P. Denes Page 1 FPPA-Rad1 UHF1x and FPPA Radiation Hardness Radiation studies performed at OPTIS (PSI) with 72 MeV p and at 88” (LBL) with 55 MeV p. These protons mimic well the environment in the ECAL p/cm 2 (72 MeV) deposits 1 MRad in the silicon and creates the equivalent displacement damage as 2x MeV n/cm 2 -- simulating 10 years of high luminosity running at  ~1.4. Summarized here are Radiation results on UHF1x elements Radiation results for FPPA ‘98 Low dose rate tests Radiation results for FPPA2000

P. Denes Page 2 FPPA-Rad1 UHF1x Passive Components Capacitors - no detectable change in C up to p/cm 2 NiCr Resistors - no detectable change in R up to p/cm 2 Diffused Resistors - Some change in non-linearity with dose: Pre-Irradiation: After 1.7x10 13 p/cm 2 : Diffused resistor appears rather non-linear. Not for precise use! Test Structure Irradiation at OPTIS

P. Denes Page 3 FPPA-Rad1 UHF1x Transistors NPN, PNP -  change, which can be (crudely) described by: I C - no change with dose I R is additional base current due to irradiation:scales with W E, and dose For n F ~ 1.3 (NPN) n F ~ 1.4 (PNP) n~ 1.5 For 5  x 1.3  NPN and PNP, increase in I B is around 2 to 3  A after p/cm 2 (Not a problem for most cases.)

P. Denes Page 4 FPPA-Rad1 Design Rule Our design uses elementary transistors of W E = 5-50  and L E = 1.3  (NPN) and L E = 1.3 or 3.3  (PNP). Based on the previous result, we adopted the “rule” I C  100  A per 5  of emitter width The only exceptions to this rule are found in The input stage for the leakage current measurement circuit (which has to go down nA input currents) Certain transistors in the preamp

P. Denes Page 5 FPPA-Rad1 FPPA ‘98 - OPTIS Irradiation dRatio/dDose [%/10 12 p/cm 2 ] Pk-2-0.1% Pk Pk Pk Pulse shape stable under irradiation

P. Denes Page 6 FPPA-Rad1 Conclusions - FPPA ‘98 Slight pedestal variation, pulse shape stable (see later, addition of “baseline control”) Linear ramps on spare MUX inputs ( FPPA ‘98 had inputs for T, IL mux ), show offset changes of 2-3 ADC channels and gain changes of  0.1% after p/cm 2 (so FPU ok)

P. Denes Page 7 FPPA-Rad1 Low Dose Rate We have looked for dose rate-dependent effects in OPTIS by reducing the beam current to the minimum and then raising it to our normal irradiation current. The lower rate is still significantly higher than what will be experienced at LHC. Some examples follow showing base current as a function of dose. The behavior is well modeled by the previous formula.

P. Denes Page 8 FPPA-Rad1 NPN W E =50  L E =1.3  (TV 4) :3622:4800:0001:1202:2403:36 Time Base Current [mA](I E =20  A/  ) W=50u 21  A/10 13 p/cm  A/10 13 p/cm 2 Flux: 2% Damage 1.7% (.36/21)

P. Denes Page 9 FPPA-Rad1 PNP W E =50  L E =1.3  (TV 5) W=50u 15  A/10 13 p/cm  A/10 13 p/cm 2 Flux: 2% Damage 2.2% (.33/15)

P. Denes Page 10 FPPA-Rad1 Model Ignore Early effect (V AF = V AR = 0) Model only forward-biased effects I KF /I S scales with W (Setup limits total current. Determine I KF from small transistors) I C unaffected by irradiation, I B gets extra term I RAD exp[V BE /n RAD V T ] ICIC IEIE IBIB IDID (n F = 1)

P. Denes Page 11 FPPA-Rad1 PNP L E = 1.3  3 emitters, 50  each I E = 1 mA, V CE = 2V NPN L E = 1.3  3 emitters, 50  each I E = 1 mA, V CE = 2V Flux fFlux 50 f Beam Off Flux fFlux 50 f Beam Off Radiation Induced Base Current

P. Denes Page 12 FPPA-Rad1 PNP L E = 1.3  3 emitters, 50  each n RAD ~ 1.2 NPN L E = 1.3  3 emitters, 50  each n RAD ~ 1.7 Flux fFlux 50 f Beam Off Flux fFlux 50 f Beam Off Radiation Induced Base Current: Fit I RAD

P. Denes Page 13 FPPA-Rad1 Flux fFlux 50 f Beam Off Flux fFlux 50 f Beam Off PNP L E = 1.3  NPN L E = 1.3  I B at fixed V BE - scales with W E Radiation Induced Base Current: Scaling

P. Denes Page 14 FPPA-Rad1 Conclusions - Low Dose Rate Simple model (ideal, rad-hard transistor + “diode”) works well Magnitude of damage (dI B / d“Rad”) roughly similar for NPN and PNP (PNP slightly more robust than NPN) Shape (n RAD ) different No “low dose rate” effect observed High Dose Rate ~ 1.25 x 10 9 “=” 2.5 x 10 9 plus ~160 Low Dose Rate ~ 2.5 x 10 7 “=” 5 x 10 7 plus ~3 ~70 MeV p/cm 2 /s ~1 MeV n/cm 2 /s Rad/s (Si)

P. Denes Page 15 FPPA-Rad1 FPPA2000 Worries about potential pedestal change (high  ) due to increase in input transistor base leakage (and external R F ) FPPA2000 has baseline control (and eliminates OUTRES) OUTRES FPPA ‘98FPPA2000

P. Denes Page 16 FPPA-Rad1 FPPA Irradiation At LBL 88” Cyclotron Previous performance maintained. Baseline control OK Fluence [10 12 p/cm 2 ] Pedestal PA Out [V->50  ] 000E+0 100E-6 200E-6 300E-6 400E-6 500E-6 600E-6 700E-6 RMS PA Out [V->50  ] Ped RMS  100 mV Baseline Shift is OK

P. Denes Page 17 FPPA-Rad1 Temperature Measurement FPPA is used to measure temperature of crystal. “10 years at  =1.4”  T < 0.2 ºK In fact, less severe due to 2nd order effects and no correction for beam heating

P. Denes Page 18 FPPA-Rad1 Conclusions UHF1x process supports this design to the desired levels Radiation behavior is easily modeled: Passive components show no effect Transistors behave like ideal devices with a B-E diode that develops a current proportional to (p) dose and scales with W E. Temperature measurement to desired precision should be ok. Baseline compensation is ok.