121228290
Intellectual system for power supply and control of magnetic component groups of particle accelerators from several MW-power sources
It is necessary for the power-consuming magnetic components of channels for beam transport in accelerators of charged particles be supplied with direct current. An individual power source is typically applied for each group of identical components. A variant of the simultaneous supply of several groups of magnets from a single medium-power source using auxiliary current shunts of different types is given by the example of a LEPTA positron storage ring. One version of using this technology with MW-power sources for a phasotron accelerator is developed. The efficiency of putting this technology into practice with the application of start-stop regimes for the phasotron is estimated.
117312301
The experimental verification of the hypothesis of the existence of the static electromagnetic field
122046947
ARES — a spectrometer for the investigation of rare particle decays and rare nuclear processes
Abstract A magnetic spectrometer intended for a wide range of investigations of rare particle and nuclear processes is described. The spectrometer consists of cylindrical proportional chambers (∼ 15000 signal wires) with gas supply and gas leakage systems, cylindrical scintillation hodoscopes, a magnet, electronics with power supplies, and a data acquisition system. Basic characteristics of the spectrometer are discussed and results of first physics experiments are presented.
16417285
Asymptotic expansions of two-loop Feynman diagrams in the Sudakov limit
Abstract Recently presented explicit formulae for asymptotic expansions of Feynman diagrams in the Sudakov limit [V.A. Smirnov, Phys. Lett. B 394 (1997) 205] are applied to typical two-loop diagrams. For a diagram with one non-zero mass these formulae provide an algorithm for analytical calculation of all powers and logarithms, i.e. coefficients in the corresponding expansion ( Q 2 ) −2 n,j =0 C nj t −n ln j t , with t = Q 2 / m 2 and j ≤ 4. Results for the coefficients at several first powers are presented. For a diagram with two non-zero masses, results for all the logarithms and the leading power, i.e. the coefficients c nj for n = 0 and j = 4,3,2,1,0 are obtained. A typical feature of these explicit formulae (written through a sum over a specific family of subgraphs of a given graph, similar to asymptotic expansions for off-shell limits of momenta and masses) is an interplay between ultraviolet, collinear and infrared divergences which represent themselves as poles in the parameter e = (4 − d )/2 of dimensional regularization. In particular, in the case of the second diagram, that is free from the divergences, individual terms of the asymptotic expansion involve all the three kinds of divergences resulting in poles, up to 1/ e 4 , which are successfully canceled in the sum.
118984277
Divergences and renormalization in p-adic quantum field theory
507905
Asymptotic expansions of Feynman integrals on the mass shell in momenta and masses
A brief review of recent results on asymptotic expansions of Feynman integrals on the mass shell in momenta and masses and their application to 2-loop calculations is presented.
119860995
Analytic renormalization of massless theories