LNF:Technology: Difference between revisions

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===2 MeV ELECTRON VAN DER GRAAF ACCELERATOR===
===2 MeV ELECTRON VAN DE GRAAFF ACCELERATOR===


[[File:Foto1electrones.png|500px|thumb|right|Electron Accelerator]]
[[File:Foto1electrones.png|500px|thumb|right|Electron Accelerator]]


This facility permits either direct irradiation with 2 MeV electron or Bremsstrahlung irradiation produced by stopping the electron beam at beam currents up to  150 µA. In this way the same type of radiation testing that is carried out using Co-60 irradiation facility can be done but more rapidly (higher and well controlled dose rate) performing the corresponding measurements during irradition, in-situ.
This facility permits material irradiation either by a 2 MeV electron beam or by Bremsstrahlung induced by stopping the electron beam. In this way, radiation testing that is normally carried out using a Co-60 source can be undertaken more rapidly (producing a larger and better controlled dose rate) while allowing in-situ measurements. Irradiation parameters (temperature, vacuum pressure, gas environment, dose rate and beam energy) are well controlled. Moreover, irradiation of relatively large components or material samples is possible. The accelerator staff can design and develop different irradiation chambers and experimental set-ups depending on irradiation requirements. Such experimental systems permit performing optical, electrical and dielectrical measurements during irradiation ("in-beam"). This makes it a unique experimental radiation facility in which simultaneous optical, electrical and dielectrical measurements can be made in the range of Hz to GHz. For this, systems to measure optical absorption and radioluminescence, electrical conductivity and dielectric properties during irradiation (in-situ) are mounted on the accelerator beam line.
Irradiation parameters (temperature, vacuum, special gas environment, dose rate and beam energy) are strictly controlled. Irradiation of relatively big components or materials is possible. The same accelerator staff design and develop different irradiation chambers and experimental set-ups depending on irradiation characteristics. The developed experimental systems permit making optical, electrical and dielectrical measurements during irradiation ("in-beam"). Particularly, this is a unique experimental radiation facility in which simultaneous optical and electrical and dielectric measurements at between Hz and GHz can be made during irradiation. Systems to measure optical absorption and radioluminescence, electrical conductivity and dielectric properties during irradiation (in-situ) are mounted in the accelerator beam line  




Beam characteristics;
Beam characteristics;
Electrons, 0.25 to 2.0 MeV, 10 pA to 150 µA
Electron energy: 0.25 to 2.0 MeV. Beam current: 10 pA to 150 µA
Samples from ≈ 3 mm2 to about 20x20 cm2
Sample size from ≈ 3 mm2 to about 20x20 cm2.
At target area unfocussed beam is ≈ 1 cm diameter
Unfocused beam diameter at target is ≈ 1 cm
Beam can be focussed to ≈ 1 mm diameter for very small samples
Beam can be focused to ≈ 1 mm diameter (for small samples)
Beam can be defocussed to ≈ 3 cm diameter  
Beam can be defocused to ≈ 3 cm diameter  
Beam can be scanned over 20x20 cm2 for very large samples
Beam can be scanned over 20x20 cm2 (for large samples)


The facility has been used for insulator work in which low dpa rates must be employed and where ionization is important. The facility includes in-beam testing at controlled temperatures in vacuum or different gas environments, for electrical, dielectric (RF), and optical properties of solid and gas insulators.
The facility has been used for studying insulators for which low displacement per atom (dpa) rates are required. The facility allows in-beam testing at a controlled temperature of the electrical, dielectric (RF), and optical properties of solid and gas insulators. Irradiation can be performed in high vacuum, air, or controlled atmospheres (such as N or He).


For insulator work typical dpa rates range from about 10-12 to 10-8 dpa/s
For insulator studies typical dpa rates range from about 10-12 to 10-8 dpa/s while ionization rates (Bremsstrahlung or direct electron irradiation) range form 0 to ≈ 104 Gy/s
and ionization rates (Bremsstrahlung or direct electron irradiation) 0 to ≈ 104 Gy/s
For steels, about 10-3 dpa/day can be achieved in samples of approximately 3x3x1 mm3.
For steels we can reach about 10-3 dpa/day in volumes of approximately 3x3x1 mm3.




Flexibility
Flexibility
The instalation is extremely flexible and has several unique in-beam systems for measuring electrical conductivity, dielectric loss and permittivity (Hz to GHz), and optical absorption and emission during irradiation over a wide range of dose rates and temperatures. Irradiations can be performed in high vacuum, air, or controlled atmosphere such as N or He. Simulation in electron accelerators offers important advantages, namely easy experimental parameter control  and high dose rates available (0 a ≈105 Gy/s).
The facility is extremely flexible and has several unique in-beam systems for measuring electrical conductivity, dielectric loss and permittivity (Hz to GHz), and optical absorption and emission during irradiation over a wide range of dose rates and temperatures. Irradiations can be performed in high vacuum, air, or controlled atmosphere such as N or He. Simulation in electron accelerators offers important advantages, namely easy experimental parameter control  and high dose rates available (0 a ≈105 Gy/s).


In-situ measurement capability and expertise.
In-situ measurement capability and expertise.
At this facility different studies on candiadate fusion insulators have been carried out, in particular electrical, optical and hydrogen and helium diffusion properties are measured routinously during irradiation, in-situ.  These studies are carried out at controlled temperature, from liquid nitrogen up to 1000 C. Available special irradiation chambers and sample holders have been designed by the accelerator staff and fabricated at the Ciemat workshops. The irradiation can be performed either in vacuum or gas at controlled pressure. (helium, nitrogen, hydrogen etc).
To date a range of studies have been carried out on fusion candidate insulators. For instance, electrical, optical as well as hydrogen and helium diffusion properties are measured during irradiation.  These studies are carried out at a controlled temperature, from liquid nitrogen up to 1000 C. For these studies special irradiation chambers and sample holders have been designed by the accelerator staff and have been fabricated at the Ciemat workshops.
 


===60 keV DANFYSIK ION IMPLANTER===
===60 keV DANFYSIK ION IMPLANTER===
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