We have estimated the level of funding required to support the efforts mentioned above. However, this estimate is necessarily rather uncertain for the moment. The financial outlook will remain so until firm decisions are made by US institutions and until the full responsibilities assigned to those groups are specified. Once responsibilities are assigned, the research group must engage in sufficient design work to prepare appropriate cost estimates. We also intend to address the preparation of a proper cost estimate as a high priority of our R&Dprogram during the coming year. A detailed, more complete document spelling out responsibilities and cost estimates will be submitted this fiscal year.
The evident 70 MCHF shortfall in CMS funding presently implies staging the detector quite severely. For the systems where the US would potentially take overall responsibility, the full muon system is estimated to cost 43 MCHF, while the HCAL plus VFCAL is estimated to cost 34 MCHF. US groups will take construction responsibility for these and other items requiring substantial funding support within the US. A view of the geography of potential US responsibilities is shown in Fig. 2, where areas covered by the US are shown shaded. These areas include all the hadronic calorimetry (barrel and endcap) and all the forward muon system.
A cost estimate of the major elements of CMS is given in Table 2. That estimate has been extensively reviewed by CERN management. The total is 407 MCHF. The channel count is higher than that of SDC or GEM due to the necessity of confronting the order of magnitude higher design luminosity at the LHC. We have made cost estimates for those areas of US responsibility using US accounting methods and report them in Table 3. The differences between the US cost estimates and the CERN cost estimates arise because of differences in accounting for labor, EDIA staffing, and contingency. Many of these items are normally excluded from CERN cost estimates. Project management costs are also not normally charged in European accounting. For that reason, we have specifically called out US Project Management in the estimate given below in Table 3. The total request is $153M.
Note that CMS accounting of US costs refers only to project cost; R&Dis not included. Note also that there will be ``common fund'' requests to support construction of large items within CMS. It has been assumed that the US groups on CMS take responsibility for items corresponding to about 102 MCHF, about 25%of the CMS total cost. Assuming a common fund of roughly 30%, then the US groups would be responsible for 27 MCHF or $18Mat the present exchange rate. The initial proposal is for US groups to purchase $1Mof workstations, which form part of the processing farm. The balance of $17Mcould be accounted for as a magnet cost of both the solenoid and steel. The remaining 75 MCHF of US project responsibilities would go into construction of CMS by the US groups. The discussion of the common fund is expected to require several iterations. It is perhaps worth noting that LEP common funds have already been implemented for LEP experiments. For example, the US groups in L3 provided a substantial fraction of the magnet cost as a common fund contribution.
Clearly, the total US cost is not accurately defined, nor are the US/CERN equivalent costs. Its value depends on the details of US involvement and upon details of CMS specific technical choices still to be made (e.g. VFCAL). However, the main points are fixed; the US wishes to take major responsibility for physically distinct detector components: the hadronic calorimeter and the forward muon system. We also wish to help design and participate in the realization of the electromagnetic calorimeter (ECAL), the tracking system, the trigger system and the DAQ system. The plan is to carry out R&D, design, build, assemble, test, commission, operate, trigger, and finally do physics with the CMS detector. The structure taken up by the US groups in CMS and the ``vertical integration'' model of US efforts are a mirror of the opportunities extended to US groups by CMS and the means to accept and fulfill those opportunities. We expect that over the next year our understanding of the US responsibilities within the subsystems will become much better defined.