Emittance measurements in the CERN PS complex

The LHC project, with its demand for small emittance beams and their monitoring, constitutes a challenge for the instruments of the CERN PS complex used hitherto to measure emittances of generally larger beams with less precision. Among these instruments, one (Beamscope) measures the betatron amplitude distribution, while the other two (SEM-grids, fast wire scanner) are recording the projected beam density. Emittances are quoted as derived from one standard width of the projected beam density, and the goal is to provide figures which refer to this definition regardless of the measurement instrument and method. The paper recalls the principles of these measurement systems and describes the mathematical methods applied to eliminate noise and measurement errors, to transform between the phase plane and its projection and the formalism used to determine the matching between machines

Longitudinal coupled-bunch instability around 1 GHZ at the CERN PS booster

The fast-growing "Ring 4" instability occurring at intensities above 6.5 1012 protons in the top one of the four rings of the CERN PS Booster (PSB) is finally explained by an asymmetry in the 40 vacuum pump manifolds common to all rings. Impedance measurements (by wire method) and numerical calculations show a sharp resonant peak (Q~2000) at 1100 MHz and shunt impedances two times higher for the Ring 4 ports as compared to the other rings. This factor is sufficient to explain that the threshold of the instability falls below the maximum intensity only in Ring 4. A final, but labor-intensive and expensive, cure consists of inserting short-circuiting sleeves into all 160 beam ports. Results of beam and impedance measurements and the planned cure will be presented and discusse

A Comparative Study of Fast Wire Scanners, Beamscope and SEM-Grids for Emittance Measurements in the PS Booster

The tight emittance budget, imposed on the production of the high-brilliance beams in the LHC preinjectors, demands the elimination of all possible sources of beam blow-up. A prerequisite for this is reliable instrumentation and evaluation methods for comparison of their data. We have made a study of three methods for emittance measurement in the PS Booster: fast wire-scanners, BeamScope, and SEM-grids in a measurement line. For the fast wire-scanners, a full Monte-Carlo simulation was made of the beam-wire interaction, for an energy range from 100 MeV to 1 GeV, and compared to measured values. Data from a scraping method (BeamScope) are compared to profile measurements, using Abel-type integral transformations. Results will be presented

Goldstone models in D+1 dimensions, D=3,4,5, supporting stable and zero topological charge solutions

We study finite energy static solutions to a global symmetry breaking Goldstone model described by an isovector scalar field in D+1 spacetime dimensions. Both topologically stable multisolitons with arbitrary winding numbers, and zero topological charge soliton--antisoliton solutions are constructed numerically in D=3,4,5. We have explored the types of symmetries the systems should be subjected to, for there to exist multisoliton and soliton--antisoliton pairs in D=3,4,5,6. These findings are underpinned by constructing numerical solutions in the $D\le 5$ examples. Subject to axial symmetry, only multisolitons of all topological charges exist in even D, and in odd D, only zero and unit topological charge solutions exist. Subjecting the system to weaker than axial symmetries, results in the existence of all the possibilities in all dimensions. Our findings apply also to finite 'energy' solutions to Yang--Mills and Yang-Mills--Higgs systems, and in principle also sigma models.Comment: 29 pages, 6 figure

Night sleep in patients with vegetative state

Polysomnographic recording of night sleep was carried out in 15 patients with the diagnosis vegetative state (syn. unresponsive wakefulness syndrome). Sleep scoring was performed by three raters, and confirmed by means of a spectral power analysis of the electroencephalogram, electrooculogram and electromyogram. All patients but one exhibited at least some signs of sleep. In particular, sleep stage N1 was found in 13 patients, N2 in 14 patients, N3 in nine patients, and rapid eye movement sleep in 10 patients. Three patients exhibited all phenomena characteristic for normal sleep, including spindles and rapid eye movements. However, in all but one patient, sleep patterns were severely disturbed as compared with normative data. All patients had frequent and long periods of wakefulness during the night. In some apparent rapid eye movement sleep episodes, no eye movements were recorded. Sleep spindles were detected in five patients only, and their density was very low. We conclude that the majority of vegetative state patients retain some important circadian changes. Further studies are necessary to disentangle multiple factors potentially affecting sleep pattern of vegetative state patients. © 2017 European Sleep Research SocietyThis study was supported by the Deutsche Forschungsgemeinschaft

Rotating Hairy Black Holes

We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.Comment: 13 pages, including 4 eps figures, LaTex forma

A Monopole-Antimonopole Solution of the SU(2) Yang-Mills-Higgs Model

As shown by Taubes, in the Bogomol'nyi-Prasad-Sommerfield limit the SU(2) Yang-Mills-Higgs model possesses smooth finite energy solutions, which do not satisfy the first order Bogomol'nyi equations. We construct numerically such a non-Bogomol'nyi solution, corresponding to a monopole-antimonopole pair, and extend the construction to finite Higgs potential.Comment: 11 pages, including 4 eps figures, LaTex format using RevTe

Multisphalerons in the Weinberg-Salam Theory

We construct multisphaleron solutions in the Weinberg-Salam theory. The multisphaleron solutions carry Chern-Simons charge $n/2$, where $n$ is an integer, counting the winding of the fields in the azimuthal angle. The well-known sphaleron has $n=1$. The multisphalerons possess axial symmetry and parity reflection symmetry. We vary the Higgs mass and the mixing angle. For small $n$ the energies of the multisphalerons are on the order of $n$ times the energy of the sphaleron and their magnetic dipole moments are on the order of $n$ times the magnetic dipole moment of the sphaleron.Comment: 18 pages, latex, 17 figures in uuencoded postscript files. THU-94/1

New nonuniform black string solutions

We present nonuniform vacuum black strings in five and six spacetime dimensions. The conserved charges and the action of these solutions are computed by employing a quasilocal formalism. We find qualitative agreement of the physical properties of nonuniform black strings in five and six dimensions. Our results offer further evidence that the black hole and the black string branches merge at a topology changing transition. We generate black string solutions of the Einstein-Maxwell-dilaton theory by using a Harrison transformation. We argue that the basic features of these solutions can be derived from those of the vacuum black string configurations.Comment: 30 pages, 12 figures; v2: more details on numerical method, references added; v3: references added, minor revisions, version accepted by journa

Static black hole solutions with axial symmetry

We construct a new class of asymptotically flat black hole solutions in Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theory. These black hole solutions are static, and they have a regular event horizon. However, they possess only axial symmetry. Like their regular counterparts, the black hole solutions are characterized by two integers, the winding number $n$ and the node number $k$ of the gauge field functions.Comment: 14 pages, including 4 postscript figures, LaTe