Energy Compression and Stabilization of Laser-Plasma Accelerators.

Laser-plasma accelerators outperform current radio frequency technology in acceleration strength by orders of magnitude. Yet, enabling them to deliver competitive beam quality for demanding applications, particularly in terms of energy spread and stability, remains a major challenge. In this Letter, we propose to combine bunch decompression and active plasma dechirping for drastically improving the energy profile and stability of beams from laser-plasma accelerators. Realistic start-to-end simulations demonstrate the potential of these postacceleration phase-space manipulations for simultaneously reducing an initial energy spread and energy jitter of ∼1-2% to ≲0.1%, closing the beam-quality gap to conventional acceleration schemes.

Proof-of-Principle Direct Measurement of Landau Damping Strength at the Large Hadron Collider with an Antidamper.

Landau damping is an essential mechanism for ensuring collective beam stability in particle accelerators. Precise knowledge of the strength of Landau damping is key to making accurate predictions on beam stability for state-of-the-art high-energy colliders. In this Letter, we demonstrate an experimental procedure that would allow quantifying the strength of Landau damping and the limits of beam stability using an active transverse feedback as a controllable source of beam coupling impedance. In a proof-of-principle test performed at the Large Hadron Collider, stability diagrams for a range of Landau octupole strengths have been measured. In the future, the procedure could become an accurate way of measuring stability diagrams throughout the machine cycle.

[The preserving-health model of employees of oil and gas industry].

The state of occupational health problem and occupational rate of accident in Russia has been studied. It has been set forward the innovation model of health care of employees in oil and gas industry based on integrated approach, which combines the medical examination practice, the objective appraisal of workplaces on working condition, use of new saving production technologies, providing the employees with the means of individual protection, teaching the personnel to occupational safety and health culture and the first medical aid. The received results approve the efficiency of application of this model.

Colony-forming activity of unipotent hemopoietic precursors under the effect of nanosized ferrites in a constant magnetic field in vitro.

We studied in vitro effect of ferrimagnetic nanoparticles in a dose of 3 mg/liter (10 maximum permissible concentrations) on colony-forming capacity of bone marrow granulocytic and monocytic precursors in a constant magnetic field at magnetic field intensity of 200 Oe. We tested powders obtained by the methods of electrical explosion of conductors (magnetite and a mixture of hematite with magnetite) or mechanochemical synthesis (cobalt ferrite). According to electron microscopy, size of particles was within 6-65 nm. Specific effect of nanopowders on functional properties of hemopoietic and stromal cells were demonstrated; this effect was not related to dissolution of these powders, but had a complex nature. It depends on the size and magnetic characteristics of powder particles, the route and dose of administration, and the presence of external magnetic field. It was emphasized that in multicellular systems a reaction of committed hemopoietic precursors mediated via cells (factors) of microenvironment cannot be excluded, the state of this system varying in different individuals and under different conditions. Our data open new vistas for the creation and targeted use of nanosized materials and technologies for individual therapy in the context of personalized medicine.