Spin Navigator Based on Correcting Dipoles of the JINR Nuclotron

JETP Letters - A spin navigator based on correcting dipoles has been proposed to manipulate the directions of protons spins in experiments at the Nuclotron synchrotron (JINR, Dubna). The...     

High-voltage power supply system for detecting equipment of DSS experiment at JINR Nuclotron

The eight-channel high-voltage power supply system based on using the Wenzel Elektronik N1130 module is described. The characteristics of 8DAC-12 and 8ADC-14 types control modules of CAMAC standard designed for high-voltage systems are presented. This system was successfully used to provide the power supply of scintillation detectors in the experiments on the study of the structure of light nuclei at JINR Nuclotron.     

Projects of Nuclotron modernization and Nuclotron-based ion collider facility (NICA) at JINR

One of the basic facilities at the Joint Institute for Nuclear Research (JINR) in Dubna is the 6 A GeV Nuclotron, which has replaced the old weak focusing 10-GeV proton accelerator Synchrophasotron. The first relativistic nuclear beams with the energy of 4.2 A GeV were obtained at the Synchrophasotron in 1971. Since that time, relativistic nuclear physics has been one of the main directions of the JINR research program. In the coming years, the new JINR flagship program assumes the experimental study of hot and dense strongly interacting QCD matter at the new JINR facility. This goal is proposed to be reached by (i) development of the existing Nuclotron accelerator facility as a basis for generation of intense beams over atomic mass range from protons to uranium and light polarized ions, (ii) design and construction of the Nuclotron-based heavy Ion Collider fAcility (NICA) with the maximum nucleon-nucleon center-of-mass collision energy of √s _NN = 9 GeV and averaged luminosity 10²⁷ cm⁻² s⁻¹, and (iii) design and construction of the Multipurpose Particle Detector (MPD) at intersecting beams. Realization of the project will lead to unique conditions for research activity of the world community. The NICA energy region is of major interest because the highest nuclear (baryonic) density under laboratory conditions can be reached there. Generation of intense polarized light nuclear beams aimed at investigation of polarization phenomena at the Nuclotron is foreseen. The text was submitted by the author in English.     

JINR participation in COMPASS project

A new fixed target experiment to study hadron structure and hadron spectroscopy has been approved at CERN as the CERN experiment NA58—COMPASS. An appropriate two-stage large acceptance spectrometer, with particle identification and calorimetry in both stages, using either polarized muon (100–200 GeV) or hadron (up to 300 GeV) beams and polarized as well as unpolarized targets is being constructed at CERN. The beams for the COMPASS were provided in the years 1999–2000 and physics measurements will start in the year 2001.     

Polarization investigations at the Nuclotron

The polarization investigations carried out at the Veksler and Baldin Laboratory of High Energies, JINR, Dubna are reviewed. Some current and future experiments at the Nuclotron accelerator complex of this laboratory are described.     

ILC activity at JINR

JINR is an active participant in the massive new international project ILC. JINR physicists are taking part in several fields of activity in the International Linear Collider (ILC), such as work on the photo injector prototype, the design and construction of cryomodules, laser metrology, cryodiagnostics, etc. The Joint Institute is one of the potential candidates for hosting the ILC, near Dubna, Russia. The status and progress of the above topics are discussed in the report. The text was submitted by the authors in English.     

Computerized Tomography of Ion Bunches at the Nuclotron

Methods for processing a digital signal proportional to the longitudinal intensity of charged particles bunches during their acceleration in a synchrotron are discussed. Computerized tomography is used to reconstruct a longitudinal two-dimensional distribution function of particles in the bunch from its profiles depending on the synchrotron motion of particles. Examples of tomographic studies of ion bunches at the Nuclotron are given.     

CMS remote center at JINR

The dedicated remote center of CMS Experiment at the LHC has been founded in JINR (Dubna). The main mission of the center is operational and efficient monitoring of the CMS detector systems, including the measurements of performance parameters during the prompt data analysis, monitoring of data acquisition and quality of data. Since 2009 the center is involved in remote shifts and operation works of the CMS.     

Status of NICA complex at JINR

New scientific program is proposed at Joint Institute for Nuclear Research (JINR) in Dubna aimed a study of hot and dense baryonic matter in the wide energy region from 2 GeV/amu to √s _NN = 11 GeV, and investigation of nucleon spin structure with polarized protons and deuterons maximum energy in the c.m. 27 GeV (for protons). To realize this program the development of JINR accelerator facility in high energy physics has started. This facility is based on the existing superconducting synchrotron—Nuclotron. The program foresees both experiments at the beams extracted from the Nuclotron, and construction of ion collider—the Nuclotron-based Ion Collider fAcility (NICA).     

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.     

Development of radiation medicine at DLNP, JINR

The Dzhelepov Laboratory of Nuclear Problems’ activity is aimed at developing three directions in radiation medicine: 3D conformal proton therapy, accelerator techniques for proton and carbon treatment of tumors, and new types of detector systems for spectrometric computed tomography (CT) and positron emission tomography (PET). JINR and IBA have developed and constructed the medical proton cyclotron C235-V3. At present, all basic cyclotron systems have been built. We plan to assemble this cyclotron at JINR in 2011 and perform tests with the extracted proton beam in 2012. A superconducting isochronous cyclotron C400 has been designed by the IBA-JINR collaboration. This cyclotron will be used for radiotherapy with proton, helium and carbon ions. The ¹²C⁶⁺ and ⁴He²⁺ ions will be accelerated to an energy of 400 MeV/amu, the protons will be extracted at the energy 265 MeV. The construction of the C400 cyclotron was started in 2010 within the framework of the Archarde project (France). Development of spectrometric CT tomographs may allow one to determine the chemical composition of a substance together with the density, measured using traditional CT. This may advance modern diagnostic methods significantly. JINR develops fundamentally new pixel detector systems for spectrometric CT. The time-of-flight (TOF) system installed in the positron emission tomograph (PET) permits essential reduction in the detector noise from occasional events of different positron annihilations. The micropixel avalanche photodiodes (MAPDs) developed at JINR allow a factor of 1.5 reduction in the resolution time for the PET TOF system and suppression of the noise level as compared to commercial PET. The development of a combined PET/MRI is of considerable medical interest, but it cannot be made with the existing PET tomographs based on detectors of compact photomultipliers due to strong alternating magnetic field of MRI. Change-over to detectors of micropixel avalanche photodiodes permits making a combined PET/MRI.     

Spin physics in few body systems at Nuclotron

The review of the recent results on spin effects in few nucleon systems obtained at LHEP-JINR are presented. The data on the deuteron analyzing powers in different reactions in the wide energy range demonstrate the sensitivity to the spin structure of the light nuclei. The future plans on the studies with polarized deuterons from new polarized ion source at Nuclotron will be reported.     

Target position monitor for the internal target station at the Nuclotron

The principle of the internal target position monitor at the Nuclotron is described. It has been developed for use in experiments with detection of particles in the forward direction. The first results obtained using the target position monitor with a polarized deuteron beam at the Nuclotron are presented. The text was submitted by the authors in English.     

Development of tools for real-time betatron tune measurements at the Nuclotron

A betatron tune measurement system was developed and tested at the Nuclotron. A white noise and chirp signals were used for transverse beam motion excitation. A custom FlexRIO digitizer module was developed which provides excitation signal generation for kicker electrodes and real-time signal acquisition from pickup electrodes. A high resolution FFT algorithm was implemented inside a NI PXI FPGA module, connected to digitizer. The measurement system is integrated with the NICA control system based on the TANGO Controls. Results and tests performed with the Nuclotron beam are presented.     

Experiments on the study of the deuteron-proton interactions at intermediate energies at Internal Target at Nuclotron

The experimental program on the study of deuteron-proton interaction at Internal Target at Nuclotron is discussed. Recent results obtained for dp-elastic scattering and dp-breakup reactions at intermediate energies are presented. The status of the DSS setup upgrade is reported.     

Spin physics at JINR: Present and future

A short review of spin physics program at JINR is presented. The proposals on spin program at the NICA collider are discussed. The main purpose of this program is to study the nucleon spin structure and other phenomena with polarized proton and deuteron beams.     

Upgrading of the LGD cluster at JINR to support DLNP experiments

Since its construction in 2005, the Computing Cluster of the Dzhelepov Laboratory of Nuclear Problems has been mainly used to perform calculations (data analysis, simulation, etc.) for various scientific collaborations in which DLNP scientists take an active part. The Cluster also serves to train specialists. Much has changed in the past decades, and the necessity has arisen to upgrade the cluster, increasing its power and replacing the outdated equipment to maintain its reliability and modernity. In this work we describe the experience of performing this upgrading, which can be helpful for system administrators to put new equipment for clusters of this type into operation quickly and efficiently.