Authors C. Rivetta– Fermilab. F. Arteche , F. Szoncso, - CERN Noise Immunity Analysis of Forward Hadron Calorimeter Front-end Electronics. Authors C. Rivetta– Fermilab. F. Arteche , F. Szoncso, - CERN Hola en los siguientes minutos voy a habrar acerca de la .. Titulo ..

OUTLINE 2-Noise considerations 3-Thermal noise 1- Introduction 2-Noise considerations 3-Thermal noise 4-Multi-transmission line model 5-Surface transfer impedance 6-Common mode rejection Examples 7-External electromagnetic field Este es el indice de la charla , el cual dividire en 7 partes . Primero … , postriormente …. Comenzamos por lo tanto con unos breves comentarios acerca del CERN y el proyectto LHC... 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

1.INTRODUCTION The goal of this study is to establish the susceptibility level to electromagnetic noise of the HF CMS calorimeter. Characterise the influence of topology and parameters on the overall FEE noise Thermal Noise Conductive Common Mode (CM) Noise Electromagnetic Interference (EMI) Generate a software tool to assist: The analysis of cable quality. Analysis of common mode effects on sensitive equipment. Conducting & radiated coupling through cables. 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

1.INTRODUCTION PMTs / QIE distance is 4 meters. Dy7 Rgnd QIE sig. QIE ref. Anode Dy8 PMT HV Cc PMTs / QIE distance is 4 meters. QIE:Sample Charge integrator with ADC QIE is a differential current mode amplifier. QIE input impedance 50 or 93 Ohms. Asymmetric dynamic range. Gain: 1fC/LSB Sampling freq.: 40MHz. 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

2. NOISE CONSIDERATIONS Low level signal processing of FEE is defined by the noise Noise at output is composed by several factors Power Spectrum nth(t) nCM(t) and nEMI(t) in frequency domain Criteria generally used 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

3. THERMAL NOISE 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

3. THERMAL NOISE Cables with low impedance increse the thermal noise ENC L Cables with low impedance increse the thermal noise There exists a critical length for the cable where the noise does not increase. Measured by T. Zimmermann, Fermilab 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

3. MULTI-CONDUCTOR TRANSMISSION LINE MODEL TEM mode R,L,C,G line parameter matrices per unit length V,I voltage & currents vectors Solution: Terminal Boundary conditions Frequency domain Time domain ) , ( 1 t z I 2 3 n D + .. . V 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. SURFACE TRANSFER IMPEDANCE Vt Zt(w)=Vt(w)/I(w) 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. SURFACE TRANSFER IMPEDANCE V2 Environment Inner Conductors V1 R2 R1 L2 L1 I0* Zt2 I0* Zt1 V0 I2 I0 I1 U0* Yt2 U0* Yt1 C20 C12 C10 CS0 RS LS Shield Outer System Inner System 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. SURFACE TRANSFER IMPEDANCE Zd (w ) Diffusion coupling due to skin effect (LF) Mh - Aperture coupling (HF) Mb - Braid inductance (HF) Define the amount of noise coupled to the internal conductors It is a characteristic parameter of shielding cable 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. COMMON MODE REJECTION Rgnd : 100ohms, 1Kohms, 10Kohms Vcm QIE sig. QIE ref. PMT Cc Cp Rgnd : 100ohms, 1Kohms, 10Kohms Cp -Parasitic capacitance of PMT, board and connections Cc- Compensation capacitance Coaxial cable RG-58 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. COMMON MODE REJECTION 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. COMMON MODE REJECTION 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

4. COMMON MODE REJECTION 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

5. EXTERNAL ELECTROMAGNETIC FIELD External magnetic field Voltage generator (VF) External electric field Current generator (IF) VF, IF are dependent of system geometry. Applicable for near fields & far fields -weak coupling. Example: Far-field, E=100uV/m (EN 55022 A) 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

5. EXTERNAL ELECTROMAGNETIC FIELD 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

5. EXTERNAL ELECTROMAGNETIC FIELD 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

5. FUTURE WORKS Final conclusions about sensitivity to CM and EM interference Extend the analysis to different HF cable prototypes. Include studies of near fields Electric field Magnetic field Extend to time domain solutions Transient effects 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002

5. CONCLUSIONS The analysis allows to quantify effects of parasitic elements and unbalances on HF configuration. The system is very sensitive to parasitic elements that unbalance the differential topology Proper selection of final cable Influence of Rgnd is important at low frequency 8th Workshop on Electronics for LHC Experiments COLMAR - France, 9-13 September 2002