1. 16 Sept. 2005 PSD 7 Liverpool 1 MHSP with position detection capability MHSP with position detection capability H. Natal da Luz a,b, J.F.C.A. Veloso a,b, N.F.C. Mendes b, J.M.F. dos Santos b, J. A. Mir c a Physics Dept., University of Aveiro, 3810-193 Aveiro, Portugal b Physics Dept., University of Coimbra, 3004-516 Coimbra, Portugal c Instrumentation Dept., CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK

2. 16 Sep. 2005 PSD 7 Liverpool 2 Outline The Micro Hole and Strip Plate – working principle; The Micro Hole and Strip Plate – working principle; Applications; Applications; 2D capability – 1D prototype; 2D capability – 1D prototype; Position linearity and resolution – results; Position linearity and resolution – results; Conclusions and future work. Conclusions and future work.

3. 16 Sep. 2005 PSD 7 Liverpool 3 The Micro Hole and Strip Plate - MHSP A MSGC and GEM combination in a single plate A MSGC and GEM combination in a single plate hole / strip pitch ~ 200  m hole / strip pitch ~ 200  m Distance between holes ~140  m Distance between holes ~140  m TopBottom 200μm

4. 16 Sep. 2005 PSD 7 Liverpool 4 The Micro-Hole & Strip Plate gas detector operation 2 multiplication stages Hole gain > 10 3 MS gain ≈ 30-100 Gain > 10 5 for several gases e.g., Veloso et al., RSI, 71(2000)2371 Maia et al., NIM A 504 (2003)364 Veloso et al., NIM A524 (2004)124

5. 16 Sep. 2005 PSD 7 Liverpool 5 Applications Atmospheric pressure: Atmospheric pressure: High gain multipliers in standard and noble-gas mixtures (simple to purify - no gas ageing) High gain multipliers in standard and noble-gas mixtures (simple to purify - no gas ageing) X-ray & UV-Photon detectors X-ray & UV-Photon detectors High pressures: High pressures: Noble gas mixtures Noble gas mixtures Dual-phase (liq/gas) detectors: Dark-matter, PET, etc. Dual-phase (liq/gas) detectors: Dark-matter, PET, etc. Medical applications Medical applications Hard X-ray & n detectors, etc. Hard X-ray & n detectors, etc.

6. 16 Sep. 2005 PSD 7 Liverpool 6 2D MHSP configuration High charge induction in top electrode (35% of the charge at the anode) allows the implementation of the 2 nd coordinate readout. By structuring both sides, 2D readout by resistive charge division is possible.

7. 16 Sep. 2005 PSD 7 Liverpool 7 MHSP with resistive charge division 1D readout implementation 1 mm anodes cathodes + holes Resistive layer Resistive layer crossing the electrodes Only 2 preamplifiers / coordinate Simple electronic system Low cost solution

8. 16 Sep. 2005 PSD 7 Liverpool 8 Position linearity Good position linearity – mean deviation ~ 0.15 mm full range Colimator holes - 2 mm in diamerter - 5 holes 109 Cd x-ray source placed @ the position of each hole

9. 16 Sep. 2005 PSD 7 Liverpool 9 Position resolution Low background – rejection logic needed for further reduction No improvement in resolution for smaller holes!! next slide Colimator holes - 2 mm in diamerter - 3 holes 109 Cd x-ray source placed @ - 0 mm position - 5 cm from the window

10. 16 Sep. 2005 PSD 7 Liverpool 10 Measurements with a pulse generator Bad division!!! – energy dependence Bad division!!! – energy dependence Position resolution is limited by the 1.3 mm fluctuation introduced by the electronic division circuit. Position resolution is limited by the 1.3 mm fluctuation introduced by the electronic division circuit. Good FWHM for constant “X L ” and “X R ” Good FWHM for constant “X L ” and “X R ”

11. 16 Sep. 2005 PSD 7 Liverpool 11 Conclusions Inexpensive and simple construction; Inexpensive and simple construction; Good position linearity; Good position linearity; Position resolution is limited by the energy dependence of the electronic readout, not yet fully exploited. Position resolution is limited by the energy dependence of the electronic readout, not yet fully exploited. The future Development of a non energy dependent electronic division readout – Goal P Resolution < 0.5mm; Development of a non energy dependent electronic division readout – Goal P Resolution < 0.5mm; MHSP structured on the top electrode for 2D position determination is under construction @ CERN; MHSP structured on the top electrode for 2D position determination is under construction @ CERN; development of a 15 x 15 cm 2 window 2D detector development of a 15 x 15 cm 2 window 2D detector

12. 16 Sep. 2005 PSD 7 Liverpool 12 Thank you for your attention!