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Sample records for antiproton acceleration scheme

  1. Antiproton acceleration in the Fermilab Main Ring and Tevatron

    International Nuclear Information System (INIS)

    Martin, P.; Dinkel, J.; Ducar, R.

    1987-01-01

    The operation of the Fermilab Main Ring and Tevatron rf systems for colliding beams physics is discussed. The changes in the rf feedback system required for acceleration of antiprotons, and the methods for achieving proper transfer of both protons and antiprotons are described. Data on acceleration and transfer efficiencies are presented

  2. CERN accelerator school: Antiprotons for colliding beam facilities

    International Nuclear Information System (INIS)

    Bryant, P.; Newman, S.

    1984-01-01

    This is a specialized course which addresses a wide spectrum of theoretical and technological problems confronting the designer of an antiproton facility for high-energy-physics research. A broad and profound basis is provided by the lecturers' substantial experience gained over many years with CERN's unique equipment. Topics include beam optics, special lattices for antiproton accumulation and storage rings, antiproton production, stochastic cooling, acceleration and storage, r.f. noise, r.f. beam manipulations, beam-beam interaction, beam stability due to ion accumulation, and diagnostics. The SPS (Super Proton Synchrotron) panti p collider, LEAR (the Low Energy Antiproton Ring at CERN), antiprotons in the ISR (Intersecting Storage Rings), the new antiproton collector (ACOL) and gas jet targets are also discussed. A table is included listing the parameters of all CERN's accelerators and storage rings. See hints under the relevant topics. (orig./HSI)

  3. A measurement of the gravitational acceleration of the antiproton

    International Nuclear Information System (INIS)

    Holzscheiter, M.H.

    1990-01-01

    A fundamental experiment in gravity proposed by us, is the measurement of the gravitational force on antimatter. This measurement would constitute the first direct test of the Weak Equivalence Principle (WEP) for antimatter. The availability of low-energy antiprotons at CERN has made such an experiment feasible, and a proposal to carry out such a measurement has been accepted by the CERN Program Committee. We plan to use a time-of-flight technique similar to that pioneered by Fairbank and Witteborn in their measurement of the gravitational force on an electron. Very slow particles are launched into a vertical drift tube and the time-of-flight spectrum of these particles is recorded. This spectrum will exhibit a cut-off point directly related to the gravitational acceleration of the particles. Obtaining very slow antiprotons involves several stages of deceleration. Antiprotons from LEAR will be initially decelerated from 2 MeV to tens of kilovolts by passing them through a thin foil. After capture and cooling in a series of ion traps, the antiprotons will be in a thermal distribution with a temperature of a few degrees Kelvin. These ultra-cold antiprotons will then be released a few at a time into the drift tube. A detector will measure the arrival time of the particles at the exit of the drift tube. H - -ion, which have almost identical electromagnetic properties to the antiprotons, will be used for comparison and as a calibration standard. 7 refs., 1 fig

  4. The CERN Antiproton Collider Programme Accelerators and Accumulation Rings

    CERN Document Server

    Koziol, Heribert

    2004-01-01

    One of CERN's most daring and successful undertakings was the quest for the intermediate bosons, W and Z. In this paper, we describe the accelerator part of the venture which relied on a number of innovations: an extension of the budding method of stochastic cooling by many orders of magnitude; the construction of the Antiproton Accumulator, depending on several novel accelerator methods and technologies; major modifications to the 26 GeV PS Complex; and the radical conversion of the 300 GeV SPS, which just had started up as an accelerator, to a protonâ€"antiproton collider. The SPS Collider had to master the beamâ€"beam effect far beyond limits reached ever before and had to function in a tight symbiosis with the huge detectors UA1 and UA2.

  5. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Cholis, Ilias [Johns Hopkins U.; Hooper, Dan [Chicago U., KICP; Linden, Tim [Ohio State U.

    2017-01-16

    The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $\\bar{p}/p$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $\\bar{p}/p$ ratio observed at rigidities above $\\sim$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.

  6. A reservoir trap for antiprotons

    CERN Document Server

    Smorra, Christian; Franke, Kurt; Nagahama, Hiroki; Schneider, Georg; Higuchi, Takashi; Van Gorp, Simon; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Yamazaki, Yasunori; Ulmer, Stefan

    2015-01-01

    We have developed techniques to extract arbitrary fractions of antiprotons from an accumulated reservoir, and to inject them into a Penning-trap system for high-precision measurements. In our trap-system antiproton storage times > 1.08 years are estimated. The device is fail-safe against power-cuts of up to 10 hours. This makes our planned comparisons of the fundamental properties of protons and antiprotons independent from accelerator cycles, and will enable us to perform experiments during long accelerator shutdown periods when background magnetic noise is low. The demonstrated scheme has the potential to be applied in many other precision Penning trap experiments dealing with exotic particles.

  7. New schemes for particle accelerators

    International Nuclear Information System (INIS)

    Nishida, Y.

    1985-01-01

    In the present paper, the authors propose new schemes for realizing the v/sub p/xB accelerator, by using no plasma system for producing the strong longitudinal waves. The first method is to use a grating for obtaining extended interaction of an electron beam moving along the grating surface with light beam incident also along the surface. Here, the light beam propagates obliquely to the grating grooves for producing strong electric field, and the electron beam propagates in parallel to the light beam. The static magnetic field is applied perpendicularly to the grating surface. In the present system, the beam interacts synchronously with the p-polarized wave which has the electric field be parallel to the grating surface. Another conventional scheme is to use a delay circuit. Here, the light beam propagates obliquely between a pair of array of conductor fins or slots. The phase velocity of the spatial harmonics in the y-direction (right angle to the array of slots) is slower than the speed of light. With the aid of powerful laser light or microwave source, it should be possible to miniaturise linacs by using the v/sub p/xB effect and schemes proposed here

  8. A measurement of the gravitational acceleration of the anti-proton

    CERN Document Server

    Holzscheiter, M H

    1990-01-01

    A fundamental experiment in gravity proposed by us, is the measurement of the gravitational force on antimatter. This measurement would constitute the first direct test of the Weak Equivalence Principle (WEP) for antimatter. The availability of low-energy antiprotons at CERN has made such an experiment feasible, and a proposal to carry out such a measurement has been accepted by the CERN Program Committee. We plan to use a time-of-flight technique similar to that pioneered by Fairbank and Witteborn in their measurement of the gravitational force on an electron. Very slow particles are launched into a vertical drift tube and the time-of-flight spectrum of these particles is recorded. This spectrum will exhibit a cut-off point directly related to the gravitational acceleration of the particles. Obtaining very slow antiprotons involves several stages of deceleration. Antiprotons from LEAR will be initially decelerated from 2 MeY to tens of kilovolts by passing them through a thin foil. After capture and cooling ...

  9. The antiproton decelerator: AD

    International Nuclear Information System (INIS)

    Baird, S.; Berlin, D.; Boillot, J.; Bosser, J.; Brouet, M.; Buttkus, J.; Caspers, F.; Chohan, V.; Dekkers, D.; Eriksson, T.; Garoby, R.; Giannini, R.; Grobner, O.; Gruber, J.; Hemery, J.Y.; Koziol, H.; Maccaferri, R.; Maury, S.; Metzger, C.; Metzmacher, K.; Moehl, D.; Mulder, H.; Paoluzzi, M.; Pedersen, F.; Riunaud, J.P.; Serre, C.; Simon, D.J.; Tranquille, G.; Tuyn, J.; Williams, B.

    1997-01-01

    In view of a possible future programme of physics with low-energy antiprotons, a simplified scheme for the provision of antiprotons at 100 MeV/c has been studied. It uses the present target area and the modified antiproton collector (AC) in its present location. In this report the modifications and the operation are discussed. (orig.)

  10. The Antiproton Accumulator and Collector and the discovery of the W & Z intermediate vector bosons

    CERN Document Server

    Chohan, Vinod

    2016-01-01

    The following sections are included: Preface ; Brief outline of the overall scheme for antiprotons of the SPS as a collider ; Antiproton production and accumulation ; The AA and AC storage rings ; Stochastic cooling and stacking ; Post-acceleration of antiprotons and beams for SPS Collider ; Proton test beams for the AA and AC from the PS ; The W and Z discoveries and the Nobel Prize ; Accumulator performance ; Acknowledgements and conclusions ; References

  11. Studies of the plasma droplet accelerator scheme

    International Nuclear Information System (INIS)

    Mori, W.B.; Joshi, C.; Dawson, J.M.; Lee, K.; Forslund, D.W.; Kindel, J.M.

    1985-01-01

    In the plasma droplet accelerator scheme, proposed by R. Palmer, a sequence of liquid micro-spheres generated by a jet printer are ionized by an incoming intense laser. The hope is that the micro-spheres now acting as conducting balls will allow efficient coupling of the incoming laser radiation into an accelerating mode. Motivated by this the authors have carried out 2D, particle simulations in order to answer some of the plasma physics questions hitherto unaddressed. In particular they find that at least for laser intensities exceeding v 0 /c=0.03 (/sup ∼/10 13 w/cm 2 for a CO 2 laser), the incident laser light is rather efficiently absorbed in a hot electron distribution. Up to 70% of the incident energy can be absorbed by these electrons which rapidly expand and fill the vacuum space between the microspheres with a low density plasma. These results indicate that it is advisable to stay clear of plasma formation and thus put on an upper limit on the maximum surface fields that can be tolerated in the droplet-accelerator scheme

  12. Studies of the plasma droplet accelerator scheme

    International Nuclear Information System (INIS)

    Mori, W.B.; Dawson, J.M.; Forslund, D.W.; Joshi, C.; Kindel, J.M.; Lee, K.

    1985-01-01

    In the plasma droplet accelerator scheme, proposed by R. Palmer, a sequence of liquid micro-spheres generated by a jet printer are ionized by an incoming intense laser. The hope is that the micro-spheres now acting as conducting balls will allow efficient coupling of the incoming laser radiation into an accelerating mode. Motivated by this we have carried out 2D, particle simulations in order to answer some of the plasma physics questions hitherto unaddressed. In particular we find that at least for laser intensities exceeding v /SUB o/ /c=0.03 ( about10 13 w/cm 2 for a CO 2 laser), the incident laser light is rather efficiently absorbed in a hot electron distribution. Up to 70% of the incident energy can be absorbed by these electrons which rapidly expand and fill the vacuum space between the microspheres with a low density plasma. These results indicate that it is advisable to stay clear of plasma formation and thus put on an upper limit on the maximum surface fields that can be tolerated in the droplet-accelerator scheme

  13. Experience with copper oxide production in antiproton source components at Fermi National Accelerator Laboratory

    International Nuclear Information System (INIS)

    Ader, Christine R.; Harms, Elvin R. Jr; Morgan, James P.

    2000-01-01

    The Antiproton (Pbar) Source at Fermi National Accelerator Laboratory is a facility comprised of a target station, two rings called the Debuncher and Accumulator and the transport lines between those rings and the remainder of the particle accelerator complex. Water is by far the most common medium for carrying excess heat away from components, primarily electromagnets, in this facility. The largest of the water systems found in Pbar is the 95 degree Fahrenheit Low Conductivity Water (LCW) system. LCW is water which has had free ions removed, increasing its resistance to electrical current. This water circuit is used to cool magnets, power supplies, and stochastic cooling components and typically has a resistivity of 11--18 megaohms-cm. For more than ten years the Antiproton rings were plagued with overheating magnets due to plugged water-cooling channels. Various repairs have been tried over the years with no permanent success. Throughout all of this time, water samples have indicated copper oxide, CuO, as the source of the contamination. Matters came to a head in early 1997 following a major underground LCW leak between the Central Utilities Building and the Antiproton Rings enclosures. Over a span of several weeks following system turn-on, some twenty magnets overheated leading to unreliable Pbar source operation. Although it was known that oxygen in the system reacts with the copper tubing to form CuO, work to remedy this problem was not undertaken until this time period. Leaks, large quantities of make-up water, infrequent filter replacement, and thermal cycling also result in an increase in the corrosion product release rate. A three-pronged approach has been implemented to minimize the amount of copper oxide available to plug the magnets: (1) installation of an oxygen removal system capable of achieving dissolved oxygen concentrations in the parts per billion (ppb) range; (2) regular closed-loop filter/flushing of the copper headers and magnets and stainless

  14. The GSI plans for an international accelerator facility for beams of ions and antiprotons

    International Nuclear Information System (INIS)

    Suemmerer, K.

    2003-01-01

    GSI proposes to build a next-generation facility for research with relativistic beams of ions and antiprotons. This facility allows a broad range of topics in nuclear and astrophysics, plasma and atomic physics to be addressed. The topic most interesting in the context of this conference is physics with high-intensity beams of exotic nuclei. In addition, a short overview of the opportunities in the other fields of nuclear physics is given

  15. Deceleration of Antiprotons in Support of Antiproton Storage/Utilization Research

    International Nuclear Information System (INIS)

    Howe, Steven D.; Jackson, Gerald P.; Pearson, J. Boise; Lewis, Raymond A.

    2005-01-01

    Antimatter has the highest energy density known to mankind. Many concepts have been studied that use antimatter for propulsion. All of these concepts require the development of high density storage. H-bar Technologies, under contract with the NASA Marshall Space Flight Center, has undertaken the first step toward development of high density storage. Demonstration of the ability to store antiprotons in a Penning Trap provides the technology to pursue research in alternative storage methods that may lead to eventually to high density concepts. H-bar Technologies has undertaken research activity on the detailed design and operations required to decelerate and redirect the Fermi National Accelerator Laboratory (FNAL) antiproton beam to lay the groundwork for a source of low energy antiprotons. We have performed a detailed assessment of an antiproton deceleration scheme using the FNAL Main Injector, outlining the requirements to significantly and efficiently lower the energy of antiprotons. This task shall require a combination of: theoretical/computation simulations, development of specialized accelerator controls programming, modification of specific Main Injector hardware, and experimental testing of the modified system. Testing shall be performed to characterize the system with a goal of reducing the beam momentum from 8.9 GeV/c to a level of 1 GeV/c or less. We have designed an antiproton degrader system that will integrate with the FNAL decelerated/transferred beam. The degrader shall be designed to maximize the number of low energy antiprotons with a beam spot sized for acceptance by the Mark I test hardware

  16. Production and post acceleration scheme for spiral

    International Nuclear Information System (INIS)

    Bibet, D.

    2001-01-01

    SPIRAL, the R.I.B. facility of GANIL uses heavy ion beams to produce radioactive atoms inside a thick target. Atoms are ionised in a compact permanent magnet ECR ion source. The compact cyclotron CIME accelerates the radioactive ions in an energy range from 1.7 to 25 MeV/u. The cyclotron acts as a mass separator with resolving power of 2500. Plastic scintillator and silicon detectors are used to tune the machine at a very low intensity. An overview of the facility, stable beam tests results and the R and D program will be presented. (authors)

  17. Antiproton radiotherapy

    CERN Document Server

    Bassler, Niels; Beyer, Gerd; DeMarco, John J.; Doser, Michael; Hajdukovic, Dragan; Hartley, Oliver; Iwamoto, Keisuke S.; Jakel, Oliver; Knudsen, Helge V.; Kovacevic, Sandra; Møller, Søren Pape; Overgaard, Jens; Petersen, Jørgen B.à; Solberg, Timothy D.; Sørensen, Brita S.; Vranjes, Sanja; Wouters, Bradly G.; Holzscheiter, Michael H.

    2008-01-01

    Antiprotons are interesting as a possible future modality in radiation therapy for the following reasons: When fast antiprotons penetrate matter, protons and antiprotons have near identical stopping powers and exhibit equal radiobiology well before the Bragg-peak. But when the antiprotons come to rest at the Bragg-peak, they annihilate, releasing almost 2 GeV per antiproton–proton annihilation. Most of this energy is carried away by energetic pions, but the Bragg-peak of the antiprotons is still locally augmented with ∼20–30 MeV per antiproton. Apart from the gain in physical dose, an increased relative biological effect also has been observed, which can be explained by the fact that some of the secondary particles from the antiproton annihilation exhibit high-LET properties. Finally, the weakly interacting energetic pions, which are leaving the target volume, may provide a real time feedback on the exact location of the annihilation peak. We have performed dosimetry experiments and investigated the rad...

  18. Antiproton production

    International Nuclear Information System (INIS)

    Lazarus, D.M.

    1987-01-01

    The results for the antiproton momentum spectrum produced in proton reactions on lead at the CERN Antiproton Accumulator is scaled to AGS operating conditions using the Sanford-Wang formula with no correction for target material. Yield predictions as a function of momentum are shown for 28.3 GeV protons on beryllium and results are converted to antiproton beam flux. The AGS Medium Energy Separated Beam has a flux which is a factor of 2 lower than Sanford-Wang predictions. This may be due to factors affecting beam acceptance

  19. Enhanced efficiency of plasma acceleration in the laser-induced cavity pressure acceleration scheme

    International Nuclear Information System (INIS)

    Badziak, J; Rosiński, M; Jabłoński, S; Pisarczyk, T; Chodukowski, T; Parys, P; Rączka, P; Krousky, E; Ullschmied, J; Liska, R; Kucharik, M

    2015-01-01

    Among various methods for the acceleration of dense plasmas the mechanism called laser-induced cavity pressure acceleration (LICPA) is capable of achieving the highest energetic efficiency. In the LICPA scheme, a projectile placed in a cavity is accelerated along a guiding channel by the laser-induced thermal plasma pressure or by the radiation pressure of an intense laser radiation trapped in the cavity. This arrangement leads to a significant enhancement of the hydrodynamic or electromagnetic forces driving the projectile, relative to standard laser acceleration schemes. The aim of this paper is to review recent experimental and numerical works on LICPA with the emphasis on the acceleration of heavy plasma macroparticles and dense ion beams. The main experimental part concerns the research carried out at the kilojoule sub-nanosecond PALS laser facility in Prague. Our measurements performed at this facility, supported by advanced two-dimensional hydrodynamic simulations, have demonstrated that the LICPA accelerator working in the long-pulse hydrodynamic regime can be a highly efficient tool for the acceleration of heavy plasma macroparticles to hyper-velocities and the generation of ultra-high-pressure (>100 Mbar) shocks through the collision of the macroparticle with a solid target. The energetic efficiency of the macroparticle acceleration and the shock generation has been found to be significantly higher than that for other laser-based methods used so far. Using particle-in-cell simulations it is shown that the LICPA scheme is highly efficient also in the short-pulse high-intensity regime and, in particular, may be used for production of intense ion beams of multi-MeV to GeV ion energies with the energetic efficiency of tens of per cent, much higher than for conventional laser acceleration schemes. (paper)

  20. High Energy Density Physics and Exotic Acceleration Schemes

    International Nuclear Information System (INIS)

    Cowan, T.; Colby, E.

    2005-01-01

    The High Energy Density and Exotic Acceleration working group took as our goal to reach beyond the community of plasma accelerator research with its applications to high energy physics, to promote exchange with other disciplines which are challenged by related and demanding beam physics issues. The scope of the group was to cover particle acceleration and beam transport that, unlike other groups at AAC, are not mediated by plasmas or by electromagnetic structures. At this Workshop, we saw an impressive advancement from years past in the area of Vacuum Acceleration, for example with the LEAP experiment at Stanford. And we saw an influx of exciting new beam physics topics involving particle propagation inside of solid-density plasmas or at extremely high charge density, particularly in the areas of laser acceleration of ions, and extreme beams for fusion energy research, including Heavy-ion Inertial Fusion beam physics. One example of the importance and extreme nature of beam physics in HED research is the requirement in the Fast Ignitor scheme of inertial fusion to heat a compressed DT fusion pellet to keV temperatures by injection of laser-driven electron or ion beams of giga-Amp current. Even in modest experiments presently being performed on the laser-acceleration of ions from solids, mega-amp currents of MeV electrons must be transported through solid foils, requiring almost complete return current neutralization, and giving rise to a wide variety of beam-plasma instabilities. As keynote talks our group promoted Ion Acceleration (plenary talk by A. MacKinnon), which historically has grown out of inertial fusion research, and HIF Accelerator Research (invited talk by A. Friedman), which will require impressive advancements in space-charge-limited ion beam physics and in understanding the generation and transport of neutralized ion beams. A unifying aspect of High Energy Density applications was the physics of particle beams inside of solids, which is proving to

  1. Antiprotons are another matter

    International Nuclear Information System (INIS)

    Hynes, M.V.

    1987-01-01

    Theories of gravity abound, whereas experiments in gravity are few in number. An important experiment in gravity that has not been performed is the measurement of the gravitational acceleration of antimatter. Although there have been attempts to infer these properties from those of normal matter, none of these theoretical arguments are compelling. Modern theories of gravity that attempt to unify gravity with the other forces of nature predict that in principle antimatter can fall differently than normal matter in the Earth's field. Some of these supergravity theories predict that antimatter will fall faster, and that normal matter will fall with a small Baryon-number dependance in the earth's field. All of these predictions violate the Weak Equivalence Principle, a cornerstone of General Relativity, but are consistent with CPT conservation. In our approved experiment at LEAR (PS-200) we will test the Weak Equivalence Principle for antimatter by measuring the gravitational acceleration of the antiproton. Through a series of deceleration stages, antiprotons from LEAR will be lowered in energy to ∼4 Kelvin at which energy the gravitational effect will be measureable. The measurement will employ the time-of-flight technique wherein the antiprotons are released vertically in a drift tube. The spectrum of time-of-flight measurements can be used to extract the gravitational acceleration experienced by the particles. The system will be calibrated using H - ions which simulates the electromagnetic behavior of the antiproton, yet is a baryon to ∼0.1%. To extract the gravitational acceleration of the antiproton relative to the H - ion with a statistical precision of 1% will require the release of ∼10 6 to 10 7 particles

  2. Antiprotons are another matter

    International Nuclear Information System (INIS)

    Hynes, M.V.

    1988-01-01

    Theories of gravity abound whereas experiments in gravity are few in number. An important experiment in gravity that has not been performed is the measurement of the gravitational acceleration of antimatter. Although there have been attempts to infer this property from those of normal matter, none of these theoretical arguments are compelling. Modern theories of gravity that attempt to unify gravity with the other forces of nature predict that in principle antimatter can fall differently than normal matter in the Earth's field. Some of these supergravity theories predict that antimatter will fall faster and that normal matter will fall with a small Baryon-number dependence in the Earth's field. All of these predictions violate the Weak Equivalence Principle, a cornerstone of General Relativity, but are consistent with CPT conservation. In our approved experiment at LEAR (PS-200) we will test the Weak Equivalence Principle for antimatter by measuring the gravitational acceleration of the antiproton. Through a series of deceleration stages, antiprotons from LEAR will be lowered in energy to ≅ 4 Kelvin at which energy the gravitational effect will be measureable. The measurement will employ the time-of-flight technique wherein the antiprotons are released vertically in a drift tube. The spectrum of time-of-flight measurements can be used to extract the gravitational acceleration experienced by the particles. The system will be calibrated using H - ions which simulate the electromagnetic behavior of the antiproton yet are baryons to ≅ 0.1%. To extract the gravitational acceleration of the antiproton relative to the H - ion with a statistical precision of 1% will require the release of ≅ 10 6 -10 7 particles. (orig.)

  3. Intermediate energy electron cooling for antiproton sources using a Pelletron accelerator

    International Nuclear Information System (INIS)

    Cline, D.B.; Adney, J.; Ferry, J.; Kells, W.; Larson, D.J.; Mills, F.E.; Sundquist, M.

    1983-01-01

    It has been shown at FNAL that the electron cooling of protons is a very efficient method for reaching high luminosity in a proton beam. The emittance of the 120 KeV electron beam used at Fermilab corresponds to a cathode temperature of 0.1 eV. In order to apply cooling techniques to GeV proton beams the electron energies required are in the MeV range. In the experiment reported in this paper the emittance of a 3-MeV Pelletron electron accelerator was measured to determine that its emittance scaled to a value appropriate for electron cooling. The machine tested was jointly owned and operated by the University of California at Santa Barbara and National Electrostatics Corporation for research into free-electron lasers which also require low emittance beams for operation. This paper describes the thermal emittance of the beam to be the area in phase space in which 90% of the beam trajectories lie and goes on to describe the emittance-measurement method both in theory and application

  4. Limitations on anti p-p luminosity with direct injection and stacking of antiprotons

    International Nuclear Information System (INIS)

    Courant, E.D.; Teng, L.C.

    1979-01-01

    If protons of very high energy impinge on a target, a large part of the resulting antiprotons are sufficiently collimated to be injectible into a stacking and accelerating ring. They can then be stacked and injected into the main proton accelerator so as to produce anti p-p collisions without low energy antiproton cooling. A scheme is presented for the VBA, where 20 TeV protons produce 9 x 10 -4 antiprotons per proton at 100 GeV, which are then stacked, accelerated to 1 TeV, and injected into the main ring. With 16 proton pulses of 10 15 protons, one obtains a luminosity of the order of 10 32 cm -2 sec -1 with a beam-beam tune shift of 10 -3 per interaction region. The beams are bunched into 1000 bunches; the orbits are separated by means of relatively modest electostatic electrodes

  5. The peculiarities of particle dynamics in the Fermi acceleration scheme

    International Nuclear Information System (INIS)

    Buts, V.A.

    2015-01-01

    With examples of discrete and distributed mathematical models of the Fermi acceleration mechanism, a usefulness, or even necessity, of taking into account of singular solutions is demonstrated. Also the role is shown of those parts of phase space where the uniqueness theorem conditions to form the dynamics of physical systems are broken. It was found that the dynamics of particles in discrete and distributed mathematical schemes of Fermi acceleration can be significantly different. The difference is due to the fact that the distributed model takes into account the effects of phase space where conditions do not correspond to those necessary for application of the uniqueness theorem. The role of singular solutions is under discussion as well.

  6. Antiproton production

    International Nuclear Information System (INIS)

    Allaby, J.V.

    1984-01-01

    The basic definitions used in the physics literature on particle production are reviewed. The data on anti p production are interpreted in order to provide an estimate of the yield of anti p's from typical target at the antiproton accumulator, including the effects of re-absorption in the target. (orig.)

  7. Antiproton Target

    CERN Multimedia

    1980-01-01

    Antiproton target used for the AA (antiproton accumulator). The first type of antiproton production target used from 1980 to 1982 comprised a rod of copper 3mm diameter and 120mm long embedded in a graphite cylinder that was itself pressed into a finned aluminium container. This assembly was air-cooled and it was used in conjunction with the Van der Meer magnetic horn. In 1983 Fermilab provided us with lithium lenses to replace the horn with a view to increasing the antiproton yield by about 30%. These lenses needed a much shorter target made of heavy metal - iridium was chosen for this purpose. The 50 mm iridium rod was housed in an extension to the original finned target container so that it could be brought very close to the entrance to the lithium lens. Picture 1 shows this target assembly and Picture 2 shows it mounted together with the lithium lens. These target containers had a short lifetime due to a combination of beam heating and radiation damage. This led to the design of the water-cooled target in...

  8. The Antiproton Accumulator becomes Antiproton Decelerator

    CERN Multimedia

    1980-01-01

    The photos show the Antiproton Accumulator (AA) transformed into Antiproton Decelerator. The AA was used at CERN between 1981 and 1999 before being replaced by the Antiproton Decelerator (AD). The AA was used to collect and stochastically cool antiprotons used in proton-antiproton collisions in the SPS collider. This lead to the discovery of the W and Z bosons in 1983 and the Nobel Prize for Carlo Rubbia and Simon van der Meer in 1984.

  9. PANDA : Strong Interaction Studies with Antiprotons

    NARCIS (Netherlands)

    Peters, Klaus; Schmitt, Lars; Stockmanns, Tobias; Messchendorp, Johan

    2017-01-01

    The Antiproton Anihilation in Darmstadt (PANDA) collaboration at the Facility for Antiproton and Ion Research (FAIR) is a cooperation of more than 400 scientists from 19 countries. FAIR will be an accelerator facility leading the European research in nuclear and hadron physics in the coming decade.

  10. Summary of Working Group 7 on 'Exotic acceleration schemes'

    International Nuclear Information System (INIS)

    Tajima, T.

    2001-01-01

    Exotic concepts of advanced acceleration technologies have been explored by Group 7 under the leadership of T. Tajima and T. Smith (who could not attend) at the AAC. Explored concepts are: (1) proton (ion) acceleration by laser, (2) additional ion acceleration methods, (3) crystal x-rays and acceleration, (4) vacuum acceleration, (5) active medium acceleration, and (6) some advanced methods in laser wakefield. The first subject of laser photon acceleration was discussed jointly with Group 1 and in the end the participants came to an agreement on the mechanism of proton acceleration by laser irradiation

  11. Antiproton fast ignition for inertial confinement fusion

    International Nuclear Information System (INIS)

    Perkins, L.J.

    1999-01-01

    With 180 MJ/microg, antiprotons offer the highest stored energy per unit mass of any known entity. The use of antiprotons to promote fast ignition in an inertial confinement fusion (ICF) capsule and produce high target gains with only modest compression of the main fuel is investigated. Unlike standard fast ignition where the ignition energy is supplied by energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. This can be considered in-situ fast ignition as it obviates the need for the external injection of the ignition energy. In the first of two candidate schemes, the antiproton package is delivered by a low-energy ion beam. In the second, autocatalytic scheme, the antiprotons are preemplaced at the center of the capsule prior to compression. In both schemes, the author estimates that ∼10 12 antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition within the ignitor zone. In addition to eliminating the need for a second, energetic fast laser and vulnerable final optics, this scheme would achieve central ignition without reliance on laser channeling through halo plasma or Hohlraum debris. However, in addition to the practical difficulties of storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a speculative scheme is the ultimate efficiency of antiproton production in an external, optimized facility. Estimates suggest that the electrical wall plug energy per pulse required for the separate production of the antiprotons is of the same order as that required for the conventional slow compression driver

  12. A modification scheme for seismic acceleration - time histories

    International Nuclear Information System (INIS)

    Bethell, J.

    1979-05-01

    A technique is described for the modification of recorded earthquake acceleration-time histories which gives reduced peak accelerations whilst leaving other significant characteristics unchanged. Such modifications are of use in constructing design basis acceleration-time histories such that all important parameters conform to a specified return period. The technique is applied to two recordings from the 1966 Parkfield earthquake, their peak accelerations being reduced in each case from about 40% g to 25% g. (author)

  13. Practical Uses of Antiprotons

    International Nuclear Information System (INIS)

    Jackson, Gerald P.

    2003-01-01

    The production of commercial quantities of antiprotons has been a reality for many years now. The deceleration and trapping of antiprotons is a relatively new activity, but has been sufficiently proven to be translated into a business enterprise. Now that NASA has a portable Penning trap for transporting antiprotons, all the elements are in place to begin the commercial distribution of antiprotons. The list of potential customers for antiprotons is continuously growing, with detailed market analyses already performed on some medical and propulsion applications. In this paper these applications are reviewed, along with their appetite for antiprotons and the steps needed to bring them to market.

  14. Practical Uses of Antiprotons

    Science.gov (United States)

    Jackson, Gerald P.

    The production of commercial quantities of antiprotons has been a reality for many years now. The deceleration and trapping of antiprotons is a relatively new activity, but has been sufficiently proven to be translated into a business enterprise. Now that NASA has a portable Penning trap for transporting antiprotons, all the elements are in place to begin the commercial distribution of antiprotons. The list of potential customers for antiprotons is continuously growing, with detailed market analyses already performed on some medical and propulsion applications. In this paper these applications are reviewed, along with their appetite for antiprotons and the steps needed to bring them to market.

  15. Physics using cold antiprotons

    CERN Document Server

    Hayano, R S

    2004-01-01

    Recent progress of low-energy antiproton physics by atomic spectroscopy and collisions using slow antiprotons collaboration at CERN AD is presented. High-precision spectroscopy of antiprotonic helium - a neutral three-body system pe**-He**2**+(=pHe**+) produced when antiprotons (p) are stopped in various phases of helium - has tested 3-body QED theories as well as proton-vs-antiproton CPT to within similar to 10**-**8. This was achieved by using a newly- developed radiofrequency quadrupole decelerator. Other ongoing and future experiments using low-energy antiprotons are discussed.

  16. Accelerating Inexact Newton Schemes for Large Systems of Nonlinear Equations

    NARCIS (Netherlands)

    Fokkema, D.R.; Sleijpen, G.L.G.; Vorst, H.A. van der

    Classical iteration methods for linear systems, such as Jacobi iteration, can be accelerated considerably by Krylov subspace methods like GMRES. In this paper, we describe how inexact Newton methods for nonlinear problems can be accelerated in a similar way and how this leads to a general

  17. Experiment to measure the gravitational force on the antiproton

    International Nuclear Information System (INIS)

    Brown, R.E.

    1985-01-01

    A collaboration has been formed to measure the acceleration of antiprotons in the earth's gravitational field. The technique is to produce, decelerate, and trap quantities of antiprotons, to cool them to untralow energy, and to measure their acceleration in a time-of-flight experiment. Present plans and the results of initial efforts toward this end are presented

  18. Physics with ultra-low energy antiprotons

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Holzscheiter, M.H.; Hughes, R.J.

    1989-01-01

    The experimental observation that all forms of matter experience the same gravitational acceleration is embodied in the weak equivalence principle of gravitational physics. However no experiment has tested this principle for particles of antimatter such as the antiproton or the antihydrogen atom. Clearly the question of whether antimatter is in compliance with weak equivalence is a fundamental experimental issue, which can best be addressed at an ultra-low energy antiproton facility. This paper addresses the issue. 20 refs

  19. Antiproton Accumulator (AA)

    CERN Multimedia

    Photographic Service

    1980-01-01

    The AA in its final stage of construction, before it disappeared from view under concrete shielding. Antiprotons were first injected, stochastically cooled and accumulated in July 1980. From 1981 on, the AA provided antiprotons for collisions with protons, first in the ISR, then in the SPS Collider. From 1983 on, it also sent antiprotons, via the PS, to the Low-Energy Antiproton Ring (LEAR). The AA was dismantled in 1997 and shipped to Japan.

  20. Antiproton physics at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, D.M. (Brookhaven National Lab., Upton, NY (United States))

    1993-06-07

    A review of antiproton physics at the Brookhaven AGS in past decade is given as well as a description of the present high energy physics program. Existing and potential facilities for antiproton physics at the AGS are discussed and are found to provide useful antiproton intensities over the momentum range proposed for SUPERLEAR in a multiple user environment. (orig.)

  1. Antiprotons get biological

    CERN Multimedia

    2003-01-01

    After its final run in September, the first results of the Antiproton Cell Experiment (ACE) look very promising. It was the first experiment to take data on the biological effects of antiproton beams to evaluate the potential of antiprotons in radiation therapy.

  2. Extraction of ultra-low-energy antiprotons from the PS200 catching trap for atomic physics experiments

    International Nuclear Information System (INIS)

    Holzscheiter, M.H.

    1996-01-01

    Approximately one million antiprotons have been captured in a large-scale Penning trap at the low energy antiproton ring at CERN. Up to 65% of the captured antiprotons have subsequently been cooled by electron cooling to energies below 1 eV and have been stored up to one hour. This has opened new discussions of the possible use of ultra-low-energy antiprotons for nuclear, atomic, and gravitational physics. For most of these experiments it will be necessary to extract the antiprotons from the trap in the form of either a continuous beam or as a bunched beam, allowing the timing structure to be used for post-acceleration schemes or as a time tag for subsequent measurements. We have designed an extraction scheme to accomplish this and have tested portions of it using a smaller-scale Penning trap loaded with protons. First results in generating a time-correlated beam of particles from a Penning trap are presented. (orig.)

  3. Designing an object-oriented scheme for accelerator equipment control

    International Nuclear Information System (INIS)

    Trofimov, N.N.

    1994-01-01

    The object-oriented analysis (OOA) and design (OOD) formalisms developed by Project Technology Inc. is presented in this report. The method was originated in 1979 with the analysis phase of a large real-time project at Lawrence Berkeley Laboratory and since that time has been used in several large-scale industrial projects. It is supported by the Teamwork CASE package from Cadre Technologies Inc. For introducing basic concepts and definitions of the OOA/OOD, a typical accelerator device example: remotely controllable power supply which is used to power magnets in an accelerator beam transfer line is used through out this report. 18 refs., 18 figs

  4. Nuclear Excitations by Antiprotons and Antiprotonic Atoms

    CERN Multimedia

    2002-01-01

    The proposal aims at the investigation of nuclear excitations following the absorption and annihilation of stopped antiprotons in heavier nuclei and at the same time at the study of the properties of antiprotonic atoms. The experimental arrangement will consist of a scintillation counter telescope for the low momentum antiproton beam from LEAR, a beam degrader, a pion multiplicity counter, a monoisotopic target and Ge detectors for radiation and charged particles. The data are stored by an on-line computer.\\\\ \\\\ The Ge detectors register antiprotonic x-rays and nuclear @g-rays which are used to identify the residual nucleus and its excitation and spin state. Coincidences between the two detectors will indicate from which quantum state the antiprotons are absorbed and to which nuclear states the various reactions are leading. The measured pion multiplicity characterizes the annihilation process. Ge&hyphn. and Si-telescopes identify charged particles and determine their energies.\\\\ \\\\ The experiment will gi...

  5. Conceptual Design of an Antiproton Generation and Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Peggs, Stephen

    2006-10-24

    The Antiproton Generation and Storage Facility (AGSF) creates copious quantities of antiprotons, for bottling and transportation to remote cancer therapy centers. The first step in the generation and storage process is to accelerate an intense proton beam down the Main Linac for injection into the Main Ring, which is a Rapid Cycling Synchrotron that accelerates the protons to high energy. The beam is then extracted from the ring into a transfer line and into a Proton Target. Immediately downstream of the target is an Antiproton Collector that captures some of the antiprotons and focuses them into a beam that is transported sequentially into two antiproton rings. The Precooler ring rapidly manipulates antiproton bunches from short and broad (in momentum) to long and thin. It then performs some preliminary beam cooling, in the fraction of a second before the next proton bunch is extracted from the Main Ring. Pre-cooled antiprotons are passed on to the Accumulator ring before the next antiprotons arrive from the target. The Accumulator ring cools the antiprotons, compressing them into a dense state that is convenient for mass storage over many hours. Occasionally the Accumulator ring decelerates a large number of antiprotons, injecting them into a Deceleration Linac that passes them into a waiting Penning trap.

  6. Conceptual Design of an Antiproton Generation and Storage Facility

    International Nuclear Information System (INIS)

    Peggs, Stephen

    2006-01-01

    The Antiproton Generation and Storage Facility (AGSF) creates copious quantities of antiprotons, for bottling and transportation to remote cancer therapy centers. The first step in the generation and storage process is to accelerate an intense proton beam down the Main Linac for injection into the Main Ring, which is a Rapid Cycling Synchrotron that accelerates the protons to high energy. The beam is then extracted from the ring into a transfer line and into a Proton Target. Immediately downstream of the target is an Antiproton Collector that captures some of the antiprotons and focuses them into a beam that is transported sequentially into two antiproton rings. The Precooler ring rapidly manipulates antiproton bunches from short and broad (in momentum) to long and thin. It then performs some preliminary beam cooling, in the fraction of a second before the next proton bunch is extracted from the Main Ring. Pre-cooled antiprotons are passed on to the Accumulator ring before the next antiprotons arrive from the target. The Accumulator ring cools the antiprotons, compressing them into a dense state that is convenient for mass storage over many hours. Occasionally the Accumulator ring decelerates a large number of antiprotons, injecting them into a Deceleration Linac that passes them into a waiting Penning trap

  7. Transport synthetic acceleration scheme for multi-dimensional neutron transport problems

    Energy Technology Data Exchange (ETDEWEB)

    Modak, R S; Kumar, Vinod; Menon, S V.G. [Theoretical Physics Div., Bhabha Atomic Research Centre, Mumbai (India); Gupta, Anurag [Reactor Physics Design Div., Bhabha Atomic Research Centre, Mumbai (India)

    2005-09-15

    The numerical solution of linear multi-energy-group neutron transport equation is required in several analyses in nuclear reactor physics and allied areas. Computer codes based on the discrete ordinates (Sn) method are commonly used for this purpose. These codes solve external source problem and K-eigenvalue problem. The overall solution technique involves solution of source problem in each energy group as intermediate procedures. Such a single-group source problem is solved by the so-called Source Iteration (SI) method. As is well-known, the SI-method converges very slowly for optically thick and highly scattering regions, leading to large CPU times. Over last three decades, many schemes have been tried to accelerate the SI; the most prominent being the Diffusion Synthetic Acceleration (DSA) scheme. The DSA scheme, however, often fails and is also rather difficult to implement. In view of this, in 1997, Ramone and others have developed a new acceleration scheme called Transport Synthetic Acceleration (TSA) which is much more robust and easy to implement. This scheme has been recently incorporated in 2-D and 3-D in-house codes at BARC. This report presents studies on the utility of TSA scheme for fairly general test problems involving many energy groups and anisotropic scattering. The scheme is found to be useful for problems in Cartesian as well as Cylindrical geometry. (author)

  8. Transport synthetic acceleration scheme for multi-dimensional neutron transport problems

    International Nuclear Information System (INIS)

    Modak, R.S.; Vinod Kumar; Menon, S.V.G.; Gupta, Anurag

    2005-09-01

    The numerical solution of linear multi-energy-group neutron transport equation is required in several analyses in nuclear reactor physics and allied areas. Computer codes based on the discrete ordinates (Sn) method are commonly used for this purpose. These codes solve external source problem and K-eigenvalue problem. The overall solution technique involves solution of source problem in each energy group as intermediate procedures. Such a single-group source problem is solved by the so-called Source Iteration (SI) method. As is well-known, the SI-method converges very slowly for optically thick and highly scattering regions, leading to large CPU times. Over last three decades, many schemes have been tried to accelerate the SI; the most prominent being the Diffusion Synthetic Acceleration (DSA) scheme. The DSA scheme, however, often fails and is also rather difficult to implement. In view of this, in 1997, Ramone and others have developed a new acceleration scheme called Transport Synthetic Acceleration (TSA) which is much more robust and easy to implement. This scheme has been recently incorporated in 2-D and 3-D in-house codes at BARC. This report presents studies on the utility of TSA scheme for fairly general test problems involving many energy groups and anisotropic scattering. The scheme is found to be useful for problems in Cartesian as well as Cylindrical geometry. (author)

  9. A new approach to experiments with non-relativistic antiprotons

    International Nuclear Information System (INIS)

    Poth, H.

    1990-05-01

    Is low-energy antiproton physics phasing out with the present round of experiments or are there good reasons to continue at an improved slow antiproton facility which could be located at a high intensity hadron accelerator? We point out, that there are four frontiers where substantial advances could be made. In particular, we discuss the low-energy frontier and emphasize that experiments with no-relativistic antiprotons would increase drastically the sensitivity and would reveal new effects. (orig.)

  10. Weighing the antiproton

    Energy Technology Data Exchange (ETDEWEB)

    Hayano, Ryugo S., E-mail: hayano@phys.s.u-tokyo.ac.jp [University of Tokyo, Department of Physics (Japan)

    2013-03-15

    Antiprotonic helium is a metastable three-body neutral atom consisting of an antiproton, a helium nucleus and an electron, which we serendipitously discovered some 20 years ago. The antiproton, which normally annihilates within a few picoseconds when injected into matter, can be 'stored' in this system for up to several microseconds, and laser spectroscopy is possible within this time window. From the laser transition frequency, the antiproton-to-electron mass ratio can be deduced to high precision. Recent progress at CERN's antiproton decelerator (AD) will be discussed.

  11. LOO: a low-order nonlinear transport scheme for acceleration of method of characteristics

    International Nuclear Information System (INIS)

    Li, Lulu; Smith, Kord; Forget, Benoit; Ferrer, Rodolfo

    2015-01-01

    This paper presents a new physics-based multi-grid nonlinear acceleration method: the low-order operator method, or LOO. LOO uses a coarse space-angle multi-group method of characteristics (MOC) neutron transport calculation to accelerate the fine space-angle MOC calculation. LOO is designed to capture more angular effects than diffusion-based acceleration methods through a transport-based low-order solver. LOO differs from existing transport-based acceleration schemes in that it emphasizes simplified coarse space-angle characteristics and preserves physics in quadrant phase-space. The details of the method, including the restriction step, the low-order iterative solver and the prolongation step are discussed in this work. LOO shows comparable convergence behavior to coarse mesh finite difference on several two-dimensional benchmark problems while not requiring any under-relaxation, making it a robust acceleration scheme. (author)

  12. Redundancy scheme for multi-layered accelerator control system

    International Nuclear Information System (INIS)

    Chauhan, Amit; Fatnani, Pravin

    2009-01-01

    The control system for SRS Indus-2 has three-layered architecture. There are VMEbus based stations at the lower two layers that are controlled by their respective CPU board. The 'Profibus' fieldbus standard is used for communication between these VME stations distributed in the field. There is a Profibus controller board at each station to implement the communication protocol. The mode of communication is master-slave (command-response) type. This paper proposes a scheme to implement redundancy at the lower two layers namely Layer-2 (Supervisory Layer / Profibus-master) and Layer-3 (Equipment Unit Interface Layer / Profibus-slave). The redundancy is for both the CPU and the communication board. The scheme uses two CPU boards and two Profi controller boards at each L-3 station. This helps in decreasing any downtime resulting either from CPU faults or communication board faults that are placed in the field area. Redundancy of Profi boards provides two active communication channels between the stations that can be used in different ways thereby increasing the availability on a communication link. Redundancy of CPU boards provides certain level of auto fault-recovery as one CPU remains active and the other CPU remains in standby mode, which takes over the control of VMEbus in case of any fault in the main CPU. (author)

  13. Antiproton chain of the FAIR storage rings

    International Nuclear Information System (INIS)

    Katayama, T; Kamerdzhiev, V; Lehrach, A; Maier, R; Prasuhn, D; Stassen, R; Stockhorst, H; Herfurth, F; Lestinsky, M; Litvinov, Yu A; Steck, M; Stöhlker, T

    2015-01-01

    In the Modularized Start Version of the Facility of Antiproton and Ion Research (FAIR) at Darmstadt Germany, the 3 GeV antiprotons are precooled in the collector ring and accumulated in the high energy storage ring (HESR). They are further accelerated to 14 GeV or decelerated to 1 GeV for the experiments with a high-density internal target. The powerful beam cooling devices, stochastic cooling and electron cooling will support the provision of a high-resolution antiproton beam. The other option of FAIR is to prepare the low energy, 300 keV antiproton beam connecting the existing storage rings ESR and CRYRING with HESR. Beam physics issues related with these concepts are described. (paper)

  14. S2 synthetic acceleration scheme for the one-dimensional S/sub n/ equations

    International Nuclear Information System (INIS)

    Lorence, L.J. Jr.; Larsen, E.W.; Morel, J.E.

    1986-01-01

    The authors have developed an S 2 synthetic acceleration method for the one-dimensional S/sub n/ equations with linear-discontinuous (LD) spatial differencing, and implemented it in a new version of the ONETRAN code. As in the diffusion-synthetic acceleration (DSA) of Morel, both the zeroth and first moments of the scattering source are accelerated. This is done by using the S 2 equations with Gauss quadrature rather than the diffusion equation as the low-order operator in the synthetic acceleration scheme

  15. Sparse Parallel MRI Based on Accelerated Operator Splitting Schemes.

    Science.gov (United States)

    Cai, Nian; Xie, Weisi; Su, Zhenghang; Wang, Shanshan; Liang, Dong

    2016-01-01

    Recently, the sparsity which is implicit in MR images has been successfully exploited for fast MR imaging with incomplete acquisitions. In this paper, two novel algorithms are proposed to solve the sparse parallel MR imaging problem, which consists of l 1 regularization and fidelity terms. The two algorithms combine forward-backward operator splitting and Barzilai-Borwein schemes. Theoretically, the presented algorithms overcome the nondifferentiable property in l 1 regularization term. Meanwhile, they are able to treat a general matrix operator that may not be diagonalized by fast Fourier transform and to ensure that a well-conditioned optimization system of equations is simply solved. In addition, we build connections between the proposed algorithms and the state-of-the-art existing methods and prove their convergence with a constant stepsize in Appendix. Numerical results and comparisons with the advanced methods demonstrate the efficiency of proposed algorithms.

  16. Antiproton Production beam and Reverse Injection System

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, G.

    1981-08-16

    The objectives of this project are two fold: (1) To extract high energy protons from the Main Ring (MR) and target them to produce antiprotons which are subsequently captured in the existing Booster accelerator; and (2) to provide a channel for injecting either protons or antiprotons into the MR from the booster in a direction opposite to that of the normal proton acceleration as colliding beams can be created. The present design, therefore, is in support of two separate larger projects, viz., the collisions of protons in the Tevatron (normal circulation direction) with 'reverse injected' protons in the MR, and the collision of normal direction protons with reverse injected antiprotons either in the MR or in the Tevatron. Figure 1 shows the layout of the project area. It spans the shortest distance between possible injection/ejection points in the existing accelerator structures, hence minimizing costs. The tunnel will lie underground at the level of the MR and booster.

  17. Acceleration of step and linear discontinuous schemes for the method of characteristics in DRAGON5

    Directory of Open Access Journals (Sweden)

    Alain Hébert

    2017-09-01

    Full Text Available The applicability of the algebraic collapsing acceleration (ACA technique to the method of characteristics (MOC in cases with scattering anisotropy and/or linear sources was investigated. Previously, the ACA was proven successful in cases with isotropic scattering and uniform (step sources. A presentation is first made of the MOC implementation, available in the DRAGON5 code. Two categories of schemes are available for integrating the propagation equations: (1 the first category is based on exact integration and leads to the classical step characteristics (SC and linear discontinuous characteristics (LDC schemes and (2 the second category leads to diamond differencing schemes of various orders in space. The acceleration of these MOC schemes using a combination of the generalized minimal residual [GMRES(m] method preconditioned with the ACA technique was focused on. Numerical results are provided for a two-dimensional (2D eight-symmetry pressurized water reactor (PWR assembly mockup in the context of the DRAGON5 code.

  18. ASACUSA hits antiproton jackpot

    CERN Multimedia

    2001-01-01

    The Japanese-European ASACUSA collaboration, which takes its name from the oldest district of Tokyo, approaches the antimatter enigma in a different way from the other two AD experiments, by inserting antiprotons into ordinary atoms. Last month the collaboration succeeded in trapping about a million antiprotons. The ASACUSA antiproton trap (lower cylinder), surmounted by its liquid helium reservoir. Looking on are Ken Yoshiki-Franzen, Zhigang Wang, Takahito Tasaki, Suzanne Reed, John Eades, Masaki Hori, Yasunori Yamazaki, Naofumi Kuroda, Jun Sakaguchi, Berti Juhasz, Eberhard Widmann and Ryu Hayano. A key element of the ASACUSA apparatus is its decelerating Radiofrequency Quadrupole magnet, RFQD. After tests with protons in Aarhus, this was installed in ASACUSA's antiproton beam last October (Bulletin 41/2000, 9 October 2000). Constructed by Werner Pirkl's group in PS Division, the RFQD works by applying an electric field to the AD antiproton pulse the opposite direction to its motion. As the antiprotons slo...

  19. Antiproton Cancer Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels

    . The stopping power of high-energetic antiprotons in tissue, is similar to that of protons. Most energy is lost per unit distance as the particle comes to rest, but when the antiprotons stops, each one will annihilate on a nuclei, releasing 1.9 GeV of energy. Most of this energy is carried away by pions, gamma...... rays and neutrons, but a part of the annihilation energy is still deposited locally as recoiling nuclear fragments with limited range. These fragments will also increase the relative biological effect at the annihilation vertex. We have masured the biological effect of an antiproton beam for the first...... to handle antiprotons. This will enable us to do treatment planning with antiprotons, and thereby bring us closer to answer the question of the potential clinical benefit of antiprotons....

  20. The CERN antiproton collector

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    The Antiproton Collector is a new ring of much larger acceptance than the present accumulator. It is designed to receive 10 8 antiprotons per PS cycle. In order to be compatible with the Antiproton Accumulator, the momentum spread and the emittances are reduced from 6% to 0.2% and from 200 π mm mrad to 25 π mm mrad respectively. In addition to the ring itself, the new target area and the modifications to the stochastic systems of the Antiproton Accumulator are described. (orig.)

  1. CERN: Antiprotons resist annihilation

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Ask any particle physicist what is the eventual fate of an antiproton in matter and he will likely tell you that It annihilates'. True as this answer is, it hides a number of fascinating questions about the actual 'route' followed by the antiproton into the nucleus where it finally stops before annihilating with a nuclear particle

  2. LEAR: antiproton extraction lines

    CERN Multimedia

    Photographic Service

    1992-01-01

    Antiprotons, decelerated in LEAR to a momentum of 100 MeV/c (kinetic energy of 5.3 MeV), were delivered to the experiments in an "Ultra-Slow Extraction", dispensing some 1E9 antiprotons over times counted in hours. Beam-splitters and a multitude of beam-lines allowed several users to be supplied simultaneously.

  3. Lattices for antiproton rings

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    After a description of the constraints imposed by the cooling of Antiprotons on the lattice of the rings, the reasons which motivate the shape and the structure of these machines are surveyed. Linear and non-linear beam optics properties are treated with a special amplification to the Antiproton Accumulator. (orig.)

  4. Searching for antiproton decay at the Fermilab Antiproton Accumulator

    International Nuclear Information System (INIS)

    Geer, S.

    1995-09-01

    This paper describes an experimental search for antiproton decay at the Fermilab Antiproton Accumulator. The E868 (APEX) experimental setup is described. The APEX data is expected to be sensitive to antiproton decay if the antiproton lifetimes is less than a few times 100,000 years

  5. Accelerated successive substitution schemes for bubble-point and dew-point calculations

    Energy Technology Data Exchange (ETDEWEB)

    Peng, D.-Y. (Univ. of Saskatchewan, Saskatoon, SK (Canada))

    1991-08-01

    Phase equilibrium calculations form an important part of the process design operations in the hydrocarbon and petroleum industry. The accelerated successive substitution (SS) algorithms developed by Mehra et al. (1983) for flash calculations have been extended to the prediction of saturation points. A transformation matrix which is used to calculate the acceleration parameter has been rewritten in a form that is applicable at the saturation conditions. Simple equations for estimating the initial values and recursive formulae according to which the iterates can be updated are presented. The proposed schemes were compared with the conventional SS method and a multivariate Newton's method. The comparison suggests that the accelerated SS schemes are more tolerant of poor initial values and sometimes more efficient than Newton's method. The features of the acceleration schemes and those of the empirical equations developed in this study are illustrated using three hydrocarbon mixtures: a 5-component mixture of n-alkanes, a typical natural gas system, and a volatile oil. 19 refs., 6 figs., 6 tabs.

  6. Study of the scheme of two-beam accelerator driver with accompanying electromagnetic wave

    International Nuclear Information System (INIS)

    Elzhov, A.V.; Kaminskij, A.K.; Kazacha, V.I.; Perel'shtejn, E.A.; Sedykh, S.N.; Sergeev, A.P.

    2000-01-01

    A novel scheme of two-beam accelerator (TBA) driver based on a linear induction accelerator is considered. In this scheme the bunched beam propagates in the accompanying enhanced microwave that provides the steady longitudinal beam bunching along the whole driver. A travelling wave tube (TWT) is used as the wave-slowing periodic structure. Major merits of the driver scheme in hand are the possibilities of providing the microwave phase and amplitude stability and the preliminary beam bunching at a rather low initial energy (∼ 1 MeV). The numerical simulation has shown that a steady state could be found when electron bunches accompanied by an amplified microwave are simultaneously accelerated in the external electric field. The total power, which is inserted into the beam by the accelerating field, transforms into the microwave power in the steady state. The first set of experiments was fulfilled with the buncher on the base of the JINR LIU-3000 linac (electron beam energy ∼ 600 keV, electron current ∼ 150 A). The considerable level of the amplified microwave power (∼ 5 MW) and high enough bunching parameter (∼ 0.4) were obtained. The electron beam bunching at the frequency of 36.4 GHz was registered by means of the Cherenkov radiation of the electron bunches that occurred at their passing through the special target. The beam keeps a high bunching level at the distance ∼ 10 cm from the TWT exit being accompanied by the amplified microwave

  7. Fermilab Antiproton source, Recycler ring and Main Injector

    Energy Technology Data Exchange (ETDEWEB)

    Nagaitsev, Sergei [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-03-22

    The antiproton source for a proton-antiproton collider at Fermilab was proposed in 1976 [1]. The proposal argued that the requisite luminosity (~1029 cm-2sec-1) could be achieved with a facility that would produce and cool approximately 1011 antiprotons per day. Funding for the Tevatron I project (to construct the Antiproton source) was initiated in 1981 and the Tevatron ring itself was completed, as a fixed target accelerator, in the summer of 1983 and the Antiproton Source was completed in 1985. At the end of its operations in 2011, the Fermilab antiproton production complex consisted of a sophisticated target system, three 8-GeV storage rings (namely the Debuncher, Accumulator and Recycler), 25 independent multi-GHz stochastic cooling systems, the world’s only relativistic electron cooling system and a team of technical experts equal to none. Sustained accumulation of antiprotons was possible at the rate of greater than 2.5×1011 per hour. Record-size stacks of antiprotons in excess of 3×1012 were accumulated in the Accumulator ring and 6×1012 in the Recycler. In some special cases, the antiprotons were stored in rings for more than 50 days. Note, that over the years, some 1016 antiprotons were produced and accumulated at Fermilab, which is about 17 nanograms and more than 90% of the world’s total man-made quantity of nuclear antimatter. The accelerator complex at Fermilab supported a broad physics program including the Tevatron Collider Run II [2], neutrino experiments using 8 GeV and 120 GeV proton beams, as well as a test beam facility and other fixed target experiments using 120 GeV primary proton beams. The following sections provide a brief description of Fermilab accelerators as they operated at the end of the Collider Run II (2011).

  8. Enhanced efficiency of plasma acceleration in the laser-induced cavity pressure acceleration scheme

    Czech Academy of Sciences Publication Activity Database

    Badziak, J.; Rosinski, M.; Jabłonski, S.; Pisarczyk, T.; Chodukowski, T.; Parys, P.; Raczka, P.; Krouský, Eduard; Ullschmied, Jiří; Liska, R.; Kucharik, M.

    2015-01-01

    Roč. 57, č. 1 (2015), 014007 ISSN 0741-3335 R&D Projects: GA MŠk(CZ) LC528; GA MŠk LM2010014 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser ion acceleration * laser plasma * fast ignition * ion diagnostics * LICPA Subject RIV: BL - Plasma and Gas Discharge Physics; BH - Optics, Masers, Lasers (UFP-V) Impact factor: 2.404, year: 2015

  9. Beam dynamics analysis of dielectric laser acceleration using a fast 6D tracking scheme

    Directory of Open Access Journals (Sweden)

    Uwe Niedermayer

    2017-11-01

    Full Text Available A six-dimensional symplectic tracking approach exploiting the periodicity properties of dielectric laser acceleration (DLA gratings is presented. The longitudinal kick is obtained from the spatial Fourier harmonics of the laser field within the structure, and the transverse kicks are obtained using the Panofsky-Wenzel theorem. Additionally to the usual, strictly longitudinally periodic gratings, our approach is also applicable to periodicity chirped (subrelativistic and tilted (deflection gratings. In the limit of small kicks and short periods we obtain the 6D Hamiltonian, which allows, for example, to obtain matched beam distributions in DLAs. The scheme is applied to beam and grating parameters similar to recently performed experiments. The paper concludes with an outlook to laser based focusing schemes, which are promising to overcome fundamental interaction length limitations, in order to build an entire microchip-sized laser driven accelerator.

  10. Application of Intel Many Integrated Core (MIC) accelerators to the Pleim-Xiu land surface scheme

    Science.gov (United States)

    Huang, Melin; Huang, Bormin; Huang, Allen H.

    2015-10-01

    The land-surface model (LSM) is one physics process in the weather research and forecast (WRF) model. The LSM includes atmospheric information from the surface layer scheme, radiative forcing from the radiation scheme, and precipitation forcing from the microphysics and convective schemes, together with internal information on the land's state variables and land-surface properties. The LSM is to provide heat and moisture fluxes over land points and sea-ice points. The Pleim-Xiu (PX) scheme is one LSM. The PX LSM features three pathways for moisture fluxes: evapotranspiration, soil evaporation, and evaporation from wet canopies. To accelerate the computation process of this scheme, we employ Intel Xeon Phi Many Integrated Core (MIC) Architecture as it is a multiprocessor computer structure with merits of efficient parallelization and vectorization essentials. Our results show that the MIC-based optimization of this scheme running on Xeon Phi coprocessor 7120P improves the performance by 2.3x and 11.7x as compared to the original code respectively running on one CPU socket (eight cores) and on one CPU core with Intel Xeon E5-2670.

  11. Looking for new gravitational forces with antiprotons

    International Nuclear Information System (INIS)

    Nieto, M.M.; Bonner, B.E.

    1987-01-01

    Quite general arguments based on the principle of equivalence and modern field theory show that it is possible for the gravitational acceleration of antimatter to be different than that for matter. Further, there is no experimental evidence to rule out the possibility. In fact, some evidence indicates there may be unexpected effects. Thus, the planned experiment to measure the gravitational acceleration of antiprotons is of fundamental importance. 20 refs., 3 figs

  12. Study of the anti-hydrogen atom and ion formation in the collisions antiproton-positronium

    International Nuclear Information System (INIS)

    Comini, Pauline

    2014-01-01

    The future CERN experiment called GBAR intends to measure the gravitational acceleration of antimatter on Earth using cold (neV) anti-hydrogen atoms undergoing a free fall. The experiment scheme first needs to cool anti-hydrogen positive ions, obtained thanks to two consecutive reactions occurring when an antiproton beam collides with a dense positronium cloud.The present thesis studies these two reactions in order to optimise the production of the anti-ions. The total cross sections of both reactions have been computed in the framework of a perturbation theory model (Continuum Distorted Wave - Final State), in the range 0 to 30 keV antiproton kinetic energy; several excited states of positronium have been investigated. These cross sections have then been integrated to a simulation of the interaction zone where antiprotons collide with positronium; the aim is to find the optimal experimental parameters for GBAR. The results suggest that the 2P, 3D or, to a lower extend, 1S states of positronium should be used, respectively with 2, less than 1 or 6 keV antiprotons. The importance of using short pulses of antiprotons has been underlined; the positronium will have to be confined in a tube of 20 mm length and 1 mm diameter. In the prospect of exciting the 1S-3D two-photon transition in positronium at 410 nm, a pulsed laser system had already been designed. It consists in the frequency doubling of an 820 nm pulsed titanium-sapphire laser. The last part of the thesis has been dedicated to the realisation of this laser system, which delivers short pulses (9 ns) of 4 mJ energy at 820 nm. (author) [fr

  13. New Experiments with Antiprotons

    Science.gov (United States)

    Kaplan, D. M.

    2011-12-01

    Fermilab operates the world's most intense antiproton source. Recently proposed experiments can use those antiprotons either parasitically during Teva-tron Collider running or after the Tevatron Collider finishes in about 2011. For example, the annihilation of 8 GeV antiprotons might make the world's most intense source of tagged D0 mesons, and thus the best near-term opportunity to study charm mixing and search for new physics via its CP-violation signature. Other possible precision measurements include properties of the X(3872) and the charmonium system. An experiment using a Penning trap and an atom interferometer could make the world's first measurement of the gravitational force on antimatter. These and other potential measurements using antiprotons could yield a broad physics program at Fermilab in the post-Tevatron era.

  14. Perspectives for polarized antiprotons

    International Nuclear Information System (INIS)

    Lenisa, Paolo

    2012-01-01

    Polarized antiprotons would open a new window in hadron physics providing access to a wealth of single and double spin observables in proton-antiproton interactions. The PAX Collaboration aims to perform the first ever measurement of the spin-dependence of the proton-antiproton cross section at the AD ring at CERN. The spin-dependence of the cross section could in principle be exploited by the spin-filtering technique for the production of a polarized antiproton beam. As a preparatory phase to the experimentation at AD, the PAX Collaboration has initiated a series of dedicated studies with protons at the COSY-ring in Juelich (Germany), aimed at the commissioning of the experimental apparatus and confirmation of the predictions for spin-filtering with protons.

  15. Antiprotonic-hydrogen atoms

    International Nuclear Information System (INIS)

    Batty, C.J.

    1989-07-01

    Experimental studies of antiprotonic-hydrogen atoms have recently made great progress following the commissioning of the low energy antiproton facility (LEAR) at CERN in 1983. At the same time our understanding of the atomic cascade has increased considerably through measurements of the X-ray spectra. The life history of the p-bar-p atom is considered in some detail, from the initial capture of the antiproton when stopping in hydrogen, through the atomic cascade with the emission of X-rays, to the final antiproton annihilation and production of mesons. The experiments carried out at LEAR are described and the results compared with atomic cascade calculations and predictions of strong interaction effects. (author)

  16. A novel source convergence acceleration scheme for Monte Carlo criticality calculations, part I: Theory

    International Nuclear Information System (INIS)

    Griesheimer, D. P.; Toth, B. E.

    2007-01-01

    A novel technique for accelerating the convergence rate of the iterative power method for solving eigenvalue problems is presented. Smoothed Residual Acceleration (SRA) is based on a modification to the well known fixed-parameter extrapolation method for power iterations. In SRA the residual vector is passed through a low-pass filter before the extrapolation step. Filtering limits the extrapolation to the lower order Eigenmodes, improving the stability of the method and allowing the use of larger extrapolation parameters. In simple tests SRA demonstrates superior convergence acceleration when compared with an optimal fixed-parameter extrapolation scheme. The primary advantage of SRA is that it can be easily applied to Monte Carlo criticality calculations in order to reduce the number of discard cycles required before a stationary fission source distribution is reached. A simple algorithm for applying SRA to Monte Carlo criticality problems is described. (authors)

  17. Multiple collision effects on the antiproton production by high energy proton (100 GeV - 1000 GeV)

    International Nuclear Information System (INIS)

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    Antiproton production rates which take into account multiple collision are calculated using a simple model. Methods to reduce capture of the produced antiprotons by the target are discussed, including geometry of target and the use of a high intensity laser. Antiproton production increases substantially above 150 GeV proton incident energy. The yield increases almost linearly with incident energy, alleviating space charge problems in the high current accelerator that produces large amounts of antiprotons

  18. An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

    Energy Technology Data Exchange (ETDEWEB)

    C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg

    2011-09-01

    We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ('afterburner'). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

  19. FERMILAB: More antiprotons

    International Nuclear Information System (INIS)

    Visnjic, Vladimir

    1993-01-01

    The excellent performance of the Fermilab antiproton complex during the recent Collider run and its future potential are the cumulative result of many improvements over the past few years, ranging from major projects like upgrading the stack-tail stochastic cooling system in the Accumulator to minor improvements like automating tuning procedures. The antiprotons are created when the 120 GeV proton beam from the Main Ring hits the target. A good target should have high yield of antiprotons, should not melt, and should not crack due to shock waves. The old copper target has been replaced by a new one made of nickel. The yield into the Debuncher is 2 x 10 -5 antiprotons/proton. While this is only marginally better than for copper, the nickel target has high melting point energy (1070 J/g) and a low rate of increase in pressure with deposited energy, making it the target of choice for the proton intensities expected in the Main Injector era (June, page 10). Of the broad spectrum of all kinds of secondaries, only a tiny fraction are 8 GeV antiprotons. The 8 GeV negative charge secondaries are bent through 3° by a new pulsed magnet. Instead of a 200-turn magnet with coils separated by epoxy as in the past, the new magnet has one turn carrying 45.5 kA of current. This single turn pulsed magnet uses radiation hard ceramic and is much more robust

  20. Measuring and manipulating an accumulated stack of antiprotons in the CERN antiproton accumulator

    International Nuclear Information System (INIS)

    Johson, R.; van der Meer, S.; Pederson, F.

    1983-01-01

    The antiproton stack is observed through Schottky scans, both longitudinal and transverse. A particular feature is the wide dynamic range needed for observing both the dense core and the freshly-deposited tail. Separating batches of antiprotons from the stack (unstacking) is a highly automated process including the measurement of the momentum distribution and the generation of a suitable RF function to remove a slice of the desired density. Multiple slices may be removed successively and a process for locally flattening the distribution to obtain equal batch intensities is used. When successive batches are unstacked and ejected, the process may have to be aborted if the particles do not arrive correctly at the user. A ''restack'' facility is provided to return any antiprotons to the stack that have been unstacked but not ejected. A missing-bucket scheme for unstacking low-intensity batches for LEAR is also described

  1. Biological Effectiveness of Antiproton Annihilation

    DEFF Research Database (Denmark)

    Maggiore, C.; Agazaryan, N.; Bassler, N.

    2004-01-01

    from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The background, description, and status...

  2. Interaction of antiprotons with nuclei

    Czech Academy of Sciences Publication Activity Database

    Hrtánková, Jaroslava; Mareš, Jiří

    2016-01-01

    Roč. 945, JAN (2016), s. 197-215 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : antiproton-nucleus interaction * antiproton annihilation * antiproton nuclear bound states Subject RIV: BE - Theoretical Physics Impact factor: 1.916, year: 2016

  3. The CERN antiproton programme

    International Nuclear Information System (INIS)

    Herr, H.

    1979-01-01

    A diagram and basic parameters of the ICE (Initial Cooling Experiment) storage ring constructed in CERN are examined. The experimental results of stochastic and electron cooling and the results of measuring of the antiproton lifetime are discussed. The main parameters of the antiproton storage are listed. Comparison between stochastic and electron cooling has shown that the latter is characterized by shorter cooling time independent of the particle number in a beam. Advantage of stochastic cooling lies in its possible usage at higher energies [ru

  4. Biological effectiveness of antiproton annihilation

    DEFF Research Database (Denmark)

    Holzscheiter, M.H.; Agazaryan, N.; Bassler, Niels

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct...... measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current...

  5. Biological effectiveness of antiproton annihilation

    CERN Document Server

    Holzscheiter, Michael H.; Bassler, Niels; Beyer, Gerd; De Marco, John J.; Doser, Michael; Ichioka, Toshiyasu; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Møller, Søren Pape; Petersen, Jorgen; Smathers, James B.; Skarsgard, Lloyd D.; Solberg, Timothy D.; Uggerhøj, Ulrik I.; Withers, H.Rodney; Vranjes, Sanja; Wong, Michelle; Wouters, Bradly G.

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in “biological dose” in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current status of the experiment are given.

  6. About the realization of laser acceleration schemes based on plasmoids in R.F. wells

    International Nuclear Information System (INIS)

    Sessler, A.M.; Wurtele, J.S.; Dzergach, A.I.; Kabanov, V.S.

    1998-06-01

    The laser acceleration of plasmoids is investigated theoretically. Preliminary studies suggest that this configuration, which is based on the forced oscillations of finite pieces of plasma contained in moving or vibrating r.f. wells, has very much simplified plasma physics compared to that of other plasma-based ion acceleration schemes. It is necessary to consider the case when the applied electric field, E, of frequency ω, is large, E ≤ e/4π var-epsilon o rλ, where r is the Classical electron radius and when the plasma density, n, is high n 2 . Realization of this proposal requires the development, among other things, of biresonant accelerating systems including oversized single-mode tue-like resonators and the connection of this resonator to a terawatt FELs. If these problems, which will be delineated, are overcome--and progress in optics gives one reason to believe they can be--then gradients of ∼ 10 GeV/m can be attained. Preliminary design of a linac, based upon this proposal and of a proof-of-principle experiment are presented

  7. Coincidence studies with antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    McGovern, M; Walters, H R J [Department of Applied Mathematics and Theoretical Physics, Queen' s University, Belfast BT7 1NN (United Kingdom); Assafrao, D; Mohallem, J R [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, P.O Box 702, 30123-970 Belo Horizonte, MG (Brazil); Whelan, Colm T, E-mail: mmcgovern06@qub.ac.u [Department of Physics, Old Dominion University, Norfolk, VA 23529-0116 (United States)

    2010-02-01

    We present a short overview of a new method for calculating fully differential cross sections that is able to describe any aspect of coincidence measurements involving heavy projectiles. The method is based upon impact parameter close coupling with pseudostates. Examples from antiproton impact ionization are shown.

  8. Progress in antiproton physics

    International Nuclear Information System (INIS)

    Miettinen, H.I.

    1976-09-01

    Some recent results on proton-antiproton collisions are reviewed. The duality structure of processes where baryon number or strangeness may be annihilated receives particular attention. Attempts to obtain experimental information on the impact parameter space structure of multiparticle processes are discussed. Suggestions for future research are made

  9. The PS 200 catching trap: A new tool for ultra-low energy antiproton physics

    International Nuclear Information System (INIS)

    Holzscheiter, M.H.; Dyer, P.L.; King, N.S.P.; Lizon, D.C.; Morgan, G.L.; Schauer, M.M.; Schecker, J.A.; Hoibraten, S.; Lewis, R.A.; Otto, T.

    1994-01-01

    Approximately one million antiprotons have been trapped and electron cooled in the PS200 catching trap from a single fast extracted pulse from LEAR. The system is described in detail, different extraction schemes are discussed, and possible applications of this instrument to ultra-low energy atomic and nuclear physics with antiprotons are mentioned

  10. Intensity-Frontier Antiproton Physics with The Antiproton Annihilation Spectrometer (TAPAS) at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Apollinari, Giorgio; /Fermilab; Asner, David M.; /PNL, Richland; Baldini, Wander; /INFN, Ferrara; Bartoszek, Larry; Broemmelsiek, Daniel R.; Brown, Charles N.; /Fermilab; Chakravorty, Alak; /St. Xavier U., Chicago; Colas, Paul; /Saclay; Derwent, Paul; /Fermilab; Drutskoy, Alexey; /Moscow, ITEP; Fortner, Michael; /Northern Illinois U. /Saclay /Indian Inst. Tech., Hyderabad

    2011-11-01

    The Fermilab Antiproton Source is the world's most intense source of antimatter. With the Tevatron program now behind us, this unique facility can help make the case for Fermilab's continued accelerator operations. The Antiproton Source can be used for unique, dedicated antimatter studies, including medium-energy {bar p}-annihilation experiments. We propose to assemble a powerful, yet cost-effective, solenoidal magnetic spectrometer for antiproton-annihilation events, and to use it at the Fermilab Antiproton Accumulator to measure the charm production cross section, study rare hyperon decays, search for hyperon CP asymmetry, precisely measure the properties of several charmonium and nearby states, and make the first measurements of the Drell-Yan continuum in medium-energy antiproton annihilation. Should the charm production cross section be as large as some have proposed, we will also be able to measure D{sup 0}-{bar D}{sup 0} mixing with high precision and discover (or sensitively limit) charm CP violation. The observation of charm or hyperon CP violation would be evidence for physics beyond the Standard Model, with possible implications for the origin of the baryon asymmetry of the universe - the question of what happened to all the antimatter that must have been produced in the Big Bang. The experiment will be carried out by an international collaboration and will require some four years of running time. As possibly the sole hadron experiment in progress at Fermilab during that time, it will play an important role in maintaining a broad particle physics program at Fermilab and in the U.S. It will thus help us to continue attracting creative and capable young people into science and technology, and introducing them to the important technologies of accelerators, detectors, and data acquisition and analysis - key roles in society that accelerator-based particle physics has historically played.

  11. Testing Quantum Chromodynamics with Antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.

    2004-10-21

    The antiproton storage ring HESR to be constructed at GSI will open up a new range of perturbative and nonperturbative tests of QCD in exclusive and inclusive reactions. I discuss 21 tests of QCD using antiproton beams which can illuminate novel features of QCD. The proposed experiments include the formation of exotic hadrons, measurements of timelike generalized parton distributions, the production of charm at threshold, transversity measurements in Drell-Yan reactions, and searches for single-spin asymmetries. The interactions of antiprotons in nuclear targets will allow tests of exotic nuclear phenomena such as color transparency, hidden color, reduced nuclear amplitudes, and the non-universality of nuclear antishadowing. The central tool used in these lectures are light-front Fock state wavefunctions which encode the bound-state properties of hadrons in terms of their quark and gluon degrees of freedom at the amplitude level. The freedom to choose the light-like quantization four-vector provides an explicitly covariant formulation of light-front quantization and can be used to determine the analytic structure of light-front wave functions. QCD becomes scale free and conformally symmetric in the analytic limit of zero quark mass and zero {beta} function. This ''conformal correspondence principle'' determines the form of the expansion polynomials for distribution amplitudes and the behavior of non-perturbative wavefunctions which control hard exclusive processes at leading twist. The conformal template also can be used to derive commensurate scale relations which connect observables in QCD without scale or scheme ambiguity. The AdS/CFT correspondence of large N{sub C} supergravity theory in higher-dimensional anti-de Sitter space with supersymmetric QCD in 4-dimensional space-time has important implications for hadron phenomenology in the conformal limit, including the nonperturbative derivation of counting rules for exclusive processes and

  12. Physics and Novel Schemes of Laser Radiation Pressure Acceleration for Quasi-monoenergetic Proton Generation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chuan S. [Univ. of Maryland, College Park, MD (United States). Dept. of Physics; Shao, Xi [Univ. of Maryland, College Park, MD (United States)

    2016-06-14

    The main objective of our work is to provide theoretical basis and modeling support for the design and experimental setup of compact laser proton accelerator to produce high quality proton beams tunable with energy from 50 to 250 MeV using short pulse sub-petawatt laser. We performed theoretical and computational studies of energy scaling and Raleigh--Taylor instability development in laser radiation pressure acceleration (RPA) and developed novel RPA-based schemes to remedy/suppress instabilities for high-quality quasimonoenergetic proton beam generation as we proposed. During the project period, we published nine peer-reviewed journal papers and made twenty conference presentations including six invited talks on our work. The project supported one graduate student who received his PhD degree in physics in 2013 and supported two post-doctoral associates. We also mentored three high school students and one undergraduate student of physics major by inspiring their interests and having them involved in the project.

  13. Laser spectroscopy of antiprotonic helium

    CERN Document Server

    Hori, M

    2005-01-01

    When antiprotons (i.e. the antimatter counterpart of protons) are stopped in helium gas, 97% of them annihilate within picoseconds by reacting with the helium nuclei; a 3% fraction, however, survive with an anomalously long lifetime of several microseconds. This longevity is due to the formation of antiprotonic helium, which is a three-body Rydberg atom composed of an antiproton, electron, and helium nucleus. The ASACUSA experimental collaboration has recently synthesized large numbers of these atoms using CERN's Antiproton Decelerator facility, and measured the atom's transition frequencies to 60 parts per billion by laser spectroscopy. By comparing the experimental results with recent three-body QED calculations and the known antiproton cyclotron frequency, we were able to show that the antiproton mass and charge are the same as the corresponding proton values to a precision of 10 parts per billion. Ongoing and future series of experiments will further improve the experimental precision by using chirp-compe...

  14. Antiproton Radiation Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael H.; Petersen, Jørgen B.B.

    2007-01-01

    the radiobiological properties using antiprotons at 50 and 125 MeV from the Antiproton Decelerator (AD) at CERN. Dosimetry experiments were carried out with ionization chambers, alanine pellets and radiochromic film. Radiobiological experiments were done with Chinese V79 WNRE hamster cells. Monte Carlo particle...... transport codes were investigated and compared with results obtained from the ionization chambers and alanine pellets. A track structure model have been applied on the calculated particle spectrum, and been used to predict the LET-dependent response of the alanine pellets. The particle transport program...... FLUKA produced data which were in excellent agreement with our ionization chamber measurements, and in good agreement with our alanine measurements. FLUKA is now being used to generate a wide range of depth dose data at several energies, including secondary particle–energy spectra, which will be used...

  15. On the antiproton discovery

    International Nuclear Information System (INIS)

    Piccioni, O.

    1989-01-01

    The author of this article describes his own role in the discovery of the antiproton. Although Segre and Chamberlain received the Nobel Prize in 1959 for its discovery, the author claims that their experimental method was his idea which he communicated to them informally in December 1954. He describes how his application for citizenship (he was Italian), and other scientists' manipulation, prevented him from being at Berkeley to work on the experiment himself. (UK)

  16. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  17. ALPHA freezes antiprotons

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Laboratories like CERN can routinely produce many different types of antiparticles. In 1995, the PS210 experiment formed the first antihydrogen atoms and a few years later, in 2002, ATRAP and ATHENA were already able to produce several thousand of them. However, no experiment in the world has succeeded in ‘trapping’ these anti-atoms in order to study them. This is the goal of the ALPHA experiment, which has recently managed to cool down the antiprotons to just a few Kelvin. This represents a major step towards trapping the anti-atom, thus opening a new avenue into the investigation of antimatter properties.   Members of the ALPHA collaboration working on the apparatus in the Antiproton Decelerator experimental hall at CERN. Just like the atom, the anti-atom is neutral. Unlike the atom, the anti-atom is made up of antiprotons (as opposed to protons in the atom) and positrons (as opposed to electrons). In order to thoroughly study the properties of the anti-atoms, scien...

  18. Extra Low ENergy Antiproton

    CERN Multimedia

    To produce dense antiproton beams at very low energies (110 keV), it has been proposed to install a small decelerator ring between the existing AD ring and the experimental area. Phase-space blowup during deceleration is compensated by electron cooling such that the final emittances are comparable to the 5MeV beam presently delivered by the AD. An immediate consequence is a significant increase in the number of trapped antiprotons at the experiments as outlined in the proposal CERN/SPSC-2009-026; SPCS-P-338. This report describes the machine parameters and layout of the proposal ELENA (Extra Low ENergy Antiproton)ring also gives an approximate estimate of cost and manpower needs. Since the initial estimate, published in 2007 (CERN-AB-2007-079), the ELENA design has evolved considerably. This is due to a new location in the AD hall to acommodate for the possibility of another experimental zone, as suggested by the SPCS, and also due to improvements in the ring optics and layout. The cost estimate that is prese...

  19. Antiproton compression and radial measurements

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jorgensen, L V; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page R D; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; Van der Werf, D P; Wurtele, J S; Yamazaki, Y

    2008-01-01

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  20. Accelerated Simplified Swarm Optimization with Exploitation Search Scheme for Data Clustering.

    Directory of Open Access Journals (Sweden)

    Wei-Chang Yeh

    Full Text Available Data clustering is commonly employed in many disciplines. The aim of clustering is to partition a set of data into clusters, in which objects within the same cluster are similar and dissimilar to other objects that belong to different clusters. Over the past decade, the evolutionary algorithm has been commonly used to solve clustering problems. This study presents a novel algorithm based on simplified swarm optimization, an emerging population-based stochastic optimization approach with the advantages of simplicity, efficiency, and flexibility. This approach combines variable vibrating search (VVS and rapid centralized strategy (RCS in dealing with clustering problem. VVS is an exploitation search scheme that can refine the quality of solutions by searching the extreme points nearby the global best position. RCS is developed to accelerate the convergence rate of the algorithm by using the arithmetic average. To empirically evaluate the performance of the proposed algorithm, experiments are examined using 12 benchmark datasets, and corresponding results are compared with recent works. Results of statistical analysis indicate that the proposed algorithm is competitive in terms of the quality of solutions.

  1. AA antiproton production target

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The first version of the antiproton production target was a tungsten rod, 11 cm long and 3 mm in diameter. The rod was embedded in graphite, pressure-seated into an outer casing of stainless steel. At the entrance to the target assembly was a scintillator screen, imprinted with circles every 5 mm in radius, which allowed to precisely aim the 26 GeV high-intensity proton beam from the PS onto the centre of the target rod. The scintillator screen was a 1 mm thick plate of Cr-doped alumina. See also 7903034 and 7905091.

  2. AA antiproton production target

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The first version of the antiproton production target was a tungsten rod, 11 cm long (actually a row of 11 rods, each 1 cm long) and 3 mm in diameter. The rod was embedded in graphite, pressure-seated into an outer casing made of stainless steel. The casing had fins for forced-air cooling. In this picture, the 26 GeV high-intensity beam from the PS enters from the right, where a scintillator screen, with circles every 5 mm in radius, permits precise aim at the target centre. See also 7903034 and 7905094.

  3. GPU-Accelerated Stony-Brook University 5-class Microphysics Scheme in WRF

    Science.gov (United States)

    Mielikainen, J.; Huang, B.; Huang, A.

    2011-12-01

    multiple levels, which correspond to various vertical heights in the atmosphere. The size of the CONUS 12 km domain is 433 x 308 horizontal grid points with 35 vertical levels. First, the entire SBU-YLIN Fortran code was rewritten in C in preparation of GPU accelerated version. After that, C code was verified against Fortran code for identical outputs. Default compiler options from WRF were used for gfortran and gcc compilers. The processing time for the original Fortran code is 12274 ms and 12893 ms for C version. The processing times for GPU implementation of SBU-YLIN microphysics scheme with I/O are 57.7 ms and 37.2 ms for 1 and 2 GPUs, respectively. The corresponding speedups are 213x and 330x compared to a Fortran implementation. Without I/O the speedup is 896x on 1 GPU. Obviously, ignoring I/O time speedup scales linearly with GPUs. Thus, 2 GPUs have a speedup of 1788x without I/O. Microphysics computation is just a small part of the whole WRF model. After having completely implemented WRF on GPU, the inputs for SBU-YLIN do not have to be transferred from CPU. Instead they are results of previous WRF modules. Therefore, the role of I/O is greatly diminished once all of WRF have been converted to run on GPUs. In the near future, we expect to have a WRF running completely on GPUs for a superior performance.

  4. Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Amole, C.; Capra, A.; Menary, S. [Department of Physics and Astronomy, York University, Toronto, M3J 1P3 Ontario (Canada); Ashkezari, M. D.; Hayden, M. E. [Department of Physics, Simon Fraser University, Burnaby, V5A 1S6 British Columbia (Canada); Baquero-Ruiz, M.; Little, A.; So, C.; Zhmoginov, A. [Department of Physics, University of California, Berkeley, California 94720 (United States); Bertsche, W. [Department of Physics, College of Science, Swansea University, SA2 8PP Swansea (United Kingdom); School of Physics and Astronomy, University of Manchester, M13 9PL Manchester (United Kingdom); Daresbury Laboratory, Cockcroft Institute, WA4 4AD Warrington (United Kingdom); Butler, E. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Cesar, C. L.; Silveira, D. M. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941 (Brazil); Charlton, M.; Deller, A.; Eriksson, S.; Isaac, C. A.; Madsen, N.; Napoli, S. C.; Shields, C. R. [Department of Physics, College of Science, Swansea University, SA2 8PP Swansea (United Kingdom); Collaboration: ALPHA Collaboration; and others

    2013-04-15

    One of the goals of synthesizing and trapping antihydrogen is to study the validity of charge-parity-time symmetry through precision spectroscopy on the anti-atoms, but the trapping yield achieved in recent experiments must be significantly improved before this can be realized. Antihydrogen atoms are commonly produced by mixing antiprotons and positrons stored in a nested Penning-Malmberg trap, which was achieved in ALPHA by an autoresonant excitation of the antiprotons, injecting them into the positron plasma. In this work, a hybrid numerical model is developed to simulate antiproton and positron dynamics during the mixing process. The simulation is benchmarked against other numerical and analytic models, as well as experimental measurements. The autoresonant injection scheme and an alternative scheme are compared numerically over a range of plasma parameters which can be reached in current and upcoming antihydrogen experiments, and the latter scheme is seen to offer significant improvement in trapping yield as the number of available antiprotons increases.

  5. Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production

    International Nuclear Information System (INIS)

    Amole, C.; Capra, A.; Menary, S.; Ashkezari, M. D.; Hayden, M. E.; Baquero-Ruiz, M.; Little, A.; So, C.; Zhmoginov, A.; Bertsche, W.; Butler, E.; Cesar, C. L.; Silveira, D. M.; Charlton, M.; Deller, A.; Eriksson, S.; Isaac, C. A.; Madsen, N.; Napoli, S. C.; Shields, C. R.

    2013-01-01

    One of the goals of synthesizing and trapping antihydrogen is to study the validity of charge–parity–time symmetry through precision spectroscopy on the anti-atoms, but the trapping yield achieved in recent experiments must be significantly improved before this can be realized. Antihydrogen atoms are commonly produced by mixing antiprotons and positrons stored in a nested Penning-Malmberg trap, which was achieved in ALPHA by an autoresonant excitation of the antiprotons, injecting them into the positron plasma. In this work, a hybrid numerical model is developed to simulate antiproton and positron dynamics during the mixing process. The simulation is benchmarked against other numerical and analytic models, as well as experimental measurements. The autoresonant injection scheme and an alternative scheme are compared numerically over a range of plasma parameters which can be reached in current and upcoming antihydrogen experiments, and the latter scheme is seen to offer significant improvement in trapping yield as the number of available antiprotons increases.

  6. Enhancing trappable antiproton populations through deceleration and frictional cooling

    Energy Technology Data Exchange (ETDEWEB)

    Zolotorev, M.; Sessler, A.; Penn, G.; Wurtele, J. S.; Charman, A. E.

    2012-03-01

    CERN currently delivers antiprotons for trapping experiments with the Antiproton Decelerator (AD), which slows the antiprotons down to about 5 MeV.This energy is currently too high for direct trapping, and thick foils are used to slow down the beam to energies which can be trapped.To allow further deceleration to $\\sim 100 \\;\\mbox{keV}$, CERN is initiating the construction of ELENA,consisting of a ring which will combine RF deceleration and electron cooling capabilities. We describe a simple frictionalcooling scheme that can serve to provide significantly improved trapping efficiency, either directly from the AD or first usinga standard deceleration mechanism (induction linac or RFQ). This scheme could be implemented in a short time.The device itself is short in length, uses accessible voltages, and at reasonable cost could serve in the interim beforeELENA becomes operational, or possibly in lieu of ELENA for some experiments. Simple theory and simulations provide a preliminary assessment of theconcept and its strengths and limitations, and highlight important areas for experimental studies, in particular to pin down the level of multiplescattering for low-energy antiprotons. We show that the frictional cooling scheme can provide a similar energy spectrum to that of ELENA,but with higher transverse emittances.

  7. Search for antiproton decay at the Fermilab antiproton accumulator

    International Nuclear Information System (INIS)

    Geer, S.; Marriner, J.; Ray, R.; Streets, J.; Lindgren, M.; Muller, T.; Quackenbush, J.; Armstrong, T.

    1994-01-01

    A search for antiproton decay has been made at the Fermilab antiproton accumulator. Limits are placed on five antiproton decay modes. At the 95% C.L. we find that τ bar p /B(bar p→e - γ)>1848 yr, τ bar p /B(bar p→e 0 π 0 )>554 yr, τ bar p /B(bar p→e - η)>171 yr,τ bar p /B(bar p→e - K S 0 )>29 yr, and τ bar p /B(bar p→e - K L 0 )>9 yr

  8. Antiproton complex at the FAIR project

    International Nuclear Information System (INIS)

    Dolinskii, A.; Knie, K.; Dimopoulou, C.; Gostishchev, V.; Litvinov, S.; Nolden, F.; Steck, M.

    2011-01-01

    This report summarizes a set of calculations for the antiproton production in a complex composed of target area, collector, separator, beam line and collector ring for the antiproton source of the future FAIR facility (Facility for Antiproton and Ion Research) at GSI, Darmstadt, Germany. The emphasis is on the optimization of the accumulation rate of antiprotons in order to maximize the luminosity of experiments with cooled antiproton beams in the High Energy Storage Ring (HESR). Results of simulations for each component of the antiproton production complex are presented in order to identify the present limitations of the antiproton production rate.

  9. The CERN SPS proton–antiproton collider

    CERN Document Server

    Schmidt, Rudiger

    2016-01-01

    One of CERN's most ambitious and successful projects was the search for the intermediate bosons, W and Z [1]. The accelerator part of the project relied on a number of innovations in accelerator physics and technology. The invention of the method of stochastic cooling and the extension by many orders of magnitude beyond the initial proof of principle demonstration allowed the construction of the Antiproton Accumulator. Major modifications to the 26 GeV PS complex and the conversion of the 300 GeV SPS, which had just started up as an accelerator, to a collider were required. The SPS collider had to master the beam–beam effect far beyond limits reached before and had to function in a tight symbiosis with the UA1 and UA2 experiments.

  10. Analog measurement of delayed antiproton annihilation time spectra in a high intensity pulsed antiproton beam

    International Nuclear Information System (INIS)

    Niestroj, A.; Hayano, R.S.; Ishikawa, T.; Tamura, H.; Torii, H.A.; Morita, N.; Yamazaki, T.; Sugai, I.; Nakayoshi, K.; Horvath, D.; Eades, J.; Widmann, E.

    1996-01-01

    An analog detection system has been developed to measure delayed antiproton annihilation time spectra for laser resonance spectroscopy of metastable antiprotonic helium atoms using the high-intensity pulsed beam of antiprotons from LEAR at CERN. (orig.)

  11. Autoresonant Excitation of Antiproton Plasmas

    CERN Document Server

    Andresen, Gorm B; Baquero-Ruiz, Marcelo; Bertsche, William; Bowe, Paul D; Butler, Eoin; Carpenter, P T; Cesar, Claudio L; Chapman, Steven; Charlton, Michael; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C; Gill, David R; Hangst, Jeffrey S; Hardy, Walter N; Hayden, Michael E; Humphries, Andrew J; Hurt, J L; Hydomako, Richard; Jonsell, Svante; Madsen, Niels; Menary, Scott; Nolan, Paul; Olchanski, Konstantin; Olin, Art; Povilus, Alexander; Pusa, Petteri; Robicheaux, Francis; Sarid, Eli; Silveira, Daniel M; So, Chukman; Storey, James W; Thompson, Robert I; van der Werf, Dirk P; Wurtele, Jonathan S; Yamazaki, Yasunori

    2011-01-01

    We demonstrate controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense, and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination.

  12. Proton-antiproton collider physics

    CERN Document Server

    Altarelli, Guido

    1989-01-01

    This volume reviews the physics studied at the CERN proton-antiproton collider during its first phase of operation, from the first physics run in 1981 to the last one at the end of 1985. The volume consists of a series of review articles written by physicists who are actively involved with the collider research program. The first article describes the proton-antiproton collider facility itself, including the antiproton source and its principle of operation based on stochastic cooling. The subsequent six articles deal with the various physics subjects studied at the collider. Each article descr

  13. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    Section 06 - 08*) of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A vacuum-tank, two bending magnets (BST06 and BST07 in blue) with a quadrupole (QDN07, in red) in between, another vacuum-tank, a wide quadrupole (QFW08) and a further tank . The tanks are covered with heating tape for bake-out. The tank left of BST06 contained the stack core pickup for stochastic cooling (see 7906193, 7906190, 8005051), the two other tanks served mainly as vacuum chambers in the region where the beam was large. Peter Zettwoch works on BST06. *) see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984)

  14. The discovery of the antiproton

    International Nuclear Information System (INIS)

    Chamberlain, Owen

    1989-01-01

    A number of groups of particle physicists competed to provide track evidence of the existence of Dirac's postulated antiproton in the mid-1950s. The work of the several teams is described briefly. The author describes the work of his own group on the Bevatron in more detail, and how they finally observed the antiproton. The article finishes with an assessment of the importance of this discovery. (UK)

  15. Measurement of interaction between antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Klein, S.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Z. M.; Li, Y.; Li, W.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, H.; Xu, N.; Xu, Z.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Z.; Zhang, J.; Zhang, S.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-11-04

    © 2015 Macmillan Publishers Limited. All rights reserved. One of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton-antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton-proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and the ir properties.

  16. Measurement of interaction between antiprotons

    Science.gov (United States)

    The Star Collaboration; Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de La Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Klein, S.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Z. M.; Li, Y.; Li, W.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, H.; Xu, N.; Xu, Z.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Z.; Zhang, J.; Zhang, S.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-11-01

    One of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton-antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton-proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.

  17. TE/TM scheme for computation of electromagnetic fields in accelerators

    International Nuclear Information System (INIS)

    Zagorodnov, Igor; Weiland, Thomas

    2005-01-01

    We propose a new two-level economical conservative scheme for short-range wake field calculation in three dimensions. The scheme does not have dispersion in the longitudinal direction and is staircase free (second order convergent). Unlike the finite-difference time domain method (FDTD), it is based on a TE/TM like splitting of the field components in time. Additionally, it uses an enhanced alternating direction splitting of the transverse space operator that makes the scheme computationally as effective as the conventional FDTD method. Unlike the FDTD ADI and low-order Strang methods, the splitting error in our scheme is only of fourth order. As numerical examples show, the new scheme is much more accurate on the long-time scale than the conventional FDTD approach

  18. Intel Xeon Phi accelerated Weather Research and Forecasting (WRF) Goddard microphysics scheme

    Science.gov (United States)

    Mielikainen, J.; Huang, B.; Huang, A. H.-L.

    2014-12-01

    The Weather Research and Forecasting (WRF) model is a numerical weather prediction system designed to serve both atmospheric research and operational forecasting needs. The WRF development is a done in collaboration around the globe. Furthermore, the WRF is used by academic atmospheric scientists, weather forecasters at the operational centers and so on. The WRF contains several physics components. The most time consuming one is the microphysics. One microphysics scheme is the Goddard cloud microphysics scheme. It is a sophisticated cloud microphysics scheme in the Weather Research and Forecasting (WRF) model. The Goddard microphysics scheme is very suitable for massively parallel computation as there are no interactions among horizontal grid points. Compared to the earlier microphysics schemes, the Goddard scheme incorporates a large number of improvements. Thus, we have optimized the Goddard scheme code. In this paper, we present our results of optimizing the Goddard microphysics scheme on Intel Many Integrated Core Architecture (MIC) hardware. The Intel Xeon Phi coprocessor is the first product based on Intel MIC architecture, and it consists of up to 61 cores connected by a high performance on-die bidirectional interconnect. The Intel MIC is capable of executing a full operating system and entire programs rather than just kernels as the GPU does. The MIC coprocessor supports all important Intel development tools. Thus, the development environment is one familiar to a vast number of CPU developers. Although, getting a maximum performance out of MICs will require using some novel optimization techniques. Those optimization techniques are discussed in this paper. The results show that the optimizations improved performance of Goddard microphysics scheme on Xeon Phi 7120P by a factor of 4.7×. In addition, the optimizations reduced the Goddard microphysics scheme's share of the total WRF processing time from 20.0 to 7.5%. Furthermore, the same optimizations

  19. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    A section of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A large vacuum-tank, a quadrupole (QDN09*), a bending magnet (BST08), another vacuum-tank, a wide quadrupole (QFW08) and (in the background) a further bending magnet (BST08). The tanks are covered with heating tape for bake-out. The tank left of QDN09 contained the kickers for stochastic pre-cooling (see 790621, 8002234, 8002637X), the other one served mainly as vacuum chamber in the region where the beam was large. Peter Zettwoch works on QFW08. * see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984) See under 7911303, 7911597X, 8004261 and 8202324. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .

  20. Antiprotonic helium atomcules

    Directory of Open Access Journals (Sweden)

    Sauge Sébastien

    2012-10-01

    Full Text Available About 3% of antiprotons ( stopped in helium are long-lived with microsecond lifetimes, against picoseconds in all other materials. This unusual longevity has been ascribed to the trapping of on metastable bound states in He+ helium atom-molecules thus named atomcules. Apart from their unique dual structure investigated by laser spectroscopy – a near-circular quasi-classical Rydberg atom with l ~ n – 1 ~ 37 or a special diatomic molecule with a negatively charged nucleus in high rotational state with J = l – the chemical physics aspects of their interaction with other atoms or molecules constitute an interesting topic for molecular physics. While atomcules may resist to million collisions in helium, molecular contaminants such as H2 are likely to destroy them in a single one, down to very low temperatures. In the Born-Oppenheimer framework, we interpret the molecular interaction obtained by ab initio quantum chemical calculations in terms of classical reactive channels, with activation barriers accounting for the experiments carried out in He and H2. From classical trajectory Monte Carlo simulations, we show that the thermalization stage strongly quenches initial populations, thus reduced to a recovered 3 % trapping fraction. This work illustrates the pertinence of chemical physics concepts to the study of exotic processes involving antimatter. New insights into the physico-chemistry of cold interstellar radicals are anticipated.

  1. In the steps of the antiproton

    CERN Multimedia

    Amsler, Claude

    2015-01-01

    Sixty years after the discovery of the antiproton at Berkeley, a look at some of the ways that studies with antiprotons at CERN have cast light on basic physics and, in particular, on fundamental symmetries.

  2. Spectroscopy of antiproton helium atoms

    International Nuclear Information System (INIS)

    Hayano, Ryugo

    2005-01-01

    Antiproton helium atom is three-body system consisting of an antiproton, electrons and a helium nucleus (denoted by the chemical symbol, p-bar H + ). The authors produced abundant atoms of p-bar 4 He + , and p-bar 3 He + in a cooled He gas target chamber stopping the p-bar beam decelerated to approximately 100 keV in the Antiproton Decelerator at CERN. A precision laser spectroscopy on the atomic transitions in the p-bar 4 He + , and in p-bar 3 He + was performed. Principle of laser spectroscopy and various modifications of the system to eliminate factors affecting the accuracy of the experiment were described. Deduced mass ratio of antiproton and proton, (|m p -bar - m p |)/m p reached to the accuracy of 10 ppb (10 -8 ) as of 2002, as adopted in the recent article of the Particle Data Group by P.J. Mohr and B.N. Taylor. This value is the highest precise data for the CPT invariance in baryon. In future, antihydrogen atoms will be produced in the same facility, and will provide far accurate value of antiproton mass thus enabling a better confirmation of CPT theorem in baryon. (T. Tamura)

  3. PHYSICS WITH ULTRA-LOW ENERGY ANTIPROTONS

    Energy Technology Data Exchange (ETDEWEB)

    M. HOLZSCHEITER

    2001-02-01

    In this report the author describes the current status of the antiproton deceleration (AD) facility at CERN, and highlights the physics program with ultra-low energy antiproton at this installation. He also comments on future possibilities provided higher intensity antiproton beams become available at Fermilab, and review possibilities for initial experiments using direct degrading of high energy antiprotons in material has been developed and proven at CERN.

  4. Dosimetric Properties of Plasma Density Effects on Laser-Accelerated VHEE Beams Using a Sharp Density-Transition Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung Hoon; Cho, Sungho; Kim, Eun Ho; Park, Jeong Hoon; Jung, Won-Gyun; Kim, Geun Beom; Kim, Kum Bae [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Min, Byung Jun [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Jaehoon [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of); Jeong, Hojin [Gyeongsang National University Hospital, Jinju (Korea, Republic of); Lee, Kitae [Korea Atomic Energy Research Institute, Deajeon (Korea, Republic of); Park, Sung Yong [Karmanos Cancer Institute, Michigan (United States)

    2017-01-15

    In this paper, the effects of the plasma density on laser-accelerated electron beams for radiation therapy with a sharp density transition are investigated. In the sharp density-transition scheme for electron injection, the crucial issue is finding the optimum density conditions under which electrons injected only during the first period of the laser wake wave are accelerated further. In this paper, we report particle-in-cell simulation results for the effects of both the scale length and the density transition ratio on the generation of a quasi-mono-energetic electron bunch. The effects of both the transverse parabolic channel and the plasma length on the electron-beam's quality are investigated. Also, we show the experimental results for the feasibility of a sharp density-transition structure. The dosimetric properties of these very high-energy electron beams are calculated using Monte Carlo simulations.

  5. Compression of Antiproton Clouds for Antihydrogen Trapping

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Hydomako, R; Jenkins, M J; Jørgensen, L V; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; Van der Werf, D P; Wurtele, J S; Yamazaki, Y

    2008-01-01

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.

  6. Using Intel Xeon Phi to accelerate the WRF TEMF planetary boundary layer scheme

    Science.gov (United States)

    Mielikainen, Jarno; Huang, Bormin; Huang, Allen

    2014-05-01

    The Weather Research and Forecasting (WRF) model is designed for numerical weather prediction and atmospheric research. The WRF software infrastructure consists of several components such as dynamic solvers and physics schemes. Numerical models are used to resolve the large-scale flow. However, subgrid-scale parameterizations are for an estimation of small-scale properties (e.g., boundary layer turbulence and convection, clouds, radiation). Those have a significant influence on the resolved scale due to the complex nonlinear nature of the atmosphere. For the cloudy planetary boundary layer (PBL), it is fundamental to parameterize vertical turbulent fluxes and subgrid-scale condensation in a realistic manner. A parameterization based on the Total Energy - Mass Flux (TEMF) that unifies turbulence and moist convection components produces a better result that the other PBL schemes. For that reason, the TEMF scheme is chosen as the PBL scheme we optimized for Intel Many Integrated Core (MIC), which ushers in a new era of supercomputing speed, performance, and compatibility. It allows the developers to run code at trillions of calculations per second using the familiar programming model. In this paper, we present our optimization results for TEMF planetary boundary layer scheme. The optimizations that were performed were quite generic in nature. Those optimizations included vectorization of the code to utilize vector units inside each CPU. Furthermore, memory access was improved by scalarizing some of the intermediate arrays. The results show that the optimization improved MIC performance by 14.8x. Furthermore, the optimizations increased CPU performance by 2.6x compared to the original multi-threaded code on quad core Intel Xeon E5-2603 running at 1.8 GHz. Compared to the optimized code running on a single CPU socket the optimized MIC code is 6.2x faster.

  7. Antiproton collisions with molecular hydrogen

    DEFF Research Database (Denmark)

    Lühr, Armin Christian; Saenz, Alejandro

    2008-01-01

    Theoretical antiproton and proton cross sections for ionization and excitation of hydrogen molecules as well as energy spectra of the ionized electrons were calculated in the impact-energy range from 8  to  4000  keV. The cross sections were computed with the close-coupling formulation of the sem......Theoretical antiproton and proton cross sections for ionization and excitation of hydrogen molecules as well as energy spectra of the ionized electrons were calculated in the impact-energy range from 8  to  4000  keV. The cross sections were computed with the close-coupling formulation...

  8. Numerical solution of the equation of neutrons transport on plane geometry by analytical schemes using acceleration by synthetic diffusion

    International Nuclear Information System (INIS)

    Alonso-Vargas, G.

    1991-01-01

    A computer program has been developed which uses a technique of synthetic acceleration by diffusion by analytical schemes. Both in the diffusion equation as in that of transport, analytical schemes were used which allowed a substantial time saving in the number of iterations required by source iteration method to obtain the K e ff. The program developed ASD (Synthetic Diffusion Acceleration) by diffusion was written in FORTRAN and can be executed on a personal computer with a hard disc and mathematical O-processor. The program is unlimited as to the number of regions and energy groups. The results obtained by the ASD program for K e ff is nearly completely concordant with those of obtained utilizing the ANISN-PC code for different analytical type problems in this work. The ASD program allowed obtention of an approximate solution of the neutron transport equation with a relatively low number of internal reiterations with good precision. One of its applications would be in the direct determinations of axial distribution neutronic flow in a fuel assembly as well as in the obtention of the effective multiplication factor. (Author)

  9. New scheme for the design and operation of proton--proton storage accelerators

    International Nuclear Information System (INIS)

    Claus, J.; Herrera, J.; Humphrey, J.; Marx, M.; Month, M.

    1977-01-01

    A new system is presented for storage accelerating rings which allows many options for operation. During injection, acceleration, and collision, the beams are maintained in the form of azimuthally long bunches. Current is built up in a low-energy, small circumference accumulator ring. Injection into the storage accelerators is carried out with the bunches phased so that they do not collide. The rf buckets can be matched to the incoming long bunches with only a small dilution. Operation of the storage rings consists of: (1) accelerating the formed bunches to any desired energy; and (2) bringing the bunches into collision by relative phasing of the rf in the two rings. This system provides considerable simplification in the design and operation of high energy p-p facilities. For example, it reduces the beam stacking time, relaxes the impedance tolerances relating to longitudinal stability, reduces the aperture utilization, and avoids radiation background problems associated with beam manipulations. A prototype design is considered, using as a basis the parameters of the ISABELLE facility. Performance characteristics and operational procedures are presented. The many advantages related to the machine and experimental aspects are discussed. In particular, cycling the energy during collisions is an interesting option. Lastly, the significance of extending such a facility to higher energy p-p collisions is outlined

  10. Studies on the construction of a new 80 MeV injector and a new injection scheme for the synchrotron of the Bonn accelerator facility ELSA

    International Nuclear Information System (INIS)

    Raecke, K.

    2001-09-01

    At the ELSA Accelerator Facility exists the opportunity to install a 80 MeV linear accelerator as an injector for the 2,5 GeV Booster Synchrotron. Because of its length the new structure cannot replace one of the linacs used today so possibilities to built up the accelerator and the transfer channels are worked out. Calculations comparing the injection efficiency of the present layout and the possible new layout show a recognizable improvement. The injection efficiency can be further improved using a single turn injection scheme. A septum magnet and a fast kicker for this injection scheme is designed. (orig.)

  11. A conservative and a hybrid early rejection schemes for accelerating Monte Carlo molecular simulation

    KAUST Repository

    Kadoura, Ahmad Salim

    2014-03-17

    Molecular simulation could provide detailed description of fluid systems when compared to experimental techniques. They can also replace equations of state; however, molecular simulation usually costs considerable computational efforts. Several techniques have been developed to overcome such high computational costs. In this paper, two early rejection schemes, a conservative and a hybrid one, are introduced. In these two methods, undesired configurations generated by the Monte Carlo trials are rejected earlier than it would when using conventional algorithms. The methods are tested for structureless single-component Lennard-Jones particles in both canonical and NVT-Gibbs ensembles. The computational time reduction for both ensembles is observed at a wide range of thermodynamic conditions. Results show that computational time savings are directly proportional to the rejection rate of Monte Carlo trials. The proposed conservative scheme has shown to be successful in saving up to 40% of the computational time in the canonical ensemble and up to 30% in the NVT-Gibbs ensemble when compared to standard algorithms. In addition, it preserves the exact Markov chains produced by the Metropolis scheme. Further enhancement for NVT-Gibbs ensemble is achieved by combining this technique with the bond formation early rejection one. The hybrid method achieves more than 50% saving of the central processing unit (CPU) time.

  12. Measurement of interaction between antiprotons

    Czech Academy of Sciences Publication Activity Database

    Adamczyk, L.; Bielčík, J.; Bielčíková, Jana; Federič, Pavol; Chaloupka, P.; Rusňák, Jan; Rusňáková, O.; Šimko, Miroslav; Šumbera, Michal; Tlustý, David; Trzeciak, B. A.; Vértési, Robert

    2015-01-01

    Roč. 527, č. 7578 (2015), s. 345-348 ISSN 0028-0836 R&D Projects: GA ČR GA13-20841S Institutional support: RVO:61389005 Keywords : STAR collaboration * antiprotons * protons Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 38.138, year: 2015

  13. Physics at CERN's Antiproton Decelerator

    CERN Document Server

    Hori, M

    2013-01-01

    The Antiproton Decelerator of CERN began operation in 1999 to serve experiments for studies of CPT invariance by precision laser and microwave spectroscopy of antihydrogen ($\\bar{\\rm H}$) and antiprotonic helium ($\\bar{p}{\\rm He}^+$). The first 12 years of operation saw cold $\\bar{\\rm H}$ synthesized by overlapping clouds of positrons ($e^+$) and antiprotons ($\\bar{p}$) confined in magnetic Penning traps. Cold $\\bar{\\rm H}$ was also produced in collisions between Rydberg positronium atoms and $\\bar{p}$. Ground-state $\\bar{\\rm H}$ was later trapped for up to $\\sim 1000$ s in a magnetic bottle trap, and microwave transitions excited between its hyperfine levels. In the $\\bar{p}{\\rm He}^+$ atom, UV transitions were measured to a precision of (2.3-5) $\\times$ $10^{-9}$ by sub-Doppler two-photon laser spectroscopy. From this the antiproton-to-electron mass ratio was determined as $M_{\\bar{p}}/m_e=$1836.1526736(23), which agrees with the p value. Microwave spectroscopy of $\\bar{p}{\\rm He}^+$ yielded a measurement o...

  14. An FFT-accelerated fdtd scheme with exact absorbing conditions for characterizing axially symmetric resonant structures

    KAUST Repository

    Sirenko, Kostyantyn

    2011-01-01

    An accurate and efficient finite-difference time-domain (FDTD) method for characterizing transient waves interactions on axially symmetric structures is presented. The method achieves its accuracy and efficiency by employing localized and/or fast Fourier transform (FFT) accelerated exact absorbing conditions (EACs). The paper details the derivation of the EACs, discusses their implementation and discretization in an FDTD method, and proposes utilization of a blocked-FFT based algorithm for accelerating the computation of temporal convolutions present in nonlocal EACs. The proposed method allows transient analyses to be carried for long time intervals without any loss of accuracy and provides reliable numerical data pertinent to physical processes under resonant conditions. This renders the method highly useful in characterization of high-Q microwave radiators and energy compressors. Numerical results that demonstrate the accuracy and efficiency of the method are presented.

  15. Reduced 3d modeling on injection schemes for laser wakefield acceleration at plasma scale lengths

    Science.gov (United States)

    Helm, Anton; Vieira, Jorge; Silva, Luis; Fonseca, Ricardo

    2017-10-01

    Current modelling techniques for laser wakefield acceleration (LWFA) are based on particle-in-cell (PIC) codes which are computationally demanding. In PIC simulations the laser wavelength λ0, in μm-range, has to be resolved over the acceleration lengths in meter-range. A promising approach is the ponderomotive guiding center solver (PGC) by only considering the laser envelope for laser pulse propagation. Therefore only the plasma skin depth λp has to be resolved, leading to speedups of (λp /λ0) 2. This allows to perform a wide-range of parameter studies and use it for λ0 Tecnologia (FCT), Portugal, through Grant No. PTDC/FIS-PLA/2940/2014 and PD/BD/105882/2014.

  16. Accelerator update

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS

  17. Accelerator update

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-09-15

    When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS has managed

  18. Anitproton-matter interactions in antiproton applications

    Science.gov (United States)

    Morgan, David L., Jr.

    1990-01-01

    By virtue of the highly energetic particles released when they annihilate in matter, antiprotons have a variety of potentially important applications. Among others, these include remote 3-D density and composition imaging of the human body and also of thick, dense materials, cancer therapy, and spacecraft propulsion. Except for spacecraft propulsion, the required numbers of low energy antiprotons can be produced, stored, and transported through reliance on current or near term technology. Paramount to these applications and to fundamental research involving antiprotons is knowledge of how antiprotons interact with matter. The basic annihilation process is fairly well understood, but the antiproton annihilation and energy loss rates in matter depend in complex ways on a number of atomic processes. The rates, and the corresponding cross sections, were measured or are accurately predictable only for limited combinations of antiproton kinetic energy and material species.

  19. The future of the antiproton accumulator

    International Nuclear Information System (INIS)

    Autin, B.

    1983-01-01

    When the Antiproton Accumulator was designed in 1977, it was considered as an element of the high energy proton-antiproton collision experiments in the CERN Super Proton Synchrotron. Since that time, antiproton physics has become more and more popular: a second experimental area was built in the SPS, the Intersecting Storage Rings started a special antiproton programme and a considerable interest has bloomed in the energy range of nuclear physics with the LEAR machine. Moreover, any projection on hadron physics in the coming years shows an insatiable appetite of experimentalists for more antiprotons. Therefore, basic studies have been pursued since the beginning of last year to transform the accumulator into an abundant source of antiprotons

  20. Antiproton source beam position system

    International Nuclear Information System (INIS)

    Bagwell, T.; Holmes, S.; McCarthy, J.; Webber, R.

    1984-05-01

    The TeV I Beam Position Monitor (BPM) system is designed to provide a useful diagnostic tool during the commissioning and operational phases of the antiproton source. Simply stated the design goal is to provide single turn position information for intensities of > 1x10 9 particles, and multi-turn (clocked orbit) information for beam intensities of > 1x10 7 particles, both with sub-millimeter resolution. It is anticipated that the system will be used during commissioning for establishing the first turn through the Debuncher and Accumulator, for aligning injection orbits, for providing information necessary to correct closed orbits, and for measuring various machine parameters (e.g. tunes, dispersion, aperture, chromaticity). During normal antiproton operation the system will be used to monitor the beam position throughout the accumulation process

  1. Development of a Simple Scheme for Prediction of Flame Acceleration and DDT

    International Nuclear Information System (INIS)

    Kim, Han Chul; Park, Jae Hong; Lee, Jung Jae; Kang, Han Byeol; Sung, Key Yong; Seul, Kwang Won; Cho, Song Won; Ryu, In Chul

    2010-01-01

    Hydrogen combustion phenomenology during severe accidents in nuclear power plants has been a safety issue. Especially, flame acceleration (FA) and Deflagration-to-Detonation Transition (DDT) are important because of their possible destructive impact on the containment or plant systems in it. Accordingly, it is the design goal to avoid FA and DDT for the hydrogen mitigation system. As a result from extensive effort dedicated to resolve the hydrogen issue, compiled information on the FA and DDT has been provided by the NEA. The FA criterion was suggested in terms of the mixture expansion ratio σ , and the criterion for onset of DDT was based on the greatness of the geometrical size of the reactive system compared with the detonation cell width λ of the average mixture composition. The DDT onset criterion reflects the current state of knowledge based on the experimental database; however, the criterion is not sufficient but a necessary condition. Therefore, it should be noted that satisfying this condition means that the possibility of DDT cannot be removed. Based on this information, a simple in-house computer program for evaluation of the FA and DDT possibility, named DEFEND (Determination of Flame Evolution and DDT), is being developed. The database for the density of combustion products analyzed by KEPCO-E and C with the CHEMKIN code was used for FA estimation. The correlation developed by Chan and Wojciechoski is incorporated for determination of the critical expansion ratio σ critical

  2. Radiation studies in the antiproton source

    International Nuclear Information System (INIS)

    Church, M.

    1990-01-01

    Experiment E760 has a lead glass (Pb-G) calorimeter situated in the antiproton source tunnel in the accumulator ring at location A50. This location is exposed to radiation from several sources during antiproton stacking operations. A series of radiation studies has been performed over the last two years to determine the sources of this radiation and as a result, some shielding has been installed in the antiproton source in order to protect the lead glass from radiation damage

  3. Design study of an Antiproton Collector for the Antiproton Accumulator (ACOL)

    International Nuclear Information System (INIS)

    Wilson, E.J.N.

    1983-01-01

    The Report gives a full description of an Antiproton Collector Ring which, placed around the existing Antiproton Accumulator at CERN, would enhance the antiproton flux available to both the SPS and LEAR by a factor of ten. The new ring and the focusing devices which precede it are designed to accept a much larger fraction of the antiproton production cone from the target. Each pulse of particles will be pre-cooled before being fed to the Antiproton Accumulator, where improved stochastic cooling systems will build up the stack. A full list of parameters is included. (orig.)

  4. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

    Science.gov (United States)

    Pilan, N.; Antoni, V.; De Lorenzi, A.; Chitarin, G.; Veltri, P.; Sartori, E.

    2016-02-01

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

  5. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

    Energy Technology Data Exchange (ETDEWEB)

    Pilan, N., E-mail: nicola.pilan@igi.cnr.it; Antoni, V.; De Lorenzi, A.; Chitarin, G.; Veltri, P.; Sartori, E. [Consorzio RFX—Associazione EURATOM-ENEA per la Fusione, Corso Stati Uniti 4, 35127 Padova (Italy)

    2016-02-15

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF{sub 6} instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

  6. The Fermilab proton-antiproton collider upgrades

    International Nuclear Information System (INIS)

    Marriner, J.P.

    1996-10-01

    The plans for increases in the Tevatron proton-antiproton collider luminosity in the near future (Run II) and the more distant future (TeV33) are described. While there are many important issues, the fundamental requirement is to produce more antiprotons and to use them more efficiently

  7. The biological effectiveness of antiproton irradiation

    International Nuclear Information System (INIS)

    Holzscheiter, Michael H.; Bassler, Niels; Agazaryan, Nzhde; Beyer, Gerd; Blackmore, Ewart; DeMarco, John J.; Doser, Michael; Durand, Ralph E.; Hartley, Oliver; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Moller, Soren Pape; Petersen, Jorgen; Skarsgard, Lloyd D.; Smathers, James B.; Solberg, Timothy D.; Uggerhoj, Ulrik I.; Vranjes, Sanja; Withers, H. Rodney; Wong, Michelle; Wouters, Bradly G.

    2006-01-01

    Background and purpose: Antiprotons travel through tissue in a manner similar to that for protons until they reach the end of their range where they annihilate and deposit additional energy. This makes them potentially interesting for radiotherapy. The aim of this study was to conduct the first ever measurements of the biological effectiveness of antiprotons. Materials and methods: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7 MeV antiprotons, 48 MeV protons, or 6 Co γ-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. Results: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which compares the response in a minimally spread out Bragg peak (SOBP) to that in the plateau as a function of particle fluence. This value was ∼3.75 times larger for antiprotons than for protons. This increase arises due to the increased dose deposited in the Bragg peak by annihilation and because this dose has a higher relative biological effectiveness (RBE). Conclusion: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest antiprotons warrant further investigation

  8. Antiproton radiation found effective in cancer research

    CERN Multimedia

    2003-01-01

    "An international collaboration of scientists has completed the first ever antiproton beam experiments designed to reveal the biological effectiveness of antiproton radiation in terminating cells used for cancer research...PBar Labs assembled the collaboration at CERN (European Organization for Nuclear Research in Geneva) to perform the measurements" (1 page).

  9. The biological effectiveness of antiproton irradiation

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Bassler, Niels; Agazaryan, Nzhde

    2006-01-01

    ever measurements of the biological effectiveness of antiprotons. Materials and methods: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7 MeV antiprotons, 48 MeV protons, or 60Co c-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose...... and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. Results: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which...... has a higher relative biological effectiveness (RBE). Conclusion: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest...

  10. The relative biological effectiveness of antiprotons

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Alsner, Jan; Bassler, Niels

    2016-01-01

    Background and purpose: Aside from the enhancement of physical dose deposited by antiprotons annihilating in tissue-like material compared to protons of the same range a further increase of biological effective dose has been demonstrated. This enhancement can be expressed in an increase of the re......Background and purpose: Aside from the enhancement of physical dose deposited by antiprotons annihilating in tissue-like material compared to protons of the same range a further increase of biological effective dose has been demonstrated. This enhancement can be expressed in an increase...... of the relative biological effectiveness (RBE) of antiprotons near the end of range. We have performed the first-ever direct measurement of the RBE of antiprotons both at rest and in flight. Materials and methods: Experimental data were generated on the RBE of an antiproton beam entering a tissue-like target...

  11. Laser-driven ultrafast antiproton beam

    Science.gov (United States)

    Li, Shun; Pei, Zhikun; Shen, Baifei; Xu, Jiancai; Zhang, Lingang; Zhang, Xiaomei; Xu, Tongjun; Yu, Yong; Bu, Zhigang

    2018-02-01

    Antiproton beam generation is investigated based on the ultra-intense femtosecond laser pulse by using two-dimensional particle-in-cell and Geant4 simulations. A high-flux proton beam with an energy of tens of GeV is generated in sequential radiation pressure and bubble regime and then shoots into a high-Z target for producing antiprotons. Both yield and energy of the antiproton beam increase almost linearly with the laser intensity. The generated antiproton beam has a short pulse duration of about 5 ps and its flux reaches 2 × 10 20 s - 1 at the laser intensity of 2.14 × 10 23 W / cm 2 . Compared to conventional methods, this new method based on the ultra-intense laser pulse is able to provide a compact, tunable, and ultrafast antiproton source, which is potentially useful for quark-gluon plasma study, all-optical antihydrogen generation, and so on.

  12. Physics with antiprotons at LEAR

    International Nuclear Information System (INIS)

    Kilian, K.

    1984-01-01

    The low energy antiproton ring LEAR started to work at CERN in 1983. It provides clean anti p beams of much higher intensity and much better quality than available so far in the range from 0.1 to 2 GeV/c momentum. 16 of the 17 accepted experiments are installed and 14 of them took first data in 1983. After approx.= 240 hours of LEAR operation very first results are available. One can expect that exciting physics results be produced in many different domains provided LEAR gets enough anti p in the future. (orig.)

  13. The proton-antiproton collider

    International Nuclear Information System (INIS)

    Evans, L.

    1988-01-01

    The subject of this lecture is the CERN Proton-Antiproton (panti p) Collider, in which John Adams was intimately involved at the design, development, and construction stages. Its history is traced from the original proposal in 1966, to the first panti p collisions in the Super Proton Synchrotron (SPS) in 1981, and to the present time with drastically improved performance. This project led to the discovery of the intermediate vector boson in 1983 and produced one of the most exciting and productive physics periods in CERN's history. (orig.)

  14. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  15. Possible kaon and antiproton factory designs for TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Craddock, M K [British Columbia Univ., Vancouver (Canada); Kost, C J; Richardson, J R [British Columbia Univ., Vancouver (Canada). TRIUMF Facility

    1979-12-01

    Two alternative designs based on proton synchrotrons and isochronous ring cyclotrons, respectively are considered for accelerating high currents (<30 ..mu..A) from TRIUMF (0.45 GeV) to energies high enough for the production of high fluxes of kaons (8-10 GeV) and antiprotons (25-30 GeV). The first synchrotron would be fast cycling at 20 Hz, with third harmonic flat-topping to aid in injection and extraction. The cw beam from TRIUMF would be extracted in 100-turn macropulses at 22 ..mu..sec intervals. With 400 ..mu..A in TRIUMF and injection over 8-20 % of the magnet cycle, 30-80 ..mu..A could be accelerated to 10 GeV. A second synchrotron would accelerate 30 ..mu..A to 30 GeV for production of antiprotons. The ring cyclotron option would also be built in two stages, 0.45 to 3 GeV (15 sectors, 10 m radius) and 3 to 8.5 GeV (30 sectors, 20 m radius). With superconducting magnets (5 T) the weight of steel could be kept below 2000 tons for each ring. Large field-free regions between the spiral ium ions, are obtained with an av the polarimetry installation is being carried out.

  16. Antiprotonic Radioactive Atom for Nuclear Structure Studies

    International Nuclear Information System (INIS)

    Wada, M.; Yamazaki, Y.

    2005-01-01

    A future experiment to synthesize antiprotonic radioactive nuclear ions is proposed for nuclear structure studies. Antiprotonic radioactive nuclear atom can be synthesized in a nested Penning trap where a cloud of antiprotons is prestored and slow radioactive nuclear ions are bunch-injected into the trap. By observing of the ratio of π+ and π- produced in the annihilation process, we can deduce the different abundance of protons and neutrons at the surface of the nuclei. The proposed method would provide a unique probe for investigating the nuclear structure of unstable nuclei

  17. Radiation protection for the antiproton production at the FAIR facility; Strahlenschutz fuer die Antiprotonenproduktion bei FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, I.; Gostischev, V.; Helmecke, M.; Kissel, R.; Knie, K.; Lang, R.; Zieser, B. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Fehrenbacher, G. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); FAIR - Facility for Antiproton and Ion Research in Europe GmbH, Darmstadt (Germany)

    2016-07-01

    FAIR (Facility for Antiproton and Ion Research) is an international accelerator centre, which will be constructed at the site of the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt. Antiprotons are produced in a metal cylinder bombarded with high-energy protons (up to 29 GeV). In addition to antiprotons, this interaction creates other secondary particles such as neutrons, pions, muons and gamma rays. The shielding of this radiation field sets high demands on the building design. Necessary radiation protection measures are based on Monte Carlo simulations of the distribution of the spatial dose rate. Furthermore the activation of components, i.e. the transformation of stable nuclei into radioactive isotopes following irradiation, must be considered. The resulting activities of up to 10{sup 11} Bq require a special concept for the handling and transport of affected elements.

  18. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  19. Prospects for antiproton experiments at Fermilab

    International Nuclear Information System (INIS)

    Kaplan, Daniel M.

    2012-01-01

    Fermilab operates the world’s most intense antiproton source. Newly proposed experiments can use those antiprotons either parasitically during Tevatron Collider running or after the end of the Tevatron Collider program. For example, the annihilation of 5 to 8 GeV antiprotons is expected to yield world-leading sensitivities to hyperon rare decays and CP violation. It could also provide the world’s most intense source of tagged D 0 mesons, and thus the best near-term opportunity to study charm mixing and, via CP violation, to search for new physics. Other measurements that could be made include properties of the X(3872) and the charmonium system. An experiment using a Penning trap and an atom interferometer could make the world’s most precise measurement of the gravitational force on antimatter. These and other potential measurements using antiprotons offer a great opportunity for a broad and exciting physics program at Fermilab in the post-Tevatron era.

  20. Antiproton Induced Fission and Fragmentation of Nuclei

    CERN Multimedia

    2002-01-01

    The annihilation of slow antiprotons with nuclei results in a large highly localized energy deposition primarily on the nuclear surface. \\\\ \\\\ The study of antiproton induced fission and fragmentation processes is expected to yield new information on special nuclear matter states, unexplored fission modes, multifragmentation of nuclei, and intranuclear cascades.\\\\ \\\\ In order to investigate the antiproton-nucleus interaction and the processes following the antiproton annihilation at the nucleus, we propose the following experiments: \\item A)~Measurement of several fragments from fission and from multifragmentation in coincidence with particle spectra, especially neutrons and kaons. \\item B)~Precise spectra of $\\pi$, K, n, p, d and t with time-of-flight techniques. \\item C)~Installation of the Berlin 4$\\pi$ neutron detector with a 4$\\pi$ Si detector placed inside for fragments and charged particles. This yields neutron multiplicity distributions and consequently distributions of thermal excitation energies and...

  1. ASACUSA measures microwave transition in antiprotonic helium

    CERN Document Server

    Eades, John

    2003-01-01

    The ASACUSA collaboration has reinforced its status as a paragon of precision physics by following up its impressive six parts in 10/sup 8/ measurement of the antiproton's charge and mass with new measurements of its magnetism. (4 refs).

  2. CERN: Antiprotons probe the nuclear stratosphere

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The outer periphery of heavy stable nuclei is notoriously difficult to study experimentally. While the well understood electromagnetic interaction between electrons (or muons) and protons has given the nuclear charge (or proton) distribution with high precision for almost all stable nuclei, neutron distribution studies are much less precise. This is especially true for large nuclear distances, where the nuclear density is small. A few previous experiments probing the nuclear ''stratosphere'' suggested that far from the centre of the nucleus (of the order of 2 nuclear radii) this stratosphere may be composed predominantly of neutrons. At the end of the sixties the term ''neutron halo'' was introduced to describe this phenomenon, but experimental evidence was scarce or even controversial, and remained so for almost a quarter of a century. Recently, the Warsaw/Munich/Berlin collaboration working within the PS203 experiment at CERN's LEAR low energy antiproton ring, proposed a new method to study the nuclear periphery using stopped antiprotons. The halo now looks firmer. A 200 MeV/c beam of antiprotons was slowed down by interactions with atomic electrons. When antiproton kinetic energy drops well below 1 keV, the particles are captured in the outermost orbits of ''exotic atoms'', where the antiprotons take the place of the usual orbital electrons. With the lower orbits in this antiprotonic atom empty, the antiproton drops toward the nuclear surface, first emitting Auger electrons and later predominantly antiprotonic X-rays. Due to the strong interaction between antiprotons and nucleons, the antiproton succumbs to annihilation with a nucleon in the rarified nuclear stratosphere, far above the innermost Bohr orbit of the atom. The annihilation probability in heavy nuclei is maximal where the nuclear density is about 3% of its central value and extends to densities many orders of magnitude smaller

  3. CERN: Antiprotons probe the nuclear stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-06-15

    The outer periphery of heavy stable nuclei is notoriously difficult to study experimentally. While the well understood electromagnetic interaction between electrons (or muons) and protons has given the nuclear charge (or proton) distribution with high precision for almost all stable nuclei, neutron distribution studies are much less precise. This is especially true for large nuclear distances, where the nuclear density is small. A few previous experiments probing the nuclear ''stratosphere'' suggested that far from the centre of the nucleus (of the order of 2 nuclear radii) this stratosphere may be composed predominantly of neutrons. At the end of the sixties the term ''neutron halo'' was introduced to describe this phenomenon, but experimental evidence was scarce or even controversial, and remained so for almost a quarter of a century. Recently, the Warsaw/Munich/Berlin collaboration working within the PS203 experiment at CERN's LEAR low energy antiproton ring, proposed a new method to study the nuclear periphery using stopped antiprotons. The halo now looks firmer. A 200 MeV/c beam of antiprotons was slowed down by interactions with atomic electrons. When antiproton kinetic energy drops well below 1 keV, the particles are captured in the outermost orbits of ''exotic atoms'', where the antiprotons take the place of the usual orbital electrons. With the lower orbits in this antiprotonic atom empty, the antiproton drops toward the nuclear surface, first emitting Auger electrons and later predominantly antiprotonic X-rays. Due to the strong interaction between antiprotons and nucleons, the antiproton succumbs to annihilation with a nucleon in the rarified nuclear stratosphere, far above the innermost Bohr orbit of the atom. The annihilation probability in heavy nuclei is maximal where the nuclear density is about 3% of its central value and extends to densities many orders of magnitude smaller. Antiproton annihilation on a proton or on a neutron at the nuclear

  4. Possible kaon and antiproton factory designs for TRIUMF

    International Nuclear Information System (INIS)

    Craddock, M.K.; Kost, C.J.; Richardson, J.R.

    1979-01-01

    Two alternative designs based on proton synchrotrons and isochronous ring cyclotrons, respectively are considered for accelerating high currents (<30 μA) from TRIUMF (0.45 GeV) to energies high enough for the production of high fluxes of kaons (8-10 GeV) and antiprotons (25-30 GeV). The first synchrotron would be fast cycling at 20 Hz, with third harmonic flat-topping to aid in injection and extraction. The cw beam from TRIUMF would be extracted in 100-turn macropulses at 22 μsec intervals. With 400 μA in TRIUMF and injection over 8-20 % of the magnet cycle, 30-80 μA could be accelerated to 10 GeV. A second synchrotron would accelerate 30 μA to 30 GeV for production of antiprotons. The ring cyclotron option would also be built in two stages, 0.45 to 3 GeV (15 sectors, 10 m radius) and 3 to 8.5 GeV (30 sectors, 20 m radius). With superconducting magnets (5 T) the weight of steel could be kept below 2000 tons for each ring. Large field-free regions between the spiral sector magnets allow room for multiple SIN-style accelerating cavities, permitting energy gains of many MeV/turn. Second or third harmonic cavities and the phase compression effect help in achieving separated turn extraction. Up to 100 % of the beam in TRIUMF could be accelerated to 8.5 GeV. (auth)

  5. Possible kaon and antiproton factory designs for TRIUMF

    International Nuclear Information System (INIS)

    Craddock, M.K.; Kost, C.J.; Richardson, J.R.

    1979-11-01

    Two alternative designs based on proton synchrotrons and isochronous ring cyclotrons, respectively are considered for accelerating high currents (>=30 μA) from TRIUMF (0.45 GeV) to energies high enough for the production of high fluxes of kaons (8-10 GeV) and antiprotons (25-30 GeV). The first synchrotron would be fast cycling at 20 Hz, with third harmonic flat-topping to aid in injection and extraction. The cw beam from TRIUMF would be extracted in 100-turn macropulses at 22 μsec intervals. With 400 μA in TRIUMF and injection over 8-20% of the magnet cycle, 30-80 μA could be accelerated to 10 GeV. A second synchrotron would accelerate 30 μA to 30 GeV for production of antiprotons. The ring cyclotron option would also be built in two stages, 0.45 to 3 GeV (15 sectors, 10 m radius) and 3 to 8.5 GeV (30 sectors, 20 m radius). With superconducting magnets (5 T) the weight of steel could be kept below 2000 tons for each ring. Large field-free regions between the spiral sector magnets allow room for multiple SIN-style accelerating cavities, permitting energy gains of many MeV/turn. Second or third harmonic cavities and the phase compression effect help in achieving separated turn extraction. Up to 100% of the beam in TRIUMF could be accelerated to 8.5 GeV. (auth)

  6. The International Facility for Antiproton and Ion Research FAIR

    International Nuclear Information System (INIS)

    Gutbrod, H. H.

    2008-01-01

    The proposed project FAIR (Facility for Antiproton and Ion Research) is an international accelerator facility of the next generation and will be built as a new company FAIR GmbH next to the site of GSI. About 15 countries have expressed their intention to become shareholders. FAIR builds on the experience and technological developments already made at the existing GSI facility, and at the FAIR partner institutes world wide and incorporates new technological concepts. At its heart is a double ring facility with a circumference of 1100 meters. A system of cooler-storage rings for effective beam cooling at high energies and various experimental halls will be connected to the facility. The existing GSI accelerators - together with the planned proton-linac - serve as injector for the new facility. The double-ring synchrotron will provide ion beams of unprecedented intensities as well as of considerably increased energy. Thereby intense beams of secondary beams - unstable nuclei or antiprotons - can be produced. The system of storage-cooler rings allows the quality of these secondary beams - their energy spread and emittance - to be drastically improved. Moreover, in connection with the double ring synchrotron, an efficient parallel operation of up to four scientific programs can be realized at a time. The project is based on many technological innovations, the most important of which are five beam properties: Highest Beam Intensities, Brilliant Beam Quality, Higher Beam Energies, Highest Beam Power, Parallel Operation

  7. Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum

    CERN Document Server

    Zurlo, N.; Amsler, C.; Bonomi, G.; Carraro, C.; Cesar, C.L.; Charlton, M.; Doser, M.; Fontana, A.; Funakoshi, R.; Genova, P.; Hayano, R.S.; Jorgensen, L.V.; Kellerbauer, A.; Lagomarsino, V.; Landua, R.; Lodi Rizzini, E.; Macri, M.; Madsen, N.; Manuzio, G.; Mitchard, D.; Montagna, P.; Posada, L.G.; Pruys, H.; Regenfus, C.; Rotondi, A.; Testera, G.; der Werf, D.P.Van; Variola, A.; Venturelli, L.; Yamazaki, Y.

    2006-01-01

    We present evidence showing how antiprotonic hydrogen, the quasistable antiproton-proton (pbar-p) bound system, has been synthesized following the interaction of antiprotons with the hydrogen molecular ion (H2+) in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques.

  8. The antiproton depth–dose curve in water

    CERN Document Server

    Bassler, N; Jäkel, O; Knudsen, H V; Kovacevic, S

    2008-01-01

    We have measured the depth–dose curve of 126 MeV antiprotons in a water phantom using ionization chambers. Since the antiproton beam provided by CERN has a pulsed structure and possibly carries a high-LET component from the antiproton annihilation, it is necessary to correct the acquired charge for ion recombination effects. The results are compared with Monte Carlo calculations and were found to be in good agreement. Based on this agreement we calculate the antiproton depth–dose curve for antiprotons and compare it with that for protons and find a doubling of the physical dose in the peak region for antiprotons.

  9. The international Facility for Antiproton and Ion Research FAIR: Challenges and Opportunities

    International Nuclear Information System (INIS)

    Hoehne, C.

    2009-01-01

    The status of FAIR, the planned 'Facility for Antiproton and Ion Research', is presented in this contribution. FAIR will be a world unique particle accelerator facility to be built as a joint project by - as of today - 16 member countries. FAIR, which is planned for construction adjacent to the GSI site in Germany, is an integrated system of particle accelerators, 2 superconducting synchrotrons and 8 storage rings, which will provide high energy and high intensity beams of ions from hydrogen to uranium with unprecedented quality and in full parallel mode. In addition highest luminosity secondary beams of rare isotopes and beams of antiprotons will be available. FAIR will combine physics research topics from different communities, i.e. nuclear physics, hadron physics, heavy-ion physics, plasma physics, atomic physics and accelerator development. Details of FAIR and the physics projects will be presented in this contribution.

  10. Antiproton-nucleus potentials from global fits to antiprotonic X-rays and radiochemical data

    Czech Academy of Sciences Publication Activity Database

    Friedman, E.; Gal, A.; Mareš, Jiří

    2005-01-01

    Roč. 761, 3/4 (2005), s. 283-295 ISSN 0375-9474 R&D Projects: GA AV ČR IAA1048305 Institutional research plan: CEZ:AV0Z10480505 Keywords : antiproton-nuclear interaction * RMF calculations * antiproton X-rays Subject RIV: BE - Theoretical Physics Impact factor: 1.950, year: 2005

  11. Antiproton Radiotherapy Peripheral Dose from Secondary Neutrons produced in the Annihilation of Antiprotons in the Target

    CERN Document Server

    Fahimian, Benjamin P; Keyes, Roy; Bassler, Niels; Iwamoto, Keisuke S; Zankl, Maria; Holzscheiter, Michael H

    2009-01-01

    The AD-4/ACE collaboration studies the biological effects of antiprotons with respect to a possible use of antiprotons in cancer therapy. In vitro experiments performed by the collaboration have shown an enhanced biological effectiveness for antiprotons relative to protons. One concern is the normal tissue dose resulting from secondary neutrons produced in the annihilation of antiprotons on the nucleons of the target atoms. Here we present the first organ specific Monte Carlo calculations of normal tissue equivalent neutron dose in antiproton therapy through the use of a segmented CT-based human phantom. The MCNPX Monte Carlo code was employed to quantify the peripheral dose for a cylindrical spread out Bragg peak representing a treatment volume of 1 cm diameter and 1 cm length in the frontal lobe of a segmented whole-body phantom of a 38 year old male. The secondary neutron organ dose was tallied as a function of energy and organ.

  12. A coarse-mesh diffusion synthetic acceleration of the source iteration scheme for one-speed discrete ordinates transport calculations in Slab geometry

    International Nuclear Information System (INIS)

    Santos, Frederico P.; Xavier, Vinicius S.; Alves Filho, Hermes; Barros, Ricardo C.

    2011-01-01

    The scattering source iterative (SI) scheme is traditionally applied to converge fine-mesh numerical solutions to fixed-source discrete ordinates (S N ) neutron transport problems. The SI scheme is very simple to implement under a computational viewpoint. However, the SI scheme may show very slow convergence rate, mainly for diffusive media (low absorption) with several mean free paths in extent. In this work we describe an acceleration technique based on an improved initial guess for the scattering source distribution within the slab. In other words, we use as initial guess for the fine-mesh scattering source, the coarse-mesh solution of the neutron diffusion equation with special boundary conditions to account for the classical S N prescribed boundary conditions, including vacuum boundary conditions. Therefore, we first implement a spectral nodal method that generates coarse-mesh diffusion solution that is completely free from spatial truncation errors, then we reconstruct this coarse-mesh solution within each spatial cell of the discretization grid, to further yield the initial guess for the fine-mesh scattering source in the first S N transport sweep (μm > 0 and μm < 0, m = 1:N) across the spatial grid. We consider a number of numerical experiments to illustrate the efficiency of the offered diffusion synthetic acceleration (DSA) technique. (author)

  13. A coarse-mesh diffusion synthetic acceleration of the scattering source iteration scheme for one-speed slab-geometry discrete ordinates problems

    International Nuclear Information System (INIS)

    Santos, Frederico P.; Alves Filho, Hermes; Barros, Ricardo C.; Xavier, Vinicius S.

    2011-01-01

    The scattering source iterative (SI) scheme is traditionally applied to converge fine-mesh numerical solutions to fixed-source discrete ordinates (S N ) neutron transport problems. The SI scheme is very simple to implement under a computational viewpoint. However, the SI scheme may show very slow convergence rate, mainly for diffusive media (low absorption) with several mean free paths in extent. In this work we describe an acceleration technique based on an improved initial guess for the scattering source distribution within the slab. In other words, we use as initial guess for the fine-mesh scattering source, the coarse-mesh solution of the neutron diffusion equation with special boundary conditions to account for the classical S N prescribed boundary conditions, including vacuum boundary conditions. Therefore, we first implement a spectral nodal method that generates coarse-mesh diffusion solution that is completely free from spatial truncation errors, then we reconstruct this coarse-mesh solution within each spatial cell of the discretization grid, to further yield the initial guess for the fine-mesh scattering source in the first S N transport sweep (μm > 0 and μm < 0, m = 1:N) across the spatial grid. We consider a number of numerical experiments to illustrate the efficiency of the offered diffusion synthetic acceleration (DSA) technique. (author)

  14. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  15. Antiprotons four times more effective than protons for cell irradiation

    CERN Multimedia

    2006-01-01

    "A pioneering experiment at CERN with potential future application in cancer therapy has produced its first results. Started in 2003, ACE (Antiproton Cell Experiment) is the first investigation of the biological effects of antiprotons." (1,5 page)

  16. Antiprotons four times more effective than protons for cell irradiation

    CERN Multimedia

    2007-01-01

    "A pioneering experiment at CERN with potential future application in cancer therapy has produced its first results. Started in 2003, ACE (Antiproton Cell Experiment) is the first investigation of the biological effects of antiprotons." (1,5 page)

  17. The PANDA experiment: Antiproton physics at FAIR

    International Nuclear Information System (INIS)

    Montagna, P.

    2011-01-01

    The new Facility for Antiproton and Ion Research (FAIR), under construction at the GSI laboratory at Darmstadt, in a few years will make available, among different types of beams, even antiproton beams with unique features. Through a High Energy Storage Ring (HESR) for antiprotons, an antiproton beam will be available in a momentum range from 1.5 to 15 GeV/c, which will interact on a hydrogen target. The products of the interaction, including hadronic systems with strangeness and/or charm, will be detected with the PANDA magnetic spectrometer (antiProton ANnihilation at DArmstadt), and the spectroscopic analysis will allow a detailed investigation on a number of open problems of the hadronic physics, as the quark confinement, the existence of non-conventional meson states (so-called glueballs and hybrids), the structure of hadrons and of the strong interaction, with particular attention to charmonium spectroscopy. An overview of the scientific program of PANDA and the current status of the project will be presented.

  18. Conceptual Design Report. Antiproton - Proton Collider Upgrade 20 GeV Rings. Technical Components and Civil Construction May, 1988

    Energy Technology Data Exchange (ETDEWEB)

    None

    1988-05-01

    This report contains a description of the design and cost estimate of two new 20 GeV rings which will be required to support the upgrade of the Fermilab Collider with a luminosity goal of 5x10 31 cm-2s-1. The new rings include an antiproton post-accumulator, denoted the Antiproton Super Booster (ASB), and a proton post-booster, denoted the Proton Super Booster (PSB). The siting of the rings is shown in Figure I-1. Both rings are capable of operation at 20 GeV, eliminating the need for ever again injecting beam into the Main Ring below transition, and significantly enhancing Main Ring performance. The Antiproton Super Booster is designed to accept and accumulate up to 4x1012 antiprotons from the existing Antiproton Accumulator, and deliver them to the Main Ring at 20 GeV for acceleration and injection into the Collider. It is also designed to accept diluted antiprotons from the Main Ring at 20 GeV for recooling. The PSB accepts 8.9 GeV protons from the existing Booster and accelerates them to 20 GeV for injection into the Main Ring. The PSB is designed to operate at 5 Hz. The siting shown in Figure I-1 has the attractive feature that it removes all Main Ring injection hardware from the AO straight section, opening the possibility of installing a third proton-antiproton interaction region in the Tevatron Collider.

  19. Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production

    DEFF Research Database (Denmark)

    Amole, C.; Ashkezari, M.D.; Baquero-Ruiz, M.

    2013-01-01

    One of the goals of synthesizing and trapping antihydrogen is to study the validity of charge-parity-time symmetry through precision spectroscopy on the anti-atoms, but the trapping yield achieved in recent experiments must be significantly improved before this can be realized. Antihydrogen atoms...... and upcoming antihydrogen experiments, and the latter scheme is seen to offer significant improvement in trapping yield as the number of available antiprotons increases....

  20. Accelerating Monte Carlo Molecular Simulations Using Novel Extrapolation Schemes Combined with Fast Database Generation on Massively Parallel Machines

    KAUST Repository

    Amir, Sahar Z.

    2013-05-01

    We introduce an efficient thermodynamically consistent technique to extrapolate and interpolate normalized Canonical NVT ensemble averages like pressure and energy for Lennard-Jones (L-J) fluids. Preliminary results show promising applicability in oil and gas modeling, where accurate determination of thermodynamic properties in reservoirs is challenging. The thermodynamic interpolation and thermodynamic extrapolation schemes predict ensemble averages at different thermodynamic conditions from expensively simulated data points. The methods reweight and reconstruct previously generated database values of Markov chains at neighboring temperature and density conditions. To investigate the efficiency of these methods, two databases corresponding to different combinations of normalized density and temperature are generated. One contains 175 Markov chains with 10,000,000 MC cycles each and the other contains 3000 Markov chains with 61,000,000 MC cycles each. For such massive database creation, two algorithms to parallelize the computations have been investigated. The accuracy of the thermodynamic extrapolation scheme is investigated with respect to classical interpolation and extrapolation. Finally, thermodynamic interpolation benefiting from four neighboring Markov chains points is implemented and compared with previous schemes. The thermodynamic interpolation scheme using knowledge from the four neighboring points proves to be more accurate than the thermodynamic extrapolation from the closest point only, while both thermodynamic extrapolation and thermodynamic interpolation are more accurate than the classical interpolation and extrapolation. The investigated extrapolation scheme has great potential in oil and gas reservoir modeling.That is, such a scheme has the potential to speed up the MCMC thermodynamic computation to be comparable with conventional Equation of State approaches in efficiency. In particular, this makes it applicable to large-scale optimization of L

  1. The Antiproton Depth-Dose Curve in Water

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael; Jäkel, Oliver

    2008-01-01

    We have measured the depth-dose curve of 126 MeV antiprotons in a water phantom using ionization chambers. Since the antiproton beam provided by CERN has a pulsed structure and possibly carries a high-LET component from the antiproton annihilation, it is necessary to correct the acquired charge...

  2. Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan

    2012-01-01

    Over the last years both cosmic-ray antiproton measurements and direct dark matter searches have proved particularly effective in constraining the nature of dark matter candidates. The present work focusses on these two types of constraints in a minimal framework which features a Majorana fermion as the dark matter particle and a scalar that mediates the coupling to quarks. Considering a wide range of coupling schemes, we derive antiproton and direct detection constraints using the latest data and paying close attention to astrophysical and nuclear uncertainties. Both signals are strongly enhanced in the presence of degenerate dark matter and scalar masses, but we show that the effect is especially dramatic in direct detection. Accordingly, the latest direct detection limits take the lead over antiprotons. We find that antiproton and direct detection data set stringent lower limits on the mass splitting, reaching 19% at a 300 GeV dark matter mass for a unity coupling. Interestingly, these limits are orthogonal to ongoing collider searches at the Large Hadron Collider, making it feasible to close in on degenerate dark matter scenarios within the next years

  3. Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2012-07-15

    Over the last years both cosmic-ray antiproton measurements and direct dark matter searches have proved particularly effective in constraining the nature of dark matter candidates. The present work focusses on these two types of constraints in a minimal framework which features a Majorana fermion as the dark matter particle and a scalar that mediates the coupling to quarks. Considering a wide range of coupling schemes, we derive antiproton and direct detection constraints using the latest data and paying close attention to astrophysical and nuclear uncertainties. Both signals are strongly enhanced in the presence of degenerate dark matter and scalar masses, but we show that the effect is especially dramatic in direct detection. Accordingly, the latest direct detection limits take the lead over antiprotons. We find that antiproton and direct detection data set stringent lower limits on the mass splitting, reaching 19% at a 300 GeV dark matter mass for a unity coupling. Interestingly, these limits are orthogonal to ongoing collider searches at the Large Hadron Collider, making it feasible to close in on degenerate dark matter scenarios within the next years.

  4. Anti- and Hypermatter Research at the Facility for Antiproton and Ion Research FAIR

    International Nuclear Information System (INIS)

    Steinheimer, J; Xu, Z; Gudima, K; Botvina, A; Mishustin, I; Bleicher, M; Stöcker, H

    2012-01-01

    Within the next six years, the Facility for Antiproton and Ion Research (FAIR) is built adjacent to the existing accelerator complex of the GSI Helmholtz Center for Heavy Ion Research at Darmstadt, Germany. Thus, the current research goals and the technical possibilities are substantially expanded. With its worldwide unique accelerator and experimental facilities, FAIR will provide a wide range of unprecedented fore-front research in the fields of hadron, nuclear, atomic, plasma physics and applied sciences which are summarized in this article. As an example this article presents research efforts on strangeness at FAIR using heavy ion collisions, exotic nuclei from fragmentation and antiprotons to tackle various topics in this area. In particular, the creation of hypernuclei and antimatter is investigated.

  5. The Antiproton and How It Was Discovered

    International Nuclear Information System (INIS)

    Eades, John

    2005-01-01

    The antiproton celebrates its 50th birthday this year. Although its existence had been suspected since the discovery of the positron in 1932, there was still doubt in some quarters that such a companion particle to the proton could exist. I will try to trace the scientific history of the antiproton from that time to the publication of the definitive paper by Chamberlain, Segre, Wiegand and Ypsilantis in November 1955, with a brief look at what happened next. The narrative will be supplemented with thoughts and opinions of some of the main actors, both at the time and in retrospect

  6. Evaporative Cooling of Antiprotons to Cryogenic Temperatures

    CERN Document Server

    Andresen, G B; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A; Hydomako, R; Jonsell, S; Kurchaninov, L; Lambo, R; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wilding, D; Wurtele, J S; Yamazaki, Y

    2010-01-01

    We report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9~K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments. The technique opens up new possibilities for cooling of trapped ions and is of particular interest in antiproton physics, where a precise CPT test on trapped antihydrogen is a long-standing goal.

  7. K-shell ionization by antiprotons

    International Nuclear Information System (INIS)

    Mehler, G.; Mueller, B.; Greiner, W.; Soff, G.

    1987-01-01

    We present first calculations for the impact parameter dependence of K-shell ionization rates in anti pCu and in anti pAg collisions at various projectile energies. We show that the effect of the attractive Coulomb potential on the Rutherford trajectory and the anti-binding effect caused by the negative charge of the antiproton result in a considerable increase of the ionization probability. Total ionization cross-sections for proton and antiproton projectiles are compared with each other and with experimental ionization cross-sections for protons. (orig.)

  8. Collisions involving antiprotons and antihydrogen: an overview

    Science.gov (United States)

    Jonsell, S.

    2018-03-01

    I give an overview of experimental and theoretical results for antiproton and antihydrogen scattering with atoms and molecules (in particular H, He). At low energies (>1 keV) there are practically no experimental data available. Instead I compare the results from different theoretical calculations, of various degrees of sophistication. At energies up to a few tens of eV, I focus on simple approximations that give reasonably accurate results, as these allow quick estimates of collision rates without embarking on a research project. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

  9. The ASACUSA experiment at CERN's AD antiproton decelerator catches antiprotons in helium, where the antiprotons replace electrons, giving exotics atoms.

    CERN Multimedia

    Loïez, P

    2000-01-01

    Photo 03: Laser beams are prepared for shooting at antiprotonic helium atoms. Left to right: Masaki Hori (Tokyo University) and John Eades (CERN). Photo 01: Dye laser triggered by "YAG" laser. Photo 02: Masaki Hori adjusting optical system of laser beams.

  10. Some preliminary considerations on antiproton-nucleus experiments

    International Nuclear Information System (INIS)

    Yavin, A.I.

    1981-05-01

    The antiproton as a probe of the atomic nucleus is discussed in the expectation that fairly intense beams of high quality will be available in 1983 at the Low Energy Antiproton Ring (LEAR) facility at CERN and possibly also in some other laboratories at a later date. Several antiproton-nucleus experiments are proposed, and the possibility of observing antiprotonic nuclei as well as antineutronic nuclei is discussed. It is demonstrated that even for the study of the elementary nucleon-antinucleon systems it could be advantageous to use nuclei rather than protons as target. The possibility of investigating several antiprotonic atomic systems is also briefly discussed [fr

  11. Using a zero-variance scheme to accelerate the fission source convergence in a Monte Carlo calculation

    International Nuclear Information System (INIS)

    Christoforou, S.; Hoogenboom, J. E.

    2009-01-01

    We have used Boltzmann entropy in order to test whether a zero-variance based scheme can speed up the fission source convergence in a Monte Carlo calculation. It is shown that the choice of the initial source distribution significantly influences the evolution of the source, even leading to cases where the source does not converge at all throughout the calculation. The results from a loosely coupled system based on the NEA/OECD source convergence benchmarks indicate that, when using a biasing scheme such as the one we have developed, there can be significant improvement in the convergence, up to 3 times faster, which coupled with an figure of merit improvement of 1.5 leads to more efficient calculations. (authors)

  12. Recent progress of laser spectroscopy experiments on antiprotonic helium

    Science.gov (United States)

    Hori, Masaki

    2018-03-01

    The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) collaboration is currently carrying out laser spectroscopy experiments on antiprotonic helium ? atoms at CERN's Antiproton Decelerator facility. Two-photon spectroscopic techniques have been employed to reduce the Doppler width of the measured ? resonance lines, and determine the atomic transition frequencies to a fractional precision of 2.3-5 parts in 109. More recently, single-photon spectroscopy of buffer-gas cooled ? has reached a similar precision. By comparing the results with three-body quantum electrodynamics calculations, the antiproton-to-electron mass ratio was determined as ?, which agrees with the known proton-to-electron mass ratio with a precision of 8×10-10. The high-quality antiproton beam provided by the future Extra Low Energy Antiproton Ring (ELENA) facility should enable further improvements in the experimental precision. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

  13. The Antiproton-Ion-Collider at FAIR

    International Nuclear Information System (INIS)

    Kruecken, R.; Fabbietti, L.; Faestemann, T.; Homolka, J.; Kienle, P.; Ring, P.; Suzuki, K.; Bosch, F.; Franzke, B.; Kozhuharov, Ch.; Litvinov, Y.; Nolden, F.; Cargnelli, M.; Fuhrmann, H.; Hirtl, A.; Marton, J.; Widmann, E.; Zmeskal, J.; Hayano, R. S.; Lenske, H.

    2006-01-01

    An antiproton-ion collider (AIC) has been proposed for the FAIR Project at Darmstadt to independently determine rms radii for protons and neutrons in stable and short lived nuclei by means of antiproton annihilation at medium energies. The AIC makes use of the ELISe electron ion collider complex to store, cool and collide antiprotons of 30 MeV energy with short lived radioactive ions in the NESR. The exotic nuclei are produced by projectile fragmentation or projectile fission and separated in the Super FRS. By detecting the loss of stored ions using the Schottky method the total absorption cross-section for antiprotons on the stored ions with mass A will be measured. Cross sections for the absorption on protons and neutrons, respectively, will be measured by the detection of residual nuclei with A-1 either by the Schottky method or by detecting them in recoil detectors after the first dipole stage of the NESR following the interaction zone. The absorption cross sections are in first order directly proportional to the mean square radii

  14. Low energy antiproton experiments - A review

    NARCIS (Netherlands)

    Jungmann, KP; Yamazaki, Y; Wada, M

    2005-01-01

    Low energy antiprotons offer excellent opportunities to study properties of fundamental forces and symmetries in nature. Experiments with them can contribute substantially to deepen our fundamental knowledge in atomic, nuclear and particle physics. Searches for new interactions can be carried out by

  15. Antiprotons in the CERN intersecting storage rings

    International Nuclear Information System (INIS)

    Bryant, P.J.

    1984-01-01

    High-sensitivity electronics for TTl and ring 2 had been developed and installed, the original experimental stochastic cooling systems in the ISR were rebuilt and considerably improved, the split-field magnet (SFM) vacuum chamber was modified, some steering dipoles were designed, made and installed, and finally innumerable interlocks and computer programs were revised for antiproton operation. (orig./HSI)

  16. Collisions of antiprotons with hydrogen molecular ions

    DEFF Research Database (Denmark)

    Lühr, Armin Christian; Saenz, Alejandro

    2009-01-01

    Time-dependent close-coupling calculations of the ionization and excitation cross section for antiproton collisions with molecular hydrogen ions are performed in an impact energy range from 0.5 keV to 10 MeV. The Born-Oppenheimer and Franck-Condon approximations as well as the impact parameter...

  17. A naturally occurring trap for antiprotons

    International Nuclear Information System (INIS)

    Eades, J.; Morita, N.; Ito, T.M.

    1993-05-01

    The phenomenon of delayed annihilation of antiprotons in helium is the first instance of a naturally occurring trap for antimatter in ordinary matter. Recent studies of this effect at CERN are summarized, and plans are described for laser excitation experiments to test its interpretation in terms of metastable exotic helium atom formation. (author)

  18. Recent results from proton-antiproton colliders

    International Nuclear Information System (INIS)

    Geer, S.

    1990-03-01

    New results from the CERN and Fermilab proton-antiproton colliders are summarised. The areas covered are jet physics, direct photon production, W and Z production and decay, heavy flavor production, the search for the top quark, and the search for more exotic phenomena. 46 refs., 20 figs., 4 tabs

  19. Calculated LET-Spectrum of Antiprotons

    DEFF Research Database (Denmark)

    Bassler, Niels

    -LET components resulting from the annihilation. Though, the calculations of dose-averaged LET in the entry region may suggest that the RBE of antiprotons in the plateau region could significantly differ from unity. Materials and Methods Monte Carlo simulations using FLUKA were performed for calculating...

  20. Three-year outcomes of a once daily fractionation scheme for accelerated partial breast irradiation (APBI) using 3-D conformal radiotherapy (3D-CRT)

    International Nuclear Information System (INIS)

    Goyal, Sharad; Daroui, Parima; Khan, Atif J; Kearney, Thomas; Kirstein, Laurie; Haffty, Bruce G

    2013-01-01

    The aim of this study was to report 3-year outcomes of toxicity, cosmesis, and local control using a once daily fractionation scheme (49.95 Gy in 3.33 Gy once daily fractions) for accelerated partial breast irradiation (APBI) using three-dimensional conformal radiotherapy (3D-CRT). Between July 2008 and August 2010, women aged ≥40 years with ductal carcinoma in situ or node-negative invasive breast cancer ≤3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study. Women were treated with APBI using 3–5 photon beams, delivering 49.95 Gy over 15 once daily fractions over 3 weeks. Patients were assessed for toxicities, cosmesis, and local control rates before APBI and at specified time points. Thirty-four patients (mean age 60 years) with Tis 0 (n = 9) and T1N0 (n = 25) breast cancer were treated and followed up for an average of 39 months. Only 3% (1/34) patients experienced a grade 3 subcutaneous fibrosis and breast edema and 97% of the patients had good/excellent cosmetic outcome at 3 years. The 3-year rate of ipsilateral breast tumor recurrence (IBTR) was 0% while the rate of contralateral breast events was 6%. The 3-year disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS) was 94%, 100%, and 100%, respectively. Our novel accelerated partial breast fractionation scheme of 15 once daily fractions of 3.33 Gy (49.95 Gy total) is a remarkably well-tolerated regimen of 3D-CRT-based APBI. A larger cohort of patients is needed to further ascertain the toxicity of this accelerated partial breast regimen

  1. Advanced Accelerator Concepts Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wurtele, Jonathan S.

    2014-05-13

    physics motivation for our experiment, one that requires only a few dozen researchers but must effectively integrate plasma, accelerator, atomic, and fundamental physics, as well as combine numerous technologies in the control, manipulation, and measurement of neutral and non-neutral particles. The ELENA ring (to which we hope to contribute, should funding be provided) is expect, when completed, to significantly enhance the performance of antihydrogen trapping by increasing by a factor of 100 the number of antiprotons that can be successfully trapped and cooled. ELENA operation is scheduled to commence in 2017. In collaboration with LBNL scientists, we proposed a frictional cooling scheme. This is an alternative cooling method to that used by ELENA. It is less complicated, experimentally unproven, and produces a lower yield of cold antiprotons. Students and postdoctoral researchers work on the trapping, cooling, transport, and nonlinear dynamics of antiprotons bunches that are provided by the AD to ALPHA; they contribute to the operation of the experiment, to software development, and to the design and operation of experiments. Students are expected to spend at summers at CERN while taking courses; after completion of courses they typically reside at CERN for most of the half-year run. The Antiproton Decelerator [AD] at CERN, along with its experiments, is the only facility in the world where antiprotons can be trapped and cooled and combined with positrons to form cold antihydrogen, with the ultimate goal of studying CPT violation and, subsequently, gravitational interactions of antimatter. Beyond the ALPHA experiment, the group worked on beam physics problems including limits on the average current in a time-dependent period cathode and new methods to create longitudinally coherent high repetition rate soft x-ray sources and wide bandwidth mode locked x-ray lasers. We completed a detailed study of quantum mechanical effects in the transit time cooling of muons.

  2. Two-photon laser spectroscopy of antiprotonic helium and the antiproton-to-electron mass ratio

    CERN Document Server

    Hori, Masaki; Barna, Daniel; Andreas Dax,; Hayano, Ryugo; Friedreich, Susanne; Juhász, Bertalan; Pask, Thomas; Widmann, Eberhard; Horváth, Dezső; Venturelli, Luca; Zurlo, Nicola; 10.1038/nature10260

    2013-01-01

    Physical laws are believed to be invariant under the combined transformations of charge, parity and time reversal (CPT symmetry). This implies that an antimatter particle has exactly the same mass and absolute value of charge as its particle counterpart. Metastable antiprotonic helium ($\\bar{p}He^+$) is a three-body atom2 consisting of a normal helium nucleus, an electron in its ground state and an antiproton ($\\bar{p}$) occupying a Rydberg state with high principal and angular momentum quantum numbers, respectively n and l, such that n ≈ l + 1 ≈ 38. These atoms are amenable to precision laser spectroscopy, the results of which can in principle be used to determine the antiproton-to-electron mass ratio and to constrain the equality between the antiproton and proton charges and masses. Here we report two-photon spectroscopy of antiprotonic helium, in which $\\bar{p}^{3}He^{+}$ and $\\bar{p}^{4}He^{+}$ isotopes are irradiated by two counter-propagating laser beams. This excites nonlinear, two-phot...

  3. Preliminary study on X-ray fluorescence computed tomography imaging of gold nanoparticles: Acceleration of data acquisition by multiple pinholes scheme

    Science.gov (United States)

    Sasaya, Tenta; Sunaguchi, Naoki; Seo, Seung-Jum; Hyodo, Kazuyuki; Zeniya, Tsutomu; Kim, Jong-Ki; Yuasa, Tetsuya

    2018-04-01

    Gold nanoparticles (GNPs) have recently attracted attention in nanomedicine as novel contrast agents for cancer imaging. A decisive tomographic imaging technique has not yet been established to depict the 3-D distribution of GNPs in an object. An imaging technique known as pinhole-based X-ray fluorescence computed tomography (XFCT) is a promising method that can be used to reconstruct the distribution of GNPs from the X-ray fluorescence emitted by GNPs. We address the acceleration of data acquisition in pinhole-based XFCT for preclinical use using a multiple pinhole scheme. In this scheme, multiple projections are simultaneously acquired through a multi-pinhole collimator with a 2-D detector and full-field volumetric beam to enhance the signal-to-noise ratio of the projections; this enables fast data acquisition. To demonstrate the efficacy of this method, we performed an imaging experiment using a physical phantom with an actual multi-pinhole XFCT system that was constructed using the beamline AR-NE7A at KEK. The preliminary study showed that the multi-pinhole XFCT achieved a data acquisition time of 20 min at a theoretical detection limit of approximately 0.1 Au mg/ml and at a spatial resolution of 0.4 mm.

  4. Investigation of silicon sensors for their use as antiproton annihilation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Pacifico, N., E-mail: nicola.pacifico@cern.ch [University of Bergen, Institute of Physics and Technology, Allégaten 55, 5007 Bergen (Norway); Aghion, S. [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Milano, Via Celoria 16, 20133 Milano (Italy); Ahlén, O. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Belov, A.S. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow 117312 (Russian Federation); Bonomi, G. [University of Brescia, Department of Mechanical and Industrial Engineering, Via Branze 38, 25133 Brescia (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Pavia, Via Agostino Bassi 6, 27100 Pavia (Italy); Bräunig, P. [Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, 69120 Heidelberg (Germany); Bremer, J. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Brusa, R.S. [Department of Physics, University of Trento, via Sommarive 14, 38123 Povo, Trento (Italy); INFN-TIFPA, via Sommarive 14, 38123 Povo, Trento (Italy); Burghart, G. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Cabaret, L. [Laboratoire Aimé Cotton, CNRS, Université Paris Sud, ENS Cachan, Bâtiment 505, Campus d' Orsay, 91405 Orsay Cedex (France); Caccia, M. [University of Insubria, Dipartimento di Scienza ed Alta Tecnologia, via Valleggio 11, Como (Italy); Canali, C. [University of Zurich, Physics Institute, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Caravita, R. [Istituto Nazionale di Fisica Nucleare, Sez. di Genova, Via Dodecaneso 33, 16146 Genova (Italy); University of Genoa, Department of Physics, Via Dodecaneso 33, 16146 Genova (Italy); Castelli, F. [University of Milano, Department of Physics, Via Celoria 16, 20133 Milano (Italy); and others

    2014-11-21

    We present here a new application of silicon sensors aimed at the direct detection of antinucleons annihilations taking place inside the sensor's volume. Such detectors are interesting particularly for the measurement of antimatter properties and will be used as part of the gravity measurement module in the AEg{sup ¯}IS experiment at the CERN Antiproton Decelerator. One of the goals of the AEg{sup ¯}IS experiment is to measure the gravitational acceleration of antihydrogen with 1% precision. Three different silicon sensor geometries have been tested with an antiproton beam to investigate their properties as annihilation detection devices: strip planar, 3D pixels and monolithic pixel planar. In all cases we were successfully detecting annihilations taking place in the sensor and we were able to make a first characterization of the clusters and tracks.

  5. Beam position pickup for antiprotons to the ISR

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    The Antiproton Project, launched for proton-antiproton collisions in the SPS (SPS collider), had a side-line for p-pbar collisions in the ISR. A new transfer line, TT6, was constructed to transport antiprotons from the 26 GeV PS to the injection line TT1 of ISR ring 2. Antiprotons were a scarce commodity. For setting up the lines, beam diagnostic devices in the antiproton path had to work reliably and precisely with just a few low-intensity pilot pules: single bunches of about 2x10**9 antiprotons every few hours. Electrostatic pickup electrodes were used to measure beam position. They could be mounted for measurement in the horizontal plane, as in this picture, or at 90 deg, for the vertical plane.

  6. Antiproton rate estimates for the 1996 E866 experiment

    International Nuclear Information System (INIS)

    Shea, J.Y.; Garcia-Solis, E.J.; Stanskas, P.J.

    1996-01-01

    There has always been a strong interest to study antiprotons produced in relativistic heavy ion collisions. A specific point has been a puzzle for years in that both ARC and RQMD predict the correct antiproton yield for Au+Au collisions at the AGS, but with two entirely different physical explanations. The RQMD is able to describe available data by relying on the enhanced production of antiprotons, followed by the annihilation of a large fraction of the produced antiprotons. Conversely, ARC describes the data by producing less antiprotons initially, but the annihilation of the antiprotons is open-quotes screenedclose quotes in the high density environment of the collision on account of collisions with mesons. It is then particularly interesting to studying the shadowing effect in the Au-Au collisions at the AGS to shine a light in the theoretical debate in heavy-ion collisions

  7. Antiproton Powered Gas Core Fission Rocket

    International Nuclear Information System (INIS)

    Kammash, Terry

    2005-01-01

    Extensive research in recent years has demonstrated that 'at rest' annihilation of antiprotons in the uranium isotope U238 leads to fission at nearly 100% efficiency. The resulting highly-ionizing, energetic fission fragments can heat a suitable medium to very high temperatures, making such a process particularly suitable for space propulsion applications. Such an ionized medium, which would serve as a propellant, can be confined by a magnetic field during the heating process, and subsequently ejected through a magnetic nozzle to generate thrust. The gasdynamic mirror (GDM) magnetic configuration is especially suited for this application since the underlying confinement principle is that the plasma be of such density and temperature as to make the ion-ion collision mean free path shorter than the plasma length. Under these conditions the plasma behaves like a fluid, and its escape from the system is analogous to the flow of a gas into vacuum from a vessel with a hole. For the system we propose we envisage radially injecting atomic or U238 plasma beam at a pre-determined position and axially pulsing an antiproton beam which upon interaction with the uranium target gives rise to near isotropic ejection of fission fragments with a total mass of 212 amu and total energy of about 160 MeV. These particles, along with the annihilation products (i.e. pions and muons) will heat the background U238 gas - inserted into the chamber just prior to the release of the antiproton - to one keV temperature. Preliminary analysis reveals that such a propulsion system can produce a specific impulse of about 3000 seconds at a thrust of about 50 kN. When applied to a round trip Mars mission, we find that such a journey can be accomplished in about 142 days with 2 days of thrusting and requiring only one gram of antiprotons to achieve it

  8. Magnetic horn of the Antiproton Accumulator (AA)

    CERN Multimedia

    Photographic Service

    1988-01-01

    In the 1960s, the invention of this "current sheet lens" has helped to greatly improve the flux of neutrino beams. It was used again at the AA, collecting antiprotons from the production target at angles too large to fit into the acceptance of the AA. It was machined from aluminium to a thickness of 1.4 mm and pulsed at 400 kA for 15 microseconds (half-sine).

  9. Reliability of the Fermilab Antiproton Source

    International Nuclear Information System (INIS)

    Harms, E. Jr.

    1993-05-01

    This paper reports on the reliability of the Fermilab Antiproton source since it began operation in 1985. Reliability of the complex as a whole as well as subsystem performance is summarized. Also discussed is the trending done to determine causes of significant machine downtime and actions taken to reduce the incidence of failure. Finally, results of a study to detect previously unidentified reliability limitations are presented

  10. Potential kaon and antiproton beams at BNL

    International Nuclear Information System (INIS)

    Lazarus, D.M.

    1991-01-01

    The AGS at Brookhaven is the worlds most prolific producer of kaons and low energy antiprotons during operations. With the imminent operation of the AGS Booster which will increase intensities by an anticipated factor of six in the next few years, it will become possible to have purified beams of particles containing strange quarks and anti-quarks with intensities comparable to the pion beams which have so successfully dominated precision hadron spectroscopy in the past. 10 refs., 3 figs

  11. Future accelerator technology

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1986-05-01

    A general discussion is presented of the acceleration of particles. Upon this foundation is built a categorization scheme into which all accelerators can be placed. Special attention is devoted to accelerators which employ a wake-field mechanism and a restricting theorem is examined. It is shown how the theorem may be circumvented. Comments are made on various acceleration schemes

  12. An analytical simulation of the ion-antiproton instabilities in the CERN Antiproton Accumulator

    International Nuclear Information System (INIS)

    Dainelli, A.; Pusterla, M.

    1988-01-01

    A direct map method with a Mathieu approach to tune modulation is proposed and used to simulate nonlinear effects on particle motion that are generated by a beam-beam-like interaction of antiprotons with ions of the residual gas in the CERN Antiproton Accumulator. Two different Gaussian ion distributions are used, and the effects of the simulated beam-beam force on the particle motion is studied in phase space, with a particular attention to high-order nonlinear resonances. (author) 16 refs., 4 figs

  13. Acceleration and higher order schemes of a characteristic solver for the solution of the neutron transport equation in 3D axial geometries

    International Nuclear Information System (INIS)

    Sciannandrone, Daniele

    2015-01-01

    The topic of our research is the application of the Method of Long Characteristics (MOC) to solve the Neutron Transport Equation in three-dimensional axial geometries. The strength of the MOC is in its precision and versatility. As a drawback, it requires a large amount of computational resources. This problem is even more severe in three dimensional geometries, for which unknowns reach the order of tens of billions for assembly-level calculations. The first part of the research has dealt with the development of optimized tracking and reconstruction techniques which take advantage of the regularities of three-dimensional axial geometries. These methods have allowed a strong reduction of the memory requirements and a reduction of the execution time of the MOC calculation. The convergence of the iterative scheme has been accelerated with a lower order transport operator (DPN) which is used for the initialization of the solution and for solving the synthetic problem during MOC iterations. The algorithms for the construction and solution of the MOC and DPN operators have been accelerated by using shared-memory parallel paradigms which are more suitable for standard desktop working stations. An important part of this research has been devoted to the implementation of scheduling techniques to improve the parallel efficiency. The convergence of the angular quadrature formula for three-dimensional cases is also studied. Some of these formulas take advantage of the reduced computational costs of the treatment of planar directions and the vertical direction to speed up the algorithm. The verification of the MOC solver has been done by comparing results with continuous-in-energy Monte Carlo calculations. For this purpose a coupling of the 3D MOC solver with the Subgroup method is proposed to take into account the effects of cross sections resonances. The full calculation of a FBR assembly requires about 2 h of execution time with differences of few pcm with respect to the

  14. Physics with antiprotons: from antihydrogen to the top-quark

    International Nuclear Information System (INIS)

    Koch, H.

    2001-01-01

    The talk gives a survey on experiments performed with antiprotons of different energies. The emphasis will be on results obtained at LEAR/CERN, but the exciting investigations with higher energy antiprotons, leading to the discovery of the intermediate bosons W + , W - , Z 0 and the top quark t, will also be discussed. (orig.)

  15. Serach for polarization effects in the antiproton production process

    CERN Multimedia

    It is proposed to study polarization effects in the production of antiprotons at the PS test beam line T11 at 3.5 GeV/c momentum. A polarization in the production process has never been studied but if existing it would allow for a rather simple and cheap way to generate a polarized antiproton beam with the existing facilities at CERN.

  16. Antiproton impact ionization of atomic hydrogen and helium

    Energy Technology Data Exchange (ETDEWEB)

    McGovern, M; Walters, H R J [Department of Applied Mathematics and Theoretical Physics, Queen' s University, Belfast BT7 INN (United Kingdom); Assafrao, D; Mohallem, J R [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, P.O Box 702, 30123-970 Belo Horizonte, MG (Brazil); Whelan, Colm T, E-mail: mmcgovern06@qub.ac.u [Department of Physics, Old Dominion University, Norfolk, VA 23529-0116 (United States)

    2009-11-01

    We shall present results for antiproton ionization of H and He ranging from fully differential cross sections to total ionization. The calculations have been made in a coupled pseudostate impact parameter approximation. It will be shown that the interaction between the antiproton and the target nucleus is very important at low energies.

  17. Antiproton-nucleus experiments at LEAR and KAON

    International Nuclear Information System (INIS)

    Yavin, A.I.

    1989-12-01

    Antimatter and matter-antimatter systems are briefly discussed. Results of the antiproton-nucleus scattering experiments at LEAR are described, with the emphasis on unfinished experiments and on proposed experiments yet untouched. A few remarks on antiproton and antideuteron experiments at KAON are then presented

  18. Low-energy antiprotons physics and the FLAIR facility

    International Nuclear Information System (INIS)

    Widmann, E

    2015-01-01

    FLAIR, the Facility for low-energy antiproton and ion research has been proposed in 2004 as an extension of the planned FAIR facility at Darmstadt, Germany. FLAIR was not included into the modularized start version of FAIR, but the recent installation of the CRYRING storage ring at GSI Darmstadt has opened new perspectives for physics with low-energy antiprotons at FAIR. (paper)

  19. Measurement of strong interaction effects in antiprotonic helium atoms

    International Nuclear Information System (INIS)

    Davies, J.D.; Gorringe, T.P.; Lowe, J.; Nelson, J.M.; Playfer, S.M.; Pyle, G.J.; Squier, G.T.A.

    1984-01-01

    The strong interaction shift and width for the 2 p level and the width for the 3d level have been measured for antiprotonic helium atoms. The results are compared with optical model calculations. The possible existence of strongly bound antiproton states in nuclei is discussed. (orig.)

  20. Measurement of strong interaction parameters in antiprotonic hydrogen and deuterium

    CERN Document Server

    Augsburger, M A; Borchert, G L; Chatellard, D; Egger, J P; El-Khoury, P; Gorke, H; Gotta, D; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Siems, T; Simons, L M

    1999-01-01

    In the PS207 experiment at CERN, X-rays from antiprotonic hydrogen and deuterium have been measured at low pressure. The strong interaction shift and the broadening of the K/sub alpha / transition in antiprotonic hydrogen were $9 determined. Evidence was found for the individual hyperfine components of the protonium ground state. (7 refs).

  1. Status of the anti-proton production beam in the CERN PS

    International Nuclear Information System (INIS)

    Cappi, R.; Evans, B.J.; Garoby, R.

    1990-01-01

    A new scheme was put into operation in November 1988 to upgrade the proton beam delivered by the 26 GeV Proton Synchrotron (PS) for anti-proton production. It makes use of quasi-adiabatic manipulations of the RF parameters to squeeze a beam filling 1/2 of the PS circumference into a 1/4 turn and can in theory preserve the longitudinal emittance. A maximum intensity of 1.68 e 13 ppp in 5 bunches at 26 GeV has been reached in the course of 22 weeks of operation. The limitations of the performance are analysed together with possible improvements. (author) 6 refs., 9 figs

  2. Studies of Lear antiproton deceleration: radiofrequency quadripole or synchrotron

    International Nuclear Information System (INIS)

    Iazzourene, F.

    1987-06-01

    The aim of this work is to study a radiofrequency quadrupole (RFQ) and a synchrotron as decelerating systems for antiprotons extracted from the Low Energy Antiproton Ring (LEAR) at CERN. Antiprotons at energies lower than those available from LEAR are need by some experiments, eg. the measurement of the mass difference between protons and antiprotons with 10 -9 accuracy, using a Smith and Princeton spectrometer, and the measurement of gravitation on the antiprotons, using a trap. Depending on the LEAR performances, one can conclude that the RFQ is suitable for the experiment on the gravitation, and the synchrotron, owing to its electron cooling system, is a better solution for the experiment on the mass difference measurement, because of the very small acceptance of the spectrometer [fr

  3. What can an antiproton and a nucleus learn from each other

    International Nuclear Information System (INIS)

    Garreta, D.

    1982-05-01

    Simple features which make a low-energy antiproton an interesting probe of the nucleus, and a nucleus an interesting target for an antiproton are presented. Then antiproton-nucleus inelastic and elastic scattering, proton knock-out reactions on nuclei, annihilation of the antiproton in nuclei are reviewed. The aims of the experiment PS184 at LEAR are given

  4. LEAP [Low-Energy Antiproton]: A balloon-borne search for low-energy cosmic-ray antiprotons

    International Nuclear Information System (INIS)

    Moats, A.R.M.

    1989-01-01

    The LEAP (Low-Energy Antiproton) experiment is a search for cosmic-ray antiprotons in the 120 MeV to 1.2 GeV kinetic energy range. The motivation for this project was the result announced by Buffington et. al. (1981) that indicated an anomalously high antiproton flux below 300 MeV; this result has compelled theorists to propose sources of primary antiprotons above the small secondary antiproton flux produced by high energy cosmic-ray collisions with nuclei in the interstellar medium. LEAP consisted of the NMSU magnetic spectrometer, a time-of-flight system designed at Goddard Space Flight Center, two scintillation detectors, and a Cherenkov counter designed and built at the University of Arizona. Analysis of flight data performed by the high-energy astrophysics group at Goddard Space Flight Center revealed no antiproton candidates found in the 120 MeV to 360 MeV range; 3 possible antiproton candidate events were found in the 500 MeV to 1.2 GeV range in an analysis done here at the University of Arizona. However, since it will be necessary to sharpen the calibration on all of the LEAP systems in order to positively identify these events as antiprotons, only an upper limit has been determined at present. Thus, combining the analyses performed at the University of Arizona and Goddard Space Flight Center, 90% confidence upper limits of 3.5 x 10 -5 in the 120 MeV to 360 MeV range and 2.3 x 10 -4 in the 500 MeV to 1.2 GeV range for the antiproton/proton ratio is indicated by the LEAP results. LEAP disagrees sharply with the results of the Buffington group, indicating a low antiproton flux at these energies

  5. Stochastic Cooling at the CERN Antiproton Decelerator

    CERN Document Server

    Carli, Christian

    2000-01-01

    When transforming the CERN Antiproton Collector (AC) into the Antiproton Decelerator (AD), the stochastic cooling systems were rebuilt to cope with the new requirements. Instead of using the original three frequency bands, (0.9-1.6 GHz, 1.6-2.45 GHz and 2.4-3.2 GHz) only the first of these was used due to lattice limitations and other constraints. The same pick-ups and kickers are in use at two different energies. As in the AC, simultaneous cooling in all three phase planes is required. Switching between two transmission paths (at 3.5 GeV/c and 2.0 GeV/c) became necessary, including separate notch filters and delay compensation for the kicker sections. The tanks has to be rendered bakeable (150 C) to make the vacuum properties (<10-10 Torr) compatible with deceleration to low energies. Further improvements included programmable, phase-invariant electronic attenuators and amplitude-invariant delays. Experience during commissioning showed that careful optimization (depth and periodicity) of the notch filters...

  6. Laser Spectroscopy of Antiprotonic Helium Atoms

    CERN Multimedia

    2002-01-01

    %PS205 %title\\\\ \\\\Following the discovery of metastable antiprotonic helium atoms ($\\overline{p}He^{+} $) at KEK in 1991, systematic studies of their properties were made at LEAR from 1991 to 1996. In the first two years the lifetime of $\\overline{p}He^{+}$ in liquid and gaseous helium at various temperatures and pressures was measured and the effect of foreign gases on the lifetime of these atoms was investigated. Effects were also discovered which gave the antiproton a 14\\% longer lifetime in $^4$He than in $^3$He, and resulted in important differences in the shape of the annihilation time spectra in the two isotopes.\\\\ \\\\Since 1993 laser spectroscopy of the metastable $\\overline{p}He^{+}$ atoms became the main focus of PS205. Transitions were stimulated between metastable and non-metastable states of the $\\overline{p}He^{+}$ atom by firing a pulsed dye laser beam into the helium target every time an identified metastable atom was present (Figure 1). If the laser frequency matched the transition energy, the...

  7. The antiproton ion collider at FAIR

    International Nuclear Information System (INIS)

    Fabbietti, L.; Faestermann, T.; Homolka, J.; Kienle, P.; Kruecken, R.; Ring, P.; Suziki, K.; Beller, P.; Bosch, F.; Frankze, B.; Kozhuharov, C.; Nolden, F.; Cargnelli, M.; Fuhrmann, H.; Hirtl, A.; Marton, J.; Widmann, E.; Zmeskal, J.; Hayano, R.S.; Yamaguchi, T.; Lenske, H.; Litvinov, Y.; Shatunov, Y.; Skrinsky, A.N.; Vostrikov, V.A.; Wycech, S.

    2005-01-01

    A novel method is proposed to determine the charge and the matter radii instable and short lived nuclei using an pBar-A collider. The experiment makes use of the appropriately modified electron-ion collider Elise, to collide 30 MeV anti-protons with 740 AMeV ions. The anti-protons are first collected in the CR ring with 3 GeV energy and then cooled in the RESR ring to 30 MeV. The heavy ions produced in the SFRS are precooled in the CR ring, cooled in the RESR ring to 740 AMeV and fed to the NESR ring. The total pBar-nucleon annihilation cross-section is measured detecting the loss of stored ions and the pBar-n, pBar-p cross-sections detecting the A - 1 (Z - 1 or N - 1) nuclei left over after the annihilation, using the Schottcky method. Theoretical predictions show that the annihilation cross-section is proportional to the mean squared radius. (author)

  8. Atomic physics of the antimatter explored with slow antiprotons

    International Nuclear Information System (INIS)

    Torii, Hiroyuki A.

    2010-01-01

    Frontiers of antimatter physics are reviewed, with a focus on our ASACUSA collaboration, doing research on 'Atomic Spectroscopy And Collisions Using Slow Antiprotons' at the 'Antiproton Decelerator' facility at CERN. Antiprotonic helium atoms give a unique test ground for testing CPT invariance between particles and antiparticles. Laser spectroscopy of this exotic atom has reached a precision of a few parts per billion in determation of the antiproton mass. We also have developed techniques to decelerate antiprotons and cool them to sub-eV energies in an electromagnetic trap at ultra-high vacuum and extract them as an ultra-slow beam at typically 250 eV. This unique low-energy beam opens up the possibility to study ionization and formation of antiprotonic atoms. The antihydrogen has been synthesized at low temperature in nested Penning traps by ATRAP and ATHENA(presently ALPHA) collaborations. Confinement of this neutral anti-atoms in a trap with magnetic field gradient is being studied, with an aim of 1S-2S laser spectroscopy in the future. ASACUSA has prepared a cusp trap for production of antihydrogen atoms, and aims at microwave spectroscopy between the hyperfine states of spin-polarized antihydrogen. A wide variety of low-energy antiproton physics also includes measurement of nuclear scattering, radiational biological effects, and gravity test of antimatter. (author)

  9. Muon, positron and antiproton interactions with atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Armour, Edward A G, E-mail: edward.armour@nottingham.ac.u [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2010-04-01

    In this paper, a description is given of some interesting processes involving the interaction of a muon, a positron, or an antiproton with atoms and molecules. The process involving a muon is the resonant formation of the muonic molecular ion, dt{mu}, in the muon catalyzed fusion cycle. In the case of a positron, the process considered is positron annihilation in low-energy positron scattering by the hydrogen molecule. The antiproton is considered as the nucleus of an antihydrogen atom interacting with simple atoms. Attention is given to antiproton annihilation through the strong interaction. An outline is given of proposed tests of fundamental physics to be carried out using antihydrogen.

  10. Prospects for antiproton physics, my perspective

    International Nuclear Information System (INIS)

    Oelert, Walter

    2012-01-01

    These closing remarks are not supposed to be a summary talk, for this please have a look to the individual contributions to be published in the proceedings, but rather some considerations on future prospects for antiproton physics. However, first I would like to appreciate the organizers idea for giving me the opportunity to thank them for a well balanced, exciting and interesting conference LEAP-2011 in this marvelous city of Vancouver. I am sure we all loved to be here and enjoyed the hospitality and the bond of friendship we could experience during these days. We appreciate the patience and help of all the local organizers where I especially would like to mention Jana Thomson for her endless and helpful assignment. Thank you all—the participants, the speakers, the conference chair, the sponsors—for making this conference a success and we are looking forward to the next occasion in this series of meetings which will be celebrated in Uppsala.

  11. Prospects for antiproton physics, my perspective

    Energy Technology Data Exchange (ETDEWEB)

    Oelert, Walter, E-mail: w.oelert@fz-juelich.de [Forschungszentrum Juelich (Germany)

    2012-12-15

    These closing remarks are not supposed to be a summary talk, for this please have a look to the individual contributions to be published in the proceedings, but rather some considerations on future prospects for antiproton physics. However, first I would like to appreciate the organizers idea for giving me the opportunity to thank them for a well balanced, exciting and interesting conference LEAP-2011 in this marvelous city of Vancouver. I am sure we all loved to be here and enjoyed the hospitality and the bond of friendship we could experience during these days. We appreciate the patience and help of all the local organizers where I especially would like to mention Jana Thomson for her endless and helpful assignment. Thank you all-the participants, the speakers, the conference chair, the sponsors-for making this conference a success and we are looking forward to the next occasion in this series of meetings which will be celebrated in Uppsala.

  12. Antiproton-nucleon physics at LEAR

    International Nuclear Information System (INIS)

    Duclos, J.

    1985-02-01

    Antiproton beams from LEAR have been supplied in 1984 to 16 experiments about 10 12 particules at 200, 300, 600 and 1500 MeV/c have been delivered during 60 days of machine time. In nuclear physics, anti p-nuclei scattering and atomic X rays have been measured. In hydrogen, atomic L and K transitions have been detected. Searches have been made for baryonia with rather negative results. The p anti p annihilation at rest in various meson channels, selecting the initial anti p-wave, has been observed. The annihilation in electron-positron pair at rest and in flight has been measured and a value of the proton form factor is derived [fr

  13. Measurement of antiproton production in $p$–He collisions at LHCb to constrain the secondary cosmic antiproton flux

    CERN Document Server

    Graziani, Giacomo

    2018-01-01

    The flux of cosmic ray antiprotons is a powerful tool for indirect detection of dark matter. The sensitivity is limited by the uncertainty on the predicted antiproton flux from scattering of primary rays on the interstellar medium. This is, in turn, limited by the knowledge of production cross-sections, notably in p–He scattering. Thanks to its internal gas target, the LHCb experiment performed the first measurement of antiproton production from collisions of LHC proton beams on He nuclei at rest. The results and prospects are presented.

  14. High energy density physics studies at the facility for antiprotons and ion research: the HEDgeHOB collaboration

    International Nuclear Information System (INIS)

    Tahir, N.A.; Stoehlker, T.; Geissel, H.; Shutov, A.; Lomonosov, I.V.; Fortov, V.E.; Piriz, A.R.; Redmer, R.; Deutsch, C.

    2011-01-01

    The forthcoming Facility for Antiprotons and Ion Research (FAIR) at Darmstadt, is going to be a unique accelerator facility that will deliver high quality, strongly bunched, well focused, intense beams of heavy ions that will lead to unprecedented specific power deposition in solid matter. This will generate macroscopic samples of High Energy Density (HED) matter with fairly uniform physical conditions. These samples can be used to study the thermophysical and transport properties of HED matter. Extensive theoretical work has been carried out over the past decade to design numerous dedicated experiments to study HED physics at the FAIR, which has provided the basis for the HEDgeHOB (High Energy Density Matter Generated by Heavy Ion Beams) scientific proposal. This work is still in progress as the feasibility studies for more experimental schemes are being carried out. Another, very important research area that will benefit tremendously from the FAIR facility, is the production of radioactive beams. A superconducting fragment separator, Super-FRS is being designed for the production and separation of rare radioactive isotopes. Unlike the HED targets, the Super-FRS production target should not be destroyed or damaged by the beam, but should remain intact during the long experimental campaign. However, the high level of specific power deposited in the production target by the high intensity ion beam at FAIR, could cause serious problems to the target survival. These HED issues related to the Super-FRS production target are also discussed in the present paper (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Do positrons and antiprotons respect the weak equivalence principle?

    International Nuclear Information System (INIS)

    Hughes, R.J.

    1990-01-01

    We resolve the difficulties which Morrison identified with energy conservation and the gravitational red-shift when particles of antimatter, such as the positron and antiproton, do not respect the weak equivalence principle. 13 refs

  16. Antiproton cell experiment: antimatter is a better killer

    CERN Multimedia

    2006-01-01

    "European Organization for Nuclear Research is reporting that results from a three year study of antiprotons for neoplasm irrdiation showed a better cellular killer with a smaller lethal dose." (1,5 page)

  17. New results on strong-interaction effects in antiprotonic hydrogen

    CERN Document Server

    Gotta, D; Augsburger, M A; Borchert, G L; Castelli, C M; Chatellard, D; El-Khoury, P; Egger, J P; Gorke, H; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the low-energy antiproton ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using charge-coupled devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (33 refs).

  18. New results on strong-interaction effects in antiprotonic hydrogen

    International Nuclear Information System (INIS)

    Anagnostopoulos, D. F.; Augsburger, M.; Borchert, G.; Castelli, C.; Chatellard, D.; El-Khoury, P.; Egger, J.-P.; Gorke, H.; Gotta, D.; Hauser, P.; Indelicato, P.; Kirch, K.; Lenz, S.; Nelms, N.; Rashid, K.; Schult, O. W. B.; Siems, Th.; Simons, L. M.

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the Low-Energy Antiproton Ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using Charge-Coupled Devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction

  19. Cosmic ray propagation in a diffusion model: a new estimation of the diffusion parameters and of the secondary antiprotons flux

    International Nuclear Information System (INIS)

    Maurin, D.

    2001-02-01

    Dark matter is present at numerous scale of the universe (galaxy, cluster of galaxies, universe in the whole). This matter plays an important role in cosmology and can not be totally explained by conventional physic. From a particle physic point of view, there exists an extension of the standard model - supersymmetry - which predicts under certain conditions the existence of new stable and massive particles, the latter interacting weakly with ordinary matter. Apart from direct detection in accelerators, various indirect astrophysical detection are possible. This thesis focuses on one particular signature: disintegration of these particles could give antiprotons which should be measurable in cosmic rays. The present study evaluates the background corresponding to this signal i. e. antiprotons produced in the interactions between these cosmic rays and interstellar matter. In particular, uncertainties of this background being correlated to the uncertainties of the diffusion parameter, major part of this thesis is devoted to nuclei propagation. The first third of the thesis introduces propagation of cosmic rays in our galaxy, emphasizing the nuclear reaction responsibles of the nuclei fragmentation. In the second third, different models are reviewed, and in particular links between the leaky box model and the diffusion model are recalled (re-acceleration and convection are also discussed). This leads to a qualitative discussion about information that one can infer from propagation of these nuclei. In the last third, we finally present detailed solutions of the bidimensional diffusion model, along with constrains obtained on the propagation parameters. The latter is applied on the antiprotons background signal and it concludes the work done in this thesis. The propagation code for nuclei and antiprotons used here has proven its ability in data analysis. It would probably be of interest for the analysis of the cosmic ray data which will be taken by the AMS experiment on

  20. The Floor's the Limit (Antiproton energies to hit new low)

    CERN Multimedia

    2000-01-01

    Celebrating the success of the RFQ in Aarhus. Left to right: Alessanda Lombardi (CERN), Iouri Bylinskii (CERN), Alex Csete (Aarhus), Ulrik Uggerhøj (Aarhus), Ryu Hayano (Tokyo, spokesman ASACUSA), Helge Knudsen (Aarhus), Werner Pirkl (CERN), Ryan Thompson (Aarhus), Søren P. Møller (Aarhus). Although in particle physics we are accustomed to strive for higher and higher energies, this is not always the most interesting thing to do with antiprotons. Indeed, as recent issues of the Bulletin have suggested, the signpost on the road to a closer look at the antiproton points towards ever-lower energies. The CERN Antiproton Decelerator decelerates antipro-tons emerging from a target placed in the path of a 26 GeV/c proton beam from 90 % of to about 10 % of the speed of light. However, even this is far too fast for many of the most interesting experiments on antiprotons planned by Danish and Japanese members of the ASACUSA collaboration. Tokyo University has therefore financed the con...

  1. Large amounts of antiproton production by heavy ion collision

    International Nuclear Information System (INIS)

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    To produce large amounts of antiprotons, on the order of several grams/year, use of machines to produce nuclear collisions are studied. These can be of either proton-proton, proton-nucleus and nucleus-nucleus in nature. To achieve high luminosity colliding beams, on the order of 10 41 m/cm 2 , a self-colliding machine is required, rather than a conventional circular colliding type. The self-colliding machine can produce additional antiprotons through successive collisions of secondary particles, such as spectator nucleons. A key problem is how to collect the produced antiprotons without capture by beam nuclei in the collision zone. Production costs for anti-matter are projected for various energy source options and technology levels. Dedicated facilities using heavy ion collisions could produce antiproton at substantially less than 1 million $/milligram. With co-production of other valuable products, e.g., nuclear fuel for power reactors, antiproton costs could be reduced to even lower values

  2. A low-energy antiproton detector prototype for AFIS

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Lingxin; Greenwald, Daniel; Hahn, Alexander; Hauptmann, Philipp; Konorov, Igor; Losekamm, Martin; Paul, Stephan; Poeschl, Thomas; Renker, Dieter [Technische Universitaet Muenchen (Germany)

    2014-07-01

    Antiprotons are produced in interactions of primary cosmic rays with earth's exosphere, where a fraction of them will be confined in the geomagnetic field in the inner van Allen Belt. The antiproton-to-proton flux ratio predicted by theory is in good agreement with recent results from the South Atlantic Anomaly (SAA) published by the PAMELA collaboration. We have designed the AFIS (Antiproton Flux in Space) project in order to extend the measurable range of antiprotons towards the low-energy region. In scope of this project a small antiproton detector consisting of scintillating fibers and silicon photomultipliers is being developed as payload for a CubeSat traversing the SAA in Low Earth Orbit. For the proof of concept we have built a prototype called ''CubeZero'' which completed its first test using pion and proton beams at PSI, Switzerland. Our primary goal was to investigate on the performance of tracking and Bragg peak identification in hardware and software. Analysis of detector performance based on data taken during this beam test is presented in this talk.

  3. Antiproton tagging and vertex fitting in a Timepix3 detector

    CERN Document Server

    Aghion, S.; The AEGIS collaboration; Antonello, M.; Belov, A.; Bonomi, G.; Brusah, R. S.; Caccia, M.; Camper, A.; Caravita, R.; Castelli, F.; Cerchiari, G.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Evans, C.; Fanì, M.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Hackstock, P.; Haider, S.; Hinterberger, A.; Holmestad, H.; Kellerbauer, A.; Khalidova, O.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lebrun, P.; Malbrunot, C.; Mariazzi, S.; Marton, J.; Matveev, V.; Müller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pacifico, N.; Pagano, D.; Penasa, L.; Petracek, V.; Prelz, F.; Prevedelli, M.; Rienaecker, B.; Robert, J.; Røhne, O. M.; Rotondi, A.; Sandaker, H.; Santoro, R.; Smestad, L.; Sorrentino, F.; Testera, G.; Tietje, I. C.; Widmann, E.; Yzombard, P.; Zimmer, C.; Zmeskal, J.; Zurlo, N.

    2018-01-01

    Studies of antimatter are important for understanding our universe at a fundamental level. There are still unsolved problems, such as the matter-antimatter asymmetry in the universe. The AEgIS experiment at CERN aims at measuring the gravitational fall of antihydrogen in order to determine the gravitational force on antimatter. The proposed method will make use of a position-sensitive detector to measure the annihilation point of antihydrogen. Such a detector must be able to tag the antiproton, measure its time of arrival and reconstruct its annihilation point with high precision in the vertical direction. This work explores a new method for tagging antiprotons and reconstructing their annihilation point. Antiprotons from the Antiproton Decelerator at CERN was used to obtain data on direct annihilations on the surface of a silicon pixel sensor with Timepix3 readout. These data were used to develop and verify a detector response model for annihilation of antiprotons in this detector. Using this model and the a...

  4. Calculated LET spectrum from antiproton beams stopping in water

    CERN Document Server

    Bassler, Niels

    2009-01-01

    Antiprotons have been proposed as a potential modality for radiotherapy because the annihilation at the end of range leads to roughly a doubling of physical dose in the Bragg peak region. So far it has been anticipated that the radiobiology of antiproton beams is similar to that of protons in the entry region of the beam, but very different in the annihilation region, due to the expected high-LET components resulting from the annihilation. On closer inspection we find that calculations of dose averaged LET in the entry region may suggest that the RBE of antiprotons in the plateau region could significantly differ from unity, which seems to warrant closer inspection of the radiobiology in this region. Materials and Methods. Monte Carlo simulations using FLUKA were performed for calculating the entire particle spectrum of a beam of 126 MeV antiprotons hitting a water phantom. Results and Discussion. In the plateau region of the simulated antiproton beam we observe a dose-averaged unrestrict...

  5. Atomic Spectroscopy and Collisions Using Slow Antiprotons \\\\ ASACUSA Collaboration

    CERN Multimedia

    Matsuda, Y; Lodi-rizzini, E; Kuroda, N; Schettino, G; Hori, M; Pirkl, W; Mascagna, V; Leali, M; Malbrunot, C L S; Yamazaki, Y; Eades, J; Simon, M; Massiczek, O; Sauerzopf, C; Nagata, Y; Knudsen, H; Uggerhoj, U I; Mc cullough, R W; Toekesi, K M; Venturelli, L; Widmann, E; Zmeskal, J; Kanai, Y; Kristiansen, H; Todoroki, K; Bartel, M A; Moller, S P; Charlton, M; Diermaier, M; Kolbinger, B

    2002-01-01

    ASACUSA (\\underline{A}tomic \\underline{S}pectroscopy \\underline{A}nd \\underline{C}ollisions \\underline{U}sing \\underline{S}low \\underline{A}ntiprotons) is a collaboration between a number of Japanese and European research institutions, with the goal of studying bound and continuum states of antiprotons with simple atoms.\\\\ Three phases of experimentation are planned for ASACUSA. In the first phase, we use the direct $\\overline{p}$ beam from AD at 5.3 MeV and concentrate on the laser and microwave spectroscopy of the metastable antiprotonic helium atom, $\\overline{p}$He$^+$, consisting of an electron and antiproton bound by the Coulomb force to the helium nucleus. Samples of these are readily created by bringing AD antiproton beam bunches to rest in helium gas. With the help of techniques developed at LEAR for resonating high precision laser beams with antiproton transitions in these atoms, ASACUSA achieved several of these first-phase objectives during a few short months of AD operation in 2000. Six atomic tr...

  6. Large amounts of antiproton production by heavy ion collision

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    To produce large amounts of antiprotons, on the order of several grams/year, use of machines to produce nuclear collisions are studied. These can be of either proton-proton, proton-nucleus and nucleus-nucleus in nature. To achieve high luminosity colliding beams, on the order of 10/sup 41/ m/cm/sup 2/, a self-colliding machine is required, rather than a conventional circular colliding type. The self-colliding machine can produce additional antiprotons through successive collisions of secondary particles, such as spectator nucleons. A key problem is how to collect the produced antiprotons without capture by beam nuclei in the collision zone. Production costs for anti-matter are projected for various energy source options and technology levels. Dedicated facilities using heavy ion collisions could produce antiproton at substantially less than 1 million $/milligram. With co-production of other valuable products, e.g., nuclear fuel for power reactors, antiproton costs could be reduced to even lower values.

  7. Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants

    CERN Document Server

    Hayano, R S

    2010-01-01

    Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN’s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended values of the fundamental physical constants.

  8. Search for Resonances in the Photoproduction of Proton-Antiproton Pairs

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, Burnham [Florida State Univ., Tallahassee, FL (United States)

    2006-01-01

    Results are reported on the reaction γp → p$\\bar{p}$p with beam energy in the range 4.8-5.5 GeV. The data were collected at the Thomas Jefferson National Accelerator Facility in CLAS experiment E01-017(G6C). The focus of this study is an understanding of the mechanisms of photoproduction of proton-antiproton pairs, and to search for intermediate resonances, both narrow and broad, which decay to p$\\bar{p}$. The total measured cross section in the photon energy range 4.8-5.5 GeV is σ = 33 ± 2 nb. Measurement of the cross section as a function of energy is provided. An upper limit on the production of a narrow resonance state previously observed with a mass of 2.02 GeV/c2 is placed at 0.35 nb. No intermediate resonance states were observed. Meson exchange production appears to dominate the production of the proton-antiproton pairs.

  9. The new large-scale international facility for antiproton and ion research in Europe, FAIR

    International Nuclear Information System (INIS)

    Rosner, Guenther

    2012-01-01

    Full text: FAIR is currently the largest project in nuclear and particle physics worldwide, with investment costs of 1.6B euro in its first phase. It has been founded by Finland, France, Germany, India, Poland, Romania, Russia, Slovenia and Sweden in Oct. 2010. The facility will provide the international scientific community with a unique and technically innovative particle accelerator system to perform cutting-edge research in the sciences concerned with the basic structure of matter in: nuclear and particle physics, atomic and anti-matter physics, high density plasma physics, and applications in condensed matter physics, biology and the bio-medical sciences. The work horse of FAIR will be a 1.1 km circumference double ring of rapidly cycling 100 and 300 Tm synchrotrons, which will be used to produce high intensity secondary beams of anti-protons and very short-lived radioactive ions. A subsequent suite of cooler and storage rings will deliver anti-proton and heavy-ion beams of unprecedented quality regarding intensity and resolution. Large experimental facilities are presently being prototyped by the APPA, CBM, NuSTAR and PANDA Collaborations to be used by a global community of more than 3000 scientists from 2018. (author)

  10. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  11. Metastable states in antiprotonic helium atoms an island stability in a sea of continuum

    CERN Document Server

    Korobov, V I

    2002-01-01

    In this contribution we consider a phenomenon of metastable states in antiprotonic helium atoms, precise spectroscopy of these states and a present-day study of the electromagnetic properties of antiprotons. Calculation of nonrelativistic energies, relativistic and QED corrections as well as the fine and hyperfine structure and the magnetic moment of an antiproton are the main parts of this study. Refs. 22 (nevyjel)

  12. Energy and energy width measurement in the FNAL antiproton accumulator

    International Nuclear Information System (INIS)

    Church, M.; Hsueh, S.; Rapidis, P.; Werkema, S.

    1991-10-01

    The Fermilab Antiproton Accumulator has recently been used to produce Charmonium resonances (charm quark, anti-charm quark bound states) in proton-antiproton annihilations using an internal H 2 gas jet target. A measurement of the resonance mass and width may be obtained from a precise knowledge of the antiproton beam energy and energy spread. The beam energy is measured to an accuracy of 1 part in 10 4 in the range 6.3 Gev to 4.1 Gev by measuring the orbit length and revolution frequency of the beam. The beam momentum spread is measured to an accuracy of 10% by measuring the beam frequency spread and the parameter η = (P beam /F rev )·(dF rev /dP beam ). These two measurement techniques are described in this report

  13. Energy and energy width measurement in the FNAL antiproton accumulator

    Energy Technology Data Exchange (ETDEWEB)

    Church, M.; Hsueh, S.; Rapidis, P.; Werkema, S.

    1991-10-01

    The Fermilab Antiproton Accumulator has recently been used to produce Charmonium resonances (charm quark, anti-charm quark bound states) in proton-antiproton annihilations using an internal H{sub 2} gas jet target. A measurement of the resonance mass and width may be obtained from a precise knowledge of the antiproton beam energy and energy spread. The beam energy is measured to an accuracy of 1 part in 10{sup 4} in the range 6.3 Gev to 4.1 Gev by measuring the orbit length and revolution frequency of the beam. The beam momentum spread is measured to an accuracy of 10% by measuring the beam frequency spread and the parameter {eta} = (P{sub beam}/F{sub rev}){center_dot}(dF{sub rev}/dP{sub beam}). These two measurement techniques are described in this report.

  14. Improved Study of the Antiprotonic Helium Hyperfine Structure

    CERN Document Server

    Pask, T.; Dax, A.; Hayano, R.S.; Hori, M.; Horvath, D.; Juhasz, B.; Malbrunot, C.; Marton, J.; Ono, N.; Suzuki, K.; Zmeskal, J.; Widmann, E.

    2008-01-01

    We report the initial results from a systematic study of the hyperfine (HF) structure of antiprotonic helium (n,l) = (37,~35) carried out at the Antiproton Decelerator (AD) at CERN. We performed a laser-microwave-laser resonance spectroscopy using a continuous wave (cw) pulse-amplified laser system and microwave cavity to measure the HF transition frequencies. Improvements in the spectral linewidth and stability of our laser system have increased the precision of these measurements by a factor of five and reduced the line width by a factor of three compared to our previous results. A comparison of the experimentally measured transition frequencies with three body QED calculations can be used to determine the antiproton spin magnetic moment, leading towards a test of CPT invariance.

  15. Relativistic hydrodynamics, heavy ion reactions and antiproton annihilation

    International Nuclear Information System (INIS)

    Strottman, D.

    1985-01-01

    The application of relativistic hydrodynamics to relativistic heavy ions and antiproton annihilation is summarized. Conditions for validity of hydrodynamics are presented. Theoretical results for inclusive particle spectra, pion production and flow analysis are given for medium energy heavy ions. The two-fluid model is introduced and results presented for reactions from 800 MeV per nucleon to 15 GeV on 15 GeV per nucleon. Temperatures and densities attained in antiproton annihilation are given. Finally, signals which might indicate the presence of a quark-gluon plasma are briefly surveyed

  16. Antiproton-decelerating Radio-Frequency Quadrupole (RFQD), inner structure.

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    The inner structure of the RFQD, withdrawn from its tank. In picture _06, the upstream end is in the back and the view is on the downstream exit. The RFQD has a length of 3.5 m and operates at a frequency of 202.4 MHz. It further decelerates antiprotons from the Antiproton Decelerator (3.5 MeV/c to 100 MeV/c, or 5.3 MeV) to very low energies around 50 keV.

  17. Antiprotons from spallation of cosmic rays on ISM

    CERN Document Server

    Donato, F

    2002-01-01

    We provide the first evaluation of the secondary interstellar cosmic antiproton flux that is fully consistent with cosmic ray nuclei in the framework of a two-zone diffusion model. We also study and conservatively quantify all possible sources of uncertainty that may affect that antiproton flux. Uncertainties related to propagation are shown to range between 10% and 25%, depending on which part of the spectrum is considered, while the ones related to nuclear physics stand around 22-25 % over all the energy spectrum.

  18. 1-4 Strangeness Production in Antiproton Induced Nuclear Reactions.

    Institute of Scientific and Technical Information of China (English)

    Feng; Zhaoqing[1

    2014-01-01

    More localized energy deposition is able to be produced in antiproton-nucleus collisions in comparison withheavy-ion collisions due to annihilation reactions. Searching for the cold quark-gluon plasma (QGP) with antiprotonbeamshas been considered as a hot topic both in experiments and in theretical calculations over the past severaldecades. Strangeness production and hypernucleus formation in antiproton-induced nuclear reactions are importancein exploring the hyperon (antihyperon)-nucleon (HN) potential and the antinucleon-nucleon interaction, whichhave been hot topics in the forthcoming experiments at PANDA in Germany.

  19. The physics of proton antiproton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Shochet, M. (Chicago Univ., IL (United States))

    1991-12-03

    This paper contains information information on: accelerator and detector; QCD studies; studies of the electroweak force; The search for the top quark; {beta} physics at hadron colliders; and the search for exotic objects and prospects for the future.

  20. The physics of proton antiproton collisions

    International Nuclear Information System (INIS)

    Shochet, M.

    1991-01-01

    This paper contains information information on: accelerator and detector; QCD studies; studies of the electroweak force; The search for the top quark; β physics at hadron colliders; and the search for exotic objects and prospects for the future

  1. A Search for universal extra dimensions in the multi-lepton channel from proton anti-proton collisions at √s = 1.8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun [Yale Univ., New Haven, CT (United States)

    2005-12-01

    In this thesis we present the results of a search for Universal Extra Dimensions (UED) with compactification radius near the TeV scale in the multi-lepton channel from proton-antiproton collisions at center-of-mass energy of 1.8 TeV at the Fermi National Accelerator Laboratory. This is the first UED search in the multi-lepton channel performed at the Tevatron.

  2. Studies on the construction of a new 80 MeV injector and a new injection scheme for the synchrotron of the Bonn accelerator facility ELSA; Studien zum Aufbau eines neuen 80 MeV-Injektors und eines neuen Injektionsschemas fuer das Synchroton der Bonner Beschleunigeranlage ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Raecke, K.

    2001-09-01

    At the ELSA Accelerator Facility exists the opportunity to install a 80 MeV linear accelerator as an injector for the 2,5 GeV Booster Synchrotron. Because of its length the new structure cannot replace one of the linacs used today so possibilities to built up the accelerator and the transfer channels are worked out. Calculations comparing the injection efficiency of the present layout and the possible new layout show a recognizable improvement. The injection efficiency can be further improved using a single turn injection scheme. A septum magnet and a fast kicker for this injection scheme is designed. (orig.)

  3. Atomic physics at the future facility for antiproton and ion research: a status report

    International Nuclear Information System (INIS)

    Gumberidze, A

    2013-01-01

    The new international accelerator Facility for Antiproton and Ion Research (FAIR) which is currently under construction in Darmstadt has key features that offer a wide range of exciting new opportunities in the field of atomic physics and related fields. The facility will provide highest intensities of relativistic beams of both stable and unstable heavy nuclei, in combination with the strong electromagnetic fields generated by high-power lasers, thus allowing to widen atomic physics research into completely new domains. In the current contribution, a short overview of the SPARC (Stored Particle Atomic physics Research Collaboration) research programme at the FAIR facility is given. Furthermore, we present the current strategy for the realization of the envisioned SPARC physics programme at the modularized start version of the FAIR facility. (paper)

  4. Far field acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  5. Indian participation in FAIR accelerator facility

    International Nuclear Information System (INIS)

    Sur, Amitava

    2015-01-01

    India is a founder member of the FAIR-GmbH, the upcoming International Accelerator Facility at Darmstadt, Germany. Indian participation at FAIR is being funded jointly by the Department of Science and Technology (DST) and the Department of Atomic Energy (DAE). Indo- FAIR Coordination Centre at Bose Institute (BI-IFCC) is coordinating the Indian efforts of both in-kind contribution as well as experimental programmes at FAIR. FAIR aims for beams of stable and unstable nuclei as well as antiprotons in a wide range of intensities and energies. A superconducting double-synchrotron SIS100/300 with a circumference of 1,100 meters and with magnetic rigidities of 100 and 300 Tm, respectively, is at the heart of the FAIR accelerator facility. The existing GSI accelerators UNILAC and SIS18 will serve as an injector. Adjacent to the large double- synchrotron is a complex system of storage- cooler rings and experiment stations, including a superconducting nuclear fragment separator (Super-FRS) and an antiproton production target. FAIR will supply rare isotope beams (RIBs) and antiproton beams. In FAIR accelerator facility up to four research programs can be run in a parallel mode. The multidisciplinary research program covers the fields of QCD studies with cooled beams of antiprotons, nucleus nucleus collisions at highest baryon density, nuclear structure and nuclear astrophysics investigations with nuclei far off stability, high density plasma physics, atomic and material science studies, radio-biological and other application-oriented studies will contribute in providing in-kind items both for the accelerator and the experiments. As per current plans Indian in kind contributions include: Power Converters, Superconducting Magnets, Beam Stopper, Vacuum Chamber. A short sample from an Indian Industry has been tested successfully at FAIR. Indian participation in building the accelerator components for FAIR is presented

  6. Annihilation of antiprotons stopped in liquid hydrogen and deuterium

    International Nuclear Information System (INIS)

    Dalkarov, O.D.; Kerbikov, B.O.; Markushin, V.E.

    1976-01-01

    Detailed analysis is given of stopping antiproton annihilation in liquid hydrogen and deuterium. Connection between capture schedule and properties of bound states in nucleon-antinucleon system is established. The theoretical predictions are compared with experimental data which appeared in 1971-75

  7. Outer casing of the AA antiproton production target

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The first version of the antiproton production target was a tungsten rod, 11 cm long (actually a row of 11 rods, each 1 cm long) and 3 mm in diameter. The rod was embedded in graphite, pressure-seated into an outer casing made of stainless steel. The casing had fins for forced-air cooling.

  8. Galactic diffusion and the antiproton signal of supersymmetric dark matter

    CERN Document Server

    Chardonnet, P; Salati, Pierre; Taillet, R

    1996-01-01

    The leaky box model is now ruled out by measurements of a cosmic ray gradient throughout the galactic disk. It needs to be replaced by a more refined treatment which takes into account the diffusion of cosmic rays in the magnetic fields of the Galaxy. We have estimated the flux of antiprotons on the Earth in the framework of a two-zone diffusion model. Those species are created by the spallation reactions of high-energy nuclei with the interstellar gas. Another potential source of antiprotons is the annihilation of supersymmetric particles in the dark halo that surrounds our Galaxy. In this letter, we investigate both processes. Special emphasis is given to the antiproton signature of supersymmetric dark matter. The corresponding signal exceeds the conventional spallation flux below 300 MeV, a domain that will be thoroughly explored by the Antimatter Spectrometer experiment. The propagation of the antiprotons produced in the remote regions of the halo back to the Earth plays a crucial role. Depending on the e...

  9. Hyperfine Structure Measurements of Antiprotonic $^3$He using Microwave Spectroscopy

    CERN Document Server

    Friedreich, Susanne

    The goal of this project was to measure the hyperfine structure of $\\overline{\\text{p}}^3$He$^+$ using the technique of laser-microwave-laser spectroscopy. Antiprotonic helium ($\\overline{\\text{p}}$He$^+$) is a neutral exotic atom, consisting of a helium nucleus, an electron and an antiproton. The interactions of the angular momenta of its constituents cause a hyperfine splitting ({HFS}) within the energy states of this new atom. The 3\\% of formed antiprotonic helium atoms which remain in a metastable, radiative decay-dominated state have a lifetime of about 1-3~$\\mu$s. This time window is used to do spectroscopic studies. The hyperfine structure of $\\overline{\\text{p}}^4$He$^+$ was already extensively investigated before. From these measurements the spin magnetic moment of the antiproton can be determined. A comparison of the result to the proton magnetic moment provides a test of {CPT} invariance. Due to its higher complexity the new exotic three-body system of $\\overline{\\text{p}}^3$He$^+$ is a cross-check...

  10. Calculated LET Spectrum from Antiproton Beams Stopping in Water

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael

    2009-01-01

    significantly differ from unity, which seems to warrant closer inspection of the radiobiology in this region. Monte Carlo simulations using FLUKA were performed for calculating the entire particle spectrum of a beam of 126 MeV antiprotons hitting a water phantom. In the plateau region of the simulated...

  11. Relative Biological Effectiveness and Peripheral Damage of Antiproton Annihilation

    CERN Multimedia

    Kavanagh, J N; Kaiser, F; Tegami, S; Schettino, G; Kovacevic, S; Hajdukovic, D; Knudsen, H; Currell, F J; Toelli, H T; Doser, M; Holzscheiter, M; Herrmann, R; Timson, D J; Alsner, J; Landua, R; Comor, J; Moller, S P; Beyer, G

    2002-01-01

    The use of ions to deliver radiation to a body for therapeutic purposes has the potential to be significant improvement over the use of low linear energy transfer (LET) radiation because of the improved energy deposition profile and the enhanced biological effects of ions relative to photons. Proton therapy centers exist and are being used to treat patients. In addition, the initial use of heavy ions such as carbon is promising to the point that new treatment facilities are planned. Just as with protons or heavy ions, antiprotons can be used to deliver radiation to the body in a controlled way; however antiprotons will exhibit additional energy deposition due to annihilation of the antiprotons within the body. The slowing down of antiprotons in matter is similar to that of protons except at the very end of the range beyond the Bragg peak. Gray and Kalogeropoulos estimated the additional energy deposited by heavy nuclear fragments within a few millimeters of the annihilation vertex to be approximately 30 MeV (...

  12. Constraints on particle dark matter from cosmic-ray antiprotons

    International Nuclear Information System (INIS)

    Fornengo, N.; Vittino, A.; Maccione, L.

    2014-01-01

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are strong, setting a lower bound on the dark matter mass of a ''thermal'' relic at about 40–80 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 3–4 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modelling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints

  13. The main injector chromaticity correction sextupole magnets: Measurements and operating schemes

    International Nuclear Information System (INIS)

    Bhat, C.M.; Bogacz, A.; Brown, B.C.; Harding, D.J.; Fang, S.J.; Martin, P.S.; Glass, H.D.; Sim, J.

    1995-05-01

    The Fermilab Main Injector (FMI) is a high intensity proton synchrotron which will be used to accelerate protons and antiprotons from 8.9 GeV/c to 150 GeV/c. The natural chromaticities of the machine for the horizontal and the vertical Planes are -33.6 and -33.9 respectively. The Δp/p of the beam at injection is about 0.002. The chromaticity requirements of the FMI, are primarily decided by the Δp/p = 0.002 of the beam at injection. This limits the final chromaticity of the FMI to be ±5 units. To correct the chromaticity in the FMI two families of sextupole magnets will be installed in the lattice, one for each plane. A sextupole magnet suitable for the FMI needs has been designed and a number of them are being built. New chromaticity compensation schemes have been worked out in the light of recently proposed faster acceleration ramps. On an R/D sextupole magnet the low current measurements have been carried out to determine the electrical properties. Also, using a Morgan coil, measurements have been performed to determine the higher ordered multipole components up to 18-poles. An overview of these result are presented here

  14. On 18 November 2010, CERN signed an agreement with the Facility for Antiproton and Ion Research (FAIR) GmbH, the company that is co-ordinating the construction of the accelerator and experiment facilities for the FAIR project in Germany.

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    The agreement, which was signed by CERN's director-general, Rolf Heuer (left) and FAIR's scientific director Boris Sharkov, concerns collaboration in accelerator sciences and technologies and other scientific domains of mutual interest.

  15. Generation of ultra-high-pressure shocks by collision of a fast plasma projectile driven in the laser-induced cavity pressure acceleration scheme with a solid target

    Czech Academy of Sciences Publication Activity Database

    Badziak, J.; Rosinski, M.; Krouský, Eduard; Kucharik, M.; Liska, R.; Ullschmied, Jiří

    2015-01-01

    Roč. 22, č. 3 (2015), s. 1-11, č. článku 032709. ISSN 1070-664X R&D Projects: GA MŠk(CZ) LD14089; GA MŠk LM2010014 EU Projects: European Commission(XE) 284464 - LASERLAB-EUROPE Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * ultra-high-pressure shocks * laser-induced cavity pressure acceleration Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.207, year: 2015

  16. Accelerating Smith-Waterman Alignment for Protein Database Search Using Frequency Distance Filtration Scheme Based on CPU-GPU Collaborative System.

    Science.gov (United States)

    Liu, Yu; Hong, Yang; Lin, Chun-Yuan; Hung, Che-Lun

    2015-01-01

    The Smith-Waterman (SW) algorithm has been widely utilized for searching biological sequence databases in bioinformatics. Recently, several works have adopted the graphic card with Graphic Processing Units (GPUs) and their associated CUDA model to enhance the performance of SW computations. However, these works mainly focused on the protein database search by using the intertask parallelization technique, and only using the GPU capability to do the SW computations one by one. Hence, in this paper, we will propose an efficient SW alignment method, called CUDA-SWfr, for the protein database search by using the intratask parallelization technique based on a CPU-GPU collaborative system. Before doing the SW computations on GPU, a procedure is applied on CPU by using the frequency distance filtration scheme (FDFS) to eliminate the unnecessary alignments. The experimental results indicate that CUDA-SWfr runs 9.6 times and 96 times faster than the CPU-based SW method without and with FDFS, respectively.

  17. An Exact and Grid-free Numerical Scheme for the Hybrid Two Phase Traffic Flow Model Based on the Lighthill-Whitham-Richards Model with Bounded Acceleration

    KAUST Repository

    Qiu, Shanwen

    2012-07-01

    In this article, we propose a new grid-free and exact solution method for computing solutions associated with an hybrid traffic flow model based on the Lighthill- Whitham-Richards (LWR) partial differential equation. In this hybrid flow model, the vehicles satisfy the LWR equation whenever possible, and have a fixed acceleration otherwise. We first present a grid-free solution method for the LWR equation based on the minimization of component functions. We then show that this solution method can be extended to compute the solutions to the hybrid model by proper modification of the component functions, for any concave fundamental diagram. We derive these functions analytically for the specific case of a triangular fundamental diagram. We also show that the proposed computational method can handle fixed or moving bottlenecks.

  18. Professor Walter Oelert, leader of the team which created the first atoms of antihydrogen at the Low Energy Antiproton Ring (LEAR) in January 1996

    CERN Document Server

    Laurent Guiraud

    1996-01-01

    Antiparticles were predicted in the work of Paul Dirac in the 1920's, since when physicists have identified all the necessary antiparticle constituents of an antiparticle atom - antielectrons (positrons), antiprotons and antineutrons. However, an antihydrogen atom wasn't produced until the PS210 experiment at CERN in 1995. PS210 used the LEAR accelerator, which was then nearing the end of its lifetime, so everything in the experiment had to work first time. After installing the equipment in spring 1995, the experiment took place in the autumn, in two hour periods over 4 weeks. The experiment team collided energetic antiprotons from LEAR with a heavy element, a challenge for them as well as the LEAR operators. Proving that antihydrogen atoms had been formed required several more weeks of data analysis, but the announcement that nine antihydrogen atoms had been produced came on 4 January 1996.

  19. Observation of Ultra-Slow Antiprotons using Micro-channel Plate

    Science.gov (United States)

    Imao, H.; Torii, H. A.; Nagata, Y.; Toyoda, H.; Shimoyama, T.; Enomoto, Y.; Higaki, H.; Kanai, Y.; Mohri, A.; Yamazaki, Y.

    2008-08-01

    Our group ASACUSA-MUSASHI has succeeded in accumulating several million antiprotons and extracting them as monochromatic ultra-slow antiproton beams (10 eV-1 keV) at CERN AD. We have observed ultra-slow antiprotons using micro-channel plates (MCP). The integrated pulse area of the output signals generated when the MCP was irradiated by ultra-slow antiprotons was 6 times higher than that by electrons. As a long-term effect, we also observed an increase in the background rate presumably due to the radioactivation of the MCP surface. Irradiating the antiproton beams on the MCP induces antiproton-nuclear annihilations only on the first layer of the surface. Low-energy and short-range secondary particles like charged nuclear fragments caused by the "surface nuclear reactions" would be the origin of our observed phenomena.

  20. Dark matter for excess of AMS-02 positrons and antiprotons

    Directory of Open Access Journals (Sweden)

    Chuan-Hung Chen

    2015-07-01

    Full Text Available We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of SU(2X that is broken to Z3 by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the SU(2X quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.

  1. Pionic annihilation of antiprotons stopped on sup 3 He

    Energy Technology Data Exchange (ETDEWEB)

    Bendiscioli, G.; Filippini, V.; Rotondi, A.; Salvini, P.; Venaglioni, A. (Pavia Univ. (Italy). Dipt. di Fisica Nucleare e Teorica Istituto Nazionale di Fisica Nucleare, Pavia (Italy)); Bossolasco, S.; Bussa, M.P.; Busso, L.; Fava, L.; Ferrero, L.; Maggiora, A.; Panzieri, D.; Piragino, G.; Piragino, R.; Tosello, F. (Turin Univ. (Italy). Ist. di Fisica Generale Istituto Nazionale di Fisica Nucleare, Turin (Italy)); Batusov, Yu.A.; Falomkin, I.V.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I. (Joint Inst. for Nuclear Research, Dubna (USSR)); Guaraldo, C. (Istituto Nazionale di Fisica Nucleare, Frascati (Italy). Lab. Nazionale di Frascati); Lodi Rizzini, E. (Brescia Univ. (Italy). Dipt. di Automazione Industriale Istituto Nazionale di Fisica Nucleare, Turin (Italy)); Haatuft, A.; Halsteinslid, A.; Myklebost, K.; Olsen, J.M. (Bergen Univ. (Norway). Dept. of Physics); Breivik, F.O.; Jacobsen, T.; Soerensen, S.O. (Oslo Univ. (Norway). Physics Dept.); Balestra

    1990-11-26

    The pionic annihilation of antiprotons stopped on {sup 3}He nuclei in a self-shunted streamer chamber exposed to the antiproton beam of LEAR is studied. The data concern charged-particle multiplicity distributions, branching ratios for different final states, the probability of final-state interaction, {pi}{sup -}, {pi}{sup +}, p and d momentum spectra, like and unlike pion angular correlations, {pi} and other charged-particle angular correlations. The comparison of the {sup 3}He data with those obtained on {sup 1}H, {sup 2}H and {sup 4}He does not reveal relevant effects due to the increase of the nucleon number; the small differences can be seen as due to a weak final-state interaction. (orig.).

  2. Pionic annihilation of antiprotons stopped on 3He

    International Nuclear Information System (INIS)

    Bendiscioli, G.; Filippini, V.; Rotondi, A.; Salvini, P.; Venaglioni, A.; Bossolasco, S.; Bussa, M.P.; Busso, L.; Fava, L.; Ferrero, L.; Maggiora, A.; Panzieri, D.; Piragino, G.; Piragino, R.; Tosello, F.; Batusov, Yu.A.; Falomkin, I.V.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I.; Guaraldo, C.; Haatuft, A.; Halsteinslid, A.; Myklebost, K.; Olsen, J.M.; Zenoni, A.

    1990-01-01

    The pionic annihilation of antiprotons stopped on 3 He nuclei in a self-shunted streamer chamber exposed to the antiproton beam of LEAR is studied. The data concern charged-particle multiplicity distributions, branching ratios for different final states, the probability of final-state interaction, π - , π + , p and d momentum spectra, like and unlike pion angular correlations, π and other charged-particle angular correlations. The comparison of the 3 He data with those obtained on 1 H, 2 H and 4 He does not reveal relevant effects due to the increase of the nucleon number; the small differences can be seen as due to a weak final-state interaction. (orig.)

  3. Constraining heavy dark matter with cosmic-ray antiprotons

    Science.gov (United States)

    Cuoco, Alessandro; Heisig, Jan; Korsmeier, Michael; Krämer, Michael

    2018-04-01

    Cosmic-ray observations provide a powerful probe of dark matter annihilation in the Galaxy. In this paper we derive constraints on heavy dark matter from the recent precise AMS-02 antiproton data. We consider all possible annihilation channels into pairs of standard model particles. Furthermore, we interpret our results in the context of minimal dark matter, including higgsino, wino and quintuplet dark matter. We compare the cosmic-ray antiproton limits to limits from γ-ray observations of dwarf spheroidal galaxies and to limits from γ-ray and γ-line observations towards the Galactic center. While the latter limits are highly dependent on the dark matter density distribution and only exclude a thermal wino for cuspy profiles, the cosmic-ray limits are more robust, strongly disfavoring the thermal wino dark matter scenario even for a conservative estimate of systematic uncertainties.

  4. Precocious scaling in antiproton-proton scattering at low energies

    International Nuclear Information System (INIS)

    Ion, D.B.; Petrascu, C.; Topor Pop, V.; Popa, V.

    1993-08-01

    The scaling of the diffraction peak in antiproton-proton scattering has been investigated from nera threshold up to 3 GeV/c laboratory momenta. It was shown that the scaling of the differential cross sections are evidentiated with a surprising accuracy not only at high energies, but also at very low ones (e.g. p LAB = 0.1 - 0.5 GeV/c), beyond the resonance and exotic resonance regions. This precocious scaling strongly suggests that the s-channel helicity conservation (SCHC) can be a peculiar property that should be tested in antiproton-proton interaction not only at high energies but also at low energy even below p LAB = 1 GeV/c. (author). 36 refs, 9 figs

  5. Testing quantum chromodynamics in anti-proton reactions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1987-10-01

    An experimental program with anti-protons at intermediate energy can serve as an important testing ground for QCD. Detailed predictions for exclusive cross sections at large momentum transfer based on perturbative QCD and the QCD sum rule form of the proton distribution amplitude are available for anti p p → γγ for both real and virtual photons. Meson-pair and lepton-pair final states also give sensitive tests of the theory. The production of charmed hadrons in exclusive anti p p channels may have a non-negligible cross section. Anti-proton interactions in a nucleus, particularly J/psi production, can play an important role in clarifying fundamental QCD issues, such as color transparency, critical length phenomena, and the validity of the reduced nuclear amplitude phenomenology

  6. Antiprotons from dark matter annihilation in the Galaxy. Astrophysical uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Evoli, Carmelo [Chinese Academy of Sciences, Beijing (China). National Astronomical Observatories; Cholis, Ilias; Ullio, Piero [SISSA, Sezione di Trieste (Italy); INFN, Sezione di Trieste (Italy); Grasso, Dario [INFN, Sezione di Pisa (Italy); Maccione, Luca [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-08-15

    The latest years have seen steady progresses in WIMP dark matter (DM) searches, with hints of possible signals suggested by both direct and indirect detection experiments. Antiprotons can play a key role validating those interpretations since they are copiously produced by WIMP annihilations in the Galactic halo, and the secondary antiproton background produced by Cosmic Ray (CR) interactions is predicted with fair accuracy and matches the observed spectrum very well. Using the publicly available numerical DRAGON code, we reconsider antiprotons as a tool to constrain DM models discussing its power and limitations. We provide updated constraints on a wide class of annihilating DM models by comparing our predictions against the most up-to-date anti p measurements, taking also into account the latest spectral information on the p, He and other CR nuclei fluxes. Doing that, we probe carefully the uncertainties associated to both secondary and DM originated antiprotons, by using a variety of distinctively different assumptions for the propagation of CRs and for the DM distribution in the Galaxy. We find that the impact of the astrophysical uncertainties on constraining the DM properties can be much stronger, up to a factor of {proportional_to}50, than the one due to uncertainties on the DM distribution ({proportional_to}2-6). Remarkably, even reducing the uncertainties on the propagation parameters derived by local observables, non-local effects can still change DM model constraints even by 50%. Nevertheless, current anti p data place tight constraints on DM models, excluding some of those suggested in connection with indirect and direct searches. Finally we discuss the power of upcoming CR spectral data from the AMS-02 observatory to drastically reduce the uncertainties discussed in this paper and estimate the expected sensitivity of this instrument to some sets of DM models. (orig.)

  7. Physics at the Fermilab Tevatron Proton-Antiproton Collider

    International Nuclear Information System (INIS)

    Geer, S.

    1994-08-01

    These lectures discuss a selection of QCD and Electroweak results from the CDF and D0 experiments at the Fermilab Tevatron Proton-Antiproton Collider. Results are presently based on data samples of about 20 pb -1 at a center-of-mass energy of 1.8 TeV. Results discussed include jet production, direct photon production, W mass and width measurements, the triboson coupling, and most exciting of all, evidence for top quark production

  8. Antiproton-helium annihilation around 45 MeV/c

    International Nuclear Information System (INIS)

    Balestra, F.; Bassolasco, S.; Bussa, M.P.; Busso, L.; Ferrero, L.; Panzieri, D.; Piragino, G.; Tosello, F.; Barbieri, R.; Bendiscioli, G.; Filippini, V.; Rotondi, A.; Salvini, P.; Zenoni, A.; Batusov, Yu.A.; Falomkin, I.V.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I.; Breivik, F.O.; Jacobsen, T.; Soerensen, S.O.

    1989-01-01

    The anti p 4 He annihilation cross section averaged over the interval 40-50 MeV/c has been measured using a streamer chamber in a magnetic field. The measured value is 1342±250 mb. It agrees with a behaviour like 1/p of the annihilation cross section. Our result has been obtained at the lowest momentum achieved till now in measurements of antiproton annihilation in flight. (orig.)

  9. Antiproton-helium annihilation around 45 MeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Balestra, F.; Bassolasco, S.; Bussa, M.P.; Busso, L.; Ferrero, L.; Panzieri, D.; Piragino, G.; Tosello, F. (Turin Univ. (Italy). Ist. di Fisica Generale; Istituto Nazionale di Fisica Nucleare, Turin (Italy)); Barbieri, R.; Bendiscioli, G.; Filippini, V.; Rotondi, A.; Salvini, P.; Zenoni, A. (Pavia Univ. (Italy). Dipt. di Fisica Nucleare e Teorica; Istituto Nazionale di Fisica Nucleare, Pavia (Italy)); Batusov, Yu.A.; Falomkin, I.V.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I. (Joint Inst. for Nuclear Research, Dubna (USSR)); Breivik, F.O.; Jacobsen, T.; Soerensen, S.O. (Oslo Univ. (Norway). Fysisk Inst.); Guaraldo, C.; Maggiora, A. (Istituto Nazionale di Fisica Nucleare, Frascati (Italy). Lab. Nazionale di Frascati); Haatuft, A.; Halsteinslid, A.; Myklebost, K.; Olsen, J.M. (Bergen Univ. (Norway). Dept. of Physics); Lodi Rizzini, E. (Brescia Univ. (Italy). Dipt. di Automazione Industriale); Masala, M. (Brescia Univ. (Italy). Dipt. di Automazione Ind

    1989-10-26

    The anti p{sup 4}He annihilation cross section averaged over the interval 40-50 MeV/c has been measured using a streamer chamber in a magnetic field. The measured value is 1342+-250 mb. It agrees with a behaviour like 1/p of the annihilation cross section. Our result has been obtained at the lowest momentum achieved till now in measurements of antiproton annihilation in flight. (orig.).

  10. Evidence of isospin effects in antiproton-nucleus annihilation

    International Nuclear Information System (INIS)

    Balestra, F.; Bossolasco, S.; Bussa, M.P.; Busso, L.; Ferrero, L.; Panzieri, D.; Piragino, G.; Tosello, F.; Barbieri, R.; Bendiscioli, G.; Rotondi, A.; Salvini, P.; Venaglioni, A.; Zenoni, A.; Batusov, Yu.A.; Falomkin, I.V.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I.; Guaraldo, C.; Maggiora, A.; Haatuft, A.; Halsteinslid, A.; Myklebost, K.; Olsen, J.M.; Breivik, F.O.; Jacobsen, T.; Soerensen, S.O.

    1989-01-01

    Antiproton- 3 He annihilation events at rest have been detected using a self-shunted streamer chamber. The ratio of the cross section for annihilation on neutrons and on protons has been measured (0.467±0.035). It is compared with other results from annihilation on free nucleons, deuterium, 3 He and 4 He. The low value of the ratio seems to indicate a strong isospin dependence of the antinucleon-nucleon P-wave amplitude. (orig.)

  11. Superconducting beam charge monitors for antiproton storage rings

    OpenAIRE

    Tympel, Volker; Neubert, Ralf; Seidel, Paul; Geithner, René; Golm, Jessica; Stöhlker, Thomas; Kurian, Febian; Sieber, Thomas; Schwickert, Marcus; Fernandes, Miguel

    2017-01-01

    A Cryogenic Current Comparator (CCC) is a new type of instruments for monitoring charged beams like ions or antiprotons. Using superconducting effects is it possible to create a nondestructive, contactless and easy to calibrate beam measurement system with a high current resolution in amplitude and time. The Meissner effect enables an effective magnetic shielding of the system. The screening current enables creation of DC-transformers and therefore a DC-current measurement system. The combina...

  12. Polarization of antiprotons by the Stern-Gerlach effect

    International Nuclear Information System (INIS)

    Kewisch, J.; Rossmanith, R.; Onel, Y.; Penzo, A.; Kreiser, H.

    1988-01-01

    A method to obtain polarized antiprotons in the low energy storage ring LEAR via spatial separation of opposite spin states is described in earlier papers (Y. Onel et al., 1986). We will discuss here in more detail a) the integration of the special magnets (spin splitter) into the LEAR optics and b) some first tracking results of particle and spin motion in these optics. (orig./HSI)

  13. Proton-antiproton interactions (experimental status of baryonium states)

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Y.

    1980-07-01

    Many experiments have been performed in the last few years to search for the existence of baryonium (baryon-antibaryon bound) states. The current status in this direction is reviewed. Prominent resonances such as the S-meson resonance, broad resonances, narrow resonances and states such as the strange baryonium states, exotic states, antiproton-proton states below threshold, six-quark states are explained. A summary of the experimental data with illustrations is presented in a table.

  14. A beam sweeping system for the Fermilab antiproton production target

    International Nuclear Information System (INIS)

    Bieniosek, F.M.

    1993-08-01

    In the Main Injector era beam intensities high enough to damage the antiproton production target will be available. In order to continue to operate with a tightly-focused primary beam spot on the target, and thus maintain yield, it will be necessary to spread the hot spot on the target by use of a beam sweeping system. This report summarizes the requirements for such a system, and addresses the issues involved in the design of a sweeping system

  15. Prospects for testing Lorentz and CPT symmetry with antiprotons

    Science.gov (United States)

    Vargas, Arnaldo J.

    2018-03-01

    A brief overview of the prospects of testing Lorentz and CPT symmetry with antimatter experiments is presented. The models discussed are applicable to atomic spectroscopy experiments, Penning-trap experiments and gravitational tests. Comments about the sensitivity of the most recent antimatter experiments to the models reviewed here are included. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

  16. Prospects for testing Lorentz and CPT symmetry with antiprotons.

    Science.gov (United States)

    Vargas, Arnaldo J

    2018-03-28

    A brief overview of the prospects of testing Lorentz and CPT symmetry with antimatter experiments is presented. The models discussed are applicable to atomic spectroscopy experiments, Penning-trap experiments and gravitational tests. Comments about the sensitivity of the most recent antimatter experiments to the models reviewed here are included.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Author(s).

  17. Accelerating Smith-Waterman Alignment for Protein Database Search Using Frequency Distance Filtration Scheme Based on CPU-GPU Collaborative System

    Directory of Open Access Journals (Sweden)

    Yu Liu

    2015-01-01

    Full Text Available The Smith-Waterman (SW algorithm has been widely utilized for searching biological sequence databases in bioinformatics. Recently, several works have adopted the graphic card with Graphic Processing Units (GPUs and their associated CUDA model to enhance the performance of SW computations. However, these works mainly focused on the protein database search by using the intertask parallelization technique, and only using the GPU capability to do the SW computations one by one. Hence, in this paper, we will propose an efficient SW alignment method, called CUDA-SWfr, for the protein database search by using the intratask parallelization technique based on a CPU-GPU collaborative system. Before doing the SW computations on GPU, a procedure is applied on CPU by using the frequency distance filtration scheme (FDFS to eliminate the unnecessary alignments. The experimental results indicate that CUDA-SWfr runs 9.6 times and 96 times faster than the CPU-based SW method without and with FDFS, respectively.

  18. Commissioning of Fermilab's Electron Cooling System for 8-GeV Antiprotons

    CERN Document Server

    Nagaitsev, Sergei; Burov, Alexey; Carlson, Kermit; Gai, Wei; Gattuso, Consolato; Hu, Martin; Kazakevich, Grigory; Kramper, Brian J; Kroc, Thomas K; Leibfritz, Jerry; Prost, Lionel; Pruss, Stanley M; Saewert, Greg W; Schmidt, Chuck; Seletsky, Sergey; Shemyakin, Alexander V; Sutherland, Mary; Tupikov, Vitali; Warner, Arden

    2005-01-01

    A 4.3-MeV electron cooling system has been installed at Fermilab in the Recycler antiproton storage ring and is being currently commissioned. The cooling system is designed to assist accumulation of 8.9-GeV/c antiprotons for the Tevatron collider operations. This paper will report on the progress of the electron beam commissioning effort as well as on detailed plans of demonstrating the cooling of antiprotons.

  19. Bubble detector measurements of a mixed radiation field from antiproton annihilation

    International Nuclear Information System (INIS)

    Bassler, Niels; Knudsen, Helge; Moller, Soren Pape; Petersen, Jorgen B.; Rahbek, Dennis; Uggerhoj, Ulrik I.

    2006-01-01

    In the light of recent progress in the study of the biological potential of antiproton tumour treatment it is important to be able to characterize the neutron intensity arising from antiproton annihilation using simple, compact and reliable detectors. The intensity of fast neutrons from antiproton annihilation on polystyrene has been measured with bubble detectors and a multiplicity has been derived as well as an estimated neutron equivalent dose. Additionally the sensitivity of bubble detectors towards protons was measured

  20. Non-linear transverse dynamics for storage rings with application to the low-energy antiproton ring (LEAR) at CERN

    International Nuclear Information System (INIS)

    Bengtsson, J.

    1988-01-01

    A tensor equation has been used to derive the equations of motion for the curvilinear coordinate system customary used for accelerators. A Hamiltonian formalism, expanded to third order in the canonical variables, describing the transverse motion in an acceleration has also been developed. Time-dependent perturbation theory has been applied and computerized using a computer algebra system. In particular, the perturbations due to magnetic sextupoles have been calculated to second power in the sextupole strength. The frequency spectra for the betatron motion close to a single resonance has been calculated by using time-independent perturbation theory. It has been shown that information about excited resonances and the type of driving field can be derived from the spectra. In particular, it is possible to obtain the amplitude and the phase of a given resonance. The results have been used to study the perturbations in the Low Energy Antiproton Ring, LEAR at CERN. (With 67 refs.) (author)

  1. Non-linear transverse dynamics for storage rings with applications to the low-energy antiproton ring (LEAR) at CERN

    International Nuclear Information System (INIS)

    Bengtsson, J.

    1988-01-01

    A tensor equation has been used to derive the equations of motion for the curvilinear coordinate system customarily used for particle accelerators. A Hamiltonian formalism, expanded to third order in the canonical variables, has also been developed to describe the transverse motion in an accelerator. Time-dependent perturbation theory has been applied and computerized using a computer-algebra system. In particular, the perturbations due to magnetic sextupoles have been calculated to second power in the sextupole strength. The frequency spectra for the horizontal and the vertical betatron motion close to a single resonance have been calculated using time-independent perturbation theory. It has been shown that information about excited resonances and the type of driving field can be derived from the spectra. In particular, it is possible to obtain the amplitude and the phase of a given resonance. The results have been used to study the perturbations in the Low Energy Antiproton Ring (LEAR) at CERN. (orig.)

  2. European Facility for Antiproton and Ion Research (FAIR): the new international center for fundamental physics and its research program

    International Nuclear Information System (INIS)

    Fortov, Vladimir E; Sharkov, Boris Yu; Stöker, H

    2012-01-01

    The Facility for Antiproton and Ion Research (FAIR) accelerator center at Darmstadt, Germany, will provide the international scientific community with unique experimental opportunities of a scope and scale out of reach for any other large-scale facility in the world. With its staff of over 2500, it is expected to fundamentally expand our knowledge of hadron, nuclear, and atomic physics and their application to cosmology, astrophysics, and technology. In this review, the design details of the accelerator complex are discussed and the experimental research program for FAIR is presented. Particular attention is paid to experiments on the extreme state of matter arising from the isochoric heating of a material by heavy-ion beams. One of the largest facilities of its kind in Europe, FAIR is a part of the strategic development roadmap for the European Strategic Forum on Research Infrastructures (ESFRI). (physics of our days)

  3. Simulation of an antiprotons beam applied to the radiotherapy

    International Nuclear Information System (INIS)

    Prata, Leonardo de Almeida

    2006-07-01

    Results for the interaction of a antiproton beam with constituent nuclei of the organic matter are presented. This method regards of the application of an computational algorithm to determine quantitatively the differential cross sections for the scattered particles, starting from the interaction of these antiprotons with the nuclei, what will allow in the future to draw the isodose curve for antiproton therapy, once these beams are expected to be used in cancer treatment soon. The calculation will be done through the application of the concepts of the method of intranuclear cascade, providing yield and differential cross sections of the scattered particles, present in the software MCMC. Th algorithm was developed based on Monte Carlo's method, already taking into account a validate code. The following physical quantities are presented: the yield of secondary particles, their spectral and angular distributions for these interactions. For the energy range taken into account the more important emitted particles are protons, neutrons and pions. Results shown that emitted secondary particles can modify the isodose curves, because they present high yield and energy for transverse directions. (author)

  4. Evaporative cooling of antiprotons and efforts to trap antihydrogen

    CERN Document Server

    Andresen, Gorm Bruun

    Evaporative cooling has proven to be an invaluable technique in atomic physics, allowing for the study of effects such as Bose-Einstein condensation. One main topic of this thesis is the first application of evaporative cooling to cold non-neutral plasmas stored in an ion trap. We (the ALPHA collaboration) have achieved cooling of a cloud of antiprotons to a temperature as low as 9 K, two orders of magnitude lowerthan ever directly measured previously. The measurements are well-described by appropriate rate equations for the temperature and number of particles. The technique has direct application to the ongoing attempts to produce trapped samples of antihydrogen. In these experiments the maximum trap depths are ex tremely shallow (~0.6 K for ground state atoms), and careful control of the trapped antiprotons and positrons used to form the (anti)atoms is essential to succes. Since 2006 powerful tools to diagnose and manipulate the antiproton and positron plasmas in the ALPHA apparatus have been developed and ...

  5. Antihydrogen formation by autoresonant excitation of antiproton plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bertsche, William Alan, E-mail: bertsche@cern.ch [Swansea University, Department of Physics (United Kingdom); Andresen, G. B. [Aarhus University, Department of Physics and Astronomy (Denmark); Ashkezari, M. D. [Simon Fraser University, Department of Physics (Canada); Baquero-Ruiz, M. [University of California, Department of Physics (United States); Bowe, P. D. [Aarhus University, Department of Physics and Astronomy (Denmark); Carpenter, P. T. [Auburn University, Department of Physics (United States); Butler, E. [CERN, Physics Department (Switzerland); Cesar, C. L. [Universidade Federal do Rio de Janeiro, Instituto de Fisica (Brazil); Chapman, S. F. [University of California, Department of Physics (United States); Charlton, M.; Eriksson, S. [Swansea University, Department of Physics (United Kingdom); Fajans, J. [University of California, Department of Physics (United States); Friesen, T. [University of Calgary, Department of Physics and Astronomy (Canada); Fujiwara, M. C.; Gill, D. R. [TRIUMF (Canada); Gutierrez, A. [University of British Columbia, Department of Physics and Astronomy (Canada); Hangst, J. S. [Aarhus University, Department of Physics and Astronomy (Denmark); Hardy, W. N. [University of British Columbia, Department of Physics and Astronomy (Canada); Hayano, R. S. [University of Tokyo, Department of Physics (Japan); Hayden, M. E. [Simon Fraser University, Department of Physics (Canada); Collaboration: ALPHA Collaboration; and others

    2012-12-15

    In efforts to trap antihydrogen, a key problem is the vast disparity between the neutral trap energy scale ({approx} 50 {mu}eV), and the energy scales associated with plasma confinement and space charge ({approx}1 eV). In order to merge charged particle species for direct recombination, the larger energy scale must be overcome in a manner that minimizes the initial antihydrogen kinetic energy. This issue motivated the development of a novel injection technique utilizing the inherent nonlinear nature of particle oscillations in our traps. We demonstrated controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm or tenuous plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination. The nature of this injection overcomes some of the difficulties associated with matching the energies of the charged species used to produce antihydrogen.

  6. Antihydrogen formation by autoresonant excitation of antiproton plasmas

    International Nuclear Information System (INIS)

    Bertsche, William Alan; Andresen, G. B.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bowe, P. D.; Carpenter, P. T.; Butler, E.; Cesar, C. L.; Chapman, S. F.; Charlton, M.; Eriksson, S.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Gutierrez, A.; Hangst, J. S.; Hardy, W. N.; Hayano, R. S.; Hayden, M. E.

    2012-01-01

    In efforts to trap antihydrogen, a key problem is the vast disparity between the neutral trap energy scale (∼ 50 μeV), and the energy scales associated with plasma confinement and space charge (∼1 eV). In order to merge charged particle species for direct recombination, the larger energy scale must be overcome in a manner that minimizes the initial antihydrogen kinetic energy. This issue motivated the development of a novel injection technique utilizing the inherent nonlinear nature of particle oscillations in our traps. We demonstrated controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm or tenuous plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination. The nature of this injection overcomes some of the difficulties associated with matching the energies of the charged species used to produce antihydrogen.

  7. Measurement of cosmic ray antiprotons from 3.7 to 19 GeV

    International Nuclear Information System (INIS)

    Hof, M.; Pfeifer, C.; Menn, W.; Simon, M.; Golden, R.L.; Stochaj, S.J.; Basini, G.; Ricci, M.

    1996-02-01

    The antiproton to proton ratio in the cosmic rays has been measured in the energy range from 3.7 to 19 GeV. This measurement was carried out using a balloon-borne superconducting magnetic spectrometer along with a gas Cherenkov counter, an imaging calorimeter and a time of flight scintillator system. The measured antiproton to proton ratio was determined to be 1.24 (+0.68, -0.51)X 10 -4 . The present result along with other recent observations show that the observed abundances of antiprotons are consistent with models, in which antiprotons are produced as secondaries during the propagation of cosmic rays in the galaxy

  8. Time-dependent density functional calculation of the energy loss of antiprotons colliding with metallic nanoshells

    International Nuclear Information System (INIS)

    Quijada, M.; Borisov, A.G.; Muino, R.D.

    2008-01-01

    Time-dependent density functional theory is used to study the interaction between antiprotons and metallic nanoshells. The ground state electronic properties of the nanoshell are obtained in the jellium approximation. The energy lost by the antiproton during the collision is calculated and compared to that suffered by antiprotons traveling in metal clusters. The resulting energy loss per unit path length of material in thin nanoshells is larger than the corresponding quantity for clusters. It is shown that the collision process can be interpreted as the antiproton crossing of two nearly bi-dimensional independent metallic systems. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Search for antiproton-nucleus states with (anti p,p) reactions

    International Nuclear Information System (INIS)

    Garreta, D.; Birien, P.; Bruge, G.; Chaumeaux, A.; Drake, D.M.; Janouin, S.; Legrand, D.; Lemaire, M.C.; Mayer, B.; Pain, J.; Peng, J.C.; Berrada, M.; Bocquet, J.P.; Monnand, E.; Mougey, J.; Perrin, P.

    1985-01-01

    We have studied (anti p,p) reactions on 12 C, 63 Cu, and 209 Bi to search for possible nuclear states formed by antiprotons and nuclei. The experiments used the 180 MeV antiproton beam from LEAR, and the high-resolution magnetic spectrometer, SPES II, to detect the outgoing protons. No evidence of antiproton-nucleus states was found. The gross features of the proton spectra are reasonably well described by intranuclear cascade model calculations, which consider proton emission following antiproton annihilations in the target nucleus. (orig.)

  10. A novel antiproton radial diagnostic based on octupole induced ballistic loss

    CERN Document Server

    Andresen, G.B.; Bowe, P.D.; Bray, C.C.; Butler, E.; Cesar, C.L.; Chapman, S.; Charlton, M.; Fajans, J.; Fujiwara, M.C.; Funakoshi, R.; Gill, D.R.; Hangst, J.S.; Hardy, W.N.; Hayano, R.S.; Hayden, M.E.; Humphries, A.J.; Hydomako, R.; Jenkins, M.J.; Jorgensen, L.V.; Kurchaninov, L.; Lambo, R.; Madsen, N.; Nolan, P.; Olchanski, K.; Olin, A.; Page, R.D.; Povilus, A.; Pusa, P.; Robicheaux, F.; Sarid, E.; Seif El Nasr, S.; Silveira, D.M.; Storey, J.W.; Thompson, R.I.; van der Werf, D.P.; Wurtele, J.S.; Yamazaki, Y.

    2008-01-01

    We report results from a novel diagnostic that probes the outer radial profile of trapped antiproton clouds. The diagnostic allows us to determine the profile by monitoring the time-history of antiproton losses that occur as an octupole field in the antiproton confinement region is increased. We show several examples of how this diagnostic helps us to understand the radial dynamics of antiprotons in normal and nested Penning-Malmberg traps. Better understanding of these dynamics may aid current attempts to trap antihydrogen atoms.

  11. A novel antiproton radial diagnostic based on octupole induced ballistic loss

    International Nuclear Information System (INIS)

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S.; Cesar, C. L.; Lambo, R.; Silveira, D. M.; Fujiwara, M. C.

    2008-01-01

    We report results from a novel diagnostic that probes the outer radial profile of trapped antiproton clouds. The diagnostic allows us to determine the profile by monitoring the time history of antiproton losses that occur as an octupole field in the antiproton confinement region is increased. We show several examples of how this diagnostic helps us to understand the radial dynamics of antiprotons in normal and nested Penning-Malmberg traps. Better understanding of these dynamics may aid current attempts to trap antihydrogen atoms

  12. Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants

    Science.gov (United States)

    Hayano, Ryugo S.

    2010-01-01

    Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN’s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended values of the fundamental physical constants. PMID:20075605

  13. Accelerated Combinatorial High Throughput Star Polymer Synthesis via a Rapid One-Pot Sequential Aqueous RAFT (rosa-RAFT) Polymerization Scheme.

    Science.gov (United States)

    Cosson, Steffen; Danial, Maarten; Saint-Amans, Julien Rosselgong; Cooper-White, Justin J

    2017-04-01

    Advanced polymerization methodologies, such as reversible addition-fragmentation transfer (RAFT), allow unprecedented control over star polymer composition, topology, and functionality. However, using RAFT to produce high throughput (HTP) combinatorial star polymer libraries remains, to date, impracticable due to several technical limitations. Herein, the methodology "rapid one-pot sequential aqueous RAFT" or "rosa-RAFT," in which well-defined homo-, copolymer, and mikto-arm star polymers can be prepared in very low to medium reaction volumes (50 µL to 2 mL) via an "arm-first" approach in air within minutes, is reported. Due to the high conversion of a variety of acrylamide/acrylate monomers achieved during each successive short reaction step (each taking 3 min), the requirement for intermediary purification is avoided, drastically facilitating and accelerating the star synthesis process. The presented methodology enables RAFT to be applied to HTP polymeric bio/nanomaterials discovery pipelines, in which hundreds of complex polymeric formulations can be rapidly produced, screened, and scaled up for assessment in a wide range of applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Antiproton storage: a comparison of proposals

    International Nuclear Information System (INIS)

    Pondrom, L.G.

    1977-01-01

    Projects to produce and store anti p's and to accelerate anti p's and p's together in the same large ring are underway at CERN and FNAL. The goal is to achieve anti pp collisions with a luminosity L approximately 10 30 cm -2 sec -1 by perhaps 1980. These experiments predate any similar effort at ISABELLE by at least four years, so it is necessary to plan an ISABELLE project which will have significantly higher luminosity. A lower bound L = 10 31 cm -2 sec -1 has been rather arbitrarily chosen. The basic numbers which enter into the luminosity calculations for the CERN and FNAL proposals are presented and are compared with what could be achieved at ISABELLE under ideal conditions

  15. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  16. Capture, Electron-Cooling and Compression of Antiprotons in a Large Penning-Trap for Physics Experiments with an Ultra-Low Energy Extracted Antiproton Beam

    CERN Multimedia

    2002-01-01

    % PS200 \\\\ \\\\The availability of ultra-low energy antiprotons is a crucial ingredient for the execution of the gravity measurements PS200. We have developed a method to provide such low energy antiprotons based on a large Penning trap (the PS200 catching trap). This system can accept a fast-extracted pulse from LEAR, reduce the energy of the antiprotons in the pulse from 5.9~MeV to several tens of kilovolts using a degrading foil, and then capture the antiprotons in a large Penning trap. These antiprotons are cooled by electrons previously admitted to the trap and are collected in a small region at the center of the trap. We have demonstrated our capability to capture up to 1~million antiprotons from LEAR in a single shot, electron cool these antiprotons, and transfer up to 95\\% of them into the inner, harmonic region. A storage time in excess of 1 hour was observed. These results have been obtained with the cryogenic trap vacuum coupled to a room temperature vacuum at about l0$ ^- ^{1} ^0 $ Torr, which is an...

  17. Simulation of an antiprotons beam applied to the radiotherapy; Simulacao de um feixe de antiprotons aplicado a radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Prata, Leonardo de Almeida

    2006-07-15

    Results for the interaction of a antiproton beam with constituent nuclei of the organic matter are presented. This method regards of the application of an computational algorithm to determine quantitatively the differential cross sections for the scattered particles, starting from the interaction of these antiprotons with the nuclei, what will allow in the future to draw the isodose curve for antiproton therapy, once these beams are expected to be used in cancer treatment soon. The calculation will be done through the application of the concepts of the method of intranuclear cascade, providing yield and differential cross sections of the scattered particles, present in the software MCMC. Th algorithm was developed based on Monte Carlo's method, already taking into account a validate code. The following physical quantities are presented: the yield of secondary particles, their spectral and angular distributions for these interactions. For the energy range taken into account the more important emitted particles are protons, neutrons and pions. Results shown that emitted secondary particles can modify the isodose curves, because they present high yield and energy for transverse directions. (author)

  18. Simulation of an antiprotons beam applied to the radiotherapy; Simulacao de um feixe de antiprotons aplicado a radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Prata, Leonardo de Almeida

    2006-07-15

    Results for the interaction of a antiproton beam with constituent nuclei of the organic matter are presented. This method regards of the application of an computational algorithm to determine quantitatively the differential cross sections for the scattered particles, starting from the interaction of these antiprotons with the nuclei, what will allow in the future to draw the isodose curve for antiproton therapy, once these beams are expected to be used in cancer treatment soon. The calculation will be done through the application of the concepts of the method of intranuclear cascade, providing yield and differential cross sections of the scattered particles, present in the software MCMC. Th algorithm was developed based on Monte Carlo's method, already taking into account a validate code. The following physical quantities are presented: the yield of secondary particles, their spectral and angular distributions for these interactions. For the energy range taken into account the more important emitted particles are protons, neutrons and pions. Results shown that emitted secondary particles can modify the isodose curves, because they present high yield and energy for transverse directions. (author)

  19. Theses. Beam studies for the CERN antiproton decelerator and a new interpretation of the resonance theory for betatron motion

    Energy Technology Data Exchange (ETDEWEB)

    De Ninno, G

    1999-07-01

    The two parts of the thesis are a mission-oriented task devoted to solve some practical problems of the Antiproton Decelerator (AD) project at CERN, and a theoretical study leading to a new method for representing and compensating betatron resonances. The AD is a new machine (at the moment under commissioning at CERN) that will allow the collection and the deceleration of an antiproton beam from 3.5 GeV/c down to 100 MeV/c (the momentum favoured for the foreseen physics experiments). The need to employ the AD magnets over a wide range required a careful study of their characteristics. The presence of a solenoid inside the AD electron cooling device generates linear coupling between the transverse degrees of freedom of the single-particle motion. Coupling can lead to operational problems and therefore a compensation scheme had tobe designed. The long-standing problem has been solved of how to establish a relationship between the two standard methods for dealing with linear coupling: the matrix approach and the Hamiltonian approach. The bridge was built by including in the Hamiltonian approach in the high frequency part of the perturbative Hamiltonian due to coupling. The procedure was generalised to the nonlinear case and, a new method was proposed for dealing both with linear and nonlinear resonances. (author)

  20. Theses. Beam studies for the CERN antiproton decelerator and a new interpretation of the resonance theory for betatron motion

    International Nuclear Information System (INIS)

    De Ninno, G.

    1999-01-01

    The two parts of the thesis are a mission-oriented task devoted to solve some practical problems of the Antiproton Decelerator (AD) project at CERN, and a theoretical study leading to a new method for representing and compensating betatron resonances. The AD is a new machine (at the moment under commissioning at CERN) that will allow the collection and the deceleration of an antiproton beam from 3.5 GeV/c down to 100 MeV/c (the momentum favoured for the foreseen physics experiments). The need to employ the AD magnets over a wide range required a careful study of their characteristics. The presence of a solenoid inside the AD electron cooling device generates linear coupling between the transverse degrees of freedom of the single-particle motion. Coupling can lead to operational problems and therefore a compensation scheme had to be designed. The long-standing problem has been solved of how to establish a relationship between the two standard methods for dealing with linear coupling: the matrix approach and the Hamiltonian approach. The bridge was built by including in the Hamiltonian approach in the high frequency part of the perturbative Hamiltonian due to coupling. The procedure was generalised to the nonlinear case and, a new method was proposed for dealing both with linear and nonlinear resonances. (author)

  1. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  2. LEAP: A balloon-borne search for low-energy cosmic ray antiprotons

    Science.gov (United States)

    Moats, Anne Rosalie Myers

    The LEAP (Low Energy Antiproton) experiment is a search for cosmic ray antiprotons in the 120 MeV to 1.2 GeV kinetic energy range. The motivation for this project was the result announced by Buffington et al. (1981) that indicated an anomalously high antiproton flux below 300 MeV; this result has compelled theorists to propose sources of primary antiprotons above the small secondary antiproton flux produced by high energy cosmic ray collisions with nuclei in the interstellar medium. LEAP consisted of the NMSU magnet spectrometer, a time-of-flight system designed at NASA-Goddard, two scintillation detectors, and a Cherenkov counter. Analysis of flight data performed by the high energy astrophysics group at Goddard Space Flight Center revealed no antiproton candidates found in the 120 MeV to 360 MeV range; 3 possible antiproton candidate events were found in the 500 MeV to 1.2 GeV range in an analysis done here at the University of Arizona. However, since it will be necessary to sharpen the calibration on all of the LEAP systems in order to positively identify these events as antiprotons, only an upper limit has been determined at present. Thus, combining the analyses performed at the University of Arizona and NASA-Goddard, 90 percent confidence upper limits of 3.5 x 10-5 in the 120 MeV to 360 MeV range and 2.3 x 10-4 in the 500 MeV to 1.2 GeV range for the antiproton/proton ratio is indicated by the LEAP results. LEAP disagrees sharply with the results of the Buffington group, indicating a low antiproton flux at these energies. Thus, a purely secondary antiproton flux may be adequate at low energies.

  3. NLSEmagic: Nonlinear Schrödinger equation multi-dimensional Matlab-based GPU-accelerated integrators using compact high-order schemes

    Science.gov (United States)

    Caplan, R. M.

    2013-04-01

    We present a simple to use, yet powerful code package called NLSEmagic to numerically integrate the nonlinear Schrödinger equation in one, two, and three dimensions. NLSEmagic is a high-order finite-difference code package which utilizes graphic processing unit (GPU) parallel architectures. The codes running on the GPU are many times faster than their serial counterparts, and are much cheaper to run than on standard parallel clusters. The codes are developed with usability and portability in mind, and therefore are written to interface with MATLAB utilizing custom GPU-enabled C codes with the MEX-compiler interface. The packages are freely distributed, including user manuals and set-up files. Catalogue identifier: AEOJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOJ_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 124453 No. of bytes in distributed program, including test data, etc.: 4728604 Distribution format: tar.gz Programming language: C, CUDA, MATLAB. Computer: PC, MAC. Operating system: Windows, MacOS, Linux. Has the code been vectorized or parallelized?: Yes. Number of processors used: Single CPU, number of GPU processors dependent on chosen GPU card (max is currently 3072 cores on GeForce GTX 690). Supplementary material: Setup guide, Installation guide. RAM: Highly dependent on dimensionality and grid size. For typical medium-large problem size in three dimensions, 4GB is sufficient. Keywords: Nonlinear Schröodinger Equation, GPU, high-order finite difference, Bose-Einstien condensates. Classification: 4.3, 7.7. Nature of problem: Integrate solutions of the time-dependent one-, two-, and three-dimensional cubic nonlinear Schrödinger equation. Solution method: The integrators utilize a fully-explicit fourth-order Runge-Kutta scheme in time

  4. View of the CERN Antiproton Decelerator (AD) and portrait of Prof. Tommy Eriksson, in charge of the AD machine.

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory in Geneva. It started operation in 2000. It decelerates antiprotons before sending them to several experiments studying antimatter : ALPHA, ASACUSA, ATRAP and ACE.

  5. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The SPS started up with 2 accelerating cavities (each consisting of 5 tank sections) in LSS3. They have a 200 MHz travelling wave structure (see 7411032 and 7802190) and 750 kW of power is fed to each of the cavities from a 1 MW tetrode power amplifier, located in a surface building above, via a coaxial transmission line. Clemens Zettler, builder of the SPS RF system, is standing at the side of one of the cavities. In 1978 and 1979 another 2 cavities were added and entered service in 1980. These were part of the intensity improvement programme and served well for the new role of the SPS as proton-antiproton collider. See also 7411032, 8011289, 8104138, 8302397.

  6. Compression of a mixed antiproton and electron non-neutral plasma to high densities

    Science.gov (United States)

    Aghion, Stefano; Amsler, Claude; Bonomi, Germano; Brusa, Roberto S.; Caccia, Massimo; Caravita, Ruggero; Castelli, Fabrizio; Cerchiari, Giovanni; Comparat, Daniel; Consolati, Giovanni; Demetrio, Andrea; Di Noto, Lea; Doser, Michael; Evans, Craig; Fanì, Mattia; Ferragut, Rafael; Fesel, Julian; Fontana, Andrea; Gerber, Sebastian; Giammarchi, Marco; Gligorova, Angela; Guatieri, Francesco; Haider, Stefan; Hinterberger, Alexander; Holmestad, Helga; Kellerbauer, Alban; Khalidova, Olga; Krasnický, Daniel; Lagomarsino, Vittorio; Lansonneur, Pierre; Lebrun, Patrice; Malbrunot, Chloé; Mariazzi, Sebastiano; Marton, Johann; Matveev, Victor; Mazzotta, Zeudi; Müller, Simon R.; Nebbia, Giancarlo; Nedelec, Patrick; Oberthaler, Markus; Pacifico, Nicola; Pagano, Davide; Penasa, Luca; Petracek, Vojtech; Prelz, Francesco; Prevedelli, Marco; Rienaecker, Benjamin; Robert, Jacques; Røhne, Ole M.; Rotondi, Alberto; Sandaker, Heidi; Santoro, Romualdo; Smestad, Lillian; Sorrentino, Fiodor; Testera, Gemma; Tietje, Ingmari C.; Widmann, Eberhard; Yzombard, Pauline; Zimmer, Christian; Zmeskal, Johann; Zurlo, Nicola; Antonello, Massimiliano

    2018-04-01

    We describe a multi-step "rotating wall" compression of a mixed cold antiproton-electron non-neutral plasma in a 4.46 T Penning-Malmberg trap developed in the context of the AEḡIS experiment at CERN. Such traps are routinely used for the preparation of cold antiprotons suitable for antihydrogen production. A tenfold antiproton radius compression has been achieved, with a minimum antiproton radius of only 0.17 mm. We describe the experimental conditions necessary to perform such a compression: minimizing the tails of the electron density distribution is paramount to ensure that the antiproton density distribution follows that of the electrons. Such electron density tails are remnants of rotating wall compression and in many cases can remain unnoticed. We observe that the compression dynamics for a pure electron plasma behaves the same way as that of a mixed antiproton and electron plasma. Thanks to this optimized compression method and the high single shot antiproton catching efficiency, we observe for the first time cold and dense non-neutral antiproton plasmas with particle densities n ≥ 1013 m-3, which pave the way for an efficient pulsed antihydrogen production in AEḡIS.

  7. Jagiellonian University Drift Chamber Calibration and Track Reconstruction in the P349 Antiproton Polarization Experiment

    CERN Document Server

    Alfs, D; Moskal, P; Zieliński, M; Grzonka, D; Hauenstein, F; Kilian, K; Lersch, D; Ritman, J; Sefzick, T; Oelert, W; Diermaier, M; Widmann, E; Zmeskal, J; Wolke, M; Nadel-Turonski, P; Carmignotto, M; Horn, T; Mkrtchyan, H; Asaturyan, A; Mkrtchyan, A; Tadevosyan, V; Zhamkochyan, S; Malbrunot-Ettenauer, S; Eyrich, W; Zink, A

    2017-01-01

    The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.

  8. What can an antiproton and a nucleus learn from each other

    International Nuclear Information System (INIS)

    Garreta, D.

    1984-01-01

    This chapter attempts to show that the - p-nucleus interaction may provide very useful information, both about the elementary - NN interaction and about nuclear structure. Topics covered include simple features which make a low-energy antiproton an interesting probe of the nucleus; simple features which make a nucleus an interesting target for an antiproton; antiproton-nucleus elastic scattering; antiproton-nucleus inelastic scattering; proton knock-out reactions on nuclei; and annihilation of the antiprotons in nuclei. The aim of experiment PS184 at the Low-Energy Antiproton Ring (LEAR) is to provide accurate data with regard to the - p-nucleus interaction in the following areas: the angular distribution of antiprotons elastically scattered from 12 C, 40 Ca, and 208 Pb; the excitation energy spectra and some angular distributions of antiprotons inelastically scattered from 12 C, 40 Ca, and 208 Pb; and the excitation energy spectra for proton knock-out reaction on 6 Li, 45 Sc, 123 Sb, and 209 B; at forward angles

  9. Trapping of antiprotons -- a first step on the way to antihydrogen

    International Nuclear Information System (INIS)

    Holzscheiter, M.H.

    1993-01-01

    A first step towards producing and effectively utilizing antihydrogen atoms consists of trapping antiprotons. The immediate next step must then be to control, i.e. trap the produced antihydrogen. The current state of the art in trapping antiprotons and positrons is reviewed, and the challenges in trapping the resulting neutral particles are discussed

  10. Status of the analysis for the search of polarization in the antiproton production process

    International Nuclear Information System (INIS)

    Alfs, D.; Asaturyan, A.; Carmignotto, M.; Diermaier, M.; Eyrich, W.; Głowacz, B.; Grzonka, D.; Hauenstein, F.; Horn, T.; Kilian, K.; Malbrunot-Ettenauer, S.; Mkrtchyan, A.; Mkrtchyan, H.; Moskal, P.; Nadel-Turonski, P.; Oelert, W.; Ritman, J.; Sefzick, T.; Tadevosyan, V.; Widmann, E.; Wolke, M.; Zhamkochyan, S.; Zieliński, M.; Zink, A.; Zmeskal, J.

    2016-01-01

    The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we present the details of performed measurements and report on the status of the ongoing analysis.

  11. Bubble detector measurements of a mixed radiation field from antiproton annihilation

    DEFF Research Database (Denmark)

    Bassler, Niels; Knudsen, Helge; Møller, Søren Pape

    2006-01-01

    In the light of recent progress in the study of the biological potential of antiproton tumour treatment it is important to be able to characterize the neutron intensity arising from antiproton annihilation using simple, compact and reliable detectors. The intensity of fast neutrons from antiproto...

  12. Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy

    Science.gov (United States)

    Ficek, Filip; Fadeev, Pavel; Flambaum, Victor V.; Jackson Kimball, Derek F.; Kozlov, Mikhail G.; Stadnik, Yevgeny V.; Budker, Dmitry

    2018-05-01

    Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.

  13. Cosmic ray propagation in a diffusion model: a new estimation of the diffusion parameters and of the secondary antiprotons flux; Propagation des rayons cosmiques dans un modele de diffusion: une nouvelle estimation des parametres de diffusion et du flux d'antiprotons secondaires

    Energy Technology Data Exchange (ETDEWEB)

    Maurin, D

    2001-02-01

    Dark matter is present at numerous scale of the universe (galaxy, cluster of galaxies, universe in the whole). This matter plays an important role in cosmology and can not be totally explained by conventional physic. From a particle physic point of view, there exists an extension of the standard model - supersymmetry - which predicts under certain conditions the existence of new stable and massive particles, the latter interacting weakly with ordinary matter. Apart from direct detection in accelerators, various indirect astrophysical detection are possible. This thesis focuses on one particular signature: disintegration of these particles could give antiprotons which should be measurable in cosmic rays. The present study evaluates the background corresponding to this signal i. e. antiprotons produced in the interactions between these cosmic rays and interstellar matter. In particular, uncertainties of this background being correlated to the uncertainties of the diffusion parameter, major part of this thesis is devoted to nuclei propagation. The first third of the thesis introduces propagation of cosmic rays in our galaxy, emphasizing the nuclear reaction responsibles of the nuclei fragmentation. In the second third, different models are reviewed, and in particular links between the leaky box model and the diffusion model are recalled (re-acceleration and convection are also discussed). This leads to a qualitative discussion about information that one can infer from propagation of these nuclei. In the last third, we finally present detailed solutions of the bidimensional diffusion model, along with constrains obtained on the propagation parameters. The latter is applied on the antiprotons background signal and it concludes the work done in this thesis. The propagation code for nuclei and antiprotons used here has proven its ability in data analysis. It would probably be of interest for the analysis of the cosmic ray data which will be taken by the AMS experiment on

  14. Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap

    CERN Document Server

    Amole, C; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Hydomako, R; Kurchaninov, L; Jonsell, S; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S

    2012-01-01

    Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antipr...

  15. Slowing down of 100 keV antiprotons in Al foils

    Directory of Open Access Journals (Sweden)

    K. Nordlund

    2018-03-01

    Full Text Available Using energy degrading foils to slow down antiprotons is of interest for producing antihydrogen atoms. I consider here the slowing down of 100 keV antiprotons, that will be produced in the ELENA storage ring under construction at CERN, to energies below 10 keV. At these low energies, they are suitable for efficient antihydrogen production. I simulate the antihydrogen motion and slowing down in Al foils using a recently developed molecular dynamics approach. The results show that the optimal Al foil thickness for slowing down the antiprotons to below 5 keV is 910 nm, and to below 10 keV is 840 nm. Also the lateral spreading of the transmitted antiprotons is reported and the uncertainties discussed. Keywords: Antiprotons, Stopping power, Slowing down, Molecular dynamics

  16. Measurement of antiproton annihilation on Cu, Ag and Au with emulsion films

    International Nuclear Information System (INIS)

    Aghion, S.; Consolati, G.; Evans, C.; Ferragut, R.; Amsler, C.; Ariga, A.; Ariga, T.; Ereditato, A.; Bonomi, G.; Bräunig, P.; Demetrio, A.; Brusa, R.S.; Cabaret, L.; Comparat, D.; Caccia, M.; Castelli, F.; Caravita, R.; Noto, L. Di; Cerchiari, G.; Doser, M.

    2017-01-01

    The characteristics of low energy antiproton annihilations on nuclei (e.g. hadronization and product multiplicities) are not well known, and Monte Carlo simulation packages that use different models provide different descriptions of the annihilation events. In this study, we measured the particle multiplicities resulting from antiproton annihilations on nuclei. The results were compared with predictions obtained using different models in the simulation tools GEANT4 and FLUKA. For this study, we exposed thin targets (Cu, Ag and Au) to a very low energy antiproton beam from CERN's Antiproton Decelerator, exploiting the secondary beamline available in the AEgIS experimental zone. The antiproton annihilation products were detected using emulsion films developed at the Laboratory of High Energy Physics in Bern, where they were analysed at the automatic microscope facility. The fragment multiplicity measured in this study is in good agreement with results obtained with FLUKA simulations for both minimally and heavily ionizing particles.

  17. Measurement of antiproton annihilation on Cu, Ag and Au with emulsion films

    Science.gov (United States)

    Aghion, S.; Amsler, C.; Ariga, A.; Ariga, T.; Bonomi, G.; Bräunig, P.; Brusa, R. S.; Cabaret, L.; Caccia, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Ereditato, A.; Evans, C.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Haider, S.; Hinterberger, A.; Holmestad, H.; Huse, T.; Kawada, J.; Kellerbauer, A.; Kimura, M.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lebrun, P.; Malbrunot, C.; Mariazzi, S.; Matveev, V.; Mazzotta, Z.; Müller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pacifico, N.; Pagano, D.; Penasa, L.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Rienaecker, B.; RØhne, O. M.; Rotondi, A.; Sacerdoti, M.; Sandaker, H.; Santoro, R.; Scampoli, P.; Simon, M.; Smestad, L.; Sorrentino, F.; Testera, G.; Tietje, I. C.; Vamosi, S.; Vladymyrov, M.; Widmann, E.; Yzombard, P.; Zimmer, C.; Zmeskal, J.; Zurlo, N.

    2017-04-01

    The characteristics of low energy antiproton annihilations on nuclei (e.g. hadronization and product multiplicities) are not well known, and Monte Carlo simulation packages that use different models provide different descriptions of the annihilation events. In this study, we measured the particle multiplicities resulting from antiproton annihilations on nuclei. The results were compared with predictions obtained using different models in the simulation tools GEANT4 and FLUKA. For this study, we exposed thin targets (Cu, Ag and Au) to a very low energy antiproton beam from CERN's Antiproton Decelerator, exploiting the secondary beamline available in the AEgIS experimental zone. The antiproton annihilation products were detected using emulsion films developed at the Laboratory of High Energy Physics in Bern, where they were analysed at the automatic microscope facility. The fragment multiplicity measured in this study is in good agreement with results obtained with FLUKA simulations for both minimally and heavily ionizing particles.

  18. Operational experience with bunch rotation momentum reduction in the Fermilab antiproton source

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Griffin, J.E.; MacLachlan, J.A.; Martin, P.S.; Meisner, K.G.; Wildman, D.

    1987-01-01

    In the Fermilab antiproton accumulation system antiprotons are produced by the delivery of trains of 120 GeV proton bunches to a production target from which antiprotons are collected with mean energy 8 GeV (kinetic) and momentum spread Δrho/rho > 3%. The antiproton beam has the time structure of the incident protons. The proton bunch spacing-to-length ratio is made as large as possible (> 20:1) so that the resulting antiproton momentum spread may be reduced by ''bunch rotation'' in a ''debunching'' ring where time spread is exchanged for momentum spread. Details of these procedures are described elsewhere; in this paper the authors report on the efficacy of these procedures during routine operation

  19. Segmented scintillation detectors with silicon photomultiplier readout for measuring antiproton annihilations

    CERN Document Server

    Sótér, A.; Kobayashi, T.; Barna, D.; Horváth, D.; Hori, M.

    2014-01-01

    The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) experiment at the Antiproton Decelerator (AD) facility of CERN constructed segmented scintillators to detect and track the charged pions which emerge from antiproton annihilations in a future superconducting radiofrequency Paul trap for antiprotons. A system of 541 cast and extruded scintillator bars were arranged in 11 detector modules which provided a spatial resolution of 17 mm. Green wavelength-shifting fibers were embedded in the scintillators, and read out by silicon photomultipliers which had a sensitive area of 1 x 1 mm^2. The photoelectron yields of various scintillator configurations were measured using a negative pion beam of momentum p ~ 1 GeV/c. Various fibers and silicon photomultipliers, fiber end terminations, and couplings between the fibers and scintillators were compared. The detectors were also tested using the antiproton beam of the AD. Nonlinear effects due to the saturation of the silicon photomultiplier were seen a...

  20. Top Production at the Tevatron: The Antiproton Awakens

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Kenneth [Nebraska U.

    2017-07-01

    A long time ago, at a laboratory far, far away, the Fermilab Tevatron collided protons and antiprotons at $\\sqrt{s} = 1.96$ TeV. The CDF and D0 experiments each recorded datasets of about 10 fb$^{-1}$. As such experiments may never be repeated, these are unique datasets that allow for unique measurements. This presentation describes recent results from the two experiments on top-quark production rates, spin orientations, and production asymmetries, which are all probes of the $p\\bar{p}$ initial state.

  1. Pontecorvo reactions of two-body antiproton annihilation in deuterium

    International Nuclear Information System (INIS)

    Kondratyuk, L.A.; Sapozhnikov, M.G.

    1988-01-01

    Rare annihilation reactions for stopped antiprotons in deuterium, p-bard→π - p; K + Σ - ; K 0 Λ, are considered using the two-step model described by the triangle diagram. It was found that the probabilities, W, of these processes are very sensitive to the behaviour of the deuteron wave function at small distances as well as to the meson form factors. It appears that the ratios R(KX)=W(KX)/W(π - p) are much less model-dependent and are about 10 -2 for R(K 0 λ) and 10 -4 for R(K + Σ - ). 17 refs.; 1 fig.; 3 tabs

  2. Evaporative cooling of antiprotons for the production of trappable antihydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, D. M.; Cesar, C. L. [Instituto de Fisica - Universidade Federal do Rio de Janeiro, 21941-972, Rio de Janeiro (Brazil); Andresen, G. B.; Bowe, P. D.; Hangst, J. S. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Ashkezari, M. D.; Hayden, M. E. [Department of Physics, Simon Fraser University, Burnaby BC, V5A 1S6 (Canada); Baquero-Ruiz, M.; Chapman, S.; Fajans, J.; Povilus, A.; So, C.; Wurtele, J. S. [Department of Physics, University of California, Berkeley, California 94720-7300 (United States); Bertsche, W. [School of Physics and Astronomy, University of Manchester, M13 9PL Manchester (United Kingdom) and Cockroft Institute, WA4 4AD Warrington (United Kingdom); Butler, E. [CERN, PH Department, CH-1211 Geneva 23 (Switzerland); Charlton, M.; Madsen, N.; Werf, D. P. van der [Department of Physics, College of Science, Swansea University, Swansea SA2 8PP (United Kingdom); Friesen, T.; Hydomako, R. [Department of Physics and Astronomy, University of Calgary AB, T2N 1N4 (Canada); and others

    2013-03-19

    We describe the implementation of evaporative cooling of charged particles in the ALPHA apparatus. Forced evaporation has been applied to cold samples of antiprotons held in Malmberg-Penning traps. Temperatures on the order of 10 K were obtained, while retaining a significant fraction of the initial number of particles. We have developed a model for the evaporation process based on simple rate equations and applied it succesfully to the experimental data. We have also observed radial re-distribution of the clouds following evaporation, explained by simple conservation laws. We discuss the relevance of this technique for the recent demonstration of magnetic trapping of antihydrogen.

  3. Commissioning of polarized-proton and antiproton beams at Fermilab

    International Nuclear Information System (INIS)

    Yokosawa, A.

    1988-01-01

    The author described the polarized-proton and polarized-antiproton beams up to 200 GeV/c at Fermilab. The beam line, called MP, consists of the 400-m long primary and 350-m long secondary beam line followed by 60-m long experimental hall. We discuss the characteristics of the polarized beams. The Fermilab polarization projects are designated at E-581/704 initiated and carried out by an international collaboration, Argonne (US), Fermilab (US), Kyoto-Kyushu-Hiroshima-KEK (Japan), LAPP (France), Northwestern University (US), Los Alamos Laboratory (US), Rice (US), Saclay (France), Serpukhov (USSR), INFN Trieste (Italy), and University of Texas (US)

  4. The antiproton depth–dose curve measured with alanine detectors

    CERN Document Server

    Bassler, Niels; Palmans, Hugo; Holzscheiter, Michael H; Kovacevic, Sandra

    2008-01-01

    n this paper we report on the measurement of the antiproton depth–dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen and Olsen for conversion of calculated dose into response. A good agreement is observed between the measured and calculated relative effectiveness although an underestimation of the measured values beyond the Bragg-peak remains unexplained. The model prediction of response of alanine towards heavy charged particles encourages future use of the alanine detectors for dosimetry of mixed radiation fields.

  5. The Antiproton Depth Dose Curve Measured with Alanine Detectors

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, Johnny Witterseh; Palmans, Hugo

    2008-01-01

    In this paper we report on the measurement of the antiproton depth dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen et Olsen for conversion of calculated dose...... into response. A good agreement was observed between the measured and calculated relative effectiveness although a slight underestimation of the calculated values in the Bragg peak remains unexplained. The model prediction of response of alanine towards heavy charged particles encourages future use...... of the alanine detectors for dosimetry of mixed radiation fields....

  6. Electrodes for stochastic cooling of the FNAL antiproton source

    International Nuclear Information System (INIS)

    Voelker, F.

    1982-11-01

    AN electrode array for stochastic cooling is being developed for use on the FNAL antiproton source. With minor power handling modifications, the same electrodes can function as pickups or as kickers. When used as pickups, a large array is needed to increase the signal-to-noise ratio. Each electrode is one element of a pair of directional coupler loops that are mounted flush with the upper and lower walls of the beam chamber. The loops, fabricated from flat metal plates, are supported by specially shaped legs

  7. High resolution X-ray spectroscopy in light antiprotonic atoms

    CERN Document Server

    Borchert, G L; Augsburger, M A; Castelli, C M; Chatellard, D; Egger, J P; El-Khoury, P; Elble, M; Gorke, H; Gotta, D; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    2000-01-01

    At the LEAR facility, CERN, antiprotonic L alpha transitions in light elements have been investigated with a focussing crystal spectrometer. The high resolution of the experiment allowed for the first time to resolve in pH/pH the 2/sup 3/P/sub 0/ state from the close-lying states 2/sup 3/P/sub 2/, 2/sup 1/P/sub 1/, and 2/sup 3/P /sub 1/. In pD the corresponding transitions were found to be more than an order of magnitude broader. To a large extent the results for pH support the meson exchange model. (15 refs).

  8. Design of a High Luminosity 100 TeV Proton-Antiproton Collider

    Science.gov (United States)

    Oliveros Tautiva, Sandra Jimena

    Currently new physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. A 10 34 cm-2 s-1 luminosity 100 TeV proton-antiproton collider is explored with 7x the energy of the LHC. The dipoles are 4.5 T to reduce cost. A proton-antiproton collider is selected as a future machine for several reasons. The cross section for many high mass states is 10 times higher in pp than pp collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per bunch crossing, because lower beam currents can produce the same rare event rates. Events are also more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller beta* for higher luminosity. To adjust to antiproton beam losses (burn rate), a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might follow the stochastic cooling rings for antiproton stacking. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and synchrotron damping. These basic ideas are explored in this work on a future 100 TeV proton-antiproton collider and the main parameters are presented.

  9. Design of a High Luminosity 100 TeV Proton Antiproton Collider

    Energy Technology Data Exchange (ETDEWEB)

    Oliveros Tuativa, Sandra Jimena [Univ. of Mississippi, Oxford, MS (United States)

    2017-04-01

    Currently new physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. A 10$^{\\,34}$ cm$^{-2}$ s$^{-1}$ luminosity 100 TeV proton-antiproton collider is explored with 7$\\times$ the energy of the LHC. The dipoles are 4.5\\,T to reduce cost. A proton-antiproton collider is selected as a future machine for several reasons. The cross section for many high mass states is 10 times higher in $p\\bar{p}$ than $pp$ collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per bunch crossing, because lower beam currents can produce the same rare event rates. Events are also more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller $\\beta^{*}$ for higher luminosity. To adjust to antiproton beam losses (burn rate), a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might follow the stochastic cooling rings for antiproton stacking. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and synchrotron damping. These basic ideas are explored in this work on a future 100 TeV proton-antiproton collider and the main parameters are presented.

  10. Nucleon charge exchange reaction and antiproton elastic scattering at intermediate energies

    International Nuclear Information System (INIS)

    Kronenfeld, J.

    1985-02-01

    This work treats the medium energy nuclear (p,n) charge exchange reaction to analog states and the low energy elastic scattering of antiprotons and investigates the central aspects of a microscopic theory based on multiple-scattering series which are pertinent to these reactions. A two-step term of the Distorted Wave Impulse Approximation (DWIA) in treating the (p,n) reaction, was included. For the very absorptive p-bar interaction with nuclei we conjecture that a partial infinite summation, constituing a renormalization of the single scattering term of the optical potential series provides the dominant feature of this interaction. In this work the excitation of analog states is calculated and it was found that the (p,n) reaction is described fairly well by the DWIA. In the first part of the work the (p,n) reaction in the energy range 100-200 MeV was treated. The DWIA calculations were based on eikonalization. In the second part of the work the p-barA interaction with the selfconsistent scheme mentioned above, for scattering energies 30-120 MeV, was examined. (author)

  11. Tradable schemes

    NARCIS (Netherlands)

    J.K. Hoogland (Jiri); C.D.D. Neumann

    2000-01-01

    textabstractIn this article we present a new approach to the numerical valuation of derivative securities. The method is based on our previous work where we formulated the theory of pricing in terms of tradables. The basic idea is to fit a finite difference scheme to exact solutions of the pricing

  12. Antiproton-hydrogen scattering at low-eV energies

    International Nuclear Information System (INIS)

    Morgan Jr., D.L.

    1993-01-01

    In the scattering of negative particles other than the electron by atoms at lab-frame energies around 10 eV, an elastic process termed 'brickwall scattering' might lead to a high probability for scattering angles around 180deg. For an antiproton slowing in hydrogen, this backward scattering would result in the loss of nearly all of its energy in a single collision, since it and a hydrogen atom have nearly the same mass. Such energy loss would have a significant effect on the energy distribution of antiprotons at energies where capture by the protons of hydrogen is possible and might, thereby, affect the capture rate and the distribution of capture states. In the semiclassical treatment of the problem with an adiabatic potential energy, brickwall scattering is indeed present, and with a substantial cross section. However, this model appears to underestimate inelastic processes. Based on calculations for negative muons on hydrogen atoms, these processes appear to occur for about the same impact parameters as brickwall scattering and thus substantially reduce its effect. (orig.)

  13. Precision tests of CPT invariance with single trapped antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Stefan [RIKEN, Ulmer Initiative Research Unit, Wako, Saitama (Japan); Collaboration: BASE-Collaboration

    2015-07-01

    The reason for the striking imbalance of matter and antimatter in our Universe has yet to be understood. This is the motivation and inspiration to conduct high precision experiments comparing the fundamental properties of matter and antimatter equivalents at lowest energies and with greatest precision. According to theory, the most sensitive tests of CPT invariance are measurements of antihydrogen ground-state hyperfine splitting as well as comparisons of proton and antiproton magnetic moments. Within the BASE collaboration we target the latter. By using a double Penning trap we performed very recently the first direct high precision measurement of the proton magnetic moment. The achieved fractional precision of 3.3 ppb improves the currently accepted literature value by a factor of 2.5. Application of the method to a single trapped antiproton will improve precision of the particles magnetic moment by more than a factor of 1000, thus providing one of the most stringent tests of CPT invariance. In my talk I report on the status and future perspectives of our efforts.

  14. Collinear wake field acceleration

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Chen, P.; Wilson, P.B.

    1985-04-01

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  15. Observation and study of bottom-meson decays to a charm meson, a proton-antiproton pair, and pions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Tae Min [Univ. of California, Santa Barbara, CA (United States)

    2010-04-27

    Bottom-meson decays with baryons show two unusual features—the branching fractions are enhanced for multibody decays and the baryon-antibaryon subsystem recoils against the other decay products—and their reasons are not yet well understood. Moreover, measurements using explicit reconstruction techniques constitute only about 1% out of about 8% of such decays. This Dissertation reports the study of ten bottom-meson decays (labeled 0– 9) to a proton-antiproton pair, a charm meson, and a system of up to two pions, using the BABAR Experiment’s 455×106 BB pairs produced with the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center.

  16. Acceleration of magnetized plasma rings

    International Nuclear Information System (INIS)

    Hartman, D.; Eddleman, J.; Hammer, J.H.

    1982-01-01

    One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  17. Nr 306 - Report made on the behalf of the Foreign affairs, defence and armed forces Commission on the bill project authorizing the approval of the convention related to the construction and exploitation of an infrastructure for research on antiprotons and ions in Europe

    International Nuclear Information System (INIS)

    Boutant, Michel

    2013-01-01

    This report first recalls the history of the project of a new European infrastructure dedicated to research on antiprotons and ions (FAIR, Facility for Antiproton and Ion Research) which should be built in Germany with the participation of nine European countries. The facility is a set of particle accelerators. Its envisaged and possible applications are indicated. The project is also part of a set of projects comprising existing or under-construction installations in France (GANIL-SPIRAL2), and Switzerland (ISOLDE). The author comments the content of the convention which specifies a rather limited French contribution. He also comments the statutes of the FAIR company

  18. Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

    Science.gov (United States)

    Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan

    2015-01-01

    After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

  19. Experience with the new reverse injection scheme in the Tevatron

    International Nuclear Information System (INIS)

    Saritepe, S.; Goderre, G.; Annala, G.; Hanna, B.; Braun, A.

    1993-01-01

    In the new injection scenario the antiproton beam is injected onto a helical Tevatron orbit to avoid the detrimental effects of the beam-beam interaction at 150 GeV. The new scenario required changes in the tuning procedures. Antiprotons are too precious to be used for tuning, therefore the antiproton injection line has to be tuned with protons by reverse injecting them from the Tevatron into the Main Ring. Previously, the reverse injection was performed in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. The orbit closure was performed in the Main Ring. In the new scheme the lambertson magnets have to be moved, separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS (Tevatron Beam Synchronized Clock) event $D8 as MRBS (Main Ring Beam Synchronized Clock) $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the Main Ring

  20. Measurements of cascade times of antiprotons in molecular hydrogen and helium

    CERN Document Server

    Bianconi, A; Corradini, M; Donzella, A; Gómez, G; Lodi-Rizzini, E; Venturelli, L; Vilar, R; Zenoni, A; Bertin, A; Bruschi, M; Capponi, M; De Castro, S; Donà, R; Galli, D; Giacobbe, B; Marconi, U; Massa, I; Piccinini, M; Semprini-Cesari, N; Spighi, R; Vagnoni, V M; Vecchi, S; Villa, M; Vitale, A; Zoccoli, A; Cicalò, C; De Falco, A; Masoni, A; Puddu, G; Serci, S; Usai, G L; Gorchakov, O E; Prakhov, S N; Rozhdestvensky, A M; Tretyak, V I; Poli, M; Gianotti, P; Guaraldo, C; Lanaro, A; Lucherini, V; Petrascu, C; Ableev, V G; Ricci, R A; Vannucci, Luigi; Filippini, V; Fontana, A; Montagna, P; Rotondi, A; Salvini, P; Mirfakhraee, N; Bussa, M P; Busso, L; Cerello, P G; Denisov, O Yu; Ferrero, L; Garfagnini, R; Grasso, A; Maggiora, A; Panzarasa, A; Panzieri, D; Tosello, F; Botta, E; Bressani, Tullio; Calvo, D; Costa, S; D'Isep, F; Feliciello, A; Filippi, A; Marcello, S; Agnello, M; Iazzi, F; Minetti, B; Tessaro, S; Santi, L

    2000-01-01

    The OBELIX experiment at CERN collected samples of antiproton annihilations at rest in different gaseous targets, such as hydrogen, deuterium and helium. We analyze a set of the Obelix data using a new technique for measuring, for the first time, the cascade times independent of the capture energy and of the antiproton stopping power. We report on measurements of the cascade times for hydrogen at 3.4, 5.8, 9.8 and 150 mbar and for helium at 8.2, 50 and 150 mbar pressure. An estimate of the antiproton capture energy in hydrogen is also presented. (12 refs).

  1. Cryogenic tunable microwave cavity at 13GHz for hyperfine spectroscopy of antiprotonic helium

    International Nuclear Information System (INIS)

    Sakaguchi, J.; Gilg, H.; Hayano, R.S.; Ishikawa, T.; Suzuki, K.; Widmann, E.; Yamaguchi, H.; Caspers, F.; Eades, J.; Hori, M.; Barna, D.; Horvath, D.; Juhasz, B.; Torii, H.A.; Yamazaki, T.

    2004-01-01

    For the precise measurement of the hyperfine structure of antiprotonic helium, microwave radiation of 12.9GHz frequency is needed, tunable over +/-100MHz. A cylindrical microwave cavity is used whose front and rear faces are meshed to allow the antiprotons and laser beams to enter. The cavity is embedded in a cryogenic helium gas target. Frequency tuning of ∼300MHz with Q values of 2700-3000 was achieved using over-coupling and an external triple stub tuner. We also present Monte-Carlo simulations of the stopping distribution of antiprotons in the low-density helium gas using the GEANT4 package with modified energy loss routines

  2. Possibility of resonant capture of antiprotons by highly charged hydrogenlike ions

    International Nuclear Information System (INIS)

    Genkin, M.; Lindroth, E.

    2009-01-01

    Recently, an experimental setup was proposed by Lapierre et al. which would allow antiprotons and highly charged ions to collide repeatedly in an electron beam ion trap (EBIT) due to a nested trap configuration. As mentioned by the authors, such a setup may open the possibility to study antiproton capture into well-defined states through a resonant process which involves simultaneous electron excitation. In the present work, we give some theoretical estimations of the feasibility of that process. It appears that the exotic dielectronic-like process of resonant anti-proton capture in highly charged ions does not seem to be completely out of reach

  3. Two photon laser spectroscopy of antiprotonic helium atoms at CERN’s AD

    CERN Document Server

    Hori, M

    2014-01-01

    The ASACUSA collaboration of CERN has carried out two-photon laser spectroscopy of antiprotonic helium atoms using counter-propagating ultraviolet laser beams. This excited some non-linear transitions of the antiproton at the wavelengths λ = 139.8–197.0 nm, in a way that reduced the thermal Doppler broadening of the observed resonances. The resulting narrow spectral lines allowed the measurement of three transition frequencies with fractional precisions of 2.3–5 parts in 109. By comparing these values with three-body QED calculations, the antiproton-to-electron mass ratio was derived as 1836.1526736(23). We briefly review these results.

  4. Survey and alignment of the Fermilab recycler antiproton storage ring

    International Nuclear Information System (INIS)

    Arics, Babatunde O.O.

    1999-01-01

    In June of 1999 Fermilab commissioned a newly constructed antiproton storage ring, the 'Recycler Ring', in the Main Injector tunnel directly above the Main Injector beamline. The Recycler Ring is a fixed 8 GeV kinetic energy storage ring and is constructed of strontium ferrite permanent magnets. The 3319.4-meter-circumference Recycler Ring consists of 344 gradient magnets and 100 quadrupoles all of which are permanent magnets. This paper discusses the methods employed to survey and align these permanent magnets within the Recycler Ring with the specified accuracy. The Laser Tracker was the major instrument used for the final magnet alignment. The magnets were aligned along the Recycler Ring with a relative accuracy of ±0.25 mm. (author)

  5. Exploring antihyperons potentials in nuclei by antiproton-nucleon reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Lorente, Alicia [Helmholtz Institut Mainz (Germany); Collaboration: PANDA-Collaboration

    2015-07-01

    The exclusive production of hyperon-Antihyperon pairs close to their production threshold in antiproton-nucleus collisions offers a unique and hitherto unexplored opportunity to study the behaviour of Antihyperons in nuclei. For the first time we analyse these reactions in a microscopic transport model using the Giessen Boltzmann-Uehling-Uhlenbeck Transportmodel (GiBUU). We find a substantial sensitivity of transverse momentum correlations of coincident AntiLambda-Lambda-pairs to the assumed depth of the AntiLambda potential. Rather than diminishing this effect, secondary scattering effects which are more pronounced at deeper AntiLambda potentials enhance this sensitivity. Because of the high cross section for this process and the simplicity of this method our results pave the way for experimental studies at the FAIR facility.

  6. Light quark spectroscopy at the Fermilab antiproton accumulator

    International Nuclear Information System (INIS)

    Armstrong, T.; Bettoni, D.; Bharadwaj, V.; Biino, C.; Borreani, G.; Broemmelsiek, D.; Buzzo, A.; Calabrese, R.; Ceccucci, A.; Cester, R.; Church, M.; Dalpiaz, P.F.; Dibenedetto, R.; Dimitroyannis, D.; Fabbri, M.G.; Fast, J.; Gianoli, A.; Ginsburg, C.; Gollwitzer, K.; Hahn, A.; Hasan, M.A.; Hsueh, S.; Lewis, R.; Luppi, E.; Macri, M.; Majewska, A.; Mandelkern, M.; Marchetto, F.; Marinelli, M.; Marques, J.; Marsh, W.; Martini, M.; Masuzawa, M.; Menichetti, E.; Migliori, A.; Mussa, R.; Pallavicini, M.; Palestini, S.; Pastrone, N.; Patrignani, C.; Peoples, J. Jr.; Pesando, L.; Petrucci, F.; Pia, M.G.; Pordes, S.; Rapidis, P.; Ray, R.; Reid, J.; Rinaudo, G.; Roccuzzo, B.; Rosen, J.L.; Santroni, A.; Sarmiento, M.; Savrie, M.; Scalisi, A.; Schultz, J.; Seth, K.K.; Smith, A.; Smith, G.A.; Sozzi, M.; Trokenheim, S.; Weber, M.; Werkema, S.; Zhang, Y.; Zhao, J.L.; Zioulas, G.

    1993-01-01

    Fermilab-experiment E-760 has confirmed the f 2 (1520) state in the 3π 0 final state in antiproton-proton annihilations in-flight (∼3.0 to 3.6 GeV c.m. energy), seen previously by Crystal Barrel and other groups at CERN at rest. The f 2 (1520) is also seen in its 2π 0 decay mode in the 2π 0 η channel and 2η decay mode in the π 0 2η channel. There are indications of this state in the 3η decay channel. The invariant mass spectrum is rich in states near 2 GeV, and amplitude and spin/parity analysis of the Dalitz plot is in progress in this mass region. (orig.)

  7. Proton-Antiproton Annihilation into Neutral Strange Mesons

    Science.gov (United States)

    Ritter, J.; Bertolotto, L.; Buzzo, A.; Debevec, P.; Drijard, D.; Easo, S.; Eisenstein, R. A.; Evangelista, C.; Eyrich, W.; Fearnley, T.; Ferro-Luzzi, M.; Fischer, H.; Franz, J.; Geyer, R.; Hamann, N. H.; Harris, P. G.; Hertzog, D. W.; Hughes, S. A.; Johansson, A.; Johansson, T.; Jones, R. T.; Kilian, K.; Kirsebom, K.; Klett, A.; Korsmo, H.; Lo Vetere, M.; Macri, M.; Marinelli, M.; Moosburger, M.; Mouëllic, B.; Oelert, W.; Ohlsson, S.; Palano, A.; Passaggio, S.; Perreau, J.-M.; Pia, M. G.; Pomp, S.; Price, M.; Reimer, P. E.; Ritter, J.; Robutti, E.; Röhrich, K.; Rook, M.; Sefzick, T.; Rössle, E.; Santroni, A.; Schmitt, H.; Steinkamp, O.; Stinzing, F.; Stugu, B.; Tayloe, R.; Tscheulin, M.; Urban, H. J.; Wirth, H.; Zipse, H.; Jetset (Ps202) Collaboration:

    1997-06-01

    In a search for gluonic hadrons, the formation channels p¯p → K sK s, p¯p → ηη, p¯p → π 0η and p¯p → π 0π 0 were studied in the mass range from 2.1 to 2.4 GeV using the Jetset (PS202) detector and an internal molecular hydrogen cluster jet target installed in the Low Energy Antiproton Ring (LEAR) at CERN. Cross sections for p¯p → K sK s have been obtained and limits are set on the non-observation of the ξ(2230). Conversely, we find evidence for a narrow signal in a preliminary analysis of our p¯p → ηη data consistent with a narrow ξ(2230).

  8. Proton-antiproton annihilation into neutral strange mesons

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, J. [Illinois Univ., Urbana (United States). Loomis Lab.; Bertolotto, L.; Buzzo, A.; Debevec, P.; Drijard, D.; Easo, S.; Eisenstein, R.A.; Evangelista, C.; Eyrich, W.; Fearnley, T.; Ferro-Luzzi, M.; Fischer, H.; Franz, J.; Geyer, R.; Hamann, N.H.; Harris, P.G.; Hertzog, D.W.; Hughes, S.A.; Johansson, A.; Johansson, T.; Jones, R.T.; Kilian, K.; Kirsebom, K.; Klett, A.; Korsmo, H.; Lo Vetere, M.; Macri, M.; Marinelli, M.; Moosburger, M.; Mouellic, B.; Oelert, W.; Ohlsson, S.; Palano, A.; Passaggio, S.; Perreau, J.-M.; Pia, M.G.; Pomp, S.; Price, M.; Reimer, P.E.; Robutti, E.; Roehrich, K.; Rook, M.; Sefzick, T.; Roessle, E.; Santroni, A.; Schmitt, H.; Steinkamp, O.; Stinzing, F.; Stugu, B.; Tayloe, R.; Tscheulin, M.; Urban, H.J.; Wirth, H.; Zipse, H.; JETSET Collaboration

    1997-06-01

    In a search for gluonic hadrons, the formation channels pp{yields}K{sub S}K{sub S}, pp{yields}{eta}{eta}, pp{yields}{pi}{sup 0}{eta} and pp{yields}{pi}{sup 0}{pi}{sup 0} were studied in the mass range from 2.1 to 2.4 GeV using the Jetset (PS202) detector and an internal molecular hydrogen cluster jet target installed in the Low Energy Antiproton Ring (LEAR) at CERN. Cross sections for pp{yields}K{sub S}K{sub S} have been obtained and limits are set on the non-observation of the {xi}(2230). Conversely, we find evidence for a narrow signal in a preliminary analysis of our pp{yields}{eta}{eta} d ata consistent with a narrow {xi}(2230). (orig.).

  9. Proton-antiproton annihilation into neutral strange mesons

    International Nuclear Information System (INIS)

    Ritter, J.; Bertolotto, L.; Buzzo, A.; Debevec, P.; Drijard, D.; Easo, S.; Eisenstein, R.A.; Evangelista, C.; Eyrich, W.; Fearnley, T.; Ferro-Luzzi, M.; Fischer, H.; Franz, J.; Geyer, R.; Hamann, N.H.; Harris, P.G.; Hertzog, D.W.; Hughes, S.A.; Johansson, A.; Johansson, T.; Jones, R.T.; Kilian, K.; Kirsebom, K.; Klett, A.; Korsmo, H.; Lo Vetere, M.; Macri, M.; Marinelli, M.; Moosburger, M.; Mouellic, B.; Oelert, W.; Ohlsson, S.; Palano, A.; Passaggio, S.; Perreau, J.-M.; Pia, M.G.; Pomp, S.; Price, M.; Reimer, P.E.; Robutti, E.; Roehrich, K.; Rook, M.; Sefzick, T.; Roessle, E.; Santroni, A.; Schmitt, H.; Steinkamp, O.; Stinzing, F.; Stugu, B.; Tayloe, R.; Tscheulin, M.; Urban, H.J.; Wirth, H.; Zipse, H.

    1997-01-01

    In a search for gluonic hadrons, the formation channels pp→K S K S , pp→ηη, pp→π 0 η and pp→π 0 π 0 were studied in the mass range from 2.1 to 2.4 GeV using the Jetset (PS202) detector and an internal molecular hydrogen cluster jet target installed in the Low Energy Antiproton Ring (LEAR) at CERN. Cross sections for pp→K S K S have been obtained and limits are set on the non-observation of the ξ(2230). Conversely, we find evidence for a narrow signal in a preliminary analysis of our pp→ηη d ata consistent with a narrow ξ(2230). (orig.)

  10. Radiation protection activities around the CERN accelerators

    International Nuclear Information System (INIS)

    Silari, M.

    1998-01-01

    In 1997 the physics programme of the SPS and LEP was seriously affected by a fire in one of the surface building of the SPS; the incident caused a delay in the LEP start-up, an interruption of several weeks in the SPS fixed-target programme, and the cancellation of the lead ion run for 1997. The consequences for the experiments were, nevertheless, kept to a minimum thanks to the excellent performance of the accelerators. The neutrino experiments even accumulated a record intensity. Experiments at the ISOLDE facility benefited from 315 shifts instead of 200 as originally scheduled, and new experiments started measuring the properties of unstable elements which play a crucial role in the stars. LEP also reached record energy and luminosity in 1997. Measurements of synchrotron radiation in the LEP tunnel were repeated at the new energy value of 92 GeV, to comply with the demands of the INB procedure. Following the end of operation of ACOL and LEAR in December 1996, decommissioning of the Antiproton Accumulator and transformation of the Antiproton Collector into the Antiproton Decelerator started. Experiments in the South Hall were dismantled during the year and the hall will be used partly as a storage area for radioactive components and partly as a test area

  11. Techniques for increasing the reliability of accelerator control system electronics

    International Nuclear Information System (INIS)

    Utterback, J.

    1993-09-01

    As the physical size of modern accelerators becomes larger and larger, the number of required control system circuit boards increases, and the probability of one of those circuit boards failing while in service also increases. In order to do physics, the experimenters need the accelerator to provide beam reliably with as little down time as possible. With the advent of colliding beams physics, reliability becomes even more important due to the fact that a control system failure can cause the loss of painstakingly produced antiprotons. These facts prove the importance of keeping reliability in mind when designing and maintaining accelerator control system electronics

  12. Approximation of antiproton spectra in pp- and pA collisions

    International Nuclear Information System (INIS)

    Demidova, E.V.; Sibirtsev, A.A.

    1989-01-01

    Phenomenological expressions, describing the inclusive cross sections of antiproton production in proton-proton and proton-nucleus collisions in 10-100 GeV energy range were obtained. 12 refs.; 10 figs

  13. Slowing down of 100 keV antiprotons in Al foils

    Science.gov (United States)

    Nordlund, K.

    2018-03-01

    Using energy degrading foils to slow down antiprotons is of interest for producing antihydrogen atoms. I consider here the slowing down of 100 keV antiprotons, that will be produced in the ELENA storage ring under construction at CERN, to energies below 10 keV. At these low energies, they are suitable for efficient antihydrogen production. I simulate the antihydrogen motion and slowing down in Al foils using a recently developed molecular dynamics approach. The results show that the optimal Al foil thickness for slowing down the antiprotons to below 5 keV is 910 nm, and to below 10 keV is 840 nm. Also the lateral spreading of the transmitted antiprotons is reported and the uncertainties discussed.

  14. Extra Low Energy Antiproton ring ELENA : from the conception to the implementation phase

    CERN Document Server

    Bartmann, W; Breuker, H; Butin, F; Carli, C; Eriksson, T; Maury, S; Pasinelli, S; Tranquille, G; Oelert, W

    2014-01-01

    The Extra Low Energy Antiproton ring (ELENA) is a CERN project aiming at constructing a small 30 m circumference synchrotron to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. The ELENA design is now well advanced and the project is moving to the implementation phase. Component design and construction are taking place at present for installation foreseen during the second half of 2015 and beginning of 2016 followed by ring commissioning until the end of 2016. New electrostatic transfer lines to the experiments will be installed and commissioned during the first half of 2017 followed by the first physics operation with ELENA. Basic limitations like Intra Beam Scattering limiting the emittances obtained under electron ...

  15. High-precision spectroscopy of antiprotonic helium-first results from the AD of CERN

    CERN Document Server

    Widmann, E

    2001-01-01

    New results of the laser and microwave spectroscopy of antiprotonic helium "atomcules" obtained in the first year of operation of the Antiproton Decelerator (AD) facility of CERN are presented. They include the discovery of three new resonant transitions and the determination of the zero-density wavelength of six transitions with an accuracy of 130 ppb in the best case. Auger rates of those states were also determined, and two of them were found to be several orders of magnitude larger than expected from a simple estimate based on the multipolarity Delta l, i.e., the jump in angular momentum required for the antiproton to reach the next lower-lying state of ionized pHe /sup ++/. Furthermore, a first signal of a two-laser microwave triple resonance to measure the hyperfine splitting in antiprotonic helium was observed. (39 refs).

  16. Comprehensive Study for an Optimized Redesign of the CERN's Antiproton Decelerator Target

    CERN Document Server

    AUTHOR|(CDS)2089345; Perillo-Marcone, Antonio; Muñoz-Cobo, Jose-Luis

    2018-04-16

    The Antiproton Decelerator Target (AD-Target) is a unique device responsible for the production of antiprotons at the European Organization for Nuclear Research (CERN). During operation, intense 26 GeV energy proton beams are impacted into its core, made of a 3 mm diameter rod of a high density material such as iridium, creating secondary particles -including antiprotons- from the nuclear reactions induced in its interior. This thesis delves into the characteristics of antiproton production and in particular in the mechanical response of the target core material, which is exposed to a rise of temperature of approximate 2000 degrees Celsius in less than 0.5 microseconds each time is impacted by the primary proton beam. A coupled numerical-experimental approach has been applied for this purpose. Specific computational tools, called hydrocodes, have been used for simulating the extreme dynamic response taking place in the target core and its containing graphite matrix, indicating their potential damage and frag...

  17. Symposium on Highlights from 14 years of LEAR Physics : "Antiproton Mass" by G. Gabrielse

    CERN Multimedia

    1998-01-01

    Symposium on Highlights from 14 years Physics hold at CERN, commemorating the closure of LEAR and giving a topical review of the impact of experiments with low energy antiprotons in their respective fields

  18. Symposium on Highlights from 14 years of LEAR Physics: "Light Antiprotonic Atoms" by R. Hayano

    CERN Multimedia

    1998-01-01

    Symposium on Highlights from 14 years of LEAR Physics hold at CERN, commemorating the closure of LEAR and giving a topical review of the impact of experiments with low energy antiprotons in their respective fields

  19. On the Utility of Antiprotons as Drivers for Inertial Confinement Fusion

    International Nuclear Information System (INIS)

    Perkins, L J; Orth, C D; Tabak, M

    2003-01-01

    By contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90MJ/(micro)g and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons ((bar p)) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both (bar p)-driven ablative compression and (bar p)-driven fast ignition, in association with 0-D and 1-D target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic energy of the injected antiproton beam required to penetrate to the desired annihilation point is always small relative to the deposited annihilation energy. We show that heavy metal seeding of the fuel and/or ablator is required to optimize local deposition of annihilation energy and determine that a minimum of ∼3x10 15 injected antiprotons will be required to achieve high yield (several hundred megajoules) in any target configuration. Target gains - i.e., fusion yields divided by the available p - (bar p) annihilation energy from the injected antiprotons (1.88GeV/(bar p)) - range from ∼3 for volumetric ignition targets to ∼600 for fast ignition targets. Antiproton-driven ICF is a speculative concept, and the handling of antiprotons and their required injection precision - temporally and spatially - will present significant technical challenges. The storage and manipulation of low-energy antiprotons, particularly in the form of antihydrogen, is a science in its infancy and a large scale-up of antiproton production over present supply methods would be

  20. On the utility of antiprotons as drivers for inertial confinement fusion

    International Nuclear Information System (INIS)

    Perkins, L. John; Orth, Charles D.; Tabak, Max

    2004-01-01

    In contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90 MJ μg -1 and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons (p-bar) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both p-bar-driven ablative compression and p-bar-driven fast ignition, in association with zero- and one-dimensional target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic energy of the injected antiproton beam required to penetrate to the desired annihilation point is always small relative to the deposited annihilation energy. We show that heavy metal seeding of the fuel and/or ablator is required to optimize local deposition of annihilation energy and determine that a minimum of ∼3 x 10 15 injected antiprotons will be required to achieve high yield (several hundred megajoules) in any target configuration. Target gains-i.e. fusion yields divided by the available p-p-bar annihilation energy from the injected antiprotons (1.88 GeV/p-bar)-range from ∼3 for volumetric ignition targets to ∼600 for fast ignition targets. Antiproton-driven ICF is a speculative concept, and the handling of antiprotons and their required injection precision - temporally and spatially - will present significant technical challenges. The storage and manipulation of low-energy antiprotons, particularly in the form of antihydrogen, is a science in its infancy and a large scale-up of antiproton production over present supply methods would be

  1. On the Utility of Antiprotons as Drivers for Inertial Confinement Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, L J; Orth, C D; Tabak, M

    2003-10-20

    By contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90MJ/{micro}g and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons ({bar p}) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both {bar p}-driven ablative compression and {bar p}-driven fast ignition, in association with 0-D and 1-D target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic energy of the injected antiproton beam required to penetrate to the desired annihilation point is always small relative to the deposited annihilation energy. We show that heavy metal seeding of the fuel and/or ablator is required to optimize local deposition of annihilation energy and determine that a minimum of {approx}3x10{sup 15} injected antiprotons will be required to achieve high yield (several hundred megajoules) in any target configuration. Target gains - i.e., fusion yields divided by the available p - {bar p} annihilation energy from the injected antiprotons (1.88GeV/{bar p}) - range from {approx}3 for volumetric ignition targets to {approx}600 for fast ignition targets. Antiproton-driven ICF is a speculative concept, and the handling of antiprotons and their required injection precision - temporally and spatially - will present significant technical challenges. The storage and manipulation of low-energy antiprotons, particularly in the form of antihydrogen, is a science in its infancy and a large scale-up of antiproton production over present supply

  2. Studies of accelerated compact toruses

    International Nuclear Information System (INIS)

    Hartman, C.W.; Eddleman, J.; Hammer, J.H.

    1983-01-01

    In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  3. Acceleration of polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1998-01-01

    The acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. Full Siberian snakes are being developed for RHIC to make the acceleration of polarized protons to 250 GeV possible. A similar scheme is being studied for the 800 GeV HERA proton accelerator

  4. Study of X-Ray and $\\gamma$-Ray Spectra from Antiprotonic Atoms at the Slowly Extracted Antiproton Beam of LEAR

    CERN Multimedia

    2002-01-01

    This experiment will study the X-ray spectra of antiprotonic atoms and the $\\gamma$ spectra of residual nuclei after the antiproton absorption. We intend to begin with measurements on selected isotopically pure targets. Strong interaction effects, the antiproton absorption and the atomic cascade are analysed through the measurement of energies, lineshapes, relative and absolute intensities of all observable lines. The experiments are continued to determine st in resolved fine structure levels and in different isotopes of the same element. Coincidence techniques may be applied. All components of the experimental set-up are already existing from previous experiments and we could begin the measurements with any slowly extracted beam of low energy at LEAR.

  5. Problems in the phenomenological analysis of cross-section difference sigmasub(pp)-sigmasub(pn) and sigmasub(antiproton proton)-sigmasub(antiproton neutron)

    International Nuclear Information System (INIS)

    Bouquet, A.; Diu, B.; Leader, E.; Nicolescu, B.

    1976-01-01

    It is shown that uncertainties in the exact value of the Glauber correction make it virtually impossible to deduce any significant conclusions about the asymptotic behaviour of the sigmasub(pp)-sigmasub(pn) and sigma sub(antiproton proton)-sigmasub(antiproton neutron) cross-section differences, if only data on pp, pd, antiproton proton and antiprotond collisions are used. Nevertheless it can be demonstrated that the imaginary part of the rho exchange amplitude is basically Regge behaved. If, on the other hand, neutron beam data on sigmasub(np) are used, it can be shown that the imaginary part of the A 2 exchange amplitude contains a non-Regge, growing, asymptotic component, reminiscent of that found in the I=) symmetric amplitude

  6. Measurement of the antiproton-nucleus annihilation cross-section at low energy

    Science.gov (United States)

    Aghai-Khozani, H.; Bianconi, A.; Corradini, M.; Hayano, R.; Hori, M.; Leali, M.; Lodi Rizzini, E.; Mascagna, V.; Murakami, Y.; Prest, M.; Vallazza, E.; Venturelli, L.; Yamada, H.

    2018-02-01

    Systematic measurements of the annihilation cross sections of low energy antinucleons were performed at CERN in the 80's and 90's. However the antiproton data on medium-heavy and heavy nuclear targets are scarce. The ASACUSA Collaboration at CERN has measured the antiproton annihilation cross section on carbon at 5.3 MeV: the value is (1.73 ± 0.25) barn. The result is compared with the antineutron experimental data and with the theoretical previsions.

  7. Antiproton production in nucleon-nucleus and nucleus-nucleus collisions at the CERN-SPS

    International Nuclear Information System (INIS)

    Kadija, K.; Schmitz, N.; Seyboth, P.

    1996-01-01

    A model for antiproton production in nucleon-nucleus and nucleus-nucleus collisions at 200 GeV per nucleon, based on the wounded nucleon model is developed. The predictions are compared to published nucleon-nucleus and sulphur-nucleus data. The results suggest the presence of similar antiproton production processes in nucleon-nucleus and nucleus-nucleus collisions near midrapidity. (orig.)

  8. Primary populations of metastable antiprotonic $^{4}He$ and $^{3}He$ atoms

    CERN Document Server

    Hori, Masaki; Hayano, R S; Ishikawa, T; Sakuguchi, J; Tasaki, T; Widmann, E; Yamaguchi, H; Torii, H A; Juhász, B; Horváth, D; Yamazaki, T

    2002-01-01

    Initial population distributions of metastable antiprotonic **4He and **3He atoms over principal and angular momentum quantum numbers were investigated using laser spectroscopy. The total fractions of antiprotons captured into the metastable states of the atoms were deduced. Cascade calculations were performed using the measure populations to reproduce the delayed annihilation time spectrum. Results showed agreement between the simulated and measured spectra. (Edited abstract) 30 Refs.

  9. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jørgensen, L V; Kerrigan, S J; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; van der Werf, D P; Yamazaki, Y

    2009-01-01

    A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.

  10. Examination of X-ray spectra from the antiprotonic helium isotopes 3He and 4He

    International Nuclear Information System (INIS)

    Schneider, M.

    1987-05-01

    Using the high intensity antiprotonic LEAR beam at CERN (Geneva), several measurements were done to investigate the X-ray spectra of the antiprotonic Helium isotopes 3 He and 4 He. For the first time antiprotons were stopped in gases at low pressures (600, 375, 72 and 36 mbar), which permitted observations on nearly isolated atoms. A newly developed method for stopping the antiprotons in gases by means of a focusing cyclotron field surrounding the target gas was used. The field was supplied by a superconducting magnet ('cyclotron trap'). The antiprotons were tangentially injected into the cyclotron field, where they slowed down by ionising the target gas. The inhomogeneous magnetic field guided the antiprotons in spiral orbits to the magnetic center. Thus, even at low pressures a very small stopping volume could be achieved. To detect the X-rays different Si(Li)- and Ge-semiconductor detectors were used, some of which were furnished with 'guard-rings'. They were used to investigate the effects of the strong interaction between the antiproton and the nucleus in the (3d → 2p) transition in both isotopes. The analyzis of this transition permitted directly the determination of the shift and width of the 2p-level. The width of the 3d-level could be determined only indirectly using an intensity balance. The utilization of gases with different pressures permitted investigations of the pressure dependence of the antiprotonic deexcitation process. The results for the widths and shifts were compared with earlier measurements and theoretical predictions. The theory agrees only partly with the measurements. The evaluation of a complex scattering length using an optical model contradicts some of the results of calculations. (orig.) [de

  11. Ion optics for accelerators

    International Nuclear Information System (INIS)

    Enge, H.A.

    1974-01-01

    A review is given of ion-optic devices used in particle accelerators, including electrostatic lenses, magnetic quadrupoles, and deflecting magnets. Tube focusing in dc accelerators is also treated, and a novel scheme for shaping the electrodes to produce strong focusing is described. The concepts of emittance (phase space) and emittance conservation are briefly discussed. Chromatic and spatial aberrations are introduced, and it is shown how they can be calculated and sometimes substantially reduced. Some examples are given

  12. Accelerator Preparations for Muon Physics Experiments at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M.J.; /Fermilab

    2009-10-01

    The use of existing Fermilab facilities to provide beams for two muon experiments - the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment - is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. Operating scenarios being investigated and anticipated accelerator improvements or reconfigurations will be presented.

  13. Interaction of antiprotons with Rb atoms and a comparison of antiproton stopping powers of the atoms H, Li, Na, K, and Rb

    DEFF Research Database (Denmark)

    Lühr, Armin Christian; Fischer, Nicolas; Saenz, Alejandro

    2009-01-01

    Ionization and excitation cross sections as well as electron-energy spectra and stopping powers of the alkali metal atoms Li, Na, K, and Rb colliding with antiprotons were calculated using a time-dependent channel-coupling approach. An impact-energy range from 0.25 to 4000 keV was considered....... The target atoms are treated as effective one-electron systems using a model potential. The results are compared with calculated cross sections for antiproton-hydrogen atom collisions....

  14. Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

    International Nuclear Information System (INIS)

    Sako, H.; Ahle, L.; Akiba, Y.

    1997-12-01

    Antiproton production in heavy ion collisions reflects subtle interplay between initial production and absorption by nucleons. Because the AGS energies (10--20 A·GeV/c) are close to the antiproton production threshold, antiproton may be sensitive to cooperative processes such as QGP and hadronic multi-step processes. On the other hand, antiproton has been proposed as a probe of baryon density due to large N anti N annihilation cross sections. Cascade models predict the maximum baryon density reaches about 10 times the normal nucleus density in central Au+Au collisions, where the strong antiproton absorption is expected. In this paper, the authors show systematic studies of antiproton production from p+A to Au+Au collisions

  15. Production of light elements by cascades from energetic antiprotons in the early Universe and problem of nuclear cosmoarcheology

    International Nuclear Information System (INIS)

    Levitan, Yu.L.; Sobol', I.M.; Khlopov, M.Yu.; Chechetkin, V.M.

    1988-01-01

    The mathematical model of the process of light-element (D and 3 He) production due to disintegration of 4 He nuclei, induced by nonequilibrium processes of production of energetic antiprotons in the early Universe is suggested. Numerical calculations show that formation of the nucleon cascade induced by antiproton slowing down increases the D and 3 He yield due to the growth of probability of disintegration of several 4 He nuclei by a single antiproton and due to disintegration of such nuclei by cascade protons. Restraints on the concentration of possible sources of energetic antiprotons in the early Universe are strengthened respectively

  16. On the determination of the energy of antiprotonic X-rays by critical absorption and the theoretical discussion of results

    International Nuclear Information System (INIS)

    Joedicke, B.

    1985-06-01

    This work examines the possibility of measuring the energies of antiprotonic X-rays by critical absorption. Scanning the periodic table many isotopes are found where the energy of an antiprotonic X-ray coincides with a K-absorption-edge of a chemical element. Those candidates where the energy can be measured with high accuracy are discussed here. Also a computer program which calculates transition energies of antiprotonic atoms is examined. Necessary additions are listed and the corrections are shown. In combination with this program the candidates are the basis for a precise determination of the mass of the antiproton. (orig.) [de

  17. Enhanced antiproton production in Pb(160 A GeV)+Pb reactions evidence for quark gluon matter?

    CERN Document Server

    Bleicher, M; Bass, S A; Soff, S; Stöcker, H

    2000-01-01

    The centrality dependence of the antiproton per participant ratio is studied in Pb(160 AGeV)+Pb reactions. Antiproton production in collisions of heavy nuclei at the CERN/SPS seems considerably enhanced as compared to conventional hadronic physics, given by the antiproton production rates in $pp$ and antiproton annihilation in $\\bar{p}p$ reactions. This enhancement is consistent with the observation of strong in-medium effects in other hadronic observables and may be an indication of partial restoration of chiral symmetry.

  18. Additive operator-difference schemes splitting schemes

    CERN Document Server

    Vabishchevich, Petr N

    2013-01-01

    Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

  19. Commissioning of the ECR ion source of the high intensity proton injector of the Facility for Antiproton and Ion Research (FAIR)

    Science.gov (United States)

    Tuske, O.; Chauvin, N.; Delferriere, O.; Fils, J.; Gauthier, Y.

    2018-05-01

    The CEA at Saclay is in charge of developing and building the ion source and the low energy line of the proton linac of the FAIR (Facility for Antiproton and Ion Research) accelerator complex located at GSI (Darmstadt) in Germany. The FAIR facility will deliver stable and rare isotope beams covering a huge range of intensities and beam energies for experiments in the fields of atomic physics, plasma physics, nuclear physics, hadron physics, nuclear matter physics, material physics, and biophysics. A significant part of the experimental program at FAIR is dedicated to antiproton physics that requires an ultimate number 7 × 1010 cooled pbar/h. The high-intensity proton beam that is necessary for antiproton production will be delivered by a dedicated 75 mA/70 MeV proton linac. A 2.45 GHz microwave ion source will deliver a 100 mA H+ beam pulsed at 4 Hz with an energy of 95 keV. A 2 solenoids low energy beam transport line allows the injection of the proton beam into the radio frequency quadrupole (RFQ) within an acceptance of 0.3π mm mrad (norm. rms). An electrostatic chopper system located between the second solenoid and the RFQ is used to cut the beam macro-pulse from the source to inject 36 μs long beam pulses into the RFQ. At present time, a Ladder-RFQ is under construction at the University of Frankfurt. This article reports the first beam measurements obtained since mid of 2016. Proton beams have been extracted from the ECR ion source and analyzed just after the extraction column on a dedicated diagnostic chamber. Emittance measurements as well as extracted current and species proportion analysis have been performed in different configurations of ion source parameters, such as magnetic field profile, radio frequency power, gas injection, and puller electrode voltage.

  20. Plasma based accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  1. A practical guide to modern high energy particle accelerators

    International Nuclear Information System (INIS)

    Holmes, S.D.

    1987-10-01

    The purpose of these lectures is to convey an understanding of how particle accelerators work and why they look the way they do. The approach taken is physically intuitive rather than mathematically rigorous. The emphasis is on the description of proton circular accelerators and colliders. Linear accelerators are mentioned only in passing as sources of protons for higher energy rings. Electron accelerators/storage rings and antiproton sources are discussed only by way of brief descriptions of the features which distinguish them from proton accelerators. The basics of how generic accelerators work are discussed, focusing on descriptions of what sets the overall scale, single particle dynamics and stability, and descriptions of the phase space of the particle beam, the information thus presented is then used to go through the exercise of designing a Superconducting Super Collider

  2. Constraining pre big-bang-nucleosynthesis expansion using cosmic antiprotons

    International Nuclear Information System (INIS)

    Schelke, M.; Catena, R.; Fornengo, N.; Masiero, A.; Pietroni, M.

    2006-06-01

    A host of dark energy models and non-standard cosmologies predict an enhanced Hubble rate in the early Universe: perfectly viable models, which satisfy Big Bang Nucleosynthesis (BBN), cosmic microwave background and general relativity tests, may nevertheless lead to enhancements of the Hubble rate up to many orders of magnitude. In this paper we show that strong bounds on the pre-BBN evolution of the Universe may be derived, under the assumption that dark matter is a thermal relic, by combining the dark matter relic density bound with constraints coming from the production of cosmic-ray antiprotons by dark matter annihilation in the Galaxy. The limits we derive can be sizable and apply to the Hubble rate around the temperature of dark matter decoupling. For dark matter masses lighter than 100 GeV, the bound on the Hubble-rate enhancement ranges from a factor of a few to a factor of 30, depending on the actual cosmological model, while for a mass of 500 GeV the bound falls in the range 50-500. Uncertainties in the derivation of the bounds and situations where the bounds become looser are discussed. We finally discuss how these limits apply to some specific realizations of non-standard cosmologies: a scalar-tensor gravity model, kination models and a Randall-Sundrum D-brane model. (Orig.)

  3. Constraining pre big-bang-nucleosynthesis expansion using cosmic antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Schelke, M. [Istituto Nazionale di Fisica Nucleare, Torino (Italy); Catena, R. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Fornengo, N. [Torino Univ. (Italy). Dipt. di Fisica Teorica]|[Istituto Nazionale di Fisica Nucleare, Torino (Italy); Masiero, A. [Pavoa Univ. (Italy). Dipt. di Fisica]|[Istituto Nazionale di Fisica Nucleare, Padova (Italy); Pietroni, M. [Istituto Nazionale di Fisica Nucleare, Padova (Italy)

    2006-06-15

    A host of dark energy models and non-standard cosmologies predict an enhanced Hubble rate in the early Universe: perfectly viable models, which satisfy Big Bang Nucleosynthesis (BBN), cosmic microwave background and general relativity tests, may nevertheless lead to enhancements of the Hubble rate up to many orders of magnitude. In this paper we show that strong bounds on the pre-BBN evolution of the Universe may be derived, under the assumption that dark matter is a thermal relic, by combining the dark matter relic density bound with constraints coming from the production of cosmic-ray antiprotons by dark matter annihilation in the Galaxy. The limits we derive can be sizable and apply to the Hubble rate around the temperature of dark matter decoupling. For dark matter masses lighter than 100 GeV, the bound on the Hubble-rate enhancement ranges from a factor of a few to a factor of 30, depending on the actual cosmological model, while for a mass of 500 GeV the bound falls in the range 50-500. Uncertainties in the derivation of the bounds and situations where the bounds become looser are discussed. We finally discuss how these limits apply to some specific realizations of non-standard cosmologies: a scalar-tensor gravity model, kination models and a Randall-Sundrum D-brane model. (Orig.)

  4. The magnetic moments of the proton and the antiproton

    CERN Document Server

    Ulmer, S.; Blaum, K.; Braeuninger, S.; Franke, K.; Kracke, H.; Leiteritz, C.; Matsuda, Y.; Nagahama, H.; Ospelkaus, C.; Rodegheri, C.C.; Quint, W.; Schneider, G.; Smorra, C.; Van Gorp, S.; Walz, J.; Yamazaki, Y.

    2014-01-01

    Recent exciting progress in the preparation and manipulation of the motional quantum states of a single trapped proton enabled the first direct detection of the particle's spin state. Based on this success the proton magnetic moment $\\mu_p$ was measured with ppm precision in a Penning trap with a superimposed magnetic field inhomogeneity. An improvement by an additional factor of 1000 in precision is possible by application of the so-called double Penning trap technique. In a recent paper we reported the first demonstration of this method with a single trapped proton, which is a major step towards the first direct high-precision measurement of $\\mu_p$. The techniques required for the proton can be directly applied to measure the antiproton magnetic moment $\\mu_{\\bar{p}}$. An improvement in precision of $\\mu_{\\bar{p}}$ by more than three orders of magnitude becomes possible, which will provide one of the most sensitive tests of CPT invariance. To achieve this research goal we are currently setting up the Baryo...

  5. Multilepton production in neutrino interactions and proton-antiproton collisions

    International Nuclear Information System (INIS)

    Valenzuela, G.N.

    1985-01-01

    In part I, we consider the class of events containing 2 or 3 leptons in (anti-neutrino deep inelastic scattering and in proton-antiproton collisions. Understanding the characteristics and rate of production of this type of event has often proven to be a theoretical challenge. We show that a cluster model involving associated-charm production not only accounts for certain dimuon events, but also affords better agreement with experiment regarding trimuons produced in neutrino interactions. We also investigate correlations between D-meson and dimuon production in p anti p collisions in the context of a cluster model which includes the possibility of finding b anti b pairs in jets. Part II consists of a study of radiation zeros in the reaction p anti p → l anti nuγX. It has been proposed that the radiation zero phenomenon could be observed in processes involving the radiative decay of the W-boson. These processes might allow the measurement of the W anomalous magnetic moment. We calculate the effect on this measurement of the decay width and the non-zero transverse momentum of the W. We find that although the radiation zero is filled in to some extent, it might still be possible to estimate the magnetic moment of the W in future experiments

  6. Studying the potential of antihyperons in nuclei with antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Lorente, Alicia; Bleser, Sebastian; Steinen, Marcell [Helmholtz-Institut Mainz (Germany); Pochodzalla, Josef [Institute for nuclear physics, JGU Mainz (Germany); Collaboration: PANDA-Collaboration

    2014-07-01

    The interaction between an antibaryon and a nucleus may shed light on the short range antibaryon-baryon force in a unique way. However, because of the deep imaginary part of the nuclear potential of antibaryons, the physics of antihyperons in nuclei is hitherto an uncharted territory. Recently it was proposed to use transverse momentum correlations of exclusively produced antihyperon-hyperon pairs in antiproton-nucleus collisions to obtain information on the antihyperon potentials relative to that of the corresponding hyperon. In the present study we use the Giessen Boltzmann-Uehling- Uhlenbeck Transportmodell (GiBUU) to explore the production of exclusive hyperon-antihyperon pairs close to threshold. Unlike the schematic calculation, these GiBBU simulations take e.g. important rescattering effects into account. In case of anti p + {sup 20}Ne → anti ΛΛ+X we confirm a significant sensitivity of transverse momentum correlations to the nuclear potential of Λs. We also explore the feasibility of such measurements at the PANDA experiment of the international facility FAIR.

  7. Collective accelerator for electron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, R.J.

    1985-05-13

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

  8. Collective accelerator for electron colliders

    International Nuclear Information System (INIS)

    Briggs, R.J.

    1985-01-01

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch

  9. Progress in advanced accelerator concepts

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1994-08-01

    A review is given of recent progress in this field, drawing heavily upon material presented at the Workshop on Advanced Accelerator Concepts, The Abbey, June 12--18, 1994. Attention is addressed to (1) plasma based concepts, (2) photo-cathodes, (3) radio frequency sources and Two-Beam Accelerators, (4) near and far-field schemes (including collective accelerators), (5) beam handling and conditioning, and (6) exotic collider concepts (such as photon colliders and muon colliders)

  10. Direct detection of antiprotons with the Timepix3 in a new electrostatic selection beamline

    Energy Technology Data Exchange (ETDEWEB)

    Pacifico, N., E-mail: nicola.pacifico@cern.ch [Institute of Physics and Technology, University of Bergen, Allgaten 55, 5007 Bergen (Norway); Aghion, S. [Politecnico of Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); INFN Milano, via Celoria 16, 20133 Milano (Italy); Alozy, J. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Amsler, C.; Ariga, A.; Ariga, T. [Laboratory for High Energy Physics, Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern (Switzerland); Bonomi, G. [Department of Mechanical and Industrial Engineering, University of Brescia, via Branze 38, 25123 Brescia (Italy); INFN Pavia, via Bassi 6, 27100 Pavia (Italy); Bräunig, P. [Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg (Germany); Bremer, J. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Brusa, R.S. [Department of Physics, University of Trento, via Sommarive 14, 38123 Povo, Trento (Italy); TIFPA/INFN Trento, via Sommarive 14, 38123 Povo, Trento (Italy); Cabaret, L. [Laboratory Aimé Cotton, University of Paris-Sud, ENS Cachan, CNRS, University Paris-Saclay, 91405 Orsay Cedex (France); Caccia, M. [INFN Milano, via Celoria 16, 20133 Milano (Italy); Department of Science, University of Insubria, Via Valleggio 11, 22100 Como (Italy); Campbell, M. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Caravita, R. [Department of Physics, University of Genova, via Dodecaneso 33, 16146 Genova (Italy); INFN Genova, via Dodecaneso 33, 16146 Genova (Italy); Castelli, F. [INFN Milano, via Celoria 16, 20133 Milano (Italy); Department of Physics, University of Milano, via Celoria 16, 20133 Milano (Italy); Cerchiari, G. [Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg (Germany); Chlouba, K. [Czech Technical University, Prague, Brehov 7, 11519 Prague 1 (Czech Republic); and others

    2016-09-21

    We present here the first results obtained employing the Timepix3 for the detection and tagging of annihilations of low energy antiprotons. The Timepix3 is a recently developed hybrid pixel detector with advanced Time-of-Arrival and Time-over-Threshold capabilities and has the potential of allowing precise kinetic energy measurements of low energy charged particles from their time of flight. The tagging of the characteristic antiproton annihilation signature, already studied by our group, is enabled by the high spatial and energy resolution of this detector. In this study we have used a new, dedicated, energy selection beamline (GRACE). The line is symbiotic to the AEgIS experiment at the CERN Antiproton Decelerator and is dedicated to detector tests and possibly antiproton physics experiments. We show how the high resolution of the Timepix3 on the Time-of-Arrival and Time-over-Threshold information allows for a precise 3D reconstruction of the annihilation prongs. The presented results point at the potential use of the Timepix3 in antimatter-research experiments where a precise and unambiguous tagging of antiproton annihilations is required.

  11. Modeling of the Near-Earth Low-Energy Antiproton Fluxes

    Directory of Open Access Journals (Sweden)

    U. B. Jayanthi

    2011-01-01

    Full Text Available The local interstellar antiproton spectrum is simulated taking into account antineutron decay, (He,p interaction, secondary and tertiary antiproton production, and the solar modulation in the “force field” approximation. Inclusive invariant cross-sections were obtained through a Monte Carlo procedure using the Multistage Dynamical Model code simulating various processes of the particle production. The results of the simulations provided flux values of 4⋅10−3 to 10−2 and 10−2 to 1.7⋅10−2 antiprotons/(2 s sr GeV at energies of 0.2 and 1 GeV, respectively, for the solar maximum and minimum epochs. Simulated flux of the trapped antiprotons in the inner magnetosphere due to galactic cosmic ray (GCR interactions with the atmospheric constituents exceeds the galactic antiproton flux up to several orders. These simulation results considering the assumptions with the attendant limitations are in comprehensive agreement with the experimental data including the PAMELA ones.

  12. Can Accelerators Accelerate Learning?

    International Nuclear Information System (INIS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-01-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  13. Can Accelerators Accelerate Learning?

    Science.gov (United States)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  14. Laser wakefield acceleration

    International Nuclear Information System (INIS)

    Esarey, E.; Ting, A.; Sprangle, P.

    1989-01-01

    The laser wakefield accelerator (LWFA) is a novel plasma based electron acceleration scheme which utilizes a relativistic optical guiding mechanism for laser pulse propagation. In the LWFA, a short, high power, single frequency laser pulse is propagated through a plasma. As the laser pulse propagates, its radial and axial ponderomotive forces nonresonantly generate large amplitude plasma waves (wakefields) with a phase velocity equal to the group velocity of the pulse. A properly phased electron bunch may then be accelerated by the axial wakefield and focused by the transverse wakefield. Optical guiding of the laser pulse in the plasma is necessary in order to achieve high energies in a single stage of acceleration. At sufficiently high laser powers, optical guiding may be achieved through relativistic effects associated with the plasma electrons. Preliminary analysis indicates that this scheme may overcome some of the difficulties present in the plasma beat wave accelerator and in the plasma wakefield accelerator. Analytical and numerical calculations are presented which study both laser pulse propagation within a plasma as well as the subsequent generation of large amplitude plasma waves. In addition, the generation of large amplitude plasma waves in regimes where the plasma waves become highly nonlinear is examined

  15. A silicon multiplicity detector system for an experiment on the interaction of antiprotons with nuclei at BNL

    International Nuclear Information System (INIS)

    Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Clement, J.M.; Empl, A.; Mutchler, G.S.; Toshkov, S.; Chan, C.S.; Kramer, M.A.; Lindenbaum, S.J.; Hallman, T.J.; Madansky, L.; Peaslee, D.C.

    1991-01-01

    A Large Angle Multiplicity Detector (LAMD) system has been developed and used at the BNL experiment E854: Antiproton Nucleus Interactions. This system performed well with an energetic antiproton beam. Charged particle multiplicity distributions from pbar annihilations were measured. We discuss the design and performance of the LAMD system in this paper. 6 refs., 10 figs

  16. Study of Anti-Hydrogen and Plasma Physics 4.Observation of Antiproton Beams and Nonneutral Plasmas

    CERN Document Server

    Hori, Masaki; Fujiwara, Makoto; Kuroda, Naofumi

    2004-01-01

    Diagnostics of antiproton beams and nonneutral plasmas are described in this chapter. Parallel plate secondary electron emission detectors are used to non-destructively observe the beam position and intensity without loss. Plastic scintillation tracking detectors are useful in determining the position of annihilations of antiprotons in the trap. Three-dimensional imaging of antiprotons in a Penning trap is discussed. The unique capability of antimatter particle imaging has allowed the observation of the spatial distribution of particle loss in a trap. Radial loss is localized to small spots, strongly breaking the azimuthal symmetry expected for an ideal trap. By observing electrostatic eigen-modes of nonneutral plasmas trapped in the Multi-ring electrode trap, the non-destructive measurement of plasma parameters is performed.

  17. Antiproton-proton annihilation into light neutral meson pairs within an effective meson theory

    Science.gov (United States)

    Wang, Ying; Bystritskiy, Yury M.; Ahmadov, Azad I.; Tomasi-Gustafsson, Egle

    2017-08-01

    Antiproton-proton annihilation into light neutral mesons in the few GeV energy domain is investigated in view of a global description of the existing data and predictions for future work at the Antiproton Annihilation at Darmstadt (PANDA) experiment at the Facility for Antiproton and Ion Research (FAIR). An effective meson model earlier developed, with mesonic and baryonic degrees of freedom in s , t , and u channels, is applied here to π0π0 production. Form factors with logarithmic s and t (u ) dependencies are applied. A fair agreement with the existing angular distributions is obtained. Applying SU(3) symmetry, it is straightforward to recover the angular distributions for π0η and η η production in the same energy range. A good agreement is generally obtained with all existing data.

  18. QCD studies with anti-protons at FAIR: Indian participation in PANDA

    International Nuclear Information System (INIS)

    Kailas, S.; Roy, B.J.; Dutta, D.; Jha, V.; Varma, R.

    2011-01-01

    The Facility for Antiproton and Ion Research (FAIR) is a future project at GSI which will extend hadron physics studies up to the charm meson region using antiproton beams together with a state-of-the-art detector antiproton annihilation at Darmstadt (PANDA). The physics aim, in a broader sense, is to address the fundamental problems of hadron physics and aspects of quantum chromo-dynamics (QCD) at low energies. The proposed work in India will consist of several parts: R and D studies of silicon micro-strip detector, development of a scintillator hodoscope with silicon photomultiplier (SiPM) readout, studies of SiPM as photon counter and simulation studies of the detector design as well as physics case studies. The present article describes the physics motivation and initial progress made towards achieving these goals. (author)

  19. Experimental setup and first measurement of DNA damage induced along and around an antiproton beam

    DEFF Research Database (Denmark)

    Kavanagh, J. N.; Currell, F. J.; Timson, D. J.

    2010-01-01

    a further enhancement due to their annihilation at the end of the path. The work presented here aimed to establish and validate an experimental procedure for the quantification of plasmid and genomic DNA damage resulting from antiproton exposure. Immunocytochemistry was used to assess DNA damage in directly......Radiotherapy employs ionizing radiation to induce lethal DNA lesions in cancer cells while minimizing damage to healthy tissues. Due to their pattern of energy deposition, better therapeutic outcomes can, in theory, be achieved with ions compared to photons. Antiprotons have been proposed to offer...... and indirectly exposed human fibroblasts irradiated in both plateau and Bragg peak regions of a 126 MeV antiproton beam at CERN. Cells were stained post irradiation with an anti-γ-H2AX antibody. Quantification of the γ-H2AX foci-dose relationship is consistent with a linear increase in the Bragg peak region...

  20. Charge asymmetry in alignment of atoms excited by protons and antiprotons

    International Nuclear Information System (INIS)

    Balashov, V.V.; Sokolik, A.A.; Stysin, A.V.

    2007-01-01

    The multichannel diffraction approximation is used to consider excitation of lithium atom by proton and antiproton impact. Calculations are performed for the energy range 100 keV - 1 MeV of incoming proton and anti-proton which should be reliable enough due to the general requirements of the multichannel diffraction approximation. The sign-of-charge effect in the alignment of produced 1s 2 3d excited state and in the linear polarization of the subsequent spontaneous 1s 2 3d → 1s 2 2p radiation is expected to be considerable. The clear sign-of-charge effect in the polarization occurs for projectile energies below 1 MeV and become stronger when going to lower energies and the difference between the proton case and the anti-proton one looks considerable enough for experimental observation

  1. Depth-Dose and LET Distributions of Antiproton Beams in Various Target Materials

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Olsen, Sune; Petersen, Jørgen B.B.

    the annihilation process. Materials We have investigated the impact of substituting the target material on  the depth-dose distribution of pristine and  spread out antiproton beams using the FLUKA Monte Carlo transport program. Classical ICRP targets are compared to water phantoms. In addition, track average...... unrestricted LET is calculated for all configurations. Finally, we investigate which concentrations of gadolinium and boron are needed in a water target in order to observe a significant change in the antiproton depth-dose distribution.  Results Results indicate, that there is no significant change...... in the depth-dose distribution and average LET when substituting the materials. Adding boron and gadolinium up to concentrations of 1 per 1000 atoms to a water phantom, did not change the depth-dose profile nor the average LET. Conclusions  According to our FLUKA calculations, antiproton neutron capture...

  2. Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons

    Science.gov (United States)

    Ulmer, S.; Mooser, A.; Nagahama, H.; Sellner, S.; Smorra, C.

    2018-03-01

    The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge-parity-time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

  3. Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons.

    Science.gov (United States)

    Ulmer, S; Mooser, A; Nagahama, H; Sellner, S; Smorra, C

    2018-03-28

    The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge-parity-time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Authors.

  4. Linear Accelerators

    International Nuclear Information System (INIS)

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics

  5. Centrifugal Separation and Equilibration Dynamics in an Electron-Antiproton Plasma

    International Nuclear Information System (INIS)

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Ashkezari, M. D.; Hayden, M. E.; Baquero-Ruiz, M.; Chapman, S.; Fajans, J.; Povilus, A.; So, C.; Bertsche, W.; Butler, E.; Charlton, M.; Deller, A.; Eriksson, S.; Humphries, A. J.; Madsen, N.; Werf, D. P. van der; Cesar, C. L.; Friesen, T.

    2011-01-01

    Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

  6. Proton-Antiproton Pair Production in Two-Photon Collisions at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hakobyan, R.S.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, Stefan; Rosenbleck, C.; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2003-01-01

    The reaction e+e- -> e+e- proton antiproton is studied with the L3 detector at LEP. The analysis is based on data collected at e+e- center-of-mass energies from 183 GeV to 209 GeV, corresponding to an integrated luminosity of 667 pb-1. The gamma gamma -> proton antiproton differential cross section is measured in the range of the two-photon center-of-mass energy from 2.1 GeV to 4.5 GeV. The results are compared to the predictions of the three-quark and quark-diquark models.

  7. A possible method to produce a polarized antiproton beam at intermediate energies

    International Nuclear Information System (INIS)

    Spinka, H.; Vaandering, E.W.; Hofmann, J.S.

    1994-01-01

    A feasible and conservative design for a medium energy polarized antiproton beam has been presented. The design requires an intense beam of unpolarized antiprotons (≥ 10 7 /sec) from a typical secondary beam line in order to achieve reasonable anti pp elastic scattering count rates. All three beam spin directions can be achieved. Methods were discussed to reverse the spin directions in modest times, and to change to a polarized proton beam if desired. It is expected that experiments with such a beam would have a profound effect on the understanding of the anti NN interaction at intermediate energies

  8. Current status of antiproton impact ionization of atoms and molecules: theoretical and experimental perspectives

    DEFF Research Database (Denmark)

    Kirchner, Tom; Knudsen, Helge

    2011-01-01

    Experimental and theoretical progress in the field of antiproton-impact-induced ionization of atoms and molecules is reviewed. We describe the techniques used to measure ionization cross sections and give an overview of the experimental results supplemented by tables of all existing data. An atte......Experimental and theoretical progress in the field of antiproton-impact-induced ionization of atoms and molecules is reviewed. We describe the techniques used to measure ionization cross sections and give an overview of the experimental results supplemented by tables of all existing data...

  9. An apparatus to measure stopping powers for low-energy antiprotons and protons

    CERN Document Server

    Andersen, H H; Ichioka, T; Knudsen, H; Møller, S P; Uggerhøj, U

    2002-01-01

    One of the experiments to be performed under the ASACUSA collaboration at the CERN Antiproton Decelerator is a measurement of the energy loss of low energy antiprotons in thin foils. An electrostatic spectrometer has been developed for this task. We describe the design and initial tests of the apparatus with protons. By changing a high-voltage applied on the target the energy of the projectile ions at impact on the target can easily be varied. In this way we have measured the stopping-power and the energy-loss straggling for protons over a wide energy range to below one keV.

  10. Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

    CERN Document Server

    Andresen, G B; Baquero-Ruiz, Marcelo; Bertsche, William; Bowe, Paul D; Butler, Eoin; Cesar, Claudio L; Chapman, Steven; Charlton, Michael; Deller, A; Eriksson, S; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C; Gill, David R; Gutierrez, A; Hangst, Jeffrey S; Hardy, Walter N; Hayden, Michael E; Humphries, Andrew J; Hydomako, Richard; Jonsell, Svante; Madsen, Niels; Menary, Scott; Nolan, Paul; Olin, Art; Povilus, Alexander; Pusa, Petteri; Robicheaux, Francis; Sarid, Eli; Silveira, Daniel M; So, Chukman; Storey, James W; Thompson, Robert I; van der Werf, Dirk P; Wurtele, Jonathan S; Yamazaki, Yasunori

    2011-01-01

    Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

  11. Scattering of antiprotons from carbon at 46.8 MeV

    International Nuclear Information System (INIS)

    Garetta, D.; Birien, P.; Bruge, G.; Chaumeaux, A.; Janouin, S.; Legrand, D.; Mallet-Lemaire, M.C.; Mayer, B.; Pain, J.; Drake, D.M.; Peng, J.C.

    1984-01-01

    Antiproton-carbon elastic and inelastic scattering cross sections have been measured at 46.8 MeV over an angular range 6 0 0 with a magnetic spectrometer. Fits to the elastic and inelastic 4.44 MeV excited state cross sections put realistic limits on the strengths of the real and imaginary parts of the antiproton-carbon optical potential. The continuum cross section due to carbon break-up appears to be smaller than it is for corresponding proton data. (orig.)

  12. First observation of laser-induced resonant annihilation in metastable antiprotonic helium atoms

    International Nuclear Information System (INIS)

    Morita, N.; Kumakura, M.; Yamazaki, T.

    1993-11-01

    We have observed the first laser-induced resonant transitions in antiprotonic helium atoms. These occur between metastable states and Auger dominated short lived states, and show that the anomalous longevity of antiprotons previously observed in helium media results from the formation of high-n high-l atomic states of p-barHe + . The observed transition with vacuum wavelength 597.259 ± 0.002 nm and lower-state lifetime 15 ± 1 ns is tentatively assigned to (n,l) = (39,35) → (38,34). (author)

  13. Particle acceleration in near critical density plasma

    International Nuclear Information System (INIS)

    Gu, Y.J.; Kong, Q.; Kawata, S.; Izumiyama, T.; Nagashima, T.

    2013-01-01

    Charged particle acceleration schemes driven by ultra intense laser and near critical density plasma interactions are presented. They include electron acceleration in a plasma channel, ion acceleration by the Coulomb explosion and high energy electron beam driven ion acceleration. It is found that under the near critical density plasma both ions and electrons are accelerated with a high acceleration gradient. The electron beam containing a large charge quantity is accelerated well with 23 GeV/cm. The collimated ion bunch reaches 1 GeV. The investigations and discussions are based on 2.5D PIC (particle-in-cell) simulations. (author)

  14. Recent progress in particle accelerators

    International Nuclear Information System (INIS)

    Cole, F.T.; Mills, F.E.

    1988-01-01

    Many accelerators have also been built for medical radiography and therapy. Electron accelerators for this application are available commercially, using the electrons directly or bremsstrahlung photons. Neutrons produced by accelerator beams have also been used for therapy with considerable success, and several proton accelerators built for physics research have been adapted for direct therapy with protons. The first proton accelerator specifically for therapy is now being built. Separate from what might be called conventional accelerator technology, an entirely new field utilizing very highly pulsed power has been developed, and beams of short pulses of thousands or millions of amperes peak current in the MeV energy range are now available. These beams have important applications in high-energy particle acceleration, controlled fusion, industrial treatment of materials, and possibly in food preservation. All of these accelerators make use of external fields of acceleration. There is also vigorous research into new methods of acceleration, in many schemes making use of the intense accelerating fields, generated by laser beams or by plasma states of matter. This research has not as yet made traditional kinds of accelerators outmoded, but many workers hope that early in the next century there will be practical new acceleration methods making use of these very high fields. These developments are discussed in detail

  15. Populations and lifetimes in the $v=n-l-1=2$ and 3 metastable cascades of $\\overline{p} He^{+}$ measured by pulsed and continuous antiproton beams

    CERN Document Server

    Hori, Masaki; Widmann, E; Yamazaki, T; Hayano, R S; Ishikawa, T; Torie, H A; Von Egidy, T; Hartmann, F; Ketzer, B; Maierl, C; Pohl, R; Kumakura, M; Morita, N; Horváth, D; Sugai, I

    2004-01-01

    Using the laser spectroscopy, the time evolution of the state population in the v equivalent n-l=2 and 3 metastable cascades of antiprotonic helium atoms were studied. The effects of the collision between antiprotonic helium and the ordinary helium atoms on the atomic cascade were also analyzed. The measurements were done using the pulsed and continuous types of antiproton beams supplied by the Low Energy Antiproton Ring. The studies revealed five phases in the life history of the metastable antiprotonic helium. (Edited abstract) 71 Refs.

  16. Accelerator Service

    International Nuclear Information System (INIS)

    Champelovier, Y.; Ferrari, M.; Gardon, A.; Hadinger, G.; Martin, J.; Plantier, A.

    1998-01-01

    Since the cessation of the operation of hydrogen cluster accelerator in July 1996, four electrostatic accelerators were in operation and used by the peri-nuclear teams working in multidisciplinary collaborations. These are the 4 MV Van de Graaff accelerator, 2,5 MV Van de Graaff accelerator, 400 kV ion implanter as well as the 120 kV isotope separator

  17. Plasma wave accelerator. II

    International Nuclear Information System (INIS)

    Mori, W.; Joshi, C.; Dawson, J.M.

    1982-01-01

    It was shown that the insertion of a cross magnetic field prevents the particles from getting out of phase with the electric field of the plasma wave in the beat wave accelerator scheme. Thus, using a CO 2 laser, n/sub c//n/sub e/ = (ω 0 /ω/sub p/) 2 approx. 35, and a 300 kG magnetic field, electrons can be (in principle) accelerated to 100 GeV in 2 meters. For comparison without the magnetic field, the same energies may be obtained in a n/sub c//n/sub e/ approx. 10 5 plasma over a distance of 100 meters

  18. Buffer-gas cooling of antiprotonic helium to 1.5 to 1.7 K, and antiproton-to–electron mass ratio

    CERN Document Server

    Hori, Masaki; Sótér, Anna; Barna, Daniel; Dax, Andreas; Hayano, Ryugo; Kobayashi, Takumi; Murakami, Yohei; Todoroki, Koichi; Yamada, Hiroyuki; Horváth, Dezső; Venturelli, Luca

    2016-01-01

    Charge, parity, and time reversal (CPT) symmetry implies that a particle and its antiparticle have the same mass. The antiproton-to-electron mass ratio Embedded Image can be precisely determined from the single-photon transition frequencies of antiprotonic helium. We measured 13 such frequencies with laser spectroscopy to a fractional precision of 2.5 × 10−9 to 16 × 10−9. About 2 × 109 antiprotonic helium atoms were cooled to temperatures between 1.5 and 1.7 kelvin by using buffer-gas cooling in cryogenic low-pressure helium gas; the narrow thermal distribution led to the observation of sharp spectral lines of small thermal Doppler width. The deviation between the experimental frequencies and the results of three-body quantum electrodynamics calculations was reduced by a factor of 1.4 to 10 compared with previous single-photon experiments. From this, Embedded Image was determined as 1836.1526734(15), which agrees with a recent proton-to-electron experimental value within 8 × 10−10.

  19. Experimental studies of VpxB electron linear accelerator

    International Nuclear Information System (INIS)

    Taura, T.; Onihashi, H.; Otsuka, K.; Nishida, Y.; Yugami, N.

    1989-01-01

    In order to demonstrate a new electron linear accelerator an electron beam is accelerated either in the conventional linear accelerator scheme or in the V p xB scheme in a same machine and higher energy gain of about 18 % is observed in the V p xB scheme as is expected from the designed values. The experimental results are compared with the numerical simulation to show reasonable agreement. (author)

  20. An Antiproton Ion Collider (AIC) for Measuring Neutron and Proton Distributions in Stable and Radioactive Nuclei

    International Nuclear Information System (INIS)

    Kienle, Paul

    2005-01-01

    An antiproton-ion collider is proposed to independently determine mean square radii for protons and neutrons in stable and short lived nuclei by means of antiproton absorption at medium energies. The experiment makes use of the electron ion collider complex (ELISE) of the GSI FAIR project with appropriate modifications of the electron ring to store, cool and collide antiprotons of 30 MeV energy with 740A MeV energy ions.The total absorption cross-section of antiprotons by the stored ions will be measured by detecting their loss by means of the Schottky noise spectroscopy method. Cross sections for the absorption on protons and neutrons, respectively, will be studied by detection of residual nuclei with A-1 either by the Schottky method or by analysing them in recoil detectors after the first dipole stage of the NESR following the interaction zone. With a measurement of the A-1 fragment momentum distribution, one can test the momentum wave functions of the annihilated neutron and proton, respectively. Furthermore by changing the incident ion energy the tails of neutron and proton distribution can be measured.The absorption cross section is at asymptotic energies in leading order proportional to the mean square radius of the nucleus. Predicted cross sections and luminosities show that the method is applicable to nuclei with production rates of about 105 s-1 or lower, depending on the lifetime of the ions in the NESR, and for half-lives down to 1 second

  1. S142 set-up to detect X-ray from antiproton-proton atoms (protonium).

    CERN Multimedia

    1978-01-01

    This experiment was designed by the Daresbury-Mainz-TRIUMF Collaboration and was located in the m14 partially separated antiproton beam in the PS South Hall. It used a gaseous hydrogen target, 1 m long, surrounded by a ring of proportional counters, surrounded in turn by a ring of 36 scintillators strips to aid in the annihilation product identification. Ugo Gastaldi (centre)

  2. Antiproton-proton elastic scattering at 1.8 TeV

    International Nuclear Information System (INIS)

    Fazal-e-Aleem; Saleem, M.; Yodh, G.B.

    1990-01-01

    The predictions, based on the generalized Chou-Yang model, are made for the most recent measurements of antiproton-proton elastic scattering at √s = 1.8 TeV. These results have been compared with the recent theoretical predictions of various models. (author)

  3. Antiproton-proton elastic scattering at 1. 8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-e-Aleem; Saleem, M. (Punjab Univ., Lahore (Pakistan). Centre for High Energy Physics); Yodh, G.B. (California Univ., Irvine, CA (USA). Dept. of Physics)

    1990-11-01

    The predictions, based on the generalized Chou-Yang model, are made for the most recent measurements of antiproton-proton elastic scattering at {radical}s = 1.8 TeV. These results have been compared with the recent theoretical predictions of various models. (author).

  4. Experimental setup and first measurement of DNA damage induced along and around an antiproton beam

    International Nuclear Information System (INIS)

    Kavanagh, J.N.; Currell, F.J.; Prise, K.M.; Schettino, G.; Currell, F.J.; Timson, D.J.; Holzscheiter, M.H.; Bassler, N.; Herrmann, R.

    2010-01-01

    Radiotherapy employs ionizing radiation to induce lethal DNA lesions in cancer cells while minimizing damage to healthy tissues. Due to their pattern of energy deposition, better therapeutic outcomes can, in theory, be achieved with ions compared to photons. Antiprotons have been proposed to offer a further enhancement due to their annihilation at the end of the path. The work presented here aimed to establish and validate an experimental procedure for the quantification of plasmid and genomic DNA damage resulting from antiproton exposure. Immunocytochemistry was used to assess DNA damage in directly and indirectly exposed human fibroblasts irradiated in both plateau and Bragg peak regions of a 126 MeV antiproton beam at CERN. Cells were stained post irradiation with an anti-γ-H2AX antibody. Quantification of the γ-H2AX foci-dose relationship is consistent with a linear increase in the Bragg peak region. A qualitative analysis of the foci detected in the Bragg peak and plateau region indicates significant differences highlighting the different severity of DNA lesions produced along the particle path. Irradiation of desalted plasmid DNA with 5 Gy antiprotons at the Bragg peak resulted in a significant portion of linear plasmid in the resultant solution. (authors)

  5. Relative Biological Effect of Antiprotons

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael

    nuclear research facility CERN. A beam of 126 MeV antiprotons, corresponding to about 12 cm range in water, was spread out to a SOBP with a width of 1 cm. Dosimetry experiments were carried out with ionization chambers, alanine pellets and radiochromic film, and the results were used for benchmarking...

  6. Spin observables in antiproton-proton to AntiLambda-Lambda and density-matrix constraints

    OpenAIRE

    Elchikh, Mokhtar; Richard, Jean-Marc

    2005-01-01

    The positivity conditions of the spin density matrix constrain the spin observables of the reaction antiproton-proton to AntiLambda-Lambda, leading to model-independent, non-trivial inequalities. The formalism is briefly presented and examples of inequalities are provided.

  7. Measurement of 0.25-3.2 GeV antiprotons in the cosmic radiation

    DEFF Research Database (Denmark)

    Mitchell, J.W.; Barbier, L.M.; Christian, E.R.

    1996-01-01

    The balloon-borne Isotope Matter-Antimatter Experiment (IMAX) was flown from Lynn Lake, Manitoba, Canada on 16-17 July 1992. Using velocity and magnetic rigidity to determine mass, we have directly measured the abundances of cosmic ray antiprotons and protons in the energy range from 0.25 to 3.2 ...

  8. Proton and antiproton interactions in hydrogen, argon and xenon at 200 GeV

    International Nuclear Information System (INIS)

    Malecki, P.

    1984-01-01

    The detailed analysis of the production of particles emitted into forward hemisphere in 200 GeV proton and antiproton interactions with hydrogen, argon and xenon targets is presented. Two-particle rapidity correlations and long-range multiplicity correlations are also discussed. (author)

  9. A method to study the antiproton-proton annihilation at rest

    International Nuclear Information System (INIS)

    Bigi, A.

    1977-01-01

    The comparison between at rest and in flight antiproton-proton annihilations cannot be extended in terms of kinematical variables referred to the collision axis that is not defined for the at rest interactions. On the basis of the momentum vectors of the final state particles, other directions can be defined, event by event, and used as reference frame

  10. Antiproton-nucleus interactions at 5 to 9 GeV/c

    International Nuclear Information System (INIS)

    Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chan, C.S.; Clement, J.M.; Eiseman, S.E.; Empl, A.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Hallman, T.J.; Kramer, M.A.; Kruk, J.; Lindenbaum, S.J.; Longacre, R.S.; Love, W.A.; Madansky, L.; Morris, W.; Mutchler, G.S.; Peaslee, D.C.; Platner, E.D.; Saulys, A.C.; Toshkov, S.

    1993-01-01

    Antiproton beams of 5, 7 and 9 GeV/c were used to interact with C, Al, Cu, Sn and Pb nuclear targets. Charged particle multiplicity distributions, strange particle production cross sections and rapidity distributions were measured. The charged particle multiplicities are reported in this paper. (orig.)

  11. Challenging the Standard Model: High-Precision Comparisons of the Fundamental Properties of Protons and Antiprotons

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The Baryon Antibaryon Symmetry Experiment (BASE-CERN) at CERN’s antiproton decelerator facility is aiming at high-precision comparisons of the fundamental properties of protons and antiprotons, such as charge-to-mass ratios, magnetic moments and lifetimes. Such experiments provide sensitive tests of the fundamental charge-parity-time invariance in the baryon sector. BASE was approved in 2013 and has measured since then, utilizing single-particle multi-Penning-trap techniques, the antiproton-to-proton charge-to-mass ratio with a fractional precision of 69 p.p.t. [1], as well as the antiproton magnetic moment with fractional precisions of 0.8 p.p.m. and 1.5 p.p.b., respectively [2]. At our matter companion experiment BASE-Mainz, we have performed proton magnetic moment measurements with fractional uncertainties of 3.3 p.p.b. [3] and 0.3 p.p.b. [4]. By combining the data of both experiments we provide a baryon-magnetic-moment based CPT test gpbar/gp = 1.000 000 000 2(15), which improves the uncertainty of p...

  12. Radiation protection activities around the CERN accelerators

    International Nuclear Information System (INIS)

    Forkel-Wirth, D.; Silari, M.

    1999-01-01

    As planned, the PS complex started up at the end of March 1998. The machines worked smoothly and the availability of the beams reached from 90% up to 96%. New record intensities were achieved for the 14 GeV/c protons for the SPS fixed-target operation and for the Pb 53+ ions. The year 1998 saw the PS complex busy with the transformation of the Antiproton Accumulator (ACOL) into the Antiproton Decelerator (AD). This project is almost finished and the first test beams of protons have already been successfully decelerated in the machine. It is envisaged that the physicists will receive a 100 MeV antiproton beam from October 1999 onwards. Major modifications of the East Hall were required due to the installation of the DIRAC experiment, some test facilities for secondary particles used by LHC experimental groups, and an irradiation area (IRRAD1) for radiation hardness tests of LHC components. The first beams to experimental areas of the East Hall were already sent from July 1998 onwards. The ISOLDE mass separator delivered 275 shifts of radioactive beams of high quality to its user community. The SPS fixed-target programme lasted from 1 April to 30 November. The successful start-up of the accelerators for both the proton and lead-ion periods was followed by stable machine running and by record intensities. The year 1998 marked the end of the operation of the neutrino beam. The dismantling of CHORUS began before the end of the year, to be followed by that of the NOMAD experiment early in 1999

  13. New practicable Siberian Snake schemes

    International Nuclear Information System (INIS)

    Steffen, K.

    1983-07-01

    Siberian Snake schemes can be inserted in ring accelerators for making the spin tune almost independent of energy. Two such schemes are here suggested which lend particularly well to practical application over a wide energy range. Being composed of horizontal and vertical bending magnets, the proposed snakes are designed to have a small maximum beam excursion in one plane. By applying in this plane a bending correction that varies with energy, they can be operated at fixed geometry in the other plane where most of the bending occurs, thus avoiding complicated magnet motion or excessively large magnet apertures that would otherwise be needed for large energy variations. The first of the proposed schemes employs a pair of standard-type Siberian Snakes, i.e. of the usual 1st and 2nd kind which rotate the spin about the longitudinal and the transverse horizontal axis, respectively. The second scheme employs a pair of novel-type snakes which rotate the spin about either one of the horizontal axes that are at 45 0 to the beam direction. In obvious reference to these axes, they are called left-pointed and right-pointed snakes. (orig.)

  14. Acceleration of the nodal program FERM

    International Nuclear Information System (INIS)

    Nakata, H.

    1985-01-01

    Acceleration of the nodal FERM was tried by three acceleration schemes. Results of the calculations showed the best acceleration with the Tchebyshev method where the savings in the computing time were of the order of 50%. Acceleration with the Assymptotic Source Extrapoltation Method and with the Coarse-Mesh Rebalancing Method did not result in any improvement on the global computational time, although a reduction in the number of outer iterations was observed. (Author) [pt

  15. Acceleration of polarized protons in the IHEP accelerator complex

    International Nuclear Information System (INIS)

    Anferov, V.A.; Ado, Yu.M.; Shoumkin, D.

    1995-01-01

    The paper considers possibility to accelerate polarized beam in the IHEP accelerator complex (including first stage of the UNK). The scheme of preserving beam polarization is described for all acceleration stages up to 400 GeV beam energy. Polarization and intensity of the polarized proton beam are estimated. The suggested scheme includes using two Siberian snakes in opposite straight sections of the UNK-1, where each snake consists of five dipole magnets. In the U-70 it is suggested to use one helical Siberian snake, which is turned on adiabatically at 10 GeV, and four pulsed quadrupoles. To incorporate the snake into the accelerator lattice it is proposed to make modification of one superperiod. This would make a 13 m long straight section. Spin depolarization in the Booster is avoided by decreasing the extraction energy to 0.9 GeV. Then no additional hardware is required in the Booster

  16. JUELICH: COSY acceleration and cooling

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The COSY cooler synchrotron at the KFA Forschungszentrum Jülich, inaugurated on 1 April, is now well on its way towards precision-defined high energy beams to open new fields for Jülich physics experiments. In two important goals, on 25 May the first beam cooled by electrons circulated inside the accelerator, then on 25 July physicists succeeded in accelerating the beam from the 270 MeV/c injection momentum to 600 MeV. Shortly after, this was pushed well above 1 GeV. Throughout the tuning process the number of stored particles increased steadily, finally peaking at 1.1 x 10 11 , a value compatible with the predicted limit at the injection energy. This success was the result of a painstaking search for the optimum parameter set, the commissioning crew being acutely aware that bringing such a large machine on line was a major experiment in its own right. The 3.3 GeV/c COSY machine belongs to the new class of hadron storage and cooler synchrotrons which started with CERN's LEAR low energy antiproton ring. COSY will 'sharpen' its beams to a narrow momentum spread using both electron and stochastic cooling to control the circulating particles. In addition it will provide space for internal experiments. Both features will allow for novel experimental approaches, and more than 100 physicists are eagerly waiting for the first proton reactions in their detectors

  17. Experimental determination of the complete spin structure for anti-proton + proton -> anti-\\Lambda + \\Lambda at anti-proton beam momentum of 1.637 GeV/c

    CERN Document Server

    Paschke, K.D.; Berdoz, A.; Franklin, G.B.; Khaustov, P.; Meyer, C.A.; Bradtke, C.; Gehring, R.; Goertz, S.; Harmsen, J.; Meier, A.; Meyer, W.; Radtke, E.; Reicherz, G.; Dutz, H.; Pluckthun, M.; Schoch, B.; Dennert, H.; Eyrich, W.; Hauffe, J.; Metzger, A.; Moosburger, M.; Stinzing, F.; Wirth, St.; Fischer, H.; Franz, J.; Heinsius, F.H.; Kriegler, E.; Schmitt, H.; Bunker, B.; Hertzog, D.; Jones, T.; Tayloe, R.; Broders, R.; Geyer, R.; Kilian, K.; Oelert, W.; Rohrich, K.; Sachs, K.; Sefzick, T.; Bassalleck, B.; Eilerts, S.; Fields, D.E.; Kingsberry, P.; Lowe, J.; Stotzer, R.; Johansson, T.; Pomp, S.; Wirth, St.

    2006-01-01

    The reaction anti-proton + proton -> anti-\\Lambda + \\Lambda -> anti-proton + \\pi^+ + proton + \\pi^- has been measured with high statistics at anti-proton beam momentum of 1.637 GeV/c. The use of a transversely-polarized frozen-spin target combined with the self-analyzing property of \\Lambda/anti-\\Lambda decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of eleven real parameters for each bin of scattering angle, each of these parameters is determined with reasonable precision. From these results all conceivable spin-correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in anti-proton + proton -> anti-\\Lambda + \\Lambda near this energy. Existing theoretical models do not give good predictions for those spin-observables that had not been previously measured.

  18. Future accelerators (?)

    Energy Technology Data Exchange (ETDEWEB)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  19. Towards stable acceleration in LINACS

    CERN Document Server

    Dubrovskiy, A D

    2014-01-01

    Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

  20. Physics with antiprotons at LEAR in the ACOL ERA

    International Nuclear Information System (INIS)

    Gastaldi, U.; Klapisch, R.; Richard, J.M.; Tran Thanh Van, J.

    1985-01-01

    The programme covered the following topics: accelerator aspects (anti-p production, LEAR, advanced developments, cooling, LEAR design inspired machines). Nucleon antinucleon interactions (panti-p atom, scattering, annihilation, spin effects, antineutron physics, antibaryon physics). Spectroscopy (light mesons, hybrids, glueballs, baryonia, quarkonia). Rare channels (form factors, CP, CPT, C, T violation, quantum mechanics tests) anti-p nucleus interactions (exotic atoms, scattering, annihilation, hypernuclei). New ideas (antigravity, high precision experiments). New detectors (new experiments, general and/or technical aspects)

  1. Measure of back angle cross sections of antiproton-nucleus elastic scattering at 48 and 180 MeV

    International Nuclear Information System (INIS)

    Berrada, M.

    1986-04-01

    Antiproton-nucleus elastic scattering was studied in the LEAR ring at CERN. The scattering cross section at back angles (θ LAB = 142 to 164 deg inclusive) was measured using plastic scintillation detectors. Analysis of experimental data at 47 MeV for a CH target and at 182 MeV for CH, C12, 016, and 018 targets produces differential cross sections for back angles less than or equal to a few dozen microbarns. These results agree with theoretical microscopic predictions. The analysis improves understanding of antiproton-nucleus interaction and introduces a constraint on the construction of optical potentials. The antiproton-nucleus potential is shown to be highly absorbing, thereby excluding S type potentials, and removing the ambiguity arising from the analysis of antiprotonic atoms. The results also show that there is no attractive pocket in the real potential likely to lead to an increase of the back angle cross sections [fr

  2. Charm Production in Interactions of Antiproton with Proton and Nuclei at \\bar{it{P}}it{ANDA} Energies

    Science.gov (United States)

    Shyam, R.; Tsushima, K.

    2018-05-01

    We study the production of charmed baryons in the antiproton-proton and antiproton-nucleus interactions within a fully covariant model that is based on an effective Lagrangian approach. The baryon production proceeds via the t-channel D^0 and D^{*0} meson-exchange diagrams. We have also explored the production of the charm-baryon hypernucleus ^{16}_{Λ_c^+}O in the antiproton-^{16}O collisions. For antiproton beam momenta of interest to the {\\bar{P}}ANDA experiment, the 0° differential cross sections for the formation of ^{16}_{Λ_c^+}O hypernuclear states with simple particle-hole configurations, have magnitudes in the range of a few μ b/sr.

  3. The measurement of antiproton-proton total cross sections and small-angle elastic scattering at low momentum

    International Nuclear Information System (INIS)

    Linssen, L.H.A.J.

    1986-01-01

    In this thesis two low-momentum antiproton-proton (anti pp) experiments are described. The first one is a set of 24 high statistics anti pp total cross section measurements as a function of the incoming antiproton momentum between p=388 MeV/c and p=599 MeV/c. These measurements simultaneously yield the charge exchange cross section (anti pp → anti nn). The second one comprises two high statistics anti pp small-angle elastic scattering measurements at p=233 MeV/c and p=272 MeV/c. The measurements were carried out using the high quality antiproton beam extracted from the Low Energy Antiproton Ring (LEAR) at CERN. The physics motivation for these experiments is a search for anti pp resonances or bound states on one hand, and a detailed study of the anti pp interaction on the other hand. (orig.)

  4. Atomic approaches in metastable antiprotonic helium atoms. REPLY to 'analysis of the lifetimes and fractions of antiprotons trapped in metastable antiprotonic-helium states' by I. Shimamura and M. Kimura

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu; Ohtsuki, Kazumasa.

    1994-08-01

    In the present note the authors clarify the purpose of YO and complement its essential points, thus showing that the criticisms of SK are inappropriate. The paper YO [1] was aimed at discussing some new aspects related to the metastability of hadronic helium atoms which had been discovered when negative kaons [2], negative pions [3] and antiprotons [4] were stopped in liquid helium. The delayed fraction, time spectrum shape and lifetimes were the observables. Further experimental studies are in progress [5], and as of today there is no successful explanation for these interesting phenomena. So, YO tried to give brief and rather qualitative estimates for the observations in an intuitive way, considering only the leading terms. The following problems are discussed in as simple a manner as possible, starting from the exotic-atom viewpoints of Condo [6] and Russell [7]: i)the atomic core polarization effect, ii)the structure and radiative lifetimes, iii)the non-statistical distribution of the angular momentum and an estimate of the delayed fraction, and iv)the isotope effect, though the title represents only i). To respond to the comments of SK, it is important to consider the correspondence between the atomic approach and the molecular approach for the metastable antiprotonic helium atom of Condo-Russell. We therefore begin this note with a discussion of this aspect. (author)

  5. The Bess Investigation of the Origin of Cosmic-ray Antiprotons and Search for Cosmological Antimatter

    Science.gov (United States)

    Mitchell, John; Yamamoto, Akira; Yoshimura, Koji; Makida, Yasuhiro; Matsuda, Shinya; Hasegawa, Masaya; Horikoshi, Atsushi; Tanaka,Ken-ichi; Suzuki, Junichi; Nishimura, Jun; hide

    2008-01-01

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) collaboration has made precise measurements of the spectra of cosmic ray antiprotons and light nuclei and conducted a sensitive search for antinuclei. Ten BESS high-latitude flights, eight from Canada and two from Antarctica, span more than a Solar cycle between 1993 and 2007/2008. BESS measurements of low-energy antiprotons constrain candidate models for dark matter including the possible signature of primordial black hole evaporation. The stringent BESS measurements of antiprotons and the elemental and isotopic spectra of H and He provide strong constraints on models of cosmic-ray transport in the Galaxy and Solar System. BESS has also reported the first antideuterium upper limit. BESS employs a superconducting magnetic-rigity spectrometer with time-of-flight and aerogel Cherenkov detectors to identify incident particles by charge, charge sign, mass, and energy. The BESS-Polar long-duration instrument has reduced lower energy limit of 100 MeV (top of the atmosphere) to increase its sensitivity to possible primary antiproton sources. BESS-Polar II was rebuilt with extended magnet lifetime, improved detector and electronic performance, and greater data storage capacity. It was flown fro Antarctica December 2007-January 2008, recording about 4.6 bission events during 24.5 days at float altitude with the magnet on. During the flight the influence of a high-speed stream in the Solar wind was observed. Details of the BESS-Polar II instrument and flight performance are reported elsewhere at this conference. The successful BESS-Polar II flight at Solar minimum is especially important. Most cosmic-ray antiprotons are secondary products of nuclear interactions of primary cosmic-ray nuclei with the interstellar gas, giving a spectrum that peaks at about 2 GeV and falls rapidly to higher and lower energies. However, BESS data taken in the previous Solar minimum show a small excess over secondary

  6. Finite Boltzmann schemes

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2006-01-01

    In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

  7. Investigation of the antiprotonic X-ray spectra of the isotopes 6Li, 7Li and 40Ca

    International Nuclear Information System (INIS)

    Barth, H.

    1987-04-01

    With the commissioning of the Low-Energy Antiproton Ring (LEAR) at CERN in Geneva a high intensity, high purity antiproton beam became available, enabling precision measurements of antiprotonic X-ray spectra to be carried out. Besides informations about properties of the elementary particle antiproton itself, as for example its mass and its magnetic moment, such measurements provide informations about the strong-interaction potential between antiproton and nucleus at very low energies, which, in turn, can be derived from the elementary antinucleon-nucleon interaction by using microscopic models. This work investigates the antiprotonic X-ray spectra of the isotopes 6 Li, 7 Li and 40 Ca. The data were taken during the experiment PS176 at LEAR. The strong interaction between antiproton and nucleus leads to an energy shift ε and an absorption width Γ of the lower level of the last observable transition and also to intensity reductions, which can be converted to an absorption width for the upper level. For the isotopes 6 Li, 7 Li and 40 Ca the following results were obtained: 6 Li: ε(2p)=(-215±25) eV, Γ(2p)=(660±170) eV and Γ(3d)=(135±16) meV, 7 Li ε(2p)=(-265±20) eV, Γ(2p)=(690±170) eV and Γ(3d)=(129±13) meV, 40 Ca: ε(4f)=(-1060±130) eV, Γ(4f)=(3670±600) eV and Γ(5g)=(34.9±3.3) eV. The results are in fair agreement with theoretical calculations, at the same time showing up the limits of present understanding of antiproton-nucleus interaction. Particularly the spin-orbit part of the strong interaction seems to play a nonnegligible role. (orig.) [de

  8. Determination of the antiproton-to-electron mass ratio by precision laser spectroscopy of $\\overline{p}He^{+}$

    CERN Document Server

    Hori, M; Eades, John; Gomikawa, K; Hayano, R S; Ono, N; Pirkl, Werner; Widmann, E; Torii, H A; Juhász, B; Barna, D; Horváth, D

    2006-01-01

    A femtosecond optical frequency comb and continuous-wave pulse- amplified laser were used to measure 12 transition frequencies of antiprotonic helium to fractional precisions of (9-16) 10/sup -9lifetimes hitherto unaccessible to our precision laser spectroscopy method. Comparisons with three-body QED calculations yielded an antiproton-to-electron mass ratio of M/sub pmacron//m/sub e/=1836.152 674(5).

  9. 132 ns Bunch Spacing in the Tevatron Proton-Antiproton Collider

    International Nuclear Information System (INIS)

    Holmes, S.D.; Holt, J.; Johnstone, J.A.; Marriner, J.; Martens, M.; McGinnis, D.

    1994-12-01

    Following completion of the Fermilab Main Injector it is expected that the Tevatron proton-antiproton collider will be operating at a luminosity in excess of 5x10 3l cm -2 with 36 proton and antiproton bunches spaced at 396 nsec. At this luminosity, each of the experimental detectors will see approximately 1.3 interactions per crossing. Potential improvements to the collider low beta and rf systems could push the luminosity beyond 10x10 3l cm -2 sec -1 , resulting in more than three interactions per crossing if the bunch separation is left unchanged. This paper discusses issues related to moving to ∼100 bunch operation, with bunch spacings of 132 nsec, in the Tevatron. Specific scenarios and associated hardware requirements are described

  10. Production of hyperfragments by antiprotons at rest annihilating on nuclei in nuclear photoemulsion

    International Nuclear Information System (INIS)

    Batusov, Yu.A.; Bunyatov, S.A.; Pontecorvo, G.B.

    1992-01-01

    Events have been observed, for the first time, of the production, departure and mesonic decay of the light hyperfragments Λ 3 H and Λ 4 H in the annihilation on the light (C, N, O, S)-nuclei of antiprotons stopping in nuclear photoemulsion. The lower limit of the production probability of Λ 3 H and Λ 4 H hyperfragments per single antiproton stopping in nuclear photoemulsion has been determined to be (6.1±3.5)x10 -4 . The charge exchange, on nucleons of the residual nucleus, of K - -mesons resulting from the annihilation process has been demonstrated to be the most probable mechanism of hyperfragment production. 17 refs.; 9 figs

  11. A Cryogenic Current Comparator for the Low Energy Antiproton Facilities at CERN

    CERN Document Server

    Fernandes, M; Welsch, CP

    2014-01-01

    Several laboratories have shown the potential of using Superconducting QUantum Interference Device (SQUID) magnetometers together with superconductor magnetic shields to measure beam current intensities in the submicro-Ampere regime. CERN, in collaboration with GSI, Jena university and Helmholtz Institute Jena, is currently working on developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings at CERN, aiming for better current resolution and overall system availability. This contribution will present the current design, including theoretical estimation of the current resolution; stability limits of SQUID systems and adaptation of the coupling circuit to the AD beam parameters; the analysis of thermal and mechanical cryostat modes.

  12. Dynamic studies of multiple configurations of CERN's Antiproton Decelerator Target core under proton beam impact

    CERN Document Server

    AUTHOR|(CDS)2248381

    Antiprotons, like many other exotic particles, are produced by impacting high energy proton beams onto fixed targets. At the European Organization for Nuclear Research (CERN), this is done in the Antiproton Decelerator (AD) Facility. The engineering challenges related to the design of an optimal configuration of the AD-Target system derive from the extremely high energy depositions reached in the very thin target core as a consequence of each proton beam impact. A new target design is foreseen for operation after 2021, triggering multiple R&D activities since 2013 for this purpose. The goal of the present Master Thesis is to complement these activities with analytical and numerical calculations, delving into the phenomena associated to the dynamic response of the target core. In this context, two main studies have been carried out. First, the experimental data observed in targets subjected to low intensity proton pulses was cross-checked with analytical and computational methods for modal analysis, applie...

  13. Antiproton cross-field diffusion in antihydrogen production experiments due to anisotropic binary interactions

    International Nuclear Information System (INIS)

    Ordonez, C.A.; Correa, J.R.

    2007-01-01

    Collisional processes in electrostatic ion storage rings and reflecting-beam-type electrostatic ion traps can be associated with anisotropic binary interactions, because shielding of the Coulomb interactions may not take place in one or more dimensions. Collisional scattering theory has recently been developed for describing the velocity-space scattering processes in such systems [J.R. Correa, Y. Chang, C.A. Ordonez, Phys. Plasmas 12 (2005) 084505]. The theory is extended to enable the effect of a magnetic field to be included. The theory is intended to be applicable, for example, to antiproton scattering within nested Penning traps that are used to produce antihydrogen [M. Amoretti et al., Nature 419 (2002) 456; G. Gabrielse et al., Phys. Rev. Lett. 89 (2002) 213401]. The theory is applied for considering the cross-magnetic-field diffusion of the antiprotons

  14. Carbon filament beam profile monitor for high energy proton-antiproton storage rings

    International Nuclear Information System (INIS)

    Evans, L.R.; Shafer, R.E.

    1979-01-01

    The measurement of the evolution of the transverse profile of the stored beams in high energy proton storage rings such as the p-anti p colliders at CERN and at FNAL is of considerable importance. In the present note, a simple monitor is discussed which will allow almost non-destructive measurement of the profile of each individual proton and antiproton bunch separately. It is based on the flying wire technique first used at CEA and more recently at the CPS. A fine carbon filament is passed quickly through the beam, acting as a target for secondary particle production. The flux of secondary particles is measured by two scintillator telescopes, one for protons and one for antiprotons, having an angular acceptance between 30 and 100 mrad. Measurements of secondary particle production performed at FNAL in this angular range show that a very respectable flux can be expected

  15. Suppression of propagating TE modes in the FNAL antiproton source stochastic beam cooling system

    International Nuclear Information System (INIS)

    Barry, W.C.

    1985-05-01

    A method of attenuating the propagation of waveguide modes in the stochastic cooling array beam pipes to be utilized in the accumulator and debuncher rings of the Fermilab antiproton source is described. The attenuation method treated involves lining the vertical walls of the beam pipes with a ferrimagnetic material. The general solution for propagation in a nonhomogeneously loaded waveguide is presented along with numerical results specific to the antiproton source beam cooling system. Also described is a broadband, automated technique for the simultaneous measurement of complex μ and epsilon developed to aid in the characterization of different ferrite materials. Permittivity and permeability data for a typical ferrite are presented along with a discussion of the effects of these parameters on waveguide mode attenuation in the ferrite lined beam pipes

  16. Antiproton production in heavy-ion collisions at energies below the threshold

    International Nuclear Information System (INIS)

    Schroeter, A.

    1993-08-01

    In the framework of this thesis the antiproton production in heavy ion collisions at projectile energies far below the threshold for anti p production in nucleon-nucleon collisions (5.63 GeV/u) was studied. A suited detection apparature was developed and constructed at the fragment separator-magnet spectrometer at the Society for Heavy Ion Research (GSI). For the identification of the antiprotons the momentum of the particles emitted in beam direction was measured and their velocity multiple-redundantly determined by means of time-of-flight measurements and threshold Cherenkov detectors. By this way the antiprotons could be in spite of low anti p production cross sections and high production rates for lighter particles (R anti p: R K - -:R π - -∼1:5*10 3 :10 7 ) background-freely determined. By this experiment for Ne+NaF, Cu, Sn, and Bi as well ass Ni+Ni collisions at incident energies between 1.6 GeV/u and 2.0 GeV/u production cross sections for antiprotons in the momentum range between 1.0 GeV/c and 2.2 GeV/c and for kaons and pions between 0.5 GeV/c and 2.8 GeV/c were measured, in order to study the influence of collisional-system size, incident energy, and secondary-particle momentum on the production probabilities and to contribute in comparison with the prognoses of theoretical models to the explanation of the particle production mechanisms. (HSI)

  17. Study of relativistic heavy-ion interactions and antiproton annihilation data

    International Nuclear Information System (INIS)

    Ghosh, D.; Roy, J.; Sengupta, R.

    1986-01-01

    The characteristics of 12 C-AgBr interaction at 4.5-GeV · c -1 · nucleon -1 incident momentum are studied by means of the photoemulsion technique, to search for shock-wave phenomena. The angular distributions indicate an anisotropic process in the nuclear matter. The results are compared with the antiproton -AgBr reaction observations of Breivik et al. (1983) at 1.4 GeV · c -1

  18. Antiproton interaction with 4He as a test of GUT cosmology

    International Nuclear Information System (INIS)

    Chechetkin, V.M.; Khlopov, M.Yu.; Zeldovich, Ya.B.

    1982-01-01

    A new possibility of checking some GUT models is suggested, basing on the analysis of their cosmological consequences and the experimental study of the anti p 4 He interaction. The study of annihilation of antiprotons with 4 He may provide limits on the possible amount of antimatter in the early Universe, limits on the probability of formation of primordial black holes and restrictions on the GUT parameters determining the properties of domains of antimatter

  19. Using the circulating beam in the Fermilab antiproton accumulator for experiments

    International Nuclear Information System (INIS)

    MacLachlan, J.A.

    1988-01-01

    The Fermilab Accumulator is a storage ring optimized for stacking and stochastic cooling 8 GeV antiprotons for the Tevatron collider. Minor modifications have been made to provide for beam in the energy range 8.0-2.9 GeV of luminosity /approximately/10 31 cm -2 s/sup - 1/ with a hydrogen jet internal target. Experience to date consists of machine studies and detector engineering run with protons. 7 refs

  20. Information on antiprotonic atoms and the nuclear periphery from the PS209 experiment

    CERN Document Server

    Trzcinska, A.; Czosnyka, T.; von Egidy, T.; Gulda, K.; Hartmann, F.J.; Iwanicki, J.; Ketzer, B.; Kisielinski, M.; Klos, B.; Kurcewicz, W.; Lubinski, P.; Napiorkowski, P.J.; Pienkowski, L.; Schmidt, R.; Widmann, E.

    2001-01-01

    In the PS209 experiments at CERN two kinds of measurements were performed: the in-beam measurement of X-rays from antiprotonic atoms and the radiochemical, off-line determination of the yield of annihilation products with mass number A_t -1 (less by 1 than the target mass). Both methods give observables which allows to study the peripheral matter density composition and distribution.

  1. Formation and decay of nuclei heated with high-energy antiprotons

    CERN Document Server

    Lott, B; Eades, J.; Egidy, T.v.; Figuera, P.; Fuchs, H.; Galin, J.; Gulda, K.; Goldenbaum, F.; Hilscher, D.; Jahnke, U.; Jastrzebski, J.; Kurcewicz, W.; Morjean, M.; Pausch, G.; Péghaire, A.; Pienkowski, L.; Polster, D.; Proschitzki, S.; Quednau, B.; Rossner, H.; Schmid, S.; Schmid, W.; Ziem, P.

    1999-01-01

    The decay of nuclei excited via the annihilation of 1.2 GeV antiprotons has been investigated. Thanks to the ability to determine the excitation energy, E sup * , for all events, largely irrespective of their mass partitions, the probabilities of the different channels at play could be estimated as a function of E sup *. The data show the prevalence of fission and evaporation up to E sup * = 4 MeV/nucleon, with no hint of a transition towards multifragmentation.

  2. Cosmic-ray antiprotons as a probe of a photino-dominated universe

    Science.gov (United States)

    Silk, J.; Srednicki, M.

    1984-01-01

    Observational tests of the hypothesis that the universe is flat and dominated by dark matter in the form of massive photinos include the production of significant fluxes of cosmic rays and gamma rays in our galactic halo. Specification of the cosmological photino density and the masses of scalar quarks and leptons determines the present annihilation rate. The predicted number of low-energy cosmic-ray antiprotons is comparable to the observed flux.

  3. Proton - antiproton annihilations to φφ mesons: results from JETSET at LEAR

    Science.gov (United States)

    Bertolotto, L.; Buzzo, A.; Debevec, P. T.; Drijard, D.; Easo, S.; Eisenstein, R. A.; Evangelista, C.; Eyrich, W.; Fearnley, T.; Ferro-Luzzi, M.; Franz, J.; Geyer, R.; Hamann, N.; Harris, Ph.; Hertzog, D. W.; Hughes, S. A.; Johansson, T.; Jones, R.; Kilian, K.; Kirsebom, K.; Klett, A.; Korsmo, H.; Lo Vetere, M.; Marinelli, M.; Moossburger, M.; Mouëllic, B.; Oelert, W.; Ohlsson, S.; Palano, A.; Passaggio, S.; Perreau, J. M.; Pia, M. G.; Pozzo, A.; Price, M.; Reimer, P. E.; Ritter, J.; Robutti, E.; Röhrich, K.; Rook, M.; Rössle, E.; Santroni, A.; Schmitt, H.; Steinkamp, O.; Stinzing, F.; Stugu, B.; Tscheulin, M.; Urban, H. J.; Wirth, H.; Zipse, H.; Jetset Collaboration

    1993-06-01

    The πp → φφ reaction has been studied in an internal target experiment at LEAR using antiprotons at various laboratory momenta spanning the region between 1 and 2 GeV/c (cms energies between 2.08 and 2.43 GeV). Cross sections have been measured at a total of 16 different energy settings over the above range. Preliminary cross sections are reported.

  4. Proton-antiproton annihilations to [phi][phi]mesons: results from JETSET at LEAR

    Energy Technology Data Exchange (ETDEWEB)

    Bertolotto, L.; Buzzo, A.; Devevec, P.T.; Drijard, D.; Easo, S.; Eisenstein, R.A.; Evangelista, C.; Eyrich, W.; Fearnley, T.; Ferro-Luzzi, M.; Franz, J.; Geyer, R.; Hamann, N.; Harris, P.; Hertzog, D.W.; Hughes, S.A.; Johansson, T.; Jones, R.; Kilian, K.; Kirsebom, K.; Klett, A.; Korsmo, H.; Lo Vetere, M.; Marinelli, M.; Moossburger, M.; Mouellic, B.; Oelert, W.; Ohlsson, S.; Palano, A.; Passaggio, S.; Perreau, J.M.; Pia, M.G.; Pozzo, A.; Price, M.; Reimer, P.E.; Ritter, J.; Robutti, E.; Roehrich, K.; Rook, M.; Roessle, E.; Santroni, A.; Schmitt, H.; Steinkamp, O.; Stinzing, F.; Stugu, B.; Tscheulin, M.; Urban, H.J.; Wirth, H.; Zipse, H. (Istituto Nazionale di Fisica Nucleare, Genoa (Italy) Genoa Univ. (Italy) Univ. of Illinois, Urbana-Champaign (United States) European Organization for Nuclear Research (CERN), Geneva (Switzerland) Istituto Nazionale di Fisica Nucleare, Bari (Italy) Bari Univ. (Italy) Physikalisches Institut, Erlangen Univ. (Germany) Fakultaet fuer Physik, Univ. Freib; JETSET Collaboration

    1993-06-07

    The [pi]p[yields][phi][phi] reaction has been studied in an internal target experiment at LEAR using antiprotons at various laboratory momenta spanning the region between 1 and 2 GeV/c (cms energies between 2.08 and 2.43 GeV). Cross sections have been measured at a total of 16 different energy settings over the above range. Preliminary cross sections are reported. (orig.)

  5. Proton-antiproton annihilations to φφmesons: results from JETSET at LEAR

    International Nuclear Information System (INIS)

    Bertolotto, L.; Buzzo, A.; Devevec, P.T.; Drijard, D.; Easo, S.; Eisenstein, R.A.; Evangelista, C.; Eyrich, W.; Fearnley, T.; Ferro-Luzzi, M.; Franz, J.; Geyer, R.; Hamann, N.; Harris, P.; Hertzog, D.W.; Hughes, S.A.; Johansson, T.; Jones, R.; Kilian, K.; Kirsebom, K.; Klett, A.; Korsmo, H.; Lo Vetere, M.; Marinelli, M.; Moossburger, M.; Mouellic, B.; Oelert, W.; Ohlsson, S.; Palano, A.; Passaggio, S.; Perreau, J.M.; Pia, M.G.; Pozzo, A.; Price, M.; Reimer, P.E.; Ritter, J.; Robutti, E.; Roehrich, K.; Rook, M.; Roessle, E.; Santroni, A.; Schmitt, H.; Steinkamp, O.; Stinzing, F.; Stugu, B.; Tscheulin, M.; Urban, H.J.; Wirth, H.; Zipse, H.

    1993-01-01

    The πp→φφ reaction has been studied in an internal target experiment at LEAR using antiprotons at various laboratory momenta spanning the region between 1 and 2 GeV/c (cms energies between 2.08 and 2.43 GeV). Cross sections have been measured at a total of 16 different energy settings over the above range. Preliminary cross sections are reported. (orig.)

  6. Electrostatic accelerators

    OpenAIRE

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We ...

  7. Simplified dark matter models in the light of AMS-02 antiproton data

    International Nuclear Information System (INIS)

    Li, Tong

    2017-01-01

    In this work we perform an analysis of the recent AMS-02 antiproton flux and the antiproton-to-proton ratio in the framework of simplified dark matter models. To predict the AMS-02 observables we adopt the propagation and injection parameters determined by the observed fluxes of nuclei. We assume that the dark matter particle is a Dirac fermionic dark matter, with leptophobic pseudoscalar or axialvector mediator that couples only to Standard Model quarks and dark matter particles. We find that the AMS-02 observations are consistent with the dark matter framework within the uncertainties. The antiproton data prefer a dark matter (mediator) mass in the 700 GeV–5 TeV region for the annihilation with pseudoscalar mediator and greater than 700 GeV (200 GeV–1 TeV) for the annihilation with axialvector mediator, respectively, at about 68% confidence level. The AMS-02 data require an effective dark matter annihilation cross section in the region of 1×10 −25 –1×10 −24 (1×10 −25 –4×10 −24 ) cm 3 /s for the simplified model with pseudoscalar (axialvector) mediator. The constraints from the LHC and Fermi-LAT are also discussed.

  8. Heavy flavour production and heavy flavour mixing at the CERN proton-antiproton collider

    International Nuclear Information System (INIS)

    Eijk, B. van.

    1987-01-01

    In this thesis some results of the proton-antiproton-collision experiment UA1 with the CERN Super Proton-Antiproton Synchrotron are presented and interpreted. Ch. 1 contians a general introduction to the physics motivations behind the proton-antiproton-collider project, a brief description of the CERN facilities and a summary of collider and UA1 physics achievements. Furthermore the concept of studying heavy flavours via their weak decays into muons is introduced. Ch. 2 gives a brief overview of the UA1 experimental set-up, while those parts of the detector that are relevant for the analysis, presented in this thesis, is discussed in some more detail. Ch. 3 contains a short introduction to, and motivation for the use of Monte Carlo techniques in event simulations, while Ch. 4 describes the framework of the recently developed 'EUROJET' event generator. In Ch. 5 a treatment is given of the theoretical background and concepts like 'quark-mixing' and 'CP-violation' are explained, also other useful definitions and formulae are introduced on which the later analysis of the same-sign to opposite-sign dimuon ratio is built. Data collection and event reconstruction is the subject of Ch. 6, while a detailed comparison between the theoretical models and experimentally obtained distributions is given in Ch. 7. Finally, in Ch. 8 some concluding remarks are made. 182 refs.; 81 figs.; 9 tabs

  9. Application of high quality antiproton beam to study charmonium and exotics above DD-bar threshold

    International Nuclear Information System (INIS)

    Barabanov, M.Y.; Vodopyanov, A.S.

    2014-01-01

    The spectroscopy of charmonium and exotic states with hidden charm is discussed. It is a good testing tool for theories of strong interactions including QCD in both perturbative and non-perturbative regime, lattice QCD, potential models and phenomenological models. An elaborated analysis of charmonium and charmed hybrid spectrum is given, and attempts to interpret recent experimental data in the above DD-bar threshold region are considered. Experiments using antiproton beam take advantage of the intensive production of particle-antiparticle pairs in antiproton-proton annihilations. Experimental data from different collaboration are analyzed with special attention given to new states with hidden charm that were discovered recently. Some of these states can be interpreted as higher-laying S, P and D wave charmonium states. But much more data on different decay modes are needed before firmer conclusions can be made. These data can be derived directly from the experiments using high quality antiproton beam with momentum up to 15 GeV/c. (authors)

  10. Simplified dark matter models in the light of AMS-02 antiproton data

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tong [ARC Centre of Excellence for Particle Physics at the Tera-scale,School of Physics and Astronomy, Monash University,Melbourne, Victoria 3800 (Australia)

    2017-04-19

    In this work we perform an analysis of the recent AMS-02 antiproton flux and the antiproton-to-proton ratio in the framework of simplified dark matter models. To predict the AMS-02 observables we adopt the propagation and injection parameters determined by the observed fluxes of nuclei. We assume that the dark matter particle is a Dirac fermionic dark matter, with leptophobic pseudoscalar or axialvector mediator that couples only to Standard Model quarks and dark matter particles. We find that the AMS-02 observations are consistent with the dark matter framework within the uncertainties. The antiproton data prefer a dark matter (mediator) mass in the 700 GeV–5 TeV region for the annihilation with pseudoscalar mediator and greater than 700 GeV (200 GeV–1 TeV) for the annihilation with axialvector mediator, respectively, at about 68% confidence level. The AMS-02 data require an effective dark matter annihilation cross section in the region of 1×10{sup −25}–1×10{sup −24} (1×10{sup −25}–4×10{sup −24}) cm{sup 3}/s for the simplified model with pseudoscalar (axialvector) mediator. The constraints from the LHC and Fermi-LAT are also discussed.

  11. Measurements of Wake-Riding Electrons in Antiproton-Carbon-Foil Collisions

    CERN Multimedia

    2002-01-01

    When a charged particle passes through dielectric media, e.g. a thin carbon foil, a ``wake'' is induced. The characteristic wake-potential shows an oscillatory behaviour, with a wavelength of about $ 2 \\pi v _{p} / \\omega _{p} _{l} $ where $ v _{p} $ is the projectile velocity and $ \\omega _{p} _{l} $ the plasmon energy of the target. This induced wake potential is superimposed on the Coulomb potential of the projectile, the latter leading to a pronounced ``cusp'' of electrons leaving the solid at $ v _{e} app v _{p} $ for positively charged projectiles in the MeV region. Correspondingly, an ``anti-cusp'' is expected for antiprotons. \\\\ \\\\ In the solid, the wake-potential leads to an attractive force on electrons, and a dynamic electronic state is predicted both for proton and antiproton projectiles. In the solid, the wake-riding electrons are travelling with the projectile speed $ v _{p} $ Upon exit of the foil, the electron released from the wake-riding state of an antiproton will suddenly find itself in th...

  12. Elementary design of a 30 TeV on 30 TeV proton antiproton collider

    International Nuclear Information System (INIS)

    Kondo, Takahiko

    1984-01-01

    A crude conceptual design was made for a 30TeV on 30TeV antiproton-proton collider. The choice of energy and antiproton-proton (instead of PP) are somewhat arbitrary. The basic parameters of the main ring are listed in a table; the bending radius, ring radius and circumference are 11.1km, 14.4km, and 90.6km, respectively; 7680 dipole magnets with maximum field of 9 Tesla; 1280 quadrupole magnets with maximum gradient of 200Tesla/m. The development of high-field, low-heat loss dipoles and quadrupoles are essential, together with the consideration for their mass production method. On the other hand, the possibility of obtaining antiproton-proton luminosity exceeding 10 32 /cm 2 sec is suggested without any fundamental limitation. With such high luminosity, however, it should be pointed out that particle detectors must face their limitation due to extremely high rate, high multiplicity interaction, requiring large steps of detector research and development efforts. (Aoki, K.)

  13. Unified interpretation of cosmic-ray nuclei and antiproton recent measurements

    International Nuclear Information System (INIS)

    Di Bernardo, Giuseppe; Gaggero, Daniele; Evoli, Carmelo; Grasso, Dario; Maccione, Luca

    2009-09-01

    We use our numerical code, DRAGON, to study the implications and the impact of recent CREAM and PAMELA data on our knowledge of the propagation properties of cosmic ray nuclei with energy >or similar 1 GeV/n in the Galaxy. We will show that B/C (as well as N/O and C/O) and anti p/p data (especially including recent PAMELA results) can consistently be matched within a unique diffusion-reacceleration model. The requirement that light nuclei and anti p data are both reproduced within experimental uncertainties places stringent limits on suitable propagation parameters. In particular, we find the allowed range of the diffusion coefficient spectral index to be 0.38 A ≅15 kms -1 ) is allowed. Furthermore, we do not need to introduce any ad hoc break in the injection spectrum of primary cosmic rays. If antiproton data are not used to constrain the propagation parameters, a larger set of models is allowed. In this case, we determine which combinations of the relevant parameters maximize and minimize the antiproton flux under the condition of still fitting light nuclei data at 95% C.L. These models may then be used to constrain a possible extra antiproton component arising from astrophysical or exotic sources (e.g. dark matter annihilation or decay). (orig.)

  14. Electrostatic accelerators

    CERN Document Server

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

  15. Accelerator development

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Because the use of accelerated heavy ions would provide many opportunities for new and important studies in nuclear physics and nuclear chemistry, as well as other disciplines, both the Chemistry and Physics Divisions are supporting the development of a heavy-ion accelerator. The design of greatest current interest includes a tandem accelerator with a terminal voltage of approximately 25 MV injecting into a linear accelerator with rf superconducting resonators. This combined accelerator facility would be capable of accelerating ions of masses ranging over the entire periodic table to an energy corresponding to approximately 10 MeV/nucleon. This approach, as compared to other concepts, has the advantages of lower construction costs, lower operating power, 100 percent duty factor, and high beam quality (good energy resolution, good timing resolution, small beam size, and small beam divergence). The included sections describe the concept of the proposed heavy-ion accelerator, and the development program aiming at: (1) investigation of the individual questions concerning the superconducting accelerating resonators; (2) construction and testing of prototype accelerator systems; and (3) search for economical solutions to engineering problems. (U.S.)

  16. Measurement of asymmetries and differential cross sections in antiproton-proton elastic scattering at momenta between 497 and 1550 MeV/c

    International Nuclear Information System (INIS)

    Kunne, R.A.

    1988-01-01

    An intermediate energy antiproton proton (anti pp) elastic scattering experiment is described. The data comprise a set of 15 measurements of the differential cross section and the asymmetry between 497 and 1550 MeV/c antiproton momentum. The measurements were carried out using the high quality antiproton beam provided by the Low Energy Antiproton Ring (LEAR) at CERN. A conventional polarized target was used, consisting of pentanol. The motivation for the measurements is the study of the anti pp interaction by providing data on the spin observable A on in a momentum range where it has never been measured before. 56 refs.; 55 figs.; 40 tabs

  17. The CLIC Multi-Drive Beam Scheme

    CERN Document Server

    Corsini, R

    1998-01-01

    The CLIC study of an e+ / e- linear collider in the TeV energy range is based on Two-Beam Acceleration (TBA) in which the RF power needed to accelerate the beam is extracted from high intensity relativistic electron beams, the so-called drive beams. The generation, acceleration and transport of the high-intensity drive beams in an efficient and reliable way constitute a challenging task. An overview of a potentially very effective scheme is presented. It is based on the generation of trains of short bunches, accelerated sequentially in low frequency superconducting cavities in a c.w. mode, stored in an isochronous ring and combined at high energy by funnelling before injection by sectors into the drive linac for RF power production. The various systems of the complex are discussed.

  18. Scheme Program Documentation Tools

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2004-01-01

    are separate and intended for different documentation purposes they are related to each other in several ways. Both tools are based on XML languages for tool setup and for documentation authoring. In addition, both tools rely on the LAML framework which---in a systematic way---makes an XML language available...... as named functions in Scheme. Finally, the Scheme Elucidator is able to integrate SchemeDoc resources as part of an internal documentation resource....

  19. RECIRCULATING ACCELERATION

    International Nuclear Information System (INIS)

    BERG, J.S.; GARREN, A.A.; JOHNSTONE, C.

    2000-01-01

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous

  20. LIBO accelerates

    CERN Multimedia

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.