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Program of scientific cooperation for PETAL



Round Table 1: Physics with the PETAL: Challenges and limitations
The discussion on this round table concerned with the key physical problems that can be approached with the PETAL installation or in joint PETAL+LIL experiments.
G. Schurtz (CELIA) presented the program of research on the inertial fusion in CELIA and a potential of PETAL for addressing the bottlenecks: stability of target compression and the laser-plasma interaction physics, the generation of high amplitude shocks and the role of hot electrons, the fast ignition issues related to the cone survival, fast electron generation and transport. The need of reproducible and robust particle sources has been underlined.
J.-N. Scheurer (CENBG) presented a program of nuclear physics research with high intensity lasers. The usefulness of the nuclear activation diagnostics has been emphasized. The of the CENBG proposed to study the NEET process with the isomeric nuclei Rb84 on PETAL+LIL experiment.
Several presentations were related to the physics of proton acceleration with lasers. A. Andreev (GOI) discussed the utilization of mass limited targets for more efficient proton acceleration. A possibility to use a nanostructured front target surface in order to improve the laser-plasma coupling has been demonstrated. Collaboration in the 3D simulations of laser interaction with mass-limited targets is proposed as well as the fabrication of such targets and joint experiments on the laser in RICTOED, Sosnovy Bor. A. Brantov (LPI) proposed a scheme of optimization of proton production in laser plasma interaction and demonstrated 3D PIC simulations that predict generation of 200 MeV protons with a 30 J laser pulse from a mass-limited target. S. Guskov (LPI) discussed a possibility of light ions (He, Li, Be, B, C) acceleration with PETAL laser and their application for the fast ignition of fusion targets. The effect of the Bragg peak opens possibilities for fine tuning of the energy deposition. Further studies can be conducted as a collaboration project.
The following subjects have been identified as suitable for collaboration and for designing experiments for PW-scale lasers:
I. Physics of fast ignition: cone survival, transport of high currents of charged particles in hot dense matter, choice of the carrier particles and optimization of ignition conditions, issues related to the shock ignition.
II. Astrophysics in laboratory with lasers: radiation accretion shocks in young stellar objects, opacity measurements for the stellar interiors, equations of state for the planet interiors. In view of limited number of shots available at the first stage of the PETAL program, it was considered to conceive and to propose the experiments that can benefit both the astrophysical and the ICF communities.
III Fundamental physics: nuclear physics with lasers (production of isomeric nuclei), physics of high intensity laser plasma interaction (strong magnetic and electric fields, nonlocal energy transport), high energy density physics (development of new, more detailed equations of state, studies of transport and optical properties of non ideal plasma, modeling of atomic transitions and opacities), laser driven melting and ablation (especially with sub-ps laser pulses). In particular, the studies in the domain of equations of state, transport and optical properties of non ideal plasma can strongly benefit from the collaboration between the scientists of JIHT and the consortium MHEDOC.
It was mutually acknowledged that the collaboration in the domain of development of secondary sources of energetic charged particles, neutrons and radiation is absolutely necessary for all envisioned applications of PETAL and the collaboration in this domain is strongly advised. The particular subjects of collaboration could be: production of quasi-monoenergetic and stable source of protons with the energy ~ 200 MeV for medical applications, laser wake field electron acceleration, new sources of X-ray radiation using solid and nano-structured targets, powerful sources of THz radiation, laser-driven gamma-ray sources.

Appendix 3: Program of scientific cooperation for PETAL

Round Table 1: Physics with the PETAL: Challenges and limitations
The discussion on this round table concerned with the key physical problems that can be approached with the PETAL installation or in joint PETAL+LIL experiments.
G. Schurtz (CELIA) presented the program of research on the inertial fusion in CELIA and a potential of PETAL for addressing the bottlenecks: stability of target compression and the laser-plasma interaction physics, the generation of high amplitude shocks and the role of hot electrons, the fast ignition issues related to the cone survival, fast electron generation and transport. The need of reproducible and robust particle sources has been underlined.
J.-N. Scheurer (CENBG) presented a program of nuclear physics research with high intensity lasers. The usefulness of the nuclear activation diagnostics has been emphasized. The of the CENBG proposed to study the NEET process with the isomeric nuclei Rb84 on PETAL+LIL experiment.
Several presentations were related to the physics of proton acceleration with lasers. A. Andreev (GOI) discussed the utilization of mass limited targets for more efficient proton acceleration. A possibility to use a nanostructured front target surface in order to improve the laser-plasma coupling has been demonstrated. Collaboration in the 3D simulations of laser interaction with mass-limited targets is proposed as well as the fabrication of such targets and joint experiments on the laser in RICTOED, Sosnovy Bor. A. Brantov (LPI) proposed a scheme of optimization of proton production in laser plasma interaction and demonstrated 3D PIC simulations that predict generation of 200 MeV protons with a 30 J laser pulse from a mass-limited target. S. Guskov (LPI) discussed a possibility of light ions (He, Li, Be, B, C) acceleration with PETAL laser and their application for the fast ignition of fusion targets. The effect of the Bragg peak opens possibilities for fine tuning of the energy deposition. Further studies can be conducted as a collaboration project.
The following subjects have been identified as suitable for collaboration and for designing experiments for PW-scale lasers:
I. Physics of fast ignition: cone survival, transport of high currents of charged particles in hot dense matter, choice of the carrier particles and optimization of ignition conditions, issues related to the shock ignition.
II. Astrophysics in laboratory with lasers: radiation accretion shocks in young stellar objects, opacity measurements for the stellar interiors, equations of state for the planet interiors. In view of limited number of shots available at the first stage of the PETAL program, it was considered to conceive and to propose the experiments that can benefit both the astrophysical and the ICF communities.
III Fundamental physics: nuclear physics with lasers (production of isomeric nuclei), physics of high intensity laser plasma interaction (strong magnetic and electric fields, nonlocal energy transport), high energy density physics (development of new, more detailed equations of state, studies of transport and optical properties of non ideal plasma, modeling of atomic transitions and opacities), laser driven melting and ablation (especially with sub-ps laser pulses). In particular, the studies in the domain of equations of state, transport and optical properties of non ideal plasma can strongly benefit from the collaboration between the scientists of JIHT and the consortium MHEDOC.
It was mutually acknowledged that the collaboration in the domain of development of secondary sources of energetic charged particles, neutrons and radiation is absolutely necessary for all envisioned applications of PETAL and the collaboration in this domain is strongly advised. The particular subjects of collaboration could be: production of quasi-monoenergetic and stable source of protons with the energy ~ 200 MeV for medical applications, laser wake field electron acceleration, new sources of X-ray radiation using solid and nano-structured targets, powerful sources of THz radiation, laser-driven gamma-ray sources.

Round Table 2: PETAL diagnostics
Several propositions for joint development of the diagnostic equipment for the PETAL experiments have been identified.
Preplasma diagnostics
The proposition of Russian colleagues consists in using a probe beam for diagnostics of the effect of the PETAL prepulse on the target. It is suggested to measure the shape of the preplasma on grazing incidence by using the shadowgraphy, interferometry and polarimetry. The possibility of having a probe beam needs to be studied. It might be possible to use the laser from VISAR station.
Moreover, a specific diagnostic can be developed that will allow to measure the pulse contrast in each shot with a very high dynamic range. This point is crucial and it needs more deep discussions.
Contact persons: Rupasov Alexander, LPI, Sebastien Hulin, CELIA
Proton streak camera, version 1
Russian scientists from RFNC-VNIITF propose to develop a proton streak camera. A scintillator will be used for converting the protons in photons. A streak camera looking the backside of spectrometer provides a temporal resolution of the signal. The proton spectrum is obtained by measuring their time of flight.
Contact persons: Loboda Evgenii, RFNC-VNIITF, Sebastien Hulin, CELIA
Proton streak camera version 2
Russian scientist from RFNC-VNIIEF propose to develop a proton streak camera that used special type cathode and secondary electron emission to convert protons current to electron current. The electron current is amplified in the EOC and a proton image with a high space and time resolution is registered using a CCD.
Contact persons: Belkov Sergey, RFNC-VNIIEF
High resolution X-ray spectroscopy
In the region 10-20 keV a Mica crystal can perform measurements. The crystal curvature can be chosen from 100 mm up to few meters. So we can consider the practical possibility to use such type of crystal in the LIL diagnostic station DP 1.12
Contact persons: Skobelev Igor, JIHT-RAS, Sebastien Hulin, CELIA
K-alpha imagery
A similar arrangement can be applied for the K-alpha imagery. With mica crystals in the 10-20 keV it seems possible to study the substrate geometry (spherical) for K-alpha imagery over 10keV.
Contact persons: Skobelev Igor, JIHT-RAS, Sebastien Hulin, CELIA
Transmission spectrometry
with very thin multilayers it is possible to obtain a transmission spectrum over 10 keV
Contact persons:: Saveliev Andrey, MSU, Sebastien Hulin, CELIA
Thomson spectrograph
The GOI/RICTOD volunteers for construction of the Thomson spectrograph for the fast proton diagnostics on PETAL. The unit that is actually under development has the magnetic field 0.2-0.3 T, a size of 60Ч60Ч250 mm and a weight of 6-8 kg. It allows recording the protons in the range of 2 – 150 MeV.
Contact persons: Andreev Alexander, GOI, Sebastien Hulin, CELIA