Trapping 1 e 16 Marko Miku University of

Trapping @ 1 e 16 Marko Mikuž University of Ljubljana & Jožef Stefan Institute Si. C weekly Aug 29, 2014

E-TCT Field Measurements • Hamamatsu n+ strip (mini-)sensors, FZ p-type, irradiated with neutrons • ENB @ 100 V – E~0. 07 V/μm from v_sum scaling – scales up to 0. 17 V/μm to account for nominal trapping – get 0. 08 V/μm with simple resistive ENB model and Ileak generated in SCR only – Implies less trapping – Can we measure trapping directly ? Hiroshima, September 2, 2013 Marko Mikuž: Sensors. . . 2

Signal modelling • In Mathematica – input: v(E), shaping CR-RC 3, τ=0, 7 ns, E = 0. 08 V/μm , nominal trapping, reduced by 2, 3 – calculate I(t), convolute with shaping x 3 nominal Hiroshima, September 2, 2013 x 2 Marko Mikuž: Sensors. . . 3

Reality • Measured I(t) in E-TCT 1 E 16 100 V • Not really what I hoped for • Oscillatory behaviour with period 1. 3 ns • Remarkable: same form in ENB and SCR Hiroshima, September 2, 2013 Marko Mikuž: Sensors. . . 4

Fudge • Tried consecutive reflections – to reproduce down swing need r=0. 9, way too much in following swings • Put oscillations in induced signal, damped by trapping – don’t ask about underlying physics Hiroshima, September 2, 2013 Marko Mikuž: Sensors. . . 5

Fudged signal nominal x 2 x 3 Hiroshima, September 2, 2013 Marko Mikuž: Sensors. . . 6