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Transcript of Portuguese groups at ISOLDE - CERN Ulrich Wahl Instituto Tecnológico e Nuclear (ITN) Sacavém...
Portuguese groups at ISOLDE - CERNPortuguese groups at ISOLDE - CERN
Ulrich WahlUlrich Wahl
Instituto Tecnológico e Nuclear (ITN) SacavémInstituto Tecnológico e Nuclear (ITN) Sacavém
Centro de Física Nuclear da Universidade de Lisboa (CFNUL)Centro de Física Nuclear da Universidade de Lisboa (CFNUL)
ISOLDE and Nuclear Solid State PhysicsISOLDE and Nuclear Solid State Physics
Portuguese experiments at ISOLDE: Portuguese experiments at ISOLDE: history, people, collaborationshistory, people, collaborations
Examples:Examples:- position-sensitive electron detector development - position-sensitive electron detector development - emission channeling lattice location of Fe in Si- emission channeling lattice location of Fe in Si- PAC investigation of O and F in High-Tc Hg-1201- PAC investigation of O and F in High-Tc Hg-1201
Conclusions amd outlookConclusions amd outlook
The ISOLDE on-line isotope separatorThe ISOLDE on-line isotope separator
Ge
Sn
Pb
Pm Ho
Cu As
Sb
Bi
Sm Er
Zn Se
Te
Po
Eu Tm
Ga Br
I
At
Gd Yb
Kr
Xe
Rn
Tb Lu
Al
C N O F
Cl
Ne
Ar
He
Sc MnTi V
B
Si P S
FeCr Co Ni
Zr Nb RuMo RhTc
Ta
Th Pa U Np PuAmCmBk Cf Es FmMdNo Lr
OsW Ir PtRe
Pd Cd In
Au
Ce
Hg
Pr
Tl
Nd Dy
Y
La Hf
Ac
Ag
Li Be
MgNa
K Ca
Rb Sr
Cs Ba
Fr Ra
surfaceionization-
+plasmadischarge
Hot
Coldlaser
selectiveionization
Available beams:Available beams:~ 600 isotopes of~ 600 isotopes of
~ 70 elements~ 70 elements
1 GeV1 GeVprotonsprotons
radioactive ion beamsradioactive ion beams
massmassseparationseparation
60 keV60 keVaccelerationacceleration
target andtarget andion sourceion source
Weak Interaction andNuclear Physics
46%
Solid State Physics22%
Particle and Astro-Physics
13%
Biology/Medicine5%
Atomic Physics15%
ISOLDE ISOLDE ExperimentsExperiments
20032003
37 Experiments
300 Users96 Institutes22 Countries375 8h-shifts of radioactive
beams
Experiments involving Portuguese groups:Experiments involving Portuguese groups:typically around 10-12 shifts per yeartypically around 10-12 shifts per year i.e. ~3% of ISOLDE availability i.e. ~3% of ISOLDE availability
Semiconductor Spectroscopysensitive to chemical nature or electronic properties
(some require radioactive istopes )
106
108
1010
1012
1014
1016
1018
1020
106
108
1010
1012
1014
1016
1018
1020
defe
ct c
once
ntra
tion
(cm
)-3
NMR
EC
Channel.
Hall
DLTS PL
ENDOR
EPR
-NMR
NMR-ON
PAC,ME
EXAFS
Experimental techniques used with radioactive isotopes at ISOLDEExperimental techniques used with radioactive isotopes at ISOLDE
Portuguese groups:Portuguese groups:emission channeling (EC)emission channeling (EC)perturbed angular correlation (PAC)perturbed angular correlation (PAC)
2000 IS390 Studies of colossal magnetoresistive oxides with radioactive isotopes ~2005 spokesperson V. Amaral (U Aveiro)
1998 IS368 Lattice location of transition metals and rare earths in semiconductors
~2006 spokesperson U. Wahl (ITN & CFNUL, then IKS Leuven)
1997 IS360 Studies of high-Tc superconductors with radioactive isotopes
~2006 spokesperson J.G. Correia (ITN & CFNUL)
1986 e- PAC at ISOLDE IS01/13 spokesperson J.C.Soares
1994 Test of new PAC probes IS-P66 spokesperson J.G. Correia
e- PAC
197mHg, 73Ge, 127Cs, 80Br
2001 New improved electron emission channeling pad detectors and
development of self-triggering front-end electronics
Cooperation agreement between ITN, CFNUL and CERN EP-ATT Group (now: PH-TA1)
History of e- PAC and EC at ISOLDE-CERN
Network of groups involvedNetwork of groups involved
CFNUL LisbonCFNUL Lisbon
Prof. José C. SoaresProf. Manuel. R. Silva
2 PhD students:Elisabete Rita
Ana C. Marques1 Diploma student:
Sonia Dias
Dr. J. Guilherme CorreiaDr. Ulrich Wahl
Dr. Heinz Haas (retired)
ITN SacavémITN Sacavém
University of AveiroUniversity of Aveiro
Prof. Vitor AmaralDr. Mario S. Reis1 PhD student:
Armandina Lopes1 Diploma student:
João C. Amaral
University of PortoUniversity of Porto
Prof. J. Pedro Araújo1 Masters student:Tania Mendonça
KU LeuvenKU Leuven(Belgium)(Belgium)
Prof. André Vantomme2 PhD students:
Bart De VriesStefan Decoster
LEUVEN
Univ. ofUniv. of Kwazulu Natal Kwazulu Natal(South Africa)(South Africa)
Prof. Krish Bharuth-Ram
University of GöttingenUniversity of Göttingen(Germany)(Germany)
Prof. Hans Hofsäss(future collaboration)
CERNCERN
Dr. Peter Weilhammer(detector development)
Funding: mainly from national sourcesFunding: mainly from national sources
CFNUL LisbonCFNUL Lisbon
Portuguese Foundation for Science & Technology(dedicated CERN project on PAC & emission channeling)
ITN SacavémITN Sacavém
University of AveiroUniversity of Aveiro
University of PortoUniversity of Porto
KU LeuvenKU Leuven(Belgium)(Belgium)
Fund for Scientific Research - Flanders(dedicated project
on emission channeling)
Univ. ofUniv. of Kwazulu Natal Kwazulu Natal(South Africa)(South Africa)
University of GöttingenUniversity of Göttingen(Germany)(Germany)
Federal Ministry of Education and Research
(dedicated project on emission channeling)
CERNCERNPortuguese Foundation
for Science & Technology(dedicated CERN project on
magnetic oxides)
2 1 0 -1 -2
10
5
0
-5
-10
2 1 0 -1 -2
10
5
0
-5
-10
+ M2:- M2 :
cn te rclwclo ckw
3.85E 3 -- 4E3
3.7E 3 -- 3.85E3
3.55E 3 -- 3.7E3
3.4E 3 -- 3.55E3
3.25E 3 -- 3.4E3
3.1E 3 -- 3.25E3
2.95E 3 -- 3.1E3
2.8E 3 -- 2.95E3
the plo t sh ows th e crystal a s
it is viewn fro m the detecto r
+ z:
- z:
+ M 1:
"on-line" display: template C:\ORIGIN\PADSPEC4.OTP read with script file C:\ORIGIN\CHANRED4.SCR
Co nve rsion elect ron emissio n ch an ne lin g with 30 mm x 30 mm Si p ad 4 d ete cto r:
- M 1:
rel.
Z-c
oor
din
ate
[m
m]
rel. M 1-angle [deg]
counts raw data
0 10 20 30 40 50 60 70 800
100
200
300
nois
e
52 keV
42 keV
12 keV
coun
ts
energy [keV]
ROI
0 10 20 30 40 50 60 70 800
100
200
300
nois
e
52 keV
42 keV
12 keV
coun
ts
energy [keV]
ROI
2 1 0 -1 -2
10
5
0
-5
-10
2 1 0 -1 -2
10
5
0
-5
-10
+ M2:- M2 :
cn te rclwclo ckw
3.37E 3 -- 3.45E3
3.29E 3 -- 3.37E3
3.21E 3 -- 3.29E3
3.12E 3 -- 3.21E3
3.04E 3 -- 3.12E3
2.96E 3 -- 3.04E3
2.88E 3 -- 2.96E3
2.8E 3 -- 2.88E3
the plo t sh ows th e crystal a s
it is viewn fro m the detecto r
+ z:
- z:
+ M 1:
"on-line" display: template C:\ORIGIN\PADSPEC4.OTP read with script file C:\ORIGIN\CHANRED4.SCR
Co nve rsion elect ron emissio n ch an ne lin g with 30 mm x 30 mm Si p ad 4 d ete cto r:
- M 1:
rel.
Z-c
oor
din
ate
[m
m]
rel. M 1-angle [deg]
counts raw data
[-1102][0001]
Arsenicoccupiesmultiple
sites in ZnO
Collaboration:ITN, CFNUL
& CERN PH-TA1 group
Future detectors:pads self-triggering
5 keV trigger 10 kHz readout
Cooled 2oC
Position-sensitive Si pad detectors for Emission Position-sensitive Si pad detectors for Emission ChannelingChanneling
7373As in ZnO low electron energy As in ZnO low electron energy
Lattice site changes of implanted Lattice site changes of implanted 5959Fe in SiFe in Si
U. Wahl U. Wahl et al.et al., accepted by Phys. Rev. B, accepted by Phys. Rev. B
Fe is gettered by at least two types of vacancy-like defectsFe is gettered by at least two types of vacancy-like defects
Following release to interstitial state re-gettering occurs at a different Following release to interstitial state re-gettering occurs at a different gettering center on ideal substitutional sitesgettering center on ideal substitutional sites
as-implanted:as-implanted:
mainly displaced mainly displaced substitutional Fesubstitutional Fe
-2
-1
0
1
2-2 -1 0 1 2
experiment-2 -1 0 1 2
1.23 - 1.27 1.19 - 1.23 1.15 - 1.19 1.11 - 1.15 1.07 - 1.11 1.03 - 1.07 0.99 - 1.03 0.95 - 0.99
simulation best fit
<111>
-2
-1
0
1
2 1.18 - 1.21 1.15 - 1.18 1.12 - 1.15 1.09 - 1.12 1.05 - 1.09 1.02 - 1.05 0.99 - 1.02 0.96 - 0.99
<100>
-2
-1
0
1
2 1.10 - 1.12 1.08 - 1.10 1.06 - 1.08 1.05 - 1.06 1.03 - 1.05 1.01 - 1.03 0.99 - 1.01 0.97 - 0.99
<110>
[deg]-2 -1 0 1 2
-2
-1
0
1
2
-2 -1 0 1 2
<211> 1.15 - 1.18 1.12 - 1.15 1.10 - 1.12 1.07 - 1.10 1.04 - 1.07 1.01 - 1.04 0.99 - 1.01 0.96 - 0.99
annealedannealed at T=300°C:at T=300°C:
mainly tetrahedral mainly tetrahedral interstitial Feinterstitial Fe
-2
-1
0
1
-2 -1 0 1 2experiment
-2 -1 0 1 2
1.56 - 1.66 1.46 - 1.56 1.37 - 1.46 1.27 - 1.37 1.17 - 1.27 1.08 - 1.17 0.98 - 1.08 0.88 - 0.98
simulation best fit
<111>
-2
-1
0
1
2 1.41 - 1.48 1.34 - 1.41 1.27 - 1.34 1.21 - 1.27 1.14 - 1.21 1.07 - 1.14 1.00 - 1.07 0.93 - 1.00
<100>
-2
-1
0
1
2 1.10 - 1.13 1.08 - 1.10 1.05 - 1.08 1.02 - 1.05 0.99 - 1.02 0.97 - 0.99 0.94 - 0.97 0.91 - 0.94
<110>
[deg]-2 -1 0 1 2
-2
-1
0
1
2
-2 -1 0 1 2
<211> 1.14 - 1.18 1.11 - 1.14 1.07 - 1.11 1.04 - 1.07 1.00 - 1.04 0.97 - 1.00 0.94 - 0.97 0.90 - 0.94
-2
-1
0
1
2
-2 -1 0 1 2experiment
-2 -1 0 1 2
1.84 - 1.97 1.71 - 1.84 1.57 - 1.71 1.44 - 1.57 1.31 - 1.44 1.18 - 1.31 1.04 - 1.18 0.91 - 1.04
simulation best fit
<111>
-2
-1
0
1
2 1.53 - 1.62 1.45 - 1.53 1.36 - 1.45 1.27 - 1.36 1.18 - 1.27 1.10 - 1.18 1.01 - 1.10 0.92 - 1.01
<100>
-2
-1
0
1
2
1.47 - 1.55 1.40 - 1.47 1.32 - 1.40 1.25 - 1.32 1.17 - 1.25 1.10 - 1.17 1.02 - 1.10 0.95 - 1.02
<110>
[deg]-2 -1 0 1 2
-2
-1
0
1
2
-2 -1 0 1 2
<211> 1.35 - 1.41 1.29 - 1.35 1.24 - 1.29 1.18 - 1.24 1.12 - 1.18 1.06 - 1.12 1.01 - 1.06 0.95 - 1.01
annealed at T=800°C:annealed at T=800°C:
mainly ideal mainly ideal substitutional Fesubstitutional Fe
Oxygen & Fluorine Configurations in Hg1201 Oxygen & Fluorine Configurations in Hg1201
(High-Tc)(High-Tc)
HgBa2CuO
4+
Tc > 92K
frequency
start stop
I Q
I
Ii
Q
1
IfIf
Q.Vzz
clock
time
Radioactive
ions
O(2)
Cu O(1)
Ba
Hg
PAC
PAC
PACExperiment
Electric Field Gradient
dopant configuration fingerprint
~ 0.20
0 2500 5000 (Mrad/s)
0
50
100
~ 0.0
0
50
100
000 2500 5000
(Mrad/s)
0.34 (a)
EFG Simulations
J.G. Correia J.G. Correia et al.et al., submited to Phys. Rev. B, submited to Phys. Rev. B
Currently and near future (till ~2006):Currently and near future (till ~2006):
IS368: Lattice location in semiconductors, e.g.IS368: Lattice location in semiconductors, e.g.
Si, Ge, SiGe, diamond, Si, Ge, SiGe, diamond, III-V, nitrides, II-VI, ZnO…III-V, nitrides, II-VI, ZnO…electrical doping, transition metals,electrical doping, transition metals,rare earths,rare earths,diluted magnetic semiconductorsdiluted magnetic semiconductors
IS360: PAC in High-Tc superconductorsIS360: PAC in High-Tc superconductors
IS390: Magnetism in manganites (CMR)IS390: Magnetism in manganites (CMR)
Conclusions and outlook:Conclusions and outlook:
After 2006: New emission channeling proposal(s) applying…After 2006: New emission channeling proposal(s) applying…
new position-sensitive detectors (self-triggering pad, CCD)new position-sensitive detectors (self-triggering pad, CCD)
- on-line experiments with short-lived isotopes- on-line experiments with short-lived isotopes- low energy electron emitters (Auger electrons?)- low energy electron emitters (Auger electrons?)
a new variety of elements (e.g. Mg, Co, Ni, Zn, Ge)a new variety of elements (e.g. Mg, Co, Ni, Zn, Ge) will be available for emission channeling will be available for emission channeling