Fermilab, Batavia, Illinois
Fermilab, Batavia, Illinois
GSI, Darmstadt
Uppsala University, Uppsala
FZJ, Julich
TSL, Uppsala
Universität Bonn, Helmholtz-Institut für Strahlen- und Kernphysik, Bonn
UU/ISV, Uppsala
GSI, Darmstadt
On behalf of the Fermilab E835 Collaboration
FZJ, Julich
INFN-Ferrara, Ferrara
* Conceptual Design Report for an International Facility for Antiprotonand Ion Research, www.gsi.de/GSI-future/cdr.** PAX Technical Proposal, www.fz-juelich.de/ikp/pax.
Fermilab, Batavia, Illinois
BINP SB RAS, Novosibirsk
Fermilab, Batavia, Illinois
Fermilab, Batavia, Illinois
The NuMI beamline at Fermilab has been operational since the spring of 2005 delivering high-intensity neutrino beams to the MINOS experiment. A beam power on target of 310 kW has been achieved and a total of more than 2·1020 protons have been delivered to the NuMI target. Upgrades to NuMI are planned in preparation for the future MINERvA and NOvA neutrino experiments increasing the NuMI beam power capability from 400 kW to 700 kW and then as much as 1.2 MW. An overview of the future upgrade to NuMI is presented.
Fermilab, Batavia, Illinois
A 0.1 A, 4.3 MeV DC electron beam is routinely used to cool 8 GeV antiprotons in Fermilab's Recycler storage ring. While the primary function of the electron cooler is to increase the longitudinal phase-space density of the antiprotons, significant transverse cooling rates have been observed as well. Numerical characterization of electron cooling is done by two types of measurements: friction force measurements by the voltage jump method and diffusion/cooling rates measurements. The paper will present the recent measurement results and will compare them to a non-magnetized model.
The Fermilab Tevatron Collider Run II program continues at the energy and luminosity frontier of high energy particle physics. The presentation will cover major improvements in the performance of the collider complex which lead to the record-breaking luminosity.
Fermilab, Batavia, Illinois
The Recycler is the primary antiproton repository for the Tevatron collider at Fermilab. Stored antiproton beam intensity has been steadily increased to about 450·1010 over the last three years. We have used the technique of longitudinal momentum mining* in the Recycler to extract constant intensity and constant longitudinal emittance antiproton bunches for collider operation since early 2005. Since then, the Recycler has played a critical role in the luminosity performance of the Tevatron; the peak proton-antiproton luminosity has been raised by a factor of about three and a world record luminosity of 2.31·1032cm-2s-1 has been achieved. Recently, many improvements have been implemented in the antiproton mining and stacking schemes used in the Recycler to handle higher intensity beam. In this paper we discuss morphing during antiproton stacking, reducing longitudinal emittance dilution, and use of soft mining buckets to maintain low peak density and control the beam instability during mining. In addition we present past and current performance of mining and beam stacking RF manipulations.
* C. M. Bhat, Phys. Letts. A Vol. 330 (2004), p 481
Fermilab, Batavia, Illinois
The more beam is cooled, the less stable it is. In the Recycler Ring, antiprotons are cooled both with stochastic and electron cooling. To stabilize it against the resistive wall instability, a digital damper is successfully used. Digital dampers can be described as linear operators with explicit time dependence, and that makes a principle difference with analogous dampers. Theoretical description of the digital dampers is presented. Electron cooling makes possible a two-beam instability of the cooled beam with the electron beam. Special features of this instability are described, and the remedy is discussed.
Fermilab, Batavia, Illinois
In 2006, GSI, together with a large international science community, presented the FAIR Baseline Technical Report (FBTR) on an unprecedented accelerator Facility for Antiproton and Ion beams Research in Europe, located in Darmstadt (Germany). This facility is based on extensive discussions and a broad range of workshops and working group reports, organized by the international user communities over a period of several years enabling unique experimental possibilities in the fields of nuclear- and astrophysics, hadron-, plasma and atomic physics as well as on applied physics. Following an in-depth evaluation of the proposal by the German Wissenschaftsrat and its recommendation to realize the facility, the Federal Government gave conditional approval for construction of FAIR in 2003. Since then the project has gone through major steps of development and significant progress has been achieved with regard to the scientific-technical and political preparation of the project under the governance of an international committee structure. The current status of the project will be reviewed.
ANL, Argonne, Illinois
Fermilab, Batavia, Illinois
An Optical Transition Radiation (OTR) detector has been installed in the Fermilab NuMI proton beamline, which operates at beam powers of up to ~300 kW, to obtain real-time, spill-by-spill beam profiles for neutrino production. A series of Optical Transition Radiation (OTR) detectors were design, constructed and installed in various beamlines at Fermilab and previous near-field OTR images of lower-intensity 120 GeV and 150 GeV protons with larger transverse beam size have been presented at BIW06 and IEEE NSS06. NuMI OTR images of 120 GeV protons for beam intensities up to 2.8·1013 at a spill rate of 0.5 Hz and small transverse beam size of ~1 mm (σ) are presented here. The NuMI OTR detector uses a 6 micron Kapton foil with 0.12 micron of aluminum which reduces beam scatter by 70% compared to an adjacent Secondary Emission Monitor (SEM). Beam profiles are extracted from the OTR images and compared to the adjacent SEM. The OTR detector provides two-dimensional beam shape such as ellipticity and tilt, as well as complementary beam centroid and beam intensity information. In addition, response of the OTR detector over different intensities and transverse positions is presented.
Northern Illinois University, DeKalb, Illinois
ANL, Argonne, Illinois
An exotic beam facility for the production of rare isotopes requires investigation of higher order optical effects, while taking into account beam-material interactions. An important component of the fragment separator is the absorber wedge, which is necessary for isotope separation. The properties of the absorber, such as the type and shape of material used, determine the resolution and transmission of the fragment separator. Nuclear reactions such as the fission and fragmentation of radioactive isotopes within the target or absorber contribute to the phase space and isotopic distributions of the beam. We have computed these distributions for all isotopes emerging from the target or absorber by implementing a limited fission model from within COSY Infinity that uses polynomial interpolations. Higher order optical aberrations have been computed and successfully eliminated by the shaping of the absorber material. COSY allows us to find the parameters of the absorber that maximize the resolution and transmission of the fragment separator. In addition, beam purity tests have been performed. From our results we have determined an appropriate location for a dump of the primary beam.
Fermilab, Batavia, Illinois
We have successfully imaged for the first time the angular distribution patterns of optical transition radiation (OTR) generated by 120-GeV proton beams passing through an Al metal plane. These experiments were performed at FNAL with the same chamber, foil, and camera design as with the near-field experiments previously reported. In this case the lens-to-CID-chip separation was remotely adjusted to provide the focus-at-infinity, or far-field optical imaging. The ~8-mrad opening angle of OTR patterns confirm/provide the calibration factors for the system. We also used linear polarizers to select the orthogonal polarization components of the radially polarized OTR. The OTR angular distribution results are compared to an existing analytical model. We show angle pointing information is available from the single-foil OTR data at the sub-mrad level and divergence information at about the 1-mrad level. Data have been obtained in transport lines both before the antiproton production target and before the NuMI target with particle intensities of about 5 to 22 x ·1012. A two-foil interferometer calculation was also performed. Single-foil experimental and modeling results will be presented.
To avoid multiple head-on collisions the proton and antiproton beams in the Tevatron move along separate helical orbits created by 7 horizontal and 8 vertical electrostatic separators. Still the residual long-range beam-beam interactions can adversely affect particle motion at all stages from injection to collision. With increased intensity of the beams it became necessary to modify the orbits in order to mitigate the beam-beam effect on both antiprotons and protons. This report summarizes the work done on optimization of the Tevatron helical orbits, outlines the applied criteria and presents the achieved results.
Fermilab, Batavia, Illinois