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The FIRST experiment: interaction region and MAPS vertex detector
Nuclear Physics B (Proc. Suppl.) 215 (2011) 157–161 www.elsevier.com/locate/npbps
The FIRST experiment: interaction region and MAPS vertex detector E. Spiritia , M. De Napolib and F. Romanob on behalf of the FIRST Collaboration a
INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Roma, Italy
b
INFN, Laboratori Nazionali del Sud, Via S. Sofia 62, I-95125 Catania, Italy
The improvement of the precision of the measurement of the nuclear cross-section, in order to fulfill the requirements of the actual Monte Carlo simulations for hadrontherapy and space radioprotection, is the main goal of the FIRST experiment. After a brief introduction on the treatment planning in hadrontherapy, this paper describes main characteristics and components of the experiment. The features of the interaction region detectors and their main needs (low material budget, high angular coverage, two tracks resolution and large trigger rate) are discussed. Special emphasis is devoted in discussing the new silicon pixel vertex detector, in particular its new developed data acquisition and its characterization with the first test results obtained with a prototype of the detector.
1. INTRODUCTION In the framework of the 5th INFN scientific commmittee TPS (Treatment Planning System) [1,2] research project a light ions fragmentation double-differential cross-section study has been setup, the project FIRST (Fragmentation of Ions Relevant for Space and Therapy). The TPS project aims to develop an automatic tool to produce a treatment planning in the new frontier of cancer therapy, the hadrontherapy. Ions heavier than protons are used in cancer therapy because of their enhanced relative biological effectiveness (RBE). Nevertheless ions have the drawback, not present with protons, that they may fragment inside the body of the patient, thus producing a dose distribution outside the region where one wants to concentrate it. Monte Carlo transport codes like FLUKA [3] or GEANT4 [4] are actually used to estimate how projectile fragmentation modifies the dose distribution and the biological effectiveness. However, due to the lack of experimental data, both on the fragmentation cross sections [5] and on the biological effectiveness of the different kind of produced fragments [6], the simulation results are not as accurate as desired. Improving the precision of the double-differential cross-section experimental data for the interesting ions for hadrontheraphy is the main motivation of 0920-5632/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.nuclphysbps.2011.03.164
the FIRST experiment [2,7]. Moreover, other fields could profit from the FIRST results like for example the estimation of the effect of GCR (Galactic Cosmic Radiation) [8] on humans, that gives the dominant contribution to the absorbed equivalent dose into interplanetary flights that are in the NASA and ESA future plans. Some interest could also be present in the study of SEE (Single Event Upset) in microelectonic circuits and in the accelerator shielding environment. 2. The FIRST experiment The experimental setup is mostly formed by an existing one used by the SPALADIN collaboration to measure nuclear cross sections at GSI [9–11]. It is made by A Large Acceptance Dipole magNet (ALADiN), the multitrack and multiplesampling TPC (Time Projection Chamber) MUSIC, the neutron detector (LAND) to evaluate neutron multiplicity and a TOF (Time Of Flight) wall of scintillators. All the projectile fragments with Z≥2 entering into the ALADiN acceptance can be tracked and identified in the TP-MUSIC IV and ToF-Wall detectors. Using the reconstructed values for the rigidity and pathlength, the charge of the particle measured by the TPMUSIC IV detector, and the time-of-flight given
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by the ToF-Wall, the velocity and the momentum vector of each detected charged particle can be reconstructed. The knowledge of velocity and momentum allows then the calculation of the particle’s mass. As shown on Fig. 1, obtained by a Fluka Monte Carlo code simulation based on the existing data, all fragments with Z≥3 are emitted with an angle smaller than 4.5◦ , Z = 2 ions span up to 12.5◦ , while protons could be emitted practically at any angle from 0◦ to 90◦ .
Figure 1. Carbon ion fragments angle (degree) and energy (MeV/nucleon) distributions evaluated by Fluka Montecarlo code simulation
At the same time the kinetic energy distribution of the emitted fragments, starting from the 400 MeV/nucleon carbon ion beam available at GSI, reach about 1 GeV for protons while is limited in a range of ±200 MeV/nucleon peaked around the beam energy for Z = 2 and smaller ranges for the heavier fragments. To measure the emission angle and energy of all fragments with a precision better than 3%, new detectors around the interaction region will be built. They consist of a 150 µm thick scintillator acting as start counter for time of flight measurements, a four xy
plane drift chamber to measure the beam position before the target, a vertex detector, made of four layer of pixel sensors each 50 µm thick, to track all charged fragments with an angular coverage of ±40◦ . Finally a fraction of the solid angle, in the plane perpendicular to the beam direction, will be equipped with a calorimeter to measure the energy of those protons and fragments which do not enter the acceptance of the ALADiN magnet. 3. The FIRST vertex detector The main requirements for the vertex detector are: the largest possible angular coverage considering a beam spot with a FWHM of 3 mm; angular resolution on tracks of ≈ 0.3◦ ; two track separation at the % level purity, to minimize systematic errors; the whole sensors thickness of just a few % of the target thickness (≈ 1 cm), to reduce the nuclear interactions of carbon ions inside the sensors; a dynamic range from about two MIPs (Minimum Ionizing Particle) signal of the protons up to the two or three order of magnitude larger signal from a carbon ion. To satisfy these requirements we propose the M26 pixel sensor to equip the vertex detector. To fit the experimental conditions, we designed a new housing board with two M26s glued on a square hole with a sensing area of (2x2) cm2 . The use of 1 mm thick PCB (Printed Circuit Board) and low profile components, allowing a distance of two consecutive boards of 2 mm, produces an overall thickness of the four vertex stations of 12 mm. In this conditions the angular coverage become ±40◦ . Finally the use of 50 µm thinned sensor (overall sensor thickness of 200 µm) allows to reduce as desired the secondary fragmentation in the vertex detector. The mechanical arrangement is shown in Fig. 2. 3.1. Mimosa 26 sensor description Mimosa26 is the most recent sensor chip developed by the Strasbourg group [12] for the EUDET [13] beam telescope (funded in the 6th European Union framework program) to be used for the ILC (International Linear Collider) vertex detector studies. The architecture of the sensor is based on two previous prototypes: Mi-
E. Spiriti et al. / Nuclear Physics B (Proc. Suppl.) 215 (2011) 157–161
159
Figure 2. Relative positions of: beam, target, four vertex stations and sensor housing board dimensions mosa22 to test the sensor part with digital output and SUZE01 which performs the zero suppression functionality. The chip has been submitted for production on December 2008 in the AMSC35B4/OPTO technology, provided by Austriamicrosystems silicon foundry, that uses an epitaxial layer thickness of 14 µm. A sensitive area of 10.6 mm x 21.2 mm is covered by 576 rows and 1152 columns of pixels with 18, 4 µm pitch with a readout time, in rolling shutter mode, of 115, 2 µs per frame. Each pixel is collecting the charge from the epitaxial layer with a Self Biased diode [14] and contains a Double Correlated Sampling circuitry for baseline removal to reduce the Fixed Pattern Noise. Every 200 ns each sampled pixel signal of a column is supplied to the end of column discriminator. The following zero suppression logic scans the 1152 discriminators output, removes the empty pixel information, stores the data in two memories and then sends the data off chip with two 80 MHz serial differential outputs.
4. The FIRST M26 Roma-Tre developed data acquisition system To fit in the Multi Branch System (MBS) for data acquisition used at GSI laboratory in Darmstadt (based on the VME standard) [15], we have developed a brand new readout system, for the M26 chips, based on the CAEN V1495 VME board [16]. The board is equipped with a FPGA (Field Programmeble Gate Array) fully configurable from the user, interfaced with LVDS and NIM standard signals. We developed the FPGA VHDL code to readout four M26 sensors on each board, then by means of four different FIFOs included in the FPGA the data are readout from the VME. Trigger functionality, common clock generation to the sensors, JTAG initialization, frame and trigger counter are also implemented. A preliminary version of this code has been used in the data taking that will be described in the following, and a VME readout data flow in excess of 10 MBytes/sec has been measured with this firmware version.
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Figure 3. Energy released in 1 µm of Silicon (KeV) at different energies of the projectile
5. The M26 pixel sensor performances with alphas and 12 C ions The behaviour of the M26 pixel sensor had to be verified with impinging particles like 12 C ions which release up to two or three orders of magnitude more charge than a MIP. The table in Fig. 3 lists the energy released by ions at different impinging energy in 1 µm of Silicon. In this work only the alpha particles from a 241 Am source and a 12 C beam at energy up to 60 MeV/nucleon have been measured. The corresponding released charge cannot easily be estimated because the ”equivalent epitaxial layer” concept used in MIP detection cannot be straightforwardly applied to the light ions case where the charge collection mechanism could be very different. The alpha particles stop completely inside the active area of the sensor and release there all their energy, while the carbon ions will cross completely the detector. In the latter case is not absolutely clear which is the fraction of charge produced in the sensor substrate that is collected. Unlike other MAPS (Monolithic Active Pixel Sensor) pixel sensors [14] the M26 does not provide an analog information on the collected charge but only a digital one; then the only variable that gives a rough information on the collected charge is the number of pixels in the cluster. This variable has been considered to evaluate the sensor performance and moreover to provide the essential response about the possibility of the
Figure 4. Cluster size (in pixels) versus distance (in mm) of the 241 Am α-source from the sensor
sensor to disantangle two close tracks produced by fragments emitted at small angle. The first measurements, performed with a M26 sensor 120 µm thick have been done using an 241 Am source emitting alpha particles at 5.4 MeV. It has been positioned at different distances in order to scan the impinging alpha energy on the sensor from 1.4 MeV (at 16 mm) up to 5.0 MeV (at 3 mm); the results show a cluster size decreasing, almost linearly, from 72 pixel/cluster to 53 pixel/cluster (see Fig.4). Similar measurements have been done with a 12 C beam at the ”INFN Laboratori Nazionali del Sud” Superconducting Cyclotron (Catania), exposing the M26 to five different carbon ion energies: 18, 27, 33, 38, 60 MeV/nucleon. The results (Fig. 5) show, at this unusual level of signals, a linear dependence from 51 pixel/cluster to 103 pixel/cluster versus the released energy in one micrometer of Silicon (released energy could be considered proportional to the released charge in the sensor). The linear relation we measured justifies us in scaling when evaluating the cluster size for the other lighter ions listed in Fig. 3. The very large cluster of ≈ 100 pixels we measured for a 12 C at 18 MeV/nucleon energy will never appear for the fragments that release much less charge in the sensor. Moreover, we can conclude
E. Spiriti et al. / Nuclear Physics B (Proc. Suppl.) 215 (2011) 157–161
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REFERENCES
Figure 5. Cluster size versus the released energy (KeV/µm) and versus the energy of the 12 C ions (MeV/nucleon)
that we will be able to disantangle tracks pair at 99% confidence level because the cluster size of the fragments will be small enough (fragments cluster diameter of ≈ 6 pixels, i.e. ≈ 100 µm). This conclusion is also based on the simulation results, which show that clusters from a tracks pair will be closer than 100 µm only in 0.3% of cases. 6. Conclusion A completely new sensor housing board, in its final version, has been designed built and tested with both sensors working. A completely independent DAQ system (firmware and readout software) for the M26 sensor has been developed and used also on test beam, and an affordable data rate larger than 10 Mbytes/sec has been verified. The data decoding software and cluster reconstruction alghoritm are ready and used for the measurements presented. Measurements with alphas and 12 C ions demonstrate that the M26 sensor is suited for the FIRST project needs. Further measurements are needed to accurately qualify the sensor performances: carbon at higher energy, lighter ions and cluster size at different incident angles.
1. C.Agodi et al. Nuovo Cim. della Societ` a Italiana di Fisica C-Geophysics and Space Physics Vol.31, Issue 1 (99-108) 2008 2. http://totlxl.to.infn.it/mediawiki/ index.php/Main_Page 3. http://www.fluka.org 4. http://geant4.cern.ch 5. A.Fleury et al. Ann.Rev.Nat. Part.Sci.24,279 (1974), GSI Scientific Report 2003-2004 and ref.therein 6. Kramer et al. Phys.Med.Biol. 2000, 45/113319-3330 7. https://www.gsi.de/search/events/ archive_e.html, ”Light Ion Fragmentation Measurements for Medical and Space Applications” 8. M.Durante Rivista del Nuovo Cim. Vol.25 N.8 (2002) 9. E. Le Gentil et al., NIM-A,562, 743−746 (2006) 10. T. Aumann Nucl. Phys. A 805 , 198c−209c (2008) 11. E. Le Gentil et al., Physical Review Letters 100, 022701 (2008). 12. http://www.iphc.cnrs.fr/-CMOS-ILC-. html 13. http://www.eudet.org 14. G. Deptuch et al., NIM-A,512, 299-309 (2003) 15. http://www-win.gsi.de/daq/ 16. http://www.caen.it/nuclear/product. php?mod=V1495
The FIRST experiment: interaction region and MAPS vertex detector E. Spiritia , M. De Napolib and F. Romanob on behalf of the FIRST Collaboration a
INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Roma, Italy
b
INFN, Laboratori Nazionali del Sud, Via S. Sofia 62, I-95125 Catania, Italy
The improvement of the precision of the measurement of the nuclear cross-section, in order to fulfill the requirements of the actual Monte Carlo simulations for hadrontherapy and space radioprotection, is the main goal of the FIRST experiment. After a brief introduction on the treatment planning in hadrontherapy, this paper describes main characteristics and components of the experiment. The features of the interaction region detectors and their main needs (low material budget, high angular coverage, two tracks resolution and large trigger rate) are discussed. Special emphasis is devoted in discussing the new silicon pixel vertex detector, in particular its new developed data acquisition and its characterization with the first test results obtained with a prototype of the detector.
1. INTRODUCTION In the framework of the 5th INFN scientific commmittee TPS (Treatment Planning System) [1,2] research project a light ions fragmentation double-differential cross-section study has been setup, the project FIRST (Fragmentation of Ions Relevant for Space and Therapy). The TPS project aims to develop an automatic tool to produce a treatment planning in the new frontier of cancer therapy, the hadrontherapy. Ions heavier than protons are used in cancer therapy because of their enhanced relative biological effectiveness (RBE). Nevertheless ions have the drawback, not present with protons, that they may fragment inside the body of the patient, thus producing a dose distribution outside the region where one wants to concentrate it. Monte Carlo transport codes like FLUKA [3] or GEANT4 [4] are actually used to estimate how projectile fragmentation modifies the dose distribution and the biological effectiveness. However, due to the lack of experimental data, both on the fragmentation cross sections [5] and on the biological effectiveness of the different kind of produced fragments [6], the simulation results are not as accurate as desired. Improving the precision of the double-differential cross-section experimental data for the interesting ions for hadrontheraphy is the main motivation of 0920-5632/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.nuclphysbps.2011.03.164
the FIRST experiment [2,7]. Moreover, other fields could profit from the FIRST results like for example the estimation of the effect of GCR (Galactic Cosmic Radiation) [8] on humans, that gives the dominant contribution to the absorbed equivalent dose into interplanetary flights that are in the NASA and ESA future plans. Some interest could also be present in the study of SEE (Single Event Upset) in microelectonic circuits and in the accelerator shielding environment. 2. The FIRST experiment The experimental setup is mostly formed by an existing one used by the SPALADIN collaboration to measure nuclear cross sections at GSI [9–11]. It is made by A Large Acceptance Dipole magNet (ALADiN), the multitrack and multiplesampling TPC (Time Projection Chamber) MUSIC, the neutron detector (LAND) to evaluate neutron multiplicity and a TOF (Time Of Flight) wall of scintillators. All the projectile fragments with Z≥2 entering into the ALADiN acceptance can be tracked and identified in the TP-MUSIC IV and ToF-Wall detectors. Using the reconstructed values for the rigidity and pathlength, the charge of the particle measured by the TPMUSIC IV detector, and the time-of-flight given
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E. Spiriti et al. / Nuclear Physics B (Proc. Suppl.) 215 (2011) 157–161
by the ToF-Wall, the velocity and the momentum vector of each detected charged particle can be reconstructed. The knowledge of velocity and momentum allows then the calculation of the particle’s mass. As shown on Fig. 1, obtained by a Fluka Monte Carlo code simulation based on the existing data, all fragments with Z≥3 are emitted with an angle smaller than 4.5◦ , Z = 2 ions span up to 12.5◦ , while protons could be emitted practically at any angle from 0◦ to 90◦ .
Figure 1. Carbon ion fragments angle (degree) and energy (MeV/nucleon) distributions evaluated by Fluka Montecarlo code simulation
At the same time the kinetic energy distribution of the emitted fragments, starting from the 400 MeV/nucleon carbon ion beam available at GSI, reach about 1 GeV for protons while is limited in a range of ±200 MeV/nucleon peaked around the beam energy for Z = 2 and smaller ranges for the heavier fragments. To measure the emission angle and energy of all fragments with a precision better than 3%, new detectors around the interaction region will be built. They consist of a 150 µm thick scintillator acting as start counter for time of flight measurements, a four xy
plane drift chamber to measure the beam position before the target, a vertex detector, made of four layer of pixel sensors each 50 µm thick, to track all charged fragments with an angular coverage of ±40◦ . Finally a fraction of the solid angle, in the plane perpendicular to the beam direction, will be equipped with a calorimeter to measure the energy of those protons and fragments which do not enter the acceptance of the ALADiN magnet. 3. The FIRST vertex detector The main requirements for the vertex detector are: the largest possible angular coverage considering a beam spot with a FWHM of 3 mm; angular resolution on tracks of ≈ 0.3◦ ; two track separation at the % level purity, to minimize systematic errors; the whole sensors thickness of just a few % of the target thickness (≈ 1 cm), to reduce the nuclear interactions of carbon ions inside the sensors; a dynamic range from about two MIPs (Minimum Ionizing Particle) signal of the protons up to the two or three order of magnitude larger signal from a carbon ion. To satisfy these requirements we propose the M26 pixel sensor to equip the vertex detector. To fit the experimental conditions, we designed a new housing board with two M26s glued on a square hole with a sensing area of (2x2) cm2 . The use of 1 mm thick PCB (Printed Circuit Board) and low profile components, allowing a distance of two consecutive boards of 2 mm, produces an overall thickness of the four vertex stations of 12 mm. In this conditions the angular coverage become ±40◦ . Finally the use of 50 µm thinned sensor (overall sensor thickness of 200 µm) allows to reduce as desired the secondary fragmentation in the vertex detector. The mechanical arrangement is shown in Fig. 2. 3.1. Mimosa 26 sensor description Mimosa26 is the most recent sensor chip developed by the Strasbourg group [12] for the EUDET [13] beam telescope (funded in the 6th European Union framework program) to be used for the ILC (International Linear Collider) vertex detector studies. The architecture of the sensor is based on two previous prototypes: Mi-
E. Spiriti et al. / Nuclear Physics B (Proc. Suppl.) 215 (2011) 157–161
159
Figure 2. Relative positions of: beam, target, four vertex stations and sensor housing board dimensions mosa22 to test the sensor part with digital output and SUZE01 which performs the zero suppression functionality. The chip has been submitted for production on December 2008 in the AMSC35B4/OPTO technology, provided by Austriamicrosystems silicon foundry, that uses an epitaxial layer thickness of 14 µm. A sensitive area of 10.6 mm x 21.2 mm is covered by 576 rows and 1152 columns of pixels with 18, 4 µm pitch with a readout time, in rolling shutter mode, of 115, 2 µs per frame. Each pixel is collecting the charge from the epitaxial layer with a Self Biased diode [14] and contains a Double Correlated Sampling circuitry for baseline removal to reduce the Fixed Pattern Noise. Every 200 ns each sampled pixel signal of a column is supplied to the end of column discriminator. The following zero suppression logic scans the 1152 discriminators output, removes the empty pixel information, stores the data in two memories and then sends the data off chip with two 80 MHz serial differential outputs.
4. The FIRST M26 Roma-Tre developed data acquisition system To fit in the Multi Branch System (MBS) for data acquisition used at GSI laboratory in Darmstadt (based on the VME standard) [15], we have developed a brand new readout system, for the M26 chips, based on the CAEN V1495 VME board [16]. The board is equipped with a FPGA (Field Programmeble Gate Array) fully configurable from the user, interfaced with LVDS and NIM standard signals. We developed the FPGA VHDL code to readout four M26 sensors on each board, then by means of four different FIFOs included in the FPGA the data are readout from the VME. Trigger functionality, common clock generation to the sensors, JTAG initialization, frame and trigger counter are also implemented. A preliminary version of this code has been used in the data taking that will be described in the following, and a VME readout data flow in excess of 10 MBytes/sec has been measured with this firmware version.
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Figure 3. Energy released in 1 µm of Silicon (KeV) at different energies of the projectile
5. The M26 pixel sensor performances with alphas and 12 C ions The behaviour of the M26 pixel sensor had to be verified with impinging particles like 12 C ions which release up to two or three orders of magnitude more charge than a MIP. The table in Fig. 3 lists the energy released by ions at different impinging energy in 1 µm of Silicon. In this work only the alpha particles from a 241 Am source and a 12 C beam at energy up to 60 MeV/nucleon have been measured. The corresponding released charge cannot easily be estimated because the ”equivalent epitaxial layer” concept used in MIP detection cannot be straightforwardly applied to the light ions case where the charge collection mechanism could be very different. The alpha particles stop completely inside the active area of the sensor and release there all their energy, while the carbon ions will cross completely the detector. In the latter case is not absolutely clear which is the fraction of charge produced in the sensor substrate that is collected. Unlike other MAPS (Monolithic Active Pixel Sensor) pixel sensors [14] the M26 does not provide an analog information on the collected charge but only a digital one; then the only variable that gives a rough information on the collected charge is the number of pixels in the cluster. This variable has been considered to evaluate the sensor performance and moreover to provide the essential response about the possibility of the
Figure 4. Cluster size (in pixels) versus distance (in mm) of the 241 Am α-source from the sensor
sensor to disantangle two close tracks produced by fragments emitted at small angle. The first measurements, performed with a M26 sensor 120 µm thick have been done using an 241 Am source emitting alpha particles at 5.4 MeV. It has been positioned at different distances in order to scan the impinging alpha energy on the sensor from 1.4 MeV (at 16 mm) up to 5.0 MeV (at 3 mm); the results show a cluster size decreasing, almost linearly, from 72 pixel/cluster to 53 pixel/cluster (see Fig.4). Similar measurements have been done with a 12 C beam at the ”INFN Laboratori Nazionali del Sud” Superconducting Cyclotron (Catania), exposing the M26 to five different carbon ion energies: 18, 27, 33, 38, 60 MeV/nucleon. The results (Fig. 5) show, at this unusual level of signals, a linear dependence from 51 pixel/cluster to 103 pixel/cluster versus the released energy in one micrometer of Silicon (released energy could be considered proportional to the released charge in the sensor). The linear relation we measured justifies us in scaling when evaluating the cluster size for the other lighter ions listed in Fig. 3. The very large cluster of ≈ 100 pixels we measured for a 12 C at 18 MeV/nucleon energy will never appear for the fragments that release much less charge in the sensor. Moreover, we can conclude
E. Spiriti et al. / Nuclear Physics B (Proc. Suppl.) 215 (2011) 157–161
161
REFERENCES
Figure 5. Cluster size versus the released energy (KeV/µm) and versus the energy of the 12 C ions (MeV/nucleon)
that we will be able to disantangle tracks pair at 99% confidence level because the cluster size of the fragments will be small enough (fragments cluster diameter of ≈ 6 pixels, i.e. ≈ 100 µm). This conclusion is also based on the simulation results, which show that clusters from a tracks pair will be closer than 100 µm only in 0.3% of cases. 6. Conclusion A completely new sensor housing board, in its final version, has been designed built and tested with both sensors working. A completely independent DAQ system (firmware and readout software) for the M26 sensor has been developed and used also on test beam, and an affordable data rate larger than 10 Mbytes/sec has been verified. The data decoding software and cluster reconstruction alghoritm are ready and used for the measurements presented. Measurements with alphas and 12 C ions demonstrate that the M26 sensor is suited for the FIRST project needs. Further measurements are needed to accurately qualify the sensor performances: carbon at higher energy, lighter ions and cluster size at different incident angles.
1. C.Agodi et al. Nuovo Cim. della Societ` a Italiana di Fisica C-Geophysics and Space Physics Vol.31, Issue 1 (99-108) 2008 2. http://totlxl.to.infn.it/mediawiki/ index.php/Main_Page 3. http://www.fluka.org 4. http://geant4.cern.ch 5. A.Fleury et al. Ann.Rev.Nat. Part.Sci.24,279 (1974), GSI Scientific Report 2003-2004 and ref.therein 6. Kramer et al. Phys.Med.Biol. 2000, 45/113319-3330 7. https://www.gsi.de/search/events/ archive_e.html, ”Light Ion Fragmentation Measurements for Medical and Space Applications” 8. M.Durante Rivista del Nuovo Cim. Vol.25 N.8 (2002) 9. E. Le Gentil et al., NIM-A,562, 743−746 (2006) 10. T. Aumann Nucl. Phys. A 805 , 198c−209c (2008) 11. E. Le Gentil et al., Physical Review Letters 100, 022701 (2008). 12. http://www.iphc.cnrs.fr/-CMOS-ILC-. html 13. http://www.eudet.org 14. G. Deptuch et al., NIM-A,512, 299-309 (2003) 15. http://www-win.gsi.de/daq/ 16. http://www.caen.it/nuclear/product. php?mod=V1495