March 3, 2009 Применение MRS APD’s в прототипе FARICH- детектора для идентификации

1. Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICE А.И.Берлев, Т.Л.Каравичева, Е.В.Карпечев,Ю.В.Купчинский, А.Б.Курепин, А.Н.Курепин, А.И.Маевская, Ю.В.Мусиенко, В.И.Разин, А.И.Решетин, Д.А.Финогеев Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia А.Ф.Данилюк, В.Л.Кириллов Boreskov Institute of Catalysis С.А.Кононов, Е.А.Кравченко, А.П.Онучин Budker Institute of Nuclear Physics, Novosibirsk, Russia March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 1)

2. Outline ☻ ALICE HMPID-system upgrade ☻ FARICH (Focusing Aerogel RICH) conception ☻ Simulation of a multi-layer aerogel radiator for FARICH-detector ☻ Design project of FARICH-detector with MRS APDs ☻ MRS APD properties (CPTA, Moscow) ☻ Winston-cone holes for light-collection ☻ Cooling system for MRS APD ☻ Schedule for the FARICH beam test at CERN March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 2) July 1, 2008 Development of FARICH-detector for the ALICE VHMPID-system at CERN Andrey Reshetin VHMPID Meeting, CERN (slide 1) Institute for Nuclear Research, Moscow July 1, 2008 Development of FARICH-detector for the ALICE VHMPID-system at CERN Andrey Reshetin VHMPID Meeting, CERN (slide 2) Institute for Nuclear Research, Moscow July 1, 2008 Development of FARICH-detector for the ALICE VHMPID-system at CERN Andrey Reshetin VHMPID Meeting, CERN (slide 1) Institute for Nuclear Research, Moscow Slide 2 July 1, 2008 Development of FARICH-detector for the ALICE VHMPID-system at CERN Andrey Reshetin VHMPID Meeting, CERN (slide 1) Institute for Nuclear Research, Moscow July 1, 2008 Development of FARICH-detector for the ALICE VHMPID-system at CERN Andrey Reshetin VHMPID Meeting, CERN

3. ALICE HMPID-system upgrade Free modules (windows) for VHMPID upgrade Each of 7 HMPID modules (42 windows): - has sizes of about 1.5 x 1.0 m - covered azimuth angle Δθ ≈ 18 degrees Each HMPID window coversΔθ ≈ 6 degrees (solid angle ΔΩ ≈ 10 msr) There are free modules (windows) for upgrade with Very High Momentum PID-system ALICE HMPID-system performances (Results of HMPID beam test runs at CERN): π/K separation: in the momentum rangefrom 1 to 3 GeV/c K/p separation: in the momentum range from1.5 to 5 GeV/c March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 3)

4. ALICE HMPID-system upgrade • An important experimental direction of the study in physics of heavy ion collisions is the measurement of the yield of high-Pt particles. The main problem is • to study the dominant mechanism of parton energy loss in compressed nuclear matter. • Data by RHIC STAR and PHENIX Collaboration • show the effect of supression of high-Pt hadrons up to a momentum • ≥ 10 GeV/c (!) Physical requirements to characteristics of the ALICE VeryHMPID system π/K separationin the momentum rangefrom 3 to 10 GeV/c K/p separationin the momentum rangefrom 5 to 14 GeV/c March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 4)

5. Photon detector n1 n2 Charged particle Aerogel FARICH conception The main goal of the FARICH concept is - to increase the number of photons by using thicker radiator; - to focus Cherenkov cones on the detector sensitive plane without degrading the angle resolution. The FARICH proximity focusing type geometry was proposed. - the use of several layers of aerogel with gradually increasing refractive indices, n3 > n2 > n1 allows to focus Cherenkov cones of the same radius; - refractive indices are determined by different proximity gaps. March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 5)

6. where: r is the average radius of the Cherenkov ring; σr, 1 pe is the mean deviation of the Cherenkov radius (for single photon). S is the ring area; Npe is the number of detected photoelectrons; σӨ is Cherenkov angle resolution in mrad; π/K sep is the pion/kaon separation power in number of standard deviations for momentum 10 GeV/c. Simulation of a multi-layer aerogel radiator for FARICH-detector Results of the simulation for momentum 10 GeV/c March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 6)

7. Design project of FARICH- Prototype with MRS APDs CONSTRUCTIONAL and FUNCTIONAL PARTS of the FARICH PROTOTYPE The FARICH Prototype consists of 1. Light-isolating box 2. Thin carbon entrance window for the beam 3. Radiator of Cherenkov photons (3-layer silica aerogel) on the support frame 4. Light-collecting plane with the matrix of Winston-cone holes 5. Photosensitive coordinate matrix with MRS APDs 6. Plate with LV-supply dividers and front-end electronics March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 7)

8. Design project of FARICH-prototype with MRS APDs MRS APD produced by CPTA , Moscow Light-collecting Cell (Winston-cone hole) Sensitive area: ≈ 1 mm2 600 pixels Diam. 3 mm ↓ Diam. 1.1 mm March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 8)

9. Design project of FARICH-prototype with MRS APDs Prototype Photosensitive Matrix R(min) = 133 mm w R(max) = 165 mm Taking into account simulation results the design Geometry for the Prototype Photosensitive Matrix has been chosen: Photosensitive ring is divided by 4 sectors:R(min)=133 mm, R(max)=165 mm, S=120 cm2 Total amount of MRS APDs:900 - on the Ring, 25 – in centre Geometrical efficiency:about 50% (APD cell sizes) and about 47% (ring sector sizes) We will have the total amount of photoelectrons: <8-9> pe / ring per event track for Prototype Matrixand <16-18> pe / ring for full scale Matrix March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 9)

10. MRS APD performances (CPTA, Moscow) Measurements of MRS APD performances were carried out by Yu.Musienkoon test benches at CERN APD Lab and D.Finogeev and Yu.Kupchinskiy at INR, Moscow As example the dependence of the photon detection efficiency PDE on a light wavelength for MRS APDs of different types is shown. We plan to use “50V-APD” for our FARICH Prototype March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 10)

11. MRS APD performances(CPTA, Moscow) For tests, the entrance windows of a few APDs was covered by a special wave length shifter film (paint) developed by Photonique SA (Geneva). Dependences of the PDE on a light wavelength for MRS “50V-APDs” and the “50V-APDs” + WLS-paint are shown. As result the WLS-film increases the PDE of about two times at 450 nm and about ten times in the range 300-400 nm. March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 11)

12. MRS APD performances (CPTA, Moscow) Dark current [mkA] APD Gain (x10^6) PDE (410 nm) [%] Dependences of the Dark current, Gain and PDE (410 nm) on Bias [V] for “50V - MRS APD” with WLS-paint produced by CPTA (Moscow). For the set of 925 MRS APD we use optimal Bias in a range of about 50-51 V 47 48 49 50 51 52 47 48 49 50 51 52 47 48 49 50 51 52 March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 12)

13. Winston-cone holes for light-collection • For APD without Winston- • cone light collection (open • version) the mean value of • amplitude spectrum is • in 230 ch. • <N> = 869 ch – for stainless • steel Winston-cone holes • Pedestal: <N(ped)> = 24 ch. • Theoretical geometrical factor: • ≈ 7.0 +/-_ 0.36 • Measured geometrical factor: • ≈ 4.1 +/- 0.62 • Estimation of light collection • efficiency: ≈ 58.6 +/- 12 % Channel H March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 13)

14. Cooling system: heat exchanger and cooler T ºC Dark noise [MHz] room +22 3.0 air option +8 0.7 water option -17 0.1 Cooling system for MRS APD • 1. Heat Exchanger: Peltier Module “Drift 1.05” 2. Cooler a) air cooler b) water cooler Work performances: Power = 131.0 W Sizes: 40×40×3.5 mm Voltage = 24.6 V Current = 8.6 A ∆T = 70 ºC Results of CPTA APD cooling (APD coupled with copper plate ∆h = 1 mm) At -17 C Dark noise can be decreased in about 20-30 times (until 0.1 MHz) (!) March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 14)

15. Schedule for the FARICH beam test at CERN Beam channel – ALICE test beam channel T10 Beam particles – negative pions (electrons) Momentum range - 2 ÷ 10 GeV/c Beam intensity - 200-500 particles/spill Beam time – October-November, 2009 14 shifts March 3, 2009 Применение MRS APD’s в прототипе FARICH-детектора для идентификации релятивистских частиц в эксперименте ALICEYuri Kupchinskiy Совещание по применению лавинных диодов, ИЯИ РАН, Москва, Питомник (slide 15)