Booster synchrotron of NICA accelerator complex

NICA is a new accelerator complex being constructed at the Joint Institute for Nuclear Research; the main task of this complex is to perform collider experiments for ion beams up to uranium with energies of up to 3.5 × 3.5 GeV/nucleon. This complex includes an electron string ion source, a 6 MeV/nucleon linear accelerator, a booster, the Nuclotron, and a collider with an average luminosity of 10²⁷ cm² s^?1. The main tasks of the booster are to accumulate up to 4 × 10^{9 197}Au³²⁺ ions, to accelerate to 600 MeV/nucleon (sufficient enough energy for completely stripping nuclei), to reduce the requirements of vacuum conditions for the Nuclotron, and to form the necessary beam emittance using an electron cooling system. The specific features of the NICA booster and the requirements for the basic systems of the synchrotron and their parameters are presented in this paper.     

A conceptual design of a power-supply system of deflecting plates for multivariate injection into the NICA accelerator complex booster

The design of the complex envisions the installation of three pairs of electric deflecting plates in the booster ring. These plates are designed to carry out the ion-beam injection into the booster in regimes of single-turn, multiturn, and multiple injection. We present a feasible scheme of a power-supply circuit that allows for all the prospective injection regimes through independent unipolar charging and discharging of the plates.     

Investigating the adiabatic beam grouping at the NICA accelerator complex

The NICA complex comprises the Booster and Nuclotron synchrotrons for accelerating particle beams to the required energy and the Collider machine, in which particle collisions are investigated. The experimental heavy-ion program deals with ions up to Au⁺⁷⁹. The light-ion program deals with polarized deuterons and protons. Grouping of a beam coasting in an ion chamber is required in many parts of the complex. Beam grouping may effectively increase the longitudinal emittance and particle losses. To avoid these negative effects, various regimes of adiabatic grouping have been simulated and dedicated experiments with a deuteron beam have been conducted at the Nuclotron machine. As a result, we are able to construct and optimize the beam-grouping equipment, which provides a capture efficiency near 100% either retaining or varying the harmonic multiplicity of the HF system.     

CFETR中性束注入系统概念设计

为了满足中国核聚变工程实验堆(CFETR)对等离子体加热和电流驱动的要求,从总体布局、束传输 系统、束源系统三方面进行了中性束注入系统的概念设计。利用参数计算的方法,根据聚变等离子体的要求明确 了中性束注入系统的性能指标和基本布局;利用束传输空间分布程序评估了束传输性能,确定了各功能部件的空 间布局结构;在此基础上,确定了束源系统的性能指标和引出系统布局方式,结合当前研发进展,明确了束源的 基本技术方案。由此完成了中性束注入系统参数指标、束传输关键尺寸、束源性能指标等设计要求,为后续工程 设计奠定了基础。     

Vacuum requirements for the booster of NICA accelerator complex

This paper presents the results of a calculation of ¹⁹⁷Au³²⁺ ion beam losses as they interact with atoms and molecules of residual gas in the acceleration chamber of the booster vacuum system of the NICA accelerator complex [1].     

Cryogenics for the future accelerator complex NICA at JINR

The NICA cryogenics will be based on the modernized liquid helium plant that was b uilt in the early 90’s for the superconducting synchrotron known as the Nuclotron. The main goals of the modernization are: increasing of the total refrigerator capacity from 4000 W to 8000 W at 4.5 K, making a new distribution system of liquid helium, and ensuring the shortest possible cool down time. These goals will be achieved by means of an additional 1000 l/hour helium liquefier and “satellite” refrigerators located near the accelerator rings. This report describes the design choices of the NICA, demonstrates helium flow diagrams with major new components and briefly informs of the liquid nitrogen system that will be used for shield cooling at 77 K and at the first stage of cooling down of three accelerator rings with the total length of about 1 km and “cold” mass of 290 tons.     

Quench detector for superconducting elements of the NICA accelerator complex

A universal quench detector is designed for new superconducting accelerators of the NICA accelerator complex under construction at JINR. The presence of a two-channel digital input permits the detector to be used both for comparing voltage across two nearest magnets by a bridge scheme and for separating a resistive constituent of the voltage across a controlled element.     

Cycling Equipment for the NICA Booster Accelerator

Physics of Particles and Nuclei Letters - Cycling equipment was developed for the Booster accelerator of the NICA complex in the form of a VME3U crate with a set of digital and optical input/output...     

Forecasting Radiation Environment around the NICA Booster

Physics of Particles and Nuclei Letters - The results of using the FLUKA package to calculate the radiation environment around building no. 1 of the Laboratory of High Energy Physics, which...     

Coherent instabilities in the booster and collider of the heavy ion accelerator complex NICA

In the first part some knowledge about the coherent instabilities in cyclic accelerators and storage rings necessary for the analysis of the collective effects in the heavy ion collider NICA is given. The second part discusses the possibilities for arising of coherent instabilities in the booster and in the collider of the NICA complex. Both coupling impedances and instability thresholds and growth rates have been estimated for single and coupled bunches. Parameters of the beam feedback system for damping of the instabilities have been analyzed. The investigation has been performed at the Veksler and Baldin Laboratory of High Energy Physics, JINR.     

Start of Electron Cooling System for the NICA Booster

In order to achieve the required beam parameters in the NICA booster, the electron cooling system (ECS) was designed and manufactured at the Institute of Nuclear Physics (INP), Novosibirsk. In 2017, the system was shipped to JINR and its assembly and commissioning started. A specific feature of this system is that, for the first time ever, the electron cooling method with a magnetized e-beam is applied at the superconducting synchrotron; this imposes some additional requirements for the design and start of the ECS, operating at room temperature. This paper describes the main steps of the ECS assembly and start at the straight section of the booster, including mounting mechanical, electrical, and plumbing systems (water, electricity, air, and oil system) and geodetic works on installing the system on site. The measured magnetic field homogeneity for the straight solenoid is given. The assembly of vacuum and magnet systems takes several steps because of the ECS design features. At the final assemblage stage of the vacuum system, the vacuum chamber is baked up and the bulk getters and the cathode of the electron gun are activated. Upon completing assembly and testing the high voltage system, the E-beam is conducted from the gun to the collector.     

Thermometry System of NICA Booster Superconducting Magnets

Physics of Particles and Nuclei Letters - The NICA accelerator complex is developed on the JINR base in Dubna for performing physical experiments on colliding beams of heavy ions. It consists of...     

Study of the Electron Cooling System of the NICA Booster

The electron cooling system for the NICA booster has been under construction and tested over the last few years at the Institute of Nuclear Physics. The design of this setup and the results of tests are detailed.     

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.     

Preliminary design of a laser accelerator beam line

A compact laser plasma accelerator(CLAPA) is being built at Peking University, which is based on an RPA-PSA mechanism or other acceleration mechanisms. The beam produced by this laser accelerator has the characteristics of short duration, high pulse current, large divergence angle, and wide energy spectrum. The beam cannot be produced by a normal ion source and accelerator. The space charge field in the initial is very strong.According to the beam parameters from preparatory experiments and theoretical simulations, a compact beam line is preliminarily designed. The beam line mainly consists of common transport elements to deliver proton beam with the energy of 1–50 MeV, energy spread of 0–±1% and current of 0–108 proton per pulse to satisfy the requirement of different experiments. The simulation result of a 15 MeV proton beam with an energy spread of ±1%, current of 400 m A, and final spot radius of 9 mm is presented in this paper.     

串列加速器电离性束流截面探测器设计

基于GIC4117串列加速器束流引出线束流测量需求,开展了电离型束流截面探测器设计工作,主要包括系统收集信号强度的计算,采用有限元软件进行电场系统、磁场系统优化设计,给出了电场系统与磁场系统设计参数。通过引入辅助磁场,测量系统能够实现束流轨道的自动校正,系统对束流的影响可以忽略。对影响测量精度的电离电子横向位置偏移进行了分析,并对电离电子进行轨迹跟踪。跟踪结果表明:电离电子在横向位置的运动偏移可以控制在0.3 mm以内,与理论分析一致。     

串列加速器电离性束流截面探测器设计

基于GIC4117串列加速器束流引出线束流测量需求,开展了电离型束流截面探测器设计工作,主要包括系统收集信号强度的计算,采用有限元软件进行电场系统、磁场系统优化设计,给出了电场系统与磁场系统设计参数。通过引入辅助磁场,测量系统能够实现束流轨道的自动校正,系统对束流的影响可以忽略。对影响测量精度的电离电子横向位置偏移进行了分析,并对电离电子进行轨迹跟踪。跟踪结果表明:电离电子在横向位置的运动偏移可以控制在0.3 mm以内,与理论分析一致。     

Conceptual design of Hefei Advanced Light Source (HALS) injection system

The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article.