RF test on coated resonant cavity

I.FAST
Inno a ion Fos e ing in Accele a o Science and Technology
Ho izon 2020 Resea ch In as uc u es GA n° 101004730
DELIVERABLE REPORT
RF es on coa ed esonan ca i y
DELIVERABLE: D9.2
Documen iden i ie :
IFAST-D9.2
Due da e o deli e able:
End o Mon h 51 (July 2025, ex ended o Oc obe 25)
Repo elease da e:
31/10/2025
Wo k package:
WP9: Inno a i e supe conduc ing ca i ies
Lead bene icia y:
INFN
Documen s a us:
Final
ABSTRACT
The goal o D9.2 is o coa and es a esonan ca i y wi h an al e na i e ma e ial o Niobium
wi h a Q0 > 10E9 a 4.2 K and 1.3 GHz. In Task 9.2, wo lines o de elopmen we e ca ied ou
o achie e he goal: he i s conce ning he coppe ca i ies se ing as subs a es, and he second
ocusing on he deposi ion se -ups. Fo bo h, al e na i e solu ions had o be iden i ied compa ed
o wha was o iginally o eseen in he p oposal, due bo h o echnological challenges ha
eme ged du ing he R&D phase o ask 9.3 and o he loss o key pa ne s.
In his documen a e epo ed he ad ancemen in seamless Cu ca i ies p oduc ion and polishing,
he desc ip ion o he wo Nb3Sn coa ing sys em designed and buil in INFN and UKRI, he
p o ocol adop ed o he i s 1.3 GHz Nb3Sn ca i y coa ed by PVD in Eu ope and inally, he
SRF pe o mances o Nb3Sn coa ings a e epo ed and discussed.
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I.FAST Conso ium, 2025
Fo mo e in o ma ion on IFAST, i s pa ne s and con ibu o s please see h ps://i as -p ojec .eu/
This p ojec has ecei ed unding om he Eu opean Union’s Ho izon 2020 Resea ch and Inno a ion p og amme
unde G an Ag eemen No 101004730. IFAST began in May 2021 and will un o 4 yea s.
Deli e y Slip
Name
Pa ne
Da e
Au ho ed
by
C. Pi a
R.Valizadeh, O.Malyshe
O. Kugele
T. P oslie
INFN
UKRI
HZB
CEA
30/09/2025
Re iewed
by
M. V e ena , L. Celona [on behal o S ee ing
Commi ee]
CERN
31/10/2025
App o ed
by
S ee ing Commi ee
31/10/2025
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TABLE OF CONTENTS
1 In oduc ion ........................................................................................................................... 4
2 Ca i y manu ac u ing ........................................................................................................... 5
2.1 Coppe ca i y manu ac u ing .......................................................................................... 5
2.1.1 1.3 GHz seamless coppe ca i y p oduc ion a Piccoli ........................................... 5
2.1.2 Coppe ca i y polishing a INFN ............................................................................ 6
2.2 Bulk niobium ca i y ........................................................................................................ 7
2.2.1 PIPPS I ca i y ea men s........................................................................................ 7
3 Thin ilm deposi ion acili ies and deposi ion p ocess ....................................................... 8
3.1. Deposi ion acili y a INFN ............................................................................................ 8
2.3 Deposi ion acili y a UKRI/STFC ............................................................................... 10
2.4 Deposi ion p ocess a UKRI/STFC ............................................................................... 11
4 SRF es ing ........................................................................................................................... 16
4.1. Resul s on QPR ............................................................................................................. 16
4.2. Resul s on Ca i y .......................................................................................................... 18
5 Conclusions .......................................................................................................................... 22
6 Re e ences ............................................................................................................................ 23
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Execu i e summa y
This documen epo s on he RF measu emen s and de elopmen s achie ed du ing he ou yea s
o he I.FAST p ojec o he p oduc ion o he i s p o o ype o a 1.3 GHz Nb3Sn ca i y ia PVD
wi h deposi ion pa ame e s compa ible wi h Cu subs a es. D9.2 b ings oge he all he esul s
and op imiza ions o he p oduc ion o SC hin ilms de eloped wi hin he di e en asks o WP9.
Du ing his wo k, hanks o he esul s ob ained in p e ious WP9 delibe a ions, i was possible o
achie e ema kable esul s ha led o ad ances in all s ages o he hin- ilm SRF ca i y p oduc ion
chain. These esul s place he Eu opean labo a o ies o he I.FAST collabo a ion in a leade ship
ole wi hin he hin- ilm SRF communi y o he de elopmen o ca i ies ope a ing a 4 K.
In pa icula : he p oduc ion o seamless ca i ies ia spinning has been au oma ed, a new coppe
polishing echnology has been de eloped and success ully es ed, a p o ocol o he deposi ion o
Nb3Sn coa ings ia PVD has been de eloped and es ed (cu en s a e o he a in he SRF
communi y), wo sys ems o Nb3Sn coa ing in 1.3 GHz ca i ies wi h inno a i e solu ions ha e
been designed and buil , he i s Nb3Sn ca i y has been deposi ed ia PVD.
1 In oduc ion
The objec i e o Deli e able 9.2, and mo e gene ally o WP9, is o p oduce a esonan ca i y
coa ed and es ed wi h an al e na i e ma e ial o Niobium wi h a Q0 > 10E9 a 4.2 K and 1.3 GHz.
A he conclusion o ARIES, Nb₃Sn was iden i ied as he mos p omising supe conduc ing ma e ial
o eplace Nb and o enable ope a ion a 4.2–4.5 K ins ead o 2 K. Consequen ly, Task 9.3 o
I.FAST ocused on de eloping a deposi ion ecipe o Nb3Sn on Cu, s a ing om plana samples
and es ed on QPR. The esul s, p esen ed in Deli e ables 9.3 [1], 9.6 [2] and [9-14], demons a e
ha he ecipes de eloped by INFN and UKRI, measu ed a HZB, exhibi su ace esis ance alues
on he o de o ens o nΩ a 400 MHz, which ep esen s he cu en s a e o he a a 4.5 K.
In Task 9.2, wo lines o de elopmen we e ca ied ou : he i s conce ning he coppe ca i ies
se ing as subs a es, and he second ocusing on he deposi ion se -ups. Fo bo h, al e na i e
solu ions had o be iden i ied compa ed o wha was o iginally o eseen in he p oposal, due bo h
o echnological challenges ha eme ged du ing he R&D phase o ask 9.3 and o he loss o key
pa ne s.
In pa icula , he impossibili y o con inuing he collabo a ion wi h PTI p e en ed access o
elec on-beam welding, which is necessa y o welding he langes o he seamless coppe ca i ies.
The de elopmen s in Task 9.3 subsequen ly highligh ed ha a hick bu e laye o Nb is equi ed
o g ow Nb₃Sn wi h a Tc > 17 K. Task 9.3 also e ealed majo di icul ies in cylind ical Nb₃Sn
a ge s p oduc ion. Howe e , some solu ions we e adop ed o s ill achie e Deli e able 9.2 by he
end o he p ojec .
The i s solu ion adop ed was o use he Piccoli seamless coppe ca i ies wi hou langes o p io
R&D es ing and hen a bulk Nb ca i y as a subs a e o eplace he coppe one o he inal
p o o ype. The second was o de elop al e na i e coa ing con igu a ions o he adi ional
cylind ical con igu a ion, hus allowing he use o comme cially a ailable plana Nb₃Sn a ge s.
Two di e en se -ups we e explo ed a INFN and UKRI.
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2 Ca i y manu ac u ing
In Task 9.2, wo indus ial pa ne s we e o iginally in ol ed in coppe ca i ies p oduc ion: Piccoli
S l (I aly) and PTI (Bela us). Piccoli should be p o iding seamless coppe ca i ies, while PTI was
going o manu ac u ing coppe and niobium ca i ies by hyd o o ming as well as o p o ide an
expe ise in EB welding o bo h he ca i y p oduced by PTI and o he lange welding o ca i ies
p oduced by Piccoli. In 2022 he PTI was excluded om IFAST, and such key expe ise was
missing o he WP9.
The solu ion adop ed was o use he Piccoli seamless coppe ca i ies wi hou langes o p io
R&D es ing and hen a bulk Nb ca i y as a subs a e o eplace he coppe one o he inal
p o o ype.
2.1 COPPER CAVITY MANUFACTURING
INFN, in collabo a ion wi h Piccoli S l, aims o imp o e he quali y o seamless Cu ca i y
p oduc ion, in pa icula he ep oducibili y, by using nume ically con olled machines ins ead o
adi ional semi-au oma ic la hes used up o now. E o s a e also being made o educe su ace
de ec s by s udying he e ec o annealing empe a u e and e alua e new s a egies o educing
cold wo k s ess.
Full de ails on he de ini ion o he p ocess pa ame e s a e epo ed in I.FAST M38 Repo [3].
A o al o 10 op imized Cu seamless ca i ies ha e been p oduced by Piccoli in he en i e p ojec .
5 ca i ies ha e been polished by INFN and used o coa ing es s in ask 9.2 and ask 9.5 [4].
2.1.1 1.3 GHz seamless coppe ca i y p oduc ion a Piccoli
The Cu ca i ies we e p oduced om 3 mm hick OFE Cu shee s. The p ocess consis s o 4 s ages
and he annealing empe a u e o 400 °C was de ined du ing he de elopmen phase desc ibed in
I.FAST M38 Repo [3].
The ca i ies p oduced do no ha e langes o acuum sealing, as hey a e used o coa ing es s.
Howe e , some ca i ies ha e a lip ha can be used wi h an adap e and indium gaske .
A es was also pe o med on he mechanical s eng h o he ca i y a e annealing a empe a u es
be ween 600 and 650 °C, which a e de ined as op imal o he Nb3Sn coa ing p ocess (see I.FAST
D9.3). The es highligh ed he possibili y o ca i y collapse du ing he pumping phase, which can
be a oided wi h app op ia e suppo s, as shown in Figu e 1. This p oblem is no a limi a ion o he
p oduc ion o he i s p o o ypes o demons a e he pe o mance o Nb3Sn coa ings, bu i mus
ce ainly be aken in o accoun in he nex s ages o de elopmen o ensu e he co ec unabili y
o he ca i ies.

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Figu e 1: F om le o igh : ca i y collapsed a e hea ea men a 650°C, ca i y mechanical suppo ed ha
passed he anneling es , ca i y lip.
2.1.2 Coppe ca i y polishing a INFN
PROJECT SUBSTRATES
The coppe ca i ies used in his p ojec we e all polished a LNL using he SUBU chemical
polishing echnique, es ed in ARIES [5].
The p o ocol used is as ollows:
• Deg easing: in NGL 1740 ba h
• Ac i a ion in sul amic acid (H3NO3S, 5 g/l)
• Chemical polishing in "SUBU5" solu ion
• P e- insing wi h acid: samples imme sed in sul amic acid (H3NO3S, 5 g/l)
• Rinsing wi h wa e : samples imme sed in demine alized wa e
• Sp aying wi h alcohol o enhance d ying
• D ying wi h Ni ogen
PLASMA ELECTROLYTIC POLISHING
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Figu e 2: Fi s ca i y polished by PEP. On he 3 pic u es on he le he ca i y du ing he inse ion in he chemical
ba h, he su ace a e he polishing p ocess. The black co e is used o o ce he polishing only in he in e nal
su ace, p e en ing he polishing o he ex e nal su ace. On he igh he emo al a e in unc ion o he ca i y
posi ion.
In pa allel, in syne gy wi h he INFN ESPP p ojec “SRF R&D o FCC-ee,” he applicabili y o
he PEP p ocess o 1.3 GHz coppe ca i ies was s udied. Compa ed o adi ional ea men s, i
o e s emo al speeds ha a e 10 imes as e and has a lowe en i onmen al impac . Fo he i s
ime, a 1.3 GHz ca i y was en i ely polished using PEP echnology wi h a good uni o mi y i we
exclude he ini ial cu -o pa (Figu e 2). The esul s ob ained a e ex emely p omising, and he
s udy will con inue by e alua ing he implemen a ion o his echnique in he FCC-ee ca i y
p oduc ion p o ocol. Mo e in o ma ion in [8].
2.2 BULK NIOBIUM CAVITY
Th ee bulk niobium ca i ies ha e been ecei ed om UKRI, along wi h one pai o langes wi h
moun ed couple and pick-up an ennas. The wo emaining pai s a e expec ed o be shipped be o e
he end o 2025.
The Nb ca i y I has been ea ed wi h HPR + langes moun ing and leak es ing a CEA. Nb ca i y
II and Nb ca i y III will be elec opolished, annealed in high acuum, HPR and leak es ed p io
o sending hem back o UKRI.
2.2.1 PIPPS I ca i y ea men s
The Nb ca i y I has ecei ed he ollowing ea men s in he class 4 clean oom:
- HPR o 1 h s (2 cycles), d ying o e nigh .
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- Leak es ed wi h langes and gaske s p o ided by UKRI: a leak was de ec ed du ing he
es .
- HPR again o 1 h s (2 cycles), d ying o e nigh .
- Leak es ed again wi h langes om UKRI and new gaske s and nu s om CEA: no leak
de ec ed.
- Shipmen back o UKRI wi h ca i y unde acuum.
T ea men o he emaining wo ca i ies is scheduled o No embe 2025.
3 Thin ilm deposi ion acili ies and deposi ion
p ocess
The esul s o D9.3 p o ided he equi emen s o he PVD sys em o be designed and buil o he
deposi ion o Nb3Sn coa ings on Cu.
In pa icula , he sys em mus ope a e in UHV a empe a u es o 700°C. Ano he equi emen
om ask 9.3 is ha i is cu en ly impossible o use cylind ical Nb3Sn a ge s due o di icul ies
encoun e ed in hei de elopmen . The e o e, a sou ce capable o using plana a ge s, which can
be ob ained by sin e ing and a e he e o e a ailable on he ma ke , mus be designed.
Two deposi ion acili ies we e designed, one a INFN and one a UKRI. The wo se ups di e
adically. INFN op ed o a ec angula magne on co e ing he en i e leng h o he ca i y,
designed speci ically o his sys em. The coa ing is made uni o m by o a ing he ca i y. UKRI,
on he o he hand, has c ea ed a con igu a ion wi h wo s anda d ci cula plana magne ons ha
mo e along he axial axis o he ca i y o uni o m he deposi ion hickness.
The INFN con igu a ion has he ad an age o ensu ing, in p inciple, be e con ol o hickness
uni o mi y, bu he ec angula magne on equi ed a long design and es ing ime. The UKRI
con igu a ion, howe e , using s anda d plana magne ons, has he ad an age o being a se -up ha
is mo e e sa ile and quicke o build, ensu ing he i s deposi ion o 1.3 GHz ca i ies wi hin he
p ojec imeline.
3.1. DEPOSITION FACILITY AT INFN
The se up (Figu e 3) consis s o a single e ical chambe , designed such ha bo h he p ocess gas
injec ion and he diagnos ic measu emen s occu a he bo om. The chambe is housed wi hin an
ITEM ack s uc u e. Vacuum is achie ed h ough a combina ion o a p ima y sc oll pump and a
u bomolecula pump. The baking sys em employs DC-powe ed hea ing bands w apped a ound
he chambe . Be o e p ocessing a e he baking phase, he p essu e inside he chambe eaches
alues in he ange o 10E-9 mba . The 1.3 GHz ca i y is moun ed on a dedica ed suppo s uc u e
designed o ensu e mechanical s abili y a he high empe a u es equi ed o Nb3Sn spu e ing. To
ensu e p ope alignmen o he suppo axis—and consequen ly o he ca i y i sel — ou s ainless
s eel ods a e inse ed in o he chambe , se ing as cen e ing guides o he suppo .
The spu e ing sou ce consis s o a ec angula , balanced magne on (Figu e 4) inse ed in o he
ca i y om he bo om o he chambe . This design allows o easy handling, pa icula ly du ing
ins alla ion and eplacemen . The basepla e suppo ing he a ge ea u es an in e nal housing wi h
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a dual unc ion: con inuous wa e low o cooling, and accommoda ion o magne s, which can be
con igu ed in h ee di e en a angemen s wi h di e en magne ic ield in ensi y.
Magne ic con inemen can be adjus ed by physically eplacing he magne s, allowing o lexible
composi ion and ield con ol. The a ge has a o al su ace a ea o 120 cm2 and hickness can be
3 o 5 mm. Two main echnical challenges we e success ully add essed in sys em design. Fi s ,
he magne on mus be inse ed in o he ca i y h ough he cu -o s, equi ing i o i wi hin a
diame e o 76 mm. Second, p ecise alignmen be ween he ca i y’s o a ional axis and he
magne on’s symme y axis is essen ial. This alignmen is ensu ed by a 50 μm e omagne ic UHV
bea ing, which enables ca i y o a ion, and a s anda d DN100CF lange, which secu es he
magne on in a ixed posi ion. Two ma e ials a e unde es ing o he basepla e: coppe and
aluminum o keep he weigh easonably low.
Figu e 3: F om le o igh : scheme o deposi ion sys em, pic u e o he deposi ion sys em a INFN, Al and Cu
Rec angula Magne on moun ed.
The magne on has been es ed and cha ac e ized by I-V cu e wi h he medium magne ic pack
con igu a ion. An image in Figu e 4 is demons a ing he plasma p oduced by he magne on
sou ce in he classical ec angula plana con igu a ion and he I-V expe imen al cu e ha p esen
a quad a ic beha iou as desc ibed by Wes wood [5]. The i s es s on samples in his inno a i e
con igu a ion ha e begun, and he deposi ion o he i s 1.3 GHz ca i y a INFN is expec ed in
he i s hal o 2026.
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langes and illed wi h d y ni ogen o 3 ba . A comple e desc ip ion o he coa ing sys em and
ca i y coa ing p o ocol is a ailable in [15].
One o he wo a ge s used shows a eas o excessi e e osion along he ace- ack a he end o he
p ocess (Figu e 14), which ha e pa ially exposed he coppe basepla e wi h possible
con amina ion o he Nb3Sn coa ing ( o be analyzed).
Figu e 14: Nb3Sn a ge a e he ca i y coa ing. Along he ace- ack, a eas whe e e osion has comple ely
consumed he a ge a e isible.
4 SRF es ing
4.1. RESULTS ON QPR
The ecipes o spu e ing Nb3Sn on o Cu ia PVD de eloped in ask 9.3 by INFN and UKRI we e
es ed on plana quad upoles (QPR) a a equency o 400 MHz be o e being applied o he 1.3
GHz ellip ical ca i ies. The QPR subs a e is Nb, so as o e alua e only he e ec o he Nb3Sn
coa ing, lea ing aside o he momen he con ibu ion o he Cu subs a e. The esul s a e epo ed
in D9.6. Fo con enience, we also epo hem he e in E o ! Re e ence sou ce no ound.. I can
be seen ha bo h samples a ope a ing empe a u es o 4.0 and 4.5 K ha e su ace esis ance (Rs)
alues below 100 nΩ up o ields o 30 mT

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Figu e 15: QPR sample su ace esis ance s peak ield on sample a di e en cooldown eloci ies. Le : INFN
sample. Righ : UKRI sample.
In pa icula , he INFN sample has a su ace esis ance is lowe han ha o he s a e-o - he-a
Vapo Tin Di usion measu ed unde he same condi ions up o 30 mT.
Two new QPRs ha e been deposi ed in INFN: one on a coppe subs a e o es he e ec o he
subs a e on su ace esis ance (awai ing RF es ing a HZB) and one deposi ed on an Nb bulk
subs a e o e alua e he ep oducibili y o he coa ing's pe o mance. The second QPR p esen s
pe o mance e en be e han he p e ious one: Rs<9 nΩ a 20 mT and 4 K. I we con e Rs in o
quali y ac o and magne ic ield in o accele a ing ield (Figu e 16), we can compa e hese esul s
wi h he pe o mance o he Nb on Cu ca i ies o LHC. We can see how he Nb3Sn coa ing allows
Quali y Fac o s a o de o magni ude highe han hose o Nb o be achie ed and pe o mance ha
po en ially o e come he equi emen s o FCC-ee.
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Figu e 16: INFN QPR sample da a con e ed in Q VS Eacc cu e and compa ed wi h LHC ca i ies and FCC-ee 2
cell pe o mance a ge [13].
4.2. RESULTS ON CAVITY
The i s e ical ca i y RF es was pe o med a HZB on a TESLA ype Nb ca i y om CEA
spu e ed wi h Nb3Sn a STFC, as desc ibed in he p e ious chap e . Fo he ini ial cha ac e iza ion
his ca i y had been equipped wi h a ixed an enna aiming a an ex e nal Q alue o 10E10
op imis ically assuming Q alues o mo e han 10E10 which ha e been demons a ed in ca i ies
coa ed by liquid in di usion. The pickup an enna had a one o de o magni ude la ge Q alue.
Upon ecep ion he ca i y was con inuously handled unde clean oom condi ions and pumped and
en ed wi h pa icle- ee pump s ands. Fo ex ended diagnos ics du ing c yogenic es ing, he
ca i y was equipped wi h i e empe a u e senso s a anged along he ca i y axis: wo a he uppe
beam ube, wo a he lowe beam ube and one a he equa o . Two luxga e senso s we e moun ed
nea he ca i y equa o , one poin ing in axial di ec ion (sensi i e o expulsion o he dominan
emnan ield), and one in azimu hal di ec ion (sensi i e o ields gene a ed by he mal cu en s).
The op and bo om lange o he ca i y we e equipped wi h ca idge hea e s in o de o enable
manipula ion o he empe a u e di e ences along he ca i y axis du ing he supe conduc ing
ansi ion, see Figu e 17E o ! Re e ence sou ce no ound..
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Figu e 17: Labelled pho o o he ca i y in he inse be o e moun ing in he c yos a
Du ing cooldown g ea ca e was aken o keep he empe a u e g adien along he ca i y axis small.
This was done by manually adjus ing he al e se ings o he c yos a and was easonably
success ul and no he mocu en s we e eco ded wi h he azimu hally placed senso s, see Figu e
18 and Figu e 19. The ca i y made a i s supe conduc ing ansi ion a 17 K. This could be clea ly
seen as a d op in bandwid h in S21 measu emen s o he an ennae ha we e pe o med pa allel o
he cooling p ocedu e. A he same ime, since no magne ic ield change was obse ed a he
e ical senso a 17 K ei he , i is easonable o assume ha 100% lux pinning o he emnan
ex e nal magne ic ield has occu ed.
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Figu e 18: Tempe a u e p og ession o e ca i y nea Tc
Figu e 19: Magne ic ield moni o ed a he ca i y equa o du ing ini ial cooldown
Once a 1.8K, i was possible o apply a ield inside he ca i y, bu un o una ely, he s o ed ene gy
was no high enough ha a su icien signal- o-noise a io o he ou going powe signal o a
success ul au o much less be a ex ac ion could be ob ained. A ne wo k analyze based be a
measu emen yielded small do s in he pola plo o S11 and S22 measu emen s, con i ming he
assump ion o s ong unde coupling (which canno be quan i ied).
I can be concluded ha he loaded quali y ac o is domina ed by Q0, hence, no Q s E cu e was
ob ained. Figu e 20 shows esul s om moni o ing he S21 o he ca i y du ing wa mup. F om
hese measu emen s he p og ession o esonan equency and he bandwid h (3dB poin ) o e
ime (whe e he passed ime co esponds o he empe a u e inc ease) a e ex ac ed. While he Tc
o he ilm was unusually high a 18.1 K his did no help wi h he RF su ace esis ance since he
supe conduc ing bandwid h is only wo o de s o magni ude highe han he no mal conduc ing
one. The eason o his poo pe o mance despi e he high Tc could be coppe con amina ion o
he ilm du ing he inal p epa a ion s ep. To e i y his, i is in ended o epea he measu emen
a e a cleaning s ep wi h a mix u e o ni ic acid and phospho ic acid which has been success ully
used o b onze ou e samples. In pa allel, we will pe o m an HPR on he ca i y and equip i wi h
an adjus able inpu couple allowing o smalle Q alues.
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Figu e 20: Le plo : P og ession o equency and ca i y empe a u e o e ime du ing inal wa mup. F equency
alues we e ob ained om a S21 measu emen aken wi h a ne wo k analyse .
Righ plo : F equency and loaded quali y ac o s empe a u e. QL was ex ac ed using a Lo en zian i .

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5 Conclusions
The wo k ca ied ou o achie e deli e able 9.2 has esul ed in six ema kable ou comes:
1. Piccoli S l, in collabo a ion wi h INFN, has de eloped a new semi-au oma ed p o ocol o
he manu ac u e o seamless Cu ca i ies ia CNC.
2. A new su ace ea men based on Plasma Elec oly ic Polishing has been de eloped.
Compa ed o adi ional ea men s, i o e s emo al speeds ha a e 10 imes as e and
has a lowe en i onmen al impac .
3. Two new acili ies op imized o Nb3Sn coa ing ia PVD ha e been designed and buil a
INFN and UKRI.
4. Inno a i e magne on sou ce is unde es ing a INFN.
5. UKRI de ine a deposi ion p o ocol o 1.3 GHz ca i y and coa success ully he i s ca i y
wi h Nb3Sn. The measu ed alue o Tc ~18 K is an index o he op imal composi ion and
phase o he Nb3Sn coa ing. The cause o unexpec edly low Q is unde u he in es iga ion
beyond IFAST p ojec .
6. The esul s ob ained om QPR RF es a 400 MHz a e cu en ly s a e-o - he-a o Nb3Sn
ilms p oduced ia PVD.
These esul s posi ion he I.FAST collabo a ion as an in e na ional e e ence o he de elopmen
o Nb3Sn ilms on Cu and, mo e gene ally, o he de elopmen o accele a o ca i ies ope a ing
a 4 K.
RF TEST ON COATED RESONANT CAVITY
Deli e able: D9.2
Da e: 31/10/2025
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6 Re e ences
[1] I.FAST WP9 membe s. (2025). Fi s 6 GHz ca i y coa ed and cha ac e ised. I.FAST D9.3
Deli e able Repo . Zenodo. h ps://doi.o g/10.5281/zenodo.16677760
[2] I.FAST WP9 membe s. (2025). Tes o hin- ilm samples. I.FAST D9.6 Deli e able Repo .
Zenodo. h ps://doi.o g/10.5281/zenodo.14905673
[3] I.FAST WP9.2 membe s. (2022). Fi s seamless coppe 1.3GHz ca i y p oduced as subs a e
o he coa ing o he SC ilm. I.FAST MS38 Miles one Repo .
Zenodo. h ps://doi.o g/10.5281/zenodo.6979934
[4] I.FAST WP9 membe s. (2025). 1.3 GHz Nb-coa ed ca i y i adia ed by lase in a gon
a mosphe e and RF es ed. I.FAST D9.5 Deli e able Repo .
Zenodo. h ps://doi.o g/10.5281/zenodo.16419102
[5] ARIES WP15 membe s. (2018). E alua ion o cleaning p ocess . ARIES D15.1 Deli e able
Repo . h ps://edms.ce n.ch/documen /1820617/1.0
[6] W. D. Wes wood, e al.; The cu en ‐ ol age cha ac e is ic o magne on spu e ing sys ems.
J. Appl. Phys. 1 Decembe 1983; 54 (12): 6841-6846. h ps://doi.o g/10.1063/1.332006
Lis o Task 9.2 publica ions
[7] D. Do o hea e al., “Recipe Op imiza ion and SRF Tes o Cu-compa ible Nb3Sn Films by DC
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ca i ies”, in P oc. 22 h In . Con . RF Supe cond. (SRF'25), Tokyo, Japan, 2025.
[13] D. Fonnesu e al., “De elopmen o Nb3Sn coa ings on coppe a INFN-LNL”, in P oc. 22 h
In . Con . RF Supe cond. (SRF'25), Tokyo, Japan, 2025.
[14] C. Benjamin e al., “Op imisa ion o Nb3Sn Thin Films o SRF Applica ions a Da esbu y
Labo a o y”, in P oc. 22 h In . Con . RF Supe cond. (SRF'25), Tokyo, Japan, 2025.
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PVD magne on spu e ing, in P oc. 22 h In . Con . RF Supe cond. (SRF'25), Tokyo, Japan, 2025.
[16] O.Malyshe , C. An oine, e al., Thin-Film SRF Roadmap Repo , in P oc. 22 h In . Con . RF
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