Károly Tőkési Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI)
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Transcript of Károly Tőkési Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI)
Károly Tőkési
Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI)
H--4001 Debrecen, P.O.Box 51, Hungary
Atomic collisions using slow antiprotons in ASACUSA at CERN
+
v
Theory
J. WangDepartment of Physics, University of Massachusetts Dartmouth, North Dartm outh, MA 02747, USA L. GulyásInstitute of Nuclear Research of the Hungarian Academy of Science (ATOMKI), Debrecen, HungaryS. BorbélyFaculty of Physics, Babes-Bolyai University,str. Kogalniceanu nr. 1, 400084 Cluj-Napoca, RomaniaS. Nagele, J. Feist, J. S. Nagele, J. Feist, Burgdörfer
Institute for Theoretical Physics, Vienna University of Technology, A1040 Vienna Austria, EU
Co-workersExperiment
H. Knudsena, H.-P.E. Kristiansena, H.D. Thomsena, U.I. Uggerhřja, T. Ichiokaa,1, S.P. Mřllerb, C.A. Hunnifordc, R.W. McCulloughc, M. Charltond, N. Kurodae, Y. Nagatae, H.A. Toriie, Y. Yamazakie,f, H. Imaof, H.H. Anderseng
a Department of Physics and Astronomy, University of Aarhus, Ny Munkegade Building 1520, 8000 Aarhus C, Denmarkb Institute for Storage Ring Facilities, University of Aarhus, Denmarkc Department of Physics and Astronomy, Queens University, Belfast, UKd Department of Physics, University of Swansea, UKe Institute of Physics, Komaba, University of Tokyo, Japanf Atomic Physics Laboratory, RIKEN, Saitama, Japang Niels Bohr Institute, University of Copenhagen, Denmark
Outlook• Why? – antimatter factory-> new energy source – test of various theories
Experiment – Theorytime-of-flight CC, CDW, CTMC
• Past Single ionization of He Single and double ionization of Ar
• Present Ionization of H and H2
• Future Differential cross sections – anti-cusp
Summary, Conclusions
Dynamic systems with more than one electron
Antiprotons do not capture electrons (one center problem, essentially)Antiprotons follow a classical path (classical orbital approximation)Very slow antiprotons can still ionize ( ”adiabatic” collisions can be investigated)
Advantages with antiprotons:
- Antiprotons can give benchmark data
Antiproton Radiotherapy – application of antiprotons??
V
p Target
Reaction Channels
0
0.2
0.4
0.6
0.8
1 10 100 1000 10000
CERN (90)MEAOCC-2 Igarashi et al (04)IPM-BGM-RESP-2: Keim et al (03)
Energy [keV]
Cro
ss s
ect
ion
[10
-16 c
m2]
Low en
ergy
antip
roto
n dat
a nee
ded
Single ionization of helium by antiproton impact
Ionization of noble gas atoms in slow antiproton collisions
Differential cross sections
Past
“Ionization of Helium and Argon by Very Slow Antiproton Impact”Knudsen et al Phys. Rev. Letters 101 (2008)
“On the double ionization of helium by very slow antiproton impact”Knudsen et al NIMB 267 244 (2009)
Experimental setup
RFQD
武蔵
AIA
extraction line
AIA
TOF SPECTRA
Ionization of helium atoms in slow antiproton collisions
Single Ionization of helium atoms in slow antiproton collisions
THEORY in the year 2009
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CERN (08) this workCERN (94) [2]CERN (90) [1]CP frozen core McGowern et al (09)TDCC Foster et al (08) AOCC: Sahoo et al (05) MEAOCC-2 Igarashi et al (04) IPM-BGM-RESP-2: Keim et al (03) LTDSE: Schultz and Krstic (03) TDDFT/OEP-SIC: Tong et al (02) IPM-BGM-RESP-1: Kirchner et al (02) MEAOCC-1: Lee et al (00) MEHC: Bent et al (98) MFIM, 7 cuts: Reading et al (97) IEV: Wehrman et al (96) IPM: wehrman et al (96)
Energy [keV]
Cro
ss s
ectio
n [1
0-16 c
m2 ]
Single ionization of Helium by antiproton impact
Double Ionization of helium atoms in slow antiproton collisions
Double Ionization of helium atoms in slow antiproton collisions
0
0.015
0.030
0.045
1 10 100 1000
CERN (08)TDCC Foster et al (08)BGM-RESP-2: Keim et al (03)BGM-RESP-1: Kirchner et al (01)MEHC : Bent, Krstic and Schultz (98)MFIM no cut: Reading et al (97)MFIM 15 cut: Reading et al (97)CERN (08) upper limit 2CERN (94) two datapoints left outCERN (90)
Energy [keV]
Cro
ss S
ectio
n [A
2 ]
Double Ionization of He by Antiproton Impact
Double Ionization of helium atoms in slow antiproton collisions
1
10
100
1 10 100 1000 10000
CERN (08) this workCERN (08) this work upper limit 2CERN (94) the two datapointsCERN (94) two datapoints left outCERN (89)Puckett and Martin (70) incl captureShah et al (89) incl captureShah et al (89) excl captureShah and Gilbody (85) incl captureShah and Gilbody (85) excl captureKnudsen et al (84)Andersen et al (87)
E [keV]
R =
+
+/
+ [1
0-3]
Helium target
Single ionization of argon atoms in slow antiproton collisions
Double ionization of argon atoms in slow antiproton collisions
Ionization of argon atoms in slow antiproton collisions
Theory:IPM-BGM-RESP
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0.2
0.5
1
2
5
1 10 100 1000
CERN (08)CERN (97)Kirchner et al (02)
Ar++
Ar+
E [keV]
Cro
ss s
ectio
n [1
0-16 c
m2 ]
Ionization of argon atoms in slow antiproton collisions
Theory:IPM-BGM-RESP
10
100
1000
1 10 100 1000 10000
Kirchner et al (02)CERN (08)CERN (97)CERN (89)CERN (87)
Energy [keV]
R =
+
+/
+ [1
0-3]
Argon target
Present
Ionization of H and H2
H+ PRL 74 (1995) 4627
pbar
σH2=2σH?
Future/Theory
Energia (eV)5 10 15 20 25
DD
CS
(cm
2 /sr/
eV)
0
1
2
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4
5
6X10-17
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vThe special case of target ionization
25 keV H+ + H(1s)
Total cross sections
Energy (keV)
0 25 50 75 100 125 150
(c
m2 )
2e-17
4e-17
6e-17
8e-17
CTMC
CDW-EIS
Experiment [Hvelplund et al, JPB, 27 (1994) 925.]CDW-EIS [Fainstein et al, PRA 36 (1987) 3639]FIM [Reading et al, 30 (1997) L189]CC [Lee et al, PRA 61 (2000) 062713]TDDFT [Tong et al, PRA 66 (2002) 032709]
Angular differential electron emission cross sections
Ejection Angle (deg.)
0 20 40 60 80 100 120 140 160 180
d/d
(
cm2 /s
r)
1e-19
1e-18
1e-17
1e-16
Ejection angle (deg.)
0 20 40 60 80 100 120 140 160 180d
/d
(cm
2 /sr)
1e-19
1e-18
1e-17
1e-16
50 keV pbar + He 100 keV pbar + HeFirst Born
CDW-EIS- pbar
CTMC- pbar
CDW-EIS- proton
CTMC- proton
Eje
ctio
n A
ngl
e (d
eg.)
20
40
60
80
100
120
140
160
Electron Energy (eV)
20 40 60 80 100 120
Eje
ctio
n A
ngl
e (d
eg.)
20
40
60
80
100
120
140
160
1e-23 1e-22 1e-21 1e-20 1e-19 1e-18 1e-17
20 40 60 80 100 120
(a)
(c)
(b)
(d)
Double differential electron emission cross sectionsE=50 keV
CDW-EIS CTMC
Antiproton
proton
Eje
ctio
n A
ngl
e (d
eg.)
20
40
60
80
100
120
140
160
Electron Energy (eV)
20 40 60 80 100 120 140 160 180 200
Eje
ctio
n A
ngl
e (d
eg.)
20
40
60
80
100
120
140
160
1e-24 1e-23 1e-22 1e-21 1e-20 1e-19 1e-18 1e-17
20 40 60 80 100 120 140 160 180 200
(a)
(c)
(b)
(d)
Double differential electron emission cross sections100 keV
CDW-EIS CTMC
Antiproton
proton
Energy (eV)
0 50 100 150 200
DD
CS
(cm
2 /sr/
eV)
1e-20
1e-19
1e-18
1e-17
1e-16
CDW antiprotonCTMC antiprotonCDW protonCTMC proton
Energy (eV)
0 50 100 150 200
DD
CS
(cm
2 /sr/
eV)
1e-21
1e-20
1e-19
1e-18
1e-17 CDW antiprotonCTMC antiprotonCDW protonCTMC proton
Energy distributions at 0 degree
50 keV pbar + He 100 keV pbar + He
Future/Experiment
PBAR RECYCLER
PBAR COLLIMATION
ELISA
Electrostatic storage ringAarhus University
From protons to biomolecules
Highest storage energy 22 keVAverage pressure <10-11 mBar Circumference 7.6 m Storage time tens of s up to minutes
Is it necessary to detect the antiprotons?
It should be possible to get some information about thetriple differential cross section by detecting the emitted electronand the emitted ion.
Also, remember that the pbar, deflected after ionization can bedetected by their emitted pions
recoil ion
electron
Pbar beam focusing
Capillary with conical shape
• we have obtained experimental benchmark data for the development of advanced models and calculations of atomic collisions in general and for ionization
• we found upper limits to the low energy double ionization cross section and to the ratio between double and single ionization cross sections.
TO BE CONTINUED ……..
Conclusions
Thank you!