Post on 04-Feb-2016
description
Charge Collection in CVD Diamond
R. KassDPF Santa Cruz 24
R. Kass 26
Radiation Damage - Basics
Charge trapping the only relevant radiation damage effect NIEL scaling questionable a priori
Egap in diamond 5 times larger than in Si
Many processes freeze out
Typical emission times order of months
Like Si at 300/5 = 60 K – Boltzmann factor
A rich source of effects and (experimental) surprises !
Radiation induced effect
DiamondOperational consequence
SiliconOperational consequence
Leakage current
small &
decreasesnone
I/V = αΦ
α ~ 4x10-17 A/cm
Heating
Thermal runaway
Space charge ~ none noneΔNeff ≈ -βΦ
β ~ 0.015 cm-1
Increase of full depletion
voltage
Charge trapping
YesCharge loss
Polarization
1/τeff = βΦ
β ~ 5-7x10-16 cm2/ns
Charge loss
Polarization
t
thttteff
vPN
)1(1
DPF Santa Cruz
Summary of RD42 Test Beam Resultsfor CVD Diamond
R. KassDPF Santa Cruz 27
Particle Energy Relative k
p 24GeV 1.0
800MeV 1.6-1.8
70MeV 2.5-2.8
25MeV 4.0-5.0
π 200MeV 2.5-3.0
k is relative damage constant