Notes, Nov 24, 2004 Instrumentation/beam physics meeting Agenda - shutdown changes and readiness a. MI/Tev SBDs 1. Bob Flora - slides in doc 1337 2. Brian Fellenz - doc 1476 3. Stephen Pordes - doc 1475 4. Alvin Tollstrup - file in doc 1337 5. Adam Para - summarized below b. Tunes - Paul Lebrun - Doc 1474 Action items: a. Tev SBD 1. Get Tev SBD data viewer working - Bob Flora 2. Implement matrix emittance calculation in FE. This will give emittances only at 150 and 980. (also dp/p for FW calculations...) Worry about what to do if RF voltage changes a little bit. Should the full phase space be saved as well?- Adam Para 3. OAC for full offline analysis using Minuit to do a constrained fit and returning the correlation matrix as well as the phase space density. 4. Add injection, flattop, squeeze triggers for storing raw distributions as is done every 30 min during HEP. Also up the ramp. 5. What has to be done to get emittances (offline, online) up the ramp? Is this of interest as a normal thing or only for the experts from stored raw distributions? For now, just get stored distributions up the ramp. 6. What about dp/p for FW transverse emittance calculations on the ramp? 7. Why was Bob Webber concerned about using the calibration input? 8. Document Tev SBD variables. - Stephen 9. Add new SBD variables to SDA and data loggers - Stephen, Jean b. MI SBD 1. come up with the old software. Once it is shown to be working properly, switch to the new software which is 2.5 mhz aware for pbars. 2. Clean up reading the RF voltages 3. What happens about the calibrations for the RF voltages? ( Bob flora, Dave Capista) 4. Add new 2.5 Mhz SBD values to SDA and data loggers Dave Capista, Jean c. tune fitters 1. Paul needs someone to read and critique his documentation 2. He needs a backup person as his AD time is very limited. 3. 21.4 mhz system a. Additional node for 21.4 mhz system b. finsh user-friendly startup system c. (future)feed-forward tune adjuster up the ramp if Tan's system fails d. automated chromoticity mesurements - no one seems interested. Wouldn't it be useful to datalog what people find each store? e. Get Brian fellenz to tune up the system. 4. 1.7 Ghz a. work on emittance mesurements - some questions about the utility of this. b. systematic errors c. (possible if people power) 24 systems in parallel to record tunes of every triplet bunch simultaneously. Details a. Tev SBD 1. The RWCMs (Resistive wall current monitors) were removed, rebuilt, and the splitting of the signals for the SBD, FBI and users( mountain range, etc.) changed. See Doc 1475 for the before and after splitting diagram that Stephen showed. Brian Fellenz showed pictures and described how the resistors were replaced with bigger ones that allowed a more secure solder joint. 2. The reflections were greatly reduced by changing the pickoff point to use the "calibration" input as the output port. See Doc 1476 for the circuit diagram. The impedance looking into the RWCM is now 50 ohms instead of 1.29. The signal is smaller, but rearranging the splits for the SBD, FBI and users (doc 1476) means that the effect is only about a 25% reduction. Brian showed the frequency response for the two ports and it is very similar. It was measured on the bench using a 50 ohm system to simulate the beam through the RWCM. The new frequency response compensates somewhat for the scope. There was some sort of 250 mhz ripple that is a mystery? 2.5 buckets of delay were also added to get any residual reflection separated in time. The new arrangement is much simpler since the scope is much more intelligent than the old one. Instead of a camac crate full of stuff, it's just the scope and a trigger card that effectively gates the beam sync for protons and pbars. 3. Bob Flora has three things left: 1. resurrect the data viewer 2. add ability to save raw data at injection, flattop, squeeze. ( This is already done for HEP.) 3. with Adam, implement online matrix calculation of longitudinal emittance. should we also store the full phase space? There seemed to be disagreement between Valeri and Alvin on the aspects of this. b. MI SBD 1. New software needs to be tested and made operational. It does 2.5 mhz at 8 Gev for pbars, by adjusting the harmonic number and reading the RF voltage, using a system developed by Bob Goodwin to capture a set of readings These are split out at the IPMs. Dave Capista was concerned about calibrations here. c. Alvin's presentation. See the file in doc 1337. Alvin showed 1. the quality of the data - beautiful! 2. Matrix method for "online" calculations and how well it works( sensitivity to noise) for different numbers of coefficients and different time divisions (beating can be a problem). He showed plots using a test gaussian input as well as with real pbar and proton pulses. He also looked at the effects of an off-center pulse. d. Adam's presentation 1. There were problems originally (feb 2004) implementing Alvin's original algorithm. The emittance value was unstable and it took too long. 2. New scope, finer sampling, averaging and work on the algorithm by Valeri, Alvin and Adam have lead to much better ideas. 3. The proposal - which will be implemented ( see action items) 1. "online" calculation using pre-calculated matrices 2. "offline" OAC with full constrained fit and the best base functions. - needs a person to help. e. Tune fitter - Paul lebrun - see Doc 1474 1. 21.4 Mhz tune fitter a. no changes in functionality or ACNET names b. Doc has a nice diagram and discussion of the software. He could use another node. c. working on better startup procedures d. The document has a nice diagram of the system 2. 1.7 GHz a. a possible upgrade is to save raw histograms on disk b. it's ready to be re-started