Table 1.

Values and uncertainty estimates (1 σ) for Method 1, irradiation in air. Dwell times were calculated to deliver 1 Gy. The measured dose was 1.022 Gy (i.e., 2.2% higher than predicted). The uncertainty in d is estimated to be 0.5 mm, resulting in a 2% uncertainty in the calculated absorbed dose. The total uncertainty is the sum in quadrature of all the components and does not include the uncertainty in the TLD reading (0.7%).

Quantity	Value	Units	Uncertainty (%)
Calculation of $D_{w,in\hspace{0.17em}air}$ from AKR
AKR (at 1 m)	$8.85\times {10}^{-6}$	$\text{Gy}\hspace{0.17em}{\mathrm{s}}^{-1}$	1
Distance d in air	50	mm	2
Correction for catheter attenuation, $At{t}_{cath}$	1.0017		0.2
Correction for TLD holder attenuation, $At{t}_{Hold}$	1.013		2
Ratio of mass energy absorption coefficients, ${\left(\frac{{\overline{\mu }}_{tr}}{\rho }\right)}_a^w$	1.11		3
Dwell time for 1 Gy =	258.2	s	4%
$At{t}_{cath}\times At{t}_{Hold}/\mathit{[}AKR\times {(1000/d)}^2\times {\left(\frac{{\overline{\mu }}_{\sigma }}{\rho }\right)}_a^w\mathit{]}$
Measurement with ionisation chamber
$M_u$	$1.81\times {10}^{-8}$	C	< 0.1
$k_{TP}{k}_{elec}$	1.006		0.1
$N_{K,ARP}$	$4.89\times {10}^7$	$\text{Gy}\hspace{0.17em}{\mathrm{C}}^{-1}$	1
Ratio of mass energy absorption coefficients, ${\left(\frac{{\overline{\mu }}_{tr}}{\rho }\right)}_a^w$	1.11		3
$k_n$	1.035		0.4
Distance d in air	50	mm	2
$D_{w,in\hspace{0.17em}air}=M_u\times k_{TP}{k}_{elec}\times N_{K,ARP}\times {\left(\frac{{\overline{\mu }}_{tr}}{\rho }\right)}_a^w\times k_n$	1.022	Gy	4%