Fermilab Linac Transfer Line to Booster.

On the left is the 400-MeV beam line from the Linac; on the right is a Booster magnet girder. The 400-MeV line transfers 400 MeV H-minus ions from the Linac (linear accelerator) to the Booster injection girder (next image). The two electrons are stripped from the H-minus ion during injection, and the beam is then accelerated to 8-Gev in the Booster synchrotron.

The Booster injection girder. H- (unpronounced "H-minus") ions (singly charged negative ions of hydrogen) pass through a "stripping foil" that removes the two valence electrons and leaves the single proton to be accelerated in the Booster.

Single Booster RF cavity.

Booster beam absorber from upstream view.

Booster Beam Absorber (viewed from down stream)

The Booster accelerates protons in discrete ensembles of beam called bunches. The number of bunches it accelerates is the ratio of the frequency of the RF signal to the revolution frequency of the beam. That ratio is called the harmonic number, h, of the accelerator. In Booster h = 84. The 84 bunches fill the machine completely. In order to cleanly transfer the beam to the Main Injector or the BNB, three of the 84 bunches are kicked out of the machine just prior to acceleration. Those bunches are kicked into this, and other absorbers in the ring.

Measuring Radiation at a Booster RF Cavity

An operations specialist measures residual radiation during a controlled access to the Booster. Particle accelerators present minimal radiation safety hazards when they are not operational. During operation, beam loss leads to activation of some components in close proximity of the beam. Most areas of the enclosure are under 5 mREM/hour measured at one foot. Some locations are higher. Areas that exceed 5o mREM/hour at one foot are considered high radiation areas and require planning and permission from the radiation safety officer (RSO). For reference, an average person living in the American mid-west receives about 315 mREM/year from all sources (cosmic rays, radon, TV, smoke detectors, air travel, etc.). This number was calculated by the US Nuclear Regulatory Commission dose calculator.

A pair of Booster RF (radio frequency) cavities used to accelerate protons to 8-GeV. Booster uses up to 20 RF cavities to accelerate protons.

Booster beam absorber

Booster Extraction

Fermilab Booster extraction beam line (top) and dump line (bottom). The extraction line delivers 8-GeV protons to either the Main Injector, the Recycler, or the Booster Neutrino Beamline (BNB). Protons bound for the MI or RR will be used primarily for making neutrinos for various experiments (NOvA, MINERvA, MINOS); others will be sent to the SY120 program and others to the Muon Campus experiments (g-2 & Mu-to-e).