Engineering topics

Tiefenback, Michael G.

Publications and source records attributed to Tiefenback, Michael G..

4 records

DOE OSTI2018

Magnetized Electron Source for JLEIC Electron Cooler

Bunched-beam electron cooling is a key feature of all proposed designs of the future electron-ion collider, and a requirement for achieving the specified collision luminosity. For the Jefferson Lab Electron Ion Collider (JLEIC), fast cooling of ion beams will be accomplished via so-called 'magnetized cooling' implemented using a recirculator ring that employs an energy recovery linac. In this contribution, we describe the production of magnetized electron beam using a compact 300 kV DC high voltage photogun with an inverted insulator geometry and alkali-antimonide photocathodes. Beam magnetization was assessed using a modest diagnostic beamline that includes YAG view screens for measuring the rotation angle of the electron beamlet passing through a narrow upstream slit. Magnetization characterization including drift emittance were measured for various gun bias voltages and laser spot sizes at the photocathode using 532 nm lasers with DC and RF time structure. With magnetized beam, photocathode lifetime at currents up to 28 mA CW was measured and high bunch charge up to 700 pC was demonstrated.

Mamun, Md Abdullah↗

DOE OSTI2018

Production of magnetized electron beam from a DC high voltage photogun

Bunched-beam electron cooling is a key feature of all proposed designs of the future electron-ion collider, and a requirement for achieving the highest promised collision luminosity. At the Jefferson Lab Electron Ion Collider (JLEIC), fast cooling of ion beams will be accomplished via so-called 'magnetized cooling' implemented using a recirculator ring that employs an energy recovery linac. In this contribution, we describe the production of magnetized electron beam using a compact 300 kV DC high voltage photogun with an inverted insulator geometry, and using alkali-antimonide photocathodes. Beam magnetization was assessed using a modest diagnostic beamline that includes YAG view screens used to measure the rotation of the electron beamlet passing through a narrow upstream aperture. Magnetization results are presented for different gun bias voltages and for different laser spot sizes at the photocathode, using 532 nm lasers with DC and RF time structure. Photocathode lifetime was measured at currents up to 4.5 mA, with and without beam magnetization.

Al Mamun, Md Abdullah↗

DOE OSTI2018

300 kV DC High Voltage Photogun with Inverted Insulator Geometry and CsK2sb Photocathode

A compact DC high voltage photogun with inverted-insulator geometry was designed, built and operated reliably at 300 kV bias voltage using alkali-antimonide photocathodes. This presentation describes key electrostatic design features of the photogun with accompanying emittance measurements obtained across the entire photocathode surface that speak to field non-uniformity within the cathode/anode gap. A summary of initial photocathode lifetime measurements at beam currents up to 4.5 mA is also presented.

Wang, Yan↗

DOE OSTI2015

Bunch length measurements using synchrotron ligth monitor

The bunch length is measured at CEBAF using an invasive technique. The technique depends on applying an energy chirp for the electron bunch and imaging it through a dispersive region. The measurements are taken through Arc1 and Arc2 at CEBAF. The fundamental equations, procedure and the latest results are given.

Ahmad, Mahmoud↗