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        To accelerate an H-minus ion beam, from 300 KeV to a maximum of 520 MeV in order to extract simultaneous proton beams
        at various energies and currents, into numerous beamlines, for delivery to targets for the designated experiments.

The  CYCLOTRON  with lid raised   The Cyclotron in the Vault with the lid raised for servicing         INSIDE  the  520 MeV  CYCLOTRON   Inside the Cyclotron with the lid raised for servicing.

Cost : The cyclotron and its associated systems cost about $12,000,000 (1974 CDN dollars)

Beam first extracted : 15 December 1974.

Peak intensity : 400 uA peak at 50% duty cycle achieved June, 1987.

Typical Operating Currents :

Beam delivered : 7,000,000 microamp-hours to March 2001.


VACUUM TANK : Defines the volume where the beam can be accelerated in a very good vacuum (reduces air molecule collisions).






Injection beam: H- ions. An "H-" beam is composed of hydrogen (1 proton (positive) & 1 electron (negative)) with 1 electron added. This results in an overall negative charge. Thus "H-" .



Vacuum pipe material : non-magnetic stainless steel

Vacuum seals : double-knife-edge steel on indium. Other forms are used for temporary setups

Magnets : Front end elements are radiation-hard and remotely handlable. The conductors are directly cooled hollow copper tubes (cooling water flows through the conductors). Noteable exceptions are the
combination magnets which are mounted on the extraction horns and guide the beam out of the cyclotron into the beamlines. Combination-magnet conductors are mineral-insulated and indirectly cooled.
Water cooling is via a closed-circuit, low-conductivity, copper-only system. Magnet specifications are available in the Control-Room copy of the TRIUMF MAGNET INDEX which lists all the beamline magnets
on the site and gives their specifications.

Vacuum system : There is some pumping from the cyclotron tank itself, beamline vacuum is primarily achieved by turbo-molecular pumps.

Beam tunes and currents: Both Achromatic and Dispersed tunes are possible:


Dimensions : 100ft (30.5m) x 100ft x 39ft (11.9m) high (from floor to underside of roof beams).

Ventilation :

Local Cyclotron Shielding :

Elevating System :


Lockup : The SAFETY SYSTEM will not allow beam to be injected until the Vault is secured. This is accomplished by a "deadman-switch" and "watchman-station" lockup search procedure. Two qualified persons
are required to perform this task. All access doors must first be closed leaving these two people inside the Vault. One person holds the dead-man switch while the other goes on a pre-determined route and checks that
no personnel are left in the vicinity, pushing buttons to activate watchman stations along the route. When all the stations have thus been activated, the two lockup personnel and anyone found in the vault must then
leave the Vault by a pre-determined door. With no one left in the Vault, this door is then locked, its key removed and inserted into the Vault Area Safety Unit (ASU) where it is held in place. This key may only be
released from the ASU, only from the Main Control room, and only if the Safety System logic is satisfied that it would be safe to do so.

If the walkaround were to be interrupted by someone opening a door and entering the Vault, or if the first member of the lock-up pair were to release the dead-man switch, or if the lockup were to take too long, the
lockup sequence would automatically be aborted, and the entire lockup sequence must be repeated.
After a successful lockup, the "Secured" sequence begins. Pushing a button on the Area Safety Unit causes a very loud horn to sound in the Vault for 1 minute. Anyone in the locked-up area hearing the horn is able to
prevent the area from becoming "Secured" by pressing any one of many Emergency Trip buttons. This person must then leave the area immediately, using a breakbolt on any exit door, if necessary. This would also
cause the vault to go unsecured. Only after a proper lockup and Secured sequence would the Central Safety System (CSS) allow beam to be injected into the Cyclotron.

Beamspill Monitors (BSM): There are numerous beamspill monitors continuously operating in the Vault that warn the Control Room if excessive beam should strike the cyclotron or beamline elements.
Some of these monitors will shut off the cyclotron if the spill reaches a pre-determined level. These BSM's are also used to measure the residual fields so that a determination can be made as to wether entry may be
permitted or denied. There are also numerous monitors measuring neutron fields and air activation. The Control Room monitors and records all radiation measurements. All monitors are calibrated and tested at least
once a year and critical monitors are done once every week during beam operation periods.

Surveys : Before any workers can do installation or maintenance in the Vault, the area is surveyed by Safety personnel and signs are posted. Every worker must carry a pocket dosimeter to record any radiation dose.
Thus, the dose for each job may be predicted for the next occurance.

CCTV : During shutdowns and extended maintenance periods, television cameras are installed in the vault. Due to radiation considerations, the cameras must be removed during beam operation.

Drainage : The Main Accelerator Building is more than twenty feet (>5m) below the water table. Pumps continuously drain the subsurface ground water into the storm sewer system.
In case of power failure, the pumps are powered by the emergency generator system.

Many systems deemed critical for both personnel and facility safety, can be powered via the five generators on site: