Safety system operation

I have been ckecking into the confusion regarding the operation of the safety system as indcated by fault reports regarding the inability to enable FC5. I will attempt to clarify the operating procedure.

All inputs to the IBSS provide a 24 VDC signal when they are in the safe state. The 24 VDC is sent from the IBSS to the device and a contact closure from the device is sent back to the IBSS. The systems that will trip the Ion Beam Safety System (IBSS) are the Ion Beam Radiation Monitoring System (IBRMS) and the DTL safety system.

The IBRMS sends 2 signals to the IBSS, IBRMS_NOT_TRIPPED and IBRMS_OK which must be satisfied to allow beam operation. The DTL safety system sends a DTL_OK signal to the IBSS which will trip the IBSS if the DTL X-ray monitors trip when the area is opened and RIB could be transported through the RFQ as determined by the status of IB 13 or if the DTL system fails. In either case, the RF would also be disabled.

IBRMS will clear the IBRMS_NOT_TRIPPED signal when any radiation monitor exceeds the trip level.The IBRMS will clear the IBRMS_OK if a zero count or low voltage condition is indicated for any of the detectors. If either of these signals is not set, the IBSS will trip the beam. Some of the IBRMS_OK conditions are not always hard failures but may be trtansient in nature. At present, there is a problem in that the IBRMS will not annunciate the initiating condition. This will be fixed.

Any time there is a safety tripfor the devices the IBSS employs to inhibit or trip beam transport in ISAC a reset must be sent to the IBSS before any of these devices can be enabled.This is done to enforce the procedure so the operator can determine the cause of a safety trip before they continue operation. Our philosophy also requires that a device be enabled by an operator action rather than have to enable set any time the requisite conditions are satisfied.

A display panel will be install to convey the status of the devices that interface to the IBSS.

The steps to take to resume operation after a safety trip are:

1. Go to the IBRMS console to determine the cause of the trip and note it in the log book.

2. If the conditions that caused the trip have been cleared generate a reset from the IBRMS console.

3. Return to the controls console and enable the safety devices.

4. Operation can resume.

Hope this clarifies things.

Lorne King