Stages and milestones of the Nuclotron upgrade Results of the Nuclotron run (#37) Works on coming Nuclotron run (#38) ConclusionStatus of the project Nuclotron-M(1st stage of the NICA/MPD)

JINR Scientific Council, Feb.21,2008

Grigory Trubnikov & NICA team

NICA goals and physics problemsby means of careful scanning in beam energy and centrality of excitation functions for the first stage Multiplicity and global characteristics of identified hadrons including multi-strange particles Fluctuations in multiplicity and transverse momenta Directed and elliptic flows for various hadrons HBT and particle correlations the second stage Electromagnetic probes (photons and dileptons)Study of in-medium properties of hadrons and nuclear matter equation of state, including a search for possible signs of deconfinement and/or chiral symmetry restoration phase transitions and QCD critical endpoint in the region of s NN=4-9 GeV Required mean luminosity is about 1027 cm-2s-1

NICA general layout

Nuclotron provides now performance of experiments on accelerated proton and ion beams (up to Fe24+, A=56) with energies up to 5,7 and 2,2 GeV/n correspondingly (project parameters for ions 6 GeV/n with Z/A = 0,5)

The Goal to reach parameters of Nuclotron by 2010 required for realization of NICA project by:

Development of new injection complexModernization of RF systemUpgrade of diagnostics and beam control systemsModernization of the vacuum systemModernization of the electric- and cryo- supply systemsDevelopment of the minimum required infrastructure 1 stage: Nuclotron-MLeaders: A.D. Kovalenko, G.V. TrubnikovDeputy leaders: V.I. Volkov, A.V. Butenko

Institute theme 02-00-1065-2008/2010

Modernization of ion source KRION to KRION 6T;Improvement of the vacuum in the Nuclotron ring;Development of the power supply system, quench detection and energy evacuation system of dipoles and quadrupoles;Modernization of the RF system (including trapping & bunching systems, controls and diagnostics);Modernization of the slow resonance extraction system for extraction of accelerated heavy ions at maximal energies;Modernization of automatic control system, diagnostics and beam control system and other systems;Transportation channel of the extracted beams and radiation safety;Improvement of the economical efficiency of the cryogenics;Continuous modernization of the injector complex (fore-injector and linac) for acceleration of heavy ions; Development and creation of high intensity polarized deutron source

Research and investigation of the beam dynamics, minimization of thebeam losses at all stages from injection to acceleration and to extraction ofthe beams (not more then 15-20%, now we have about 70-80%).10 stages-subprojects of the Nuclotron-M project

Development of heavy ion source KRION (team of .. Donets and .D.Donets)Construction and test of the new ion source with 6 T solenoid within the coming two years is the main goal of the project. The fist Au32+ ion beams have been obtained in October 2006. Ionization time was 100 ms. The total intensity was of 1.2*109 ions/pulse. Developed and tested injection technology of Au atoms to KRION-2. Obtained Au beams with charge up to including Au51+. Results achieved in last run at KRION: intensity of the Au51+ is 108, at extraction duration 8 secThe new important feature of the source is capability of operation at high pulse repetition rate in the case of production heavy ions at intermediate charged states, was considered. U30+ intensity of (4-8)1010 ions/sec can be reached in the case of the pulse repetition rate of 5-10 Hz.

The fundamental parameter of a KRION-type source is a factor j - product of electron current density and ionization time. The j, depends on the applied external magnetic field (now not >3T).Ionization capability (left plot) and experimental results from the ion source KRION-2 on generation of highly charged state gold ions. - Design and construction of the new heavy ion source KRION-6T aimed at generation of heavy ion beams with q/A up to 0.33 (for example Au65+ Au69+);

- Study of the electron string phenomenon at different conditions (B up to 6 T, Ee up to 25 keV). The further investigation of tubular electron-string ion source;

- Preparation of the existing source KRION-2 to the run at Nuclotron aimed at acceleration of the ion beams at atomic mass range A ~ 100 (for example, I43+, A=127).

Goal: Provide stable, safe and long operation of Nuclotron magnetic system at B = 2 T and B field ramp not less then 1 T/s The new improved unit for energy damp from the magnets in the case of quench (so-called thyristor switch) was designed, constructed and tested. Produce and put into operation six such units for both the dipoles and the quadrupoles power supply circuits. Scheme of the Nuclotron structural magnets power supply (thyristor switches marked with yellow) Modernization of the power supply system , quench detection and energy evacuation system (team of V.Karpinsky, E.Ivanov)The other works on improvement of the power supplies for bending magnets of injection channel, beam extraction line from the Nuclotron to experimental area, building 205 are also included into the project.

At the present time there is no possibility to pump out gaseous He defusing into the beam pipe through non-hermetic connection near the beam extraction pipe inside the cryostat.Two stages of the system improvement are proposed:Stage 1: necessary development within the Nuclotron-MStage 2: will be considered within the NICA TDR Upgrade of the Nuclotron ring vacuum system (team of H. Khodzhibagiyan)The averaged presure in the Nuclotron beam pipe is estimated to about ~ 2-310-8 Torr (nitrogen equivalent at 300 K). This value was measured during the last run in Nov. 2007

Development of the accelerator RF system, upgrade of the electronics and the particle capture scheme (department of O.Brovko, A.Eliseev)Construction and put into operation the third RF station that will allow to provide acceleration of the particles at the magnetic field ramp up to 2 T/s.

Increase of the Nuclotron longitudinal acceptance by means of design and put into operation adiabatic scheme of the particle trapping and adequate increase of the particle trapping efficiency (by a factor of two).

Modernization of the system of the frequency/ field control electronics. This system is especially important because of the planned operation of the accelerator with different ion species within the same run.

Preparation of the project for relativistic heavy ion bunch compression system with the parameters suitable for the NICA.

Heavy ion beam extraction at maximum beam energy ( leaders V.Volkov, A.Butenko,A.Taratin, A.Sidorov)The most problematic is the first problem. Maximum ESS voltage is limited at the present time to about 125 kV by the electrical discharges. It is proposed to modify the ESS unit. The use of a crystal septum is considered as additional possibility to provide additional deflection of the extracted ions to the ESS. It could be possible to provide the extraction at maximum accelerator rigidity without replacement of the ESS. - Modernization of electrostatic septum (ESS) aimed at increase of operation voltage up to 200 kV to provide necessary deflection of the extracted particles up to the magnetic rigidity of the Nuclotron correspond to the NICA specification (B >1.8 T ) - Put into operation additional correcting power supply for the Lambertson magnet of the beam extraction system - Design and realization of heavy ion extraction scheme with the use of a crystal septum. - Design of a scheme for fast extraction of compressed heavy ion bunch.

Modernization of the Nuclotron control system, beam diagnostics and the accelerator complex parameters (V.Volkov, B.Vasilishin, V.Andreev) Basic goals: Development of the Nuclotron control and local network systems for higher reliability, extended possibilities of the existing system, put into operation the advanced industrial PC farm; Upgrade of the sub-system for the accelerator magnetic field control; Modernization of the sub-system for beam extraction control; Improvement of operation parameters of the equipment for extracted beam diagnostics (extended dynamic range of the measured beam intensities, better accuracy, less materials along a beam path are suppose after the planned modernization);

Fig. 5. General scheme of the existing NCS.Nuclotron Control System (NCS) The NCS includes two levels: 1) the front-end level (FEL) based on the ADVANTECH industrial computers and 2) the operator level (OPL). Modernization of the FEL suppose put into operation of the new modern computers and replace some of the old data collection equipment by the advanced systems produced by National Instruments, CyberResearch, DATATRANSLATION, GaGe, ADVANTECH, ACQUITEK, MEASUREMENT COMPUTING and others. The OPL include work stations at central and local control panels of the accelerator complex. This level provide collection and visualization of the information from sub-systems, store the data archive as well as to provide direct control of accelerator system and their adjustment during the running time.Fig. 6. Structural scheme of the NCS: 50 PCs (20 Front End and 30 work station computers are combined in the system). The Nuclotron web-server is available for the outside users.The averaged information traffic through the NCS is reached by the present time to about 400 Kb/s while the maximum traffic value during the active part of the Nuclotron cycle is about 4 Mb/s. The NCS is distributed system, the cable distance reach of about 500 m. Structural scheme of the NCS is shown in Fig. 6. The NCS is based on the local computer network (LCN) of the accelerator complex. The LCN is a sub-unit of the LHE network.Subproject SP1.6 Modernization of the Nuclotron control system, beam diagnostics and the accelerator complex parameters ( leader V.Volkov, B.Vasilishin, V.Andreev)

Subproject SP1.6 Modernization of the Nuclotron control system, beam diagnostics and the accelerator complex parameters ( leader V.Volkov, B.Vasilishin, V.Andreev) Upgrade of the sub-system for the accelerator magnetic field control Practically all basic parameters will be improved substantially

Subproject SP1.6 Modernization of the Nuclotron control system, beam diagnostics and the accelerator complex parameters ( leader V.Volkov, B.Vasilishin, V.Andreev) Beam extraction control The proposed upgrade of the subsystem is based on the use of more powerful elements for the data collection, functional generator and timer units. Structural schemes of the ubsystem and the extracted beam spill feedback control apparatus are shown in Fig.8.1 and Fig. 8.2. The module 1622 YRDA by Cyber Research will be used for the data collection, while the modules PCI-6713 by National Instruments is proposed for the analogue functional generator upgrade. The pilot version of extracted beam spill control equipment is now under operation at the accelerator. The analogues MWPC, digital MWPC and scintillator counters are used for the extracted beam current monitors. Extracted beam diagnostics Coasting bunched beam diagnostics Beam loss monitoring system The proposed system is based on registration of thermal neutrons flux near the accelerator cryostat. This sub-system contain 64 neutron detectors installed near structural quadrupoles. The test measuring channel was designed and checked. Improvement of the existing beam closed orbit diagnostic base on 20 BPM's is planned also. Basic goal is extension of the measurements (limited at present by insufficient signal-to-noise ratio due to influence of RF acceleration stations) over the total accelerator cycle.The main disadvantage of the existing system is that all the devices are fixed at the beam line, thus additional material is crossing by the beam. Within the frames of the NICA project the movable measuring blocks will be designed and installed in vacuum boxes of the beam transfer line. R&D work on the beam monitors based on scintillator fibers (SciFi detectors, like developed within the program R&D 17 at CERN) is planned also.

Beam dynamics study and minimization of the particle losses at all the stages of accelerator cycleThe losses can be reduced by factor 5-6 due to improvement of RF trapping scheme and precise beam dynamics study during first 100-200 s after injectionBeam-time of 800 hours is requested in 2007-09 for the studies

Beam transfer lines and radiation shield (sector of P.Rukojatkin) - Modernization of the main beam extraction and transport line from the Nuclotron beam output window to the building 205; - Minimization of the material along the beam path; - Design and mounting of automatic system of the power supply control for optic elements; - Minimization of energy consumption at transport lines for extracted beams.

Modernization of the cryogenic system (leaders N.Agapov, V.Batin) Design and construction of the system for diagnostic and computer control of the existing helium refrigerators KGU-1600/4.5 and all helium circuit;

Design, construction and put into operation the system for re-condensation of a cold gaseous nitrogen evaporated after cooling heat screens of the Nuclotron ring cryogenic modules; - factor 2-3 of economical efficiency

Reparation and partial replacement of the cryogenic equipment that have exceeded tolerable operation period.

Design of the new fore-injector with injection and extraction lines (leaders V.Monchinsky, A.Sidorin, V.Kobets, A.Govorov)The new heavy ion injector is necessary for realization of NICA project. The approved basic concept of the NICA injector is based on the new ion source KRION-6T and linear accelerator (with fore-injector) to provide acceleration of heavy ion beams (q/A 0.12) up to 6 MeV/u. Construction of the new linac with fore-injector will be performed within the frames of a separate project INJECTOR NICA - Modernization of the existing linac LU-20: improvement of vacuum pumping system including beam transport line to the nuclotron, development of the linac control system

Design and construction of high intensity polarized light ion source.(leaders V.Fimushkin, A.Kovalenko)The main direction of work aimed at increase of polarized beam intensity at the Nuclotron is connected with the design and construction of the new high current polarized ion source (IPSN) based on the equipment of CIPIOS polarized proton and deuteron ion source from Bloomington. The work is carried out in collaboration with INR (Troitsk). The ion source equipment (not completed) was transported to Dubna from IUCF (Indiana University, Bloomington, USA). Some parts of a suitable equipment for the new source were presented from DAPHNIA (Saclay).

Subproject SP1.10 Design and construction of high intensity polarized deuteron ion source. (leaders V.Fimushkin, A.Kovalenko)

The new heavy ion source KRION-6T, upgrade of pre-accelerators and improvement of vacuum in LU-20 and injection line is supposed in the frames of project Nuclotron-M. The existing complex will be used for protons, deuterons, polarized deuterons and light ions (Z/A > 0.3). Design of the new pre-accelerator with injection and extraction lines (leaders A.Sidorin, V.Kobets, V.Monchinsky, A.Govorov)The limiting charge-to-mass ratio of ion accelerated in the LU-20 is q/A 0.3. The possibility of the KRION-type ion source with the magnetic field of 3 T and energy of the electron beam up to 6 keV (existing version of the source) can provide ion beam of 127I43+ , i.e. ions with q/A 0.34. Thus, it is possible to perform a test acceleration of heavy ion beam with atomic mass of 130 at the Nuclotron after completion of the work on improvement of vacuum in the accelerator chamber. Acceleration of gold ions will be performed after construction of KRION-6T ion source. A.D. Kovalenko, Section of APT BF JINR, Dec.07

Well focused tasks of Nuclotron-M program, 100-300 h. Pre-requisit for NICA & physics.Physics ready to start Work with POLARIS (conditional): requires successful Nuclotron-M stages (high intensity, energy)

Ions of 6Li had been accelerated up to 25 MeV/u;

Measured value of circulated beam lifetime using comparison of deuterons and 2+ ( >3ms) corresponds to the pressure ~210-8 Torr ( for N2 equivalent)

First experiments were successfully started with pseudoadiabatic trapping at magnetic field plateau. It was shown that the beam intensity can be increased by factor 2;

Experiments on series connection of magnets and lenses allowed to decrease amplitude of magnetic field ripple up to 15 times;

Methodical shifts aimed on investigation of particle losses on the first turns were performed.

Some other technical experiments and methodical studies were done and some new diagnostic equipment were installed and successfully tested.29.10.07 16.11.07

(450 hours)RUN # 37

Next run ( 38)May 2008 (~ from 17 May to 15 June) Program:Systems preparation, cooling 140-150 hours;Physical shifts 290-310 hours: DELTA-2 (50), Energy-Transmutation (12), NIS-GIBS (134), TPD (58), FAZA (46)Methodical shifts 140-160 hours: vacuum improvement, vacuum measurements and spectrometry, adiabatic trapping, new prototype of BTF, new prototype of transition sensors, test of prototype of evacuation system, RF system upgrade and diagnostics, new prototype line of power supply for correctors, injection matching, corrected beam-bump, power supply system upgrade, existing Linac modernization,

Total revisionSpecially developed plan of revision and modernization(started mid. Jan08) ~ 140 positions

positionResponsible persGeodesy in the tunnel, alignment of optic elements ButenkoRevision and repairing of LU-20 vacuum systems, cryopumpingMonchinskyRevision of pick-up station, new BTF prototypeBrovkoSlepnevRF system upgrade, shielding, diagnosticsBrovkoWater supply point upgradeSeminRevision of beam-bump (correctors 43, 44, 52, 53)VolkovPower supply system modernizationKarpinsky..Development of new protection and safety systemButenkoAlfeev

New injection complex: New ion source prototype (KRION-6T) in progressModernization of RF system work had been startednew Linac Contract with IHEP is under signing Vacuum system -equipment is partially installed on deliveryPower supply system and control of magnetic system- 1st block is under testingUpgrade of beam diagnostics - in good continuous progress

Required R&D priority task for Nuclotron runsThis stage has to be completed by 2010 providing:- Accelerated heavy ions with A ~ 100 200Beam intensity ~ 107 A/pulse Beam energy > 3,5 GeV/nRequired infrastructureStatus on Nuclotron-M 1 stage of the NICA project

The New Parametric Current Transformer (in flange)for non-destructive measurement of average beam current...Contract with Bergoz Instrumentation.NPCT is ordered has to be installed by May08

Vacuum measurement unit TPG 300 Feb 08Several new pumps Feb 08, April 08Mass spectrometer Prisma+ QMS 200 F Feb 08 Pumping stations, valves, sensors Feb 08, Apr08Very fruitful collaboration with Vacuum Praha - Modernization of the Nuclotron vacuum system: step-by-step

Work with modernization of energy evacuation systemis in good progress

Scheme of Unified Accelerator Division works !Groups and sectors of high-professional specialists joined from LPPactively instill into Nuclotron-M (beam diagnostics, thermo- and magneto- metry,RF and HV technique, LINAC, ) and NICA (injection, extraction, beam dampers, transportation channels, cryogenics, beam cooling, ) projects.Modernization of cryogenic systems:Upgrade of RF system and diagnostics:Modernization at LU-20 complexInfrastructure !Control room,beam diagnostics

Strategic plan of the JINR accelerator complex is development in the High Energy physics + adequate scientific program. Priority task project NICA/MPD

Realisation of the 1st stage in 2008-2010 has principal importance for critical decision on the proposed strategy of JINR accelerator complex developmentConclusion

Program of physics research at Nuclotron is directly coordinated to strategy development of accelerator complex at the 1st stage (Nuclotron-M)

Organization of the Russian and Foreign cooperation, attraction of the external resources one of the necessary conditions for successful completion of the projectActive work for collaboration is in progress with Helmholz association, GSI, CERN, and other centers on the joint operations on creation accelerator complexes NICA and FAIR for further joint execution of the actual physics research

Good start is under way with IHEP (Protvino) realization of the task of injector creation, joint workshop 13-14 Feb08

Thank you for your attention !

Fig.4. General scheme of the Nuclotron cryogenics. 1 - vacuum shell; 2 - heat shield; 3 - suuply header; 4 - return header; 5 - dipole magnet; 6 - quadrupole magnet; 7 - subcooler; 8 - separator; 9 - refrigerator; 10 - gas bag; 11 - storage vessel; 12,14,15,17 - compressors; 13,16 - purifiers.