Laser acceleration of ion beams

1
Laser acceleration of ion beams

• M.Chubaryan1, A.V. Prozorkevich2,
• S.A. Smolyansky2 and I.A. Egorova2
• 1JINR, Dubna
• 2Saratov State University

2
Introduction

• The most powerful particle accelerator, is under
  construction at CERN, that is 8.6-kilometer-diamet
  er LHC. The collisions of its two
  seven-trillion-volt proton beams should tell us
  what gives particles their mass.
• To provide high energy by linear accelerator is
  very expensive and need a great construction.
• Recently scientists consider new methods of the
  particle acceleration by the laser radiation.
  Therefore, we want examine possibility of the
  acceleration of the nucleus (from He to Au).

But
3
Surfing on plasmas
J.Chandrashekar Scientific American, may 05,
2006
J.M. Dawson from the University of California,
Los Angeles first proposed this general method in
1979.

• The process works in this way
• A pulse from an intense laser creates a
  disturbance in the plasma. The beam creating a
  region of excess positive charge and a region of
  excess negative charge and forming an electron
  bubble around the positive region.
• This region inside bubble pulls the negatively
  charged electrons back.

4
The bubble regime

• The disturbance forms a wave of the Coulomb field
  that travels through the plasma with the bubble
  at nearly the speed of light and accelerates any
  charged particles that come under its influence.

Experiments have been taking place recently gave
good results. Problem The realization of
similarly process for positive ions is not
developed.
5
The methods of acceleration with using of the
gradient force
A.V.Gaponov, M.A.Miller, JETPH,34,242 (1958)

• We will begin with consideration of a principle
  of action of this force. Let us consider a plane
  standing electro-magnetic wave.

Since particles move aside the reduction of
potential then as time goes by they gather in
units. In each point gradient force has a
cross-section and longitudinal component. But the
longitudinal component in the sum gives zero.
Hence the gradient force operates only with a
cross-section direction and it does not bring the
contribution to the longitudinal acceleration.
The plane electro-magnetic wave potential
6
Acceleration by means of high-frequency moving
knots.

• Using fluctuations with various frequencies it is
  possible to carry out the accelerated movement of
  potential holes and, hence, to make accelerations
  of the particles localized in holes.
• Using fluctuations with various frequencies it is
  possible to carry out the accelerated movement of
  potential holes and, hence, to make accelerations
  of the particles localized in holes.

Movement of knot occurs at change of frequency of
one of lasers
7

• Because of cross-section heterogeneous fields an
  intensive laser beam can push out particles from
  the field
• It occurs when frequency of a wave is much larger
  then own frequency of a particle. Using it, it is
  possible to accelerate particles
• 1. By the front of the ultra short laser
  impulse.
• 2. By the moving laser focus
• The focus motion is carried out by changing of a
  focal length at time.

8
Is the theory relativistic or nonrelativistic?

• The basic parameter of the theory
• (the adiabatic parameter)
• allows to select the characteristic
• regions

is the average of electric field
is the frequency of field
The nonrelativistic region
ion charge
The relativistic region
The ultrarelativistic region
ion mass
9
Parameter as a function of ion charge and mass
for some laser fields (Y.I.Salamin)