title: Obtaining the intrinsic electron spectrum of linear accelerators using the relation between the current of the bending magnet and the absorbed dose in water.
abstract: OBJECTIVE
  To present a novel methodology to model the intrinsic electron spectra of a linear accelerator and its situation with respect to the energy window.
  
  
  METHODS
  The spectra are obtained by fitting the variation of R(50) and the maximum dose rate measured in a water phantom with the bending magnet current. The obtained spectra are verified with a realistic Monte Carlo simulation of the accelerator.
  
  
  RESULTS
  The intrinsic spectra and their relative position with respect to the energy window of the bending magnet have been obtained for a Siemens Mevatron KDS and an ELEKTA SL20 accelerators.
  
  
  CONCLUSIONS
  Using this method in the commissioning and scheduled revisions of the accelerator, the tuning of the current of the bending magnet could be done in such a way that both the quality of the beam and the dose rate would reach a better long-term stability.
authors.affiliation: Servicio de Radiofísica, Hosp. Univ. San Cecilio, Granada, Spain. jasx77@gmail.com
authors.forename: Jose M
authors.initials: JM
authors.lastname: de la Vega
authors.forename: Damián
authors.initials: D
authors.lastname: Guirado
authors.forename: Manuel
authors.initials: M
authors.lastname: Vilches
authors.forename: Jose I
authors.initials: JI
authors.lastname: Perdices
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Lallena
mesh_terms: D004583:Electrons; D008280:Magnetics; D010315:Particle Accelerators; D014867:Water
chemical_list: D014867:Water