1 / 9

Closed Orbit Digital Display at the PS

Closed Orbit Digital Display at the PS. Present status, possible evolution Jean-Pierre Potier PS/BD. Closed Orbit Digital Display at the PS - Present use. A system named "Closed Orbit Digital Display" (CODD) but in fact a Trajectory Digital Display Used since ~1967 in various versions

gaia
Download Presentation

Closed Orbit Digital Display at the PS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Closed Orbit Digital Display at the PS Present status, possible evolution Jean-Pierre Potier PS/BD J.P.Potier September 14th, 2001

  2. Closed Orbit Digital Display at the PS - Present use • A system named "Closed Orbit Digital Display" (CODD) but in fact a Trajectory Digital Display • Used since ~1967 in various versions • Present use J.P.Potier September 14th, 2001

  3. Closed Orbit and trajectory acquition in the PS complex PS ring case • One system, the CODD, measuring trajectories on two following turns to deduce oscillations or closed orbit. • A very sophisticated system using: • Base line restoration, gating and integration on 2 turns on a specific bunch providing 240 signals to be digitised. • Phase lock loop to keep synchronism with bunches during acceleration despite RF harmonics changes, bunch merging and splitting etc... • Heavily depending on RT control to follow all RF frequency changes => and necessitating constant nursing by competent people. J.P.Potier September 14th, 2001

  4. Closed Orbit and trajectory acquition in the PS complex (suite) Other circular accelerators of the PS complex Closed orbit acquisition • PSB and in the future in LEIR (and before in AA and AC): a normaliser system providing H and V in ~mm. • AD and before in LEAR: a receiver or network analyser technique without any need of synchronisation. • EPA: Since ~1993 a normaliser system. => all very simple and mainly without maintenance outside shutdowns. but not providing oscillation information... Injection oscillations • PSB: dedicated system: the half turn measurement. • AA : For re-injected H+ vis the loop there was a dedicated system using one PU and a fast digitiser (this has been re-used for AD beam through the loop). • EPA : a trajectory system similar to the PS CODD. Initially it was used as well for closed orbit acquition with BLR, fine synchronisation etc... J.P.Potier September 14th, 2001

  5. Closed Orbit: the normaliser approach Test of a PSB normaliser on a PS-PU with a jump of +/-4mm produced by a radial perturbation (october 27th, 2001, J.Durand and J.Gonzalez) Trace 1: sum of 3 beam control radial PU, trace 2: normaliser, trace 3: CODD phase discriminator EASTB 6.53E10 in 1 bunch PU sensivity 2E10. T1 0.5V/sq, T2 0.5V/sq, T3 0.05V/sq SFTION 8 bunches each 2E9 charges PU sensivity 1E10. T1 0.5V/sq, T2 0.2V/sq, T3 0.05V/sq J.P.Potier September 14th, 2001

  6. Closed Orbit Digital Display at the PS - the normaliser approach Performances of the present normaliser prototype No synchronisation. Calibrated LF signal proportional to the position available. Better position resolution: 0.1 mm in 40 dB range Dynamic range > 50 dB (PU sum signal from 6 mV to 2 V) H and V plane simultaneously Rise time when the beam arrives in the machine: 2 ms Rise time for a fast closed orbit change of 2mm: ~200 s. J.P.Potier September 14th, 2001

  7. Closed Orbit and trajectory acquition in the PS complex How to simplify ? Split the functions • Use normaliser technique in all applications not requesting a specific bunch acquired at a specific turn(s) all around the PS ring => mostly all cases except injection(s). • At PS injection(s) use an oscillation measurement: 1 or 2 PUs (at 1/4 betatron wave lentgh) digitised by flash ADCs over 100 turns or more to measure and correct PS injection errors and PSB recombination errors. • The same scheme can be used at extraction or for studies if necessary J.P.Potier September 14th, 2001

  8. Closed Orbit and trajectory acquition in the PS complex How to implement ? A possible scenario • Start by implementing the new normaliser on the PS providing a continuous monitoring of the closed orbit H/V and the MRP along the cycle each ~1 ms (use SAMPLER). • Limit the use of the CODD at injection(s) with a simplified synchronisation system (no more harmonics changes). • Experiment with the injection oscillation and recombination measurements using fast ADCs (cf. J.F.Comblin tests with the sensitive PU for ions). • Depending on experience remove the CODD at injection • If the need stays and depending on market evolution replace CODD by flash ADC and appropriate software. J.P.Potier September 14th, 2001

  9. Closed Orbit and trajectory acquition in the PS complex How to implement ? A possible (provocative?) time table • Implementation of the new normaliser hardware end of 2002 shut down. Installation of a provisional software (lack of software specialists) during 2002 to experiment with the new system and prototype applications. • Experiment in 2002 with fast ADCs (with 500 MHz sampling rate) to prototype the injection and recombination diagnostics (ABS) (cf. J.F.Comblin). • Depending on experience and software availability restrict the CODD at injection(s) end 2002. • Depending on experience with flash ADCs remove CODD at injection in 2003 • If the need stays and depending on market evolution replace later on CODD by flash ADC and appropriate software. J.P.Potier September 14th, 2001

More Related