CORSAIRMaking radioactivity measurements on building materials accessible to everyone

08 May 2020 – EGU General Assembly 2020

https://project-corsair.eu/

A. Serafini, D. Abbado, M. Alberi, P. Carconi, E. Chiarelli, P. De Felice, A. Deserventi, M. Donati, E. Fanchini, L. Fanucci, A. Fazio, F. Giordano, P. Grignani, G. Guiducci, A. Iovene, L. Luciani, G. Manessi, F. Mantovani, M. Marini, A. Masuelli, S. Mohsen, M. Morichi, G. Merlino, A. Pepperosa, K. G. C. Raptis, F. Rogo, V. Strati, G. Tona

Our detector: a full ɣ-spectroscopic laboratory packed in 4 kg

2

2’’x 2’’ CeBr3

1.25 cm Pb shielding

PMT MCA ɣstream

ElementEnergy [keV]

FWHM [keV]

Resolution [%]

Pb KX-ray 75.0 11.2 14.9

Th 212Pb 238.6 14.8 6.2

U 214Pb 295.2 15.7 5.3

U 214Pb 351.9 19.7 5.6

Th 228Ac 911.1 26.2 2.9

Th 228Ac 969.0 24.4 2.5

U 214Bi 1120.3 30.0 2.7

K 40K 1460.8 36.1 2.5

U 214Bi 1765.0 44.5 2.5

U 214Bi 2204.2 40.2 1.8

Th 208Tl 2614.0 53.5 2.0

U: 400 ppm

Th: 800 ppm K: 48%

Measurement duration: 16 h 3

Characterization of the detector resolution

Characterization of the detector resolution

4

𝑹𝒆𝒔𝒐𝒍𝒖𝒕𝒊𝒐𝒏 % = 𝟏𝟏𝟎/ 𝑬 [𝒌𝒆𝑽]

5

Characterization of the internal activity

» Initial 10 min measurement with reference materials used for energy calibration.

» 32 h measurement with detector shielded by > 10 cm of lead on each side.

» Final 10 min measurement with reference materials for confirming initial energy calibration.

U: 400 ppm

Th: 800 ppm K: 48%

Characterization of the internal activity

Total counts: 2.3 cps

Total counts: 360.5 cps

6

Shielding characterization via Monte Carlo simulations

7

5 m

5 m

0.5

m

Investigating the potentialities of Monte Carlo simulation for assessing

soil water content via proximal gamma-ray spectroscopyBaldoncini, M., M. Albéri, C. Bottardi, E. Chiarelli, K. G. C. Raptis, V. Strati, and F. Mantovani

Journal of Environmental Radioactivity, 192, 105-116 (2018)

From Monte Carlo simulations to reality

8

0.0001

0.001

0.01

0.1

1

0 500 1000 1500 2000 2500 3000

0.0001

0.001

0.01

0.1

1

0 500 1000 1500 2000 2500 3000

Cp

s

Cp

s

Energy [keV]

0.0001

0.001

0.01

0.1

1

0 500 1000 1500 2000 2500 3000

Cp

s

Energy [keV]

Measured internal activity

Spectra obtained from Monte Carlo

Predicted spectrum

Detector resolution

Understanding the shielding effect via Monte Carlo simulations

9

0%

20%

40%

60%

80%

100%

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50

Shielding thickness d

Total counts between 0.3 MeV and 3.0 MeV

IN [cps] OUT [cps] TOT [cps]

0.00 cm 16 32 48

0.75 cm 16 17 33

1.00 cm 16 15 31

1.25 cm 16 13 29

2.00 cm 16 10 26

CpsOUT (d) = e - 0.71 d [cm] x CpsOUT (0)

d [cm]

Cp

s w

/ sh

ield

ing

Cp

s w

/o s

hie

ldin

g

Optimizing shielding thickness for detector portability

10

Components Mass

2’’x 2’’ CeBr3 crystal 0.53 kg

PMT 1.05 kg

1.25 cm Pb shielding 1.90 kg

MCA ɣstream 0.70 kg

Total mass 4.18 kg

0

2

4

6

8

10

0 0.5 1 1.5 2 2.5 3

Tota

l mas

s [k

g]

Shielding thickness [cm]

0%

20%

40%

60%

80%

100%

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Shielding thickness [cm]

Cp

s w

/ sh

ield

ing

Cp

s w

/o s

hie

ldin

g

Shielded thickness has been chosen to be 1.25 cm:

» Expected to enable a 60% reduction of background signal (gamma rays coming from the sides and the top of the detector);

» Allows to maintain the detector lightweight and portable with a total mass of 4.2 kg.

40%

11

Experimental validation of Monte Carlo simulation

𝒄𝒑𝒔𝑺𝒉𝒊𝒆𝒍𝒅 [𝟎. 𝟑 − 𝟑𝑴𝒆𝑽]

𝒄𝒑𝒔𝑵𝒐 𝒔𝒉𝒊𝒆𝒍𝒅 [𝟎. 𝟑 − 𝟑𝑴𝒆𝑽]= 𝟎. 𝟑𝟗

12

CORSAIR system measuring stone materials at quarries

CORSAIR server

Unsuitable for sale

Suitablefor sale

Further investigation

in lab