TIGER documentation

QDC mode

Efine with wrap-around effect explained

The counter for the ADC performing the charge digitization has a wrap-around effect such that very high signals (just below the saturation point) have 1008 < Efine < 1024.

For these values the measurement is still linear, so in order to apply the usual conversion using the calibration line (Efine = const + slope * Qin) we need first to shift them by 1024. Therefore we can define a new variable Efine_new given by:

• Efine_new = Efine (for Efine < 1008)
• Efine_new = Efine - 1024 (for Efine > 1007)

In this way, the values of Efine between (1008, 1023) are shifted to the region (-16, -1) and thus correspond to the very high charge signals, with Efine_new = -16 being the new value of saturation. This is explained in the Figure on the right and the Table below.

Qin	Efine	Efine_new	Description
5	385	385	normal region
10	340	340	normal region
15	295	295	normal region
20	250	250	normal region
20	205	205	normal region
30	160	160	normal region
35	115	115	normal region
40	70	70	normal region
45	25	25	normal region
46	16	16	normal region
47	7	7	normal region
48	1022	-2	wrap-around region, still linear -> apply Efine_new
49	1013	-11	wrap-around region, still linear -> apply Efine_new
50	1008	-16	saturation
55	1008	-16	saturation
60	1008	-16	saturation

Output words

TIGER output words

• Event word: 64 bits, includes digitized information for each hit
• Count words: 64 bits, includes information about internal counters
• Framing word: 64 bits, includes information about frame word used for time reference and SEU count detected for each frame

TIGER padframe

TIGER padframe