1. 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 1 1

2. Atomki, Debrecen, Hungary

3. Looking for mountains…

4. Before accelerator: deccelerator
27Al(α,n)30P
First nuclear reaction in Debrecen
CO2 pressure → α-energy

5. Before accelerator: deccelerator
excitation function determined
with activation method

6. LUNA history: overground contribution
Same experimental approach at higher energies
Different experimental approach at higher energies
Feasibility studies (target properties)
Auxiliary experiments (half-lives, stopping power)

7. Strategic Research Infrastructures
Atomki: 7% of Hungary’s RI % 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

8. New Tandetron Laboratory

9. 17O(p,)18F Advanced hydrogen burning key reaction
Preliminary results: poster prize at EuNPC, 2015

10. Target preparation and analysis
evaporation, Atomic Layer Deposition
in situ SNMS-XPS-SPM + µIBA 1 1

11. Low energy 3He(α,γ)7Be activation
Activation vs. in beam approach:
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 !!! 1 1

12. 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:  = EDH2+=233 keV
6Li(d,n)7Be:  = EDH2+=233 keV
10B(p,)7Be:  = EDH2+=233 keV
 beam and beam stop purity is crucial

13. 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

14. 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

15. Production of 7Be at Atomki via the 7Li(p,n)7Be nuclear reaction
He-gas in
Water in
He-gas out
Water out
Copper backing
Li-target
Thickness: d = 2.5 mm
Vacuum window foil
21 µm DURATHERM
Proton beam
Ep = 10.5 MeV; Ip = 18 A
magnetically deflected and rotated
Irradiation time: tirr = 105 h
Produced activity: A = 7x109 Bq
Target cooling:
Bombarded surface: He-gas jet (pHe=1.6 bar; T  300 K)
Back side of the Cu backing: Water stream

16. Recent upgrades at the vertical isotope production beam line
New control software
New target
cooling systems
and pneumatics
New electronics for beam rotating
New target unit for 7Be production
New hardware for the control and for the vacuum systems

18. LUNA members from Atomki
Z. Elekes
Zs. Fülöp
Gy. Gyürky
E. Somorjai (prof. emeritus)
T. Szücs