Here are some results of ABCD2T and ABCD2NT irradiation

Six chips were mounted on a single-sided Oslo-type hybrid. There were 3 ABCD2T and 3 ABCD2NT chips on the hybrid. The irradiation was done in 4 steps and after each step a number of threshold scans was performed from which gain, noise and thresholds (50% points) were determined. The irradiation steps were: 2*10¹³ , 5*10¹³ , 1*10¹⁴ and 2*10¹⁴ n/cm². Note that after the third step (1*10¹⁴ n/cm²) ABCD2NT chips returned only 0-hit data (and the trailer) which means that they were digitaly alive but no measurement of their analogue performance could be measured.

Gain:

• Gain vs. fluence for ABCD2T and for ABCD2NT
• Gain vs. preamp bias after irradiation with 2*10**14 neutrons for ABCD2T
• Distribution of individual channel gains for chip 0 before and after irradiation for ABCD2T

Noise:

• Noise at 1.75fC vs. fluence for ABCD2T and for ABCD2NT
• Noise at 1.75fC vs preamp bias after irradiation with 2*10**14 neutrons for ABCD2T
• Distribution of individual channel gains for chip 0 before and after irradiation for ABCD2T

Thresholds and TrimDACs:

• Thresholds at 1.75 fC not trimmed vs. fluence for ABCD2T and for ABCD2NT
• RMS of Thresholds at 1.75 fC not trimmed vs. fluence for ABCD2T and for ABCD2NT
• Thresholds at 1.75fC not trimmed vs. preamp bias after rradiation with 2*10**14 neutrons for ABCD2T
• RMS of Thresholds at 1.75fC not trimmed vs. preamp bias after rradiation with 2*10**14 neutrons for ABCD2T
• Thresholds at 1.75 fC trimmed vs fluence for ABCD2T
• Distribution of thresholds trimmed and not trimmed for Chip 0 before and after irradiation ABCD2T
• TrimDAC characteristics for Chip 0 TrimDACs

Conclusions:

ABCD2T:

• chips work after irradiation with 2x10¹⁴n/cm²
• preamplifier range at wich chps work is smaller than before irradiation
• before: chips work at any setting; after: chips work below ~200uA
• gain dropped from 70 mV/fC to ~ 40 mV/fC
• noise increased form 400 ENC to 800 ENC
• threshold spread increased form ~10mV to 20mV but can be trimmed down to 3mV

ABCD2NT:

• chips still work after 5x10¹³n/cm² (with simillar behaviour of gain, noise and thresholds as in the case of ABCD2T chips)
• after 1x10¹⁴n/cm² chips return only 0-hit data