  Irradiations at Ultra High Dose Rate (UHDR) regimes, exceeding 40 Gy/s in
single fractions lasting less than 200 ms, have shown an equivalent antitumor
effect compared to conventional radio-therapy with reduced harm to normal
tissues. This work details the hardware and software modi-fications implemented
to deliver 10 MeV UHDR electron beams with a Linear Accelerator Elekta SL 18 MV
and the beam characteristics obtained. GafChromic EBT XD films and an Advanced
Markus chamber were used for the dosimetry characterization, while a silicon
sensor assessed the machine's beam pulses stability and repeatability. Dose per
pulse, average dose rate and instantaneous dose rate in the pulse were
evaluated for four experimental settings, varying the source-to-surface
dis-tance and the beam collimation, i.e. with and without the use of a
cylindrical applicator. Results showed dose per pulse from 0.6 Gy to a few tens
of Gy and average dose rate up to 300 Gy/s. The obtained results demonstrate
the possibility to perform in-vitro radiobiology experiments and test of new
technologies for beam monitoring and dosimetry at the upgraded LINAC, thus
contributing to the electron UHDR research field.
