137745598
Concept for a lead-ion accelerating facility at CERN
55444273
Present Performance of the CERN Proton Linac
The original 1973 design specification of the CERN 50 MeV Proton Linac was for a 150 mA beam but this intensity was rarely used. Preliminary tests for the high brightness beam required for LHC indicated that 170 mA could be produced for short pulses (30 Ps). Since then further optimisation has enabled the 170 mA to be delivered reliably, within the nominal emittances and dispersion, in long pulses (120 Ps) to the user, the PS Booster (PSB), about 80 m downstream of the linac. The improvements will be described along with the steps envisaged to attain a goal of more than 180 mA.
102555920
The LHC Lead Ion Injector Chain
115300845
Status and first beam measurements on the CERN RFQ
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.
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.
122222802
Can the hawking effect thaw a broken symmetry
Abstract A spontaneously broken symmetry is shown not to be restored as witnessed by accelerating (Rindler) observers. To one-loop thermal contributions appear only in differences between Minkowski and Rindler vacuum matrix elements. All observers obtain (up to coordinate transformations) the same matrix elements of physical operators. Identical effective potentials and order parameters are obtained by all observers.
7781549
Top quark seesaw model, vacuum structure, and electroweak precision constraints
We present a complete study of the vacuum structure of top quark seesaw models of the electroweak symmetry breaking, including bottom quark mass generation. Such models emerge naturally from bosonic extra dimensions. We perform a systematic gap equation analysis and develop an improved broken phase formulation for including exact seesaw mixings. The composite Higgs boson spectrum is studied in the large-${N}_{c}$ fermion-bubble approximation and an improved renormalization group approach. The theoretically allowed parameter space is restrictive, leading to well-defined predictions. We further analyze the electroweak precision constraints. Generically, a heavy composite Higgs boson with a mass of $\ensuremath{\sim}1 \mathrm{TeV}$ is predicted, yet fully compatible with the precision data.
120478961
Moving mirrors in Schrödinger picture
Abstract We formulate the problem of accelerating mirrors upon which quantum fields satisfy Dirichlet boundary conditions, with the associated Hawking effect, in a functional Schrodinger picture. Systems of this kind model some aspects of gravitational collapse leading to the formation of a black-hole. The criterion for the non-separability of the mode expansion in space- and time-dependences is the non-vanishing of a certain second-rank antisymmetric functional, the analogue of an electromagnetic field strength. Arbitrarily moving mirrors involves the functional analogue of the quantum mechanics of a charged particle in an external magnetic field. It is solved explicitly for a special case corresponding to the analogue of gravitational collapse.
115909941
Possible cosmological origin of the ultra high energy cosmic rays
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.