Summary of NIU LC Calorimeter activities: status and plans ========================================================== Status (09/01-06/02): 1. Started working jointly with UTA on the Digital HCAL proposal in Sep, sent it out in Nov. The proposal is not LCD-specific per se, but the idea is to use LCD as the main case study. Title: Development of New Hadronic Calorimeter Technology PI's: Gerald Blazey, Dhiman Chakraborty, Manuel Martin, Vishnu Zutshi. Agency: US DoE(nergy)'s Advanced Detector Research Program. Status: $45K approved for NIU (May, 2002). 2. Since then, things have evolved a bit. For now, we are focusing on LCD only, but have added the E-flow algorithm development as a major component of our effort. Currently we are working on 3 fronts: a. Hardware: NIU is investigating the feasibility of a scintillator-based design. In the current baseline, the barrel hadronic calorimeter consists of ~30M sq. cm. of active layers. We are mainly considering regular hexagon-shaped cells of ~10 sq cm (avg). Prototype cells of various thickness and fiber-routing scheme have been machined and are being evaluated together with fibers of different shapes, dimensions, and materials. Preliminary results indicate that light yield is sufficient for VLPC readout (Quantum eff ~60%). Metal Resistive Semiconductors, an emerging technology which offer ~30% quantum eff, but operate at room temp, are being considered as an altenative to VLPCs. UTA and ANL are looking into GEM and RPCs respectively. b. Software: All of the current LCD software suite, including event generation, detector simulation, and analysis (PYTHIA+GISMO+JAS) has been ported to linux platforms at NIU and FNAL where we have acquired a 40-CPU piece of the Fixed Target farm. All of the software has been certified. We are using these to evaluate variants of the baseline design. The facility is run by NIU, and is available to everyone (even non-NIU people). It is also being used by NICADD's muon group and Argonne's DHCal group. GEANT4 has been installed and tested on several NIU machines. We are presently testing it for prototype simulation in stand-alone mode. We are also working closely with the Simulation/software working group centered at SLAC, towards the transition to a GEANT4-based full- detector simulation. c. Algorithm development: The main objective here is to develop effective E-flow algorithms that will lead to a jet resolution of ~30%*sqrt(E). The common denominator between E-flow and digital hadron calorimetry is small cell-size, but beyond that each has its own agenda. To a certain extent, the algorithm development for each of these is independent of the hardware technology choice. We think that the scintillator-based design is likely to be best-suited for a hybrid digital-sampling calorimeter. Two independent clustering algorithms are taking shape and we are trying to associate energy clusters within a jet with charged tracks. 3. Plans for the coming year: a. Hardware: - More extensive evaluation of fiber-routing and readout options, choice of WLS and clear fibers (next few weeks). - Build DAQ, store data in format accessible by analysis routines (summer). - Build a prototype tower (12 layers, 7 cells per layer) and test it with cosmic rays (summer+fall). - Once the extruder becomes available (Dec 2002), produce more prototypes of higher quality and with different variations. - If all goes well, try beam-test in late 2003. b. Software: - Certify the GEANT4-based prototype simulation facility (Apr-Aug, 2002). - Once certified, the facility will be open to everybody, not only for calorimeter, but for simulation of other (sub-)detectors as well. - We are closely collaborating with the SLAC group on several software tasks. The most important ones are: 1. having the ability to process the output of a GEANT4-based detector simulator with the standard JAS-based reconstruction+analysis software, and 2. transition from the projective (tower-based) to a more general (cell-based) geometry in the calorimeter. This is crucial for E-flow/Digital calorimeter where cells in different layers will have different angular sizes. - Automate web-based user interface for simulation requests (Summer). c. Algorithm development: - Development and thorough optimization of digital/E-flow techniques. - Tune thresholds, understand MIP response. - Understand possible non-linearities and complications arising from leakage through a relatively thin HCAL (~4.5 lambda at theta=pi/2). - Comprehensive optimization of lateral and longitudinal segmentation of active and absorber medium and choice of absorber. - Aid to muon id. - Preliminary analysis note by Spring, 2003. 4. Talks given: - Chicago LC workshop (Jan, 2002): * The NIU-UTA DHCAL proposal - Chakraborty * Preliminary results from a digital approach to calorimetry - Zutshi * LCD sotware porting experience - McIntosh * Leakage of hadronic jets into the muon system - Chakraborty - Calor 2002 (Caltech, Mar, 2002): * Towards an E-flow algorithm for the LCD - Zutshi - ECFA/DESY workshop (St. Malo, Apr 2002): * DHCAL/E-flow efforts in the US - Maciel 5. Web site: nicadd.niu.edu, nicadd.niu.edu/dhcal 6. Resources: People: We have 4 graduate students devoting all of their research time to LCD projects. All of the students are in their first year of grad school, and have considerable course loads. Eight more senior physicists are devoting varying fractions of their time to LCD (probably ~25% on average). The manpower is more or less evenly distributed between hardware, software (simulations), and algorithm development. We are hiring several summer students to help us with our software and hardware tasks. Funds: Department of Education (through NICADD), HECA (IL state), DoE (the Advanced Detector Research program). Facilities: - Machine shop, test stand, DAQ, computing facilities at NIU. - A portion of Fermilab's Linux farm operated by NIU. - Electronics and testing facilities at FNAL. - Scintillator extruder (to become available in Dec, 2002) at NIU.