The main task of this work is to find a fast and robust way to determine pp-collision time
at the SPD experiment. Using physics motivations, from the input flux of reconstructed particles’ tracks we ...identify a subset of pions which is used to calculate the unbiased estimation of the event collision time. The uncertainty of the estimation is about 30 ps. This method is fast (less than 300 ns per event) and reliable, thus it will allow to process the high flux of input events at the SPD experiment.
Methods for processing a digital signal observed from a four-electrode transverse position sensor of ion bunches during acceleration in a synchrotron are discussed. A method has been developed for ...reconstructing the ion distribution function along the length of a bunch performing betatron oscillations during acceleration. The results are used to display the bunch length evolution performing betatron oscillations and identify the fractional part of the number of the free betatron oscillations of ion bunches during the acceleration of xenon ions in the JINR booster synchrotron.
Methods for processing a digital signal proportional to the longitudinal intensity of ions in bunches during their acceleration in a synchrotron are discussed. Computer tomography is employed to ...reconstruct the longitudinal 2D ion distribution function in a bunch using data on its longitudinal profiles that depend on the bunch length and the synchrotron motion of particles. Presented are examples of tomographic reconstruction of the longitudinal distribution function of xenon ions in the JINR superconducting booster synchrotron prior to extraction (after acceleration) and on the injection plateau also with the activated electron cooling system.
Methods for monitoring the root-mean-square bunch length during injection into the booster superconducting synchrotron of the NICA complex are discussed. Digital signals for the pulsed component of ...the current proportional to the longitudinal intensity of ions circulating in the synchrotron are processed using the method of moments of the distribution function of charged particles in a bunch. Examples of the application of the proposed methods are given for a short bunch of carbon ions injected into a booster superconducting synchrotron in a constant magnetic field where the accelerating RF field is turned on later.
Portrait of a Scientist Zhabitsky, V. M.
Physics of particles and nuclei letters,
08/2023, Letnik:
20, Številka:
4
Journal Article
Recenzirano
The article is dedicated to the memory of Prof. V.P. Sarantsev, a well-known Russian scientist and leading expert in the physics and technology of accelerators.
Methods for monitoring the longitudinal momentum spread of ions within a bunch during injections into a synchrotron are discussed. The method of moments for the distribution function of charged ...particles in a bunch is used when processing a digital signal for the pulse component of the current proportional to the longitudinal intensity of ions circulating in a synchrotron. Examples of using the proposed methods during the injection of a short bunch of carbon ions into the JINR superconducting booster synchrotron and Nuclotron are presented.
After having announced the statistically significant observation (5.6σ) of the new exotic πK atom, the DIRAC experiment at the CERN proton synchrotron presents the measurement of the corresponding ...atom lifetime, based on the full πK data sample: τ=(5.5−2.8+5.0)×10−15 s. By means of a precise relation (≈1%) between atom lifetime and scattering length, the following value for the S-wave isospin-odd πK scattering length a0−=13(a1/2−a3/2) has been derived: |a0−|=(0.072−0.020+0.031)Mπ−1.
The observation of hydrogenlike πK atoms, consisting of π^{-}K^{+} or π^{+}K^{-} mesons, is presented. The atoms are produced by 24 GeV/c protons from the CERN PS accelerator, interacting with ...platinum or nickel foil targets. The breakup (ionization) of πK atoms in the same targets yields characteristic πK pairs, called "atomic pairs," with small relative momenta Q in the pair center-of-mass system. The upgraded DIRAC experiment observed 349±62 such atomic πK pairs, corresponding to a signal of 5.6 standard deviations. This is the first statistically significant observation of the strange dimesonic πK atom.
The possibility of applying a damping system of coherent transverse beam oscillations in a synchrotron using a positive feedback mode for the short-time excitation of coherent particle oscillations ...is discussed. Examples of excitation modes for the parameters of the LHC Damper system are presented.
The results of a search for hydrogen-like atoms consisting of π∓K± mesons are presented. Evidence for πK atom production by 24 GeV/c protons from CERN PS interacting with a nickel target has been ...seen in terms of characteristic πK pairs from their breakup in the same target (178±49) as well as in terms of produced πK atoms (653±42). Using these results, the analysis yields a first value for the πK atom lifetime of τ=(2.5−1.8+3.0) fs and a first measurement of the S-wave isospin-odd πK scattering length |a0−|=13|a1/2−a3/2|=(0.11−0.04+0.09)Mπ−1 (aI for isospin I).
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