R3B - meeting April GSI Readout concepts for the CALIFA detector options dynamic range preamplifier solution digital solution digital readout chain Roman Gernhäuser, TU-München The dynamic range problem

R3B - meeting April GSI CALIFA Detector Layout large volume! CsI barrel or/and Phoswich front cap different requirements in different areas CALIFA: large doppler shift : 0.5 E  < E lab < 3 E   high granularity  many channels to read (5500)‏

R3B - meeting April GSI Hardware Options Still many options PDs are they possible? (Lund tests)‏ Single/double APDs from Hamamatsu Temperature control or/and HV control(4.3 %/C o, 2.2 V/C o )‏ (Olof will discuss this) PMT – Readout Phoswich + PMT (Uppsala tests)‏ Focus on CsI One APD unit per crystal (1 channel)‏ 5% 662 keV

R3B - meeting April GSI The Dynamic Range Problem Assuming we want to see 100 keV gammas and 200 MeV protons in the same setting: 5 keV Min bin size 50 keV Preamp noise 2 MeV10 keVResolution 200 MeV Proton100 keV GammaEnergy Range 40k peak sensing ADC is not existing preamp noise just covers 4k (also a problem with sampling ADC)‏ solution: range splitting MeV linear (4k)‏ MeV (2k)‏ two full DAQ chains/crystal lin / log preamp time over threshold

R3B - meeting April GSI Preamplifier (Mesytec Solutions) Special development for large capacity detector – 1nF Temperature control and HV / gain adjust for each APD, if possible for each cluster only (xx k€)‏ Invest costs will be roughly 35.- € /channel )‏ log(E) [MeV] Output [V] Log preamp where is the knee? optimum slopes? how to calibrate? Lin preamp 2 independent preamps with common first loop 2 different ranges (2 x costs, power, cabeling and space)‏ Automatic range switching in case of a multiplexed readout? Different Preamps forward and backward?

R3B - meeting April GSI Moving Window Deconvolution Signal Filter out F[n] = a i * FADC[n-i] i=0,N a 0 = 1 a i = 1/TAU preamp i = 1, L-1 a L = /TAU preamp Properties Transforms an exponential into a rectangular function of L points. G[n] = G[n-1] + a * (FADC[n-1] – FADC[n-L] )‏Reduced version Several steps Offset subtraction, MWD, Trapezoidal Filter also range problem

R3B - meeting April GSI Time over Threshold (ideal)‏ Alberto Pullia IEEE 2004 Advantage: linear t(E), trigger signal, high rates Disadvantage:clipping of first loop not handled typ. used for fast risetimes

R3B - meeting April GSI Simple TOT - Method ln(E)‏ t (E)‏ THR tot ~  [ln (E) – ln(THR)]  tot = const E = THR *exp(t/  )‏  E/E =  t /    t = 200ns,  = 50  s A(t) = E exp(-t/  )‏ Preamplifier signal Needs up to a ms to recover from a particle range

R3B - meeting April GSI ADC Module (rev2)‏ HADES -development 16 x 40MHz 12 bit ADC 2Gb interface Temperature and power monitoring CLK / TRG, LVDS interface FPGA: MWD – moving window deconvolution (DGF), 14 bit eff. + e.g. APV multiplexed rdo. Internal module trigger different algorithms in parallel ca 70.- / channel 2x8f ADC FPGA Slow control SFP LVDS I/O

R3B - meeting April GSI System Layout ADC Module 16 ch ADC Module 16 ch Fiber TRBnet TRB-HUB ECP2M I 100 ECP2M I 100 TRB Slow control ETH 100Mb 4x ETH 1 Gb TRB Trigger control VULOM + FAN IO BUTIS? trigger / clk

R3B - meeting April GSI Test System

R3B - meeting April GSI Summary home made high flexibility infinite range power consumption off detector modular no deadtime no restrictions on latency home made more cabeling high power consuption no direct PMT readout