Update on Active RADMON sensors Federico Ravotti TSLEACMS
- Slides: 6
Update on Active RADMON sensors Federico Ravotti (TS-LEA-CMS) Maurice Glaser & Michael Moll (PH-TA 1 -SD) M. Glaser RADMON Meeting 22 -07 -2004
Active Radiation Monitors • + new devices (D 2) 0. 4 mm oxide thickness; Rad. FETs • Isochronal Characterization of all FET types under way! p-i-n diodes • Investigation on thick devices for high sensitivity measurements under way! Optically Stimulated Luminescence (OSL) M. Glaser • Annealing studies under way! • Radiation Hardness problems with the Readout electronics under investigation! RADMON Meeting 22 -07 -2004 2
Rad. FETs M. Glaser RADMON Meeting 22 -07 -2004 3
OSL on-line sensor OSLs deposed on Ga. As. P photodiodes for CERN sensor Ga. As. P + OSL coupled with a NIR LED OSL+B OSL pure OSL+ Paraffin NIR LED known Radiation Hardness problems: Diodes In. Ga. As. P/In. P 1050 nm under investigation! Ga. As. P photo-sensor unexpected Radiation Hardness problems: (~ 30 % signal loss after ~ 2 x 1013 Feq) • Problem under investigation; • Research of new solutions. M. Glaser RADMON Meeting 22 -07 -2004 4
Passive Radiation Monitors Polymer-Alanine (PAD) Radio-Photo Luminescent (RPL) Gafchromicâ Sensitive Films Calibration campaign 2003 in the mixed g/n field of CERN-PS IRRAD 2 Facility (@ 50 cm from the beam axis) 24 Ge. V/c protons (HD-810) M. Glaser RADMON Meeting 22 -07 -2004 5
Readout parameters Active Dosimeter External bias Readout Input Pre-irradiation output Rad. FETs not needed DC i = 10 m. A ÷ 160 m. A depending on MTC 1 V to 3 V depending on tox OSLs ± 5 V (on-board (2003 sensor) electronics) BPW 34 F not needed (w ~ 300 mm) After irradiation output � Reference Val. ~ 10 V (1. 6 mm) ~ 4 V (0. 25 mm) 100 Gy ~ 41 V (0. 25 mm) 100 k Gy 10 -15 sec DC stimulation on LED with i = 50 m. A noise ~ 200 m. V with Gout=10 ~ 2 V with Gout=10 100 Gy Fast pulse (180 ms) with Forward i = 1 m. A 0. 5 V ~ 50 V (linear operation) 4. x 1014 cm-2 (Feq) Pad structures not needed Leakage current at full depletion V = 100 V ? ~ n. A order ~ m. A order 1014÷ 1015 cm-2 (Feq) PT 100 Temp Probe not needed DC i = 1 m. A 0. 1 V (0 ºC) # # M. Glaser RADMON Meeting 22 -07 -2004 6
