T1 and T2 beryllium target failure history was investigated back to 2000 (as far as XSTRIP records were readily available).  For each target cassette the following were noted: length of time the target was subject to direct beam, length of time the target was on the ladder w/o direct beam, and method of failure.  The purpose of the study was to devise a target replacement strategy so that T1 and T2 beryllium targets are preemptively retired from service to reduce the occurrence of failure while running which causes loss of beam time, extra dose to personnel, and damage to equipment.

The following recommendations are the result of the study:
- T1 beryllium targets should be retired after 9.0 months of running time
- T2 beryllium targets should be retired after 12.0 months of running time
- Multiple targets should be installed on each target ladder (at least 2, possibly 3) so that targets may be switched during a running period if required and less target assembly moves are required

A PDF copy of the Excel spreadsheet is attached which includes target use history, failure history, summary of results, and more specific recommendations for each target assembly.  This study and the replacement plan recommendations were reviewed and endorsed by Grant Minor and Yuri Bylinski.  This spreadsheet should be reviewed and updated every shutdown period (including Fall mini-shutdowns), as well as anytime there is a target failure.