N. D. Topilin

A study of an air medium influence on the rectilinearity of laser ray proliferation towards the using for large distances and high-precision metrology

The influence of a turbulent air medium on a laser beam space localization precision was studied experimentally. For a helium-neon one-mode laser LGN-302 and for a solid-state multimode laser DS-670, the laser ray coordinate measurement uncertainties were determined with 1 m step for the distances up to 9 m from the laser source. It was found that the σ values at 9 m distance are equal to σ(DS-670) = 21 μm and σ(LGN-302) = 12 μm. To reduce the turbulent air medium influence on the laser ray space localization precision, the laser beam was positioned inside a heat-isolating tube. Very significant decrease of σ values was achieved at 9 m from the source: σ*(DS-670) = 2 μm and σ*(LGN-302) = 2.5 μm. The work is made within a framework of a preparation to the creation of a high-precision large-distance laser metrology to be possibly used for long linear collider component alignment.

Laser beam fiducial line application for metrological purposes

The possibility for a collimated one-mode laser beam used as a fiducial line is considered. The technology for an “extended” laser beam formation and application for a much-extended fiducial line is proposed.

Development and application of the complex hardware/software system for controlled assembly of the ATLAS hadron tile calorimeter

A complex hardware/software system and geometrical control methods developed by the authors for controlling both the main components and the final assembly of the ATLAS hadron tile calorimeter are described. The developed system has been employed at all stages of the construction that provided high design precision in assembling the world’s largest experimental high-energy physics facility.

Optimization of a large aperture dipole magnet for baryonic matter studies at Nuclotron

The aperture of the dipole magnet SP41 has been enlarged for the studies of dense baryonic matter properties at Nuclotron. The homogeneity of the magnetic field in the magnet centre has been improved. The measurement results of the magnetic field components and integral are compared with results of 3D TOSCA calculations. PACS: 07.55.Db, 29.30.AjThe aperture of the dipole magnet SP41 has been enlarged for the studies of dense baryonic matter properties at Nuclotron. The homogeneity of the magnetic field in the magnet centre has been improved. The measurement results of the magnetic field components and integral are compared with results of 3D TOSCA calculations.

Production tools to manufacture straw chambers used in multipurpose detector for NICA-MPD project

We describe a new approach in the production of technological devices to manufacture high-precision holes in the ring elements of submodules of the Straw EC Tracker with a precision position relative to each other and the assembly table for pasting the ring frame elements of the submodules with thin-film drift tubes according to the strict requirements for their diameters.

Full-scale prototype of the circular track detector for the multipurpose detector facility at the NICA acceleration complex

The development of the NICA heavy ion collider, which is now under way, assumes the development of a Multipurpose Detector (MPD), including an end-cap tracker (EC) (which can be a wheel-type tracker based on thin-wall drift tubes (straws) similar to the inner detector of the transition radiation tracker (TRT) in the ATLAS experiment). The identical front and back tracker modules mounted behind the TPC are to ensure the detection of Au-Au ion collision products in the pseudorapidity range from 1.4 to 2.1 with good track parameters of reconstructed events. Each module will contain 60 circular straw planes and maximum straw occupancy will be no higher than 0.2 particle per collision. The NICA EC is substantially different from its analogue and requires a certain amount of R&D. The first results from applying new technology to make a full-scale prototype of the circular EC detector for NICA are presented.

The Module Nuclear Absorber of the ATLAS Hadron Calorimeter (An Experiment of Controlled Assembly on the Surface and Underground)

The Hadron Calorimeter of the ATLAS spectrometric complex is a principal part of the whole setup. This paper describes the developed concept and methods for the controlled construction of a steel nuclear calorimeter absorber which provides calorimeter assembly on the surface and in the underground experimental hall meeting the required design tolerances.

Beam transport channels and beam injection and extraction systems of the NICA accelerator complex

A new accelerator complex is being constructed at the Joint Institute for Nuclear Research as a part of the Nuclotron-based Ion Collider fAcility (NICA) project. The goal is to conduct experiments with colliding ion beams (at the first stage of the project) and colliding polarized proton/deuteron beams (at the second stage). Transport beam channels and the systems of beam injection and extraction for synchrotrons and collider rings are an important connecting link for the whole accelerator facility. The design of the primary beam-transport channels and injection/extraction systems are presented. Special attention is paid to various aspects of dynamics of beams in their transfer between the NICA accelerators.

High-voltage electron cooler project for NICA collider

A high-voltage electron cooling system (ECS) with electron energy reaching 2.5 MeV for the NICA collider is being designed at the Joint Institute for Nuclear Research. The ECS is being developed in correspondence with the available experience in manufacturing similar systems from around the world. The main feature of this design is the use of two cooling electron beams (one beam per collider ring); electrons are accelerated and decelerated by a common high-voltage generator. A conceptual project of high-voltage ECS has been developed. The cooler consists of three tanks filled with SF6 gas under pressure. Two of them contain electron-beam forming systems; each system consists of two electron guns, two electron collectors, and accelerating-decelerating tubes placed in a longitudinal magnetic field generated by a solenoid. The third tank contains a high-voltage generator based on the voltage-multiplying circuit.

Beam transportation lines for the NICA project

A heavy-ion collider, i.e., the Nuclotron-based Ion Collider Facility (NICA), is being developed at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The aim of this project is to construct a new accelerator complex for conducting experiments with colliding ion beam (at the first stage of the project) and with polarized proton and deuteron beams (at the second stage). The NICA accelerator complex will consist of two linear accelerators, two synchrotrons, two collider rings, and beam transportation lines. The magnetic lattice and diagnostic and correction systems for the NICA beam transportation lines are described in this report.