Events

Dosimetric workshop...

M. M. Merkin, Doctor of Engineering Science, Head of Silicon Detector Laboratory of Lomonosov Moscow State University,
V.A. Elin, Candidate of Engineering Science, resident of the Skolkovo technological cluster, DO-RA project manager.

Recently, we came across an Internet article describing a potential possibility of measuring ionizing radiation, using a smartrphone, its integrated photo/video camera, and a special software program for the adobe purposes. The research has been conducted by a group of scientists of the National Laboratory, Idaho, led by a scientist Joshua Cogliaty. The same group has developed their own software application for the purpose of research, under the name CellRad. We have thoroughly studied that research in order to benefit for the domestic dosimetry in case a territory is contaminated with fissionable radioactive substances and no full-scale dosimeter is available. And there you are!

Postulate: any semiconductor appliance can be used as an ionizing radiation (hereinafter referred to as IR) detector. Sometimes in laboratories, the experimentalists use ordinary diodes as a monitor of IR bundle, when no high-quality IR detectors are available at hand. But, what is wise to use for the specific task in the domestic dosimetry is another question.

Now, let us take a look at the conclusion in the foreign article which is in fact devoted to the measurement of IR.

“This project has demonstrated that a smartphone with a camera can be used as a low sensitivity dose rate meter. If the radiation is coming from a known direction, with sufficient data, limited spectrum information can be determined. There are better detectors than a cellphone camera will likely every be, but there are many more cellphones around than high-quality radiation detectors, which means there are times when the cellphone can be the best detector available”.

That is, from the very beginning the article states a lower sensitivity of a mobile telephone as a radiation detector in the form of its integrated photo/video camera, if there is no other means for measuring the dose rate (radiation background) around!

Then, let us take a look at Table No. 3: the measurement error (StdDev) for 1 mrem/hr is 300%!!!

The foreign research provides for nothing at all for lower IR amounts. The measurements results only become rational beginning from the dose rate of 1,000mrem/hr.

But, 1mrem/hr = 10µSv/h. However, in the living environment, around 0.10µSv/h to 0.20µSv/h or higher dose rates need to be measured, that is a radiation level intensity 50 to 100 times as low as the value given in the research.

As regards the last line in Table No. 3, there are no words for that – this is 100 roentgens per hour! With this dose rate, sitting for one hour beside the radiation source means a need for one year of treatment, and three hours means that you just need go to the funeral service.

At 10µSv/h the dosimeter must just cry out alerting you that the dose rate is 40 times as high as the permissible value!

Apparently, that research has only been considered from the point of the academic interest – yes, it is possible to detect IR, and this fact confirms the postulate that any semiconductor appliance can be used for displaying IR.

We should do justice to the scientists from the National Laboratory, Idaho – they admit at the end of their experiments that measurement of ionizing radiation is only possible using high-quality radiation detectors, but the photo/video cameras of ordinary smartphones can be nothing of the kind...