lekernel changed the topic of #m-labs to: Mixxeo, Migen, MiSoC & other M-Labs projects :: fka #milkymist :: Logs http://irclog.whitequark.org/m-labs
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<rjo>
sb0: llvmlite: nice. i'll spin new travis scripts and packages.
<rjo>
sb0: re cfl driver. one should not call that an "ion" trap, more of a dust trap..
<rjo>
sb0: for paul traps the parameters (voltage, frequency, charge and mass) need to be in a certain range to provide stable trapping.
<rjo>
do you know your parameters?
<rjo>
i think for macroscopic particles with the usual charge (corn starch) frequencies will be in the 50-5000 Hz range
<rjo>
and voltages in the ~kV. but just guessing.
<rjo>
and the corn starch needs to be dry to not stick together.
<rjo>
usually the particles charge with the same sign. and once these things are charged they will repell.
<sb0>
rjo, the designs I've seen use 2-3kV and 50-60Hz. I think I'm pretty much in the same range for the voltages, but some orders of magnitude higher for the frequency
<rjo>
higher?
<rjo>
ah. you are higher.
<sb0>
yeah, those CCFL inverters use a small resonant ferrite transformer, a wide guess for the frequency range would be 5kHz-100kHz
<rjo>
yes. if you have a ~20kHz flyback, that will drop the trap strength by almost 6 orders of magnitude ;)
<sb0>
ah. maybe that explains it
<sb0>
how does the trap strength vary with the frequency, exactly?
<rjo>
pseudopotential goes as (voltage/frequency)**2
<sb0>
mh. let's see how far I can lower the frequency of this thing...
<sb0>
why do you use MHz frequencies for the atoms, by the way?
<sb0>
to prevent wide oscillations?
<rjo>
Omega_rf >> omega_secular, and we want large omega_secular.
<GitHub151>
artiq/master bfe980d Sebastien Bourdeauducq: py2llvm: distinguish between llvmlite Module and ModuleRef
<rjo>
even if the secondary is only a single layer?
<sb0>
tesla coils have high frequencies too, and according to that page you need a bit less than a million volts at just 1kHz
<sb0>
you can do a million-volt tesla coil, but that will flash over any reasonably sized trap. and huge traps need higher voltages. seems any frequency above than a couple dozen Hz is a no-go for dust traps.
<rjo>
sb0: i was thinking about someting resonant at 60Hz. but the coils (and caps) might be large
<rjo>
sb0: which llvm-or1k do we need for llvmlite? still the same old one? mine does not seem to have AsmParser/Parser.h
<rjo>
oh so that part of llvmlite is merely a fancy templating system ;)
<rjo>
with text-IR output.
<sb0>
yes
<rjo>
ah well. i guess that's ok.
<sb0>
it's not slower than llvmpy afaict
<sb0>
btw if you want to run stuff on the board, the new command is "artiq_run.py <module_name>", e.g. "examples$ ../frontend/artiq_run.py mandelbrot"
<sb0>
it goes through the hardware database now
<rjo>
1mH and 1µF cap would give you an 80Hz. i believe you can get kV/µF caps from the trash.
<rjo>
sb0: i gave the pdb and ddb a cursory look but have not played with it. maybe i get some time off from fighting with my trap..
<sb0>
in sham shui po they sell a lot of vacuum tube audiophile stuff in the streets, including nice HV caps. a good part of it is grossly overpriced and with "features" such as gold-plated leads and hand-rolled dielectric material, but I can have a closer look
<rjo>
ha. i would buy hand-rolled cigars any time. but not hand rolled caps!
<rjo>
why is clang actually needed?
<sb0>
clang is not needed
<rjo>
why is it in the installation notes then?
<sb0>
I just installed it because I try to build the misoc stuff with it, which doesn't work yet
<sb0>
due to missing bits in the MC assembler
<rjo>
still there in 3.5?
<sb0>
re. installation notes, I'd rather end up skipping GCC/binutils, since LLVM is a necessary evil with ARTIQ
<rjo>
agreed.
<sb0>
afaik yes
<sb0>
I heard about an Italian fork that fixes it, but the modifications are not merged yet, and I have not tried
<rjo>
maintaining llvm-or1k looks like herding cats.
<sb0>
seems to be the case with maintaining llvm-anything