Beam-Beam Study on the Upgrade of Beijing Electron Positron Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, S.; /Beijing, Inst. High Energy Phys.; Cai, Y.

2006-02-10

It is an important issue to study the beam-beam interaction in the design and performance of such a high luminosity collider as BEPCII, the upgrade of Beijing Electron Positron Collider. The weak-strong simulation is generally used during the design of a collider. For performance a large scale tune scan, the weak-strong simulation studies on beam-beam interaction were done, and the geometry effects were taken into account. The strong-strong simulation studies were done for investigating the luminosity goal and the dependence of the luminosity on the beam parameters.

Physics Goals for the Planned Next Linear Collider Engineering Test Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raubenheimer, Tor O

2001-10-02

The Next Linear Collider (NLC) Collaboration is planning to construct an Engineering Test Facility (ETF) at Fermilab. As presently envisioned, the ETF would comprise a fundamental unit of the NLC main linac to include X-band klystrons and modulators, a delay-line power-distribution system (DLDS), and NLC accelerating structures that serve as loads. The principal purpose of the ETF is to validate stable operation of the power-distribution system, first without beam, then with a beam having the NLC pulse structure. This paper concerns the possibility of configuring and using the ETF to accelerate beam with an NLC pulse structure, as well asmore » of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.« less

Physics goals for the planned next linear collider engineering test facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Courtlandt L Bohn et al.

2001-06-26

The Next Linear Collider (NLC) Collaboration is planning to construct an Engineering Test Facility (ETF) at Fermilab. As presently envisioned, the ETF would comprise a fundamental unit of the NLC main linac to include X-band klystrons and modulators, a delay-line power-distribution system (DLDS), and NLC accelerating structures that serve as loads. The principal purpose of the ETF is to validate stable operation of the power-distribution system, first without beam, then with a beam having the NLC pulse structure. This paper concerns the possibility of configuring and using the ETF to accelerate beam with an NLC pulse structure, as well asmore » of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.« less

Physics goals for the planned next linear collider engineering test facility.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohn, C.; Michelotti, L.; Ostiguy, J.-F.

2001-07-17

The Next Linear Collider (NLC) Collaboration is planning to construct an Engineering Test Facility (ETF) at Fermilab. As presently envisioned, the ETF would comprise a fundamental unit of the NLC main linac to include X-band klystrons and modulators, a delay-line power-distribution system (DLDS), and NLC accelerating structures that serve as loads. The principal purpose of the ETF is to validate stable operation of the power-distribution system, first without beam, then with a beam having the NLC pulse structure. This paper concerns the possibility of configuring and using the ETF to accelerate beam with an NLC pulse structure, as well asmore » of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.« less

Feasibility of Colliding-beam fast-fission reactor via 238U80++238 U80+ --> 4 FF + 5n + 430 MeV beam with suppressed plutonium and direct conversion of fission fragment (FF) energy into electricity and/or Rocket propellant with high specific impulse

NASA Astrophysics Data System (ADS)

Maglich, Bogdan; Hester, Tim; Calsec Collaboration

2015-10-01

Uranium-uranium colliding beam experiment1, used fully ionized 238U92+ at energy 100GeV --> <-- 100 GeV, has measured total σ = 487 b. Reaction rate of colliding beams is proportional to neutron flux-squared. First functional Auto-Collider3-6, a compact Migma IV, 1 m in diameter, had self-colliding deuterons, D+, of 725 KeV --> <-- 725 KeV, resulting in copious production of T and 3He. U +U Autocollider``EXYDER'' will use strong-focusing magnet7, which would increase reaction rate by 104. 80 times ionized U ions accelerated through 3 MV accelerator, will collide beam 240 MeV --> <-- 240 MeV. Reaction is: 238U80+ +238 U80+ --> 4 FF + 5n + 430 MeV. Using a simple model1 fission σf ~ 100 b. Suppression of Pu by a factor of 106 will be achieved because NO thermal neutron fission can take place; only fast, 1-3 MeV, where σabs is negligible. Direct conversion of 95% of 430 MeV produced is carried by electrically charged FFs which are magnetically funneled for direct conversion of energy of FFs via electrostatic decelerators4,11. 90% of 930 MeV is electrically recoverable. Depending on the assumptions, we project electric _ power density production of 20 to 200 MWe m-3, equivalent to Thermal 1.3 - 13 GWthm-3. If one-half of unburned U is used for propulsion while rest powers system, heavy FF ion mass provides specific impulse Isp = 106 sec., 103 times higher than current rocket engines.

Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stancari, Giulio; Previtali, Valentina; Valishev, Alexander

Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. We are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. Themore » expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.« less

Status of the NICA project at JINR

NASA Astrophysics Data System (ADS)

Kekelidze, Vladimir; Kovalenko, Alexandr; Lednicky, Rihard; Matveev, Viktor; Meshkov, Igor; Sorin, Alexandr; Trubnikov, Grigory

2017-03-01

The NICA (Nuclotron-based Ion Collider fAcility) project is now under active realization at the Joint Institute for Nuclear Research (JINR, Dubna). The main goal of the project is a study of hot and dense strongly interacting matter in heavy-ion (up to Au) collisions at the center-of-mass energies up to 11 GeV per nucleon. Two modes of operation are foreseen, collider mode and extracted beams, with two detectors: MPD and BM@N. The both experiments are in preparation stage. An average luminosity in the collider mode is expected to be 1027 cm-2 s-1 for Au (79+). Extracted beams of various nuclei with maximum momenta of 13 GeV/c (for protons) will be available. A study of spin physics with extracted and colliding beams of polarized deuterons and protons at energies up to 27 GeV (for protons) is foreseen with the NICA facility. The proposed program allows one to search for possible signs of phase transitions and critical phenomena as well as to shed light on the problem of the nucleon spin structure.

Electron cloud buildup driving spontaneous vertical instabilities of stored beams in the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Romano, Annalisa; Boine-Frankenheim, Oliver; Buffat, Xavier; Iadarola, Giovanni; Rumolo, Giovanni

2018-06-01

At the beginning of the 2016 run, an anomalous beam instability was systematically observed at the CERN Large Hadron Collider (LHC). Its main characteristic was that it spontaneously appeared after beams had been stored for several hours in collision at 6.5 TeV to provide data for the experiments, despite large chromaticity values and high strength of the Landau-damping octupole magnet. The instability exhibited several features characteristic of those induced by the electron cloud (EC). Indeed, when LHC operates with 25 ns bunch spacing, an EC builds up in a large fraction of the beam chambers, as revealed by several independent indicators. Numerical simulations have been carried out in order to investigate the role of the EC in the observed instabilities. It has been found that the beam intensity decay is unfavorable for the beam stability when LHC operates in a strong EC regime.

Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure

DOE PAGES

Zha, Hao; Latina, Andrea; Grudiev, Alexej; ...

2016-01-20

The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures for its main linacs. In order to maintain beam stability in multibunch operation, long-range transverse wakefields must be suppressed by 2 orders of magnitude between successive bunches, which are separated in time by 0.5 ns. Such strong wakefield suppression is achieved by equipping every accelerating structure cell with four damping waveguides terminated with individual rf loads. A beam-based experiment to directly measure the effectiveness of this long-range transverse wakefield and benchmark simulations was made in the FACET test facility at SLAC using a prototype CLIC accelerating structure. Furthermore,more » the experiment showed good agreement with the simulations and a strong suppression of the wakefields with an unprecedented minimum resolution of 0.1 V/(pC mm m).« less

Novel Application of Density Estimation Techniques in Muon Ionization Cooling Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohayai, Tanaz Angelina; Snopok, Pavel; Neuffer, David

The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate muon beam ionization cooling for the first time and constitutes a key part of the R&D towards a future neutrino factory or muon collider. Beam cooling reduces the size of the phase space volume occupied by the beam. Non-parametric density estimation techniques allow very precise calculation of the muon beam phase-space density and its increase as a result of cooling. These density estimation techniques are investigated in this paper and applied in order to estimate the reduction in muon beam size in MICE under various conditions.

Distinct signals of the gauge-Higgs unification in e+e- collider experiments

NASA Astrophysics Data System (ADS)

Funatsu, Shuichiro; Hatanaka, Hisaki; Hosotani, Yutaka; Orikasa, Yuta

2017-12-01

Effects of Kaluza-Klein excited neutral vector bosons (Z‧ bosons) in the gauge-Higgs unification on e+e- → q bar q ,ℓ+ℓ- cross sections are studied, particularly in future e+e- collider experiments with polarized beams. Significant deviations in the energy and polarization dependence in σ (μ+μ-), the lepton forward-backward asymmetry, Rb (μ) ≡ σ (b bar b) / σ (μ+μ-) and the left-right asymmetry from the standard model are predicted.

Electron Lenses for the Large Hadron Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stancari, Giulio; Valishev, Alexander; Bruce, Roderik

Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as anmore » option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.« less

Initial performance studies of a general-purpose detector for multi-TeV physics at a 100 TeV pp collider

DOE PAGES

Chekanov, S. V.; Beydler, M.; Kotwal, A. V.; ...

2017-06-13

This paper describes simulations of detector response to multi-TeV physics at the Future Circular Collider (FCC-hh) or Super proton-proton Collider (SppC) which aim to collide proton beams with a centre-of-mass energy of 100 TeV. The unprecedented energy regime of these future experiments imposes new requirements on detector technologies which can be studied using the detailed geant4 simulations presented in this paper. The initial performance of a detector designed for physics studies at the FCC-hh or SppC experiments are described with an emphasis on measurements of single particles up to 33 TeV in transverse momentum. Furthermore, the granularity requirements for calorimetrymore » are investigated using the two-particle spatial resolution achieved for hadron showers.« less

Initial performance studies of a general-purpose detector for multi-TeV physics at a 100 TeV pp collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chekanov, S. V.; Beydler, M.; Kotwal, A. V.

This paper describes simulations of detector response to multi-TeV physics at the Future Circular Collider (FCC-hh) or Super proton-proton Collider (SppC) which aim to collide proton beams with a centre-of-mass energy of 100 TeV. The unprecedented energy regime of these future experiments imposes new requirements on detector technologies which can be studied using the detailed geant4 simulations presented in this paper. The initial performance of a detector designed for physics studies at the FCC-hh or SppC experiments are described with an emphasis on measurements of single particles up to 33 TeV in transverse momentum. Furthermore, the granularity requirements for calorimetrymore » are investigated using the two-particle spatial resolution achieved for hadron showers.« less

Quadrupole Alignment and Trajectory Correction for Future Linear Colliders: SLC Tests of a Dispersion-Free Steering Algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assmann, R

2004-06-08

The feasibility of future linear colliders depends on achieving very tight alignment and steering tolerances. All proposals (NLC, JLC, CLIC, TESLA and S-BAND) currently require a total emittance growth in the main linac of less than 30-100% [1]. This should be compared with a 100% emittance growth in the much smaller SLC linac [2]. Major advances in alignment and beam steering techniques beyond those used in the SLC are necessary for the next generation of linear colliders. In this paper, we present an experimental study of quadrupole alignment with a dispersion-free steering algorithm. A closely related method (wakefield-free steering) takesmore » into account wakefield effects [3]. However, this method can not be studied at the SLC. The requirements for future linear colliders lead to new and unconventional ideas about alignment and beam steering. For example, no dipole correctors are foreseen for the standard trajectory correction in the NLC [4]; beam steering will be done by moving the quadrupole positions with magnet movers. This illustrates the close symbiosis between alignment, beam steering and beam dynamics that will emerge. It is no longer possible to consider the accelerator alignment as static with only a few surveys and realignments per year. The alignment in future linear colliders will be a dynamic process in which the whole linac, with thousands of beam-line elements, is aligned in a few hours or minutes, while the required accuracy of about 5 pm for the NLC quadrupole alignment [4] is a factor of 20 higher than in existing accelerators. The major task in alignment and steering is the accurate determination of the optimum beam-line position. Ideally one would like all elements to be aligned along a straight line. However, this is not practical. Instead a ''smooth curve'' is acceptable as long as its wavelength is much longer than the betatron wavelength of the accelerated beam. Conventional alignment methods are limited in accuracy by errors in the survey and the fiducials. Beam-based alignment methods ideally only depend upon the BPM resolution and generally provide much better precision. Many of those techniques are described in other contributions to this workshop. In this paper we describe our experiences with a dispersion-free steering algorithm for linacs. This algorithm was first suggested by Raubenheimer and Ruth in 1990 [5]. It h as been studied in simulations for NLC [5], TESLA [6], the S-BAND proposal [7] and CLIC [8]. The dispersion-free steering technique can be applied to the whole linac at once and returns the alignment (or trajectory) that minimizes the dispersive emittance growth of the beam. Thus it allows an extremely fast alignment of the beam-line. As we will show dispersion-free steering is only sensitive to quadrupole misalignments. Wakefield-free steering [3] as mentioned before is a closely related technique that minimizes the emittance growth caused by both dispersion and wakefields. Due to hardware limitations (i.e. insufficient relative range of power supplies) we could not study this method experimentally in the SLC. However, its systematics are very similar to those of dispersion-free steering. The studies of dispersion-free steering which are presented made extensive use of the unique potential of the SLC as the only operating linear collider. We used it to study the performance and problems of advanced beam-based optimization tools in a real beam-line environment and on a large scale. We should mention that the SLC has utilized beam-based alignment for years [9], using the difference of electron and positron trajectories. This method, however, cannot be used in future linear colliders. The goal of our work is to demonstrate the performance of advanced beam-based alignment techniques in linear colliders and to anticipate possible reality-related problems. Those can then be solved in the design state for the next generation of linear colliders.« less

Coherent Beam-Beam Instability in Collisions with a Large Crossing Angle

NASA Astrophysics Data System (ADS)

Ohmi, K.; Kuroo, N.; Oide, K.; Zhou, D.; Zimmermann, F.

2017-09-01

In recent years the "crab-waist collision" scheme [P. Raimondi, Proceedings of 2nd SuperB Workshop, Frascati, 2006.; M. Zobov et al., Phys. Rev. Lett. 104, 174801 (2010), 10.1103/PhysRevLett.104.174801] has become popular for circular e+ e- colliders. The designs of several future colliders are based on this scheme. So far the beam-beam effects for collisions under a large crossing angle with or without crab waist were mostly studied using weak-strong simulations. We present here strong-strong simulations showing a novel strong coherent head-tail instability, which can limit the performance of proposed future colliders. We explain the underlying instability mechanism starting from the "cross-wake force" induced by the beam-beam interaction. Using this beam-beam wake, the beam-beam head tail modes are studied by an eigenmode analysis. The instability may affect all collider designs based on the crab-waist scheme. We suggest an experimental verification at SuperKEKB during its commissioning phase II.

Collider and Detector Protection at Beam Accidents

NASA Astrophysics Data System (ADS)

Rakhno, I. L.; Mokhov, N. V.; Drozhdin, A. I.

2003-12-01

Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occured at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section.

Selection of the elastic scattering events in interactions of the NICA colliding proton (deuteron) beams

NASA Astrophysics Data System (ADS)

Sharov, Vasily

2017-03-01

The features of the kinematics of elastic pp (dd) scattering in the collider system, as well as some issues concerning registration and selection of elastic scattering events in the NICA colliding beams are considered. Equality and the opposite direction of the scattered particle momenta provide a powerful selection criterion for elastic collisions. Variants of the organization of the trigger signal for recording tracks of secondary particles and DAQ system are given. The estimates of the characteristics of elastic NN processes are obtained from available dσ/dΩCM data for the elastic pp and np scattering. The paper presents examples of simulations using the Monte-Carlo of elastic pp scattering in the colliding proton beams and quasi-elastic np scattering in the colliding deuteron beams and evaluates the outputs of these processes at the NICA collider.

Review of hydrodynamic tunneling issues in high power particle accelerators

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Piriz, A. R.

2018-07-01

Full impact of one Large Hadron Collider (LHC) 7 TeV proton beam on solid targets made of different materials including copper and carbon, was simulated using an energy deposition code, FLUKA and a two-dimensional hydrodynamic code, BIG2, iteratively. These studies showed that the penetration depth of the entire beam comprised of 2808 proton bunches significantly increases due to a phenomenon named hydrodynamic tunneling of the protons and the shower. For example, the static range of a single 7 TeV proton and its shower is about 1 m in solid copper, but the full LHC beam will penetrate up to about 35 m in the target, if the hydrodynamic effects were included. Due to the potential implications of this result on the machine protection considerations, it was decided to have an experimental verification of the hydrodynamic tunneling effect. For this purpose, experiments were carried out at the CERN HiRadMat (High Radiation to Materials) facility in which extended solid copper cylindrical targets were irradiated with the 440 GeV proton beam generated by the Super Proton Synchrotron (SPS). Simulations of beam-target heating considering the same beam parameters that were used in the experiments, were also performed. These experiments not only confirmed the existence of the hydrodynamic tunneling, but the experimental measurements showed very good agreement with the experimental results as well. This provided confidence in the work on LHC related beam-matter heating simulations. Currently, a design study is being carried out by the international community (with CERN taking the leading role) for a post LHC collider named, the Future Circular Collider (FCC) which will accelerate two counter rotating proton beams up to a particle energy of 50 TeV. Simulations of the full impact of one FCC beam comprised of 10,600 proton bunches with a solid copper target have also been done. These simulations have shown that although the static range of a single 50 TeV proton and its shower in solid copper is around 1.8 m, the entire beam will penetrate up to about 350 m in the target. Feasibility studies of developing a water beam dump for the FCC have also been carried out. A review of this work and its implications on machine protection system are presented in this paper.

Implications of HARP Results for the Energy of the Proton Driver for a Neutrino Factory and Muon Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strait, J.; Mokhov, N.V.; Striganov, S.I.

2010-06-09

Cross-section data from the HARP experiment for pion production by protons from a tantalum target have been convoluted with the acceptance of the front-end channel for the proposed neutrino factory or muon collider and integrated over the full phase space measured by HARP, to determine the beam-energy dependence of the muon yield. This permits a determination of the optimal beam energy for the proton driver for these projects. The cross-section data are corrected for the beam-energy dependent 'amplification' due to the development of hadronic showers in a thick target. The conclusion is that, for constant beam power, the yield ismore » maximum for a beam energy of about 7 GeV, but it is within 10% of this maximum for 4 < T{sub beam} < 11 GeV, and within 20% of the maximum for T{sub beam} as low as 2 GeV. This result is insensitive to which of the two HARP groups results are used, and to which pion generator is used to compute the thick target effects.« less

Status of the Future Circular Collider Study

NASA Astrophysics Data System (ADS)

Benedikt, Michael

2016-03-01

Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute, to design an energy frontier hadron collider (FCC-hh) in a new 80-100 km tunnel with a centre-of-mass energy of about 100 TeV, an order of magnitude beyond the LHC's, as a long-term goal. The FCC study also includes the design of a 90-350 GeV high-luminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines will be assessed and concepts for experiments will be developed in time for the next update of the European Strategy for Particle Physics by the end of 2018. The presentation will summarize the status of machine designs and parameters and discuss the essential technical components to be developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets with a field of 16 T for the hadron collider and high-power, high-efficiency RF systems for the lepton collider. In addition the unprecedented beam power presents special challenges for the hadron collider for all aspects of beam handling and machine protection. First conclusions of geological investigations and implementation studies will be presented. The status of the FCC collaboration and the further planning for the study will be outlined.

Numerical calculation of ion polarization in the NICA collider

NASA Astrophysics Data System (ADS)

Kovalenko, A. D.; Butenko, A. V.; Kekelidze, V. D.; Mikhaylov, V. A.; Kondratenko, M. A.; Kondratenko, A. M.; Filatov, Yu N.

2016-02-01

The NICA Collider with two solenoid Siberian snakes is “transparent” to the spin. The collider transparent to the spin provides a unique capability to control any polarization direction of protons and deuterons using additional weak solenoids without affecting orbital parameters of the beam. The spin tune induced by the control solenoids must significantly exceed the strength of the zero-integer spin resonance, which contains a coherent part associated with errors in the collider's magnetic structure and an incoherent part associated with the beam emittances. We present calculations of the coherent part of the resonance strength in the NICA collider for proton and deuteron beams.

Testing beam-induced quench levels of LHC superconducting magnets

NASA Astrophysics Data System (ADS)

Auchmann, B.; Baer, T.; Bednarek, M.; Bellodi, G.; Bracco, C.; Bruce, R.; Cerutti, F.; Chetvertkova, V.; Dehning, B.; Granieri, P. P.; Hofle, W.; Holzer, E. B.; Lechner, A.; Nebot Del Busto, E.; Priebe, A.; Redaelli, S.; Salvachua, B.; Sapinski, M.; Schmidt, R.; Shetty, N.; Skordis, E.; Solfaroli, M.; Steckert, J.; Valuch, D.; Verweij, A.; Wenninger, J.; Wollmann, D.; Zerlauth, M.

2015-06-01

In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam-induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy deposition in the coils is compared to the quench levels predicted by electrothermal models, thus allowing one to validate and improve the models which are used to set beam-dump thresholds on beam-loss monitors for run 2.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, W.; Gu, X.; Altinbas, Z.

Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider (RHIC) in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. As of this date the implemented compensation scheme approximately doubled the peak and average luminosities.

NICA project at JINR: status and prospects

NASA Astrophysics Data System (ADS)

Kekelidze, V. D.

2017-06-01

The project NICA (Nuclotron-based Ion Collider fAcility) is aimed to study hot and dense baryonic matter in heavy-ion collisions in the energy range up to 11.0 AGeV . The plan of NICA accelerator block development includes an upgrade of the existing superconducting (SC) synchrotron Nuclotron and construction of the new injection complex, SC Booster, and SC Collider with two interaction points (IP). The heavy-ion collision program will be performed with the fixed target experiment Baryonic Matter at Nuclotron (BM@N) at the beam extracted from the Nuclotron, and with Multi-Purpose Detector (MPD) at the first IP of NICA Collider. Investigation of nucleon spin structure and polarization phenomena is foreseen with the Spin Physics Detector (SPC) at the second IP of the Collider.

Analysis of 440 GeV proton beam-matter interaction experiments at the High Radiation Materials test facility at CERN

NASA Astrophysics Data System (ADS)

Burkart, F.; Schmidt, R.; Raginel, V.; Wollmann, D.; Tahir, N. A.; Shutov, A.; Piriz, A. R.

2015-08-01

In a previous paper [Schmidt et al., Phys. Plasmas 21, 080701 (2014)], we presented the first results on beam-matter interaction experiments that were carried out at the High Radiation Materials test facility at CERN. In these experiments, extended cylindrical targets of solid copper were irradiated with beam of 440 GeV protons delivered by the Super Proton Synchrotron (SPS). The beam comprised of a large number of high intensity proton bunches, each bunch having a length of 0.5 ns with a 50 ns gap between two neighboring bunches, while the length of this entire bunch train was about 7 μs. These experiments established the existence of the hydrodynamic tunneling phenomenon the first time. Detailed numerical simulations of these experiments were also carried out which were reported in detail in another paper [Tahir et al., Phys. Rev. E 90, 063112 (2014)]. Excellent agreement was found between the experimental measurements and the simulation results that validate our previous simulations done using the Large Hadron Collider (LHC) beam of 7 TeV protons [Tahir et al., Phys. Rev. Spec. Top.--Accel. Beams 15, 051003 (2012)]. According to these simulations, the range of the full LHC proton beam and the hadronic shower can be increased by more than an order of magnitude due to the hydrodynamic tunneling, compared to that of a single proton. This effect is of considerable importance for the design of machine protection system for hadron accelerators such as SPS, LHC, and Future Circular Collider. Recently, using metal cutting technology, the targets used in these experiments have been dissected into finer pieces for visual and microscopic inspection in order to establish the precise penetration depth of the protons and the corresponding hadronic shower. This, we believe will be helpful in studying the very important phenomenon of hydrodynamic tunneling in a more quantitative manner. The details of this experimental work together with a comparison with the numerical simulations are presented in this paper.

BM@N and MPD experiments at NICA

NASA Astrophysics Data System (ADS)

Kekelidze, Vladimir; Kolesnikov, Vadim; Sorin, Alexander

2018-02-01

The project NICA (Nuclotron-based Ion Collider fAcility) aims to study hot and baryon rich QCD matter in heavy ion collisions in the energy range = 4 - 11 GeV. The rich heavy-ion physics program will be performed at two experiments, BM@N (Baryonic Matter at Nuclotron) at beams extracted from the Nuclotron, and at MPD (Multi-Purpose Detector) at the NICA collider. This program covers a variety of phenomena in strongly interacting matter of the highest baryonic density, which includes study of collective effects, production of hyperon and hypernuclei, in-medium modification of meson properties, and event-by-event fluctuations.

Feasibility Studies for Single Transverse-Spin Asymmetry Measurements at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC)

DOE PAGES

Kikoła, Daniel; Echevarria, Miguel García; Hadjidakis, Cynthia; ...

2017-05-17

Measurement of Single Transverse-Spin Asymmetrymore » $$A_N$$ for various quarkonia states and Drell-Yan lepton pairs can shed light on the orbital angular momentum of quarks and gluons, a fundamental ingredient of the spin puzzle of the proton. The AFTER@LHC experiment combines a unique kinematic coverage and large luminosities of the Large Hadron Collider beams to deliver precise measurements, complementary to the knowledge provided by collider experiments such as RHIC. Here, we report on sensitivity studies for $$J/\\Psi$$, $$\\Upsilon$$ and Drell-Yan $$A_N$$ done using the performance of a LHCb-like and ALICE-like detectors, combined with a polarised hydrogen and $^3$He target. Particularly, such research will provide new insights and knowledge about transverse-momentum-dependent parton distribution functions for quarks and gluons and on twist-3 collinear matrix elements in a proton and a neutron.« less

Discovering New Light States at Neutrino Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Essig, Rouven; /SLAC; Harnik, Roni

2011-08-11

Experiments designed to measure neutrino oscillations also provide major opportunities for discovering very weakly coupled states. In order to produce neutrinos, experiments such as LSND collide thousands of Coulombs of protons into fixed targets, while MINOS and MiniBooNE also focus and then dump beams of muons. The neutrino detectors beyond these beam dumps are therefore an excellent arena in which to look for long-lived pseudoscalars or for vector bosons that kinetically mix with the photon. We show that these experiments have significant sensitivity beyond previous beam dumps, and are able to partially close the gap between laboratory experiments and supernovaemore » constraints on pseudoscalars. Future upgrades to the NuMI beamline and Project X will lead to even greater opportunities for discovery. We also discuss thin target experiments with muon beams, such as those available in COMPASS, and show that they constitute a powerful probe for leptophilic PNGBs.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchanan, Charles D.; Cline, David B.; Byers, N.

Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics;more » (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R D.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics;more » (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R & D.« less

A Wedge Absorber Experiment at MICE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, David; Mohayai, Tanaz; Rogers, Chris

2017-05-01

Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

Numerical Analysis of Parasitic Crossing Compensation with Wires in DA$$\\Phi$$NE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valishev, A.; Shatilov, D.; Milardi, C.

2015-06-24

Current-bearing wire compensators were successfully used in the 2005-2006 run of the DAΦNE collider to mitigate the detrimental effects of parasitic beam-beam interactions. A marked improvement of the positron beam lifetime was observed in machine operation with the KLOE detector. In view of the possible application of wire beam-beam compensators for the High Luminosity LHC upgrade, we revisit the DAΦNE experiments. We use an improved model of the accelerator with the goal to validate the modern simulation tools and provide valuable input for the LHC upgrade project.

Final muon cooling for a muon collider

NASA Astrophysics Data System (ADS)

Acosta Castillo, John Gabriel

To explore the new energy frontier, a new generation of particle accelerators is needed. Muon colliders are a promising alternative if muon cooling can be made to work. Muons are 200 times heavier than electrons, so they produce less synchrotron radiation, and they behave like point particles. However, they have a short lifetime of 2.2 mus and the beam is more difficult to cool than an electron beam. The Muon Accelerator Program (MAP) was created to develop concepts and technologies required by a muon collider. An important effort has been made in the program to design and optimize a muon beam cooling system. The goal is to achieve the small beam emittance required by a muon collider. This work explores a final ionization cooling system using magnetic quadrupole lattices with a low enough beta* region to cool the beam to the required limit with available low Z absorbers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Derbenev, Yaroslav S.; Morozov, Vasiliy; Lin, Fanglei

We present a complete scheme for managing the polarization of ion beams in Jefferson Lab's proposed Medium-energy Electron-Ion Collider (MEIC). It provides preservation of the ion polarization during all stages of beam acceleration and polarization control in the collider's experimental straights. We discuss characteristic features of the spin motion in accelerators with Siberian snakes and in accelerators of figure-8 shape. We propose 3D spin rotators for polarization control in the MEIC ion collider ring. We provide polarization calculations in the collider with the 3D rotator for deuteron and proton beams. The main polarization control features of the figure-8 design aremore » summarized.« less

Initial performance studies of a general-purpose detector for multi-TeV physics at a 100 TeV pp collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chekanov, S. V.; Beydler, M.; Kotwal, A. V.

This paper describes simulations of detector response to multi-TeV physics at the Future Circular Collider (FCC-hh) or Super proton-proton Collider (SppC) which aim to collide proton beams with a centre-of-mass energy of 100 TeV. The unprecedented energy regime of these future experiments imposes new requirements on detector technologies which can be studied using the detailed GEANT4 simulations presented in this paper. The initial performance of a detector designed for physics studies at the FCC-hh or SppC experiments is described with an emphasis on measurements of single particles up to 33 TeV in transverse momentum. The reconstruction of hadronic jets hasmore » also been studied in the transverse momentum range from 50 GeV to 26 TeV. The granularity requirements for calorimetry are investigated using the two-particle spatial resolution achieved for hadron showers.« less

Radiation-Thermal Sintering of Zirconia Powder Compacts Under Conditions of Bilateral Heating Using Beams of Low-Energy Electrons

NASA Astrophysics Data System (ADS)

Ghyngazov, S. A.; Frangulyan, T. S.; Chernyavskii, A. V.; Goreev, A. K.; Naiden, E. P.

2015-06-01

Comparative experiments on sintering zirconia ceramics are performed using colliding beams of low-energy electrons and under conditions of thermal heating. The density and microhardness of ceramic materials manufactured via different processes are determined. The use of a regime of bilateral heating by high-intensity,low-energy electron beams is shown to intensify the sintering process and yield material specimens with improved characteristics compared to those formed by thermal sintering.

A review of the Fermilab fixed-target program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rameika, R.

1994-12-01

All eyes are now on the Fermilab collider program as the intense search for the top quark continues. Nevertheless, Fermilab`s long tradition of operating a strong, diverse physics program depends not only on collider physics but also on effective use of the facilities the Laboratory was founded on, the fixed-target beamlines. In this talk the author presents highlights of the Fermilab fixed-target program from its (not too distant) past, (soon to be) present, and (hopefully, not too distant) future program. The author concentrates on those experiments which are unique to the fixed-target program, in particular hadron structure measurements which usemore » the varied beams and targets available in this mode and the physics results from kaon, hyperon and high statistics charm experiments which are not easily accessible in high p{sub T} hadron collider detectors.« less

Commissioning of the Electron-Positron Collider VEPP-2000 after the Upgrade

NASA Astrophysics Data System (ADS)

Shatunov, Yu.; Belikov, O.; Berkaev, D.; Gorchakov, K.; Zharinov, Yu.; Zemlyanskii, I.; Kasaev, A.; Kirpotin, A.; Koop, I.; Lysenko, A.; Motygin, S.; Perevedentsev, E.; Prosvetov, V.; Rabusov, D.; Rogovskii, Yu.; Senchenko, A.; Timoshenko, M.; Shatilov, D.; Shatunov, P.; Shvarts, D.

2018-05-01

The VEPP-2000 electron-positron collider has been operating at BINP since 2010. Applying the concept of round colliding beams allows us to reach the record value of the beam-beam parameter, ξ 0.12. The VEPP-2000 upgrade, including the connection to the new BINP Injection Complex, the improvement of the BEP booster, and the BEP-VEPP-2000 transfer channels for operation at 1 GeV, substantially increases the installation luminosity. Data collection is in progress.

A plasma lens for a linear collider final focus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norem, J.; Cline, D.B.; Cole, B.

High density relativistic beams propagating in a plasma are affected by fields induced by plasma motion. We consider the possible use of a plasma cell very close to the interaction point of a linear collider where the self-pinch induced in the relativistic beams can be used to increase the luminosity of colliding beams. We describe the benefits of this self-pinch, as well as some engineering details on the production of the required plasma. 18 refs., 5 figs., 1 tab.

Effects of Resonant and Random Excitations on the Proton Beam in the Large Hadron Collider, with Applications to the Design of Pulsed Hollow Electron Lenses for Active Halo Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitterer, Miriam; Stancari, Giulio; Valishev, Alexander

We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses (HEL) for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation,more » a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies.« less

Status of DAFNE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Preger, M.; /Frascati; Alesini, D.

DA{Phi}NE is a double ring electron-positron collider, designed to provide very high luminosity at the energy of the {Phi} resonance (1.02 GeV c.m.). After storing the first beam in fall 1997, the collider was commissioned without solenoidal detectors until the end of 1998, reaching a single bunch luminosity of 1.6 x 10{sup 30} cm{sup -2}s{sup -1} with 20 mA in each beam, corresponding to a beam-beam tune shift of {approx} 0.03. A longitudinal bunch-to-bunch feedback has been implemented, allowing the storage of more than 0.5 A in 30 bunches for both electrons and positrons. The KLOE detector, embedded into amore » superconducting solenoid with strong longitudinal field integral (2.4 Tm, to be compared to a magnetic rigidity of 1.7 Tm) compensated by two other solenoids of opposite field, was installed in winter 1999 and commissioning resumed with a careful correction of the coupling effects. Particular effort has been dedicated to the reduction of background in the experiment, which led to the possibility of injecting the beams in interaction without switching off data taking. The total stored current has reached more than 1 A in each beam, while a transverse feedback system has been realized to counteract vertical instabilities occurring during injection. The collider is now running in the multibunch mode for KLOE data taking with peak luminosity up to 1.8 x 10{sup 31} cm{sup -2}s{sup -1} and integrated luminosity larger than 0.8 pb{sup -1} per day.« less

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Sancho, J. Blanco; Shutov, A.; Schmidt, R.; Piriz, A. R.

2012-05-01

The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%-20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect). It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials) at CERN using the proton beam from the Super Proton Synchrotron (SPS), to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle energy in the SPS beam is 440 GeV while it has the same bunch structure as the LHC beam, except that it has only up to 288 bunches. Beam focal spot sizes of σ=0.1, 0.2, and 0.5 mm have been considered. The phenomenon of significant hydrodynamic tunneling due to the hydrodynamic effects is also expected for the experiments.

Beam Dynamics in an Electron Lens with the Warp Particle-in-cell Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stancari, Giulio; Moens, Vince; Redaelli, Stefano

2014-07-01

Electron lenses are a mature technique for beam manipulation in colliders and storage rings. In an electron lens, a pulsed, magnetically confined electron beam with a given current-density profile interacts with the circulating beam to obtain the desired effect. Electron lenses were used in the Fermilab Tevatron collider for beam-beam compensation, for abort-gap clearing, and for halo scraping. They will be used in RHIC at BNL for head-on beam-beam compensation, and their application to the Large Hadron Collider for halo control is under development. At Fermilab, electron lenses will be implemented as lattice elements for nonlinear integrable optics. The designmore » of electron lenses requires tools to calculate the kicks and wakefields experienced by the circulating beam. We use the Warp particle-in-cell code to study generation, transport, and evolution of the electron beam. For the first time, a fully 3-dimensional code is used for this purpose.« less

Capture, acceleration and bunching rf systems for the MEIC booster and storage rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shaoheng; Guo, Jiquan; Lin, Fanglei

2015-09-01

The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. The electron collider ring accepts electrons from CEBAF at energies from 3 to 12 GeV. Protons and ions are delivered to a booster and captured in a long bunch before being ramped and transferred to the ion collider ring. The ion collider ring accelerates a small number of long ion bunches to colliding energy before they are re-bunched into a high frequency train of very short bunches for colliding. Two sets of low frequency RF systems are needed for the long ion bunch energymore » ramping in the booster and ion collider ring. Another two sets of high frequency RF cavities are needed for re-bunching in the ion collider ring and compensating synchrotron radiation energy loss in the electron collider ring. The requirements from energy ramping, ion beam bunching, electron beam energy compensation, collective effects, beam loading and feedback capability, RF power capability, etc. are presented. The preliminary designs of these RF systems are presented. Concepts for the baseline cavity and RF station configurations are described, as well as some options that may allow more flexible injection and acceleration schemes.« less

Lattice design and expected performance of the Muon Ionization Cooling Experiment demonstration of ionization cooling

NASA Astrophysics Data System (ADS)

Bogomilov, M.; Tsenov, R.; Vankova-Kirilova, G.; Song, Y.; Tang, J.; Li, Z.; Bertoni, R.; Bonesini, M.; Chignoli, F.; Mazza, R.; Palladino, V.; de Bari, A.; Cecchet, G.; Orestano, D.; Tortora, L.; Kuno, Y.; Ishimoto, S.; Filthaut, F.; Jokovic, D.; Maletic, D.; Savic, M.; Hansen, O. M.; Ramberger, S.; Vretenar, M.; Asfandiyarov, R.; Blondel, A.; Drielsma, F.; Karadzhov, Y.; Charnley, G.; Collomb, N.; Dumbell, K.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Oates, A.; Owens, P.; Stokes, G.; Warburton, P.; White, C.; Adams, D.; Anderson, R. J.; Barclay, P.; Bayliss, V.; Boehm, J.; Bradshaw, T. W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Tucker, M.; Wilson, A.; Watson, S.; Bayes, R.; Nugent, J. C.; Soler, F. J. P.; Gamet, R.; Barber, G.; Blackmore, V. J.; Colling, D.; Dobbs, A.; Dornan, P.; Hunt, C.; Kurup, A.; Lagrange, J.-B.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Uchida, M. A.; Cobb, J. H.; Lau, W.; Booth, C. N.; Hodgson, P.; Langlands, J.; Overton, E.; Robinson, M.; Smith, P. J.; Wilbur, S.; Dick, A. J.; Ronald, K.; Whyte, C. G.; Young, A. R.; Boyd, S.; Franchini, P.; Greis, J. R.; Pidcott, C.; Taylor, I.; Gardener, R. B. S.; Kyberd, P.; Nebrensky, J. J.; Palmer, M.; Witte, H.; Bross, A. D.; Bowring, D.; Liu, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.; Freemire, B.; Hanlet, P.; Kaplan, D. M.; Mohayai, T. A.; Rajaram, D.; Snopok, P.; Suezaki, V.; Torun, Y.; Onel, Y.; Cremaldi, L. M.; Sanders, D. A.; Summers, D. J.; Hanson, G. G.; Heidt, C.; MICE Collaboration

2017-06-01

Muon beams of low emittance provide the basis for the intense, well-characterized neutrino beams necessary to elucidate the physics of flavor at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using rf cavities. The combined effect of energy loss and reacceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.

High energy density physics effects predicted in simulations of the CERN HiRadMat beam-target interaction experiments

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

2016-12-01

Experiments have been done at the CERN HiRadMat (High Radiation to Materials) facility in which large cylindrical copper targets were irradiated with 440 GeV proton beam generated by the Super Proton Synchrotron (SPS). The primary purpose of these experiments was to confirm the existence of hydrodynamic tunneling of ultra-relativistic protons and their hadronic shower in solid materials, that was predicted by previous numerical simulations. The experimental measurements have shown very good agreement with the simulation results. This provides confidence in our simulations of the interaction of the 7 TeV LHC (Large Hadron Collider) protons and the 50 TeV Future Circular Collider (FCC) protons with solid materials, respectively. This work is important from the machine protection point of view. The numerical simulations have also shown that in the HiRadMat experiments, a significant part of thetarget material is be converted into different phases of High Energy Density (HED) matter, including two-phase solid-liquid mixture, expanded as well as compressed hot liquid phases, two-phase liquid-gas mixture and gaseous state. The HiRadMat facility is therefore a unique ion beam facility worldwide that is currently available for studying the thermophysical properties of HED matter. In the present paper we discuss the numerical simulation results and present a comparison with the experimental measurements.

Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider

DOE PAGES

Fischer, W.; Gu, X.; Drees, K. A.; ...

2017-09-13

A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015)]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a lattice for the minimization of beam-beam generated resonance driving terms. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, W.; Gu, X.; Drees, K. A.

A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015)]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a lattice for the minimization of beam-beam generated resonance driving terms. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

Test of Relativistic Gravity for Propulsion at the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Felber, Franklin

2010-01-01

A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

Search of strangelets and “forward” physics on the collider

NASA Astrophysics Data System (ADS)

Kurepin, A. B.

2016-01-01

A new stage of the collider experiments at the maximum energy of protons and nuclei at the LHC may lead to the discovery of new phenomena, as well as to confirm the effects previously observed only at very high energies in cosmic rays. A specific program of the experiments is so-called “forward” physics, i.e. the study of low-angle processes. Of the most interesting phenomena can be noted the detection in cosmic rays events called Centauro, which could be explained as the strangelets production. Centauro represent events with small multiplicity and with a strong suppression of electromagnetic component. Since the energy of the beams at the collider and kinematic parameters of the forward detectors CASTOR (CMS), TOTEM, LHCf and the ADA and ADC (ALICE) are close to the parameters and energies of abnormal events in cosmic rays, it is possible to reproduce and investigate in details these events in the laboratory.

Simulation of Crab Waist Collisions In DA$$\\Phi$$NE With KLOE-2 Interaction Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zobov, M.; Drago, A.; Gallo, A.

2015-06-24

After the successful completion of the SIDDHARTA experiment run with crab waist collisions, the electron-positron collider DAΦNE has started routine operations for the KLOE-2 detector. The new interaction region also exploits the crab waist collision scheme, but features certain complications including the experimental detector solenoid, compensating anti-solenoids, and tilted quadrupole magnets. We have performed simulations of the beam-beam collisions in the collider taking into account the real DAΦNE nonlinear lattice. In particular, we have evaluated the effect of crab waist sextupoles and beam-beam interactions on the DAΦNE dynamical aperture and energy acceptance, and estimated the luminosity that can be potentiallymore » achieved with and without crab waist sextupoles in the present working conditions. A numerical analysis has been performed in order to propose possible steps for further luminosity increase in DAΦNE such as a better working point choice, crab sextupole strength optimization, correction of the phase advance between the sextupoles and the interaction region. The proposed change of the e- ring working point was implemented and resulted in a significant performance increase.« less

Beam energy scan with asymmetric collision at RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C.; Alessi, J.; Beebe, E.

A beam energy scan of deuteron-gold collision, with center-of-mass energy at 19.6, 39, 62.4 and 200.7 GeV/n, was performed at the Relativistic Heavy Ion Collider in 2016 to study the threshold for quark-gluon plasma (QGP) production. The lattice, RF, stochastic cooling and other subsystems were in different configurations for the various energies. The operational challenges changed with every new energy. The operational experience at each energy, the operation performance, highlights and lessons of the beam energy scan are reviewed in this report.

A polarized atomic-beam target for COSY-Jülich

NASA Astrophysics Data System (ADS)

Eversheim, P. D.; Altmeier, M.; Felden, O.; Glende, M.; Walker, M.; Hiemer, A.; Gebel, R.

1998-01-01

An atomic-beam target (ABT) for the EDDA experiment has been built in Bonn and was tested for the very first time at the cooler synchrotron COSY. The ABT differs from the polarized colliding-beams ion source for COSY in the DC-operation of the dissociator and the use of permanent 6-pole magnets. At present the beam optics of the ABT is set-up for maximum density in the interaction zone, but for target-cell operation it can be modified to give maximum intensity. The modular concept of this atomic ground-state target allows to provide all vector- (and tensor) polarizations for protons and deuterons, respectively. Up to now the polarization of the atomic-beam could be verified by the EDDA experiment to be ≳80% with a density in the interaction zone of ≳1011atoms/cm2.

Development work for a superconducting linear collider

NASA Technical Reports Server (NTRS)

Matheisen, Axel

1995-01-01

For future linear e(+)e(-) colliders in the TeV range several alternatives are under discussion. The TESLA approach is based on the advantages of superconductivity. High Q values of the accelerator structures give high efficiency for converting RF power into beam power. A low resonance frequency for the RF structures can be chosen to obtain a large number of electrons (positrons) per bunch. For a given luminosity the beam dimensions can be chosen conservatively which leads to relaxed beam emittance and tolerances at the final focus. Each individual superconducting accelerator component (resonator cavity) of this linear collider has to deliver an energy gain of 25 MeV/m to the beam. Today s.c. resonators are in use at CEBAF/USA, at DESY/Germany, Darmstadt/Germany KEK/Japan and CERN/Geneva. They show acceleration gradients between 5 MV/m and 10 MV/m. Encouraging experiments at CEA Saclay and Cornell University showed acceleration gradients of 20 MV/m and 25 MV/m in single and multicell structures. In an activity centered at DESY in Hamburg/Germany the TESLA collaboration is constructing a 500 MeV superconducting accelerator test facility (TTF) to demonstrate that a linear collider based on this technique can be built in a cost effective manner and that the necessary acceleration gradients of more than 15 MeV/m can be reached reproducibly. The test facility built at DESY covers an area of 3.000 m2 and is divided into 3 major activity areas: (1) The testlinac, where the performance ofthe modular components with an electron beam passing the 40 m long acceleration section can be demonstrated. (2) The test area, where all individual resonators are tested before installation into a module. (3) The preparation and assembly area, where assembly of cavities and modules take place. We report here on the design work to reach a reduction of costs compared to actual existing superconducting accelerator structures and on the facility set up to reach high acceleration gradients in a reproducible way.

Polarized muon beams for muon collider

NASA Astrophysics Data System (ADS)

Skrinsky, A. N.

1996-11-01

An option for the production of intense and highly polarized muon beams, suitable for a high-luminosity muon collider, is described briefly. It is based on a multi-channel pion-collection system, narrow-band pion-to-muon decay channels, proper muon spin gymnastics, and ionization cooling to combine all of the muon beams into a single bunch of ultimately low emittance.

The LHCb Detector at the LHC

NASA Astrophysics Data System (ADS)

LHCb Collaboration; Alves, A. Augusto, Jr.; Filho, L. M. Andrade; Barbosa, A. F.; Bediaga, I.; Cernicchiaro, G.; Guerrer, G.; Lima, H. P., Jr.; Machado, A. A.; Magnin, J.; Marujo, F.; de Miranda, J. M.; Reis, A.; Santos, A.; Toledo, A.; Akiba, K.; Amato, S.; de Paula, B.; de Paula, L.; da Silva, T.; Gandelman, M.; Lopes, J. H.; Maréchal, B.; Moraes, D.; Polycarpo, E.; Rodrigues, F.; Ballansat, J.; Bastian, Y.; Boget, D.; DeBonis, I.; Coco, V.; David, P. Y.; Decamp, D.; Delebecque, P.; Drancourt, C.; Dumont-Dayot, N.; Girard, C.; Lieunard, B.; Minard, M. N.; Pietrzyk, B.; Rambure, T.; Rospabe, G.; T'Jampens, S.; Ajaltouni, Z.; Bohner, G.; Bonnefoy, R.; Borras, D.; Carloganu, C.; Chanal, H.; Conte, E.; Cornat, R.; Crouau, M.; Delage, E.; Deschamps, O.; Henrard, P.; Jacquet, P.; Lacan, C.; Laubser, J.; Lecoq, J.; Lefèvre, R.; Magne, M.; Martemiyanov, M.; Mercier, M.-L.; Monteil, S.; Niess, V.; Perret, P.; Reinmuth, G.; Robert, A.; Suchorski, S.; Arnaud, K.; Aslanides, E.; Babel, J.; Benchouk, C.; Cachemiche, J.-P.; Cogan, J.; Derue, F.; Dinkespiler, B.; Duval, P.-Y.; Garonne, V.; Favard, S.; LeGac, R.; Leon, F.; Leroy, O.; Liotard, P.-L.; Marin, F.; Menouni, M.; Ollive, P.; Poss, S.; Roche, A.; Sapunov, M.; Tocco, L.; Viaud, B.; Tsaregorodtsev, A.; Amhis, Y.; Barrand, G.; Barsuk, S.; Beigbeder, C.; Beneyton, R.; Breton, D.; Callot, O.; Charlet, D.; D'Almagne, B.; Duarte, O.; Fulda-Quenzer, F.; Jacholkowska, A.; Jean-Marie, B.; Lefrancois, J.; Machefert, F.; Robbe, P.; Schune, M.-H.; Tocut, V.; Videau, I.; Benayoun, M.; David, P.; DelBuono, L.; Gilles, G.; Domke, M.; Futterschneider, H.; Ilgner, Ch; Kapusta, P.; Kolander, M.; Krause, R.; Lieng, M.; Nedos, M.; Rudloff, K.; Schleich, S.; Schwierz, R.; Spaan, B.; Wacker, K.; Warda, K.; Agari, M.; Bauer, C.; Baumeister, D.; Bulian, N.; Fuchs, H. P.; Fallot-Burghardt, W.; Glebe, T.; Hofmann, W.; Knöpfle, K. T.; Löchner, S.; Ludwig, A.; Maciuc, F.; Sanchez Nieto, F.; Schmelling, M.; Schwingenheuer, B.; Sexauer, E.; Smale, N. J.; Trunk, U.; Voss, H.; Albrecht, J.; Bachmann, S.; Blouw, J.; Deissenroth, M.; Deppe, H.; Dreis, H. B.; Eisele, F.; Haas, T.; Hansmann-Menzemer, S.; Hennenberger, S.; Knopf, J.; Moch, M.; Perieanu, A.; Rabenecker, S.; Rausch, A.; Rummel, C.; Rusnyak, R.; Schiller, M.; Stange, U.; Uwer, U.; Walter, M.; Ziegler, R.; Avoni, G.; Balbi, G.; Bonifazi, F.; Bortolotti, D.; Carbone, A.; D'Antone, I.; Galli, D.; Gregori, D.; Lax, I.; Marconi, U.; Peco, G.; Vagnoni, V.; Valenti, G.; Vecchi, S.; Bonivento, W.; Cardini, A.; Cadeddu, S.; DeLeo, V.; Deplano, C.; Furcas, S.; Lai, A.; Oldeman, R.; Raspino, D.; Saitta, B.; Serra, N.; Baldini, W.; Brusa, S.; Chiozzi, S.; Cotta Ramusino, A.; Evangelisti, F.; Franconieri, A.; Germani, S.; Gianoli, A.; Guoming, L.; Landi, L.; Malaguti, R.; Padoan, C.; Pennini, C.; Savriè, M.; Squerzanti, S.; Zhao, T.; Zhu, M.; Bizzeti, A.; Graziani, G.; Lenti, M.; Lenzi, M.; Maletta, F.; Pennazzi, S.; Passaleva, G.; Veltri, M.; Alfonsi, M.; Anelli, M.; Balla, A.; Battisti, A.; Bencivenni, G.; Campana, P.; Carletti, M.; Ciambrone, P.; Corradi, G.; Dané, E.; Di Virgilio, A.; DeSimone, P.; Felici, G.; Forti, C.; Gatta, M.; Lanfranchi, G.; Murtas, F.; Pistilli, M.; Poli Lener, M.; Rosellini, R.; Santoni, M.; Saputi, A.; Sarti, A.; Sciubba, A.; Zossi, A.; Ameri, M.; Cuneo, S.; Fontanelli, F.; Gracco, V.; Miní, G.; Parodi, M.; Petrolini, A.; Sannino, M.; Vinci, A.; Alemi, M.; Arnaboldi, C.; Bellunato, T.; Calvi, M.; Chignoli, F.; DeLucia, A.; Galotta, G.; Mazza, R.; Matteuzzi, C.; Musy, M.; Negri, P.; Perego, D.; Pessina, G.; Auriemma, G.; Bocci, V.; Buccheri, A.; Chiodi, G.; Di Marco, S.; Iacoangeli, F.; Martellotti, G.; Nobrega, R.; Pelosi, A.; Penso, G.; Pinci, D.; Rinaldi, W.; Rossi, A.; Santacesaria, R.; Satriano, C.; Carboni, G.; Iannilli, M.; Massafferri Rodrigues, A.; Messi, R.; Paoluzzi, G.; Sabatino, G.; Santovetti, E.; Satta, A.; Amoraal, J.; van Apeldoorn, G.; Arink, R.; van Bakel, N.; Band, H.; Bauer, Th; Berkien, A.; van Beuzekom, M.; Bos, E.; Bron, Ch; Ceelie, L.; Doets, M.; van der Eijk, R.; Fransen, J.-P.; de Groen, P.; Gromov, V.; Hierck, R.; Homma, J.; Hommels, B.; Hoogland, W.; Jans, E.; Jansen, F.; Jansen, L.; Jaspers, M.; Kaan, B.; Koene, B.; Koopstra, J.; Kroes, F.; Kraan, M.; Langedijk, J.; Merk, M.; Mos, S.; Munneke, B.; Palacios, J.; Papadelis, A.; Pellegrino, A.; van Petten, O.; du Pree, T.; Roeland, E.; Ruckstuhl, W.; Schimmel, A.; Schuijlenburg, H.; Sluijk, T.; Spelt, J.; Stolte, J.; Terrier, H.; Tuning, N.; Van Lysebetten, A.; Vankov, P.; Verkooijen, J.; Verlaat, B.; Vink, W.; de Vries, H.; Wiggers, L.; Ybeles Smit, G.; Zaitsev, N.; Zupan, M.; Zwart, A.; van den Brand, J.; Bulten, H. J.; de Jong, M.; Ketel, T.; Klous, S.; Kos, J.; M'charek, B.; Mul, F.; Raven, G.; Simioni, E.; Cheng, J.; Dai, G.; Deng, Z.; Gao, Y.; Gong, G.; Gong, H.; He, J.; Hou, L.; Li, J.; Qian, W.; Shao, B.; Xue, T.; Yang, Z.; Zeng, M.; Muryn, B.; Ciba, K.; Oblakowska-Mucha, A.; Blocki, J.; Galuszka, K.; Hajduk, L.; Michalowski, J.; Natkaniec, Z.; Polok, G.; Stodulski, M.; Witek, M.; Brzozowski, K.; Chlopik, A.; Gawor, P.; Guzik, Z.; Nawrot, A.; Srednicki, A.; Syryczynski, K.; Szczekowski, M.; Anghel, D. V.; Cimpean, A.; Coca, C.; Constantin, F.; Cristian, P.; Dumitru, D. D.; Dumitru, D. T.; Giolu, G.; Kusko, C.; Magureanu, C.; Mihon, Gh; Orlandea, M.; Pavel, C.; Petrescu, R.; Popescu, S.; Preda, T.; Rosca, A.; Rusu, V. L.; Stoica, R.; Stoica, S.; Tarta, P. D.; Filippov, S.; Gavrilov, Yu; Golyshkin, L.; Gushchin, E.; Karavichev, O.; Klubakov, V.; Kravchuk, L.; Kutuzov, V.; Laptev, S.; Popov, S.; Aref'ev, A.; Bobchenko, B.; Dolgoshein, V.; Egorychev, V.; Golutvin, A.; Gushchin, O.; Konoplyannikov, A.; Korolko, I.; Kvaratskheliya, T.; Machikhiliyan, I.; Malyshev, S.; Mayatskaya, E.; Prokudin, M.; Rusinov, D.; Rusinov, V.; Shatalov, P.; Shchutska, L.; Tarkovskiy, E.; Tayduganov, A.; Voronchev, K.; Zhiryakova, O.; Bobrov, A.; Bondar, A.; Eidelman, S.; Kozlinsky, A.; Shekhtman, L.; Beloous, K. S.; Dzhelyadin, R. I.; Gelitsky, Yu V.; Gouz, Yu P.; Kachnov, K. G.; Kobelev, A. S.; Matveev, V. D.; Novikov, V. P.; Obraztsov, V. F.; Ostankov, A. P.; Romanovsky, V. I.; Rykalin, V. I.; Soldatov, A. P.; Soldatov, M. M.; Tchernov, E. N.; Yushchenko, O. P.; Bochin, B.; Bondar, N.; Fedorov, O.; Golovtsov, V.; Guets, S.; Kashchuk, A.; Lazarev, V.; Maev, O.; Neustroev, P.; Sagidova, N.; Spiridenkov, E.; Volkov, S.; Vorobyev, An; Vorobyov, A.; Aguilo, E.; Bota, S.; Calvo, M.; Comerma, A.; Cano, X.; Dieguez, A.; Herms, A.; Lopez, E.; Luengo, S.; Garra, J.; Garrido, Ll; Gascon, D.; Gaspar de Valenzuela, A.; Gonzalez, C.; Graciani, R.; Grauges, E.; Perez Calero, A.; Picatoste, E.; Riera, J.; Rosello, M.; Ruiz, H.; Vilasis, X.; Xirgu, X.; Adeva, B.; Cid Vidal, X.; MartÉnez Santos, D.; Esperante Pereira, D.; Fungueiriño Pazos, J. L.; Gallas Torreira, A.; Gómez, C. Lois; Pazos Alvarez, A.; Pérez Trigo, E.; Pló Casasús, M.; Rodriguez Cobo, C.; Rodríguez Pérez, P.; Saborido, J. J.; Seco, M.; Vazquez Regueiro, P.; Bartalini, P.; Bay, A.; Bettler, M.-O.; Blanc, F.; Borel, J.; Carron, B.; Currat, C.; Conti, G.; Dormond, O.; Ermoline, Y.; Fauland, P.; Fernandez, L.; Frei, R.; Gagliardi, G.; Gueissaz, N.; Haefeli, G.; Hicheur, A.; Jacoby, C.; Jalocha, P.; Jimenez-Otero, S.; Hertig, J.-P.; Knecht, M.; Legger, F.; Locatelli, L.; Moser, J.-R.; Needham, M.; Nicolas, L.; Perrin-Giacomin, A.; Perroud, J.-P.; Potterat, C.; Ronga, F.; Schneider, O.; Schietinger, T.; Steele, D.; Studer, L.; Tareb, M.; Tran, M. T.; van Hunen, J.; Vervink, K.; Villa, S.; Zwahlen, N.; Bernet, R.; Büchler, A.; Gassner, J.; Lehner, F.; Sakhelashvili, T.; Salzmann, C.; Sievers, P.; Steiner, S.; Steinkamp, O.; Straumann, U.; van Tilburg, J.; Vollhardt, A.; Volyanskyy, D.; Ziegler, M.; Dovbnya, A.; Ranyuk, Yu; Shapoval, I.; Borisova, M.; Iakovenko, V.; Kyva, V.; Kovalchuk, O.; Okhrimenko, O.; Pugatch, V.; Pylypchenko, Yu; Adinolfi, M.; Brook, N. H.; Head, R. D.; Imong, J. P.; Lessnoff, K. A.; Metlica, F. C. D.; Muir, A. J.; Rademacker, J. H.; Solomin, A.; Szczypka, P. M.; Barham, C.; Buszello, C.; Dickens, J.; Gibson, V.; Haines, S.; Harrison, K.; Jones, C. R.; Katvars, S.; Kerzel, U.; Lazzeroni, C.; Li, Y. Y.; Rogers, G.; Storey, J.; Skottowe, H.; Wotton, S. A.; Adye, T. J.; Densham, C. J.; Easo, S.; Franek, B.; Loveridge, P.; Morrow, D.; Morris, J. V.; Nandakumar, R.; Nardulli, J.; Papanestis, A.; Patrick, G. N.; Ricciardi, S.; Woodward, M. L.; Zhang, Z.; Chamonal, R. J. U.; Clark, P. J.; Clarke, P.; Eisenhardt, S.; Gilardi, N.; Khan, A.; Kim, Y. M.; Lambert, R.; Lawrence, J.; Main, A.; McCarron, J.; Mclean, C.; Muheim, F.; Osorio-Oliveros, A. F.; Playfer, S.; Styles, N.; Xie, Y.; Bates, A.; Carson, L.; da Cunha Marinho, F.; Doherty, F.; Eklund, L.; Gersabeck, M.; Haddad, L.; Macgregor, A. A.; Melone, J.; McEwan, F.; Petrie, D. M.; Paterson, S. K.; Parkes, C.; Pickford, A.; Rakotomiaramanana, B.; Rodrigues, E.; Saavedra, A. F.; Soler, F. J. P.; Szumlak, T.; Viret, S.; Allebone, L.; Awunor, O.; Back, J.; Barber, G.; Barnes, C.; Cameron, B.; Clark, D.; Clark, I.; Dornan, P.; Duane, A.; Eames, C.; Egede, U.; Girone, M.; Greenwood, S.; Hallam, R.; Hare, R.; Howard, A.; Jolly, S.; Kasey, V.; Khaleeq, M.; Koppenburg, P.; Miller, D.; Plackett, R.; Price, D.; Reece, W.; Savage, P.; Savidge, T.; Simmons, B.; Vidal-Sitjes, G.; Websdale, D.; Affolder, A.; Anderson, J. S.; Biagi, S. F.; Bowcock, T. J. V.; Carroll, J. L.; Casse, G.; Cooke, P.; Donleavy, S.; Dwyer, L.; Hennessy, K.; Huse, T.; Hutchcroft, D.; Jones, D.; Lockwood, M.; McCubbin, M.; McNulty, R.; Muskett, D.; Noor, A.; Patel, G. D.; Rinnert, K.; Shears, T.; Smith, N. A.; Southern, G.; Stavitski, I.; Sutcliffe, P.; Tobin, M.; Traynor, S. M.; Turner, P.; Whitley, M.; Wormald, M.; Wright, V.; Bibby, J. H.; Brisbane, S.; Brock, M.; Charles, M.; Cioffi, C.; Gligorov, V. V.; Handford, T.; Harnew, N.; Harris, F.; John, M. J. J.; Jones, M.; Libby, J.; Martin, L.; McArthur, I. A.; Muresan, R.; Newby, C.; Ottewell, B.; Powell, A.; Rotolo, N.; Senanayake, R. S.; Somerville, L.; Soroko, A.; Spradlin, P.; Sullivan, P.; Stokes-Rees, I.; Topp-Jorgensen, S.; Xing, F.; Wilkinson, G.; Artuso, M.; Belyaev, I.; Blusk, S.; Lefeuvre, G.; Menaa, N.; Menaa-Sia, R.; Mountain, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Abadie, L.; Aglieri-Rinella, G.; Albrecht, E.; André, J.; Anelli, G.; Arnaud, N.; Augustinus, A.; Bal, F.; Barandela Pazos, M. C.; Barczyk, A.; Bargiotti, M.; Batista Lopes, J.; Behrendt, O.; Berni, S.; Binko, P.; Bobillier, V.; Braem, A.; Brarda, L.; Buytaert, J.; Camilleri, L.; Cambpell, M.; Castellani, G.; Cataneo, F.; Cattaneo, M.; Chadaj, B.; Charpentier, P.; Cherukuwada, S.; Chesi, E.; Christiansen, J.; Chytracek, R.; Clemencic, M.; Closier, J.; Collins, P.; Colrain, P.; Cooke, O.; Corajod, B.; Corti, G.; D'Ambrosio, C.; Damodaran, B.; David, C.; de Capua, S.; Decreuse, G.; Degaudenzi, H.; Dijkstra, H.; Droulez, J.-P.; Duarte Ramos, D.; Dufey, J. P.; Dumps, R.; Eckstein, D.; Ferro-Luzzi, M.; Fiedler, F.; Filthaut, F.; Flegel, W.; Forty, R.; Fournier, C.; Frank, M.; Frei, C.; Gaidioz, B.; Gaspar, C.; Gayde, J.-C.; Gavillet, P.; Go, A.; Gracia Abril, G.; Graulich, J.-S.; Giudici, P.-A.; Guirao Elias, A.; Guglielmini, P.; Gys, T.; Hahn, F.; Haider, S.; Harvey, J.; Hay, B.; Hernando Morata, J.-A.; Herranz Alvarez, J.; van Herwijnen, E.; Hilke, H. J.; von Holtey, G.; Hulsbergen, W.; Jacobsson, R.; Jamet, O.; Joram, C.; Jost, B.; Kanaya, N.; Knaster Refolio, J.; Koestner, S.; Koratzinos, M.; Kristic, R.; Lacarrère, D.; Lasseur, C.; Lastovicka, T.; Laub, M.; Liko, D.; Lippmann, C.; Lindner, R.; Losasso, M.; Maier, A.; Mair, K.; Maley, P.; Mato Vila, P.; Moine, G.; Morant, J.; Moritz, M.; Moscicki, J.; Muecke, M.; Mueller, H.; Nakada, T.; Neufeld, N.; Ocariz, J.; Padilla Aranda, C.; Parzefall, U.; Patel, M.; Pepe-Altarelli, M.; Piedigrossi, D.; Pivk, M.; Pokorski, W.; Ponce, S.; Ranjard, F.; Riegler, W.; Renaud, J.; Roiser, S.; Rossi, A.; Roy, L.; Ruf, T.; Ruffinoni, D.; Saladino, S.; Sambade Varela, A.; Santinelli, R.; Schmelling, S.; Schmidt, B.; Schneider, T.; Schöning, A.; Schopper, A.; Seguinot, J.; Snoeys, W.; Smith, A.; Smith, A. C.; Somogyi, P.; Stoica, R.; Tejessy, W.; Teubert, F.; Thomas, E.; Toledo Alarcon, J.; Ullaland, O.; Valassi, A.; Vannerem, P.; Veness, R.; Wicht, P.; Wiedner, D.; Witzeling, W.; Wright, A.; Wyllie, K.; Ypsilantis, T.

2008-08-01

The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). The initial configuration and expected performance of the detector and associated systems, as established by test beam measurements and simulation studies, is described.

RF System for the MICE Demonstration of Ionisation Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronald, K.; et al.

2017-04-01

Muon accelerators offer an attractive option for a range of future particle physics experiments. They can enable high energy (TeV+) high energy lepton colliders whilst mitigating the difficulty of synchrotron losses, and can provide intense beams of neutrinos for fundamental physics experiments investigating the physics of flavor. The method of production of muon beams results in high beam emittance which must be reduced for efficient acceleration. Conventional emittance control schemes take too long, given the very short (2.2 microsecond) rest lifetime of the muon. Ionisation cooling offers a much faster approach to reducing particle emittance, and the international MICE collaborationmore » aims to demonstrate this technique for the first time. This paper will present the MICE RF system and its role in the context of the overall experiment.« less

SuperB Progress Report for Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biagini, M.E.; Boni, R.; Boscolo, M.

2012-02-14

This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. With this document we propose a new electron positron colliding beam accelerator to be built in Italy to study flavor physics in the B-meson system at an energy of 10 GeV in the center-of-mass. This facility is called a high luminosity B-factory with a project name 'SuperB'. This project builds on a long history of successful e+e- colliders built around themore » world, as illustrated in Figure 1.1. The key advances in the design of this accelerator come from recent successes at the DAFNE collider at INFN in Frascati, Italy, at PEP-II at SLAC in California, USA, and at KEKB at KEK in Tsukuba Japan, and from new concepts in beam manipulation at the interaction region (IP) called 'crab waist'. This new collider comprises of two colliding beam rings, one at 4.2 GeV and one at 6.7 GeV, a common interaction region, a new injection system at full beam energies, and one of the two beams longitudinally polarized at the IP. Most of the new accelerator techniques needed for this collider have been achieved at other recently completed accelerators including the new PETRA-3 light source at DESY in Hamburg (Germany) and the upgraded DAFNE collider at the INFN laboratory at Frascati (Italy), or during design studies of CLIC or the International Linear Collider (ILC). The project is to be designed and constructed by a worldwide collaboration of accelerator and engineering staff along with ties to industry. To save significant construction costs, many components from the PEP-II collider at SLAC will be recycled and used in this new accelerator. The interaction region will be designed in collaboration with the particle physics detector to guarantee successful mutual use. The accelerator collaboration will consist of several groups at present universities and national laboratories. In Italy these may include INFN Frascati and the University of Pisa, in the United States SLAC, LBNL, BNL and several universities, in France IN2P3, LAPP, and Grenoble, in Russia BINP, in Poland Krakow University, and in the UK the Cockcroft Institute. The construction time for this collider is a total of about four years. The new tunnel can be bored in about a year. The new accelerator components can be built and installed in about 4 years. The shipping of components from PEP-II at SLAC to Italy will take about a year. A new linac and damping ring complex for the injector for the rings can be built in about three years. The commissioning of this new accelerator will take about a year including the new electron and positron sources, new linac, new damping ring, new beam transport lines, two new collider rings and the Interaction Region. The new particle physics detector can be commissioned simultaneously with the accelerator. Once beam collisions start for particle physics, the luminosity will increase with time, likely reaching full design specifications after about two to three years of operation. After construction, the operation of the collider will be the responsibility of the Italian INFN governmental agency. The intent is to run this accelerator about ten months each year with about one month for accelerator turn-on and nine months for colliding beams. The collider will need to operate for about 10 years to provide the required 50 ab{sup -1} requested by the detector collaboration. Both beams as anticipated in this collider will have properties that are excellent for use as sources for synchrotron radiation (SR). The expected photon properties are comparable to those of PETRA-3 or NSLS-II. The beam lines and user facilities needed to carry out this SR program are being investigated.« less

Diagnostics of the Fermilab Tevatron using an AC dipole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyamoto, Ryoichi

2008-08-01

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of themore » beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.« less

The MICE Muon Beam on ISIS and the beam-line instrumentation of the Muon Ionization Cooling Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogomilov, M.; Karadzhov, Y.; Kolev, D.

2012-05-01

The international Muon Ionization Cooling Experiment (MICE), which is under construction at the Rutherford Appleton Laboratory (RAL), will demonstrate the principle of ionization cooling as a technique for the reduction of the phase-space volume occupied by a muon beam. Ionization cooling channels are required for the Neutrino Factory and the Muon Collider. MICE will evaluate in detail the performance of a single lattice cell of the Feasibility Study 2 cooling channel. The MICE Muon Beam has been constructed at the ISIS synchrotron at RAL, and in MICE Step I, it has been characterized using the MICE beam-instrumentation system. In thismore » paper, the MICE Muon Beam and beam-line instrumentation are described. The muon rate is presented as a function of the beam loss generated by the MICE target dipping into the ISIS proton beam. For a 1 V signal from the ISIS beam-loss monitors downstream of our target we obtain a 30 KHz instantaneous muon rate, with a neglible pion contamination in the beam.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogomilov, M.; Tsenov, R.; Vankova-Kirilova, G.

Muon beams of low emittance provide the basis for the intense, well-characterized neutrino beams necessary to elucidate the physics of flavor at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using rf cavities. The combinedmore » effect of energy loss and reacceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.« less

Thermostructural characterization and structural elastic property optimization of novel high luminosity LHC collimation materials at CERN

NASA Astrophysics Data System (ADS)

Borg, M.; Bertarelli, A.; Carra, F.; Gradassi, P.; Guardia-Valenzuela, J.; Guinchard, M.; Izquierdo, G. Arnau; Mollicone, P.; Sacristan-de-Frutos, O.; Sammut, N.

2018-03-01

The CERN Large Hadron Collider is currently being upgraded to operate at a stored beam energy of 680 MJ through the High Luminosity upgrade. The LHC performance is dependent on the functionality of beam collimation systems, essential for safe beam cleaning and machine protection. A dedicated beam experiment at the CERN High Radiation to Materials facility is created under the HRMT-23 experimental campaign. This experiment investigates the behavior of three collimation jaws having novel composite absorbers made of copper diamond, molybdenum carbide graphite, and carbon fiber carbon, experiencing accidental scenarios involving the direct beam impact on the material. Material characterization is imperative for the design, execution, and analysis of such experiments. This paper presents new data and analysis of the thermostructural characteristics of some of the absorber materials commissioned within CERN facilities. In turn, characterized elastic properties are optimized through the development and implementation of a mixed numerical-experimental optimization technique.

Spin Transparency Mode in the NICA Collider with Solenoid Siberian Snakes for Proton and Deuteron Beam

NASA Astrophysics Data System (ADS)

Kovalenko, A. D.; Butenko, A. V.; Mikhaylov, V. A.; Kondratenko, M. A.; Kondratenko, A. M.; Filatov, Yu N.

2017-12-01

Two solenoid Siberian Snakes are required to obtain ion polarization in spin transparency mode of the NICA collider. The snake solenoids with a total field integral of 2×50 T·m are placed into the straight sections of the NICA collider. It allows one to control polarization of protons and deuterons up to 13.5 GeV/c and 4 GeV/c respectively. The snakes introduce a strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in the NICA collider with solenoid Snakes are presented.

Pulse-by-pulse energy measurement at the Stanford Linear Collider

NASA Astrophysics Data System (ADS)

Blaylock, G.; Briggs, D.; Collins, B.; Petree, M.

1992-01-01

The Stanford Linear Collider (SLC) collides a beam of electrons and positrons at 92 GeV. It is the first colliding linac, and produces Z(sup 0) particles for High-Energy Physics measurements. The energy of each beam must be measured to one part in 10(exp 4) on every collision (120 Hz). An Energy Spectrometer in each beam line after the collision produces two stripes of high-energy synchrotron radiation with critical energy of a few MeV. The distance between these two stripes at an imaging plane measures the beam energy. The Wire-Imaging Synchrotron Radiation Detector (WISRD) system comprises a novel detector, data acquisition electronics, readout, and analysis. The detector comprises an array of wires for each synchrotron stripe. The electronics measure secondary emission charge on each wire of each array. A Macintosh II (using THINK C, THINK Class Library) and DSP coprocessor (using ANSI C) acquire and analyze the data, and display and report the results for SLC operation.

Scanning Synchronization of Colliding Bunches for MEIC Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Derbenev, Yaroslav S.; Popov, V. P.; Chernousov, Yu D.

2015-09-01

Synchronization of colliding beams is one of the major issues of an electron-ion collider (EIC) design because of sensitivity of ion revolution frequency to beam energy. A conventional solution for this trouble is insertion of bent chicanes in the arcs space. In our report we consider a method to provide space coincidence of encountering bunches in the crab-crossing orbits Interaction Region (IR) while repetition rates of two beams do not coincide. The method utilizes pair of fast kickers realizing a bypass for the electron bunches as the way to equalize positions of the colliding bunches at the Interaction Point (IP).more » A dipole-mode warm or SRF cavities fed by the magnetron transmitters are used as fast kickers, allowing a broad-band phase and amplitude control. The proposed scanning synchronization method implies stabilization of luminosity at a maximum via a feedback loop. This synchronization method is evaluated as perspective for the Medium Energy Electron-Ion collider (MEIC) project of JLab with its very high bunch repetition rate.« less

Quasi-isochronous muon collection channels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ankenbrandt, Charles M.; Neuffer, David; Johnson, Rolland P.

2015-04-26

Intense muon beams have many potential commercial and scientific applications, ranging from low-energy investigations of the basic properties of matter using spin resonance to large energy-frontier muon colliders. However, muons originate from a tertiary process that produces a diffuse swarm. To make useful beams, the swarm must be rapidly captured and cooled before the muons decay. In this STTR project a promising new concept for the collection and cooling of muon beams to increase their intensity and reduce their emittances was investigated, namely, the use of a nearly isochronous helical cooling channel (HCC) to facilitate capture of the muons intomore » RF bunches. The muon beam can then be cooled quickly and coalesced efficiently to optimize the luminosity of a muon collider, or could provide compressed muon beams for other applications. Optimal ways to integrate such a subsystem into the rest of a muon collection and cooling system, for collider and other applications, were developed by analysis and simulation. The application of quasi-isochronous helical cooling channels (QIHCC) for RF capture of muon beams was developed. Innovative design concepts for a channel incorporating straight solenoids, a matching section, and an HCC, including RF and absorber, were developed, and its subsystems were simulated. Additionally, a procedure that uses an HCC to combine bunches for a muon collider was invented and simulated. Difficult design aspects such as matching sections between subsystems and intensity-dependent effects were addressed. The bunch recombination procedure was developed into a complete design with 3-D simulations. Bright muon beams are needed for many commercial and scientific reasons. Potential commercial applications include low-dose radiography, muon catalyzed fusion, and the use of muon beams to screen cargo containers for homeland security. Scientific uses include low energy beams for rare process searches, muon spin resonance applications, muon beams for neutrino factories, and muon colliders as Higgs factories or energy-frontier discovery machines.« less

Lattice design and expected performance of the Muon Ionization Cooling Experiment demonstration of ionization cooling

DOE PAGES

Bogomilov, M.; Tsenov, R.; Vankova-Kirilova, G.; ...

2017-06-19

Muon beams of low emittance provide the basis for the intense, well-characterized neutrino beams necessary to elucidate the physics of flavor at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using rf cavities. The combinedmore » effect of energy loss and reacceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.« less

Integral Equation for the Equilibrium State of Colliding Electron Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warnock, Robert L.

2002-11-11

We study a nonlinear integral equation for the equilibrium phase distribution of stored colliding electron beams. It is analogous to the Haissinski equation, being derived from Vlasov-Fokker-Planck theory, but is quite different in form. We prove existence of a unique solution, thus the existence of a unique equilibrium state, for sufficiently small current. This is done for the Chao-Ruth model of the beam-beam interaction in one degree of freedom. We expect no difficulty in generalizing the argument to more realistic models.

Preliminary design of the beam screen cooling for the Future Circular Collider of hadron beams

NASA Astrophysics Data System (ADS)

Kotnig, C.; Tavian, L.

2015-12-01

Following recommendations of the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. This study considers an option for a very high energy (100 TeV) hadron-hadron collider located in a quasi-circular underground tunnel having a circumference of 80 to 100 km. The synchrotron radiation emitted by the high-energy hadron beam increases by more than two orders of magnitude compared to the LHC. To reduce the entropic load on the superconducting magnets’ refrigeration system, beam screens are indispensable to extract the heat load at a higher temperature level. After illustrating the decisive constraints of the beam screen's refrigeration design, this paper presents a preliminary design of the length of a continuous cooling loop comparing helium and neon, for different cooling channel geometries with emphasis on the cooling length limitations and the exergetic efficiency.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acosta Castillo, John Gabriel

To explore the new energy frontier, a new generation of particle accelerators is needed. Muon colliders are a promising alternative, if muon cooling can be made to work. Muons are 200 times heavier than electrons, so they produce less synchrotron radiation, and they behave like point particles. However, they have a short lifetime of 2.2more » $$\\mathrm{\\mu s}$$ and the beam is more difficult to cool than an electron beam. The Muon Accelerator Program (MAP) was created to develop concepts and technologies required by a muon collider. An important effort has been made in the program to design and optimize a muon beam cooling system. The goal is to achieve the small beam emittance required by a muon collider. This work explores a final ionization cooling system using magnetic quadrupole lattices with a low enough $$\\beta^{\\star} $$ region to cool the beam to the required limit with available low Z absorbers.« less

Accelerator Science: Collider vs. Fixed Target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, Don

Particle physics experiments employ high energy particle accelerators to make their measurements. However there are many kinds of particle accelerators with many interesting techniques. One important dichotomy is whether one takes a particle beam and have it hit a stationary target of atoms, or whether one takes two counter rotating beams of particles and smashes them together head on. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of these two powerful methods of exploring the rules of the universe.

Accelerator Science: Collider vs. Fixed Target

ScienceCinema

Lincoln, Don

2018-01-16

Particle physics experiments employ high energy particle accelerators to make their measurements. However there are many kinds of particle accelerators with many interesting techniques. One important dichotomy is whether one takes a particle beam and have it hit a stationary target of atoms, or whether one takes two counter rotating beams of particles and smashes them together head on. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of these two powerful methods of exploring the rules of the universe.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Syphers, M. J.; Chattopadhyay, S.

An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW levelmore » intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.« less

Recent progress in neutrino factory and muon collider research within the Muon Collaboration

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. M. Alsharoa; Charles M. Ankenbrandt; Muzaffer Atac

2003-08-01

We describe the status of our effort to realize a first neutrino factory and the progress made in understanding the problems associated with the collection and cooling of muons towards that end. We summarize the physics that can be done with neutrino factories as well as with intense cold beams of muons. The physics potential of muon colliders is reviewed, both as Higgs Factories and compact high energy lepton colliders. The status and timescale of our research and development effort is reviewed as well as the latest designs in cooling channels including the promise of ring coolers in achieving longitudinalmore » and transverse cooling simultaneously. We detail the efforts being made to mount an international cooling experiment to demonstrate the ionization cooling of muons.« less

Beam dynamic simulations of the CLIC crab cavity and implications on the BDS

NASA Astrophysics Data System (ADS)

Shinton, I. R. R.; Burt, G.; Glasman, C. J.; Jones, R. M.; Wolski, A.

2011-11-01

The Compact Linear Collider (CLIC) is a proposed electron positron linear collider design aiming to achieve a centre of mass energy of up to 3 TeV. The main accelerating structures in CLIC operate at an X-band frequency of 11.994 GHz with an accelerating gradient of 100 MV/m. The present design requires the beams to collide at a small crossing angle of 10 mrad per line giving a resultant overall crossing angle of 20 mrad. Transverse deflecting cavities, referred to as "Crab cavities", are installed in the beam delivery system (BDS) of linear collider designs in order to ensure the final luminosity at the interaction point (IP) is comparable to that in a head on collision. We utilise the beam tracking code PLACET combined with the beam-beam code GUINEA-PIG to calculate the resulting luminosity at the IP. We follow a similar tuning procedure to that used for the design of the ILC crab cavities and anitcrab cavities. However an unexpected loss in luminosity of 10% was observed for the 20 mrad design was observed. It was discovered that the action of the crab cavities can affect the geometric aberrations resulting from the sextupoles used to correct chromatic effects in the beam delivery system. This has direct consequences regarding the design of the present CLIC BDS.

Participation in the ARGUS experiment at the DORIS Collider at DESY, Hamburg, Germany and participation in the AMY experiment at the Tristan Collider in Tsukuba, Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darden, C.; Rosenfeld, C.

1990-01-01

This paper discusses electron-positron annihilation at high energy. This work began in 1977 with the DASP II Collaboration at the DORIS storage ring of the DESY Laboratory in Hamburg. The collaboration's first publication reported the observation of the narrow {Upsilon} resonance at 9.46 GeV, confirming the original observation of this state in proton-nucleus collisions at Fermilab. To enable investigations of the {Upsilon} family of resonances the DORIS ring was rebuilt for reliable operation at the top of its energy range where the {Upsilon} states are accessible. In addition a new detector, ARGUS, was installed at one interaction region. This papermore » also discusses the AMY Collaboration which investigates electron-positron annihilation at energies from 50 to 65 GeV. The AMY detector is in the beam of the TRISTAN collider of the KEK Laboratory in Tsukuba, Japan.« less

THE RHIC SEQUENCER.

DOE Office of Scientific and Technical Information (OSTI.GOV)

VAN ZEIJTS,J.; DOTTAVIO,T.; FRAK,B.

The Relativistic Heavy Ion Collider (RHIC) has a high level asynchronous time-line driven by a controlling program called the ''Sequencer''. Most high-level magnet and beam related issues are orchestrated by this system. The system also plays an important task in coordinated data acquisition and saving. We present the program, operator interface, operational impact and experience.

Status of experiments at LLNL on high-power X-band microwave generators

NASA Astrophysics Data System (ADS)

Houck, Timothy L.; Westenskow, Glen A.

1994-05-01

The Microwave Source Facility at the Lawrence Livermore National Laboratory (LLNL) is studying the application of induction accelerator technology to high-power microwave generators suitable for linear collider power sources. We report on the results of two experiments, both using the Choppertron's 11.4 GHz modulator and a 5-MeV, 1-kA induction beam. The first experimental configuration has a single traveling-wave output structure designed to produce in excess of 300 MW in a single fundamental waveguide. This output structure consists of 12 individual cells, the first two incorporating de-Q-ing circuits to dampen higher order resonant modes. The second experiment studies the feasibility of enhancing beam to microwave power conversion by accelerating a modulated beam with induction cells. Referred to as the `reacceleration experiment,' this experiment consists of three traveling-wave output structures designed to produce about 125 MW per output and two induction cells located between the outputs. Status of current and planned experiments are presented.

Protection of the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Schmidt, R.; Assmann, R.; Carlier, E.; Dehning, B.; Denz, R.; Goddard, B.; Holzer, E. B.; Kain, V.; Puccio, B.; Todd, B.; Uythoven, J.; Wenninger, J.; Zerlauth, M.

2006-11-01

The Large Hadron Collider (LHC) at CERN will collide two counter-rotating proton beams, each with an energy of 7 TeV. The energy stored in the superconducting magnet system will exceed 10 GJ, and each beam has a stored energy of 362 MJ which could cause major damage to accelerator equipment in the case of uncontrolled beam loss. Safe operation of the LHC will therefore rely on a complex system for equipment protection. The systems for protection of the superconducting magnets in case of quench must be fully operational before powering the magnets. For safe injection of the 450 GeV beam into the LHC, beam absorbers must be in their correct positions and specific procedures must be applied. Requirements for safe operation throughout the cycle necessitate early detection of failures within the equipment, and active monitoring of the beam with fast and reliable beam instrumentation, mainly beam loss monitors (BLM). When operating with circulating beams, the time constant for beam loss after a failure extends from apms to a few minutes—failures must be detected sufficiently early and transmitted to the beam interlock system that triggers a beam dump. It is essential that the beams are properly extracted on to the dump blocks at the end of a fill and in case of emergency, since the beam dump blocks are the only elements of the LHC that can withstand the impact of the full beam.

Observations of beam losses due to bound-free pair production in a heavy-ion collider.

PubMed

Bruce, R; Jowett, J M; Gilardoni, S; Drees, A; Fischer, W; Tepikian, S; Klein, S R

2007-10-05

We report the first observations of beam losses due to bound-free pair production at the interaction point of a heavy-ion collider. This process is expected to be a major luminosity limit for the CERN Large Hadron Collider when it operates with (208)Pb(82+) ions because the localized energy deposition by the lost ions may quench superconducting magnet coils. Measurements were performed at the BNL Relativistic Heavy Ion Collider (RHIC) during operation with 100 GeV/nucleon (63)Cu(29+) ions. At RHIC, the rate, energy and magnetic field are low enough so that magnet quenching is not an issue. The hadronic showers produced when the single-electron ions struck the RHIC beam pipe were observed using an array of photodiodes. The measurement confirms the order of magnitude of the theoretical cross section previously calculated by others.

RF pulse shape control in the compact linear collider test facility

NASA Astrophysics Data System (ADS)

Kononenko, Oleksiy; Corsini, Roberto

2018-07-01

The Compact Linear Collider (CLIC) is a study for an electron-positron machine aiming at accelerating and colliding particles at the next energy frontier. The CLIC concept is based on the novel two-beam acceleration scheme, where a high-current low-energy drive beam generates RF in series of power extraction and transfer structures accelerating the low-current main beam. To compensate for the transient beam-loading and meet the energy spread specification requirements for the main linac, the RF pulse shape must be carefully optimized. This was recently modelled by varying the drive beam phase switch times in the sub-harmonic buncher so that, when combined, the drive beam modulation translates into the required voltage modulation of the accelerating pulse. In this paper, the control over the RF pulse shape with the phase switches, that is crucial for the success of the developed compensation model, is studied. The results on the experimental verification of this control method are presented and a good agreement with the numerical predictions is demonstrated. Implications for the CLIC beam-loading compensation model are also discussed.

BPM Breakdown Potential in the PEP-II B-factory Storage Ring Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weathersby, Stephen; Novokhatski, Alexander; /SLAC

2010-02-10

High current B-Factory BPM designs incorporate a button type electrode which introduces a small gap between the button and the beam chamber. For achievable currents and bunch lengths, simulations indicate that electric potentials can be induced in this gap which are comparable to the breakdown voltage. This study characterizes beam induced voltages in the existing PEP-II storage ring collider BPM as a function of bunch length and beam current.

Luminosity geometric reduction factor from colliding bunches with different lengths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verdu-Andres, S.

In the interaction point of the future electron-Ion collider eRHIC, the electron beam bunches are at least one order of magnitude shorter than the proton beam bunches. With the introduction of a crossing angle, the actual number of collisions resulting from the bunch collision gets reduced. Here we derive the expression for the luminosity geometric reduction factor when the bunches of the two incoming beams are not equal.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiltsev, V.

The idea of exploring collisions in the center-of-mass system to fully exploit the energy of the accelerated particles had been given serious consideration by the Norwegian engineer and inventor Rolf Wideröe, who had applied for a patent on the idea in 1943 (and got the patent in 1953 [1]) after considering the kinematic advantage of keeping the center of mass at rest to produce larger momentum transfers. Describing this advantage G.K.O’Neill, one of the collider pioneers, wrote in 1956 [2]: “…as accelerators of higher and higher energy are built, their usefulness is limited by the fact that the energy availablemore » for creating new particles is measured in the center-of-mass system of the target nucleon and the bombarding particle. In the relativistic limit, this energy rises only as the square root of the accelerator energy. However, if two particles of equal energy traveling in opposite directions could be made to collide, the available energy would be twice the whole energy of one particle...” Therefore, no kinetic energy is wasted by the motion of the center of mass of the system, and the available reaction energy E R = 2E beam (while a particle with the same energy E beam colliding with another particle of the mass m at rest produces only E R = (2E beam m)½ in the extreme relativistic case.) One can also add that the colliders are “cleaner” machines with respect to the fixed target ones since the colliding beams do not interact with the target materials. The other advantage is that it is much easier to organize collisions of beams composed of matter-antimatter particles, like in electron-positron and proton-antiproton colliders.« less

Analysis of 440 GeV proton beam–matter interaction experiments at the High Radiation Materials test facility at CERN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkart, F.; Schmidt, R.; Wollmann, D.

2015-08-07

In a previous paper [Schmidt et al., Phys. Plasmas 21, 080701 (2014)], we presented the first results on beam–matter interaction experiments that were carried out at the High Radiation Materials test facility at CERN. In these experiments, extended cylindrical targets of solid copper were irradiated with beam of 440 GeV protons delivered by the Super Proton Synchrotron (SPS). The beam comprised of a large number of high intensity proton bunches, each bunch having a length of 0.5 ns with a 50 ns gap between two neighboring bunches, while the length of this entire bunch train was about 7 μs. These experiments established the existencemore » of the hydrodynamic tunneling phenomenon the first time. Detailed numerical simulations of these experiments were also carried out which were reported in detail in another paper [Tahir et al., Phys. Rev. E 90, 063112 (2014)]. Excellent agreement was found between the experimental measurements and the simulation results that validate our previous simulations done using the Large Hadron Collider (LHC) beam of 7 TeV protons [Tahir et al., Phys. Rev. Spec. Top.--Accel. Beams 15, 051003 (2012)]. According to these simulations, the range of the full LHC proton beam and the hadronic shower can be increased by more than an order of magnitude due to the hydrodynamic tunneling, compared to that of a single proton. This effect is of considerable importance for the design of machine protection system for hadron accelerators such as SPS, LHC, and Future Circular Collider. Recently, using metal cutting technology, the targets used in these experiments have been dissected into finer pieces for visual and microscopic inspection in order to establish the precise penetration depth of the protons and the corresponding hadronic shower. This, we believe will be helpful in studying the very important phenomenon of hydrodynamic tunneling in a more quantitative manner. The details of this experimental work together with a comparison with the numerical simulations are presented in this paper.« less

Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C.; Marusic, A.; Minty, M.

2014-09-09

To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximizemore » the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.« less

CCD developments for particle colliders

NASA Astrophysics Data System (ADS)

Stefanov, Konstantin D.

2006-09-01

Charge Coupled Devices (CCDs) have been successfully used in several high-energy physics experiments over the last 20 years. Their small pixel size and excellent precision provide superb tool for studying of short-lived particles and understanding the nature at fundamental level. Over the last years the Linear Collider Flavour Identification (LCFI) collaboration has developed Column-Parallel CCDs (CPCCD) and CMOS readout chips to be used for the vertex detector at the International Linear Collider (ILC). The CPCCDs are very fast devices capable of satisfying the challenging requirements imposed by the beam structure of the superconducting accelerator. First set of prototype devices have been designed, manufactured and successfully tested, with second-generation chips on the way. Another idea for CCD-based device, the In-situ Storage Image Sensor (ISIS) is also under development and the first prototype is in production.

Online beam energy measurement of Beijing electron positron collider II linear accelerator

NASA Astrophysics Data System (ADS)

Wang, S.; Iqbal, M.; Liu, R.; Chi, Y.

2016-02-01

This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

Online beam energy measurement of Beijing electron positron collider II linear accelerator.

PubMed

Wang, S; Iqbal, M; Liu, R; Chi, Y

2016-02-01

This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

Prospects for the study of the properties of dense nuclear matter at the NICA heavy-ion complex at JINR (Dubna)

NASA Astrophysics Data System (ADS)

Kolesnikov, V. I.

2017-06-01

The NICA (Nuclotron-based Ion Collider fAcility) project is aimed in the construction at JINR (Dubna) a modern accelerator complex equipped with three detectors: the MultiPurpose Detector (MPD) and the Spin Physics Detector (SPD) at the NICA collider, as well as a fixed target experiment BM&N which will be use extracted beams from the Nuclotron accelerator. In this report, an overview of the main physics objectives of the NICA heavy-ion program will be given and the recent progress in the NICA construction (both accelerator complex and detectors) will be described.

Investigation of beam self-polarization in the future e + e - circular collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gianfelice-Wendt, E.

The use of resonant depolarization has been suggested for precise beam energy measurements (better than 100 keV) in the e +e - Future Circular Collider (FCC-e +e -) for Z and WW physics at 45 and 80 GeV beam energy respectively. Longitudinal beam polarization would benefit the Z peak physics program; however it is not essential and therefore it will be not investigated here. In this paper the possibility of self-polarized leptons is considered. As a result, preliminary results of simulations in presence of quadrupole misalignments and beam position monitors (BPMs) errors for a simplified FCC-e +e - ring are presented.

Investigation of beam self-polarization in the future e + e - circular collider

DOE PAGES

Gianfelice-Wendt, E.

2016-10-24

The use of resonant depolarization has been suggested for precise beam energy measurements (better than 100 keV) in the e +e - Future Circular Collider (FCC-e +e -) for Z and WW physics at 45 and 80 GeV beam energy respectively. Longitudinal beam polarization would benefit the Z peak physics program; however it is not essential and therefore it will be not investigated here. In this paper the possibility of self-polarized leptons is considered. As a result, preliminary results of simulations in presence of quadrupole misalignments and beam position monitors (BPMs) errors for a simplified FCC-e +e - ring are presented.

Investigation of beam self-polarization in the future e+e- circular collider

NASA Astrophysics Data System (ADS)

Gianfelice-Wendt, E.

2016-10-01

The use of resonant depolarization has been suggested for precise beam energy measurements (better than 100 keV) in the e+e- Future Circular Collider (FCC-e+e-) for Z and W W physics at 45 and 80 GeV beam energy respectively. Longitudinal beam polarization would benefit the Z peak physics program; however it is not essential and therefore it will be not investigated here. In this paper the possibility of self-polarized leptons is considered. Preliminary results of simulations in presence of quadrupole misalignments and beam position monitors (BPMs) errors for a simplified FCC-e+e- ring are presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bane, K.L.F.; Adolphsen, C.; Li, Z.

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, duemore » to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm.« less

Improvements of the target lifetime in the RHIC polarimeter

NASA Astrophysics Data System (ADS)

Steski, D. B.; Huang, H.; Kewisch, J.; Sukhanova, L.; Zelenski, A.

2018-05-01

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is the only collider in the world to collide polarized protons. It is critical to the RHIC experimental program that the polarization of the proton beam is measured. This is accomplished with the Coulomb Nuclear Interference (CNI) polarimeter. The targets used in the RHIC CNI polarimeter are 50 nm thick, 25 mm long and <10 µm wide. As the beam intensity in RHIC has increased and the beam size has decreased, the lifetime of these targets has decreased dramatically. During the 2013 polarized proton experimental run, the targets needed to be replaced twice. This resulted in additional work and lost beam time. Before the 2015 experimental run, metal shields were installed around the ends of the targets which greatly improved the target lifetime. The results from the 2015 experimental run and plans for the 2017 experimental run will be discussed.

Experimental observations of nonlinearly enhanced 2omega-UH electromagnetic radiation excited by steady-state colliding electron beams

NASA Technical Reports Server (NTRS)

Intrator, T.; Hershkowitz, N.; Chan, C.

1984-01-01

Counterstreaming large-diameter electron beams in a steady-state laboratory experiment are observed to generate transverse radiation at twice the upper-hybrid frequency (2omega-UH) with a quadrupole radiation pattern. The electromagnetic wave power density is nonlinearly enhanced over the power density obtained from a single beam-plasma system. Electromagnetic power density scales exponentially with beam energy and increases with ion mass. Weak turbulence theory can predict similar (but weaker) beam energy scaling but not the high power density, or the predominance of the 2omega-UH radiation peak over the omega-UH peak. Significant noise near the upper-hybrid and ion plasma frequencies is also measured, with normalized electrostatic wave energy density W(ES)/n(e)T(e) approximately 0.01.

Gridded thermionic gun and integral superconducting ballistic bunch compression cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schultheiss, Thomas

Electron-Ion colliders such as the Medium energy Electron Ion Collider (MEIC) being developed by JLAB require high current electrons with low energy spread for electron cooling of the collider ring. Accelerator techniques for improving bunch charge, average current, emittance, and energy spread are required for Energy Recovery Linacs (ERLs) and Circulator Rings (CR) for next generation colliders for nuclear physics experiments. Example candidates include thermionic-cathode electron guns with RF accelerating structures. Thermionic cathodes are known to produce high currents and have excellent lifetime. The success of the IR and THz Free-Electron Laser (FEL) designed and installed by Advanced Energy Systemsmore » at the Fritz Haber Institute (FHI) of the Max Planck Society in Berlin [1,2] demonstrates that gridded thermionic cathodes and rf systems be considered for next generation collider technology. In Phase 1 Advanced Energy Systems (AES) developed and analyzed a design concept using a superconducting cavity pair and gridded thermionic cathode. Analysis included Beam Dynamics and thermal analysis to show that a design of this type is feasible. The latest design goals for the MEIC electron cooler were for electron bunches of 420 pC at a frequency of 952.6 MHz with a magnetic field on the cathode of 2kG. This field magnetizes the beam imparting angular momentum that provides for helical motion of the electrons in the cooling solenoid. The helical motion increases the interaction time and improves the cooling efficiency. A coil positioned around the cathode providing 2kG field was developed. Beam dynamics simulations were run to develop the particle dynamics near the cathode and grid. Lloyd Young added capability to Tstep to include space charge effects between two plates and include image charge effects from the grid. He also added new pepper-pot geometry capability to account for honeycomb grids. These additions were used to develop the beam dynamics for this gun. The general design is a modified ballistic compression cavity pair with two independently powered cells [3]. The first is a cathode cell that includes the thermionic cathode and grid to provide for beam bunching. The second is a full cell with independent phasing and field levels designed to minimize energy spread. The primary goal for Phase II is to manufacture a superconducting gun with a thermionic cathode and imbedded coil. The system developed here is applicable to many high current electron accelerators. The analysis and design constraints imposed by the magnetized cathode make the cathode system developed here more complicated and limited than one without the magnetized beam constraints. High power ERLs would benefit by a gun with the capabilities shown here, 400 mA or more of current. ERLs hold great promise for electron cooling experiments, advanced light sources and Free Electron Lasers. This high current electron injector is a technological advance that will place the requirements for an ERL capable of providing quality bunches needed for cooling within the MEIC circulator ring within reach. This injector would have application to future ERLs around the world.« less

Enhanced Compton Backscattering in a Periodic Mirror System for Polarized Positron Beam Generation

NASA Astrophysics Data System (ADS)

Miyahara, Yoshikazu

2002-05-01

By colliding a circularly polarized high power laser beam with a high-energy electron beam, intense circularly polarized γ-rays can be generated, which in turn can be used to produce a longitudinally polarized positron beam for a linear collider. In the present paper, an optical mirror system with periodic focal points is considered to generate intense polarized γ-rays. A CO2 laser beam propagates back and forth in a series of holed mirrors in a straight line. The diffraction loss through the holes is negligibly small, so that the laser beam can be used repeatedly for the collision. The beam size is reduced to 22 μm at a minimum and kept the same in 20 unit cells, ten of which are combined in series. A 5.8 GeV electron beam is focused to 30 μm at a minimum in a series of triplets of permanent quadrupole magnets to generate γ-rays of 60 MeV at a maximum. A γ-ray yield required for a positron beam in a linear collider can be obtained by 10 laser sources with a power of 3.1 kW each, which is considerably lower than the total power assumed in a previous proposal.

RF pulse compression for future linear colliders

NASA Astrophysics Data System (ADS)

Wilson, Perry B.

1995-07-01

Future (nonsuperconducting) linear colliders will require very high values of peak rf power per meter of accelerating structure. The role of rf pulse compression in producing this power is examined within the context of overall rf system design for three future colliders at energies of 1.0-1.5 TeV, 5 TeV, and 25 TeV. In order to keep the average AC input power and the length of the accelerator within reasonable limits, a collider in the 1.0-1.5 TeV energy range will probably be built at an x-band rf frequency, and will require a peak power on the order of 150-200 MW per meter of accelerating structure. A 5 TeV collider at 34 GHz with a reasonable length (35 km) and AC input power (225 MW) would require about 550 MW per meter of structure. Two-beam accelerators can achieve peak powers of this order by applying dc pulse compression techniques (induction linac modules) to produce the drive beam. Klystron-driven colliders achieve high peak power by a combination of dc pulse compression (modulators) and rf pulse compression, with about the same overall rf system efficiency (30-40%) as a two-beam collider. A high gain (6.8) three-stage binary pulse compression system with high efficiency (80%) is described, which (compared to a SLED-II system) can be used to reduce the klystron peak power by about a factor of two, or alternatively, to cut the number of klystrons in half for a 1.0-1.5 TeV x-band collider. For a 5 TeV klystron-driven collider, a high gain, high efficiency rf pulse compression system is essential.

Investigating the adiabatic beam grouping at the NICA accelerator complex

NASA Astrophysics Data System (ADS)

Brovko, O. I.; Butenko, A. V.; Grebentsov, A. Yu.; Eliseev, A. V.; Meshkov, I. N.; Svetov, A. L.; Sidorin, A. O.; Slepnev, V. M.

2016-12-01

The NICA complex comprises the Booster and Nuclotron synchrotrons for accelerating particle beams to the required energy and the Collider machine, in which particle collisions are investigated. The experimental heavy-ion program deals with ions up to Au+79. The light-ion program deals with polarized deuterons and protons. Grouping of a beam coasting in an ion chamber is required in many parts of the complex. Beam grouping may effectively increase the longitudinal emittance and particle losses. To avoid these negative effects, various regimes of adiabatic grouping have been simulated and dedicated experiments with a deuteron beam have been conducted at the Nuclotron machine. As a result, we are able to construct and optimize the beam-grouping equipment, which provides a capture efficiency near 100% either retaining or varying the harmonic multiplicity of the HF system.

Development of semiconductor tracking: The future linear collider case

NASA Astrophysics Data System (ADS)

Savoy-Navarro, Aurore

2011-04-01

An active R&D on silicon tracking for the linear collider, SiLC, is pursued since several years to develop the new generation of large area silicon trackers for the future linear collider(s). The R&D objectives on new sensors, new front end processing of the signal, and the related mechanical and integration challenges for building such large detectors within the proposed detector concepts are described. Synergies and differences with the LHC construction and upgrades are explained. The differences between the linear collider projects, namely the international linear collider, ILC, and the compact linear collider, CLIC, are discussed as well. Two final objectives are presented for the construction of this important sub-detector for the future linear collider experiments: a relatively short term design based on micro-strips combined or not with a gaseous central tracker and a longer term design based on an all-pixel tracker.The R&D objectives on sensors include single sided micro-strips as baseline for the shorter term with the strips from large wafers (at least 6 in), 200 μm thick, 50 μm pitch and the edgeless and alignment friendly options. This work is conducted by SiLC in collaboration with three technical research centers in Italy, Finland, and Spain and HPK. SiLC is studied as well, using advanced Si sensor technologies for higher granularity trackers especially short strips and pixels all based on 3D technology. New Deep Sub-Micron CMOS mix mode (analog and digital) FE and readout electronics are developed to fully process the detector signals currently adapted to the ILC cycle. It is a high-level processing and a fully programmable ASIC; highly fault tolerant. In its latest version, handling 128 channels will equip these next coming years larger size silicon tracking prototypes at test beams. Connection of the FEE chip on the silicon detector especially in the strip case is a major issue. Very preliminary results with inline pitch adapter based on wiring were just achieved. Bump-bonding or 3D vertical interconnect is the other SiLC R&D objective. The goal is to simplify the overall architecture and decrease the material budget of these devices. Three tracking concepts are briefly discussed, two of which are part of the ILC Letter of Intent of the ILD and SiD detector concepts. These last years, SiLC successfully performed beam tests to experience and test these R&D lines.

Beam-beam interaction study of medium energy eRHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hao,Y.; Litvinenko, V. N.; Ptitsyn, V.

Medium Energy eRHIC (MeRHIC), the first stage design of eRHIC, includes a multi-pass ERL that provides 4GeV high quality electron beam to collide with the ion beam of RHIC. It delivers a minimum luminosity of 10{sup 32} cm{sup -2}s{sup -1}. Beam-beam effects present one of major factors limiting the luminosity of colliders. In this paper, both beam-beam effects on the electron beam and the proton beam in MeRHIC are investigated. The beam-beam interaction can induce a head-tail type instability of the proton beam referred to as the kink instability. Thus, beam stability conditions should be established to avoid proton beammore » loss. Also, the electron beam transverse disruption by collisions has to be evaluated to ensure that the beam quality is good enough for the energy recovery pass. The relation of proton beam stability, electron disruption and consequential luminosity are carried out after thorough discussion.« less

The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumbaugh, A.; Briegel, C.; Brown, B.C.

2011-11-01

A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. Themore » system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and show a number of examples of its use in both the Main Injector and Tevatron.« less

The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

NASA Astrophysics Data System (ADS)

Baumbaugh, A.; Briegel, C.; Brown, B. C.; Capista, D.; Drennan, C.; Fellenz, B.; Knickerbocker, K.; Lewis, J. D.; Marchionni, A.; Needles, C.; Olson, M.; Pordes, S.; Shi, Z.; Still, D.; Thurman-Keup, R.; Utes, M.; Wu, J.

2011-11-01

A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. The system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and show a number of examples of its use in both the Main Injector and Tevatron.

Molecular formation in the stagnation region of colliding laser-produced plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Shboul, K. F.; Hassan, S. M.; Harilal, S. S.

2016-10-27

The laser-produced colliding plasmas have numerous attractive applications and stagnation layer formed during collisions between plasmas is a useful system for understanding particle collisions and molecular formation in a controlled way. In this article, we explore carbon dimer formation and its evolutionary paths in a stagnation layer formed during the interaction of two laser-produced plasmas. Colliding laser produced plasmas are generated by splitting a laser beam into two sub-beams and then focus them into either a single flat (laterally colliding plasmas) or a V-shaped graphite targets (orthogonally colliding plasmas). The C2 formation in the stagnation region of both colliding plasmamore » schemes is investigated using optical spectroscopic means and compared with emission features from single seed plasma. Our results show that the collisions among the plasmas followed by the stagnation layer formation lead to rapid cooling causing enhanced carbon dimer formation. In addition, plasma electron temperature, density and C2 molecular temperature were measured for the stagnation zone and compared with seed plasma.« less

Unavoidable trapped mode in the interaction region of colliding beams

DOE PAGES

Novokhatski, Alexander; Sullivan, Michael; Belli, Eleonora; ...

2017-11-22

Here, we discuss the nature of the electromagnetic fields excited by the beams in the beam pipe of an interaction region. In trying to find an optimum geometry for this region with a minimum of electromagnetic wave excitation, we have discovered one mode, which remains even in a very smooth geometry. This mode has a longitudinal electrical component and can be easily excited by the beam. By analyzing the structure of this mode we have found a way to absorb this mode. The work was done in connection with a proposal for a future electron-positron collider.

A Study on Double Event Detection for PHENIX at RHIC

NASA Astrophysics Data System (ADS)

Vazquez-Carson, Sebastian; Phenix Collaboration

2016-09-01

Many measurements made in Heavy Ion experiments such as PHENIX at RHIC focus on geometrical properties because phenomena such as collective flow give insight into quark-gluon plasma and the strong nuclear force. As part of this investigation, PHENIX has taken data in 2016 for deuteron on gold collisions at several energies. An acceptable luminosity is achieved by injecting up to 120 separate bunches each with billions of ions into the storage ring, from which two, separate beams are made to collide. This method has a drawback as there is a chance for multiple pairs of nuclei to collide in a single bunch crossing. Data taken in a double event cannot be separated into two independent events and has no clear interpretation. This effect's magnitude is estimated and incorporated in published results as a systematic uncertainty and studies on this topic have already been conducted within PHENIX. I develop several additional algorithms to flag multiple interaction events by examining the time dependence of data from the two Beam-Beam Counters - detectors surrounding the beam pipe on opposite ends of the interaction region. The algorithms are tested with data, in which events with double interactions are artificially produced using low luminosity data. I am working at the University of Colorado at Boulder on behalf of the PHENIX collaboration.

The design and construction of the MICE Electron-Muon Ranger

NASA Astrophysics Data System (ADS)

Asfandiyarov, R.; Bene, P.; Blondel, A.; Bolognini, D.; Cadoux, F.; Debieux, S.; Drielsma, F.; Giannini, G.; Graulich, J. S.; Husi, C.; Karadzhov, Y.; Lietti, D.; Masciocchi, F.; Nicola, L.; Noah Messomo, E.; Prest, M.; Rothenfusser, K.; Sandstrom, R.; Vallazza, E.; Verguilov, V.; Wisting, H.

2016-10-01

The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter installed in the beam line of the Muon Ionization Cooling Experiment (MICE). The experiment will demonstrate ionization cooling, an essential technology needed for the realization of a Neutrino Factory and/or a Muon Collider. The EMR is designed to measure the properties of low energy beams composed of muons, electrons and pions, and perform the identification particle-by-particle. The detector consists of 48 orthogonal layers of 59 triangular scintillator bars. The readout is implemented using FPGA custom made electronics and commercially available modules. This article describes the construction of the detector from its design up to its commissioning with cosmic data.

Beam dynamics studies at DAΦNE: from ideas to experimental results

NASA Astrophysics Data System (ADS)

Zobov, M.; DAΦNE Team

2017-12-01

DAΦNE is the electron-positron collider operating at the energy of Φ-resonance, 1 GeV in the center of mass. The presently achieved luminosity is by about two orders of magnitude higher than that obtained at other colliders ever operated at this energy. Careful beam dynamic studies such as the vacuum chamber design with low beam coupling impedance, suppression of different kinds of beam instabilities, investigation of beam-beam interaction, optimization of the beam nonlinear motion have been the key ingredients that have helped to reach this impressive result. Many novel ideas in accelerator physics have been proposed and/or tested experimentally at DAΦNE for the first time. In this paper we discuss the advanced accelerator physics studies performed at DAΦNE.

Design study of an YBCO-coated beam screen for the super proton-proton collider bending magnets

NASA Astrophysics Data System (ADS)

Gan, Pingping; Zhu, Kun; Fu, Qi; Li, Haipeng; Lu, Yuanrong; Easton, Matt; Liu, Yudong; Tang, Jingyu; Xu, Qingjin

2018-04-01

In order to reduce the beam impedance and refrigeration power dramatically, we have designed a high temperature superconductor (HTS) coated beam screen to screen the cold chamber walls of the super proton-proton collider bending magnets from beam-induced heat loads. It employs an absorber, inspired by the future circular collider studies, to absorb the immense synchrotron radiation power of 12.8 W/m emitted from the 37.5 TeV proton beams. Such a structure has the advantage of decreasing the electron cloud effect and improving the beam vacuum. We have compared the critical magnetic field and current density and accessibility of two potential HTS materials for the beam screen, TlBa2Ca2Cu3O9-δ (Tl-1223) and Yttrium Barium Copper Oxide (YBCO) and finally chose YBCO for coating. The beam screen is tentatively designed to work at 55-70 K because of the limited development of the YBCO material. The thermal analysis with oxygen cooling fluid indicates that the YBCO conductor can maintain its superconductivity even if the synchrotron radiation hits the YBCO-coated surface and the mechanical analysis shows that the structure has the ability to resist the Lorenz force during magnet quenches.

Beam Induced Hydrodynamic Tunneling in the Future Circular Collider Components

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

2016-08-01

A future circular collider (FCC) has been proposed as a post-Large Hadron Collider accelerator, to explore particle physics in unprecedented energy ranges. The FCC is a circular collider in a tunnel with a circumference of 80-100 km. The FCC study puts an emphasis on proton-proton high-energy and electron-positron high-intensity frontier machines. A proton-electron interaction scenario is also examined. According to the nominal FCC parameters, each of the 50 TeV proton beams will carry an amount of 8.5 GJ energy that is equivalent to the kinetic energy of an Airbus A380 (560 t) at a typical speed of 850 km /h . Safety of operation with such extremely energetic beams is an important issue, as off-nominal beam loss can cause serious damage to the accelerator and detector components with a severe impact on the accelerator environment. In order to estimate the consequences of an accident with the full beam accidently deflected into equipment, we have carried out numerical simulations of interaction of a FCC beam with a solid copper target using an energy-deposition code (fluka) and a 2D hydrodynamic code (big2) iteratively. These simulations show that, although the penetration length of a single FCC proton and its shower in solid copper is about 1.5 m, the full FCC beam will penetrate up to about 350 m into the target because of the "hydrodynamic tunneling." These simulations also show that a significant part of the target is converted into high-energy-density matter. We also discuss this interesting aspect of this study.

Applications of High Intensity Proton Accelerators

NASA Astrophysics Data System (ADS)

Raja, Rajendran; Mishra, Shekhar

2010-06-01

Superconducting radiofrequency linac development at Fermilab / S. D. Holmes -- Rare muon decay experiments / Y. Kuno -- Rare kaon decays / D. Bryman -- Muon collider / R. B. Palmer -- Neutrino factories / S. Geer -- ADS and its potential / J.-P. Revol -- ADS history in the USA / R. L. Sheffield and E. J. Pitcher -- Accelerator driven transmutation of waste: high power accelerator for the European ADS demonstrator / J. L. Biarrotte and T. Junquera -- Myrrha, technology development for the realisation of ADS in EU: current status & prospects for realisation / R. Fernandez ... [et al.] -- High intensity proton beam production with cyclotrons / J. Grillenberger and M. Seidel -- FFAG for high intensity proton accelerator / Y. Mori -- Kaon yields for 2 to 8 GeV proton beams / K. K. Gudima, N. V. Mokhov and S. I. Striganov -- Pion yield studies for proton driver beams of 2-8 GeV kinetic energy for stopped muon and low-energy muon decay experiments / S. I. Striganov -- J-Parc accelerator status and future plans / H. Kobayashi -- Simulation and verification of DPA in materials / N. V. Mokhov, I. L. Rakhno and S. I. Striganov -- Performance and operational experience of the CNGS facility / E. Gschwendtner -- Particle physics enabled with super-conducting RF technology - summary of working group 1 / D. Jaffe and R. Tschirhart -- Proton beam requirements for a neutrino factory and muon collider / M. S. Zisman -- Proton bunching options / R. B. Palmer -- CW SRF H linac as a proton driver for muon colliders and neutrino factories / M. Popovic, C. M. Ankenbrandt and R. P. Johnson -- Rapid cycling synchrotron option for Project X / W. Chou -- Linac-based proton driver for a neutrino factory / R. Garoby ... [et al.] -- Pion production for neutrino factories and muon colliders / N. V. Mokhov ... [et al.] -- Proton bunch compression strategies / V. Lebedev -- Accelerator test facility for muon collider and neutrino factory R&D / V. Shiltsev -- The superconducting RF linac for muon collider and neutrino factory - summary of working group 2 / J. Galambos, R. Garoby and S. Geer -- Prospects for a very high power CW SRF linac / R. A. Rimmer -- Indian accelerator program for ADS applications / V. C. Sahni and P. Singh -- Ion accelerator activities at VECC (particularly, operating at low temperature) / R. K. Bhandari -- Chinese efforts in high intensity proton accelerators / S. Fu, J. Wang and S. Fang -- ADSR activity in the UK / R. J. Barlow -- ADS development in Japan / K. Kikuchi -- Project-X, SRF, and very large power stations / C. M. Ankenbrandt, R. P. Johnson and M. Popovic -- Power production and ADS / R. Raja -- Experimental neutron source facility based on accelerator driven system / Y. Gohar -- Transmutation mission / W. S. Yang -- Safety performance and issues / J. E. Cahalan -- Spallation target design for accelerator-driven systems / Y. Gohar -- Design considerations for accelerator transmutation of waste system / W. S. Yang -- Japan ADS program / T. Sasa -- Overview of members states' and IAEA activities in the field of Accelerator Driven Systems (ADS) / A. Stanculescu -- Linac for ADS applications - accelerator technologies / R. W. Garnett and R. L. Sheffield -- SRF linacs and accelerator driven sub-critical systems - summary working groups 3 & 4 / J. Delayen -- Production of Actinium-225 via high energy proton induced spallation of Thorium-232 / J. Harvey ... [et al.] -- Search for the electric dipole moment of Radium-225 / R. J. Holt, Z.-T. Lu and R. Mueller -- SRF linac and material science and medicine - summary of working group 5 / J. Nolen, E. Pitcher and H. Kirk.

First experimental evidence of hydrodynamic tunneling of ultra-relativistic protons in extended solid copper target at the CERN HiRadMat facility

NASA Astrophysics Data System (ADS)

Schmidt, R.; Blanco Sancho, J.; Burkart, F.; Grenier, D.; Wollmann, D.; Tahir, N. A.; Shutov, A.; Piriz, A. R.

2014-08-01

A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.

Correction to AD/RHIC-47, Beam Transfer From AGS to RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Claus, J.; Foelsche, H.

1988-12-12

RHIC an acronym for Relativistic Heavy Ion Collider, is a facility for colliding heavy ions with each other, proposed for construction at Brookhaven National Laboratory. This facility and the motivation for building it, have been described. It consists of two intersecting storage rings and the purpose of this note is to describe how these two rings are to be filled with beam.

Design of beam optics for the future circular collider e + e - collider rings

DOE PAGES

Oide, Katsunobu; Aiba, M.; Aumon, S.; ...

2016-11-21

A beam optics scheme has been designed for the future circular collider- e +e - (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [P. Raimondi, D. Shatilov, and M. Zobov, arXiv:physics/0702033; P. Raimondi, M. Zobov, and D. Shatilov, in Proceedings of the 22nd Particle Accelerator Conference, PAC-2007, Albuquerque, NM (IEEE, New York, 2007), p. TUPAN037.] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system withoutmore » additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So-called “tapering” of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [A. Chancé et al., Proceedings of IPAC’16, 9–13 May 2016, Busan, Korea, TUPMW020 (2016).] as closely as possible. Sufficient transverse/longitudinal dynamic aperture (DA) has been obtained, including major dynamical effects, to assure an adequate beam lifetime in the presence of beamstrahlung and top-up injection. In particular, a momentum acceptance larger than ±2% has been obtained, which is better than the momentum acceptance of typical collider rings by about a factor of 2. The effects of the detector solenoids including their compensation elements are taken into account as well as synchrotron radiation in all magnets. The optics presented in this study is a step toward a full conceptual design for the collider. Finally, a number of issues have been identified for further study.« less

Design of beam optics for the future circular collider e + e - collider rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oide, Katsunobu; Aiba, M.; Aumon, S.

A beam optics scheme has been designed for the future circular collider- e +e - (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [P. Raimondi, D. Shatilov, and M. Zobov, arXiv:physics/0702033; P. Raimondi, M. Zobov, and D. Shatilov, in Proceedings of the 22nd Particle Accelerator Conference, PAC-2007, Albuquerque, NM (IEEE, New York, 2007), p. TUPAN037.] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system withoutmore » additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So-called “tapering” of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [A. Chancé et al., Proceedings of IPAC’16, 9–13 May 2016, Busan, Korea, TUPMW020 (2016).] as closely as possible. Sufficient transverse/longitudinal dynamic aperture (DA) has been obtained, including major dynamical effects, to assure an adequate beam lifetime in the presence of beamstrahlung and top-up injection. In particular, a momentum acceptance larger than ±2% has been obtained, which is better than the momentum acceptance of typical collider rings by about a factor of 2. The effects of the detector solenoids including their compensation elements are taken into account as well as synchrotron radiation in all magnets. The optics presented in this study is a step toward a full conceptual design for the collider. Finally, a number of issues have been identified for further study.« less

Design of beam optics for the future circular collider e+e- collider rings

NASA Astrophysics Data System (ADS)

Oide, K.; Aiba, M.; Aumon, S.; Benedikt, M.; Blondel, A.; Bogomyagkov, A.; Boscolo, M.; Burkhardt, H.; Cai, Y.; Doblhammer, A.; Haerer, B.; Holzer, B.; Jowett, J. M.; Koop, I.; Koratzinos, M.; Levichev, E.; Medina, L.; Ohmi, K.; Papaphilippou, Y.; Piminov, P.; Shatilov, D.; Sinyatkin, S.; Sullivan, M.; Wenninger, J.; Wienands, U.; Zhou, D.; Zimmermann, F.

2016-11-01

A beam optics scheme has been designed for the future circular collider-e+e- (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [P. Raimondi, D. Shatilov, and M. Zobov, arXiv:physics/0702033; P. Raimondi, M. Zobov, and D. Shatilov, in Proceedings of the 22nd Particle Accelerator Conference, PAC-2007, Albuquerque, NM (IEEE, New York, 2007), p. TUPAN037.] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system without additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So-called "tapering" of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [A. Chancé et al., Proceedings of IPAC'16, 9-13 May 2016, Busan, Korea, TUPMW020 (2016).] as closely as possible. Sufficient transverse/longitudinal dynamic aperture (DA) has been obtained, including major dynamical effects, to assure an adequate beam lifetime in the presence of beamstrahlung and top-up injection. In particular, a momentum acceptance larger than ±2 % has been obtained, which is better than the momentum acceptance of typical collider rings by about a factor of 2. The effects of the detector solenoids including their compensation elements are taken into account as well as synchrotron radiation in all magnets. The optics presented in this paper is a step toward a full conceptual design for the collider. A number of issues have been identified for further study.

Research in High Energy Physics at Duke University

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kotwal, Ashutosh V.; Goshaw, Al; Kruse, Mark

2013-07-29

This is the Closeout Report for the research grant in experimental elementary particle physics, carried out by the Duke University High Energy Physics (HEP) group. We re- port on physics results and detector development carried out under this grant, focussing on the recent three-year grant period (2010 to 2013). The Duke HEP group consisted of seven faculty members, two senior scientists, ve postdocs and eight graduate students. There were three thrusts of the research program. Measurements at the energy frontier at CDF and ATLAS were used to test aspects of elementary particle theory described by the Stan- dard Model (SM)more » and to search for new forces and particles beyond those contained within the SM. The neutrino sector was explored using data obtained from a large neutrino detector located in Japan, and R & D was conducted on new experiments to be built in the US. The measurements provided information about neutrino masses and the manner in which neutri- nos change species in particle beams. Two years ago we have started a new research program in rare processes based on the Mu2E experiment at Fermilab. This research is motivated by the search for the ! e transition with unprecedented sensitivity, a transition forbidden in the standard model but allowed in supersymmetric and other models of new physics. The high energy research program used proton and antiproton colliding beams. The experiments were done at the Fermilab Tevatron (proton-antiproton collisions at a center of mass energy of 1.96 TeV) and at the CERN Large Hadron Collider (proton-proton collisions at 7-8 TeV). The neutrino program used data obtained from the Super-Kamiokande detec- tor. This water- lled Cherenkov counter was used to detect and measure the properties of neutrinos produced in cosmic ray showers, and from neutrino beams produced from acceler- ators in Japan. The Mu2E experiment will use a special stopped muon beam to be built at Fermilab.« less

Research in High Energy Physics at Duke University

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goshaw, Alfred; Kotwal, Ashutosh; Kruse, Mark

2013-07-29

This is the Closeout Report for the research grant in experimental elementary particle physics, carried out by the Duke University High Energy Physics (HEP) group. We re- port on physics results and detector development carried out under this grant, focussing on the recent three-year grant period (2010 to 2013). The Duke HEP group consisted of seven faculty members, two senior scientists, five postdocs and eight graduate students. There were three thrusts of the research program. Measurements at the energy frontier at CDF and ATLAS were used to test aspects of elementary particle theory described by the Stan- dard Model (SM)more » and to search for new forces and particles beyond those contained within the SM. The neutrino sector was explored using data obtained from a large neutrino detector located in Japan, and R & D was conducted on new experiments to be built in the US. The measurements provided information about neutrino masses and the manner in which neutri- nos change species in particle beams. Two years ago we have started a new research program in rare processes based on the Mu2E experiment at Fermilab. This research is motivated by the search for the {mu} {yields} e transition with unprecedented sensitivity, a transition forbidden in the standard model but allowed in supersymmetric and other models of new physics. The high energy research program used proton and antiproton colliding beams. The experiments were done at the Fermilab Tevatron (proton-antiproton collisions at a center of mass energy of 1.96 TeV) and at the CERN Large Hadron Collider (proton-proton collisions at 7-8 TeV). The neutrino program used data obtained from the Super-Kamiokande detector. This water-filled Cherenkov counter was used to detect and measure the properties of neutrinos produced in cosmic ray showers, and from neutrino beams produced from acceler- ators in Japan. The Mu2E experiment will use a special stopped muon beam to be built at Fermilab.« less

Measurement of top quark polarization in top-antitop lepton+jets final states at DØ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Augsten, Kamil

This thesis presents a measurement of the top quark polarization in themore » $$t\\overline{t}$$ events produced in $$p\\overline{p}$$ collisions at $$\\sqrt{s}=1.96$$ TeV using data corresponding to 9.7 fb$$^{-1}$$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The final states used in the measurement contain one lepton and at least three jets. The polarization is measured using the angular distribution of leptons along three different axes: the beam axis, the helicity axis, and the transverse axis normal to the $$t\\overline{t}$$ production plane. This is the first measurement of top quark polarization at the Tevatron Collider in lepton+jets final states, and the first measurement of transverse polarization in $$t\\overline{t}$$ production. The polarization along the beam axis is combined with the previous result in the dilepton final states by the D0 experiment. The observed distributions are consistent with the Standard Model of nearly no polarization and no indication for beyond Standard Model physics is observed. The measurement offers legacy result from unique Tevatron Collider data and provides more information about the top quark production and decays, about the properties of the heaviest elementary particle.« less

Radiation protection and environmental management at the relativistic heavy ion collider.

PubMed

Musolino, S V; Briggs, S L; Stevens, A J

2001-01-01

The Relativistic Heavy Ion Collider (RHIC) is a high energy hadron accelerator built to study basic nuclear physics. It consists of two counter-rotating beams of fully stripped gold ions that are accelerated in two rings to an energy of 100 GeV/nucleon or protons at 250 GeV/c. The beams can be stored for a period of five to ten hours and brought into collision for experiments during that time. The first major physics objective is to recreate a state of matter, the quark-gluon plasma, that has been predicted to have existed at a short time after the creation of the universe. Because there are only a few other high energy particle accelerators like RHIC in the world, the rules promulgated in the US Code of Federal Regulations under the Atomic Energy Act, State regulations, or international guidance documents do not cover prompt radiation from accelerators to govern directly the design and operation of a superconducting collider. Special design criteria for prompt radiation were developed to provide guidance tor the design of radiation shielding. Environmental Management at RHIC is accomplished through the ISO 14001 Environmental Management System. The applicability, benefits, and implementation of ISO 14001 within the framework of a large research accelerator complex are discussed in the paper.

Staging optics considerations for a plasma wakefield acceleration linear collider

NASA Astrophysics Data System (ADS)

Lindstrøm, C. A.; Adli, E.; Allen, J. M.; Delahaye, J. P.; Hogan, M. J.; Joshi, C.; Muggli, P.; Raubenheimer, T. O.; Yakimenko, V.

2016-09-01

Plasma wakefield acceleration offers acceleration gradients of several GeV/m, ideal for a next-generation linear collider. The beam optics requirements between plasma cells include injection and extraction of drive beams, matching the main beam beta functions into the next cell, canceling dispersion as well as constraining bunch lengthening and chromaticity. To maintain a high effective acceleration gradient, this must be accomplished in the shortest distance possible. A working example is presented, using novel methods to correct chromaticity, as well as scaling laws for a high energy regime.

A magnetic field cloak for charged particle beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capobianco-Hogan, K. G.; Cervantes, R.; Deshpande, A.

Shielding charged particle beams from transverse magnetic fields is a common challenge for particle accelerators and experiments. In this study, we demonstrate that a magnetic field cloak is a viable solution. It allows for the use of dipole magnets in the forward regions of experiments at an Electron Ion Collider (EIC) and other facilities without interfering with the incoming beams. The dipoles can improve the momentum measurements of charged final state particles at angles close to the beam line and therefore increase the physics reach of these experiments. In contrast to other magnetic shielding options (such as active coils), amore » cloak requires no external powering. We discuss the design parameters, fabrication, and limitations of a magnetic field cloak and demonstrate that cylinders made from 45 layers of YBCO high-temperature superconductor, combined with a ferromagnetic shell made from epoxy and stainless steel powder, shield more than 99% of a transverse magnetic field of up to 0.45 T (95% shielding at 0.5 T) at liquid nitrogen temperature. Lastly, the ferromagnetic shell reduces field distortions caused by the superconductor alone by 90% at 0.45 T.« less

A magnetic field cloak for charged particle beams

NASA Astrophysics Data System (ADS)

Capobianco-Hogan, K. G.; Cervantes, R.; Deshpande, A.; Feege, N.; Krahulik, T.; LaBounty, J.; Sekelsky, R.; Adhyatman, A.; Arrowsmith-Kron, G.; Coe, B.; Dehmelt, K.; Hemmick, T. K.; Jeffas, S.; LaByer, T.; Mahmud, S.; Oliveira, A.; Quadri, A.; Sharma, K.; Tishelman-Charny, A.

2018-01-01

Shielding charged particle beams from transverse magnetic fields is a common challenge for particle accelerators and experiments. We demonstrate that a magnetic field cloak is a viable solution. It allows for the use of dipole magnets in the forward regions of experiments at an Electron Ion Collider (EIC) and other facilities without interfering with the incoming beams. The dipoles can improve the momentum measurements of charged final state particles at angles close to the beam line and therefore increase the physics reach of these experiments. In contrast to other magnetic shielding options (such as active coils), a cloak requires no external powering. We discuss the design parameters, fabrication, and limitations of a magnetic field cloak and demonstrate that cylinders made from 45 layers of YBCO high-temperature superconductor, combined with a ferromagnetic shell made from epoxy and stainless steel powder, shield more than 99% of a transverse magnetic field of up to 0.45 T (95% shielding at 0.5 T) at liquid nitrogen temperature. The ferromagnetic shell reduces field distortions caused by the superconductor alone by 90% at 0.45 T.

A magnetic field cloak for charged particle beams

DOE PAGES

Capobianco-Hogan, K. G.; Cervantes, R.; Deshpande, A.; ...

2017-10-02

Shielding charged particle beams from transverse magnetic fields is a common challenge for particle accelerators and experiments. In this study, we demonstrate that a magnetic field cloak is a viable solution. It allows for the use of dipole magnets in the forward regions of experiments at an Electron Ion Collider (EIC) and other facilities without interfering with the incoming beams. The dipoles can improve the momentum measurements of charged final state particles at angles close to the beam line and therefore increase the physics reach of these experiments. In contrast to other magnetic shielding options (such as active coils), amore » cloak requires no external powering. We discuss the design parameters, fabrication, and limitations of a magnetic field cloak and demonstrate that cylinders made from 45 layers of YBCO high-temperature superconductor, combined with a ferromagnetic shell made from epoxy and stainless steel powder, shield more than 99% of a transverse magnetic field of up to 0.45 T (95% shielding at 0.5 T) at liquid nitrogen temperature. Lastly, the ferromagnetic shell reduces field distortions caused by the superconductor alone by 90% at 0.45 T.« less

Impact of the resistive wall impedance on beam dynamics in the Future Circular e+e- Collider

NASA Astrophysics Data System (ADS)

Migliorati, M.; Belli, E.; Zobov, M.

2018-04-01

The Future Circular Collider study, which aims at designing post-LHC particle accelerator options, is entering in the final stage, which foresees a conceptual design report containing the basic requirements for a hadron and a lepton collider, as well as options for an electron-proton machine. Due to the high beam intensities of these accelerators, collective effects have to be carefully analyzed. Among them, the finite conductivity of the beam vacuum chamber represents a major source of impedance for the electron-positron collider. By using numerical and analytical tools, a parametric study of longitudinal and transverse instabilities caused by the resistive wall is performed in this paper for the case of the Future Circular Collider lepton machine, by taking into account also the effects of coating, used to fight the electron cloud build up. It will be proved that under certain assumptions the coupling impedance of a two layer system does not depend on the conductivity of the coating and this property represents an important characteristic for the choice of the material itself. The results and findings of this study have an impact on the machine design in several aspects. In particular the quite low threshold of single bunch instabilities with respect to the nominal beam current and the not negligible power losses due to the resistive wall are shown, together with the necessity of a new feedback system to counteract the fast transverse coupled bunch instability. The importance of a round vacuum chamber to avoid the quadrupolar tune shift is also discussed. Finally the crucial importance of the beam pipe material coating and thickness choice for the above results is underlined.

Successful Beam-Beam Tuneshift Compensation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishofberger, Kip Aaron

2005-01-01

The performance of synchrotron colliders has been limited by the beam-beam limit, a maximum tuneshift that colliding bunches could sustain. Due to bunch-to-bunch tune variation and intra-bunch tune spread, larger tuneshifts produce severe emittance growth. Breaking through this constraint has been viewed as impossible for several decades. This dissertation introduces the physics of ultra-relativistic synchrotrons and low-energy electron beams, with emphasis placed on the limits of the Tevatron and the needs of a tuneshift-compensation device. A detailed analysis of the Tevatron Electron Lens (T EL) is given, comparing theoretical models to experimental data whenever possible. Finally, results of Tevatron operationsmore » with inclusion of the T EL are presented and analyzed. It is shown that the T EL provides a way to shatter the previously inescapable beam-beam limit.« less

The Equilibrium State of Colliding Electron Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warnock, R

2003-12-12

We study a nonlinear integral equation that is a necessary condition on the equilibrium phase space distribution function of stored, colliding electron beams. It is analogous to the Haissinski equation, being derived from Vlasov-Fokker-Planck theory, but is quite different in form. The equation is analyzed for the case of the Chao-Ruth model of the beam-beam interaction in one degree of freedom, a so-called strong-strong model with nonlinear beam-beam force. We prove existence of a unique solution, for sufficiently small beam current, by an application of the implicit function theorem. We have not yet proved that this solution is positive, asmore » would be required to establish existence of an equilibrium. There is, however, numerical evidence of a positive solution. We expect that our analysis can be extended to more realistic models.« less

Particle beam injection system

DOEpatents

Jassby, Daniel L.; Kulsrud, Russell M.

1977-01-01

This invention provides a poloidal divertor for stacking counterstreaming ion beams to provide high intensity colliding beams. To this end, method and apparatus are provided that inject high energy, high velocity, ordered, atomic deuterium and tritium beams into a lower energy, toroidal, thermal equilibrium, neutral, target plasma column that is magnetically confined along an endless magnetic axis in a strong restoring force magnetic field having helical field lines to produce counterstreaming deuteron and triton beams that are received bent, stacked and transported along the endless axis, while a poloidal divertor removes thermal ions and electrons all along the axis to increase the density of the counterstreaming ion beams and the reaction products resulting therefrom. By balancing the stacking and removal, colliding, strong focused particle beams, reaction products and reactions are produced that convert one form of energy into another form of energy.

Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons

NASA Astrophysics Data System (ADS)

Babzien, Marcus; Ben-Zvi, Ilan; Kusche, Karl; Pavlishin, Igor V.; Pogorelsky, Igor V.; Siddons, David P.; Yakimenko, Vitaly; Cline, David; Zhou, Feng; Hirose, Tachishige; Kamiya, Yoshio; Kumita, Tetsuro; Omori, Tsunehiko; Urakawa, Junji; Yokoya, Kaoru

2006-02-01

A free relativistic electron in an electromagnetic field is a pure case of a light-matter interaction. In the laboratory environment, this interaction can be realized by colliding laser pulses with electron beams produced from particle accelerators. The process of single photon absorption and reemission by the electron, so-called linear Thomson scattering, results in radiation that is Doppler shifted into the x-ray and γ-ray regions. At elevated laser intensity, nonlinear effects should come into play when the transverse motion of the electrons induced by the laser beam is relativistic. In the present experiment, we achieved this condition and characterized the second harmonic of Thomson x-ray scattering using the counterpropagation of a 60 MeV electron beam and a subterawatt CO2 laser beam.

Observation of the second harmonic in Thomson scattering from relativistic electrons.

PubMed

Babzien, Marcus; Ben-Zvi, Ilan; Kusche, Karl; Pavlishin, Igor V; Pogorelsky, Igor V; Siddons, David P; Yakimenko, Vitaly; Cline, David; Zhou, Feng; Hirose, Tachishige; Kamiya, Yoshio; Kumita, Tetsuro; Omori, Tsunehiko; Urakawa, Junji; Yokoya, Kaoru

2006-02-10

A free relativistic electron in an electromagnetic field is a pure case of a light-matter interaction. In the laboratory environment, this interaction can be realized by colliding laser pulses with electron beams produced from particle accelerators. The process of single photon absorption and reemission by the electron, so-called linear Thomson scattering, results in radiation that is Doppler shifted into the x-ray and gamma-ray regions. At elevated laser intensity, nonlinear effects should come into play when the transverse motion of the electrons induced by the laser beam is relativistic. In the present experiment, we achieved this condition and characterized the second harmonic of Thomson x-ray scattering using the counterpropagation of a 60 MeV electron beam and a subterawatt CO2 laser beam.

Particle Physics after the Higgs-Boson Discovery: Opportunities for the Large Hadron Collider

DOE PAGES

Quigg, Chris

2015-08-24

The first run of the Large Hadron Collider at CERN brought the discovery of the Higgs boson, an apparently elementary scalar particle with a mass of 125 GeV, the avatar of the mechanism that hides the electroweak symmetry. Then, a new round of experimentation is beginning, with the energy of the proton–proton colliding beams raised to 6.5 TeV per beam, from 4 TeV at the end of the first run. I summarize what we have learned about the Higgs boson, and calls attention to some issues that will be among our central concerns in the near future.

Quantum radiation reaction in laser-electron-beam collisions.

PubMed

Blackburn, T G; Ridgers, C P; Kirk, J G; Bell, A R

2014-01-10

It is possible using current high-intensity laser facilities to reach the quantum radiation reaction regime for energetic electrons. An experiment using a wakefield accelerator to drive GeV electrons into a counterpropagating laser pulse would demonstrate the increase in the yield of high-energy photons caused by the stochastic nature of quantum synchrotron emission: we show that a beam of 10(9) 1 GeV electrons colliding with a 30 fs laser pulse of intensity 10(22)  W cm(-2) will emit 6300 photons with energy greater than 700 MeV, 60× the number predicted by classical theory.

Fast polarimetry of the colliding proton beams based on the elastic pp analyzer using the NICA detectors

NASA Astrophysics Data System (ADS)

Sharov, V. I.

2017-12-01

It is shown that the existing data on analyzing power An of the elastic pp scattering could be successfully applied for polarimetry of the colliding proton beams using the NICA detectors. Performed calculations of the count rates of the elastic events have revealed that the polarimeter based on using An for elastic pp will have a high polarization measurement velocity.

Low emittance electron storage rings

NASA Astrophysics Data System (ADS)

Levichev, E. B.

2018-01-01

Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

Polarized Negative Light Ions at the Cooler Synchrotron COSY/Juelich

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gebel, R.; Felden, O.; Rossen, P. von

2005-04-06

The polarized ion source at the cooler synchrotron facility COSY of the research centre Juelich in Germany delivers negative polarized protons or deuterons for medium energy experiments. The polarized ion source, originally built by the universities of Bonn, Erlangen and Cologne, is based on the colliding beams principle, using after an upgrade procedure an intense pulsed neutralized caesium beam for charge exchange with a pulsed highly polarized hydrogen beam. The source is operated at 0.5 Hz repetition rate with 20 ms pulse length, which is the maximum useful length for the injection into the synchrotron. Routinely intensities of 20 {mu}Amore » are delivered for injection into the cyclotron of the COSY facility. For internal targets the intensity of 2 mA and a polarization up to 90% have been reached. Reliable long-term operation for experiments at COSY for up to 9 weeks has been achieved. Since 2003 polarized deuterons with different combinations of vector and tensor polarization were delivered to experiments.« less

Test beam studies of possibilities to separate particles with gamma factors above 103 with straw based Transition Radiation Detector

NASA Astrophysics Data System (ADS)

Belyaev, N.; Cherry, M. L.; Doronin, S. A.; Filippov, K.; Fusco, P.; Konovalov, S.; Krasnopevtsev, D.; Kramarenko, V.; Loparco, F.; Mazziotta, M. N.; Ponomarenko, D.; Pyatiizbyantseva, D.; Radomskii, R.; Rembser, C.; Romaniouk, A.; Savchenko, A.; Shulga, E.; Smirnov, S.; Smirnov, Yu; Sosnovtsev, V.; Spinelli, P.; Teterin, P.; Tikhomirov, V.; Vorobev, K.; Zhukov, K.

2017-12-01

Measurements of hadron production in the TeV energy range are one of the tasks of the future studies at the Large Hadron Collider (LHC). The main goal of these experiments is a study of the fundamental QCD processes at this energy range, which is very important not only for probing of the Standard Model but also for ultrahigh-energy cosmic particle physics. One of the key elements of these experiments measurements are hadron identification. The only detector technology which has a potential ability to separate hadrons in this energy range is Transition Radiation Detector (TRD) technology. TRD prototype based on straw proportional chambers combined with a specially assembled radiator has been tested at the CERN SPS accelerator beam. The test beam results and comparison with detailed Monte Carlo simulations are presented here.

Implementation of depolarization due to beam-beam effects in the beam-beam interaction simulation tool GUINEA-PIG++

NASA Astrophysics Data System (ADS)

Rimbault, C.; Le Meur, G.; Blampuy, F.; Bambade, P.; Schulte, D.

2009-12-01

Depolarization is a new feature in the beam-beam simulation tool GUINEA-PIG++ (GP++). The results of this simulation are studied and compared with another beam-beam simulation tool, CAIN, considering different beam parameters for the International Linear Collider (ILC) with a centre-of-mass energy of 500 GeV.

New results on diamond pixel sensors using ATLAS frontend electronics

NASA Astrophysics Data System (ADS)

Keil, M.; Adam, W.; Berdermann, E.; Bergonzo, P.; de Boer, W.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Dulinski, W.; Doroshenko, J.; Doucet, M.; van Eijk, B.; Fallou, A.; Fischer, P.; Fizzotti, F.; Kania, D.; Gan, K. K.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kaplon, J.; Kass, R.; Knöpfle, K. T.; Koeth, T.; Krammer, M.; Logiudice, A.; mac Lynne, L.; Manfredotti, C.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Pan, L. S.; Pernicka, M.; Perera, L.; Riester, J. L.; Roe, S.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Trischuk, W.; Tromson, D.; Vittone, E.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M.

2003-03-01

Diamond is a promising sensor material for future collider experiments due to its radiation hardness. Diamond pixel sensors have been bump bonded to an ATLAS pixel readout chip using PbSn solder bumps. Single chip devices have been characterised by lab measurements and in a high-energy pion beam at CERN. Results on charge collection, spatial resolution, efficiency and the charge carrier lifetime are presented.

A Multi-TeV Linear Collider Based on CLIC Technology : CLIC Conceptual Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aicheler, M; Burrows, P.; Draper, M.

This report describes the accelerator studies for a future multi-TeV e +e - collider based on the Compact Linear Collider (CLIC) technology. The CLIC concept as described in the report is based on high gradient normal-conducting accelerating structures where the RF power for the acceleration of the colliding beams is extracted from a high-current Drive Beam that runs parallel with the main linac. The focus of CLIC R&D over the last years has been on addressing a set of key feasibility issues that are essential for proving the fundamental validity of the CLIC concept. The status of these feasibility studiesmore » are described and summarized. The report also includes a technical description of the accelerator components and R&D to develop the most important parts and methods, as well as a description of the civil engineering and technical services associated with the installation. Several larger system tests have been performed to validate the two-beam scheme, and of particular importance are the results from the CLIC test facility at CERN (CTF3). Both the machine and detector/physics studies for CLIC have primarily focused on the 3 TeV implementation of CLIC as a benchmark for the CLIC feasibility. This report also includes specific studies for an initial 500 GeV machine, and some discussion of possible intermediate energy stages. The performance and operation issues related to operation at reduced energy compared to the nominal, and considerations of a staged construction program are included in the final part of the report. The CLIC accelerator study is organized as an international collaboration with 43 partners in 22 countries. An associated report describes the physics potential and experiments at CLIC and a shorter report in preparation will focus on the CLIC implementation strategy, together with a plan for the CLIC R&D studies 2012–2016. Critical and important implementation issues such as cost, power and schedule will be addressed there.« less

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abeyratne, S; Ahmed, S; Barber, D

2012-08-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectivelymore » utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF linac will serve as a full-energy injector, and, if needed, provide top-off refilling. The CEBAF fixed-target nuclear physics program can be simultaneously operated since the filling time of the electron ring is very short. The ion complex for MEIC consists of sources for polarized light ions and unpolarized light to heavy ions, an SRF ion linac with proton energy up to 280 MeV, a 3 GeV prebooster synchrotron, a large booster synchrotron for proton energy up to 20 GeV, and a medium-energy collider ring with energy up to 100 GeV. The ion complex can accelerate other species of ions with corresponding energies at each accelerating stage. There are three collision points planned for MEIC. Two of them are for collisions with medium-energy ions; the third is for low energy ion beams stored in a dedicated low-energy compact storage ring, as a possible follow-on project.« less

SimTrack: A compact c++ library for particle orbit and spin tracking in accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Yun

2015-06-24

SimTrack is a compact c++ library of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam-beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam-beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam-beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture,more » physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.« less

First Operational Experience With a High-Energy Physics Run Control System Based on Web Technologies

NASA Astrophysics Data System (ADS)

Bauer, Gerry; Beccati, Barbara; Behrens, Ulf; Biery, Kurt; Branson, James; Bukowiec, Sebastian; Cano, Eric; Cheung, Harry; Ciganek, Marek; Cittolin, Sergio; Coarasa Perez, Jose Antonio; Deldicque, Christian; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez-Reino, Robert; Gulmini, Michele; Hatton, Derek; Hwong, Yi Ling; Loizides, Constantin; Ma, Frank; Masetti, Lorenzo; Meijers, Frans; Meschi, Emilio; Meyer, Andreas; Mommsen, Remigius K.; Moser, Roland; O'Dell, Vivian; Oh, Alexander; Orsini, Luciano; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schieferdecker, Philipp; Schwick, Christoph; Shpakov, Dennis; Simon, Michal; Sumorok, Konstanty; Yoon, Andre Sungho

2012-08-01

Run control systems of modern high-energy particle physics experiments have requirements similar to those of today's Internet applications. The Compact Muon Solenoid (CMS) collaboration at CERN's Large Hadron Collider (LHC) therefore decided to build the run control system for its detector based on web technologies. The system is composed of Java Web Applications distributed over a set of Apache Tomcat servlet containers that connect to a database back-end. Users interact with the system through a web browser. The present paper reports on the successful scaling of the system from a small test setup to the production data acquisition system that comprises around 10.000 applications running on a cluster of about 1600 hosts. We report on operational aspects during the first phase of operation with colliding beams including performance, stability, integration with the CMS Detector Control System and tools to guide the operator.

Status of the Electromagnetic Calorimeter Trigger system at the Belle II experiment

NASA Astrophysics Data System (ADS)

Kim, S. H.; Lee, I. S.; Unno, Y.; Cheon, B. G.

2017-09-01

The Belle II experiment at the SuperKEKB collider in Japan has been under the construction toward a physics run in 2018 with an ultimate target of 40 times higher instantaneous luminosity than the KEKB collider. The main physics motivation is to search for the New Physics from heavy quark/lepton flavor decays. In order to select an event of interest efficiently under much higher luminosity and beam background environment than the KEKB, we have upgraded the Electromagnetic Calorimeter (ECL) hardware trigger system. It would be realized by the improvement of ECL trigger logic based on two main triggers, the total energy and the number of clusters, with an FPGA-based flexible architecture and a high speed serial link for the data transfer. We report the current status of hardware, firmware, and software that has been achieved so far. The overall scheme of the system will be presented as well.

Beam Dynamics Considerations in Electron Ion Colliders

NASA Astrophysics Data System (ADS)

Krafft, Geoffrey

2015-04-01

The nuclear physics community is converging on the idea that the next large project after FRIB should be an electron-ion collider. Both Brookhaven National Lab and Thomas Jefferson National Accelerator Facility have developed accelerator designs, both of which need novel solutions to accelerator physics problems. In this talk we discuss some of the problems that must be solved and their solutions. Examples in novel beam optics systems, beam cooling, and beam polarization control will be presented. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

Analyzing high energy physics data using database computing: Preliminary report

NASA Technical Reports Server (NTRS)

Baden, Andrew; Day, Chris; Grossman, Robert; Lifka, Dave; Lusk, Ewing; May, Edward; Price, Larry

1991-01-01

A proof of concept system is described for analyzing high energy physics (HEP) data using data base computing. The system is designed to scale up to the size required for HEP experiments at the Superconducting SuperCollider (SSC) lab. These experiments will require collecting and analyzing approximately 10 to 100 million 'events' per year during proton colliding beam collisions. Each 'event' consists of a set of vectors with a total length of approx. one megabyte. This represents an increase of approx. 2 to 3 orders of magnitude in the amount of data accumulated by present HEP experiments. The system is called the HEPDBC System (High Energy Physics Database Computing System). At present, the Mark 0 HEPDBC System is completed, and can produce analysis of HEP experimental data approx. an order of magnitude faster than current production software on data sets of approx. 1 GB. The Mark 1 HEPDBC System is currently undergoing testing and is designed to analyze data sets 10 to 100 times larger.

Linear beam dynamics and ampere class superconducting RF cavities at RHIC

NASA Astrophysics Data System (ADS)

Calaga, Rama R.

The Relativistic Heavy Ion Collider (RHIC) is a hadron collider designed to collide a range of ions from protons to gold. RHIC operations began in 2000 and has successfully completed five physics runs with several species including gold, deuteron, copper, and polarized protons. Linear optics and coupling are fundamental issues affecting the collider performance. Measurement and correction of optics and coupling are important to maximize the luminosity and sustain stable operation. A numerical approach, first developed at SLAC, was implemented to measure linear optics from coherent betatron oscillations generated by ac dipoles and recorded at multiple beam position monitors (BPMs) distributed around the collider. The approach is extended to a fully coupled 2D case and equivalence relationships between Hamiltonian and matrix formalisms are derived. Detailed measurements of the transverse coupling terms are carried out at RHIC and correction strategies are applied to compensate coupling both locally and globally. A statistical approach to determine BPM reliability and performance over the past three runs and future improvements also discussed. Aiming at a ten-fold increase in the average heavy-ion luminosity, electron cooling is the enabling technology for the next luminosity upgrade (RHIC II). Cooling gold ion beams at 100 GeV/nucleon requires an electron beam of approximately 54 MeV and a high average current in the range of 50-200 mA. All existing e-Coolers are based on low energy DC accelerators. The only viable option to generate high current, high energy, low emittance CW electron beam is through a superconducting energy-recovery linac (SC-ERL). In this option, an electron beam from a superconducting injector gun is accelerated using a high gradient (˜ 20 MV/m) superconducting RF (SRF) cavity. The electrons are returned back to the cavity with a 180° phase shift to recover the energy back into the cavity before being dumped. A design and development of a half-cell electron gun and a five-cell SRF linac cavity are presented. Several RF and beam dynamics issues ultimately resulting in an optimum cavity design are discussed in detail.

High energy beam impact tests on a LHC tertiary collimator at the CERN high-radiation to materials facility

NASA Astrophysics Data System (ADS)

Cauchi, Marija; Aberle, O.; Assmann, R. W.; Bertarelli, A.; Carra, F.; Cornelis, K.; Dallocchio, A.; Deboy, D.; Lari, L.; Redaelli, S.; Rossi, A.; Salvachua, B.; Mollicone, P.; Sammut, N.

2014-02-01

The correct functioning of a collimation system is crucial to safely operate highly energetic particle accelerators, such as the Large Hadron Collider (LHC). The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN High-Radiation to Materials (HiRadMat) facility, involved 440 GeV proton beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained, together with some first outcomes from visual inspection and a comparison of such results with numerical simulations.

WEDGE ABSORBERS FOR MUON COOLING WITH A TEST BEAM AT MICE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, David; Acosta, J.; Summers, D.

2016-10-18

Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

Static beam-based alignment for the Ring-To-Main-Linac of the Compact Linear Collider

NASA Astrophysics Data System (ADS)

Han, Y.; Latina, A.; Ma, L.; Schulte, D.

2017-06-01

The Compact Linear Collider (CLIC) is a future multi-TeV collider for the post-Large Hadron Collider era. It features high-gradient acceleration and ultra-low emittance to achieve its ambitious goals of high collision energy and peak luminosity. Beam-based alignment (BBA) techniques are mandatory for CLIC to preserve the ultra-low emittances from the damping rings to the interaction point. In this paper, a detailed study of BBA techniques has been carried out for the entire 27 km long ``Ring-To-Main-Linac'' (RTML) section of the CLIC, to correct realistic static errors such as element position offsets, angle, magnetic strength and dynamic magnetic centre shifts. The correction strategy is proved to be very effective and leads to a relaxation of the pre-alignment tolerances for the component installation in the tunnel. This is the first time such a large scale and complex lattice has been corrected to match the design budgets. The techniques proposed could be applied to similarly sized facilities, such as the International Linear Collider, where a similar RTML section is used, or free-electron lasers, which, being equipped with linacs and bunch compressors, present challenges similar to those of the CLIC RTML. Moreover, a new technique is investigated for the emittance tuning procedure: the direct measurement of the interactions between the beams and a set of a few consecutive laser wires. The speed of this technique can be faster comparing to the traditional techniques based on emittance reconstructed from beam size measurements at several positions.

Design of a high-bunch-charge 112-MHz superconducting RF photoemission electron source

NASA Astrophysics Data System (ADS)

Xin, T.; Brutus, J. C.; Belomestnykh, Sergey A.; Ben-Zvi, I.; Boulware, C. H.; Grimm, T. L.; Hayes, T.; Litvinenko, Vladimir N.; Mernick, K.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Severino, F.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Xiao, B.; Xie, H.; Zaltsman, A.

2016-09-01

High-bunch-charge photoemission electron-sources operating in a continuous wave (CW) mode are required for many advanced applications of particle accelerators, such as electron coolers for hadron beams, electron-ion colliders, and free-electron lasers. Superconducting RF (SRF) has several advantages over other electron-gun technologies in CW mode as it offers higher acceleration rate and potentially can generate higher bunch charges and average beam currents. A 112 MHz SRF electron photoinjector (gun) was developed at Brookhaven National Laboratory to produce high-brightness and high-bunch-charge bunches for the coherent electron cooling proof-of-principle experiment. The gun utilizes a quarter-wave resonator geometry for assuring beam dynamics and uses high quantum efficiency multi-alkali photocathodes for generating electrons.

Observation of electron cloud instabilities and emittance dilution at the Cornell electron-positron Storage ring Test Accelerator

DOE PAGES

Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; ...

2016-04-11

Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnostics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud withmore » stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains, 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this study we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.« less

Observation of Electron Cloud Instabilities and Emittance Dilution at the Cornell Electron-Positron Storage Ring Test Accelerator

NASA Astrophysics Data System (ADS)

Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; Dugan, G. F.; Flanagan, J.; McArdle, K. E.; Miller, M. I.; Palmer, M. A.; Ramirez, G. A.; Sonnad, K. G.; Totten, M. M.; Tucker, S. L.; Williams, H. A.

2016-04-01

Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnotics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.

A possible layout of the Spin Physics Detector with toroid magnet.

NASA Astrophysics Data System (ADS)

Nagaytsev, A. P.

2017-12-01

The Spin Physics Detector project for carrying out experiments at the 2-nd interaction point of the NICA collider is under preparation. The design of the collider allows reaching collision energy in the c.m.s. as high as √s = 26 GeV for polarized proton-proton collisions and √s = 12 GeV for polarized deuteron-deuteron collisons with a luminosity of up to 1032 cm2 s-1 (for protons) and 1031cm2s-1 for deuterons. Such a high luminosity of polarized beams interactions opens unique possibilities to investigate a variety of polarization phenomena including those related to the nucleon spin structure. A proposal for the experimental set-up based on a toroid type magnet is presented.

Crab Waist Collision at DAFNE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milardi, C.; Alesini, D.; Biagini, M.E.

DAFNE is an accelerator complex consisting of a double ring lepton collider working at the c.m. energy of the {Phi}-resonance (1.02 GeV) and an injection system. In its original configuration the collider consisted of two independent rings, each {approx}97 m long, sharing two 10 m long interaction regions (IR1 and IR2) where the KLOE and FINUDA or DEAR detectors were respectively installed. A full energy injection system, including an S-band linac, 180 m long transfer lines and an accumulator/damping ring, provides fast and high efficiency electron positron injection also in topping-up mode during collisions. Recently the DAFNE collider has beenmore » upgraded in order to implement a new collision scheme based on large Piwinski angle and cancellation of the synchro-betatron resonances by means of electromagnetic sextupoles (Crab-Waist compensation). The novel approach has proved to be effective in improving beam-beam interaction and collider luminosity.« less

A test of the Feynman scaling in the fragmentation region

NASA Technical Reports Server (NTRS)

Doke, T.; Innocente, V.; Kasahara, K.; Kikuchi, J.; Kashiwagi, T.; Lanzano, S.; Masuda, K.; Murakami, H.; Muraki, Y.; Nakada, T.

1985-01-01

The result of the direct measurement of the fragmentation region will be presented. The result will be obtained at the CERN proton-antiproton collider, being exposured the Silicon calorimeters inside beam pipe. This experiment clarifies a long riddle of cosmic ray physics, whether the Feynman scaling does villate at the fragmentation region or the Iron component is increasing at 10 to the 15th power eV.

Design study of the CEPC booster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Chuang

2014-12-10

Design study of the CEPC booster is reported. The booster provides 120 GeV beams for the collider with topup injection frequency of 0.1 Hz. To save cost, energy of the linac injector for the booster is chosen as 6GeV, corresponding to the magnetic field of 30 Gs. In this paper, lattice of the booster is described; the low injection energy issues are studied; beam transfer from linac to booster and from booster to collider are discussed.

Design of a High Luminosity 100 TeV Proton-Antiproton Collider

NASA Astrophysics Data System (ADS)

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.

Design of a High Luminosity 100 TeV Proton Antiproton Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveros Tuativa, Sandra Jimena

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 10more » $$^{\\,34}$$ 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.« less

High Pressure Gas Filled RF Cavity Beam Test at the Fermilab MuCool Test Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freemire, Ben

2013-05-01

The high energy physics community is continually looking to push the limits with respect to the energy and luminosity of particle accelerators. In the realm of leptons, only electron colliders have been built to date. Compared to hadrons, electrons lose a large amount of energy when accelerated in a ring through synchrotron radiation. A solution to this problem is to build long, straight accelerators for electrons, which has been done with great success. With a new generation of lepton colliders being conceived, building longer, more powerful accelerators is not the most enticing option. Muons have been proposed as an alternativemore » particle to electrons. Muons lose less energy to synchrotron radiation and a Muon Collider can provide luminosity within a much smaller energy range than a comparable electron collider. This allows a circular collider to be built with higher attainable energy than any present electron collider. As part of the accelerator, but separate from the collider, it would also be possible to allow the muons to decay to study neutrinos. The possibility of a high energy, high luminosity muon collider and an abundant, precise source of neutrinos is an attractive one. The technological challenges of building a muon accelerator are many and diverse. Because the muon is an unstable particle, a muon beam must be cooled and accelerated to the desired energy within a short amount of time. This requirement places strict requisites on the type of acceleration and focusing that can be used. Muons are generated as tertiary beams with a huge phase space, so strong magnetic fields are required to capture and focus them. Radio frequency (RF) cavities are needed to capture, bunch and accelerate the muons. Unfortunately, traditional vacuum RF cavities have been shown to break down in the magnetic fields necessary for capture and focusing.« less

3D-FBK Pixel Sensors: Recent Beam Tests Results with Irradiated Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Micelli, A.; /INFN, Trieste /Udine U.; Helle, K.

2012-04-30

The Pixel Detector is the innermost part of the ATLAS experiment tracking device at the Large Hadron Collider, and plays a key role in the reconstruction of the primary vertices from the collisions and secondary vertices produced by short-lived particles. To cope with the high level of radiation produced during the collider operation, it is planned to add to the present three layers of silicon pixel sensors which constitute the Pixel Detector, an additional layer (Insertable B-Layer, or IBL) of sensors. 3D silicon sensors are one of the technologies which are under study for the IBL. 3D silicon technology ismore » an innovative combination of very-large-scale integration and Micro-Electro-Mechanical-Systems where electrodes are fabricated inside the silicon bulk instead of being implanted on the wafer surfaces. 3D sensors, with electrodes fully or partially penetrating the silicon substrate, are currently fabricated at different processing facilities in Europe and USA. This paper reports on the 2010 June beam test results for irradiated 3D devices produced at FBK (Trento, Italy). The performance of these devices, all bump-bonded with the ATLAS pixel FE-I3 read-out chip, is compared to that observed before irradiation in a previous beam test.« less

Harmonic Kicker RF Cavity for the Jefferson Lab Electron-Ion Collider EM Simulation, Modification, and Measurements

NASA Astrophysics Data System (ADS)

Overstreet, Sarah; Wang, Haipeng

2017-09-01

An important step in the conceptual design for the future Jefferson Lab Electron-Ion Collider (JLEIC) is the development of supporting technologies for the Energy Recovery Linac (ERL) Electron Cooling Facility. The Harmonic Radiofrequency (RF) kicker cavity is one such device that is responsible for switching electron bunches in and out of the Circulator Cooling Ring (CCR) from and to the ERL, which is a critical part of the ion cooling process. Last year, a half scale prototype of the JLEIC harmonic RF kicker model was designed with resonant frequencies to support the summation of 5 odd harmonics (95.26 MHz, 285.78 MHz, 476.30 MHz, 666.82 MHz, and 857.35 MHz); however, the asymmetry of the kicker cavity gives rise to multipole components of the electric field at the electron-beam axis of the cavity. Previous attempts to symmetrize the electric field of this asymmetrical RF cavity have been unsuccessful. The aim of this study is to modify the existing prototype for a uniform electric field across the beam pathway so that the electron bunches will experience nearly zero beam current loading. In addition to this, we have driven the unmodified cavity with the harmonic sum and used the wire stretching method for an analysis of the multipole electric field components.

Optimization of the beam crossing angle at the ILC for e+e‑ and γ γ collisions

NASA Astrophysics Data System (ADS)

Telnov, V. I.

2018-03-01

At this time, the design of the International Linear Collider (ILC) is optimized for e+e‑ collisions; the photon collider (γ γ and >=) is considered as an option. Unexpected discoveries, such as the diphoton excess digamma(750) seen at the LHC, could strongly motivate the construction of a photon collider. In order to enable the γ γ collision option, the ILC design should be compatible with it from the very beginning. In this paper, we discuss the problem of the beam crossing angle. In the ILC technical design [1], this angle is 14 mrad, which is just enough to provide enough space for the final quadrupoles and outgoing beams. For γ γ collisions, the crossing angle must be larger because the low-energy electrons that result from multiple Compton scattering get large disruption angles in collisions with the opposing electron beam and some deflection in the solenoidal detector field. For a 2E0=500 GeV collider, the required crossing angle is about 25 mrad. In this paper, we consider the factors that determine the crossing angle as well as its minimum permissible value that does not yet cause a considerable reduction of the γ γ luminosity. It is shown that the best solution is to increase the laser wavelength from the current 1 μm (which is optimal for 2E0=500 GeV) to 2 μm as this makes possible achieving high γ γ luminosities at a crossing angle of 20 mrad, which is also quite comfortable for e+e‑ collisions, does not cause any degradation of the e+e‑ luminosity and opens the possibility for a more energetic future collider in the same tunnel (e.g., CLIC). Moreover, the 2 μm wavelength is optimal for a 2E0 = 1 TeV collider, e.g., a possible ILC energy upgrade. Please consider this paper an appeal to increase the ILC crossing angle from 14 to 20 mrad.

Update on the CeC PoP 704 MHz 5-cell cavity cryomodule design and fabrication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brutus, J. C.; Belomestnykh, S.; Ben-Zvi, I.

2015-05-03

A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the new technique of cooling proton and ion beams that may increase the beam luminosity in certain cases, by as much as tenfold. The 704 MHz cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22MeV. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cellmore » SRF for CeC PoP experiment.« less

Accelerator physics and technology challenges of very high energy hadron colliders

NASA Astrophysics Data System (ADS)

Shiltsev, Vladimir D.

2015-08-01

High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton-proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This paper briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

Accelerator physics and technology challenges of very high energy hadron colliders

DOE PAGES

Shiltsev, Vladimir D.

2015-08-20

High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton–proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This article briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

Focusing Electron Beams at SLAC.

ERIC Educational Resources Information Center

Taylor, Richard L.

1993-01-01

Describes the development of a set of magnets that focus high-energy electron and positron beams causing them to collide, annihilate each other, and generate new particles. Explains how dipoles bend the beam, how quadrupoles focus the beam, how the focal length is calculated, and the superconducting final focus. (MDH)

High-temperature superconductor coating for coupling impedance reduction in the FCC-hh beam screen

NASA Astrophysics Data System (ADS)

Krkotić, Patrick; Niedermayer, Uwe; Boine-Frankenheim, Oliver

2018-07-01

The international Future Circular Collider study develops a conceptual design for a post Large Hadron Collider particle accelerator using 16 T superconducting dipoles for achieving p-p center-of-mass collision energies up to 100 TeV. One concern for this project is the beam coupling impedance especially at injection energy. A copper coated beam screen as in the LHC is planned, but preliminary studies indicate that copper at the high operating temperature of 50 K might not provide a sufficiently low impedance for a stable beam. In order to reduce the coupling impedance, we investigate high-temperature superconductors as a possible coating material in combination with copper as a hybrid system. The effect of different coating combinations are estimated through numerical calculations to identify the best hybrid beam screen coating system.

First experimental evidence of hydrodynamic tunneling of ultra–relativistic protons in extended solid copper target at the CERN HiRadMat facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, R.; Grenier, D.; Wollmann, D.

2014-08-15

A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like themore » Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.« less

CLASHING BEAM PARTICLE ACCELERATOR

DOEpatents

Burleigh, R.J.

1961-04-11

A charged-particle accelerator of the proton synchrotron class having means for simultaneously accelerating two separate contra-rotating particle beams within a single annular magnet structure is reported. The magnet provides two concentric circular field regions of opposite magnetic polarity with one field region being of slightly less diameter than the other. The accelerator includes a deflector means straddling the two particle orbits and acting to collide the two particle beams after each has been accelerated to a desired energy. The deflector has the further property of returning particles which do not undergo collision to the regular orbits whereby the particles recirculate with the possibility of colliding upon subsequent passages through the deflector.

Proceedings of the Eleventh International Conference on Calorimetry in Particle Physics

NASA Astrophysics Data System (ADS)

Cecchi, Claudia

The Pamela silicon tungsten calorimeter / G. Zampa -- Design and development of a dense, fine grained silicon tungsten calorimeter with integrated electronics / D. Strom -- High resolution silicon detector for 1.2-3.1 eV (400-1000 nm) photons / D. Groom -- The KLEM high energy cosmic rays collector for the NUCLEON satellite mission / M. Merkin (contribution not received) -- The electromagnetic calorimeter of the Hera-b experiment / I. Matchikhilian -- The status of the ATLAS tile calorimeter / J. Mendes Saraiva -- Design and mass production of Scintillator Pad Detector (SPD) / Preshower (PS) detector for LHC-b experiment / E. Gushchin -- Study of new FNAL-NICADD extruded scintillator as active media of large EMCal of ALICE at LHC / O. Grachov -- The CMS hadron calorimeter / D. Karmgard (contribution not received) -- Test beam study of the KOPIO Shashlyk calorimeter prototype / A. Poblaguev -- The Shashlik electro-magnetic calorimeter for the LHCb experiment / S. Barsuk -- Quality of mass produced lead-tungstate crystals / R. Zhu -- Status of the CMS electromagnetic calorimeter / J. Fay -- Scintillation detectors for radiation-hard electromagnetic calorimeters / H. Loehner -- Energy, timing and two-photon invariant mass resolution of a 256-channel PBWO[symbol] calorimeter / M. Ippolitov -- A high performance hybrid electromagnetic calorimeter at Jefferson Lab / A. Gasparian -- CsI(Tl) calorimetry on BESHI / T. Hu (contribution not received) -- The crystal ball and TAPS detectors at the MAMI electron beam facility / D. Watts -- Front-end electronics of the ATLAS tile calorimeter / R. Teuscher -- The ATLAS tilecal detector control system / A. Gomes -- Performance of the liquid argon final calibration board / C. de la Taille -- Overview of the LHCb calorimeter electronics / F. Machefert -- LHCb preshower photodetector and electronics / S. Monteil -- The CMS ECAL readout architecture and the clock and control system / K. Kloukinas -- Test of the CMS-ECAL trigger primitive generation / N. Regnault -- Optical data links for the CMS ECAL / J. Grahl (contribution not received) -- CMS ECAL off-detector electronics / R. Alemany Fernandez -- Performance of a low noise readout ASIC for the W-Si calorimeter physics prototype for the future linear collider / C. de la Taille -- Properties of a sampling calorimeter with warm-liquid ionization chambers / S. Plewnia -- Calorimetry and the DO experiment / R. Zitoun (contribution not received) -- Data quality monitoring for the DØ calorimeter / V. Shary -- Status of the construction of the ATLAS electromagnetic liquid argon calorimeter, overview of beam test performance studies / L. Serin -- Uniformity of response of ATLAS liquid argon EM calorimeter / O. Gaunter -- Status of the ATLAS liquid argon hadronic endcap calorimeter construction / M. Vincter -- Results from particle beam tests of the ATLAS liquid argon endcap calorimeters / M. Lefebvre -- First results of the DREAM project / R. Wigmans -- Electron and muon detection with a dual-readout (DREAM) calorimeter / N. Akchurin -- The neutron zero degree calorimeter for the ALICE experiment / M. Gallio -- The liquid xenon scintillation calorimeter of the MEG experiment: operation of a large prototype / G. Signorelli -- Detection of high energy particles using radio frequency signals / C. Hebert -- Hadronic shower simulation / J.-P. Wellisch -- E.M. and hadronic shower simulation with FLUKA / G. Battistoni -- Simulation of the LHCb electromagnetic calorimeter response with GEANT4 / P. Robbe -- Comparison of beam test results of the combined ATLAS liquid argon endcap calorimeters with GEANT3 and GEANT4 simulations / D. Salihagić -- GEANT4 hadronic physics validation with LHC test-beam data / C. Alexa -- The full simulation of the GLAST LAT high energy gamma ray telescope / F. Longo -- Response of the KLOE electromagnetic calorimeter to low-energy particles / T. Spadaro -- Calorimeter algorithms for DØ; / S. Trincaz-Duvoid -- Identification of low P[symbol] muon with the ATLAS tile calorimeter / G. Usai -- Electron and photon reconstruction with fully simulated events in the CMS experiment / G. Daskalakis -- Expected performance of Jet, [symbol] and [symbol] reconstruction in ATLAS / I. Vivarelli -- LHCb calorimeter from trigger to physics / O. Deschamps -- The calibration strategy of CMS electromagnetic calorimeter / P. Meridiani -- Energy and impact point reconstruction in the CMS ECAL (testbeam results from 2003) / I. B. van Vulpen -- The jet energy scale and resolution in the DO calorimeter / A. Kupco (contribution not received) -- Precision linearity studies of the ATLAS liquid argon EM calorimeter / G. Graziani -- Calibration of the ATLAS tile calorimeter / F. Sarri -- Performance of the CMS ECAL laser monitoring source in the test beam / A. Bornheim -- Energy reconstruction algorithms and their influence on the ATLAS tile calorimeter / E. Fullana -- Study of the biological effectiveness of ionizing radiations for a more realistic evaluation of the radiation quality in hadrontherapy / R. Cherubini (contribution not received) -- New dosimetry technologies for IMRT (Intensity Modulated Radio Therapy) / A. Piermattei -- Photon neutron radiotherapy / G. Giannini (contribution not received) -- Recent developments in molecular imaging / G. Zavattini (contribution not received) -- Performance goals and design considerations for a linear collider calorimeter / F. Sefkow -- Improving the jet reconstruction with the particle flow method; an introduction / J.-C. Brient -- Fine grained SiW ECAL for a linear collider detector / D. Strom (in the silicon session) -- Silicon-tungsten sampling electromagnetic calorimeter for the TeV electron-positron linear collider / J.-C. Brient -- LCCAL: a calorimeter prototype for future linear colliders / S. Miscetti -- Analog vs digital hadron calorimetry at a future electron-positron linear collider / S. Magill -- Toward a scintillator based heal and tail catcher for the LC calorimeter / M. Martin (contribution not received) -- Minical options, description in MC, calibration, plans for test beam prototype / G. Eigen (contribution not received) -- Photodetector options for a scintillator heal / E. Popova (contribution not received) -- Very low background scintillators in DAMA project: results and perspectives / R. Bernabei -- EDELWEISS Ge cryogenics detectors: main performance and physics results / X. Navick (contribution not received) -- Review of massive underground detectors / A. Rubbia -- Review of neutrino telescopes underwater and under ice / A. Capone (contribution not received) -- The fluorescence detector of the Pierre Auger Observatory / R. Caruso -- The EUSO mission for the observation of ultra high energy cosmic rays from space / A. Petrolini -- Performance of a 3D imaging electromagnetic calorimeter for the AMSO2 space experiment / C. Adloff -- Beam test calibration of the balloon borne imaging calorimeter for the CREAM experiment / P. Maestro.

Transverse profile of the electron beam for the RHIC electron lenses

NASA Astrophysics Data System (ADS)

Gu, X.; Altinbas, Z.; Costanzo, M.; Fischer, W.; Gassner, D. M.; Hock, J.; Luo, Y.; Miller, T.; Tan, Y.; Thieberger, P.; Montag, C.; Pikin, A. I.

2015-10-01

The transverse profile of the electron beam plays a very important role in assuring the success of the electron lens beam-beam compensation, as well as its application in space charge compensation. To compensate for the beam-beam effect in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, we recently installed and commissioned two electron lenses. In this paper, we describe, via theory and simulations using the code Parmela, the evolution of the density of the electron beam with space charge within an electron lens from the gun to the main solenoid. Our theoretical analysis shows that the change in the beam transverse density is dominated by the effects of the space charge induced longitudinal velocity reduction, not by those of transverse Coulomb collisions. We detail the transverse profile of RHIC electron-lens beam, measured via the YAG screen and pinhole detector, and also describe its profile that we assessed from the signal of the electron-backscatter detector (eBSD) via scanning the electron beam with respect to the RHIC beam. We verified, in simulations and experiments, that the distribution of the transverse electron beam is Gaussian throughout its propagation in the RHIC electron lens.

Calculation of the transverse kicks generated by the bends of a hollow electron lens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stancari, Giulio

2014-03-25

Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam in high-energy accelerators. They were used in the Fermilab Tevatron collider for abort-gap clearing, beam-beam compensation, and halo scraping. A beam-beam compensation scheme based upon electron lenses is currently being implemented in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. This work is in support of a conceptual design of hollow electron beam scraper for the Large Hadron Collider. It also applies to the implementation of nonlinear integrable optics with electron lenses in the Integrable Optics Testmore » Accelerator at Fermilab. We consider the axial asymmetries of the electron beam caused by the bends that are used to inject electrons into the interaction region and to extract them. A distribution of electron macroparticles is deposited on a discrete grid enclosed in a conducting pipe. The electrostatic potential and electric fields are calculated using numerical Poisson solvers. The kicks experienced by the circulating beam are estimated by integrating the electric fields over straight trajectories. These kicks are also provided in the form of interpolated analytical symplectic maps for numerical tracking simulations, which are needed to estimate the effects of the electron lens imperfections on proton lifetimes, emittance growth, and dynamic aperture. We outline a general procedure to calculate the magnitude of the transverse proton kicks, which can then be generalized, if needed, to include further refinements such as the space-charge evolution of the electron beam, magnetic fields generated by the electron current, and longitudinal proton dynamics.« less

Higgs, SUSY and the standard model at /γγ colliders

NASA Astrophysics Data System (ADS)

Hagiwara, Kaoru

2001-10-01

In this report, I surveyed physics potential of the γγ option of a linear e +e - collider with the following questions in mind: What new discovery can be expected at a γγ collider in addition to what will be learned at its ' parent' e +e -linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e - beams, we find that a γγ collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e -e - system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a γγ collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay angular correlations of final state particles, and the pattern of interference with the Standard Model amplitudes. A few comments are given for SUSY particle studies at a γγ collider, where a pair of charged spinless particles is produced in the s-wave near the threshold. Squark-onium may be discovered. An e ±γ collision mode may measure the Higgs- Z-γ coupling accurately and probe flavor oscillations in the slepton sector. As a general remark, all the Standard Model background simulation tools should be prepared in the helicity amplitude level, so that simulation can be performed for an arbitrary set of Stokes parameters of the incoming photon beams.

A new analysis technique to measure fusion excitation functions with large beam energy dispersions

NASA Astrophysics Data System (ADS)

Figuera, P.; Di Pietro, A.; Fisichella, M.; Lattuada, M.; Shotter, A. C.; Ruiz, C.; Zadro, M.

2018-01-01

Peculiar nuclear structures of two colliding nuclei such has clustering, neutron halo/skin or very low breakup thresholds can affect the reaction dynamics below the Coulomb barrier and this may also have astrophysical consequences. In order to have a better understanding of this topic, in the last decade, several experiments were performed. A typical experimental challenge of such studies is the need to measure excitation functions below the Coulomb barrier, having a strong energy dependence, with rather large beam energy dispersions inside the target. This may easily lead to ambiguities in associating the measured cross section with a proper beam energy. In this paper a discussion on this topic is reported and a new technique to deal with the above problem will be proposed.

An EUDET/AIDA Pixel Beam Telescope for Detector Development

NASA Astrophysics Data System (ADS)

Rubinskiy, I.; EUDET Consortium; AIDA Consortium

Ahigh resolution(σ< 2 μm) beam telescope based on monolithic active pixel sensors (MAPS) was developed within the EUDET collaboration. EUDET was a coordinated detector R&D programme for the future International Linear Collider providing test beam infrastructure to detector R&D groups. The telescope consists of six sensor planes with a pixel pitch of either 18.4 μm or 10 μmand canbe operated insidea solenoidal magnetic fieldofupto1.2T.Ageneral purpose cooling, positioning, data acquisition (DAQ) and offine data analysis tools are available for the users. The excellent resolution, readout rate andDAQintegration capabilities made the telescopea primary beam tests tool also for several CERN based experiments. In this report the performance of the final telescope is presented. The plans for an even more flexible telescope with three differentpixel technologies(ATLASPixel, Mimosa,Timepix) withinthenew European detector infrastructure project AIDA are presented.

Scaling behavior of circular colliders dominated by synchrotron radiation

NASA Astrophysics Data System (ADS)

Talman, Richard

2015-08-01

The scaling formulas in this paper — many of which involve approximation — apply primarily to electron colliders like CEPC or FCC-ee. The more abstract “radiation dominated” phrase in the title is intended to encourage use of the formulas — though admittedly less precisely — to proton colliders like SPPC, for which synchrotron radiation begins to dominate the design in spite of the large proton mass. Optimizing a facility having an electron-positron Higgs factory, followed decades later by a p, p collider in the same tunnel, is a formidable task. The CEPC design study constitutes an initial “constrained parameter” collider design. Here the constrained parameters include tunnel circumference, cell lengths, phase advance per cell, etc. This approach is valuable, if the constrained parameters are self-consistent and close to optimal. Jumping directly to detailed design makes it possible to develop reliable, objective cost estimates on a rapid time scale. A scaling law formulation is intended to contribute to a “ground-up” stage in the design of future circular colliders. In this more abstract approach, scaling formulas can be used to investigate ways in which the design can be better optimized. Equally important, by solving the lattice matching equations in closed form, as contrasted with running computer programs such as MAD, one can obtain better intuition concerning the fundamental parametric dependencies. The ground-up approach is made especially appropriate by the seemingly impossible task of simultaneous optimization of tunnel circumference for both electrons and protons. The fact that both colliders will be radiation dominated actually simplifies the simultaneous optimization task. All GeV scale electron accelerators are “synchrotron radiation dominated”, meaning that all beam distributions evolve within a fraction of a second to an equilibrium state in which “heating” due to radiation fluctuations is canceled by the “cooling” in RF cavities that restore the lost energy. To the contrary, until now, the large proton to electron mass ratio has caused synchrotron radiation to be negligible in proton accelerators. The LHC beam energy has still been low enough that synchrotron radiation has little effect on beam dynamics; but the thermodynamic penalty in cooling the superconducting magnets has still made it essential for the radiated power not to be dissipated at liquid helium temperatures. Achieving this has been a significant challenge. For the next generation p, p collider this will be even more true. Furthermore, the radiation will effect beam distributions on time scales measured in minutes, for example causing the beams to be flattened, wider than they are high. In this regime scaling relations previously valid only for electrons will be applicable also to protons.

Measurement of Transverse Wakefields Induced by a Misaligned Positron Bunch in a Hollow Channel Plasma Accelerator.

PubMed

Lindstrøm, C A; Adli, E; Allen, J M; An, W; Beekman, C; Clarke, C I; Clayton, C E; Corde, S; Doche, A; Frederico, J; Gessner, S J; Green, S Z; Hogan, M J; Joshi, C; Litos, M; Lu, W; Marsh, K A; Mori, W B; O'Shea, B D; Vafaei-Najafabadi, N; Yakimenko, V

2018-03-23

Hollow channel plasma wakefield acceleration is a proposed method to provide high acceleration gradients for electrons and positrons alike: a key to future lepton colliders. However, beams which are misaligned from the channel axis induce strong transverse wakefields, deflecting beams and reducing the collider luminosity. This undesirable consequence sets a tight constraint on the alignment accuracy of the beam propagating through the channel. Direct measurements of beam misalignment-induced transverse wakefields are therefore essential for designing mitigation strategies. We present the first quantitative measurements of transverse wakefields in a hollow plasma channel, induced by an off-axis 20 GeV positron bunch, and measured with another 20 GeV lower charge trailing positron probe bunch. The measurements are largely consistent with theory.

Measurement of Transverse Wakefields Induced by a Misaligned Positron Bunch in a Hollow Channel Plasma Accelerator

NASA Astrophysics Data System (ADS)

Lindstrøm, C. A.; Adli, E.; Allen, J. M.; An, W.; Beekman, C.; Clarke, C. I.; Clayton, C. E.; Corde, S.; Doche, A.; Frederico, J.; Gessner, S. J.; Green, S. Z.; Hogan, M. J.; Joshi, C.; Litos, M.; Lu, W.; Marsh, K. A.; Mori, W. B.; O'Shea, B. D.; Vafaei-Najafabadi, N.; Yakimenko, V.

2018-03-01

Hollow channel plasma wakefield acceleration is a proposed method to provide high acceleration gradients for electrons and positrons alike: a key to future lepton colliders. However, beams which are misaligned from the channel axis induce strong transverse wakefields, deflecting beams and reducing the collider luminosity. This undesirable consequence sets a tight constraint on the alignment accuracy of the beam propagating through the channel. Direct measurements of beam misalignment-induced transverse wakefields are therefore essential for designing mitigation strategies. We present the first quantitative measurements of transverse wakefields in a hollow plasma channel, induced by an off-axis 20 GeV positron bunch, and measured with another 20 GeV lower charge trailing positron probe bunch. The measurements are largely consistent with theory.

Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

PubMed

Kondo, K; Kanesue, T; Tamura, J; Okamura, M

2010-02-01

Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

Beam dynamics issues in linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seeman, J.T.

1989-06-01

The primary goal of present and future linear colliders is to maximize the integrated luminosity for the experimental program. Beam dynamics plays a central role in the maximization of integrated luminosity. It is the major issue in the production of small beam sizes and low experimental backgrounds and is also an important factor in the production of particle numbers, in the acceleration process, and in the number of bunches. The beam dynamics effects on bunches which are extracted from the damping rings, accelerated in the linac, collimated, momentum analyzed, and finally delivered to the final focus are reviewed. The effectsmore » of bunch compression, transverse and longitudinal wakefields, BNS damping, energy definition, dispersion, emittance, bunch aspect ratio, feedback, and stability are all important. 11 refs., 1 tab.« less

A Detector Scenario for a Muon Cooling Demonstration Experiment

NASA Astrophysics Data System (ADS)

McDonald, Kirk T.; Lu, Changguo; Prebys, Eric J.

1998-04-01

As a verification of the concept of ionization cooling of a muon beam, the Muon Collider Collaboration is planning an experiment to cool the 6-dimensional normalized emittance by a factor of two. We have designed a detector system to measure the 6-dimensional emittance before and after the cooling apparatus. To avoid the cost associated with preparation of a muon beam bunched at 800 MHz, the nominal frequency of the RF in the muon cooler, we propose to use an unbunched muon beam. Muons will be measured in the detector individually, and a subset chosen corresponding to an ideal input bunch. The muons are remeasured after the cooling apparatus and the output bunch emittance calculated to show the expected reduction in phase-space volume. The technique of tracing individual muons will reproduce all effects encountered by a bunch except for space-charge.

Nuclotron-Based Ion Collider Facility (nica)

NASA Astrophysics Data System (ADS)

Meshkov, I.; Sissakian, A.; Sorin, A.

2008-09-01

The project of an ion collider accelerator complex NICA that is under development at JINR is presented. The article is based on the Conceptual Design Report (CDR)1 of the NICA project delivered in January 2008. The article contains NICA facility scheme, the facility operation scenario, its elements parameters, the proposed methods of intense ion beam acceleration and achievement of the required luminosity of the collider. The symmetric mode of the collider operation is considered here and most attention is concentrated on the luminosity provision in collisions of uranium ions (nuclei).

Emittance preservation in plasma-based accelerators with ion motion

DOE PAGES

Benedetti, C.; Schroeder, C. B.; Esarey, E.; ...

2017-11-01

In a plasma-accelerator-based linear collider, the density of matched, low-emittance, high-energy particle bunches required for collider applications can be orders of magnitude above the background ion density, leading to ion motion, perturbation of the focusing fields, and, hence, to beam emittance growth. By analyzing the response of the background ions to an ultrahigh density beam, analytical expressions, valid for nonrelativistic ion motion, are derived for the transverse wakefield and for the final (i.e., after saturation) bunch emittance. Analytical results are validated against numerical modeling. Initial beam distributions are derived that are equilibrium solutions, which require head-to-tail bunch shaping, enabling emittancemore » preservation with ion motion.« less

Ring Imaging Cherenkov Detector Technologies for Particle Identification in the Electron-Ion Collider Experiments

NASA Astrophysics Data System (ADS)

He, X.

In the proposed Electron-Ion Collider (EIC) experiments, particle identification (PID) of the final state hadrons in the semi-inclusive deep inelastic scattering allows the measurement of flavor-dependent gluon and quark distributions inside nucleons and nuclei. The EIC PID consortium (eRD14 Collaboration) has been formed for identifying and developing PID detectors using Ring Imaging Cherenkov (RICH) techniques for the EIC experiments. A modular Ring Imaging Cherenkov (mRICH) detector has been designed for particle identification in the momentum coverage from 3 GeV/c to 10 GeV/c. The mRICH detector consists of an aerogel radiator block, a Fresnel lens, a mirror-wall and a photosensor plane. The first prototype of this detector was successfully tested at Fermi National Accelerator Laboratory in April 2016 for verifying the detector working principles. This talk will highlight the mRICH beam test results and their comparison with GEANT4-based detector simulations. An implementation of the mRICH detector concept in the Forward Angle sPHENIX spectrometer at BNL will also be mentioned in this talk.

Accelerators (4/5)

ScienceCinema

Metral, Elias

2017-12-09

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

Accelerators (5/5)

ScienceCinema

None

2018-05-16

1a) Introduction and motivation; 1b) History and accelerator types; 2) Transverse beam dynamics; 3a) Longitudinal beam dynamics; 3b) Figure of merit of a synchrotron/collider; 3c) Beam control; 4) Main limiting factors; 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

Transverse emittance-preserving arc compressor for high-brightness electron beam-based light sources and colliders

NASA Astrophysics Data System (ADS)

Di Mitri, S.; Cornacchia, M.

2015-03-01

Bunch length magnetic compression is used in high-brightness linacs driving free-electron lasers (FELs) and particle colliders to increase the peak current of the injected beam. To date, it is performed in dedicated insertions made of few degrees bending magnets and the compression factor is limited by the degradation of the beam transverse emittance owing to emission of coherent synchrotron radiation (CSR). We reformulate the known concept of CSR-driven optics balance for the general case of varying bunch length and demonstrate, through analytical and numerical results, that a 500 pC charge beam can be time-compressed in a periodic 180 deg arc at 2.4 GeV beam energy and lower, by a factor of up to 45, reaching peak currents of up to 2 kA and with a normalized emittance growth at the 0.1 μ \\text{m} rad level. The proposed solution offers new schemes of beam longitudinal gymnastics; an application to an energy recovery linac driving FEL is discussed.

Compensation of the long-range beam-beam interactions as a path towards new configurations for the high luminosity LHC

DOE PAGES

Fartoukh, Stéphane; Valishev, Alexander; Papaphilippou, Yannis; ...

2015-12-01

Colliding bunch trains in a circular collider demands a certain crossing angle in order to separate the two beams transversely after the collision. The magnitude of this crossing angle is a complicated function of the bunch charge, the number of long-range beam-beam interactions, of β* and type of optics (flat or round), and possible compensation or additive effects between several low-β insertions in the ring depending on the orientation of the crossing plane at each interaction point. About 15 years ago, the use of current bearing wires was proposed at CERN in order to mitigate the long-range beam-beam effects [J.P. Koutchouk,more » CERN Report No. LHC-Project-Note 223, 2000], therefore offering the possibility to minimize the crossing angle with all the beneficial effects this might have: on the luminosity performance by reducing the need for crab-cavities or lowering their voltage, on the required aperture of the final focus magnets, on the strength of the orbit corrector involved in the crossing bumps, and finally on the heat load and radiation dose deposited in the final focus quadrupoles. In this paper, a semianalytical approach is developed for the compensation of the long-range beam-beam interactions with current wires. This reveals the possibility of achieving optimal correction through a careful adjustment of the aspect ratio of the β functions at the wire position. We consider the baseline luminosity upgrade plan of the Large Hadron Collider (HL-LHC project), and compare it to alternative scenarios, or so-called ''configurations,'' where modifications are applied to optics, crossing angle, or orientation of the crossing plane in the two low-β insertions of the ring. Furthermore, for all these configurations, the beneficial impact of beam-beam compensation devices is then demonstrated on the tune footprint, the dynamical aperture, and/or the frequency map analysis of the nonlinear beam dynamics as the main figures of merit.« less

Beam-Beam Interaction Simulations with Guinea Pig (LCC-0125)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sramek, C

2003-11-20

At the interaction point of a particle accelerator, various phenomena occur which are known as beam-beam effects. Incident bunches of electrons (or positrons) experience strong electromagnetic fields from the opposing bunches, which leads to electron deflection, beamstrahlung and the creation of electron/positron pairs and hadrons due to two-photon exchange. In addition, the beams experience a ''pinch effect'' which focuses each beam and results in either a reduction or expansion of their vertical size. Finally, if a beam's disruption parameter is too large, the beam can develop a sinusoidal distortion, or two-stream (kink) instability. This project simulated and studied these effectsmore » as they relate to luminosity, deflection angles and energy loss in order to optimize beam parameters for the Next Linear Collider (NLC). Using the simulation program Guinea Pig, luminosity, deflection angle and beam energy data was acquired for different levels of beam offset and distortion. Standard deflection curves and luminosity plots agreed with theoretical models but also made clear the difficulties of e-e- feedback. Simulations emphasizing kink instability in modulated and straight beam collisions followed qualitative behavioral predictions and roughly fit recent analytic calculations. A study of e-e- collisions under design constraints for the NLC provided new estimates of how luminosity, beamstrahlung energy loss, upsilon parameter and deflection curve width scale with beam cross-sections ({sigma}{sub x}, {sigma}{sub y}, {sigma}{sub z}) and number of particles per bunch (N). Finally, this same study revealed luminosity maxima at large N and small {sigma}{sub y} which may merit further investigation.« less

Impact of large beam-induced heat loads on the transient operation of the beam screens and the cryogenic plants of the Future Circular Collider (FCC)

NASA Astrophysics Data System (ADS)

Correia Rodrigues, H.; Tavian, L.

2017-12-01

The Future Circular Collider (FCC) under study at CERN will produce 50-TeV high-energy proton beams. The high-energy particle beams are bent by 16-T superconducting dipole magnets operating at 1.9 K and distributed over a circumference of 80 km. The circulating beams induce 5 MW of dynamic heat loads by several processes such as synchrotron radiation, resistive dissipation of beam image currents and electron clouds. These beam-induced heat loads will be intercepted by beam screens operating between 40 and 60 K and induce transients during beam injection. Energy ramp-up and beam dumping on the distributed beam-screen cooling loops, the sector cryogenic plants and the dedicated circulators. Based on the current baseline parameters, numerical simulations of the fluid flow in the cryogenic distribution system during a beam operation cycle were performed. The effects of the thermal inertia of the headers on the helium flow temperature at the cryogenic plant inlet as well as the temperature gradient experienced by the beam screen has been assessed. Additionally, this work enabled a thorough exergetic analysis of different cryogenic plant configurations and laid the building-block for establishing design specification of cold and warm circulators.

Design and system integration of the superconducting wiggler magnets for the Compact Linear Collider damping rings

NASA Astrophysics Data System (ADS)

Schoerling, Daniel; Antoniou, Fanouria; Bernhard, Axel; Bragin, Alexey; Karppinen, Mikko; Maccaferri, Remo; Mezentsev, Nikolay; Papaphilippou, Yannis; Peiffer, Peter; Rossmanith, Robert; Rumolo, Giovanni; Russenschuck, Stephan; Vobly, Pavel; Zolotarev, Konstantin

2012-04-01

To achieve high luminosity at the collision point of the Compact Linear Collider (CLIC), the normalized horizontal and vertical emittances of the electron and positron beams must be reduced to 500 and 4 nm before the beams enter the 1.5 TeV linear accelerators. An effective way to accomplish ultralow emittances with only small effects on the electron polarization is using damping rings operating at 2.86 GeV equipped with superconducting wiggler magnets. This paper describes a technical design concept for the CLIC damping wigglers.

PREFACE: Joint IPPP Durham/Cockcroft Institute/ICFA Workshop on Advanced QED methods for Future Accelerators

NASA Astrophysics Data System (ADS)

Bailey, I. R.; Barber, D. P.; Chattopadhyay, S.; Hartin, A.; Heinzl, T.; Hesselbach, S.; Moortgat-Pick, G. A.

2009-11-01

The joint IPPP Durham/Cockcroft Institute/ICFA workshop on advanced QED methods for future accelerators took place at the Cockcroft Institute in early March 2009. The motivation for the workshop was the need for a detailed consideration of the physics processes associated with beam-beam effects at the interaction points of future high-energy electron-positron colliders. There is a broad consensus within the particle physics community that the next international facility for experimental high-energy physics research beyond the Large Hadron Collider at CERN should be a high-luminosity electron-positron collider working at the TeV energy scale. One important feature of such a collider will be its ability to deliver polarised beams to the interaction point and to provide accurate measurements of the polarisation state during physics collisions. The physics collisions take place in very dense charge bunches in the presence of extremely strong electromagnetic fields of field strength of order of the Schwinger critical field strength of 4.4×1013 Gauss. These intense fields lead to depolarisation processes which need to be thoroughly understood in order to reduce uncertainty in the polarisation state at collision. To that end, this workshop reviewed the formalisms for describing radiative processes and the methods of calculation in the future strong-field environments. These calculations are based on the Furry picture of organising the interaction term of the Lagrangian. The means of deriving the transition probability of the most important of the beam-beam processes - Beamsstrahlung - was reviewed. The workshop was honoured by the presentations of one of the founders, V N Baier, of the 'Operator method' - one means for performing these calculations. Other theoretical methods of performing calculations in the Furry picture, namely those due to A I Nikishov, V I Ritus et al, were reviewed and intense field quantum processes in fields of different form - namely those present in intense lasers - were also presented. Within the Furry picture the lowest order physics processes are represented by one vertex Feynman diagrams. Additionally, higher order processes in the Furry picture are thought to be important and are still not fully studied. The Advanced QED methods workshop also benefited greatly from reports on ongoing and planned experimental work on quantum processes in intense external fields. Some of the experiments reviewed were the NA43 and NA63 experiments using the inter atomic fields in aligned crystals at CERN. In the past, evidence has been obtained from successful experiments using an intense laser at the SLAC experiment E144. The possibility now exists for new experiments with intense laser light with the planned XFEL at DESY and the European Extreme Light Infrastructure. For upcoming accelerator projects, computer simulations of the first order processes in the Furry Picture during the bunch-bunch collision are being performed using the programs CAIN and Guinea-Pig++. The implementation of spin dynamics in these simulation programs was reported on at the workshop. This relatively small workshop generated a very productive intermix of theoretical, experimental and computational developments covering this important field of physics. Fruitful discussions took place covering improvements to the models, estimations of the remaining theoretical uncertainties and future updates to the existing simulations. It was felt that ongoing workshops in the same field would be of benefit to all those involved. The organisers would like to express their sincere thanks to all of the attendees for their contributions, to the staff of the Cockcroft Institute for hosting the workshop, to the IPPP at Durham for providing substantial funding and administrative support, and to ICFA for their sponsorship. We would also like to thank IOP Publishing for their assistance in publishing our proceedings in the Journal of Physics: Conference Series.

Measurement of Transverse Wakefields Induced by a Misaligned Positron Bunch in a Hollow Channel Plasma Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindstrom, C. A.; Adli, E.; Allen, J. M.

Hollow channel plasma wakefield acceleration is a proposed method to provide high acceleration gradients for electrons and positrons alike: a key to future lepton colliders. However, beams which are misaligned from the channel axis induce strong transverse wakefields, deflecting beams and reducing the collider luminosity. This undesirable consequence sets a tight constraint on the alignment accuracy of the beam propagating through the channel. Direct measurements of beam misalignment-induced transverse wakefields are therefore essential for designing mitigation strategies. We present the first quantitative measurements of transverse wakefields in a hollow plasma channel, induced by an off-axis 20 GeV positron bunch, andmore » measured with another 20 GeV lower charge trailing positron probe bunch. Furthermore, the measurements are largely consistent with theory.« less

Measurement of Transverse Wakefields Induced by a Misaligned Positron Bunch in a Hollow Channel Plasma Accelerator

DOE PAGES

Lindstrom, C. A.; Adli, E.; Allen, J. M.; ...

2018-03-23

Hollow channel plasma wakefield acceleration is a proposed method to provide high acceleration gradients for electrons and positrons alike: a key to future lepton colliders. However, beams which are misaligned from the channel axis induce strong transverse wakefields, deflecting beams and reducing the collider luminosity. This undesirable consequence sets a tight constraint on the alignment accuracy of the beam propagating through the channel. Direct measurements of beam misalignment-induced transverse wakefields are therefore essential for designing mitigation strategies. We present the first quantitative measurements of transverse wakefields in a hollow plasma channel, induced by an off-axis 20 GeV positron bunch, andmore » measured with another 20 GeV lower charge trailing positron probe bunch. Furthermore, the measurements are largely consistent with theory.« less

Photon generator

DOEpatents

Srinivasan-Rao, Triveni

2002-01-01

A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

Impact of beam-beam effects on precision luminosity measurements at the ILC

NASA Astrophysics Data System (ADS)

Rimbault, C.; Bambade, P.; Mönig, K.; Schulte, D.

2007-09-01

In this paper, the impact of beam-beam effects on the precision luminosity measurement at the International Linear Collider is investigated quantitatively for the first time. GUINEA-PIG, a beam-beam interaction simulation tool, is adapted to treat the space charge effects affecting the Bhabha events used in this measurement. The biases due to the resulting changes in kinematics are evaluated for different center-of-mass energies and beam parameters.

A free-jet Hg target operating in a high magnetic field intersecting a high-power proton beam

NASA Astrophysics Data System (ADS)

Graves, Van; Spampinato, Philip; Gabriel, Tony; Kirk, Harold; Simos, Nicholas; Tsang, Thomas; McDonald, Kirk; Peter Titus; Fabich, Adrian; Haseroth, Helmut; Lettry, Jacques

2006-06-01

A proof-of-principal experiment to investigate the interaction of a proton beam, high magnetic field, and high-Z target is planned to take place at CERN in early 2007. This experiment is part of the Muon Collider Collaboration, with participants from Brookhaven National Laboratory, Princeton University, Massachusetts Institute Of Technology, European Organization for Nuclear Research-CERN, Rutherford Appleton Laboratory, and Oak Ridge National Laboratory. An unconstrained mercury jet target system that interacts with a high power (1 MW) proton beam in a high magnetic field (15 T) is being designed. The Hg jet diameter is 1-cm with a velocity up to 20 m/s. A laser optical diagnostic system will be incorporated into the target design to permit observation of the dispersal of the jet resulting from interaction with a 24 GeV proton beam with up to 20×1012 ppp. The target system includes instruments for sensing mercury vapor, temperature, flow rate, and sump tank level, and the means to position the jet relative to the magnetic axis of a solenoid and the proton beam. The design considerations for the system include all issues dealing with safely handling approximately 23 l of Hg, transporting the target system and the mercury to CERN, decommissioning the experiment, and returning the mildly activated equipment and Hg to the US.

A free-jet Hg target operating in a high magnetic field intersecting a high-power proton beam

NASA Astrophysics Data System (ADS)

Van Graves; Spampinato, Philip; Gabriel, Tony; Kirk, Harold; Simos, Nicholas; Tsang, Thomas; McDonald, Kirk; Peter Titus; Fabich, Adrian; Haseroth, Helmut; Lettry, Jacques

2006-06-01

A proof-of-principal experiment to investigate the interaction of a proton beam, high magnetic field, and high- Z target is planned to take place at CERN in early 2007. This experiment is part of the Muon Collider Collaboration, with participants from Brookhaven National Laboratory, Princeton University, Massachusetts Institute Of Technology, European Organization for Nuclear Research-CERN, Rutherford Appleton Laboratory, and Oak Ridge National Laboratory. An unconstrained mercury jet target system that interacts with a high power (1 MW) proton beam in a high magnetic field (15 T) is being designed. The Hg jet diameter is 1-cm with a velocity up to 20 m/s. A laser optical diagnostic system will be incorporated into the target design to permit observation of the dispersal of the jet resulting from interaction with a 24 GeV proton beam with up to 20×10 12 ppp. The target system includes instruments for sensing mercury vapor, temperature, flow rate, and sump tank level, and the means to position the jet relative to the magnetic axis of a solenoid and the proton beam. The design considerations for the system include all issues dealing with safely handling approximately 23 l of Hg, transporting the target system and the mercury to CERN, decommissioning the experiment, and returning the mildly activated equipment and Hg to the US.

Design of a high-bunch-charge 112-MHz superconducting RF photoemission electron source

DOE PAGES

Xin, T.; Brutus, J. C.; Belomestnykh, Sergey A.; ...

2016-09-01

High-bunch-charge photoemission electron-sources operating in a continuous wave (CW) mode are required for many advanced applications of particle accelerators, such as electron coolers for hadron beams, electron-ion colliders, and free-electron lasers (FELs). Superconducting RF (SRF) has several advantages over other electron-gun technologies in CW mode as it offers higher acceleration rate and potentially can generate higher bunch charges and average beam currents. A 112 MHz SRF electron photoinjector (gun) was developed at Brookhaven National Laboratory (BNL) to produce high-brightness and high-bunch-charge bunches for the Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment. Lastly, the gun utilizes a quarter-wave resonator (QWR) geometrymore » for assuring beam dynamics, and uses high quantum efficiency (QE) multi-alkali photocathodes for generating electrons.« less

Theory and measurements of emittance preservation in plasma wakefield acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederico, Joel

2016-12-01

In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditionsmore » necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.« less

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Bruce, R.; Assmann, R. W.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

2014-08-01

The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokosawa, A.

The first polarized collider where we collide 250-GeV/c beams of 70% polarized protons at high luminosity is under construction. This will allow a determination of the nucleon spin-dependent structure functions over a large range in x and a collection of sufficient W and Z events to investigate extremely interesting spin-related phenomena.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokosawa, A.

The first polarized collider where one collides 250-GeV/c beams of 70% polarized protons at high luminosity is under construction. This will allow a determination of the nucleon spin-dependent structure functions over a large range in x and a collection of sufficient W and Z events to investigate extremely interesting spin-related phenomena.

NSAC Recommends a Relativistic Heavy-Ion Collider.

ERIC Educational Resources Information Center

Physics Today, 1984

1984-01-01

Describes the plan submitted by the Nuclear Science Advisory Committee to the Department of Energy and National Science Foundation urging construction of an ultrarelativistic heavy-ion collider designed to accelerate nucleon beams of ions as heavy as uranium. Discusses the process of selecting the type of facility as well as siting. (JM)

Muon collider interaction region design

DOE PAGES

Alexahin, Y. I.; Gianfelice-Wendt, E.; Kashikhin, V. V.; ...

2011-06-02

Design of a muon collider interaction region (IR) presents a number of challenges arising from low β* < 1 cm, correspondingly large beta-function values and beam sizes at IR magnets, as well as the necessity to protect superconducting magnets and collider detectors from muon decay products. As a consequence, the designs of the IR optics, magnets and machine-detector interface are strongly interlaced and iterative. A consistent solution for the 1.5 TeV center-of-mass muon collider IR is presented. It can too provide an average luminosity of 10 34 cm -2s -1 with an adequate protection of magnet and detector components.

The Electron Beam Ion Source (EBIS)

ScienceCinema

Brookhaven Lab

2017-12-09

Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

Beam-dynamic effects at the CMS BRIL van der Meer scans

NASA Astrophysics Data System (ADS)

Babaev, A.

2018-03-01

The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is responsible for the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS experiment. The project is engaged in operating and developing new detectors (luminometers), adequate for the experimental conditions associated with high values of instantaneous luminosity delivered by the CERN LHC . BRIL operates several detectors based on different physical principles and technologies. Precise and accurate measurements of the delivered luminosity is of paramount importance for the CMS physics program. The absolute calibration of luminosity is achieved by the van der Meer method, which is carried out under specially tailored conditions. This paper presents models used to simulate of beam-dynamic effects arising due to the electromagnetic interaction of colliding bunches. These effects include beam-beam deflection and dynamic-β effect. Both effects are important to luminosity measurements and influence calibration constants at the level of 1-2%. The simulations are carried out based on 2016 CMS van der Meer scan data for proton-proton collisions at a center-of-mass energy of 13 TeV.

CCD-based vertex detector for ILC

NASA Astrophysics Data System (ADS)

Stefanov, Konstantin D.

2006-12-01

Charge Coupled Devices (CCDs) have been successfully used in several high-energy physics experiments over the last 20 years. Their small pixel size and excellent precision provide a superb tool for studying of short-lived particles and understanding the nature at fundamental level. Over the last few years the Linear Collider Flavour Identification (LCFI) collaboration has developed Column-Parallel CCDs (CPCCD) and CMOS readout chips, to be used for the vertex detector at the International Linear Collider (ILC). The CPCCDs are very fast devices capable of satisfying the challenging requirements imposed by the beam structure of the superconducting accelerator. The first set of prototype devices have been successfully designed, manufactured and tested, with second generation chips on the way. Another idea for CCD-based device, the In-situ Storage Image Sensor (ISIS) is also under development and the first prototype has been manufactured.

Top-up injection schemes for future circular lepton collider

NASA Astrophysics Data System (ADS)

Aiba, M.; Goddard, B.; Oide, K.; Papaphilippou, Y.; Saá Hernández, Á.; Shwartz, D.; White, S.; Zimmermann, F.

2018-02-01

Top-up injection is an essential ingredient for the future circular lepton collider (FCC-ee) to maximize the integrated luminosity and it determines the design performance. In ttbar operation mode, with a beam energy of 175 GeV, the design lifetime of ∼1 h is the shortest of the four anticipated operational modes, and the beam lifetime may be even shorter in actual operation. A highly robust top-up injection scheme is consequently imperative. Various top-up methods are investigated and a number of suitable schemes are considered in developing alternative designs for the injection straight section of the collider ring. For the first time, we consider multipole-kicker off-energy injection, for minimizing detector background in top-up operation, and the use of a thin wire septum in a lepton storage ring, for maximizing the luminosity.

Accomplishments of the heavy electron particle accelerator program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, D.; Stratakis, D.; Palmer, M.

The Muon Accelerator Program (MAP) has completed a four-year study on the feasibility of muon colliders and on using stored muon beams for neutrinos. That study was broadly successful in its goals, establishing the feasibility of heavy lepton colliders (HLCs) from the 125 GeV Higgs Factory to more than 10 TeV, as well as exploring using a μ storage ring (MSR) for neutrinos, and establishing that MSRs could provide factory-level intensities of νe (more » $$\\bar{ve}$$) and $$\\bar{vμ}$$ (νμ) beams. The key components of the collider and neutrino factory systems were identified. Feasible designs and detailed simulations of all of these components have been obtained, including some initial hardware component tests, setting the stage for future implementation where resources are available and the precise physics goals become apparent.« less

Muon Sources for Particle Physics - Accomplishments of the Muon Accelerator Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, D.; Stratakis, D.; Palmer, M.

The Muon Accelerator Program (MAP) completed a four-year study on the feasibility of muon colliders and on using stored muon beams for neutrinos. That study was broadly successful in its goals, establishing the feasibility of lepton colliders from the 125 GeV Higgs Factory to more than 10 TeV, as well as exploring using a μ storage ring (MSR) for neutrinos, and establishing that MSRs could provide factory-level intensities of νe (ν more » $$\\bar{e}$$) and ν $$\\bar{μ}$$) (ν μ) beams. The key components of the collider and neutrino factory systems were identified. Feasible designs and detailed simulations of all of these components were obtained, including some initial hardware component tests, setting the stage for future implementation where resources are available and clearly associated physics goals become apparent« less

MeRHIC - staging approach to eRHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ptitsyn,V.; Beebe-Wang, J.; Ben-Zvi, I.

Design of a medium energy electron-ion collider (MeRHIC) is under development at the Collider-Accelerator Department at BNL. The design envisions construction of a 4 GeV electron accelerator in a local area inside and near the RHIC tunnel. Electrons will be produced by a polarized electron source and accelerated in energy recovery linacs. Collisions of the electron beam with 100 GeV/u heavy ions or with 250 GeV polarized protons will be arranged in the existing IP2 interaction region of RHIC. The luminosity of electron-proton collisions at the 10{sup 32} cm{sup -2}s{sup -1} level will be achieved with 50 mA CW electronmore » current and presently available proton beam parameters. Efficient proton beam cooling at collision energy may bring the luminosity to 10{sup 33} cm{sup -2}s{sup -1}. An important feature of MeRHIC is that it serves as a first stage of eRHIC, a future electron-ion collider at BNL with both higher luminosity and energy reach. The majority of MeRHIC accelerator components will be used in eRHIC.« less

Physics at the SPS.

PubMed

Gatignon, L

2018-05-01

The CERN Super Proton Synchrotron (SPS) has delivered a variety of beams to a vigorous fixed target physics program since 1978. In this paper, we restrict ourselves to the description of a few illustrative examples in the ongoing physics program at the SPS. We will outline the physics aims of the COmmon Muon Proton Apparatus for Structure and Spectroscopy (COMPASS), north area 64 (NA64), north area 62 (NA62), north area 61 (NA61), and advanced proton driven plasma wakefield acceleration experiment (AWAKE). COMPASS studies the structure of the proton and more specifically of its spin. NA64 searches for the dark photon A', which is the messenger for interactions between normal and dark matter. The NA62 experiment aims at a 10% precision measurement of the very rare decay K + → π + νν. As this decay mode can be calculated very precisely in the Standard Model, it offers a very good opportunity to look for new physics beyond the Standard Model. The NA61/SHINE experiment studies the phase transition to Quark Gluon Plasma, a state in which the quarks and gluons that form the proton and the neutron are de-confined. Finally, AWAKE investigates proton-driven wake field acceleration: a promising technique to accelerate electrons with very high accelerating gradients. The Physics Beyond Colliders study at CERN is paving the way for a significant and diversified continuation of this already rich and compelling physics program that is complementary to the one at the big colliders like the Large Hadron Collider.

Physics at the SPS

NASA Astrophysics Data System (ADS)

Gatignon, L.

2018-05-01

The CERN Super Proton Synchrotron (SPS) has delivered a variety of beams to a vigorous fixed target physics program since 1978. In this paper, we restrict ourselves to the description of a few illustrative examples in the ongoing physics program at the SPS. We will outline the physics aims of the COmmon Muon Proton Apparatus for Structure and Spectroscopy (COMPASS), north area 64 (NA64), north area 62 (NA62), north area 61 (NA61), and advanced proton driven plasma wakefield acceleration experiment (AWAKE). COMPASS studies the structure of the proton and more specifically of its spin. NA64 searches for the dark photon A', which is the messenger for interactions between normal and dark matter. The NA62 experiment aims at a 10% precision measurement of the very rare decay K+ → π+νν. As this decay mode can be calculated very precisely in the Standard Model, it offers a very good opportunity to look for new physics beyond the Standard Model. The NA61/SHINE experiment studies the phase transition to Quark Gluon Plasma, a state in which the quarks and gluons that form the proton and the neutron are de-confined. Finally, AWAKE investigates proton-driven wake field acceleration: a promising technique to accelerate electrons with very high accelerating gradients. The Physics Beyond Colliders study at CERN is paving the way for a significant and diversified continuation of this already rich and compelling physics program that is complementary to the one at the big colliders like the Large Hadron Collider.

Inclusive gamma-ray spectra from psi/3095/ and psi-prime/3684/ decays

NASA Technical Reports Server (NTRS)

Biddick, C. J.; Burnett, T. H.; Masek, G. E.; Miller, E. S.; Smith, J. G.; Stronski, J. P.; Sullivan, M. K.; Vernon, W.; Badtke, D. H.; Barnett, B. A.

1977-01-01

Inclusive gamma-ray experiments were carried out in a e(+)e(-) colliding-beam apparatus with NaI(Tl) arrays as detectors. The inclusive gamma-ray spectra, after cosmic-ray background subtraction, are shown as histograms for the decays of the psi(3095) and psi-prime(3684). The psi spectrum has no significant narrow structure, while the psi-prime spectrum shows at least four peaks. Three major radiative decays of the psi-prime(3684) are found, and their respective branching fractions are computed.

Dump system concepts for the Future Circular Collider

NASA Astrophysics Data System (ADS)

Bartmann, W.; Atanasov, M.; Barnes, M. J.; Borburgh, J.; Burkart, F.; Goddard, B.; Kramer, T.; Lechner, A.; Ull, A. Sanz; Schmidt, R.; Stoel, L. S.; Ostojic, R.; Rodziewicz, J.; van Trappen, P.; Barna, D.

2017-03-01

The Future Circular Collider (FCC-hh) beam dump system must provide a safe and reliable extraction and dilution of the stored beam onto a dump absorber. Energy deposition studies show that damage limits of presently used absorber materials will already be reached for single bunches at 50 TeV. A fast field rise of the extraction kicker is required in order to sufficiently separate swept single bunches on the extraction protection absorbers in case of an asynchronous beam dump. In line with this demand is the proposal of a highly segmented extraction kicker system which allows for accepting a single kicker switch erratic and thus, significantly reduces the probability of an asynchronous beam dump. Superconducting septa are foreseen to limit the overall system length and power consumption. Two extraction system concepts are presented and evaluated regarding overall system length, energy deposition on absorbers, hardware requirements, radiation issues, and layout flexibility.

Mercury Handling for the Target System for a Muon Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graves, Van B; Mcdonald, K; Kirk, H.

2012-01-01

The baseline target concept for a Muon Collider or Neutrino Factory is a free-stream mercury jet being impacted by an 8-GeV proton beam. The target is located within a 20-T magnetic field, which captures the generated pions that are conducted to a downstream decay channel. Both the mercury and the proton beam are introduced at slight downward angles to the magnetic axis. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. The impact energy of the remaining beam and jet are substantial, and it is required that splashes andmore » waves be controlled in order to minimize the potential for interference of pion production at the target. Design issues discussed in this paper include the nozzle, splash mitigation in the mercury pool, the mercury containment vessel, and the mercury recirculation system.« less

SimTrack: A compact c++ code for particle orbit and spin tracking in accelerators

DOE PAGES

Luo, Yun

2015-08-29

SimTrack is a compact c++ code of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam–beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam–beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam–beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture,more » physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.« less

Epicyclic helical channels for parametric resonance ionization cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johson, Rolland Paul; Derbenev, Yaroslav

Proposed next-generation muon colliders will require major technical advances to achieve rapid muon beam cooling requirements. Parametric-resonance Ionization Cooling (PIC) is proposed as the final 6D cooling stage of a high-luminosity muon collider. In PIC, a half-integer parametric resonance causes strong focusing of a muon beam at appropriately placed energy absorbers while ionization cooling limits the beam’s angular spread. Combining muon ionization cooling with parametric resonant dynamics in this way should then allow much smaller final transverse muon beam sizes than conventional ionization cooling alone. One of the PIC challenges is compensation of beam aberrations over a sufficiently wide parametermore » range while maintaining the dynamical stability with correlated behavior of the horizontal and vertical betatron motion and dispersion. We explore use of a coupling resonance to reduce the dimensionality of the problem and to shift the dynamics away from non-linear resonances. PIC simulations are presented.« less

Final implementation, commissioning, and performance of embedded collimator beam position monitors in the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Baud, Guillaume; Bruce, Roderik; Gasior, Marek; Mereghetti, Alessio; Mirarchi, Daniele; Olexa, Jakub; Redaelli, Stefano; Salvachua, Belen; Valloni, Alessandra; Wenninger, Jorg

2017-08-01

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also allow for reducing operational margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts, therefore decreasing the β* and increasing the luminosity reach of the LHC. In this paper, the results from the commissioning of the embedded BPMs in the LHC are presented. The data acquisition and control software architectures are reviewed. A comparison with the standard alignment technique is provided, together with a fill-to-fill analysis of the measured orbit in different machine modes, which will also be used to determine suitable beam interlocks for a tighter collimation hierarchy.

Compensation Techniques in Accelerator Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sayed, Hisham Kamal

2011-05-01

Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Twomore » problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.« less

Proposed studies of strongly coupled plasmas at the future FAIR and LHC facilities: the HEDgeHOB collaboration

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Lomonosov, I. V.; Shutov, A.; Udrea, S.; Deutsch, C.; Fortov, V. E.; Gryaznov, V.; Hoffmann, D. H. H.; Jacobi, J.; Kain, V.; Kuster, M.; Ni, P.; Piriz, A. R.; Schmidt, R.; Spiller, P.; Varentsov, D.; Zioutas, K.

2006-04-01

Detailed theoretical studies have shown that intense heavy-ion beams that will be generated at the future Facility for Antiprotons and Ion Research (FAIR) (Henning 2004 Nucl. Instrum. Methods B 214 211) at Darmstadt will be a very efficient tool to create high-energy-density (HED) states in matter including strongly coupled plasmas. In this paper we show, with the help of two-dimensional numerical simulations, the interesting physical states that can be achieved considering different beam intensities using zinc as a test material. Another very interesting experiment that can be performed using the intense heavy-ion beam at FAIR will be generation of low-entropy compression of a test material such as hydrogen that is enclosed in a cylindrical shell of a high-Z material such as lead or gold. In such an experiment, one can study the problem of hydrogen metallization and the interiors of giant planets. Moreover, we discuss an interesting method to diagnose the HED matter that is at the centre of the Sun. We have also carried out simulations to study the damage caused by the full impact of the Large Hadron Collider (LHC) beam on a superconducting magnet. An interesting outcome of this study is that the LHC beam can induce HED states in matter.

Analysis and modeling of proton beam loss and emittance growth in the Relativistic Heavy Ion Collider

DOE PAGES

Luo, Y.; Fischer, W.; White, S.

2016-02-04

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we will present the operational observations at the routine proton physics stores. In addition, the mechanisms for the beam loss, transverse emittance growth, and bunch lengthening are analyzed. Lastly, numerical calculations and multiparticle tracking are used to model these observations.

Wedge Absorbers for Final Cooling for a High-Energy High-Luminosity Lepton Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, David; Mohayai, Tanaz; Snopok, Pavel

2016-06-01

A high-energy high-luminosity muon collider scenario requires a "final cooling" system that reduces transverse emittance to ~25 microns (normalized) while allowing longitudinal emittance increase. Ionization cooling using high-field solenoids (or Li Lens) can reduce transverse emittances to ~100 microns in readily achievable configurations, confirmed by simulation. Passing these muon beams at ~100 MeV/c through cm-sized diamond wedges can reduce transverse emittances to ~25 microns, while increasing longitudinal emittance by a factor of ~5. Implementation will require optical matching of the exiting beam into downstream acceleration systems.

Calculations of safe collimator settings and β* at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Bruce, R.; Assmann, R. W.; Redaelli, S.

2015-06-01

The first run of the Large Hadron Collider (LHC) at CERN was very successful and resulted in important physics discoveries. One way of increasing the luminosity in a collider, which gave a very significant contribution to the LHC performance in the first run and can be used even if the beam intensity cannot be increased, is to decrease the transverse beam size at the interaction points by reducing the optical function β*. However, when doing so, the beam becomes larger in the final focusing system, which could expose its aperture to beam losses. For the LHC, which is designed to store beams with a total energy of 362 MJ, this is critical, since the loss of even a small fraction of the beam could cause a magnet quench or even damage. Therefore, the machine aperture has to be protected by the collimation system. The settings of the collimators constrain the maximum beam size that can be tolerated and therefore impose a lower limit on β*. In this paper, we present calculations to determine safe collimator settings and the resulting limit on β*, based on available aperture and operational stability of the machine. Our model was used to determine the LHC configurations in 2011 and 2012 and it was found that β* could be decreased significantly compared to the conservative model used in 2010. The gain in luminosity resulting from the decreased margins between collimators was more than a factor 2, and a further contribution from the use of realistic aperture estimates based on measurements was almost as large. This has played an essential role in the rapid and successful accumulation of experimental data in the LHC.

405th Brookhaven Lecture

ScienceCinema

Vadim Ptitsyn

2018-04-18

"E-RHIC - Future Electron-Ion Collider at BNL. While RHIC scientists continue their quest to look deep into nuclear phenomena resulting from collisions of ion beams and beams of polarized protons, new design work is under way for a possible extension of RHIC to include e-RHIC, a 10-billion electron volt, high-intensity polarized proton beam.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohmi, K.

In recent high luminosity colliders, the finite crossing angle scheme becomes popular to gain the multiplicity of luminosity with multi-bunch or long bunch operation. Success of KEKB showed that the finite crossing angle scheme was no problem to achieve the beam-beam parameter up to 0.05. The authors have studied the beam-beam interactions with/without crossing angle toward higher luminosity. They discuss how the crossing angle affects the beam-beam parameter and luminosity in the present KEK B factory (KEKB) using computer simulations.

Phase Rotation of Muon Beams for Producing Intense Low-Energy Muon Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, D.; Bao, Y.; Hansen, G.

2016-01-01

Low-energy muon beams are useful for rare decay searches, which provide access to new physics that cannot be addressed at high-energy colliders. However, muons are produced within a broad energy spread unmatched to the low-energy required. In this paper we outline a phase rotation method to significantly increase the intensity of low-energy muons. The muons are produced from a short pulsed proton driver, and develop a time-momentum correlation in a drift space following production. A series of rf cavities is used to bunch the muons and phase-energy rotate the bunches to a momentum of around 100 MeV/c. Then another groupmore » of rf cavities is used to decelerate the muon bunches to low-energy. This obtains ~0.1 muon per 8 GeV proton, which is significantly higher than currently planned Mu2e experiments, and would enable a next generation of rare decay searches, and other intense muon beam applications.« less

Turning the LHC ring into a new physics search machine

NASA Astrophysics Data System (ADS)

Orava, Risto

2017-03-01

The LHC Collider Ring is proposed to be turned into an ultimate automatic search engine for new physics in four consecutive phases: (1) Searches for heavy particles produced in Central Exclusive Process (CEP): pp → p + X + p based on the existing Beam Loss Monitoring (BLM) system of the LHC; (2) Feasibility study of using the LHC Ring as a gravitation wave antenna; (3) Extensions to the current BLM system to facilitate precise registration of the selected CEP proton exit points from the LHC beam vacuum chamber; (4) Integration of the BLM based event tagging system together with the trigger/data acquisition systems of the LHC experiments to facilitate an on-line automatic search machine for the physics of tomorrow.

BEAM DYNAMICS ANALYSIS FOR THE ULTRA-FAST KICKER IN CIRCULAR COOLER RING OF JLEIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.

An ultra-fast kicker system consisting of four quarter wavelength resonator based deflecting cavities was developed that simultaneously resonates at 10 subharmonic modes of the 476.3MHz bunch repetition frequency. Thus every 10th bunch in the bunch train will experience a transverse kick while all the other bunches are undisturbed. This fast kicker is being developed for the Energy Recovery Linac (ERL) based electron Circular Cooler Ring (CCR) in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously MEIC). The electron bunches can be reused 10-30 turns thus the beam current in the ERL can be reduced to 1/10 - 1/30 (150mAmore » - 50mA) of the cooling bunch current (1.5A). In this paper, several methods to synthesize such a kicker waveform and the comparison made by the beam dynamics tracking in Elegant will be discussed.« less

Design and Beam Test Results for the sPHENIX Electromagnetic and Hadronic Calorimeter Prototypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aidala, C.A.; et al.

The sPHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) will perform high precision measurements of jets and heavy flavor observables for a wide selection of nuclear collision systems, elucidating the microscopic nature of strongly interacting matter ranging from nucleons to the strongly coupled quark-gluon plasma. A prototype of the sPHENIX calorimeter system was tested at the Fermilab Test Beam Facility as experiment T-1044 in the spring of 2016. The electromagnetic calorimeter (EMCal) prototype is composed of scintillating fibers embedded in a mixture of tungsten powder and epoxy. The hadronic calorimeter (HCal) prototype is composed of tilted steel plates alternating with plastic scintillator. Results of the test beam reveal the energy resolution for electrons in the EMCal ismore » $$2.8\\%\\oplus~15.5\\%/\\sqrt{E}$$ and the energy resolution for hadrons in the combined EMCal plus HCal system is $$13.5\\%\\oplus 64.9\\%/\\sqrt{E}$$. These results demonstrate that the performance of the proposed calorimeter system is consistent with \\geant simulations and satisfies the sPHENIX specifications.« less

First Observation of Three-Neutron Sequential Emission from 25O

NASA Astrophysics Data System (ADS)

Sword, C.; Brett, J.; Deyoung, P. A.; Frank, N.; Karrick, H.; Kuchera, A. N.; MoNA Collaboration

2017-09-01

An active area of nuclear physics research is to evaluate models of the nuclear force by studying the structure of neutron-rich isotopes. In this experiment, a 101.3 MeV/u 27Ne beam from the National Superconducting Cyclotron Laboratory collided with a liquid deuterium target. The collision resulted in two-proton removal from the 27Ne beam which created excited 25O that decayed into three neutrons and an 22O fragment. The neutrons were detected by arrays of scintillating plastic bars, while a 4-Tesla dipole magnet placed directly after the target redirected charged fragments to a series of charged-particle detectors. From measured velocities of the neutrons and 22O fragments, the decay energy of 25O was calculated on an event-by-event basis with invariant mass spectroscopy. Using GEANT4, we simulated the decay of all nuclei that could have been created by the beam collision. By successfully fitting simulated decay processes to experimental data, we determined the decay processes present in the experiment. This work is supported by the National Science Foundation under Grants No. PHY-1306074 and No. PHY-1613188.

Pre-Town Meeting on spin physics at an Electron-Ion Collider

NASA Astrophysics Data System (ADS)

Aschenauer, Elke-Caroline; Balitsky, Ian; Bland, Leslie; Brodsky, Stanley J.; Burkardt, Matthias; Burkert, Volker; Chen, Jian-Ping; Deshpande, Abhay; Diehl, Markus; Gamberg, Leonard; Grosse Perdekamp, Matthias; Huang, Jin; Hyde, Charles; Ji, Xiangdong; Jiang, Xiaodong; Kang, Zhong-Bo; Kubarovsky, Valery; Lajoie, John; Liu, Keh-Fei; Liu, Ming; Liuti, Simonetta; Melnitchouk, Wally; Mulders, Piet; Prokudin, Alexei; Tarasov, Andrey; Qiu, Jian-Wei; Radyushkin, Anatoly; Richards, David; Sichtermann, Ernst; Stratmann, Marco; Vogelsang, Werner; Yuan, Feng

2017-04-01

A polarized ep/ eA collider (Electron-Ion Collider, or EIC), with polarized proton and light-ion beams and unpolarized heavy-ion beams with a variable center-of-mass energy √{s} ˜ 20 to ˜ 100 GeV (upgradable to ˜ 150 GeV) and a luminosity up to ˜ 10^{34} cm-2s-1, would be uniquely suited to address several outstanding questions of Quantum Chromodynamics, and thereby lead to new qualitative and quantitative information on the microscopic structure of hadrons and nuclei. During this meeting at Jefferson Lab we addressed recent theoretical and experimental developments in the spin and the three-dimensional structure of the nucleon (sea quark and gluon spatial distributions, orbital motion, polarization, and their correlations). This mini-review contains a short update on progress in these areas since the EIC White paper (A. Accardi et al., Eur. Phys. J. A 52, 268 (2016)).

Neutron dosimetry at a high-energy electron-positron collider

NASA Astrophysics Data System (ADS)

Bedogni, Roberto

Electron-positron colliders with energy of hundreds of MeV per beam have been employed for studies in the domain of nuclear and sub-nuclear physics. The typical structure of such a collider includes an LINAC, able to produce both types of particles, an accumulator ring and a main ring, whose diameter ranges from several tens to hundred meters and allows circulating particle currents of several amperes per beam. As a consequence of the interaction of the primary particles with targets, shutters, structures and barriers, a complex radiation environment is produced. This paper addresses the neutron dosimetry issues associated with the operation of such accelerators, referring in particular to the DAΦ NE complex, operative since 1997 at INFN-Frascati National Laboratory (Italy). Special attention is given to the active and passive techniques used for the spectrometric and dosimetric characterization of the workplace neutron fields, for radiation protection dosimetry purposes.

Pre-Town Meeting on spin physics at an Electron-Ion Collider

DOE PAGES

Aschenauer, Elke-Caroline; Balitsky, Ian; Bland, Leslie; ...

2017-04-14

A polarized ep/eA collider (Electron-Ion Collider, or EIC), with polarized proton and light-ion beams and unpolarized heavy-ion beams with a variable center-of-mass energy √s ~ 20 to ~ 100 GeV (upgradable to ~ 150 GeV) and a luminosity up to ~10 34 cm -2s -1, would be uniquely suited to address several outstanding questions of Quantum Chromodynamics, and thereby lead to new qualitative and quantitative information on the microscopic structure of hadrons and nuclei. During this meeting at Jefferson Lab we addressed recent theoretical and experimental developments in the spin and the three-dimensional structure of the nucleon (sea quark andmore » gluon spatial distributions, orbital motion, polarization, and their correlations). Finally, this mini-paper contains a short update on progress in these areas since the EIC White paper (A. Accardi et al., Eur. Phys. J. A 52, 268 (2016)).« less

Exploration of a High Luminosity 100 TeV Proton Antiproton Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveros, Sandra J.; Summers, Don; Cremaldi, Lucien

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. We explore a 10more » $$^{\\,34}$$ cm$$^{-2}$$ s$$^{-1}$$ luminosity, 100 TeV $$p\\bar{p}$$ collider with 7$$\\times$$ the energy of the LHC but only 2$$\\times$$ as much NbTi superconductor, motivating the choice of 4.5 T single bore dipoles. 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 beam crossing, because lower beam currents can produce the same rare event rates. Events are more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller $$\\beta^{*}$$ for higher luminosity. A Fermilab-like $$\\bar p$$ source would disperse the beam into 12 momentum channels to capture more antiprotons. Because stochastic cooling time scales as the number of particles, 12 cooling ring sets would be used. Each set would include phase rotation to lower momentum spreads, equalize all momentum channels, and stochastically cool. One electron cooling ring would follow the stochastic cooling rings. Finally antiprotons would be recycled during runs without leaving the collider ring by joining them to new bunches with synchrotron damping.« less

Design of a synchrotron radiation detector for the test beam lines at the Superconducting Super Collider Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutton, R.D.

1994-01-01

As part of the particle- and momentum-tagging instrumentation required for the test beam lines of the Superconducting Super Collider (SSC), the synchrotron radiation detector (SRD) was designed to provide electron tagging at momentum above 75 GeV. In a parallel effort to the three test beam lines at the SSC, schedule demands required testing and calibration operations to be initiated at Fermilab. Synchrotron radiation detectors also were to be installed in the NM and MW beam lines at Femilab before the test beam lines at the SSC would become operational. The SRD is the last instrument in a series of threemore » used in the SSC test beam fines. It follows a 20-m drift section of beam tube downstream of the last silicon strip detector. A bending dipole just in of the last silicon strip detector produces the synchrotron radiation that is detected in a 50-mm-square cross section NaI crystal. A secondary scintillator made of Bicron BC-400 plastic is used to discriminate whether it is synchrotron radiation or a stray particle that causes the triggering of the NaI crystal`s photo multiplier tube (PMT).« less

In vacuum diamond sensor scanner for beam halo measurements in the beam line at the KEK Accelerator Test Facility

NASA Astrophysics Data System (ADS)

Liu, S.; Bogard, F.; Cornebise, P.; Faus-Golfe, A.; Fuster-Martínez, N.; Griesmayer, E.; Guler, H.; Kubytskyi, V.; Sylvia, C.; Tauchi, T.; Terunuma, N.; Bambade, P.

2016-10-01

The investigation of beam halo transverse distributions is important for the understanding of beam losses and the control of backgrounds in Future Linear Colliders (FLC). A novel in vacuum diamond sensor (DSv) scanner with four strips has been designed and developed for the investigation of the beam halo transverse distributions and also for the diagnostics of Compton recoil electrons after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for the ILC and CLIC linear collider projects. Using the DSv, a dynamic range of ∼106 has been successfully demonstrated and confirmed for the first time in simultaneous beam core (∼109 electrons) and beam halo (∼103 electrons) measurements at ATF2. This report presents the characterization, performance studies and tests of diamond sensors using an α source, as well as using the electron beams at PHIL, a low energy < 5 MeV photo-injector at LAL, and at ATF2. First beam halo measurement results using the DSv at ATF2 with different beam intensities and vacuum levels are also presented. Such measurements not only allow one to evaluate the different sources of beam halo generation but also to define the requirements for a suitable collimation system to be installed at ATF2, as well as to optimize its performance during future operation.

Elementary Particle Physics and High Energy Phenomena: Final Report for FY2010-13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cumalat, John P.; de Alwis, Senarath P.; DeGrand, Thomas A.

2013-06-27

The work under this grant consists of experimental, theoretical, and phenomenological research on the fundamental properties of high energy subnuclear particles. The work is conducted at the University of Colorado, the European Organization for Nuclear Research (CERN), the Japan Proton Accelerator Research Complex (J-PARC), Fermi National Accelerator Laboratory (FNAL), SLAC National Accelerator Laboratory (SLAC), Los Alamos National Laboratory (LANL), and other facilities, employing neutrino-beam experiments, test beams of various particles, and proton-proton collider experiments. It emphasizes mass generation and symmetry-breaking, neutrino oscillations, bottom particle production and decay, detector development, supergravity, supersymmetry, superstrings, quantum chromodynamics, nonequilibrium statistical mechanics, cosmology, phase transitions,more » lattice gauge theory, and anomaly-free theories. The goals are to improve our understanding of the basic building blocks of matter and their interactions. Data from the Large Hadron Collider at CERN have revealed new interactions responsible for particle mass, and perhaps will lead to a more unified picture of the forces among elementary material constituents. To this end our research includes searches for manifestations of theories such as supersymmetry and new gauge bosons, as well as the production and decay of heavy-flavored quarks. Our current work at J-PARC, and future work at new facilities currently under conceptual design, investigate the specifics of how the neutrinos change flavor. The research is integrated with the training of students at all university levels, benefiting both the manpower and intellectual base for future technologies.« less

Particle capture device

DOEpatents

Jayne, John T.; Worsnop, Douglas R.

2016-02-23

In example embodiments, particle collection efficiency in aerosol analyzers and other particle measuring instruments is improved by a particle capture device that employs multiple collisions to decrease momentum of particles until the particles are collected (e.g., vaporized or come to rest). The particle collection device includes an aperture through which a focused particle beam enters. A collection enclosure is coupled to the aperture and has one or more internal surfaces against which particles of the focused beam collide. One or more features are employed in the collection enclosure to promote particles to collide multiple times within the enclosure, and thereby be vaporized or come to rest, rather than escape through the aperture.

Energy dependence of elliptic flow over a large pseudorapidity range in Au+Au collisions at the BNL relativistic heavy ion collider.

PubMed

Back, B B; Baker, M D; Ballintijn, M; Barton, D S; Betts, R R; Bickley, A A; Bindel, R; Budzanowski, A; Busza, W; Carroll, A; Chai, Z; Decowski, M P; García, E; Gburek, T; George, N; Gulbrandsen, K; Gushue, S; Halliwell, C; Hamblen, J; Hauer, M; Heintzelman, G A; Henderson, C; Hofman, D J; Hollis, R S; Hołyński, R; Holzman, B; Iordanova, A; Johnson, E; Kane, J L; Katzy, J; Khan, N; Kucewicz, W; Kulinich, P; Kuo, C M; Lin, W T; Manly, S; McLeod, D; Mignerey, A C; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Pernegger, H; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Rosenberg, L; Sagerer, J; Sarin, P; Sawicki, P; Seals, H; Sedykh, I; Skulski, W; Smith, C E; Stankiewicz, M A; Steinberg, P; Stephans, G S F; Sukhanov, A; Tang, J-L; Tonjes, M B; Trzupek, A; Vale, C; van Nieuwenhuizen, G J; Vaurynovich, S S; Verdier, R; Veres, G I; Wenger, E; Wolfs, F L H; Wosiek, B; Woźniak, K; Wuosmaa, A H; Wysłouch, B

2005-04-01

This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of square root of s(NN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of eta(')=|eta|-y(beam), scale with approximate linearity throughout eta('), implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.

A First Assessment of Two-Beam Linear Colliders and Longer-Term Two-Beam R& D Issues at SLAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loew, Greg

2001-06-05

The purpose of this document is to summarize the work that has been done at SLAC in the last three or four months to assess the possibilities of two-beam linear colliders proposed by Ron Ruth, and to compare these colliders to the current NLC designs and their costs. The work is based on general discussions with C. Adolphsen, D. Burke, J. Irwin, J. Paterson, R. Ruth, T. Lavine and T. Raubenheimer, with considerable work done by the latter two. Given the complexities of these machines, the fact that the designs are far from complete and that all cost estimates aremore » still in a state of flux, it is clear that the conclusions drawn in this report cannot be cast in concrete. On the other hand, it does not seem too early to present the results that have been gathered so far, even if the facts contain significant uncertainties and the costs have large error bars. Now that R. Ruth has returned to SLAC, he will be able to add his point of view to the discussion. At this time, the conclusions presented here are the sole responsibility of the author.« less

Design and Development of a Prototype Permanent Magnet for Focusing/Defocusing for Electron-Ion Colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, Bob

Electron-ion colliders (EIC) have been identified as an ideal tool to study the next frontier of nuclear physics – the gluon force that holds the building blocks of matter together, and which is a fundamental component of the theory of Quantum Chromodynamics (QCD). Future electron-ion colliders under consideration can be based on the Energy Recovery Linac (ERL) architecture. The beam lines for this architecture could be built of the newly developed Non-Scaling Fixed Field Alternating Gradient (NS FFAG) structure, so that they can transfer multiple energies within the same aperture. This structure allows for the use of compact, economical quadupolemore » permanent magnets. In this SBIR, we propose to design and to manufacture prototype quadrupole permanent magnets of focusing/defocusing combined function for use in this beam line. For our SBIR project, we proposed to design and build the focusing/defocusing quadrupole with a gradient strength of 50 T/m and with a beam gap of 16mm. The proposed permanent magnet material is SmCo because of its higher radiation resistance as compared to NdBFe2. The use of permanent magnets will reduce the overall cost. For Phase I, we took a recent design by Dr. Dejan Trbojevic, and reran Tosca code on the design to optimize the iron yoke with respect to the thickness of SmCo. We then fabricated one prototype focusing/defocusing combined function quadruple and measured field quality dG/Go. Our plan for Phase II is that, based on our Phase I prototype experience, we shall improve the design and fabricate a production quadruple, and design and incorporate coils for skew dipoles and normal quadrupole correctors, etc. In addition, we shall fabricate enough quadrupoles for one cell. The development of quadrupole permanent magnets is of fundamental importance for there application in the future electron-ion colliders. This accelerator structure will also advance the development of muon accelerators and allow for the development of compact, simplified, less expensive proton accelerators which will promote their use in areas such as proton cancer therapy, and for high-power proton drivers for tritium and neutron production, waste transmutation, driving a sub-critical nuclear reactor to produce energy, cargo contain inspection, and radioisotope production. Proton cancer therapy has been identified as a particularly attractive and viable commercial application for the immediate future.« less

Survey of beam instrumentation used in SLC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ecklund, S.D.

A survey of beam instruments used at SLAC in the SLC machine is presented. The basic utility and operation of each device is briefly described. The various beam instruments used at the Stanford Linear Collider (SLC), can be classified by the function they perform. Beam intensity, position and size are typical of the parameters of beam which are measured. Each type of parameter is important for adjusting or tuning the machine in order to achieve optimum performance. 39 refs.

Diffraction measurements using the LHC Beam Loss Monitoring System

NASA Astrophysics Data System (ADS)

Kalliokoski, Matti

2017-03-01

The Beam Loss Monitoring (BLM) system of the Large Hadron Collider protects the machine from beam induced damage by measuring the absorbed dose rates of beam losses, and by triggering beam dump if the rates increase above the allowed threshold limits. Although the detection time scales are optimized for multi-turn losses, information on fast losses can be recovered from the loss data. In this paper, methods in using the BLM system in diffraction studies are discussed.

The first colliders: AdA, VEP-1 and Princeton-Stanford

NASA Astrophysics Data System (ADS)

Shiltsev, Vladimir

The idea of exploring collisions in the center-of-mass system to fully exploit the energy of the accelerated particles had been given serious consideration by the Norwegian engineer and inventor Rolf Wideröe, who applied for a patent on the idea in 1943 (and got the patent in 1953 [1]) after considering the kinematic advantage of keeping the center of mass at rest to produce larger momentum transfers. Describing this advantage, G. K. O'Neill, one of the collider pioneers, wrote in 1956 [2]: "... as accelerators of higher and higher energy are built, their usefulness is limited by the fact that the energy available for creating new particles is measured in the center-of-mass system of the target nucleon and the bombarding particle. In the relativistic limit, this energy rises only as the square root of the accelerator energy. However, if two particles of equal energy traveling in opposite directions could be made to collide, the available energy would be twice the whole energy of one particle ... " Therefore, no kinetic energy is wasted by the motion of the center of mass of the system, and the available reaction energy ER = 2Ebeam (while a particle with the same energy Ebeam colliding with another particle of the mass m at rest produces only ER = (2Ebeamm)1/2 in the extreme relativistic case). One can also add that the colliders are "cleaner" machines with respect to the fixed-target ones since the colliding beams do not interact with the target materials. The other advantage is that it is much easier to organize collisions of beams composed of matter-antimatter particles, like in electron-positron and proton-antiproton colliders...

High energy density physics issues related to Future Circular Collider

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

2017-07-01

A design study for a post-Large Hadron Collider accelerator named, Future Circular Collider (FCC), is being carried out by the International Scientific Community. A complete design report is expected to be ready by spring 2018. The FCC will accelerate two counter rotating beams of 50 TeV protons in a tunnel having a length (circumference) of 100 km. Each beam will be comprised of 10 600 proton bunches, with each bunch having an intensity of 1011 protons. The bunch length is of 0.5 ns, and two neighboring bunches are separated by 25 ns. Although there is an option for 5 ns bunch separation as well, in the present studies, we consider the former case only. The total energy stored in each FCC beam is about 8.5 GJ, which is equivalent to the kinetic energy of Airbus 380 (560 t) flying at a speed of 850 km/h. Machine protection is a very important issue while operating with such powerful beams. It is important to have an estimate of the damage caused to the equipment and accelerator components due to the accidental release of a partial or total beam at a given point. For this purpose, we carried out numerical simulations of full impact of one FCC beam on an extended solid copper target. These simulations have been done employing an energy deposition code, FLUKA, and a two-dimensional hydrodynamic code, BIG2, iteratively. This study shows that although the static range of a single FCC proton and its shower is about 1.5 m in solid copper, the entire beam will penetrate around 350 m into the target. This substantial increase in the range is due to the hydrodynamic tunneling of the beam. Our calculations also show that a large part of the target will be converted into high energy density matter including warm dense matter and strongly coupled plasmas.

Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitterer, M.; Stancari, G.; Valishev, A.

2017-06-13

Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.

Making beam splitters with dark soliton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiglitz, Ken

2010-10-15

We show with numerical simulations that for certain simple choices of parameters, the waveguides induced by colliding dark solitons in a Kerr medium yield a complete family of beam splitters for trapped linear waves, ranging from total transmission to total deflection. The way energy is transferred from one waveguide to another is similar to that of a directional coupler, but no special fabrication is required. Dark soliton beam splitters offer potential advantages over their bright soliton counterparts: Their transfer characteristics do not depend on the relative phase or speed of the colliding solitons; dark solitons are generally more robust thanmore » bright solitons; and the probe peaks at nulls of the pump, enhancing the signal-to-noise ratio for probe detection. The last factor is especially important for possible application to quantum information processing.« less

The CERN Large Hadron Collider as a tool to study high-energy density matter.

PubMed

Tahir, N A; Kain, V; Schmidt, R; Shutov, A; Lomonosov, I V; Gryaznov, V; Piriz, A R; Temporal, M; Hoffmann, D H H; Fortov, V E

2005-04-08

The Large Hadron Collider (LHC) at CERN will generate two extremely powerful 7 TeV proton beams. Each beam will consist of 2808 bunches with an intensity per bunch of 1.15x10(11) protons so that the total number of protons in one beam will be about 3x10(14) and the total energy will be 362 MJ. Each bunch will have a duration of 0.5 ns and two successive bunches will be separated by 25 ns, while the power distribution in the radial direction will be Gaussian with a standard deviation, sigma=0.2 mm. The total duration of the beam will be about 89 mus. Using a 2D hydrodynamic code, we have carried out numerical simulations of the thermodynamic and hydrodynamic response of a solid copper target that is irradiated with one of the LHC beams. These calculations show that only the first few hundred proton bunches will deposit a high specific energy of 400 kJ/g that will induce exotic states of high energy density in matter.

Project Nuclotron-based Ion Collider fAcility at JINR

NASA Astrophysics Data System (ADS)

Kekelidze, V. D.; Matveev, V. A.; Meshkov, I. N.; Sorin, A. S.; Trubnikov, G. V.

2017-09-01

The project of Nuclotron-based Ion Collider fAcility (NICA) that is under development at JINR (Dubna) is presented. The general goals of the project are experimental studies of both hot and dense baryonic matter and spin physics (in collisions of polarized protons and deuterons). The first program requires providing of heavy ion collisions in the energy range of √ {{s_{NN}}} = 4-11 Gev at average luminosity of L = 1 × 1027 cm-2 s-1 for 197Au79+ nuclei. The polarized beams mode is proposed to be used in energy range of √ {{s_{NN}}} = 12-27 Gev (protons at luminosity of L ≥ 1 × 1030 cm-2 s-1. The report contains description of the facility scheme and its characteristics in heavy ion operation mode. The Collider will be equipped with two detectors—MultiPurpose Detector (MPD), which is in an active stage of construction, and Spin Physics Detector (SPD) that is in the stage of conceptual design. Fixed target experiment "Baryonic matter at Nuclotron" (BM@N) will be performed in very beginning of the project. The wide program of applied researches at NICA facility is being developed as well.

LINEAR COLLIDER PHYSICS RESOURCE BOOK FOR SNOWMASS 2001.

DOE Office of Scientific and Technical Information (OSTI.GOV)

ABE,T.; DAWSON,S.; HEINEMEYER,S.

The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decademore » or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup {minus}} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup {minus}} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup {minus}} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup {minus}} experiments can provide.« less

Linear Collider Physics Resource Book for Snowmass 2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peskin, Michael E

The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decademore » or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide.« less

LHC: The Emptiest Space in the Solar System

ERIC Educational Resources Information Center

Cid-Vidal, Xabier; Cid, Ramon

2011-01-01

Proton beams have been colliding at 7 TeV in the Large Hadron Collider (LHC) since 30 March 2010, meaning that the LHC research programme is underway. Particle physicists around the world are looking forward to using the data from these collisions, as the LHC is running at an energy three and a half times higher than previously achieved at any…

Beam position monitoring system at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Bergan, W. F.; Forster, M. J.; Meller, R. E.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Palmer, M. A.; Holtzapple, R. L.

2017-09-01

The Cornell Electron-positron Storage Ring (CESR) has been converted from a High Energy Physics electron-positron collider to operate as a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS) and to conduct accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Some of the specific topics that were targeted for the initial phase of operation of the storage ring in this mode, labeled CESRTA (CESR as a Test Accelerator), included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CESRTA occurred over a several year period and is described elsewhere. As a part of this conversion the CESR beam position monitoring (CBPM) system was completely upgraded to provide the needed instrumental capabilities for these studies. This paper describes the new CBPM system hardware, its function and representative measurements performed by the upgraded system.

High-quality electron beam generation in a proton-driven hollow plasma wakefield accelerator

NASA Astrophysics Data System (ADS)

Li, Y.; Xia, G.; Lotov, K. V.; Sosedkin, A. P.; Hanahoe, K.; Mete-Apsimon, O.

2017-10-01

Simulations of proton-driven plasma wakefield accelerators have demonstrated substantially higher accelerating gradients compared to conventional accelerators and the viability of accelerating electrons to the energy frontier in a single plasma stage. However, due to the strong intrinsic transverse fields varying both radially and in time, the witness beam quality is still far from suitable for practical application in future colliders. Here we demonstrate the efficient acceleration of electrons in proton-driven wakefields in a hollow plasma channel. In this regime, the witness bunch is positioned in the region with a strong accelerating field, free from plasma electrons and ions. We show that the electron beam carrying the charge of about 10% of 1 TeV proton driver charge can be accelerated to 0.6 TeV with a preserved normalized emittance in a single channel of 700 m. This high-quality and high-charge beam may pave the way for the development of future plasma-based energy frontier colliders.

MEXnICA, Mexican group in the MPD-NICA experiment at JINR

NASA Astrophysics Data System (ADS)

Rodríguez Cahuantzi, M.; MEXnICA Group

2017-10-01

The Nuclotron Ion Collider fAcility (NICA) accelerator complex is currently under construction at the Joint Institute for Nuclear Research (JINR) laboratory located in the city of Dubna in the Russian Federation. The main goal of NICA is to collide heavy ion nuclei to study the properties of the phase diagram of strongly interacting matter at high baryon density. In this accelerator complex, two big particle detectors are planned to be installed: Spin Physics Detector (SPD) and Multi-Purpose Detector (MPD). At the design luminosity, the event rate in the MPD interaction region is about 6 kHz; the total charged particle multiplicity would exceeds 1000 in the most central Au+Au collisions at \\sqrt{{sNN}} = 11 {{GeV}}. Since the middle of 2016 a group of researchers and students from Mexican institutions was formed (MEXnICA). The main goal of the MEXnICA group is to collaborate in the experimental efforts of MPD-NICA proposing a BEam-BEam counter detector which we called BEBE. In this written general aspects of MPD-NICA detector and BEBE are discussed. This material was shown in a contributed talk given at the XXXI Annual Meeting of the Mexican Division of Particles and Fields held in the Physics Department of CINVESTAV located in Mexico City during the last week of May 2017.

A Centrality and Event Plane Detector for STAR to Complete the Phase Diagram of Quantum Chromodynamics

NASA Astrophysics Data System (ADS)

Halal, George; STAR Collaboration

2017-09-01

The properties of the nearly perfect liquid, Quark Gluon Plasma (QGP), which filled the universe a microsecond after the Big Bang are studied by colliding heavy-ions at relativistic energies. Our project focuses on building and testing an Event Plane Detector (EPD) for the STAR experiment and analyzing the data collected from collisions. When a minimum ionizing particle hits one of the optically-isolated tiles of this detector, which are made of scintillator plastic, it lights up. The light then travels through a wavelength-shifting fiber embedded in the tile to a clear optical fiber to be detected by silicon photo-multipliers. This detector is an improved version of the Beam-Beam Counter, which is currently at STAR. It will help us measure the centrality and event plane of collisions with more precision. Data collected will aid us in mapping out the transition phase between the QGP and hadronic matter, which evolved into the chemical elements we see today, and in searching for a unique critical point in the phase diagram of Quantum Chromodynamics matter. In 2017, a commissioning run has taken place at RHIC, colliding protons at 510 GeV and gold ions at 54.4 GeV. Some data analysis from one eighth of the EPD that is installed will also be discussed.

Development of sampling calorimeter with segmented lead glass absorber

NASA Astrophysics Data System (ADS)

Terada, R.; Takeshita, T.; Itoh, H.; Kanzaki, I.

2018-02-01

Sampling calorimeter is indispensable for physics measurement at collider experiment with PFA. Uncertainty of deposit energy at absorber layer degrades energy resolution. This problem will be solved by using lead glass as absorber, which is clear and heavy. High energy particles produce Cherenkov lights whose light yield corresponds to the track length in the lead glass. This information from the absorber will improve the energy resolution of the calorimeter. Performance of this calorimeter prototype tested for electrons at ELPH beam at Tohoku University has been described. We discuss the problems and its capabilities.

CLIC Project Overview

ScienceCinema

Latina, Andrea

2017-12-11

The CLIC study is exploring the scheme for an electron-positron collider with a centre-of-mass energy of 3 TeV in order to make the multi-TeV range accessible for physics. The current goal of the project is to demonstrate the feasibility of the technology by the year 2010. Recently, important progress has been made concerning the high-gradient accelerating structure tests and the experiments with beam in the CLIC test facility, CTF3. On the organizational side, the CLIC international collaborations have significantly gained momentum, boosting the CLIC study.

The upgrade of the ATLAS first-level calorimeter trigger

NASA Astrophysics Data System (ADS)

Yamamoto, Shimpei; Atlas Collaboration

2016-07-01

The first-level calorimeter trigger (L1Calo) had operated successfully through the first data taking phase of the ATLAS experiment at the CERN Large Hadron Collider. Towards forthcoming LHC runs, a series of upgrades is planned for L1Calo to face new challenges posed by the upcoming increases of the beam energy and the luminosity. This paper reviews the ATLAS L1Calo trigger upgrade project that introduces new architectures for the liquid-argon calorimeter trigger readout and the L1Calo trigger processing system.

Elastic Scattering and Total Cross-Section in p+p Reactions --As Measured by the LHC Experiment TOTEM at √{s} = 7 TeV--

NASA Astrophysics Data System (ADS)

Csörgő, T.; Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Berardi, V.; Berretti, M.; Bossini, E.; Bozzo, M.; Brogi, P.; Brücken, E.; Buzzo, A.; Cafagna, F. S.; Calicchio, M.; Catanesi, M. G.; Covault, C.; Csanád, M.; Deile, M.; Dimovasili, E.; Doubek, M.; Eggert, K.; Eremin, V.; Ferretti, R.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Intonti, M. R.; Janda, M.; Kašpar, J.; Kopal, J.; Kundrát, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lokajíček, M.; Lo Vetere, M.; Lucas Rodríguez, F.; Macrí, M.; Magaletti, L.; Magazzù, G.; Mercadante, A.; Meucci, M.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Noschis, E.; Novák, T.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Perrot, A.-L.; Pedreschi, E.; PetäJäjärvi, J.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Sanguinetti, G.; Santroni, A.; Scribano, A.; Sette, G.; Snoeys, W.; Spinella, F.; Sziklai, J.; Taylor, C.; Turini, N.; Vacek, V.; Vítek, M.; Welti, J.; Whitmore, J.; Totem Collaboration

Proton-proton elastic scattering has been measured by the TOTEMexperiment at the CERN Large Hadron Collider at √{s} = 7 TeV in special runs with the Roman Pot detectors placed as close to the outgoing beam as seven times the transverse beam size. The differential cross-section measurements are reported in the |t|-range of 0.36 to 2.5 GeV^{2}. Extending the range of data to low t values from 0.02 to 0.33 GeV^2, and utilizing the luminosity measurements of CMS, the total proton-proton cross section at √{s} = 7 TeV is measured to be (98.3 ± 0.2^{stat} ± 2.8^{syst}) mb.

Magnetic Frequency Response of HL-LHC Beam Screens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrone, M.; Martino, M.; De Maria, R.

Magnetic fields used to control particle beams in accelerators are usually controlled by regulating the electrical current of the power converters. In order to minimize lifetime degradation and ultimately luminosity loss in circular colliders, current-noise is a highly critical figure of merit of power converters, in particular for magnets located in areas with high beta-function, like the High Luminosity Large Hadron Collider (HL-LHC) insertions. However, what is directly acting upon the beam is the magnetic field and not the current of the power converter, which undergoes several frequency-dependent transformations until the desired magnetic field, seen by the beam, is obtained.more » Beam screens are very rarely considered when assessing or specifying the noise figure of merit, but their magnetic frequency response is such that they realize relatively effective low pass filtering of the magnetic field produced by the system magnet-power converter. This work aims at filling this gap by quantifying the expected impact of different beam screen layouts for the most relevant HL-LHC insertion magnets. A welldefined post-processing technique is used to derive the frequency response of the different multipoles from multi-physics Finite Element Method (FEM) simulation results. In addition, a well approximated analytical formula for the low-frequency range of multi-layered beam screens is presented.« less

Observing a light dark matter beam with neutrino experiments

NASA Astrophysics Data System (ADS)

Deniverville, Patrick; Pospelov, Maxim; Ritz, Adam

2011-10-01

We consider the sensitivity of fixed-target neutrino experiments at the luminosity frontier to light stable states, such as those present in models of MeV-scale dark matter. To ensure the correct thermal relic abundance, such states must annihilate via light mediators, which in turn provide an access portal for direct production in colliders or fixed targets. Indeed, this framework endows the neutrino beams produced at fixed-target facilities with a companion “dark matter beam,” which may be detected via an excess of elastic scattering events off electrons or nuclei in the (near-)detector. We study the high-luminosity proton fixed-target experiments at LSND and MiniBooNE, and determine that the ensuing sensitivity to light dark matter generally surpasses that of other direct probes. For scenarios with a kinetically-mixed U(1)' vector mediator of mass mV, we find that a large volume of parameter space is excluded for mDM˜1-5MeV, covering vector masses 2mDM≲mV≲mη and a range of kinetic mixing parameters reaching as low as κ˜10-5. The corresponding MeV-scale dark matter scenarios motivated by an explanation of the galactic 511 keV line are thus strongly constrained.

Plasma Accelerators Race to 10 GeV and Beyond

NASA Astrophysics Data System (ADS)

Katsouleas, Tom

2005-10-01

This paper reviews the concepts, recent progress and current challenges for realizing the tremendous electric fields in relativistic plasma waves for applications ranging from tabletop particle accelerators to high-energy physics. Experiments in the 90's on laser-driven plasma wakefield accelerators at several laboratories around the world demonstrated the potential for plasma wakefields to accelerate intense bunches of self-trapped particles at rates as high as 100 GeV/m in mm-scale gas jets. These early experiments offered impressive gradients but large energy spread (100%) and short interaction lengths. Major breakthroughs have recently occurred on both fronts. Three groups (LBL-US, LOA-France and RAL-UK) have now entered a new regime of laser wakefield acceleration resulting in 100 MeV mono-energetic beams with up to nanoCoulombs of charge and very small angular spread. Simulations suggest that current lasers are just entering this new regime, and the scaling to higher energies appears attractive. In parallel with the progress in laser-driven wakefields, particle-beam driven wakefield accelerators are making large strides. A series of experiments using the 30 GeV beam of the Stanford Linear Accelerator Center (SLAC) has demonstrated high-gradient acceleration of electrons and positrons in meter-scale plasmas. The UCLA/USC/SLAC collaboration has accelerated electrons beyond 1 GeV and is aiming at 10 GeV in 30 cm as the next step toward a ``plasma afterburner,'' a concept for doubling the energy of a high-energy collider in a few tens of meters of plasma. In addition to wakefield acceleration, these and other experiments have demonstrated the rich physics bounty to be reaped from relativistic beam-plasma interactions. This includes plasma lenses capable of focusing particle beams to the highest density ever produced, collective radiation mechanisms capable of generating high-brightness x-ray beams, collective refraction of particles at a plasma interface, and acceleration of intense proton beams from laser-irradiated foils.

Design criteria for prompt radiation limits on the relativistic heavy ion collider site.

PubMed

Stevens, A; Musolino, S; Harrison, M

1994-03-01

The Relativistic Heavy Ion Collider (RHIC) is a superconducting colliding beam accelerator facility that is currently under construction. Relatively small amounts of energy depositing in the coils of superconducting magnets can result in a "quench," the irreversible transition to the normal resistive state. The quench limit of superconducting magnets, therefore, constrains local beam loss throughout the injection, acceleration, and storage cycles to extremely low levels. From a practical standpoint, it follows that there is essentially no prompt radiation in most regions due to normal operations. The design of shielding is, therefore, principally driven by the consequences of a single pulse fault at full energy in one of the two storage rings. Since there are no regulatory requirements or guidance documents that prescribe radiological performance goals for this situation, the RHIC Project has proposed a scheme to classify the various areas of the RHIC complex based on Design Basis Accident faults. The criteria is then compared to existing regulatory requirements and guidance recommendations.

Fermilab Tevatron and Pbar source status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, H.

1986-08-01

The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently undermore » evaluation to accomplish these goals: luminosity increase to 5 x 10/sup 31/ cm/sup -2/sec/sup -1/, production rates up to 4 x 10/sup 11/ antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade. (LEW)« less

Projections for neutral Di-Boson and Di-Higgs interactions at FCC-he collider

NASA Astrophysics Data System (ADS)

Kuday, S.; Saygın, H.; Hoş, İ.; Çetin, F.

2018-07-01

As a high energy e-p collider, FCC-he, has been recently proposed with sufficient energy options to investigate Higgs couplings. To analyze the sensitivity on Higgs boson couplings, we focus specifically on the CP-even and CP-odd Wilson coefficients with hhZZ and hhγγ four-point interactions of Higgs boson with Effective Lagrangian Model through the process e- p → hhje-. We simulate the related processes in FCC-he, with 60 GeV and 120 GeV e- beams and 50 TeV proton beam collisions. We present the exclusion limits on these couplings both for 68% and 95% C.L. in terms of integrated luminosities.

Polarized γ source based on Compton backscattering in a laser cavity

NASA Astrophysics Data System (ADS)

Yakimenko, V.; Pogorelsky, I. V.

2006-09-01

We propose a novel gamma source suitable for generating a polarized positron beam for the next generation of electron-positron colliders, such as the International Linear Collider (ILC), and the Compact Linear Collider (CLIC). This 30-MeV polarized gamma source is based on Compton scattering inside a picosecond CO2 laser cavity generated from electron bunches produced by a 4-GeV linac. We identified and experimentally verified the optimum conditions for obtaining at least one gamma photon per electron. After multiplication at several consecutive interaction points, the circularly polarized gamma rays are stopped on a target, thereby creating copious numbers of polarized positrons. We address the practicality of having an intracavity Compton-polarized positron source as the injector for these new colliders.

PERLE. Powerful energy recovery linac for experiments. Conceptual design report

NASA Astrophysics Data System (ADS)

Angal-Kalinin, D.; Arduini, G.; Auchmann, B.; Bernauer, J.; Bogacz, A.; Bordry, F.; Bousson, S.; Bracco, C.; Brüning, O.; Calaga, R.; Cassou, K.; Chetvertkova, V.; Cormier, E.; Daly, E.; Douglas, D.; Dupraz, K.; Goddard, B.; Henry, J.; Hutton, A.; Jensen, E.; Kaabi, W.; Klein, M.; Kostka, P.; Lasheras, N.; Levichev, E.; Marhauser, F.; Martens, A.; Milanese, A.; Militsyn, B.; Peinaud, Y.; Pellegrini, D.; Pietralla, N.; Pupkov, Y.; Rimmer, R.; Schirm, K.; Schulte, D.; Smith, S.; Stocchi, A.; Valloni, A.; Welsch, C.; Willering, G.; Wollmann, D.; Zimmermann, F.; Zomer, F.

2018-06-01

A conceptual design is presented of a novel energy-recovering linac (ERL) facility for the development and application of the energy recovery technique to linear electron accelerators in the multi-turn, large current and large energy regime. The main characteristics of the powerful energy recovery linac experiment facility (PERLE) are derived from the design of the Large Hadron electron Collider, an electron beam upgrade under study for the LHC, for which it would be the key demonstrator. PERLE is thus projected as a facility to investigate efficient, high current (HC) (>10 mA) ERL operation with three re-circulation passages through newly designed SCRF cavities, at 801.58 MHz frequency, and following deceleration over another three re-circulations. In its fully equipped configuration, PERLE provides an electron beam of approximately 1 GeV energy. A physics programme possibly associated with PERLE is sketched, consisting of high precision elastic electron–proton scattering experiments, as well as photo-nuclear reactions of unprecedented intensities with up to 30 MeV photon beam energy as may be obtained using Fabry–Perot cavities. The facility has further applications as a general technology test bed that can investigate and validate novel superconducting magnets (beam induced quench tests) and superconducting RF structures (structure tests with HC beams, beam loading and transients). Besides a chapter on operation aspects, the report contains detailed considerations on the choices for the SCRF structure, optics and lattice design, solutions for arc magnets, source and injector and on further essential components. A suitable configuration derived from the here presented design concept may next be moved forward to a technical design and possibly be built by an international collaboration which is being established.

Linear Collider Physics Resource Book Snowmass 2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronan

The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decademore » or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.« less

CEPC booster design study

DOE PAGES

Bian, Tianjian; Gao, Jie; Zhang, Chuang; ...

2017-12-10

In September 2012, Chinese scientists proposed a Circular Electron Positron Collider (CEPC) in China at 240 GeV center-of-mass energy for Higgs studies. The booster provides 120 GeV electron and positron beams to the CEPC collider for top-up injection at 0.1 Hz. The design of the full energy booster ring of the CEPC is a challenge. The ejected beam energy is 120 GeV and the injected beam energy is 6 GeV. Here in this paper we describe two alternative schemes, the wiggler bend scheme and the normal bend scheme. For the wiggler bend scheme, we propose to operate the booster ringmore » as a large wiggler at low energy and as a normal ring at high energy to avoid the problem of very low dipole magnet fields. Finally, for the normal bend scheme, we implement the orbit correction to correct the earth field.« less

Simulation of radiation damping in rings, using stepwise ray-tracing methods

DOE PAGES

Meot, F.

2015-06-26

The ray-tracing code Zgoubi computes particle trajectories in arbitrary magnetic and/or electric field maps or analytical field models. It includes a built-in fitting procedure, spin tracking many Monte Carlo processes. The accuracy of the integration method makes it an efficient tool for multi-turn tracking in periodic machines. Energy loss by synchrotron radiation, based on Monte Carlo techniques, had been introduced in Zgoubi in the early 2000s for studies regarding the linear collider beam delivery system. However, only recently has this Monte Carlo tool been used for systematic beam dynamics and spin diffusion studies in rings, including eRHIC electron-ion collider projectmore » at the Brookhaven National Laboratory. Some beam dynamics aspects of this recent use of Zgoubi capabilities, including considerations of accuracy as well as further benchmarking in the presence of synchrotron radiation in rings, are reported here.« less

CEPC booster design study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bian, Tianjian; Gao, Jie; Zhang, Chuang

In September 2012, Chinese scientists proposed a Circular Electron Positron Collider (CEPC) in China at 240 GeV center-of-mass energy for Higgs studies. The booster provides 120 GeV electron and positron beams to the CEPC collider for top-up injection at 0.1 Hz. The design of the full energy booster ring of the CEPC is a challenge. The ejected beam energy is 120 GeV and the injected beam energy is 6 GeV. Here in this paper we describe two alternative schemes, the wiggler bend scheme and the normal bend scheme. For the wiggler bend scheme, we propose to operate the booster ringmore » as a large wiggler at low energy and as a normal ring at high energy to avoid the problem of very low dipole magnet fields. Finally, for the normal bend scheme, we implement the orbit correction to correct the earth field.« less

Numerical simulations of energy deposition caused by 50 MeV—50 TeV proton beams in copper and graphite targets

NASA Astrophysics Data System (ADS)

Nie, Y.; Schmidt, R.; Chetvertkova, V.; Rosell-Tarragó, G.; Burkart, F.; Wollmann, D.

2017-08-01

The conceptual design of the Future Circular Collider (FCC) is being carried out actively in an international collaboration hosted by CERN, for the post-Large Hadron Collider (LHC) era. The target center-of-mass energy of proton-proton collisions for the FCC is 100 TeV, nearly an order of magnitude higher than for LHC. The existing CERN accelerators will be used to prepare the beams for FCC. Concerning beam-related machine protection of the whole accelerator chain, it is critical to assess the consequences of beam impact on various accelerator components in the cases of controlled and uncontrolled beam losses. In this paper, we study the energy deposition of protons in solid copper and graphite targets, since the two materials are widely used in magnets, beam screens, collimators, and beam absorbers. Nominal injection and extraction energies in the hadron accelerator complex at CERN were selected in the range of 50 MeV-50 TeV. Three beam sizes were studied for each energy, corresponding to typical values of the betatron function. Specifically for thin targets, comparisons between fluka simulations and analytical Bethe equation calculations were carried out, which showed that the damage potential of a few-millimeter-thick graphite target and submillimeter-thick copper foil can be well estimated directly by the Bethe equation. The paper provides a valuable reference for the quick evaluation of potential damage to accelerator elements over a large range of beam parameters when beam loss occurs.

Design of the large hadron electron collider interaction region

NASA Astrophysics Data System (ADS)

Cruz-Alaniz, E.; Newton, D.; Tomás, R.; Korostelev, M.

2015-11-01

The large hadron electron collider (LHeC) is a proposed upgrade of the Large Hadron Collider (LHC) within the high luminosity LHC (HL-LHC) project, to provide electron-nucleon collisions and explore a new regime of energy and luminosity for deep inelastic scattering. The design of an interaction region for any collider is always a challenging task given that the beams are brought into crossing with the smallest beam sizes in a region where there are tight detector constraints. In this case integrating the LHeC into the existing HL-LHC lattice, to allow simultaneous proton-proton and electron-proton collisions, increases the difficulty of the task. A nominal design was presented in the the LHeC conceptual design report in 2012 featuring an optical configuration that focuses one of the proton beams of the LHC to β*=10 cm in the LHeC interaction point to reach the desired luminosity of L =1033 cm-2 s-1 . This value is achieved with the aid of a new inner triplet of quadrupoles at a distance L*=10 m from the interaction point. However the chromatic beta beating was found intolerable regarding machine protection issues. An advanced chromatic correction scheme was required. This paper explores the feasibility of the extension of a novel optical technique called the achromatic telescopic squeezing scheme and the flexibility of the interaction region design, in order to find the optimal solution that would produce the highest luminosity while controlling the chromaticity, minimizing the synchrotron radiation power and maintaining the dynamic aperture required for stability.

Efficiency Versus Instability in Plasma Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebedev, Valeri; Burov, Alexey; Nagaitsev, Sergei

2017-01-05

Plasma wake-field acceleration in a strongly nonlinear (a.k.a. the blowout) regime is one of the main candidates for future high-energy colliders. For this case, we derive a universal efficiency-instability relation, between the power efficiency and the key instability parameter of the witness bunch. We also show that in order to stabilize the witness bunch in a regime with high power efficiency, the bunch needs to have high energy spread, which is not presently compatible with collider-quality beam properties. It is unclear how such limitations could be overcome for high-luminosity linear colliders.

Charge recombination in the muon collider cooling channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernow, R. C.; Palmer, R. B.

2012-12-21

The final stage of the ionization cooling channel for the muon collider must transversely recombine the positively and negatively charged bunches into a single beam before the muons can be accelerated. It is particularly important to minimize any emittance growth in this system since no further cooling takes place before the bunches are collided. We have found that emittance growth could be minimized by using symmetric pairs of bent solenoids and careful matching. We show that a practical design can be found that has transmission {approx}99%, emittance growth less than 0.1%, and minimal dispersion in the recombined bunches.

ISR effects for resonant Higgs production at future lepton colliders

DOE PAGES

Greco, Mario; Han, Tao; Liu, Zhen

2016-11-04

We study the effects of the initial state radiation on themore » $s$-channel Higgs boson resonant production at $$\\mu^+\\mu^-$$ and $e^+e^-$ colliders by convoluting with the beam energy spread profile of the collider and the Breit-Wigner resonance profile of the signal. We assess their impact on both the Higgs signal and SM backgrounds for the leading decay channels $$h\\rightarrow b\\bar b,\\ WW^*$$. In conclusion, our study improves the existing analyses of the proposed future resonant Higgs factories and provides further guidance for the accelerator designs with respect to the physical goals.« less

Assessment of neutron skyshine near unmodified Accumulator Debuncher storage rings under Mu2e operational conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cossairt, J.Donald; /Fermilab

2010-12-01

Preliminary plans for providing the proton beam needed by the proposed Mu2e experiment at Fermilab will require the transport of 8 GeV protons to the Accumulator/Debuncher where they be processed into an intensity and time structure useful for the experiment. The intensities involved are far greater that those encountered with antiprotons of the same kinetic energy in the same beam enclosures under Tevatron Collider operational conditions, the operating parameters for which the physical facilities of the Antiproton Source were designed. This note explores some important ramifications of the proposed operation for radiation safety and demonstrates the need for extensive modificationsmore » of significant portions of the shielding of the Accumulator Debuncher storage rings; notably that underneath the AP Service Buildings AP10, AP30, and AP50. While existing shielding is adequate for the current operating mode of the Accumulator/Debuncher as part of the Antiproton Source used in the Tevatron Collider program, without significant modifications of the shielding configuration in the Accumulator/Debuncher region and/or beam loss control systems far more effective than seen in most applications at Fermilab, the proposed operational mode for Mu2e is not viable for the following reasons: 1. Due to skyshine alone, under normal operational conditions large areas of the Fermilab site would be exposed to unacceptable levels of radiation where most of the Laboratory workforce and some members of the general public who regularly visit Fermilab would receive measurable doses annually, contrary to workforce, public, and DOE expectations concerning the As Low as Reasonably Achievable (ALARA) principle. 2. Under normal operational conditions, a sizeable region of the Fermilab site would also require fencing due to skyshine. The size of the areas involved would likely invite public inquiry about the significant and visible enlargement of Fermilab's posted radiological areas. 3. There would be aesthetics questions about the employment of so much new fencing on the Fermilab site. 4. The assumption of only 1.0% 'normal condition' beam losses over the three locations is regarded as being extremely optimistic. Thus, it is evident that it is necessary to pursue shielding improvements to support viable operation of the Mu2e experiment.« less

Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

Balance functions have been measured in terms of relative pseudorapidity ( Δη ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider (RHIC) from Au + Au collisions atmore » $$\\sqrt{s}$$$_{NN}$$ = 7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at $$\\sqrt{s}$$$_{NN}$$ = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). Finally, the narrowing of the balance function in central collisions at $$\\sqrt{s}$$$_{NN}$$ = 7.7 GeV implies that a QGP is still being created at this relatively low energy.« less

Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

NASA Astrophysics Data System (ADS)

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.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; 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, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; 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, Filip, P.; Fisyak, Y.; Flores, C. E.; 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.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; 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, Z. M.; Li, X.; Li, W.; Li, Y.; 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. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; 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. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, 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.; Sandacz, A.; 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, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; 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.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

2016-08-01

Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.

Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

DOE PAGES

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

2016-08-16

Balance functions have been measured in terms of relative pseudorapidity ( Δη ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider (RHIC) from Au + Au collisions atmore » $$\\sqrt{s}$$$_{NN}$$ = 7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at $$\\sqrt{s}$$$_{NN}$$ = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). Finally, the narrowing of the balance function in central collisions at $$\\sqrt{s}$$$_{NN}$$ = 7.7 GeV implies that a QGP is still being created at this relatively low energy.« less

Reinventing the Accelerator for the High Energy Frontier

ScienceCinema

Rosenzweig, James [UCLA, Los Angeles, California, United States

2017-12-09

The history of discovery in high-energy physics has been intimately connected with progress in methods of accelerating particles for the past 75 years. This remains true today, as the post-LHC era in particle physics will require significant innovation and investment in a superconducting linear collider. The choice of the linear collider as the next-generation discovery machine, and the selection of superconducting technology has rather suddenly thrown promising competing techniques -- such as very large hadron colliders, muon colliders, and high-field, high frequency linear colliders -- into the background. We discuss the state of such conventional options, and the likelihood of their eventual success. We then follow with a much longer view: a survey of a new, burgeoning frontier in high energy accelerators, where intense lasers, charged particle beams, and plasmas are all combined in a cross-disciplinary effort to reinvent the accelerator from its fundamental principles on up.

Ghost imaging with atoms

NASA Astrophysics Data System (ADS)

Khakimov, R. I.; Henson, B. M.; Shin, D. K.; Hodgman, S. S.; Dall, R. G.; Baldwin, K. G. H.; Truscott, A. G.

2016-12-01

Ghost imaging is a counter-intuitive phenomenon—first realized in quantum optics—that enables the image of a two-dimensional object (mask) to be reconstructed using the spatio-temporal properties of a beam of particles with which it never interacts. Typically, two beams of correlated photons are used: one passes through the mask to a single-pixel (bucket) detector while the spatial profile of the other is measured by a high-resolution (multi-pixel) detector. The second beam never interacts with the mask. Neither detector can reconstruct the mask independently, but temporal cross-correlation between the two beams can be used to recover a ‘ghost’ image. Here we report the realization of ghost imaging using massive particles instead of photons. In our experiment, the two beams are formed by correlated pairs of ultracold, metastable helium atoms, which originate from s-wave scattering of two colliding Bose-Einstein condensates. We use higher-order Kapitza-Dirac scattering to generate a large number of correlated atom pairs, enabling the creation of a clear ghost image with submillimetre resolution. Future extensions of our technique could lead to the realization of ghost interference, and enable tests of Einstein-Podolsky-Rosen entanglement and Bell’s inequalities with atoms.

Material characterisation and preliminary mechanical design for the HL-LHC shielded beam screens operating at cryogenic temperatures.

NASA Astrophysics Data System (ADS)

Garion, C.; Dufay-Chanat, L.; Koettig, T.; Machiocha, W.; Morrone, M.

2015-12-01

The High Luminosity LHC project (HL-LHC) aims at increasing the luminosity (rate of collisions) in the Large Hadron Collider (LHC) experiments by a factor of 10 beyond the original design value (from 300 to 3000 fb-1). It relies on new superconducting magnets, installed close to the interaction points, equipped with new beam screen. This component has to ensure the vacuum performance together with shielding the cold mass from physics debris and screening the cold bore cryogenic system from beam induced heating. The beam screen operates in the range 40-60 K whereas the magnet cold bore temperature is 1.9 K. A tungsten-based material is used to absorb the energy of particles. In this paper, measurements of the mechanical and physical properties of such tungsten material are shown at room and cryogenic temperature. In addition, the design and the thermal mechanical behaviour of the beam screen assembly are presented also. They include the heat transfer from the tungsten absorbers to the cooling pipes and the supporting system that has to minimise the heat inleak into the cold mass. The behaviour during a magnet quench is also presented.

Generation of High Brightness X-rays with the PLEIADES Thomson X-ray Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, W J; Anderson, S G; Barty, C P J

2003-05-28

The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm2/mrad2. Simulationsmore » of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.« less

Numerical Study of Electrostatic Field Distortion on LPTPC End-Plates based on Bulk Micromegas Modules

NASA Astrophysics Data System (ADS)

Bhattacharya, Purba; Bhattacharya, Deb Sankar; Mukhopadhyay, Supratik; Majumdar, Nayana; Bhattacharya, Sudeb; Colas, Paul; Attié, David

2018-02-01

The R&D activities for the linear collider TPC (LC-TPC) are currently working on the adoption of the micro pattern devices for the gaseous amplification stage. Several beam tests have been carried out at DESY with a 5 GeV electron beam in a 1 T superconducting magnet. We worked on a large prototype TPC with an end-plate that was built, for the first time, using seven resistive bulk Micromegas modules. During experiments, reduced signal sensitivity was observed at the boundary of these modules. Electrostatic field distortion near the module boundaries was considered to be the possible major reason behind these observations. In the present work, we will explore this hypothesis through numerical simulation. Our aim has been to understand the origin of distortions observed close to the edges of the test beam modules and to explore the possibility of using the Garfield simulation framework for investigating a phenomenon as complex as distortion.

Reaching record-low β* at the CERN Large Hadron Collider using a novel scheme of collimator settings and optics

NASA Astrophysics Data System (ADS)

Bruce, R.; Bracco, C.; De Maria, R.; Giovannozzi, M.; Mereghetti, A.; Mirarchi, D.; Redaelli, S.; Quaranta, E.; Salvachua, B.

2017-03-01

The Large Hadron Collider (LHC) at CERN is built to collide intense proton beams with an unprecedented energy of 7 TeV. The design stored energy per beam of 362 MJ makes the LHC beams highly destructive, so that any beam losses risk to cause quenches of superconducting magnets or damage to accelerator components. Collimators are installed to protect the machine and they define a minimum normalized aperture, below which no other element is allowed. This imposes a limit on the achievable luminosity, since when squeezing β* (the β-function at the collision point) to smaller values for increased luminosity, the β-function in the final focusing system increases. This leads to a smaller normalized aperture that risks to go below the allowed collimation aperture. In the first run of the LHC, this was the main limitation on β*, which was constrained to values above the design specification. In this article, we show through theoretical and experimental studies how tighter collimator openings and a new optics with specific phase-advance constraints allows a β* as small as 40 cm, a factor 2 smaller than β*=80 cm used in 2015 and significantly below the design value β*=55 cm, in spite of a lower beam energy. The proposed configuration with β*=40 cm has been successfully put into operation and has been used throughout 2016 as the LHC baseline. The decrease in β* compared to 2015 has been an essential contribution to reaching and surpassing, in 2016, the LHC design luminosity for the first time, and to accumulating a record-high integrated luminosity of around 40 fb-1 in one year, in spite of using less bunches than in the design.

Long bunch trains measured using a prototype cavity beam position monitor for the Compact Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cullinan, F. J.; Boogert, S. T.; Farabolini, W.

2015-11-19

The Compact Linear Collider (CLIC) requires beam position monitors (BPMs) with 50 nm spatial resolution for alignment of the beam line elements in the main linac and beam delivery system. Furthermore, the BPMs must be able to make multiple independent measurements within a single 156 ns long bunch train. A prototype cavity BPM for CLIC has been manufactured and tested on the probe beam line at the 3rd CLIC Test Facility (CTF3) at CERN. The transverse beam position is determined from the electromagnetic resonant modes excited by the beam in the two cavities of the pickup, the position cavity and the referencemore » cavity. The mode that is measured in each cavity resonates at 15 GHz and has a loaded quality factor that is below 200. Analytical expressions for the amplitude, phase and total energy of signals from long trains of bunches have been derived and the main conclusions are discussed. The results of the beam tests are presented. The variable gain of the receiver electronics has been characterized using beam excited signals and the form of the signals for different beam pulse lengths with the 2/3 ns bunch spacing has been observed. The sensitivity of the reference cavity signal to charge and the horizontal position signal to beam offset have been measured and are compared with theoretical predictions based on laboratory measurements of the BPM pickup and the form of the resonant cavity modes as determined by numerical simulation. Lastly, the BPM was calibrated so that the beam position jitter at the BPM location could be measured. It is expected that the beam jitter scales linearly with the beam size and so the results are compared to predicted values for the latter.« less

Long bunch trains measured using a prototype cavity beam position monitor for the Compact Linear Collider

NASA Astrophysics Data System (ADS)

Cullinan, F. J.; Boogert, S. T.; Farabolini, W.; Lefevre, T.; Lunin, A.; Lyapin, A.; Søby, L.; Towler, J.; Wendt, M.

2015-11-01

The Compact Linear Collider (CLIC) requires beam position monitors (BPMs) with 50 nm spatial resolution for alignment of the beam line elements in the main linac and beam delivery system. Furthermore, the BPMs must be able to make multiple independent measurements within a single 156 ns long bunch train. A prototype cavity BPM for CLIC has been manufactured and tested on the probe beam line at the 3rd CLIC Test Facility (CTF3) at CERN. The transverse beam position is determined from the electromagnetic resonant modes excited by the beam in the two cavities of the pickup, the position cavity and the reference cavity. The mode that is measured in each cavity resonates at 15 GHz and has a loaded quality factor that is below 200. Analytical expressions for the amplitude, phase and total energy of signals from long trains of bunches have been derived and the main conclusions are discussed. The results of the beam tests are presented. The variable gain of the receiver electronics has been characterized using beam excited signals and the form of the signals for different beam pulse lengths with the 2 /3 ns bunch spacing has been observed. The sensitivity of the reference cavity signal to charge and the horizontal position signal to beam offset have been measured and are compared with theoretical predictions based on laboratory measurements of the BPM pickup and the form of the resonant cavity modes as determined by numerical simulation. Finally, the BPM was calibrated so that the beam position jitter at the BPM location could be measured. It is expected that the beam jitter scales linearly with the beam size and so the results are compared to predicted values for the latter.

Performance of a reentrant cavity beam position monitor

NASA Astrophysics Data System (ADS)

Simon, Claire; Luong, Michel; Chel, Stéphane; Napoly, Olivier; Novo, Jorge; Roudier, Dominique; Rouvière, Nelly; Baboi, Nicoleta; Mildner, Nils; Nölle, Dirk

2008-08-01

The beam-based alignment and feedback systems, essential operations for the future colliders, require high resolution beam position monitors (BPMs). In the framework of the European CARE/SRF program, a reentrant cavity BPM with its associated electronics was developed by the CEA/DSM/Irfu in collaboration with DESY. The design, the fabrication, and the beam test of this monitor are detailed within this paper. This BPM is designed to be inserted in a cryomodule, work at cryogenic temperature in a clean environment. It has achieved a resolution better than 10μm and has the possibility to perform bunch to bunch measurements for the x-ray free electron laser (X-FEL) and the International Linear Collider (ILC). Its other features are a small size of the rf cavity, a large aperture (78 mm), and an excellent linearity. A first prototype of a reentrant cavity BPM was installed in the free electron laser in Hamburg (FLASH), at Deutsches Elektronen-Synchrotron (DESY) and demonstrated its operation at cryogenic temperature inside a cryomodule. The second, installed, also, in the FLASH linac to be tested with beam, measured a resolution of approximately 4μm over a dynamic range ±5mm in single bunch.

New collider scheme at LBL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pugh, H.G.

1984-07-01

This paper presents current ideas from Berkeley concerning a possible new facility for studying the phase transition from hadronic matter to quark matter. The physics ideas have evolved over a period of more than five years, the VENUS concept for a 25 GeV/nucleon colliding beam facility having been presented in 1979. The concept for the Minicollider has been, like that of VENUS, the work of Hermann Grunder and Christoph Leemann.

SSC [Superconducting Super Collider] Project: Technical Training for the Future of Texas. Navarro College/Dallas Community College District. Final Report for Year One.

ERIC Educational Resources Information Center

Orsak, Charles; McGlohen, Patti J.

The Superconducting Super Collider Laboratory (SSCL) is a national lab for research on the fundamental forces and constituents of the universe. A major part of the research will involve an oval ring 54 miles in circumference through which superconducting magnets will steer two beams of protons in opposite directions. In response to the…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogacz, Alex; Bruning, Oliver; Cruz-Alaniz, E.

Unprecedently high luminosity of 10 34 cm -2 s -1, promised by the LHeC accelerator complex poses several beam dynamics and lattice design challenges. As part of accelerator design process, exploration of innovative beam dynamics solutions and their lattice implementations is the key to mitigating performance limitations due to fundamental beam phenomena, such as: synchrotron radiation and collective instabilities. This article will present beam dynamics driven approach to accelerator design, which in particular, addresses emittance dilution due to quantum excitations and beam breakup instability in a large scale, multi-pass Energy Recovery Linac (ERL). The use of ERL accelerator technology tomore » provide improved beam quality and higher brightness continues to be the subject of active community interest and active accelerator development of future Electron Ion Colliders (EIC). Here, we employ current state of though for ERLs aiming at the energy frontier EIC. We will follow conceptual design options recently identified for the LHeC. The main thrust of these studies was to enhance the collider performance, while limiting overall power consumption through exploring interplay between emittance preservation and efficiencies promised by the ERL technology. Here, this combined with a unique design of the Interaction Region (IR) optics gives the impression that luminosity of 10 34 cm -2 s -1 is indeed feasible.« less

Novel Lattice Solutions for the LHeC

DOE PAGES

Bogacz, Alex; Bruning, Oliver; Cruz-Alaniz, E.; ...

2017-08-01

Unprecedently high luminosity of 10 34 cm -2 s -1, promised by the LHeC accelerator complex poses several beam dynamics and lattice design challenges. As part of accelerator design process, exploration of innovative beam dynamics solutions and their lattice implementations is the key to mitigating performance limitations due to fundamental beam phenomena, such as: synchrotron radiation and collective instabilities. This article will present beam dynamics driven approach to accelerator design, which in particular, addresses emittance dilution due to quantum excitations and beam breakup instability in a large scale, multi-pass Energy Recovery Linac (ERL). The use of ERL accelerator technology tomore » provide improved beam quality and higher brightness continues to be the subject of active community interest and active accelerator development of future Electron Ion Colliders (EIC). Here, we employ current state of though for ERLs aiming at the energy frontier EIC. We will follow conceptual design options recently identified for the LHeC. The main thrust of these studies was to enhance the collider performance, while limiting overall power consumption through exploring interplay between emittance preservation and efficiencies promised by the ERL technology. Here, this combined with a unique design of the Interaction Region (IR) optics gives the impression that luminosity of 10 34 cm -2 s -1 is indeed feasible.« less

ICFA Beam Dynamics Newsletter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben-Zvi I.; Kuczewski A.; Altinbas, Z.

2012-07-01

The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL featuresmore » a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.« less

Trajectory measurements and correlations in the final focus beam line at the KEK Accelerator Test Facility

NASA Astrophysics Data System (ADS)

Renier, Y.; Bambade, P.; Tauchi, T.; White, G. R.; Boogert, S.

2013-06-01

The Accelerator Test Facility 2 (ATF2) commissioning group aims to demonstrate the feasibility of the beam delivery system of the next linear colliders (ILC and CLIC) as well as to define and to test the tuning methods. As the design vertical beam sizes of the linear colliders are about few nanometers, the stability of the trajectory as well as the control of the aberrations are very critical. ATF2 commissioning started in December 2008, and thanks to submicron resolution beam position monitors (BPMs), it has been possible to measure the beam position fluctuation along the final focus of ATF2 during the 2009 runs. The optics was not the nominal one yet, with a lower focusing to make the tuning easier. In this paper, a method to measure the noise of each BPM every pulse, in a model-independent way, will be presented. A method to reconstruct the trajectory’s fluctuations is developed which uses the previously determined BPM resolution. As this reconstruction provides a measurement of the beam energy fluctuations, it was also possible to measure the horizontal and vertical dispersion function at each BPMs parasitically. The spatial and angular dispersions can be fitted from these measurements with uncertainties comparable with usual measurements.

Bulk properties of the medium produced in relativistic heavy-ion collisions from the beam energy scan program

NASA Astrophysics Data System (ADS)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, 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.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; 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.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; 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.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

2017-10-01

We present measurements of bulk properties of the matter produced in Au+Au collisions at √{sN N}=7.7 ,11.5 ,19.6 ,27 , and 39 GeV using identified hadrons (π±, K±, p , and p ¯) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (|y |<0.1 ) results for multiplicity densities d N /d y , average transverse momenta 〈pT〉 , and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.

Cold chemistry with cold molecules

NASA Astrophysics Data System (ADS)

Shagam, Yuval

Low temperature chemistry has been predicted to be dominated by quantum effects, such as shape resonances, where colliding particles exhibit wave-like behavior and tunnel through potential barriers. Observation of these quantum effects provides valuable insight into the microscopic mechanism that governs scattering processes. Our recent advances in the control of neutral supersonic molecular beams, namely merged beam experiments, have enabled continuous tuning of collision energies from the classical regime at room temperature down to 0.01 kelvin, where a quantum description of the dynamics is necessary. I will discuss our use of this technique to study how the dynamics change when molecules participate in collisions, demonstrating the crucial role the molecular quantum rotor plays. We have found that at low temperatures rotational state of the molecule can strongly affect collision dynamics considerably changing reaction rates, due to the different symmetries of the molecular wavefunction.

Next generation HOM-damping

NASA Astrophysics Data System (ADS)

Marhauser, Frank

2017-06-01

Research and development for superconducting radio-frequency cavities has made enormous progress over the last decades from the understanding of theoretical limitations to the industrial mass fabrication of cavities for large-scale particle accelerators. Key technologies remain hot topics due to continuously growing demands on cavity performance, particularly when in pursuit of high quality beams at higher beam currents or higher luminosities than currently achievable. This relates to higher order mode (HOM) damping requirements. Meeting the desired beam properties implies avoiding coupled multi-bunch or beam break-up instabilities depending on the machine and beam parameters that will set the acceptable cavity impedance thresholds. The use of cavity HOM-dampers is crucial to absorb the wakefields, comprised by all beam-induced cavity Eigenmodes, to beam-dynamically safe levels and to reduce the heat load at cryogenic temperature. Cavity damping concepts may vary, but are principally based on coaxial and waveguide couplers as well as beam line absorbers or any combination. Next generation energy recovery linacs and circular colliders call for cavities with strong HOM-damping that can exceed the state-of-the-art, while the operating mode efficiency shall not be significantly compromised concurrently. This imposes major challenges given the rather limited damping concepts. A detailed survey of established cavities is provided scrutinizing the achieved damping performance, shortcomings, and potential improvements. The scaling of the highest passband mode impedances is numerically evaluated in dependence on the number of cells for a single-cell up to a nine-cell cavity, which reveals the increased probability of trapped modes. This is followed by simulations for single-cell and five-cell cavities, which incorporate multiple damping schemes to assess the most efficient concepts. The usage and viability of on-cell dampers is elucidated for the single-cell cavity since it can push the envelope towards quasi HOM-free operation suited for next generation storage and collider rings. Geometrical end-cell shape alterations for the five-cell cavity with already efficient mode damping are discussed as a possibility to further lower specific high impedance modes. The findings are eventually put into relation with demanding impedance instability thresholds in future collider rings.

Next generation HOM-damping

DOE PAGES

Marhauser, Frank

2017-05-15

Research and development for superconducting radio-frequency cavities has made enormous progress over the last decades from the understanding of theoretical limitations to the industrial mass fabrication of cavities for large-scale particle accelerators. Key technologies remain hot topics due to continuously growing demands on cavity performance, particularly when in pursuit of high quality beams at higher beam currents or higher luminosities than currently achievable. This relates to Higher Order Mode (HOM) damping requirements. Meeting the desired beam properties implies avoiding coupled multi-bunch or beam break-up instabilities depending on the machine and beam parameters that will set the acceptable cavity impedance thresholds.more » The use of cavity HOM-dampers is crucial to absorb the wakefields, comprised by all beam-induced cavity Eigenmodes, to beam-dynamically safe levels and to reduce the heat load at cryogenic temperature. Cavity damping concepts may vary, but are principally based on coaxial and waveguide couplers as well as beam line absorbers or any combination. Next generation Energy Recovery Linacs and circular colliders call for cavities with strong HOM-damping that can exceed the state-of-the-art, while the operating mode efficiency shall not be significantly compromised concurrently. This imposes major challenges given the rather limited damping concepts. A detailed survey of established cavities is provided scrutinizing the achieved damping performance, shortcomings, and potential improvements. The scaling of the highest passband mode impedances is numerically evaluated in dependence on the number of cells for a single-cell up to a nine-cell cavity, which reveals the increased probability of trapped modes. This is followed by simulations for single-cell and five-cell cavities, which incorporate multiple damping schemes to assess the most efficient concepts. The usage and viability of on-cell dampers is elucidated for the single-cell cavity since it can push the envelope towards quasi HOM-free operation suited for next generation storage and collider rings. Geometrical end-cell shape alterations for the five-cell cavity with already efficient mode damping are discussed as a possibility to further lower specific high impedance modes. Lastly, the findings are eventually put into relation with demanding impedance instability thresholds in future collider rings.« less

Detectors for Linear Colliders: Calorimetry at a Future Electron-Positron Collider (3/4)

ScienceCinema

Thomson, Mark

2018-04-16

Calorimetry will play a central role in determining the physics reach at a future e+e- collider. The requirements for calorimetry place the emphasis on achieving an excellent jet energy resolution. The currently favoured option for calorimetry at a future e+e- collider is the concept of high granularity particle flow calorimetry. Here granularity and a high pattern recognition capability is more important than the single particle calorimetric response. In this lecture I will describe the recent progress in understanding the reach of high granularity particle flow calorimetry and the related R&D; efforts which concentrate on test beam demonstrations of the technological options for highly granular calorimeters. I will also discuss alternatives to particle flow, for example the technique of dual readout calorimetry.

Development of a Bunched Beam Electron Cooler based on ERL and Circulator Ring Technology for the Jefferson Lab Electron-Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, Stephen V.; Derbenev, Yaroslav S.; Douglas, David R.

Jefferson Lab is in the process of designing an electron ion collider with unprecedented luminosity at a 45 GeV center-of-mass energy. This luminosity relies on ion cooling in both the booster and the storage ring of the accelerator complex. The cooling in the booster will use a conventional DC cooler similar to the one at COSY. The high-energy storage ring, operating at a momentum of up to 100 GeV/nucleon, requires novel use of bunched-beam cooling. There are two designs for such a cooler. The first uses a conventional Energy Recovery Linac (ERL) with a magnetized beam while the second usesmore » a circulating ring to enhance both peak and average currents experienced by the ion beam. This presentation will describe the design of both the Circulator Cooling Ring (CCR) design and that of the backup option using the stand-alone ERL operated at lower charge but higher repetition rate than the ERL injector required by the CCR-based design.« less

Reliability of Beam Loss Monitors System for the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Guaglio, G.; Dehning, B.; Santoni, C.

2004-11-01

The employment of superconducting magnets in high energy colliders opens challenging failure scenarios and brings new criticalities for the whole system protection. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particle losses, while at medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standard databases. All the data have been processed by reliability software (Isograph). The analysis ranges from the components data to the system configuration.

Final 6D Muon Ionization Colling using Strong Focusing Quadrupoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, T. L.; Acosta, J. G.; Cremaldi, L. M.

2016-11-15

Abstract Low emittance muon beam lines and muon colliders are potentially a rich source of BSM physics for future exper- imenters. A muon beam normalized emittance of ax,y,z = (280, 280, 1570)µm has been achieved in simulation with short solenoids and a betatron function of 3 cm. Here we use ICOOL and MAD-X to explore using a 400 MeV/c muon beam and strong focusing quadrupoles to achieve a normalized transverse emittance of 100 µm and complete 6D cooling. The low beta regions, as low as 5 mm, produced by the quadrupoles are occupied by dense, low Z absorbers, such asmore » lithium hydride or beryllium, that cool the beam transversely. Equilibrium transverse emittance is linearly proportional to the transverse betatron function. Reverse emittance exchange with septa and/or wedges is then used to decrease transverse emittance from 100 to 25 µm at the expense of longitudinal emittance for a high energy lepton collider. Cooling challenges include chromaticity correction, ssband overlap, quadrupole acceptance, and staying in phase with RF.« less

Laboratory Directed Research and Development Program: Annual report to the Department of Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogeka, G.J.; Romano, A.J.

1994-12-01

Project program summaries are presented for: effect of bacterial spore protein on mutagenesis; cellular toxicity of coaine and cocaethylene; calcinfication in marine alga (global carbon cycling); advanced permanent magnet materials; a high flux neutron source; genetics of drug addiction; microdialysis; analysis of powder diffraction data; accelerator technology; nucleic acids and proteins and their interactions, by small-angle XRD; enhancement of microplanar beam radiation therapy of gliosarcoma; relaxographic and functional MRI; low-temperature infrared laser absorption spectroscopy; photodesorption of H{sub 2}; helical magnet for RHIC; novel microporous solids; chemistry and physics of stratospheric aerosols (ozone depletion); rf source for linear colliders; resonance Ramanmore » detection of VOCs; synthesis of plant fatty acids with unusual double bond positions; outer surface proteins of the Lyme disease spirochete; multiwire proportional chambers for collider muons; self-organized criticality; PCR-SSCP detection of genetic changes at single cell level; proton facility for cancer therapy; and visible free-electron laser experiment.« less

Comparative Study of button BPM Trapped Mode Heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron,P.; Singh, O.

2009-05-04

The combination of short bunches and high currents found in modern light sources and colliders can result in the deposition of tens of watts of power in BPM buttons. The resulting thermal distortion is potentially problematic for maintaining high precision beam position stability, and in the extreme case can result in mechanical damage. We present a simple algorithm that uses the input parameters of beam current, bunch length, button diameter, beampipe aperture, and fill pattern to calculate a relative figure-of-merit for button heating. Data for many of the world's light sources and colliders is compiled in a table. Using themore » algorithm, the table is sorted in order of the relative magnitude of button heating.« less

Collider shot setup for Run 2 observations and suggestions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Annala, J.; Joshel, B.

1996-01-31

This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This ismore » the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb{sup {minus}1}/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb{sup {minus}1} for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent `components`: procedures, hardware, controls, and sociology. These components don`t directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components.« less

Experimental Verification of Predicted Oscillations near a Spin Resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolanoski, Hermann; /Humboldt U., Berlin

2011-12-05

The E166 experiment at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme for the production of polarized positrons which is suitable for implementation in a future Linear Collider. A multi-GeV electron beam passed through a helical undulator to generate multi-MeV, circularly polarized photons which were then converted in a thin target to produce positrons (and electrons) with longitudinal polarization above 80% at 6 MeV. The results are in agreement with GEANT4 simulations that include the dominant polarization-dependent interactions of electrons, positrons and photons in matter.

Simulations of space charge neutralization in a magnetized electron cooler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerity, James; McIntyre, Peter M.; Bruhwiler, David Leslie

Magnetized electron cooling at relativistic energies and Ampere scale current is essential to achieve the proposed ion luminosities in a future electron-ion collider (EIC). Neutralization of the space charge in such a cooler can significantly increase the magnetized dynamic friction and, hence, the cooling rate. The Warp framework is being used to simulate magnetized electron beam dynamics during and after the build-up of neutralizing ions, via ionization of residual gas in the cooler. The design follows previous experiments at Fermilab as a verification case. We also discuss the relevance to EIC designs.

Left-handed and right-handed U(1) gauge symmetry

NASA Astrophysics Data System (ADS)

Nomura, Takaaki; Okada, Hiroshi

2018-01-01

We propose a model with the left-handed and right-handed continuous Abelian gauge symmetry; U(1) L × U(1) R . Then three right-handed neutrinos are naturally required to achieve U(1) R anomaly cancellations, while several mirror fermions are also needed to do U(1) L anomaly cancellations. Then we formulate the model, and discuss its testability of the new gauge interactions at collider physics such as the large hadron collider (LHC) and the international linear collider (ILC). In particular, we can investigate chiral structure of the interactions by the analysis of forward-backward asymmetry based on polarized beam at the ILC.

Development of a High-Average-Power Compton Gamma Source for Lepton Colliders

NASA Astrophysics Data System (ADS)

Pogorelsky, Igor; Polyanskiy, Mikhail N.; Yakimenko, Vitaliy; Platonenko, Viktor T.

2009-01-01

Gamma- (γ-) ray beams of high average power and peak brightness are of demand for a number of applications in high-energy physics, material processing, medicine, etc. One of such examples is gamma conversion into polarized positrons and muons that is under consideration for projected lepton colliders. A γ-source based on the Compton backscattering from the relativistic electron beam is a promising candidate for this application. Our approach to the high-repetition γ-source assumes placing the Compton interaction point inside a CO2 laser cavity. A laser pulse interacts with periodical electron bunches on each round-trip inside the laser cavity producing the corresponding train of γ-pulses. The round-trip optical losses can be compensated by amplification in the active laser medium. The major challenge for this approach is in maintaining stable amplification rate for a picosecond CO2-laser pulse during multiple resonator round-trips without significant deterioration of its temporal and transverse profiles. Addressing this task, we elaborated on a computer code that allows identifying the directions and priorities in the development of such a multi-pass picosecond CO2 laser. Proof-of-principle experiments help to verify the model and show the viability of the concept. In these tests we demonstrated extended trains of picosecond CO2 laser pulses circulating inside the cavity that incorporates the Compton interaction point.

Estimation of stopped protons at energies relevant for a beam energy scan at the BNL Relativistic Heavy Ion Collider

NASA Astrophysics Data System (ADS)

Thakur, Dhananjaya; Jakhar, Sunil; Garg, Prakhar; Sahoo, Raghunath

2017-04-01

The recent net-proton fluctuation results of the STAR (Solenoidal Tracker At RHIC) experiment from the beam energy scan (BES) program at the BNL Relativistic Heavy Ion Collider (RHIC) have drawn much attention to exploring the QCD critical point and the nature of deconfinement phase transition. There has been much speculation that the nonmonotonic behavior of κ σ2 of the produced protons around √{sN N} = 19.6 GeV in the STAR results may be due to the existence of a QCD critical point. However, the experimentally measured proton distributions contain protons from heavy resonance decays, from baryon stopping, and from direct production processes. These proton distributions are used to estimate the net-proton number fluctuation. Because it is difficult to disentangle the protons from the above-mentioned sources, it is better to devise a method which will account for the directly produced baryons (protons) to study the dynamical fluctuation at different center-of-mass energies. This is because it is assumed that any associated criticality in the system could affect the particle production mechanism and hence the dynamical fluctuation in various conserved numbers. In the present work, we demonstrate a method to estimate the number of stopped protons at RHIC BES energies for central 0-5% Au +Au collisions within STAR acceptance and discuss its implications on the net-proton fluctuation results.

Thermomechanical assessment of the effects of a jaw-beam angle during beam impact on Large Hadron Collider collimators

NASA Astrophysics Data System (ADS)

Cauchi, Marija; Assmann, R. W.; Bertarelli, A.; Carra, F.; Lari, L.; Rossi, A.; Mollicone, P.; Sammut, N.

2015-02-01

The correct functioning of a collimation system is crucial to safely and successfully operate high-energy particle accelerators, such as the Large Hadron Collider (LHC). However, the requirements to handle high-intensity beams can be demanding, and accident scenarios must be well studied in order to assess if the collimator design is robust against possible error scenarios. One of the catastrophic, though not very probable, accident scenarios identified within the LHC is an asynchronous beam dump. In this case, one (or more) of the 15 precharged kicker circuits fires out of time with the abort gap, spraying beam pulses onto LHC machine elements before the machine protection system can fire the remaining kicker circuits and bring the beam to the dump. If a proton bunch directly hits a collimator during such an event, severe beam-induced damage such as magnet quenches and other equipment damage might result, with consequent downtime for the machine. This study investigates a number of newly defined jaw error cases, which include angular misalignment errors of the collimator jaw. A numerical finite element method approach is presented in order to precisely evaluate the thermomechanical response of tertiary collimators to beam impact. We identify the most critical and interesting cases, and show that a tilt of the jaw can actually mitigate the effect of an asynchronous dump on the collimators. Relevant collimator damage limits are taken into account, with the aim to identify optimal operational conditions for the LHC.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokosawa, A.

The first polarized collider, where we collide 250 GeV/c beams of 70% polarized protons at high luminosity, is under construction. This will allow a determination of the nuclear spin-dependent structure functions over a large range in x, and a collection of sufficient W and Z events to investigate extremely interesting spin-related phenomena. For these measurements, two major RHIC detectors will be used simultaneously whose functions are complimentary. Expected event rates given in this paper are for the STAR detector.

Large Hadron Collider commissioning and first operation.

PubMed

Myers, S

2012-02-28

A history of the commissioning and the very successful early operation of the Large Hadron Collider (LHC) is described. The accident that interrupted the first commissioning, its repair and the enhanced protection system put in place are fully described. The LHC beam commissioning and operational performance are reviewed for the period from 2010 to mid-2011. Preliminary plans for operation and future upgrades for the LHC are given for the short and medium term.

Design study of beam transport lines for BioLEIR facility at CERN

NASA Astrophysics Data System (ADS)

Ghithan, S.; Roy, G.; Schuh, S.

2017-09-01

The biomedical community has asked CERN to investigate the possibility to transform the Low Energy Ion Ring (LEIR) accelerator into a multidisciplinary, biomedical research facility (BioLEIR) that could provide ample, high-quality beams of a range of light ions suitable for clinically oriented, fundamental research on cell cultures and for radiation instrumentation development. The present LEIR machine uses fast beam extraction to the next accelerator in the chain, eventually leading to the Large Hadron Collider (LHC) . To provide beam for a biomedical research facility, a new slow extraction system must be installed. Two horizontal and one vertical experimental beamlines were designed for transporting the extracted beam to three experimental end-stations. The vertical beamline (pencil beam) was designed for a maximum energy of 75 MeV/u for low-energy radiobiological research, while the two horizontal beamlines could deliver up to 440 MeV/u. One horizontal beamline shall be used preferentially for biomedical experiments and shall provide pencil beam and a homogeneous broad beam, covering an area of 5 × 5 cm2 with a beam homogeneity of ±5%. The second horizontal beamline will have pencil beam only and is intended for hardware developments in the fields of (micro-)dosimetry and detector development. The minimum full aperture of the beamlines is approximately 100 mm at all magnetic elements, to accommodate the expected beam envelopes. Seven dipoles and twenty quadrupoles are needed for a total of 65 m of beamlines to provide the specified beams. In this paper we present the optical design for the three beamlines.

End-to-end simulation of bunch merging for a muon collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bao, Yu; Stratakis, Diktys; Hanson, Gail G.

2015-05-03

Muon accelerator beams are commonly produced indirectly through pion decay by interaction of a charged particle beam with a target. Efficient muon capture requires the muons to be first phase-rotated by rf cavities into a train of 21 bunches with much reduced energy spread. Since luminosity is proportional to the square of the number of muons per bunch, it is crucial for a Muon Collider to use relatively few bunches with many muons per bunch. In this paper we will describe a bunch merging scheme that should achieve this goal. We present for the first time a complete end-to-end simulationmore » of a 6D bunch merger for a Muon Collider. The 21 bunches arising from the phase-rotator, after some initial cooling, are merged in longitudinal phase space into seven bunches, which then go through seven paths with different lengths and reach the final collecting "funnel" at the same time. The final single bunch has a transverse and a longitudinal emittance that matches well with the subsequent 6D rectilinear cooling scheme.« less

nuSTORM and A Path to a Muon Collider

DOE PAGES

Adey, David; Bayes, Ryan; Bross, Alan; ...

2015-05-20

Our article reviews the current status of the nuSTORM facility and shows how it can be utilized to perform the next step on the path toward the realization of a μ +μ - collider. This review includes the physics motivation behind nuSTORM, a detailed description of the facility and the neutrino beams it can produce, and a summary of the short-baseline neutrino oscillation physics program that can be carried out at the facility. The idea for nuSTORM (the production of neutrino beams from the decay of muons in a racetrack-like decay ring) was discussed in the literature more than 30more » years ago in the context of searching for noninteracting (sterile) neutrinos. However, only in the past 5 years has the concept been fully developed, motivated in large part by the facility's unmatched reach in addressing the evolving data on oscillations involving sterile neutrinos. Finally, this article reviews the basics of the μ +μ -collider concept and describes how nuSTORM provides a platform to test advanced concepts for six-dimensional muon ionization cooling.« less

Aberration compensation in a Skew parametric-resonance ionization cooling channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sy, Amy V.; Derbenev, Yaroslav S.; Morozov, Vasiliy

Skew Parametric-resonance Ionization Cooling (Skew PIC) represents a novel method for focusing of highly divergent particle beams, as in the final 6D cooling stage of a high-luminosity muon collider. In the muon collider concept, the resultant equilibrium transverse emittances from cooling with Skew PIC are an order of magnitude smaller than in conventional ionization cooling. The concept makes use of coupling of the transverse dynamic behavior, and the linear dynamics are well-behaved with good agreement between analytic solutions and simulation results. Compared to the uncoupled system, coupling of the transverse dynamic behavior purports to reduce the number of multipoles requiredmore » for aberration compensation while also avoiding unwanted resonances. Aberration compensation is more complicated in the coupled case, especially in the high-luminosity muon collider application where equilibrium angular spreads in the cooling channel are on the order of 200 mrad. We present recent progress on aberration compensation for control of highly divergent muon beams in the coupled correlated optics channel, and a simple cooling model to test the transverse acceptance of the channel.« less

Ultra-short wavelength x-ray system

DOEpatents

Umstadter, Donald [Ann Arbor, MI; He, Fei [Ann Arbor, MI; Lau, Yue-Ying [Potomac, MD

2008-01-22

A method and apparatus to generate a beam of coherent light including x-rays or XUV by colliding a high-intensity laser pulse with an electron beam that is accelerated by a synchronized laser pulse. Applications include x-ray and EUV lithography, protein structural analysis, plasma diagnostics, x-ray diffraction, crack analysis, non-destructive testing, surface science and ultrafast science.

Contributions to the mini-workshop on beam-beam compensation in the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiltsev, V.

1998-02-01

The purpose of the Workshop was to assay the current understanding of compensation of the beam-beam effects in the Tevatron with use of low-energy high-current electron beam, relevant accelerator technology, along with other novel techniques of the compensation and previous attempts. About 30 scientists representing seven institutions from four countries--FNAL, SLAC, BNL, Novosibirsk, CERN, and Dubna were in attendance. Twenty one talks were presented. The event gave firm ground for wider collaboration on experimental test of the compensation at the Tevatron collider. This report consists of vugraphs of talks given at the meeting.

2 TeV HEB beam abort at the SSCL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schailey, R.; Bull, J.; Clayton, T.

1993-05-01

The High Energy Booster (HEB) of the Superconducting Super Collider Laboratory (SSCL) will require a full aperture beam abort over a dynamic energy range of 200 GeV to 2 TeV. Since the HEB is a bi-polar machine, both clockwise (CW) and the counter-clockwise (CCW) beam aborts are required. Also, the stored beam energy of 6.55 MJ in the superconducting HEB imposes upon the full aperture requirement. In this report, we describe the abort channels in the HEB utility straight sections, aperture restrictions, mechanical interferences and solutions, kicker misfires, and a 1 TeV beam absorber.

ION BEAM POLARIZATION DYNAMICS IN THE 8 GEV BOOSTER OF THE JLEIC PROJECT AT JLAB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondratenko, A. M.; Kondratenko, M. A.; Morozov, Vasiliy

2016-05-01

In the Jefferson Lab’s Electron-Ion Collider (JLEIC) project, an injector of polarized ions into the collider ring is a superconducting 8 GeV booster. Both figure-8 and racetrack booster versions were considered. Our analysis showed that the figure-8 ring configuration allows one to preserve the polarization of any ion species during beam acceleration using only small longitudinal field with an integral less than 0.5 Tm. In the racetrack booster, to pre-serve the polarization of ions with the exception of deu-terons, it suffices to use a solenoidal Siberian snake with a maximum field integral of 30 Tm. To preserve deuteron polarization, wemore » propose to use arc magnets for the race-track booster structure with a field ramp rate of the order of 1 T/s. We calculate deuteron and proton beam polari-zations in both the figure-8 and racetrack boosters includ-ing alignment errors of their magnetic elements using the Zgoubi code.« less

Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider

NASA Astrophysics Data System (ADS)

Yee-Rendon, Bruce; Lopez-Fernandez, Ricardo; Barranco, Javier; Calaga, Rama; Marsili, Aurelien; Tomás, Rogelio; Zimmermann, Frank; Bouly, Frédéric

2014-05-01

Crab cavities (CCs) are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC) project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

Generating Low Beta Regions with Quadrupoles for Final Muon Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acosta, J. G.; Cremaldi, L. M.; Hart, T. L.

2017-05-01

Muon beams and colliders are rich sources of new physics, if muons can be cooled. A normalized rms transverse muon emittance of 280 microns has been achieved in simulation with short solenoids and a betatron function of 3 cm. Here we use ICOOL, G4beamline, and MAD-X to explore using a 400 MeV/c muon beam and strong focusing quadrupoles to approach a normalized transverse emittance of 100 microns and finish 6D muon cooling. The low beta regions produced by the quadrupoles are occupied by dense, low Z absorbers, such as lithium hydride or beryllium, that cool the beam. Equilibrium transverse emittancemore » is linearly proportional to the beta function. Reverse emittance exchange with septa and/or wedges is then used to decrease transverse emittance from 100 to 25 microns at the expense of longitudinal emittance for a high energy lepton collider. Work remains to be done on chromaticity correction.« less

The Muon Collider as a $H/A$ factory

DOE PAGES

Eichten, Estia; Martin, Adam; Univ. of Notre Dame, IN

2013-11-22

We show that a muon collider is ideally suited for the study of heavy H/A scalars, cousins of the Higgs boson found in two-Higgs doublet models and required in supersymmetric models. The key aspects of H/A are: (1) they are narrow, yet have a width-to-mass ratio far larger than the expected muon collider beam-energy resolution, and (2) the larger muon Yukawa allows efficient s-channel production. We study in detail a representative Natural Supersymmetry model which has a 1.5 Tev H/A withmore » $$m_H$$- $$m_A$$ = 10 Gev. The large event rates at resonant peak allow the determination of the individual H and A resonance parameters (including CP) and the decays into electroweakinos provides a wealth of information unavailable to any other present or planned collider.« less

Muon Colliders: The Next Frontier

ScienceCinema

Tourun, Yagmur

2017-12-22

Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

Low Emittance Guns for the ILC Polarized Electron Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.

Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressedmore » by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {>=}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {>=}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.« less

Low Emittance Guns for the ILC Polarized Electron Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, J.E.; Brachmann, A.; Ioakeimidi, K.

Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressedmore » by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {ge}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {ge}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.« less

R&D of a High-Performance DIRC Detector for a Future Electron-Ion Collider

NASA Astrophysics Data System (ADS)

Allison, Stacey Lee

An Electron-Ion Collider (EIC) is proposed as the next big scientific facility to be built in the United States, costing over $1 billion in design and construction. Each detector concept for the electron/ion beam interaction point is integrated into a large solenoidal magnet. The necessity for excellent hadronic particle identification (pion/kaon/proton) in the barrel region of the solenoid has pushed research and development (R&D) towards a new, high-performance Detection of Internally Reflected Cherenkov light (DIRC) detector design. The passage of a high energy charged particle through a fused silica bar of the DIRC generates optical Cherenkov radiation. A large fraction of this light propagates by total internal reflection to the end of the bar, where the photon trajectories expand in a large volume before reaching a highly segmented photo-detector array. The spatial and temporal distribution of the Cherenkov light at the photo-detector array allows one to reconstruct the angle of emission of the light relative to the incident charged particle track. In order to reach the desired performance of 3sigma pi/K separation at 6 GeV/c particle momentum a new 3-layer spherical lens focusing optic with a lanthanum crown glass central layer was designed to have a nearly flat focal plane. In order to validate the EIC DIRC simulation package, a synergistic test beam campaign was carried out in 2015 at the CERN PS with the PANDA Barrel DIRC group using a prototype DIRC detector. Along with the analysis of the CERN test beam data, measurements of the focal plane of the 3-layer lens were performed using a custom-built laser setup at Old Dominion University. Radiation hardness of the lanthanum crown glass was tested using a 160 keV X-ray source and a monochromator at the Catholic University of America. Results of these test-bench experiments and the analysis of the 2015 CERN test beam data are presented here.

R&D of a high-performance DIRC detector for a future electron-ion collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allison, Staceu L.

An Electron-Ion Collider (EIC) is proposed as the next big scientific facility to be built in the United States, costing over $1 billion in design and construction. Each detector concept for the electron/ion beam interaction point is integrated into a large solenoidal magnet. The necessity for excellent hadronic particle identification (pion/kaon/proton) in the barrel region of the solenoid has pushed research and development (R&D) towards a new, high-performance Detection of Internally Reflected Cherenkov light (DIRC) detector design. The passage of a high energy charged particle through a fused silica bar of the DIRC generates optical Cherenkov radiation. A large fractionmore » of this light propagates by total internal reflection to the end of the bar, where the photon trajectories expand in a large volume before reaching a highly segmented photo-detector array. The spatial and temporal distribution of the Cherenkov light at the photo-detector array allows one to reconstruct the angle of emission of the light relative to the incident charged particle track. In order to reach the desired performance of 3sigma pi/K separation at 6 GeV/c particle momentum a new 3-layer spherical lens focusing optic with a lanthanum crown glass central layer was designed to have a nearly at focal plane. In order to validate the EIC DIRC simulation package, a synergistic test beam campaign was carried out in 2015 at the CERN PS with the PANDA Barrel DIRC group using a prototype DIRC detector. Along with the analysis of the CERN test beam data, measurements of the focal plane of the 3-layer lens were performed using a custom-built laser setup at Old Dominion University. Radiation hardness of the lanthanum crown glass was tested using a 160 keV X-ray source and a monochromator at the Catholic University of America. Results of these test-bench experiments and the analysis of the 2015 CERN test beam data are presented here.« less

Beam dynamics pre-design with KONUS principle for the DTL of SPPC p-Linac

NASA Astrophysics Data System (ADS)

Liu, Jing; Li, Haipeng; Lu, Yuanrong; Su, Jiancang; Liu, Xiaolong; Fu, Qi

2018-04-01

As the Higgs bosons were observed on the LHC in 2012, a two-stage particle collider program named CEPC-SPPC is proposed for precise measurement of Higgs properties and exploring the new physics models. In order to deliver a 2.1-TeV proton beam into the Super Proton-Proton Collider (SPPC), the injector chain will use a 1.2-GeV proton linac (p-Linac) and three synchrotrons of p-RCS, MSS and SS. This paper focuses on the preliminary conceptual design of the DTL within the p-Linac and mainly concerns about the beam dynamics studies. Taking advantages of the KONUS principle and LORASR code, a 325 MHz, 50.65 MeV DTL design which is composed of three tanks in 15.6 m will be presented. The whole DTL contains 129 gaps for beam acceleration, one quadruple doublet which is behind the buncher and eight quadruple triplets of which three are located after each tank, respectively. The aims of this pre-study are to optimize the acceleration electric field distribution together with the focusing magnetic field parameters, enhance the beam transmission quality of beam envelopes, particle distribution and energy spread, then improve the DTL performance in terms of transmission efficiency and so on. The results of the analyses show that the DTL pre-design achieves 16.8 times high energy gain and meets all the p-Linac requirements well.

Polarized He 3 + 2 ions in the Alternate Gradient Synchrotron to RHIC transfer line

DOE PAGES

Tsoupas, N.; Huang, H.; Méot, F.; ...

2016-09-06

The proposed electron-hadron collider (eRHIC) to be built at Brookhaven National Laboratory (BNL) will allow the collisions of 20 GeV polarized electrons with 250 GeV polarized protons, or 100 GeV/n polarized 3He +2 ions, or other unpolarized ion species. The large value of the anomalous magnetic moment of the 3He nucleus G He=(g₋2)/2=₋4.184 (where g is the g-factor of the 3He nuclear spin) combined with the peculiar layout of the transfer line which transports the beam bunches from the Alternate Gradient Synchrotron (AGS) to the Relativistic Heavy Ion Collider (RHIC) makes the transfer and injection of polarized 3He ions frommore » AGS to RHIC (AtR) a special case as we explain in the paper. Specifically in this paper we calculate the stable spin direction of a polarized 3He beam at the exit of the AtR line which is also the injection point of RHIC, and lastly, we discuss a simple modifications of the AtR beam-transfer-line, to perfectly match the stable spin direction of the injected polarized 3He beam to that of the circulating beam, at the injection point of RHIC.« less

DAΦNE operation with electron-cloud-clearing electrodes.

PubMed

Alesini, D; Drago, A; Gallo, A; Guiducci, S; Milardi, C; Stella, A; Zobov, M; De Santis, S; Demma, T; Raimondi, P

2013-03-22

The effects of an electron cloud (e-cloud) on beam dynamics are one of the major factors limiting performances of high intensity positron, proton, and ion storage rings. In the electron-positron collider DAΦNE, namely, a horizontal beam instability due to the electron-cloud effect has been identified as one of the main limitations on the maximum stored positron beam current and as a source of beam quality deterioration. During the last machine shutdown in order to mitigate such instability, special electrodes have been inserted in all dipole and wiggler magnets of the positron ring. It has been the first installation all over the world of this type since long metallic electrodes have been installed in all arcs of the collider positron ring and are currently used during the machine operation in collision. This has allowed a number of unprecedented measurements (e-cloud instabilities growth rate, transverse beam size variation, tune shifts along the bunch train) where the e-cloud contribution is clearly evidenced by turning the electrodes on and off. In this Letter we briefly describe a novel design of the electrodes, while the main focus is on experimental measurements. Here we report all results that clearly indicate the effectiveness of the electrodes for e-cloud suppression.

Development and testing of a double length pets for the CLIC experimental area

NASA Astrophysics Data System (ADS)

Sánchez, L.; Carrillo, D.; Gavela, D.; Lara, A.; Rodríguez, E.; Gutiérrez, J. L.; Calero, J.; Toral, F.; Samoshkin, A.; Gudkov, D.; Riddone, G.

2014-05-01

CLIC (compact linear collider) is a future e+e- collider based on normal-conducting technology, currently under study at CERN. Its design is based on a novel two-beam acceleration scheme. The main beam gets RF power extracted from a drive beam through power extraction and transfer structures (PETS). The technical feasibility of CLIC is currently being proved by its Third Test Facility (CTF3) which includes the CLIC experimental area (CLEX). Two Double Length CLIC PETS will be installed in CLEX to validate their performance with beam. This paper is focused on the engineering design, fabrication and validation of this PETS first prototype. The design consists of eight identical bars, separated by radial slots in which damping material is located to absorb transverse wakefields, and two compact couplers placed at both ends of the bars to extract the generated power. The PETS bars are housed inside a vacuum tank designed to make the PETS as compact as possible. Several joint techniques such as vacuum brazing, electron beam and arc welding were used to complete the assembly. Finally, several tests such as dimensional control and leak testing were carried out to validate design and fabrication methods. In addition, RF measurements at low power were made to study frequency tuning.

European organization for nuclear research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoenbacher, H.; Tavlet, M.

1987-09-10

The CERN Intersecting Storage Rings (ISR) operated from 1971 to 1984. During that time high-energy physics experiments were carried out with 30 GeV colliding proton beams. At the end of this period the machine was decommissioned and dismantled. This involved the movement of about 1000 machine elements, e.g., magnets, vacuum pumps, rf cavities, etc., 2500 racks, 7000 shielding blocks, 3500 km of cables and 7 km of beam piping. All these items were considered to be radioactive until the contrary was proven. They were then sorted, either for storage and reuse or for radioactive or non-radioactive waste. The paper describesmore » the radiation protection surveillance of this project which lasted for five months. It includes the radiation protection standards, the control of personnel and materials, typical radioactivity levels and isotopes, as well as final cleaning and decommissioning of an originally restricted radiation area to a free accessible area.« less

Bulk properties of the medium produced in relativistic heavy-ion collisions from the beam energy scan program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

We present measurements of bulk properties of the matter produced in Au+Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$= 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons (π ±, K ±, p, and $$\\bar{p}$$) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (| y | < 0.1) results for multiplicity densities dN / dy, average transverse momenta $$\\langle$$pT$$\\rangle$$, and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.« less

Bulk properties of the medium produced in relativistic heavy-ion collisions from the beam energy scan program

DOE PAGES

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

2017-10-13

We present measurements of bulk properties of the matter produced in Au+Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$= 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons (π ±, K ±, p, and $$\\bar{p}$$) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (| y | < 0.1) results for multiplicity densities dN / dy, average transverse momenta $$\\langle$$pT$$\\rangle$$, and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.« less

A novel in situ trigger combination method

DOE PAGES

Buzatu, Adrian; Warburton, Andreas; Krumnack, Nils; ...

2013-01-30

Searches for rare physics processes using particle detectors in high-luminosity colliding hadronic beam environments require the use of multi-level trigger systems to reject colossal background rates in real time. In analyses like the search for the Higgs boson, there is a need to maximize the signal acceptance by combining multiple different trigger chains when forming the offline data sample. In such statistically limited searches, datasets are often amassed over periods of several years, during which the trigger characteristics evolve and system performance can vary significantly. Reliable production cross-section measurements and upper limits must take into account a detailed understanding ofmore » the effective trigger inefficiency for every selected candidate event. We present as an example the complex situation of three trigger chains, based on missing energy and jet energy, that were combined in the context of the search for the Higgs (H) boson produced in association with a $W$ boson at the Collider Detector at Fermilab (CDF). We briefly review the existing techniques for combining triggers, namely the inclusion, division, and exclusion methods. We introduce and describe a novel fourth in situ method whereby, for each candidate event, only the trigger chain with the highest a priori probability of selecting the event is considered. We compare the inclusion and novel in situ methods for signal event yields in the CDF $WH$ search. This new combination method, by virtue of its scalability to large numbers of differing trigger chains and insensitivity to correlations between triggers, will benefit future long-running collider experiments, including those currently operating on the Large Hadron Collider.« less

A novel in situ trigger combination method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buzatu, Adrian; Warburton, Andreas; Krumnack, Nils

Searches for rare physics processes using particle detectors in high-luminosity colliding hadronic beam environments require the use of multi-level trigger systems to reject colossal background rates in real time. In analyses like the search for the Higgs boson, there is a need to maximize the signal acceptance by combining multiple different trigger chains when forming the offline data sample. In such statistically limited searches, datasets are often amassed over periods of several years, during which the trigger characteristics evolve and system performance can vary significantly. Reliable production cross-section measurements and upper limits must take into account a detailed understanding ofmore » the effective trigger inefficiency for every selected candidate event. We present as an example the complex situation of three trigger chains, based on missing energy and jet energy, that were combined in the context of the search for the Higgs (H) boson produced in association with a $W$ boson at the Collider Detector at Fermilab (CDF). We briefly review the existing techniques for combining triggers, namely the inclusion, division, and exclusion methods. We introduce and describe a novel fourth in situ method whereby, for each candidate event, only the trigger chain with the highest a priori probability of selecting the event is considered. We compare the inclusion and novel in situ methods for signal event yields in the CDF $WH$ search. This new combination method, by virtue of its scalability to large numbers of differing trigger chains and insensitivity to correlations between triggers, will benefit future long-running collider experiments, including those currently operating on the Large Hadron Collider.« less

INSTRUMENTS AND METHODS OF INVESTIGATION: Giant pulses of thermal neutrons in large accelerator beam dumps. Possibilities for experiments

NASA Astrophysics Data System (ADS)

Stavissky, Yurii Ya

2006-12-01

A short review is presented of the development in Russia of intense pulsed neutron sources for physical research — the pulsating fast reactors IBR-1, IBR-30, IBR-2 (Joint Institute for Nuclear Research, Dubna), and the neutron-radiation complex of the Moscow meson factory — the 'Troitsk Trinity' (RAS Institute for Nuclear Research, Troitsk, Moscow region). The possibility of generating giant neutron pulses in beam dumps of superhigh energy accelerators is discussed. In particular, the possibility of producing giant pulsed thermal neutron fluxes in modified beam dumps of the large hadron collider (LHD) under construction at CERN is considered. It is shown that in the case of one-turn extraction ov 7-TeV protons accumulated in the LHC main rings on heavy targets with water or zirconium-hydride moderators placed in the front part of the LHC graphite beam-dump blocks, every 10 hours relatively short (from ~100 µs) thermal neutron pulses with a peak flux density of up to ~1020 neutrons cm-2 s-1 may be produced. The possibility of applying such neutron pulses in physical research is discussed.

Optimization of Magnet Strength for Event Reconstruction and Analysis at FNAL SeaQuest

NASA Astrophysics Data System (ADS)

Carstens, Paul; SeaQuest Collaboration

2016-09-01

The Fermilab E906/SeaQuest experiment primarily means to study the nucleon sea and its antiquark distribution. This experiment collides a 120 GeV proton beam with one of several fixed targets. E906/SeaQuest probes the quark sea with the Drell-Yan process in which a quark from the beam annihilates an antiquark from the target producing a virtual photon that decays into a pair of muons. Two magnets focus the muons through four detector stations in the spectrometer. The first is a solid iron magnet, which also serves as the beam dump and absorber. The second, an open aperture magnet, is the momentum analyzing magnet and is positioned between the first two detector stations. A tracking program reconstructs the trajectories of the particles in the detector to discern their kinematics. In order to correctly analyze data, the magnetic field strength must be accurately known since it affects the momentum of particles passing through the field. This poster focuses on how the magnet's effect on the transverse momentum of the muons affects kinematic reconstruction of both simulated and real events. This research was supported by US DOE MENP Grant DE-FG02-03ER41243 be added to my submission.

l- and n-changing collisions during interaction of a pulsed beam of Li Rydberg atoms with CO2

NASA Astrophysics Data System (ADS)

Dubreuil, B.; Harnafi, M.

1989-07-01

The pulsed Li atomic beam produced in our experiment is based on controlled transversely-excited-atmospheric CO2 laser-induced ablation of a Li metal target. The atomic beam is propagated in vacuum or in CO2 gas at low pressure. Atoms in the beam are probed by laser-induced fluorescence spectroscopy. This allows the determination of time-of-flight and velocity distributions. Li Rydberg states (n=5-13) are populated in the beam by two-step pulsed-laser excitation. The excited atoms interact with CO2 molecules. l- and n-changing cross sections are deduced from the time evolution of the resonant or collision-induced fluorescence following this selective excitation. l-changing cross sections of the order of 104 AṦ are measured; they increase with n as opposed to the plateau observed for Li* colliding with a diatomic molecule. This behavior is qualitatively well explained in the framework of the free-electron model. n-->n' changing processes with large cross sections (10-100 AṦ) are also observed even in the case of large electronic energy change (ΔEnn'>103 cm-1). These results can be interpreted in terms of resonant-electronic to vibrational energy transfers between Li Rydberg states and CO2 vibrational modes.

Latest R&D news and beam test performance of the highly granular SiW-ECAL technological prototype for the ILC

NASA Astrophysics Data System (ADS)

Irles, A.

2018-02-01

High precision physics at future colliders as the International Linear Collider (ILC) require unprecedented high precision in the determination of the energy of final state particles. The needed precision will be achieved thanks to the Particle Flow algorithms (PF) which require highly granular and hermetic calorimeters systems. The physical proof of concept of the PF was performed in the previous campaign of beam tests of physic prototypes within the CALICE collaboration. One of these prototypes was the physics prototype of the Silicon-Tungsten Electromagnetic Calorimeter (SiW-ECAL) for the ILC. In this document we present the latest news on R&D of the next generation prototype, the technological prototype with fully embedded very front-end (VFE) electronics, of the SiW-ECAL. Special emphasis is given to the presentation and discussion of the first results from the beam test done at DESY in June 2017. The physics program for such beam test consisted in the calibration and commissioning of the current set of available SiW ECAL modules; the test of performance of individual slabs under 1T magnetic fields; and the study of electromagnetic showers events.

Potential for luminosity improvement for low-energy RHIC operation with long bunches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedotov, A.; Blaskiewicz, M.

Electron cooling was proposed to increase luminosity of the RHIC collider for heavy ion beams at low energies. Luminosity decreases as the square of bunch intensity due to the beam loss from the RF bucket as a result of the longitudinal intra beam scattering (IBS), as well as due to the transverse emittance growth because of the transverse IBS. Both transverse and longitudinal IBS can be counteracted with electron cooling. This would allow one to keep the initial peak luminosity close to constant throughout the store essentially without the beam loss. In addition, the phase-space density of the hadron beamsmore » can be further increased by providing stronger electron cooling. Unfortunately, the defining limitation for low energies in RHIC is expected to be the space charge. Here we explore an idea of additional improvement in luminosity, on top of the one coming from just IBS compensation and longer stores, which may be expected if one can operate with longer bunches at the space-charge limit in a collider. This approach together with electron cooling may result in about 10-fold improvement in total luminosity for low-energy RHIC program.« less

Etude Experimentale du Photo-Injecteur de Fermilab (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carneiro, Jean-Paul

2001-01-01

TESLA (TeV Superconducting Linear Accelerator) is an international collaboration which is studying the feasibility of anmore » $e^+e^-$ collider of energy 0.8 TeV in the center of mass. One of the first goals of this collaboration was to construct a prototype linear accelerator at the DESY Laboratory in Hamburg, the TESLA Test Facility (TTF), in order to establish the technical basis for the collider. Two injectors were developed for TTF: a thermionic injector (developed by LAL-Orsay, IPN-Orsay, and CEA-Saclay) and a photo-injector (developed by Fermilab). The thermionic injector was used from February 1997 to October 1998, and then it was replaced by the photo-injector, which was first operated in December 1998. Another photo-injector, identical to the one delivered to TTF, was installed at Fermilab in the $$A{\\emptyset}$$ Building. The first beam from the latter was produced on 3 March 1999. The photo-injector consists of an RF gun, followed by a superconducting cavity. The RF gun is a 1.625-cell copper cavity with a resonant frequency of 1.3 GHz. The gun contains a cesium telluride ($$C_{s_2}$$Te) photo-cathode, which is illuminated by UV pulses from a Nd:YLF laser. The system can produce trains of 800 bunches of photo-electrons of charge 8 nC per bunch with spacing between bunches of 1$$\\mu$$s and 10 Hz repetition rate. Upon emerging from the RF gun, the beam energy is 4 to 5 MeV; the beam is then rapidly accelerated by the superconducting cavity to an energy of 17 to 20 MeV. Finally, a magnetic chicane, consisting of 4 dipoles, produces longitudinal compression of the electron bunches. This thesis describes the installation of the photo-injector at Fermilab and presents the experimentally-measured characteristics of the injector. The principal measurements were quantum eciency, dark current, transverse emittance, and bunch length. The conclusion from these studies is that the quality of the photo-injector beam fullls the design goals. The photo-injector at Fermilab is presently available for user experiments, including the production of at beams and plasma wake eld acceleration.« less

Impact of 7-TeV/c large hadron collider proton beam on a copper target

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Goddard, B.; Kain, V.; Schmidt, R.; Shutov, A.; Lomonosov, I. V.; Piriz, A. R.; Temporal, M.; Hoffmann, D. H. H.; Fortov, V. E.

2005-04-01

The large hadron collider (LHC) will allow for collision between two 7TeV/c proton beams, each comprising 2808 bunches with 1.1×1011 protons per bunch, traveling in opposite direction. The bunch length is 0.5ns and two neighboring bunches are separated by 25ns so that the duration of the entire beam is about 89μs. The beam power profile in the transverse direction is a Gaussian with a standard deviation of 0.2mm. The energy stored in each beam is about 350MJ that is sufficient to melt 500kg of copper. In case of a failure in the machine protection systems, the entire beam could impact directly onto an accelerator equipment. A first estimate of the scale of damage resulting from such a failure has been assessed for a solid copper target hit by the beam by carrying out three-dimensional energy deposition calculations and two-dimensional numerical simulations of the hydrodynamic and thermodynamic response of the target. This work has shown that the penetration depth of the LHC protons will be between 10 and 40m in solid copper. These calculations show that material conditions obtained in the target are similar to those planned for beam impact at dedicated accelerators designed to study the physics of high-energy-density states of matter, for example, the Facility for Antiprotons and Ion Research at the Gesellschaft für Schwerionenforschung, Darmstadt [W. F. Henning, Nucl. Instrum Methods Phys. Res. B 214, 211 (2004)].

Measured and simulated heavy-ion beam loss patterns at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Hermes, P. D.; Bruce, R.; Jowett, J. M.; Redaelli, S.; Salvachua Ferrando, B.; Valentino, G.; Wollmann, D.

2016-05-01

The Large Hadron Collider (LHC) at CERN pushes forward to new regimes in terms of beam energy and intensity. In view of the combination of very energetic and intense beams together with sensitive machine components, in particular the superconducting magnets, the LHC is equipped with a collimation system to provide protection and intercept uncontrolled beam losses. Beam losses could cause a superconducting magnet to quench, or in the worst case, damage the hardware. The collimation system, which is optimized to provide a good protection with proton beams, has shown a cleaning efficiency with heavy-ion beams which is worse by up to two orders of magnitude. The reason for this reduced cleaning efficiency is the fragmentation of heavy-ion beams into isotopes with a different mass to charge ratios because of the interaction with the collimator material. In order to ensure sufficient collimation performance in future ion runs, a detailed theoretical understanding of ion collimation is needed. The simulation of heavy-ion collimation must include processes in which 82 + 208Pb ions fragment into dozens of new isotopes. The ions and their fragments must be tracked inside the magnetic lattice of the LHC to determine their loss positions. This paper gives an overview of physical processes important for the description of heavy-ion loss patterns. Loss maps simulated by means of the two tools ICOSIM [1,2] and the newly developed STIER (SixTrack with Ion-Equivalent Rigidities) are compared with experimental data measured during LHC operation. The comparison shows that the tool STIER is in better agreement.

Modeling of beam-induced damage of the LHC tertiary collimators

NASA Astrophysics Data System (ADS)

Quaranta, E.; Bertarelli, A.; Bruce, R.; Carra, F.; Cerutti, F.; Lechner, A.; Redaelli, S.; Skordis, E.; Gradassi, P.

2017-09-01

Modern hadron machines with high beam intensity may suffer from material damage in the case of large beam losses and even beam-intercepting devices, such as collimators, can be harmed. A systematic method to evaluate thresholds of damage owing to the impact of high energy particles is therefore crucial for safe operation and for predicting possible limitations in the overall machine performance. For this, a three-step simulation approach is presented, based on tracking simulations followed by calculations of energy deposited in the impacted material and hydrodynamic simulations to predict the thermomechanical effect of the impact. This approach is applied to metallic collimators at the CERN Large Hadron Collider (LHC), which in standard operation intercept halo protons, but risk to be damaged in the case of extraction kicker malfunction. In particular, tertiary collimators protect the aperture bottlenecks, their settings constrain the reach in β* and hence the achievable luminosity at the LHC experiments. Our calculated damage levels provide a very important input on how close to the beam these collimators can be operated without risk of damage. The results of this approach have been used already to push further the performance of the present machine. The risk of damage is even higher in the upgraded high-luminosity LHC with higher beam intensity, for which we quantify existing margins before equipment damage for the proposed baseline settings.

Radiation damage in the diamond based beam condition monitors of the CMS experiment at the Large Hadron Collider (LHC) at CERN

NASA Astrophysics Data System (ADS)

Guthoff, Moritz; Afanaciev, Konstantin; Dabrowski, Anne; de Boer, Wim; Lange, Wolfgang; Lohmann, Wolfgang; Stickland, David

2013-12-01

The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector efficiency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, because of the high number of low energy neutrons in these regions. The signal decrease was stronger than expected from the number of simulated defects. Here polarization from trapped charge carriers in the defects is a likely candidate for explaining the difference, as suggested by Transient Current Technique (TCT) measurements. A single-crystalline (sCVD) diamond sensor shows a faster relative signal decrease than a pCVD sensor mounted at the same location. This is expected, since the relative increase in the number of defects is larger in sCVD than in pCVD sensors.

RF System Requirements for a Medium-Energy Electron-Ion Collider (MEIC) at JLab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimmer, Robert A; Hannon, Fay E; Guo, Jiquan

2015-09-01

JLab is studying options for a medium energy electron-ion collider that could fit on the JLab site and use CEBAF as a full-energy electron injector. A new ion source, linac and booster would be required, together with collider storage rings for the ions and electrons. In order to achieve the maximum luminosity these will be high-current storage rings with many bunches. We present the high-level RF system requirements for the storage rings, ion booster ring and high-energy ion beam cooling system, and describe the technology options under consideration to meet them. We also present options for staging that might reducemore » the initial capital cost while providing a smooth upgrade path to a higher final energy. The technologies under consideration may also be useful for other proposed storage ring colliders or ultimate light sources.« less

Preliminary design of CERN Future Circular Collider tunnel: first evaluation of the radiation environment in critical areas for electronics

NASA Astrophysics Data System (ADS)

Infantino, Angelo; Alía, Rubén García; Besana, Maria Ilaria; Brugger, Markus; Cerutti, Francesco

2017-09-01

As part of its post-LHC high energy physics program, CERN is conducting a study for a new proton-proton collider, called Future Circular Collider (FCC-hh), running at center-of-mass energies of up to 100 TeV in a new 100 km tunnel. The study includes a 90-350 GeV lepton collider (FCC-ee) as well as a lepton-hadron option (FCC-he). In this work, FLUKA Monte Carlo simulation was extensively used to perform a first evaluation of the radiation environment in critical areas for electronics in the FCC-hh tunnel. The model of the tunnel was created based on the original civil engineering studies already performed and further integrated in the existing FLUKA models of the beam line. The radiation levels in critical areas, such as the racks for electronics and cables, power converters, service areas, local tunnel extensions was evaluated.

Model identification of new heavy Z‧ bosons at ILC with polarized beams

NASA Astrophysics Data System (ADS)

Pankov, A. A.; Tsytrinov, A. V.

2017-12-01

Extra neutral gauge bosons, Z‧s, are predicted by many theoretical scenarios of physics beyond the Standard Model, and intensive searches for their signatures will be performed at present and future high energy colliders. It is quite possible that Z‧s are heavy enough to lie beyond the discovery reach expected at the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z‧ exchanges may occur at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We here discuss in this context the expected sensitivity to Z‧ parameters of fermion-pair production cross sections at the planned International Linear Collider (ILC), especially as regards the potential of distinguishing different Z‧ models once such deviations are observed. Specifically, we evaluate the discovery and identification reaches on Z‧ gauge bosons pertinent to the E 6, LR, ALR, and SSM classes of models at the ILC.

Laser ion source for isobaric heavy ion collider experiment.

PubMed

Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

2016-02-01

Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is (96)Ru + (96)Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.

Measurement of the intensity of the beam in the abort gap at the Tevatron utilizing synchrotron light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman-Keup, R.; Lorman, E.; Meyer, T.

2005-05-01

This paper discusses the implementation of abort gap beam intensity monitoring at the Tevatron collider at Fermilab. There are two somewhat independent monitors which measure the intensity of the synchrotron light emitted by particles in the abort gaps. One system uses a gated Photomultiplier Tube (PMT) to measure the light intensity, and the other system uses a single lens telescope, gated image intensifier, and Charge Injection Device (CID) camera to image the beam.

Production and integration of the ATLAS Insertable B-Layer

NASA Astrophysics Data System (ADS)

Abbott, B.; Albert, J.; Alberti, F.; Alex, M.; Alimonti, G.; Alkire, S.; Allport, P.; Altenheiner, S.; Ancu, L. S.; Anderssen, E.; Andreani, A.; Andreazza, A.; Axen, B.; Arguin, J.; Backhaus, M.; Balbi, G.; Ballansat, J.; Barbero, M.; Barbier, G.; Bassalat, A.; Bates, R.; Baudin, P.; Battaglia, M.; Beau, T.; Beccherle, R.; Bell, A.; Benoit, M.; Bermgan, A.; Bertsche, C.; Bertsche, D.; Bilbao de Mendizabal, J.; Bindi, F.; Bomben, M.; Borri, M.; Bortolin, C.; Bousson, N.; Boyd, R. G.; Breugnon, P.; Bruni, G.; Brossamer, J.; Bruschi, M.; Buchholz, P.; Budun, E.; Buttar, C.; Cadoux, F.; Calderini, G.; Caminada, L.; Capeans, M.; Carney, R.; Casse, G.; Catinaccio, A.; Cavalli-Sforza, M.; Červ, M.; Cervelli, A.; Chau, C. C.; Chauveau, J.; Chen, S. P.; Chu, M.; Ciapetti, M.; Cindro, V.; Citterio, M.; Clark, A.; Cobal, M.; Coelli, S.; Collot, J.; Crespo-Lopez, O.; Dalla Betta, G. F.; Daly, C.; D'Amen, G.; Dann, N.; Dao, V.; Darbo, G.; DaVia, C.; David, P.; Debieux, S.; Delebecque, P.; De Lorenzi, F.; de Oliveira, R.; Dette, K.; Dietsche, W.; Di Girolamo, B.; Dinu, N.; Dittus, F.; Diyakov, D.; Djama, F.; Dobos, D.; Dondero, P.; Doonan, K.; Dopke, J.; Dorholt, O.; Dube, S.; Dzahini, D.; Egorov, K.; Ehrmann, O.; Einsweiler, K.; Elles, S.; Elsing, M.; Eraud, L.; Ereditato, A.; Eyring, A.; Falchieri, D.; Falou, A.; Fausten, C.; Favareto, A.; Favre, Y.; Feigl, S.; Fernandez Perez, S.; Ferrere, D.; Fleury, J.; Flick, T.; Forshaw, D.; Fougeron, D.; Franconi, L.; Gabrielli, A.; Gaglione, R.; Gallrapp, C.; Gan, K. K.; Garcia-Sciveres, M.; Gariano, G.; Gastaldi, T.; Gavrilenko, I.; Gaudiello, A.; Geffroy, N.; Gemme, C.; Gensolen, F.; George, M.; Ghislain, P.; Giangiacomi, N.; Gibson, S.; Giordani, M. P.; Giugni, D.; Gjersdal, H.; Glitza, K. W.; Gnani, D.; Godlewski, J.; Gonella, L.; Gonzalez-Sevilla, S.; Gorelov, I.; Gorišek, A.; Gössling, C.; Grancagnolo, S.; Gray, H.; Gregor, I.; Grenier, P.; Grinstein, S.; Gris, A.; Gromov, V.; Grondin, D.; Grosse-Knetter, J.; Guescini, F.; Guido, E.; Gutierrez, P.; Hallewell, G.; Hartman, N.; Hauck, S.; Hasi, J.; Hasib, A.; Hegner, F.; Heidbrink, S.; Heim, T.; Heinemann, B.; Hemperek, T.; Hessey, N. P.; Hetmánek, M.; Hinman, R. R.; Hoeferkamp, M.; Holmes, T.; Hostachy, J.; Hsu, S. C.; Hügging, F.; Husi, C.; Iacobucci, G.; Ibragimov, I.; Idarraga, J.; Ikegami, Y.; Ince, T.; Ishmukhametov, R.; Izen, J. M.; Janoška, Z.; Janssen, J.; Jansen, L.; Jeanty, L.; Jensen, F.; Jentzsch, J.; Jezequel, S.; Joseph, J.; Kagan, H.; Kagan, M.; Karagounis, M.; Kass, R.; Kastanas, A.; Kenney, C.; Kersten, S.; Kind, P.; Klein, M.; Klingenberg, R.; Kluit, R.; Kocian, M.; Koffeman, E.; Korchak, O.; Korolkov, I.; Kostyukhina-Visoven, I.; Kovalenko, S.; Kretz, M.; Krieger, N.; Krüger, H.; Kruth, A.; Kugel, A.; Kuykendall, W.; La Rosa, A.; Lai, C.; Lantzsch, K.; Lapoire, C.; Laporte, D.; Lari, T.; Latorre, S.; Leyton, M.; Lindquist, B.; Looper, K.; Lopez, I.; Lounis, A.; Lu, Y.; Lubatti, H. J.; Maeland, S.; Maier, A.; Mallik, U.; Manca, F.; Mandelli, B.; Mandić, I.; Marchand, D.; Marchiori, G.; Marx, M.; Massol, N.; Mättig, P.; Mayer, J.; McGoldrick, G.; Mekkaoui, A.; Menouni, M.; Menu, J.; Meroni, C.; Mesa, J.; Michal, S.; Miglioranzi, S.; Mikuž, M.; Miucci, A.; Mochizuki, K.; Monti, M.; Moore, J.; Morettini, P.; Morley, A.; Moss, J.; Muenstermann, D.; Murray, P.; Nakamura, K.; Nellist, C.; Nelson, D.; Nessi, M.; Nisius, R.; Nordberg, M.; Nuiry, F.; Obermann, T.; Ockenfels, W.; Oide, H.; Oriunno, M.; Ould-Saada, F.; Padilla, C.; Pangaud, P.; Parker, S.; Pelleriti, G.; Pernegger, H.; Piacquadio, G.; Picazio, A.; Pohl, D.; Polini, A.; Pons, X.; Popule, J.; Portell Bueso, X.; Potamianos, K.; Povoli, M.; Puldon, D.; Pylypchenko, Y.; Quadt, A.; Quayle, B.; Rarbi, F.; Ragusa, F.; Rambure, T.; Richards, E.; Riegel, C.; Ristic, B.; Rivière, F.; Rizatdinova, F.; RØhne, O.; Rossi, C.; Rossi, L. P.; Rovani, A.; Rozanov, A.; Rubinskiy, I.; Rudolph, M. S.; Rummler, A.; Ruscino, E.; Sabatini, F.; Salek, D.; Salzburger, A.; Sandaker, H.; Sannino, M.; Sanny, B.; Scanlon, T.; Schipper, J.; Schmidt, U.; Schneider, B.; Schorlemmer, A.; Schroer, N.; Schwemling, P.; Sciuccati, A.; Seidel, S.; Seiden, A.; Šícho, P.; Skubic, P.; Sloboda, M.; Smith, D. S.; Smith, M.; Sood, A.; Spencer, E.; Stramaglia, M.; Strauss, M.; Stucci, S.; Stugu, B.; Stupak, J.; Styles, N.; Su, D.; Takubo, Y.; Tassan, J.; Teng, P.; Teixeira, A.; Terzo, S.; Therry, X.; Todorov, T.; Tomášek, M.; Toms, K.; Travaglini, R.; Trischuk, W.; Troncon, C.; Troska, G.; Tsiskaridze, S.; Tsurin, I.; Tsybychev, D.; Unno, Y.; Vacavant, L.; Verlaat, B.; Vigeolas, E.; Vogt, M.; Vrba, V.; Vuillermet, R.; Wagner, W.; Walkowiak, W.; Wang, R.; Watts, S.; Weber, M. S.; Weber, M.; Weingarten, J.; Welch, S.; Wenig, S.; Wensing, M.; Wermes, N.; Wittig, T.; Wittgen, M.; Yildizkaya, T.; Yang, Y.; Yao, W.; Yi, Y.; Zaman, A.; Zaidan, R.; Zeitnitz, C.; Ziolkowski, M.; Zivkovic, V.; Zoccoli, A.; Zwalinski, L.

2018-05-01

During the shutdown of the CERN Large Hadron Collider in 2013-2014, an additional pixel layer was installed between the existing Pixel detector of the ATLAS experiment and a new, smaller radius beam pipe. The motivation for this new pixel layer, the Insertable B-Layer (IBL), was to maintain or improve the robustness and performance of the ATLAS tracking system, given the higher instantaneous and integrated luminosities realised following the shutdown. Because of the extreme radiation and collision rate environment, several new radiation-tolerant sensor and electronic technologies were utilised for this layer. This paper reports on the IBL construction and integration prior to its operation in the ATLAS detector.

Dissipative dynamics in quasifission

NASA Astrophysics Data System (ADS)

Oberacker, V. E.; Umar, A. S.; Simenel, C.

2014-11-01

Quasifission is the primary reaction mechanism that prevents the formation of superheavy elements in heavy-ion fusion experiments. Employing the time-dependent density functional theory approach, we study quasifission in the systems Ca,4840+238U . Results show that for 48Ca projectiles the quasifission is substantially reduced in comparison to the 40Ca case. This partly explains the success of superheavy element formation with 48Ca beams. For the first time, we also calculate the repartition of excitation energies of the two fragments in a dynamic microscopic theory. The differences between both systems are interpreted in terms of initial neutron to proton asymmetry of the colliding partners.

Fundamental cavity impedance and longitudinal coupled-bunch instabilities at the High Luminosity Large Hadron Collider

NASA Astrophysics Data System (ADS)

Baudrenghien, P.; Mastoridis, T.

2017-01-01

The interaction between beam dynamics and the radio frequency (rf) station in circular colliders is complex and can lead to longitudinal coupled-bunch instabilities at high beam currents. The excitation of the cavity higher order modes is traditionally damped using passive devices. But the wakefield developed at the cavity fundamental frequency falls in the frequency range of the rf power system and can, in theory, be compensated by modulating the generator drive. Such a regulation is the responsibility of the low-level rf (llrf) system that measures the cavity field (or beam current) and generates the rf power drive. The Large Hadron Collider (LHC) rf was designed for the nominal LHC parameter of 0.55 A DC beam current. At 7 TeV the synchrotron radiation damping time is 13 hours. Damping of the instability growth rates due to the cavity fundamental (400.789 MHz) can only come from the synchrotron tune spread (Landau damping) and will be very small (time constant in the order of 0.1 s). In this work, the ability of the present llrf compensation to prevent coupled-bunch instabilities with the planned high luminosity LHC (HiLumi LHC) doubling of the beam current to 1.1 A DC is investigated. The paper conclusions are based on the measured performances of the present llrf system. Models of the rf and llrf systems were developed at the LHC start-up. Following comparisons with measurements, the system was parametrized using these models. The parametric model then provides a more realistic estimation of the instability growth rates than an ideal model of the rf blocks. With this modeling approach, the key rf settings can be varied around their set value allowing for a sensitivity analysis (growth rate sensitivity to rf and llrf parameters). Finally, preliminary measurements from the LHC at 0.44 A DC are presented to support the conclusions of this work.

Demonstration of the hollow channel plasma wakefield accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gessner, Spencer J.

2016-09-17

A plasma wakefield accelerator is a device that converts the energy of a relativistic particle beam into a large-amplitude wave in a plasma. The plasma wave, or wakefield, supports an enormous electricfield that is used to accelerate a trailing particle beam. The plasma wakefield accelerator can therefore be used as a transformer, transferring energy from a high-charge, low-energy particle beam into a high-energy, low-charge particle beam. This technique may lead to a new generation of ultra-compact, high-energy particle accelerators. The past decade has seen enormous progress in the field of plasma wakefield acceleration with experimental demonstrations of the acceleration ofmore » electron beams by several gigaelectron-volts. The acceleration of positron beams in plasma is more challenging, but also necessary for the creation of a high-energy electron-positron collider. Part of the challenge is that the plasma responds asymmetrically to electrons and positrons, leading to increased disruption of the positron beam. One solution to this problem, first proposed over twenty years ago, is to use a hollow channel plasma which symmetrizes the response of the plasma to beams of positive and negative charge, making it possible to accelerate positrons in plasma without disruption. In this thesis, we describe the theory relevant to our experiment and derive new results when needed. We discuss the development and implementation of special optical devices used to create long plasma channels. We demonstrate for the first time the generation of meter-scale plasma channels and the acceleration of positron beams therein.« less

The SLAC linac as used in the SLC collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seeman, J.T.; Abrams, G.; Adolphsen, C.

The linac of the SLAC Linear Collider (SLC) must accelerate three high intensity bunches on each linac pulse from 1.2 GeV to 50 GeV with minimal increase of the small transverse emittance. The procedures and adjustments used to obtain this goal are outlined. Some of the accelerator parameters and components which interact are the beam energy, transverse position, component alignment, RF manipulation, feedback systems, quadrupole lattice, BNS damping, energy spectra, phase space matching, collimation, instrumentation and modelling. The method to bring these interdependent parameters collectively into specification has evolved over several years. This review is ordered in the sequence whichmore » is used to turn on the linac from a cold start and produce acceptable beams for the final focus and collisions. Approximate time estimates for the various activities are given. 21 refs.« less

Coupling Correction and Beam Dynamics at Ultralow Vertical Emittance in the ALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steier, Christoph; Robin, D.; Wolski, A.

2008-03-17

For synchrotron light sources and for damping rings of linear colliders it is important to be able to minimize the vertical emittance and to correct the spurious vertical dispersion. This allows one to maximize the brightness and/or the luminosity. A commonly used tool to measure the skew error distribution is the analysis of orbit response matrices using codes like LOCO. Using the new Matlab version of LOCO and 18 newly installed power supplies for individual skew quadrupoles at the ALS the emittance ratio could be reduced below 0.1% at 1.9 GeV yielding a vertical emittance of about 5 pm. Atmore » those very low emittances, additional effects like intra beam scattering become more important, potentially limiting the minimum emittance for machine like the damping rings of linear colliders.« less

Cryogenic studies for the proposed CERN large hadron electron collider (LHEC)

NASA Astrophysics Data System (ADS)

Haug, F.; LHeC Study Team, The

2012-06-01

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option, referred to as the "Linac-Ring" version consists of a race-track re-circulating energyrecovery type machine with two 1 km long straight acceleration sections. The 944 high field 2 K SC cavities dissipate 30 kW at CW operation. Eight 10 kW @ 4.5 K refrigerators are proposed. The particle detector contains a combined SC solenoid and dipole forming the cold mass and an independent liquid argon calorimeter. Cooling is done with two individual small sized cryoplants; a 4.5 K helium, and a 87 K liquid nitrogen plant.

Beam test of CSES silicon strip detector module

NASA Astrophysics Data System (ADS)

Zhang, Da-Li; Lu, Hong; Wang, Huan-Yu; Li, Xin-Qiao; Xu, Yan-Bing; An, Zheng-Hua; Yu, Xiao-xia; Wang, Hui; Shi, Feng; Wang, Ping; Zhao, Xiao-Yun

2017-05-01

The silicon-strip tracker of the China Seismo-Electromagnetic Satellite (CSES) consists of two double-sided silicon strip detectors (DSSDs) which provide incident particle tracking information. A low-noise analog ASIC VA140 was used in this study for DSSD signal readout. A beam test on the DSSD module was performed at the Beijing Test Beam Facility of the Beijing Electron Positron Collider (BEPC) using a 400-800 MeV/c proton beam. The pedestal analysis results, RMSE noise, gain correction, and intensity distribution of incident particles of the DSSD module are presented. Supported by the XXX Civil Space Programme

Helical Channel Design and Technology for Cooling of Muon Beams

NASA Astrophysics Data System (ADS)

Yonehara, K.; Derbenev, Y. S.; Johnson, R. P.

2010-11-01

Novel magnetic helical channel designs for capture and cooling of bright muon beams are being developed using numerical simulations based on new inventions such as helical solenoid (HS) magnets and hydrogen-pressurized RF (HPRF) cavities. We are close to the factor of a million six-dimensional phase space (6D) reduction needed for muon colliders. Recent experimental and simulation results are presented.

Jefferson Lab Science: Present and Future

DOE PAGES

McKeown, Robert D.

2015-02-12

The Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab comprise a unique facility for experimental nuclear physics. Furthermore, this facility is presently being upgraded, which will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics. Further in the future, it is envisioned that the Laboratory will evolve into an electron-ion colliding beam facility.

Evaluation of beam halo from beam-gas scattering at the KEK Accelerator Test Facility

NASA Astrophysics Data System (ADS)

Yang, R.; Naito, T.; Bai, S.; Aryshev, A.; Kubo, K.; Okugi, T.; Terunuma, N.; Zhou, D.; Faus-Golfe, A.; Kubytskyi, V.; Liu, S.; Wallon, S.; Bambade, P.

2018-05-01

In circular colliders, as well as in damping rings and synchrotron radiation light sources, beam halo is one of the critical issues limiting the performance as well as potentially causing component damage and activation. It is imperative to clearly understand the mechanisms that lead to halo formation and to test the available theoretical models. Elastic beam-gas scattering can drive particles to large oscillation amplitudes and be a potential source of beam halo. In this paper, numerical estimation and Monte Carlo simulations of this process at the ATF of KEK are presented. Experimental measurements of beam halo in the ATF2 beam line using a diamond sensor detector are also described, which clearly demonstrate the influence of the beam-gas scattering process on the transverse halo distribution.

Cold quantum-controlled rotationally inelastic scattering of HD with H2 and D2 reveals collisional partner reorientation

NASA Astrophysics Data System (ADS)

Perreault, William E.; Mukherjee, Nandini; Zare, Richard N.

2018-05-01

Molecular interactions are best probed by scattering experiments. Interpretation of these studies has been limited by lack of control over the quantum states of the incoming collision partners. We report here the rotationally inelastic collisions of quantum-state prepared deuterium hydride (HD) with H2 and D2 using a method that provides an improved control over the input states. HD was coexpanded with its partner in a single supersonic beam, which reduced the collision temperature to 0-5 K, and thereby restricted the involved incoming partial waves to s and p. By preparing HD with its bond axis preferentially aligned parallel and perpendicular to the relative velocity of the colliding partners, we observed that the rotational relaxation of HD depends strongly on the initial bond-axis orientation. We developed a partial-wave analysis that conclusively demonstrates that the scattering mechanism involves the exchange of internal angular momentum between the colliding partners. The striking differences between H2/HD and D2/HD scattering suggest the presence of anisotropically sensitive resonances.

Test beam studies of silicon timing for use in calorimetry

DOE PAGES

Apresyan, A.; Bolla, G.; Bornheim, A.; ...

2016-04-12

The high luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN is expected to provide instantaneous luminosities of 5 X 10 34 cm –2 s –1. The high luminosities expected at the HL-LHC will be accompanied by a factor of 5 to 10 more pileup compared with LHC conditions in 2015, causing general confusion for particle identification and event reconstruction. Precision timing allows to extend calorimetric measurements into such a high density environment by subtracting the energy deposits from pileup interactions. Calorimeters employing silicon as the active component have recently become a popular choice for the HL-LHC and futuremore » collider experiments which face very high radiation environments. In this article, we present studies of basic calorimetric and precision timing measurements using a prototype composed of tungsten absorber and silicon sensor as the active medium. Lastly, we show that for the bulk of electromagnetic showers induced by electrons in the range of 20 GeV to 30 GeV, we can achieve time resolutions better than 25 ps per single pad sensor.« less

ForwArd Search ExpeRiment at the LHC

NASA Astrophysics Data System (ADS)

Feng, Jonathan L.; Galon, Iftah; Kling, Felix; Trojanowski, Sebastian

2018-02-01

New physics has traditionally been expected in the high-pT region at high-energy collider experiments. If new particles are light and weakly coupled, however, this focus may be completely misguided: light particles are typically highly concentrated within a few mrad of the beam line, allowing sensitive searches with small detectors, and even extremely weakly coupled particles may be produced in large numbers there. We propose a new experiment, forward search experiment, or FASER, which would be placed downstream of the ATLAS or CMS interaction point (IP) in the very forward region and operated concurrently there. Two representative on-axis locations are studied: a far location, 400 m from the IP and just off the beam tunnel, and a near location, just 150 m from the IP and right behind the TAN neutral particle absorber. For each location, we examine leading neutrino- and beam-induced backgrounds. As a concrete example of light, weakly coupled particles, we consider dark photons produced through light meson decay and proton bremsstrahlung. We find that even a relatively small and inexpensive cylindrical detector, with a radius of ˜10 cm and length of 5-10 m, depending on the location, can discover dark photons in a large and unprobed region of parameter space with dark photon mass mA'˜10 - 500 MeV and kinetic mixing parameter ɛ ˜10-6-10-3. FASER will clearly also be sensitive to many other forms of new physics. We conclude with a discussion of topics for further study that will be essential for understanding FASER's feasibility, optimizing its design, and realizing its discovery potential.

Improving calorimeter resolution using temperature compensation calculations

NASA Astrophysics Data System (ADS)

Smiga, Joseph; Purschke, Martin

2017-01-01

The sPHENIX experiment is an upgrade of the existing PHENIX apparatus at the Relativistic Heavy-Ion Collider (RHIC). The new detector improves upon measurements of various physical processes, such as jets of particles created during heavy-ion collisions. Prototypes of various calorimeter components were tested at the Fermilab Test Beam Facility (FTBF). This analysis tries to compensate the effects of temperature drifts in the silicon photomultipliers (SiPMs). Temperature data were used to calculate an appropriate compensation factor. This analysis will improve the achievable resolution and will also determine how accurately the temperature must be controlled in the final experiment. This will improve the performance of the calorimeters in the sPHENIX experiment. This project was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships Program (SULI).

RICH upgrade in LHCb experiment

NASA Astrophysics Data System (ADS)

Pistone, A.; LHCb RICH Collaboration

2017-01-01

The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). The second long shutdown of the LHC is currently scheduled to begin in 2019. During this period the LHCb experiment with all its sub-detectors will be upgraded in order to run at an instantaneous luminosity of 2 × 10^{33} cm ^{-2} s ^{-1} , about a factor 5 higher than the current luminosity, and to read out data at a rate of 40MHz into a flexible software-based trigger. The Ring Imaging CHerenkov (RICH) system will require new photon detectors and modifications to the optics of the upstream detector. Tests of the prototype of the smallest constituent of the new RICH system have been performed during testbeam sessions at the North Area test beam facility at CERN in the last years.

Ringing in the new physics: The politics and technology of electron colliders in the United States, 1956--1972

NASA Astrophysics Data System (ADS)

Paris, Elizabeth

The ``November Revolution'' of 1974 and the experiments that followed consolidated the place of the Standard Model in modern particle physics. Much of the evidence on which these conclusions depended was generated by a new type of tool: colliding beam storage rings, which had been considered physically unfeasible twenty years earlier. In 1956 a young experimentalist named Gerry O'Neill dedicated himself to demonstrating that such an apparatus could do useful physics. The storage ring movement encountered numerous obstacles before generating one of the standard machines for high energy research. In fact, it wasn't until 1970 that the U.S. finally broke ground on its first electron-positron collider. Drawing extensively on archival sources and supplementing them with the personal accounts of many of the individuals who took part, Ringing in the New Physics examines this instance of post-World War II techno-science and the new social, political and scientific tensions that characterize it. The motivations are twofold: first, that the chronicle of storage rings may take its place beside mathematical group theory, computer simulations, magnetic spark chambers, and the like as an important contributor to a view of matter and energy which has been the dominant model for the last twenty-five years. In addition, the account provides a case study for the integration of the personal, professional, institutional, and material worlds when examining an episode in the history or sociology of twentieth century science. The story behind the technological development of storage rings holds fascinating insights into the relationship between theory and experiment, collaboration and competition in the physics community, the way scientists obtain funding and their responsibilities to it, and the very nature of what constitutes ``successful'' science in the post- World War II era.

Optics measurement and correction for the Relativistic Heavy Ion Collider

NASA Astrophysics Data System (ADS)

Shen, Xiaozhe

The quality of beam optics is of great importance for the performance of a high energy accelerator like the Relativistic Heavy Ion Collider (RHIC). The turn-by-turn (TBT) beam position monitor (BPM) data can be used to derive beam optics. However, the accuracy of the derived beam optics is often limited by the performance and imperfections of instruments as well as measurement methods and conditions. Therefore, a robust and model-independent data analysis method is highly desired to extract noise-free information from TBT BPM data. As a robust signal-processing technique, an independent component analysis (ICA) algorithm called second order blind identification (SOBI) has been proven to be particularly efficient in extracting physical beam signals from TBT BPM data even in the presence of instrument's noise and error. We applied the SOBI ICA algorithm to RHIC during the 2013 polarized proton operation to extract accurate linear optics from TBT BPM data of AC dipole driven coherent beam oscillation. From the same data, a first systematic estimation of RHIC BPM noise performance was also obtained by the SOBI ICA algorithm, and showed a good agreement with the RHIC BPM configurations. Based on the accurate linear optics measurement, a beta-beat response matrix correction method and a scheme of using horizontal closed orbit bumps at sextupoles for arc beta-beat correction were successfully applied to reach a record-low beam optics error at RHIC. This thesis presents principles of the SOBI ICA algorithm and theory as well as experimental results of optics measurement and correction at RHIC.

Polarized positrons in Jefferson lab electron ion collider (JLEIC)

NASA Astrophysics Data System (ADS)

Lin, Fanglei; Grames, Joe; Guo, Jiquan; Morozov, Vasiliy; Zhang, Yuhong

2018-05-01

The Jefferson Lab Electron Ion Collider (JLEIC) is designed to provide collisions of electron and ion beams with high luminosity and high polarization to reach new frontier in exploration of nuclear structure. The luminosity, exceeding 1033 cm-2s-1 in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm-2s-1, is achieved by high-rate collisions of short small-emittance low-charge bunches with proper cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) and electron can be easily preserved, manipulated and maintained by taking advantage of the unique figure-8 shape rings. With a growing physics interest, polarized positron-ion collisions are considered to be carried out in the JLEIC to offer an additional probe to study the substructure of nucleons and nuclei. However, the creation of polarized positrons with sufficient intensity is particularly challenging. We propose a dedicated scheme to generate polarized positrons. Rather than trying to accumulate "hot" positrons after conversion, we will accumulate "cold" electrons before conversion. Charge accumulation additionally provides a novel means to convert high repetition rate (>100 MHz) electron beam from the gun to a low repetition rate (<100 MHz) positron beam for broad applications. In this paper, we will address the scheme, provide preliminary estimated parameters and explain the key areas to reach the desired goal.

News | Computing

Science.gov Websites

Support News Publications Computing for Experiments Computing for Neutrino and Muon Physics Computing for Collider Experiments Computing for Astrophysics Research and Development Accelerator Modeling ComPASS - Impact of Detector Simulation on Particle Physics Collider Experiments Daniel Elvira's paper "Impact

Beam energy dependence of pseudorapidity distributions of charged particles produced in relativistic heavy-ion collisions

NASA Astrophysics Data System (ADS)

Basu, Sumit; Nayak, Tapan K.; Datta, Kaustuv

2016-06-01

Heavy-ion collisions at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN probe matter at extreme conditions of temperature and energy density. Most of the global properties of the collisions can be extracted from the measurements of charged-particle multiplicity and pseudorapidity (η ) distributions. We have shown that the available experimental data on beam energy and centrality dependence of η distributions in heavy-ion (Au +Au or Pb +Pb ) collisions from √{sNN}=7.7 GeV to 2.76 TeV are reasonably well described by the AMPT model, which is used for further exploration. The nature of the η distributions has been described by a double Gaussian function using a set of fit parameters, which exhibit a regular pattern as a function of beam energy. By extrapolating the parameters to a higher energy of √{sNN}=5.02 TeV, we have obtained the charged-particle multiplicity densities, η distributions, and energy densities for various centralities. Incidentally, these results match well with some of the recently published data by the ALICE Collaboration.

Plasma wakefield acceleration experiments at FACET II

NASA Astrophysics Data System (ADS)

Joshi, C.; Adli, E.; An, W.; Clayton, C. E.; Corde, S.; Gessner, S.; Hogan, M. J.; Litos, M.; Lu, W.; Marsh, K. A.; Mori, W. B.; Vafaei-Najafabadi, N.; O'shea, B.; Xu, Xinlu; White, G.; Yakimenko, V.

2018-03-01

During the past two decades of research, the ultra-relativistic beam-driven plasma wakefield accelerator (PWFA) concept has achieved many significant milestones. These include the demonstration of ultra-high gradient acceleration of electrons over meter-scale plasma accelerator structures, efficient acceleration of a narrow energy spread electron bunch at high-gradients, positron acceleration using wakes in uniform plasmas and in hollow plasma channels, and demonstrating that highly nonlinear wakes in the ‘blow-out regime’ have the electric field structure necessary for preserving the emittance of the accelerating bunch. A new 10 GeV electron beam facility, Facilities for Accelerator Science and Experimental Test (FACET) II, is currently under construction at SLAC National Accelerator Laboratory for the next generation of PWFA research and development. The FACET II beams will enable the simultaneous demonstration of substantial energy gain of a small emittance electron bunch while demonstrating an efficient transfer of energy from the drive to the trailing bunch. In this paper we first describe the capabilities of the FACET II facility. We then describe a series of PWFA experiments supported by numerical and particle-in-cell simulations designed to demonstrate plasma wake generation where the drive beam is nearly depleted of its energy, high efficiency acceleration of the trailing bunch while doubling its energy and ultimately, quantifying the emittance growth in a single stage of a PWFA that has optimally designed matching sections. We then briefly discuss other FACET II plasma-based experiments including in situ positron generation and acceleration, and several schemes that are promising for generating sub-micron emittance bunches that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider.

Plasma wakefield acceleration experiments at FACET II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, C.; Adli, E.; An, W.

During the past two decades of research, the ultra-relativistic beam-driven plasma wakefield accelerator (PWFA) concept has achieved many significant milestones. These include the demonstration of ultra-high gradient acceleration of electrons over meter-scale plasma accelerator structures, efficient acceleration of a narrow energy spread electron bunch at high-gradients, positron acceleration using wakes in uniform plasmas and in hollow plasma channels, and demonstrating that highly nonlinear wakes in the 'blow-out regime' have the electric field structure necessary for preserving the emittance of the accelerating bunch. A new 10 GeV electron beam facility, Facilities for Accelerator Science and Experimental Test (FACET) II, is currentlymore » under construction at SLAC National Accelerator Laboratory for the next generation of PWFA research and development. The FACET II beams will enable the simultaneous demonstration of substantial energy gain of a small emittance electron bunch while demonstrating an efficient transfer of energy from the drive to the trailing bunch. In this paper we first describe the capabilities of the FACET II facility. We then describe a series of PWFA experiments supported by numerical and particle-in-cell simulations designed to demonstrate plasma wake generation where the drive beam is nearly depleted of its energy, high efficiency acceleration of the trailing bunch while doubling its energy and ultimately, quantifying the emittance growth in a single stage of a PWFA that has optimally designed matching sections. Here, we briefly discuss other FACET II plasma-based experiments including in situ positron generation and acceleration, and several schemes that are promising for generating sub-micron emittance bunches that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider.« less

Plasma wakefield acceleration experiments at FACET II

DOE PAGES

Joshi, C.; Adli, E.; An, W.; ...

2018-01-12

During the past two decades of research, the ultra-relativistic beam-driven plasma wakefield accelerator (PWFA) concept has achieved many significant milestones. These include the demonstration of ultra-high gradient acceleration of electrons over meter-scale plasma accelerator structures, efficient acceleration of a narrow energy spread electron bunch at high-gradients, positron acceleration using wakes in uniform plasmas and in hollow plasma channels, and demonstrating that highly nonlinear wakes in the 'blow-out regime' have the electric field structure necessary for preserving the emittance of the accelerating bunch. A new 10 GeV electron beam facility, Facilities for Accelerator Science and Experimental Test (FACET) II, is currentlymore » under construction at SLAC National Accelerator Laboratory for the next generation of PWFA research and development. The FACET II beams will enable the simultaneous demonstration of substantial energy gain of a small emittance electron bunch while demonstrating an efficient transfer of energy from the drive to the trailing bunch. In this paper we first describe the capabilities of the FACET II facility. We then describe a series of PWFA experiments supported by numerical and particle-in-cell simulations designed to demonstrate plasma wake generation where the drive beam is nearly depleted of its energy, high efficiency acceleration of the trailing bunch while doubling its energy and ultimately, quantifying the emittance growth in a single stage of a PWFA that has optimally designed matching sections. Here, we briefly discuss other FACET II plasma-based experiments including in situ positron generation and acceleration, and several schemes that are promising for generating sub-micron emittance bunches that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider.« less

Electron gun jitter effects on beam bunching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, M. S.; Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk; Centre for High Energy Physics, University of the Punjab, Lahore 45590

For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps whichmore » eventually deteriorates both the beam performance and the injection rate to the storage ring.« less

Production, formation, and transport of high-brightness atomic hydrogen beam studies for the relativistic heavy ion collider polarized source upgrade.

PubMed

Kolmogorov, A; Atoian, G; Davydenko, V; Ivanov, A; Ritter, J; Stupishin, N; Zelenski, A

2014-02-01

The RHIC polarized H(-) ion source had been successfully upgraded to higher intensity and polarization by using a very high brightness fast atomic beam source developed at BINP, Novosibirsk. In this source the proton beam is extracted by a four-grid multi-aperture ion optical system and neutralized in the H2 gas cell downstream from the grids. The proton beam is extracted from plasma emitter with a low transverse ion temperature of ∼0.2 eV which is formed by plasma jet expansion from the arc plasma generator. The multi-hole grids are spherically shaped to produce "geometrical" beam focusing. Proton beam formation and transport of atomic beam were experimentally studied at test bench.

Measurement techniques for low emittance tuning and beam dynamics at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Dobbins, J. A.; Forster, M. J.; Kreinick, D. L.; Meller, R. E.; Peterson, D. P.; Ramirez, G. A.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Williams, H. A.; Palmer, M. A.; Holtzapple, R. L.; Flanagan, J.

2018-03-01

After operating as a High Energy Physics electron-positron collider, the Cornell Electron-positron Storage Ring (CESR) has been converted to become a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS). Over the course of several years CESR was adapted for accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Initially some specific topics were targeted for accelerator physic research with the storage ring in this mode, labeled CesrTA. These topics included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud (EC) development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CesrTA occurred over a several year period, described elsewhere [1–3]. A number of specific instruments were developed for CesrTA. Much of the pre-existing instrumentation was modified to accommodate the scope of these studies and these are described in a companion paper [4]. To complete this research, a number of procedures were developed or modified, often requiring coordinated measurements among different instruments [5]. This paper provides an overview of types of measurements employed for the study of beam dynamics during the operation of CesrTA.

Drive beam stabilisation in the CLIC Test Facility 3

NASA Astrophysics Data System (ADS)

Malina, L.; Corsini, R.; Persson, T.; Skowroński, P. K.; Adli, E.

2018-06-01

The proposed Compact Linear Collider (CLIC) uses a high intensity, low energy drive beam to produce the RF power needed to accelerate a lower intensity main beam with 100 MV/m gradient. This scheme puts stringent requirements on drive beam stability in terms of phase, energy and current. The consequent experimental work was carried out in CLIC Test Facility CTF3. In this paper, we present a novel analysis technique in accelerator physics to find beam drifts and their sources in the vast amount of the continuously gathered signals. The instability sources are identified and adequately mitigated either by hardware improvements or by implementation and commissioning of various feedbacks, mostly beam-based. The resulting drive beam stability is of 0.2°@ 3 GHz in phase, 0.08% in relative beam energy and about 0.2% beam current. Finally, we propose a stabilisation concept for CLIC to guarantee the main beam stability.

The HL-LHC Accelerator Physics Challenges

NASA Astrophysics Data System (ADS)

Fartoukh, S.; Zimmermann, F.

The conceptual baseline of the HL-LHC project is reviewed, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

Construction of the DHCAL

NASA Astrophysics Data System (ADS)

Francis, Kurt; CALICE Collaboration

Particle Flow Algorithms (PFAs) have been proposed as a method of improving the jet energy resolution of future colliding beam detectors. PFAs require calorimeters with high granularity to enable three-dimensional imaging of events. The Calorimeter for the Linear Collider Collaboration (CALICE) is developing and testing prototypes of such highly segmented calorimeters. In this context, a large prototype of a Digital Hadron Calorimeter (DHCAL) was developed and constructed by a group led by Argonne National Laboratory. The DHCAL consists of 52 layers, instrumented with Resistive Plate Chambers (RPCs) and interleaved with steel absorber plates. The RPCs are read out by 1 x 1 cm2 pads with a 1-bit resolution (digital readout). The DHCAL prototype has approximately 480,000 readout channels. This talk reports on the design, construction and commissioning of the DHCAL. The DHCAL was installed at the Fermilab Test Beam Facility in fall 2010 and data was collected through the summer 2011.

Generating high-brightness electron beams via ionization injection by transverse colliding lasers in a plasma-wakefield accelerator.

PubMed

Li, F; Hua, J F; Xu, X L; Zhang, C J; Yan, L X; Du, Y C; Huang, W H; Chen, H B; Tang, C X; Lu, W; Joshi, C; Mori, W B; Gu, Y Q

2013-07-05

The production of ultrabright electron bunches using ionization injection triggered by two transversely colliding laser pulses inside a beam-driven plasma wake is examined via three-dimensional particle-in-cell simulations. The relatively low intensity lasers are polarized along the wake axis and overlap with the wake for a very short time. The result is that the residual momentum of the ionized electrons in the transverse plane of the wake is reduced, and the injection is localized along the propagation axis of the wake. This minimizes both the initial thermal emittance and the emittance growth due to transverse phase mixing. Simulations show that ultrashort (~8 fs) high-current (0.4 kA) electron bunches with a normalized emittance of 8.5 and 6 nm in the two planes, respectively, and a brightness of 1.7×10(19) A rad(-2) m(-2) can be obtained for realistic parameters.

Design of 140 MW X-band Relativistic Klystron for Linear Collider

NASA Astrophysics Data System (ADS)

Dolbilov, G. V.; Azorsky, N. I.; Shvetsov, V. S.; Balakin, V. E.; Avrakhov, P. V.; Kazakov, S. Yu.; Teryaev, V. E.; Vogel, V. F.

1997-05-01

It has been reported at EPAC-96 on successful experimental results on achievement of 100 MW output rf power in a wide aperture (15 mm), high gain (80 dB) 14 GHz VLEPP klystron with distributed suppression of parasitic oscillations (G.V. Dolbilov et al., Proc. EPAC-96, Sitges (Barselona), 10-14 June, 1996, Vol. 3, p. 2143). This report presents design of an electrodynamic structure of the X-band klystron for linear collider with a higher efficiency up to 56 % which will be achieved at the same parameters of the electron beam (U = 1 MeV, I = 250 A, emittance 0.05 π cm\\cdotrad). Design rf output power of the klystron is 140 MW. Experimental investigations of electrodynamic structure of the klystron are planned to perform using the driving beam of the JINR LIA-3000 induction accelerator (E = 1 MeV, I = 250 A, τ = 250 ns).

State of the art in electromagnetic modeling for the Compact Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, Arno; Kabel, Andreas; Lee, Lie-Quan

SLAC's Advanced Computations Department (ACD) has developed the parallel 3D electromagnetic time-domain code T3P for simulations of wakefields and transients in complex accelerator structures. T3P is based on state-of-the-art Finite Element methods on unstructured grids and features unconditional stability, quadratic surface approximation and up to 6th-order vector basis functions for unprecedented simulation accuracy. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with fast turn-around times, aiding the design of the next generation of accelerator facilities. Applications include simulations of the proposed two-beam accelerator structures for the Compact Linear Collider (CLIC) - wakefieldmore » damping in the Power Extraction and Transfer Structure (PETS) and power transfer to the main beam accelerating structures are investigated.« less

A Laser Cavity for a Future Photon Collider at ILC

NASA Astrophysics Data System (ADS)

Klemz, G.; Moenig, K.

2006-04-01

Within a future photon-collider based on the infrastructure of ILC the energy of near-infrared laser photons will be boosted by Compton backscattering on a high energy electron beam to well above 100 GeV. By reason of luminosity, an extremely powerful lasersystem is required that will exceed today's state-of-the-art capabilities. An auxiliary cavity for resonantly enhancing the optical peak-power can relax demands on the power output of the laser. In this paper a possible design and the static aspects of a passive cavity are discussed.

Simulator for beam-based LHC collimator alignment

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Aßmann, Ralph; Redaelli, Stefano; Sammut, Nicholas

2014-02-01

In the CERN Large Hadron Collider, collimators need to be set up to form a multistage hierarchy to ensure efficient multiturn cleaning of halo particles. Automatic algorithms were introduced during the first run to reduce the beam time required for beam-based setup, improve the alignment accuracy, and reduce the risk of human errors. Simulating the alignment procedure would allow for off-line tests of alignment policies and algorithms. A simulator was developed based on a diffusion beam model to generate the characteristic beam loss signal spike and decay produced when a collimator jaw touches the beam, which is observed in a beam loss monitor (BLM). Empirical models derived from the available measurement data are used to simulate the steady-state beam loss and crosstalk between multiple BLMs. The simulator design is presented, together with simulation results and comparison to measurement data.

The Belle II Pixel Detector Data Acquisition and Background Suppression System

NASA Astrophysics Data System (ADS)

Lautenbach, K.; Deschamps, B.; Dingfelder, J.; Getzkow, D.; Geßler, T.; Konorov, I.; Kühn, W.; Lange, S.; Levit, D.; Liu, Z.-A.; Marinas, C.; Münchow, D.; Rabusov, A.; Reiter, S.; Spruck, B.; Wessel, C.; Zhao, J.

2017-06-01

The Belle II experiment at the future SuperKEKB collider in Tsukuba, Japan, features a design luminosity of 8 · 1035 cm-2s-1, which is a factor of 40 larger than that of its predecessor Belle. The pixel detector (PXD) with about 8 million pixels is based on the DEPFET technology and will improve the vertex resolution in beam direction by a factor of 2. With an estimated trigger rate of 30 kHz, the PXD is expected to generate a data rate of 20 GBytes/s, which is about 10 times larger than the amount of data generated by all other Belle II subdetectors. Due to the large beam-related background, the PXD requires a data acquisition system with high-bandwidth data links and realtime background reduction by a factor of 30. To achieve this, the Belle II pixel DAQ uses an FPGA-based computing platform with high speed serial links implemented in the ATCA (Advanced Telecommunications Computing Architecture) standard. The architecture and performance of the data acquisition system and data reduction of the PXD will be presented. In April 2016 and February 2017 a prototype PXD-DAQ system operated in a test beam campaign delivered data with the whole readout chain under realistic high rate conditions. Final results from the beam test will be presented.

Rectilinear six-dimensional ionization cooling channel for a muon collider: A theoretical and numerical study

DOE PAGES

Stratakis, Diktys; Palmer, Robert B.

2015-03-06

A Muon Collider requires a reduction of the six-dimensional emittance of the captured muon beam by several orders of magnitude. In this study, we describe a novel rectilinear cooling scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we detail its basic features. Then, we establish the theoretical framework to predict and evaluate the performance of ionization cooling channels and discuss its application to our specific case. In conclusion, we present the first end-to-end simulation of 6D cooling for a Muon Collider and show a notable reduction of the 6D emittance bymore » five orders of magnitude. We find good agreement between simulation and theory.« less

Design study of an optical cavity for a future photon collider at ILC

NASA Astrophysics Data System (ADS)

Klemz, G.; Mönig, K.; Will, I.

2006-08-01

Hard photons well above 100 GeV have to be generated in a future photon collider which essentially will be based on the infrastructure of the planned International Linear Collider (ILC). The energy of near-infrared laser photons will be boosted by Compton backscattering against a high-energy relativistic electron beam. For high effectiveness, a very powerful laser system is required that exceeds today's state-of-the-art capabilities. In this paper a design of an auxiliary passive cavity is discussed that resonantly enhances the peak-power of the laser. The properties and prospects of such a cavity are addressed on the basis of the specifications for the European TeV Energy Superconducting Linear Accelerator (TESLA) proposal. Those of the ILC are expected to be similar.

Lattice QCD at finite temperature and density from Taylor expansion

NASA Astrophysics Data System (ADS)

Steinbrecher, Patrick

2017-01-01

In the first part, I present an overview of recent Lattice QCD simulations at finite temperature and density. In particular, we discuss fluctuations of conserved charges: baryon number, electric charge and strangeness. These can be obtained from Taylor expanding the QCD pressure as a function of corresponding chemical potentials. Our simulations were performed using quark masses corresponding to physical pion mass of about 140 MeV and allow a direct comparison to experimental data from ultra-relativistic heavy ion beams at hadron colliders such as the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN. In the second part, we discuss computational challenges for current and future exascale Lattice simulations with a focus on new silicon developments from Intel and NVIDIA.

AN ENGINEERING SOLUTION TO THE RHIC BEAM ABORT KICKER UPGRADE.

DOE Office of Scientific and Technical Information (OSTI.GOV)

ZHANG,W.ROSER,T.SANDBERG,J.TAN,Y.ET AL.

2004-05-23

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is the world largest superconducting accelerator for nuclear energy research. Particle beams traveling in opposite directions in two accelerator rings, Blue and Yellow, collide at six interaction regions to create phenomena of the early universe. There are more than 1700 superconducting magnets and very sophisticate and delicate large detectors inside the RHIC tunnel. With high beam intensity and ultra high beam energy, an inadvertent loss of beam can result severe damage to the superconducting magnets and detectors. Beam abort kickers are used to remove beam safely from the ring. Themore » large inductive load, high current capability, short beam gap, and high reliability are the challenging issues of this system design. With high intensity and high momentum beam operation, it is desirable to have all high voltage modulators located outside of RHIC tunnel. However, to generate 22 kA output current per modulator with fast rise time, a conventional low impedance PFN and matched transmission cable design can push the operation voltage easily into 100 kV range. The large quantity of high voltage pulse transmission cables required by conventional design is another difficult issue. Therefore, the existing system has all ten high voltage modulators located inside RHIC tunnel. More than a hundred plastic packaged mineral oil filled high voltage capacitors raise serious concerns of fire and smoking threats. Other issues, such as kicker misfire, device availability in the future, and inaccessibility during operation, also demand an engineering solution for the future upgrade. In this paper, we investigate an unconventional approach to meet the technical challenges of RHIC beam abort system. The proposed design has all modulators outside of the RHIC tunnel. It will transmit output pulse through high voltage cables. The modulators will utilize solid-state switches, and operate at a maximum voltage in 30 to 50 kV range.« less

Soft Fusion Energy Path: Isotope Production in Energy Subcritical/Economy Hypercritical D +D Colliding-Beam Mini Fusion Reactor `Exyder'

NASA Astrophysics Data System (ADS)

Hester, Tim; Maglich, Bogdan; Calsec Collaboration

2015-03-01

Bethe1 and Sakharov2 argued for soft fusion energy path via isotope production, substantiated by Manheimer3. - Copious T and 3He production4 , 5 from D(d, p) T and D(d, n) 3He reactions in 725 KeV D +D colliding beams was measured in weak-focusing Self-Collider6 , 7 radius 0.15 m, in B = 3.12 T, non-linearly stabilized by electron cloud oscillations8 to confinement time = 24 s. Simulations6 predict that by switching to strong focusing9, 10 deuterons 0.75 MeV each, generate 1 3He +1T +1p + 1n at total input energy cost 10.72 MeV. Economic value of T and 3He is 65 and 120 MeV/atom, respectively. We obtain economic gain 205MeV/10.72 MeV ~ 2,000% i.e. 3He production funds cost of T. If first wall is made of Thorium n's will breed 233U releasing 200 MeV/fission, at neutron cost 5.36 MeV versus 160 MeV in beam on target, resulting in no cost 3He production, valued 75K/g. 1. Physics Today, May 1979, p.44; 2. Memoirs, Vintage Books, (1992); 3. Phys. Today, May 2012 p. 12; 4. Phys. Rev. Lett. 54, 796 (1985); 5. Bull. APS, 57, No. 3 (2012); 6. Part. Acc.1, (1970); 7. ANEUTRONIC FUSION NIM A 271 1-167 (1988); 8. Phys. Rev. Lett. 70, 1818 (1993); 9. Part. Acc. 34, 13 (1990).

Review of results from CESR (Cornell Electron Storage Ring) and DORIS (DOpple RIng Spiecher)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shibata, E.I.

1989-01-01

Selected results from e/sup +/e/sup /minus// colliding beam experiments operating in the ..sqrt..s approx. 10 GeV region are reviewed. Photon and ..pi pi.. transitions from the UPSILON(1S), UPSILON(2S), and UPSILON(3S) bound states have been used to study the spectroscopy of the b/bar b/ system. The UPSILON(4S), which decays almost exclusively to B/bar B/, has been used to search for rare exclusive decay modes of B mesons and to measure B/sup 0//bar B//sup 0/ mixing. Searches for the Higgs particle have been made in UPSILON and B decays. 43 refs., 13 figs., 2 tabs.

Physics and Analysis at a Hadron Collider - An Introduction (1/3)

ScienceCinema

None

2018-05-11

This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

Operational experience with nanocoulomb bunch charges in the Cornell photoinjector

DOE PAGES

Bartnik, Adam; Gulliford, Colwyn; Bazarov, Ivan; ...

2015-08-19

Characterization of 9–9.5 MeV electron beams produced in the dc-gun based Cornell photoinjector is given for bunch charges ranging from 20 pC to 2 nC. Comparison of the measured emittances and longitudinal current profiles to optimized 3D space charge simulations yields excellent agreement for bunch charges up to 1 nC when the measured laser distribution is used to generate initial particle distributions in simulation. Analysis of the scaling of the measured emittance with bunch charge shows that the emittance scales roughly as the square root of the bunch charge up to 300 pC, above which the trend becomes linear. Furthermore,more » these measurements demonstrate that the Cornell photoinjector can produce cathode emittance dominated beams meeting the emittance and peak current specifications for next generation free electron lasers operating at high repetition rate. In addition, the 1 and 2 nC results are relevant to the electron ion collider community.« less

Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at √{sN N}=7.7 -62.4 GeV

NASA Astrophysics Data System (ADS)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; 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, 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, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; 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, H. Z.; Huang, B.; 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.; 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, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; 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.; Niida, T.; 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.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; 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.; 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, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; 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, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; 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, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

2016-01-01

Elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √{sN N}= 7.7 -62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √{sN N}= 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.

Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at s N N = 7.7 – 62.4 GeV

DOE PAGES

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

2016-01-19

Here, elliptic flow (v 2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √s NN = 7.7–62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √s NN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v 2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v 2 for most particles relative to antiparticles, already observedmore » for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.« less

ER@CEBAF: A test of 5-pass energy recovery at CEBAF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogacz, S. A.; Douglas, D.; Dubbe, C.

2016-06-06

Jefferson Lab personnel have broad expertise in the design, commissioning, and operation of multiple energy recovery linacs (ERLs): the CEBAF Front-End Test (early 1990s), CEBAF-ER (2003), the IR Free Electron Laser (FEL) Demo, the IR FEL Upgrade, and the UV FEL Driver (1997-2014). Continued development of this core competency has led to this collaborative proposal to explore the forefronts of ERL technology at high energy in a unique expansion of CEBAF capability to a 5-pass ERL with negligible switchover time and programmatic impact to the CEBAF physics program. Such a capability would enable world-class studies of open issues in high-energymore » ERL beam dynamics that are relevant to future facilities such as electron-ion colliders (EICs). This proposal requests support from the CEBAF Program Advisory Committee to seek funding for hardware installation, and a prospective 12 days of beam time circa Fall 2018 for commissioning this high-energy multi-pass ERL experiment in CEBAF.« less

Development of an Abort Gap Monitor for High-Energy Proton Rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beche, J.-F.; Byrd, J.; De Santis, S.

2004-11-10

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the 'abort gap', and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitormore » based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider.« less

Development of an abort gap monitor for high-energy proton rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beche, Jean-Francois; Byrd, John; De Santis, Stefano

2004-05-03

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitormore » based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider« less

100 km CEPC parameters and lattice design

NASA Astrophysics Data System (ADS)

Wang, D.; Gao, J.; Yu, C. H.; Zhang, Y.; Wang, Y. W.; Su, F.; Y Zhai, J.; Bai, S.; Geng, H. P.; Bian, T. J.; Wang, N.; Cui, X. H.; Zhang, C.; Qin, Q.

2017-07-01

The 100km double ring configuration with shared superconducting RF system has been defined as baseline by the circular electron positron collider (CEPC) steering committee. Based on this new scheme, we will get higher luminosity for Higgs (+170%) keeping the beam power in preliminary conceptual design report (Pre-CDR) or to reduce the beam power (19 MW) while keeping same luminosity. CEPC will be compatible with W and Z experiment. The luminosity for Z is designed at the level of 1035 cm-2s-1. The requirement for the energy acceptance of Higgs has been reduced to 1.5% by enlarging the ring to 100 km. The optics of arc and final focus system (FFS) with crab sextupoles has been designed, and also some primary dynamic aperture (DA) results were introduced. Work supported by the National Key Programme for S&T Research and Development (Grant NO. 2016YFA0400400) and the National Natural Science Foundation of China (11505198, 11575218, 11605210 and 11605211).

Optimization methodology for the global 10 Hz orbit feedback in RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Chuyu; Hulsart, R.; Mernick, K.

To combat beam oscillations induced by triplet vibrations at the Relativistic Heavy Ion Collider (RHIC), a global orbit feedback system was developed and applied at injection and top energy in 2011, and during beam acceleration in 2012. Singular Value Decomposition (SVD) was employed to determine the strengths and currents of the applied corrections. The feedback algorithm was optimized for different magnetic configurations (lattices) at fixed beam energies and during beam acceleration. While the orbit feedback performed well since its inception, corrector current transients and feedback-induced beam oscillations were observed during the polarized proton program in 2015. In this paper, wemore » present the feedback algorithm, the optimization of the algorithm for various lattices and the solution adopted to mitigate the observed current transients during beam acceleration.« less

Optimization methodology for the global 10 Hz orbit feedback in RHIC

DOE PAGES

Liu, Chuyu; Hulsart, R.; Mernick, K.; ...

2018-05-08

To combat beam oscillations induced by triplet vibrations at the Relativistic Heavy Ion Collider (RHIC), a global orbit feedback system was developed and applied at injection and top energy in 2011, and during beam acceleration in 2012. Singular Value Decomposition (SVD) was employed to determine the strengths and currents of the applied corrections. The feedback algorithm was optimized for different magnetic configurations (lattices) at fixed beam energies and during beam acceleration. While the orbit feedback performed well since its inception, corrector current transients and feedback-induced beam oscillations were observed during the polarized proton program in 2015. In this paper, wemore » present the feedback algorithm, the optimization of the algorithm for various lattices and the solution adopted to mitigate the observed current transients during beam acceleration.« less

Vlasov analysis of microbunching instability for magnetized beams

DOE PAGES

Tsai, C. -Y.; Derbenev, Ya. S.; Douglas, D.; ...

2017-05-19

For a high-brightness electron beam with low energy and high bunch charge traversing a recirculation beamline, coherent synchrotron radiation and space charge effect may result in the microbunching instability (MBI). Both tracking simulation and Vlasov analysis for an early design of Circulator Cooler Ring for the Jefferson Lab Electron Ion Collider reveal significant MBI. It is envisioned these could be substantially suppressed by using a magnetized beam. In this work, we extend the existing Vlasov analysis, originally developed for a non-magnetized beam, to the description of transport of a magnetized beam including relevant collective effects. As a result, the newmore » formulation will be further employed to confirm prediction of microbunching suppression for a magnetized beam transport in a recirculating machine design.« less

Enabling Intensity and Energy Frontier Science with a Muon Accelerator Facility in the U.S.: A White Paper Submitted to the 2013 U.S. Community Summer Study of the Division of Particles and Fields of the American Physical Society

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delahaye, J-P.; Ankenbrandt, C.; Bogacz, A.

2013-08-01

A staged approach towards muon based facilities for Intensity and Energy Frontier science, building upon existing and proposed facilities at Fermilab, is presented. At each stage, a facility exploring new physics also provides an R&D platform to validate the technology needed for subsequent stages. The envisioned program begins with nuSTORM, a sensitive sterile neutrino search which also provides precision neutrino cross-section measurements while developing the technology of using and cooling muons. A staged Neutrino Factory based upon Project X, sending beams towards the Sanford Underground Research Facility (SURF), which will house the LBNE detector, could follow for detailed exploration ofmore » neutrino properties at the Intensity Frontier, while also establishing the technology of using intense bunched muon beams. The complex could then evolve towards Muon Colliders, starting at 126 GeV with measurements of the Higgs resonance to sub-MeV precision, and continuing to multi-TeV colliders for the exploration of physics beyond the Standard Model at the Energy Frontier. An Appendix addresses specific questions raised by the Lepton Colliders subgroup of the CSS2013 Frontier Capabilities Study Group.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, C. -Y.; Derbenev, Ya. S.; Douglas, D.

For a high-brightness electron beam with low energy and high bunch charge traversing a recirculation beamline, coherent synchrotron radiation and space charge effect may result in the microbunching instability (MBI). Both tracking simulation and Vlasov analysis for an early design of Circulator Cooler Ring for the Jefferson Lab Electron Ion Collider reveal significant MBI. It is envisioned these could be substantially suppressed by using a magnetized beam. In this work, we extend the existing Vlasov analysis, originally developed for a non-magnetized beam, to the description of transport of a magnetized beam including relevant collective effects. As a result, the newmore » formulation will be further employed to confirm prediction of microbunching suppression for a magnetized beam transport in a recirculating machine design.« less

Noise estimation of beam position monitors at RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, X.; Bai, M.; Lee, S. Y.

2014-02-10

Beam position monitors (BPM) are used to record the average orbits and transverse turn-by-turn displacements of the beam centroid motion. The Relativistic Hadron Ion Collider (RHIC) has 160 BPMs for each plane in each of the Blue and Yellow rings: 72 dual-plane BPMs in the insertion regions (IR) and 176 single-plane modules in the arcs. Each BPM is able to acquire 1024 or 4096 consecutive turn-by-turn beam positions. Inevitably, there are broadband noisy signals in the turn-by-turn data due to BPM electronics as well as other sources. A detailed study of the BPM noise performance is critical for reliable opticsmore » measurement and beam dynamics analysis based on turn-by-turn data.« less

Rotating field mass and velocity analyzer

NASA Technical Reports Server (NTRS)

Smith, Steven Joel (Inventor); Chutjian, Ara (Inventor)

1998-01-01

A rotating field mass and velocity analyzer having a cell with four walls, time dependent RF potentials that are applied to each wall, and a detector. The time dependent RF potentials create an RF field in the cell which effectively rotates within the cell. An ion beam is accelerated into the cell and the rotating RF field disperses the incident ion beam according to the mass-to-charge (m/e) ratio and velocity distribution present in the ion beam. The ions of the beam either collide with the ion detector or deflect away from the ion detector, depending on the m/e, RF amplitude, and RF frequency. The detector counts the incident ions to determine the m/e and velocity distribution in the ion beam.

COLLIDE: Collisions into Dust Experiment

NASA Technical Reports Server (NTRS)

Colwell, Joshua E.

1999-01-01

The Collisions Into Dust Experiment (COLLIDE) was completed and flew on STS-90 in April and May of 1998. After the experiment was returned to Earth, the data and experiment were analyzed. Some anomalies occurred during the flight which prevented a complete set of data from being obtained. However, the experiment did meet its criteria for scientific success and returned surprising results on the outcomes of very low energy collisions into powder. The attached publication, "Low Velocity Microgravity Impact Experiments into Simulated Regolith," describes in detail the scientific background, engineering, and scientific results of COLLIDE. Our scientific conclusions, along with a summary of the anomalies which occurred during flight, are contained in that publication. We offer it as our final report on this grant.

REPORT OF THE SNOWMASS M6 WORKING GROUP ON HIGH INTENSITY PROTON SOURCES.

DOE Office of Scientific and Technical Information (OSTI.GOV)

CHOU,W.; WEI,J.

The M6 working group had more than 40 active participants (listed in Section 4). During the three weeks at Snowmass, there were about 50 presentations, covering a wide range of topics associated with high intensity proton sources. The talks are listed in Section 5. This group also had joint sessions with a number of other working groups, including E1 (Neutrino Factories and Muon Colliders), E5 (Fixed-Target Experiments), M1 (Muon Based Systems), T4 (Particle Sources), T5 (Beam dynamics), T7 (High Performance Computing) and T9 (Diagnostics). The M6 group performed a survey of the beam parameters of existing and proposed high intensitymore » proton sources, in particular, of the proton drivers. The results are listed in Table 1. These parameters are compared with the requirements of high-energy physics users of secondary beams in Working Groups E1 and E5. According to the consensus reached in the E1 and E5 groups, the U.S. HEP program requires an intense proton source, a 1-4 MW Proton Driver, by the end of this decade.« less

List of Posters

NASA Astrophysics Data System (ADS)

List of Posters: Dark matter annihilation in the Galactic galo, by Dokuchaev Vyacheslav, et al. NEMO developments towards km3 telescope in the Mediterranean Sea. The NEMO project. Neutrino Mediterranean Observatory By Antonio Capone, NEMO Collaboration. Alignment as a result from QCD jet production or new still unknown physics at LHC? By Alexander Snigirev. Small-scale fluctuations of extensive air showers: systematics in energy and muon density estimation By Grigory Rubtsov. SHINIE: Simulation of High-Energy Neutrino Interacting with the Earth By Lin Guey-Lin, et al.. Thermodynamics of rotating solutions in n+1 dimensional Einstein - Maxwell -dilation gravity By Ahmad Sheykhi, et al.. Supernova neutrino physics with future large Cherenkov detectors By Daniele Montanino. Crossing of the Cosmological Constant Barrier in the string Inspired Dark Energy Model By S. Yu. Vernov. Calculations of radio signals produced by ultra-high and extremely high energy neutrino induced cascades in Antarctic ice By D. Besson, et al.. Inflation, Cosmic Acceleration and string Gravity By Ischwaree Neupane. Neutrino Physics: Charm and J/Psi production in the atmosphere By Liudmila Volkova. Three generation flavor transitions and decays of supernova relic neutrinos By Daniele Montanino. Lattice calculations & computational quantum field theory: Sonification of Quark and Baryon Spectra By Markum Harald, et al.. Generalized Kramers-Wannier Duality for spin systems with non-commutative symmetry By V. M. Buchstaber, et al.. Heavy ion collisions & quark matter: Nuclear matter jets and multifragmentation By Danut Argintaru, et al.. QCD hard interactions: The qT-spectrum of the Higgs and Slepton-pairs at the LHC By Guiseppe Bozzi. QCD soft interactions: Nonperturbative effects in Single-Spin Asymmetries: Instantons and TMD-parton distributions By Igor Cherednikov, et al.. Gluon dominance model and high multiplicity By Elena Kokoulina. Resonances in eta pi- pi- pi+ system By Dmitry Ryabchikov. Saturation effects in diffractive scattering at LHC By Oleg Selugin. A nonperturbative expansion method in QCD and R-related quantities By Igor Solovtsov. Z-scaling and high multiplicity particle Production in bar pp/pp & AA collisions at Tevatron and RHIC By Mikhail Tokarev. Scaling behaviour of the reactionsdd - > p↑ /3H and pd - > pd with pT at energy I-2 GeV By Yuri Uzikov. [ADS Note: Title formula can not be rendered correctly in ASCII.] CP violation, rare decays, CKM: Precision Measurements of the Mass of the Top Quark at CDF (Precision Top Mass Measurements at CDF) By Daniel Whiteson. Measurement of the Bs Oscillation at CDF By Luciano Ristori. The Bs mixing phase at LHCb By J. J. van Hunen. ATLAS preparations for precise measurements of semileptonic rare B decays By K. Toms. Hadron spectroscopy & exotics: Searches for radial excited states of charmonium in experiments using cooled antiproton beams By M. Yu. Barabanov. Retardation effects in the rotating string model By Fabien Buisseret and Claude Semay. Final results from VEPP-2M (CMD-2 and SND) By G. V. Fedotovich. Heavy Quark Physics: Prospects for B physics measurements using the CMS detector at the LHC By Andreev Valery. Heavy flavour production at HERA-B By Andrey Bogatyrev. B-Meson subleading form factors in the Heavy Quark Effective Theory (HQET) By Frederic Jugeau. Beyond the Standard Model: Monopole Decay in a Variable External Field By Andrey Zayakin. Two-Loop matching coefficients for the strong coupling in the MSSM By Mihaila Luminita. Test of lepton flavour violation at LHC By Hidaka Keisho. Looking at New Physics through 4 jets and no ET By Maity Manas. Are Preons Dyons? Naturalness of Three Generations By Das Chitta Ranjan. SUSY Dark Matter at Linear Collider By Sezen Sekmen, Mehmet Zeyrek. MSSM light Higgs boson scenario and its test at hadron colliders By Alexander Belyaev. Antiscalar Approach to Gravity and Standard Model By E. Mychelkin. GRID distributed analysis in high energy physics: PAX: Physics Analysis Design and Application on the GRID By Martin Erdmann, et al.. D0 and the (SAM) GRID: An ongoing success story DO Collaboration. R & D for future accelerators, detectors & new facilities: High Level Trigger Selection in the CMS experiment By Monica Vazquez Acosta. R&D for a Helical Undulator Based Positron Source for the International Linear Collider By Phil Allport. Muon Detection, Reconstruction and Identification in CMS By Ivan Belotelov. Acoustic Measurements for EeV Neutrino Detection at the South Pole By Sebastian Böser. The PSI source of ultracold neutrons (UCN) By Manfred Daum. The LHCb Pixel Hybrid Photon Detectors (Characterization of Nybrig Photon Detectors for the LHCb experiment) By Neville Harnew, et al.. Semi-Insulating GaN-radiation hard semiconductor for ionizing radiation detectors By Juozas Vaitkus. Monitored Drift Tube end-cap spectrometer for the ATLAS detector By Dmitri Kotchetkov. Development of Focusing Aerogel RICH By Sergey Kononov, et al.. Electromagnetic Calibration of the Hadronic Tile Calorimeter Modules of the ATLAS detector at the LHC By Iouri Koultchitski. A Study of Proximity focusing RICH with Multiple Refractive Index Aerogel Radiator By Peter Krizan. The Heavy Flavor Tracker (HFT) for STAR By Vasil Kuspil. ATLAS Liquid Argon Calorimeter ATLAS Collaboration: Field Emission in HEP Colliders Initiated by a Relativistic Positively Charged Bunch of Particles By Boris Levchenko. MICE: the international Muon Ionization Cooling Experiment By Kenneth Long. In situ calibration of the CMS electromagnetic calorimeter By Augustino Lorenzo. The Transition Radiation Tracker for the ATLAS experiment at the LHC By Victor Maleev. Resonance depolarization and Compton-Backscattering technique for beam energy measurement of VEPP-4M collider By Ivan Nikolaev, et al.. CCD - based Pixel Detectors by LCFI By Andrei Nomerotski. The SiD Detector Concept for the International Linear Collider By Dmitry Onoprienko. CMS Hadron Calorimetry, Calibration, and Jets/Missing Transverse Energy Measurements By Sergey Petrushanko. The CMS Silicon Tracker By Oliver Pooth. Drift Chamber for CMD-3 detector By Alexandr Popov, et al.. Vacuum Phototriods for the CMS ECAL Endcap crystal calorimeter By Vladimir Postoev. CMS Silicon Tracker: Track Reconstruction and Alignment By Frank-Peter Schilling. eRHIC - A precision electron-proton/ion collider facility at Brookhaven National Laboratory By Bernd Surrow. Development of tracking detectors with industrially produced GEM foils By Bernd Surrow, et al.. A Linear Collider Facility with High Intensity e+e- beams (A high intensity e+e- Linear Collider Facility at low energy) By Andre Schoening. Construction of the BESIII detector for tau-charm physics By Yifang Wang. The HERMES Recoil Detector By Sergey Yashchenko. Simulation of MICE in G4 MICE MICE Experiment: The new DO Layer O silicon detector The DO trigger upgrade for RUNIIb The Do Collaboration. Operational experiences with the silicon detector at CDF By Jeannine Wagner. Mathematical aspects of QFT & string theory: Electron in superstrong Coulomb field By D. Gitman. Stability of a non-commutative Jackiw-Teitelboim gravity By Fresneda Rodrigo, et al.. 4d gravity localized on thick branes: the complete mass spectrum By Alfredo Herrera-Aguilar. On Emergence of Quantum Mechanics By L. V. Prokhorov.

TRANSIENT BEAM LOADING EFFECTS IN RF SYSTEMS IN JLEIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Haipeng; Guo, Jiquan; Rimmer, Robert A.

2016-05-01

The pulsed electron bunch trains generated from the Continuous Electron Beam Accelerator Facility (CEBAF) linac to inject into the proposed Jefferson Lab Electron Ion Collider (JLEIC) e-ring will produce transient beam loading effects in the Superconducting Radio Frequency (SRF) systems that, if not mitigated, could cause unacceptably large beam energy deviation in the injection capture, or exceed the energy acceptance of CEBAF’s recirculating arcs. In the electron storage ring, the beam abort or ion clearing gaps or uneven bucket filling can cause large beam phase transients in the (S)RF cavity control systems and even beam loss due to Robinson instability.more » We have first analysed the beam stability criteria in steady state and estimated the transient effect in Feedforward and Feedback RF controls. Initial analytical models for these effects are shown for the design of the JLEIC e-ring from 3GeV to 12GeV.« less

HUNTING THE QUARK GLUON PLASMA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

LUDLAM, T.; ARONSON, S.

2005-04-11

The U.S. Department of Energy's Relativistic Heavy Ion Collider (RHIC) construction project was completed at BNL in 1999, with the first data-taking runs in the summer of 2000. Since then the early measurements at RHIC have yielded a wealth of data, from four independent detectors, each with its international collaboration of scientists: BRAHMS, PHENIX, PHOBOS, and STAR [1]. For the first time, collisions of heavy nuclei have been carried out at colliding-beam energies that have previously been accessible only for high-energy physics experiments with collisions of ''elementary'' particles such as protons and electrons. It is at these high energies thatmore » the predictions of quantum chromodynamics (QCD), the fundamental theory that describes the role of quarks and gluons in nuclear matter, come into play, and new phenomena are sought that may illuminate our view of the basic structure of matter on the sub-atomic scale, with important implications for the origins of matter on the cosmic scale. The RHIC experiments have recorded data from collisions of gold nuclei at the highest energies ever achieved in man-made particle accelerators. These collisions, of which hundreds of millions have now been examined, result in final states of unprecedented complexity, with thousands of produced particles radiating from the nuclear collision. All four of the RHIC experiments have moved quickly to analyze these data, and have begun to understand the phenomena that unfold from the moment of collision as these particles are produced. In order to provide benchmarks of simpler interactions against which to compare the gold-gold collisions, the experiments have gathered comparable samples of data from collisions of a very light nucleus (deuterium) with gold nuclei, as well as proton-proton collisions, all with identical beam energies and experimental apparatus. The early measurements have revealed compelling evidence for the existence of a new form of nuclear matter at extremely high density and temperature--a medium in which the predictions of QCD can be tested, and new phenomena explored, under conditions where the relevant degrees of freedom, over nuclear volumes, are expected to be those of quarks and gluons, rather than of hadrons. This is the realm of the quark gluon plasma, the predicted state of matter whose existence and properties are now being explored by the RHIC experiments.« less

Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simos, N.; Zhong, Z.; Ghose, S.

Here, a comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have beenmore » studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10 20 p/cm 2. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF) selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (~5×10 18 p cm -2). In addition, the studied MoGRCF compound grade suffered a high degree of structural degradation while being irradiated in a vacuum after a fluence ~5×10 20 p cm -2. Finally, x-ray diffraction studies on irradiated C/C composites and a carbon-fiber-reinforced Mo-graphite compound revealed (a) low graphitization in the “as-received” 3D C/C and high graphitization in the MoGRCF compound, (b) irradiation-induced graphitization of the least crystallized phases in the carbon fibers of the 2D and 3D C/C composites, (c) increased interplanar distances along the c axis of the graphite crystal with increasing fluence, and (d) coalescence of interstitial clusters after irradiation forming new crystalline planes between basal planes and excellent agreement with fast neutron irradiation effects.« less

Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

DOE PAGES

Simos, N.; Zhong, Z.; Ghose, S.; ...

2016-11-16

Here, a comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have beenmore » studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10 20 p/cm 2. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF) selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (~5×10 18 p cm -2). In addition, the studied MoGRCF compound grade suffered a high degree of structural degradation while being irradiated in a vacuum after a fluence ~5×10 20 p cm -2. Finally, x-ray diffraction studies on irradiated C/C composites and a carbon-fiber-reinforced Mo-graphite compound revealed (a) low graphitization in the “as-received” 3D C/C and high graphitization in the MoGRCF compound, (b) irradiation-induced graphitization of the least crystallized phases in the carbon fibers of the 2D and 3D C/C composites, (c) increased interplanar distances along the c axis of the graphite crystal with increasing fluence, and (d) coalescence of interstitial clusters after irradiation forming new crystalline planes between basal planes and excellent agreement with fast neutron irradiation effects.« less

Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

NASA Astrophysics Data System (ADS)

Simos, N.; Zhong, Z.; Ghose, S.; Kirk, H. G.; Trung, L.-P.; McDonald, K. T.; Kotsina, Z.; Nocera, P.; Assmann, R.; Redaelli, S.; Bertarelli, A.; Quaranta, E.; Rossi, A.; Zwaska, R.; Ammigan, K.; Hurh, P.; Mokhov, N.

2016-11-01

A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have been studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5 ×1020 p /cm2 . The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF) selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (˜5 ×1018 p cm-2 ). In addition, the studied MoGRCF compound grade suffered a high degree of structural degradation while being irradiated in a vacuum after a fluence ˜5 ×1020 p cm-2 . Finally, x-ray diffraction studies on irradiated C/C composites and a carbon-fiber-reinforced Mo-graphite compound revealed (a) low graphitization in the "as-received" 3D C/C and high graphitization in the MoGRCF compound, (b) irradiation-induced graphitization of the least crystallized phases in the carbon fibers of the 2D and 3D C/C composites, (c) increased interplanar distances along the c axis of the graphite crystal with increasing fluence, and (d) coalescence of interstitial clusters after irradiation forming new crystalline planes between basal planes and excellent agreement with fast neutron irradiation effects.

Analyses of 476 MHz and 952 MHz Crab Cavities for JLAB Electron Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, HyeKyoung; Castilla, Alejandro; Delayen, Jean R.

2016-05-01

The Center for Accelerator Science at Old Dominion University has designed, fabricated and successfully tested a crab cavity for Electron Ion Collider at Jefferson Lab (JLEIC) [1]. This proof-of-principle cavity was based on the earlier MEIC design which used 748.5 MHz RF system. The updated JLEIC (called MEIC earlier) design [2] utilizes the components from PEP-II. It results in the change on the bunch repetition rate of stored beam to 476.3 MHz. The ion ring collider will eventually require 952.6 MHz crab cavities. This paper will present the analyses of crab cavities of both 476 MHz and 952 MHz options.more » It compares advantages and disadvantages of the options which provide the JLEIC design team important technical information for a system down selection.« less

Anomaly Detection for Beam Loss Maps in the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Bruce, Roderik; Redaelli, Stefano; Rossi, Roberto; Theodoropoulos, Panagiotis; Jaster-Merz, Sonja

2017-07-01

In the LHC, beam loss maps are used to validate collimator settings for cleaning and machine protection. This is done by monitoring the loss distribution in the ring during infrequent controlled loss map campaigns, as well as in standard operation. Due to the complexity of the system, consisting of more than 50 collimators per beam, it is difficult to identify small changes in the collimation hierarchy, which may be due to setting errors or beam orbit drifts with such methods. A technique based on Principal Component Analysis and Local Outlier Factor is presented to detect anomalies in the loss maps and therefore provide an automatic check of the collimation hierarchy.

Cavity beam position monitor system for the Accelerator Test Facility 2

NASA Astrophysics Data System (ADS)

Kim, Y. I.; Ainsworth, R.; Aryshev, A.; Boogert, S. T.; Boorman, G.; Frisch, J.; Heo, A.; Honda, Y.; Hwang, W. H.; Huang, J. Y.; Kim, E.-S.; Kim, S. H.; Lyapin, A.; Naito, T.; May, J.; McCormick, D.; Mellor, R. E.; Molloy, S.; Nelson, J.; Park, S. J.; Park, Y. J.; Ross, M.; Shin, S.; Swinson, C.; Smith, T.; Terunuma, N.; Tauchi, T.; Urakawa, J.; White, G. R.

2012-04-01

The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1μm for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.

The Physics of Beams: The Andrew Sessler Symposium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barletta, W.A.

1996-03-01

These proceedings represent papers presented at the Andrew Sessler Symposium held at the Lawrence Berkeley National Laboratory in honor of Andrew Sessler{close_quote}s over forty years of major scientific contributions to accelerator and beam physics as well as in celebration of his 65th birthday. The symposium was sponsored by the United States Department of Energy. The topics discussed include linear colliders, past history and future speculations, ELOISATRON at 100 TeV beam, manipulating charged particle beams by means of plasma and collective instabilities in accelerator and storage rings. There were 10 papers presented and 8 have been abstracted for the Energy Sciencemore » and Technology database.(AIP)« less

Conceptual Design for CLIC Gun Pulser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Tao

The Compact Linear Collider (CLIC) is a proposed future electron-positron collider, designed to perform collisions at energies from 0.5 to 5 TeV, with a nominal design optimized for 3 TeV (Dannheim, 2012). The Drive Beam Accelerator consists of a thermionic DC gun, bunching section and an accelerating section. The thermionic gun needs deliver a long (~143us) pulse of current into the buncher. A pulser is needed to drive grid of the gun to generate a stable current output. This report explores the requirements of the gun pulser and potential solutions to regulate grid current.

Thermal issues at the SSC

NASA Technical Reports Server (NTRS)

Ranganathan, Raj P.; Dao, Bui V.

1992-01-01

A variety of heat transfer problems arise in the design of the Superconducting Super Collider (SSC). One class of problems is to minimize heat leak from the ambient to the SSC rings, since the rings contain superconducting magnets maintained at a temperature of 4 K. Another arises from the need to dump the beam of protrons (traveling around the SSC rings) on to absorbers during an abort of the collider. Yet another category of problems is the cooling of equipment to dissipate the heat generated during operation. An overview of these problems and sample heat transfer results are given in this paper.

MEIC electron cooling program

DOE PAGES

Derbenev, Yaroslav S.; Zhang, Yuhong

2014-12-01

Cooling of proton and ion beams is essential for achieving high luminosities (up to above 10 34 cm -2s -1) for MEIC, a Medium energy Electron-Ion Collider envisioned at JLab [1] for advanced nuclear science research. In the present conceptual design, we utilize the conventional election cooling method and adopted a multi-staged cooling scheme for reduction of and maintaining low beam emittances [2,3,4]. Two electron cooling facilities are required to support the scheme: one is a low energy (up to 2 MeV) DC cooler installed in the MEIC ion pre-booster (with the proton kinetic energy up to 3 GeV); themore » other is a high electron energy (up to 55 MeV) cooler in the collider ring (with the proton kinetic energy from 25 to 100 GeV). The high energy cooler, which is based on the ERL technology and a circulator ring, utilizes a bunched electron beam to cool bunched proton or ion beams. To complete the MEIC cooling concept and a technical design of the ERL cooler as well as to develop supporting technologies, an R&D program has been initiated at Jefferson Lab and significant progresses have been made since then. In this study, we present a brief description of the cooler design and a summary of the progress in this cooling R&D.« less

Energy dependence of polarization across broad deexcitation gamma-ray line profiles

NASA Astrophysics Data System (ADS)

Werntz, Carl; Lang, F. L.

1998-04-01

The energy profiles of deexcitation gamma-ray lines from recoiling inelastically scattered nuclei exhibit detailed structure. MeV-wide gamma-ray lines from the direction of the Orion nebula have been detected (H. Bloemen, et al., Astr. and Astrophys. L5, 281 (1994).) by COMPTEL whose source is postulated to be cosmic ray carbon and oxygen nuclei shock accelerated near supernova remnants colliding with ambient hydrogen and helium. Even when the heavy ion velocity distributions are isotropic, structure characteristic of the multipolarity of the gamma transition remains (A. M. Bykov et al, Astr. and Astrophys. 607, L37 (1996); B. Kozlovsky et al, Astrophys. J. 484, (1997).). In experiments in which the energy dependent structure of the deexcitation gamma-ray profiles is not resolved, the gammas display a high degree of linear polarization that rapidly changes with gamma-beam angle. We calculate the polarization, both linear and circular, as a function of gamma-ray energy across the laboratory line profiles of C12*(4.44) and O16*(6.13) inelastically excited by protons and alphas. We then investigate the polarization in the surviving structures for isotropic energetic ions colliding with ^1H and ^4He.

Transverse profile of the electron beam for the RHIC electron lenses

DOE PAGES

Gu, X.; Altinbas, Z.; Costanzo, M.; ...

2015-07-10

To compensate for the beam-beam effects from the proton-proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for bothmore » the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an Yttrium Aluminum Garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage.« less

Ion Motion Induced Emittance Growth of Matched Electron Beams in Plasma Wakefields.

PubMed

An, Weiming; Lu, Wei; Huang, Chengkun; Xu, Xinlu; Hogan, Mark J; Joshi, Chan; Mori, Warren B

2017-06-16

Plasma-based acceleration is being considered as the basis for building a future linear collider. Nonlinear plasma wakefields have ideal properties for accelerating and focusing electron beams. Preservation of the emittance of nano-Coulomb beams with nanometer scale matched spot sizes in these wakefields remains a critical issue due to ion motion caused by their large space charge forces. We use fully resolved quasistatic particle-in-cell simulations of electron beams in hydrogen and lithium plasmas, including when the accelerated beam has different emittances in the two transverse planes. The projected emittance initially grows and rapidly saturates with a maximum emittance growth of less than 80% in hydrogen and 20% in lithium. The use of overfocused beams is found to dramatically reduce the emittance growth. The underlying physics that leads to the lower than expected emittance growth is elucidated.

Studies of beam position monitor stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tenenbaum, P.

1998-05-01

The authors present the results from two studies of the time stability between the mechanical center of a beam position monitor and its electrical/electronic center. In the first study, a group of 93 BPM processors was calibrated via Test Pulse Generator once per hour in order to measure the contribution of the readout electronics to offset drifts. In the second study, a triplet of stripline BPMs in the Final Focus Test Beam, separated only by drift spaces, was read out every 6 minutes during 1 week of beam operation. In both cases offset stability was observed to be on themore » order of microns over time spans ranging from hours to days, although during the beam study much worse performance was also observed. Implications for the beam position monitor system of future linear collider systems are discussed.« less

Landau Damping of Beam Instabilities by Electron Lenses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiltsev, V.; Alexahin, Yuri; Burov, A.

2017-06-26

Modern and future particle accelerators employ increasingly higher intensity and brighter beams of charged particles and become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, beam feedback dampers and use of chromatic effects, become less effective and insufficient. We show that, in contrast, Lorentz forces of a low-energy, a magnetically stabilized electron beam, or "electron lens", easily introduces transverse nonlinear focusing sufficient for Landau damping of transverse beam instabilities in accelerators. It is also important that, unlike other nonlinear elements, the electron lens provides the frequency spread mainly at the beam core,more » thus allowing much higher frequency spread without lifetime degradation. For the parameters of the Future Circular Collider, a single conventional electron lens a few meters long would provide stabilization superior to tens of thousands of superconducting octupole magnets.« less

Three dimensional δf simulations of beams in the SSC

NASA Astrophysics Data System (ADS)

Koga, J.; Tajima, T.; Machida, S.

1993-12-01

A three dimensional δf strong-strong algorithm has been developed to apply to the study of such effects as space charge and beam-beam interaction phenomena in the Superconducting Super Collider (SSC). The algorithm is obtained from the merging of the particle tracking code Simpsons used for 3 dimensional space charge effects and a δf code. The δf method is used to follow the evolution of the non-gaussian part of the beam distribution. The advantages of this method are twofold. First, the Simpsons code utilizes a realistic accelerator model including synchrotron oscillations and energy ramping in 6 dimensional phase space with electromagnetic fields of the beams calculated using a realistic 3 dimensional field solver. Second, the beams are evolving in the fully self-consistent strong-strong sense with finite particle fluctuation noise is greatly reduced as opposed to the weak-strong models where one beam is fixed.

Landau Damping of Beam Instabilities by Electron Lenses

DOE PAGES

Shiltsev, V.; Alexahin, Yuri; Burov, A.; ...

2017-09-27

Modern and future particle accelerators employ increasingly higher intensity and brighter beams of charged particles and become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, beam feedback dampers, and use of chromatic effects, become less effective and insufficient. Here, we show that, in contrast, Lorentz forces of a low-energy, magnetically stabilized electron beam, or “electron lens,” easily introduce transverse nonlinear focusing sufficient for Landau damping of transverse beam instabilities in accelerators. It is also important to note that, unlike other nonlinear elements, the electron lens provides the frequency spread mainly at themore » beam core, thus allowing much higher frequency spread without lifetime degradation. For the parameters of the Future Circular Collider, a single conventional electron lens a few meters long would provide stabilization superior to tens of thousands of superconducting octupole magnets.« less

High-intensity polarized H- ion source for the RHIC SPIN physics

NASA Astrophysics Data System (ADS)

Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Kolmogorov, A.; Davydenko, V.

2017-08-01

A novel polarization technique had been successfully implemented for the RHIC polarized H- ion source upgrade to higher intensity and polarization. In this technique a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. The use of high-brightness primary beam and large cross-sections of charge-exchange cross-sections resulted in production of high intensity H- ion beam of 85% polarization. High beam brightness and polarization resulted in 75% polarization at 23 GeV out of AGS and 60-65% beam polarization at 100-250 GeV colliding beams in RHIC. The status of un-polarized magnetron type (Cs-vapour loaded) BNL source is also discussed.

Impedance computations and beam-based measurements: A problem of discrepancy

NASA Astrophysics Data System (ADS)

Smaluk, Victor

2018-04-01

High intensity of particle beams is crucial for high-performance operation of modern electron-positron storage rings, both colliders and light sources. The beam intensity is limited by the interaction of the beam with self-induced electromagnetic fields (wake fields) proportional to the vacuum chamber impedance. For a new accelerator project, the total broadband impedance is computed by element-wise wake-field simulations using computer codes. For a machine in operation, the impedance can be measured experimentally using beam-based techniques. In this article, a comparative analysis of impedance computations and beam-based measurements is presented for 15 electron-positron storage rings. The measured data and the predictions based on the computed impedance budgets show a significant discrepancy. Three possible reasons for the discrepancy are discussed: interference of the wake fields excited by a beam in adjacent components of the vacuum chamber, effect of computation mesh size, and effect of insufficient bandwidth of the computed impedance.

Successive approximation algorithm for beam-position-monitor-based LHC collimator alignment

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Nosych, Andriy A.; Bruce, Roderik; Gasior, Marek; Mirarchi, Daniele; Redaelli, Stefano; Salvachua, Belen; Wollmann, Daniel

2014-02-01

Collimators with embedded beam position monitor (BPM) button electrodes will be installed in the Large Hadron Collider (LHC) during the current long shutdown period. For the subsequent operation, BPMs will allow the collimator jaws to be kept centered around the beam orbit. In this manner, a better beam cleaning efficiency and machine protection can be provided at unprecedented higher beam energies and intensities. A collimator alignment algorithm is proposed to center the jaws automatically around the beam. The algorithm is based on successive approximation and takes into account a correction of the nonlinear BPM sensitivity to beam displacement and an asymmetry of the electronic channels processing the BPM electrode signals. A software implementation was tested with a prototype collimator in the Super Proton Synchrotron. This paper presents results of the tests along with some considerations for eventual operation in the LHC.

Relativistic Hydrodynamics for Heavy-Ion Collisions

ERIC Educational Resources Information Center

Ollitrault, Jean-Yves

2008-01-01

Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…

Strong field QED in lepton colliders and electron/laser interactions

NASA Astrophysics Data System (ADS)

Hartin, Anthony

2018-05-01

The studies of strong field particle physics processes in electron/laser interactions and lepton collider interaction points (IPs) are reviewed. These processes are defined by the high intensity of the electromagnetic fields involved and the need to take them into account as fully as possible. Thus, the main theoretical framework considered is the Furry interaction picture within intense field quantum field theory. In this framework, the influence of a background electromagnetic field in the Lagrangian is calculated nonperturbatively, involving exact solutions for quantized charged particles in the background field. These “dressed” particles go on to interact perturbatively with other particles, enabling the background field to play both macroscopic and microscopic roles. Macroscopically, the background field starts to polarize the vacuum, in effect rendering it a dispersive medium. Particles encountering this dispersive vacuum obtain a lifetime, either radiating or decaying into pair particles at a rate dependent on the intensity of the background field. In fact, the intensity of the background field enters into the coupling constant of the strong field quantum electrodynamic Lagrangian, influencing all particle processes. A number of new phenomena occur. Particles gain an intensity-dependent rest mass shift that accounts for their presence in the dispersive vacuum. Multi-photon events involving more than one external field photon occur at each vertex. Higher order processes which exchange a virtual strong field particle resonate via the lifetimes of the unstable strong field states. Two main arenas of strong field physics are reviewed; those occurring in relativistic electron interactions with intense laser beams, and those occurring in the beam-beam physics at the interaction point of colliders. This review outlines the theory, describes its significant novel phenomenology and details the experimental schema required to detect strong field effects and the simulation programs required to model them.

The Web Based Monitoring Project at the CMS Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez-Perez, Juan Antonio; Badgett, William; Behrens, Ulf

The Compact Muon Solenoid is a large a complex general purpose experiment at the CERN Large Hadron Collider (LHC), built and maintained by many collaborators from around the world. Efficient operation of the detector requires widespread and timely access to a broad range of monitoring and status information. To the end the Web Based Monitoring (WBM) system was developed to present data to users located anywhere from many underlying heterogeneous sources, from real time messaging systems to relational databases. This system provides the power to combine and correlate data in both graphical and tabular formats of interest to the experimenters,more » including data such as beam conditions, luminosity, trigger rates, detector conditions, and many others, allowing for flexibility on the user’s side. This paper describes the WBM system architecture and describes how the system has been used from the beginning of data taking until now (Run1 and Run 2).« less

The web based monitoring project at the CMS experiment

NASA Astrophysics Data System (ADS)

Lopez-Perez, Juan Antonio; Badgett, William; Behrens, Ulf; Chakaberia, Irakli; Jo, Youngkwon; Maeshima, Kaori; Maruyama, Sho; Patrick, James; Rapsevicius, Valdas; Soha, Aron; Stankevicius, Mantas; Sulmanas, Balys; Toda, Sachiko; Wan, Zongru

2017-10-01

The Compact Muon Solenoid is a large a complex general purpose experiment at the CERN Large Hadron Collider (LHC), built and maintained by many collaborators from around the world. Efficient operation of the detector requires widespread and timely access to a broad range of monitoring and status information. To that end the Web Based Monitoring (WBM) system was developed to present data to users located anywhere from many underlying heterogeneous sources, from real time messaging systems to relational databases. This system provides the power to combine and correlate data in both graphical and tabular formats of interest to the experimenters, including data such as beam conditions, luminosity, trigger rates, detector conditions, and many others, allowing for flexibility on the user’s side. This paper describes the WBM system architecture and describes how the system has been used from the beginning of data taking until now (Run1 and Run 2).

Web Based Monitoring in the CMS Experiment at CERN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Badgett, William; Borrello, Laura; Chakaberia, Irakli

2014-09-03

The Compact Muon Solenoid (CMS) is a large and complex general purpose experiment at the CERN Large Hadron Collider (LHC), built and maintained by many collaborators from around the world. Efficient operation of the detector requires widespread and timely access to a broad range of monitoring and status information. To this end the Web Based Monitoring (WBM) system was developed to present data to users located anywhere from many underlying heterogeneous sources, from real time messaging systems to relational databases. This system provides the power to combine and correlate data in both graphical and tabular formats of interest to themore » experimenters, including data such as beam conditions, luminosity, trigger rates, detector conditions, and many others, allowing for flexibility on the user side. This paper describes the WBM system architecture and describes how the system was used during the first major data taking run of the LHC.« less

Final Report for U.S. DOE GRANT No. DEFG02-96ER41015 November 1, 2010 - April 30, 2013 entitled HIGH ENERGY ACCELERATOR AND COLLIDING BEAM USER GROUP at the UNIVERSITY of MARYLAND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadley, Nicholas; Jawahery, Abolhassan; Eno, Sarah C

2013-07-26

We have finished the third year of a three year grant cycle with the U.S. Department of Energy for which we were given a five month extension (U.S. D.O.E. Grant No. DEFG02-96ER41015). This document is the fi nal report for this grant and covers the period from November 1, 2010 to April 30, 2013. The Maryland program is administered as a single task with Professor Nicholas Hadley as Principal Investigator. The Maryland experimental HEP group is focused on two major research areas. We are members of the CMS experiment at the LHC at CERN working on the physics of themore » Energy Frontier. We are also analyzing the data from the Babar experiment at SLAC while doing design work and R&D towards a Super B experiment as part of the Intensity Frontier. We have recently joined the LHCb experiment at CERN. We concluded our activities on the D experiment at Fermilab in 2009.« less

Development of movable mask system to cope with high beam current

NASA Astrophysics Data System (ADS)

Suetsugu, Y.; Shibata, K.; Sanami, T.; Kageyama, T.; Takeuchi, Y.

2003-07-01

The KEK B factory (KEKB), a high current electron-positron collider, has a movable mask (or collimator) system to reduce the background noise in the BELLE detector coming from spent particles. The early movable masks, however, had severe problems of heating, arcing, and vacuum leaks over the stored beam current of several hundred mA. The cause is intense trapped higher order modes (HOMs) excited at the mask head, where the cross section of the beam chamber changed drastically. The mask head, made of copper-tungsten alloy or pure copper, was frequently damaged by hitting of the high energy beam at the same time. Since the problems of the mask were revealed, several kinds of improved masks have been designed employing rf technologies in dealing with the HOM and installed to the ring step by step. Much progress has come from adopting a trapped-mode free structure, where the mask was a bent chamber itself. Recently the further improved mask with a reduced HOM design or HOM dampers was developed to suppress the heating of vacuum components near the mask due to the HOM traveling from the mask. To avoid damage to the mask head, on the other hand, a titanium mask head was tried. The latest masks are working as expected now at the stored beam current of 1.5 A. Presented are the problems and experiences on the movable mask system for the KEKB, which are characteristic of and common in a high intensity accelerator.

Studies for a Dedicated B Detector at the Fermilab Collider

NASA Astrophysics Data System (ADS)

McBride, Patricia

1996-06-01

The observation of CP violation in the B system is one of the great experimental challenges of the next decade. Several B factories are already planned, however, there will be many interesting measurements awaiting a second generation of B exeriments. Studies are being carried out to design a dedicated collider B experiment for the Tevatron at Fermilab. A dedicated B detector at a hadron collider will have a physics reach beyond that of experiments scheduled to begin operation before the end of the decade.

Delivering the world's most intense muon beam

NASA Astrophysics Data System (ADS)

Cook, S.; D'Arcy, R.; Edmonds, A.; Fukuda, M.; Hatanaka, K.; Hino, Y.; Kuno, Y.; Lancaster, M.; Mori, Y.; Ogitsu, T.; Sakamoto, H.; Sato, A.; Tran, N. H.; Truong, N. M.; Wing, M.; Yamamoto, A.; Yoshida, M.

2017-03-01

A new muon beam line, the muon science innovative channel, was set up at the Research Center for Nuclear Physics, Osaka University, in Osaka, Japan, using the 392 MeV proton beam impinging on a target. The production of an intense muon beam relies on the efficient capture of pions, which subsequently decay to muons, using a novel superconducting solenoid magnet system. After the pion-capture solenoid, the first 36° of the curved muon transport line was commissioned and the muon flux was measured. In order to detect muons, a target of either copper or magnesium was placed to stop muons at the end of the muon beam line. Two stations of plastic scintillators located upstream and downstream from the muon target were used to reconstruct the decay spectrum of muons. In a complementary method to detect negatively charged muons, the x-ray spectrum yielded by muonic atoms in the target was measured in a germanium detector. Measurements, at a proton beam current of 6 pA, yielded (10.4 ±2.7 )×1 05 muons per watt of proton beam power (μ+ and μ-), far in excess of other facilities. At full beam power (400 W), this implies a rate of muons of (4.2 ±1.1 )×1 08 muons s-1 , among the highest in the world. The number of μ- measured was about a factor of 10 lower, again by far the most efficient muon beam produced. The setup is a prototype for future experiments requiring a high-intensity muon beam, such as a muon collider or neutrino factory, or the search for rare muon decays which would be a signature for phenomena beyond the Standard Model of particle physics. Such a muon beam can also be used in other branches of physics, nuclear and condensed matter, as well as other areas of scientific research.

Studies of electron cooling at DESY

NASA Astrophysics Data System (ADS)

Balewski, K.; Brinkmann, R.; Derbenev, Y.; Floettmann, K.; Wesolowski, P.; Gentner, M.; Husmann, D.; Steier, C.

2000-02-01

A possibility to improve the luminosity in hadron colliders is to apply electron cooling. For the e-p and possibly in the future for e-ion a cooling scheme is proposed for the HERA collider which improves the brightness of the hadron beam in two steps. In a first step the hadron beam is cooled at an energy of 15-20 GeV in the pre-accelerator PETRA. In a second step the hadrons are cooled at top energy in HERA, mainly to maintain the beam quality. The first part of the cooler in PETRA consists of a thermionic gun which delivers electron bunches of 120 keV. These bunches are then compressed so that they fit into a 208 MHz travelling wave linac where they are accelerated to an energy of 10 MeV. Gun, compressor, and linac are surrounded by a solenoid so that emittance growth is avoided especially at the low energy end. In order to reduce the energy spread of the electron beam and to lengthen it, the electrons run through a decompressor before they are brought together with the hadron beam in a 40 m long cooling section which is again surrounded by a solenoid. In this paper a schematic layout of the system will be presented and simulation results of the first part of the cooler will be shown. The cooler in HERA consists of a small electron storage ring with two long straight sections. It is shown that all requirements of such a ring running at an energy between 180 and 450 MeV can be met to fight emittance growth in case of light hadron beams (protons) and to cool heavy ions sufficiently fast.

Design of An 18 MW Beam Dump for 500 GeV Electron/Positron Beams at An ILC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amann, John; /SLAC; Arnold, Ray

This article presents a report on the progress made in designing 18 MW water based Beam Dumps for electrons or positrons for an International Linear Collider (ILC). Multi-dimensional technology issues have to be addressed for the successful design of the Beam Dump. They include calculations of power deposition by the high energy electron/positron beam bunch trains, computational fluid dynamic analysis of turbulent water flow, mechanical design, process flow analysis, hydrogen/oxygen recombiners, handling of radioactive 7Be and 3H, design of auxiliary equipment, provisions for accident scenarios, remote window exchanger, radiation shielding, etc. The progress made to date is summarized, the currentmore » status, and also the issues still to be addressed.« less

Simulation of PEP-II Accelerator Backgrounds Using TURTLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barlow, R.J.; Fieguth, T.; /SLAC

2006-02-15

We present studies of accelerator-induced backgrounds in the BaBar detector at the SLAC B-Factory, carried out using LPTURTLE, a modified version of the DECAY TURTLE simulation package. Lost-particle backgrounds in PEP-II are dominated by a combination of beam-gas bremstrahlung, beam-gas Coulomb scattering, radiative-Bhabha events and beam-beam blow-up. The radiation damage and detector occupancy caused by the associated electromagnetic shower debris can limit the usable luminosity. In order to understand and mitigate such backgrounds, we have performed a full program of beam-gas and luminosity-background simulations, that include the effects of the detector solenoidal field, detailed modeling of limiting apertures in bothmore » collider rings, and optimization of the betatron collimation scheme in the presence of large transverse tails.« less

Development of an S-band cavity Beam Position Monitor for ATF2

NASA Astrophysics Data System (ADS)

Heo, A.; Kim, E.-S.; Kim, H.; Son, D.; Honda, Y.; Tauchi, T.

2013-04-01

We have developed an S-band cavity Beam Position Monitor (BPM) in order to measure the position of an electron beam in the final focus area at ATF2, which is the test facility for the final focus design for the International Linear Collider (ILC). The lattice of the ILC Beam Delivery System (BDS) has been modified, requiring a larger physical aperture of 40 mm in the final focus area. The beam orbit measurement in this area is now covered with high resolution S-Band cavity BPMs. In this paper we summarize the design of the cavity BPM and the first experimental results. The calibration slopes were measured as 0.87 counts/μm in the x-coordinate direction and 1.16 counts/μm in the y-coordinate direction.

Summary of the Optics, IR, Injection, Operations, Reliability and Instrumentation Working Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wienands, U.; /SLAC; Funakoshi, Y.

2012-04-20

The facilities reported on are all in a fairly mature state of operation, as evidenced by the very detailed studies and correction schemes that all groups are working on. First- and higher-order aberrations are diagnosed and planned to be corrected. Very detailed beam measurements are done to get a global picture of the beam dynamics. More than other facilities the high-luminosity colliders are struggling with experimental background issues, mitigation of which is a permanent challenge. The working group dealt with a very wide rage of practical issues which limit performance of the machines and compared their techniques of operations andmore » their performance. We anticipate this to be a first attempt. In a future workshop in this series, we propose to attempt more fundamental comparisons of each machine, including design parameters. For example, DAPHNE and KEKB employ a finite crossing angle. The minimum value of {beta}*{sub y} attainable at KEKB seems to relate to this scheme. Effectiveness of compensation solenoids and turn-by-turn BPMs etc. should be examined in more detail. In the near future, CESR-C and VEPP-2000 will start their operation. We expect to hear important new experiences from these machines; in particular VEPP-2000 will be the first machine to have adopted round beams. At SLAC and KEK, next generation B Factories are being considered. It will be worthwhile to discuss the design issues of these machines based on the experiences of the existing factory machines.« less

Construction and response of a highly granular scintillator-based electromagnetic calorimeter

NASA Astrophysics Data System (ADS)

Repond, J.; Xia, L.; Eigen, G.; Price, T.; Watson, N. K.; Winter, A.; Thomson, M. A.; Cârloganu, C.; Blazey, G. C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Gadow, K.; Göttlicher, P.; Hartbrich, O.; Kotera, K.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Reinecke, M.; Sefkow, F.; Sudo, Y.; Tran, H. L.; Kaplan, A.; Schultz-Coulon, H.-Ch.; Bilki, B.; Northacker, D.; Onel, Y.; Wilson, G. W.; Kawagoe, K.; Sekiya, I.; Suehara, T.; Yamashiro, H.; Yoshioka, T.; Alamillo, E. Calvo; Fouz, M. C.; Marin, J.; Navarrete, J.; Pelayo, J. Puerta; Verdugo, A.; Chadeeva, M.; Danilov, M.; Gabriel, M.; Goecke, P.; Graf, C.; Israeli, Y.; Kolk, N. Van Der; Simon, F.; Szalay, M.; Windel, H.; Bilokin, S.; Bonis, J.; Pöschl, R.; Thiebault, A.; Richard, F.; Zerwas, D.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cornat, R.; Cvach, J.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Polak, I.; Smolik, J.; Vrba, V.; Zalesak, J.; Zuklin, J.; Choi, W.; Kotera, K.; Nishiyama, M.; Sakuma, T.; Takeshita, T.; Tozuka, S.; Tsubokawa, T.; Uozumi, S.; Jeans, D.; Ootani, W.; Liu, L.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Ikuno, T.; Sudo, Y.; Takahashi, Y.; Götze, M.; Calice Collaboration

2018-04-01

A highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 X0 depth and 180 × 180mm2 transverse dimensions was constructed, consisting of 2160 individually read out 10 × 45 × 3mm3 scintillator strips. This prototype was tested using electrons of 2-32 GeV at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined to be (12 . 5 ± 0 . 1(stat.) ± 0 . 4(syst.)) % /√{ E [ GeV ] } ⊕(1.2 ± 0.1 (stat.)-0.7+0.6 (syst.)) %, where the uncertainties correspond to statistical and systematic sources, respectively.

Selective Deuteron Acceleration and Neutron Production on the Vulcan PW Laser

NASA Astrophysics Data System (ADS)

Krygier, A. G.; Morrison, J. T.; Freeman, R. R.; Ahmed, H.; Green, J. A.; Alejo, A.; Kar, S.; Vassura, L.

2014-10-01

Fast neutron sources are important for a variety of applications including radiography and the detection of sensitive materials. Here we report on the results of an experiment using the Vulcan PW laser at Rutherford Appleton Laboratory to produce a nearly pure deuterium ion beam via Target Normal Sheath Acceleration. The typical contaminants are suppressed by freezing a μ m's thick layer of heavy water vapor (D2 O) onto a cryogenic target during the shot sequence. Neutrons were generated by colliding the accelerated deuterons were into secondary targets made of deuterated plastic in the pitcher-catcher arrangement. Absolute yields for deuterium ions and neutrons are reported. This work is supported by DOE Contract DE-FC02-04ER54789.

Modular focusing ring imaging Cherenkov detector for electron-ion collider experiments

NASA Astrophysics Data System (ADS)

Wong, C. P.; Alfred, M.; Allison, L.; Awadi, M.; Azmoun, B.; Barbosa, F.; Barion, L.; Bennett, J.; Brooks, W.; Butler, C.; Cao, T.; Chiu, M.; Cisbani, E.; Contalbrigo, M.; Datta, A.; Del Dotto, A.; Demarteau, M.; Durham, J. M.; Dzhygadlo, R.; Elder, T.; Fields, D.; Furletova, Y.; Gleason, C.; Grosse-Perdekamp, M.; Harris, J.; Haseler, T. O. S.; He, X.; van Hecke, H.; Horn, T.; Hruschka, A.; Huang, J.; Hyde, C.; Ilieva, Y.; Kalicy, G.; Kimball, M.; Kistenev, E.; Kulinich, Y.; Liu, M.; Majka, R.; McKisson, J.; Mendez, R.; Nadel-Turonski, P.; Park, K.; Peters, K.; Rao, T.; Pisani, R.; Qiang, Y.; Rescia, S.; Rossi, P.; Sarajlic, O.; Sarsour, M.; Schwarz, C.; Schwiening, J.; da Silva, C. L.; Smirnov, N.; Stien, H. D.; Stevens, J.; Sukhanov, A.; Syed, S.; Tate, A. C.; Toh, J.; Towell, C. L.; Towell, R. S.; Tsang, T.; Turisini, M.; Wagner, R.; Wang, J.; Woody, C.; Xi, W.; Xie, J.; Zhao, Z. W.; Zihlmann, B.; Zorn, C.

2017-11-01

A powerful new electron-ioncollider (EIC) has been recommended in the 2015 Long Range Plan for Nuclear Science for probing the partonic structure inside nucleons and nuclei with unprecedented precision and versatility [1]. EIC detectors are currently under development [2], all of which require hadron identification over a broad kinematic range. A prototype ring imaging Cherenkov detector has been developed for hadron identification in the momentum range from 3 GeV/c to 10 GeV/c. The key feature of this new detector is a compact and modular design, achieved by using aerogel as radiator and a Fresnel lens for ring focusing. In this paper, the results from a beam test of a prototype device at Fermilab are reported.

Impact-based piezoelectric energy harvester for multidimensional, low-level, broadband, and low-frequency vibrations

NASA Astrophysics Data System (ADS)

Zhang, Hongjiang; Jiang, Senlin; He, Xuefeng

2017-05-01

This letter proposes an impact-based piezoelectric energy harvester that uses a rolling bead contained in a bracket that is supported by a spring. Under either translational or rotational base excitation, the bead moves within the bracket and collides with piezoelectric cantilevers that are located around the bracket; these collisions cause the piezoelectric beams to vibrate and thus produce electrical outputs. The low rolling friction and the motion amplification effect of the spring make the resulting device suitable for collection of low-level vibration energy. Experiments show that the proposed harvester is promising for use in scavenging of energy from the multidimensional, low-level, broadband, and low-frequency vibrations that occur in natural environments.

Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)

ScienceCinema

Brookhaven Lab - Fulvia Pilat

2017-12-09

To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

INJECTION OPTICS FOR THE JLEIC ION COLLIDER RING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozov, Vasiliy; Derbenev, Yaroslav; Lin, Fanglei

2016-05-01

The Jefferson Lab Electron-Ion Collider (JLEIC) will accelerate protons and ions from 8 GeV to 100 GeV. A very low beta function at the Interaction Point (IP) is needed to achieve the required luminosity. One consequence of the low beta optics is that the beta function in the final focusing (FF) quadrupoles is extremely high. This leads to a large beam size in these magnets as well as strong sensitivity to errors which limits the dynamic aperture. These effects are stronger at injection energy where the beam size is maximum, and therefore very large aperture FF magnets are required tomore » allow a large dynamic aperture. A standard solution is a relaxed injection optics with IP beta function large enough to provide a reasonable FF aperture. This also reduces the effects of FF errors resulting in a larger dynamic aperture at injection. We describe the ion ring injection optics design as well as a beta-squeeze transition from the injection to collision optics.« less

Characterization of the International Linear Collider damping ring optics

NASA Astrophysics Data System (ADS)

Shanks, J.; Rubin, D. L.; Sagan, D.

2014-10-01

A method is presented for characterizing the emittance dilution and dynamic aperture for an arbitrary closed lattice that includes guide field magnet errors, multipole errors and misalignments. This method, developed and tested at the Cornell Electron Storage Ring Test Accelerator (CesrTA), has been applied to the damping ring lattice for the International Linear Collider (ILC). The effectiveness of beam based emittance tuning is limited by beam position monitor (BPM) measurement errors, number of corrector magnets and their placement, and correction algorithm. The specifications for damping ring magnet alignment, multipole errors, number of BPMs, and precision in BPM measurements are shown to be consistent with the required emittances and dynamic aperture. The methodology is then used to determine the minimum number of position monitors that is required to achieve the emittance targets, and how that minimum depends on the location of the BPMs. Similarly, the maximum tolerable multipole errors are evaluated. Finally, the robustness of each BPM configuration with respect to random failures is explored.

Essay: Robert H. Siemann As Leader of the Advanced Accelerator Research Department

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colby, Eric R.; Hogan, Mark J.; /SLAC

Robert H. Siemann originally conceived of the Advanced Accelerator Research Department (AARD) as an academic, experimental group dedicated to probing the technical limitations of accelerators while providing excellent educational opportunities for young scientists. The early years of the Accelerator Research Department B, as it was then known, were dedicated to a wealth of mostly student-led experiments to examine the promise of advanced accelerator techniques. High-gradient techniques including millimeter-wave rf acceleration, beam-driven plasma acceleration, and direct laser acceleration were pursued, including tests of materials under rf pulsed heating and short-pulse laser radiation, to establish the ultimate limitations on gradient. As themore » department and program grew, so did the motivation to found an accelerator research center that brought experimentalists together in a test facility environment to conduct a broad range of experiments. The Final Focus Test Beam and later the Next Linear Collider Test Accelerator provided unique experimental facilities for AARD staff and collaborators to carry out advanced accelerator experiments. Throughout the evolution of this dynamic program, Bob maintained a department atmosphere and culture more reminiscent of a university research group than a national laboratory department. His exceptional ability to balance multiple roles as scientist, professor, and administrator enabled the creation and preservation of an environment that fostered technical innovation and scholarship.« less

A HELICAL MAGNET DESIGN FOR RHIC.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WILLEN,E.; GUPTA,R.; JAIN,A.

1997-05-12

Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. Specifications are for low current superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A magnet meeting the requirements has been developed that uses a small diameter cable wound into helical grooves machined into a thick-walled aluminum cylinder.

New Approaches to Final Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuffer, David

2014-11-10

A high-energy muon collider scenario require a “final cooling” system that reduces transverse emittances by a factor of ~10 while allowing longitudinal emittance increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of the alternative approach. A more explicit understanding of solenoidal cooling beam dynamics is introduced.

An overview of near-barrier fusion studies with stable beams

NASA Astrophysics Data System (ADS)

Trotta, M.; Stefanini, A. M.; Beghini, S.; Behera, B. R.; Corradi, L.; Fioretto, E.; Gadea, A.; Itkis, M. G.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Mărginean, N.; Mason, P.; Montagnoli, G.; Pokrovsky, I. V.; Sagaidak, R. N.; Scarlassara, F.; Silvestri, R.; Szilner, S.

2007-05-01

An overview of results in fusion studies with stable beams spanning different mass regions and energy ranges is presented. The advantages offered by studying channel coupling effects, involving low-lying excited states of the colliding nuclei, as well as the difficulties in understanding the influence of transfer couplings on fusion, are firstly remarked. The competition of fusion with quasi-fission in heavy systems and the unexpected steep falloff of fusion cross sections at far sub-barrier energies are finally discussed.

The FONT5 Bunch-by-Bunch Position and Angle Feedback System at ATF2

NASA Astrophysics Data System (ADS)

Apsimon, R. J.; Bett, D. R.; Burrows, P. N.; Christian, G. B.; Constance, B.; Davis, M. R.; Gerbershagen, A.; Perry, C.; Resta-Lopez, J.

The FONT5 upstream beam-based feedback system at ATF2 is designed to correct the position and angle jitter at the entrance to the ATF2 final-focus system, and also to demonstrate a prototype intra-train feedback system for the International Linear Collider interaction point. We discuss the hardware, from stripline BPMs to kickers, and RF and digital signal processing, as well as presenting results from the latest beam tests at ATF2.

Advanced Accelerators: Particle, Photon and Plasma Wave Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Ronald L.

2017-06-29

The overall objective of this project was to study the acceleration of electrons to very high energies over very short distances based on trapping slowly moving electrons in the fast moving potential wells of large amplitude plasma waves, which have relativistic phase velocities. These relativistic plasma waves, or wakefields, are the basis of table-top accelerators that have been shown to accelerate electrons to the same high energies as kilometer-length linear particle colliders operating using traditional decades-old acceleration techniques. The accelerating electrostatic fields of the relativistic plasma wave accelerators can be as large as GigaVolts/meter, and our goal was to studymore » techniques for remotely measuring these large fields by injecting low energy probe electron beams across the plasma wave and measuring the beam’s deflection. Our method of study was via computer simulations, and these results suggested that the deflection of the probe electron beam was directly proportional to the amplitude of the plasma wave. This is the basis of a proposed diagnostic technique, and numerous studies were performed to determine the effects of changing the electron beam, plasma wave and laser beam parameters. Further simulation studies included copropagating laser beams with the relativistic plasma waves. New interesting results came out of these studies including the prediction that very small scale electron beam bunching occurs, and an anomalous line focusing of the electron beam occurs under certain conditions. These studies were summarized in the dissertation of a graduate student who obtained the Ph.D. in physics. This past research program has motivated ideas for further research to corroborate these results using particle-in-cell simulation tools which will help design a test-of-concept experiment in our laboratory and a scaled up version for testing at a major wakefield accelerator facility.« less

A conceptual solution for a beam halo collimation system for the Future Circular hadron-hadron Collider (FCC-hh)

NASA Astrophysics Data System (ADS)

Fiascaris, M.; Bruce, R.; Redaelli, S.

2018-06-01

We present the first conceptual solution for a collimation system for the hadron-hadron option of the Future Circular Collider (FCC-hh). The collimation layout is based on the scaling of the present Large Hadron Collider collimation system to the FCC-hh energy and it includes betatron and momentum cleaning, as well as dump protection collimators and collimators in the experimental insertions for protection of the final focus triplet magnets. An aperture model for the FCC-hh is defined and the geometrical acceptance is calculated at injection and collision energy taking into account mechanical and optics imperfections. The performance of the system is then assessed through the analysis of normalized halo distributions and complete loss maps for an ideal lattice. The performance limitations are discussed and a solution to improve the system performance with the addition of dispersion suppression collimators around the betatron cleaning insertion is presented.

Thermal and Structural Analysis of Beamline Components in the Mu2e Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Luke Daniel

2016-01-01

Fermi National Accelerator Laboratory will be conducting the high energy particle physics experiment Muons to Electrons (Mu2e). In this experiment, physicists will attempt to witness and understand an ultra-rare process which is the conversion of a muon into the lighter mass electron, without creating additional neutrinos. The experiment is conducted by first generating a proton beam which will be collided into a target within the production solenoid (PS). This creates a high-intensity muon beam which passes through a transport solenoid (TS) and into the detector solenoid (DS). In the detector solenoid the muons will be stopped in an aluminum targetmore » and a series of detectors will measure the electrons produced. These components have been named the DS train since they are coupled and travel on a rail system when being inserted or extracted from the DS. To facilitate the installation and removal of the DS train, a set of external stands and a support stand for the instrumentation feed-through bulkhead (IFB) have been designed. Full analysis of safety factors and performance of these two designs has been completed. The detector solenoid itself will need to be maintained to a temperature of 22°C ± 10°C. This will minimize thermal strain and ensure the accurate position of the components is maintained to the tolerance of 2 mm. To reduce the thermal gradient, a passive heating system has been developed and reported.« less

Simulation of 10 A electron-beam formation and collection for a high current electron-beam ion source

NASA Astrophysics Data System (ADS)

Kponou, A.; Beebe, E.; Pikin, A.; Kuznetsov, G.; Batazova, M.; Tiunov, M.

1998-02-01

Presented is a report on the development of an electron-beam ion source (EBIS) for the relativistic heavy ion collider at Brookhaven National Laboratory (BNL) which requires operating with a 10 A electron beam. This is approximately an order of magnitude higher current than in any existing EBIS device. A test stand is presently being designed and constructed where EBIS components will be tested. It will be reported in a separate paper at this conference. The design of the 10 A electron gun, drift tubes, and electron collector requires extensive computer simulations. Calculations have been performed at Novosibirsk and BNL using two different programs, SAM and EGUN. Results of these simulations will be presented.

High energy Coulomb-scattered electrons for relativistic particle beams and diagnostics

DOE PAGES

Thieberger, P.; Altinbas, Z.; Carlson, C.; ...

2016-03-29

A new system used for monitoring energetic Coulomb-scattered electrons as the main diagnostic for accurately aligning the electron and ion beams in the new Relativistic Heavy Ion Collider (RHIC) electron lenses is described in detail. The theory of electron scattering from relativistic ions is developed and applied to the design and implementation of the system used to achieve and maintain the alignment. Commissioning with gold and 3He beams is then described as well as the successful utilization of the new system during the 2015 RHIC polarized proton run. Systematic errors of the new method are then estimated. Lastly, some possiblemore » future applications of Coulomb-scattered electrons for beam diagnostics are briefly discussed.« less

Performance on the low charge state laser ion source in BNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okamura, M.; Alessi, J.; Beebe, E.

On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au 32+. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavymore » Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).« less

1985 Particle Accelerator Conference: Accelerator Engineering and Technology, 11th, Vancouver, Canada, May 13-16, 1985, Proceedings

NASA Astrophysics Data System (ADS)

Strathdee, A.

1985-10-01

The topics discussed are related to high-energy accelerators and colliders, particle sources and electrostatic accelerators, controls, instrumentation and feedback, beam dynamics, low- and intermediate-energy circular accelerators and rings, RF and other acceleration systems, beam injection, extraction and transport, operations and safety, linear accelerators, applications of accelerators, radiation sources, superconducting supercolliders, new acceleration techniques, superconducting components, cryogenics, and vacuum. Accelerator and storage ring control systems are considered along with linear and nonlinear orbit theory, transverse and longitudinal instabilities and cures, beam cooling, injection and extraction orbit theory, high current dynamics, general beam dynamics, and medical and radioisotope applications. Attention is given to superconducting RF structures, magnet technology, superconducting magnets, and physics opportunities with relativistic heavy ion accelerators.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lovelace, III, Henry H.

In accelerator physics, models of a given machine are used to predict the behaviors of the beam, magnets, and radiofrequency cavities. The use of the computational model has become wide spread to ease the development period of the accelerator lattice. There are various programs that are used to create lattices and run simulations of both transverse and longitudinal beam dynamics. The programs include Methodical Accelerator Design(MAD) MAD8, MADX, Zgoubi, Polymorphic Tracking Code (PTC), and many others. In this discussion the BMAD (Baby Methodical Accelerator Design) is presented as an additional tool in creating and simulating accelerator lattices for the studymore » of beam dynamics in the Relativistic Heavy Ion Collider (RHIC).« less

Ion Motion Induced Emittance Growth of Matched Electron Beams in Plasma Wakefields

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Weiming; Lu, Wei; Huang, Chengkun

2017-06-14

Plasma-based acceleration is being considered as the basis for building a future linear collider. Nonlinear plasma wakefields have ideal properties for accelerating and focusing electron beams. Preservation of the emittance of nano-Coulomb beams with nanometer scale matched spot sizes in these wakefields remains a critical issue due to ion motion caused by their large space charge forces. We use fully resolved quasistatic particle-in-cell simulations of electron beams in hydrogen and lithium plasmas, including when the accelerated beam has different emittances in the two transverse planes. The projected emittance initially grows and rapidly saturates with a maximum emittance growth of lessmore » than 80% in hydrogen and 20% in lithium. The use of overfocused beams is found to dramatically reduce the emittance growth. In conclusion, the underlying physics that leads to the lower than expected emittance growth is elucidated.« less

Design and performance of a high resolution, low latency stripline beam position monitor system

NASA Astrophysics Data System (ADS)

Apsimon, R. J.; Bett, D. R.; Blaskovic Kraljevic, N.; Burrows, P. N.; Christian, G. B.; Clarke, C. I.; Constance, B. D.; Dabiri Khah, H.; Davis, M. R.; Perry, C.; Resta López, J.; Swinson, C. J.

2015-03-01

A high-resolution, low-latency beam position monitor (BPM) system has been developed for use in particle accelerators and beam lines that operate with trains of particle bunches with bunch separations as low as several tens of nanoseconds, such as future linear electron-positron colliders and free-electron lasers. The system was tested with electron beams in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan. It consists of three stripline BPMs instrumented with analogue signal-processing electronics and a custom digitizer for logging the data. The design of the analogue processor units is presented in detail, along with measurements of the system performance. The processor latency is 15.6 ±0.1 ns . A single-pass beam position resolution of 291 ±10 nm has been achieved, using a beam with a bunch charge of approximately 1 nC.

Final cooling for a high-energy high-luminosity lepton collider

NASA Astrophysics Data System (ADS)

Neuffer, D.; Sayed, H.; Acosta, J.; Hart, T.; Summers, D.

2017-07-01

A high-energy muon collider requires a "final cooling" system that reduces transverse emittance by a factor of ~ 10, while allowing the longitudinal emittance to increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches, which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of an alternative approach. Wedge-based emittance exchange could provide much of the required transverse cooling with longitudinal heating. Li-lens and quadrupole focusing systems could also provide much of the required final cooling.

Energy Dependence of Elliptic Flow over a Large Pseudorapidity Range in Au+Au Collisions at the BNL Relativistic Heavy Ion Collider

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2005-04-01

This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of √(sNN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of η'=|η|-ybeam, scale with approximate linearity throughout η', implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.

High Energy Colliding Beams; What Is Their Future?

NASA Astrophysics Data System (ADS)

Richter, Burton

The success of the first few years of LHC operations at CERN, and the expectation of more to come as the LHC's performance improves, are already leading to discussions of what should be next for both proton-proton and electron-positron colliders. In this discussion I see too much theoretical desperation caused by the so-far-unsuccessful hunt for what is beyond the Standard Model, and too little of the necessary interaction of the accelerator, experimenter, and theory communities necessary for a scientific and engineering success. Here, I give my impressions of the problem, its possible solution, and what is needed to have both a scientifically productive and financially viable future.