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Scarpine, V. E.

Paper Title Page
TUPAS032 Prospects of Diagnostics with Optical Diffraction Radiation in Hadron Colliders 1721
 
  • T. Sen, V. E. Scarpine, R. Thurman-Keup
    Fermilab, Batavia, Illinois
  
  Optical diffraction radiation has been observed and recently used to measure the beam size of electrons at KEK. This non-invasive technique also holds promise for imaging beams close to the interaction point in hadron colliders. In this paper we consider the feasibility of this technique for the Tevatron and the LHC.  
THOAC02 OTR Imaging of Intense 120 GeV Protons in the NuMI Beamline at FNAL 2639
 
  • V. E. Scarpine, G. R. Tassotto
    Fermilab, Batavia, Illinois
  • A. H. Lumpkin
    ANL, Argonne, Illinois
  
  Funding: Work Supported by the U. S. Department of Energy under Contract No. DE-AC02-CH03000 and Contract No. DE-AC02-06CH11357.

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.

 
slides icon Slides  
FRPMN113 Initial Far-Field OTR Images Generated by 120-GeV Protons at FNAL 4378
 
  • A. H. Lumpkin
    ANL, Argonne, Illinois
  • V. E. Scarpine, G. R. Tassotto
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by U. S. Department of Energy, Office of Science,under Contract No. DE-AC02-06CH11357 and by U. S. Department of Energy under Contract No. DE-AC02-CH03000.

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.

 
FRPMS011 Design of an Electro-Optical Sampling Experiment at the AWA Facility 3901
 
  • J. Ruan, H. Edwards, V. E. Scarpine, C.-Y. Tan, R. Thurman-Keup
    Fermilab, Batavia, Illinois
  • YL. Li, J. G. Power
    ANL, Argonne, Illinois
  • T. J. Maxwell
    Northern Illinois University, DeKalb, Illinois
  
  Funding: Supported by US DOE

The free space electro-optical (EO) sampling technique is a powerful tool for analyzing the longitudinal charge density of an ultrashort e-beam. In this paper, we present

  1. experimental results for a laser-based mock-up of the EO experiment* and
  2. a design for a beam-based, single-shot, EO sampling experiment using the e-beam from the Argonne Wakefield Accelerator (AWA) RF photoinjector.
For the mock-up, a tabletop terahertz experiment is conducted in the AWA laser room. The mock-up uses an IR beam incident on <110> ZnTe crystal to produce a THz pulse via optical rectification. Detection is based on the cross correlation between the THz field and the probe IR laser field in a second <110> ZnTe crystal. Potential application of this technique to the ILC accelerator test facility at Fermilab is also presented.

* Yuelin Li, Appl. Phys. Lett. 88, 251108, 2006