6
Plasma Acceleration
6.1 Motivations
105 Plasma acceleration is an emerging and promising field,
6.2 Early steps of
whose rapid progress is enabled by developments in laser
plasma acceleration technology — particularly by the method of chirped pulse
107
amplification. Plasma accelerators of electrons — the pri6.3 Laser intensity and mary focus of this chapter — are the backbones of future
ionization
108 compact light sources. Proton and ion plasma acceleration,
6.4 The concept of laser briefly discussed here and in closer detail in Chapter 9, are a
acceleration
114 potential way to improve future medical accelerators.
6.5 Betatron radiation
The aim of this chapter, after a brief introduction and dissources
118 cussion of the motivations for pursuit of plasma acceleration,
6.6 Glimpse into the
is to develop the framework that will help us to estimate the
future
120 parameters of laser plasma-based light sources, so as to be
6.7 Plasma acceleration prepared for Chapter 7.
aiming at TeV 122
6.8 Laser-plasma and
protons
124
6.1 Motivations
The “Livingston plot,” which depicts the energy of accelerated beams versus time (Fig. 1.6), illustrates the great history of accelerators and related inventions. It also shows the
Recalling the use of Acceler- signs of saturation, highlighting the need for the next breakating Science TRIZ method: through in accelerator technology.
1) Define the problem in
Traditionally, accelerating structures have been made
terms of generic contradic from metal (normal conductive or super-conductive) and
tion parameters (Table 1.4). are typically limited in their accelerating gradient to E z <
To be improved: rate of E 100 MeV/m. This limitation is imposed by the properties of
change; what gets worse: in- the materials — since damage to the accelerating structure’s
tegrity.
walls (deterioration of their integrity) limits the gradient.
2) Use the contradiction maThe “accelerating structures” produced on the fly in
trix (Table 1.5) to obtain the plasma by a laser pulse are, however, made from a material
relevant inventive principle that is already “damaged” (plasma), and therefore do not ex— replace material that can hibit the same limitations due to the material’s properties.
be damaged with other mePlasma acceleration was first proposed by T. Tajima and
dia, which either cannot be J. Dawson in 1979, which was, in fact, too early for laser and
damaged (light) or is already beam technologies to be ready to realize the proposed ap“damaged” (e.g., plasma).
proach. Consequent parallel developments of laser and beam
3) Translate the generic in- technologies — specifically those aimed at creating short,
ventive principle into a spe powerful pulses — created the new reality making the laser
cific solution — plasma ac plasma acceleration the area with the highest degree of synceleration.
ergy between the physics of plasma, lasers and accelerators.
We should also recall (see margin notes) our discussion
105
DOI: 10.1201/b18696-6
Plasma Acceleration
6.1 Motivations
105 Plasma acceleration is an emerging and promising field,
6.2 Early steps of
whose rapid progress is enabled by developments in laser
plasma acceleration technology — particularly by the method of chirped pulse
107
amplification. Plasma accelerators of electrons — the pri6.3 Laser intensity and mary focus of this chapter — are the backbones of future
ionization
108 compact light sources. Proton and ion plasma acceleration,
6.4 The concept of laser briefly discussed here and in closer detail in Chapter 9, are a
acceleration
114 potential way to improve future medical accelerators.
6.5 Betatron radiation
The aim of this chapter, after a brief introduction and dissources
118 cussion of the motivations for pursuit of plasma acceleration,
6.6 Glimpse into the
is to develop the framework that will help us to estimate the
future
120 parameters of laser plasma-based light sources, so as to be
6.7 Plasma acceleration prepared for Chapter 7.
aiming at TeV 122
6.8 Laser-plasma and
protons
124
6.1 Motivations
The “Livingston plot,” which depicts the energy of accelerated beams versus time (Fig. 1.6), illustrates the great history of accelerators and related inventions. It also shows the
Recalling the use of Acceler- signs of saturation, highlighting the need for the next breakating Science TRIZ method: through in accelerator technology.
1) Define the problem in
Traditionally, accelerating structures have been made
terms of generic contradic from metal (normal conductive or super-conductive) and
tion parameters (Table 1.4). are typically limited in their accelerating gradient to E z <
To be improved: rate of E 100 MeV/m. This limitation is imposed by the properties of
change; what gets worse: in- the materials — since damage to the accelerating structure’s
tegrity.
walls (deterioration of their integrity) limits the gradient.
2) Use the contradiction maThe “accelerating structures” produced on the fly in
trix (Table 1.5) to obtain the plasma by a laser pulse are, however, made from a material
relevant inventive principle that is already “damaged” (plasma), and therefore do not ex— replace material that can hibit the same limitations due to the material’s properties.
be damaged with other mePlasma acceleration was first proposed by T. Tajima and
dia, which either cannot be J. Dawson in 1979, which was, in fact, too early for laser and
damaged (light) or is already beam technologies to be ready to realize the proposed ap“damaged” (e.g., plasma).
proach. Consequent parallel developments of laser and beam
3) Translate the generic in- technologies — specifically those aimed at creating short,
ventive principle into a spe powerful pulses — created the new reality making the laser
cific solution — plasma ac plasma acceleration the area with the highest degree of synceleration.
ergy between the physics of plasma, lasers and accelerators.
We should also recall (see margin notes) our discussion
105
DOI: 10.1201/b18696-6