1Antimatter (e+, Ps, H-bar) physics Laboratory Lea Di NotoDepartment of Physics –University of TrentoINFN
2Research 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 PsGiancarlo Nebbia (INFN)detectorslaserG. Ferrari (CNR)
3(antimatter experiment :gravity interferometry spectroscopy) AEgIS(antimatter experiment :gravity interferometry spectroscopy)Goals:Measurement of g on anti-hydrogenAnti-hydrogen spectroscopyMethods:Produce an Hbar beamMoirè deflectometerMotivations:verify the Weak equivalence principle (WEP)Verify the CPTantimatter disappearance
4activities of Trento group e+ beamPs spectroscopyPs cooling & converter213p5 T - 4KtrapMoirèDeflectometerPositron sourcePositron accumulatorTransfer line1 T mKAnti-hydrogen productionAD SIDE/31
5AEgIS experiment in short Positron-cooled positronium converter2 ns bunch 108 positronis (1 mm in diameter)Lasers for Ps excitation in Rydberg statesAntiprotons 100 mKAnti hydrogen beamStark accelerationMoirèdeflectometer
9Ps cooling – first result of Ps cooling Mariazzi S, Salemi A and Brusa R S2008 Phys. Rev. BMariazzi , Bettotti, Brusa,2010 Phys. Rev. Lett
10Permanence time of Ps in nano-channels before escaping into vacuum Ps energy spectraz0tftp<tm> = <tp> + <tf>tp = 18 ns
11at the intense positron source NEPOMUC at the FRMII reactor with the TOF apparatusat the intense positron source NEPOMUC at the FRMII reactorTunable nanochannels will allow to study:Cooling and thermalization at temperature < 150 KCooling and thermalization in presence of decorated surfacesRelations between diffusion and tortuosityIt 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.
12Anti-hydrogen production 3. Ps spectroscopy3Ps spectroscopyp5 T - 4KtrapMoirèDeflectometerPositron sourcePositron accumulatorTransfer line1 T mKAnti-hydrogen productionAD SIDE/31
13sampleDetector portsMagnetic field terminatorBuncherValveOur simulation to transport positron bunch from accumulator to the target with duration of 5 ns and a spot of 3 mm diameter !
15Planned experiments with Ps chamber FIRST GOAL:Study of production efficiency of Ps in Rydberg stateOTHER GOAL:Rydberg state in presence of magnetic fieldMotional stark effectPs laser coolingJump between different levels (microwave)METHOD:Ps production and detection by PbF2 scintillatorExcitation up to n=3Excitation from n=3 to n>15n=3continuumn=16.05 eV205 nmhigh n~0.75 eV~1650 nm
16Summary Our work is about: Running AEgIS positron bunched beam Ps production in AEgISFoundamental studies on Ps cooling(TOF at FRMII-Munich)Development of a new apparatus for Ps spectroscopy measurements
17Preventivo 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 vuotoImpianti attrezzature 0Altre immobilizzazioni 22 k€-8 k€ per 5 switch-12 k€ per gruppo pompaggio (Turbo, scroll, ionica)-2 k€ per valvola