A regular (sixteenth) workshop on particle accelerators was convened in the Russian proton accelerator center Protvino on October 20-22,1998. The national workshop, organized by the Institute for High Energy Physics (IHEP) and the Joint Institute for Nuclear Research (JINR), was supported by the Ministry for Atomic Energy of Russian Federation, the Russian Ministry for Science and Technology, and the Russian Academy of Sciences.
The first Conference on Particle Accelerators in the Soviet Union was held in 1968 in Moscow, thirty years ago. In his Workshop 98 address. Chairman Atlant A.Vasiliev reviewed the history of the biennial Russian Workshops and their impact on Particle Accelerators. The 16th workshop was attended by 250 physicists from Moscow, St.Petersburg, Novosibirsk, Tomsk, Saratov, Kharkov, Dubna, Troitsk, Obninsk, and Protvino. The major accelerator centers worldwide were also represented: CERN (Switzerland), DESY (Germany), Fermilab and BNL (USA), TRIUMF (Canada), KEK (Japan).
The submitted reports were presented at the plenary and panel sessions. Over 130 reports were delivered on the status of existing accelerators and development of new machines, as well as on using particle accelerators in diverse areas of science and technology. The oral and poster talks were presented at the following panel sessions: · Current trends in accelerators technology. Projects for new large accelerators. (Chairman - A.A. Vasiliev). · Superconducting accelerators and cryogenic systems. (Chairman - K.P.Myznikov, IHEP). · Colliders. (Chairman - V.E.Balakin, BINP). · Accelerating structures and high-power radio-frequency equipment. (Chairman - S.K.Esin, INR RAS). · Radiation problems at accelerators. (Chairman - V.N.Lebedev, IHEP). · Systems for control and diagnostics. (Chairman - A.F.Dunaitsev, IHEP). · Magnetic and vacuum systems of accelerators, power supplies. (Chairman - M.F.Vorogushin, RIFE). · Heavy ions accelerators. (Chairman - l.N.Meshkov, JINR). · Particle dynamics in accelerators and storage rings, new methods of acceleration. (Chairman - E.F.Troyanov, IHEP). · Linear and circular accelerators of high intensity. (Chairman - V.A.Teplyakov, IHEP) · Accelerators for medicine, industry and applied research. (Chairman - V.A.Glukhikh, RIFE). · Upgrade and development of the existing accelerators. (Chairman - Yu.M.Ado, IHEP). An overview of high energy physics was given by S.S.Gershtein of IHEP, in the invited paper "Main Problems of High Energy Physics". The physical motivation for future particle accelerators and capabilities of B factories and the LUG were reviewed. Possible further accelerators such as photon and muon colliders, and Very Large Hadron Collider (VLHC) were also discussed.
lgor N.Meshkov (JINR) gave an overview of various schemes for colliders and the status of the development of key components and various test facilities in his report "Current Trends in Accelerator Technology". This review summarized the reports on the current status of accelerator science reported at the 17th International Conference on High Energy Accelerators (September 7-12,1998, Dubna).
Alexander D.Kovalenko described the status of Dubna superconducting heavy ion accelerator - Nuclotron. The accelerator of relativistic ions with strong focusing, commissioned at the Laboratory of High Energies JINR in March 1993, became the third hadron machine (after Tevatron and HERA) equipped with superconducting magnets. At this superconducting synchrotron, protons and nuclei of heavy elements (including uranium) are accelerated up to energies of 12 GeV and 6 GeV per nucleon, respectively. The use of superconducting magnets resulted in a relatively low size of the ring (252 m in perimeter) as a whole (80 ton).
Nuclotron is based on a miniature iron-shaped field superconducting magnets. Nuclotron-type technology was proposed for the new VLHC project (Ec.m.=2 x 100 TeV) as well as for intermediate energy synchrotrons and storage rings (100-500 MeV/u) of different applications. The plans for development of a novel superferric design at 2 T and estimated parameters of a 2x 100 TeV proton (nuclei) synchrotron/collider based on the Nuclotron-type cryomagnetic system were presented.
A short review was also given including the Nuclotron physics research program as well as development of accelerator systems such as the slow extraction one. The designed and achieved parameters of the Nuclotron systems used during 12 runs of the accelerator operation were presented.
Anatoly D.Nikulin from the Bochvar All-Russia Scientific Research Institute of Inorganic Materials (BARSIIM, Moscow) described the history and progress of High-Temperature Superconducting (HTS) materials. Early hopes of HTS to operate at liquid-nitrogen temperature were soon dashed by the difficulties of making wire out of the brittle oxide materials and achieving high current- carrying capicity.
Nevertheless ten years of work on the HTS materials have led to recent successes, including laboratory demonstration of 250-metre long silver (Ag) sheathed Bi-2223 multifilaments wire tape conductors by the BARSIIM. Significant progress in the development of HTS base conductor manufactured by the "powder in tube" method reached during the recent years makes these conductors promising in high current applications at liquid nitrogen temperatures.
The basis of this optimistic forecast is high values of the critical current density up to 3x104A/cm2 at 77 K in the self-magnetic field of "2223" (Bi) samples and intensive evolution of the process used to manufacture long multifilamentary wires. The cost of HTS wire would decrease down to $0.8 per ampere x metre for power applications, and researchers hope that it will be a stepping stone to the large-scale commercialisation of the high-temperature superconductors.
With low thermal conductivity and excellent critical transport property, HTS current lead has promising prospects for application in electrical power engineering, and now much effort is spent at BARSHM and IHEP on constructing Bi(2223) Current Lead of I kA.
Quadrupoles with a high gradient field are needed at collider for high luminosity due to the requirements on emittance in the low-beta insertion cites. In the frame of the collaboration between IHEP, BARSIIM and FNAL, a design of a Nb3Sn quadrupole with a high gradient field (220 T/m) is being developed at IHEP.
Experimental investigations of the physics of electron-positron collisions are in progress at the Budker Institute of Nuclear Physics (BINP, Novosibirsk). The status report on VEPP-2M and VEPP- 4M was presented by S.l. Mishnev. At present, the physical experimental program has started at new detector KEDR installed at the modified storage ring VEPP-4M. The possibilities to measure the total cross-section of e+e- annihilation in the energy range from 0.7 GeV to 1.8 GeV were also discussed. The luminosity of the VEPP-2M boasted by superconducting wiggler magnet in the energy range from 2x200 MeV to 2x700 MeV.
The Protvino branch of BINP in collaboration with the KEK Laboratories (Japan) presented the experimental test results of the klystron with a PPM focusing system The high-power klystron developed by BINP successfully generated the 77 MW peak power with the pulse width of 0.1 microsec at the frequency 11.424 GHz. The output power in RF loads was 68 MW with RF pulse duration equal to 300 ns, and the gun voltage equal to 533 kV. It is possible to avoid the beam interception by increasing the magnetic field magnitude in the output section of PPM. These results are a part of the R&D programs at KEK for the future electron-positron linear collider in the ambitious X-band region.
The Protvino branch of BINP reported about development a new type of Beam Position Monitor (BPM) with submicron resolution. In first tests at the BNL (USA) was demonstrated 0.15 micron resolution on beam position.
Much effort is spent worldwide on constructing a safe nuclear plant for generating electricity and development of advanced nuclear power technologies for nuclear waste transmutation. Much interest is focused on a scheme with a linear proton accelerator that is used to produce an intense neutron flux. Efforts to implement this conceptual designes were discussed at IHEP, ITEP and the Moscow Engineering Physics Institute.
The Institute of Theoretical and Experimental Physics (ITEP, Moscow) is planning to upgrade its ion facility to reach the output of 1TW at beam energy of up to 3 GeV per nucleon. Boris Yu. Sharkov (ITEP, Moscow) described the international program of the upgraded ion facility which will include research in relativistic nuclear physics.
The current trends for hadron therapy were illuminated by V.S.Khoroshkov (ITEP). Plans for a center of proton-ion therapy in Moscow, based on a medical machine (H' accelerator), were discussed by the specialists from ITEP, Moscow Institute of Radio Engineering, Moscow hospitals and by the physicists from IHEP.
Host-physicists from the IHEP laboratories presented many interesting talks. Alexander V. Vasilev and his colleagues (Institutes of Protvino and Obninsk) proposed a project of precision beams for hadron therapy, where patients are treated with a linear proton accelerator l-LOO (since 1985 out of operation as injector of the U-70). Alvarez-type linac with the total length of 80 m has operated as long as 4700 h. Physicists presented a new facility using carbon ions at this linac.
Alexander G.Afonin reported the record value of extraction efficiency to be over than 40%. This was achieved by using a short Si-crystal 5 mm long, that is bent at a small angle of 1.5 mrad to extract 70 GeV protons. Sergei V.Ivanov reviewed a set of longitudinal feedback systems foreseen around RF 200 MHz in the IHEP 600 GeV UNK PS project. Performance data on these circuits which would govern acceleration of intense beam were estimated. The feedback systems are needed at accelerator for high energy due strong requirements on emittance.
The participants of the workshop were informed of advances in constructing the 600-GeV proton accelerator UNK in Protvino, and had an opportunity of inspecting the tunnel section with installed equipment for injecting the proton beam transported from the existing 70-GeV machine (the strong-focusing synchrotron U-70).
UNK is a large complex for accelerating and storage 6x1014 protons for fixed target experiments. The accelerating-storage complex is situated in an underground circular tunnel with circumference of 20.77 km. Up to now the long tunnel with a 5.1 m diameter has been excavated and j prepared for installing the equipment. Above 1500 conventional magnets (dipole 5.8 m long) have j been manufactured at the Research Institute of Electrophysical Equipment (RIFE, St.Petersburg), j but further fabrication of magnets has stopped because of suspended funding, and thus production I order has not yet been completed.
The first stage of UNK is the 600 GeV proton accelerator (V-600), and it include a proton injection channel (commissioned in 1994), ring accelerator in the underground tunnel, buildings of conventional engineering systems. About $760 US million have been used for the accelerator purposes out and the necessary financing for the operational launch of U-600 makes near $170 US million. Tunneling has been fully completed and now the ring tunnel (circumference 20.77 km) has the second long in the world (after LEP), but tunnel diameter is 5.2 m.
In 1998 the "Proton" electric substation (rated up 400 MW) commissioned and U-70 electric equipment connected to Kursk Atomic Station. The research program at U-600 is unique due to high intensity of the proton beam (5x1014 ppp) and the wide spectrum of the secondary particle beams. The U-70 proton accelerator will be employed in a novel capacity as the UNK injector.
Leonid Shirshov
"Beam Dynamics Newsleter", N 19, april 1999