Speaker
Description
For the next generation of high-power lasers, like ZEUS and MTW-OPAL, electron energies from 10 GeV to 100 GeV are expected. Conventional magnet spectrometers will have a huge footprint in the laboratory at these energies to maintain resolution, compromising the compactness of by plasma-based accelerators. Because of this, new ways to measure multi-GeV electron spectra will need to be developed.
Electromagnetic calorimeters are well-established detectors in the high-energy physics community, where they are used to characterize leptons and photons created in a collision event. The length of these detectors scales logarithmically with incoming energy, requiring up to 30 radiation lengths to stop particles even at TeV energies (lead, for example, has a radiation length of 5.6 mm). As high-energy leptons or photons enter a calorimeter, they create a particle shower dominated by bremsstrahlung and pair production. The shape of the shower depends on the energy of the incoming radiation.
We have designed sampling calorimeters for wakefield accelerators using alternating layers of lead and scintillating fibers. With the help of GEANT4 simulations we have developed a methodology using the transverse and longitudinal evolution of the shower to characterize beams at the GeV level. Preliminary experimental results obtained at the 10 PW beamline at ELI-NP suggest that electrons above 5 GeV were measured in the calorimeter, in good agreement with measurements from a magnet spectrometer.
| Working group | WG5 |
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