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This procedure is written for the LPL operation after the 100J upgrade. The LPL upgrade changed the beam size and relay imaging after the 1" CD amplifier. The upgraded setup employed new irises and new camera imagers for alignment checks with higher precision. The new procedure includes the hardware turn-on, the software turn-on, a new alignment routine (using imagers and irises), commands for SHG and HWP optimization, and recipes for new pulse shapes. 

TO DO

  • first turn the chillers on then the power supply for the front end (to prevent unecessary error messages)
  • add a step saying 'wait for the edrive alarm sound to turn on'
  • add a step saying 'open the LPL control window from the MEChome screen'
  • add a capability to put by default 'dither' to Yes
  • press Y after the dither step again
  • press Y until happy with the shape
  • after SHG optimization, if you want to check Scope B enable 10 Hz on nsSlicer

Turn on hardware

  • Set hutch to “Class 1”, or “Class 4 Glass Laser”, or “Class 4 Dual Laser”, or “Class 4 Split Mode
  • At the LSS display, badge in and open Shutter S4, and press the “Press to reset interlocks"

  • Turn on four TDK Lambda power supplies. Power switch to “1” .Press the tiny “out” button at each of the 4 supplies.

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Figure 5: choose the pulse recipe: use commend "meclas.LPL.psmenu()"                                Figure 6: shape the 10Hz pulse as designed. 

Physical inspection of the beam

Go to class 4 and open the roll up doors to inspect the quality of the 10Hz 527nm beam. If the 527nm beam profile looks good, then proceed with firing amplifier heads. If the beam profile has spatial features that look irregular, it may be necessary to adjust the pinhole position in the VSF to confirm that there is no "flaring" of light at the pinhole. If there is some visible sign of clipping in the pinhole and/or irregular profile when observing beam on orange paper, then make adjustments in both axis of the VSF pinhole to minimize the clipping/flaring of the beam. This adjusment, in turn, should improve the spatial profile of the beam when observed on the orange paper.

Open the beam monitor camerascameras 

There are 6 cameras in the upgraded LPL layout: the new camview can be opened in mechome [detectors>view-long pulse Laser Cams> dropdown (figure below 1)]. For camview detail please check New Camview Feature

The full alignment using these 6 cameras is recommended. For operation and monitoring purposes only LPL_100J_1,  LPL_100J_3,  LPL_100J_4, are needed to open. For full alignment, using these 6 cameras is recommended. These imagers locations and descriptions are as followed (figure below 2). 

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Run " meclas.HWP.HWP_opt()". You can alsorun one or two arms by " meclas.HWP.HWP_opt(armsQ='ABIJ)". No need to run this if no changes to HWP's were made in effort to "trim" energy. 

Fire a shot

  • Make sure the final shutter, T3a and T3b, are closed. If it is open, make sure things are properly blocked inside the target chamber.
  • check event sequence configuration: play status "stopped" in case the lamps got misfired.
  • change camera trigger to "single shot": in MEC Home> EVR > New MEC LAS EVR > Front Panel B change to 182 (single shot) from 43 (10Hz)
  • change Ns Slicer and Lamps to single shot: Long pulse laser operation> click Single buttons on NsSlicer and Lamps
  • Charge: MEC:PFN> click "stop", "Stand By", "Ready" and "Charge"
  • Fire: click "single shot"
  • run postshot: meclas.LPL.pspostshot(save_flag = True, display = True), it shows a plot and energy output.
  • or show energy meter: meclas.EMeters.EGall()

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