1Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

A miniature detector for gamma rays (and neutrons?)

G.Alimonti, P.Finocchiaro, A.Pappalardo

in collaboration with Microsensor s.r.l.

• The importance of the “culture of radiation”• What’s on the market• A new miniradmeter?

Making the public more familiar with radiation

2Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

radiation is part of our lives

problem: making the public more familiar with radiation

3Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

problem: making the public more familiar with radiation

underestimations and big mistakes from the past...

4Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

http://www.iradgeiger.com

Radiation is no longer invisibleThe iRad is a revolutionary device that allows you to detect radiation using your Apple iOS device. The iRad works with the iPhone 5, 4S, 4, 3GS, and 3G. It also works with all generations of iPads and iPods. The free iRad Geiger app allows you to map, log, alarm, and measure radiation and seamlessly share this information in the cloud.

5Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

iRad Geiger

6Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

Elegant and Robust Carbon Fiber DesignThe carbon fiber body of the iRad Alpha was designed to be tough and light. Carbon fiber is virtually transparent to radiation, which minimizes shielding of the detector from the enclosure.

iRad Alpha

7Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

http://gammapix.com

8Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

Gamma Pix Software Products can add radiation detection capability to hundreds of millions of existing and already deployed smart phones, webcams and surveillance cameras. The patented technology (U.S. Patents 7,391,028 & 7,737,410 plus foreign filings) uses web downloadable software to analyze, within seconds, video or still images for the telltale signature of gamma radiation hitting the sensor. The gamma rays light up pixels near the location of impact as shown in the animation below. The two figures below left show image data taken during tests at Oak Ridge National Laboratory.

Gamma Pix

9Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

Very smart idea to exploit an already existing “sensor” with a few euros application but:

• Very slow response (if you want reliability) or very approximate (more from Jef)• Response depends on the type of CCD sensor that the device uses. If a phone

/tablet is produced with different camera from the series one, the result is unpredictable

• The app exists in several versions depending on the model of the iPhone, but not all models are supported.

• It is not possible to obtain the spectrum of the radiation (the thickness of the     sensor is inadequate).• An app based on a sensor not guaranteed (and reproducible) may give

unpredictable results and since our target is the “culture of radiation”, the whole thing could be strongly counterproductive (false alarms and panic, imagine what happens if facebook users start posting wrong higher rates).

  A sensor with known and well defined characteristics is needed.

10Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

possible step-up: a cheap and performing personal detector

current version

Gamma spectrum with 137Cs sourceFWHM 10% @662keV

minimum overall detector size ≈ 4mm x 4mm x 4mm minimum overall sensitive volume 3mm x 3mm x 3mm

the rest is battery, discrete components electronics, empty space

could be integrated inside a mobile phone or tablet

scintillator (CsI) & photosensor (SiPM@30V)

4mm4mm

4mm

cost for moderate quantities (50-100 pcs) ≈ € 35

spectrum obtained in ≈5min with a source 20kBq @1cm

and 2x2 mm CsI (30K events)

11Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

possible step-up: a cheap and performing personal detector

sensor electronics

Gamma spectrum with 22Na source(2” detector, same MCA)

cost for moderate quantities (50-100 pcs) ≈ € 50

includes signal amplification, MCA, USB connection

25mm

operated from 12V to 24V

25mm

spectrum obtained with a 50x50 mm equivalent

electronics and 2” CsI

12Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

... at no additional cost

the miniradmeter can be used as a simple counter (dosimeter)...

...or it can provide spectral analysis features...

Gamma spectrum with 137Cs sourceFWHM 10% @662keV

gives rise to additional 1cps

detection at 10sigma in 2min

2 MBq 137Cs source @1m or20kBq (tiny lab) source @10cm doubles the natural background

13Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

2.7MBq gamma source dose at 1m ≈ 0.0003 mSv/h

household radon

international limit for nuclear workers

≈ saturation

sensor dynamical range

dynamical range

14Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

possible improvement: sensitivity to alpha and/or beta

provide a thin mica window

insert an aluminum absorber sheet

device sensitive to beta radiation (discrimination)

device sensitive to alpha and beta radiation

(more suited for a plug-in application)

15Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

possible improvement: sensitivity to thermal neutrons

use a neutron converter (INFN patent pending)

Use plastic shield as moderator: device sensitive to neutrons

device sensitive to thermal neutrons

(definitely more suited for a plug-in application)

16Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

The End

17Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

radiation is part of our lives

problem: making the public more familiar with radiation

18Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

problem: making the public more familiar with radiation

cosmic rays, food, radon, seawater

19Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

problem: making the public more familiar with radiation

nuclear medicine, industry, reactors, radwaste storage

20Miniradmeter: a miniature detector for gamma rays (and neutrons?) G.Alimonti, P.Finocchiaro

problem: making the public more familiar with radiation

example: gamma exposure in USA