The discovery of chirped pulse amplification has led to great improvements in laser technology,enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometer...The discovery of chirped pulse amplification has led to great improvements in laser technology,enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers.Protons with energies of tens of MeV can be accelerated using,for instance,target normal sheath acceleration and focused on secondary targets.Under such conditions,nuclear reactions can occur,with the production of radioisotopes suitable for medical application.The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators.In this paper,we study the production of^(67)Cu,^(63)Zn,^(18)F,and^(11)C,which are currently used in positron emission tomography and other applications.At the same time,we study the reactions^(10)B(p,α)^(7)Be and^(70)Zn(p,4n)^(67)Ga to put further constraints on the proton distributions at different angles,as well as the reaction^(11)B(p,α)^(8)Be relevant for energy production.The experiment was performed at the 1 PW laser facility at VegaⅢin Salamanca,Spain.Angular distributions of radioisotopes in the forward(with respect to the laser direction)and backward directions were measured using a high purity germanium detector.Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera[Nucl.Instrum.Methods Phys.Res.,Sect.A 637,164–170(2011)].展开更多
The time-of-flight technique coupled with semiconductor detectors is a powerful instrument to provide real-time characterization of ions accelerated because of laser-matter interactions.Nevertheless,the presence of st...The time-of-flight technique coupled with semiconductor detectors is a powerful instrument to provide real-time characterization of ions accelerated because of laser-matter interactions.Nevertheless,the presence of strong electromagnetic pulses(EMPs)generated during the interactions can severely hinder its employment.For this reason,the diagnostic system must be designed to have high EMP shielding.Here we present a new advanced prototype of detector,developed at ENEA-Centro Ricerche Frascati(Italy),with a large-area(15 mm×15 mm)polycrystalline diamond sensor having 150 μm thickness.The tailored detector design and testing ensure high sensitivity and,thanks to the fast temporal response,high-energy resolution of the reconstructed ion spectrum.The detector was offline calibrated and then successfully tested during an experimental campaign carried out at the PHELIX laser facility(E_(L)~100 J,τ_(L)=750 fs,I_(L)(1-2.5)×10^(19)W/cm^(2))at GSI(Germany).The high rejection to EMP fields was demonstrated and suitable calibrated spectra of the accelerated protons were obtained.展开更多
文摘The discovery of chirped pulse amplification has led to great improvements in laser technology,enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers.Protons with energies of tens of MeV can be accelerated using,for instance,target normal sheath acceleration and focused on secondary targets.Under such conditions,nuclear reactions can occur,with the production of radioisotopes suitable for medical application.The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators.In this paper,we study the production of^(67)Cu,^(63)Zn,^(18)F,and^(11)C,which are currently used in positron emission tomography and other applications.At the same time,we study the reactions^(10)B(p,α)^(7)Be and^(70)Zn(p,4n)^(67)Ga to put further constraints on the proton distributions at different angles,as well as the reaction^(11)B(p,α)^(8)Be relevant for energy production.The experiment was performed at the 1 PW laser facility at VegaⅢin Salamanca,Spain.Angular distributions of radioisotopes in the forward(with respect to the laser direction)and backward directions were measured using a high purity germanium detector.Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera[Nucl.Instrum.Methods Phys.Res.,Sect.A 637,164–170(2011)].
基金funding from the Euratom research and training program 2014-2018 and 2019-2020 under grant agreement No.633053funding from LASERLAB-EUROPE(grant agreement No.654148,European Union’s Horizon 2020 research and innovation program)supported by the Ministry of Science and Higher Education of the Russian Federation(Agreement with Joint Institute for High Temperatures RAS No.075-15-2020-785,dated 23 September 2020).
文摘The time-of-flight technique coupled with semiconductor detectors is a powerful instrument to provide real-time characterization of ions accelerated because of laser-matter interactions.Nevertheless,the presence of strong electromagnetic pulses(EMPs)generated during the interactions can severely hinder its employment.For this reason,the diagnostic system must be designed to have high EMP shielding.Here we present a new advanced prototype of detector,developed at ENEA-Centro Ricerche Frascati(Italy),with a large-area(15 mm×15 mm)polycrystalline diamond sensor having 150 μm thickness.The tailored detector design and testing ensure high sensitivity and,thanks to the fast temporal response,high-energy resolution of the reconstructed ion spectrum.The detector was offline calibrated and then successfully tested during an experimental campaign carried out at the PHELIX laser facility(E_(L)~100 J,τ_(L)=750 fs,I_(L)(1-2.5)×10^(19)W/cm^(2))at GSI(Germany).The high rejection to EMP fields was demonstrated and suitable calibrated spectra of the accelerated protons were obtained.
