LOGIC OF THE MASTER SIGNAL

For any combination of sections i and j when j ≠  i-1, i, i + 1 

 M=TOF(C _i -> C _j ) x A _j (>2mip) x A^- _i-1 x A^- _i x A^- _{i +1} 

TOF(C _i -> C _j ) - сsignal of the time-of-flight system corresponding to passage of a relativistic charged particle from  C _i to C _j . 
A (>2mip) - a signal of the A counter corresponding by its amplitude to registration of two or more minimum ionizing particles. 
A^- - absence of a signal in the A counter. 

SELECTION OF EVENTS BASED ON THE DRIFT CHAMBERS DATA

The master signal commands reading of the drift chambers data into the onboard processor which selects events by the 'picture' in the drift chambers of i and j sections.

CYGAM, unlike the traditional telescopes, does not have a special energy detector and can not measure energy of each registered photon. This drawback is a price for the large field of view but the price does not seem to be too high because 

• Even in presence of the energy detector the energy spectrum may be measured in detail only for a few brightest sources. For most of the sources registered by EGRET the energy spectra were described by an index of the supposed power-law spectrum. 

• The physical processes responsible for the high energy gamma-ray emission can not result in narrow lines or sharp irregularities in the energy spectra of compact sources for revelation of which good energy resolution is needed. 

• Till now the data on the energy spectra had not been playing important role in the registered sources identification. 

• In the CYGAM experiment for the sources with Ig(>1ГэВ)>10 ^-8 сm ^-2 s ^-1 the power-law spectrum index may be estimated from the pair opening angles distribution. 

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