Cornell University Unit Name

"Digital Hadron Calorimeter with RPCs"

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We develop a Hadron Calorimeter for the Linear Collider, which will be optimized for the application of Particle Flow Algorithms (PFAs). The latter request a calorimeter with extremely fine segmentation of the readout, of the order of 1 cm² latteraly and layer-by-layer longitudinally. We propose to achieve this fine segmentation using Resistive Plate Chambers as active medium. Due to the fine segmentation of the readout a simple digital (one-bit resolution) readout is sufficient to provide the necessary energy resolution for single hadrons. Both the SiD and the LDC concepts feature a digital hadron calorimeter with RPC readout as default option for the hadron calorimeter.

We plan to build a prototype hadron calorimeter section with 400,000 readout channels. We completed the R&D on the chambers and will complete the prototyping of the electronic readout system in calendar year 2005. In calendar year 2006 we will construct the prototype section (120 RPCs), provided our funding requests will be approved (see below).

In 2007 we will move to the FNAL MT6 test beam. The purpose of exposing the prototype section to a test beam is a) to measure hadronic showers with unprecedented spatial resolution, b) to validate the simulation of hadronic showers in great detail (a prerequisit for optimizing the Linear Collider detectors with respect to the application of PFAs), c) to validate the concept of a digital hadron calorimeter, d) to validate our technical approach to a fine granularity hadron calorimeter using RPCs, and finally e) to compare the performance with a more traditional approach based on scintillator and analog (multi-bit) readout being developed in Europe.

Of course, our plans can only be realized with significant support from the funding agencies. The cost of the prototype section is estimated to be of the order of $1M. Funding proposals have been submitted to both the DOE and the NSF. So far the results have been totally inadequate.

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Please address the following questions in your statement.

• What are the goals of this R&D project. How does this R&D project address the needs of one or more of the detector concepts?

• If there are multiple institutions participating in this project, please describe the distribution of responsibilities.

• Are there significant recent results?

• What are the plans for the near future(about 1 year)? What are the plans on a time scale of 2 to 3 years?

• Are there critical items that must be addressed before significant results can be obtained from this project?

• Is the support for this project sufficient? Are there significant improvements that could be made with additional support?