55769041
The High Voltage System for the High Intensity CERN Proton Source
For the RFQ injector mounted on the CERN 50 MeV proton linac, the source needs to provide about 300 mA of 100 keV beam in pulses of 20 to 150 μs at 1 Hz. Although the high voltage supply is fairly conventional, a number of measures had to be taken to ensure not only the reliability of the source electronics, but also other equipments installed in the near vicinity. In view of the high current demanded from the source, a new and very simple form of beam load compensation was developed to stabilise the preinjector voltage to values acceptable to the RFQ.
119401628
The Electron Cooling Device for LEAR
The experiments1,2,3 in which low energetic protons were cooled by a “cold” electron beam have proved that this method is a very powerful technique to improve low energy beams and to increase their phase space density by several orders of magnitude in short times. The theoretical understanding of the cooling process is well advanced4,5,6. The applications of this technique, which was invented and developed in Novosibirsk, are manifold7. It seems to be clear that its main domain is the cooling of non-relativistic ions. However, also at extremely high energies, cooling of protons and antiprotons with stored electrons (cooled themselves by synchrotron radiation) can be contemplated8,9.
121894301
Studies on ECR4 for the CERN ion program
The CERN heavy ion community, and some other high energy physics experiments, are starting to demand other ions, both heavy and light, in addition to the traditional lead ions. Studies of the behavior of the afterglow for different operation modes of the ECR4 at CERN have been continued to try to understand the differences between pulsed afterglow and continuous operation, and their effect on ion yield and beam reproducibility. The progress in adapting the source and ion beam characteristics to meet the new demands will be presented, as will new information on voltage holding problems in the extraction.
115300845
Status and first beam measurements on the CERN RFQ
102555920
The LHC Lead Ion Injector Chain
55729922
Experiments on a 14.5 GHz ECR Source
A device for measuring the speed of the wind at medium altitude by the Doppler effect within the visible frequency range comprises a laser which emits pulses of light, a telescope which receives a scattered light and an interferometer used to measure the spectral shift of the scattered light in relation to the emitted pulse of light. The interferometer is a Fabry-Perot interferometer in which a part of one of the two mirrors of the interferometer is covered with an excess thickness of silica to form two separate filters. The spacing of the two mirrors and the excess thickness of silica are determined in such a manner that the pass bands of each one of the two filters thus constructed are centered on the flanks of the spectral distribution of the backscattered light.
8899144
Lecture Notes for Massless Spinor and Massive Spinor Triangle Diagrams
These notes present the details of the computation of massless and massive spinor triangle loops for consistent anomalies in gauge theories.
112091395
Power Distribution in a CMS Tracker for the SLHC
An upgraded tracker for CMS will need a new architecture for powering to keep the power dissipated in the power cables to acceptable levels. Inductor topologies to reduce the stray magnetic field are discussed together with measurements of the magnetic field produced by prototype inductors. A transformer based DC-DC converter has the potential to produce a high stepdown ratio whilst producing a low stray field and retaining high efficiency. The relative merits of buck configuration and transformer based DC-DC converters are discussed.
122717656
Renormalization in indefinite metric theories
We consider the Lee model,V ⇆ N+θ, and a two neutral scalar meson model with indefinite metrics. It is shown that in general the coupling will cause positive definite bare states to become negative length dressed states through renormalization effects. This can render the theory unphysical depending upon the auxiliary conditions imposed with the indefinite metric.
119634910
Energy-density fluctuations in de Sitter space
Abstract Quantum fluctuations in de Sitter space or in the de Sitter phase of an inflationary universe give rise to a spectrum of classical energy-density perturbations which is scale invariant. The analysis presented in this letter is based on a consistent expansion in powers of ħ, and on the functional Schrodinger approach to quantum field theory in de Sitter space. The result holds for a large class of initial states of the quantum field, including the Bunch-Davies vacuum.
15093335
Topcolor assisted technicolor
A condensate, tt, arising from O(TeV) scale “topcolor”, in addition to technicolor (and ETC) may naturally explain the gauge hierarchy, the large top quark mass, and contains a rich system of testable consequences. A triplet of strongly coupled pseudo-Nambu-Goldstone bosons, “top-pions”, near the top mass scale is a generic prediction of the models. A new class of technicolor schemes and associated phenomenology is suggested in this approach.