Prototype Calorimeters for Linear Collider Detectors

For several years, CALICE has been testing highly granular calorimeter prototypes using analogue readout. These devices are envisaged for particle flow [1] application in a future linear collider detector. A novel alternative, especially interesting for the hadron calorimeter, is to use a simplified digital (= 1 – bit) readout coupled with very small cell sizes. In the past year the first large scale (1m3) digital HCAL has been operated by CALICE in test beams at Fermilab. This detector uses glass RPCs as active elements within an iron absorber structure. The RPCs are read out through 1x1 cm2 pads with a single threshold, providing a digital image of the hadronic or electromagnetic shower with high spatial resolution. We report on the technical performance of this calorimeter, and show first physics results on shower reconstruction.