Synchrotron Utilization Section

The beamlines are enclosed in radiation shielding enclosures called hutches made of lead sheets sandwiched in between M.S. sheets. A typical beamline consists of three hutches- Optics hutch, Intermediate hutch and Experimental hutch. Entry to hutches is forbidden during beamline experiments. This requires implementation of interlocks to make sure that no one is present inside beamline during operation.
Personnel Safety Interlocking System (PSIS) is designed to protect the people from being exposed to radiations present inside beamline hutches during beamline operation. The final control element to stop radiations as well as beam is the safety shutter inside the shielding wall. PSIS ensures that certain conditions are met in a proper sequence before safety shutter is allowed to open.Thus beam is brought into the beamline after search procedure is followed. If any condition arises which may cause accidental exposure, PSIS will generate NOT OK and will CLOSE the safety shutter immediately. Figure 2 shows the various panels of PSIS.

1. PSIS ensures that a search has been carried out and beamline hutches are secured by electrical door locks before taking out the synchrotron beam.
2. It ensures that the beam is shut off in case of any potentially unsafe condition.
3. PSIS is basically a Search & Secure System essential for licensing of beamline operation from AERB.
4. The system is fail-safe, redundant, scalable and configurable.



Fig 1a: Main Controller
Fig 1b: Search & Scram Panel	Fig 1c: Door Exit
Fig 1d: Door Lock	Fig 1e: Status display Panel

Ozone removal and interlocks:

Two exhaust fans are installed at White-beam Experimental hutch for removal of ozone formed inside the hutch. Air flow switch is mounted on each fan duct to monitor the air flow in the duct. These air flow switches are used along with timers to interlock SS and hutch doors for the safe operation of the beamline.

1. If both or any one of the two fans is not operating, SS is not allowed to Open. 2. If SS is closed and exhaust fans are working, doors will remain locked for 3 mins. This will ensure that ozone inside the hutch has been removed before opening hutch doors and allowing entry inside the hutch. 3. If any fan stops working during experiments at beamline, SS will be closed immediately and hutch doors will remain locked for 10 mins to allow natural decay of ozone.