A short introduction into the physics at the Antiproton Decelerator at CERN Michael Doser March 10, 2015 11:23 World Scientific Review Volume - 9.75in x 6.5in Schopper˙v3 page 11 11 cooling and storing a minute number of antiprotons in ICE, a 9 order of magnitude improved lower limit on the lifetime of antiprotons could be obtained [58]. This fundamental advance allowed CERN’s antiproton complex (figs. 4 and 5) consisting of the antiproton production target, the Antiproton Accumulator (AA) and the Antiproton Collector (AC) and the low energy antiproton ring (LEAR) - THE ANTIPROTON ACCUMULATOR,COLLECTOR AND DECELERATOR RINGS and relying on the Proton Synchrotron which produces 26 GeV/c protons, to be proposed [59] and rapidly built (AA start-up in 1980, LEAR began operation in 1982, AC from 1987 onwards). !"#$%"&$'(#'%)$'*+%The development",-(%(+'./01'%)$'#"-2%',*-%"3!$',)42"32'$5,$-"&$+%',$-#(-&$6'7"%)'%)$'*"6'(#'2%(3)*2%"3' of antiproton trapping and electron cooling techniques by 3((!"+89'Gabrielse:;<' 2%",=!*%$2' et al. "6$+%"3*!' [60] in 1986 6$3*4 at' !"#$%"&$2' CERN’s #(-' dedicated *+%",-(%(+2' antiproton *+6' ,-(%(+21' experimental ,-*3%"3*!!4' facil- "+#"+"%$' 3(&,*-$6'7"%)'%)$'-$>="-$6'6*42'(#'*33=&=!*%"(+'%"&$?';-"(-'%('@:A1'%)$'$5,$-"&$+%*!!4'!(7$-'!"&"%' ity LEAR finally allowed carrying out precision experiments on trapped and cooled #(-'*+%",-(%(+2'7*2'(+!4'BCD'E2'F6$-"G$6'#-(&'H=HH!$'3)*&H$-'%-*3I2J?'K$2,"%$'#*"%)'"+'%)$(-41'"%'7*2'*' +"8)%&*-$'antiprotons %(' !*=+3)' and *' &=!%"&"!!"(+ working towardsL6(!!*-' ,-(M$3%' the study "+' 2=3)' of antihydrogen *' 2"%=*%"(+?' <(' atoms -$&(G$' first 6(=H%21' at LEAR *' 3-=6$' *+%",-(%(+',-from(6=3%"(+'%*-8$%'7*2'"+2$-%$6'"+%('%)$'%-*+2#$-'!"+$'H$%7$$+';N'*+6'@:A1'7)"3)'3(+G$-%$6' 1986 to 1996, and - since 2000 - at the unique Antiproton Decelerator (AD) BD'O$PQfacility!' ,-(%(+2' (transformed F%)$' &*5"&=&' from &(&$+%=&' the AC), %-*+2#$-*H!$' which hosts "+' all %)$' existing !"+$J' %(' C experiments'O$PQ!' *+%",-(%(+2' requir- F%)$' &*5"&=&'ing 2%(-*H!$' trapped "+' antiprotons. @:AJ?' @+' %)"2' Confinement 7*4' *' H$*&' of (#' antiprotons CRD' *+%",-(%(+2' in ion 3(=!6' traps for H$' 2%seconds(-$6' *+6' (or 7*2' 2%(3)*2%"3*!!4'3((!$6'"+'@:A?'S(=-'6*42'!*%$-1'TD'7$-$'2%"!!'3"-3=!*%"+8?'<)"2'$2%*H!"2)$6'*'+$7'!(7$-'days) opened up major improvements in the determination of the antiproton’s mass, !"&"%'#(-'%)$'6$3*4charge, but'!"#$%"&$'(#'UC')'*%'-$2%1'*+'"&,-(G$&$+%'H4'/'(-6$-2'(#'&*8+"%=6$'*+6'*'-$!"$#'#(-' also of its magnetic moment (although it took until 2012 to surpass the %)(2$'7)('+$$6$6'&(-$'%)*+'M=2%'#*"%)precision achievable in antiprotonic'"+':;<?' helium transitions). Furthermore, the forma- <)$'-$2=!%2'#-(&'@:A'!$6'%('*'-*,"6'6$3"2"(+'%('8('*)$*6'7"%)'%)$'3(+2%-=3%"(+'(#'%)$'V+%",-(%(+'tion and trapping of antihydrogen atoms, precision spectroscopy of antihydrogen, or V33=&=!*%(-'FVVJ'H*2$6'(+'2%(3)*2%"3'3((!"+8?'<)$'*+%",-(%(+2'7$-$'3((!$6'*+6'*33=&=!*%$6'6"-$3%!4'precise measurementsAntiprotons of the protonium energy at levelsCERN: without a collisional short broadening pre-history *%' U?W'O$PQcould!' .BD1' also BB01' be envisaged, 7)$-$' %)$' 4"$!6' prepared #-(&' and CX'O$P - byQ! 2014'F;NJ' - ,-(%(+2' partly achieved. "2' )"8)$2%?' <)$' (G$-*!!' 23)$&$' FS"8?'CJ'*!2('"+G(!G$6'&*M(-'&(6"#"3*%"(+2'%('%)$';N?' The first facility capable of producing antiprotons at CERN was the Proton Synchrotron; completed in 1959; meson spectroscopy with antiprotons (from 1965) and exotic atoms incorporating them stochastic cooling (proposed in 1968 by S. van der Meer, published in 1972); successfully tested in the Initial Cooling Experiment (ICE) in 1978 ' !"#$%&''Y*4(=%'(#'Fig. 4.%)$' Layout:AZ['*33$!$-*%(-2'"+'B/TB?'YAVZ1'2%"!!'=+6$-'3(+2 of the CERN accelerators in 1981. LEAR, still%-=3%"(+'"+'B/TB1'"2'*!2('2)(7+ under construction in 1981, is' also :(+2%-=3%"(+'shownAntiproton [58]. From (#' %)$'Accumulator 2000 VV' onwards,H$8*+' "+' the(AA), B/\/?' AA Antiproton was @+' V,-"!'transformed B/TB1' Collector into %)$' the #"-2%' Antiproton(AC) ,-(%(+ and]*+%",-(%(+' Decelerator, low energy 3(!!"2"(+2' and antiproton ring (LEAR): now houses at CERN all experiments worldwide relying on low energy antiprotons. (33=--$6'"+'%)$'@NZ1'*%'CAA start-up 'in^' C1980W'O$P?'<)$'N;N'#(!!(7$6'(+'%)$')$$!21'7"%)'3(!!"2"(+2'*%'C, LEAR began operation in 1982, AC from 1987'^ 'C\Uonwards'O$P'(+' BD'_=!4'B/TB?'<)$'#"-2%'`'6*%*'7$-$'%*I$+'"+'B/TC'*+6'%)$'6"23(G$-4'(#'%)$'`'*+6'a'7*2'*++(=+3$6'"+' B/TU?' @+' (-6$-'AD start %(' 2*%"2#4' in 2000 %)$', $G$-ELENAL"+3-$*2"+8' commissioning *,,$%"%$' (#' in *+%",-(%(+' 2018: looking =2$-21' %)$'at another V+%",-(%(+' very :(!!$3%(-' active decade with antiprotons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b$P'Y"+*31'%)$'TDD'b$P'c((2%$-'*+6'%)$'CW'O$P';N'FS"8?'CJ'7$-$',=2)$6')*-6'%('6$!"G$-'*+' "+%$+2$',-(%(+' H$*&' (+' %)$' ,-(6=3%"(+'%*-8$%?'<)$' H=-2%' (#'*+%",-(%(+2' $&$-8"+8' *-(=+6' U?W'O$PQ!' 22 space for future overview of AD facility (anti)atomic physics experiments ELENA: extraction ALPHA-g ASACUSA of antiprotons at PUMA? 100 keV; ALPHA GBAR trapping efficiency ATRAP BASE goes from ~1% at I & II AD to O(100%); _ AEgIS 107 p /100s physics at the AD _ _ H / pHe _ Gravity w/ H Spectroscopy ALPHA ALPHA-g GBAR ASACUSA AEgIS ATRAP ACE BASE PUMA Nuclear Matter-Antimatter physics interactions Symmetries_ ( p / p ) antihydrogen _ H spectroscopy (1s-2s, GS HFS, others?) _ ALPHA: continuous formation and trapping of H _ ASACUSA: continuous formation and beam of H* _ H for WEP tests _ _ AEgIS: pulsed formation and beam of H* (H) _ ALPHA-g: release of trapped H _ GBAR: formation, trapping and cooling of H+ Schematic overview: AEgIS (Antimatter Experiment: gravity, Interferometry, Spectroscopy) Physics goals: measurement of the gravitational interaction between _ _ _ matter and antimatter, H spectroscopy, antiprotonic atoms (pp, pCs), Ps, ... ¡ Anti-hydrogen formation via Charge exchange process with Ps* _ • o-Ps produced in SiO target close to p; laser-excited to Ps* _ 2 _ • H temperature defined by p temperature → Schematic¡ Advantages: overview_ ¡ Pulsed H production (time_ of flight – Stark acceleration) ¡ Narrow and well-defined H n-state distribution ¡ Colder production than via standard process possible positronium 4 _ converter ¡ Rydberg Ps & σ ≈ � 0 � → H position-sensitiformationve enhanced e+ detector Ps Ps grating 1 grating 2 laser excitation Ps* Ps* H* H* H beam antiproton accelerating trap electric field H* atomic L L beam pulsed production_ beam gratings produce periodic pattern on detector; of H* formation measure gravity-induced vertical shift of fringes Physics goals: measurement_ of the gravitational interaction between matter and antimatter, H spectroscopy, ... _ AEgIS experiment Development of nuclear emulsions with 1 mm spatial SETUP resolution for the AEgIS experiment M. Kimura on behalf of the AEgIS collaboration. Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern Contact e-mail: [email protected] Chamber for Ps Chamber for Ps experiments experiments The AEgIS experiment Emulsion in high vacuum Positron accumulator The goal of the AEgIS experiment (CERN AD6) is to test the Weak Experiments with emulsions under 1T trap Equivalence Principle (WEP) using antihydrogen . The gravitational sag high vacuum have not been of a beam will be measured with a precision of 1% on Dg/g by means of performed so far. We therefore tested Positron trap a moiré deflectometer and a position sensitive annihilation detector. The their behavior in respect to such required position resolution should be a few mm to achieve the 1% goal. conditions. Water loss in the gelatine can produce cracks in the emulsion 5T trap OVC Thin metal window UHV layer compromising the mechanical stability (mm level needed). Therefore TOF Target for Ps we developed glycerine treatment to Moiré deflectometer avoid this effect. Glycerine can Fig. 3. Emulsion films after 3.5 days in the production and vacuum chamber without glycerine Position detector _ efficiently prevent the elasticity loss treatment (A) and with treatment (B). Fig.1 Left: Schematic view of the AEgH formationIS detectors. Right: Dg/g vs. number of in the emulsion (see fig. 3). particles for a position sensitive detector resolution of 1 mm (red) and 10 mm (blue). Nuclear emulsions Emulsion properties after glycerine treatment Positron PositronPositron transfer line Nuclear emulsions are photographic film with extremely high spatial Since the glycerine treatment changed the composition of the emulsion accumulator resolution, better than 1 mm. In recent experiments such as OPERA, large layer, we investigated : source area nuclear emulsions were used thanks to the impressive developments • The detection efficiency per AgBr crystal with 6 GeV/c pions in automated scanning systems. For AEgIS, we developed nuclear • The background in terms of the fog density Antiproton line -5~ -7 Positron Antiproton line emulsions which can be used in ordinary vacuum (OVC, 10 mbar). (the number of noise grains per 103 mm3) trap This opens new applications in antimatter physics research. Fig. 4. Left: Crystal sensitivity vs. glycerine concentration. Fig. 2. Left: AgBr crystals in emulsion Right: Fog density vs. glycerine layers observed by SEM. content for films kept in vacuum : A minimum ionizing track (MIP) of Right for 3.5 days (square), compared a 10 GeV/c pion. 1 mm to atmospheric pressure(dots). Exposure13 of nuclear emulsions to stopping antiprotons Proof of principle using a miniature moiré deflectometer We performed exposures with stopping antiprotons in June and December, We irradiated emulsion films with antiprotons passing through a small E.#Widmann 2012.