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UCRL Orbit Program

Description: The following report records the use of the double-precision THEMIS code to integrate the motion of Mars and Venus in order to obtain a complete set of rectangular equatorial coordinates over the interval 1600-2000 A.D.
Date: July 15, 1958
Creator: Levee, Richard & Brady, Joseph L.
Partner: UNT Libraries Government Documents Department

Operations with the digital orbit feedback system in the NSLS x-ray ring

Description: The digital filtering and eigenvector decomposition-based orbit correction is performed by two dedicated HP 742/743 rt micros which communicate with Motorola CPU based orbit-measuring and orbit-correction systems. The correction algorithm in the DFbk was orthogonalized with respect of the analog global harmonic feedback. Operational results concerning improvements in the noise suppression at low frequencies and especially in the dc drift as well as in the orbit stability are shown. Efforts are underway to improve the resolution of the orbit measuing system and the sampling rate using 16 bit 400 kHz ADC`s which will allow orbit sampling with high resolution at 4 kHz frequency.
Date: May 1, 1996
Creator: Bozoki, E.; Rammamorthy, S.; Singh, O.; Tang, Y. & Friedman, A.
Partner: UNT Libraries Government Documents Department

Global DC closed orbit correction experiment on the NSLS x-ray ring

Description: In this note are described the global DC closed orbit correction experiments conducted on the X-ray ring at National Synchrotron Light Source (NSLS). The beam response matrix, defined as beam motion at BPM locations per unit kick by corrector magnets, was measured and then inverted using the technique of singular value decomposition (SVD). The product of the inverted matrix and the difference orbit gives the incremental kick strengths necessary to correct the orbit. As a result, the r.m.s. orbit error around the ring was reduced from 208 {mu}m to 61 {mu}m.
Date: September 15, 1992
Creator: Chung, Y.; Decker, G. & Evans, K.
Partner: UNT Libraries Government Documents Department

Normal mode tunes for linear coupled motion in six dimensional phase space. Informal report

Description: The motion of a particle in 6-dimensional phase space in the presence of linear coupling can be written as the sum of 3 normal mode. A cubic equation is found for the tune of the normal modes, which allows the normal mode tune to be computed from the 6 x 6 one turn transfer matrix. This result is similar to the quadratic equation found for the normal mode tune for the motion of a particle in 4-dimensional phase space. These results are useful in tracking programs where the one turn transfer matrix can be computed by multiplying the transfer matrices of each element of the lattice. The tune of the 3 normal modes for motion in 6-dimensional phase space can then be found by solving the cubic equation. Explicit solutions of the cubic equation for the tune are given in terms of the elements of the 6 x 6 one turn transfer matrix.
Date: January 1, 1995
Creator: Parzen, G.
Partner: UNT Libraries Government Documents Department

The Los Alamos Photon Counting Detector Debris Detection Project: An update

Description: At Los Alamos, the authors have been pursuing a project for space debris detection using a photon counting detector with high spatial and time resolution. By exploiting the three dimensionality of the high quality data, they expect to be able to detect an orbiting object of size below 2 cm, using a moderate size telescope and state-of-the-art photon counting detector. A working tube has been used to collect skyward looking data during dusk. In this paper, they discuss the progress in the development of detector and data acquisition system. They also report on analysis and results of these data sets.
Date: March 1, 1995
Creator: Ho, Cheng; Priedhorsky, W.; Baron, M. & Casperson, D.
Partner: UNT Libraries Government Documents Department

Closed Orbit Distortion and the Beam-Beam Interaction

Description: We study the applicability of beam-beam deflection techniques as a tuning tool for the SLAC/LBL/LLNL B factory, PEP-II. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the IP, provide distinct coordinate- or frequency-space signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed.
Date: February 23, 2007
Creator: Furman, M.; Chin, Y.; Eden, J.; /LBL, Berkeley; Kozanecki, W.; /DAPNIA, Saclay /SLAC et al.
Partner: UNT Libraries Government Documents Department


Description: Inclusion of nonlinearities in the equations for phase oscillations derived for studying proton bunch behavior in the Brooknaven AGS leads to a new stable equilibrium point for the bunch not coincident with the usual stable phase angie. Equations and equilibrium point stability are examined. (D.C.W.)
Date: December 1, 1961
Creator: Hahn, H.
Partner: UNT Libraries Government Documents Department

Effect of synchrotron motion on the closed orbit distortion in crossing beams

Description: When beams collide with non-zero crossing angles, there is a dipole component to the beam-beam force, thus introducing a closed orbit distortion. If the force experienced by a particle is antisymmetric about the collision center, then the distorted orbit still passes through the collision center but with a changed slope, resulting in a shift from the nominal crossing angle. This antisymmetry in the force occurs for coasting beams, while for bunched beams, it is the case for particles at the center of the bunches, assuming that the bunches overlap exactly around the collision center. The presence of synchrotron motion means that the beam- beam force experienced by a particle modulates as the particle moves back amd forth within the bunch. Specifically, a symmetric component to the force is introduced. If the synchrotron period is much longer tham the betatron period, the modulation of the force is adiabatic, and so the effect is a modulation of the closed orbit. The symmetric compoment of the dipole force causes; shift in the closed orbit at the collision center. This indicates a tendency for the beams to separate, which in turn changes the mature of the force between the two beams. The closed orbit shift is calculated. Some comments on self-consistency are made. It is indicated how under certain circumstances, a self-consistent solution may not exist. The case of SPEAR is considered. It is shown that for small crossing angles, the orbit shift at the collision center is larger than the beam size, indicating a major effect. Further-more, it is argued that a self-consistent solution cannot exist. For coasting beams, small angle crossings can be designed so that only the antisymmetric component of the dipole force is prcsemt. Thus, the predominant effect is a shift in the nominal crossing angle. (auth)
Date: January 29, 1974
Creator: Month, M.
Partner: UNT Libraries Government Documents Department


Description: Three simultaneous polar-coordinate component equations in an aximuthally homogeneous magnetic field of a cyclotron are integrated by a fixed- point program on the IBM 650 computer to give the orbits of particles in the cyclotron. A regenerator action for extracting particles is computed as an inpulse once each turn as a subprogram when desired. The program is described and instructions for its use are included. (auth)
Date: May 12, 1958
Creator: Stubbins, W.F.
Partner: UNT Libraries Government Documents Department

Progress Report for UNLV High Pressure Science and Engineering Center

Description: In this report we present results of an in-depth analysis of the SP error densities for 29 satellites. These satellites were divided into three groups--Low Earth Orbit (LEO), Near Circular Orbit (NCO) and Highly Eccentric Orbit (HEO). Included in the first group were those satellites with eccentricities of less than 0.2 and perigees below 450km. The second group included satellites in near circular orbits (eccentricities of less than 0.015) and perigees from 700km to 1500km. The third group consisted of those satellites that were in highly eccentric orbits, namely those with eccentricities greater than 0.2. These satellites have perigees far into the thermosphere. Table 1 contains a summary of the orbit characteristics for the 29 satellites. In our study we attempted to unravel and elucidate the networks of relationships above. The satellite groupings and the report are organized in a way that reflects these efforts. We begin in Section 2 with a summary of the methods used in our analysis. One objective in this study was to establish a baseline for future work in satellite orbit propagators. Section 2 contains descriptions of the SP, truth orbits, and the satellite observation data used to establish this baseline. In the report we show how satellite error densities evolve in time up to thirty-six hours. We present error profiles, error histograms, rms errors and 95/9970 confidence limits for the along-track cross-track, and radial axes of motion for satellites in each of the three groupings. We present results of a regression analysis that establishes a physical model of the error densities. We also link the errors in the various regimes to the quality and quantity of the observational data.
Date: November 20, 1998
Creator: Mailhiot, C.; Pepper, D.; Lindle, D. & Nicol, M.
Partner: UNT Libraries Government Documents Department

The elliptical multipole wiggler project

Description: The elliptical multipole wiggler (EMW) has been designed, constructed, and installed in the X13 straight section of the NSLS X-ray Ring. The EMW generates circularly polarized photons in the energy range of 0.1-10 keV with AC modulation of polarization helicity. The vertical magnetic field of 0.8 T is produced by a hybrid permanent magnet structure with a period of 16 cm. The horizontal magnetic field of 0.22 T is generated by an electromagnet, the core of which is fabricated from laminated iron to operate with a switching frequency up to 100 Hz. There are dynamic compensation trim magnets at the wiggler ends to control the first and second field integrals with very high accuracy throughout the AC cycle. The residual closed orbit motion due to the electromagnet AC operation is discussed.
Date: June 1, 1995
Creator: Gluskin, E.; Frachon, D. & Ivanov, P.M.
Partner: UNT Libraries Government Documents Department

Paraxial expansion of a static magnetic field in a ring accelerator

Description: In the paraxial approximation, trajectories of beam particles in a ring accelerator are computed expanded in powers of lateral displacements and slopes from a closed reference orbit. To do this, one needs first the expanded expressions of the magnetic field and potentials producing the particle motion. This is derived here in a most general form.
Date: June 1, 1995
Creator: Teng, L.C.
Partner: UNT Libraries Government Documents Department

High velocity impact experiment (HVIE)

Description: The HVIE space project was conceived as a way to measure the absolute EOS for approximately 10 materials at pressures up to {approximately}30 Mb with order-of-magnitude higher accuracy than obtainable in any comparable experiment conducted on earth. The experiment configuration is such that each of the 10 materials interacts with all of the others thereby producing one-hundred independent, simultaneous EOS experiments The materials will be selected to provide critical information to weapons designers, National Ignition Facility target designers and planetary and geophysical scientists. In addition, HVIE will provide important scientific information to other communities, including the Ballistic Missile Defense Organization and the lethality and vulnerability community. The basic HVIE concept is to place two probes in counter rotating, highly elliptical orbits and collide them at high velocity (20 km/s) at 100 km altitude above the earth. The low altitude of the experiment will provide quick debris strip-out of orbit due to atmospheric drag. The preliminary conceptual evaluation of the HVIE has found no show stoppers. The design has been very easy to keep within the lift capabilities of commonly available rides to low earth orbit including the space shuttle. The cost of approximately 69 million dollars for 100 EOS experiment that will yield the much needed high accuracy, absolute measurement data is a bargain!
Date: February 1, 1998
Creator: Toor, A.; Donich, T. & Carter, P.
Partner: UNT Libraries Government Documents Department

Global orbit feedback utilizing analog and digital technologies

Description: At the NSLS, an analog global orbit feedback system is used in regular operations, and a digital global orbit feedback system is available in machine physics studies on the X-Ray Ring. Here, the authors discuss the relative merits of utilizing analog and digital technology in orbit feedback. Results of experiments are reported characterizing the performance of the analog and digital systems when operated individually or together. They give their thoughts on plans for future development of the orbit feedback systems at the NSLS.
Date: July 1997
Creator: Singh, O.; Tang, Y.; Ramamoorthy, S.; Krinsky, S. & Yu, L. H.
Partner: UNT Libraries Government Documents Department

Fast ion orbits in spherical tokamaks

Description: In a spherical tokamak, the 1/R variation of the toroidal field is extreme, and for a given value of the safety factor a relatively low average toroidal field can be used, together with large plasma current and large plasma minor radius and elongation. The poloidal and toroidal fields are then of similar size. In consequence, the orbits of fast ions depart considerably from the guiding center orbits because of gyromotion in the small magnetic fields in the low field side.
Date: July 20, 1995
Creator: Solano, E.R.
Partner: UNT Libraries Government Documents Department

Relativistic charged particle in the dipole-sphere configuration I. Classical and semiclassical surface orbits

Description: The classical and semiclassical orbits of a relativistic charged particle on a rotating sphere threaded by a magnetic dipole field are examined. The rotational and dipole axes are in general not aligned. Several physically distinct regimes emerge, depending on the relative sizes of the total energy, canonical azimuthal angular momentum, and magnetic field strength. Magnetic flux enclosed by orbits is quantised very close to the poles. Application of this system to neutron star magnetic fields and questions for future research are outlined.
Date: January 1, 1997
Creator: Gopinath, K.S.; Kennedy, D.C. & Gelb, J.M.
Partner: UNT Libraries Government Documents Department

Correction of closed orbit distortions in the horizontal direction

Description: Many computer programs with a variety of algorithms exist for controlling the closed orbit in synchrotrons. The scope of this note is rather modest in comparison. Based on a simple model, a study has been made to find out statistically how much kick angle is needed by each steering element and how much residual closed orbit deviation should be expected when the closed orbit is steered to go through the center of seven position monitors (M{sub 2} through M{sub 8}) in each cell. Seven independent kicks are supplied by two trim dipoles B{sub U} and B{sub D}, and six steering elements (H{sub 1} through H{sub 6}) with H{sub 3} and H{sub 4} assumed to have the same kick angle. If it is necessary to remove H{sub 3} to make a space there for a correction skew quadrupole (in every other cell), the kick angle of H{sub 4} would have to be doubled.
Date: February 1, 1988
Creator: Ohnuma, S.
Partner: UNT Libraries Government Documents Department

Characterization and equalization of the AC responses of the corrector magnets for the APS local orbit feedback system

Description: Local feedback for the APS storage ring uses local bumps to control the position and angle of the positron beam through each x-ray source point. Induced eddy currents in the aluminum vacuum chamber dominate the AC characteristics of the corrector magnetic fields. Small differences in the geometries at each magnet location change the eddy current effects and result in bump closure errors which must be reduced in order to minimize the coupling between each of the many local loops and the global control loop. By a combination of flux-damping coils, flux-shielding copper sheets, and a set of steel laminations for end-flux clamping, the differences of the eddy current effects between two corrector magnets were reduced from 0.18 Gm/A to 0.035 Gm/A in the frequency span of 0.1-100 Hz.
Date: August 1, 1997
Creator: Doose, C. & Kim, S.H.
Partner: UNT Libraries Government Documents Department

Dispersion in the presence of strong transverse wakefields

Description: To minimize emittance growth in a long linac, it is necessary to control the wakefields by correcting the beam orbit excursions. In addition, the particle energy is made to vary along the length of the bunch to introduce a damping, known as the BNS damping, to the beam break-up effect. In this paper, the authors use a two-particle model to examine the relative magnitudes of the various orbit and dispersion functions involved. The results are applied to calculate the effect of a closed orbit bump and a misaligned structure. It is shown that wake-induced dispersion is an important contribution to the beam dynamics in long linacs with strong wakefields like SLC.
Date: July 1, 1997
Creator: Assmann, R. & Chao, A.
Partner: UNT Libraries Government Documents Department