8/12/2000Guy Crockford BI days New application software for SPS wire scanner controls G.Crockford SL/OP

8/12/2000Guy Crockford BI days Motivation Need to eradicate OS9 and TG3 systems in favour of LynxOS on PowerPC and TG8 (SL/CO supported hardware). Improved emittance measurement facilities required for LHC machine developments. Old application and server software written in Decide to replace this with more efficient software, better able to meet user requirements and ease software maintenance.

8/12/2000Guy Crockford BI days User Requirements Need 2 pairs of wire scanner in both non dispersive region and high dispersion section. Intensity range of bunches from I=10^9 to I > 10^12 (need for optical filters). Multi-bunch FAST WS allowing measurements: –Averaged over the whole batch. –On different slices of the batch. –On selected single bunches (given sufficient spacing). SLOW measurement for general use. IN and OUT scan performed in the same cycle.

8/12/2000Guy Crockford BI days The Hardware for fast/slow measurements Two hardware requirements for fast acquisition. –Fast signal response from photo multiplier. –Beam synchronous timing to allow acquisition gating. 2 photo multipliers installed in LSS4. 1 connected to a local amplifier in the tunnel, and a 50 ohm impedance line to the surface giving fast signal response, but with the disadvantage of a noisier signal. 1 connected directly to a 1 kilo ohm line to the surface providing a slow measurement integrated over 3 SPS turns. Provides less noisy measurement, integrated over the whole beam, which works for all types of beam.

8/12/2000Guy Crockford BI days BSG for fast acquisition Beam synchronous gate has 7 programmable fast acquisition modes. Currently set as follows. Fixed Target, 2 batches, 10 acquisitions (2*5 CPS extractions). Lead Ions, 4 batches, 4 acquisitions. 4 LHC beam options. –3 batches, 3 acquisitions. –1 batch, 3 acquisitions (3 slices of same batch). –1 bunch, 1 acquisition (effectively same as slow). –1 batch, 1 acquisition. 1 user option, single gate, adjustable with respect to the revolution frequency and adjustable gate size. Effective resolution of the fast acquisition is of the order of 200ns.

8/12/2000Guy Crockford BI days The Software Chose to integrate wire scanner into TZ measurement application. –1 standard application for many BI systems (already used for SEM, Fast SEM, OTR, TLPOS). –Measurement selection presented in a standard way. –Takes advantage of the TZ database infrastructure. –Application completely data-driven. New equipment can be added, parameters modified for different super cycles without touching the software. Separate application provided by BI oriented for equipment specialists.

8/12/2000Guy Crockford BI days 20007

8/12/2000Guy Crockford BI days New software features Predefined optical filter control. Filter selection dependant on which HW selected and acquisition mode (fast or slow). Both Potentiometer and Ruler data returned with each scan (in practice the optical ruler is limited to slow wire velocity and therefore very low intensity beams). Chi squared fitting routine to calculate fit beam size and position. Visualization of several profiles from a single scan in the case of fast measurements. Jitter on wire start time measurement improved by a factor 10. Now less than 1ms jitter. Improved normalized emittance calculation. Scanner address (family,member), filters, configuration parameters and twiss parameters all stored in TZ database.

8/12/2000Guy Crockford BI days Measurement parameters Acquisition mode (fast or slow). –For fast measurement, BSG file option (1-7). –If user option 7 selected. Gate delay (micro seconds). Gate size (micro seconds). Acquisition time for IN scan. Delay between IN and OUT scan. HT of photo multiplier (volts). Fitting routine (rms or chi squared). Fit threshold. Momentum spread (DP/P).

8/12/2000Guy Crockford BI days Hardware plans for 2001 BA2 wire scanners to be moved to BA5. –Rotational scanner at moves to –Linear scanner at moves to BA4 installation. –High dispersion region scanner at –Non dispersive region scanner at –Linear scanner at moves to Calculation of the delay between start of wire movement and beam crossing (wire fly time). Modification of photo multiplier electronics. –Single PM in the tunnel, slow/fast mode switching at surface.

8/12/2000Guy Crockford BI days Acknowledgments J.KoopmanHardware installation. G.FerioliHardware installation. H.HillerServer and BI application. J.J.GrasConsultations.