B. N. Sukhina

Bio: B. N. Sukhina is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Electron cooling & Electron. The author has an hindex of 5, co-authored 8 publications receiving 166 citations.

Experiments on Electron Cooling

Abstract: Experiments on electron cooling were carried out on the antiproton storage ring, NAP-M, using 50 MeV proton beams, cooled with 27 keV electrons from a three electrode gun. The proton beam lifetime increased from 900 s to 5,000 s with electron cooling. Diagnostic methods are described, and some possible applications of electron cooling are discussed. (PMA)

Temperature relaxation in a magnetized electron beam

Abstract: The velocity distribution of electrons in an intense beam shaped in an electrostatic accelerating device is strongly anisotropic: the electron longitudinal-velocity scatter is much less than that of the transverse velocities When such a beam moves in a drift chamber, the longitudinal and transverse temperatures become equalized This process slows down substantially when the beam is shaped and transported in a device with a longitudinal magnetic field The present paper is devoted to an investigation of this effect

Magnetic field alignment in the beam-beam compensation device

Abstract: The guiding solenoidal magnetic field of the Tevatron beam-beam compensation device has to be carefully aligned with respect to a straight trajectory of the antiproton beam. We present in this paper an optical method which allows to measure the direction of the magnetic field, results of magnetic measurements, and results of the field quality improvement with dipole correctors.

Mass and lifetime measurements of exotic nuclei in storage rings

Abstract: Mass and lifetime measurements lead to the discovery and understanding of basic properties of matter. The isotopic nature of the chemical elements, nuclear binding, and the location and strength of nuclear shells are the most outstanding examples leading to the development of the first nuclear models. More recent are the discoveries of new structures of nuclides far from the valley of stability. A new generation of direct mass measurements which allows the exploration of extended areas of the nuclear mass surface with high accuracy has been opened up with the combination of the Experimental Storage Ring ESR and the FRragment Separator FRS at GSI Darmstadt. In-flight separated nuclei are stored in the ring. Their masses are directly determined from the revolution frequency. Dependent on the half-life two complementary methods are applied. Schottky Mass Spectrometry SMS relies on the measurement of the revolution frequency of electron cooled stored ions. The cooling time determines the lower half-life limit to the order of seconds. For Isochronous Mass Spectrometry IMS the ring is operated in an isochronous ion-optical mode. The revolution frequency of the individual ions coasting in the ring is measured using a time-of-flight method. Nuclides with lifetimes down to microseconds become accessible. With SMS masses of several hundreds nuclides have been measured simultaneously with an accuracy in the 2 x 10(-7)-range. This high accuracy and the ability to study large areas of the mass surface are ideal tools to discover new nuclear structure properties and to guide improvements for theoretical mass models. In addition, nuclear half-lives of stored bare and highly charged ions have been measured. This new experimental development is a significant progress since nuclear decay characteristics are mostly known for neutral atoms. For bare and highly charged ions new nuclear decay modes become possible, such as bound-state beta decay. Dramatic changes in the nuclear lifetime have been observed in highly charged ions compared to neutral atoms due to blocking of nuclear decay channels caused by the modified atomic interaction. High ionization degrees prevail in hot stellar matter and thus these experiments have great relevance for the understanding of the synthesis of elements in the universe and astrophysical scenarios in general.

Laser-enhanced electron-ion capture and antihydrogen formation

Abstract: The electron-ion capture rate for low electron energies is calculated for various electron velocity distributions. Capture rates for electron-ion recombination stimulated by irradiation with light are evaluated. The results are applied to electron cooling and to positron-antiproton recombination to form antihydrogen. It is shown that laser-induced capture is a powerful method to study the electron cooling process and to maximize the antihydrogen rate. With this technique a pulsed antihydrogen beam of selectable energy and well collimated with an intensity of a few atoms per second can be anticipated.

Dissociative recombination with ion storage rings.

Abstract: ▪ Abstract The development of heavy-ion storage-cooler rings for atomic physics has made it possible to produce high-quality beams of molecular ions that are internally cold. The stored molecular-ion beam is immersed in a cold electron bath, which gives a beam of low divergence and small cross-sectional area. The electron cooler also serves as a target for electron–molecular ion collision experiments. This allows the study of dissociative recombination of cold molecules with respect to cross sections, branching ratios, and angular distibutions at an unprecedented luminosity.

Experimental demonstration of relativistic electron cooling.

Abstract: We report on an experimental demonstration of electron cooling of high-energy antiprotons circulating in a storage ring. In our experiments, electron cooling, a well-established method at low energies (< 500 MeV/nucleon), was carried out in a new region of beam parameters, requiring a multi-MeV dc electron beam and an unusual beam transport line. In this letter we present the results of the longitudinal cooling force measurements and compare them with theoretical predictions.

The future GSI facility

Abstract: This talk describes the technical characteristics and physics program of the future GSI facility, which has recently been approved by the German government.