Construction of a New Beamline at the SUNY Geneseo Pelletron Accelerator for Calibrating a Thomson Parabola Megan Crossman, Steven Hupcher, Charlie Freeman, Stephen Padalino: SUNY Geneseo Christian Stoeckl: Laboratory For Laser Energetics A new beamline with a general-purpose scattering chamber was constructed at the SUNY Geneseo 1.7 MV Pelletron accelerator laboratory. The beamline is equipped with a general-purpose 28 inch scattering chamber which includes a target manipulator system, faraday cup, and a mounting for a surface barrier detector. Sighting through steering magnet Completed new line Gafchromic (HD-810) Radiochromic film (RCF), normally used in medical dosimetry, was placed in the new scattering chamber in an effort to create proton dose calibrations. Irradiated RCF with estimated angles of incidence RCF upon immediate removal from scattering chamber Incident Beam SBD RCF Faraday Cup Au Foil Schematic of RCF scattering experiment Target Chamber Lid Target Chamber Gold Foil SBD Schematic of Thomson Parabola as it will be used for calibration on the new beamline at SUNY Geneseo Abstract New Beamline Scattering Chamber Thomson Parabola Rutherford Scattering Experiment Radiochromic Film Motivation The new beamline will be used for a wide variety of experiments: •Calibration of a Thomson Parabola •General Rutherford scattering •Calibration of radiochromic film •Experiments involving carbon ion beams •Experiments requiring the utilization of the large chamber Future Plans Twenty-eight inch scattering chamber Target manipulator and surface barrier detector in chamber Target manipulator with gold foils for Rutherford scattering experiment Magnetically coupled target manipulator The new beamline will be used for experiments with Radiochromic and CR-39 film as well as experiments with carbon ion beams. The Laboratory for Laser Energetics at the University of Rochester hopes to use SUNY Geneseo’s data from the low energy proton Thomson Parabola calibrations upon the installation of the Thomson Parabola at Multiterawatt Laser Facility. Plot of the color density as a function of the inverse sin 4 (θ/2). Color density should be proportional to radiation dose so the plot should be linear based on Rutherford’s scattering equation. 1911: Thomson’s brilliant idea: what happens if we use parallel electric and magnetic fields to deflect ions? The goal of the Thomson Parabola is to measure proton energies ~0.5 MeV to ~20 MeV with energy uncertainties of 10% or better. x (magnetic) • Deflection due to magnetic field ~q/p • Deflection due to Electric field ~q/KE • Ion traces form parabolic curves on detector plane N S Electric Deflection toward bottom of screen (y direction) Magnetic Deflection into screen (x direction) B q x c p 2 E q y c KE 2 2 p KE m 2 2 E B c m y x q c y (electric) Note: c E and c B depend on electric and magnetic field strengths and geometry only Possible applications include: •Fast Ignition •Medical Proton Therapy •Injector for traditional accelerators Blow-off plasma Accelerated Protons and other ions Laser Incidence Planar Target E ~ 1 TV/m Thomson Parabola Pinhole NEC 1.5MV Tandem Pelletron Accelerator (5SDH) Aligning quadrupole magnets Assembling the Thomson Parabola The chamber of the Multiterawatt Laser Use of Thomson Parabola on MTW for measuring high energy protons. Accelerator prior to installation The new line in operation 3D CAD drawing of the Thomson Parabola on MTW Funded in part by the US Department of Energy through the Laboratory for Laser Energetics