This paper describes the use of Siberian snake lattice to accelerate polarized beams in the superconducting super collider. (LSP)
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Energy Citations Database
Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized ...
DOE Information Bridge
The experimental equipment and setup used to accelerate a polarized deuteron beam at the Dubna synchrophasotron are briefly described. Basic characteristics of the cryogenic source of polarized deuterons POLARIS are presented. The results of measurements ...
The acceleration and storage of high energy polarized proton beams has made tremendous progress over the last forty years challenging along the way the technologies, precision and the understanding of the beam dynamics of accelerators. This progress is most evident in that one can now ...
NASA Astrophysics Data System (ADS)
A review is given of the theory of polarized beams in circular accelerators or storage rings, and the effects of depolarizing resonances, both steady state and passage through resonance, are discussed. The resonance width is evaluated, and the possibilities of accelerating polarized particles ...
>A possible method of obtaining beams or polarized nuclei by making use of the Lamb shift of the metastable level is described. (auth)
This paper first introduces the basic techniques for polarized proton beams: spin flip, resonance jumps, Siberian Snakes, etc., and then concludes with a report on the Workshop on Acceleration and Storage of Polarized Protons and Electrons in Very Large M...
As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species including polarized proton beams. The acceleration of polarized beams in both the ...
A set of equipment designed to obtain quasimonochromatic linearly polarized high-energy photons in a linear accelerator is described. A beam of quasimonochromatic linearly polarized photons was obtained by coherent bremsstrahlung of electrons in diamond m...
We studied depolarization mechanisms of polarized proton acceleration in high energy accelerators with snakes and found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We a...
Initial design for the Siberian Snake method of polarized beam acceleration in the Superconducting Super Collider is presented. A snake is an alternating sequence of horizontal and vertical bends designed to rotate the spin (of a particle beam) by 180 degrees about an axis that lies in the horizontal plane.
The Relativistic Heavy Ion Collider provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the ...
The present status and performance of the polarized ion source at RCNP (Research Center for Nuclear Physics) are summarized. Recent success of the acceleration of the beam polarized in the horizontal plane by the AVF cyclotron is reported.
Measurements at future electron accelerators will require unprecedented precision in the determination of electron beam polarization. Existing and novel electron beam polarization measurement schemes are examined, and ideas are being presented of how to to achieve sub-1% precision in ...
High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. However, the acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial ...
The acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate ...
The loss or initial polarization of a proton beam during acceleration in a synchrocyclotron is investigated. It is shown that, due to resonance effects, substantial depolarization occurs unless the field inhomogeneities are kept well below 0.01%. (auth)
This paper discusses the concept of Siberian snakes for polarized proton beams in high energy accelerators. 4 refs. (LSP)
This paper discusses the concept of Siberian snakes for polarized proton beams in high energy accelerators. 4 refs.
The report is dedicated to the problem of formation and maintenance of polarized proton and deuteron colliding beams in the collider of Nuclotron-based Ion Collider Facility (NICA). The NICA project is under development at JINR presently. The schemes of polarized proton and deuteron beams ...
The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high ...
This lecture note reviews physics of spin motion in a synchrotron, spin depolarization mechanisms of spin resonances, and methods of overcoming the spin resonances during acceleration. Techniques used in accelerating polarized ions in the low/medium energ...
The direct optical pumping of accelerated hydrogen atoms is shown to be really possible. The method allows to obtain a spin polarized H ion beam with the polarization degree = 1 and the real intensity which is close to the currently intensity of nonpolari...
The Cooler Synchrotrons and storage ring COSY at the Forschungszentrum Juelich accelerates protons to momenta between 600 MeV/c and 3300 MeV/c [2]. At present the beam is used at four internal and three external target places. In addition, a polarized beam can be produced and accelerated at ...
The question of whether polarized beams of 12 GeV or, preferably, higher energy can be produced at other existing or planned accelerators is explored. Sources of polarized H/sup -/ ions suitable for injection into accelerators appear to be feasible with intensities in the milliampere range (an ...
Monoenergetic electron beams have been generated in the self-injection scheme of laser acceleration. In applications of these laser accelerated electron beams, stable and controllable electron beams are necessary. A stable electron beam is generated in the self-injection ...
Modifications made on the ZGS to allow the acceleration of polarized deuterons and the operational experiences with the first production run with this beam are described.
This paper contains a short summary on accelerator designs. Kaon factory, boosters, polarized beams and power supplies are all briefly mentioned.
Siberian Snakes provide a practical means of obtaining polarized proton beams in large accelerators. The effect of snakes can be understood by studying the dynamics of spin precession in an accelerator with snakes and a single spin resonance. This leads t...
The operation of a high energy polarized proton beam is described. A 2 micron of polarized H(-) was accelerated through the Linac to 200 MeV with a polarization of about 65%. One micron A was injected into the alternating gradient synchrotron (AGS) and acceleration attempts ...
Topics of interest to the Saturne program, including the status of the polarized beam project, and the accumulator/booster ring, are discussed. The status of the colliding beam accelerator (CBA) is covered. (GHT)
The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam ...
The RHIC spin design goal assumes 2 x 10{sup 11} proton/bunch with 70% polarization. As the injector to RHIC, polarized protons have been accelerated at the AGS for years to increase the polarization transmission efficiency. Several novel techniques have been applied in the AGS to overcome the intrinsic and ...
While there has been a previous study of accelerating polarized beam at the SSC, we have looked at several alternative approaches, including polarizing stored beam, using polarized gas jets, and using secondary polarized beams. We ...
This report describes activities in the polarization field at Budker Institute of Nuclear Physics. It concerns the radiative beam polarization, flipper and Siberian snake techniques and accurate beam energy measurements for electron and proton machines. Three new developments in the field of radiative ...
International Linear Collider, ILC, is a future energy-frontier electron-positron machine currently under design by a world-wide collaboration. Utilizing the advantage of linear accelerator, a polarized electron beam plays an essential role for various key physics studies. In addition to the default operation-mode, options are proposed ...
The measurement of the polarization of the accelerated proton beam at the Argonne ZGS has become a straightforward procedure. However, measurement of the polarization of a proton beam accelerated in a very high energy accelerator or stored in a very ...
Recent advances in electron and positron sources have resulted in new capabilities driven in most cases by the increasing demands of advanced accelerating systems. Electron sources for brighter beams and for high average-current beams are described. The status and remaining challenges for polarized electron ...
The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole (RFQ) for acceleration between the polarized H/sup -/ source and the Alvarez Linac. The RFQ accelerator is now in operation with low beam currents. The results of low and ...
Polarized proton beams were accelerated successfully at RHIC up to 100 Gev with the use of Siberian Snakes. Although the snakes were designed to preserve polarization, the successful acceleration and storage of polarized beams was dependent also on ...
Since the last High Energy Physics Symposium, there has been considerable progress in the field of polarized electron accelerators. Projects well into construction include the SLC, HERA, and LEP. The status of polarized beams for these projects is discussed in this session. Semiclassical and quantum mechanical ...
Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high ...
In order to study the spin structure of the neutron at high energy, a beam rich in polarized neutrons needs to be developed. The neutron has no charge and cannot be accelerated, so either deuterons or helions must be considered. When it comes to spin manipulation and stability of the polarization in a circular ...
This lecture note reviews physics of spin motion in a synchrotron, spin depolarization mechanisms of spin resonances, and methods of overcoming the spin resonances during acceleration. Techniques used in accelerating polarized ions in the low/medium energy synchrotrons, such as the ZGS, the AGS, SATURNE, and the KEK PS and PS Booster ...
Theoretical investigations show that linearly and radially polarized multiterawatt and petawatt laser beams, focused to subwavelength waist radii, can directly accelerate protons and carbon nuclei, over micron-size distances, to the energies required for hadron cancer therapy. Ions accelerated by radially ...
PubMed
As part of the RHIC project, the RHIC machine will also be able to accelerate polarized proton beam bunches. The bunches will be extracted from the AGS machine, with kinetic energy T = 25 GeV, and transferred into RHIC via the AtR transfer line. When the ...
This article provides a pedagogical review of spin rotators and Siberian Snakes used in the manipulation and attainment of stored high energy spin polarized beams (SHESPB).
E-print Network
During this year polarized deuteron and heavy-ion beams have been used increasingly. The acceleration of horizontally polarized deuteron beam was successfully performed this year and it will be available for experimental studies. The magnetic spectrograph...
Polarized electron beams are now in routine use in particle accelerators for nuclear and high energy physics experiments. These beams are presently produced by dc-biased photoelectron sources combined with rf chopping and bunching systems with inherently ...
Polarized electrons are a valuable commodity for nuclear physics research and every effort must be made to preserve them during transport. Measurements of the beam emitted from the polarized source at the Thomas Jefferson National Accelerator Facility (Je...
It is shown that a beam of polarized nucleons with momentum slightly exceeding the average momentum of a nucleon in a nuclear accelerator may be obtained by means of inelastic scattering of high energy nuclei on a hydrogen target. The idea of the proposed...
This paper first introduces the basic techniques for polarized proton beams: spin flip, resonance jumps, Siberian Snakes, etc., and then concludes with a report on the Workshop on Acceleration and Storage of Polarized Protons and Electrons in Very Large Machines. 25 references, 5 figures, 2 tables.
Polarimeters are necessary tools for measuring the beam polarization during the acceleration process as well as a yardstick for performing spin physics experiments. In what follows, I will describe the principles of measuring the proton beam polarization and the techniques that are employed at ...
Polarimeters are necessary tools for measuring and maintaining the beam polarization during the acceleration process. They serve, as well, as a yardstick for performing spin physics experiments. In this paper, I will describe the principles of measuring proton beam polarization and the ...
A brief introduction to electron scattering with polarized beams as a precise tool for studying electromagnetic structure of nucleons and nuclei will be presented. The status of a parity violating experiment SAMPLE at Bates using a polarized beam to probe the strange quark content of proton will be reported. The ...
Experiments with polarized beams at RHIC will provide fundamental tests of QCD, and the electro-weak interaction reveal the spin structure of the proton. Polarization asymmetries and parity violation are the strong signatures for identification of the fundamental processes, which are otherwise inaccessible. Such experiments require the ...
The AGS Polarized Beam Project was started in 1980. The first beam was accelerated in March 1984, followed by commissioning studies and a high energy physics run at 16.5 GeV at an average 30% polarization. The Linac portion of the project included a new polarized H/sup -/ ...
The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron (ZGS) with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven Alternating Gradient Synchrotron (AGS). A description of the project was ...
An accelerator-based experiment was performed using the CEBAF accelerator of the Thomas Jefferson National Accelerator Facility to investigate a predicted sensitivity of the beam polarization to the vertical betatron orbit in the recirculation arcs. This is the first measurement of any such ...
The spin physics program of the Laboratory of High Energies, JINR, was started in early 1980s when polarized deuterons were accelerated at the Dubna 10 GeV machine (Synchrophasotron). The source of polarized deuteron POLARIS provides deuterons in both vec...
We discuss the basics of polarized positron production by low energy polarized electrons. Efficiency of conversion approx0.1-1% might be interesting for the Continuous Electron Beam Accelerator Facility (CEBAF) and the International Linear Collider (ILC).
Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power ...
To achieve high energy polarized proton collisions polarized beams first have to be accelerated which requires an understanding of the evolution of spin during acceleration and the tools to control it. The acceleration of polarized ...
The proposed experiment E-166 at SLAC is designed to demonstrate the possibility of producing longitudinally polarized positrons from circularly polarized photons to be used in future Linear Collider. The experimental set-up utilizes a low emittance 50 GeV electron beam passing through a helical undulator in the Final Focus Test ...
A proposed NLC polarized positron source utilizes a 150 GeV electron beam passing through a helical undulator. The resulting flux of polarized photons is converted in a thin positron production target. Spin polarized positrons are captured using a high field flux concentrator followed by an ...
After the successful operation of a high energy polarized proton beam at the Argonne Laboratory Zero Gradient Synchrotron (ZGS) was terminated, plans were made to commission such a beam at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). On February 23, 1984, 2 ..mu..A of polarized H/sup ...
At the Relativistic Heavy Ion Collider (RHIC), scientists are investigating not only the primordial properties of the universe but also another fundamental question of particle physics: the property of "spin." A particle's spin comes from its intrinsic angular momentum and is a basic property such as charge or mass. Many existing and future high energy and nuclear physics experiments ...
We studied depolarization mechanisms of polarized proton acceleration in high energy accelerators with snakes and found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the ...
SLAC has successfully accelerated high energy polarized electrons for the Stanford Linear Collider and fixed polarized nuclear target experiments. The polarized electron beams at SLAC use a gallium arsenide (GaAlAs for E-142) photon emission source to provide the beam of ...
Electron acceleration in vacuum driven by a tightly focused radially polarized Gaussian beam has been studied in detail. Weniger transformation method is used to eliminate the divergence of the radially polarized electromagnetic field derived from the Lax series approach. And, electron dynamics in an intense ...
Marchenko, V. and M. K. Hudson, Beam-driven ion acoustic solitary waves in the auroral acceleration region, J. Geophys. Res., 100, 19791, 1995. Matsumoto ...
NASA Website
The acceleration of polarized protons in multi-GeV machines is a great challenge for accelerator physicists. An essential part of such development is the primary source of polarized H- ions. Recent studies at TRIUMF and INR, Moscow, showed that pulsed Optically Pumped Polarized Ion Source ...
High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full ...
Coordinated bending and acceleration of an intense space-charge-dominated ion beam has been achieved for the first time. This required the development of a variable waveform, precision, bi-polar high voltage pulser and a precision, high repetition rate induction core modulator. Waveforms applied to the induction cores ...
In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton ...
In recent years, high energy physicists have become increasingly interested in the possible spin effects at high energies. To study those spin effects, it is desirable to have beams with high energy, high intensity and high polarization. In this talk, we briefly review the present status and the prospects for the near future of high energy ...
A code, SPINK, to track polarized particles in a circular accelerator, in particular RHIC [1], is been used to: find conditions for safely crossing depolarizing resonances, using Siberian Snakes; find the best conditions to match the spin of the injected beam to the ring lattice; study the operation of Spin Rotators and study the ...
The HESR at FAIR is being designed to accelerate and store unpolarized antiprotons in the momentum range from 1.5 to 15 Ge V/c. Different scenarios are proposed to accelerate polarized proton and antiproton beams and finally store and collide them. In this paper required modifications and extensions of the ...
In a high energy accelerator the polarization distribution of the beam can vary substantially across the beam. This decreases the amount of polarization provided to experiments. A method has been developed to calculate the beam polarization distribution ...
The Stanford Linear Accelerator has been running with polarized electrons both in the collider (SLC) mode and in the fixed target mode. The accelerators polarized electron source is based on a thin, strained GaAs photocathode, which is held at a negative high voltage and illuminated by a Titanium Sapphire laser. ...
The acceleration of polarized electron beams in the blowout regime of plasma-based acceleration is explored. An analytical model for the spin precession of single beam electrons, and depolarization rates of zero emittance electron beams, is derived. The role of finite ...
Longitudinally polarized electron beams for high energy collisions provide a sensitive way to explore the electroweak process as well as an effective means to measure spin dependent properties of particles. Once created, such beams are readily accelerated by linacs without loss of polarization, ...
There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the ...
Important polarization data were reviewed at the Symposium, but there is grave danger that some accelerators will be turned off before we are finished with them. The ZGS is an important case in point. Both polarized beams and polarized targets are needed to unravel fully the quantum-mechanical ...
The feasibility of performing electron scattering experiments with polarized targets in electron storage rings is discussed. Three examples of the physics which would be accessible with this novel method are given. It is noted that this new method is compatible with recent proposals for linac-stretcher-ring accelerator designs. A new method for producing a ...
The feasibility of performing electron scattering experiments with polarized targets in electron storage rings is discussed. Three examples of the physics which would be accessible with this novel method are given. It is noted that this new method is compatible with recent proposals for linac-stretcher-ring accelerator designs. A new method of producing a ...
Polarization transfer collisions between protons, atomic hydrogen, or deuterium and optically pumped alkali-metal vapour are implemented in the high current optically pumped polarized ion source (OPPIS) and the laser driven source (LDS) of nuclear polarized atoms for target applications. The OPPIS technique overcomes the limitations on ...
Atomic-beam techniques are used to develop a polarized proton source for a 50-Mev proton linear accelerator. An accelerated beam with an intensity of 7.5 x 10/sup 7/ protons per second and a polarization of 0.32 is obtained. The construction of the source, its ...
Acceleration of polarized proton beams and experiments with them at RHIC require fast and reliable measurements of the polarization. The polarimeter presented here uses very high figure of merit of the elastic pC scattering at very low momenta transfer si...
Modifications made on the ZGS to allow the acceleration of polarized deuterons and the operational experiences with the first production run with this beam are described. (ERA citation 04:041499)
A program is proposed for upgrading the usefulness and attractiveness of ZGS polarized facilities to the user community. It is hoped that the advance approval or completion of parts (or all) of such a program will lead to an accelerated interest in propos...
This summary is an overview on Polarized Beams and Targets based on presentations at the 5th International Symposium on High-Energy Spin Physics and the two Workshops on Targets and on Accelerators. The highlights of the Symposium were, in my opinion, the results on irradiated NH3 polarized target material, and the ...
Several schemes have been proposed for adding a positron beam option at the Continuous Electron Beam Facility (CEBAF) at Jefferson Laboratory (JLAB). They involve using a primary beam of electrons or gamma rays striking a target to produce a positron beam. At JLAB electron beams are produced ...
The longitudinal component of a focused beam is split into two parts along the optical axis to obtain a longitudinally polarized long focal depth using amplitude filtering based on Euler transformation and a radially polarized Bessel-Gaussian beam. Numerical results indicate that long focal depth and FWHM can be ...
The measurement of circular polarization at energies higher than 5 Mev using the forward Compton scattering of gamma rays is discussed. Attempts were made to measure the circular polarization of bremsstrahlung radiation produced by electrons accelerated in a Betatron to an energy of 22 Mev. The x rays were collimated to a ...
This is a brief report on the first measurement of the continuous momentum dependence of the analyzing power in proton-proton elastic scattering during polarized beam acceleration from 1.1 to 4.4 GeV/c. The measurement was done in the KEK-PS tunnel using ...
The new AGS Booster is designed to accelerate low intensity polarized protons and heavy ions, and high intensity protons. The wide range of beam parameters and the vacuum, thermal and radiation environment, presented challenges in the instrumentation desi...
Use of buncher in the external injection system of the isochronous cyclotron is intended to enlarge the luminosity, which is especially important during acceleration of very low-current beams of the polarized and multicharged ions. Problems of two-gap par...
A theoretical model was developed to explain observations of collective ion acceleration in linear systems. A linearized calculation for the pinch mechanism considered is carried out using the two mass approximation for the relativistic electron beam. This model differs from the picture previously constructed in that the polarization ...
A method for the high-precision measurement of the hadron polarized beam energy in circular accelerators by measuring the spin precession frequencies is offered. The problem of the particles energy measurement with accuracy better, than the beam energy spread, first of all, is connected with influence of ...
The Joint Institute for Nuclear Research (JINR) at Dubna has built a new 12 GeV/c accelerator with superconducting magnets (the Nuclotron) which can provide 3-12 GeV/c polarized deuteron beams, with high intensity and good polarization. Using a break-up o...
The Relativistic Heavy Ion Collider (RHIC) as the first high energy polarized proton collider was designed t o provide polarized proton collisions a t a maximum beam energy of 250 GeV. I t has been providing collisions a t a beam energy of 100 Gel' since 2001. Equipped with two full Siberian snakes in each ...
Recent experiments at the Indiana University Cyclotron Facility (IUCF) have demonstrated that Siberian Snakes'' can be used to preserve the polarization of an accelerated polarized beam in a circular accelerator. Retrofitting full snakes into ...
Siberian Snakes provide a practical means of obtaining polarized proton beams in large accelerators. The effect of snakes can be understood by studying the dynamics of spin precession in an accelerator with snakes and a single spin resonance. This leads to a new class of energy independent spin depolarizing ...
The AGS Booster was designed to accelerate beams from 2{times}10{sup 10} polarized protons to 1.5{times}10{sup 13} protons and heavy ions through Au{sup +33}. The range of beam parameters and the high vacuum, and radiation environment presented challenges for the beam instrumentation. Some ...
There is a brief review of the history of polarized proton beams and the unexpected and still unexplained large transverse spin effects found in high energy proton spin experiments at the ZGS, AGS and Fermilab. Next there is a detailed discussion of Siberian snakes and some of their tests at the IUCF Cooler Ring. Finally there is a report on the use of ...
We report on the development and testing of a polarimeter for the high energy polarized proton and antiproton beam at Fermi National Accelerator Laboratory (FNAL). The polarimeter was designed to make use of a small but well-known analyzing power in the region of Coulomb-nuclear interference (CNI) in order to obtain an absolute ...
Polarized Electron Source workshops have been held at varying intervals, beginning in 1983 when Charles Sinclair convened the first at SLAC. Since that time, three workshops were held in conjunction with the International Spin Symposia and two at other occasions. The increasing importance of polarized electron beams at ...
A series of experiments were conducted with the polarized proton beam of the Zero Gradient Synchrotron (ZGS) at Argonne National Laboratory in order to: (1) study the feasibility of adiabatically crossing intrinsic depolarizing resonances as an alternative to the fast tune-shift crossing presently used; (2) determine the amount of depolarization due to ...
The RCNP polarized ion source employs cold ({approx} 30 K) atomic beam technology and an electron cyclotron resonance ionizer. The source has been intensively operational since fall in 1994 to provide polarized protons to experimental researches at 200-400 MeV. Developments have been continued to increase the long term stability of the ...
The RCNP polarized ion source employs cold (~ 30 K) atomic beam technology and an electron cyclotron resonance ionizer. The source has been intensively operational since fall in 1994 to provide polarized protons to experimental researches at 200-400 MeV. Developments have been continued to increase the long term stability of the source ...
Presently, only two methods of producing beams of polarized electrons for injection into linear accelerators are in use. Each of these methods uses optical pumping by circularly polarized light to produce electron polarization. In one case, electron polarization is ...
Due to its spin structure polarized 3He serves as a suitable substitute for a polarized neutron target. The 3He-gas is polarized at pressures of about 1 mbar via the metastability exchange optical pumping method. After compression to 5 bar and filling to target cells the gas is used as a target for scattering experiments at the ...
A device is described for correcting the exit trajectory of a beam of particles accelerated by an isochronous cyclotron or a synchrocyclotron. It is provided with two conjugated electromagnets having pole pieces in the form of rounded sectors at their ends. These electromagnets are both excited with coils, and the currents traversing these coils ...
A source of polarized electrons has been installed at the superconducting Darmstadt electron linear accelerator S-DALINAC. Experiments with polarized electrons from 100 keV to about 80 MeV are expected to commence in early 2011. This contribution summarizes the status of the polarized source as well as ongoing ...
Using multidimensional particle-in-cell simulations we study ion acceleration from a foil irradiated by a circularly polarized laser pulse at 10;{22} W/cm;{2} intensity. When the foil is shaped initially in the transverse direction to match the laser intensity profile, three different regions (acceleration, transparency, and ...
Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with {approximately}99% uptime during continuous operation, this source is a key factor in ...
The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole Accelerator for acceleration between the polarized source and the Alvarez Linac. Although operation has commenced with a few ..mu.. amperes of H/sup -/ beam, it is ...
A tagged photon beam coherently emitted in Si monocrystal by electron beam with energy E/sub e/ = 31 GeV and intensity 4x10 exp 4 particle/pulse at pulse duration up to 1.7 s has been obtained at the Serpukhov proton accelerator. The intensity of photons ...
Polarized proton beams have been accelerated, stored and collided at 100GeV per beam in the Relativistic Heavy Ion Collider (RHIC) with longitudinal polarization. The essential equipment includes four Siberian snakes, eight spin rotators and fast relative polarimeters in each of the two RHIC ...
The authors have irradiated and studied dynamic nuclear polarization in ammonia, deuterated ammonia, butanol borane ammonia, methylamine, ethane and lithium borohydride in order to test these substances for potential use as polarized target materials. These studies were conducted using a polarized target system operating at a ...
The Relativistic Heavy Ion Collider at Brookhaven National Laboratory provides polarized proton beams for the investigation of the nucleon spin structure. For polarimetry, carbon-proton and proton-proton scattering is used in the Coulomb nuclear interference region at small momentum transfer (-t). Fast polarization measurements of each ...
This Letter presents an investigation of the excitation of an upper hybrid wave (UHW) by cross focusing of two intense laser beams in a collisionless hot magnetoplasma, when relativistic and ponderomotive nonlinearities are operative. The electric vectors of the two beams are polarized along uniform static magnetic field and the ...
As part of the RHIC project, the RHIC machine will also be able to accelerate polarized proton beam bunches. The bunches will be extracted from the AGS machine, with kinetic energy T = 25 GeV, and transferred into RHIC via the AtR transfer line. When the RHIC machine accelerates polarized ...
We propose a direct electron acceleration scheme that uses a two-color pulsed radially polarized laser beam. The two-color scheme achieves electron acceleration exceeding 90% of the theoretical energy gain limit, over twice of what is possible with a one-color pulsed beam of equal total energy ...
The plasma wakefield accelerator (PWFA) is an accelerator concept based on utilizing a large amplitude plasma wave to accelerate relativistic electrons to ultra-high energy. The plasma wave represents the wave produced by a relativistic beam as it passes through a cold plasma. As the beam ...
We recently studied the first acceleration of a spin-polarized beam through a depolarizing resonance using a partial Siberian snake. We accelerated polarized protons from 95 to 140 MeV while ramping a 10% partial Siberian snake along with the acceleration cycle. The 10% ...
High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for ...
A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by ...
In the laser-plasma interaction, the laser beam is treated as a linearly polarized plane wave. However there are many categories of electromagnetic wave (EMW) which depend on the spatial variations of polarization and phase. Our interest is how the interaction of charged particles with EMW and the resultant macroscopic behaviors of the ...
The Brookhaven Relativistic Heavy Ion Collider (RHIC) provides the unique opportunity to collide polarized proton beams at a center-of-mass energy of up to 500 GeV and luminosities of up to 2 x 10{sup 32} cm{sup {minus}2} s{sup {minus}1}. Such high luminosity and high energy polarized proton collisions will open up the possibility of ...
The physics of laser-plasma interactions has undergone dramatic improvements in recent years. By directing a multi-TW, ultrashort laser pulse onto a thin foil or a gas jet, it is nowadays possible to produce multi-MeV proton, ion and electron beams. Although much progress has been made in characterizing and improving the quality of such laser-generated ...
Polarized protons were injected and accelerated in the clockwise ring of RHIC to commission the first full helical Siberian snake ever used in an accelerator. With the snake turned on, the stable spin direction is in the horizontal plane. Vertically polarized protons were injected with the snake off. The snake was ...
On February 23, 1984, 2 ..mu..A of polarized H/sup -/ was accelerated through the linac to 200 MeV with a polarization of 65%. 1 ..mu..A was injected into the AGS and acceleration attempts began. Several short tests were made until June 1984 when full time effort began. By June 26, the AGS ...
The theory of depolarization in circular accelerators is presented. The spin equation is first expressed in terms of the particle orbit and then converted to the equivalent spinor equation. The spinor equation is then solved for three different situations: (1) a beam on a flat top near a resonance, (2) uniform acceleration through an ...
The project assumes the design and construction of a universal high-intensity source of polarized deuterons (protons) using a charge-exchange plasma ionizer. The output ?D+ (?H+) current of the source is expected to be at a level of 10 mA. The polarization will be up to 90% of the maximal vector (�1) for ?D+ (?H+) and tensor (+1,?2) for ?D+ ...
In the acceleration of polarized protons in RHIC many spin depolarizing resonances are encountered. Helical Siberian snakes will be used to overcome depolarizing effects. The behavior of polarization can be studied by numerical tracking in a model accelerator. That allows one to check the strength of the ...
Planning for the conversion of the AGS Linac to H/sup -/ acceleration was begun in 1979; installation was completed in 1983. Discussion of this work and of the operational experience will be presented. The AGS Polarized Beam Project was begun in 1980. The design of the new H/sup -/ polarized source, the low Energy ...
Measurements of the total spin-dependent cross section difference for a polarized-neutron beam scattering from a polarized-proton target, ?sigmaT, have been made for incident neutron energies between 10 and 20 MeV. Both beam and target spin axes were oriented transverse to the momentum direction. ?sigmaT is ...
... Descriptors : *Linear accelerators, *Ion accelerators, *Particle accelerator components, *Electron accelerators, *Proton accelerators, Electron beams ...
DTIC Science & Technology
Polarized protons can be produced by the parity-violating decay of either lambda or sigma hyperons. A secondary bema of polarized protons can then be produced without the difficult procedure of accelerating polarized protons. The preservation of the polarization while the protons are being ...
We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse ...
Idaho State University and the Idaho Accelerator Center are developing a polarized photon facility in the 10 MeV region using the off axis bremsstrahlung technique. Initial tests have been performed with the aim of using the high analyzing power of the photodisintegration of the deuteron to measure the beam ...
The Indiana University Cyclotron Facility (IUCF) is in the process of commissioning a new synchrotron that is designed to rapidly accumulate, accelerate and inject beam into the IUCF Cooler ring. The Cooler Injector Synchrotron (CIS) is filled by the strip injection of 7 MeV negative ions that were pre-accelerated by an RFQ-DTL linear ...
We have studied the feasibility of polarized proton acceleration in rhe J-PARC accelerator facility, consisting of a 400 MeV linac, a 3 GeV rapid cycling synchrotron (RCS) and a 50 GeV synchrotron (MR). We show how the polarization of the beam can be preserved using an rf dipole in the RCS and ...
LAMPF now operates reliably producing 500 mu A of H exp + beam and a few mu A of H exp - beam or 10 nA polarized H exp - beam. Beam loss in the accelerator is quite acceptable at these currents. This level of performance has been achieved through solution...
We have measured the polarization of light emitted in optical transitions in P V, O VII and O VIII, produced by beam foil excitation, using a 400 keV phosphorus beam from a heavy ion accelerator and a 36 MeV oxygen beam from a Tandem Van de Graaff generator.
The RHIC spin program requires 2 x 10{sup 11} proton/bunch with 70% polarization. As the injector to RHIC, AGS is the bottleneck for preserving polarization: there is no space for a full snake to overcome numerous depolarizing resonances. An ac dipole and a partial snake have been used to preserve beam polarization ...
We have made the first observation of a charged particle beam by means of its electro-optical effect on the propagation of laser light in a birefringent crystal at the Brookhaven National Laboratory Accelerator Test Facility. Polarized infrared light was coupled to a LiNbO{sub 3} crystal through a polarization ...
This talk will review the state of the art of high polarization GaAs photoguns used worldwide. Subject matter will include drive laser technology, photocathode material, gun design, vacuum requirements and photocathode lifetime as a function of beam current. Recent results have demonstrated high current, 85% polarized ...
A new polarized ion source has been constructed at RCNP. It employs cold ({similar_to}35 K) atomic beam technology and an electron cyclotron resonance ionizer. The source was assembled and installed on the shielding roof of the AVF cyclotron in Feb. 1994. Performance tests of the atomic beam section was started in March. Protons were ...
A polarized H{sup -} and D{sup -} ion source is newly constructed. Atomic H or D beams from a dissociator with a cooled nozzle enter a system of permanent sextupole magnets and a radio-frequency transition (RFT) where they are focused and polarized. They enter a downstream electron-cyclotron-resonance (ECR) heated plasma ionizer from ...
