This is an au ho -c ea ed, un-copyedi ed e sion o a con e ence pape published in
Measu emen : Senso s, 2025, 10.1016/j.measen.2024.101708. The p esen e sion is
a ailable o open access, DOI: 10.7795/810.20250711
TRACEABLE LOW ACTIVITY CONCENTRATION
CALIBRATION OF RADON DETECTORS FOR CLIMATE
CHANGE OBSERVATION NETWORKS
Rö ge , S e an1 0000-0002-4750-9563;
Anne e Rö ge 1 0000-0001-6858-5795;
Flo ian Me es1,2 0000-0003-0217-2845;
Sco Chambe s3 0000-0002-2521-959X;
Alan G i i hs3 0000-0003-1135-1810;
Roge Cu coll4 0000-0002-8025-673X;
Claudia G ossi4 0000-0001-6678-4440;
1 Physikalisch-Technische Bundesans al , B aunschweig, Ge many.
2 Bundesam ü S ahlenschu z, Neuhe be g, Ge many.
3 Aus alian Nuclea Science and Technology O ganisa ion (ANSTO), Sydney, Aus alia.
4 Ins i u de Tècniques Ene gè iques (INTE) o he Uni e si a Poli ècnica de Ca alunya (UPC),
Ba celona, Spain.
DOI: h ps://doi.o g/10.1016/j.measen.2024.101708
Ve ö en lichungsjah : 2025
Acknowledgemen : Resea ch unding:
• The p ojec 19ENV01 aceRadon has ecei ed unding om he EMPIR
p og amme co- inanced by he Pa icipa ing S a es and om he Eu opean
Union's Ho izon 2020 esea ch and inno a ion p og amme.
• The p ojec 23IND07 RadonNET has ecei ed unding om he Eu opean
Pa ne ship on Me ology, co- inanced om he Eu opean Union’s Ho izon
Eu ope Resea ch and Inno a ion P og amme and by he Pa icipa ing
S a es.
• The p ojec NuClim (ID 101166515) has ecei ed unding om he
EURATOM2027 p og am, co- inanced by he Eu opean Union’s Ho izon
EURATOM P og amme (2023-NRT-01-09) and by he Pa icipa ing S a es.
This is an au ho -c ea ed, un-copyedi ed e sion o a con e ence pape published in
Measu emen : Senso s, 2025, 10.1016/j.measen.2024.101708. The p esen e sion is
a ailable o open access, DOI: 10.7795/810.20250711
Angaben zum U hebe ech : BY 4.0; This wo k is licensed unde he C ea i e
Commons A ibu ion 4.0 In e na ional License.
© 2025 he au ho (s), published by Else ie , Science Di ec
Zi ie o m: S e an Rö ge , Anne e Rö ge , Flo ian Me es, Sco Chambe s, Alan
G i i hs, Roge Cu coll, Claudia G ossi:
T aceable low ac i i y concen a ion calib a ion o adon de ec o s o clima e
change obse a ion ne wo ks,
Measu emen : Senso s, Volume 38, Supplemen , 2025, 101708, ISSN 2665-
9174, h ps://doi.o g/10.1016/j.measen.2024.101708.
1 o 6
XIV IMEKO Wo ld Cong ess “Think Me ology”
Augus 26
−
29, 2024, Hambu g, Ge many
TRACEABLE LOW ACTIVITY CONCENTRATION CALIBRATION OF RA-
DON DETECTORS FOR CLIMATE CHANGE OBSERVATION NETWORKS
S e an Rö ge a*, Anne e Rö ge a, Flo ian Me esa,d, Sco Chambe sb, Alan G i i hsb, Roge Cu collc, Claudia
G ossic
a Physikalisch-Technische Bundesans al , B aunschweig, Ge many, S e an.R[email p o ec ed], Anne e.Roe ge @PTB.de
b ANSTO, Aus alia, Sco .Chambe [email protected] .au, Alan.G i [email p o ec ed] .au
c Ins i u e o Ins i u e o Ene gy Technologies, Uni e si a Poli ècnica de Ca alunya, Spain, Roge .Cu c[email p o ec ed],
[email p o ec ed]du
d Bundesam ü S ahlenschu z, Ge many, F[email p o ec ed]
* Co esponding au ho
Abs ac − Radon gas is he la ges sou ce o public expo-
su e o na u ally occu ing adioac i i y, and concen a ion
maps based on a mosphe ic measu emen s aid de elope s in
complying wi h EU Sa e y S anda d Regula ions. Bu adon
can also be used as a ace o e alua e dispe sal models im-
po an o suppo ing success ul g eenhouse gas (GHG) mi -
iga ion s a egies. Tha is why eliable measu emen s o low-
le el adon ac i i y concen a ions, such as hose ound in he
en i onmen (< 20 Bq∙m-3), a e impo an o bo h adia ion
p o ec ion and clima e esea ch. Despi e he eno mous
changes in adon me ology ha ha e occu ed in ecen yea s
ac i i y concen a ions below 100 Bq∙m-3 had no been sub-
jec o me ological esea ch so a . This e okes new chal-
lenges which a e he de elopmen o aceable me hods and
obus echnology o measu emen s o en i onmen al low-
le el adon ac i i y concen a ions and adon luxes om he
soil. Bo h a e impo an o de i e in o ma ion on g eenhouse
gas luxes in he en i onmen and he e o e a e impo an o
planning he educ ion s a egy.
In he amewo k o he EMPIR p ojec 19ENV01 ac-
eRadon [1], s able a mosphe es wi h low-le el ac i i y con-
cen a ions o adon ha e been p oduced o enable calib a ion
o adon de ec o s capable o measu ing hese en i onmen al
ac i i y concen a ions. The equi ed aceabili y o he cali-
b a ion a e y low ac i i y concen a ions, was no possible
in he pas .
To achie e his goal, low ac i i y sou ces o adium ha e
been p oduced [2,3] wi h di e en me hods and di e en
cha ac e is ics. Sou ces down o ew Bq o 226Ra ha e been
de eloped and cha ac e ized leading o unce ain ies as low
as 2 % (k=1), e en in case o he lowes ac i i y sou ces. Ad-
di ionally, sou ces wi h medium and high ac i i ies we e p o-
duced, wi h ad anced p oduc ion me hods like ion implan a-
ion o mass sepa a ed 226Ra in di e en a ge ma e ials.
As an ou come, o he i s - ime aceable me hods o
measu ing low-le el a mosphe ic adon ac i i y concen a-
ions in he ange o 1 Bq·m-3 o 50 Bq·m-3 wi h unce ain ies
below 5 % (k=1) a e now a ailable. To compa e he pe o -
mance o he sou ces in applica ion, e.g., o es ablish a e e -
ence a mosphe e, a calib a ion exe cise wi h wo highly sen-
si i e, la ge olume, low adon ac i i y concen a ion de ec-
o s o di e en design and p inciple was ca ied ou a he
PTB. The de ails o he calib a ion p ocedu e o hese unique
p o o ypes o de ec o s a e p esen ed. The esul s o he
cha ac e iza ion o he de ec o s a e discussed and as a con-
clusion new de elopmen s in he ield o adon me ology a e
p esen ed.
The p ojec 19ENV01 aceRadon ecei ed unding om
he EMPIR p og amme co- inanced by he Pa icipa ing
S a es and om he Eu opean Union's Ho izon 2020 esea ch
and inno a ion p og amme.
Keywo ds: adon, low-ac i i y concen a ion, ace , cli-
ma e change, calib a ion, unce ain y
1. INTRODUCTION
The opic o adon me ology is no new: In ac , adon
has been a challenge in adia ion p o ec ion o cen u ies. Bu
i de eloped a comple ely new guise in he ield o en i on-
men al measu emen ne wo ks o clima e moni o ing. As a
noble gas, i is an ideal ace o es ima ing g eenhouse gas
luxes. Wi h i s help, ca bon dioxide o me hane luxes om
he g ound o e a b oadly dis ibu ed egion [4] can be meas-
u ed and used o clima e modelling. Thus, he adioac i e el-
emen adon u ns ou o be a s oke o luck o clima e e-
sea ch: Me ology has success ully p o ided solu ions o
make use o adon in clima e obse a ion and o use he same
da a o be e p o ec people agains i s ha m ul e ec . Con-
sequen ly, he esul s om 19ENV01 aceRadon gained
wo ldwide a en ion: Fo calib a ion, in e compa isons [5],
he de elopmen o new ins umen a ion and a mosphe ic
models.
2. METHODS OF RADON CALIBRATIONS
2.1. Classi ica ion o calib a ion p ocedu es
T aceabili y o ac i i y concen a ion (Bq·m–3) in he con-
cep o he e ised SI sys em means ha he basic uni s sec-
ond (s) and me e (m) a e de ined by undamen al cons an s
and a e ealised by a Na ional Me ology Ins i u e (NMI). To
ealise he uni , he con en ionally ue alue o he quan i y
o be measu ed has o be es ima ed, in his case he adon ac-
i i y concen a ion. The ollowing p ocedu es o his ha e
been es ablished o applica ion in so-called adon calib a ion
chambe s:
P ocedu e 1: A p ima y me hod based on a e e ence ac-
i i y concen a ion ealised by a p ima y adon gas s anda d
2 o 6
[6] and a calib a ion olume (bo h alues a e aceable o na-
ional s anda ds). The esul is a calib a ion ac o o a meas-
u emen de ice (sys em unde es ) calib a ed in such an a -
mosphe e. Such a de ice can be add essed as a seconda y
s anda d a e wa ds.
P ocedu e 2: A seconda y me hod based on calib a ion ia
a e e ence moni o enclosed in he same a mosphe e as he
sys em unde es . This p ocedu e is essen ially based on p o-
cedu e 1 as i implemen s a seconda y s anda d (calib a ed o
ins ance by p ocedu e 1) and uses i o de e mine he e e -
ence ac i i y o de e mine a calib a ion ac o o ano he de-
ice.
P ocedu e 3: A p ima y/seconda y calib a ion in a con-
s an a mosphe e based on a adium emana ion sou ce. This
me hod can be p ima y o seconda y wi h espec o he com-
ponen s used. I is a long- e m p ocedu e (8 – 10 hal -li es o
222Rn), as adioac i e equilib ium is needed. I can be ope -
a ed in a closed sys em o in an open sys em.
P ocedu e 4: A p ima y calib a ion in a non-cons an a -
mosphe e based on a adium emana ion sou ce in a closed
olume. The sys em unde es needs high sensi i i y o
achie e small unce ain ies. I is ope a ed in a closed sys em
implemen ing sui able ins umen a ion and a da a-d i en
compu a ion. As a esul , i is no longe necessa y o wai o
equilib ium o be eached, as he p ocedu e is based on da a
measu ed du ing he build-up phase [2, 7-9]. Fu he mo e, he
da a analysis yields comple e in o ma ion abou he cha ac-
e is ics o he sys em unde es , like backg ound indica ion,
calib a ion ac o (k), o sensi i i y (kc =1/k) cha ac e is ic
limi s and linea i y can be de i ed.
P ocedu e 5: A calib a ion by a p ima y single adon ac-
i i y injec ion in o a sys em unde es : Pulse calib a ion.
2.2. Sys ems unde es : ANSTO 200 L and ARMON 2
Two p o o ypes o new en i onmen al adon moni o s we e
es ed a he PTB acco ding o p ocedu e 4: One moni o de-
eloped by he Aus alian Nuclea Science and Technology
O ganisa ion (ANSTO), he ANSTO 200 L and ano he one,
he ARMON 2 om he Ins i u e o Ene gy Technologies,
Uni e si a Poli ècnica de Ca alunya, Spain (INTE UPC).
The physical p inciple o ope a ion o he ANSTO 200 L is
ha o a wo- il e dual low-loop adon de ec o [10]: Ambi-
en ae osols, adon p ogeny ( il e ) and ho on (220Rn) (delay
olume) a e emo ed om he sampled ai , which hen passes
di ec ly in o a chambe as pa o he i s low loop ( he “ex-
e nal” o sampling low loop). New adon p ogeny o m in
his chambe unde con olled condi ions. A second low-
loop ( he “in e nal” low loop) epea edly d aws his ai
h ough a second il e inside he chambe , which cap u es he
newly o med p ogeny o coun ing. The -decays o he
sho -li ed 218Po and 214Po on his il e a e coun ed using a
zinc sulphide / pho omul iplie ube (ZnS-PMT) assembly.
The 30 min -coun a e ela es o a adon ac i i y concen a-
ion. This ela ion is gi en by calib a ion wi h a known
sou ce.
The physical p inciple o ope a ion o he ARMON 2 is
based on collec ion o posi i e 218Po+ ca ions [11], om he
-decay o 222Rn wi hin he de ec ion olume, on he su ace
o a semiconduc o de ec o . 218Po+ ca ions, gene a ed wi hin
a known olume, a e ound o be in he o m o singly cha ged
posi i e ions abou 88 % o he ime, while he neu al a oms
occu he emaining 12 %. The 218Po+ is p oduced om he
s ipping o o bi al elec ons by he depa ing α-pa icle o by
he ecoil mo ion. When a high elec ic po en ial is applied o
he in e nal su ace o he de ec ion olume and he de ec o
i sel is main ained a 0 V po en ial, an elec os a ic ield is
gene a ed inside he olume, causing he cha ged 218Po+ ca i-
ons o be collec ed a he de ec o su ace wi hin sho ime.
In he case o he ARMON 2, a Passi a ed Implan ed Plana
Silicon (PIPS) de ec o is used. A p eampli ie and an ampli-
ie a e hen used o ampli y and shape he cha ge signal com-
ing om he de ec o o a Gaussian unc ion in o de o be
ead by a mul ichannel analyse (MCA), which ans o ms i
in o coun s o speci ic ene gy bins. The spec a gene a ed
can be analysed wi h comme cial so wa e. ARMON 2
makes use o MAESTRO (Mul ichannel Analyze Emula ion
So wa e, om ORTEC).
2.3. P ima y calib a ion in non-equilib ium
The SI aceabili y o a calib a ion wi h espec o 222Rn
ac i i y concen a ion is ealised by applying he p ocedu e
desc ibed by p ocedu e numbe 4. The 226Ra ac i i y is p o-
ided h ough mass sepa a ed ion implan ed sou ces as de-
sc ibed in [7] which ha e been cha ac e ised acco ding o
hei 222Rn emana ion applying De ined Solid Angle -spec-
ome y (DSA) and -spec ome y using High Pu i y Ge -
manium (HPGe) de ec o s [3]. The olume used o calib a-
ion is he clima e chambe o PTB, o me ly known as adon
e e ence chambe wi h a ee o ai olume o Vcham-
be = 21.224(17) m3 in he case o he wo desc ibed de ec o s
placed inside he chambe olume.
Th ee di e en sou ces ha e been used in di e en com-
bina ion, o achie e 5 di e en equilib ium ac i i y concen-
a ions. The 226Ra emana ion sou ces and hei cha ac e is ic
alues a e gi en in Table 1.
Table 1: The sou ces used o calib a ion wi h hei unique names,
ac i i y o 226Ra and emana ion ac o .
Sou ce name
Ac i i y
Bq
Emana ion
S2018_1121
1104 (5)
0.467(9)
S2018_1120
922 (4)
0.308(3)
S2018_1133
601.2(25)
0.273(4)
The empo al e olu ion o he p oduced 222Rn ac i i y con-
cen a ions wi h he measu emen esul s o all he adon ac-
i i y concen a ion de ec o s used o calib a ion o moni o -
ing is shown in Figu e 1. All alues gi en a e a e aged alues
o e 30 min o in eg a ion ime.
3 o 6
The h ee comme cial indoo ai adon ac i i y concen a-
ion de ec o s o ype AlphaGUARD a e ma ked wi h smalle
do s and indica ed as “AG”. The sca e ing o he esul s, a e
calib a ion wi h alues e en below CA = 0 Bq·m–3 p o e ha
hese de ec o s a e no well sui ed o ou doo ai ac i i y con-
cen a ion le els and ime esol ed measu emen s, simply be-
cause o hei smalle ac i e olume, which limi s hei coun -
ing s a is ics. AG0626 was used as a backg ound and leakage
moni o o he lab en i onmen and was he e o e placed in
he clima e con olled (100 % ou doo ai , high ai exchange
a e) lab oom.
The de ailed esul s o his calib a ion exe cise o he
ARMON 2 de ec o as example a e gi en in Figu e 2 wi h
he ela i e di e ence ( esidual) be ween he measu ed e-
sul s and he p oduced 222Rn ac i i y concen a ion in ai .
The colou ed a eas ma k he di e en se ings du ing he
calib a ion o backg ound and he di e en combina ions o
he sou ces explained in Table 1, used o his calib a ion.
Using his de ia ion be ween he p ima y de i ed calib a-
ion si ua ion and he measu emen esul s o he de ec o s
used, he s a is ical dis ibu ions o he de ec o s a e de i ed
as a his og am and a e shown in Figu e 3.
The colou ed a eas in Figu e 3 ma k he 95 % co e age
in e al o he p obabili y dis ibu ion o he esul s gi en by
he espec i e de ec o . As a alue in he espec i e colou he
a ibu ed s a is ical unce ain y o he expansion ac o o
k = 2 is gi en. The la ge di e ence o mo e han a ac o o
wo be ween he wo AlphaGURADs o he same ype is ex-
plained wi h he age and he his o y o hese de ec o s, which
leads o di e en in e nal con amina ion o he de ec o s wi h
210Po and he e o e o di e en alues o backg ound sub ac-
ion. La ge alues o sub ac ed backg ound, especially o
small coun a es p oduces la ge luc ua ion in he di e ence.
This al eady indica es ha he de e mina ion o he back-
g ound plays an impo an ole in calib a ion o de ec o s o
small ac i i y concen a ion alues wi h low desi ed unce -
ain y.
Figu e 1: S a is ical sp ead o he di e ence be ween measu ed al-
ues and he e e ence alues de i ed om he sou ces as his og am
in loga i hmic p esen a ion. The his og ams a e no malised o equal
su ace. The numbe s gi en a e he espec i e s anda d de ia ions
o he his og am in Bq∙m-3. The colou ed a ea is he 95 % co e age
in e al o he espec i e his og am
Figu e 3: CA(222Rn) ac i i y concen a ion measu ed in Bq∙m-3 o e ime wi h he ARMON 2 compa ed wi h he 222Rn ac i i y concen a ion
supplied by he e e ence sou ces in he aceable olume o he clima e chambe .
Figu e 2: Calib a ed 222Rn ac i i y concen a ion measu emen e-
sul s o di e en adon de ec o s. Th ee comme cially a ailable Al-
phaGUARD de ec o s o di e en age, in pa allel wi h he wo newly
de eloped scien i ic ou doo ai adon de ec o s (ANSTO 200 L,
ARMON 2). AG0626 used as a backg ound moni o in he lab
oom. All he o he s we e placed in he calib a ion chambe meas-
u ing iden ical 222Rn ac i i y concen a ion.
4 o 6
The alues o he wo scien i ic g ade ac i i y concen a-
ion de ec o s a e gi en in mo e de ail in Figu e 4.
The wid h o he dis ibu ion in de ia ion o Bq·m–3 shows
ha he s a is ical luc ua ions o he ANSTO 200 L is smalle
han ha o he ARMON 2, which can be explained by he
ac i e olume o hese de ec o s. The in e nal low loop o
he ANSTO 200 L de ec o , ha can be ega ded as he ac i e
olume, has a olume o 200 L, whe eas he elec os a ic col-
lec ion sphe e o he ARMON 2, which is o be ega ded as
i s ac i e olume is only 20 L.
To de e mine a ully aceable calib a ion o he wo de ec o s
no only he s a is ical unce ain ies o he measu ed coun
a es has o be aken in o accoun bu also he ull unce ain y
budge s o he calib a ion acili y and sou ces. Since no sec-
onda y calib a ion s anda ds ( aceable de ices) ha e been
used, no ans e unce ain ies mus be conside ed. The cha -
ac e isa ion o he sou ces includes se e al measu emen s
which esul in unco ela ed s a is ical unce ain ies. The un-
ce ain y o he p ima y -ac i i y measu emen s anda d co -
ela es wi h he unce ain y o all he sou ces. The de e mina-
ion o he sensi i i y and he backg ound o he de ec o s
he e o e includes co ela ed and unco ela ed unce ain y
dis ibu ions o he de ec o measu emen s esul s as well as
o he p ima y ac i i y concen a ion p oduc ion. This is
aken in o accoun applying an O hogonal Dis ance Reg es-
sion (ODR) in wo s eps o he unco ela ed unce ain y con-
ibu ions and unce ain y p opaga ion o he co ela ed un-
ce ain y con ibu ions. The esul ing calib a ions a e summa-
ised o he ANSTO 200 L in Figu e 5 and he ARMON 2
in Figu e 6. The da k g een a eas ma k he unce ain y a eas
o k = 1, he ligh g een a eas o k = 2.
2.4. Calib a ion using pulsed ac i i y
Ins ead o wai ing o s able condi ions and adioac i e equi-
lib ium, an al e na i e me hod is o use a de ined, sho pulse
o 222Rn ac i i y and lush i h ough a de ec o . This, oge he
wi h ca e ul modelling, allows o much sho e calib a ion
ime and e en a de ined calib a ion olume is no needed. Bu
he absolu e ac i i y is essen ial.
The e alua ion o he esul s o he e y ecen pulse meas-
u emen s show easonable ag eemen wi h he sensi i i y de-
e mined in Sec ion 2.3.
This holds ue o he ARMON 2 which again allows o
spec al esolu ion as well as o he ANSTO 200 L which
does no ha e he abili y o dis inguish be ween he di e en
p ogeny o 222Rn wi hin he de ec o ou pu . The algo i hm
anyhow wo ks as well wi h he sum o all p ogeny.
The esul s o he ARMON 2 measu emen s a e shown in
Figu e 7: 3-dimensional ep esen a ion o he ime and ene gy
(channel) esol ed esponse o he ARMON 2 de ec o o a
de ined 222Rn pulse applied a ime 0 a he ai inle o he
Figu e 6: S a is ical sp ead o he di e ence be ween measu ed al-
ues and he e e ence alues de i ed om he sou ces as his og am
in linea p esen a ion. The his og ams a e no malised o equal su -
ace. The numbe s gi en a e he espec i e s anda d de ia ions o
he his og am in Bq∙m-3. The colou ed a ea is he 95 % co e age
in e al o he espec i e his og am.
Figu e 4: Resul s o he calib a ion ac o o he ANSTO 200 L de-
ec o applying all sou ces and combina ions measu ed, aking co -
ela ed and unco ela ed con ibu ions o he sou ce cha ac e isa-
ion in o accoun .
Figu e 5: Resul s o he calib a ion ac o o he ARMON 2 de ec-
o applying all sou ces and combina ions measu ed, aking co e-
la ed and unco ela ed con ibu ions o he sou ce cha ac e isa ion
in o accoun .
Figu e 7: 3-dimensional ep esen a ion o he ime and ene gy (chan-
nel) esol ed esponse o he ARMON 2 de ec o o a de ined 222Rn
pulse applied a ime 0 a he ai inle o he de ec o . A he lowe
channels (5-10) 218Po ep esen s he as e esponse o he de ec o
and channel (20-30) he slowe esponse o 214Po is isible.
5 o 6
de ec o . A he lowe channels (5-10) 218Po ep esen s he
as e esponse o he de ec o and channel (20-30) he slowe
esponse o 214Po is isible. Figu e 7 is he 3-dimensional ep-
esen a ion o he measu ed coun s as a unc ion o ime and
-ene gy showing he whole in o ma ion ecei ed du ing one
pulse measu emen .
E o ! Re e ence sou ce no ound. is he p ojec ion o
Figu e 7 o he ime axis showing he build-up, decay and
lush ou o he sepa a e 222Rn p ogeny.
While Figu e 9 is he p ojec ion o he -ene gy axis o he
ARMON 2 and displays he ene gy esolu ion ea u es o he
de ec o showing he di e en p ogeny o 222Rn ha ha e
been eco ded du ing he pulse.
The de ailed analysis o he da a and he unce ain y o he
pulse calib a ion is s ill in p og ess bu seems o be in good
ag eemen wi h he calib a ions pe o med in sec ion 2.3.
Wi h his new ype o calib a ion and he no iceably sho e
ime i akes o pe o m he calib a ion, a ecalib a ion o de-
ec o s in ield will become possible using 222Rn ee aged
syn he ic ai , e en a ou doo en i onmen al ac i i y concen-
a ion le els. Repea ed calib a ion du ing measu emen and
applying ML echniques p omises a calib a ion e en wi h en-
i onmen al ai .
RESULTS AND DISCUSSION
The esul s o he calib a ion exe cise as well as o bo h sci-
en i ic de ec o s a e ema kably good. Especially wi h espec
o he ac ha a ully SI aceable calib a ion o backg ound
and sensi i i y has ne e be o e been ca ied ou wi h all cal-
ib a ion poin s being below 50 Bq·m–3 and using a ime eso-
lu ion o 30 min. Rema kable as well is he achie ed assigned
unce ain y o below 5 % (k = 1) o he sensi i i y o bo h
de ec o s. The calib a ion unce ain y o he ANSTO 200 L
de ec o is wi h 3.9 % a li le bi smalle as o he AR-
MON 2 whe eas he s anda d de ia ion o he ARMON 2
measu emen s wi h ega d o he p oduced ac i i y concen-
a ions, unde his e y cons an labo a o y condi ions, is be-
low 1 %. The backg ound eading o he ARMON 2 is
smalle han he ANSTO 200 L, which is due o i s -ene gy
esol ing capabili y and educes i s unce ain y e en wi h a
compa ably smalle ac i e olume.
3. CONCLUSIONS
One o he wo ld's g ea es challenges lies in comba ing
clima e change. Alongside his, he issue o adiological
sa e y seemed less p ominen o a long ime, bu he adio-
ac i e ace " adon" combines bo h challenges. This b ough
oge he di e en scien i ic b anches wi h a common need:
new me ology o he de e mina ion o g eenhouse gas
luxes and o he imp o emen o ambien dose moni o ing
ne wo ks in he en i onmen .
Poli ical decisions need alid da a. Implemen ing expen-
si e measu es, whe he in clima e p o ec ion o adia ion p o-
ec ion, always means he need o make he success o hese
measu es measu able. Can me ology make i s con ibu ion
he e?
The conso ium o he aceRadon p ojec has aken up
his challenge by looking o sui able me ics ha could ena-
ble an assessmen . This b ough he adioac i e noble gas a-
don in o ocus: Making measu able wha was no measu able
be o e, p o iding us wo hy da a whe e he e was no com-
pa abili y be o e and hus pa ing he way o new app oaches
like he Radon T ace Me hod (RTM) is a p omising way how
me ology can con ibu e o comba clima e change. The ac-
eRadon p ojec showed wha is possible when compe ences
a e b ough oge he :
• new SI aceabili y chains o measu emen quan i ies
used in clima e obse a ion and adia ion p o ec ion
we e de eloped,
• new cus ome calib a ion se ices we e p o ided,
• new ypes o de ices we e made a ailable,
• a s anda d p o ocol o he applica ion o he Radon
T ace Me hod (RTM) o enable e ie al o g een-
house gas luxes a a mosphe ic clima e gas moni o -
ing s a ions and o use adon lux da a o he iden i-
ica ion o Radon P io i y A eas (RPA) was p o-
ided,
• Radon lux models and in en o ies ha e been ali-
da ed,
• new aceable measu emen s o adon ac i i y con-
cen a ion and adon lux we e suppo ed by dosime -
ic and spec ome ic da a om he adiological ea ly
wa ning ne wo ks in Eu ope,
• as a u he ou come easy o use dynamic adon and
adon lux maps o clima e change esea ch and a-
dia ion p o ec ion in line wi h Council Di ec i e
2013/59/EURATOM, including hei use o iden i y
RPA and adon wash-ou peaks we e p o ided.
Bu he e is s ill some wo k o do o adia ion p o ec ion:
The g ow h o buildings in la ge ci ies and he ac ha hei
ai condi ioning en ails high ene gy cos s, p o ides new chal-
lenges: E icien insula ion o he building and low ai ex-
change a es will be desi able. Howe e , s ong insula ion
and low ai exchange a e can lead o high le els o adon
ac i i y concen a ion. The e o e, he Eu opean Me ology
Ne wo k o Radia ion P o ec ion (EMN RP) [12] iden i ied
his need as a op p io i y and he Eu opean Pa ne ship on
Me ology (EPM) p o ided unding o i wi h he p ojec
23IND07 RadonNET wi hin i s 2023 indus y call.
On he o he hand, he Radon T ace Me hod (RTM) es-
ablished as a e icien ool o G een House Gas (GHG) es i-
ma es and clima e modelling. F om his he need o mo e SI
aceable measu emen s wi h smalle unce ain ies a ose. And
Figu e 8:
-ene gy depended on dis ibu ion o e en s eco ded
wi h he ARMON 2 du ing he passage o a de ined ac i i y pulse
o 222Rn in loga i hmic ep esen a ion.
6 o 6
led o he unding o a EURATOM p ojec unde FP9 (Ho i-
zon Eu ope) wi h he name “Nuclea obse a ions o imp o e
Clima e esea ch and GHG emission es ima es” (NuClim),
s a ing in 2024 and aiming o p o ide an accu a e and ime-
a ying baseline e e ence le el o Eu opean GHG concen-
a ions based on nuclea obse a ions. The s a egy o
achie e his will make use o a mosphe ic adon concen a-
ion measu emen s a oceanic emo e si es o iden i y baseline
condi ions, ep esen a i e o hemisphe ic backg ound alues,
which is essen ial o he imp o emen o he cha ac e isa ion
o he seasonali y and in e -annual beha iou s o adon con-
cen a ions in he ma ine bounda y laye o he No h A lan ic
Ocean o assis he e alua ion o anspo and con ec i e
mixing schemes o global clima e and chemical anspo
models. As well as o educe he unce ain y on long- e m
ends in mid-la i ude No he n Hemisphe e baseline concen-
a ions o selec ed GHGs o help educe unce ain ies in
global clima e change p ojec ions.
ACKNOWLEDGMENTS
The p ojec 19ENV01 aceRadon has ecei ed unding
om he EMPIR p og amme co- inanced by he Pa icipa ing
S a es and om he Eu opean Union's Ho izon 2020 esea ch
and inno a ion p og amme.
The p ojec 23IND07 RadonNET has ecei ed unding
om he Eu opean Pa ne ship on Me ology, co- inanced by
he Eu opean Union’s Ho izon Eu ope Resea ch and Inno a-
ion P og amme and by he Pa icipa ing S a es.
The p ojec NuClim (ID 101166515) has ecei ed unding
om he EURATOM2027 p og am, co- inanced by he Eu-
opean Union’s Ho izon EURATOM P og amme (2023-
NRT-01-09) and by he Pa icipa ing S a es.
REFERENCES
[1] A. Rö ge e al: New me ology o adon a he en i onmen-
al le el, in Meas. Sci. Technol. 32, 124008, 2021, DOI:
h ps://doi.o g/10.1088/1361-6501/ac298d
[2] S. Rö ge e al.: E olu ion o aceable adon emana ion
sou ces om MBq o ew Bq, in Applied Radia ion and Iso-
opes, Volume 196, 110726, 2023, DOI:
h ps://doi.o g/10.1016/j.ap adiso.2023.110726
[3] F. Me es e . al.: De elopmen o 222Rn emana ion sou ces
wi h in eg a ed quasi 2 ac i e moni o ing, in In . J. En i-
on. Res. Public Heal h 2022, 19, 840,
h ps://doi.o g/10.3390/ije ph19020840
[4] I. Le in e al.: Ve i ica ion o Ge man me hane emission in-
en o ies and hei ecen changes based on a mosphe ic
obse a ions, in J. Geophys. Res., 104, D3, 3447 – 3456,
1999. DOI: h ps://doi.o g/10.1029/1998JD100064
[5] C G ossi e al.: Cha ac e izing he au oma ic adon lux
ans e s anda d sys em Au o lux: labo a o y calib a ion
and ield expe imen s, in A mos. Meas. Tech., 16, 2655–
2672, 2023, h ps://doi.o g/10.5194/am -16-2655-2023
[6] J. L. Picolo: Absolu e measu emen o adon 222 ac i i y, in
Nuclea Ins umen s and Me hods in Physics Resea ch Sec ion
A, Volume 369, Issues 2–3, 1996, Pages 452-457, ISSN 0168-
9002, DOI: h ps://doi.o g/10.1016/S0168-9002(96)80029-5
[7] F. Me es, e . al.: Ion implan a ion o 226Ra o a p ima y
222Rn emana ion s anda d, in Applied Radia ion and Iso-
opes, Volume 181, Ma ch 2022, 110093, DOI:
h ps://doi.o g/10.1016/j.ap adiso.2021.110093
[8] S. Rö ge , e al: Radon me ology o use in clima e change
obse a ion and adia ion p o ec ion a he en i onmen al
le el, in Ad . Geosci., 57, 37–47, 2022, DOI:
h ps://doi.o g/10.5194/adgeo-57-37-2022
[9] A. Rö ge , e al.: Me ology in as uc u e o adon me-
ology a he en i onmen al le el, in Ac a IMEKO, Vol. 12,
No.2 (2023), DOI: h ps://ac a.imeko.o g/index.php/ac a-
imeko/a icle/ iew/1440
[10] S. Chambe s, e al.: Po able wo- il e dual- low-loop
222Rn de ec o : s and-alone moni o and calib a ion
ans e de ice, in Ad . Geosci., 57, 63–80, 2022, DOI:
h ps://doi.o g/10.5194/adgeo-57-63-2022
[11] R. Cu coll, e al.: Full cha ac e iza ion and calib a ion o a
ans e s anda d moni o o a mosphe ic adon and ho-
on measu emen s, in EGUsphe e, 2023, P ep in DOI:
h ps://doi.o g/10.5194/egusphe e-2023-2680
[12] Eu opean Me ology Ne wo k o Radia ion P o ec ion Web-
si e: h ps://www.eu ame .o g/eu opean-me ology-ne -
wo ks/ adia ion-p o ec ion/abou -us (las accessed 2024-04-
22)
