Download Atomki - Agenda INFN

Underground Astrophysics at Surface Facilities:
the Atomki case
Zs. Fülöp
ATOMKI, Debrecen, Hungary
LUNA Collaboration
Germany, Hungary, Italy, UK
When time, money, manpower matter:
A network of satellite overground labs is needed
Atomki, Debrecen, Hungary
Looking for mountains…
Before accelerator: deccelerator
• 27Al(α,n)30P
• First nuclear reaction in Debrecen
• CO2 pressure → α-energy
Before accelerator: deccelerator
excitation function determined
with activation method
LUNA history: overground contribution
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Same experimental approach at higher energies
Different experimental approach at higher energies
Feasibility studies (target properties)
Auxiliary experiments (half-lives, stopping power)
Atomki: 7% of Hungary’s RI --- 20% of physics RI
Strategic Research Infrastructures
All validated by the NEKIFUT (Hungarian ESFRI) committee
Atomki facilities:
• Atomki Accelerator Centre
• Atomki Environmental Laboratory
• Atomki Nuclear and Astrophysics Laboratory
New Tandetron Laboratory
17O(p,)18F
• Advanced hydrogen
burning key reaction
• Preliminary results: poster
prize at EuNPC, 2015
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Target preparation and analysis
• evaporation, Atomic Layer Deposition
• in situ SNMS-XPS-SPM + µIBA
Low energy 3He(α,γ)7Be activation
Activation vs. in beam approach:
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Partly independent (irradiation + off-line γ)
Inherent 4π cross section (no angular effects)
Off-line part can be repeated (long half-life)
Well-known background (no beam induced bg)
No summing problems
– Cannot reach “low” energy
A good tool to investigate systematic errors !!!
Complementary Measurements at
ATOMKI
Catcher purity investigation overground:
possible DH2+ or DD+ parasitic beam along with 6Li or
10B impurity in beam stop:
•6Li(p,)7Be:  = 7.7nb @ EDH2+=233 keV
•6Li(d,n)7Be:  = 1.08mb @ EDH2+=233 keV
•10B(p,)7Be:  = 5.75b @ EDH2+=233 keV
 beam and beam stop purity is crucial
OFHC catcher purity
• Irradiations by 700 keV p and d at ATOMKI
• Analysis of residual activity
• 6Li(d,n)7Be cross section → subPPM 6Li concentration
7Be
custom reference source production
• Irradiation of LiF targets at ATOMKI
• 7Li(p,n)7Be, Ep=2.5 MeV
• Thin backings
• Protective layer
• 50 cps gamma
Reference activity:
• ISO 9001 ATOMKI
• LNGS
Production of 7Be at Atomki
via the 7Li(p,n)7Be nuclear reaction
Proton beam
Ep = 10.5 MeV; Ip = 18 A
magnetically deflected and rotated
Irradiation time: tirr = 105 h
Li-target
Produced activity: A = 7x109 Bq
Thickness: d = 2.5 mm
Vacuum window foil
21 µm DURATHERM
Copper backing
He-gas in
He-gas out
Water in
Water out
Target cooling:
Bombarded surface: He-gas jet (pHe=1.6 bar; T  300 K)
Back side of the Cu backing: Water stream
Recent upgrades at the vertical isotope
production beam line
New hardware for the
control and for the vacuum
systems
New control software
New target
cooling systems
and pneumatics
New target unit for
7Be production
New electronics
for beam rotating
LUNA members from Atomki
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Z. Elekes
Zs. Fülöp
Gy. Gyürky
E. Somorjai (prof. emeritus)
T. Szücs