CAS (2015009)

  6. Parameter optimization for Doppler laser cooling of a low-energy heavy ion beam at the storage ring S-LSR

    NASA Astrophysics Data System (ADS)

    Osaki, Kazuya; Okamoto, Hiromi

    2014-05-01

    S-LSR is a compact ion storage ring constructed at Kyoto University several years ago. The ring is equipped with a Doppler laser cooling system aimed at beam crystallization. Bearing in mind hardware limitations in S-LSR, we try to find an optimum set of primary experimental parameters for the production of an ultracold heavy ion beam. Systematic molecular dynamics simulations are carried out for this purpose. It is concluded that the detuning and spot size of the cooling laser should be chosen around -42 MHz and 1.5 mm, respectively, for the most efficient cooling of 40 keV ^{24}Mg^+ beams in S-LSR. Under the optimum conditions, the use of the resonant coupling method followed by radio-frequency field ramping enables us to reach an extremely low beam temperature on the order of 0.1 K in the transverse degrees of freedom. The longitudinal degree of freedom can be cooled to close to the Doppler limit; i.e., to the mK range. We also numerically demonstrate that it is possible to establish a stable, long one-dimensionally ordered state of ions.

  7. Effects of ring-porous and diffuse-porous stem wood anatomy on the hydraulic parameters used in a water flow and storage model.

    PubMed

    Steppe, Kathy; Lemeur, Raoul

    2007-01-01

    Calibration of a recently developed water flow and storage model based on experimental data for a young diffuse-porous beech tree (Fagus sylvatica L.) and a young ring-porous oak tree (Quercus robur L.) revealed that differences in stem wood anatomy between species strongly affect the calibrated values of the hydraulic model parameters. The hydraulic capacitance (C) of the stem storage tissue was higher in oak than in beech (939.8 versus 212.3 mg MPa(-1)). Model simulation of the elastic modulus (epsilon) revealed that this difference was linked to the higher elasticity of the stem storage tissue of oak compared with beech. Furthermore, the hydraulic resistance (R (x)) of beech was about twice that of oak (0.1829 versus 0.1072 MPa s mg(-1)). To determine the physiological meaning of the R (x) parameter identified by model calibration, we analyzed the stem wood anatomy of the beech and oak trees. Calculation of stem specific hydraulic conductivity (k (s)) of beech and oak with the Hagen-Poiseuille equation confirmed the differences in R (x) predicted by the model. The contributions of different vessel diameter classes to the total hydraulic conductivity of the xylem were calculated. As expected, the few big vessels contributed much more to total conductivity than the many small vessels. Compared with beech, the larger vessels of oak resulted in a higher k (s) (10.66 versus 4.90 kg m(-1) s(-1) MPa(-1)). The calculated ratio of k (s) of oak to beech was 2, confirming the R (x) ratio obtained by model calibration. Thus, validation of the R (x) parameter of the model led to identification of its physiological meaning.

  8. The Fermilab recycler ring

    SciTech Connect

    Martin Hu

    2001-07-24

    The Fermilab Recycler is a permanent magnet storage ring for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler Ring.

  9. Application of the Green's function method to some nonlinear problems of an electron storage ring: Part 1, The Green's function for the Fokker-Planck equation

    SciTech Connect

    Kheifets, S.

    1982-07-01

    For an electron storage ring the beam size evaluation including beam-beam interaction gives an example of such a problem. Another good example is finding the beam size for a nonlinear machine. The present work gives a way to solve some of these problems, at least in principle. The approach described here is an application of the well known Green's function method, which in this case is applied to the Fokker-Planck equation governing the distribution function in the phase space of particle motion. The new step made in this paper is to consider the particle motion in two degrees of freedom rather than in one dimension, a characteristic of all the previous work. This step seems to be necessary for an adequate description of the problem, at least for the class of problems which are considered below. This work consists of the formal solution of the Fokker-Planck equation in terms of its Green's function and describing the Green's function itself. The Green's function and the description of some of its properties can be found in the Appendices. I discuss the distribution function in the transverse phase space of a particle and it's Fokker-Planck equation for a simple case of a weak focusing machine. Part of this paper is devoted to describing the Green's function and solution of this equation. Then this technique is applied to a strong focusing machine and finally there is a discussion of applicability of this method, its limitations and relation to other methods. 13 refs.

  10. Determination of the angular and energy dependence of hard constituent scattering from. pi. /sup 0/ pair events at the CERN intersecting storage rings

    SciTech Connect

    Angelis, A.L.S.; Besch, H.J.; Blumenfeld, B.J.

    1982-08-23

    We present data on proton-proton collisions, obtained at the CERN Intersecting Storage Rings, in which two roughly back-to-back ..pi../sup 0/'s of high transverse momentum (p/sub T/) were produced. The angular distribution of the dipion axis relative to the collision axis is found to be independent of both the effective mass m of the dipion system and the centre-of-mass energy ..sqrt..s of the proton-proton collision. The cross-sections dsigma/dm at the two values of ..sqrt..s satisfy a scaling law of the form dsigma/dm = G(x)/m/sup n/, where x = m(..pi../sup 0/,..pi../sup 0/)/..sqrt..s and n = 6.5 +- 0.5. We show from our data that the leading ..pi../sup 0/ carries most of the momentum of the scattered parton. Given this fact, the axis of the dipion system follows closely the direction of the scattered constituents, and we exploit this to determine the angular dependence of the hard-scattering subprocess. We also compare our data with the lowest order QCD predictions using structure functions as determined in deep-inelastic scattering and fragmentation functions from electron-positron annihilation.

  11. Precise determination of the 1s Lamb Shift in hydrogen-like heavy ions at the ESR storage ring using microcalorimeters

    NASA Astrophysics Data System (ADS)

    Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Grabitz, P.; Ilieva, S.; Kiselev, O.; Kilbourne, C.; McCammon, D.; Meier, J. P.; Scholz, P.

    2015-11-01

    The precise determination of the energy of the Lyman α1 and α2 lines in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. To improve the precision of such experiments, the new detector concept of microcalorimeters, which detect the temperature change of an absorber after an incoming particle or photon has deposited its energy as heat, is now exploited. The microcalorimeters for x-rays used in these experiments consist of arrays of silicon thermometers and x-ray absorbers made of high-Z material. With such detectors, a relative energy resolution of about 1 per mille is obtained in the energy regime of 50-100 keV. Two successful measurement campaigns to determine the 1s Lamb Shift in Pb81+ and Au78+ have been completed: a prototype array has been applied successfully for the determination of the 1s Lamb Shift of Pb81+ at the ESR storage ring at GSI in a first test experiment. Based on the results of this test, a full array with 32 pixels has been equipped and has recently been applied to determine the 1s Lamb Shift in Au78+ ions. The energy of the Lyman-α1 line agrees within error bars well with theoretical predictions. The obtained accuracy is already comparable to the best accuracy obtained with conventional germanium detectors for hydrogen-like uranium.

  12. Spectral radiant power measurements of VUV and soft x-ray sources using the electron storage ring BESSY as a radiometric standard source.

    PubMed

    Fischer, J; Kühne, M; Wende, B

    1984-12-01

    A method is described for measuring the spectral radiant power of VUV and soft x-ray sources using the electron storage ring BESSY as a radiometric standard source of calculable spectral radiant power and degree of polarization. An ellipsoidal grazing incidence mirror stigmatically images the stored electrons or the source under investigation in equal optical conditions into a toroidal grating monochromator. The monochromator can be rotated around its optical axis in UHV conditions to account for different degrees of polarization of the two sources. The accuracy presently available with this method is demonstrated by a measurement of the spectral concentration of radiant intensity of a laser-produced tungsten plasma in the wavelength range between 7 and 100 nm with an overall uncertainty of 10%. A detailed analysis of the contributions to this uncertainty shows that the major part of it is caused by the presently uncertain knowledge of the polarizing properties of the radiometric instrumentation and by the uncertainty of the correction procedure which accounts for the influence of higher diffraction orders of the monochromator grating. The results of the radiation measurements of the laser-produced tungsten plasma let us expect that this source type has the potential to serve as a radiometric transfer standard in the VUV and soft x-ray range below 100 nm.

  13. STORAGE RING CROSS-SECTION MEASUREMENTS FOR ELECTRON IMPACT SINGLE AND DOUBLE IONIZATION OF Fe{sup 9+} AND SINGLE IONIZATION OF Fe{sup 10+}

    SciTech Connect

    Hahn, M.; Novotny, O.; Savin, D. W.; Becker, A.; Grieser, M.; Krantz, C.; Wolf, A.; Lestinsky, M.; Repnow, R.; Mueller, A.; Schippers, S.; Spruck, K.

    2012-11-20

    We have measured electron impact ionization from the ground state of Fe{sup 9+} and Fe{sup 10+} over the relative electron-ion collision energy ranges 200-1900 eV and 250-1800 eV, respectively. The ions were confined in an ion storage ring long enough for essentially all metastable levels to radiatively relax to the ground state. For single ionization, we find a number of discrepancies between the existing theoretical cross sections and our results. The calculations appear to neglect some excitation-autoionization (EA) channels, particularly from n = 3 to n' excitations, which are important near threshold, and those from n = 2 {yields} 3 excitations, which contribute at about 650 eV. Conversely, at higher energies the calculations appear to overestimate the importance of EA channels due to excitation into levels where n {>=} 4. The resulting experimental rate coefficients agree with the most recent theory for Fe{sup 9+} to within 16% and for Fe{sup 10+} to within 19% at temperatures where these ions are predicted to form in collisional ionization equilibrium. We have also measured double ionization of Fe{sup 9+} forming Fe{sup 11+} in the energy range 450-3000 eV and found that although there is an appreciable cross section for direct double ionization, the dominant mechanism appears to be through direct ionization of an inner shell electron producing an excited state that subsequently stabilizes through autoionization.

  14. Single differential projectile ionization cross sections d σ/dEe for 50 AMeV U28+ in the ESR storage ring

    NASA Astrophysics Data System (ADS)

    Hagmann, Siegbert; Hillenbrand, Pierre-Michel; Stoehlker, Thomas; Litvinov, Yuri; Appa-Sparc Collaboration

    2013-05-01

    The very high intensity beams of relativistic high Z ions with incident collision energies up to 2.7AGeV requested for experiments using the SIS100 synchrotron of FAIR require that 1.3 1011 ions at 2.6Hz be injected from SIS12/18 into SIS100. The needed luminosity of the beam can only be achieved for such high Z ions when - considering the space charge limit (~A/q2) - a low charge state q of the ion to be accelerated keeps the particle density at the highest feasible level. For a thorough understanding of beam loss it is imperative that the mechanisms active in projectile ionization be understood quantitatively to provide benchmarks for advancedab initio theories beyond first order. We have embarked on an experimental investigation of single differential projectile ionization cross sections d σ/dEe (SDCS) for single and multiple ionization of U28+in the ESR storage ring by measuring the electron loss to continuum (ELC) cusp at 00 with respect to the beam axis employing our imaging forward electron spectrometer. This was motivated by the high relative fraction of multiple ionization estimated to exceed 40%. We report first results for absolute projectile ionization SDCS for U28+. We find a remarkably high asymmetry for the ELC cusp. This is at strong variance with the line shape expected for validity of first order theories.

  15. Application of the Green's function method to some nonlinear problems of an electron storage ring: Part 2, Checking the method by a quadrupole perturbation

    SciTech Connect

    Kheifets, S.

    1982-10-01

    In the first part of this work I described a general approach to some storage ring problems. The basic concept and the main equations were developed there. The next natural step in this work should be an application of the developed technique to some particular nonlinear problem. Instead, I found it useful to apply the method to the case of a field gradient perturbation first. This happened to be plausible not only as a check of the method, but, more importantly, as a way to resolve several troublesome difficulties encountered in subsequent calculations. The present note does not contain any new results. Still, the work is felt to be necessary as a support for all the future applications of the method. I consider here the effect of a global gradient error in a weak-focusing machine and the effect of a local gradient error in a strong focusing machine. The distribution function of a particle bunch for a perturbed lattice in these cases can be written explicitly. The expansion of this distribution function as a series perturbation terms produces the first and the second order corrections to the unperturbed function. From them we calculate, then, corresponding second moments. A similar expansion of the distribution function is found by the Green's function method described of this work. The second moments are found independently with the help of this distribution function. The comparison of these two results is one way to check the method and the correctness of the calculations. This comparison is done for the first and second order perturbations. 4 refs., 2 tabs.

  16. Study for ILC Damping Ring at KEKB

    SciTech Connect

    Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; Pivi, M.; /SLAC

    2011-11-04

    ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

  17. The CERN Intersecting Storage Rings

    NASA Astrophysics Data System (ADS)

    Myers, Stephen

    The following sections are included: * Introduction and history * Phase displacement and stacking * Vacuum * Working lines and space charge compensation * Schottky scans * Centring the accumulated beam in the aperture * Inserting markers in the stack * Acceleration by phase displacement * Computer control of accelerators * Working close to the integer * Low β insertions and luminosity * Stochastic cooling * Summary: What did ISR teach us? * References

  18. Ground Movement in SSRL Ring

    SciTech Connect

    Sunikumar, Nikita; /UCLA /SLAC

    2011-08-25

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  19. Cobalt hydroxide/oxide hexagonal ring-graphene hybrids through chemical etching of metal hydroxide platelets by graphene oxide: energy storage applications.

    PubMed

    Nethravathi, C; Rajamathi, Catherine R; Rajamathi, Michael; Wang, Xi; Gautam, Ujjal K; Golberg, Dmitri; Bando, Yoshio

    2014-03-25

    The reaction of β-Co(OH)2 hexagonal platelets with graphite oxide in an aqueous colloidal dispersion results in the formation of β-Co(OH)2 hexagonal rings anchored to graphene oxide layers. The interaction between the basic hydroxide layers and the acidic groups on graphene oxide induces chemical etching of the hexagonal platelets, forming β-Co(OH)2 hexagonal rings. On heating in air or N2, the hydroxide hybrid is morphotactically converted to porous Co3O4/CoO hexagonal ring-graphene hybrids. Porous NiCo2O4 hexagonal ring-graphene hybrid is also obtained through a similar process starting from β-Ni0.33Co0.67(OH)2 platelets. As electrode materials for supercapacitors or lithium-ion batteries, these materials exhibit a large capacity, high rate capability, and excellent cycling stability.

  20. 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

    SciTech Connect

    Le Pimpec, F.; Kirby, R.E.; King, F.K.; Pivi, M.; /SLAC

    2006-01-25

    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.

  1. 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.

  2. Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  3. Vascular ring

    MedlinePlus

    ... with aberrant subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... accounts for less than 1% of all congenital heart problems. The condition occurs as often in males ...

  4. Neptune's rings

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  5. Vortex rings

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Leonard, Anthony

    1992-01-01

    The vortex-ring problem in fluid mechanics is examined generally in terms of formation, the steady state, the duration of the rings, and vortex interactions. The formation is studied by examining the generation of laminar and turbulent vortex rings and their resulting structures with attention given to the three stages of laminar ring development. Inviscid dynamics is addressed to show how core dynamics affects overall ring motion, and laminar vortex structures are described in two dimensions. Viscous and inviscid structures are related in terms of 'leapfrogging', head-on collisions, and collisions with a no-slip wall. Linear instability theory is shown to successfully describe observational data, although late stages in the breakdown are not completely understood. This study of vortex rings has important implications for key aerodynamic issues including sound generation, transport and mixing, and vortex interactions.

  6. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  7. Metal-Organic Framework with Aromatic Rings Tentacles: High Sulfur Storage in Li-S Batteries and Efficient Benzene Homologues Distinction.

    PubMed

    Li, Meng-Ting; Sun, Yu; Zhao, Kai-Sen; Wang, Zhao; Wang, Xin-Long; Su, Zhong-Min; Xie, Hai-Ming

    2016-12-07

    We designed and fabricated a fluorophore-containing tetradentate carboxylate ligand-based metal-organic framework (MOF) material with open and semiopen channels, which acted as the host for sulfur trapped in Li-S batteries and sensor of benzene homologues. These channels efficiently provide a π-π* conjugated matrix for the charge transfer and guest molecule trapping. The open channel ensured a much higher loading quantitative of sulfur (S content-active material, 72 wt %; electrode, 50.4 wt %) than most of the MOF/sulfur composites, while the semiopen channel possessing aromatic rings tentacles guaranteed an outstanding specific discharge capacity (1092 mA h g(-1) at 0.1 C) accompanied by good cycling stability. To our surprise, benefiting from special π-π* conjugated conditions, compound 1 could be a chemical sensor for benzene homologues, especially for 1,2,4-trimethylbenzene (1,2,4-TMB). This is the first example of MOFs materials serving as a sensor of 1,2,4-TMB among benzene homologues. Our works may be worthy of use for references in other porous materials systems to manufacture more long-acting Li-S batteries and sensitive chemical sensors.

  8. Ghostly Ring

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for poster version

    This image shows a ghostly ring extending seven light-years across around the corpse of a massive star. The collapsed star, called a magnetar, is located at the exact center of this image. NASA's Spitzer Space Telescope imaged the mysterious ring around magnetar SGR 1900+14 in infrared light. The magnetar itself is not visible in this image, as it has not been detected at infrared wavelengths (it has been seen in X-ray light).

    Magnetars are formed when a massive giant star ends its life in a supernova explosion, leaving behind a super dense neutron star with an incredibly strong magnetic field. The ring seen by Spitzer could not have formed during the original explosion, as any material as close to the star as the ring would have been disrupted by the supernova shock wave. Scientists suspect that the ring my actually be the edges of a bubble that was hollowed out by an explosive burst from the magnetar in 1998. The very bright region near the center of the image is a cluster of young stars, which may be illuminating the inner edge of the bubble, making it look like a ring in projection.

    This composite image was taken using all three of Spitzer's science instruments. The blue color represents 8-micron infrared light taken by the infrared array camera, green is 16-micron light from the infrared spectograph, and red is 24-micron radiation from the multiband imaging photometer.

  9. Luminescent Rings

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This view shows the unlit face of Saturn's rings, visible via scattered and transmitted light. In these views, dark regions represent gaps and areas of higher particle densities, while brighter regions are filled with less dense concentrations of ring particles.

    The dim right side of the image contains nearly the entire C ring. The brighter region in the middle is the inner B ring, while the darkest part represents the dense outer B Ring. The Cassini Division and the innermost part of the A ring are at the upper-left.

    Saturn's shadow carves a dark triangle out of the lower right corner of this image.

    The image was taken in visible light with the Cassini spacecraft wide-angle camera on June 8, 2005, at a distance of approximately 433,000 kilometers (269,000 miles) from Saturn. The image scale is 22 kilometers (14 miles) per pixel.

    The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

    For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

  10. Cave Rings

    DTIC Science & Technology

    2010-10-13

    hypothesis, that cave rings are formed in the same manner as coffee rings[3], that is, due to the enhanced deposition at the edges of sessile drops ...Literature The ‘splash ring’ conjecture is described in [5]. It is claimed that 45◦ is the most probable angle for secondary drops to be ejected at, and that...ring’ is the deposit formed when a sessile drop of a solution containing dissolved particles, such as coffee or salt, dries. This was investigated by

  11. STORAGE RING CROSS SECTION MEASUREMENTS FOR ELECTRON IMPACT SINGLE AND DOUBLE IONIZATION OF Fe{sup 13+} AND SINGLE IONIZATION OF Fe{sup 16+} AND Fe{sup 17+}

    SciTech Connect

    Hahn, M.; Novotny, O.; Savin, D. W.; Becker, A.; Grieser, M.; Krantz, C.; Repnow, R.; Wolf, A.; Bernhardt, D.; Mueller, A.; Schippers, S.; Spruck, K.; Lestinsky, M.

    2013-04-10

    We report measurements of electron impact ionization for Fe{sup 13+}, Fe{sup 16+}, and Fe{sup 17+} over collision energies from below threshold to above 3000 eV. The ions were recirculated using an ion storage ring. Data were collected after a sufficiently long time that essentially all the ions had relaxed radiatively to their ground state. For single ionization of Fe{sup 13+}, we find that previous single pass experiments are more than 40% larger than our results. Compared to our work, the theoretical cross section recommended by Arnaud and Raymond is more than 30% larger, while that of Dere is about 20% greater. Much of the discrepancy with Dere is due to the theory overestimating the contribution of excitation-autoionization via n = 2 excitations. Double ionization of Fe{sup 13+} is dominated by direct ionization of an inner shell electron accompanied by autoionization of a second electron. Our results for single ionization of Fe{sup 16+} and Fe{sup 17+} agree with theoretical calculations to within the experimental uncertainties.

  12. CHEER, Canadian high energy electron ring

    NASA Astrophysics Data System (ADS)

    Hemingway, R. J.

    The Institute of Particle Physics (IPP) in Canada have received funds from the Natural Sciences and Engineering Research Council (NSERC) to pursue a study which looks at the feasibility of adding an external electron storage ring at one of the long straight sections of the Tevatron. The machine, as currently configured, has a 300 MeV Linac injector, a 300 MeV accumulator ring, a 2 GeV booster synchrotron, and a 10 GeV storage ring holding 120 mA of either electrons or positrons. Particular attention has been paid to beam polarisation and the design of the interaction region.

  13. 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.

  14. Kayser-Fleischer Rings

    MedlinePlus

    ... to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring ... Diet & Nutrition Kayser-Fleischer Rings Wilson Disease FAQs Definitions Transplantation For Patients & Families Resources Membership Events Centers ...

  15. Large diameter metal ring seal prevents gas leakage at 5000 psi

    NASA Technical Reports Server (NTRS)

    Middelkoop, J. H.

    1966-01-01

    Large metal ring seal prevents gas leakage in hydrogen, helium, or nitrogen storage bottles at pressures up to 5,000 psi. The grooved ring seal which contains elastomer O-rings is installed between the mating faces of the access cover and the storage bottle.

  16. Ringing wormholes

    SciTech Connect

    Konoplya, R.A.; Molina, C.

    2005-06-15

    We investigate the response of traversable wormholes to external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in the two brane Randall-Sundrum model and was previously found within Einstein gravity with a conformally coupled scalar field. The evolution of perturbations of a wormhole is similar to that of a black hole and represents damped oscillations (ringing) at intermediately late times, which are suppressed by power-law tails (proportional to t{sup -2} for monopole perturbations) at asymptotically late times.

  17. Storage Ring Technology for Free Electron Lasers.

    DTIC Science & Technology

    1984-04-01

    Because of this it was easy to lose all of 20 ..... %"€ the stored beam by accidently exciting the strongly coupled tune while seeking the weaker tune...calculation also applies to was supported by the DRET, the Centre d’Etudes Nucleaires de high-pover input laser beams (a0 > 1) provided one Saclay DPC SPP SP

  18. Present status of Rare-RI Ring facility at RIBF

    NASA Astrophysics Data System (ADS)

    T Yamaguchithe Rare-RI Ring Collaboration

    2015-11-01

    A new storage ring facility called the Rare-RI Ring is currently under preparation at the RI Beam Factory (RIBF) in RIKEN. The storage ring is dedicated to the single-ion precision mass spectrometry of neutron-rich exotic nuclei. The masses are essential to elucidate the evolution of the nuclear shell structure far from the β stability and to determine the pathway of astrophysical nucleosynthesis. Such exotic nuclei are provided by the large-acceptance superconducting fragment separator, BigRIPS, at the RIBF accelerator complex. The experimental principle of the Rare-RI Ring mass measurements is based on isochronous mass spectrometry combined with the individual injection technique. This novel technique enables exotic species of interest to be produced randomly, in time to be sequentially stored in the storage ring. The Rare-RI Ring facility realizes the most efficient measurements for rare isotopes. An overview of the project is presented, along with its present status.

  19. Energy Storage.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  20. Kinetics of ring formation

    NASA Astrophysics Data System (ADS)

    Ben-Naim, E.; Krapivsky, P. L.

    2011-06-01

    We study reversible polymerization of rings. In this stochastic process, two monomers bond and, as a consequence, two disjoint rings may merge into a compound ring or a single ring may split into two fragment rings. This aggregation-fragmentation process exhibits a percolation transition with a finite-ring phase in which all rings have microscopic length and a giant-ring phase where macroscopic rings account for a finite fraction of the entire mass. Interestingly, while the total mass of the giant rings is a deterministic quantity, their total number and their sizes are stochastic quantities. The size distribution of the macroscopic rings is universal, although the span of this distribution increases with time. Moreover, the average number of giant rings scales logarithmically with system size. We introduce a card-shuffling algorithm for efficient simulation of the ring formation process and we present numerical verification of the theoretical predictions.

  1. Dynamics of neutral molecules stored in a ring

    SciTech Connect

    Crompvoets, Floris M.H.; Bethlem, Hendrick L.; Kuepper, Jochen; Roij, Andre J.A. van; Meijer, Gerard

    2004-06-01

    A decelerated beam of neutral ammonia molecules is injected into an electrostatic storage ring. Electrostatic lenses are used to map the emittance of the decelerator onto the acceptance of the ring. The tangential velocity spread of the package of molecules in the ring is set to less than 1 m/s. The package of molecules can be observed for more than 50 distinct round trips, corresponding to 40 m in circular orbit and almost 0.5 s storage time, sufficiently long for a first investigation of its transversal motion in the ring.

  2. Ringing phenomenon of the fiber ring resonator.

    PubMed

    Ying, Diqing; Ma, Huilian; Jin, Zhonghe

    2007-08-01

    A resonator fiber-optic gyro (R-FOG) is a high-accuracy inertial rotation sensor based on the Sagnac effect. A fiber ring resonator is the core sensing element in the R-FOG. When the frequency of the fiber ring resonator input laser is swept linearly with time, ringing of the output resonance curve is observed. The output field of the fiber ring resonator is derived from the superposition of the light transmitted through the directional coupler directly and the multiple light components circulated in the fiber ring resonator when the frequency of the laser is swept. The amplitude and phase of the output field are analyzed, and it is found that the difference in time for different light components in the fiber ring resonator to reach a point of destructive interference causes the ringing phenomenon. Finally the ringing phenomenon is observed in experiments, and the experimental results agree with the theoretical analysis well.

  3. Asymmetric dipolar ring

    DOEpatents

    Prosandeev, Sergey A.; Ponomareva, Inna V.; Kornev, Igor A.; Bellaiche, Laurent M.

    2010-11-16

    A device having a dipolar ring surrounding an interior region that is disposed asymmetrically on the ring. The dipolar ring generates a toroidal moment switchable between at least two stable states by a homogeneous field applied to the dipolar ring in the plane of the ring. The ring may be made of ferroelectric or magnetic material. In the former case, the homogeneous field is an electric field and in the latter case, the homogeneous field is a magnetic field.

  4. Saturn's Spectacular Ring System

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Saturn's beautiful rings have fascinated astronomers since they were first observed by Galileo in 1610. The main rings consist of solid particles mostly in the 1 cm - 10 m range, composed primarily of water ice. The ring disk is exceptionally thin - the typical local thickness of the bright rings is tens of meters, whereas the diameter of the main rings is 250,000 km! The main rings exhibit substantial radial variations "ringlets", many of which are actively maintained via gravitational perturbations from Saturn's moons. Exterior to the main rings lie tenuous dust rings, which have little mass but occupy a very large volume of space. This seminar will emphasize the physics of ring-moon interactions, recent advances in our understanding of various aspects of the rings obtained from observations taken during 1995 when the rings appeared edge-on to the Earth and then to the Sun, and observations in subsequent years from HST.

  5. PULSED POWER APPLICATIONS IN HIGH INTENSITY PROTON RINGS.

    SciTech Connect

    ZHANG, S.Y.; SANDBERG, J.; ET AL.

    2005-05-16

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

  6. Stirling engine piston ring

    DOEpatents

    Howarth, Roy B.

    1983-01-01

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

  7. Birth Control Ring

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Ring KidsHealth > For Teens > Birth Control Ring Print A A A What's in this ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ring ...

  8. New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring

    SciTech Connect

    de Pater, I; Hammel, H B; Gibbard, S G; Showalter, M R

    2006-02-02

    We compare near-infrared observations of the recently discovered outer rings of Uranus with HST results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced via impacts into the embedded moon Mab, which apparently orbits at a location where non-gravitational perturbations favor the survival and spreading of sub-micron sized dust. R/2003 U 2 more closely resembles Saturn's G ring.

  9. 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.

  10. Jupiter's Main Ring/Ring Halo

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (28.5 miles) per picture element (pixel) along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun; the ring was approximately 2.3 million kilometers (1.4 million miles) away. The arc on the far right of the image is produced when sunlight is scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

    Jupiter's ring system is composed of three parts - - a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, outside the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the figure's far left side. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa (top image). A faint mist of particles can be seen above and below the main rings. This vertically extended 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. To accentuate faint features in the bottom image of the ring halo, different brightnesses are shown through color. Brightest features are white or yellow and the

  11. 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.

  12. New dust belts of Uranus: one ring, two ring, red ring, blue ring.

    PubMed

    de Pater, Imke; Hammel, Heidi B; Gibbard, Seran G; Showalter, Mark R

    2006-04-07

    We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G ring, which is red, a typical color for dusty rings.

  13. Saturn's F-Ring

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This narrow-angle camera image of Saturn's F Ring was taken through the Clear filter while at a distance of 6.9 million km from Saturn on 8 November 1980. The brightness variations of this tightly-constrained ring shown here indicate that the ring is less uniform in makeup than the larger rings. JPL managed the Voyager Project for NASA's Office of Space Science

  14. On certain Hecke rings

    PubMed Central

    Evens, Sam; Bressler, Paul

    1987-01-01

    We examine rings that embed into the smash product of the group algebra of the Weyl group with the field of meromorphic functions on the Cartan subalgebra and are generated by elements that satisfy braid relations. We prove that every such ring is isomorphic to either the Hecke algebra, the nil Hecke ring, or the group algebra of the Weyl group. PMID:16593804

  15. The Jumping Ring Experiment

    ERIC Educational Resources Information Center

    Baylie, M.; Ford, P. J.; Mathlin, G. P.; Palmer, C.

    2009-01-01

    The jumping ring experiment has become central to liquid nitrogen shows given as part of the outreach and open day activities carried out within the University of Bath. The basic principles of the experiment are described as well as the effect of changing the geometry of the rings and their metallurgical state. In general, aluminium rings are…

  16. Rings Around Uranus

    ERIC Educational Resources Information Center

    Maran, Stephen P.

    1977-01-01

    Events leading up to the discovery of the rings of Uranus are described. The methods used and the logic behind the methods are explained. Data collected to prove the existence of the rings are outlined and theories concerning the presence of planetary rings are presented. (AJ)

  17. Soft normed rings.

    PubMed

    Uluçay, Vakkas; Şahin, Mehmet; Olgun, Necati

    2016-01-01

    Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft normed rings by soft set theory. The notions of soft normed rings, soft normed ideals, soft complete normed rings are introduced and also several related properties and examples are given.

  18. Saturn's largest ring.

    PubMed

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

    2009-10-22

    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

  19. On the solar dust ring(s)

    NASA Astrophysics Data System (ADS)

    Mukai, T.

    Based on a mechanism to form the solar dust ring, it is proved that the observed peak in infrared F-corona cannot be explained by silicate type grains alone. Preliminary analysis on the recent infrared data of the F-corona by Maihara et al. (1984) has suggested that the ring particles have different physical properties compared with the dust grains, which produce the background F-corona.

  20. Dust and Planetary Rings

    NASA Astrophysics Data System (ADS)

    Siddiqui, Muddassir

    ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring

  1. Energy storage

    NASA Astrophysics Data System (ADS)

    Kaier, U.

    1981-04-01

    Developments in the area of energy storage are characterized, with respect to theory and laboratory, by an emergence of novel concepts and technologies for storing electric energy and heat. However, there are no new commercial devices on the market. New storage batteries as basis for a wider introduction of electric cars, and latent heat storage devices, as an aid for solar technology applications, with satisfactory performance standards are not yet commercially available. Devices for the intermediate storage of electric energy for solar electric-energy systems, and for satisfying peak-load current demands in the case of public utility companies are considered. In spite of many promising novel developments, there is yet no practical alternative to the lead-acid storage battery. Attention is given to central heat storage for systems transporting heat energy, small-scale heat storage installations, and large-scale technical energy-storage systems.

  2. Slowing of Vortex Rings

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell; Bolster, Diogo; Hershberger, Robert

    2008-11-01

    We have investigated the slowing of vortex rings in water which are created with very thin cores. We find that these rings propagate with no measurable change in diameter or core size. The drag appears to be the result of viscous forces on the core. A simple model for this drag describes experimental data in terms of a drag coefficient, which depends only on Reynolds number. Barenghi's group at Newcastle found that the translational velocity of a ring in an inviscid fluid perturbed by Kelvin waves decreases with increasing amplitude of Kelvin waves. This suggests that the velocity of vortex rings in a viscous fluid may well depend on the amplitude of Kelvin waves at the time of formation. Rings with substantial amplitude of Kelvin waves will be expected to move more slowly than rings with little or no Kelvin wave amplitude. We present experimental data confirming this suggestion.

  3. Antiproton cooling in the Fermilab Recycler Ring

    SciTech Connect

    Nagaitsev, S.; Bolshakov, A.; Broemmelsiek, D.; Burov, Alexey V.; Carlson, K.; Gattuso, C.; Hu, M.; Kazakevich, G.; Kramper, B.; Kroc, T.; Leibfritz, J.; Prost, L.; Pruss, S.; Saewert, G; Schmidt, C.W.; Seletskiy, S.; Shemyakin, A.; Sutherland, M.; Tupikov, V.; Warner, A.; Zenkevich, P.; /Fermilab /Moscow, ITEP /Novosibirsk, IYF /Rochester U.

    2005-12-01

    The 8.9-GeV/c Recycler antiproton storage ring is equipped with both stochastic and electron cooling systems. These cooling systems are designed to assist accumulation of antiprotons for the Tevatron collider operations. In this paper we report on an experimental demonstration of electron cooling of high-energy antiprotons. At the time of writing this report, the Recycler electron cooling system is routinely used in collider operations. It has helped to set recent peak luminosity records.

  4. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  5. Saturn's E ring revisited

    NASA Astrophysics Data System (ADS)

    Feibelman, W. A.; Klinglesmith, D. A.

    1980-07-01

    Images of the E ring of Saturn obtained by the image processing of photographs of the 1966 edge-on presentation of the planet's ring plane are presented. Two methods of image enhancement were used: scanning with an image quantizer operated in the derivative mode to enhance contrast and computerized subtraction of a circularly symmetric image of the overexposed Saturn disk. Further photographic and CCD observation confirming the existence of the ring extending to twice the diameter of the A ring, which was not detected by the Pioneer 11 imaging photopolarimeter, is indicated.

  6. Jupiter's Ring Halo

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

    Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.

    A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest

  7. Modified spiral wound retaining ring

    NASA Technical Reports Server (NTRS)

    Lawson, A. G. (Inventor)

    1980-01-01

    A spiral wound retaining ring with angled ends is described. The ring is crimped at the same angle as the ring ends to maintain a constant thickness dimension. The angling of the ends of the ring and crimp allow the ends to be positioned closer together while maintaining enough clearance to enable insertion and removal of the ring. By reducing the separation distance between the ends a stronger ring results since the double layer area of the ring is maximized.

  8. Contactless Magnetic Slip Ring

    NASA Technical Reports Server (NTRS)

    Kumagai, Hiroyuki (Inventor); Deardon, Joe D. (Inventor)

    1997-01-01

    A contactless magnetic slip ring is disclosed having a primary coil and a secondary coil. The primary and secondary coils are preferably magnetically coupled together, in a highly reliable efficient manner, by a magnetic layered core. One of the secondary and primary coils is rotatable and the contactless magnetic slip ring provides a substantially constant output.

  9. Illustration of Saturn's Rings

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This illustration shows a close-up of Saturn's rings. These rings are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.

  10. Birth Control Ring

    MedlinePlus

    ... It? The birth control ring is a soft, flexible, doughnut-shaped ring about 2 inches (5 centimeters) in diameter. It is inserted into the vagina, where it slowly releases hormones — the chemicals the body makes to control organ function — through the vaginal wall into the ...

  11. Steroidal contraceptive vaginal rings.

    PubMed

    Sarkar, N N

    2003-06-01

    The development of steroid-releasing vaginal rings over the past three decades is reviewed to illustrate the role of this device as an effective hormonal contraceptive for women. Vaginal rings are made of polysiloxane rubber or ethylene-vinyl-acetate copolymer with an outer diameter of 54-60 mm and a cross-sectional diameter of 4-9.5 mm and contain progestogen only or a combination of progestogen and oestrogen. The soft flexible combined ring is inserted in the vagina for three weeks and removed for seven days to allow withdrawal bleeding. Progesterone/progestogen-only rings are kept in for varying periods and replaced without a ring-free period. Rings are in various stages of research and development but a few, such as NuvaRing, have reached the market in some countries. Women find this method easy to use, effective, well tolerated and acceptable with no serious side-effects. Though the contraceptive efficacy of these vaginal rings is high, acceptability is yet to be established.

  12. Smoke Ring Physics

    NASA Astrophysics Data System (ADS)

    Huggins, Elisha

    2011-11-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampère's law in an introductory physics course. We discuss these common features.

  13. Smoke Ring Physics

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2011-01-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  14. EBT ring physics

    SciTech Connect

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)

  15. Telemetry carrier ring and support

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor)

    1992-01-01

    A telemetry carrier ring for use in a gas turbine engine includes an annular support ring connected to the engine and an annular carrier ring coupled to the support ring, each ring exhibiting different growth characteristics in response to thermal and mechanical loading. The carrier ring is coupled to the support ring by a plurality of circumferentially spaced web members which are relatively thin in an engine radial direction to provide a predetermined degree of radial flexibility. the web members have a circumferential width and straight axial line of action selected to transfer torque and thrust between the support ring and the carrier ring without substantial deflection. The use of the web members with radial flexibility provides compensation between the support ring and the carrier ring since the carrier ring grows at a different rate than the supporting ring.

  16. Jupiter's Gossamer Rings Explained.

    NASA Astrophysics Data System (ADS)

    Hamilton, D. P.

    2003-05-01

    Over the past several years, Galileo measurements and groundbased imaging have drastically improved our knowledge of Jupiter's faint ring system. We now recognize that the ring consists of four components: a main ring 7000km wide, whose inner edge blossoms into a vertically-extended halo, and a pair of more tenuous Gossamer rings, one associated with each of the small moons Thebe and Amalthea. When viewed edge on, the Gossamer rings appear as diaphanous disks whose thicknesses agree with the vertical excursions of the inclined satellites from the equatorial plane. In addition, the brightness of each Gossamer ring drops off sharply outside the satellite orbits. These correlations allowed Burns etal (1999, Science, 284, 1146) to argue convincingly that the satellites act as sources of the dusty ring material. In addition, since most material is seen inside the orbits of the source satellites, an inwardly-acting dissipative force such as Poynting-Robertson drag is implicated. The most serious problem with this simple and elegant picture is that it is unable to explain the existence of a faint swath of material that extends half a jovian radius outward from Thebe. A key constraint is that this material has the same thickness as the rest of the Thebe ring. In this work, we identify the mechanism responsible for the outward extension: it is a shadow resonance, first investigated by Horanyi and Burns (1991, JGR, 96, 19283). When a dust grain enters Jupiter's shadow, photoelectric processes shut down and the grain's electric charge becomes more negative. The electromagnetic forces associated with the varying charge cause periodic oscillations in the orbital eccentricity and semimajor axis as the orbital pericenter precesses. This results in a ring which spreads both inward and outward of its source satellite while preserving its vertical thickness - just as is observed for the Thebe ring. Predictions of the model are: i) gaps of micron-sized material interior to Thebe and

  17. Ring chromosome 4.

    PubMed Central

    McDermott, A; Voyce, M A; Romain, D

    1977-01-01

    A mentally and physically retarded boy with a 46,XY,ring (4) (p16q35) chromosome complement is described. Chromosome banding showed that the amount of chromosome material deleted from the ring chromosome 4 was minimal, apparently no more than the telomeres. Chromosomal aberrations appear to be restricted to the production of double-sized dicentric rings, and aneuploidy. The mosiacism resulting from the behavioural peculiarities of ring chromosomes is described as dynamic mosaicism. It is suggested that the clinical features associated with this ring chromosome are more likely to be the result of the effects of a diploid/monosomy 4/polysomy 4 mosaicism than to the deficiency of the telomeric regions of the chromosome. Images PMID:881718

  18. Jupiter's Rings: Sharpest View

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons spacecraft took the best images of Jupiter's charcoal-black rings as it approached and then looked back at Jupiter. The top image was taken on approach, showing three well-defined lanes of gravel- to boulder-sized material composing the bulk of the rings, as well as lesser amounts of material between the rings. New Horizons snapped the lower image after it had passed Jupiter on February 28, 2007, and looked back in a direction toward the sun. The image is sharply focused, though it appears fuzzy due to the cloud of dust-sized particles enveloping the rings. The dust is brightly illuminated in the same way the dust on a dirty windshield lights up when you drive toward a 'low' sun. The narrow rings are confined in their orbits by small 'shepherding' moons.

  19. The Enceladus Ring

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] The Enceladus Ring (labeled)

    This excellent view of the faint E ring -- a ring feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the ring, among a field of stars in the background.

    The E ring extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view.

    Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E ring's expanse. Helene skirts the outer parts of the E ring, but here it is projected in front of a region deeper within the ring.

    Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione.

    An interesting feature of note in this image is the double-banded appearance of the E-ring, which is created because the ring is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the ring have nonzero inclinations (a similar affect is seen in Jupiter's gossamer ring). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus.

    One possible explanation is that all the E ring particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane.

    Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally

  20. Earth: A Ringed Planet?

    NASA Astrophysics Data System (ADS)

    Hancock, L. O.; Povenmire, H.

    2010-12-01

    Among the most beautiful findings of the Space Age have been the discoveries of planetary rings. Not only Saturn but also Jupiter, Uranus and Neptune have rings; Saturn’s ring system has structures newly discovered; even Saturn's moon Rhea itself has a ring. All these are apparently supplied by material from the planetary moons (Rhea's ring by Rhea itself). The question naturally arises, why should the Earth not have a ring, and on the other hand, if it does, why has it not been observed? No rings have yet been observed in the inner solar system, but after all, rings in the inner solar system might simply tend to be fainter and more transient than those of the outer solar system: the inner solar system is more affected by the solar wind, and the Sun’s perturbing gravitational influence is greater. J.A. O’Keefe first suggested (1980) that Earth might have a ring system of its own. An Earth ring could account for some climate events. O’Keefe remarked that formation or thickening of a ring system in Earth’s equatorial plane could drive glaciation by deepening the chill of the winter hemisphere. (It is very well established that volcanic dust is an effective agent for the extinction of sunlight; this factor can be overwhelmingly apparent in eclipse observations.) O’Keefe died in 2000 and the speculation was not pursued, but the idea of an Earth ring has a prima facie reasonableness that calls for its renewed consideration. The program of this note is to hypothesize that, as O’Keefe proposed: (a) an Earth ring system exists; (b) it affects Earth's weather and climate; (c) the tektite strewn fields comprise filaments of the ring fallen to Earth's surface on various occasions of disturbance by comets or asteroids. On this basis, and drawing on the world's weather records, together with the Twentieth Century Reanalysis by NCEP/CIRES covering the period 1870-2010 and the geology of the tektite strewn fields, we herein propose the hypothesized Earth ring

  1. Seal ring installation tool

    NASA Technical Reports Server (NTRS)

    Haselmaier, L. Haynes (Inventor)

    2004-01-01

    A seal ring tool that allows an installer to position a primary seal ring between hub ends of pipe flanges that are being assembled together. The tool includes a pivoting handle member and extension arms attached to the pivoting handle member. The ends of the arms have side indentation type longitudinal grooves angled toward one another for holding the primary seal ring in place between the hubs of respective pipes that are to be attached together. The arms of the tool can also have flat sides that can be used to abut against an optional second larger seal that is supported within a groove in one of the hub ends so that the second hub end can then be moved against the other side of the primary seal ring. Once the seal ring is positioned between the pipe hubs, the pipe hubs can be moved about the seal ring due to the flat sides of the arms of the tool. The tool eliminates the chances of damaging and contaminating seal rings being installed within pipe hubs that are being attached to one another.

  2. Dynamics of the Uranian Rings

    NASA Technical Reports Server (NTRS)

    Dermott, S. F.

    1984-01-01

    Some of the problems of the shepherding satellite model of Goldreich ant tremaine are discussed. The following topics are studied: (1) optical depths of the all the observed narrow rings; (2) satellite and ring separation timescales; (3) ring edge sharpness; (4) shock formation in narrow rings; (5) the existence of small satellites near the Uranian rings; and (6) the apse and node alignments of the eccentric and inclined rings.

  3. Alternative parallel ring protocols

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Foudriat, E. C.; Maly, Kurt J.; Kale, V.

    1990-01-01

    Communication protocols are know to influence the utilization and performance of communication network. The effect of two token ring protocols on a gigabit network with multiple ring structure is investigated. In the first protocol, a mode sends at most one message on receiving a token. In the second protocol, a mode sends all the waiting messages when a token is received. The behavior of these protocols is shown to be highly dependent on the number of rings as well as the load in the network.

  4. Supernumerary small ring chromosome.

    PubMed Central

    Kaffe, S; Kim, H J; Hsu, L Y; Brill, C B; Hirschhorn, K

    1977-01-01

    A supernumerary small ring chromosome was found in 30% of cultured peripheral leucocytes and 50% of skin fibroblasts in a 6-year-old boy with mild mental retardation and midline cleft palate. The extra chromosome appeared to carry a densely staining region on Giemsa banding. The banding patterns of the remaining 46 chromosomes were normal. C banding indicated that the ring chromosome contained mainly centromeric constitutive heterochromatin. Chromosome analysis of both parents showed normal karyotypes by both conventional and banding techniques; thus the origin of the ring chromosome could not be determined. Images PMID:604496

  5. Theodolite Ring Lights

    NASA Technical Reports Server (NTRS)

    Clark, David

    2006-01-01

    Theodolite ring lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite ring light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite ring light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.

  6. Duke storage rink UV/VUV FEL: Status and prospects

    SciTech Connect

    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 and the Duke storage ring are discussed.

  7. Saturn's dynamic D ring

    USGS Publications Warehouse

    Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.

    2007-01-01

    The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to a much broader and more diffuse 250-km wide feature. In addition, its center of light has shifted inwards by over 200 km relative to other features in the D ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

  8. Ultrasonic Newton's rings

    SciTech Connect

    Hsu, D.K. ); Dayal, V. )

    1992-03-09

    Interference fringes due to bondline thickness variation were observed in ultrasonic scans of the reflected echo amplitude from the bondline of adhesively joined aluminum skins. To demonstrate that full-field interference patterns are observable in point-by-point ultrasonic scans, an optical setup for Newton's rings was scanned ultrasonically in a water immersion tank. The ultrasonic scan showed distinct Newton's rings whose radii were in excellent agreement with the prediction.

  9. Bending the Rings

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Saturn's rings appear strangely warped in this view of the rings seen through the upper Saturn atmosphere.

    The atmosphere acts like a lens in refracting (bending) the light reflected from the rings. As the rings pass behind the overexposed limb (edge) of Saturn as seen from Cassini, the ring structure appears to curve downward due to the bending of the light as it passes through the upper atmosphere.

    This image was obtained using a near-infrared filter. The filter samples a wavelength where methane gas does not absorb light, thus making the far-off rings visible through the upper atmosphere.

    By comparing this image to similar ones taken using filters where methane gas does absorb, scientists can estimate the vertical profile of haze and the abundance of methane in Saturn's high atmosphere.

    The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 14, 2005, through a filter sensitive to wavelengths of infrared light centered at 938 nanometers and at a distance of approximately 197,000 kilometers (123,000 miles) from Saturn. The image scale is 820 meters (2,680 feet) per pixel.

  10. Optimizing ring-based CSR sources

    SciTech Connect

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

    2004-01-01

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

  11. Propellers in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2014-04-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings [5, 8]. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~ 100m in size) have been identified in Saturn's A ring through their propeller signature in the images [10, 7, 9, 11]. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring [6, 2]. In this paper we present our new results about by now classical A ring propellers and more enigmatic B ring population. Due to the presence of self-gravity wakes the analysis of propeller brightness in ISS images always bears some ambiguity [7, 9] and consequently the exact morphology of propellers is not a settled issue. In 2008 we obtained a fortunate Cassini Ultraviolet Imaging Spectrograph (UVIS) occultation of the largest A ring propeller Bleriot. Utilizing Cassini ISS images we obtain Bleriot orbit and demonstrate that UVIS Persei Rev42 occultation did cut across Bleriot about 100km downstream from the center. The occultation itself shows a prominent partial gap and higher density outer flanking wakes, while their orientation is consistent with a downstream cut. While in the UVIS occultation the partial gap is more prominent than the flanking wakes, the features mostly seen in Bleriot images are actually flanking wakes. One of the most interesting aspects of the A ring propellers are their wanderings, or longitudinal deviations from a pure circular orbit [11]. We numerically investigated the possibility of simple moon

  12. Experimental results from the small isochronous ring

    SciTech Connect

    Eduard Pozdeyev

    2005-05-01

    The Small Isochronous Ring (SIR) is a compact, low-energy storage ring designed to investigate the beam dynamics of high-intensity isochronous cyclotrons and synchrotrons at the transition energy. The ring was developed at Michigan State University (MSU) and has been operational since December 2003. It stores 20 keV hydrogen beams with a peak current of 10-20 microamps for up to 200 turns. The transverse and longitudinal profiles of extracted bunches are measured with an accuracy of approximately 1 mm. The high accuracy of the measurements makes the experimental data attractive for validation of multi-particle space charge codes. The results obtained in the ring show a fast growth of the energy spread induced by the space charge forces. The energy spread growth is accompanied by a breakup of the beam bunches into separated clusters that are involved in the vortex motion specific to the isochronous regime. The experimental results presented in the paper show a remarkable agreement with simulations performed with the code CYCO. In this paper, we discuss specifics of space charge effects in the isochronous regime, present results of experiments in SIR, and conduct a detailed comparison of the experimental data with results of simulations.

  13. Ring correlations in random networks

    NASA Astrophysics Data System (ADS)

    Sadjadi, Mahdi; Thorpe, M. F.

    2016-12-01

    We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

  14. Study of Intrabeam Scattering in Low Energy Electron Rings

    SciTech Connect

    Venturini, Marco

    2002-08-08

    The paper contains a study of intrabeam scattering in a low energy electron storage ring to be used as part of a Compton back-scattering x-ray source. We discuss time evolution of emittance and dependence of IBS growth rates on lattice parameters.

  15. DC-Powered Jumping Ring

    NASA Astrophysics Data System (ADS)

    Jeffery, Rondo N.; Amiri, Farhang

    2016-02-01

    The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant differences from the AC case. In particular, the ring does not fly off the core but rises a short distance and then falls back. If the ring jumps high enough, the rising and the falling motion of the ring does not follow simple vertical motion of a projectile. This indicates that there are additional forces on the ring in each part of its motion. Four possible stages of the motion of the ring with DC are identified, which result from the ring current changing directions during the jump in response to a changing magnetic flux through the moving ring.

  16. Propellers in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~<500m in size) have been indirectly identified in Saturn's A ring through their propeller signature in the images. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring. In this paper we present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B

  17. Experimental Calibration of VUV Ring Optics

    NASA Astrophysics Data System (ADS)

    Safranek, J.; Kramer, S. L.

    1997-05-01

    The individual quadrupole gradients, undulator focusing, beam position monitor (BPM) gains, and orbit steering magnet calibrations in the NSLS VUV Ring were determined by analyzing the measured orbit response matrix with the computer code LOCO (J. Safranek, Beam-based Modeling and Control of Storage Rings, these proceedings.). The measured orbit response matrix is the change in orbit at the BPMs with changes in steering magnet excitation. The analysis showed beta function distortions of 25 and 35 percent horizontally and vertically. The design periodicity of the optics was restored by adjusting the quadrupole gradients to restore the periodicity of the response matrix. This lead to an increase of about 18 percent in the beam lifetime at 500 mA with a slight (3 and 7 percent) decrease in both the horizontal and vertical electron emittances as determined from the beam sizes measured using a synchrotron light monitor.

  18. Piston Ring Pressure Distribution

    NASA Technical Reports Server (NTRS)

    Kuhn, M.

    1943-01-01

    The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses, Of these internal engine components, the piston and piston rings are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the components, The piston ring is a well-known component and has been used in its present shape in the steam engine of the last century, Corresponding to its importance, the piston ring has been a rich field for creative activity and it is noteworthy that in spite of this the ring has maintained its shape through the many years. From the many and complicated designs which have been suggested as a packing between piston and cylinder wall hardly one suggestion has remained which does not resemble the original design of cast iron rectangular ring.

  19. Stacked Corrugated Horn Rings

    NASA Technical Reports Server (NTRS)

    Sosnowski, John B.

    2010-01-01

    This Brief describes a method of machining and assembly when the depth of corrugations far exceeds the width and conventional machining is not practical. The horn is divided into easily machined, individual rings with shoulders to control the depth. In this specific instance, each of the corrugations is identical in profile, and only differs in diameter and outer profile. The horn is segmented into rings that are cut with an interference fit (zero clearance with all machining errors biased toward contact). The interference faces can be cut with a reverse taper to increase the holding strength of the joint. The taper is a compromise between the interference fit and the clearance of the two faces during assembly. Each internal ring is dipped in liquid nitrogen, then nested in the previous, larger ring. The ring is rotated in the nest until the temperature of the two parts equalizes and the pieces lock together. The resulting assay is stable, strong, and has an internal finish that cannot be achieved through other methods.

  20. Rings in the solar system

    SciTech Connect

    Pollack, J.B.; Cuzzi, J.N.

    1981-11-01

    Saturn, Jupiter, and Uranus have rings with different structure and composition. The rings consist of tiny masses in independent orbits. Photographs and data obtained by the Voyager project have aided in the understanding of Saturn's rings. Spokes have been found in B ring and boards, knots, and twist in F ring. Particles on the order of a micrometer in size are believed to occur in F, B, and A rings. The dominant component is water ice. The rings of Uranus are narrow and separated by broad empty regions. The technique used to study them has been stellar occulation. Nothing is known of particle size. The dominant component is believed to be silicates rich in compounds that absorb sunlight. Jupiter's rings consist of 3 main parts: a bright ring, a diffuse disk, and a halo. Use of Pioneer 10 data and other techniques have indicated particle sizes on the order of several micrometers and some at least a centimeter in diameter. The architecture of the ring system results from the interplay of a number of forces. These include gravitational forces due to moons outside the rings and moonlets embedded in them, electromagnetic forces due to the planet's rotating magnetic field, and even the gentle forces exerted by the dilute gaseous medium in which the rings rotate. Each of these forces is discussed. Several alternative explanations of how the rings arose are considered. The primary difference in these hypotheses is the account of the relationship between the ring particles of today and the primordial ring material. (SC)

  1. Physics of planetary rings

    NASA Astrophysics Data System (ADS)

    Gorkavyi, N.

    2007-08-01

    It is difficult to enumerate all the surprises presented by the planetary rings. The Saturnian rings are stratified into thousands of ringlets and the Uranian rings are compressed into narrow streams, which for some reason or other differ from circular orbits like the wheel of an old bicycle. The edge of the rings is jagged and the rings themselves are pegged down under the gravitational pressure of the satellites, bending like a ship's wake. There are spiral waves, elliptical rings, strange interlacing of narrow ringlets, and to cap it all one has observed in the Neptunian ring system three dense, bright arcs - like bunches of sausages on a transparent string. For celestial mechanics this is a spectacle as unnatural as a bear's tooth in the necklace of the English queen. In the dynamics of planetary rings the physics of collective interaction was supplemented by taking collisions between particles into account. One was led to study a kinetic equation with a rather complex collision integral - because the collisions are inelastic - which later on made it possible, both by using the Chapman-Enskog method and by using the solution of the kinetic equation for a plasma in a magnetic field, to reduce it to a closed set of (hydrodynamical) moment equations [1]. The hydrodynamical instabilities lead to the growth of short-wavelength waves and large-scale structures of the Saturnian rings [1]. We have shown that the formation of the existing dense Uranian rings is connected with the capture of positively drifting ring particles in inner Lindblad resonances which arrest this drift [1]. After the formation of dense rings at the positions of satellite resonances the collective interaction between resonant particles is amplified and the rings can leave the resonance and drift away from the planet and the parent resonance. We can expect in the C ring an appreciable positive ballistic particle drift caused by the erosion of the B ring by micrometeorites. It is therefore natural

  2. Deployable Fresnel Rings

    NASA Technical Reports Server (NTRS)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

    2014-01-01

    Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

  3. Rings dominate western Gulf

    NASA Astrophysics Data System (ADS)

    Vidal L., Francisco V.; Vidal L., Victor M. V.; Molero, José María Pérez

    Surface and deep circulation of the central and western Gulf of Mexico is controlled by interactions of rings of water pinched from the gulf's Loop Current. The discovery was made by Mexican oceanographers who are preparing a full-color, 8-volume oceanographic atlas of the gulf.Anticyclonic warm-core rings pinch off the Loop Current at a rate of about one to two per year, the scientists of the Grupo de Estudios Oceanográficos of the Instituto de Investigaciones Eléctricas (GEO-IIE) found. The rings migrate west until they collide with the continental shelf break of the western gulf, almost always between 22° and 23°N latitude. On their westward travel they transfer angular momentum and vorticity to the surrounding water, generating cyclonic circulations and vortex pairs that completely dominate the entire surface and deep circulation of the central and western gulf.

  4. Ring laser gyroscope anode

    SciTech Connect

    Ljung, B.H.

    1981-03-17

    An anode for a ring laser gyroscope which provides improved current stability in the glow discharge path is disclosed. The anode of this invention permits operation at lower currents thereby allowing a reduction of heat dissipation in the ring laser gyroscope. The anode of one embodiment of this invention is characterized by a thumbtack appearance with a spherical end where the normal sharp end of the thumbtack would be located. The stem of the anode extends from the outside of the gyroscope structure to the interior of the structure such that the spherical end is substantially adjacent to the laser beam.

  5. GUARD RING SEMICONDUCTOR JUNCTION

    DOEpatents

    Goulding, F.S.; Hansen, W.L.

    1963-12-01

    A semiconductor diode having a very low noise characteristic when used under reverse bias is described. Surface leakage currents, which in conventional diodes greatly contribute to noise, are prevented from mixing with the desired signal currents. A p-n junction is formed with a thin layer of heavily doped semiconductor material disposed on a lightly doped, physically thick base material. An annular groove cuts through the thin layer and into the base for a short distance, dividing the thin layer into a peripheral guard ring that encircles the central region. Noise signal currents are shunted through the guard ring, leaving the central region free from such currents. (AEC)

  6. Unidirectional ring lasers

    DOEpatents

    Hohimer, J.P.; Craft, D.C.

    1994-09-20

    Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity is disclosed. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction. 21 figs.

  7. Unidirectional ring lasers

    DOEpatents

    Hohimer, John P.; Craft, David C.

    1994-01-01

    Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction.

  8. Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry

    2004-01-01

    The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.

  9. Radiation issues in a radioactive ion decay ring.

    PubMed

    Magistris, M; Silari, M

    2005-01-01

    In a beta-beam facility, a pure beam of electron neutrinos, or their antiparticles, are produced by the decay of fully stripped radioactive ions (6He and 18Ne) circulating in a storage ring. Since the beam is not extracted from the ring, all the particles will eventually be lost somewhere in the machine and thus activate the accelerator components and the surrounding concrete and rock. In particular, as nuclei change their charge in beta-decay, a large part of the particles will be lost in the arcs of the decay ring and mainly irradiate the magnets. The density of inelastic interactions of hadrons in the magnets, concrete and rock and the track-length distribution of secondary hadrons were calculated by means of the FLUKA Monte Carlo code. These values were used to estimate the induced radioactivity in the facility, the dose rates expected in the decay ring and the consequences for the environment.

  10. Energy Storage

    SciTech Connect

    Mukundan, Rangachary

    2014-09-30

    Energy storage technology is critical if the U.S. is to achieve more than 25% penetration of renewable electrical energy, given the intermittency of wind and solar. Energy density is a critical parameter in the economic viability of any energy storage system with liquid fuels being 10 to 100 times better than batteries. However, the economical conversion of electricity to fuel still presents significant technical challenges. This project addressed these challenges by focusing on a specific approach: efficient processes to convert electricity, water and nitrogen to ammonia. Ammonia has many attributes that make it the ideal energy storage compound. The feed stocks are plentiful, ammonia is easily liquefied and routinely stored in large volumes in cheap containers, and it has exceptional energy density for grid scale electrical energy storage. Ammonia can be oxidized efficiently in fuel cells or advanced Carnot cycle engines yielding water and nitrogen as end products. Because of the high energy density and low reactivity of ammonia, the capital cost for grid storage will be lower than any other storage application. This project developed the theoretical foundations of N2 catalysis on specific catalysts and provided for the first time experimental evidence for activation of Mo 2N based catalysts. Theory also revealed that the N atom adsorbed in the bridging position between two metal atoms is the critical step for catalysis. Simple electrochemical ammonia production reactors were designed and built in this project using two novel electrolyte systems. The first one demonstrated the use of ionic liquid electrolytes at room temperature and the second the use of pyrophosphate based electrolytes at intermediate temperatures (200 – 300 ºC). The mechanism of high proton conduction in the pyrophosphate materials was found to be associated with a polyphosphate second phase contrary to literature claims and ammonia production rates as high as 5X 10

  11. Ring Flame Stabilizer

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Ring Flame Stabilizer has been developed in conjunction with Lewis Research Center. This device can lower pollutant emissions (which contribute to smog and air pollution) from natural-gas appliances such as furnaces and water heaters by 90 percent while improving energy efficiency by 2 percent.

  12. Ring of Stellar Death

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image from NASA's Spitzer Space Telescope shows a dying star (center) surrounded by a cloud of glowing gas and dust. Thanks to Spitzer's dust-piercing infrared eyes, the new image also highlights a never-before-seen feature -- a giant ring of material (red) slightly offset from the cloud's core. This clumpy ring consists of material that was expelled from the aging star.

    The star and its cloud halo constitute a 'planetary nebula' called NGC 246. When a star like our own Sun begins to run out of fuel, its core shrinks and heats up, boiling off the star's outer layers. Leftover material shoots outward, expanding in shells around the star. This ejected material is then bombarded with ultraviolet light from the central star's fiery surface, producing huge, glowing clouds -- planetary nebulas -- that look like giant jellyfish in space.

    In this image, the expelled gases appear green, and the ring of expelled material appears red. Astronomers believe the ring is likely made of hydrogen molecules that were ejected from the star in the form of atoms, then cooled to make hydrogen pairs. The new data will help explain how planetary nebulas take shape, and how they nourish future generations of stars.

    This image composite was taken on Dec. 6, 2003, by Spitzer's infrared array camera, and is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

  13. Exotic damping ring lattices

    SciTech Connect

    Palmer, R.B.

    1987-05-01

    This paper looks at, and compares three types of damping ring lattices: conventional, wiggler lattice with finite ..cap alpha.., wiggler lattice with ..cap alpha.. = 0, and observes the attainable equilibrium emittances for the three cases assuming a constraint on the attainable longitudinal impedance of 0.2 ohms. The emittance obtained are roughly in the ratio 4:2:1 for these cases.

  14. Ring laser scatterometer

    DOEpatents

    Ackermann, Mark; Diels, Jean-Claude

    2005-06-28

    A scatterometer utilizes the dead zone resulting from lockup caused by scatter from a sample located in the optical path of a ring laser at a location where counter-rotating pulses cross. The frequency of one pulse relative to the other is varied across the lockup dead zone.

  15. Reading, Writing, and Rings!

    ERIC Educational Resources Information Center

    Aschbacher, Pamela; Li, Erika; Hammon, Art

    2008-01-01

    "Reading, Writing, and Rings!" was created by a team of elementary teachers, literacy experts, and scientists in order to integrate science and literacy. These free units bring students inside NASA's Cassini-Huygens mission to Saturn. The authors--a science teacher and education outreach specialist and two evaluators of educational programs--have…

  16. Making Molecular Borromean Rings

    ERIC Educational Resources Information Center

    Pentecost, Cari D.; Tangchaivang, Nichol; Cantrill, Stuart J.; Chichak, Kelly S.; Peters, Andrea J.; Stoddart, Fraser J.

    2007-01-01

    A procedure that requires seven 4-hour blocks of time to allow undergraduate students to prepare the molecular Borromean rings (BRs) on a gram-scale in 90% yield is described. The experiment would serve as a nice capstone project to culminate any comprehensive organic laboratory course and expose students to fundamental concepts, symmetry point…

  17. Fabrication and test of prototype ring magnets for the ALS (Advanced Light Source)

    SciTech Connect

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

    1989-03-01

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

  18. Recycler ring conceptual design study

    SciTech Connect

    Jackson, G.

    1995-07-18

    The Tevatron Collider provides the highest center of mass energy collisions in the world. To fully exploit this unique tool, Fermilab is committed to a program of accelerator upgrades for the purpose of increasing the Collider luminosity. Over the past 7 years the luminosity has been increased from a peak of 1.6{times}10{sup 30}cm{sup {minus}2}sec{sup {minus}1} in 1989 to over 3{times}10{sup 31}cm{sup {minus}2}sec{sup {minus}1} during 1995. The Main Injector will supply a larger flux of protons for antiproton production and more intense proton bunches for use in the Collider, and this is expected to increase the peak luminosity to close to 1{times}10{sup 32}cm{sup {minus}2}sec{sup {minus}1}. Further increases in luminosity will require additional upgrades to the Fermilab accelerator complex. This report documents the design of a new fixed-energy storage ring to be placed in the Main Injector tunnel which will provide an initial factor of 2 increase to 2{times}10{sup 32}cm{sup {minus}2}sec{sup {minus}1}, and ultimately provide the basis for an additional order of magnitude luminosity increase up to 1{times}10{sup 33}cm{sup {minus}2}sec{sup {minus}1}.

  19. Ring Bubbles of Dolphins

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  20. Rings from Close Encounters

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Weve recently discovered narrow sets of rings around two minor planets orbiting in our solar system. How did these rings form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected Ring SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow ring systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have rings. But how did these rings form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the rings were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of

  1. Conceptual Design of an Antiproton Generation and Storage Facility

    SciTech Connect

    Peggs, Stephen

    2006-10-24

    The Antiproton Generation and Storage Facility (AGSF) creates copious quantities of antiprotons, for bottling and transportation to remote cancer therapy centers. The first step in the generation and storage process is to accelerate an intense proton beam down the Main Linac for injection into the Main Ring, which is a Rapid Cycling Synchrotron that accelerates the protons to high energy. The beam is then extracted from the ring into a transfer line and into a Proton Target. Immediately downstream of the target is an Antiproton Collector that captures some of the antiprotons and focuses them into a beam that is transported sequentially into two antiproton rings. The Precooler ring rapidly manipulates antiproton bunches from short and broad (in momentum) to long and thin. It then performs some preliminary beam cooling, in the fraction of a second before the next proton bunch is extracted from the Main Ring. Pre-cooled antiprotons are passed on to the Accumulator ring before the next antiprotons arrive from the target. The Accumulator ring cools the antiprotons, compressing them into a dense state that is convenient for mass storage over many hours. Occasionally the Accumulator ring decelerates a large number of antiprotons, injecting them into a Deceleration Linac that passes them into a waiting Penning trap.

  2. Hydrogen Storage

    SciTech Connect

    2008-11-01

    This 2-page fact sheet provides a brief introduction to hydrogen storage technologies. Intended for a non-technical audience, it explains the different ways in which hydrogen can be stored, as well as the technical challenges and research goals for storing hydrogen on board a vehicle.

  3. Archive Storage Media Alternatives.

    ERIC Educational Resources Information Center

    Ranade, Sanjay

    1990-01-01

    Reviews requirements for a data archive system and describes storage media alternatives that are currently available. Topics discussed include data storage; data distribution; hierarchical storage architecture, including inline storage, online storage, nearline storage, and offline storage; magnetic disks; optical disks; conventional magnetic…

  4. Flywheel energy storage. II - Magnetically suspended superflywheel

    NASA Technical Reports Server (NTRS)

    Kirk, J. A.; Studer, P. A.

    1977-01-01

    This article, the second of a two part paper, describes the general design requirements for a flywheel energy storage system. A new superflywheel energy storage system, using a spokeless, magnetically suspended, composite material pierced disk rotor is proposed. The new system is configured around a permanent magnet ('flux biased') magnetic suspension system with active 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 stationary armature coils is proposed. There is no mechanical contact with the rotating ring and long life and low run down losses are projected. A discussion of major components for a 10 kwh system is presented.

  5. Inorganic glass ceramic slip rings

    NASA Technical Reports Server (NTRS)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  6. Infrared Extraction Change for the NSLS-II Storage Ring

    SciTech Connect

    Blednykh,A.; Carr, L.; Coburn, D.; Krinsky, S.

    2009-05-04

    The short- and long-range wakepotentials have been studied for the design of the infrared (IR) extraction chamber with large full aperture: 67mm vertical and 134mm horizontal. The IR-chamber will be installed within a 2.6m long wide-gap bending magnet with 25m bend radius. Due to the large bend radius it is difficult to separate the light from the electron trajectory. The required parameters of the collected IR radiation at the extraction mirror are {approx}50mrad horizontal and {approx}25mrad vertical (full radiation opening angles). If the extraction mirror is seen by the beam, resonant modes are generated in the chamber. In this paper, we present the detailed calculated impedance for the design of the far-IR chamber, and show that placing the extraction mirror in the proper position eliminates the resonances. In this case, the impedance reduces to that of a simple tapered structure, which is acceptable in regard to its impact on the electron beam.

  7. Spin dynamics in storage rings and linear accelerators

    SciTech Connect

    Irwin, J.

    1994-04-01

    The purpose of these lectures is to survey the subject of spin dynamics in accelerators: to give a sense of the underlying physics, the typical analytic and numeric methods used, and an overview of results achieved. Consideration will be limited to electrons and protons. Examples of experimental and theoretical results in both linear and circular machines are included.

  8. Fiberoptics-Based Instrumentation for Storage Ring BeamDiagnostics

    SciTech Connect

    Byrd, John M.; De Santis, Stefano; Yin, Yan

    2007-04-18

    In several cases, coupling synchrotron light into opticalfibers can substantially facilitate the use of beam diagnosticinstrumentation, that measures longitudinal beam properties by detectingsynchrotron radiation. It has been discussed in [1]with some detail, howfiberoptics can bring the light at relatively large distances from theaccelerator, where a variety of devices can be used to measure beamproperties and parameters. Light carried on a fiber can be easilyswitched between instruments so that each one of them has 100 percent ofthe photons available, rather than just a fraction , when simultaneousmeasurements are not indispensable. From a more general point of view,once synchrotron light is coupled into the fiber, the vast array oftechniques and optoelectronic devices, developed by the telecommunicationindustry becomes available.In this paper we present the results of ourexperiments at the Advanced Light Source, where we tried to assess thechallenges and limitations of the coupling process and determine whatlevel of efficiency one can typically expect to achieve.

  9. The SLS Storage Ring Vertical Position Monitoring System

    SciTech Connect

    Zelenika, Sasa

    2004-05-12

    The goal of monitoring the vertical position of the SLS machine was achieved by employing a capacitive gauge-based Hydrostatic Leveling System (HLS). Although all the preliminary results showed that the aimed HLS micrometric range resolutions and accuracies have been reached, the long-time behavior of the system revealed considerable drifts. A satisfactory solution could eventually be reached only by adding to the working fluid a fungicide.

  10. Verification of Coulomb order in a storage ring

    SciTech Connect

    Hasse, Rainer W.

    1999-12-10

    We verify theoretically that the anomalous longitudinal temperature reduction of strongly electron cooled heavy ions in the ESR at very low density is explained by the fact that there is no intrabeam scattering and that the particles by their Coulomb repulsion cannot pass each other any more. At the achievable momentum spreads Coulomb order is reached at particle distances of the order of centimeters. It is also shown that under the given experimental conditions in the proton NAP-M experiment of 1980 intrabeam heating counteracts Coulomb order.

  11. Verification of Coulomb Order in a Storage Ring

    SciTech Connect

    Rainer W. Hasse

    1999-12-31

    We verify theoretically that the anomalous longitudinal temperature reduction of strongly electron cooled heavy ions in the ESR at very low density is explained by the fact that there is no intrabeam scattering and that the particles by their Coulomb repulsion cannot pass each other any more. At the achievable momentum spreads Coulomb order is reached at particle distances of the order of centimeters. It is also shown that under the given experimental conditions in the proton NAP-M experiment of 1980 intrabeam heating counteracts Coulomb order.

  12. GENERATION OF SUBPICOSECOND X-RAY PULSES IN STORAGE RINGS

    SciTech Connect

    Zholents, Alexander A.

    2007-06-19

    Supicosecond x-ray pulses are routinely produced at ALS,BESSY and SLS with slicing technique and used in pump-probe experimentswith controlled delay between laser pump pulses and x-ray probe pulses.New development aiming for a production of a subpicosecond x-ray pulsesusing rf orbit deflection technique is under way at APS. Both techniqueswill be reviewed here.

  13. Stochastic beam dynamics in quasi-isochronous storage rings

    SciTech Connect

    Bai, M.; Jeon, D.; Lee, S.Y.; Ng, K.Y.; Riabko, A.; Zhao, X. |

    1997-03-01

    We investigate effects of quantum fluctuation, potential well distortion, quantum lifetime, and Touschek lifetime of the quasi-isochronous (QI) dynamical system. The Fokker-Planck equation is employed to study the equilibrium bunch distribution. The quantum lifetime in the moderate damping regime is compared with analytical formulae. The effects of harmonic radio-frequency phase modulation on equilibrium distribution function, quantum lifetime reduction, and the occurrence of stochastic resonance are studied. The formula for the Touschek lifetime for the QI dynamical system is derived and studied. {copyright} {ital 1997} {ital The American Physical Society}

  14. Longitudinal instabilities in circular accelerator and storage rings

    SciTech Connect

    Pellegrini, C.

    1981-01-01

    The general problem of the longitudinal stability of bunched beams is reviewed. Although there is no general solution it is possible to identify regions in the frequency-risetime space where we can obtain approximate solutions. The collective oscillation frequency is written, and expressions for the effective coupling impedance are given for the high or low frequency and slow and fast blow-up regimes.

  15. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    SciTech Connect

    Pugliese, D.; Stuchlík, Z. E-mail: zdenek.stuchlik@physics.cz

    2015-12-15

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

  16. Ring closure in actin polymers

    NASA Astrophysics Data System (ADS)

    Sinha, Supurna; Chattopadhyay, Sebanti

    2017-03-01

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers.

  17. DC-Powered Jumping Ring

    ERIC Educational Resources Information Center

    Jeffery, Rondo N.; Farhang, Amiri

    2016-01-01

    The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant…

  18. Uranus: the rings are black.

    PubMed

    Sinton, W M

    1977-11-04

    An upper limit of 0.05 is established for the geometric albedo of the newly discovered rings of Uranus. In view of this very low albedo, the particles of the rings cannot be ice-covered as are those of rings A and B of Saturn.

  19. Computer Simulation of Antiproton RF Stacking in the Precooler Ring

    SciTech Connect

    Takayama, K.; Ruggiero, A.G.

    1981-01-16

    It has been recently proposed a scheme to produce a high-intensity antiproton beam in a precooler ring with functions of both stochastic cooling and accumulating. According to this scheme 13 batches from {bar p}-target are stacked and precooled on the stacking orbit every Main Ring cycle. After that the precooled beam is transported in a second storage ring (the Accumulator) and cooled for several hours together with previous {bar p} batches. As alternative it has also been proposed to decelerate each precooler pulse down to 200 MeV at which energy it can be transferred in a modified Electron Cooling Ring for storage and further cooling. The sequence of stacking operations in the Precooler consists of (1) injecting a P beam pulse onto the injection orbit, capturing it by standing-by RF buckets, rotating the bunch in the stationary RF buckets, and reducing the bucket height so that the stationary bucket will surround tightly the bunch, (2) decelerating to the stacking orbit and (3) finally turning off the RF adiabatically, allowing the beam to debunch. This sequence is repeated 13 times to build up a complete stack every Main Ring cycle. The above steps require fairly complicated manipulations of RF system parameters. The 13 {bar P}-batches are separated by 100 msec from each other for target heating considerations. In the present study, the above sequence of stacking is investigated by numerical simulation.

  20. Recording PEP2 Ring Beam Losses at SLAC

    SciTech Connect

    Zelazny, M.; Gromme, T.; Himel, T.; Hendrickson, L.; Krauter, K.; /SLAC

    2005-09-30

    The PEP2 (e+)(e-) storage rings contain many complex interrelated systems. When the beam aborts, examining a record of the orbit from the time just before the abort can help identify the root cause. At the Stanford Linear Accelerator Center (SLAC) a system has been developed to continuously record beam orbits from Beam Position Monitors (BPMS) into a circular buffer. When the beam is aborted the buffers are frozen and their contents are stored for later analysis. BPM orbits are saved on a turn by turn basis for 2800 turns in both the high energy ring (HER) and the low energy ring (LER). Each BPM Processor (BPMP) can either monitor the HER or the LER, but not both as the readout of the two rings is multiplexed into a single readout channel. Tools exist as part of the SLAC Control Program (SCP) to collect, display, and save the data. A physicist or operator can choose a few BPMS in which to view all 2800 turns to identify the turn in which the beam went awry; then ask for that specific orbit from all of the BPMS in the storage ring to determine the root cause of the abort.

  1. Satellite Rings Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.

    The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000.

    Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  2. Saturn Ring Observer

    NASA Technical Reports Server (NTRS)

    Spilker, T. R.

    2001-01-01

    Answering fundamental questions about ring particle characteristics, and individual and group behavior, appears to require close-proximity (a few km) observations. Saturn's magnificent example of a ring system offers a full range of particle sizes, densities, and behaviors for study, so it is a natural choice for such detailed investigation. Missions implementing these observations require post-approach Delta(V) of approximately 10 km/s or more, so past mission concepts called upon Nuclear Electric Propulsion. The concept described here reduces the propulsive Delta(V) requirement to as little as 3.5 km/s, difficult but not impossible for high-performance chemical propulsion systems. Additional information is contained in the original extended abstract.

  3. Delivery Ring Lattice Modifications for Transitionless Deceleration

    SciTech Connect

    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 this 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.

  4. Strained Ring Energetic Binders

    DTIC Science & Technology

    1993-08-27

    polyhomobenzvalene ( PHBV ). PHBV was not found to have the mechanical instability problems of PBV, but was still thermally unstable (Tonset - 660C, Tmax - 1090C...DISCUSSION 4 Polybenzvalene (PBV) 4 Polyhomobenzvalene ( PHBV ) 6 Chain-Transfer Studies 11 CONCLUSIONS 15 EXPERIMENTAL PROCEDURES 16 .F 4E 19 APPENDICES A...strained ring polymers similar to PBV are known. The investigation of one of these polymers, polyhomobenzvalene ( PHBV ), is also described in this report

  5. Which Ringed Planet...!?

    NASA Astrophysics Data System (ADS)

    2002-12-01

    Don't worry - you are not the only one who thought this was a nice amateur photo of planet Saturn, Lord of the Rings in our Solar System! But then the relative brightness and positions of the moons may appear somewhat unfamiliar... and the ring system does look unusually bright when compared to the planetary disk...?? Well, it is not Saturn, but Uranus , the next giant planet further out, located at a distance of about 3,000 million km, or 20 times the distance between the Sun and the Earth. The photo shows Uranus surrounded by its rings and some of the moons, as they appear on a near-infrared image that was obtained in the K s -band (at wavelength 2.2 µm) with the ISAAC multi-mode instrument on the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory (Chile) . The exposure was made on November 19, 2002 (03:00 hrs UT) during a planetary research programme. The observing conditions were excellent (seeing 0.5 arcsec) and the exposure lasted 5 min. The angular diameter of Uranus is about 3.5 arcsec. The observers at ISAAC were Emmanuel Lellouch and Thérése Encrenaz of the Observatoire de Paris (France) and Jean-Gabriel Cuby and Andreas Jaunsen (both ESO-Chile). The rings The rings of Uranus were discovered in 1977, from observations during a stellar occultation event by astronomer teams at the Kuiper Airborne Observatory (KAO) and the Perth Observatory (Australia). Just before and after the planet moved in front of the (occulted) star, the surrounding rings caused the starlight to dim for short intervals of time. Photos obtained from the Voyager-2 spacecraft in 1986 showed a multitude of very tenuous rings. These rings are almost undetectable from the Earth in visible light. However, on the present VLT near-infrared picture, the contrast between the rings and the planet is strongly enhanced. At the particular wavelength at which this observation was made, the infalling sunlight is almost completely absorbed by gaseous methane present in the planetary atmosphere

  6. Precooler Ring Vacuum System

    SciTech Connect

    Moenich, J.

    1980-10-02

    The precooler vacuum system, as proposed by FNAL, is based on a suitable modification of the existing Electron Cooling Ring System. Because of the magnetic cycle of the bending magnets, distributed ion pumping, as exists in the Electron Cooling Ring, is not applicable. Instead, the proposed pumping will be done with commercial appendage ion pumps mounted approximately every two meters around the circumference of the ring. The loss of effective pumping speed and non-uniformity of system pressure with appendage pumps may not be major considerations but the large number required does effect experimental and analytical equipment placement considerations. There is a distributed pumping technique available which: (1) is not affected by the magnetic cycle of the bending magnets; (2) will provide a minimum of four times the hydrogen pumping speed of the proposed appendage ion pumps; (3) will require no power during pumping after the strip is activated; (4) will provide the heat source for bakeout; (5) is easily replaceable; and (6) can be purchased, installed, and operated at a generous economic advantage over the presently proposed ion pumped system. The pumping technique referred to is non-evaporable gettering with ST101 Zr/Al pumping strip. A technical description of this pumping strip is given on Data Sheet 1 and 2 attached to this report.

  7. Saturn's ``Gossamer'' Ring: The F Ring's Inner Sheet

    NASA Astrophysics Data System (ADS)

    Showalter, M. R.; Burns, J. A.; Hamilton, D. P.

    1998-09-01

    Recent Galileo and Earth-based images have revealed for the first time that Jupiter's ``gossamer'' ring is actually composed of two rings, one bounded at the outer edge by Amalthea and the other bounded by Thebe. Dynamical models suggest that these rings are composed of dust grains ejected off the surfaces of the two moons, which then evolve inward under Poynting-Robertson drag. A very faint sheet of material filling the region between Saturn's A and F Rings reported by Burns et al. (BAAS 15, 1013--1014, 1983) may be a dynamically analogous system, in which dust escapes from the F Ring and evolves inward to the A Ring. Unlike Jupiter's gossamer rings, however, the inner sheet of Saturn's F Ring has been well observed from a large range of phase angles and visual wavelengths by Voyager. Voyager images reveal that this faint ring shows a tenfold increase in brightness between phase angles of 125(deg) and 165(deg) , indicating that it is composed of fine dust microns in size. Preliminary estimates of the normal optical depth fall in the range 1--2*E(-4) , depending on the dust size distribution assumed. Initial spectrophotometry reveals that the ring is neutral in color. The ring is uniform in brightness over the entire region between the two rings, with no evidence for internal structure associated with Prometheus and Atlas, suggesting that neither of these embedded moons acts as either a source or a sink. We will refine the aforementioned measurements and develop photometric models to better constrain the properties of the dust in this ring. This will enable us to relate the dust population to that in the F Ring proper, and to better explore the dynamical processes at work.

  8. Helmet latching and attaching ring

    NASA Technical Reports Server (NTRS)

    Chase, E. W.; Viikinsalo, S. J. (Inventor)

    1970-01-01

    A neck ring releasably secured to a pressurized garment carries an open-ended ring normally in the engagement position fitted into an annular groove and adapted to fit into a complementary annular groove formed in a helmet. Camming means formed on the inner surface at the end of the helmet engages the open-ended ring to retract the same and allow for one motion donning even when the garment is pressurized. A projection on the end of the split ring is engageable to physically retract the split ring.

  9. Mass of Saturn's A ring

    NASA Technical Reports Server (NTRS)

    Horn, L. J.; Russell, C. T.

    1993-01-01

    The mass of Saturn's A ring is reestimated using the behavior of spiral density waves embedded in the ring. The Voyager photopolarimeter (PPS) observed the star delta-Scorpii as it was occulted by Saturn's rings during the Voyager 2 flyby of Saturn in 1981 producing a radial profile of the rings. We examined forty spiral density waves in the Voyager PPS data of the A ring including 10 weaker waves that have not been previously analyzed by means of an autoregressive power spectral technique called Burg. The strengths of this new method for ring studies are that weaker, less extended waves are easily detected and characterized. This method is also the first one which does not require precise knowledge of the resonance location and phase of the wave in order to calculate the surface mass density. Uncertainties of up to 3 km are present in the currently available radial scales for Saturn's rings.

  10. A season in Saturn's rings: Cycling, recycling and ring history

    NASA Astrophysics Data System (ADS)

    Esposito, L. W.; Meinke, B. K.; Albers, N.; Sremcevic, M.

    2012-04-01

    Cassini experiments have watched Saturn's ring system evolve before our eyes. Images and occultations show changes and transient events. The rings are a dynamic and complex geophysical system, incompletely modeled as a single-phase fluid. Key Cassini observations: High resolution images show straw, propellers, embedded moonlets, and F ring objects. Multiple UVIS, RSS and VIMS occutlations indicate multimodal ringlet and edge structure, including free and forced modes along with stochastic perturbations that are most likely caused by nearby mass concentrations. Vertical excursions are evident at ring edges and in other perturbed regions. The rings are occasionally hit by meteorites that leave a signature that may last centuries; meteoritic dust pollutes the rings. Temperature, reflectance and transmission spectra are influenced by the dynamical state of the ring particles. Saturn's Equinox 2009: Oblique lighting exposed vertical structure and embedded objects. The rings were the coldest ever. Images inspired new occultation and spectral analysis that show abundant structure in the perturbed regions. The rings are more variable and complex than we had expected prior to this seasonal viewing geometry. Sub-kilometer structure in power spectral analysis: Wavelet analysis shows features in the strongest density waves and at the shepherded outer edge of the B ring. Edges are variable as shown by multiple occultations and occultations of double stars. F ring kittens: 25 features seen in the first 102 occultations show a weak correlation with Prometheus location. We interpret these features as temporary aggregations. Simulation results indicate that accretion must be enhanced to match the kittens' size distribution. Images show that Prometheus triggers the formation of transient objects. Propellers and ghosts: Occulations and images provide evidence for small moonlets in the A, B and C rings. These indicate accretion occurs inside the classical Roche limit. Implications

  11. New Views of Jupiter's Rings

    NASA Astrophysics Data System (ADS)

    Burns, J. A.

    1998-09-01

    Jupiter's rings are the archetype of ethereal planetary rings (very-low optical-depth bands containing micron-sized "dust"). As a result of much improved observations by Galileo (Ockert-Bell* -- most citations are et al. and Icarus in press* or this meeting) and Keck (de Pater*), we now understand the nature of such rings. The ring has three components: a 104 km-thick toroidal halo (1.4-1.7 RJ; normal optical depth t = 10-6), a thin main ring (1.7-1.8 RJ; t = 10-6), and a pair of exterior gossamer rings (1.8-3.5RJ; t = 10-7). The main ring has patchy ( 20-30 percent) brightness. The ring is reddish and its particles satisfy a -2.5 differential power-law size distribution. Because particle lifetimes are brief, the rings must be continually regenerated, by collisions into parent bodies, which may be unseen or may be the known small ring-moons (Thomas*, Simonelli). The gossamer ring seems to be collisional ejecta derived from the ring-moons Amalthea and Thebe, and evolving inward by Poynting-Robertson drag (Burns). The particles drift through many electromagnetic resonances, clustering around synchronous orbit, which produce jumps in the particles' inclinations (Hamilton). The main ring is probably debris from Adrastea and Metis, which orbit in the equatorial plane. The halo particles are driven vertically by electromagnetic forces, which may be resonant (Schaffer & Burns) or not (Horanyi & Cravens). When halo orbits become highly distorted, particles are lost into Jupiter. Similar faint rings may be attendant to all small, close-in satellites (Showalter).

  12. The Possibility of Polarisation in the LHeC Ring-Ring Scenario

    SciTech Connect

    Barber, D.P.; Wienands, H.U.; Fitterer, M.; Burkhardt, H.; /CERN

    2012-05-08

    A proposal to add 60-GeV electron and positron beams to the LHC at CERN (LHeC) is currently being prepared. The provision of electron and positron longitudinal polarisation is an important component of the proposal and we are examining the feasibility of Sokolov-Ternov self-polarisation at energies up to 60 GeV in a storage ring in the LHC tunnel. But at this energy the attainable polarisation can be very strongly limited by depolarising effects. This paper summarises first calculations of the attainable polarisation including estimates of the efficacy of Siberian Snakes for weakening synchrotron sideband resonances.

  13. Tree Rings: Timekeepers of the Past.

    ERIC Educational Resources Information Center

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  14. Ring currents in azulene

    NASA Astrophysics Data System (ADS)

    Paxton, A. T.; Todorov, T. N.; Elena, A. M.

    2009-11-01

    We propose a self consistent polarisable ion tight binding theory for the study of push-pull processes in aromatic molecules. We find that the method quantitatively reproduces ab initio calculations of dipole moments and polarisability. We apply the scheme in a simulation which solves the time dependent Schrödinger equation to follow the relaxation of azulene from the second excited to the ground states. We observe rather spectacular oscillating ring currents which we explain in terms of interference between the HOMO and LUMO states.

  15. Wave structure in planetary rings

    NASA Astrophysics Data System (ADS)

    Horn, Linda Joyce

    1992-01-01

    Planetary rings contain a wealth of wavelike structure that is driven by gravitational resonance interactions with nearby satellites. Wave behavior is a powerful tool for estimating physical ring parameters that are key to our understanding of ring origin and evolution. A new technique, utilizing the Burg autoregressive power spectral algorithm, was developed for probing the physical characteristics of rings and for detecting waves that are not otherwise visible. Data from the Voyager photopolarimeter (PPS) stellar occultations by the rings of Saturn, Uranus, and Neptune and the Voyager radio science (RSS) occultation by Saturn's rings were used. Local surface mass density estimates are obtained from the dispersion of 40 spiral density waves in Saturn's A ring, including 10 weaker waves not previously analyzed. Surface mass densities vary from 20 to 60 gm sq cm. Increasing optical depth is not correlated with increasing surface mass density, especially after the Keeler gap, suggesting that ring particle size and composition are not uniform throughout the A ring. Saturn's A ring mass is reestimated using the surface mass densities and is 5.2 +/- 1.3 x 1021 gm. The wakes of Saturn's satellite Pan are not short timescale phenomena because the effects of Pan's gravitational perturbations persist for more than one Pan encounter. Four additional Pan wakes were discovered at longitudes greater than 360 deg. Collective effects such as collisions modify the wake dispersion more extensively at greater longitudes. Pan is the dominant mass in the Encke gap. A spiral density wave was detected inside the Uranian delta ring. Upper and lower bounds were estimated for the surface mass density of the delta ring 5 less than or equal to sigma less than or equal to 10 gm/sq cm, the viscosity 10 less than or equal to nu less than or equal to 40 sq cm/sec, and the local ring height 7 less than or equal to h less than or equal to 20 m. These values are comparable to the corresponding

  16. The Charging of Planetary Rings

    NASA Astrophysics Data System (ADS)

    Graps, Amara L.; Horanyi, M.; Havnes, O.; Gruen, E.

    2008-09-01

    Planetary rings have an undeniable aesthetic appeal, resulting in media icons of ringed planets as descriptive of the planetary sciences field as a whole. Such far-reaching symbolism might not be misplaced, however, because planetary rings represent a fundamental class of planetary structure that invites interdisciplinary investigations from specialists in dust, gravitational, plasma, collisional, and radiative transfer physics, due to: its sub-micron to meters-sized particles, its immersion in the planet's magnetic field, its embedded moonlets and its close proximity to the ringed planet's ionosphere and innermost moons. As such, planetary rings are a metaphoric bridge through a wide range of planetary physical processes. Processes to charge ring particles have different relative dynamical effects, dependent upon the rings' particle sizes, and the ring's plasma, magnetic and gravitational environments. This presentation will review what is known about the charging parameters and processes of planetary rings, in particular the sum of the individual currents from the time-varying charge dQ/dt, of the planetary ring particle. The individual currents depend on the environmental plasma conditions: number density, flow speed, temperature, and mass for the currents: electron and ion capture from the plasma, ion currents to a moving grain, photoelectron emission, secondary electron emission, thermionic effects, with stochastic charging influencing all of the above. Since rings are an ensemble of particles, ("cloud" Ring), we will define an ensemble, and consider the above currents, including those for the smallest ring particles, the dust particles, to arrive at a table giving charge potential and other relevant parameters.

  17. Buoyant Norbury's vortex rings

    NASA Astrophysics Data System (ADS)

    Blyth, Mark; Rodriguez-Rodriguez, Javier; Salman, Hayder

    2014-11-01

    Norbury's vortices are a one-parameter family of axisymmetric vortex rings that are exact solutions to the Euler equations. Due to their relative simplicity, they are extensively used to model the behavior of real vortex rings found in experiments and in Nature. In this work, we extend the original formulation of the problem to include buoyancy effects for the case where the fluid that lies within the vortex has a different density to that of the ambient. In this modified formulation, buoyancy effects enter the problem through the baroclinic term of the vorticity equation. This permits an efficient numerical solution of the governing equation of motion in terms of a vortex contour method that tracks the evolution of the boundary of the vortex. Finally, we compare our numerical results with the theoretical analysis of the short-time evolution of a buoyant vortex. Funded by the Spanish Ministry of Economy and Competitiveness through grant DPI2011-28356-C03-02 and by the London Mathematical Society.

  18. Ring Image Analyzer

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry V.

    2012-01-01

    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  19. Gas storage materials, including hydrogen storage materials

    DOEpatents

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2014-11-25

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material, such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  20. Gas storage materials, including hydrogen storage materials

    DOEpatents

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2013-02-19

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.