Design of the ELIMAIA ion collection system

Abstract

A system of permanent magnet quadrupoles (PMQs) is going to be realized by INFN-LNS to be used as a collection system for the injection of laser driven ion beams up to 60 MeV/u in an energy selector based on four resistive dipoles. This system is the first element of the ELIMED (ELI-Beamlines MEDical and Multidisciplinary applications) beam transport, dosimetry and irradiation line that will be developed by INFN-LNS (It) and installed at the ELI-Beamlines facility in Prague (Cz). ELIMED will be the first user's open transport beam-line where a controlled laser-driven ion beam will be used for multidisciplinary researches. The definition of well specified characteristics, both in terms of performances and field quality, of the magnetic lenses is crucial for the system realization, for the accurate study of the beam dynamics and for the proper matching with the magnetic selection system which will be designed in the next months. Here, we report the design of the collection system and the adopted solutions in order to realize a robust system form the magnetic point of view. Moreover, the first preliminary transport simulations are also described.

Time of Flight based diagnostics for high energy laser driven ion beams

“…In particular, a thin (about 100 µm) pDD will be used to measure the TOF signal at about 2 m downstream the source, i.e after the PMQ system, and a thick (about 500 µm) sDD will be used to measure the TOF signal of the proton group selected by the energy selection, downstream the in-vacuum beamline at about 9 m from the source. Indeed, according to ion beam optics studies [4], about 20% of the particles generated at the source, i.e. about 10 9 in the worse case, will be transmitted through the focusing system with a broad energy distribution, therefore a low capacitance, fast detector suitable for high intensity loss measurements, as a thin pDD, will allow to measure the TOF of the whole proton group with a reasonably good time resolution with a 2 m flight path even for the fastest energy component.…”

“…A permanent magnet quadrupole system (PMQs) will be placed few cm downstream the target (i.e. the laser driven ion source) allowing collecting and focusing of the beam energy component of interest [3,4]. The PMQ system is followed by an energy selector system (ESS), dedicated to ion beam selection in terms of species and energy, based on a magnetic chicane, which consists of four resistive magnet dipoles.…”

The ELIMED transport and dosimetry beamline for laser-driven ion beams

“…They will be placed 200 mm upstream and downstream the ESS, and will have a 30 mm diameter. In [27] is demonstrated the necessity to use a magnetic chicane to control the energy distribution of the selected beam, as a simple collimation system on the focal point does not allow a proper selection. results to be 12%, namely about 107 particles per laser shot.…”

“…2.1. The collection system The PMQs system consists of five quadrupoles as described in Table 1 [27,28]. The system has to collect a wide range of ion energies, Fig.…”

“…H is higher than the main magnetic material coercitivity and, to avoid demagnetization, materials with different coercitivity are used. The field analysis, performed as described in [31], shows a gradient uniformity better than 2% and an integrated field uniformity better than o0:3% within a radius of 12 mm [27,28].…”