- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 1

MUSETT: the segmented Si array for the focal plane of theVAMOS spectrometer

Ch. THEISEN – CEA Saclay

Christophe.theisen@cea.fr

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 2

What is MUSETT

•MUr de Silicium pour l’Etude des Transfermium par Tagging•Collaboration Saclay - Ganil•Spectroscopy of heavy element with VAMOS and EXOGAM using the RDT

technique

Motivations :•VAMOS : well adapted to asymmetric reactions

– Large angular acceptance– Large transmission– Beam rejection with the Wien Filter

•EXOGAM : high efficiency (single and coincidences).

Constrains:– Very slow and very heavy ions– Optics of Vamos– Alpha particle spectroscopy– Segmentation for the RDT technique– Time stamping– Option : energy loss and tracking of heavy ions

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 3

MUSETT at VAMOS + EXOGAM

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 4

VAMOS optics

Wien Filter tuned on residues; dipole on

Wien Filter tuned on beam; dipole off

Beam dispersion background

Beam focused

Optics optimized on residues in both cases

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 5

VAMOS optics

Beam

1+ 5+ 10+

Beam

WF tuned on recoils WF tuned on beam

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 6

Si detectors

(Not a MUST II detector, this is a MUSETT one…)

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 7

Si detectors

•Characteristics

– 300 μm thick

– 10 x 10 cm2

– 128 + 128 strips

– 3 % Al grid

– Front side : No Aluminum layer. < 0.25 μm B implantation

– Depletion ~ 30 V. Nominal voltage ~ 60 V.

– Provided by Micron Semiconductor

– 2 evaluation detector + 1 prototype received

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 8

Si detectors

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 9

Si detectors mechanics

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 10

Electronics and DAQ for Si detectors

•See next presentation…

ATHED

CVM

MUVI

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 11

Gas detectors

Bi 150MeV55 MeV

D DSSD

Elect

16 MeV

Elect

57 MeV

α

IC

Elect

5-10 Torr Iso

Energy loss

Escaped radioactivity

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 12

Gas detector

Constrains

•Large dynamics : heavy ions + escaped radioactivity

– Hybrid detector Ionisation Chamber + Drift Chamber

•Small energy loss of heavy ions

– Low pressure

•Small effect on/off Si Wall

•Coexistence of IC/DC fields

•Integration in HARPEE mechanics

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 13

Mechanics integration

•Integration in the HARPEE mechanics : easy installation / maintenance

– Si Wall module

– Gas detector module

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 14

Status

•3 Si detectors received

•ATHED ASICs : ready

•COFEE Front-end being tested

•CVM VME readout and DAQ ready. Need to be tested with COFEE.

•MUVI VXI readout : prototypes OK. Production soon

•Mechanics for Si : drawing ready, prototype soon

•Gas detector : R & D phase. Prototype 2007

- Christophe THEISEN - INTAG Workshop GSICEA DSM Dapnia SPhNMay 25th, 2007 15

Perspectives

S3 focal plane

SPIRAL2