Athena module construction
Download
1 / 26

ATHENA - Module Construction - PowerPoint PPT Presentation


  • 123 Views
  • Uploaded on

ATHENA - Module Construction. P. Riedler, J. Rochet. 1. ATHENA. ATHENA is an experiment at the CERN antiproton decelerator (AD). The first run took place in August 2000. Goals:. Antihydrogen production. Unambiguous detection. Study of recombination. Longterm goal (2-3 years):

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' ATHENA - Module Construction' - lonato


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Athena module construction

ATHENA - Module Construction

P. Riedler, J. Rochet


1. ATHENA

  • ATHENA is an experiment at the CERN antiproton decelerator (AD).

  • The first run took place in August 2000.

Goals:

  • Antihydrogen production

  • Unambiguous detection

  • Study of recombination

Longterm goal (2-3 years):

CPT-test with a

precision of 10-12-10-15

(spectroscopy of 1S-2S)


2. ATHENA Vertex Detector

A detector system surrounds the recombination zone to detect H via its annihilation signals:

2 x 511 keV g

“back-to-back”

Charged pions

Silicon strip detectors

CsI crystals + photodiodes

Determine the charged vertex and check the collinearity of the 2 g within a time-window (~1µs).


Petra’s activities (Nov. 1998-March 2001) in ATHENA:

Silicon Vertex Detector:

Strip detector design and design checks for 77K

Tendering and industry contact for production of silicon detectors

Testing and QA

Development of module design for 77K environment

Construction of all ATHENA silicon strip modules

Beamcounter:

Development of ultra-thin silicon beamcounter (6-67µm) for 5.3MeV antiprotons at 10K (5x107 mips per µm)


Schematic cross-section of the ATHENA vertex Detector

  • Cylindrical symmetry

  • Outer diameter: 139.7 mm

  • Inner diameter: 75 mm

  • Length: 241.1 mm

  • Temperature: 77K

  • Vacuum: 10-7 mbar

  • 16-fold symmetry

  • 2 layers Si strip-detectors

  • 192 CsI crystals with Si

  • photodiodes

  • 8960 read-out channels





4. Constraints

  • Double sided strip detectors

    • handling

    • connections on both sides required

  • Temperature range: 77 K-300 K

    • mechanical stability (different TEC) - BUS!

    • glue

  • Two layers of double sided detectors within 37.5mm radius

    • bonds

    • mounting


5. Gluing and matching of the module components

Glue: araldite W106 low temperature mixture (50:50)

(Advice from the group of M. Hominal at CERN)

Temperature cycling (300K-77K-300K)


5.1 Glue Deposit:

  • Reliable

  • Regular

  • Repeatable

Commercial glue dispenser

+

Alignment setup with microscope


Alignment hole on the jig for

needle

Final setting glue drop for 18s every 10.6mm, 3bar N2


Silicon

Glas

Always weigh the two components of the glue!


5.2 Material matching

Production of prototypes:

Prototype 0: 160 mm Si + PCB hybrid + capton (V0)

Prototype 1: 162 mm Si + alumine hybrid + alumine bus (V1)

Prototype 2: 162 mm Si + alumine hybrid + glass (D263) bus (V1)

Prototype 3: 162 mm Si + alumine hybrid + alumine bus (V1)

Prototype 4: 162 mm Si + alumine hybrid + glass (AF45) bus (V1)

Prototype 5: 162 mm Si + alumine hybrid + carbon bus (V1)

Prototype 6: 162 mm Si + alumine hybrid + silicon bus (V1)


Tests with lN2

Alumine bus - prototype module seen from the side at lN2 temperature

The silicon detectors did not break!!!

Glass bus - prototype module seen from the side at lN2 temperature


Thermal expansion coefficients:

Capton ~30 ppm/K

Alumine 6.5-6.7 ppm/K

Glass D263 7.2 ppm/K

Glass AF 45 4.5 ppm/K

Carbon 2.1 ppm/K

Silicon 2.6-4.2 ppm/K

(~40µ deviation)

Bus:

Produced on 200mm Si wafer (400µ)

Chr-Al-Ti-Ni-Au on 10µ polyimide

(bonding tests!)

Laser-cutting

NEW!


6. Module Construction

Precision:

<100µm over the full detector length required (164 mm)

Align the detectors to one reference line on one jig

no alignment in z required!

Microscope reference: n+ implantation edge



2. Align second detector to referene line

measure deviation over full length

Distance piece for bus

Reference line


3. Apply glue

Weigh the two components (Mettler-Toledo)


4. Bus mounted

control if pads on detector and bus are well alined

mount fixation (recheck alignment)

Remove chuck from alignment station (store 24 hours)





(0/0)

n+ implant edge


ad