WEPPO —  Poster Session   (12-Jun-13   10:30—12:30)
Chair: T. Eriksson, CERN, Geneva, Switzerland

Paper	Title	Page
WEPPO01	Fast Laser Cooling of Long Lived Ion Beams	94
	E.G. Bessonov, A.L. Osipov LPI, Moscow, Russia A.A. Mikhailichenko Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	The peculiarity of the fast laser cooling of the long lived excited ion beams is discussed. In this case Robinson damping criterion is not valid as frictional forces take place not only at the moment of their interaction with laser beam but in time delay between the interaction time and the gamma release (deexcitation) for the order of some periods of betatron oscillations*. The optimization of the lattice for this case of cooling is discussed. Fast cooling based on both electronic and nuclear transitions is important for the physics of colliding ion beams and light sources based on relativistic ion beams**. * E.G. Bessonov, Proc. COOL 2009, China, p. 91-93; arxiv:0808.2342; ** E.G.Bessonov, http://arxiv.org/abs/1301.5335.
WEPPO02	Stacking Modes with Barrier Buckets Method in NICA Collider	97
	A.V. Smirnov, I.N. Meshkov, A.O. Sidorin, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia A.V. Eliseev JINR/VBLHEP, Dubna, Moscow region, Russia T. Katayama GSI, Darmstadt, Germany
	A new accelerator complex NICA is under construction at JINR now. The main goal of this project is to reach a very high luminosity of 1027 [cm-2 c-1] in the colliding experiments with gold ions in the energy range of 1 – 4.5 GeV/u. Both electron and stochastic cooling methods will be used to provide the necessary beam parameters. The beam stacking in the longitudinal phase space with stationary and moving barrier buckets in NICA Collider under action of cooling methods or without cooling are presented in this report.
WEPPO03	Operational Experience with the HESR Electron Cooler Test Set-up	100
	M.W. Bruker, K. Aulenbacher, J. Dietrich, S. Friederich, A. Hofmann, T. Weilbach HIM, Mainz, Germany K. Aulenbacher IKP, Mainz, Germany
	The electron cooler test set-up built at Helmholtz-Institut Mainz as a feasibility study for the electron cooling device at the High Energy Storage Ring (HESR) at FAIR has been set in operation. One of the main goals of the test set-up is to evaluate the gun design proposed by TSL (Uppsala) with respect to vacuum handling, EM fields and the resulting beam parameters. Another purpose of the set-up is to achieve an energy recuperation efficiency of 1 - 10-5. To measure this quantity, a Wien filter will be employed, which will also prove capable of mitigating collection losses. Recent developments and operational experiences with the test set-up will be presented.
	Poster WEPPO03 [4.290 MB]
WEPPO04	Collector for Electron Cooling Systems with Suppression of Reflected Electron Flux	103
	M.I. Bryzgunov, A.V. Bubley, V.A. Chekavinskiy, I.A. Gusev, A.V. Ivanov, M.N. Kondaurov, V.M. Panasyuk, V.V. Parkhomchuk, D.N. Pureskin, A.A. Putmakov, V.B. Reva, D.V. Senkov, D.N. Skorobogatov BINP SB RAS, Novosibirsk, Russia
	Results of testing of the collector with Wien filter in the 2 MeV electron cooling system for COSY synchrotron are presented. Efficiency of a collector in high voltage electron cooling devices is important from the point of view of the load on high voltage power supply, radiation safety and vacuum conditions in the system. The collector for 2 MeV COSY cooler is supplemented with Wien filter which allows increase efficiency of the system by deflection secondary electron flux in crossed transverse electric and magnetic fields. Results of tests show that such solution provides efficiency of recuperation in the cooler up to 10-5. After tests some changes were made in the construction of the Wien filter to improve quality of the collector performance.
WEPPO05	Powering of the HV-Solenoids at the HESR Electron Cooler	107
	A. Hofmann, K. Aulenbacher, M.W. Bruker, J. Dietrich, S. Friederich, T. Weilbach HIM, Mainz, Germany
	The experiments at the planned 'High Energy Storage Ring' (HESR) require magnetised electron cooling. One of the challenges is the powering of the HV-solenoids, which are located on so-called separation boxes inside a high voltage vessel. Because the separation boxes sit on electrical potential, a floating power supply for the HV-solenoids is needed. A currently discussed concept is the use of turbo generators. The turbo generators, an assembly of a turbine and an electrical generator, will also be used as floating supply for a cascade generator generating the potential difference between the individual separation boxes. The turbine is powered by gas, e.g. dry air or -preferantially - sulphur hexafluoride, under high pressure, consequently driving the generator which delivers an electrical power of 5 kW. The high pressure gas could be generated outside the high voltage vessel and guided to the turbine afterwards. The presentation gives an overview of the turbo generator project: an introduction, a status report and a road map will be given.
	Poster WEPPO05 [3.402 MB]
WEPPO07	Matching of Magnetic Field with Energy of Electrons in 2 MeV COSY Cooler	110
	V.M. Panasyuk, M.I. Bryzgunov, A.V. Bubley, V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia
	In the high energy electron cooler for COSY the beam energy range is wide (24 keV- 2 MeV). Typical guiding magnetic fields are 0.5 kG in accelerating tube, 1kG in transport channels and 2 kG in cooling solenoid and adjoining 45 degree toroids. As a result we have two sections with longitudinal gradient of field, three 90 degree bends and 45 degree toroid before solenoid entrance. In such circumstances the conditions of passage of electrons through the channel and theirs entrance into solenoid without heating are discussed. Also the results of using of correctors and pick-up system are considered.
WEPPO08	Electron Cooler for the NICA Collider	113
	S. Yakovenko, E.V. Ahmanova, A.G. Kobets, I.N. Meshkov, R.V. Pivin, A.Yu. Rudakov, A.V. Shabunov, A.V. Smirnov, N.D. Topilin, Yu.A. Tumanova JINR, Dubna, Moscow Region, Russia A.A. Filippov Allrussian Electrotechnical Institute, Moskow, Russia A.V. Ivanov, V.V. Parkhomchuk BINP SB RAS, Novosibirsk, Russia
	The goal of the cooling system of the NICA collider is to meet the required parameters of ion beams in energy range of 1–4.5GeV/u that corresponds to the 0.5–2.5 of the electron MeV. The electron cooler is developed according to the available world practice of manufacturing of similar systems. The main peculiarity of the electron cooler for the NICA collider is use of two cooling electron beams (one electron beam per each ring of the collider) that never has been done. The acceleration and deceleration of the electron beams is produced by common high-voltage generator. The cooler consist of three tanks. Two of them contain acceleration/deceleration tubes and are immersed in superconducting solenoids. The third one contains HV generator. The scheme of the electron cooler, its main parameters and operation regime are presented.
	Poster WEPPO08 [0.443 MB]
WEPPO10	Beam Profile Measurements for Magnetized High Energy Cooling Devices	116
	T. Weilbach, K. Aulenbacher, M.W. Bruker HIM, Mainz, Germany
	Recent developments in the field of magnetized high energy electron coolers, have led to special demands on the beam diagnostics. Since commonly used diagnostic tools such as the recombination rate of electrons and protons to H0 are not useful for the antiproton beam of the HESR at FAIR new methods are needed. Hence for beam profile measurements a system based on beam induced fluorescence (BIF) was built. This quite simple system images the light generated by the interaction of the beam with the residual gas onto a PMT. A more elaborated system, the Thomson Laser Scanner (TLS) - the non-relativistic version of the Laser Wire Scanner - is proposed as a method for non-invasive measurement of all phase space components. Both methods are implemented in the beamline of a a 100 keV photo gun. Beam profile measurements with BIF as well as first results of the TLS will be presented.
	Poster WEPPO10 [1.712 MB]
WEPPO11	LEPTA Project: Towards Positronium	119
	A.G. Kobets, E.V. Ahmanova, V.I. Lokhmatov, I.N. Meshkov, V. Pavlov, A.Yu. Rudakov, A.A. Sidorin, S. Yakovenko JINR, Dubna, Moscow Region, Russia M.K. Eseev NAFU, Arkhangelsk, Russia
	The Low Energy Positron Toroidal Accumulator (LEPTA) at JINR is close to be commissioned with circulating positron beam. The LEPTA facility is a small positron storage ring equipped with the electron cooling system and positron injector. The maximum positron energy is of 10 keV. The main goal of the project is generation of intensive flux of Positronium (Ps) atoms - the bound state of electron and positron, and setting up experiments on Ps in-flight. The report presents an advance in the project: up-grade of LEPTA ring magnetic system, status of the construction of positron transfer channel, and the electron cooling system, first results of low energy positron beam formation with 22Na radioactive positron source of radioactivity of 25 mCi.
WEPPO12	Compass for Measuring the Magnetic Lines Straightness at the Cooling Section in Vacuum	121
	A.V. Bubley, M.I. Bryzgunov, V.G. Cheskidov, M.G. Fedotov, V.K. Gosteev, O.I. Meshkov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia V. Kamerdzhiev, G. Langenberg FZJ, Jülich, Germany
	The 2 MeV cooler is under construction at COSY synchrotron. Due to high energy it is very strict requirement for the magnetic field homogeneity at the cooling solenoid. Since the magnetic field has to be adjusted during the accelerator operation, the measurement system is installed inside vacuum chamber. The design and features of this system are described in the article, as well as preliminary results are discussed.
WEPPO13	Simulation Study of Beam Cooling with Electron Energy Modulation	124
	L.J. Mao FZJ, Jülich, Germany J. Dietrich HIM, Mainz, Germany J. Dietrich DELTA, Dortmund, Germany J. Li, X.D. Yang IMP, Lanzhou, People's Republic of China
	The electron cooling is less efficient for hot ion beam because the cooling force reduces rapidly at high electron-ion relative velocity. A possibility of electron cooling for ion beam with large velocity spread was studied by simulation. The electron beam velocity swept through the ion velocity distribution during cooling procedure. The average friction force will be increased at high electron-ion relative velocity range. The results show a fast beam distribution shrinking could be achieved through the electron energy sweep method. The cooling time dependence on the modulation frequency and amplitude was investigated by simulation. The simulation results also show different ion beam longitudinal velocity distribution can be produced via electron energy modulation.
WEPPO14	Present Status of Coherent Electron Cooling Proof-of-principle Experiment	127
	I. Pinayev, S.A. Belomestnykh, I. Ben-Zvi, K.A. Brown, J.C. Brutus, L. DeSanto, A. Elizarov, C. Folz, D.M. Gassner, Y. Hao, R.L. Hulsart, Y.C. Jing, D. Kayran, R.F. Lambiase, V. Litvinenko, G.J. Mahler, M. Mapes, W. Meng, R.J. Michnoff, T.A. Miller, M.G. Minty, P. Orfin, A. Pendzick, F. Randazzo, T. Rao, T. Roser, J. Sandberg, B. Sheehy, J. Skaritka, K.S. Smith, L. Snydstrup, R. Than, R.J. Todd, J.E. Tuozzolo, G. Wang, D. Weiss, M. Wilinski, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA G.I. Bell, J.R. Cary, K. Paul, B.T. Schwartz, S.D. Webb Tech-X, Boulder, Colorado, USA C.H. Boulware, T.L. Grimm, R. Jecks, N. Miller Niowave, Inc., Lansing, Michigan, USA M.A. Kholopov, P. Vobly BINP SB RAS, Novosibirsk, Russia M. Poelker JLAB, Newport News, Virginia, USA
	We conduct proof-of-the-principle experiment of coherent electron cooling (CEC), which has a potential to significantly boost luminosity of high-energy, high-intensity hadron colliders. In this paper, we present the progress with experimental equipment including the first tests of the electron gun and the magnetic measurements of the wiggler prototype. We describe current design status as well as near future plans.
WEPPO15	ELENA: From the First Ideas to the Project	130
	G. Tranquille, P. Belochitskii, T. Eriksson, L.V. Jørgensen, S. Maury CERN, Geneva, Switzerland W. Oelert FZJ, Jülich, Germany
	The LEIR electron cooler was successfully commissioned in 2006 and is used to routinely cool and accumulate high brightness beams of Pb54+ ions for the LHC. Some initial measurements on the performance of the device were reported in 2007 but did not fully study the influence of the electron beam current and density distribution on beam cooling. We present a compilation of measurements performed over the last years during dedicated machine study sessions which aim to shed some light as to the effectiveness of electron cooling with hollow beams.
	Poster WEPPO15 [2.817 MB]
WEPPO16	The ELENA Electron Cooler: Parameter Choice and Expected Performance	133
	G. Tranquille, A. Frassier, L.V. Jørgensen CERN, Geneva, Switzerland
	Electron cooling will be central to the success of the ELENA project which aims to increase by a factor of up to 100 the number of antiprotons available for the trap experiments. Because of the tight space constraints, the design of the device will be based on the compact electron cooler in operation on the S-LSR ring in Kyoto. The biggest challenge will be to generate a cold and stable electron beam at an energy of just 55 eV in order to cool the 100 keV antiprotons. The use of photocathodes is excluded because their relatively short lifetimes would require too many vacuum interventions during operations. We present the design parameters of our cooler as well as the results of the cooling performance simulations made with BetaCool and on-going work into "cold" cathodes.
	Poster WEPPO16 [2.939 MB]
WEPPO17	Results from Step I of MICE and Physics Plan for Step IV	136
	V. Blackmore Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	The Muon Ionisation Cooling Experiment (MICE) will demonstrate ionisation cooling, an essential technology for a Neutrino Factory and/or Muon Collider, by measuring a 10% reduction in emittance of a muon beam. A realistic demonstration requires beams closely resembling those expected at the front-end of a Neutrino Factory, i.e. with large transverse emittance and momentum spreads. The MICE muon beam line at ISIS, RAL, was built to provide beams of different momenta and emittance so that the performance of the cooling channel can be fully explored. During the initial stage of MICE, a novel technique based on time-of-flight counters was used to establish that the beam emittances are in the range 0.7–2.8 mm-rad, with central momenta from 170–280 MeV/c, and momentum spreads of about 20 MeV/c. These beams will be increased by means of scattering from high-Z material in the next stage of MICE and measured using magnetic spectrometers. Finally, low-Z absorbers such as liquid hydrogen and LiH will be used to reduce the emittance of the beam. The physics program of this step of MICE will be discussed, including all stages necessary for a first demonstration of ionisation cooling. On behalf of the MICE Collaboration
WEPPO18	Progress Towards the Completion of the MICE Apparatus	139
	K. Ronald, A.J. Dick, C.G. Whyte USTRAT/SUPA, Glasgow, United Kingdom
	MICE aims to demonstrate 10% ionisation cooling of a synthesised beam of muons by its interaction with low Z absorber materials followed by restoration of translational momentum in RF linacs. Extensions to the apparatus required to achieve STEP IV, including the first absorber cell, of either liquid hydrogen or lithium hydride, sandwiched between two particle tracking spectrometers shall be described. Two very large superconducting spectrometer solenoids and one focus coil solenoid, manufactured in the US and UK, will provide a magnetic field of ~4 T respectively in the volume of the two trackers and the absorber cell. The development, testing and integration of these challenging components will be reported. Progress towards STEPs V & VI including tests of the RF cavities to demonstrate the required 8 MV/m gradient in a strong magnetic field will be presented, including the RF drive system to deliver 2 MW, 1 ms pulses of 201 MHz frequency at a PRF of 1Hz, the distribution network to deliver 1 MW to each cavity with correct RF phasing, diagnostics to determine the gradient and transit phase of the muons and the development of the very large diameter magnets required for the linacs. on behalf of the MICE Collaboration
WEPPO19	The Novel Optical Notch Filter for Stochastic Cooling at the ESR	142
	W. Maier, C. Dimopoulou, R. Hettrich, F. Nolden, C. Peschke, P. Petri, M. Steck GSI, Darmstadt, Germany
	In the frame of the development for the FAIR facility at GSI, notch filter cooling is essential for the stochastic cooling system of the CR (Collector Ring). A prototype notch filter based on optical components has been developed and built. The focus was to achieve sufficient notch depth and low dispersion of the filter transfer function. The compact optical notch filter was integrated into the ESR stochastic cooling system. Momentum cooling of heavy ion beams was successfully demonstrated. The layout of the notch filter as well as experimental results are presented
WEPPO20	RF-System for Stochastic Cooling in the FAIR Collector Ring	146
	C. Peschke, R.M. Böhm, C. Dimopoulou, F. Nolden, P. Petri GSI, Darmstadt, Germany
	The collector ring (CR) of the FAIR project is designed for fast stochastic cooling of rare isotope and antiproton beams injected at different velocities. A flexible rf signal processing scheme for the stochastic cooling system will be presented. It includes cooling with time of flight (TOF), notch filter and Palmer methods. A Palmer pick-up with Faltin electrodes is foreseen for pre-cooling of hot rare isotope beams. For TOF and notch filter methods, a horizontal and a vertical pick-up tank with movable cryogenic slotline electrodes for ions with two different velocities is under development. The layout of this slotline pick-up tank will also be presented.
	Poster WEPPO20 [2.410 MB]
WEPPO21	Design of the Palmer Pickup for Stochastic Pre-cooling of Heavy Ions at the CR	149
	L. Thorndahl CERN, Geneva, Switzerland D. Barker, C. Dimopoulou, C. Peschke GSI, Darmstadt, Germany
	We detail the design and optimisation of modified Faltin type pick-ups for the pre-cooling of heavy ions in the CR ring at GSI. The design challenge includes simultaneous optimisation of large pick-up impedance, 50 Ω characteristic impedance, frequency independence over a large bandwidths and phase velocity matched to particle velocity. Although heavy ions offer large signals due to their charge, their relatively slow velocity is difficult to match in Faltin type pick-ups while maintaining a flat frequency response and a 50 Ω characteristic impedance. We explain the design process, and show how multiple parameters are simultaneously optimised using genetic algorithms, which are suitable for optimization problems with large and complex search spaces.