Pivin, R.
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DEVELOPMENT OF THE POSITRON INJECTOR FOR LEPTA FACILITY |
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V. Bykovsky¹, I. Meshkov¹, V. Pavlov¹, R. Pivin¹, A. Rudakov¹, G. Trubnikov¹, S. Yakovenkoª¹, M.K. Eseev² ¹Joint Institute for Nuclear Research, Dubna, Russia ²Lomonosov Pomor State University, Arkhangelsk, Russia Abstract An injector of the low energy positrons for the accumulator LEPTA has being assembled at JINR. The injector is based on 22Na radioactive source. Positrons from the source are moderated in the solid neon. The cryogenic source of slow positrons has been tested with a isotope 22Na of the initial activity of 0.8 MBk. The continuous slow positron beam with average energy of 1.2 eV, width of a spectrum 1 eV has been obtained. The achieved moderator efficiency is about 1 %. The accumulation process in the positron trap was investigated with electron flux. The life time of the electrons in the trap, τlife≥80 s and capture efficiency ε~0.4 have been obtained. The maximum number of the accumulated particle was Nexper = 2∙108 at the initial flux of 5∙106 electrons per sec. ª – corresponding author |
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SIMULATION OF PELLET TARGET EXPERIMENTS WITH BETACOOL CODE |
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A. Smirnov¹, A. Sidorin¹, D. Krestnikovª¹, R. Pivin¹, D. Prasuhn², M. Wolke² ¹Joint Institute for Nuclear Research, Dubna, Russia ²Institut für Kernphysik, Forschungszentrum Jülich GmbH, Jülich, Deutsch Abstract In last years at GSI (Germany) new accelerator complex project FAIR is being realized. One of the most important goals of this project is caring out an experiment with internal target PANDA [1]. The only way to achieve design luminosity value is to use a pellet target. However, such a target is coming up with short-scale luminosity variation. Peak to mean luminosity ratio can reach a big value unacceptable for detector. A numerical simulation of this experiment is connected to two different time-scale processes. The first one is the short-time process, which describes luminosity variations while one pellet is crossing the beam. This process can be about tenths microsecond long. The long-time process of the beam parameter evolution (particle number, transverse and longitudinal profiles) are defined by the beam losses and equilibrium between target heating and electron cooling. This article presents the numerical simulations with BETACOOL code [2] which allows solving both these tasks. ª – corresponding author |
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SIMULATION STUDY OF STABLE AND MOVING BARRIER BUCKETS USING BETACOOL CODE |
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A. Smirnov, A. Sidorin, R. Pivinª, D. Krestnikov Institute of High Current Electronics, Siberian Branch of the Russian Academy of Sciences, Tomsk State University, Tomsk, Russia Abstract A moving barrier RF bucket is an effective ion beam accumulation method used, for instance, in Fermilab's Recycler and proposed for NESR at FAIR project. A possible application of a stationary RF bucket is to compensate an ionization energy loss in experiments with an internal target. The ionization energy loss is the main physical effect limiting the experiment duration. The barrier bucket application permits to sufficiently decrease of a required power of a cooling system when a high resolution in an experiment is necessary[1]. Recently a new program was developed for barrier RF bucket simulation for FAIR rings [2]. To compare predictions of different models and to estimate efficiency of the barrier bucket application in internal target experiments the new algorithms were implemented into Betacool program [3] also. ª – corresponding author |
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STATUS OF THE LEPTA PROJECT |
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V. Bykovsky, E. Ahmanova, V.I. Kaplin, V.N. Karpinsky, A. Kobetsª, V. Lokhmatov, V. Malakhov, I. Meshkov, R. Pivin, A. Rudakov, G. Trubnikov, S. Yakovenko Joint Institute for Nuclear Research, Dubna, Russia Abstract The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron cooling system. The project positron energy is of 4÷10 keV. The main goal of the facility is to generate an intense flux of positronium atoms – the bound state of electron and positron. The focusing system of the LEPTA ring after solenoidal magnetic field remeasurement and correction has been tested with pulsed electron beam by elements. Some resonant effects of beam focusing have been observed. Storage ring of LEPTA facility was commissioned in September 2004. Since then the ring was equipped with additional beam diagnostics. The magnetic field quality in the ring was improved. Results of testing the storage ring with electron beam after the upgrade are presented. The experiments aiming to increase the life time of the circulating electron beam and test the electron cooling elector beam are in progress. ª – corresponding author |
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