Download or read book Energy Scaling of Spin Tune Due to RHIC Snakes written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Dynamics And Snakes In Synchrotrons written by Shyh-yuan Lee and published by World Scientific Publishing Company. This book was released on 1997-06-19 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: The success in the standard model and to the continuing research for a better understanding of the quantum chromodynamics has resulted in a great interest in spin physics among high energy and nuclear physics. Advances in accelerator technology have also spurred renewed interest in accelerating and storing highly aligned spin particles in synchrotrons and storage rings. The development of polarized ion sources and polarized electron sources have seen remarkable progress. With these advances in ion sources, there is a growing interest in the acceleration and maintenence of this polarization.This book is intended to be used as a graduate/senior undergraduate textbook in accelerator physics and sciences. The subject deals with acceleration and storage of polarized beams in high energy synchrotrons. The material covers the equation of motion for polarized beams in synchrotrons, spin depolarizing resonances, practical methods used in overcoming spin resonances, effects of spin rotators — called Siberian snakes — on the polarization vector, snake resonances, Sokolov-Ternov radiative polarization of electrons, and design principles of spin rotators. Experimental results of many polarized beam experiments are compared with theoretical analyses.Each chapter is also followed by exercises, which are intended to reinforce the concepts discussed, to derive useful formulae for applications, and to provide an introduction to some published literatures related to the polarized beam dynamics.
Download or read book Impact on Spin Tune From Horizontal Orbital Angle Between Snakes and Orbital Angle Between Spin Rotators written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To keep the spin tune in the spin depolarizing resonance free region is required for accelerating polarized protons to high energy. In RHIC, two snakes are located at the opposite side of each accelerator. They are configured to yield a spin tune of 1/2. Two pairs of spin rotators are located at either side of two detectors in each ring in RHIC to provide longitudinal polarization for the experiments. Since the spin rotation from vertical to longitudinal is localized between the two rotators, the spin rotators do not change the spin tune. However, due to the imperfection of the orbits around the snakes and rotators, the spin tune can be shifted. This note presents the impact of the horizontal orbital angle between the two snakes on the spin tune, as well as the effect of the vertical orbital angle between two rotators at either side of the collision point on the spin tune.
Download or read book Spin Tune Dependence on Closed Orbit in RHIC written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polarized proton beams are accelerated in RHIC to 250 GeV energy with the help of Siberian Snakes. The pair of Siberian Snakes in each RHIC ring holds the design spin tune at 1/2 to avoid polarization loss during acceleration. However, in the presence of closed orbit errors, the actual spin tune can be shifted away from the exact 1/2 value. It leads to a corresponding shift of locations of higher-order ('snake') resonances and limits the available betatron tune space. The largest closed orbit effect on the spin tune comes from the horizontal orbit angle between the two snakes. During RHIC Run in 2009 dedicated measurements with polarized proton beams were taken to verify the dependence of the spin tune on the local orbits at the Snakes. The experimental results are presented along with the comparison with analytical predictions.
Download or read book OBSERVATIONS OF SNAKE RESONANCE IN RHIC written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Siberian snakes now become essential in the polarized proton acceleration. With proper configuration of Siberian snakes, the spin precession tune of the beam becomes 1/2 which avoids all the spin depolarizing resonance. However, the enhancement of the perturbations on the spin motion can still occur when the spin precession tune is near some low order fractional numbers, called snake resonances, and. the beam can be depolarized when passing through the resonance. The snake resonances have been confirmed in the spin tracking calculations, and observed in RHIC with polarized proton beam. Equipped with two full Siberian snakes in each ring, RHIC provides us a perfect facility for snake resonance studies. This paper presents latest experimental results. New insights are also discussed.
Download or read book Snake Calibration in RHIC written by and published by . This book was released on 2002 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: A proper understanding of the response of the spin orientation due to the currents in the four helices which make up each snake is necessary to control spin tune, avoid snake resonances and facilitate the operation of the RHIC spin flipper. The effect of the helical dipole snakes in RHIC is to rotate the spin orientation an angle [mu] about an axis at an angle [phi] in the horizontal plane. With two snakes the combined effect gives rise to a spin precession frequency which is determined by the [mu] and [phi] angles at each snake. Depolarization or spin flipping can occur when this spin tune is near an external driving frequency. We employed the RHIC spin flipper in this way to determine the spin tune and thus verify spin tune predictions based upon previous field measurements of the snake. We also considered the response of snake resonances locations to spin tune as another way of verifying spin tune predictions.
Download or read book Reducing Spin Tune Shift by Matching DX Prime at Snakes in RHIC written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Tracking in RHIC with One Full Snake and One Partial Snake Effect of Orbit Harmonics written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The New Conceptual Design of Snakes and Spin Rotators in RHIC written by and published by . This book was released on 1990 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss the generalized snake configurations, which offers either the advantages of shorter total snake length and smaller horizontal orbit displacement in the compact configuration or the dual functions of a snake and a 90° spin rotation for the helicity state. The generalized snake is then applied to the polarized proton collision in RHIC. The possible schemes of obtaining high luminosity are discussed.
Download or read book Studies of Polarized Beam Acceleration and Siberian Snakes written by and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune of imperfection resonances, each snake resonance splits into two. Thus the available betatron tune space becomes smaller. Some constraints on polarized beam colliders were also examined.
Download or read book Numerical Studies of Siberian Snakes and Spin Rotators for RHIC written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the program of polarized protons in RHIC, two Siberian snakes and four spin rotators per ring will be used. The Snakes will produce a complete spin flip. Spin Rotators, in pairs, will rotate the spin from the vertical direction to the horizontal plane at a given insertion, and back to the vertical after the insertion. Snakes, 180° apart and with their axis of spin precession at 90° to each other, are an effective means to avoid depolarization of the proton beam in traversing resonances. Classical snakes and rotators are made with magnetic solenoids or with a sequence of magnetic dipoles with fields alternately directed in the radial and vertical direction. Another possibility is to use helical magnets, essentially twisted dipoles, in which the field, transverse the axis of the magnet, continuously rotates as the particles proceed along it. After some comparative studies, the authors decided to adopt for RHIC an elegant solution with four helical magnets both for the snakes and the rotators proposed by Shatunov and Ptitsin. In order to simplify the construction of the magnets and to minimize cost, four identical super conducting helical modules will be used for each device. Snakes will be built with four right-handed helices. Spin rotators with two right-handed and two left-handed helices. The maximum field will be limited to 4 Tesla. While small bore helical undulators have been built for free electron lasers, large super conducting helical magnets have not been built yet. In spite of this difficulty, this choice is dictated by some distinctive advantages of helical over more conventional transverse snakes/rotators: (i) the devices are modular, they can be built with arrangements of identical modules, (ii) the maximum orbit excursion in the magnet is smaller, (iii) orbit excursion is independent from the separation between adjacent magnets, (iv) they allow an easier control of the spin rotation and the orientation of the spin precession axis.
Download or read book Numerical Optimization of Siberian Snakes and Spin Rotators for RHIC written by and published by . This book was released on 1995 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure of the four Siberian Snakes and eight Spin Rotators being designed for RHIC is discussed. These devices consist each of four helical dipoles. Results of orbit and spin tracking through the magnets are presented. 14 refs., 8 figs., 4 tabs.
Download or read book Effect of Various Errors on the Spin Tune and Stable Spin Axis written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Even though RHIC has two full Siberian snakes in each ring, there are various perturbations to the ideal case including orbit errors at the snakes, experiment solenoids, injection bumps, and interlaced horizontal-vertical bumps at the hydrogen jet polarimeter. These errors can cause depolarization by shifting the spin tune and tilting the stable spin direction away from vertical. Tilting of the stable spin axis can enhance horizontal depolarizing resonances. This paper presents preliminary results for some of these error scenarios, as well as their impact on the stable spin directions at STAR and PHENIX.
Download or read book Spin Physics written by Donald G. Crabb and published by American Inst. of Physics. This book was released on 2009-08-25 with total page 1236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topics covered in the conference ranged from the physics that can be done with polarized beams of particles (protons, electrons, gamma-rays, etc.) to the techniques and instrumentation necessary to achieve this. Topics included: nucleon structure measurements (from where does the spin of the proton and neutron come), the acceleration, storage and polarization of particle beams and the polarized targets and sources necessary for mounting the experiments.
Download or read book Snake Resonances written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 resonances, called snake resonances. In designing a large accelerator with snakes to preserve the spin polarization, there is an added constraint on the choice of the vertical betatron tune due to the snake resonances. 11 refs., 4 figs.
Download or read book PSTP 2007 written by Ahovi Kponou and published by American Institute of Physics. This book was released on 2008-02-25 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Upton, New York, 10-14 September 2007
Download or read book Internal Spin Structure Of The Nucleon Proceedings Of The Symposium written by Vernon W Hughes and published by World Scientific. This book was released on 1995-07-14 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic of the internal spin structure of the nucleon has become an unusually active subfield of particle and nuclear physics, together with the relevant technologies. This volume presents up-to-date coverage.All the talks given at the symposium can be found in the volume. In addition, selected articles are reprinted, including two early papers which record initial thinking about the topic, all experimental papers giving data on nucleon spin structure functions determined from polarized lepton-nucleon scattering, and two valuable previously unpublished papers.
