# Cryogenics
## Microsim
### Live player
<div class="microsim-player">
<iframe src="https://editor.p5js.org/sciencenibber/full/1unm-XNLx" width="100%" height="620" frameborder="0" sandbox="allow-scripts allow-same-origin"></iframe>
</div>
<div class="microsim-fallback">
<img src="Microsims/thumbs/Cryogenics.png" alt="Cryogenics microsim poster" style="width:100%;border:1px solid #4445;border-radius:6px;">
<p><em>Live microsim (desktop) · <a href="https://editor.p5js.org/sciencenibber/sketches/1unm-XNLx">open sketch in the p5.js editor</a></em></p>
</div>
**Editor URL:** https://editor.p5js.org/sciencenibber/sketches/1unm-XNLx
**Description (100 words):**
A four-phase Helium-4 phase diagram in (T, P) space, with temperature on a linear axis from 0.5–7 K and pressure on a log axis from 1 kPa to 3.16 MPa. The reader drags a yellow marker — or clicks anywhere inside the plot to jump it — and the bottom-left readout names the current phase: gas, liquid He I, liquid He II (superfluid), solid, or supercritical fluid. The saturation curve, magenta lambda line, and grey melting curve are drawn from NIST-fitted anchor points; the critical point at 5.195 K and the lower lambda point at 2.172 K are labelled landmarks. Arrow keys nudge the marker for fine control.
```js
// =====================================================================
// Cryogenics.js -- Wikitube microsim
// Article: Cryogenics en.wikitube.io/wiki/Cryogenics
// Room: Helium Pattern: A (phase diagram, state-space)
// ---------------------------------------------------------------------
// Idea: an interactive Helium-4 phase diagram in (T, P) space, with
// log-scale pressure axis. The reader drags a marker on the diagram
// and watches it cross between the four named phases of helium-4:
//
// * gas (vapor) T > T_sat(P) or P < P_sat(T)
// * liquid He I T_lambda < T < T_critical, P > P_sat
// * liquid He II (superfluid) T < T_lambda, below the saturation curve
// * solid P > P_melt(T)
// * supercritical fluid T > 5.195 K and P > 0.227 MPa
//
// Helium is the only element with no solid phase at 0 K under any
// pressure below ~2.5 MPa -- you must compress it. That single fact
// is the defining oddity of cryogenic physics.
//
// The canonical equation behind every boundary on this diagram is the
// Clausius-Clapeyron relation:
//
// dP/dT = L / (T * dV)
//
// Integrating with constant latent heat over a narrow temperature
// range gives the familiar exp(-L/RT) saturation form. The saturation
// curve here is implemented as a piecewise-linear interpolation
// through 11 NIST-fitted anchor points -- more accurate than a single
// Antoine fit across the full T range.
//
// Key He-4 landmarks shown on the diagram:
// * normal boiling point (1 atm): T = 4.222 K, P = 0.1013 MPa
// * critical point: T = 5.195 K, P = 0.227 MPa
// * lower lambda point: T = 2.172 K, P = 0.00505 MPa
// * upper lambda point: T = 1.763 K, P = 3.01 MPa
// * minimum melting pressure: P ~ 2.53 MPa (T -> 0)
//
// Visual layout (720 x 520 canvas):
// * top-left: HUD title + en.wikitube.io/wiki/Cryogenics subtitle
// * top-right: control hints (drag, arrow keys, click-to-jump)
// * center: phase diagram, T x-axis 0.5-7 K, P y-axis 1 kPa - 3.16 MPa (log)
// * filled regions tinted by phase (gas warm, liquids cold blue,
// He II deeper, solid grey, supercritical fade)
// * boundaries drawn as curves with phase-color outlines
// * critical point marked with X, lower lambda point with a circle
// * reader's marker is a draggable yellow dot
// * bottom: live (T, P, phase) readout + canonical equation
//
// Conventions (Wikitube Betterfire Standard v0):
// * single ARTICLE constant at the top, single quotes
// * p5.disableFriendlyErrors = true to keep the editor console clean
// * non-ASCII (Greek lambda, dots, arrows) lives in COMMENTS ONLY;
// every text() string literal is ASCII (the editor preview pipeline
// mangles non-ASCII in strings)
// * Energy-room palette (P5_JS_EDITOR section 4): dark BG, HOT/COLD
// tones, STRUCT grey, TRAJ accent
//
// No sliders -- the diagram is the controller. Mouse drag and arrow
// keys move the marker; clicking inside the plot rect jumps to that
// (T, P). The plot itself is the slider.
// =====================================================================
const ARTICLE = 'Cryogenics';
const TITLE = ARTICLE.replace(/_/g, ' ');
p5.disableFriendlyErrors = true;
// ----- Energy room palette (P5_JS_EDITOR section 4, line 165) --------
const BG = 18;
const FG = 240;
const DIM = [240, 240, 240, 140];
const HOT = [220, 110, 60]; // warm: gas / supercritical
const COLD = [60, 130, 220]; // cool: liquid He I
const COLDER = [40, 80, 180]; // deeper cool: liquid He II (superfluid)
const STRUCT = [120, 130, 150]; // structural grey: solid
const TRAJ = [240, 220, 80]; // reader marker (yellow accent)
const SCRATCH = [120, 120, 120, 90]; // grid / scratch lines
const ACCENT = [200, 100, 220]; // lambda line (magenta)
// ----- He-4 phase-diagram landmarks ----------------------------------
const T_LAMBDA = 2.172; // K, lambda transition at saturation
const T_CRIT = 5.195; // K, critical point
const P_CRIT = 0.227; // MPa, critical pressure
const T_NBP = 4.222; // K, normal boiling point (1 atm)
const P_NBP = 0.1013; // MPa, atmospheric
const P_MELT_MIN = 2.53; // MPa, minimum melting pressure at T -> 0
const T_LAMBDA_UPPER = 1.763; // K, upper lambda point
const P_LAMBDA_UPPER = 3.010; // MPa, upper lambda pressure
// ----- He-4 saturation-pressure anchor points (NIST-fitted) ----------
// Each row is [T (K), P_sat (MPa)]. Piecewise-linear interp between
// adjacent anchors in (T, log P) space gives the smoothest visual.
const SAT_ANCHORS = [
[1.50, 0.000471],
[2.00, 0.003130],
[2.172, 0.005050], // lower lambda point (intersects lambda line)
[2.50, 0.010300],
[3.00, 0.030900],
[3.50, 0.057300],
[4.00, 0.081600],
[4.222, 0.101300], // normal boiling point
[4.50, 0.128000],
[5.00, 0.196000],
[5.195, 0.227000] // critical point
];
// ----- Plot axes (data ranges; pixel ranges set in setup) ------------
const T_MIN = 0.5; // K
const T_MAX = 7.0; // K
const P_MIN_LOG = -3; // log10(P in MPa); P = 1 kPa
const P_MAX_LOG = 0.5; // log10(P in MPa); P ~ 3.16 MPa
// ----- Plot rectangle in canvas pixels (set in setup) ----------------
let plotX, plotY, plotW, plotH;
// ----- Reader's draggable marker state ------------------------------
let mark = { T: T_NBP, P: P_NBP }; // start at the normal boiling point
let dragging = false;
function setup() {
createCanvas(720, 520);
pixelDensity(2);
textFont('system-ui');
// Plot area: leaves room for HUD top + readout bottom + axis labels.
plotX = 80;
plotY = 70;
plotW = width - 100;
plotH = height - 160;
}
function draw() {
background(BG);
// Order: phase field (cheap raster) -> axes -> boundaries -> landmarks
// -> reader's marker -> HUD. Later layers always paint on top.
drawPhaseField();
drawAxes();
drawSaturationCurve();
drawLambdaLine();
drawMeltingCurve();
drawLandmarks();
drawMarker();
drawHUD();
}
// =====================================================================
// Coordinate transforms: (T [K], P [MPa]) <-> (px, py) in canvas pixels
// =====================================================================
function tToPx(T) {
return map(T, T_MIN, T_MAX, plotX, plotX + plotW);
}
function pxToT(px) {
return map(px, plotX, plotX + plotW, T_MIN, T_MAX);
}
function pToPy(P) {
const logP = Math.log10(Math.max(P, 1e-6));
return map(logP, P_MIN_LOG, P_MAX_LOG, plotY + plotH, plotY);
}
function pyToP(py) {
const logP = map(py, plotY + plotH, plotY, P_MIN_LOG, P_MAX_LOG);
return Math.pow(10, logP);
}
// =====================================================================
// Phase-boundary functions
// =====================================================================
// Saturation pressure -- piecewise linear in (T, log P) across the
// anchor table. Outside the table's T range, returns the nearest end.
function pSat(T) {
if (T <= SAT_ANCHORS[0][0]) return SAT_ANCHORS[0][1];
if (T >= SAT_ANCHORS[SAT_ANCHORS.length - 1][0]) return SAT_ANCHORS[SAT_ANCHORS.length - 1][1];
for (let i = 0; i < SAT_ANCHORS.length - 1; i++) {
const [T0, P0] = SAT_ANCHORS[i];
const [T1, P1] = SAT_ANCHORS[i + 1];
if (T >= T0 && T <= T1) {
const frac = (T - T0) / (T1 - T0);
const logP0 = Math.log10(P0);
const logP1 = Math.log10(P1);
return Math.pow(10, logP0 + frac * (logP1 - logP0));
}
}
return SAT_ANCHORS[SAT_ANCHORS.length - 1][1];
}
// Melting pressure P_melt(T) -- quadratic-ish above the minimum.
// Valid for T < ~5 K; extrapolates beyond. He has no solid phase
// below P_MELT_MIN at any T (unique among the elements).
function pMelt(T) {
return P_MELT_MIN + 0.155 * T * T;
}
// Lambda line -- returns the T at which the lambda transition occurs
// at a given P. Linear in (T, log P) between the lower and upper
// lambda points captures the gentle leftward bend with pressure.
function tLambda(P) {
const P_lo = SAT_ANCHORS[2][1]; // 0.00505 MPa, lower lambda point
const P_hi = P_LAMBDA_UPPER; // 3.01 MPa, upper lambda point
if (P <= P_lo) return T_LAMBDA;
if (P >= P_hi) return T_LAMBDA_UPPER;
const frac = (Math.log10(P) - Math.log10(P_lo)) /
(Math.log10(P_hi) - Math.log10(P_lo));
return T_LAMBDA + frac * (T_LAMBDA_UPPER - T_LAMBDA);
}
// Phase classifier: returns one of
// 'gas', 'He I', 'He II', 'solid', 'supercritical'.
// Order of checks matters (solid first wins over liquid, etc.).
function classifyPhase(T, P) {
if (P > pMelt(T)) return 'solid';
if (T >= T_CRIT && P >= P_CRIT) return 'supercritical';
if (T >= T_CRIT) return 'gas';
if (P < pSat(T)) return 'gas';
if (T < tLambda(P)) return 'He II';
return 'He I';
}
// =====================================================================
// Drawing
// =====================================================================
// Cheap raster: sample a coarse grid, paint each cell by phase color.
// 90 x 60 cells = 5400 small rects, well within p5's frame budget.
function drawPhaseField() {
const NX = 90, NY = 60;
const dx = plotW / NX, dy = plotH / NY;
noStroke();
for (let i = 0; i < NX; i++) {
for (let j = 0; j < NY; j++) {
const px = plotX + (i + 0.5) * dx;
const py = plotY + (j + 0.5) * dy;
const T = pxToT(px);
const P = pyToP(py);
const phase = classifyPhase(T, P);
let r, g, b, a;
switch (phase) {
case 'gas': r = HOT[0]; g = HOT[1]; b = HOT[2]; a = 35; break;
case 'He I': r = COLD[0]; g = COLD[1]; b = COLD[2]; a = 80; break;
case 'He II': r = COLDER[0]; g = COLDER[1]; b = COLDER[2]; a = 130; break;
case 'solid': r = STRUCT[0]; g = STRUCT[1]; b = STRUCT[2]; a = 150; break;
case 'supercritical': r = HOT[0]; g = HOT[1]; b = HOT[2]; a = 100; break;
default: r = 200; g = 200; b = 200; a = 0;
}
fill(r, g, b, a);
rect(px - dx / 2, py - dy / 2, dx + 1, dy + 1);
}
}
}
function drawAxes() {
push();
noFill();
stroke(SCRATCH);
strokeWeight(1);
rect(plotX, plotY, plotW, plotH);
// T-axis tick marks (every 1 K) + labels
noStroke();
fill(...DIM);
textSize(10);
textAlign(CENTER, TOP);
for (let T = 1; T <= 7; T++) {
const x = tToPx(T);
stroke(SCRATCH); line(x, plotY + plotH, x, plotY + plotH + 4);
noStroke(); text(T, x, plotY + plotH + 6);
}
// P-axis tick marks (every decade, log scale) + labels
textAlign(RIGHT, CENTER);
for (let logP = P_MIN_LOG; logP <= Math.floor(P_MAX_LOG); logP++) {
const P = Math.pow(10, logP);
const y = pToPy(P);
stroke(SCRATCH); line(plotX - 4, y, plotX, y);
noStroke(); text(formatPressure(P), plotX - 6, y);
}
// Axis titles
noStroke();
fill(...DIM);
textSize(12);
textAlign(CENTER, TOP);
text('T [K]', plotX + plotW / 2, plotY + plotH + 24);
push();
translate(plotX - 56, plotY + plotH / 2);
rotate(-PI / 2);
text('P [MPa, log scale]', 0, 0);
pop();
pop();
}
function formatPressure(P) {
if (P >= 1) return P.toFixed(1);
if (P >= 0.01) return P.toFixed(2);
if (P >= 0.0001) return P.toFixed(4);
return P.toExponential(0);
}
function drawSaturationCurve() {
push();
noFill();
stroke(...COLD);
strokeWeight(2);
beginShape();
for (let T = SAT_ANCHORS[0][0]; T <= T_CRIT; T += 0.05) {
vertex(tToPx(T), pToPy(pSat(T)));
}
endShape();
// Inline label near the boiling-point tick on the curve
noStroke();
fill(...COLD);
textSize(10);
textAlign(LEFT, CENTER);
text('saturation (boil)', tToPx(T_NBP) + 6, pToPy(P_NBP));
pop();
}
function drawLambdaLine() {
push();
noFill();
stroke(...ACCENT);
strokeWeight(2);
beginShape();
// Walk in log P from the lower lambda point up to the upper lambda point.
const P_lo = SAT_ANCHORS[2][1];
const P_hi = P_LAMBDA_UPPER;
const steps = 40;
for (let i = 0; i <= steps; i++) {
const f = i / steps;
const logP = Math.log10(P_lo) + f * (Math.log10(P_hi) - Math.log10(P_lo));
const P = Math.pow(10, logP);
const T = T_LAMBDA + f * (T_LAMBDA_UPPER - T_LAMBDA);
vertex(tToPx(T), pToPy(P));
}
endShape();
// Label
noStroke();
fill(...ACCENT);
textSize(10);
textAlign(LEFT, BOTTOM);
text('lambda line (He I -> He II)', tToPx(T_LAMBDA) + 4, pToPy(0.5));
pop();
}
function drawMeltingCurve() {
push();
noFill();
stroke(...STRUCT);
strokeWeight(2);
beginShape();
let started = false;
for (let T = T_MIN; T <= T_MAX; T += 0.05) {
const P = pMelt(T);
if (P > Math.pow(10, P_MAX_LOG)) continue; // off the top of the chart
vertex(tToPx(T), pToPy(P));
started = true;
}
endShape();
// Solid-region label
if (started) {
noStroke();
fill(...STRUCT);
textSize(11);
textAlign(CENTER, CENTER);
text('solid', tToPx(0.85), pToPy(2.7));
}
pop();
}
function drawLandmarks() {
push();
// Critical point -- yellow X
stroke(...TRAJ);
strokeWeight(2);
const cpx = tToPx(T_CRIT), cpy = pToPy(P_CRIT);
line(cpx - 6, cpy - 6, cpx + 6, cpy + 6);
line(cpx - 6, cpy + 6, cpx + 6, cpy - 6);
noStroke();
fill(...TRAJ);
textSize(10);
textAlign(LEFT, BOTTOM);
text('critical (5.195 K, 0.227 MPa)', cpx + 8, cpy - 4);
// Lower lambda point -- magenta open circle
noFill();
stroke(...ACCENT);
strokeWeight(2);
circle(tToPx(T_LAMBDA), pToPy(0.00505), 8);
noStroke();
fill(...ACCENT);
textSize(10);
textAlign(LEFT, TOP);
text('lambda pt (2.172 K)', tToPx(T_LAMBDA) + 6, pToPy(0.00505) + 4);
// Normal boiling point -- small cyan tick
fill(...COLD);
noStroke();
circle(tToPx(T_NBP), pToPy(P_NBP), 5);
pop();
}
function drawMarker() {
// Update marker from mouse if dragging.
if (dragging) {
const px = constrain(mouseX, plotX, plotX + plotW);
const py = constrain(mouseY, plotY, plotY + plotH);
mark.T = pxToT(px);
mark.P = pyToP(py);
}
const mx = tToPx(mark.T);
const my = pToPy(mark.P);
push();
// Outer halo
noFill();
stroke(...TRAJ);
strokeWeight(1);
circle(mx, my, 18);
// Filled center
fill(...TRAJ);
noStroke();
circle(mx, my, 8);
pop();
}
// =====================================================================
// Input handling
// =====================================================================
function mousePressed() {
// Inside the plot rect: click-to-jump and begin drag.
if (mouseX >= plotX && mouseX <= plotX + plotW &&
mouseY >= plotY && mouseY <= plotY + plotH) {
mark.T = pxToT(mouseX);
mark.P = pyToP(mouseY);
dragging = true;
}
}
function mouseReleased() { dragging = false; }
function keyPressed() {
// Arrow keys nudge the marker for fine control.
const dT_step = 0.05;
const dlogP = 0.05;
if (keyCode === LEFT_ARROW) mark.T = Math.max(T_MIN, mark.T - dT_step);
if (keyCode === RIGHT_ARROW) mark.T = Math.min(T_MAX, mark.T + dT_step);
if (keyCode === UP_ARROW) mark.P = Math.pow(10, Math.min(P_MAX_LOG, Math.log10(mark.P) + dlogP));
if (keyCode === DOWN_ARROW) mark.P = Math.pow(10, Math.max(P_MIN_LOG, Math.log10(mark.P) - dlogP));
}
// =====================================================================
// HUD
// =====================================================================
function drawHUD() {
// Top-left: title + Wikitube URL (Betterfire Standard rule 2)
noStroke();
fill(FG);
textAlign(LEFT, TOP);
textSize(20);
text(TITLE, 14, 12);
fill(...DIM);
textSize(12);
text('Wikitube microsim . en.wikitube.io/wiki/Cryogenics', 14, 36);
// Top-right: control hints (Betterfire Standard rule 3)
textAlign(RIGHT, TOP);
textSize(10);
text('drag the dot to move', width - 14, 12);
text('arrow keys nudge', width - 14, 24);
text('click anywhere in plot to jump', width - 14, 36);
// Bottom-left: live readout
const phase = classifyPhase(mark.T, mark.P);
const phaseLabel =
phase === 'He II' ? 'liquid He II (superfluid)' :
phase === 'He I' ? 'liquid He I' :
phase === 'gas' ? 'gas (He vapor)' :
phase === 'solid' ? 'solid He' :
phase === 'supercritical' ? 'supercritical fluid' :
phase;
fill(...DIM);
textAlign(LEFT, BOTTOM);
textSize(12);
text('T = ' + nf(mark.T, 0, 2) + ' K P = ' + formatPressure(mark.P) + ' MPa',
14, height - 22);
fill(FG);
textSize(13);
text('phase: ' + phaseLabel, 14, height - 6);
// Bottom-right: canonical equation (Betterfire Standard rule 4)
textAlign(RIGHT, BOTTOM);
fill(FG);
textSize(13);
text('dP/dT = L / (T * dV) [Clausius-Clapeyron]', width - 14, height - 6);
}
// =====================================================================
// End of Cryogenics.js -- Wikitube microsim, Helium room, Pattern A.
// =====================================================================
```
## Links (Wikipedia order)
<!-- injected from _registry/childlinks/Cryogenics.json (2026-07-30T02:09:12Z) -->
`Absolute_zero` · `Biology` · [[Boiling_point]] · `Cell_(biology)` · `Celsius` · `Chemical_reactor` · `Cold_chain` · `Cryoablation` · `Cryobiology` · `Cryoconservation_of_animal_genetic_resources` · `Cryocooler` · `Cryoelectronics` · `Cryogen_(song)` · `Cryogenic_(band)` · `Cryogenic_fuel` · `Cryogenic_grinding` · `Cryogenic_hardening` · `Cryogenic_processor` · `Cryogenic_storage_dewar` · `Cryonics` · `Cryopreservation` · `Cryosurgery` · `Deposition_(phase_transition)` · `Detroit` · `Don_Rittner` · [[Electric_power_transmission]] · `Electron_microscope` · `Fahrenheit` · `Flash_freezing` · `Freon` · `Frozen_food` · `Gas` · `Greek_language` · `Heat_treating` · `Heike_Kamerlingh_Onnes` · [[Helium]] · `Humidity` · `Hydrocarbon` · [[Hydrogen]] · `International_Energy_Agency` · `International_Institute_of_Refrigeration` · `James_Dewar` · `James_Webb_Space_Telescope` · `Kelvin` · `LNG_carrier` · `LNG_storage_tank` · `Liquefied_gas` · `Liquefied_natural_gas` · [[Liquid_helium]] · `Liquid_hydrogen` · `Liquid_nitrogen` · `Liquid_oxygen` · `Low-temperature_technology_timeline` · `Low_Temperature_Physics_(journal)` · `Lowest_temperature_recorded_on_Earth` · [[Magnetic_resonance_imaging]] · `Manhattan` · `Mill_(grinding)` · `NASA` · [[Neon]] · `Nightclub` · [[Nitrogen]] · [[Nuclear_magnetic_resonance]] · `Orbit` · `Organism` · [[Oxygen]] · `Pfizer–BioNTech_COVID-19_vaccine` · [[Physics]] · `Popular_culture` · `Protein` · `Pulse_tube_refrigerator` · `RP-1` · `Rankine_scale` · `Resistance_thermometer` · `Sergei_Korolev` · `Silicon_bandgap_temperature_sensor` · `Soviet_space_program` · `Space_Shuttle` · `Spintronics` · `Statin` · `Stem-cell_therapy` · `Stem_cell` · `Stirling_engine` · `Structural_biology` · [[Superconductivity]] · `Temperature` · `Tupolev` · `Vaccine` · `Vacuum_flask` · `Variable-range_hopping` · `Very_Large_Telescope` · [[Wayback_Machine]] · `Ypsilanti,_Michigan`
## From the Real GENERATIVE library
*Cryogenics — placed from the Real G.E.N.E.R.A.T.I.V.E. course library (Engineering room). Source: Wikimedia Commons (via Wikipedia article media). [Details & license](https://commons.wikimedia.org/wiki/File:Liquidnitrogen.jpg).*
> In physics, cryogenics is the production and behaviour of materials at very low temperatures. ([Wikipedia](https://en.wikipedia.org/wiki/Cryogenics))
<!-- REAL-GENERATIVE-MEDIA:END -->
<!-- LOCAL-MEDIA-PASS:START -->
## From the vault media library
!Cryogenics thumb.png
*Cryogenics — from the vault's own media holdings, placed 2026-07-09. MTN / Wikitube.io original · CC BY-SA 4.0.*
<!-- LOCAL-MEDIA-PASS:END -->
> **Room:** [[Helium]] · **Status:** ✅ shipped
## Overview
**Cryogenics** is the branch of [[Physics|physics]] and [[Engineering|engineering]] concerned with the production and behaviour of materials at very low temperatures, conventionally below **120 K** (−153 °C), where the major atmospheric gases — oxygen, nitrogen, argon, and most importantly helium and hydrogen — liquefy at atmospheric pressure. Cryogenic engineering is distinguished from ordinary refrigeration by its working fluids and thermodynamic cycles: cooling below 77 K (the [[Boiling_point|boiling point]] of liquid nitrogen) requires multi-stage cascades, the Linde-Hampson Joule-Thomson cycle (effective only for gases below their inversion temperature), the Claude cycle (adding an expansion engine), Gifford-McMahon and pulse-tube regenerative refrigerators, or — for sub-Kelvin work — a He-3/He-4 [[Dilution_refrigerator|dilution refrigerator]]. Canonical temperature landmarks descend from liquid oxygen (90 K) through liquid nitrogen (77 K), liquid hydrogen (20 K), [[Liquid_helium|liquid helium]]-4 (4.222 K), liquid helium-3 (3.19 K), and into milli- and micro-kelvin regimes reached by adiabatic demagnetisation and laser cooling. Liquid **helium-4** is the workhorse coolant of the 1.5–5 K regime — uniquely so, since no other element remains liquid at atmospheric pressure below 20 K — and its superfluid lambda transition at **2.17 K** is the most important phase phenomenon in cryogenic physics, underwriting every helium-cooled superconducting [[System|system]]. Practical cryogenic systems are dominated by their insulation: vacuum-jacketed Dewar vessels (1892), multilayer insulation, and vapour-cooled radiation shields. Cryogenics underwrites superconducting magnets (MRI, NMR, the LHC at 1.9 K), infrared and submillimetre astronomy, semiconductor wafer processing, quantum-computing dilution fridges below 20 mK, cryosurgery and cryopreservation, and liquid-propellant aerospace — making it the bedrock infrastructure of nearly every laboratory or industrial process operating below 77 K.
## See also
- Room hub: [[Helium]]
- p5.js Editor conventions: P5 JS EDITOR
- Wiki root: MAIN
---
*Scaffolded by `generative-microsim` from row 23 of the Helium sheet on 2026-05-11T20:32:02Z.*
<!-- REAL-GENERATIVE-MEDIA:START -->
<!-- CRAFT-LINK:START g12 -->
*Built to the [[WT!P5_js_Microsim_Master_Class|p5.js Master Class]].*
<!-- CRAFT-LINK:END -->
<!-- COMPENDIUMLINK:BEGIN g19 — generated from _registry/plans/THURY_COMPENDIUM_SECTIONS.md; do not hand-edit inside -->
**Part of the [[WT!Thury_Hydrodynamics_Compendium|Thury Hydrodynamics Compendium]]** — main article for section 26, *Cryogenics*. Related sections: [[Hydrogen_economy]] · [[Superfluidity]] · [[Nuclear_fusion]].
<!-- COMPENDIUMLINK:END -->
<!-- THURYSIM:BEGIN g21 — Thury Compendium microsim (framework build, specs/sims/Cryogenics.json); do not hand-edit inside -->
**Microsim — three.js (Wikitube framework):** *Cryogenics*
<div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/thury/Cryogenics.html" data-title="Cryogenics"></div>
*Built from `MICROSIM_GUIDE/specs/sims/Cryogenics.json`; part of the [[WT!Thury_Hydrodynamics_Compendium|Thury Hydrodynamics Compendium]] set.*
<!-- THURYSIM:END -->
## Wikipedia : Wikitube
**Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Cryogenics) : [Wikitube](https://en.wikitube.io/wiki/Cryogenics)
## Previous hub tags
Tree parents: [[Helium]] · [[Helium-3]] · [[Hydrogen]] · [[Oxygen]].
Legacy hubs: none.
---
*Sources: 1 legacy note. Minted wave 1, 2026-07-30 (v1.6 order).*