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Beam Requests and Allocations

There are usually two high-intensity running periods a year at TRIUMF, a long period of about 20 weeks in the spring and summer, plus a short period of about 9 weeks in the autumn. Beam time is usually allocated in quanta of "weeks" - 5-7 days (8-14 shifts) of 24-hour-per-day operation - separated by maintenance days during which any apparatus changes are normally completed.

Spokespersons for EEC-approved experiments will be contacted by TRIUMF management approximately 100 days before each beam period and asked to submit beam time requests using the interactive forms.

After the beam time requests have been collected, they are ordered according to the priority rating given by the EEC and according to the remaining beam allocation available. (Experiments which have not taken beam-time for two years and have not appeared in front of the EEC are no longer eligible.) The head of the TRIUMF science division, with the help of the beamline coordinators, produces a rough outline of the schedule, and then each beamline coordinator provides a possible schedule for the respective channel(s). Experiments are then placed on the schedule according to priority, preferred instrument availability, and preferred period.

With luck, there will be enough beam-time available to satisfy all the outstanding requests, but that is unusual. When conflicts occur, the scince division head makes the final selection of which experiment will get time, taking into account: the past performance (effective use of beam-time, publications); thesis requirements; how much total beam-time is already allocated to that same group; and the possibility of delaying the experiment to the next beam period (when it would be given precedence over other experiments of equal priority).

A draft schedule is circulated to get feedback, in particular for those cases where some of the specific requirements could not be met or conflicting demands could not be resolved. A final scheduling meeting is held at TRIUMF and the schedule is then frozen.


next up previous
Next: Timing of Beam Requests Up: Having an Experiment Approved Previous: The Experimental Proposal

The TRIUMF CMMS