Frequently Asked Questions (FAQ)

What is this structure I see on the beam?

The Main Injector (MI) has a circumference time of 11.13 microseconds. Since we do not fill the entire MI with beam for test-beam cycles, the beam spill will have gaps with a periodicity of 11 μs. There is also the 53 MHz used to accelerate the beam to 120 GeV for extraction. There is also a 60 Hz structure left on the beam due to the line power feeding the magnets of the transport line. For more details see Beam Delivery Path.


Why am I seeing more than one track? What is the double occupancy?

If beam were extracted smoothly, only one particle per MI RF bucket would be extracted per rotation, but for intensities up to 100 kHz, double occupancy occurs 35% of the time and two particles are extracted instead. This percentage can increase at higher intensities. For more details see Beam Delivery Path.


Where should I put my experiment?

If you need muons or flammable gas you will need to be in one of the MT6 Section 2 areas. If you are a small experiment and sensitive to temperature, light or scattering in air, you may want to be in one of the MT6 Section 1 areas. If you are testing a high-rate tracking detector with little mass you may want to be in the M03 area. If you are a long-term experiment (months) or need protons/pions with low energies (200MeV – 1GeV), you should be in the MCenter beamline. For more details see the descriptions of Beam Areas.


What training do I need?

Everyone who comes to the facility will need FTBF Hazard Awareness. Most people will need Controlled Access Training, and Radworker if they are going to make accesses to the beamline. To see the full list of training and how to schedule classes see Training.


How can I tell if I’m receiving beam?

Monitor the beam using the beam profile monitors, found on ACNET page S45, and other parameters found on page S60. For details, see How to Receive Beam. For more information on using ACNET pages and devices, see the ACNET Guide.


How do I communicate with the enclosure/control room?

Phones with speaker capabilities are located throughout the facility and each enclosure/control room has its own extension. Click here for more details.


How far are the targets from the user area?

See Beam Delivery Path.


How much does it cost?

Users are not charged for non-proprietary work if the user intends to publish the research results in  the open literature.