Edda Gschwendtner1

Status of the TPG

B. Bene, A. Blondel, E. Gschwendtner, J.-P. Richeux, R. Sandstrom, O. Voloshyn Universite de Geneve

S. Giani, J.-C. Legrand, R. de Oliveira, L. Ropelewski, F. Sauli, M. Van StenisCERN, Geneva

M.G. Catanesi, E. RadicioniINFN, sezioni di Bari

V. Ableev, U. Gastaldi, M. Lollo, M. Rigato, P. TemnikovINFN-LNL, Legnaro

F. Abrosino, G. Chiefari, M. Napolitano, V. Palladino, L. Roscilli, G. SaracinoUniversita e sezioni INFN, Napoli

M. Apollonio, P. Chimenti, G. GianniniUniversita e sezione INFN, Trieste

Edda Gschwendtner2

TPG project

TPC

GEM

hexaboardelectronics

mechanics

Newly fabricated GEMs Hexaboard Mechanics

Modifications Electronics

Preamps FADCs

HARP TPC Software

Software

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TPC The test-bed: available

infrastructure from the HARP experiment Beam area Solenoid Field-cage Gas Electronics DAQ

2.2m long solenoid, 0.7T field. <1% disuniformity over

1.5m 80cm diameter field-cage,

1.5m long

Edda Gschwendtner4

Modifications from HARP TPC to MICE TPC

• removal of the inner field cage

• installation of an adapter flange for hosting the TPG head

• modified end-plate with holders of X-ray sources

Edda Gschwendtner5

In the end, the test should provide simultaneously

1. Many longitudinal tracks (as in MICE)2. With Kr in the gas, a flow of low energy photons3. With calibration sources in the end-plates a first example of

the calibration system for MICE and flows of photons of various energies (from few KeV to MeV)

Altogether a demonstration very near the MICE conditions.

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GEMs

6 GEM foils 6 support rings Assembly and certifying procedure:

HV tests both on raw GEMs and supports Glue 1 GEM to 1 support HV test on glued GEMs Solder resistors HV test again

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GEMs and supports

3 circular GEM supports, with spacers and space provided for resistor chains

GEM being stretched before gluing on support. Following previous experiences (i.e. COMPASS), the GEMs are divided in 8 sectors, powered independently.

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GEM HV test

Newly designed probe holder

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GEM glued on support

GEM completed with support and resistors for the voltage divider

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Hexaboard

First hexaboard is finished. Delivered on time but unusable for full test.

Damaged at last production step (pressing/gluing)

The hexaboard has been characterized with measurements of strip capacitance

Maybe usable for minor measurements, to be verified within a few days.

3 hexaboards are ordered One will possibly be finished for test-beam measurements now!

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Hexaboard: active surface

Layer M

Layer N

Layer O

Connector

1

1

36 1

36

36

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Hexapads & strips•Active surface of a prototype hexaboard

300 m

3 layers of strips running under the pads

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Hexaboard back (connectors) side

• Mechanical support structure

• Prototype hexaboard glued to a support and seen from the connectors side.

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1st Hexaboard prototype characterization

Layer Mfor shorcut: C==0

-10

0

10

20

30

40

50

60

70

80

90

0 100 200 300 400 500 600

strip number

C [

pF

]

n:n+1

connector

Capacitance between neighbouring strips are measured for the 3 layers.

Typically good values are in the 10pF range. A short-circuit was verified with an ohmmeter…

Extended areas in short and some strips with capacitance higher than normal, but overall shape of the plot is right connections inside the Hexa are not just random

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TPG head assembly and location of cablesDesign of the complete assembly of the TPG head, with

• HV guard ring: field-defining ring to be matched to the corresponding strip on the field-cage

• 3 GEM supports

• Hexaboard and its support

• Main flange with feeds for HV and gas

Study of signal routing from the hexaboard to the preamplifier boards via flat cables. Similar to final MICE setup (RF shielding is here missing, not necessary for test beam).

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Electronics

16 strips

16 strips

16 strips

flexi-cables

48 channelspreamp board

Pico-coax bundle

2 x 24 channels to FADCPico-coax bundle

Actions: Inverted polarity at FADCs: hardware

modification, simple but lengthy Measure gain curves for preamplifiers

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Software

DAQ HARP, done

Reconstruction geometry and unpacking Modify clustering

First in planes Then in pads

Pattern Recognition & Fit Use same software as for HARP

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Plans: first stage

All components are ready. NOW detector is being assembled.

Test of TPG head in small volume Assemble hexaboard, 3 GEMs Gas-piping... Ar/CO2 80/20 Assemble TPG head and close with 5cm field-cage Instrument detector X-ray measurements Possibly tracks, but no magnetic field.

TPG head can be tested without waiting 2 days for gas flushing or purging in the big field cage

Good test already for many parameters relevant to MICE

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Plans: second stage Mount into HARP TPC only after TPG head

fully commissioned First gas: Ar/CH4 91/9 Present time window for measurements with

magnetic field (X-rays, cosmics, parasitic beam), is until 15.11

Longer period maybe possible, to be seen with PS coordination

Winter shutdown of the CERN accelerator complex lasts till next spring. Resuming operation in April. Complete characterization of the detector.