2026 Notebook

Nanowires(With CD): 3 shots per location, +50um fudge factor, Streak set to 100ns

321070-322029

Oscilloscope: Ch1 MIT-PMT(1“ Lead), Ch2 Al Diode, Ch3 OUR-PMT(1” Lead), CH4 Cu Diode

Test Claude with Nanowires(with CD) set up

~20 spots, 5 shots each: 320183-293

15 locations, at 5 shots per, at different fudge factors

0um:320466-540 -150um: 542-616 -100um: 618-703 -50um: 705-779 +50um: 781-855 +150um: 886-984 +100um: 986-1068

Oscilloscope: Ch1 MIT-PMT(1“ Lead), Ch2 Al Diode, Ch3 OUR-PMT(1” Lead), CH4 Cu Diode

Did some testing with different fudge factors, it was hard to see anything. even the Diode signal was low.

Oscilloscope: Ch1 MIT-PMT(1“ Lead), Ch2 Al Diode, Ch3 OUR-PMT(1” Lead), CH4 Cu Diode

Nano wires without CD:

800um raster steps

Rastering started at 319538-755, again at 782-841, 843-3200056

streak stopped at 319899

rastering again t 320058-171

so I realized the I wasn't rastering and the short pulse created a hole in the Saph.

we test just a Saph window, and got the same results at the D2O/DTi.

we moved to a lot of CD2 tape and CH.

MIT Users left on Friday

Monday we will take NanoWires

got everything ready to go, including the drilling in the code, but there was an iris closed so we had to vent. then we found cracks in the 200um glass, after a few shots. and went home for the day.

did some drilling, but got a late start due to changing the delay from 53ns to 47.5ns(Steve said too). because we our saturating Frodo's signal, we never were at focus, so it took 5-7 shots to get a decent signal. Non signal on our PMT, but there was on MIT's

I helped set up but I had to leave for Delanies birthday. they did both short and long pulse and get signal on our PMT. they learned that drilling with the short pulse 3-4 times was benefiting

I took shots of just the ring pulse, with variable delay times of the wedge laser. the particles were too dense and it was very hard to see. the goal was to see the shock

MIT WEEK 2, FIRST HALF

We did more shots on the CD2. Gil coded the rastering, so that we can zigzag cross the CD2 tape. we got 1 bubble on Monday. The PMT seems to be shorting when under vacuum. still idk why.

On Tuesday, we started testing the delay line and the long pulse. Gil made a telescope to better focus the delayed beam, so that it doesn't torch an optic. while I created a delay ling for after the compressor using 2inch optics. At the end, before the compressor was best. Since I took some 2inch mounts from the long path, Yun we created the long path with 1 inch optics and realigned everything.

I went to move the frame the holds the CD2 target out of the way, but ended up breaking the mount the holds the 35mm lens. I replaced it with the one the ucsd students were using.

On Wednesday, Gil got the fast diode set, so that we can see the timing between the wedge laser and long pulse. and he got the Frodo, auto focusing to work. We did some shots onto the CD2 foil, with only the ring pulse. But couldn't see any convergence of the ring. Yun created the nanoparticle target. I made reconnected the flipper motor to auto block and unblock the Frodo laser. I did some shots with just the long pulse onto the nanoparticle target. and I think I see convergence. Especially at 760,585,000 ps and 760,605,000ps delay.

Week 1 of MIT DONE

we started Tuesday - Friday: started working on the delay line and the point stability. While discussing, the best way to get high neutron yield. We went through different ideas, such as :

• different nano particle such as Ti and Ti2 with D2O, nanowires, and CD2.
• using ps focus pulses, instead of our fs
• no rings
• thinner sapphires or even holes

ps focus beam won't work because ps it too long of time scale to get energy into the system.

we want more energy, short time scale, but low intensity. so that leaves the size of the beam to be our main variable. Gil added that we can just more the target 2-3 Rayleigh lengths away from focus and get a lower intensity

We ended Friday but firing at CD2 solid film, with just the entire short pulse, all 20 mJ. we got a single neutron bubble, which is great! still need to understand the PMT.

we Got the new focus and got FRODO to work.

1. Get the Focus of the main beam and the TCC FADUCIAL at the same spot on the focal spot monitor.
2. then get FRODO light to the same location and same focal plane as the main beam. Use the mirror in front of the Frodo camera to steer Frodo light into it. This tells your when the mains beam is at the focus by comparing in to FRODOs.

the other week, spoke with Mario about the next steps for Galadriel. After Pacific Fusion, with Sean, we move to MIT campaign. Then after might move back to Pacific Fusion and in June move to UCSD.

RECAP PACIFIC FUSION WORK, WITH SEAN:

The goal was to measure the nanosecond decay of the fast emission of BrF2 scintillator, which is UV(~240nm). The company also wanted us to test ZnO, which has emissions near 400nm.

the best way to measured it was to we found to measure this was to drill a 1cm diameter hole in a 2mm thick Al plate. place the

AT the beam splitter where the laser goes to the time Fud fiber and the nozzle. The total distance from the BS to the pin hole of the Spectrometer is ~306cm through the nozzle, and 55cm+the fiber length(~500cm) through the timing path.

I learned a bit more regarding the Timing of inhibiting and deInihbting.

1. you should always Inhibit first, so that the 10Hz doesn't start firing immediately
2. You looping is structured by either a WHILE loop inside a FOR loop, or a WHILE loop inside a WHILE loop
3. The Big loop will define how many shots your want
4. just before the smaller WHILE loop, deInhibit the system, The start the WHILE loop
5. this smaller WHILE loop is so that the system is constantly waiting for the 5V at 10Hz signal so it can start
6. immediately after the WHILE loop, reInhibit the system.

MIT User meeting 04/15/2026

• Calvin Smith will be joining us
• Badge will good for 4 weeks
• Yun had a slide show
• The Bubble detectors need to be compressed for at least 30mins(manufacture)
• Place 2 detectors in vacuum(bought pump) for 1 hour, and no new bubble were generated
• They have more saph windows
• They will send over nanoparticles before hand( law could hault this) 2mg total
• IP discussion: No update from GA legal
• Wedge laser needs to be tested for the jitter(maybe 10ns, TOO High). Prioritize the original Probe laser.
• (We can control the timing we tell the probe to go and the)
• Layout changed due to the streak camera moved
• DO we want a 1D streak image or a 2D image Andor(or the wedge and a Basler b/c andor and wedge are both 2ns)
• 1D is better for the science, 2D is good for the paper
• We need to know truly when he short pulse shows up and when the ring converges
• We can use the Spectrometer,
• Can use a fiber to collect the light generated from the ring shock convergence or the Spectrometer
• Their Investors want to explore a partntership with GA
• Need to find a better way to collimate the probe laser. The diverge is TOO Large

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

200ns Sweep window,
Tab 'Ramp': Advanced shows TR:0 2 0 , SP:0 0 200

1us Sweep window,
Tab 'Ramp': Advanced shows TR:0 9 0 , SP:0 4 0

5us Sweep window,
Tab 'Ramp': Advanced shows TR:0 26 0 , SP:0 4 0

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

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).

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

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

• 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

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.

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