kRad exposure:

H. Wieman 9/8/04

Review of the expected dose for HFT for Dulinski

The average hit rate during a fill at the inner layer at 1.5 cm radius is covered in:

http://www-rnc.lbl.gov/~wieman/HitDensityMeasuredLuminosity3.htm

And it is based on Tom Roser luminosity projections for RHIC

http://www.star.bnl.gov/protected/future/planning-docs/roser-lumi.doc

particle flux at the inner radius of 1.5 cm

Years 2006-2009

doubles for 2010 and doubles again in 2011

dose assuming 40% duty factor and 21 week operation per year

energy loss for min I in silicon

definition of rad see:
http://physics.nist.gov/cuu/Units/outside.html

This is the dose in kRad for the Silicon at 1.5 cm with predicted luminosity in 2008, 21 weeks per year and 40% operating efficiency

If the luminosity goes up as Roser prediction then the total dose for 2008-2011 operation will be 16 krad. In the past from TPC studies at STAR it was believed that the total dose was almost entirely from interactions. There is now some evidence that beam gas may also contribute. This will have to be measured.