118976170
Operating experience with the NAL 200-MeV linac.
117804340
DESIGN OF PROTON LINEAR ACCELERATORS FOR ENERGIES UP TO 300 Mev
Extension of the conventional 2 pi structure for particle acceleration to 200 Mev or higher requires minimization of power losses by optimizing cavity and drift-tube parameters. Using a previously developed method, an optimization of the cavity drift-tube dimensions was made at 200 Mc and at energies of 50, 100, 150, and 200 Mev to give minimum power losses for cylindrical tubes. Drift tubes of other shapes may reduce observed high-energy power losses due to currents in the drift-tube surface. Ellipsoidal tubes appear more efficient than the cylindrical tubes. (D.C.W.)
123057920
Magnetic Guide Field Measurements and Corrections in the MURA 50‐MeV Electron Accelerator. VI
Methods of measurement and correction of the magnetic fields of the MURA 50‐MeV electron accelerator are described. Measurements of the vertical and horizontal field components were made and the field errors corrected. Correction coils, iron shims, and adjustment of magnet positions were used to produce fields within the required tolerances. Computer methods were used to calculate needed corrections and to evaluate the quality of the corrections achieved.
55868408
400-MeV upgrade for the Fermilab linac
Fermilab plans to upgrade the Tevatron to expand the physics research program in both the fixed target and the collider operating modes. The first phase of this program is to increase the energy of the H{sup -} linac from 200 to 400 MeV in order to reduce the incoherent space change tuneshift at injection into the Booster which can limit either the brightness or the total intensity of the beam. The linac upgrade will be achieved by replacing the last four 201 MeV, with seven 805 MHz side-coupled cavity modules operating at an average axial field of about 8 MV/m. This will allow acceleration to 400 MeV in the existing Linac enclosure. 4 refs., 3 figs., 1 tab.
111257994
RF Perturbation Measurements in Long Linac Cavities
Equipment and procedures have been developed for measuring the axial accelerating electric field in proton linear accelerator cavities. The method used is the usual one of measuring the change in resonant frequency caused by a small perturbing sphere on the axis of the cavity. The frequency change is determined at millimeter intervals along the axis by measuring the corresponding period length using an on-line digital computer. The computation is carried out on the computer so that the derived fields can be obtained, integrated, plotted, and compared. The method is rapid and the increased precision of the measurement allows better knowledge of the fields in operating linear accelerators. This equipment has been used on the 50-MeV linac injector for the Zero Gradient Synchrotron at Argonne National Laboratory.1 It has also been used to measure the axial field in a cavity with fields which can be calculated using a field computational program.2 The measured and calculated field values have been compared.
210069014
Cooling Scenario Study Week
118984920
Hidden Local and Non-local Symmetries of S-matrices of N=2,4,8 SYM in D=2+1
This talk, based principally on [1], is devoted to properties of tree-level S-matrices of N = 2,4,8 SYM inD = 2 + 1. We’ll discuss an on-shell formalism for three-dimensional theories inspired by the spinor-helicityframework in four spacetime dimensions. Our framework will be shown be to particularly well suited for theextraction of hidden symmetries and algebraic structures that the scattering amplitudes of the three-dimensionaltheories posses. In particular we shall discuss the manifest SO(N) symmetry of the S-matrix to all orders inperturbation theory; a symmetry that the Lagrangians of these theories do not have. After a brief discussionof the ramiﬁcation of the SO(N) invariance to the D2 − M2 brane dualities, we shall introduce an on-shellsuperﬁeld framework for three-dimensional theories and end with a surprising hint of the existence of non-localsymmetries for the S-matrix of the N = 8 theory.
119106209
Holographic three-point functions of giant gravitons
Working within the AdS/CFT correspondence we calculate the three-point function of two giant gravitons and one pointlike graviton using methods of semi classical string theory and considering both the case where the giant gravitons wrap an S3 ⊂ S5 and the case where the giant gravitons wrap an S3 ⊂ AdS5. We likewise calculate the correlation function in $ \mathcal{N} = 4 $ SYM using two Schur polynomials and a single trace chiral primary. We find that the gauge and string theory results have structural similarities but do not match perfectly, and interpret this in terms of the Schur polynomials’ inability to interpolate between dual giant and pointlike gravitons.
48341289
Holographic dual of the Eguchi-Kawai mechanism
A bstractThe holographic dual of $ \mathcal{N} $ = 2*, D = 4 supersymmetric Yang-Mills theory has many features common to 5d CFT. We interpret this as a manifestation of Eguchi-Kawai mechanism.
14018969
Supersymmetric Wilson loops in diverse dimensions
We consider supersymmetric Wilson loopsla Zarembo in planar supersym- metric Yang-Mills theories in diverse dimensions. Using perturbation theory we show that these loops have trivial vacuum expectation values to second order in the 't Hooft coupling. We review the known superspace results which, for specific dimensions, extend this triviality to all orders in the 't Hooft coupling. Using the gauge/gravity correspondence, we construct the explicit dual fun- damental string solutions corresponding to these Wilson loops for the case of circular geometry. We find that the regularized action of these string solutions vanishes. We also generalize the framework of calibrated surfaces to prove the vanishing of the regularized action for loops of general geometry. We propose a possible string-side manifestation of the gauge theory generalized Konishi anomaly in seven dimensions.
14615477
Exact 1/4 BPS loop- : Chiral primary correlator
Abstract Correlation functions of 1 / 4 BPS Wilson loops with the infinite family of 1 / 2 BPS chiral primary operators are computed in N = 4 super-Yang–Mills theory by summing planar ladder diagrams. Leading loop corrections to the sum are shown to vanish. The correlation functions are also computed in the strong-coupling limit by examining the supergravity dual of the loop–loop correlator. The strong coupling result is found to agree with the extrapolation of the planar ladders. The result is related to known correlators of 1 / 2 BPS Wilson loops and 1 / 2 BPS chiral primaries by a simple re-scaling of the coupling constant, similar to an observation of Drukker [N. Drukker, hep-th/0605151] for the case of the 1 / 4 BPS loop vacuum expectation value.