The XBPM has been re-calibrated and positional feedback can be used.
Limited testing at 94% attenuation has shown that when the beam is moved to the edge of the camera region at 5x magnification, the beam will be returned to the predefined origin.
Please keep in mind that at high attenuation, the reported beam position will not be accurate and the beam may be moved away from the defined origin. This can be tested by turning off feedback, moving to the required attenuation and observing if the reported position deviates significantly from that reported with standard attenuation (94%). If this occurs, leave the positional feedback off until returning to a lower level of attenuation.
If problems are noticed with beam drift or any malfunction of the positional feedback system, please notify the staff.