  The anticoincidence shield (ACS) of the INTEGRAL-spectrometer SPI consists of
512 kg of BGO crystals. This massive scintillator allows the measurement of
gamma-ray bursts (GRBs) with a very high sensitivity. Estimations have shown
that with the ACS some hundred gamma-ray bursts per year on the 5 sigma level
can be detected, having an equivalent sensitivity to BATSE. The GRB detection
will be part of the real-time INTEGRAL burst-alert system (IBAS). The ACS
branch of IBAS will produce burst alerts and light curves with 50 ms
resolution. It is planned to use ACS burst alerts in the 4th interplanetary
network (IPN).
