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Title: Large dynamic range diagnostics for high current electron LINACs

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} andmore » demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.« less
Authors:
 [1]
  1. Thomas Jefferson National Accelerator Facility 12000 Jefferson Avenue, Newport News, VA 23606 (United States)
Publication Date:
OSTI Identifier:
22280694
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1563; Journal Issue: 1; Conference: Workshop to explore physics opportunities with intense, polarized electron beams at 50-300 MeV, Cambridge, MA (United States), 14-16 Mar 2013; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BEAM CURRENTS; BEAM DYNAMICS; BEAM EMITTANCE; BEAM MONITORS; BEAM PRODUCTION; BEAM PROFILES; CEBAF ACCELERATOR; ELECTRON BEAMS; ENERGY RECOVERY; EQUILIBRIUM; FREE ELECTRON LASERS; MEV RANGE; PERFORMANCE TESTING; REVIEWS