THE FRONT-END READOUT

Transcription

1 THE FRONT-END READOUT MAURIZIO PEREGO GIANUIGI PESSINA ANDREA FASCIA CAUDIO ARNAODI SERGIO PARMEGGIANO ROERTO GAIGHER INFN Isttuto Nazonale d Fsca Nucleare and Unversta' degl Stud d Mlano-cocca, Va Celora 16, 0133 Mlano Italy PESSINA@MI.INFN.IT 1

2 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; X NEW 8. READOUT FOR CUORICINO: NEW PROTOTYPE. NEW

3 SIGNA TO NOISE RATIO, S/N E S D T T A V O VON A N E S V THE PARTICE ENERGY IS CONVERTED TO THE OUTPUT SIGNA O N A D V ON THE SIGNA TO NOISE RATIO IS: THE NOISE SOURCES COMINE TO PRODUCE THE OUTPUT NOISE S N + 1 t VO e m d π = + 1 VON d π V V O ON SCHWARTZ INEQUAITY df 3

4 SIGNA TO NOISE RATIO, S/N: CONFIGURATIONS E S D Z D C P WRONG HERE A e A C A e A + - VO V + V - VOTAGE SENSITIVE PREAMPIFIER RIGHT HERE Z F Z F1 Z F A = Z F + Z Z F1 F1 CHARGE SENSITIVE PREAMPIFIER Z D E S D ET S CA: Z = Z 1 C 1 C Z >> Z D A FOR OTH THE CONFIGURATIONS IT RESUTS: A P C P F S N C A e A e Z A - + E V O VIRTUA GROUND V S D + A df 4

5 5 SIGNA TO NOISE RATIO, S/N: CONSIDERATIONS SIGNA TO NOISE RATIO, S/N: CONSIDERATIONS IF THE SERIES NOISE IS NEGIGIE THEN: A D df S E 4 N S INDEPENDENT FROM THE INPUT IMPEDANCE A O AO A C C e e = A O AO A C C = SINCE THE PREAMP. INPUT NOISE SATISFIES: THERE IS AN OPTIMUM AREA FOR THE PREAMP. INPUT DEVICE A D P A df C e S E 4 N S IF THE PARASITIC CAPACITANCE IS ARGE THE EFFECT OF THE SERIES NOISE IS INCREASED:

6 6 OOMETER CHARACTERISTICS 1, 1 AR.UN. 0,8 0,6 0,4 0, 0 msec STATIC IMPEDANCE: R DYNAMIC IMPEDANCE: Z = Z 1+ τ 1+ τ R Z 1 R 3 Z Z 0 = Z = R IMPORTANT FOR PARAE NOISE

7 7 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

8 8 CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION THE READOUT OF OOMETERS IS IMPEMENTED WITH THE VOTAGE SENSITIVE CONFIGURATION ASED ON 3 MAIN REASONS: IT AOWS DC COUPING WITH THE IAS FOR THE OOMETER INDEPENDENT FROM THE INPUT CIRCUIT OF THE PREAMP THE CHARGE SENS. PREAM. HAS THE INPUT VOTAGE FIXED; FROM AOVE THE CHARACTERIZATION OF THE OOMETER IS EASIER TO MAKE; THE OOMETER OAD IMPEDANCE CAN E VERY ARGE AND THE EECTRO-THERMA FEEDACK IS NOT REGENERATIVE WITH THE CHARGE SENS. PREAM. THE OAD IMPEDANCE IS ZERO, AND THE EECTRO-THERMA FEEDACK MAY REAK INTO OSCIATION THE DETECTOR. IN ADDITION WE ADOPT THE DIFFERENTIA SENSITIVE CONFIGURATION THAT AOWS TO TAKE ENEFIT OF NON-INTRINSIC EFFECTS SUCH AS MICROPHONISM AND CROSS-TAK: R Z D R + -

9 9 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

10 10 3.a EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN: MICROPHONISM ONISM MICROPHONISM IS GIVEN Y EFFECTS: DETECTOR FRICTION; MOVEMENT OF THE CONNECTING WIRES. C P C C P PO cos O t WITH R D THE DETECTOR IMPEDANCE AND O THE MONOCHROMATIC OSCIATING FREQUENCY: Z C C V o D P V P IAS sn o t 1+ C P Z C o D P MECHANICA VIRATIONS OF WIRES AND DETECTOR. AND, IF THE DETECTOR IMPEDANCE IS ARGE ENOUGH, Z D C P > O : C V V P IAS sn ot C P c P+ + IF THE CONNECTING WIRES ARE TIED TOGETHER THEY VIRATES THE SAME WAY AND THEIR MICROPHONISM ECOMES A COMMON MODE SIGNA, THAT CANCE OUT AT THE PREAM. INPUTS: c P- - V 1+ Z o C Z C o D D P P V IAS C C C C sn P+ P o P+ P t 0

11 3.b EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN: CROSS-TAK CH1 C P C CR IF THE DETECTOR IMPEDANCE IS ARGE ENOUGH: C V CR V1 C + C CR P CH C P CH1 c P c P + - THE DIFFERENTIA CONFIGURATION AOWS ASO TO TO REAIZE A SUPPRESSION OF THE CROSS-TAK. CH c P C CR c P + - THE INDUCING SIGNA IS GENERATED Y PAIR OF COUPED WIRES TERMINATES ON PAIR OR COUPED WIRES: IT ECOMES A COMMON MODE SIGNA. 11

12 1 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

13 THE COD EECTRONIC AOWS: MINIMIZE INK MICROPHONISM FURTHER; TO NU THE PARAE NOISE OF THE PREAM. UT.: IT CONSUMES POWER INSIDE THE FRIDGE; IT NEEDS A ARGER NUMER OF CONNECTING WIRES. THE POSSIE FUTURE nv/ Hz 103 k 11 k MX11D MX11D T= 111 K I DS =1 ma V DS =1 V COD EECTRONIC FRIDGE THE PRESENT SNJ903 T= 106 K K Hz nv/ Hz 0.1 DUA S JFET Hz 13

14 14 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

15 15 SEMI-COD EECTRONIC THE SEMI-COD EECTRONIC AOWS TO NU THE PARAE SHOT NOISE OF THE FRONT-END EECTRONIC. WITH GOOD S JFET A COOING OF A FEW TENS OF DEGREES O C IT IS ENOUGH TO MAKE THE SHOT NOISE TOTAY NEGIGIE. THIS RESUT HAS EEN OTAINED WITH A PETIER CE AS COOING DEVICE. α I G T = I G T 1 e /T 1 α /T e + VDG R Par VGD=0.95V 000 = qe G α VGD=.1V K, η = for generaton current. η 1500 VGD=3.V 1000 VGD=4.85V 500 T K Ig fa CUORE MAY E DESIGNED TO HAVE A SPECIA OX WITH SUCH A CONTROED TEMPERATURE

16 16 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

17 17 ROOM TEMPERATURE EECTRONIC THE ROOM TEMPERATURE EECTRONIC IS THE MORE PRACTICA. IT NEEDS THE MINIMA NUMER OF CONNECTING WIRES; IT DOES NOT NEED SPECIA REFRIGERATION; IT DOES NOT CONSUMES POWER AT COD. FRIDGE C P + - C P UT.. IN CONTRAST IT NEEDS SPECIA DESIGN TO OTAIN OW PARAE AND SERIES NOISE.

18 18 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

19 19 THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE AT THE MOMENT THE OAD RESISTORS ARE THE MAIN SOURCE OF NOISE COMING FROM THE FRONT-END. THEIR SPECIFICATIONS ARE: TO E AE TO E STAE AT OW TEMPERATURE; TO E OF ARGE VAUE GΩ, AND MORE; TO SHOW ONY THERMA NOISE AND NOT OW FREQUENCY NOISE; TO E CHEAPER. R Z D R + - THE TYPICA PARAE NOISE OF THE OAD RESISTOR IS OF THE FORM: 4K = R T αv + R 1 f AT PRESENT OUR RESISTORS HAVE: 3 1 α 4 10 Ω AND WORK AT ROOM TEMP. IF OPERATED AT ROOM TEMP. FOR HAVING THE SAME THERMA NOISE OF THE OOMETER THE OAD RESISTOR MUST SATISFIES: T Z T 1 R R 600 GΩ! T R T 10

20 0 RESOUTION OF THE 0 CHANNE ARRAY RESOUTION OF THE 0 CHANNE ARRAY D A ON -1/ 0 ON O FWHM Z WHERE : V df V V E +

21 OAD RESISTOR SEECTION 100 RESISTORS USED AT PRESENT 9 V V WEWYN NEW µv/ Hz 1 0 V SIEGERT R = 3 GΩ Hz 1 10 µv/ Hz 1 0 V R = 10 GΩ Hz 1 10 MICRO-OHM: META FIM, PURCHASED MINI-SYSTEM: NCr VERY HIGH COST. R V e V R = α f NEW R/ V/ R/ V/ e α V/ R = f / = α V R f 1 4 R/n V/n R/n V/n e α V/n R = f / n n = α V R f n 1 1

22 OUTINE 1. SIGNA TO NOISE RATIO, S/N;. CHOICE OF THE POSSIE PREAMPIFIER CONFIGURATION; 3. EFFECTS OF NOISE SOURCES OF NON INTRINSIC ORIGIN AND THEIR REDUCTION; 4. COD EECTRONIC; 5. SEMI-COD EECTRONIC; 6. ROOM TEMPERATURE EECTRONIC; 7. THE OAD RESISTOR EFFECT ON NOISE PERFORMANCE; 8. READOUT FOR CUORICINO: NEW PROTOTYPE.

23 3 SPECIFICATIONS AND FRONT-END CHARACTERISTICS 1. INDEPENDENT ADJUST OF THE IAS OF THE OOMETER;. OAD RESISTOR SEECTION FOR OOMETER CHARACTERIZATION; 3. SHORT CIRCUIT TO GND OF THE PREAMPIFIER INPUTS; 4. DIFFERENTIA VOTAGE CONFIGURATION, WARM AND COD; 5. DC COUPING; 6. 3 nv/ 1 Hz OF SERIES NOISE; 7. INPUT EAKAGE CURRENT FOR THE NOISE < 0,5 pa; 8. PSSRR > 100 d; 9. THERMA DRIFT < 0,5 µv/ o C; 10. SEECTION OF THE ANTIAISING FITERING FREQUENCY; 11. AUTO OFFSET COMPENSATION; 1. SEECTION OF THE OUTPUT OFFSET EVE; 13. POSSIE SPY OF ANY SEECTED CHANNE WHIE THE EXP. IS RUNNING; 14. REMOTE PROGRAMMING OF THE AOVE SEECTING PROPERTIES; 15. SMA SPACE OCCUPATION.

24 4 THE READOUT OF THE 0 CHANNE ARRAY 6 CHANNES + 1 SUPPY VOTAGE X 1 19nch RACK= 4 RACK FOR THE WHOE ARRAY TWO OARDS PER CHANNE: A DIGITA OARD AN ANAOG OARD

25 5 THE PROTOTYPE FOR CUORICINO NEW ONY 1 OARD IS USED. THE OARD HAS 6 AYERS: 3 DEDICATED TO THE DIGITA CIRCUITRY AND 3 ARE FOR THE ANAOG CIRCUITRY. THE NEW PROTOTYPE HAS A SPACE OCCUPATION THAT IS 1/3 THE OD ONE WITH IMPROVED FEATURES. THE FRONT-END OF CUORICINNO WI OCUPE THE SAME SPACE AS THE FRONT-END OF MIETA