We will work together with PSI staff to develop a more complete safety plan to the standards of the laboratory, however we do not expect to have any unusual hazards on this experiment. Areas of safety are listed below:
Issue: The photomultiplier tubes (360 of them) are operated up to about 2500 volts.
Hazard: There is a potential shock hazard if the high voltage is contacted or if grounding fails.
Action: The HV to the photo tubes will be turned off, if maintenance of the tubes or bases is required. Under normal operation the HV is controlled by a slow-control computer. The controls will include an ``off for maintenance'' option. The high voltage supply (LeCroy Research model 1440) has low current trip limits on each HV line. Thus sustained currents are not possible. Only SHV connectors and HV-rated coaxial cables (RG-59) are used.
Issue: The scintillators and light guides are flammable plastic materials.
Hazard: When plastic burns, there is a potential for noxious fumes. A fire would damage the experiment.
Action: There is no obvious source of fire, since there are no nearby sources of intense heat. The total quantity of plastic is also not large.
Issue: Each photomultiplier assembly has 1 to 2 coaxial signal cables and 1 HV cable.
Hazard: Cable is flammable.
Action: Cable will be chosen to meet PSI fire regulations. There will be no obvious sources of heat to ignite the cables.
Issue: The calibration and monitoring system of the detector uses a pulsed nitrogen Class-IIIb laser, which operates in the UV at 337 nm.
Hazard: UV light is a personal hazard. HV is present.
Action: The HV in the laser is completely sealed. In normal operation the safety hazard of the laser is low since the laser light is completely enclosed by a jacketed optical fiber. Only persons trained in laser safety may operate the laser. One person will be designated as being in charge of safe operation of the laser. A standard caution label is fixed to the laser housing. The laser can only be operated if the master key is engaged, and the key will be available only to qualified personnel. During laser maintenance operations, eye protection will be mandatory.
Issue: Low activity (<100 microcuries) sealed beta and gamma sources are used from time to time to test the detectors.
Hazard: The sources represent a source of ionizing radiation.
Action: One person will be designated to be in charge of radioactive sources and for the training in their use, storage, and inventory. Radiation monitoring will be in accord with PSI regulations.