This page: http://monitor.mikes.fi/ionclock/

Notes - Comb - Ion - Cavity - DAQ

Archived notes: index_2019 index_2020 index_2021
Machines and IPs:
Strontium/linux .45.99 (strontium.ad.vtt.fi) (192.168.10.1) - since 2021-12-03 IP = .45.15
win: .45.23 (ESPTE1M012-ioni.ad.vtt.fi)
kavi: .45.190 (kavi.ad.vtt.fi)
comb: .45.15 (192.168.10.18)
N210 SDR: (192.168.10.20)

News and notable results

  • 2021-04-30: trapping again after IR-camera BBR-characterization. New machined alu C-beam mount
  • 2021-01-25: first ions trapped after x-mas break. Intensifier+PCO needed for beam-alignment
  • 2021-01-22: new mu-shields delivered. inner and mid-shields installed and fit ok
  • 2020-12-03: Initial measurement of repumper-shift: -2600 (C1) to -2900 Hz (C4)
  • 2020-11-18: New Ion page for clock-run data
  • 2020-11-04: clock run with new HelRes (now 14.424 MHz) and new B-beam direction, but only 800us probe
  • 2020-09-24: Move 2019 results to index_2019
  • 2020-09-24: Secular frequencies with tickler + photon-correlation
  • 2020-09-23: new 14.404 MHz Magic-RF Helical-Resonator
  • 2020-07-02: Fourier limited 4 Hz linewidth with 180ms probe-pulse. Night, no metro.
  • 2020-06-11: Second clock run, OD2 with 4ms probe, only C1, C2 peaks.
  • 2020-05-17: D5/2 lifetime, random-telegraph method with 405nm and fit
  • 2020-04-24: First clock run! 2.5ms probe, stability 2e-13/sqrt(tau_s)
  • 2020-04-01: trapping single ion again, after 405 laser broke
  • 2020-01-31: Move comb-plots to comb
  • 2020-01-15: For temperatures, see DAQ
  • 2019-12-19: Micromotion map, 3D pictures
  • 2019-11-29: Cavity mode number, Comb mode number. Cavity absolute frequency.
  • 2019-11-08: -C2 Zeeman component linewidth estimate of 800 Hz.
  • 2019-11-05: Zeeman peaks with B-shield (1.6 uT estimate).
  • 2019-11-04: Now with first B-shield. Laminated plywood + metglas.
  • 2019-07-12: Zeeman peaks in ambient (66uT estimate) B-field. First clock-spectrum!
  • 2019-07-10: Initial clock-transition search...
  • 2019-07-10: Page created.
  • 2019-06-18: ion photo and secular frequencies

  • 2022-01-20

    Check peak-height balance with peak-search?
    ID18297 is peak-search with OD1/1.5 ms
    Do we get same C+/C- balance from this as the last clock-run result '271 deg' ?
        h+     h-      S
    C1  42.68  34.73   +0.103 (clockrun +0.109)
    C2  46.16  47.13   -0.010 (clockrun -0.018)
    C4  46.39  39.07   +0.086 (clockrun +0.052)
    
    Waveplate Thorlabs AHWP05M-600
    wavelength  retardation
    422         0.47522
    674         0.5005
    
    C1 peaks:

    C2 peaks:

    C4 peaks:

    5-minute mean from clock-run
    S = [ counts(C+) - counts(C-) ] / [ counts(C+) + counts(C-) ]
    waveplate   S1    S2      S4
    274         0.214 -0.165  -0.022 (15min mean)
    272         0.093 -0.082  -0.016
    271         0.109 -0.018  +0.052  (stdevs 0.095, 0.085, 0.086 )
    268 ('vertical')
    260         0.213 -0.040  -0.026
    
    16:06 to 271 deg
    (674nm ion-breadboard servo-electronics removed, no power-stabilization)
    15:22 to 274 (+6 deg)
    15:14 waveplate to 260 (-8 deg from vertical)
    15:04 waveplate to 272 (+4 deg )
    14:59 lower gains g1=0.1, g2=0
    14:55 set to 269 (+1 deg)
    14:50 initial angle for waveplate 268 deg - fast axis on waveplate approximately vertical
    experimental 1..5ms clock run - could we see C+/C- balance from clock-run, and slowly adjust waveplate?
    g1=0.5, g2=0

    Install lambda/2 waveplate in B-beam on breadboard. Use this waveplate to get balanced C+/C- counts?

    fix PMT dark counts with better alu-foil around PMT and camera-cube
    Back to OD1 and peak search with 1.5 ms
    peak heights from gaussian fit, FWHM AOM
         +h     +FWHM   -h    -FWHM    S
    C1   44.4   279 Hz  46.1   256     -0.019
    C2   39.3   260     44.3   271     -0.060
    C4   40.7   266     (something happened during -C4 scan?? too many dark-count photons, ion dark state not detected correctly!)
    
    C1 peaks:

    C2 peaks:

    C4 peaks:


    OD2 filter should give ca 10-fold 4-5 ms tau_pi?
    rises to 3-4ms, then noise?


    ID 18271 / 18272 is +C1 flop with OD1 filter
    looks reasonably good? tau_pi as expected 3-fold ca 1.5 ms


    ID 18270 is rabiflop on +C1, OD0 no filter, ca 400-500us tau_pi


    Peak-height asymmetry is now quite big?
    gaussian fits to 500us peak-search
    peak-height in counts / 100 shots
        +     -      S=(b-r)/(b+r) where b/r mean Cn+ and Cn-
    C1  47.6  52.3   -0.048
    C2  50.4  42.8   +0.082
    C4  45.4  43.6   +0.020
    

    ID18268 is 0.5ms peak search. 160Hz step 4000Hz AOM span
    C1 peaks:

    C2 peaks:

    C4 peaks:


    ID 18266 rabiflop on +C1, no OD filter, optimized power


    Increase fiber-power servo setpoint 3.0 -> 3.5 V

    ID 18264 rabiflop on +C1, no OD filter, optimized power


    Optimize 674 power to B-beam. 40 -> 450 nW at chamber exit.
    Switch to no OD filter.

    rabiflop looks ok to 3-4 ms - do peak search with 3.3ms probe? ID18257 is 3.3ms peak search. 20Hz step 500Hz AOM span
    C1 peaks:

    C2 peaks:

    C4 peaks:

    ID18257 rabiflop on +C1

    08:12local uMotion A 4.1%, B 4.8%, C 0.1%

    2022-01-19

    ID 18251 Rabi flop with fiber noise + power servos on. Power servo gain adjusted to a low value.


    ID 18250 Rabi flop with fiber noise servo activated


    ID 18249 is rabiflop after uMotion minimization
    fiber-noise from R&S fixed frequency, power-servo off


    ID 18240 run uMotion minization.
    Optimal voltages (Common mode, diff): [ 0.10926128 24.70072518 56.08856022] (outside scan range)
    at this voltage uMotions: A 5.7%, B 6.5%, C 2.8%

    uMotions: A: 19%, B: 14%, C: 19% at [-6.05, 0.2017, 25.0914, 55.8821]
    16:25local A/C back to high setting

    ID 18235 repeat with R&S driving the fiber servo. Power servo off.

    ID 18234 repeat with more points, adjust frequency from comb ( will see large drift as lab temp rises?)

    ID 18232 lowered A/C, power-servo (ion breadboard) off. some oscillation?


    ID 18230 is flop with lowered A/C



    15:53local try lower A/C 25 Hz?

    Try switching back to servo+VCO for fiber-noise?
    ID 18229 is flop with fiber-noise servo + VCO?


    ID 18225: Rabi flop, OD2, 18 dB att.

    ID 18223: Rabi flop, OD2, 18 dB att.


    OD2 filter in place.
    Switch intra-cavity power servo off.


    (Zeeman AOM drive level vs. power meter 2020-04 python script on linux machine)
    What is the effect of Zeeman AOM drive level?
    18 dB attenuation is the usual setting used for now
    ID 18208 is 19 dB
    ID 18209 is 20 dB
    ID 18210 is 21 dB
    ID 18211 is 22 dB
    ID 18212 is 23 dB
    ID 18213 is 24 dB
    ID 18214 is 25 dB
    ID 18215 is 26 dB
    ID 18216 is 27 dB
    ID 18217 is 28 dB












    ID18206 with intra-cavity servo on (should not matter?)

    ID 18205 is same flop R&S frequency offset 10 Hz (should not matter?)


    ID 18204 is flop with R&S fixed frequency and ion-breadboard power-servo on
    (note working in lab now causes laser drift...)


    Replace fiber-noise servo+VCO with fixed frequency from R&S generator, 178.5MHz and +5 dBm. R&S locked to 10 MHz from maser
    ID 18203 is rabiflop with R&S-generator, power-servo still off
    slightly better coherence?


    ID 18202 is rabiflop with power-servo off - this increases 674nm power


    Power-stabilization for 674nm light on ion breadboard
    Out-of-loop measured with Thorlabs Si-photodiode (variable gain) from B-beam on breadboard. Shows 50Hz component but quite weak?



    Fiber-noise error-signal spectrum, with Win-computer and NI DAQ-card:
    50Hz and 150 Hz components

    Peak around 1600Hz is beat-note between VCO (ca 178.5 MHz) and reference signal (artiq DDS 2*278.5 MHz) - includes both VCO instability and the fiber-noise we want to suppress?
    50Hz and 150Hz components

    2022-01-18

    No experiments over night...don't understand decoherence..

    ID 18187 is flop to 100ms
    ID_18184 is same rabiflop with 500 shots for more statistics?

    Seems like we have a lot of decoherence?
    ID_18182 is rabiflop on +C1 with OD0, ca 1000us tau_pi. flop contrast decays to half at maybe 5 ms?


    Try OD3, rabiflop shows risign counts to 40ms, then flat = incoherent??


    Go to OD4 where we expect tau_pi 70ms? run peak-search to see spectrum
    ID18169 is peak-search with OD4/70ms
    1Hz step 50Hz AOM span, initialized with linecenter from comb
    C1 peaks:


    Test new clock-run program with minimized extra dead-time. Get close to 45ms effective dead-time
    Book-keeping etc. database-writes are now in a separate thread - should not contribute to clock-cycle dead time much
    test-run around 16-17 local with OD0/700us (674nm power not as much as before in B-beam), g1=0.2, g2=0.0025
    QPN-limit seems to be easily achieved (clock-laser more stable than ion?) but reaching QPN-limit line takes >10 servo-cycles.
    observations from 700us test-run
    
    - All counts very good C1/2/4 +/- R/B C1=[ (20.6, 20.9), (21.2, 21.2)  ]  C2= [ (21.0, 21.3), (21.2, 21.1)  ] C4 = [ (20.6, 21.3) , (23.0, 22.8) ] (includes short dark-moment also..)
    - Reaching QPN-line takes >10 servo-cycles (higher g1 would make this happen sooner?)
    - Ion data is worse than Maser at around 2-3 servo-cycles already (tau > 10s)
    - 700us gives Fourier limit 1142 Hz
    - D4-2*D2-D1 = -14.276 (212.509) Hz  (can we use abs(Dsum) < FWHM as sanity-check, here FWHM=5*stdev(Dsum) - check if this holds for longer probe length?
    - B-field equivalence from pairs: B1-B4 = -0.28 (8.8) nT and B2-B4 = 0.395 (4.39) nT  - derive sanity check that depends on probe-length from these also?
    - g-ratio sanity check?
    - EQS-slope +0.269 (10.759) Hz/mj-prime-squared, N = 653 - surprisingly similar to runs with long probe?
    - servo-cycle length now very close to programmed pulse-sequence, measured effective dead-time 45.066 ms (check pulse timing, 45 ms programmed?)
    - now using limited sum 2nd-order servo-term, limited to past 25 servo-cycles, can't say much about this from 700us run
    


    Check for 50/100Hz signals:
    - FALC monitor output, no significant 50 Hz component
    - Cavity transmitted power detector, no significant 50 Hz component when power-servo on
    - no large 50Hz component when intra-cavity power servo off
    Fiber-noise servo:
    - error signal shows 50Hz and 150 Hz peaks both when servo on and off?
    - control-signal to VCO is ca 9.8VDC but shows no large 50Hz component
    - 422nm power shows 100Hz component?

    Coolinglaser shutter seems to cause mechanical disturbance, seen as noise on the beat-note spectrum?
    no shutter
    peak-search in progress
    peak-search in progress, waterfall while 10 shots fired spectrum disturbed - short dead-time between bursts shows OK spectrum?
    no shutter, waterfall

    ID_18085 is peak-search with OD2/2.9ms
    C1 peaks:

    C2 peaks:

    C4 peaks:


    check 674nm power?
    ID_18080 is rabiflop on +C1 with OD0 - visually ca 450us or so (same as before?)
    ID_18082 is flop on +C1 with OD2 - expect 10-fold tau_pi? artiq-fit gives 2.9ms
    ID_18084 is OD2 again - to longer taus - drifted off resonance?
    OD0
    OD2

    Temperature now settled higher with A/C at 45Hz?

    ID18077 peak-search OD5/100ms
    C1 peaks:

    C2 peaks:

    C4 peaks:


    Count-statistics and clock-run results do not look that great. Is intra-cavity power-servo limiting power so that ion-breadboard servo not locked?

    2022-01-17

    try g1=0.1, g2=0.0005
    g1=0.1 g2=0.005 seems to oscillate, too high g2?
    try finite sum for Iterm - use previous 25 servo-cycles?
    try higher gain g1=0.4?

    start OD5/100ms clock-run, new artiq-program with less dead-time and constant (?) servo-cycle length?
    g1 = 0.2, g2 = 0.001, n_shots = 10
    Initialize with comb-linecenter and B-value from last clock run

    Test new clock-run program that should have better dead-time and no memory-leak?
    Prome time (ms)     measured dead-time (ms)    measured servo-cycle for 2*6*10 probes (s)
    0.4 ms              46-47 ms                   5.6 - 5.7 s  -> 47.5 ms per shot
    4 ms                46-47 ms                   6.1 s -> 50.8 ms per shot
    40 ms               48 ms                      10.6 s -> 88 ms per shot
    100 ms              48 ms                      17.8 s -> 148.3 ms oer shot
    

    Intra-cavity power stabilization is now on

    Install 10m PM fibre between ECDL and Comb - however 10m is a bit short, order custom longer fibre?

    check if 422nm stays locked to Rb-line?
    ca14:30local set AC up to 45 Hz - check later if 100ms spectra are still ok? and if temperature now more stable?

    Toptica ECDL has been kept locked now by stepping the temperature set-point whenever the FALC slow integrator reaches +2V or -2V
    4V is the limit for FALC, so this could be expanded a bit? Integrator-voltage controls Piezo with -0.5 V/V gain - this could also be increased?
    Now it seems we sit at the +2V or -2V limit mostly?


    uMotion A 10.7%, B 5.8 %, C 4.9%

    Lots of laser drift now... stop clock run.
    Continue 225ms clock-run with lower gains, g1=0.2, g2=0.001

    Preliminary results from previous clock-run
    
    suggested voltages for zero EQS = [-6.5123 0.2017 24.4904 55.8821]
    
    
    B4 = 4.819549 uT  (u=23 pT) 
    EQS-slope = +0.286 ( 0.087/sqrt(N=559) )
    g-ration 1.668078142 (u=0.000005957/sqrt(559))
    Dsum -0.096 Hz (u=1.841 / sqrt(?))
    

    B counts 103.3 / 2.0 in 10ms
    09:34: fluorescence recovered
    09:30 405nm on
    09:28 all beams on, clearout on
    stop spectrum scan.
    09:27 ion dark?

    ID18006 is peak search, OD6/225ms. lineshape should give scale for optimal gain?
    FWHM/3 is optimal gain only if peak-height is 50%?
    0.3 Hz AOM step, 15 Hz AOM span, 51 pts/peak
    C1 peaks:

    C2 peaks:

    C4 peaks:


    07:33local stop clock run. maybe gains were too high, many values oscillate and QPN-limit not reached? gains were g1=0.4 and g2=0.0025

    2022-01-16

    cycle duration ca 43s (ideal 2*6*10*(225ms+50ms) = 33s)
    Try to start 225ms clock run with linecenter from comb and latest B guess.
    latest B guess 4.81928
    Try rabiflop again with B-beam - max at maybe 225ms?
    Ugh, previous spectrum was with C-beam?? (from uMotion measurement)
    Try rabiflop on the one we guess is the carrier.
    Carrier height quite low?
    +C1          75 864 250?? -> B1 =  2*13524 Hz / Z1 = 4.819634 uT ?
    -50Hz SB(?)  75 864 224..6
    -100Hz SB(?) 75 864 203
    linecenter   75 850 726 (while scan ongoing this changed to ..728...727 )
    
    ID17992 is peak-search, intialize with comb linecenter and B = 4.8 uT
    0.4 Hz step to make it go faster (0.27 Hz would give the usual 5 pts/FWHM)
    Try to find at least C1+ and refine B-estimate from this?


    Try new coil-currents with horizontal B-direction, old direction was nearly vertical
    I1 = 0.1319, I2 = -11.4598, I3 = -0.8224
    Previous currents "I(-35deg)" I1 = -2.4623, I2 = -1.668, I3 = -16.5163 - from C4 clock-run B = 4.794473(20) uT (u=20 pT)

    uMotion 100kphot: A 13.4%, B 8.9%, C 7.3%
    B-beam counts now 108 (10) / 2 (1.5) in 10ms
    16:36 fluorescence recovered
    16:35 all beams on, clearout on
    16:30 ion dark?
    300ms clock-run starts after peak-search, maybe ca 14-15 local

    ID17981 is peak search to show carrier-peaks. OD6/300ms, 0.27 Hz AOM step, 20 Hz span, 75 pts/peak
    laser-drift should be low (?), and clock-run peak-centers used to center these scans
    C1 peaks:

    C2 peaks:

    C4 peaks:


    09:23 stop clock run. self-comparison doesn't show much better statistics compared to 100ms or 40ms clock runs? because jump-statistics not very good at 300ms?

    2022-01-15

    17:03 start clock-run, OD6/300ms, g1=0.4, g2=0.0025, n_shots=10. servo-cycle-lenght ca 52s (ideally 2*6*10*(300ms+50ms) = 42s)

    ID17978 is peak-search with OD6/300ms - because why not..
    200 Hz AOM span, 0.27 Hz AOM step, 741 pts/peak. Fourier limit 2.67 Hz optical, 1.33 Hz AOM
    measurement takes ca 100*(300 ms + 50 ms) = 35 s / point. Current laser-drift -5 mHz/s AOM, so 0.175 Hz AOM per point (65% of frequency step!, 13% of FWHM)
    Need to wait for drift compensation to work well (<1 mHz/s AOM ?) before these spectra look OK?


    Even a short visit to the lab to add OD-filter, stop clock-run, and start a peak-search (maybe <5 min?) causes disturbance in air-conditioning and cavity-drift to change
    Vaisala room-temp sensor (at top of clock-laser rack(?)) shows ca +0.2 C change.
    Cavity-drift was stable, and drift-compensated light showed <1 mHz/s AOM for many hours, but then jumps to -5.7 mHz/s AOM suddenly
    AOM-frequency changes by -10 Hz/30min, so -20 Hz optical in 30 min


    ID17977 is peak-search with OD5/100ms
    (right of center peaks compressed, and left of center stretched, due to laser-drift)
    +C1: sidebands not significantly changed by better +5VDC supply to PDH-EOM?
    Fourier-limit 0.8/100ms = 8Hz optical, 4 Hz AOM. AOM-step is 0.8 Hz so 5 steps/FWHM - carrier peak roughly Fourier-limited (some uncompensated laser-drift after visit to lab)


    Menlo comb-control software had crased sometime during the night!?
    This stops plotting etc. programs that ask the menlo-software (over XML-RPC) for the rep-rate frequency
    re-starting comb-control software seems to work - need to manually enable auto-control again

    Memory and load on artiq-machine during clock-run:
    memory use drops when clock-run stopped


    2022-01-14

    18:16 try to start clock-run with OD2/4ms
    Initialize with comb_linecenter and old B-value
    cavity-drift is now quiite high..

    Add Dsum_valid check for the Dsum = D4 - 2*D2 - D1 where Dn is the Zeeman-pair peak separation in optical Hz
    Criterion is abs(Dsum) < 0.8/t_probe - which seems to be valid for the clock-run yesterday?

    Use new Zeeman-shift coefficients based on previous clock-run:
    Z1  5.612044246439378
    Z2  11.188548496368087
    Z4  27.989141239175556
    

    comb-measurement shows linecenter 75.850914 MHz ca 4 kHz lower compared to yesterday

    16:46 ion went dark? Fluorescence recovers after Rb-relock

    PMT counts in 10ms: A 44.8 / 2.4, B 78.6 / 2.2, C 95.5 / 1.8
    uMotion 100kphot A 9.2%, B 4.7%, C 3.6%
    use slot10 OD1 filter for 422nm

    14:37 ion! (beam-config was not optimal, loading time might have been shorter?)
    14:30:30Z load with 1.7A

    Check helres tuning with antenna analyzer (AA-55 Zoom)
    Before tuning VSWR is 1.07 at 14.4245 MHz
    Tune fore resonance at 14.424 MHz

    set Vbias to last uMotion optimum V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.2017, 25.0914, 55.8821]

    16:20 close cavity doors again
    Open cavity door, EOM temperature controller has +5VDC supply (center positive) AC/DC wall-wart - replace with +5VDC from Siglent PSU

    13:25 405nm off - no ion
    13:16 also 405nm on
    13:13local try full power for 422nm and all beams on

    at some point ion went dark? (clock-laser also unlocked)
    trying to fix computer & artiq issues with memorey leak. try latest artiq update?

    9:16L: Stop clock run
    Memory seems to be leaking during clock run.

    2022-01-13

    18:13local re-start once more with line-center from comb and sane B-estimate

    this was not running correctly Dsum (zeemna-shift-sum, not discriminant-sum...) was not close to zero, and B-estimate from C1/2/4 pairs was not consistent.
    18:06 re-start again, with g1=0.2 and g2=0.0005
    After each R/B probing cycle this gives the frequency correction added to the previous peak-center frequency value:
    
    servo_error(R, B):
        if R+B == 0:
            D = 0.0  # avoid divide-by-zero
        else:
            D = ( ( B - R )/( B + R ) )
        Pterm = g1*(FWHM/3.0)*D
        Dsum += D
        Iterm = g2*(FWHM/3.0)*Dsum
        return Pterm + Iterm
    

    17:13 enable 2nd order gain
    17:10 re-initialize, now g=0.5

    17:00 re-initialize again, now smaller gain - since g=1 seemed to be too much? gain now g=0.1
    with this small gain servos are not able to track clock-laser that drifts a lot

    16:53 re-initialize with center/B from C1 (C2/4 was not locked right?)

    16:29 re-initialize again with comb-linecenter, now OD5/100ms
    cycle-time ca 26.4s / 120 shots = 220ms /shot, probe-ratio 45 %

    16:17 Re-initialize with line-center and B from C2 servo

    print:C1 center 75.85415673015876 MHz, B-field 4.781531666067326 uT
    print:C2 center 75.85416877910049 MHz, B-field 4.779032499703762 uT
    print:C4 center 75.8541321613757 MHz, B-field 4.7812504020944635 uT
    C4 is wrong!? (B-field of C1 and C2 probably right - matches OD0/400us peak-search below)
    
    Dsum settles around +100Hz - so some servo(s) not locked right!?
    16:04 switch to OD4/40ms clock-run
    cycle-time ca 18.9s / 120 shots = 157 ms / shot, probe-ratio 40/157 = 25.4%

    15:57 try switching to OD2/4ms clock run
    cycle-time ca 14.2s / 120 shots = 118 ms / shot, probe-ratio 4/118 = 3 %

    15:54local start comb-measurement
    Try to start clock-run with OD4/400us and only 10 shots. cycle-time for 6 peaks * 2 R/B * 10 shots = 120 shots is ca 13s. 108ms/shot - most of this is overhead??

    OD0/400us peak-search
    +C1 Center =  75 867 621 
    -C1 Center =  75 840 789
    C1 Linecenter =  75 854 205
    B1 estimate =  4.781419
    +C2 Center =  75 880 935
    -C2 Center =  75 827 427
    C2 Linecenter =  75 854 181
    B2 estimate =  4.782252
    +C4 Center =  75 921 106
    -C4 Center =  75 787 284
    C4 Linecenter =  75 854195
    B4 estimate =  4.781147 
    

    ID17837 is uMotion optimization 4x4x4 grid, 200kphotons/histogram
    Optimal voltages (Common mode, diff): [ 0.20165608 25.09144063 55.88206965]
    300kphotons: A 2.6%, B 0.9%, C 1.7%
    600kphotons: A 2.3%, B 1.2%, C 1.7% (ca 70-100s per beam)
    Still some problem with very long photon-correlation measurements - now first bin seems overpopulated and sine-fit fails.
    in repeated measurement last bin is overpopulated? check number-type for timestamp - overflow?
    maximum time-stamp seems to be 1e11 (ns) - so duration of measurement 100s ? problems after this, because measurement returns only zeros?




    Fix bug with uMotion detection where sometimes last bin of histogram was incorrect. Bins must be given explicitly to histogram-function, not just number of bins. If just number of bins given, input data ends abruptly at t_mod, but last bin may extend beyond t_mod and becomes underfilled.

    uMotion A 7.9%, B 5.2%, C 6.4%

    2022-01-12

    Leave PMT monitor.



    Back to fiber-noise servo + VCO, compare this to last spectrum?


    relock laser, gain to "4", spectrum again?
    FALC slow integrator output to Fine-in-1 of DLCPro, used with "Analog Remote Control ARC" Piezo gain of -0.5 V/V (use Windows program to set this)
    +C1 now 75 867 129


    ID17802 is scan of +C1 with FALC-gain turned down to "3" - this slightly increases the brightness of the TEM00 mode on the camera, so more light transmitted through cavity?
    laser unlocked?


    ID17799 is peak-search with OD5/100ms. Fiber-noise servo+VCO replaced by fixed-frequency R&S signal source, locked to 10MHz, set at 178.5 MHz and +5 dBm
    servo free-running phase-detector shows oscillations with maybe 1-5s period - so fiber causes 0.2...1 Hz shift for 674nm?
    Noise-spectrum of this signal is rich with various peaks - but not so clearly at 50Hz or 100Hz?
    Initilize peak-search with ca +70 Hz shifted linecenter 75 853 628 - to centralize peaks better after laser drift?
    +C1 75 867 114
    C1 peaks:


    ID17797 is peak-search with OD5/100ms to see level of 50/100Hz sidebands today
    Note FALC gain trimpot at "7" - this could be changed also to see effect on sidebands?
    laser drift causes peaks left of center to be compressed, and right of center to be stretched out? (measuring left->right (or right->left) would compress or stretch all peaks the same?)
    For -C1, reduce FALC gain to "6"
    FALC monitor output does not show any 50 Hz component (?)
    +C1 carrier 75 867 000 (+40Hz from 400us peak-search)
    -C1 carrier 75 840 214 (+60Hz from 400us peak-search)
    +C2 ca 75 880 390 (estimate ends ..323 so +67 Hz from estimate)
    
    C1 peaks:

    +C2 scan interrupted to test fiber-servo off

    ID17795 is peak-search with OD0/400us to find line-center (no comb data now measured..)
    +C1 Center = 75 866 963
    -C1 Center = 75 840 154
    C1 Linecenter = 75 853 558  (ca +400Hz AOM from yesterday)
    B1 estimate =  4.777137
    
    C1 peaks:


    turn the power-servo on
    clock-laser power with power-servo off/on (question from below, is ratio 4.2/3.47 or larger?). at Zeeman AOM power-meter shows 256uW (on) / 164 uW (off) - so photodiode voltage 4.2 V not real, detector saturated!

    ID17789 is uMotion minimization 4x4x4 grid, 100k photons
    Optimal voltages (Common mode, diff): [ 0.20270735 25.11391536 56.15910653]
    now get: A 6.2%, B 5.9%, C 6.4%

    8:30local uMotion A 13%, B 5.5%, C 9.6%

    2022-01-11

    ID17785 is peak-search with OD5/100ms. 50Hz/150Hz peaks of in-loop power servo detector slightly improved with RF-rectifier + DMM off
    comb-measurement not running, so laser drift might be large?
    +C1 measured with power-servo ON
    -C1 power-servo OFF. relative 674nm power rises from 3.4775 V to 4.2135 V - so probe pulse is slightly too long - but should show big changes in 50/100Hz sidebands anyway?
    (check if 4.2 V is saturation of photodiode - or a real measurement?)

    C1 peaks:

    C2 peaks:

    C4 peaks:


    In-loop 674nm power detector PSD measured with Windows computer DAQ + labview program
    power-servo off: no peaks, flat spectrum ca -102 dB
    servo on: rectifier PSU on and close to photodiode-cable. flat level at ca -95 dB. 50Hz peak ca -77dB
    on/improved: rectifier PSU off (or far away from cable) 50 Hz peak -86 dB (reduced by ~10 dB)


    ID17782 is peak-search again, with program outputting 1/2/4 linecenters and B-estimate correctly now?
    make sure the program that sets peak-positions from linecenter and B-estimate also uses the new coefficients!
    +C1 75 866 578
    -C1 75 839 781
    C1 Linecenter =  75 853 179 7
    B1 estimate =  4.774940
    +C2 75 879 871
    -C2 75 826 376
    C2 Linecenter =  75 853 124
    B2 estimate =  4.781101
    +C4 75 920 107
    -C4 75 786 196
    C4 Linecenter =  75 853 151 
    B4 estimate =  4.784308
    comb linecenter at end of search: 75 853 160
    

    Comb linecenter 75 853 156
    ID17779 is OD0/400us peak-search with power-servo on. Initilized with B 4.781518 uT from yesterday (not very precise?)
    +C1 75 866 619 
    -C1 75 839 771
    C1 Linecenter = 75 853 195
    B1  =  4.783925 uT  (this was not using the revised Zeeman-shift coefficients - improve program so it uses the new coefficients!)
    

    ID17772 is 4x4x4 uMotion scan with ranges 0.1...0.3 23...27 50...58 V. 100kphotons/histogram
    Optimal voltages (Common mode, diff): [ 0.17934357 25.1647457 56.70578304]
    A 10.5%, B 7.7%, C 9%

    12local uMotion A 21.5%, B 16.9%, C 14%

    search for 50Hz disturbance of clock-laser.
    intra-cavity power detector seems ok - no large 50 Hz component
    ion-breadboard power-stabilizing detector (in-loop) shows 50 Hz (and odd harmonics 150 Hz etc) component when power servo locked!?
    Try improving power-supply to this detector (and/or servo electronics) - try also spectrum with power-servo off. maybe try also out-of-loop detector to verify?

    2022-01-10

    clock-laser unlocked, run fluorescence monitor instead..

    ID17765 peak search OD5/100ms
    C1 peaks:

    C2 peaks:

    C4 peaks:


    ID17763 repeat peak search, OD0/400us
    Initialized with 75.852700 MHz and 4.798 uT
    +C1  75 866 138
    -C1  75 839 323
    C1 Linecenter = 75 852 730 
    B1 estimate =  4.77813 uT
    +C4 75.91967173679576
    -C4 75.78583910623868
    
    C1 peaks:

    C2 peaks:

    C4 peaks:


    B-counts now 102.1 / 2.3 in 10ms

    ID17750 is 4x4x4 uMotion optimization
    Optimal voltages (Common mode, diff): [ 0.19533684 25.178081 57.44754843]
    A 4.7%, B 1.3%, C 2%


    At V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 57.0]
    A 10.6%, B 4.8%, C 19.3%

    EMM seems to have changed slightly, but not too much?
    V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 57.45]
    A 17.7%, B 9.8%, C 13.8%

    V34diff   B-contr
    56.45     7.7% (2.02)
    57.0      4% (-0.71)
    57.45     12% (phase -1.18)
    58.45     28.1% (-0.85)
    
    positioning of outer shield is quite sensitive - not to clip either A-beam or B-beam (bigger tolerances for ASE and C? they go better through middle of holes?)
    camera objective alu-foil grounding test. objective alufoil grounded
    install outer shield - outer shield grounded to optical table with clip+lead
    restart artiq with revised beam-names, same as old names, A is horizontal beam, B is used for loading and clock-runs.
    RF-rectifier power-supply on/off seems to raise and lower the 50Hz/150Hz peaks seen in the in-loop power-detector signal
    moving 230VAC wires far away from Photodiode coax seems to lower peaks?

    fits to rabiflops
       A+   A-   R+   R-   Rmean
    C1 0.39 0.38 1060 1056 1058
    C2 0.35 0.42 1101 1061 1081
    C4 0.41 0.44 1252 1173 1213
    
    ID17679 is flop on C1+
    ID17681 is flop on C1-
    ID17683 is flop on C2+
    ID17685 is flop on C2-
    ID17687 is flop on C4+
    ID17689 is flop on C4-


    ID17678 is peak-search again, now with correct beam
    C1+  75 866 153
    C1-  75 839 227
    C1_Linecenter = 75 852 690
    C1_B 4.7980 uT
    C2+  75 879 559
    C2-  75 825 897
    C4+  75 919 823
    C4-  75 785 600
    
    C1 peaks:

    C2 peaks:

    C4 peaks:

    ID17676 is peak-search at new suggested I(-35deg) (note this is C beam by accident...)
    I1 = -2.4623, I2 = -1.668, I3 = -16.5163
    C1 peaks:

    C2 peaks:

    C4 peaks:


    ID17674 is spectrum scan with I0 giving zero B
    I0 = [I1 = -4.5801, I2 = -0.3075, I3 = 0.8179 ]

    New coil currents to try I = [ -2.4623 -1.6680 -16.5163 ]
    
    currents that give zero B: I0 = [-4.5801 -0.3075 0.8179]
    
    New Zeeman-sensitivities that give consistent B1, B2, B4 estimates were used since 2021-12-15
    Further revised sensitivities:
    Component   kHz/uT          (2021-12-15)    old NRC values
    C1           5.61195897      5.61204387      5.6124
    C2          11.188804337    11.188552619    11.190
    C3          22.412722269                    22.415
    C4          27.989567640    27.98914811     27.992
    C5          39.213485573                    39.217
    
    C4-2*C2-C1  -4e-9           -0.000001        -0.004
    

    bias-voltage for zero EMM seems to follow double-exponential with 4h and 24h time-constants
    (attempted outer-shield installation on Friday - but could not find ion so went back to inner+mid shield configuration)
    Find some way of grounding extra charges on camera objective after removing&handling??

    10:17local uMotion at V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 57.45]
    A 1.8%, B 9.5%, C 6.8%

    10:11local uMotion A 26%, B 37%, C 19%
    V34diff   A-contr
    58.7      26%
    57.7      5.5% (phase -0.8621)
    57.45     0.7% 
    57.2      5.2 (+2.0)
    56.7      16.3% (+2.1)
    56.2      25.6 (+2.0)
    

    2022-01-09

    Results from fitting:
    B = B0 + A I % uT
    A =   [  0.2668  0.4134  0.2731 ]  % uT/mA  coil-sensitivity
    B0 =  [  1.222   0.1271 -0.2233 ]  % uT     background field
    
    compare to 2021-01-26 results (12 months ago!)
    A = [ 0.2649  0.4196  0.2713 ]
    B0 = [ 1.1847  0.4244  -0.2796 ]
    
    






    27 spectrum scans in queue.
    17:15 first scan done in 2290s = 0.64 hours
    estimate for remaining 26-scans 26*0.64 = 16.5 hours - finish by 10 Monday?

    16local kiky-Sunday: try to measure coil-characterization?
    Comb on
    A-counts now 31.4 / 1.1 in 10ms (lab lights off)
    Set detuning to 208MHz now counts 70.6 / 3.9 in 10ms (back lab lights on)
    uMotion A 3.3%, B 3.5%, C 9.3% at voltages V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 58.7]
    clock-laser on - remove OD-filters, coil characterization with short 400us or so probe ok
    400us peak-search with old coil-currents:
    this gives good enough excitation-levels for peaks to do coil-characterization?
    +C1  75 866 427
    -C1  75 839 037 (separation 27 kHz AOM)
    +C2  75 880 010
    -C2  75 825 402 separation 54.6 kHz AOM
    +C4  75 921 051
    -C4  75 784 370 separation 136 kHz AOM
    now at  I(-35deg) = [-2.1843 -1.3241 -16.8557] mA - gives ca 4.8 uT field
    
    maybe 100 kHz AOM scan range is OK?
    with 200 Hz AOM step this is 501pts/scan - duration ca 2300s per scan.
    
    ID      name                 Coil-currents [mA]
                                 I1        I2        I3
    17602   2022-01-09-coil1     -2.1843   -1.3241   -16.8557
    17605   coil2                0         0         0
    17607   coil3                +2        0         0
    17609   coil4                -2        0         0
    17611   coil5                +4        0         0    done 19:48, all 5 components fit in 100 kHz scan
    17613   coil6                -4        0         0    B close to zero?
    17615   coil7                +6        0         0    done 21:05, C1-C4, not C5
    17617   coil8                -6        0         0
    17619   coil9                0         +2        0
    17621   coil10               0         -2        0
    17623   coil11               0         +4        0
    17625   coil12               0         -4        0
    17627   coil13               0         +6        0
    17629   coil14               0         -6        0
    17631   coil15               0         0         +2
    17633   coil16               0         0         -2
    17635   coil17               0         0         +4
    17637   coil18               0         0         -4
    17639   coil19               0         0         +6
    17641   coil20               0         0         -6
    17643   coil21               +10       0         0
    17645   coil22               -10       0         0
    17647   coil23               0         +10       0
    17649   coil23               0         -10       0
    17651   coil25               0         0         +10      done 08:30?
    17653   coil26               0         0         -10
    17655   coil27               -2.1843   -1.3241   -16.8557
    
    C1 peaks:

    C2 peaks:

    C4 peaks:


    leave A-beam. PMT counts are low because 422-detuning AOM left at ca 200 MHz. counts 29.4 / 1.2 in 10ms
    09:44local leave at V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 59.7]
    here get A 1.3%, B 3.7%, C 3.9%

    V34diff     A contrast
    62.2        38.1%
    61.2        22.7%
    60.2        6.5% (phase -0.29)
    59.2        7.6% (phase +2.47)
    
    09:39 fluorescence restored (7 mins with all beams on + clearout)
    clearout on
    09:32local ion dark? all beams on (was only newB-beam over night)

    2022-01-08

    21:20local optimum now ca V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 62.2] ( ca -3V change on V34diff in 9 hours since 12local)

    V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 65.2]
    gives good minimum, V34diff still +10 V higher compared to previous stable voltages


    ID17532 is 4x4x4 uMotion scan
    suggested optimum V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.252, 25.48, 68.2] A 43%, B 52%, C 42% - not so good minimum..

    ca12 local uMotion:
    V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.2641, 22.5872, 63.0]

    scanning V34diff shows A-minimum ca 63V
    V34diff ca 73V gives sharper image
    11:52 fluorescence restored - lot's of EMM
    leave all beams on
    10:10local ion dark?

    2022-01-07

    17:26local EMM zero roughly at V34diff +91V now - down from 100-102V initially

    Turn off clock-laser and comb

    Use OD1 filter for 422nm

    ID17454 is coarse tickler for z-mode (figure for paper?) 10ms gate

    ID17455 is same tickler but 30ms gate - but we loose all fluorescence at resonance
    ID17459 is repeat 30ms, but more DDS attenuation - see a slight peak upward at resonance
    ID17460 repeat
    ID17461 repeat
    ID17462 is photon-correlation scan, 22 dB attenuation

    ID17463 is photon-correlation scan, 19 dB attenuation

    ID17464 with 17 dB attenuation

    ID17466 coarse tickler, but loose fluorescence at resonance
    ID17472 coarse tickler, all beams, asymmetric resonance, 7 dB att.
    ID17473 coarse tickler, all beams, 8 dB, asymmetric narrower resonance
    ID17474 coarse tickler, all beams, 9 dB, only two points slightly lower fluorescence
    ID17476 more points gives ca 4pts wide resonance

    ID17477 is similar, more points, asymetric resonance


    ID17446 is fourth 4x4x4 scan [0...0.5] [22...24] [100...104]
    double n_photons to 40k
    Optimal voltages (Common mode, diff): [ 0.26413521 22.58716818 100.46592698] - within scan range, so applied by program
    Now uMotion A 9.7%, B 8.6%, C 9.9%


    At V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.2316, 23.0835, 102.3162]
    uMotion A 1.3%, B 22% !??, C 7.9%
    (Note still high 422nm power and non-optimal detuning in use..)


    ID17439 is third uMotion scan 4x4x4 with ranges [0...0.5] [18...20] [99...105]
    Optimal voltages (Common mode, diff): [ 0.2315798 23.08354858 102.31619867] - again outside scan range..

    Try again 4x4x4 uMotion optimization, ranges V12diff= -0.25...+1 V34diff = 100..115
    found Optimal voltages (Common mode, diff): [ 0.27318177 19.10685086 102.01429658] - outside of scan range..

    ID17420 uMotion minimization 4x4x4 points in range: V12diff = [0, 3], V34cm=[24, 26], V34diff=[90, 110]
    (detuning not at 208MHz now - but maybe it doesn't matter for this coarse search?)
    optimal voltage has V34diff as high as +114V...

    Reasonable looking ion-images for all beams found at voltages V12cm , V12diff, V34cm, V34diff = [ -6.05, 1.5, 25.1946, 99.4376]
    uMotion with full power 422nm at this voltage:
    A 59%, B 56%, C 76%


    Try to manually scan voltages to find rough EMM minimum?
    old voltages were [ -6.05, 0.2399, 25.1946, 55.4376] - expect mostly changes in V34diff and possibly V12diff

    install outer shield
    camera focus-micrometer at "7"
    working with camera-objective seems to cause changes in E-field at ion and large EMM?
    Could not find ion-image with outer shield installed, so remove it again and use only inner+mid-shields.
    Now ion-image is blurred with C-beam, and cooling does not work with A or B beam


    11 local work in lab (temperature will change..)

    ID17118 is peak-search to see current level of 50/100 Hz sidebands
    initialized on last clock-run line-center and B
    120 Hz span, 0.8 Hz step, 151 pts/peak
    C1 peaks:

    (stop scan after C1- 50 Hz sideband)

    09:58local stop clock-run

    2022-01-06


    From 8h of clock-run, EQS_slope = -0.045 (0.091/sqrt(146)) Hz/mj-prime-squared
    EQS = (C1, C2, C4) = (+0.12 (0.30), +0.04 (0.29) , -0.15 (0.32) ) Hz, N=146
    Now at V12cm = -6.05 V
    
    2022-01-05 results at V12cm = -6.2635 V were EQS_slope = +0.206 (0.075/sqrt(157))
    
    Linear fit gives zero EQS at V12cm = -6.0884 V (try this for next clock-run?)
    

    19:40local restart clock-run with new 'S-balance' parameter computed & stored - to visualice balance between Cn+ and Cn- peak height
    if Rn+ and Bn+ and the quantum jump count for Cn+ (same for -), then Sn = [ (Rn+ + Bn+) - (Rn- + Bn-) ] / [ (Rn+ + Bn+) + (Rn- + Bn-) ]
    if C- C+ peak-height imbalance is caused by S-state population distribution we expect S1 = -S2 = -S4 (?)

    From 8 hours of clock-run get:
    S1 +0.060 ( 0.116/sqrt(155) = 0.0093)
    S2 -0.065 ( 0.109/sqrt(155) = 0.0088)
    S4 -0.074 ( 0.113/sqrt(155) = 0.0091)
    signs are as expected.
    possibly wave-plate before A-fiber could be used to fine-tune balance (i.e. linear polarization of 422nm beam) ? 
    but data collection is slow - hour(s) per waveplate-setting?
    

    09:00local re-start clock-run with 2nd-order gain set to zero, and increased 1st-order gain to optimal = FWHM/3
    Current run settings:
    P_gain = 1.0 * FWHM/3
    I_gain = 0.0
    
    Previous run settings:
    P_gain = 0.5* FWHM/2
    I_gain = 0.05 * P_gain
    
    Peik2006a uses only 4 shots/RB-side, and k=3e-4...3e-3
    
    

    With oscillating lab-temp 2nd-order peak-servo seems to do more harm than good?
    results show oscillating abs(B) correlated with temperature - not physical/real?

    2022-01-05

    17:08local leave lab
    Leave 100ms clock-run
    Work on computing optical freqs from mean(C1,C2,C4) line-centers

    disconnect 405nm AC/DC powersupply - replace with wires to +12VDC supply powering pulse-stretcher? But 405nm PCB+laser has + as grounded side...

    Note temperature changes in lab from maybe 10:30 local cause large drifts..
    10:22local at start of servo-cycle 294, set new bias voltages for zero EQS, V12cm=-6.05 V
    V12cm , V12diff, V34cm, V34diff = [ -6.05, 0.2399, 25.1946, 55.4376]

    These results at V12cm = -6.2635
    2021-12-16 results show EQS zero-crossing at ca V12cm = -6.05 V
    We are now at [ -6.2635 0.23985782 24.91625425 55.43757527] move along voltage vector dV = 0.2135 * [1 0 1.3037 0]
    New voltages [-6.05 0.23985782 25.1945942 55.43757527 ]

    Now get EQS = [-0.51 (0.23), -0.18 (0.23), +0.69 (0.27)] Hz with N=157 servo-cycles (8 hours), 100ms probe
    Corresponding EQS_slope = 0.206 (0.075) Hz/mj-prime-squared (N=157 servo cycles)
    (NOTE coil currents were changed after 2021-12-16/17 measurements so EQS values not directly comparable - but this should not change zero-crossing V12cm value?)

    2021-12-17 EQS-measurements showed EQS = [C1 C2 C4] = [-0.298 (0.269), -0.040 (0.242), +0.337 (0.262) ] Hz with N=120 servo-cycles, 120ms probe
    10:07local clock-run ongoing, servo index 289

    2022-01-04


    19:25local re-initialize with C1/2 linecenter and B, zero EQS (previous intialization had EQS for V12cm=0!??)
    one peak of C4 servo was probably locked to a 50 Hz sideband??

    Try to start clock-run.
    servo-cycle duration ca 182 seconds
    probing time is 6 peaks * 2 R/B sides * 100 shots * 100 ms probe = 120 seconds. t_probe/t_cycle = 66%, t_dead/t_cycle = 34%. t_dead(effective) = 52 ms
    How does the servo find the peaks and counts settle to half-max of peak?
    n_servo  +C1_R +C1_B -C1_R -C1_B +C2_R +C2_B -C2_B -C2_R +C4_R +C4_B -C4_R -C4_B
    0        6     2     9     7     33    2     4     23    5     28    14    4   (C1 totally lost?)
    1        1     2     30    3     47    3     3     32    1     30    23    1   (found -C1)
    2        3     1     33    3     24    12    4     29    2     28    22    3
    3        17    6     18    12    8     22    4     40    4     32    19    27  (+C1 found?, only -C4 somewhat balanced?)
    4        24    7     12    34    1     38    3     36    7     40    10    17
    5        47    1     10    28    6     26    3     38    6     30    6     14  (+C1 max imbalance)
    6        41    8     3     26    12    16    6     41    8     30    7     25
    7        17    21    13    21    19    32    8     33    10    14    9     23  (somewhat balanced on all peaks? -C2 most off)
    8        23    29    9     20    15    23    24    24    6     21    12    19  ( +C1 ok, -C2 ok)
    9        10    37    11    39    11    36    12    21    24    13    4     26
    and so on...
    servo gains should be checked - doesn't seem to converge very fast (or 2nd order servo takes long time to find true uncompensated drift value?)
    

    +C1 measured three times today: with PDH/EOM transformers, with PMT Siglent supply, with Pulse-Stretcher Siglent supply


    ID17079 is 100ms peak search with also pulse-stretcher powered from Siglent PSU (+12 V, ca 20 mA or less)

    abort scan and try 100ms clock-run for evening/night

    ID17076 is 100ms peak-search with new PMT supply

    stop scan after -C1

    Power PMT from +5 V output of Siglent powersupply (this powers also +24 V for Zeeman AOM RF amplifier)

    PMT +5 VDC
    Pulse-stretcher +12 VDC
    both PMT and pulse-stretcher have simple AC/DC powersupplies - possibly need to change both?
    reconnect camera

    Try to repeat 100ms spectrums, now with transformers on EOM/PDH signals
    ID17069 is 100ms peak-search
    clock-laser and comb only running for 10 minutes before scan - so drift may not be well compensated..
    C1 peaks:
    12:14local stop camera program and disconnect USB3 cable from camera (at camera/ion breadboard) - this might have caused a false 60-70 jump poin in dataset!?
    camera disconnected before any 50/100Hz sideband on -C1?

    C2:

    abort scan at end of +C2 - try improving PMT power-source?

    comb data shows linecenter 75 852 850 (ca -20 Hz from yesterday)
    Install FTB-1-6 RF transformers on cables from Toptica to EOM and from PDH-detector to Toptica

    Clock-laser relocking - simple on/off of the FALC fast-servo locks laser to TEM00 again, but at one mode too low beat-note frequency
    falc-OFF, then Lowering ECDL piezo voltage by ca 1V, then falc-ON, locks to correct TEM00 mode again
    this could maybe be automated? (does FALC have computer control of servo-on/off, or just mechanical switch?)

    check uMotion 300kphot A 1.1%, B ~0% !, C 1.4%


    back to OD1 for 422nm laser
    10:24:20 ion fluorescence recovered!
    to max 422nm power (this helped previously, 422nm also useful for dissociating molecule?)
    all beams ABC on
    10:21 turn on 405nm laser
    10:20local ion now dark? molecule?
    clock-laser jumped to TEM01 mode at some point during +C4 scan

    2022-01-03

    17:05local leave lab

    RID17060 is peak-search with OD3+OD2 / 100 ms probe
    Fourier limit 4 Hz AOM, 8 Hz optical - this should clearly separate Rabi-sidebands from 50/100Hz sidebands
    0.8 Hz AOM step, 150 Hz AOM span, 187 pts/peak
    Comb data shows about 2.4 mHz/s AOM of residual drift - each peak takes maybe 15 min (??) to scan - laser drift is 2.16 Hz AOM during 15 min (should not obscure/distort 50/100Hz sidebands much?)
    C1 peaks:

    C2 peaks:

    C4 peaks:


    Go to OD3+OD2, expect 120ms tau_pi!?
    ID17058 is flop on +C1. visually ca 100-110ms tau_pi



    ID17057 is peak-search with OD3+OD1 / 40 ms probe
    Fourier limit 10 Hz AOM, 20 Hz optical - this should show 50/100 Hz sidebands? (but Rabi-sidebands may overlap..)
    Span is 100 Hz AOM, 200 Hz optical - should show +/- 50 Hz sidebands at least, possibly only one +/- 100 Hz sideband if carrier not well centered
    step is 2 Hz AOM, so 51 points/peak

    Gaussian fit to spectrum fails..

    C1 peaks:

    abort scan and go to OD5!?
    OD3+OD1=OD4 for 674nm - expect ca 40ms tau_pi?
    RID17055 is flop on +C1 - shows approx 40ms tau_pi


    OD2 filter for 674nm - expect ca 4ms tau_pi
    ID17054 is peak-search with OD2/4 ms probe
    +C1 75 866 543 ( -9 Hz from OD0 result)
    -C1 75 839 201 (+7 Hz from OD0 result)
    C1_center 75 852 872 (+3 Hz from OD0 result)
    B1 4.8720215
    comb_center 75 852 871
    abort this scan and go to OD4
    
    C1 peaks:



    ID17053 is peak-search with OD0 / 400us probe. old abs(B)-estimate and latest line-center from comb
    +C1 75 866 552
    -C1 75 839 195
    C1_center 75 852 874  
    B1 4.874725 uT  (old estimate 4.87098 OK?)
    comb_center 75 852 869
    +C2 75 880 073
    -C2 75 825 641
    +C4 75 921 075
    -C4 75 784 690
    
    C1 peaks:

    C2 peaks:

    C4 peaks:

    background/dark counts quite high with back lab-lights on? threshold now 26 / 10 ms
    ID17052 is rabiflop on +C1 - same 400us tau_pi as before

    comb line-center prediction 75 852 865
    start automatic drift-comp
    beat-note ca 15.538 MHz (15.547 MHz on 2021-12-21)
    start comb and clock-laser. clock-laser beat-note was maybe 10 modes too low (ca 11 MHz) - ECDL piezo reduced from 56 V down to ca 49 V to find right TEM00 mode


    Photon collection efficiency bounded 295..305.

    RID17038 is A-beam detuning scan, 1000ms gate
    RID17039 is A-beam counts 9952.6 / 722.1 bright/dark in 1000ms
    RID17041 is B-beam detuning scan
    RID17042 is B-beam counts 10020.7 / 718.5
    RID17044 is C-beam detuning scan
    RID17045 is C-beam counts 7240.3 / 745.6


    RID 17033 is uMotion optimization in 4x4x4 grid - now with fixed shutters!?
    reduce photon count to 25 k per histogram to make it faster
    Optimal voltages (Common mode, diff): [ 0.23985782 24.91625425 55.43757527]
    Now uMotion 300k:
    A 0.92 %
    B 0.5 %
    C 1.1 %
    


    uMotion 300kphotons again with fixed shutters:
    A 11.6% in 42s
    B 7.4% in 41s
    C 12.8% in 37s
    

    back to original voltages V12cm , V12diff, V34cm, V34diff = [ -6.2635, 0.238, 25.0238, 54.9503]
    Shutters were not working properly - abort run. Press and hold "enable" on C-shutter should fix things?
    ID 17019 is 4x4x4 uMotion minimization scan
    Voltage ranges [[0.22 0.26], [24 26], [54 56]] - (more intellingent scan-range would be better, based on current uMotion measured, and known voltage sensitivities from previous scans)

    reduce 422nm power to slot10/OD1

    uMotion with 422nm OD1, 300k photons (these are probably WRONG, because C-shutter was permanently on??)
    A 2.2% in 28.45 s
    B 2.8% in 27.4 s
    C 11.8% in 37.4 s !!
    repeat C 11.7% in 39.8s
    
    100ms counts with 422nm OD1
    A 137.0 / 7.2
    B 152.3 / 7.7
    C 73.8 / 7.3
    

    100ms Counts with 422nm OD0/full power
    A 342 / 11  "newB"
    B 357 / 12  "oldA"
    C 334 / 10 
    

    100ms PMT counts while loading is RID17001

    count rise to ca 4000 / 100ms when ion appears
    13:50:40 ion! loading time 5min 40s
    PMT counts ca 120-170 / 100ms while loading, lab back-lights on (front lights off)
    assume old current-setting for 461nm laser is ok(?)
    13:45local start load with 1.7A dispenser. 422nm laser detuning 208MHz, OD0/full-power, all beams
    empty trap with RF on/off

    Install FTB-1-6 RF transformers on 100MHz and 10MHz cables from AHM3. Installed before distribution-amp inputs, PRI side towards maser, SEC side towards distribution amplifier

    11:00 No sign of ion in 15min - lost?

    422nm OD0 max power
    check if ion still stored? 422nm laser on, all beams, repumper+clearout, 405nm on

    10:45local turn down AC to 30Hz - to stop oscillation?

    Copy this html page to create 2021 archive index_2021
    Remove 2021 content from this main page for clarity


    For 2021 results see index_2021

    For 2020 results see index_2020

    For 2019 results see index_2019