Download
Share
Print this page
  1. Manuals
  2. Brands
  3. AMPLITUDE Manuals
  4. Measuring Instruments
  5. Magma 200
  6. Startup procedure

AMPLITUDE Magma 200 Startup Procedure

Cfel
Hide thumbs Also See for Magma 200:

Advertisement

Quick Links

Download this manual
CFEL – Magma 200
Amplitude Laser
Start-up procedure

Advertisement

loading
Need help?

Need help?

Do you have a question about the Magma 200 and is the answer not in the manual?

Questions and answers

Related Manuals for AMPLITUDE Magma 200

Summary of Contents for AMPLITUDE Magma 200

  • Page 1 CFEL – Magma 200 Amplitude Laser Start-up procedure...

  • Page 2: General Warning

    I. General Warning Golden rule: Pump first, seed second! There is serious danger to the laser system if the full power of the previous amplifier is seeded into the next one wihtout the amplifier diode been on. The crystal is convergent without the pump on so it will focus the high energy pulses.
  • Page 3 II. Laser composition Figure 2: Laser installation in the CFEL laboratory The laser system Magma 200 is composed of: 4 laser-head units on the optical tables: • Magma 25 • • • Compressor Several electronics units: • One rack oscillator situated near the regenerative amplifier •...
  • Page 4 • Two diagnostics control racks (one for each multipass amplifier – MP1 and MP2) which control the shutter, check the temperature of the laser system and control the motorized mount of each system. Cooling devices: • One deionized chiller for the regenerative and MP 1 amplifier •...
  • Page 5 IV. 1. Synchronization Log into the host PC located near the regenerative amplifier. Start the control program ElliOOs, login Amplitude and no password (see the manual of the Control Command: CCM for more information) and select the sub-menu Instruments/ Selectpulse.
  • Page 6 Figure 5 : First menu of the SelectPulse interface IV. 2. Regulation Stabilizer Go into the menu Regulation of the CCM and checked that each regulation is turn OFF and connected to the right camera. Figure 6: Regulation interface – Regulation menu [ p.6 ] Start-up procedure / September 2019...
  • Page 7 On the sub-menu settings of the regulation interface one can see the camera selection for the regulation. For the regen beam stabilization the NF Regen should be selected, for the MP1 => NF MP1, for MP2 => NF MP2. Figure 7 : Regulation interface – Settings menu IV.
  • Page 8 Figure 9 : Diode control interface (regenerative amplifier) First check that the current is sent to 0 %, then slide the power supply and output to the green position as can be seen on the picture above. Then slowly increase the set current (10 % step) to the standby value of 50 %.
  • Page 9 IV. 4. Regenerative amplifier First the oscillator control unit (see bellow) needs to be turned on. Check that the rear panel is ON, in standby mode the laser button should be red then turn the laser key to “laser ON”. Figure 10 : Front panel of the front-end Log into the Lasers –...
  • Page 10 Figure 12 : Magma 25 (regenerative amplifier) control software – Synchro sub-menu Open the Regen shutter and check that the seed going into MP1 is minimized (use IR card) and the shutter of MP1 is OFF. Now return to the diode interface and slowly ramp up the pumps Set the regenerative amplifier pump to 53 % in slow steps of 1 % (to have ~8.2 mJ displayed in camera energy-tab) while monitoring the beam profile with the cameras.
  • Page 11 IV. 5. Diodes ramp-up to nominal value and regenerative amplifier final amplification Go into the respective interface and slowly (by 10 % increased) ramp up the diode power of MP1 and MP2. The nominal value for MP1 diode is 95 %, while the nominal value for MP2 diode is 80 %. Go in to the regen stabilizer software and turn on the Regen beam stabilizer (stabilization tab) and turn on recording of the beam position (camera tab).
  • Page 12 Figure 14: NF Regen camera interface – energy sub-menu Before further amplification can be made the regenerative amplifier’s spectrum needs to be checked. Typically, 15 min warm-up of the regenerative amplifier at full energy is needed for the regenerative amplifier spectrum to be at his nominal value, see picture bellow. A spectrometer has been set-up to look at the leak of the first mirror after the regenerative amplifier.
  • Page 13 Figure 15 : Red: reference spectrum of the regen after thermalization (~15min). Black: Regen spectrum at full power before thermalizing. IV. 6. First Multipass amplifier – MP1 First check that no energy is seeded into MP1 and that the laser diode is still ON. NF and FF regen camera Regen...
  • Page 14 Open the shutter of the MP1 amplifier Figure 17 : Key Rack – MP1 shutter key Gradually turn the half-wave plate (at the center of Figure 16) to increase the energy inside the MP1 amplifier until the camera after MP1 detects the beam. If the beam profile of MP1 looks correct (as seen on Figure 18) at low energy, turn the wave-plate until the camera displays the lineout profiles of the beam, which means the MP1 regulation can be activated as the centroid of the beam is calculated.
  • Page 15 Switch on the beam stabilization as soon as the lineout profiles are displayed. Figure 19: MP1 regulation interface – Regulation sub-menu Wait until the beam is centered on the camera indicated by red crosshair on the NF MP1 camera menu or wait for the regulation of MP1 to switch to “Aligned”. Check that no energy is seeded in MP2 and proceed to send the whole regen energy in MP1 by turning the previously mentioned waveplate (while checking the beam profile on the near field MP1 camera) to reach 85 mJ output.
  • Page 16 IV. 6. Second Multipass amplifier – MP2 Make sure the input of the compressor is blocked and open MP2 shutter.. Figure 20: Key Rack – MP2 shutter key Open the camera for MP2 and start to send a small portion of energy into MP2 until the camera display shows the line-profiles of the beam on the sides of the screen, see Figure 22.
  • Page 17 Figure 22: NF MP2 camera interface If the beam profile resembles the standard one at low energy, turn on MP2 beam stabilizer. Wait until the beam is centered on the camera indicated by red crosshair on the NF MP2 camera menu or wait for the regulation of MP2 to switch to align mode.
  • Page 18 IV. 7. Safety Checks During the use of the laser system a safety checks can be implemented so that if the laser system would deviate too much from its “standard points” a security will alert and cut the seed of the laser system.
  • Page 19 Figure 24: Safety panel situated on the main interface of the CCM Figure 25: Safety menu click into nominal for activation once the start-up procedure of the laser system is completed. [ p.19 ] Start-up procedure / September 2019...
  • Page 20 Putting the system in stand-by mode: For this system it is crucial to turn down the seed first and then the pumps!!! The reason is that the thermal lenses of the crystals would cause the seed to be focused when the pumps would be ramped down first.
  • Page 21 Complete shut down of the laser system To completely stop the laser system, which is recommended if the laser remains unused for more than a week to save component’s lifetime, start by putting the laser in standby mode as described in section V.
  • Page 22 VII. Most crucial maintenance procedures: VII. 1. Water filters for the building water Filters at back of chillers will have to be cleaned whenever dirty (about every month). This is an easy cleaning and only requires the corresponding module to be stopped for a couple of minutes (turn of seed, turn off pump diode…).

  • Page 23: Water Level

    VII. 3. Internal cooling water/optishield solution in the chillers The deionized water or the mixture of deionized water and Optishield (additive against algae) in the chillers (internal cooling cycle) needs to be changed around every 6 months. All the chillers have been label explaining if they need to be filled with deionized water or a mix of demineralized water and Optishield.
  • Page 24 To do that, the lid of the regen needs to be opened while the regen is operating at full power. Before opening the lid of the regen, an informative note should be sent to Amplitude for warranty purposes, if you are not familiar with this operation a discussion prior to the opening is recommended. The Pockel’s cell position then can be tweaked via two screws with a hex 3 key to recover the spectrum.