BI day 2000 08/12/001

PIPOS Project (TT2 & TT10)(Beam performances)

PIPOS Project (TT2 & TT10)(Beam performances)

G. VismaraG. Vismara

Present situation Proposals Beam parameters Technical solution Beam measurements Conclusions

BI day 2000 08/12/002

Present situationPresent situation

- No Bpm’s in TT2- No Bpm’s in TT2

- 7 BPM’s in TT10- 7 BPM’s in TT10

- TLPOS electronics:- TLPOS electronics: Is not conceived to measure

heavy ions and LHC beams Requires gain switching Obsolete components Difficult maintenance

BI day 2000 08/12/003

ProposalsProposals

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)

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BPM layoutBPM layout

BPCK replaced by BPCLfrom TI12 & 18 and TT70

Electrodes Placed on hor. & vert. axesAperture ± 66.5 mm

BI day 2000 08/12/005

Beam TypesBeam 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

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Frequency Spectrum-100

-80

-60

-40

-20

0

20

40

0 100 200 300 400 500 600

MHz

dBV

Fix Target (Max)

LHC (Max)

Special beam (min)

Heavy I ons (min)

97.5 dB

Dynamic & frequency spectrumDynamic & frequency spectrum

f0 = 22.8 MHz

f0 = 200 MHz

BI day 2000 08/12/007

LPFilter

LPFilter

A

B

LogampI to V

Converter

Diff.Ampli

Position = K * VoutLogamp

I to VConverter

Logarithmic normalizationLogarithmic 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)] (Vout)

where Vout is the voltage difference between the log-amp outputs

BPFilter

BPFilter

BI day 2000 08/12/008

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 dBInput noise: < 1.5 nV/HzNon conformance lin.: < 0.3 dBLimiter Bandwidth: D.C. to >2 GHzVideo Bandwidth: D.C. to 30 MHz

12dB

Full-waveDetector

Ampli-limiter

+LimiterOut

-

Log- amp. Out

+I n-

12 dB

Full-waveDetector

Ampli-limiter

12 dB

Full-waveDetector

Ampli-limiter

12 dB

Full-waveDetector

Ampli-limiter

12 dB

Full-waveDetector

Ampli-limiter-80 -60 -40 -20 0 dBm

.4

.8

1.2

1.6

2.0

0

1.0

-1.0

2.0

-2.0

dB

V

Logarithmic amplifier description

Logarithmic amplifier description

BI day 2000 08/12/009

Beam signals (Heavy Ions)Beam signals (Heavy Ions)

H = 500 ns/div

V = 200 mV/div

Output Level = -51.7 dBV

for 2*1010 charge/16 bunches

H = 500 ns/divV = 20 mV/div 1.8 mm/divResolution= 85 m (V plane)for 1 s integration time

H = 500 ns/divV = 20 mV/div 1.8 mm/divResolution= 85 m (V plane)for 1 s integration time

1 s 1 s

22 MHz BP filter22 MHz BP filter

BI day 2000 08/12/0010

Calibration signal (Sgl LHC bunch)

Calibration signal (Sgl LHC bunch)

H = 200 ns/divV = 200 mV/divOutput level = -37.8 dBVfor 1*1010 p/bunch

H = 100 ns/divV = 10 mV/div .9 mm/divResolution = 45 m over 100 ns integration time

22 MHz BP filter22 MHz BP filter

100 ns

100 ns

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Calibration signal (Fix Target)

Calibration signal (Fix Target)

H = .5 s/divV = 200 mV/divOutput Level = -37.2 dBVfor .2*1010 p/b and 500 b

H = .5 s/divV = 10 mV/div .9 mm/divResolution = 25 m for 1 s integration time

Single channel (-D)Single channel (-D) Difference (position) (U-D)Difference (position) (U-D)

200 MHz BP filter200 MHz BP filter

1 s1 s1 s1 s

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Position errors & resolutions (rms)

Position errors & resolutions (rms)

Non-conformity to log function:Position dependence versus intensity:

Zero for a centered beamUp to 250 m for a 11 mm off-center beam

200 MHz channel:Fix Target: 25 m/ 1010 p/b and > 400 bunchesLHC : 40 m/1010 p/b and 84 bunches

22 MHz channel: LHC single: 50 m/1010 p/bHeavy Ions (Fix Target): 50 m/1010 Charges/bSpecial : ??

BI day 2000 08/12/0013

Digitization & AcquisitionDigitization & Acquisition

Log-amp signals (BW < 4 MHz) are send to the auxiliary buildings, via coaxial cables

A modified version of MoposMopos digitizer, with integrator and 14 bit ADC

To improve S/N ratio two integration times are implemented (100 ns and 1 s)

Acquisition is identical to Mopos Mopos system (VME power PC & PMC MACI)

BI day 2000 08/12/0016

ConclusionsConclusions

A special effort has been done to reduce the cost as much as possibleInvestment 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!”Good luck to my successor!”