The Spallation Neutron Source (SNS) ring, which is presently being commissioned at Oak Ridge National Laboratory, is designed to accumulate high-intensity protons. Ultrahigh vacuum of 10-9 torr is required in the accumulator ring to minimize beam-residual...
National Technical Information Service (NTIS)
The Fermi National Accelerator Laboratory (Fermilab) is building an Accumulator Ring to store antiprotons for high energy physics proton-antiproton collisions in the Tevatron accelerator. The Accumulator Ring approximately 474 m in circumference, consists...
The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with (approx.) 100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chamb...
In this document the authors summarize the following: (1) an overview of basic concepts of ultrahigh vacuum needed for the APS project, (2) a description of vacuum design and calculations for major parts of APS, including linac, linac waveguide, low energy undulator test line, positron accumulator ring (PAR), ...
DOE Information Bridge
An average pressure of 3 x 10{sup -10} Torr is required in order to store a beam of antiprotons (for up to 20 hours) in the Fermilab Accumulator Ring. The Accumulator Ring has a circumference of 474 m and consists of 114 main magnets which surround a continuous, stainless-steel vacuum chamber ...
The Spallation Neutron Source ring, which is presently being commissioned at Oak Ridge National Laboratory, is designed to accumulate high-intensity protons. Ultrahigh vacuum of 10{sup -9} torr is required in the accumulator ring to minimize beam-residual gas ionization. To reduce the ...
Energy Citations Database
BNL is undertaking the design, construction and commissioning of the Spallation Neutron Source (SNS) accumulator ring and the beam transport lines [l]. Ultrahigh vacuum of 10{sup {minus}9} Torr is required in the accumulator ring to minimize beam-gas ionization, a contributing factor to the e-p ...
High energy proton storage rings are designed to make maximal use of the available vacuum chamber aperture. This is dictated primarily by economic considerations. The accumulation of current in a typical high energy ring creates a rather unusual beam conf...
This paper reports on the results of investigation of possible fast transverse instabilities in the NSNS Accumulator Ring. The instability may be caused by the presence of stripline devices like kicker magnets, the active damper system, and by the RF cavities, and the sharp steps of the vacuum pipe. The instability can be overcome by ...
It has been speculated that the intensity limitation observed in the Los Alamos Proton Storage Ring (PSR) is caused by a coherent instability induced by the presence of pockets of electrons generated by scattering with the molecules of the vacuum residual gas. A theoretical explanation of the e-p instability of course does exist, and is similar to the one ...
BNL is responsible for the design and construction of the US Spallation Neutron Source (SNS) accumulator ring. Titanium Nitride (TiN) coating on the stainless steel vacuum chamber of the SNS accumulator ring is needed to reduce the secondary electron yield (SEY) and the undesirable resonant ...
The latest designs for high-intensity proton rings require minimizing beam-induced radioactivation of the vacuum chamber. Although the tune depression in the ring is much smaller than in high-intensity linacs, space-charge contributions to halo formation and, hence, beam loss may be significant. This paper reviews our current ...
This note summarizes and analyzes the Accumulator Ring's pressure data taken during the recent commissioning run (March-October, 1985) and during the three week interval immediately after the end of the commissioning run. Emphasis is placed upon the questions raised in reference [1], viz.: (1) What is the ultimate vacuum ...
The design, fabrication and performance of a vacuum system for the BEPCII storage ring are described in this paper. The arc beam pipes and their antechambers are made by machining upper and lower chamber halves, then welding them at the periphery to form a complete chamber. The photon absorbers and the pumping stations are located in the antechambers. The ...
NASA Astrophysics Data System (ADS)
The Fermilab Antiproton Source Accumulator and Debuncher rings require 5 kickers in total. These range in design from conventional ferrite delay line type magnets, with ceramic beam tubes to mechanically complex shuttered kickers situated entirely in the Accumulator Ring's 10/sup -10/ torr ...
The vacuum system for Heavy Ion Fusion machines can be divided according to pressure into 4 parts: (a) Ion Sources; (b) Linear Accelerators; (c) Circular Accelerators, Accumulators and Storage Rings; and (d) Reactors. Since ion sources will need rather conventional pumping arrangements and reactors will operate with greater pressures, ...
The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H- injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. ...
The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H{sup -} injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron-cloud is expected to be one of the intensity-limiting mechanisms that complicate ring ...
The theory and principles of accumulator rings are given as an introduction to the description of the design and performance of the AdA accumulation ring. (J.S.R.)
The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton transfers in and out of the Recycler Ring take place through two transfer lines connecting the Recycler to the Main Injector. Transfer line layout and operation of beam transfers will be described. Particular attention has been paid to ...
The Fermi National Accelerator Laboratory (Fermilab) is building an Accumulator Ring to store antiprotons for high energy physics proton-antiproton collisions in the Tevatron accelerator. The Accumulator Ring approximately 474 m in circumference, consists of many quadrupole and dipole magnets connected with ...
The Fermi National Accelerator Laboratory (Fermilab) is building an accumulator ring to store antiprotons for high energy physics proton-antiproton collisions in the Tevatron accelerator. The accumulator ring, approximately 474 m in circumference, consists of many quadrupole and dipole magnets connected with ...
Modern physics still has fundamental problems concerning invariance and/or violation of symmetries. Precision measurements of the characteristics of ortho- and para-positronium are certainly suited to help solving such fundamental questions. The method of positronium generation, based on a low energy positron storage ring equipped with an electron cooling system, gives the ...
The large electron positron storage ring (LEP) preinjector will provide the particles to be stored in the LEP. It is composed of a high-intensity linear accelerator (linac) providing 200-MeV electrons for the production of positrons, a low-intensity linac (LIL) for the acceleration of electrons and positrons to 600 MeV (LIL), and an electron positron ...
The Large Electron Positron Storage Ring (LEP), under construction at CERN, will be supplied with particles produced by the newly bulit LEP Injector Linac (LIL) of 600 MeV, followed by an Electron Positron Accumulator (EPA) of 600 MeV; electrons and positrons will be further accelerated to 3.5 GeV in the existing multipurpose Proton Synchrotron (PS) and, ...
In the Spallation Neutron Source, after multiple injections to an accumulator ring, a final extraction delivers the full proton beam to the target, achieved by a series of kickers and a thin septum magnet. Here we discuss the lattice geometry, beam dynamics and optics, and the vacuum, electromagnetic and mechanical design aspects of ...
The stainless steel vacuum chambers of the 248m accumulator ring of Spallation Neutron Source (SNS) are coated with(approx) 100 nm of titanium nitride (TiN) to reduce the secondary electron yield. The coating is produced by DC magnetron sputtering using a...
The lecturer expects the students to know the fundamentals of vacuum physics and vacuum engineering, that is, kinetic theory of gases, pressure units, gas flow regimes, conductance for aperture and tubes, vacuum pumps, vacuum components, and vacuum system materials1, 2. This knowledge is ...
The Spallation Neutron Source accelerator utilizes H- charge exchange injection to merge a 1 GeV, 1 MW beam from a linac into an accumulator ring. The design calls for the 545 keV foil-stripped electrons to be absorbed by an electron catcher located below the foil. However, multiple observations of hardware damage caused by stripped electrons indicate that ...
Laser ablation on rings of fish scale has been used to analyze the historical accumulation of polychlorinated biphenyls (PCB) in striped bass in the Watts Bar Reservoir. Rings on a fish scale grow in a pattern that forms a record of the fish's chemical intake. In conjunction with the migration patterns of fish monitored by ecologists, ...
Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2pm. Bunch train filling pattern is proposed to mitigate the instability and bunch-by-bunch feedback is applied to suppress it. Multibunch train fill pattern is introduced in the electron beam to reduce the number of ...
The overall objective of this study is to obtain insights into the dynamic coupling between the storage ring vacuum chamber and girder, and an assessment of the potential for unacceptable vibration amplitudes that would require redesign of the vacuum cham...
The Advanced Light Source (ALS) storage rings 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 ...
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...
The drawings listed provide the information for construction of the listed titles of the SLAC PEP vacuum systems (window assembly-vacuum chamber septum, vacuum chamber septum, and vacuum fault module). The septum vacuum chamber is used in the electron and positron ring ...
This paper describes the simulation studies on the motions of stripped electrons generated in the injection section of the Spallation Neutron Source (SNS) accumulator ring and the effective collection mechanism. Such studies are important for high intensity machines, in order to reduce beam loss and protect other components in the vicinity. The magnetic ...
The Spallation Neutron Source accumulator ring is described. Also described are the challenging accelerator physics problems associated with space charge issues, injection, extraction, and beam loss.
The Spallation Neutron Source Accumulator ring is described. Also described are the challenging accelerator physics problems associated with space charge issues, injection, extraction, and beam loss.
In preparation for the heavy ion program of the Large Hadron Collider at CERN, accumulation and cooling tests with lead ion beams have been performed in the Low Energy Antiproton Ring. These tests have revealed that due to the unexpected large outgassing of the vacuum system, the dynamic pressure of the ring could ...
The use of spiral-sector magnets for the accumulators of ribbon beams in storage rings is considered. (AIP)
... The ring resonator functions as an accumulator in the ... RESONATORS, CIRCUITS, DATA RATE, ACCUMULATORS, MODULATION, AMPLITUDE ...
DTIC Science & Technology
The listed drawings provide the information for constructing the vacuum devices of the PEP experiment detectors as listed. One drawing is listed as obsolete, but is included for historical interest and completeness. The DELCO Vacuum Chamber Drawings define the detector's vacuum chamber as used on PEP. The HRS Vent and ...
Electron cloud due to beam-induced multipacting is one of the main concerns for the high intensity. Electrons generated and accumulated inside the beam pipe form an ''electron cloud'' that interacts with the circulating charged particle beam. With sizeable amount of electrons, this interaction can cause beam instability, beam loss and ...
The development of bakeable high-vacuum flanges for the ORNL PIG Facility is reported. The general design approach for this type flange is to obtain a bakeable vacuum seal by first welding thin metal rings to a set of heavy metal flanges, and then edge-welding the rings together. This design sllows the ...
Lecture I deals with the behavior of particles in the nonlinear field arising from the electromagnetic interaction of colliding beams. The case treated, that of counter-rotating proton beams crossing each other at a non-zero angle, has the simple feature that the force between the beam is one dimensional. In lecture II, an analysis of the development of traveling waves on particle beams is ...
O-rings in an effort to find a type of metal ring that would be more ... The aluminum O-rings used in the tests were fabricated from type 1100 ...
NASA Website
Optical prots ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), ...
Optical ports ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (beam passes through the window at left), ...
Vacuum Gauge Calibration Apparatus. Electron. Beam Welding Titanium Ring. Electron. Beam Welding Titanium Ring. Electron Beam. Welding. Titanium Eing ...
Place the bolts into another set of plastic bags. Remove the O-Ring in the. O- Ring grooves of the flanges and place them into separate plastic bags to ...
A 700 MeV electron storage ring designed for synchrotron radiation applications is described. Lattice and stability calculations are presented and the vacuum, correction and injection systems are discussed.
The loads and resulting stresses in the seal ring are calculated and compared to the allowables for the service from ASME Boiler and Pressure Vessel Code.
Many metal bellows are used on storage ring vacuum chambers. They allow the ring to accomodate deformations associated with alignment, mechanical assembly and thermal expansion. The NSLS has two such electron storage rings, the VUV ring and the X-Ray ring. Both ...
Magnetic elements for an accumulator storage ring for a 1 GeV Spallation Neutron Source (SNS) have been under design. The accumulation of very high intensity protons in a storage ring requires beam optical elements of very high purity to minimize higher o...
The design of a 75-m radius, 8-GeV storage ring to be used for stochastic cooling and accumulation of antiprotons is described. The stochastic cooling systems have imposed strenuous requirements on the lattice and the resulting ring design is rather novel.
The influence of electron scattering by accumulation of ions and neutral atoms on the cross section of the electron ring is studied. It is shown that the part of scattering is a cause of the increase of the cross section of the ring during the time of acc...
In application of polymeric materials to the fusion experimental reactor, outgas and vacuum seal characteristics of irradiated polyimide were studied. Crystalline polyimide is used as a test specimen, which is cut into the equivalent of O-ring V40 for JIS...
In storage rings employing superconducting magnets, the use of a cold bore as a cryopump appears, at first glance, as simple and economical. Since the selection of a cold or warm vacuum system has far-reaching implications on the basic design, each system...
... slight vacuum. The ring-opening polymerization of caprolactam proceeds by an activated monomer mechanism. Copolymerizations ...
... ACCELERATORS, *ION ACCELERATORS, RINGS, VACUUM APPARATUS, ELECTRONS, MAGNETIC FIELDS, CROSSED FIELD DEVICES ...
... developed. Common end products are curtain rod ends and rings, aerosol deodorant caps, and cosmetic closures. Electro ...
... and remachining. This included electropolishing of the vacuum chamber and polishing of all gold O-ring surfaces. The box ...
The injector for the Advanced Photon Source incorporates a 450-MeV positron accumulator ring (PAR) to decrease the filling time with the 2-Hz synchrotron. In addition to accumulating positrons from the linac, the PAR damps the beam and reduces the bunch l...
An all metal reusable o-ring sealing arrangement is disclosed for sealing two concentric tubes in an ultra-high vacuum system. An o-ring of a heat recoverable alloy such as nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The o-ring is installed ...
An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the ...
Test of the viton O-ring deformation has been performed for a new type of large sized vacuum window having a diameter of more than 80 mm. To prevent a vacuum leak mainly caused by the crack of optical window, a new standard for the viton O-ring has been p...
The NSLS X-ray ring exhibits a direct correlation between photon beam motion, and distortion of the ring vacuum chamber induced by fluctuations in the cooling system. We have made long term measurements of photon beam vertical position, accelerator vacuum...
A study was made to determine the effects of a shift in the electron orbital plane and resulting displacement of the wiggler photon beam striking the inner surface of the existing vacuum chamber outer wall. The wiggler beam/vacuum chamber geometry is shown. 7 figures.
A study was made to determine the effects of a shift in the electron orbital plane and resulting displacement of the wiggler photon beam striking the inner surface of the existing vacuum chamber outer wall. The wiggler beam/vacuum chamber geometry is show...
At the wire and the press sections of the paper machine water is removed from the paper web with a vacuum system. The vacuum is mainly generated by liquid ring pumps and turbocompressors. The report will present a method that reduces the electric power ne...
The arrangement of RFQ vacuum system is briefly described. The projections of the vacuum level using standard out-gassing rates for the RFQ major components are compared with measurements. The permeation of water through the Viton O-rings of the LCW manif...
In a vacuum generating system having a liquid ring vacuum pump preceded in a gas flow path by a precompressor and followed by a liquid separator, the precompressor is driven by steam produced in a heat exchanger in contact with the working fluid of the vacuum pump. The working fluid is kept at a temperature ...
A bakable (200/sup 0/C) aluminium alloy vacuum chamber and bellows (6063-T6) with an aluminium alloy (2219-T87) flange and metal seal (Helicoflex-HN: aluminium O-ring) has been constructed. Such components may be used in the assemblies of the vacuum chambers in proton synchrotrons and electron storage rings.
The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with {approx}100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chambers and kicker modules, some up to 5m in length and 36cm in diameter, coated with ...
The design of the vacuum system for the PEP-II B Factory High-Energy Ring is reviewed. The thermal design and vacuum requirements are particularly challenging in PEP-II due to high stored beam currents up to 3.0 amps in 1658 bunches. The vacuum chambers for the HER arcs are fabricated by electron beam welding ...
A casing vacuum system which applies a controlled vacuum to the space within the casing of an oil well in order to maintain the gas pressure in the well within a certain range and thereby improve the recovery of petroleum from the well. A preferred embodiment of the casing vacuum system utilizes a vacuum pump ...
An all metal reusable o-ring sealing arrangement is disclosed for sealing two concentric tubes in an ultra-high vacuum system. An o-ring of a heat recoverable alloy such as nitinol is concentrically positioned between protruding sealing rings of the conce...
HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed synchrotron/cooler/storage ring accelerator optimized for advanced atomic physics research. The ring has a circumference of 46.8 m, a bore diameter of about 15 cm, and requires a vacuum of ...
The paper presents the results on studying the radiation conditions caused by induced radioactivity of the accelerator units in the ring hall. The data on the induced radioactivity level just on the ring vacuum chamber are reported. Radiation conditions i...
Bremsstrahlung is produced in the Advanced Photon Source (APS) storage ring when the positron beam interacts with the storage-ring components or with the residual gas molecules in the storage-ring vacuum. The interaction of the positrons with the gas mole...
The Spallation Neutron Source comprises a 1 GeV, 1.4 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the $H^0$ excited states created during the $H^-$ charge exchange injection into the accumulator ring, the stripper foil is located inside one of ...
The Oak Ridge Spallation Neutron Source comprises a 1 GeV, 1.5 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H0 excited states created during the H- charge-exchange injection into the accumulator ring, the stripper foil is located inside one ...
The Spallation Neutron Source comprises a 1 GeV, 1.4 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H0 excited states created during the H charge exchange injection into the accumulator ring, the stripper foil is located inside one of the ...
An ancillary pumping system has been designed and installed in the Advanced Photon Source (APS) storage ring. This vacuum system has the ability to pump sectors of the storage ring down from room pressure to ultra-high vacuum (UHV). The ancillary system is a {open_quotes}dry{close_quotes} system that uses a ...
HPL value. The HPCC random ring bandwidth was multiplied by the number of MPI ... Figure 1: Accumulated Random Ring Bandwidth versus HPL performance. ...
The rings of the National Synchrotron Light Source (NSLS) have been supplying light to numerous users for approximately a decade and we recently enjoyed a fully conditioned machine vacuum at design currents. A brief description of the X-Ray storage ring, the VUV storage ring and their current supply is given along ...
A high level of current dependent bunch lengthening has been observed in the north damping ring of the Stanford Linear Collider (SLC), indicating that the ring's impedance is very inductive. This level of bunch lengthening will limit the performance of the SLC. In order to study the problem of bunch lengthening in the damping ...
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 ...
The stainless steel vacuum chambers of the 248 m accumulator ring of the Spallation Neutron Source are to be coated with ~100 nm of titanium nitride (TiN). This is to minimize the secondary electron yield from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few ...
UHV system for synchrotron radiation source Indus-2 was developed and commissioned. The specified ultimate vacuum in 10-10 mbar range was achieved. This vacuum deteriorates with the injection of electron beam into the storage ring mainly due to photon induced desorption (PID). Initially, the PID yield may be as high as 10-1 ...
In the SNS accumulator ring, ceramic vacuum chambers are used for the 8 injection. kickers to avoid shielding of a fast-changing kicker field and to minimize eddy current heating. The inner surface of the ceramic chambers was coated with Cu to reduce the beam coupling impedance and provide passage for beam image current, and a TiN over ...
The stainless steel vacuum chambers of the 248m accumulator ring of Spallation Neutron Source (SNS) are coated with {approx} 100 nm of titanium nitride (TiN) to reduce the secondary electron yield. The coating is produced by DC magnetron sputtering using a long cathode imbedded with permanent magnets. The outgassing rates of several ...
The purpose of this document is to: (1) Explain the ALS vacuum policy and specifications for beamlines and experiment endstations. (2) Provide guidelines related to ALS vacuum policy to assist in designing beamlines which are in accordance with ALS vacuum policy. This document supersedes LSBL-116. The Advanced Light Source is a third ...
During accumulation the RF beam current in the spallation neutron source ring rises from 0 to 50 amperes. A clean, 250 nanosecond gap is needed for the extraction kicker risetime. Large momentum spread and small peak current are needed to prevent instabil...
The injection of electron beams to TRISTAN Accumulation Ring (AR) was started in November 1983 and the positron injection started in November 1985. For the injection of electron and positron beams to AR, the unique kicker system was developed. In the kick...
We are reporting the results of studies on issues related to the injection stripping foil in the Spallation Neutron Source (SNS) accumulator ring. The problems related to foil heating and foil lifetime, such as current density distribution and temperature...
This paper reports on the results of investigation of possible fast transverse instabilities in the NSNS Accumulator Ring. The instability may be caused by the presence of stripline devices like kicker magnets, the active damper system, and by the RF cavi...
Three fast kicker units have been designed, tested, and installed in the positron accumulator ring (PAR) at the Advanced Photon Source (APS) for beam injection and extraction. The performance of these kicker units has been satisfactory. This presents the design and test results.
As a key component of the Spallation Neutron Source (SNS) Project, the Accumulator Ring will collect the proton beam from the SNS LINAC at an intensity of 2 x 10(sup 14) per pulse at 60 Hz for a total power of 2 MW, exceeding present performance value of ...
The PEP-II Low-Energy Ring will operate at a nominal energy of 3.1 GeV with a positron beam current of 2.1 A. Design parameters for vacuum components are 3.5 GeV at 3 A. The arc vacuum system is based on an aluminum antechamber concept. It consists of 192...
The vacuum characteristics of the APS storage ring vacuum chamber prototype, Section One (S1), is presented. The base pressure achieved was 4 {times} 10{sup {minus}11}, the welds contained no virtual or real leaks, the NeG strip mounting design and activation procedures have been determined, and S1 was found contaminated with ...
Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate ...
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 ...
The Positron Accumulator Ring (PAR) is designed to accumulate and damp positrons from the 450-MeV linac during the 0.5-s cycle time of the injector synchrotron for the APS 7-GeV storage ring. During 0.4 s of each synchrotron cycle, up to 24 linac pulses are injected into the horizontal phase space of the PAR at a ...
Ball bearings for the L-SAT antenna pointing mechanism (APM) were tested in vacuum with external diameter clearance (i.e., free fit rings) and held in-situ with clamp rings. The influence of speed, temperature, internal preload, axial ring clamping force,...
We present a new stationary, asymptotically flat solution of 5D Einstein-Maxwell gravity describing a Saturn-like black object: a rotating black hole surrounded by a rotating dipole black ring. The solution is generated by combining the vacuum black Saturn solution and the vacuum black ring solution with ...
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 ...
in the vacuum system are made of Viton and were purchased from MDC Vacuum Components Corp. To get an estimate of the pressure rating for a KF-25 centering ring the Viton O-rings were tested in a water pressure test setup. A new dry clean Viton O-ring used with polished flanges fails at 11-14 ...
E-print Network
An improved evacuated optical structure is disclosed comprising an optical bench mounted in a vacuum vessel in a manner which inhibits transmission of movement of the vacuum vessel to the optical bench, yet provides a compact and economical structure. The vacuum vessel is mounted, through a sidewall thereof, to a support wall at four ...
DOEpatents
In 1996, due to a catastrophic kicker chamber failure in the SLC electron damping ring, the ring vacuum system was contaminated for several months. During this time, the vertical emittance of the beam extracted from the ring was increased by a large factor (4--20). The emittance slowly decreased as the ...
suppression of generation and accumulation of secondary particles is a traditional method for suppression the transverse electron-proton instability: improve the vacuum, use a gap in beam for electron removing, use cleaning electrodes, suppressing secondary emission. But opposite solution is also possible. Transverse e-p instability in proton ...
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 ...
The ILC positron damping ring comprises hundreds of meters of wiggler sections, where many more photons than in the arcs are emitted, and with the smallest beampipe aperture of the ring. A significant electron-cloud density can therefore be accumulated vi...
Many metal bellows are used on storage ring vacuum chambers. They allow the ring to accommodate deformations associated with alignment, mechanical assembly and thermal expansion. The NSLS has two such electron storage rings, the vuv ring and the x-ray ring. Both ...
Many metal bellows are used on storage ring vacuum chambers. They allow the ring to accommodate deformations with alignment, mechanical assembly and thermal expansion. The national synchrotron light source (NSLS) has two such electron storage rings, the VUV ring and the X-ray ...
The SNS Ring off-line parallel simulation environment based on the Unified Accelerator Libraries (UAL) has been implemented and used for extensive full-scale beam dynamics studies arising in high-intensity rings. The paper describes the structure of this environment and its application to the development and analysis of the SNS ...
Requirements are provided for NSLS beam line front ends and vacuum interlocks. Guidelines are provided for UHV beam line vacuum systems, including materials, vacuum hardware (pumps, valves, and flanges), acoustic delay lines and beam line fast valves, instrumentation, fabrication and testing, and the NSLS cleaning facility. Also ...
Formation and accumulation of defect structures at interfaces between polysilanes and vacuum-evaporated gold (Au) electrodes are discussed quantitatively by low energy positron annihilation spectroscopy. The size distribution of the defects at the interface is analyzed based on the values of ortho-positronium (o-Ps) lifetime (?3), and no effect of the ...
The combination of a heavy-ion storage ring with the intense photon beams from a synchrotron light source present new opportunities for research in atomic physics. At Brookhaven a design for such a facility has been proposed as the basis of a comprehensive National Atomic Physics Facility. Vacuum considerations are an important factor in its performance ...
We study the nonlinear interaction of laser light with vacuum for a large angular aperture at electromagnetic field strengths far below the Schwinger limit. The polarization and magnetization in vacuum irradiated by a focused laser beam clearly differ from those in matter. This is due to the dependence on the Lorentz invariant, which results in a ...
The vacuum system for PEP will be similar in design, construction and operation to the system currently in operation at SPEAR. There will, of course, be quantitative differences since the closed path of PEP will be 10 times longer than the SPEAR path. Som...
A discussion is given of the design and operation of the Tokapole II device. The following topics are considered: physics considerations, vacuum vessel, poloidal field, ring and support design, toroidal field, vacuum system, initial results, and future plans. (MOW)
radiation fan distributions, the situation of SR must be studied separately. #12;Vacuum chamber in the central � Vacuum chamber � Collision tuning monitors � Supporting system � Summary #12;Layout of the storage ring for synchrotron radiation application. The switch of two modes is to control the power supplies of SCQ and SCB
This note will examine many different scenarios, both optimistic and pessimistic, for the performance of the B Factory. The primary reason for this is to establish limits for the emittances in the two rings. This information will be needed to ensure that the vacuum chambers are sized to permit the maximum flexibility. 3 refs., 3 tabs.
the rubber hose is generally adequate for small sys- tems (where vacuum connections are under one ... cone rubber-coated bellows and a sliding 0-ring seal. ...
We investigate the consequences of using a Lorentz-like transformation to connect measurements between a inertial a rotating frame of reference. We obtain a new rotating vacuum (of a massless scalar field) different from the Minkowski one. After this we c...
The parameters that are required for the vacuum chamber of the B Factory High Energy Ring (HER) are presented here using the existing PEP chamber parameters for comparison. Each parameter will be discussed separately and the complete parameter sets for th...
Chemical cleaning, vacuum firing, glow discharge cleaning and insitu bakeout have become standard practice for lowering the outgassing rate and removing surface contaminants in the ultra high vacuum systems of particle accelerators and storage rings. This...
In the storage ring of the 7 GeV Advanced Photon Source, there are 480 vacuum-chamber end flanges and 80 tube welded joints, accounting for a total of 560 full-penetration weldments. This note is to give an estimation of the longitudinal and transverse lo...
The development of an electron cloud in the vacuum chambers of high intensity positron and proton storage rings may limit the machine performances by inducing beam instabilities, beam emittance increase, beam loss, vacuum pressure increases and increased ...
A 51 MHz, 200 KV, aluminum cavity, in vacuum, has been built, tested and set in operation on the Frascati storage ring. Problems encountered in building, vacuum sealing and conditioning are illustrated. Behaviour on the accelerator is also mentioned.
A technique is described for sealing lithium fluoride windows to pyrex tubing using seals of silver chloride with intermediate siiver rings. Vacuum systems using these seals were satisfactory for several years. (J.R.D.)
We study the stationary asymptotically flat five-dimensional vacuum solution describing black di-ring: two concentric black rings. We give an outline of solution generating methods to construct the black di-ring and introduce the rod structures of the black di-ring and the seed solutions. We ...
In positron and proton storage rings, electrons produced by photoemission, ionization, and secondary emission accumulate in the vacuum chamber during multibunch operation with close spacing. A positron or proton bunch passing through this "electron cloud" experiences a force similar to a short-range wake field. This effective wake ...
PubMed
High energy proton storage rings are designed to make maximal use of the available vacuum chamber aperture. This is dictated primarily by economic considerations. The accumulation of current in a typical high energy ring creates a rather unusual beam configuration: in particular, a ribbon beam in a circular chamber ...
An instability in the proton storage ring (PSR) is observed as fast loss of beam during accumulation and storage when the injected beam current exceeds a threshold value. Instabilities are observed during both coasting-beam and bunched-beam operation. Large coherent transverse oscillations occur prior to and during the beam loss. The growth times are ...
A simple model is developed for the admittance of a metal-insulator-semiconductor (MIS) capacitor which includes the effect of a guard ring surrounding the Ohmic contact to the semiconductor. The model predicts most of the features observed in a MIS capacitor fabricated using regioregular poly(3-hexylthiophene) as the active semiconductor and polysilsesquioxane as the gate ...
Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the US Spallation Neutron Source (SNS) accumulator ring. There are two reasons for using ceramic chambers in kickers: (1) to avoid shielding of a fast-changing external magnetic field by metallic chamber walls; and (2) to reduce heating due to eddy currents. The ...
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 ...
The 7-GeV Advanced Photon Source (APS) design includes a storage ring having a 1060-m circumference with the capability of accommodating 34 insertion devices (ID) and their associated photon beam lines. An additional 35 photon lines can be provided from bending magnets. The vacuum system for the storage ring is designed to maintain a ...
The overall objective of this study is to obtain insights into the dynamic coupling between the storage ring vacuum chamber and girder, and an assessment of the potential for unacceptable vibration amplitudes that would require redesign of the vacuum chamber supports. Specific objectives include determination of the vibrational ...
The six straight sections of the PEP II High Energy Ring (HER) serve various functions: lattice tuning, beam injection and abort, providing space for rf cavities, longitudinal and transverse feedback, beam diagnostics and the interaction point. A stainless steel vacuum system has been designed; prototypes are currently being built. Cooling is required due ...
This paper examines a high-voltage vacuum lead-in for an electron accelerator based on a disk insulator with a dc rating of 300 kV. The potential distribution along the vacuum surface of the insulator is set by gradient rings of a special shape and a resistance divider. The shape of the gradient rings protects the ...
New low-impedance vacuum chambers were installed in the SLC damping rings for the 1994 run after finding a single bunch instability with the old chamber. Although the threshold is lower with the new vacuum chamber, the instability is less severe, and we are now routinely operating at intensities of 4.5 {times} 10{sup 10} particles per ...
Preliminary design results for the vacuum system of the 6 GeV storage ring which is being planned at RIKEN, are presented. The vacuum system is designed to maintain a beam-on operating pressure of 1 x 10/sup 10/ Torr. This report places special emphasis on the new vacuum chamber whose antechamber is with two ...
The process of ion accumulation in the relativistic electron beams with the account of ion-ion recharge and ionization is calculated. The accumulation of nitrogen ions from the residual gas during the compression of electron rings in heavy ion accelerator...
This note will examine many different scenarios, both optimistic and pessimistic, for the performance of the B Factory. The primary reason for this is to establish limits for the emittances in the two rings. This information will be needed to ensure that ...
MATERIAL: VITON. DUROMETER: 75. LUBRICATE O-RINGS WITH DOW. CORNING HIGH VACUUM GREASE. SAE J1926/1 PORT. MODIFIED LENGTH. 2X 180� APART ...
, The vacuum seals are made up with copper gaskets, except for two Viton O-rings located at the end of the main
by a vacuum switch and an RG-17 cable to the collector ring assembly on the driver. The network is used for rrdumping" any residual bank energy after a ...
... Abstract : A soft x-ray undulator is to be based at the vacuum-ultraviolet storage ring at the National Synchrotron Light Source, NSLS. ...
Optical ports ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), ...
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 materials research program. The Storage Ring's 1104 m circumference is divided into 40 sectors which contain ...
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 ...
Progress has been made on the two major components of the project, the tests of storage cells for polarized atoms under various operating conditions, and the construction of a new atomic beam source which conforms to the high vacuum requirements of storage rings.
To simplify installation and speed testing of the Advanced Photon Source (APS) storage ring magnets, vacuum chambers and magnet power supplies, a modular approach was developed. All but the dipole magnets are independently controlled. Pulse width modulate...
As a result of more detailed engineering studies of vacuum chamber components and related accelerator physics studies, the circumference of the APS storage ring is increased by 44 m to a value of 1104 m. The increase is 1.1 m for each of the 40 sectors. T...
We simulate the pressure profile of residual gases from basic principles using detailed beam pipe geometry and the relevant physical parameters. These profiles are compared with the actual ion gauge measurements and is being used to predict the vacuum contribution to the Recycler Ring beam lifetime.
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-electro...
The present invention relates to a fixture to be used during pressure/vacuum testing. The fixture includes a shell having a main body and a coupling ring surrounding the main body. The coupling ring has threads for engaging an external thread connection o...
We summarize the expected ion effects in the PEP-II High Energy Ring, considering both a uniform vacuum pressure and a local pressure bump in the IR quadrupoles.
At first the main principles for operation and building of liquid ring pumps are remembered and an experiment is described which allowed to assess the performance data of such pumps when used to pump helium gas with oil. Although they have been designed t...
Bremsstrahlung is produced in the APS storage ring by the interaction of positrons with the residual gas molecules in the vacuum chamber of the storage ring. The bremsstrahlung production causes a serious challenge in shielding the insertion-device beamli...
