Signal count

The number of energy signals to be amplified for TIARA is dependent on the configuration used for the array. The maximum number of signals that can be taken from all of the detectors is quite large, and it would require a big investment to be able to instrument them all simultaneously. For the initial phase of operation with TIARA, it seems more appropriate to find a compromise on the number of channels that are instrumented simultaneously. The cost to the experimenter will be the need to devise a plan for each experiment whereby channels can be omitted or amalgamated in the cabling, so as to fit within the number of channels that are instrumented. A count of the maximum number of channels available from the array, and a scheme for amalgamating channels in a typical experiment, are included in Table 3. From this information, it is apparent that a 256 channel system is a realistic requirement for the first phase of operation of the array.

 

Table 3: Signal count for TIARA in its fully instrumented configuration. Many experiments would not need to instrument all of the channels at one time, or could optimise the use of resources by coupling together channels in selected detectors, thus keeping within a 256 channel maximum. The table shows how the 332 channels could be amalgamated to work within the 256 limit in a typical experiment.

Description		Number	Signals	Maximum
		In Array	Instrumented	Possible
Barrel strips	resistive strips	28	56	56
Forward annulus	front rings	60	60	60
	rear sectors	32	32	32
Back annulus	front rings	60	30	60
	rear sectors	32	16	32
Zero degree $\Delta E_x$	resistive strips	16	16	32
$\Delta E_y$	strips	16	16	32
E	CsI/SiLi	1	1	16
PPAC tracking	x,y,t	3	9	9
Timing channels	telescope/array	3	3	3
TOTAL			239	332