44 research outputs found
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A compilation of the data on the low-. beta. spools
Each of the high gradient correction quadrupoles associated with the new low-{beta} lattice is built into a package which contains correction coils similar to the correction coils in the existing Tevatron spool packages. These coils have been measured in Lab 5. The quench currents are measured in a vertical dewar. The only correction element which failed the quench test was TSL003. In that one case the skew dipole coil quenched at 90A, lower than the required current of 100A. The strength of the various coils (the magnetic field B is measured at a radius of 1 in. with 50A in the coil) and the harmonic composition of the magnetic field due to the various coils are measured with the coil warm using a 11Hz signal in the coils. The strength of a coil can be used to compute a transfer constant. The transfer constant is then used to compute the current needed to generate the value of the field in the coil needed for Tevatron operation. Currently, I believe, nominal values of the transfer constants are used, but it would be better if the actual values were available and used
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Linear aperture criteria for a standard cell lattice
Among the parameters which need to be specified in the design of the SSC are the cell length (l/sub c/) and the coil diameter (d/sub c/). The quality of the magnetic field of the bending magnets, reflected in both small multipole coefficients and a small sigma for these coefficients, improve as d/sub c/ increases. Similarly the smaller ..beta.. resulting from a decreased l/sub c/ results in an increased admittance (for a constant size beam pipe). Unfortunately increasing d/sub c/ and/or l/sub c/ would result in increasing the cost of the SSC. It is not only desirable but necessary to understand how the performance of an accelerator depends on d/sub c/ and l/sub c/ so that we can have confidence that the SSC when built will work. It should be straightforward to know whether or not an accelerator, once built, works or not. There are however no well accepted tools or criteria for deciding whether or not a proposed design of an accelerator will provide acceptable performance. This is particularly so in the case of accelerators built of superconducting magnets in which the magnetic field is determined by the current distribution in the coils. 3 figs
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A prototype lattice design for a 2 TeV {mu}{sup +} {minus} {mu}{sup {minus}} collider
This is a description of a prototype lattice for a {mu}-{mu} collider. It is not intended to be a final design, that is the design for a collider lattice which will be built. This prototype design will need to be optimized as the constraints and the requirements for the collider are better understood. As this is done the present design will be replaced by a superior design. Nonetheless this prototype can be used as a benchmark and a means of identifying problems. This is a geometric design, that is the beam energy does not enter into the properties of the elements of the design. Since the proposed energy for the {mu}-{mu} collider is 2TeV {times} 2TeV this energy has been used to compute the gradients needed in the quadrupoles. At an energy of 2TeV, and with superconducting dipoles of {approximately}8T the circumference of the ring is {approximately}6km. Since the luminosity depends exponentially on the length of the lattice an important design criterion will be to minimize the length of the ring. This will be done with careful design of the interaction regions (IR), the utility straight sections, and even the standard cells in the arcs
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Amplitude dependence of the tune shift
Recent studies in the Tevatron have measured the tune shift as a function of the displacement from a closed orbit. The measured values of tune shift were found to be much smaller than one would expect from the measured distribution of the normal octupole moments in the Tevatron. Tracking studies performed to see if, and under what conditions, the observed results could be obtained are reported. The effect of linear coupling is taken into consideration, and is found to significantly reduce the coefficient of the tune shift. The dependence of the tune shift on the initial coordinate of a particle in the presence of a distribution of octupole moments is calculated. The ''smear'' is calculated as a function of linear coupling. (LEW
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Rotations of the low-{beta} quadrupoles: Coupling in the Tevatron and the effect on the luminosity
It is now generally recognized that a large roll, {approx} 6--7 mr, in a triplet low-{beta} quadrupole, which couples the horizontal and vertical motion of the beam, can significantly reduce the luminosity and impact the operation of the Tevatron. The question then arises, what is the effect of the small rolls of the low-{beta} quadrupoles on the luminosity. They will consider random rolls with a {sigma} = 1,2 and 4mr which can be expected due to errors in the surveys, or changes in alignment after the survey. In the actual operation of the Tevatron they attempt to correct for the coupling and so this study will consider correction schemes and will compare the luminosity, after correction, with a configuration with no rolls
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Tracking results using a standard cell lattice
This is a summary of results obtained by tracking a single particle through a lattice composed of a r.f. cavity and standard FODO cells. The lattice also includes two families of sextupoles for controlling the chromaticity. The parameters of the cells, i.e. their length and phase advance, closely resemble those of the Fermilab Main Ring or the Tevatron. We therefore have a model lattice which is similar to that of those accelerators but without the straight sections present in the actual machines. It is hoped that the simplified model used will exhibit the salient features of the actual accelerator but will be simpler to understand. 8 figs., 1 tab
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The performance of the Tevatron collider at Fermilab
This paper will describe the actual operating performance of the Tevatron, operating as a collider, and will indicate the planned upgrades which will enhance, the physics results coming from the experiments being performed at Fermilab