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2026 Notebook

04/16/2026

Trying to why the 20ns sweep window for the streak camera has the weird effect

100ns Sweep window, at 760,350,000ps delay:

Tab 'Ramp': Advanced shows TR:0 0 150 , SP:0 0 200

20ns Sweep window, at 760,500,000ps delay:

Tab 'Ramp': Advanced shows TR:0 0 75 , SP:0 0 200

5ns Sweep window, at 760,713,000ps delay:

Tab 'Ramp': Advanced shows TR:0 0 0 , SP:0 0 0

03/31/2026

Update for all the stuff that happened last week and yesterday.

For the Students and their imaging:

  • after some struggle to understand the magnified diffraction rings. we choose to image larger pin holes(200um, 100um, back to 50um)
  • we found at larger pinholes, we could determine the edges better, and gain a better frame of reference as we move back to the 50um pinhole
  • we found the focus of the 50um pinholes, and then place in a 3mm tube.
  • with a lot of alignment, we got the exiting light at the focus and could see the diffraction and the size of the whole

Inlite Laser Update:

  • Gil swapped the laser head, and found it didn't have the doubling crystal.
  • What we thought was the doubler was just a filter for the 532nm light.
  • On Friday we used the laptop software to adjust the Eff , but to no avail.
  • on Monday(yesterday), Chris help Gil found out the doubler was missing a Waveplate so we were actually changing any polarization
  • Placing this WP in, 532nm spiked.
  • Gil placed the laser onto the mounts and start the alignment through the AMP
  • we found that the laptop will Hard Code certain value, like if Trigger is EXT or INT
  • that needs to change with the laptop before plugging to the computer.
  • Also, the Pointing Vector of the laser onto the Regen Crystal changes the wavelength effect, So resetting the Mazzler(Cuts off wavelength) will help.
  • When it come to the Delays. The Pockel Delay is the Q-Switch Delay. And we don't adjust that
  • we only should adjust the Flash Delay(near 545500ns)
  • We adjust 1 mirror for the Inlite laser alignment and 1 WP
  • we adjust 1 mirror for the Stretched Oscillator beam

03/10/2026

Gil got in early, and ran a Q3xQ1 runs with thick acrylic.

im trying the same runs, but with 3.5mm step size. First set with 4mm Teflon(550keV Stopping) then 6mm teflon(700keV stopping).

03/06/2026

I ran simulations on the different quadrupoles configurations.On my personal laptop Jupyter. We physically test Quad1 with 2,1, then 3 magnets per pole, then Quad1 with 3 and Quad2 with 1 magnet. Look for the times started to know when each starts. as well as the image to know when the Quads are Flipped up or down.

we used the Teledyne_3 (Off Brem)

Q3xQ1: BG:295103, Strt:295104, End:295823
Q3xQ0: BG:294262, Strt:294263, End:295102
Q1xQ0: BG:293421, Strt:293422, End:294261
Q2xQ0: BG:292307, Strt:292308, End:293420

02/23-28/2026

THÉODEN = Tapered Housing Extraction Of Diverging EmissioN

Found the Equation the relates the focal length to the a magnetic field strength and energy of the electron

When approximating for the thin Len ray equation, you miss a factor of 1/2, where you you would have caught it if you did Busch’s theorem. Which accounts for the rotation the electron will do, which then you take the average of the movement in both the xy-plane.(adding the 1/2)

f_Busch’s theorem = 2*f_thin lens

02/16-20/2026

  • we removed the MIT Users EXP. Put back the Espec and Gas Jet Nozzle.
  • The Inlite Laser head dropped in power, so I did a Flush of the cooling system.
  • Laser head should be 260mJ of 532nm, but we were getting 200mJ
  • The last block on the laser head in the doubler( 1064 to 532), alignment will effect energy
  • plug grey usb to laptop and open GUI, go to Service User, Pswd: 1064532
  • We discuss putting in a permanent Magnetics to focus the E beam. Should get f~1.5cm to 29cm for 100keV to 1MeV
  • Check the Alignment of the ESpec on Friday. We Put in a small stripe of Eljen EJ-262, and a large strip of Eljen EJ-212. Saw the electrons

01/12-30/2026

MIT USERS

Yun Kai came to the lab. We got the short pulse and long pulse to meet at TCC. We use Frodo's green laser and another green diode laser to align the beams, plus send the light to Frodo's Basler and the Streak Camera. The short pulse is very sensitive, since the travel distance is so much longer.

We were able to get an image of the both pulses, on our cameras, by inserting a Microscope slide at TCC to reflect the short pulse.

Notes for warming up:

  • the max Flash lamp Voltage is 1205V, we have been aligning with 1135V or 1160V
  • Before you open the AMP shutter. Set the Flash lamp to 1205 and turn on the NF and FF Beam Stabs. Then turn them off → set the flash lamp to 1135 → Open AMP shutter → Attenuator.

Notes for next time:

  • We should delay the short pulse after the compressor, so that align through the compressor is maintained
  • Use the andor camera, or more power for probe beam to see the shadow.

01/05-07/2026

over the break oscillator was working but didn't mode lock when we got back. we walked the 2 cavity mirrors and the stepper motors to get a small mode lock. we ultimately Set the Stepper Motors to Default, Greased the slit motor threads. and did very small adjustment to the horiztonial knob of the M7 mirror. it became way more consistent now.

The slit motor travel is about 23mm or 87k counts.

the configuration for the MIT Users are 800nm at 40mJ after the Amp, with 0.8mm diameter beam, and 300ps pulses.

Damage threshold is Energy/ Area. and Power is Energy/PulseTime

Our laser rating for damage is 0.0795J/cm^2. per pulse

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