A FEW QUICK FACTS ABOUT THE TRIUMF CYCLOTRON
CYCLOTRON FUNCTION :
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 INSIDE the 520 MeV CYCLOTRON
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 : 16,000,000 microamp-hours to March 2010.
VACUUM TANK : Defines the volume where the beam can be accelerated in a very good vacuum (reduces air molecule collisions).
VACUUM TANK SUPPORT STRUCTURE :
A 12-armed "spider" support structure weighing about 120 tons (109,000kg), was fabricated from 12' high 3' wide steel I-beams. Its primary purpose is to anchor the upper tie-rods thus resisting the atmospheric load on the lid. It also supports the upper magnet sectors, tank lid and internal components when the lid is lifted. When lowered, the spider rests on the top of the 12 jack columns.
MAGNET COIL :
ACCELERATION SYSTEM :
INJECTION SYSTEM :
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-" .
BEAM EXTRACTION SYSTEM :
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:
CYCLOTRON LOCATION : " THE VAULT "
Dimensions : 100ft (30.5m) x 100ft x 39ft (11.9m) high (from floor to underside of roof beams).
This shielding prevents hazardous forms of radiation (neutrons, protons, gamma and beta rays), produced when the cyclotron is operating, from escaping the Vault.
Two large (~3K cu.ft/min.) blowers (one on-line, one standby) exhaust air from the vault through HEPA filters,
thus ensuring that the Vault is always kept at a negative pressure and that any active
particles are contained.
Local Cyclotron Shielding :
More than 200 moveable high-density concrete blocks surround the cyclotron to shield work areas. These blocks were constructed with metallic aggregate (iron ore from Texada Island B.C.) and are ~40% heavier than normal concrete (5,400 v.s. 4,000 lbs/cu.yd.) These blocks contain a high percentage of water to trap neutrons and heavy elements to stop gammas.
Elevating System :
Twelve jack columns each comprise a twenty-horsepower electric motor, two Highfield 60:1 gear-reduction boxes and two jack screws. These jacks elevate the "spider" support structure which thereby lifts the upper magnet halves, tank lid and internal components, a total weight of ~2000 tons. The time it takes for the elevating system to reach the 48-inch (122cm) upper limit, is 35 minutes.
Each pair of jacks has a servo which reads the amount the jack has moved. When the lid is travelling, each of the 12 servos is constantly compared to a master servo which is being driven by a small motor at a rate which is just a bit slower than the jacking system.
When a jack servo gets 0.03 inch ahead of the master servo, the elevating control system shuts off the respective motor until the master servo catches up. The entire top half of the cyclotron (~2000 tons) can be raised 48 inches with no more than + or - 0.050 inches difference between the jacks. Interlocks stop the entire system if any jack goes out of range.
SAFETY 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 numerous watchman stations along the route ensures that the entire area is searched. 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 automatically locked in place. Subsequently this key may only be released from the ASU, only from the Main Control room, and only if the Central Safety System logic is satisfied that it would be safe to do so.
If the searach procedure was 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 an automated announcement and warning horn to sound in the Vault for 1 minute. Anyone in the locked-up area hearing this 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 will 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: