Silicon strip detectors for two-dimensional soft x-ray imaging at normal incidence Pedro Rato Mendes LIP Lisbon and University of Algarve, Portugal Amsterdam, September 2002

IWoRID AmsterdamPedro Rato Mendes et al. Outline Collaboration members Objectives Experimental setup Energy calibration Imaging results Conclusions and future work

IWoRID AmsterdamPedro Rato Mendes et al. Collaboration members M. C. Abreu a, G. Baldazzi b, D. Bollini b, E. Cabal Rodriguez c, W. Dabrowski d, A. Diaz Garcia c, M. Gambaccini e, P. Giubellino f, M. Gombia b, P. Grybos d, M. Idzik d,f, A. Marzari-Chiesa g, L. M. Montano h, F. Prino i, L. Ramello i, P. Rato Mendes a, S. Rodrigues a, M. Sitta i, P. Sousa a, K. Swientek d, A. Taibi e, A. Tuffanelli e, R. Wheadon f, P. Wiacek d a LIP and University of Algarve, Faro, Portugal b Dipartimento di Fisica dellUniversità di Bologna and INFN, Bologna, Italy c CEADEN, Havana, Cuba d Faculty of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, Cracow, Poland e Dipartimento di Fisica dellUniversità di Ferrara and INFN, Ferrara, Italy f INFN, Torino, Italy g Dipartimento di Fisica Sperimentale dellUniversità di Torino and INFN, Torino, Italy h CINVESTAV, Mexico City, Mexico i Dipartimento di Scienze e Tecnologie Avanzate dellUniversità del Piemonte Orientale and INFN, Alessandria, Italy

IWoRID AmsterdamPedro Rato Mendes et al. Objectives Develop a simple prototype system for 2-D soft x-ray imaging using silicon strip detectors Motivations for this prototype –spin-off from high-energy physics –RX64 chip designed for this application –simple laboratory setup and data-acquisition –advanced education for young physicists RX64 and its main applications: talk by L. Ramello, this conference W. Dabrowski et al., RX64 – A Fully Integrated 64-channel IC for Readout of Silicon Detectors Used for X-Ray Position Sensitive Measurements, IEEE NSS/MIC 2001, San Diego

IWoRID AmsterdamPedro Rato Mendes et al. Experimental setup Equipment –board with 1-sided microstrip detectors and RX64 chips 300 m thick Si, 132 strips at 100 m pitch (ITC-IRST, Trento, Italy) RX64 chip by W. Dabrowski and collaborators (Cracow, Poland) one or two chips per board (64 or 128 channels) –PC with NI PCI-DIO-96 interface + LabVIEW 6i software –scanning system controlled by stepper motor –radiation sources ( 57 Co, 109 Cd, 241 Am for fluorescence) –power supplies, cables Two-dimensional image acquisition –acquire 1-D profiles for each collimator position –form 2-D image by juxtaposition of 1-D profiles

IWoRID AmsterdamPedro Rato Mendes et al. Experimental setup 64 silicon microstrip detector RX channels (preamp, shaper, discriminator) - 64 pseudo-random counters (20-bit) - internal calibration circuit (1 mV to 30 mV) - I/O on chip (interface with external bus) PC National Instruments PCI-DIO-96 LabVIEW 6i

IWoRID AmsterdamPedro Rato Mendes et al. First test board (one RX64 chip) cm 2 detector RX64

IWoRID AmsterdamPedro Rato Mendes et al. Energy calibration Method –perform discriminator threshold scan –differentiate integral spectrum –fit energy peaks on differential spectrum integral spectrum differential spectrum

IWoRID AmsterdamPedro Rato Mendes et al. Energy calibration Calibration using Co57 and Cd109 sources (board with one RX64 chip, average on all channels)

IWoRID AmsterdamPedro Rato Mendes et al. Energy calibration Calibration using Am241 x-ray fluorescence source (board with two RX64 chips, average on all channels)

IWoRID AmsterdamPedro Rato Mendes et al. Scanning system scanning detector board stepper motor radioactive source Pb collimator

IWoRID AmsterdamPedro Rato Mendes et al. Imaging results – one RX64 chip Pb 0.5 mm thick 300 kBq 109 Cd source – 22 keV Ag K x-rays 15 mm thick Pb collimator, 300 µm wide slit microstrip detector scanning system mm 2

IWoRID AmsterdamPedro Rato Mendes et al. Imaging results – two RX64 chips 300 kBq 109 Cd source – 22 keV Ag K x-rays 15 mm thick Pb collimator, 300 µm wide slit LOW CONTRAST snail shell HIGH CONTRAST 8-pin integrated circuit mm 2

IWoRID AmsterdamPedro Rato Mendes et al. Conclusions Prototype main features –one-sided silicon microstrip detectors –simple readout electronics based on RX64 chip –simple 2-D scanning system Future developments –larger area sensors / more readout chips –new chip version with two thresholds –x-ray tube as radiation source We have built and tested a simple prototype for 2-D soft x-ray imaging