Vladimir Borisov

Superconducting Magnets for the NICA Accelerator Collider Complex

NICA is a new accelerator collider complex under construction at JINR. The facility is aimed at providing collider experiments with heavy ions up to Uranium in a center of mass energy range from 4 to 11 GeV/u and an average luminosity up to 1027 cm -2 s-1. The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting booster synchrotron, the existing 6 AGeV superconducting synchrotron Nuclotron, and a new superconducting collider consisting of two rings, each of about 500 m in circumference. The booster synchrotron and the NICA collider are based on an iron-dominated “window frame”-type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the development of the full size model magnets for the booster synchrotron as well as for the NICA collider is presented. The test results of model magnets are discussed. The status of the creation of a facility for serial tests of superconducting magnets for the NICA project is described.

Low-noise pulsed current source for magnetic-field measurements of magnets for accelerators

The schematic diagram, design, and technical characteristics of the pulsed current source developed and produced for the magnetic-field measurement system of superconducting magnets for accelerators are described. The current source is based on the current regulator with pass transistor bank in the linear mode. Output current pulses (0–100 A) are produced by utilizing the energy of the preliminarily charged capacitor bank (5–40 V), which is additionally charged between pulses. The output current does not have the mains frequency and harmonics ripple. The relative noise level is less than–100 dB (or 10–5) of RMS value (it is defined as the ratio of output RMS noise current to a maximal output current of 100 A within the operating bandwidth, expressed in dB). The work was performed at the Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research (JINR).

Superconducting Magnets for the NICA Accelerator Collider Project

Nuclotron-based Ion Collider fAcility (NICA) is a new accelerator collider complex under construction at the Joint Institute for Nuclear Research. The facility is aimed at providing collider experiments with heavy ions up to Gold in the center of mass energy from 4 to 11 GeV/u and an average luminosity up to 1 · 1027 cm-2s-1 for Au79+. The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting booster synchrotron, the existing 6-AGeV superconducting synchrotron Nuclotron, and a new superconducting collider consisting of two rings, each 503 m in circumference. The booster synchrotron and the NICA collider are based on an iron-dominated “window frame”-type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the serial production and test of the magnets for the booster synchrotron and the development of the full-size model magnets for the NICA collider is presented. The test results of magnets are discussed. The status of the construction of the facility for serial tests of superconducting magnets for the NICA project is described.

Serial Magnetic Measurements for the NICA Quadruple Magnets of the NICA Booster Synchrotron

NICA is a new accelerator collider complex under construction at JINR, Dubna. More than 250 superconducting magnets are needed for the NICA booster and collider. The NICA Booster magnetic system includes 48 quadrupole superconducting magnets. The rotating coils probe developed for series magnetic measurements of booster quadrupoles doublets, as well as measuring methods are described. Results of magnetic measurements in cryogenic conditions for 12 doublets are presented and discussed. INTRODUCTION At the Laboratory of High Energy Physics (LHEP), serial assembly and testing of NICA Booster magnets were started at end of 2016 at the special facility [1]. The program of testing of magnets includes «warm» and «cold» magnetic measurements. It is necessary to assemble and test 48 quadrupole magnets for the NICA booster synchrotron. According to the specification, a magnetic measurement system, which is able to measure the effective length, magnetic field harmonics and magnetic axis in cold magnet inside the cryostat, is needed. QUADRUPLE MAGNET FOR THE NICA BOOSTER Figure 1: Booster doublet of quadrupole magnets. The Nuclotron-type design [2],[3] based on a cold iron yoke and a saddle shaped SC coil have been chosen for booster quadrupole magnets. The doublet consists of a focusing and a defocusing lattice quadrupole magnets, which are connected with each other in a single rigid mechanical construction of about 1.8 m length (see Fig.1). The main parameters of the quadrupole magnets are presented in Table 1. SPECIFICATION FOR MAGNETIC MEASUREMENTS According to the specification, following parameters of a quadrupole magnet have to be measured with the required tolerances:  Relative standard deviation of effective lengths 4 5 10 eff eff eff L L L         � = �2(�) ∞ −∞ � �2(0)  The magnetic axis with respect to magnets fiducials. σ(Δx), σ (Δy) ≤ 0.1 mm  Relative integrated harmonics 2 ∗ , 2 ∗ , 3 ∗ ≤5∙10

Measurement of the magnetic-field parameters of the NICA Booster dipole magnet

Serial assembly and tests of dipole and quadrupole magnets of the NICA Booster have started at the Laboratory of High Energy Physics of the Joint Institute for Nuclear Research (JINR). The accelerator is fitted with Nuclotron-type magnets with a superconducting winding and an iron yoke for shaping the needed magnetic field. The design of magnets for NICA was optimized (based on the experience gained in constructing and operating the JINR Nuclotron) for the production of magnetic fields of the required configuration in terms of the beam dynamics in the accelerator and the collider. Measurements of parameters of the field of each magnet are expected to be performed in the process of assembly and testing of each module of the magnet-cryostat system of the NICA Booster and Collider. The results of magnetic measurements for the NICA Booster dipole magnet are presented.