Summary of Tom's Talk:

• Transport Elements to and from the IP

Using PT's and Yuri's current optics decks, and Andy's very raw calculations of engineered magnet sizes Tom showed plan views of the IP.  As currently specified there are several interferences between the injection and extraction lines.   Furthermore, unless we can limit the detector solenoid to less than 2 Tesla it appears that we will need some sort of flux compensator, whose size and complexity may negate the advantages of  using REC permanent magnets in the final lenses.   There is currently NO good idea, either for the SMALL or LARGE detector, of how to support the final 5 magnet lens package.

• M1 and M2 masking

In an attempt to optimize the dimensions of the M1 and M2 masks, Takashi and Tom have stumbled on the realization that the best way to present the pairs is not in the p_t vs. theta plane, but rather in the R_max vs. z plane.  Here R_max is the maximum radius a particle can achieve in a given solenoid field, and z is the z coordinate at which it reached this maximum.  The resulting plot traces out a "stay-clear" area and presents the border that the M1 mask may not protrude into.  One need only choose desired acceptance angle and find the minimum z (for a given field strength) that M1 can extend to, thereby trading calorimetric acceptance against tracking chamber backgrounds. One finds that increasing the field from 2 to 6 Tesla results in an increase of acceptance of a factor of two, for a given mask geometry.

In the ZDR, the M2 mask was a 10 cm wall tungsten cylinder that covered Q1; the 10 cm was chosen based on Schulte's tesla work.  Takashi finds that this wall may be as thin as 6 cm.  This calculation is based on the number of photons entering the tracking chamber as a function of wall thickness.  As the photon background has a constant component from the interaction of the pairs around z=0, it does not pay to increase the wall to very large thicknesses.

Tom Markiewicz, 08/14/00