?????????? MRS APD

1

• ?????????? MRS APDs ? ????????? FARICH-?????????
  ??? ????????????? ?????????????? ?????? ?
  ???????????? ALICE
• ?.?.??????, ?.?.??????????, ?.?.????????,
  ?.?.??????????, ?.?.???????, ?.?.???????,
  ?.?.????????, ?.?.????????, ?.?.?????,
  ?.?.???????, ?.?.????????
• Institute for Nuclear Research of the Russian
  Academy of Sciences, Moscow, Russia
• ?.?.???????, ?.?.????????
• Boreskov Institute of Catalysis
• ?.?.???????, ?.?.?????????, ?.?.??????
• Budker Institute of Nuclear Physics,
• Novosibirsk, Russia

March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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 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

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 ?? 18 degrees Each HMPID window covers
?? 6 degrees (solid angle ?O 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)
p/K separation in the
momentum range from 1 to 3 GeV/c
K/p separation in the momentum
range from 1.5 to 5 GeV/c
March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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 p/K separation in
the momentum range from 3 to 10 GeV/c K/p
separation in the momentum range from 5 to 14
GeV/c
March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 4)
5
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 gt n2 gt n1
allows to focus Cherenkov cones of the same
radius - refractive indices are determined by
different proximity gaps.
March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 5)
6
Simulation of a multi-layer aerogel radiator for
FARICH-detector
Results of the simulation for momentum 10 GeV/c

• where
• r is the average radius of the Cherenkov ring
• sr, 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
• s? is Cherenkov angle resolution in mrad
• p/K sep is the pion/kaon separation power in
  number of standard deviations for momentum 10
  GeV/c.

March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 7)
8
Design project of FARICH-prototype with MRS APDs
MRS APD produced by CPTA , Moscow
Light-collecting Cell (Winston-cone hole)
Diam. 3 mm ? Diam. 1.1 mm
Sensitive area 1 mm2 600 pixels
March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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, S120 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 lt8-9gt pe / ring per
event track for Prototype Matrix and lt16-18gt pe
/ ring for full scale Matrix
March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 9)
10
MRS APD performances (CPTA, Moscow)

• Measurements of
• MRS APD performances were carried out
• by
• Yu.Musienko on 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 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 11)
12
MRS APD performances (CPTA, Moscow)
Dark current mkA
APD Gain (x106)
PDE (410 nm)
47
48
49
50
51
52
47
48
49
50
51
52
47
48
49
50
51
52

• 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

March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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.
• ltNgt 869 ch for stainless
• steel Winston-cone holes
• Pedestal ltN(ped)gt 24 ch.
• Theoretical geometrical factor
• 7.0 /-_ 0.36
• Measured geometrical factor
• 4.1 /- 0.62
• Estimation of light collection
• efficiency 58.6 /- 12

H
Channel
March 3, 2009 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 13)
14
Cooling system heat exchanger and cooler
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
40403.5 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 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(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 ?????????? MRS APDs ?
????????? FARICH-????????? ??? ?????????????

?????????????? ?????? ? ???????????? ALICE


Yuri Kupchinskiy ????????? ?? ??????????
???????? ??????, ??? ???, ??????, ????????
(slide 15)