[DUSELScience] Message from DUSEL-Cascades Collaboration

[Marvin Marshak]

Dear DUSEL colleagues:

As the S3 evaluation of proposals has been completed, our group  
thought we should make the materials on DUSEL-Cascades available to  
the science community.  We have opened our web site at http:// 
www.int.washington.edu/s3/.

DUSEL-Cascades is a proposal to use the parallel Pioneer and Cascades  
tunnels, the deepest and longest in the US, to create in two steps a  
laboratory with unique characteristics.  The initial plan calls for  
establishing a horizontal rail-supported level at a depth of 1040m  
(comparable to Kamioka) and a second aligned level at 1760m  
(comparable to Frejus).  The facility is designed for later expansion  
to very great depths. We believe such a plan would encourage near- 
term partnerships in underground science with Canada and Asia, while  
setting the stage for a future very deep (2350m) third level,  
suitable for large experiments, that could be developed with our  
international partners.

DUSEL-Cascades would be a dedicated facility clean from the portal to  
depth.  The laboratory would become a siding off the mainline railway  
linking Seattle and Chicago, part of the most direct cargo route  
between Asia and the eastern US.   Thus our design is built around  
the concept of efficient cargo-container support of major experiments  
from distant US and international laboratories.  The materials on the  
web site describe basic features of the proposed laboratory,  
including its all-electric design, tracked transport of containers,  
ducted ventilation, and special safety features.

As access currently exists to the proposed laboratory site, it was  
possible to characterize the deep rock and its variations.  Mappings  
were done at 45 tunnel stations, at 100-ft intervals throughout the  
area where rooms would be excavated. The results are an average RQD  
of 94% (excellent) and RMR of 83 (Class I).  These values are likely  
conservative as laboratory tests were made with wall rock that had  
been blasted.  Consistent with this expectation, minimum RMRs based  
on the stand-up times of unsupported 10m spans in the tunnel range  
from the low to mid 90s.  Thus the rock quality compares favorably  
with the Tochibora Mine, the tentative HyperK site.  The web site  
describes rail-supported construction of a half-megaton cavity by  
stacked drift excavation, and the resulting on-axis long-baseline  
neutrino program that would then be possible with a FermiLab superbeam.

Warren Buck

Wick Haxton

Paula Heron

Bob Holtz

Phil Long

Tullis Onstott

for the collaboration