Update on Active RADMON sensors

Federico Ravotti (TS-LEA-CMS)

Maurice Glaser & Michael Moll

(PH-TA1-SD)

M. Glaser RADMON Meeting 22-07-2004 2

Active Radiation Monitors

RadFETs

p-i-n diodes

Optically Stimulated

Luminescence (OSL)

• + new devices (D2) 0.4 m oxide thickness;

• Isochronal Characterization of all FET types

under way!

• Investigation on thick devices for

high sensitivity measurements

under way!

• Annealing studies under way!

• Radiation Hardness problems with

the Readout electronics under

investigation!

M. Glaser RADMON Meeting 22-07-2004 3

RadFETs

M. Glaser RADMON Meeting 22-07-2004 4

OSL on-line sensor

OSLs deposed on GaAsP

photodiodes for CERN sensor OSL

pure

OSL+B

OSL+

Paraffin

GaAsP + OSL coupled with a NIR LED

NIR LED known Radiation Hardness problems:

Diodes InGaAsP/InP 1050 nm under investigation!

GaAsP photo-sensor unexpected Radiation Hardness problems:

(~ 30 % signal loss after ~ 2x1013 eq)

• Problem under investigation;

• Research of new solutions.

M. Glaser RADMON Meeting 22-07-2004 5

Passive Radiation Monitors Polymer-Alanine (PAD)

Radio-Photo Luminescent (RPL)GafchromicSensitive Films

Calibration campaign 2003 in the mixed /n field of CERN-PS IRRAD2 Facility

(@ 50 cm from the beam axis)

24 GeV/c protons

(HD-810)

M. Glaser RADMON Meeting 22-07-2004 6

Readout parameters

Active Dosimeter

External bias Readout InputPre-irradiation

outputAfter irradiation

output 

    Reference Val.

RadFETs not neededDC i = 10 A ÷ 160 A

depending on MTC1 V to 3 V

depending on tox

~ 10 V (1.6 m) ~ 4 V (0.25 m)

100 Gy

        ~ 41 V (0.25 m) 100k Gy

OSLs (2003

sensor)

± 5V (on-board electronics)

10-15 sec DC stimulation on LED with i = 50 mA

noise ~ 200 V with Gout=10

~ 2 V with Gout=10 100 Gy

BPW34F (w ~ 300 m)

not neededFast pulse (180 ms) with

Forward i = 1 mA0.5 V

~ 50 V (linear operation)

4.x1014 cm-2 (eq)

Pad structures

not neededLeakage current at full depletion V = 100 V ?

~ nA order ~ mA order1014÷ 1015 cm-2

(eq)

PT100 Temp Probe

not needed DC i = 1 mA 0.1 V (0 ºC) #