How it Works: Plasma Wakefield Acceleration with Positrons

researchers use large and powerful

particle accelerators to study nature's

fundamental particles and forces in

particle collisions in 2012 for instance

scientists discovered the Higgs boson

and collisions of two proton beams at

CERN's Large Hadron Collider or LHC

since protons are composite particles

collisions at the LHC are very complex

and difficult to analyze therefore

particle physicists plan a next

generation Collider that would smash

elementary particles into one another

electrons and their antimatter siblings

positrons however current technology

would require accelerators that are tens

of kilometers long and researchers are

looking for alternatives that shrink the

size of colliders while accelerating

particles to increasingly high energies

one promising approach is plasma

wakefield acceleration which has been

shown to work efficiently for electrons

this approach uses pairs of electrons

bunches when an electron dry Bunch

brought up to speed and slacks Fassett

facility enters an ionized gas or plasma

it creates a plasma wake that

researchers used to focus and accelerate

a trailing electron bunch for a positron

Bunch following an electron or positron

drive Bunch the situation is much more

challenging no matter where the

researchers place the trailing positron

Bunch it would experience defocusing in

the wake field depending on the location

the trailing bunch would also slow down

now researchers have found a new method

to speed up positrons instead of using

two bunches

they found that a single positron bunch

interacts with the plasma in a way that

the bunch head creates a wake field that

is accelerating and focusing for the

bunch tail plasma wake field

acceleration for electrons and positrons

could be used one day to build Collider

structures that are a hundred to a

thousand times shorter than current

designs even before then they could

potentially be used as a small-scale

add-on to existing or future linear

accelerators boosting their energy and

collision power

SLAC National Accelerator Laboratory