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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