X ray Tube Dose Rate Calculator Widget

X-ray Tube Dose Rate Calculator Widget

Source: Design & implementation by Dr Chris Robbins (Grallator) / Facilitated by Ionactive radiation protection resource

For formal radiation safety advice, visit our Radiation Protection Adviser (RPA) services page. 

This radiation protection widget is an excellent training / educational resource for those involved in NDT x-ray (industrial radiography), medical x-rays, research and related users. It may also be of use to Radiation Protection Supervisors (RPS) or Radiation Protection Advisers (RPA). Those involved in x-ray room shielding design may also find this resource helpful.

Ionactive has worked with Dr Chris Robbins (Grallator) to create this resource exclusively for Ionactive. Chris is a whizz at mathematics, physics, nuclear physics and coding and it's a pleasure to be working with him.

The widget includes some basic information on how it creates its results. If you would like a more in-depth explanation then head over to this resource: Calculate an estimate of x-ray dose rate from an x-ray tube given kV and mA. To compare and contrast the widget output with other historic data, you might also find the following resource useful: X-ray equipment: Constant potential 50-200 KV. Enjoy!

Tip! Note the difference in absorbed dose between tissue and bone. A human body is neither all bone or tissue, so weighting can be used to simulate a whole body dose (this is a rough approximation since the body is made up of many more components). For example, for 150 kV at 1mA with 1mm Al the weighted average dose rate will be somewhere between 2.3-2.6 Gy/h. The reasoning behind this is explained here: Calculate an estimate of x-ray dose rate from an x-ray tube given kV and mA.

Shielding. Want to explore x-ray shielding? This complementary resource may be of interest: Diagnostic X-ray Shielding / Transmission Calculator

What if I have a different anode? 

The calculator is based on a tungsten (W) anode. We have produced some conversion tables for copper, molybdenum, and rhodium anodes. Simply pick the closest kV and Al (filter) and multiply the output of the calculator (dose rate) by the appropriate conversion factor. In time we may have this integrated into the calculator. 

Copper (Cu) conversion factors

kV

1 mm Al

2 mm Al

3 mm Al

4 mm Al

6 mm Al

8 mm Al

50

0.196

0.098

0.049

0.025

0.006

0.002

80

0.258

0.169

0.111

0.073

0.031

0.014

100

0.297

0.226

0.170

0.129

0.074

0.042

120

0.311

0.247

0.196

0.155

0.098

0.061

150

0.322

0.264

0.217

0.178

0.120

0.081

200

0.331

0.285

0.246

0.213

0.159

0.118

250

0.340

0.306

0.275

0.247

0.198

0.159

300

0.350

0.326

0.302

0.279

0.238

0.201

 
Molybdenum (Mo) conversion factors

kV

1 mm Al

2 mm Al

3 mm Al

4 mm Al

6 mm Al

8 mm Al

50

0.284

0.161

0.091

0.051

0.036

0.005

80

0.374

0.267

0.191

0.136

0.069

0.035

100

0.431

0.356

0.294

0.243

0.166

0.113

120

0.451

0.389

0.336

0.290

0.216

0.161

150

0.467

0.416

0.371

0.331

0.263

0.209

200

0.481

0.451

0.425

0.404

0.349

0.307

250

0.496

0.487

0.478

0.476

0.436

0.408

300

0.511

0.521

0.528

0.546

0.521

0.508

 
Rhodium (Rh) conversion factors

kV

1 mm Al

2 mm Al

3 mm Al

4 mm Al

6 mm Al

8 mm Al

50

0.304

0.178

0.104

0.061

0.021

0.007

80

0.400

0.295

0.218

0.160

0.087

0.046

100

0.461

0.394

0.336

0.287

0.209

0.152

120

0.483

0.429

0.382

0.340

0.271

0.213

150

0.500

0.459

0.422

0.389

0.330

0.276

200

0.515

0.498

0.484

0.475

0.437

0.404

250

0.474

0.413

0.361

0.316

0.242

0.252

300

0.530

0.462

0.403

0.351

0.345

0.288

 
Conversion factor information

The X-ray Tube Dose Rate Calculator provides a quick dose rate estimate based on common x-ray machine parameters like kV, mA, and aluminium (Al) filtration. These calculations assume a tungsten anode, which is typical in general radiography and industrial x-ray systems. Not all x-ray tubes use tungsten, some applications (like mammography or certain analytical systems) use alternative anodes such as copper (Cu), molybdenum (Mo), or rhodium (Rh). Because different anode materials produce different x-ray spectra, the resulting dose rates can vary significantly.

To account for this, we have provided a set of conversion factors. These enable you to adjust the tungsten-based dose rate from our calculator to suit a different anode material. Simply multiply the tungsten dose rate by the appropriate factor from the table (based on your tube's kV and Al filtration). These factors have been derived using published spectral data and simulation methods that compare the x-ray output of each anode material to tungsten under identical conditions. 

Please note that the x-ray widget and conversion tables are intended as an educational resource to aid understanding of x-ray tubes and radiation protection. For formal assessments or IRR17  compliance, you should always consult a Radiation Protection Adviser (RPA).
 

This revolution, the information revolution, is a revolution of free energy as well, but another kind: free intellectual energy.

– Steve Jobs -