BI day /12/00 1 PIPOS Project (TT2 & TT10) (Beam performances) G. Vismara  Present situation  Proposals  Beam parameters  Technical solution  Beam measurements  Conclusions

BI day /12/00 2 Present situation - No Bpm’s in TT2 - 7 BPM’s in TT10 - TLPOS electronics:  Is not conceived to measure heavy ions and LHC beams  Requires gain switching  Obsolete components  Difficult maintenance

BI day /12/00 3 Proposals  Studies & specifications  G.Arduini & M.Giovannozzi  Steering optimization requires:  6 BPM’s in TT2  14 BPM’s in TT10  Electronics in BA269 (50%) & BA1 (50%)  Reduced cost for cables & G.P. equipment's  Active electronics present in the tunnel  Inconvenience: BPCL-1006 difficult to access (on opposite side of the custom door)

BI day /12/00 4 BPM layout  BPCK replaced by BPCL  from TI12 & 18 and TT70  Electrodes  Placed on hor. & vert. axes  Aperture ± 66.5 mm

BI day /12/00 5 Beam Types  Fix target protons  2000 bunches spaced by 5 ns, 1.7 ns wide  Heavy ions for Fix target  16 bunches spaced by 131 ns, 15 ns wide  LHC  single / 84 bunch spaced by 25 ns, 2.1 ns wide  Heavy ions for LHC  4 bunches spaced by 125 ns, 2.4 ns wide  Special beams  1,8,16 bunches spaced by 262 ns, 15 ns wide

BI day /12/00 6 Dynamic & frequency spectrum f 0 = 22.8 MHz f 0 = 200 MHz

BI day /12/00 7 LP Filter LP Filter A B Logamp I to V Converter Diff. Ampli Position = K * V out Logamp I to V Converter Logarithmic normalization A spectral line is selected, compressed by a logarithmic amplifier, filtered and applied to a differential amplifier. The position response is Pos.  [log(A/B)] = [log(A)-log(B)]  (V out ) where V out is the voltage difference between the log-amp outputs BP Filter BP Filter

BI day /12/00 8 New generation circuits use several cascaded limiting amplifiers, with fix gain and wide bandwidth. Full wave rms detectors are applied among each stage and by summing theirs output signals, a good approximation to a logarithmic transfer function is obtained. Input dynamic range : >90 dB Input noise: < 1.5 nV/  Hz Non conformance lin.:<  0.3 dB Limiter Bandwidth:D.C. to >2 GHz Video Bandwidth: D.C. to 30 MHz Logarithmic amplifier description

BI day /12/00 9 Beam signals (Heavy Ions) H = 500 ns/div V = 200 mV/div Output Level = dBV for 2*10 10 charge/16 bunches H = 500 ns/div V = 20 mV/div  1.8 mm/div Resolution= 85  m (V plane) for 1  s integration time H = 500 ns/div V = 20 mV/div  1.8 mm/div Resolution= 85  m (V plane) for 1  s integration time 1  s 22 MHz BP filter

BI day /12/00 10 Calibration signal (Sgl LHC bunch)  H = 200 ns/div  V = 200 mV/div  Output level = dBV for 1*10 10 p/bunch  H = 100 ns/div  V = 10 mV/div .9 mm/div  Resolution = 45  m over 100 ns integration time 22 MHz BP filter 100 ns

BI day /12/00 11 Calibration signal (Fix Target) H =.5  s/div V = 200 mV/div Output Level = dBV for.2*10 10 p/b and 500 b H =.5  s/div V = 10 mV/div .9 mm/div Resolution = 25  m for 1  s integration time Single channel (-D) Difference (position) (U-D) 200 MHz BP filter 1  s

BI day /12/00 12 Position errors & resolutions (rms)  Non-conformity to log function:  Position dependence versus intensity: Zero for a centered beam Up to 250  m for a  11 mm off-center beam  200 MHz channel:  Fix Target: 25  m/ p/b and > 400 bunches  LHC : 40  m/10 10 p/b and 84 bunches  22 MHz channel:  LHC single: 50  m/10 10 p/b  Heavy Ions (Fix Target): 50  m/10 10 Charges/b  Special : ??

BI day /12/00 13 Digitization & Acquisition  Log-amp signals (BW < 4 MHz) are send to the auxiliary buildings, via coaxial cables Mopos  A modified version of Mopos digitizer, with integrator and 14 bit ADC  To improve S/N ratio two integration times are implemented (100 ns and 1  s) Mopos  Acquisition is identical to Mopos system (VME power PC & PMC MACI)

BI day /12/00 14 Timing  Only 1st Log-amp in the beam line offers auto-trigger capability  Individual timing is required for each BPM’s  Fast timing ( SPS injection pre-pulses, rev.frequency)  Extremely long and jitter free delay units  Beam and Calibration timing are different  Slow timing (GMT) to initialize elementary cycle settings

BI day /12/00 15 Calibration  Remotely triggered  Single or 40 MHz LHC bunch simulation  It offers 0 db (center) and -6 dB ratio  +6dB ratio obtained by switching coax. relays  Center position can be cross calibrate with beam, by switching electrodes (coaxial relays)

BI day /12/00 16 Conclusions  A special effort has been done to reduce the cost as much as possible  Investment per channel still extremely low  cables and digital electronics & services represent the largest part of the budget (~78%)  Schedule: TT2 line will be put into operation current 2001 and TT10 after 2001/02 shut- down “Good luck to my successor!”