GGG Un accelerometro differenziale in rotazione veloce per

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GGG Un accelerometro differenziale in rotazione veloce per la verifica del principio di equivalenza

GGG Un accelerometro differenziale in rotazione veloce per la verifica del principio di equivalenza INFN-CSNII, Roma 6 Ottobre 2005

GGG lab 2005 (March)

GGG lab 2005 (March)

GGG DESIGN 2005 • Motor on axis with double cardanic motor-rotor joint (multi-body rotor)

GGG DESIGN 2005 • Motor on axis with double cardanic motor-rotor joint (multi-body rotor) • Automated control of (very) low frequency tilt noise (tiltmeter+PZT) with 24 -bit read out • Automated control of all 3 whirl frequencies with narrow digital filter • 16 -bit rotating electronics + switch to high sensitivity scale (1 bit about 7 x 10 -9 m); 24 -bit ready to test • Resonance crossing without passive damper, room freed used by • Inductive (contactless!) power coupler to power rotating electronics (no more sliding contacts…)

motor-rotor double cardanic joint (3 D electroerosion). . reduce torque hence noise (in cruise

motor-rotor double cardanic joint (3 D electroerosion). . reduce torque hence noise (in cruise phase, limit it to ball bearings friction Motor free from sliding contacts, wires alog axis, phase lags adjusting gears (only cooling system left… less noise…) GGG: some hardware Inductive (contactless) power coupler to power rotating bridge electronics

Q MEASUREMENTS AT NATURAL FREQUENCIES (I) Q measured from free oscillations of full system

Q MEASUREMENTS AT NATURAL FREQUENCIES (I) Q measured from free oscillations of full system at its natural frequencies (system not spining): 0. 0553 Hz (18 sec) 0. 891 Hz (1. 1 sec) 1. 416 Hz (0. 7 sec) Rotordynamics theory of supercritical rotor states that Q value relevant while in supercritical rotation (and also for thermal noise) is Q at the spin frequency (a few Hz. . )… good…

Q MEASUREMENTS AT NATURAL FREQUENCIES (II) Rotordynamics theory states that in supercritical rotation (defined

Q MEASUREMENTS AT NATURAL FREQUENCIES (II) Rotordynamics theory states that in supercritical rotation (defined by spin frequency > natural frequencies) whirl motions arise at each natural frequency whose growth is determined by the Q of the full system at the SPIN frequency of the system (not at the natural frequency …. . ) Integration time available until whirl of period Tw grows by factor k High Q is crucial for slow whirl growth, and since Q at higher frequencies is larger this shows how whirls can be managed… In supercritical rotation thermal noise also depends on Q at the spin frequency (not at the –low- natural one) and this is a crucial advantage. .

Q MEASUREMENTS FROM WHIRL MOTIONS - 2003 Q (negative) measured (with fixed electronics) from

Q MEASUREMENTS FROM WHIRL MOTIONS - 2003 Q (negative) measured (with fixed electronics) from growth of whirl at 0. 08 Hz (12. 5 s differential period). June 17, 2003 Q=400 2. 5 Hz spin rate No whirl active control on At this spin frequency the Q of the suspensions (as measured with non spinning system) should be higher then 95000 there must be a source of large losses in the system when it spins in addition to losses in the Cu. Be suspensions

Q MEASUREMENT from WHIRL MOTION - September 2005, fixed electronics Spin period 6. 25

Q MEASUREMENT from WHIRL MOTION - September 2005, fixed electronics Spin period 6. 25 sec (0. 16 Hz), whirl period 13 sec (O. 0765 Hz), whirl control off

Q MEASUREMENT from WHIRL MOTION - Sept 2005, rotating electronics Spin period 6. 25

Q MEASUREMENT from WHIRL MOTION - Sept 2005, rotating electronics Spin period 6. 25 sec (0. 16 Hz), whirl period 13 sec (O. 0765 Hz), whirl control off

Q MEASUREMENTS 0. 0553 Hz (18 sec) 0. 891 Hz (1. 1 sec) 3020

Q MEASUREMENTS 0. 0553 Hz (18 sec) 0. 891 Hz (1. 1 sec) 3020 -3430 1. 416 Hz (0. 7 sec)

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts- 0 spin, May

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts- 0 spin, May 2005 Geomechanics tiltmeter (used also by Seattle group) as sensor; PZT as actuators; tiltmeter zero defined by capacitance sensors between TMs. System NOT spinning (Tiltmeter given by BO unit - X, Y channels both working at the time )

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts-0. 9 Hz spin

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts-0. 9 Hz spin rate, July 2005 (I) 0. 9 Hz spin rate – Y channel of tiltmeter (not shown here) more noisy…

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts-0. 9 Hz spin

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts-0. 9 Hz spin rate July 2005 (II) 0. 9 spin rate – Y axis of Geomechanics tiltmer needs attention… agreement with V. Iafolla for installation of small-scale version of ISA tiltmeter (better…)

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts Role of Read-Out

RESULTS from TILT MEASUREMENTS Automated Control of Low Frequency Terrain Tilts Role of Read-Out Electronics (Sept-Oct 2005)

DIFFERENTIAL MOTION of ROTATING TEST CYLINDERS from Rotating Capacitance Bridges: improvements since 2002 2005

DIFFERENTIAL MOTION of ROTATING TEST CYLINDERS from Rotating Capacitance Bridges: improvements since 2002 2005 data have been taken at INFN lab in Pisa-San Piero (INFN funding)

DIFFERENTIAL MOTION of the ROTATING TEST CYLINDERS: 2005 PSD comparison PSD of shorter run

DIFFERENTIAL MOTION of the ROTATING TEST CYLINDERS: 2005 PSD comparison PSD of shorter run (Sept-Oct, still running but no tilt control, incorporating important Aug-Sept hardware improvments) and longer run (July, with tilt control) are comparable ….

LOW FREQUENCY NOISE - Local Temperature Daily Changes? Diurnal temperature effects on the electronics

LOW FREQUENCY NOISE - Local Temperature Daily Changes? Diurnal temperature effects on the electronics of rotating capacitance bridges? NOTE that: diurnal variation of average on rotating elctrocinc is high frequency in lab frame, but daily amplitude variation of signal amplitude affects calibration, hence lab signal at same daily frequency (1 October 2005, clear day, large daily temperature excursion…)

ETA: In the field of the Sun In 1 yr GGG can improve by

ETA: In the field of the Sun In 1 yr GGG can improve by a factor 100; would still need significant improvements to compete with Seattle results… In the field of the Earth from space (GG orbit) In 1 yr GGG can improve by a factor 50. In space we would gain: 1500 (weaker suspensions for absence of weight); 100 (no motor, no terrain tilts) 7. 5· 106 total, reaching GG target of 10 -17 …. .

GGG “MILESTONES” for 2006 30. 06. 2006 Long duration measurements with 10 -8 m

GGG “MILESTONES” for 2006 30. 06. 2006 Long duration measurements with 10 -8 m sensitivity at 1/day frequencies (priority to duration of runs rather than to low natural differential frequency) Achieve 10 -9 m sensitivity in relative displacements of 31. 12. 2006 test cylinders at 1/day frequencies

PERSONE-PISA A. Nobili PA 100% G. L. Comandi Assegnista 100% E. Polacco PO 30%

PERSONE-PISA A. Nobili PA 100% G. L. Comandi Assegnista 100% E. Polacco PO 30% F. Maccarrone RU 50% G. Mengali PA 50% M. L. Chiofalo Ric t. determ 40% P. Christillin PA 30% Totale ricercatori equivalenti 4

PERSONE-BOLOGNA S. Focardi P 0 70% P. Baldi PO 50% E. Campari PA 50%

PERSONE-BOLOGNA S. Focardi P 0 70% P. Baldi PO 50% E. Campari PA 50% G. Casula Ric-Ist Naz Geofisica 30% F. Palmonari PO 20% G. Levi RU 20% Totale ricercatori equivalenti 2. 4 + Roma 2 DTZ: M. Bassan (30%), V. Iafolla (30%); F. Santoli (30%)

ASSEGNAZIONI 2004 (KE) Missioni intermo PI Missioni estero Materiale consumo Materiale inventariabile Costruzione apparati

ASSEGNAZIONI 2004 (KE) Missioni intermo PI Missioni estero Materiale consumo Materiale inventariabile Costruzione apparati Totale 3, 5 5 20 30 30, 0 88. 5 + 20 SJ BO 4, 0 2, 0 5 15 5, 0 31 119. 5+20=139. 5

ASSEGNAZIONI 2005 (KE) Missioni intermo PI Missioni estero Materiale consumo Materiale inventariabile Costruzione apparati

ASSEGNAZIONI 2005 (KE) Missioni intermo PI Missioni estero Materiale consumo Materiale inventariabile Costruzione apparati Totale 3, 5 3 13 17, 5 26, 5 62 BO 2, 0 0 4, 5 6 0 12, 5 Roma 2 (dotazione) Totale 2 76, 5

RICHIESTE 2006 (KE) Missioni intermo PI 3, 5 Missioni estero Materiale consumo 4 Materiale

RICHIESTE 2006 (KE) Missioni intermo PI 3, 5 Missioni estero Materiale consumo 4 Materiale inventariabile 15 Disegni di parti meccaniche: 5. Componenti elettroniche: 7. Materiale da laboratorio: 3 BO 3, 0 0 Roma 2 (dotazione) 23+43 Strumentazione elettronica: 8. Viti micrometriche controller e PZT per prove in parallelo alla presa dati: 15. Nuova camera a vuoto completa (IVA inclusa): 43 (offerta) 5 Materiale da laboratorio Costruzione apparati 0 Totale 40, 0 85. 5+ Parti meccaniche ad 43= hoc: 20. Sospensioni 128, 5 ad elettroerosione in Cu. Be: 15. Progettazione elettronica digitale: 5 15, 0 23 Sospensioni e parti meccaniche ad hoc per prove di nuovi design 3 108, 5+43+3=154, 5

PREVISIONI di MASSIMA per i PROSSIMI 3 ANNI (KE) 2007 130 KE: Per completare

PREVISIONI di MASSIMA per i PROSSIMI 3 ANNI (KE) 2007 130 KE: Per completare al meglio la fase dimostrativa del funzionamento e delle potenzialità dello strumento 2008: 150 KE Sia che si proceda a sospendere cardanicamente tutto l’apparato per una misura di EP a terra sia che si decida di iniziare a costruire un prototipo dell’accelerometro per l’esperimento spaziale 2008 -2009: 150 KE in caso di misura di EP a terra; TBD (ma dello stesso ordine perché lo strumento si costruisce comunque in casa…) in caso di costruzione dell’accelerometro per l’esperimento spaziale

We also have a regular visitor in the lab ….

We also have a regular visitor in the lab ….