The Flash Beam Loss Monitor System

Transcription

1 MDI Diagnose und Instrumentierung The Flash Beam Loss Monitor System Thomas Wamsat, MDI for the diagnostics team FLASH Operator Training Thomas Wamsat Flash Operator Training 3. Nov Seite 1

2 Content > Introduction > Structure and functionality > Alarms, thresholds etc. > Beam Halo Monitor > Ionisation Chamber > Troubleshooting Thomas Wamsat Flash Operator Training 3. Nov Seite 2

3 Introduction 85 BLMs installed in Flash1 55 BLMs installed in Flash2 6 BLMs will be installed in FlashForward Protecting accelerator components from damage and excessive activation (as part of the machine protection system) In particular protecting the undulators, take seriously care about losses in undulator area! Thomas Wamsat Flash Operator Training 3. Nov Seite 3

4 Structure and functionality utca based electronics, distributed along the machine in several Crates Flash1, Flash2, FlashForward) 8 channel RTM with analog signal processing and 45 MHz 14bit ADC DAMC2 FPGA board for digital signal processing HV generation within the BLM, no HV cables needed Test LED to get alive feedback How it works in short words: Charged particles (beam losses) hit the scintillator which converts them into light. The photomultiplier tube (PMT) transforms the light into an electric signal Thomas Wamsat Flash Operator Training 3. Nov Seite 4

5 Alarms, thresholds etc. Single pulse alarm Triggers, as soon as the set limit is exceeded Multi pulse alarm Needs two terms to trigger: 1. signal exceeds threshold 2. number of allowed pulses overshoot Integral alarm Triggers if the number of integrated samples exceeds threshold Comparator alarm Analog backup, threshold is chosen thus it triggers a little bit above single threshold HV tracing alarm When the high voltage gets too low so the PMT cannot work properly it causes a permanent alarm Slow protection alarm (not enabled at Flash) Counts recurrent alarms from macropulse to macropulse, if alarm is gone the counter decreases. When number of recurrent alarms is exceeded it causes a permanent alarm no beam possible Reset by operator is needed Thomas Wamsat Flash Operator Training 3. Nov Seite 5

6 Alarms, threshlods etc. Scaling the y-axis to single alarm threshold Same loss, different single pulse threshold Resolution of panels not high enough to show discrete bunches Thomas Wamsat Flash Operator Training 3. Nov Seite 6

7 Alarms, threshlods etc. BLM Slow Protection Stops beam as in panels explained conditions Can be disabled by operators for max. 30min (causes an logbook entry) Responsible for this system: Christian Grün Thomas Wamsat Flash Operator Training 3. Nov Seite 7

8 Beam Halo Monitor (BHM) Kind of BLM, crystals instead of scintillators Direct in front of the dump within the concrete block Uses same electronics and panels [1] A.Ignatenko, Desy-Thesis Thomas Wamsat Flash Operator Training 3. Nov Seite 8

9 Ionisation Chambers Dump fibers and ionisation chambers in parallel along the last two meters before the dump window Ionisation chambers are not connected to any thresholds or MPS, just observable Dump fiber behave like normal BLMs Thomas Wamsat Flash Operator Training 3. Nov Seite 9

10 Troubleshooting If the BLM signal looks like this: -> Probably the ADC lost its config Open the Controls window in the Main Taskbar and click on MicroTCA Systems Use the Flash1 DIAG or Flash2 DIAG slide respectively Search for the panel, which includes the faulty BLM Click on FADC config, if this does not help, call an expert Thomas Wamsat Flash Operator Training 3. Nov Seite 10

11 Thank you for your attention Thomas Wamsat Flash Operator Training 3. Nov Seite 11