Characterizing the EBIS-C Spectrometer

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Characterizing the EBIS-C Spectrometer

• Leah VanNahmen
• REU 2006
• Kansas State University

2
Introduction

• Spectrometer Basics
• Recoil Ions
• Beam Fragments
• Summary
• Applications

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Spectrometer Basics

• GOAL Determine initial momentum of all products
  from a collision
• Gas Jet Recoil Ions
• Particle Beam Beam Fragments
• Detector MCP and PSD collect TOF and Final
  Position

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Recoil Ions

• We find recoil ions initial momentum from TOF
  using momentum conversion
• Problem Particles with different initial
  momenta can have the same TOF

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Recoil Ions
Solution Space and Time Focusing

• Make voltage hill
• Best focusing if 2nd applied voltage is 82.8 of
  1st voltage

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Recoil Ions

• The EBIS-C spectrometer has great focusing!

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Beam Fragments
Problem Magnification

• Magnification of Y Position

• Magnification of Y Velocity

D vt
Spectrometer Axis
Spectrometer Axis
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Beam Fragments

• Solution Find an equation to correct for both
  kinds of magnification

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Beam Fragments

• Overall Magnification Solution
• Overall magnified Y position magnification of Y
  position x initial y position magnification of
  Y velocity x initial Y velocity x TOF
• Ym MYi x Yi MVy x vy x TOF

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Summary

• Apply two voltages to spectrometer to focus
  recoil ions
• Correct for magnification of beam fragments
• End up with enough equations to find the initial
  momentum of all the products from a collision

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Applications

• This characterization will allow experimenters to
  quickly and easily focus the EBIS-C spectrometer
  and correct for the magnification it causes
• The spectrometer will be used in the EBIS-C
  beamline for future experiments..

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Applications
Gas Jet Particle Beam Physics
CO Ar11 Dissociation of CO2
Ar/He HD and H2 CID and DC
He H2 Vibrational State Effects

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Applications

• In Ar/He experiment
• Ar H2
• H H Ar
• H H Ar