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...
National Technical Information Service (NTIS)
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 ...
Energy Citations Database
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.
DOE Information Bridge
The Advanced Photon Source (APS) injector consists of a 250-MeV electron linac, a 450-MeV positron linac, a 450-MeV positron accumulator ring (PAR), and a 7-GeV synchrotron. The purpose of the PAR is to accumulate and damp positrons from the 60-Hz linac during each cycle of the 2-Hz ...
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 length. The PAR ...
The injector for the Advanced Photon Source (APS) incorporates a 450-MeV positron accumulator ring (PAR) to accumulate and damp positrons from the 60Hz linac during each cycle of the 2-Hz synchrotron. An overview of PAR hardware is presented. Commissioning of the PAR is ...
A number of correction magnets are required for the advanced photon source (APS) machine to correct the beam. There are five kinds of correction magnets for the storage ring, two for the injector synchrotron, and two for the positron accumulator ring (PAR...
The Advanced Photon Source (APS) consists of four separate machines: linac, booster, positron accumulator ring (PAR) and storage ring (SR), plus three transfer lines interconnecting the machines. At least one thin, pulsed septum magnet is located at each ...
The new positron injection scheme is as follows. The cycle rate of the injector synchrotron is increased to 2 Hz. During 0.4 sec of each 0.5-sec synchrotron cycle, 24 linac pulses are injected into the horizontal phase space of the PAR at a 60-Hz rate. Each injected pulse occupies about 1/3 of the circumference of the accumulator ring. ...
A pulsed septum magnet has been designed and constructed for beam injection and extraction in the Advanced Photon Source at Argonne National Laboratory. The magnets will be similar for the Positron Accumulator Ring (PAR), the Injector Synchrotron, and the...
Three fast Pulsed kicker/bumper magnets are required in the positron accumulator ring (PAR) for the purpose of beam injection and/or extraction at 450 MeV. According to the Conceptual Design Report (CDR), these three magnets have, identical specifications...
To inject beams from the positron accumulator ring (PAR) into the synchrotron, a pulsed kicker magnet is used. The specifications of this kicker magnet and the power supply unit are listed and discussed in this report.
In the design of fast pulsed kicker/bumper units for a positron accumulator ring (PAR) at APS, different pulse forming networks (PFN) are considered and different structures for the magnet are studied and simulated. This paper describes some design considerations and computer simulation results of different designs. 4 refs., 6 figs.
Upgraded versions of cavities for the APS positron accumulator ring (PAR) have been built and are being tested. Two cavities are in the PAR: a fundamental 9.8-MHz cavity and a twelfth harmonic 117.3-MHz cavity. Both cavities have been manufactured for higher voltage operation with improved Q-factors, reliability, ...
The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel ...
In this document the authors summarize the following: (1) an overview of basic concepts of ultrahigh vacuum needed for the APS project, (2) a description of vacuum design and calculations for major parts of APS, including linac, linac waveguide, low energy undulator test line, positron accumulator ring (PAR), booster synchrotron ...
A 22.5 (mu)H, 22.5 m(Omega) transformer septum magnet must be pulsed at a 60 Hz rate to inject beam from a 450 MeV positron linac into a positron accumulator ring (PAR) and to extract beam from it. Of the 60 pulses per second the first 24 are used for inj...
The Positron Accumulator Ring (PAR) is part of the APS injection system. It receives 24 30-ns FWHM bursts of 450-MeV positrons, and compresses them into 6-nC, 290-ps rms bunches. Striplines were selected as beam position monitors (BPMs) to assure that goo...
This paper describes the proposed low-level rf system of the positron accumulator ring (PAR), the injector synchrotron, and the storage ring of the 7-GeV Advanced Photon Source. Four rf systems are described since the PAR consists of a fundamental frequency system at 9.8 MHz and a harmonic ...
We describe the rf system of the positron accumulator ring (PAR) of the 7-GeV Advanced Photon Source. Two rf systems are described: a fundamental frequency system at 9.8 MHz, and a twelfth harmonic system at 117.3 MHz. A block diagram of an accelerating unit is shown and descriptions of various amplifier subsystems are given (including ...
The mechanical design, construction, and assembly procedure of six different septum magnet designs used in the Advanced Photon Source (APS) facility will be described. This will include a positron accumulator ring (PAR) AC septum magnet, a synchrotrons thin injection septum AC thin and thick extraction septa, and storage ...
Two photon monitors have been designed and installed in the positron accumulator ring (PAR) of the Advanced Photon Source. The photon monitors characterize the beam`s transverse profile, bunch length, emittance, and energy spread in a nonintrusive manner. An optical transport line delivers synchrotron light from the ...
Argonne National Laboratory is designing a 7-GeV Advanced Photon Source (APS). The rf systems of the APS include 10-MHz and 120-MHz systems for the Positron Accumulator Ring (PAR), a multicell 352-MHz system for the booster synchrotron, and a system of mode-damped, single-cell 352-MHz cavities for the storage ring. ...
The shielding estimates for the Electron and Positron Linacs and the Booster Synchrotron, contained in the 1987 Conceptual Design Report (CDR) of the APS (ANL-87-15), have been reviewed and recalculated, along with newly initiated calculations of the required shielding for the addition of a Positron Accumulator Ring (PAR). Several new ...
Initial results from the Optical synchrotron radiation (OSR) monitors for the Advanced Photon Source (APS) have been obtained. Data using electron beams on the positron accumulator ring (PAR) at 400 MeV, the injector synchrotron (IS) up to 7-GeV, and the main storage ring (SR) at 4.5 and 7 GeV address both ...
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 cavities for the dual frequency system of the APS PAR are described. The system uses two frequencies: a 9.78MHz fundamental system for the particle accumulation and a 117.3MHz twelfth harmonic system for the bunch compression. The cavities have been built, installed, tested, and used for storing the beam in the PAR for about a ...
This paper describes the development status of the beam position monitoring system for the Advanced Photon Source (APS), a third-generation light source now under construction at Argonne National Laboratory. The accelerator complex will consist of an electron linac, a positron linac, a positron accumulator ring (PAR), an injector ...
The Annex to the 7-GeV Advanced Photon Source Conceptual Design Report updates the Conceptual Design Report of 1987 (CDR-87) to include the results of further optimization and changes of the design during the past year. The design changes can be summarized as affecting three areas: the accelerator system, conventional facilities, and experimental systems. Most of the changes in the accelerator ...
A pulsed septum magnet has been designed and constructed for beam injection and extraction in the Advanced Photon Source at Argonne National Laboratory. The magnets will be similar for the Positron Accumulator Ring (PAR), the Injector Synchrotron, and the Storage Ring. The septum itself is 2 mm thick and consists ...
This note details measurements of the APS positron linac klystron and accelerating structure gain and presents an analysis of the data using fits to simple mathematical models. The models are used to investigate the sensitivity of the energy dependence of the output positron beam to klystron parameters. The gain measurements are separated into two parts: first, the energy gains of the accelerating ...
A software tool-oriented approach has been adopted in the commissioning of the Advanced Photon Source (APS) at Argonne National Laboratory, particularly in the commissioning of the Positron Accumulator Ring (PAR). The general philosophy is to decompose a complicated procedure involving measurement, data processing, and control into a ...
The Advanced Photon Source (APS) is a third-generation synchrotron radiation source that stores positrons in a storage ring. The choice of positrons as accelerating particles was motivated by the usual reason: to eliminate the degradation of the beam caused by trapping of positively charged dust particles or ions. The third-generation synchrotron radiation sources are designed ...
Plans for time-resolving the synchrotron radiation emitted by circulating particle beams and characterizing parameters of those beams for the three rings in the Advanced Photon Source (APS) are briefly presented. The APS includes a 450-MeV positron accumulator ring (PAR), a 0.45-to-7-GeV injector synchrotron (IS), ...
The APS system will contain three rings. The first is a positron accumulator ring (PAR). Its function is to coalesce 24, 30-ns-long positron bunches into one 290-ps bunch. The second is the injector synchrotron (IS). It accelerates the 450-MeV positron bunches to 7 Gev for injection into the storage ...
The Advanced Photon Source (APS) accelerator facility is made up of five major subsystems in addition to the linac: the positron accumulator ring (PAR), low energy transport (LET), booster synchrotron (SYNCH), high energy transport (HET), the storage ring (SR). Each subsystem has multiple magnet power supply ...
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.
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 Advanced Photon Source (APS) design incorporated a positron accumulator ring (PAR) as part of the injector chain. In order to increase reliability and accommodate other uses of the injector, APS will run with electrons, eliminating the need for the PAR, provided another method of eliminating rf bucket pollution ...
The Advanced Photon Source (APS) consists of four separate machines: linac, booster, positron accumulator ring (PAR) and storage ring (SR), plus three transfer lines interconnecting the machines. At least one thin, pulsed septum magnet is located at each splice joint. The stray field tolerances for two of these ...
The injector system of the Advanced Photon Source (APS) consists of a linac capable of producing 450-MeV positrons or > 650-MeV electrons, a positron accumulator ring (PAR), and a booster synchrotron designed to accelerate particles to 7 GeV. There are long periods of time when these machines are not required for filling the main ...
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...
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...
. Immunofluorescence microscopy revealed that the formation of FtsZ rings at the mid-cell, the earliest molecular event the formation of FtsZ rings at the mid-cell by 20 min. These results suggest that one major function of Par known cytological event in bacterial cytokinesis is the assembly of FtsZ in a mid-cell ...
E-print Network
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...
This report consists of three parts. The first part describes a numerical analysis method for the electromagnetic field analysis of a septum magnet. A novel improvement to the treatment of exciting currents in the time-domain is proposed. The second part discusses numerical predictions of the electromagnetic characteristics of the APS PAR septum. The time variations of stray ...
NASA Astrophysics Data System (ADS)
Plans to eliminate the positron accumulator ring (PAR) from the Advanced Photon Source (APS) injector complex have created the need for a device to limit the allowable beam charge injected into the APS injector synchrotrons. The beam shut-off current monitor (BESOCM) was chosen to provide this function. This new application of the ...
The following is a list of the main components used for production and acceleration of positrons for the 7-GeV Advanced Photon Source. 1. 200 MeV Electron Linac (2.8 GHz. Rep. Rate 60 Hz). 2. Tungsten Positron Production Target. 3. 450-MeV Positron Linac (2.8 GHz Rep. Rate 60 Hz). 4. Energy Spread Suppresser (Debuncher). 5. 450-MeV Positron Accumulator ...
A number of correction magnets are required for the advanced photon source (APS) machine to correct the beam. There are five kinds of correction magnets for the storage ring, two for the injector synchrotron, and two for the positron accumulator ring (PAR). Table I shoes a summary of the correction magnet power ...
The Procedure Execution Manager (PEM) combines a complete scripting environment for coding accelerator operation procedures with a manager application for executing and monitoring the procedures. PEM is based on Tcl/Tk, a supporting widget library, and the dp-tcl extension for distributed processing. The scripting environment provides support for distributed, parallel execution of procedures along ...
The Procedure Execution Manager (PEM) combines a complete scripting environment for coding accelerator operation procedures with a manager application for executing and monitoring of the procedures. PEM is based on Tcl/Tk, a supporting graphics library, and the dp-tcl extension for distributed processing. A careful design balance has been achieved which meets the flexibility requirements of ...
A 9.8-MHz RF accelerating cavity is developed for the first harmonic system in the APS PAR and an aluminum unit is tested. The design goal si 40 kV at the accelerating gap, Q-factor of {approximately} 7,000 for the accelerating mode, 1.2-m diameter, 1.6-m length with good mechanical strength and stability. The design employs no dielectric or ferrite loading for tuning. The ...
A 22.5 {mu}H, 22.5 m{Omega} transformer septum magnet must be pulsed at a 60 Hz rate to inject beam from a 450 MeV positron linac into a positron accumulator ring (PAR) and to extract beam from it. Of the 60 pulses per second the first 24 are used for injection and the 30th for extraction. The 25th through the 29th are not used. This ...
Two radio frequency (RF) cavities are needed in the Positron Accumulator Ring (PAR) of the Advanced Photon Source. One is for the first harmonic frequency at 9.8 MHz, and the other is for the twelfth harmonic frequency at 118 MHz. This note reports on the design of the 118 MHz RF cavity. Computer models are used to find the mode ...
Studies on the synergistic effects of mercury and temperature on the phytoplankton of Par Pond showed that there was a synergistic effect on production when the organisms were shocked with warm or cold water. When the phytoplankton were transferred from c...
The parA and parB genes of Pseudomonas aeruginosa are located approximately 8 kb anticlockwise from oriC. ParA is a cytosolic protein present at a level of around 600 molecules per cell in exponential phase, but the level drops about fivefold in stationary phase. Overproduction of full-length ParA or the N-terminal ...
PubMed Central
Matching the longitudinal beam emittance with separatrix acceptance in a ring accelerator has been considered. The aim of the matching is an intensity increase at the expense of the capture enhance and weakening of the Coulomb effect. Matching process par...
The Positron Accumulator Ring (PAR) consists of 8 dipole magnets connected in series. These magnets are energized via one 12-pulse dc power supply. The power supply consists of four phase controlled half-wave wye group converters. Each of the two half-wave converters are connected through an interphase transformer to obtain a full-wave ...
This paper describes the design and simulation of power circuits for the 4 Advanced Photon Source (APS) pulsed septum magnets which will be transformer type or transformer coupled to their switching circuits. Three are for synchrotron injection, extraction and Storage Ring injection, operating at a 2 Hz pulse rate; one is for the Positron Accumulator ...
HPL value. The HPCC random ring bandwidth was multiplied by the number of MPI ... Figure 1: Accumulated Random Ring Bandwidth versus HPL performance. ...
NASA Website
- tial for the viability of C. crescentus. Depletion of ParB inhibits the formation of stable FtsZ rings repression, resulting in the formation of an FtsZ ring and cell division. B. Under conditions of Par that these two alleles are detrimental for cell viability. In E. coli, a critical concentration of FtsZ
The apicobasal polarity of epithelial cells is critical for organ morphogenesis and function, and loss of polarity can promote tumorigenesis. Most epithelial cells form when precursor cells receive a polarization cue, develop distinct apical and basolateral domains and assemble junctions near their apical surface. The scaffolding protein PAR-3 regulates epithelial cell ...
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...
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 Hough transform provides a paradigm for multi-dimensional pattern detection and more general parameter extraction. It has good properties in noise, but as usually implemented requires an accumulator array whose size is exponential in the number of par...
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...
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 ...
To ensure inheritance by daughter cells, many low-copy number bacterial plasmids, including the R1 drug-resistance plasmid, encode their own DNA segregation systems. The par operon of plasmid R1 directs construction of a simple spindle structure that converts free energy of polymerization of an actin-like protein, ParM, into work required to move sister ...
To ensure inheritance by daughter cells, many low-copy number bacterial plasmids, including the R1 drug-resistance plasmid, encode their own DNA segregation systems. The par operon of plasmid R1 directs construction of a simple spindle structure that converts free energy of polymerization of an actin-like protein, ParM, into work required to move ...
One of the research and development thrusts at the Advanced Photon Source (APS) is to use an rf gun as a low-emittance electron source for injection into the 100- to 650-MeV linac subsystem and subsequent transport to an undulator test area. This configuration would combine the acceleration capability of the 200-MeV S-band electron linac and the in-line 450-MeV positron linac that normally provide ...
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...
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 with a mean diameter ...
CSR, a new Cooler-Storage-Ring project, is the post-acceleration system of the Heavy Ion Research Facility in Lanzhou (HIRFL). It consists of a main ring (CSRm) and an experimental ring (CSRe). From the HIRFL cyclotron system the heavy ions will be accumulated, cooled and accelerated in the CSRm, then extracted ...
Ubiquitin mediated protein degradation is crucial for regulation of cell signaling and protein quality control. Poly(ADP-ribose) (PAR) is a cell-signaling molecule that mediates changes in protein function through binding at PAR binding sites. Here we characterize the PAR binding protein, Iduna, and show that it is a ...
PubMed
The result of investigation and comparison of a series of transverse phase space painting schemes for the injection of SNS accumulator ring [1] is reported. In this computer simulation study, the focus is on the creation of closed orbit bumps that give desired distributions at the target. Space charge effects such as tune shift, emittance growth and beam ...
Equations are derived for the change of the second-order moments of the distribution functions of the ions in a ring. The storage of singly-charged ions of a neutral gas and the successive increase in the charge state of the ions are investigated. From the equations for the moments we obtain a system of equations which determines the slow variation of the rms dimensions of the ...
Two independent high beam current shut-off current monitoring systems (BESOCM) have been installed in the APS linac and the low energy transport line to provide personnel safety protection in the event of acceleration of excessive beam currents. Beam current is monitored by a fast current transformer (FCT) and fully redundant supervisory circuits connected to the Access Control Interlock System ...
Three fast Pulsed kicker/bumper magnets are required in the positron accumulator ring (PAR) for the purpose of beam injection and/or extraction at 450 MeV. According to the Conceptual Design Report (CDR), these three magnets have, identical specifications and are expected to produce identical magnetic fields. Therefore, they will have ...
The accumulator ring of the Spallation Neutron Source (SNS) [1] will accumulate a proton beam, injected from a LINAC, into a single bunch containing {approximately} 2.1 x 10{sup 14} protons at a maximum energy of 1.3 GeV. The single bunch with length {approximately}650 nsec and a gap of {approximately}290 nsec will circulate into the ...
The design of the antiproton source for the Fermilab Tevatron-I project (TeV-I) incorporates two separate rings. The Accumulator Ring uses a stochastic cooling/stacking system to accumulate a sufficient number of antiprotons for use in the Tevatron collider. The Debuncher Ring rotates buckets ...
