\section{Future prospects}
\label{sec:future}

This work is planned to continue with a new sensor, TPAC1.1,
which has been designed and fabricated and is about to undergo
first tests at the time of writing. This sensor is the same
size as TPAC1.0 and has the same number of pixels. It is 
I/O compatible with TPAC1.0 and so can use the same sensor PCB
and DAQ system.

The new sensor will only contain the pre-shape quadrant 1
pixel design. It will also implement several fixes, such as
the decoupling of the comparator and monostable power meshes
and correcting the SRAM memory write corruption.
Small adjustments have been made to the pixel layout to
improve the pixel uniformity for noise and gain.

If this sensor functions as expected, then it should be
possible to use it in an electron beam test to generate real EM showers
and sample the hit densities following various thicknesses
of tungsten. This would give invaluable data on the
fine granularity properties of EM showers and so would
allow much firmer predictions of the realistic performance
of a binary ECAL.

The actual verification of a binary ECAL resolution could
not be done with TPAC1.1 since the sensor is only 
$1 \times 1$\,cm$^2$. A real demonstration of a binary
ECAL stack would require a large scale sensor but this
is not available at this time.
