1. R3B - meeting April 2009@ 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

2. R3B - meeting April 2009@ 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)‏

3. R3B - meeting April 2009@ 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% Resolution @ 662 keV

4. R3B - meeting April 2009@ 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 0 - 20MeV linear (4k)‏ 10 - 200 MeV (2k)‏ two full DAQ chains/crystal lin / log preamp time over threshold

5. R3B - meeting April 2009@ 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?

6. R3B - meeting April 2009@ 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 = -1 + 1/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

7. R3B - meeting April 2009@ 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

8. R3B - meeting April 2009@ 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

9. R3B - meeting April 2009@ 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

10. R3B - meeting April 2009@ 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

11. R3B - meeting April 2009@ GSI Test System

12. R3B - meeting April 2009@ 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