1. Antimatter (e+, Ps, H-bar) physics Laboratory
Lea Di Noto
Department of Physics –University of Trento
INFN

2. Research group e+ - Ps detectors laser Roberto S. Brusa
S. Mariazzi ( assegnista cof. INFN)
L. Di Noto (PhD)
L. Penasa (tecnico l)
M. Bettonte (tecnico nl)
e Ps
Giancarlo Nebbia (INFN)
detectors
laser
G. Ferrari (CNR)

3. (antimatter experiment :gravity interferometry spectroscopy)
AEgIS
(antimatter experiment :gravity interferometry spectroscopy)
Goals:
Measurement of g on anti-hydrogen
Anti-hydrogen spectroscopy
Methods:
Produce an Hbar beam
Moirè deflectometer
Motivations:
verify the Weak equivalence principle (WEP)
Verify the CPT
antimatter disappearance

4. activities of Trento group
e+ beam
Ps spectroscopy
Ps cooling & converter 2 1 3 p
5 T - 4K
trap
Moirè
Deflectometer
Positron source
Positron accumulator
Transfer line
1 T mK
Anti-hydrogen production
AD SIDE
/31

5. AEgIS experiment in short
Positron-cooled positronium converter
2 ns bunch 108 positronis (1 mm in diameter)
Lasers for Ps excitation in Rydberg states
Antiprotons 100 mK
Anti hydrogen beam
Stark acceleration
Moirè
deflectometer

6. 1. Pulsed positron beam

7. 2. Positronium cooling & converterPs
Positronium converter
Positron beam
Vacuum
Mariazzi S, Salemi A and Brusa R S 2008 Phys. Rev. B

8. Trento TOF Apparatus BEAM Prompt peak 16 ns 2 channeltrons
target position
5 NaI scintillators zo

9. Ps cooling – first result of Ps cooling
Mariazzi S, Salemi A and Brusa R S
2008 Phys. Rev. B
Mariazzi , Bettotti, Brusa,
2010 Phys. Rev. Lett

10. Permanence time of Ps in nano-channels before escaping into vacuum
Ps energy spectra z0 tf tp
<tm> = <tp> + <tf>
tp = 18 ns

11. at the intense positron source NEPOMUC at the FRMII reactor
with the TOF apparatus
at the intense positron source NEPOMUC at the FRMII reactor
Tunable nanochannels will allow to study:
Cooling and thermalization at temperature < 150 K
Cooling and thermalization in presence of decorated surfaces
Relations between diffusion and tortuosity
It is important to note that the rectangular extension of the Tao-Eldrup model (RTE), considering Ps in equilibrium at the sample temperature of 300 K, would give a lifetime of ns for Ps annihilating in channels with 5-8 nm size. The measured mean Ps annihilation lifetime value seems to point out that a large fraction of Ps annihilate hot also in the closed channels. In this case a different Ps temperature from the thermal should be used in the RTE model. If we use as a first approximation the T= 1100±300 K (average temperature of the found thermal and cooled distributions), the RTE gives a reduced lifetime of 51±8 ns in fairly agreement with the measured one.

12. Anti-hydrogen production
3. Ps spectroscopy 3
Ps spectroscopy p
5 T - 4K
trap
Moirè
Deflectometer
Positron source
Positron accumulator
Transfer line
1 T mK
Anti-hydrogen production
AD SIDE
/31

13. sample
Detector ports
Magnetic field terminator
Buncher
Valve
Our simulation to transport positron bunch from accumulator to the target with duration of 5 ns and a spot of 3 mm diameter !

14. 3 Tilted
CF16 Flange
45°
Three tilted flange

15. Planned experiments with Ps chamber
FIRST GOAL:
Study of production efficiency of Ps in Rydberg state
OTHER GOAL:
Rydberg state in presence of magnetic field
Motional stark effect
Ps laser cooling
Jump between different levels (microwave)
METHOD:
Ps production and detection by PbF2 scintillator
Excitation up to n=3
Excitation from n=3 to n>15
n=3
continuum
n=1
6.05 eV
205 nm
high n
~0.75 eV
~1650 nm

16. Summary Our work is about: Running AEgIS positron bunched beam
Ps production in AEgIS
Foundamental studies on Ps cooling
(TOF at FRMII-Munich)
Development of a new apparatus for Ps spectroscopy measurements

17. Preventivo 2013 Missioni estere  22 k€ + 8 k€ (sub iudice)
Missioni interne  3 k€
Missioni estere  22 k€ + 8 k€ (sub iudice)
Materiale di consumo  4 k€ per materiale da vuoto
Impianti attrezzature  0
Altre immobilizzazioni  22 k€
-8 k€ per 5 switch
-12 k€ per gruppo pompaggio (Turbo, scroll, ionica)
-2 k€ per valvola