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TG-51 photon beam calibration

Physics-accurate virtual water tank. Build your setup, deliver a beam, work through the protocol. Every reading comes from a real model of the geometry you configure — no fudge toward the right answer.

session 803715
BetaSimulator in active development. Treat numbers as pedagogical, not clinical — protocol values, kQ tables, and workflows are still being tuned. Report issues through the in-app feedback so we can iterate quickly.

Treatment room

6 MVSSD100.0water surface01020305.00 cmdepth to scale · SSD not to scale

Beam's eye

10.0 × 10.0 cm @ 100

Electrometer

CHARGE+300 V
0.000nC
MU 0○ standby
next fire (100 MU)≈ 14.645 nC
chamber NE 2571 · r_cav 0.315 cm
ND,w(⁶⁰Co) = 5.443 cGy/nC
Pelec = 1.000 (electrometer cert.)
room 23.5 °C · 97.43 kPa

Linac console

Energy
Dose rate600 MU/min
Monitor units
MU
Field X
cm
Field Y
cm
SSD
cm
Lead foil at 30 cm

Chamber positioning

Chamber
Depth of chamber centre
cm
Snap depth
Lateral offset
cm
Polarising voltage
Auto PDD scan
from
to
step
50 pts

Locks the setup, sweeps the chamber from from to toin step-cm increments, and logs a reading at each. Small step + wide range gives a dense PDD curve. Auto-jumps to the PDD plot tab when done.

Work through the protocol yourself. Nothing here is auto-filled from the machine: every value must come from your own readings and arithmetic. The final entry is checked against the machine's true output at dmax for a 10×10 field at SSD 100, tolerance ±1%.

1. Beam quality
%dd(10)x%
kQ
2. Chamber corrections
P_TP
P_ion
P_pol
3. Final calibration
M (100 MU)nC
D_w at 10 cm (100 MU)cGy
Output at d_maxcGy/MU
Training simulation. Beam data, kQ values and correction magnitudes are modelled, not measured. Independent study material; not affiliated with, endorsed by, or sponsored by any certifying board or professional society.
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