11 Application of Accelerators and Storage Rings
739
Fig. 11.32 TULIP (Turning
LInac for Proton therapy)
all-linac solution (courtesy of
Mohammad Vaziri—TERA
Foundation)
A proposed system is the high-frequency proton linac rotating around the
patient—according to a scheme named TULIP and patented by TERA [109] which
is based on the same 5.7 GHz linac designed for CABOTO (Fig. 11.32).
An original development concerns laser-driven ion beams and is based on protons
accelerated by illuminating a thin target with powerful (10 18 –10 20 W/cm 2 ) and short
(30–50 fs) laser pulses. When the laser pulse hits the target—with thickness of the
few micrometers—electrons are violently accelerated producing an electric field of
the order of teravolt per meter which draws behind the protons for the surface of
the target itself. The phenomenon has been studied experimentally reaching proton
energies of more than 10 MeV with promising results [110]. The energy spectrum is
continuous and computations show that, using proper combination of target shapes
and laser power, a 3% energy spread can be obtained [111]. The advantages of
a laser-driven system are that the ion beams can be generated very close to the
patient and that optical elements can substitute the cumbersome and heavy beamline
elements including the gantries. The most relevant challenge is probably the short
pulse duration which is linked to the unknown biological effects of the high dose
rates, the impossibility of controlling the beam intensity during the irradiation,
and the potential risk of overdose. An important issue is also linked to very low
repetition rate of few hertz which would extend the irradiation to unacceptable
time. The implementation process is complex and still several years are foreseen
to create, around the laser-driven 200 MeV proton beam, the whole infrastructures
for a therapy facility [112].
Acknowledgment
The authors are grateful to the International Atomic Energy Agency and in particular
to Joao Alberto Osso and Amirreza Jalilian for the discussions and for providing
739
Fig. 11.32 TULIP (Turning
LInac for Proton therapy)
all-linac solution (courtesy of
Mohammad Vaziri—TERA
Foundation)
A proposed system is the high-frequency proton linac rotating around the
patient—according to a scheme named TULIP and patented by TERA [109] which
is based on the same 5.7 GHz linac designed for CABOTO (Fig. 11.32).
An original development concerns laser-driven ion beams and is based on protons
accelerated by illuminating a thin target with powerful (10 18 –10 20 W/cm 2 ) and short
(30–50 fs) laser pulses. When the laser pulse hits the target—with thickness of the
few micrometers—electrons are violently accelerated producing an electric field of
the order of teravolt per meter which draws behind the protons for the surface of
the target itself. The phenomenon has been studied experimentally reaching proton
energies of more than 10 MeV with promising results [110]. The energy spectrum is
continuous and computations show that, using proper combination of target shapes
and laser power, a 3% energy spread can be obtained [111]. The advantages of
a laser-driven system are that the ion beams can be generated very close to the
patient and that optical elements can substitute the cumbersome and heavy beamline
elements including the gantries. The most relevant challenge is probably the short
pulse duration which is linked to the unknown biological effects of the high dose
rates, the impossibility of controlling the beam intensity during the irradiation,
and the potential risk of overdose. An important issue is also linked to very low
repetition rate of few hertz which would extend the irradiation to unacceptable
time. The implementation process is complex and still several years are foreseen
to create, around the laser-driven 200 MeV proton beam, the whole infrastructures
for a therapy facility [112].
Acknowledgment
The authors are grateful to the International Atomic Energy Agency and in particular
to Joao Alberto Osso and Amirreza Jalilian for the discussions and for providing