1 Hydride and deuteride powders
Column key: D/M is the deuterium-to-metal atom ratio in the loaded lattice. GHS is the Globally Harmonized System hazard classification; SDS is the safety data sheet shipped with each lot.
| Consumable | Form and particle size | Purity | D/M target | Safety class | Handling notes |
|---|---|---|---|---|---|
| Pd (palladium black or powder) | Loose agglomerates 1 to 30 um built from 5 to 20 nm primary crystallites (estimate); sieve to 1 to 10 um for suspension work | 99.9% minimum; 99.995% trace-metals grades are catalog items | D/Pd 0.6 to 0.7 after gas loading (program concept physics) | Flammable solid, fine metal dust (GHS02, H228) | Argon glovebox; grounded, non-sparking tools; antistatic scoops; never sweep dry |
| PdDx pre-loaded target | Pd powder loaded in-house from D2 gas; target D/Pd 0.70 plus or minus 0.05, confirmed by gravimetric mass uptake and a pressure-composition check | Inherits base powder purity | 0.65 to 0.75 program target | Flammable dust; freshly dehydrided surfaces can ignite in air | Load in a Parr-class vessel at 1 to 5 bar D2, 80 to 150 C; transfer through the glovebox; store under a D2 or argon headspace and use within days |
| Ti sponge | Chunks 3 to 19 mm as shipped; crush under argon to 1 to 5 mm for vessel loading | 99.5% and 99.95% metals-basis catalog grades | D/Ti toward 1.9 (approaching TiD2) at 300 to 500 C under 1 to 10 bar D2 (estimate) | Low hazard as chunks; generated fines are flammable | Load chunks directly; crushing makes fines, collect them for disposal as flammable solid |
| Ti powder | Catalog mesh fractions: -100 mesh (below 150 um), -200 mesh (below 75 um); -325 mesh (below 44 um) preferred for suspensions | 99.4 to 99.5% metals basis | D/Ti toward 1.9 | Flammable solid (GHS02, H228); dry fine powder can be pyrophoric | Keep under argon; order wetted transport grades where offered and dry in vacuum immediately before deuteriding |
| TiD2 | Milled powder, 1 to 20 um (estimate) | 98% metal basis; 7.8% D by mass at exact TiD2 stoichiometry | D/Ti 1.7 to 2.0 | Dust class per lot SDS; releases D2 on heating above about 400 C (estimate) | Store sealed under argon; no open flame anywhere in the room during weighing; keep quantities below 100 g per container |
| Zr powder | Catalog -50 mesh (below 300 um); mill or buy below 44 um for suspension use | 99.5% catalog grade | D/Zr toward 2.0 at 400 to 600 C under D2 (estimate) | Pyrophoric when fine (GHS02); wetted grades used for transport | Glovebox only; room-temperature vacuum dry; keep lot sizes small |
| ZrD2 | Milled powder, 1 to 20 um (estimate) | 98% metal basis; 4.2% D by mass at exact ZrD2 stoichiometry | D/Zr 1.8 to 2.0 | Hydride dust; releases D2 above about 600 C (estimate) | As TiD2; avoid long air exposure because surface oxide blocks isotope uptake |
| Ni, carbonyl grade | Spherical particles, Fisher sub-sieve sizer size 2.5 to 3.5 um (estimate), soft agglomerates to 20 um | 99.5%+ metal basis (carbonyl process grades) | H/Ni or D/Ni below 1; program control target about 0.5 (estimate) | Flammable dust (H228) plus health classes: skin sensitizer and suspected inhalation carcinogen (H317, H351 class) | Weigh in a hood with dust collection; HEPA pickup only; nitrile gloves and dedicated spatulas |
Design lesson carried into the build: titanium and zirconium deuterides give close to two deuterons per metal atom at roughly one fiftieth of the palladium price, so the first suspension platforms are TiD2 and ZrD2 based, with PdDx reserved for the mobility-matched comparison cells.
2 Piezoelectric powders
d33 is the longitudinal piezoelectric charge coefficient in picocoulombs per newton. Curie temperature is the ferroelectric transition temperature; above it the poled state collapses.
| Composition | d33 (pC/N) | Particle size | Curie temperature | Safety class | Notes |
|---|---|---|---|---|---|
| BaTiO3 (barium titanate) | about 190 for poled ceramic (textbook composition tables, Jaffe, Cook and Jaffe, Piezoelectric Ceramics, Academic Press, 1971) | Below 3 um at 99% as a confirmed catalog powder (Sigma-Aldrich 208108) | about 120 to 130 C | Low-hazard dust | Lead-free main line; dopant-softened grades reach higher d33 but complicate supply |
| PZT-5H (lead zirconate titanate, soft Navy Type VI class) | about 593 (standard composition table value; manufacturer datasheets list 580 to 650) | Sieve to 1 to 20 um from sintered discs or custom powder lots (estimate) | about 193 C | Lead oxide content: reproductive-toxicant class; RoHS exemption applies to piezoelectric ceramics | Highest d33 of the four; poling field 2 to 3 kV/mm at 120 to 150 C |
| PZT-5A (soft Navy Type II class) | about 374 (standard composition table value) | As PZT-5H | about 365 C | Lead oxide content, as PZT-5H | Thermal margin for heated vessels; second soft-composition arm of the matrix |
| ZnO (zinc oxide, wurtzite) | 12.4 single crystal (standard reference value; see Ozgur et al., J. Appl. Phys. 98, 041301, 2005) | Reagent powder, 1 to 5 um grades common | No ferroelectric Curie point below the melting point, about 1975 C | Aquatic-toxicant dust class | Low-field control composition of the matrix |
| LiNbO3 (lithium niobate, congruent) | 6.0 at 25 C (crystal datasheet: d31 -0.85, d22 20.8, d15 69.2; Crystal Technology DC-12 data sheet) | Powder on request or crushed congruent crystal; optical wafers 10 x 10 x 0.5 mm for seed crystals | 1142.3 plus or minus 0.7 C (Crystal Technology DC-12 data sheet) | Low-hazard dust | Low-field control composition with extreme temperature margin |
Poling is part of the specification, not an option: as-shown powders ship unpoled and give no net d33 in the suspension. Pole by corona or contact field at 3 to 5 kV/mm near 120 to 150 C for PZT and BaTiO3, or buy poled sintered discs and crush them under argon to 1 to 20 um, recording a Berlincourt-meter d33 for every lot. Crushed grains keep the polarization direction of their parent axis, so assume per-grain orientation spread and carry at least half of nominal d33 into field estimates (estimate).
Design lesson carried into the build: run all four compositions in one vessel geometry. PZT-5H and BaTiO3 are the active arms; ZnO and LiNbO3, with d33 two orders of magnitude lower, are the like-for-like comparison compositions that isolate the piezoelectric variable.
3 Carrier fluids
Viscosity values at 25 C unless noted. STF is shear-thickening fluid: a suspension whose viscosity rises sharply above a threshold shear rate.
| Fluid | Viscosity | Shear-thickening window | Notes |
|---|---|---|---|
| Fumed silica (hydrophilic, Brunauer-Emmett-Teller area 175 to 225 m2/g, about 12 nm primary particles; AEROSIL 200 datasheet) | n/a as powder | In polypropylene glycol at 15 to 25 wt%: thickening onset about 0.1 to 10 per second, viscosity rise of 10^2 to 10^4 times (estimate; literature class of Raghavan and Khan, J. Colloid Interface Sci. 185, 57, 1997) | Workhorse STF; dry the silica at 110 C under vacuum before dispersion |
| Polypropylene glycol, molar mass about 725 | 60 to 100 mPa-s (estimate) | carrier only | Inert to dry hydrides; the standard non-aqueous STF base |
| Cornstarch in glycerol or glycerol-water | Base liquid 100 to 1400 mPa-s depending on glycerol fraction | 30 to 45 wt% starch: onset about 10 to 100 per second with a discontinuous jump (estimate; phenomenology per Brown and Jaeger, Rep. Prog. Phys. 77, 046602, 2014) | Food-safe handling, coarse grains 5 to 20 um; rapid prototyping fluid for force-chain geometry only, never a D-bearing platform |
| Deuterated glycerol, above 98 atom % D | about 950 to 1400 mPa-s, within 2% of normal glycerol (estimate) | Use as the base for fully deuterated STFs at the loadings above | Fully deuterated non-aqueous carrier for slurry runs |
| Deuterated alkanes: dodecane-d26 and hexadecane-d34, 98 atom % D (confirmed catalog items) | dodecane-d26 about 1.4 mPa-s, hexadecane-d34 about 3 mPa-s (standard alkane values) | carrier only, no thickening by itself | Lowest-viscosity fully deuterated carriers; combine with fumed silica and hydride solids |
| D2O, heavy water, 99.9 atom % D (confirmed catalog item, Sigma-Aldrich 151882) | 1.25 mPa-s at 20 C; freezes at 3.8 C | carrier only; electrolyte recipes from the program concept: 2 M K2CO3 or 6 M D2SO4 in D2O | Ionic screening suppresses static contact-gap fields, so pair this carrier with 20 kHz ultrasound or pulsed-discharge excitation |
| Ionic liquid: 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM BF4), 98%+ (confirmed catalog item) | about 80 to 110 mPa-s when dry (estimate) | carrier only | Negligible vapor pressure, electrochemical window about 4 V; dry to below 100 ppm water at 80 C under vacuum and store over molecular sieve |
Design lesson carried into the build: the first suspension is fumed silica plus hydride particles in deuterated glycerol or deuterated alkane, a non-screening deuterated matrix; the D2O electrolyte cell is stage two, driven hard so that transients outrun the ionic screening.
4 Gases
| Gas | Purity specification | Container | Regulator and plumbing | Safety class |
|---|---|---|---|---|
| D2 (deuterium) | Linde HiQ scientific 2.8 grade: D2 at or above 99.8%, O2 at or below 5 ppm, N2 at or below 10 ppm, H2O at or below 10 ppm (manufacturer datasheet); isotope-labeled packs at 99.8 atom % D from Cambridge Isotope Laboratories and Sigma-Aldrich | Lecture bottles of about 50 to 100 liters gas at standard conditions (estimate); 50 g and 100 g isotope packs equal about 560 and 1120 liters gas (stoichiometric arithmetic) | Two-stage stainless-diaphragm regulator, Compressed Gas Association (CGA) 350 connection, outlet 0 to 50 psi (0 to 3.5 bar) for hydride loading; add a getter purifier to push O2 and H2O below 1 ppm at the vessel inlet | Compressed flammable gas (GHS02 plus GHS04), UN 1957 |
| H2 (hydrogen) | 99.999% (ultra high purity) for hydrogen-analog control runs | 40 to 50 L cylinder at 150 to 200 bar, about 6 to 9 cubic meters gas (estimate) | CGA 350 two-stage stainless regulator | Compressed flammable gas (GHS02 plus GHS04), UN 1049 |
| Ar (argon) | 99.999%, H2O below 5 ppm | 40 to 50 L cylinder (estimate) | CGA 580 two-stage stainless regulator | Compressed gas, asphyxiant in confined spaces (GHS04), UN 1006 |
Handling: dedicated leak-checked manifold with metal tube fittings; three pressurize-and-vent purge cycles before every D2 fill; flashback arrestor on hydrogen-bearing lines; cylinders chained to a wall rack; room oxygen monitor when more than one cylinder is open.
Design lesson carried into the build: ex-situ gas loading of TiD2 and ZrD2 powders from these cylinders is the cheapest isotope path; buy deuterium as isotope-grade packs for the first campaign and switch to cylinder supply only when consumption passes about one pack per month.
5 Excitation and thermal hardware
| Equipment class | Specification | Confirmed examples | Role in the device |
|---|---|---|---|
| Ultrasonic processors, 20 kHz class | 400 to 2000 W electrical, titanium horn tips 12.7 to 25.4 mm diameter, amplitude control 20 to 100%, pulse mode | Hielscher UP400St (400 W, 24 kHz), UIP1000hdT (1000 W, 20 kHz), UIP2000hdT (2000 W, 20 kHz); Sonics and Materials VCX 750 (750 W, 20 kHz); Branson SFX550 (550 W, 20 kHz) | Primary mechanical drive: builds and breaks force chains in the suspension at kilohertz rates |
| Ultrasonic baths and cleaning transducers, 40 kHz class | Heated baths and bonded transducer modules, sweep frequency, 40 kHz industrial transducer stacks | Branson Bransonic CPX and CPXH series and the Branson 3800 series (40 kHz transducers); APC International cleaning transducer modules in standard 28, 40, 80 kHz classes; bare 40 kHz Langevin stacks from piezo vendors | Distributed vessel-wall drive; comparison of standing-wave versus horn geometries |
| Function generators | Dual-channel arbitrary waveform, burst, sweep and chirp modes, 30 MHz class or better | Siglent SDG1032X (30 MHz) and SDG1062X (60 MHz); Aim-TTi TG5011A (50 MHz) | Drive profiles for the amplifiers and pulsed stages; burst timing for excitation-off interleave |
| RF power amplifiers | Broadband, 10 kHz upward, 50-ohm output, Class A preferred for capacitive loads | Electronics and Innovation 240L (Class A, 10 kHz to 12 MHz, about 40 W); E&I 1140LA (1000 W, 10 kHz to 2 MHz) | Scaled drive of 20 and 40 kHz transducers through a tuning network |
| High-voltage piezo amplifiers | Four-quadrant, capacitive-load rated | Trek 5/80-HS (0 to plus or minus 5 kV, 80 mA) and Trek PZD700A (0 to plus or minus 700 V), Advanced Energy | Lot poling of piezo powders and direct field-bias experiments |
| Pulsed-discharge capacitor bank | Polypropylene pulse capacitors, 0.1 to 2 uF at 1 to 5 kV, low-inductance buswork, charging resistor chain | Switch: Behlke HTS series high-voltage MOSFET (metal-oxide-semiconductor field-effect transistor) stacks, a family spanning 1 to 150 kV built as direct replacements for ignitron-era tubes; legacy ignitron tubes remain available for high-current banks | Millisecond to microsecond current pulses through arc electrodes: the pulsed-plasma excitation variant |
| DC high-voltage supplies | 1 kV upward, reversible polarity options, 10 W to 1200 W classes | Spellman SL series (10 to 1200 W); Glassman PS and WX class units in the surplus channel (75 kV class seen); Sorensen SG series (AMETEK, to 1000 V) for low-side bias and bank charging | Capacitor bank charging, electrochemical bias of electrolyte cells |
| Cartridge and band heaters | Incoloy-sheath cartridge heaters, 6 to 19 mm diameter, 100 to 1000 W, watt density to about 30 W per square centimeter; mica band heaters for vessel clamping | Omega CIR series cartridge heaters; Omega band heaters | Deuteride loading cycles at 80 to 600 C in the pressure vessels |
| PID temperature controllers | Proportional-integral-derivative control, ramp and soak, K-type thermocouple input, 25 A solid-state relay output | Omega CN7500 series controllers with K-type thermocouples and solid-state relays | Setpoint ramps of 1 to 5 C per minute for loading and outgassing cycles |
| Loading pressure vessels | Non-stirred, T316 stainless, 100 to 600 mL, general-purpose heads of about 1900 psi class (estimate), rupture disc and D2-rated needle valves | Parr Series 4760 (100 to 600 mL); Series 4700 (22 to 45 mL); Series 4740 high-pressure/high-temperature (25 and 75 mL) | Gas loading of hydride-forming powders; sealed suspension runs |
Design lesson carried into the build: buy the 20 kHz processor first, one function generator plus one Class A amplifier second, and the capacitor bank last; every excitation class drives the same vessel geometry so results stay comparable across drives.
6 Cross-cutting storage and compatibility rules
- Hydride and deuteride powders live in an argon glovebox, in sealed steel cans, segregated from oxidizers and acids, each can labeled with lot, isotope, D/M and date.
- Piezo powders containing lead (PZT) have their own labeled tray, spill kit and waste stream; gloves and lab coat are mandatory, and the waste stream never mixes with hydride scrap.
- D2O, deuterated carriers and ionic liquids are moisture-managed: opened bottles return to the desiccator or glovebox antechamber within minutes.
- Every powder transfer uses grounded, non-sparking tools; vacuum pickups and HEPA-filtered dust collection replace brushes and compressed air.
- Gases: two regulators per gas (one spare, purged and capped), flashback arrestors, and a written purge sequence posted at the manifold.
Sister documents: OUTLINE.md and PLAN-12-MONTH.md hold the program plan; prior-art/ holds the experiment record this design trades against.