Purpose 

To familiarize LCLS associates and technicians with the XPP mode-change process and related instrument features.

To provide procedural information and a go-to reference for hands-on Mode change training.

Background

The XPP instrument has the capability to expose experimental samples to either a high-fluence (PINK) X-ray beam or a highly monochromatic (MONO) beam. 

X-ray beam type selection is determined by the experimental team and is based on sample attributes and experimental goals. 

A reconfiguration (aka a mode-change) of the XPP beamline places the experimental sample and accompanying diagnostic raft into the appropriate beam type. 

The two standard configuration modes for XPP instrument are: XPP Mode (PINK beam), and FEH Mode (MONO beam).

Technician (minimum) requirements

  1. Proficient in starting up and operating XPP EPICS control screens, ion pump controllers, and MKS pressure gauge readouts. 
  2. Proficient in UHV and the operation of gate valves, EVAC and KF flanges, roughing pumps, turbo pumps, and ion pumps.
  3. Proficient in the safe use of hand tools and be able to safely lift and carry beampipe sections up to 20 kg mass.
  4. Knowledgeable in the safe use of the hutch drift pipe lifting device and able to correct misalignment and sync errors.
  5. Knowledgeable in LN Dewar change out, and in the layout and operation of the hutch dry nitrogen system.
  6. Knowledgeable in the use of ServiceNow ticketing, directing the Duty Technician to config-control locks.

Subject Matter Experts (SMEs)

  1. XPP Area Manager, Daniel Stefanescu (daniel@slac.stanford.edu) c: 408-460-8834
  2. Lasers Area Manager, Adam White (adamwh@slac.stanford.edu) 
  3. LCLS Technician, Ivan Curiel (ivanc@slac.stanford.edu) 
  4. XPP Lead Scientist, Diling Zhu (dlzhu@slac.stanford.edu)

Resource List

  1. Resource:  Mode-Change to XPP Checklist
  2. Resource:  Mode-Change to FEH Checklist
  3. Resource:  XPP Drift Lifter Manual
  4. Resource:  XPP Hutch Matterport

Progress Matrix


Partially Trained

Fully Trained

Subject Matter Expert

Skill #1

XPP vacuum system control

Under direction or supervision, must be able to open the EPICS TechScreen and determine the XPP vacuum system condition on any Hutch or Control Room terminal.  Must be able to execute vacuum system configurations when instructed to do so.Must be able to configure the XPP vacuum system for vent, for mode-change, and for pumpdown.  Must be able to stop and to reverse any XPP vacuum system operation, bringing the system to a safe condition and be able to restore the vacuum pressure baseline.Must be able to detect off-normal situations and provide corrective actions.  Must be able to successfully train other operators, and be able to perform all of the vacuum system configuration without supervision.

Skill #2

XPP beamline reconfiguration

Under direction or supervision, must be able to check pressures, isolate components, power on/off gauges and pumps, operate gate valves, clean-dissemble flanges, transport pipe sections, operate drift lifter.Must perform all of the mode-change operations with minimal supervision.  Must be able to lead part or all of the mode change operation.

Must be able to detect off-normal conditions during beamline configuration and to provide corrective actions.  Must be able to successfully train other operators.

Training Process

  1. Print out and study the Mode-Change Checklist.
  2. Print out and study the XPP Vacuum System Schematic.
  3. Bring the printouts to XPP hutch and simulate (run through) a mode change in place.
  4. Assist with EPICS and beamline configuration at the earliest upcoming Mode-change.
  5. When comfortable with the process, ask to lead part or all of the Mode change.


Remember, when the job is done right, we have a happy Vader! 


Mode change checklist: 








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