For the next ten years the Tevatron offers the best possibility to
understand pomeron exchange and
the transition between non-perturbative and perturbative QCD.
The addition of the FPD would greatly increase the physics reach of
the hard diffractive physics program with no negative impact on the
current DØ physics program.
We stress that the measurements of jets and
particles will be done
with the upgraded DØ detector,
which will be very well suited to this purpose.
The FPD will be used to ensure that we have large diffractive data samples
and that we can divide them into 
and |t| bins.
It will allow accurate determination of pomeron structure
and hard diffractive cross
sections, permitting us to greatly expand the knowledge
of the field of hard diffraction.
ACKNOWLEDGEMENTS
We thank our colleagues in the D/O/ Collaboration for their support in preparing this document. We thank the staffs at Fermilab and collaborating institutions for their contributions to this work, and acknowledge support from the Department of Energy and National Science Foundation (U.S.A.), CNPq and CAPES (Brazil).
We would like to thank numerous members of the Beams Division for their encouragement, help, and many useful discussions. Specifically, Sasha Drozhdin did many background simulations in conjunction with Nikolai Mokhov, and the proposal would not have been possible without them; Mike Martens provided us with tracking programs and showed us how to use them; Carol Johnstone and John Johnstone helped us with lattice issues; Stan Pruss also was a valuable resource.
Ernie Villegas and Andy Stefanik performed studies showing that the supporting the moved-in quadrupole was feasible. Thanks to Newton Oliveira and Iuri Pepe of Instituto de Fisica da Universidade da Bahia/Universidade da Bahia who worked on the Roman pot design. Kurt Krempetz performed initial Roman pot cost estimates. Thanks also to Mike Albrow, Hirofumi Ikeda, and Phil Melese of the CDF Collaboration for discussions about the CDF Tokyo pots. Thanks to Carlos Avila of E811 for many useful discussions about their Roman pots and techniques.