PT Journal
AU Ullan, M
   Benitez, V
   Quirion, D
   Zabala, M
   Pellegrini, G
   Lozano, M
   Lacasta, C
   Soldevila, U
   Garcia, C
   Fadeyev, V
   Wortman, J
   DeFilippis, J
   Shumko, M
   Grillo, AA
   Sadrozinski, HFW
TI Low-resistance strip sensors for beam-loss event protection
SO Nuclear Instruments & Methods in Physics Research A
JI Nucl. Instrum. Methods Phys. Res. A
PY 2014
BP 252
EP 257
VL 765
DI 10.1016/j.nima.2014.05.089
LA English
DE Silicon radiation detectors; Strip sensors; Punch through protection; Beam loss; HL-LHC; ATLAS Upgrade
AB AC coupled silicon strip sensors can be damaged in case of a beam loss due to the possibility of a large charge accumulation in the bulk, developing very high voltages across the coupling capacitors which can destroy them. Punch-through structures are currently used to avoid this problem helping to evacuate the accumulated charge as large voltages are developing. Nevertheless, previous experiments, performed with laser pulses, have shown that these structures can become ineffective in relatively long strips. The large value of the implant resistance can effectively isolate the "far" end of the strip from the punchthrough structure leading to large voltages. We present here our developments to fabricate lowresistance strip sensors to avoid this problem. The deposition of a conducting material in contact with the implants drastically reduces the strip resistance, assuring the effectiveness of the punch-through structures. First devices have been fabricated with this new technology. Initial results with laser tests show the expected reduction in peak voltages on the low resistivity implants. Other aspects of the sensor performance, including the signal formation, are not affected by the new technology.
ER