(Damian, Heinz 7/15/1998)

We tested octagon hybrids of the following configuration

OCTA081,OCTA082,OCTA083,OCTA084:

New octagon hybrid, new 128-channel chip (2^nd batch), no detector connected

OCTA006:

Old octagon hybrids, old 128-channel chip (1^st batch), old octagon sensor bonded to the chip but not biased.

We tested the gain and pedestal using the calibration pulses. The noise is given for un-bonded channels only (in case of the OCTA006) and is common-mode-corrected.

The supply voltages used were :

Vfp=-350mV, Vfs=+700mV, Ipre=500uA,Isha=41uA,Ibuf=140uA

All chip are drawing the right current.

OCTA083: did not work at all (no pedestal, no signal)

OCTA082: pedestal was ok, but no signal

OCTA084: pedestal ok, signal ok

OCTA081: pedestal ok, signal ok

OCTA006: pedestal ok, signal ok

In details: In the following I want to give the pedestal variation (in mV and corresponding MIPS), the gain in our test system after the analog amplifier (in mV/fC)

And the noise. We measured the noise of the pure analog line, without the hybrid connected, i.e. the noise in the analog amplifier and cables. The value was 0.45 mV. The noise figure given in the table is corrected for this noise (quadratic subtracted)

In following you will find the plots for gain,noise and pedestal. On Octagon 006 only the odd channels are bonded.