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detectors [2013/12/13 18:56]
pereira [Ionization Chamber] |
detectors [2013/12/13 19:04]
pereira [Hodoscope] |
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| {{:wiki:crdc-section-drift.jpg?600|Principle of operation of a CRDC.}} | {{:wiki:crdc-section-drift.jpg?500|Principle of operation of a CRDC.}} |
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| An ionization chamber downstream of both [[Detectors#Cathode Readout Drift Chambers (CRDC)|CRDCs]] is used to identify the Z number of the transmitted nuclei from their energy loss. The detector has an active volume of __xxx cm x xxx cm x xxx cm__ and is filled with P10 gas (90% argon, 10% methane) at a typical pressure of 300 torr, although this value can be increased up to 600 torr for light nuclei. The detector consists of 16 stacked-parallel plate ion chambers with narrow anode-cathode gaps, placed along the detector’s central axis, perpendicular to the beam direction (see picture below). The plates are constructed from 70 mg/cm<sup>2</sup> polypropylene with 0.05 µm of aluminum evaporated on each side. The entrance and exit windows of the chamber are made of 14 mg/cm<sup>2</sup> Mylar with an overlay of Kevlar filaments and epoxy. | An ionization chamber downstream of both [[Detectors#Cathode Readout Drift Chambers (CRDC)|CRDCs]] is used to identify the Z number of the transmitted nuclei from their energy loss. The detector has an active volume of __xxx cm x xxx cm x xxx cm__ and is filled with P10 gas (90% argon, 10% methane) at a typical pressure of 300 torr, although this value can be increased up to 600 torr for light nuclei. The detector consists of 16 stacked-parallel plate ion chambers with narrow anode-cathode gaps, placed along the detector’s central axis, perpendicular to the beam direction (see picture below). The plates are constructed from 70 mg/cm<sup>2</sup> polypropylene with 0.05 µm of aluminum evaporated on each side. The entrance and exit windows of the chamber are made of 14 mg/cm<sup>2</sup> Mylar with an overlay of Kevlar filaments and epoxy. |
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| {{:wiki:ion-chamber-picture.jpg|Picture of the S800 ionization chamber with its alternating cathode and anode plates.}} | {{:wiki:ion-chamber-picture.jpg?550|Picture of the S800 ionization chamber with its alternating cathode and anode plates.}} |
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| {{:wiki:ion-chamber-drawing.jpg|Schematic representation of the principle of operation of the ionization chamber.}} | {{:wiki:ion-chamber-drawing.jpg?550|Schematic representation of the principle of operation of the ionization chamber.}} |
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| ===== Hodoscope ===== | ===== Hodoscope ===== |
| A Cs(Na) hodoscope detector located downstream of the [[Detectors#Plastic scintillators|E1 scintillator]] is used to measure the total kinetic energy of implanted nuclei, allowing the identification of different charge states. An additional use recently tested is the measurement of isomer gamma-rays emitted from implanted nuclei. | A Cs(Na) hodoscope detector located downstream of the [[Detectors#Plastic scintillators|E1 scintillator]] is used to measure the total kinetic energy of implanted nuclei, allowing the identification of different charge states. An additional use recently tested is the measurement of isomer gamma-rays emitted from implanted nuclei. |
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| | {{:wiki:hodoscope-drawing.jpg?500|Schematic layout of the S800 Hodoscope.}} |
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| The hodoscope is composed 32 sodium-doped cession iodide CsI(Na) scintillating crystals manufactured by [[http://www.scintitech.com/|ScintiTech]]. Each crystal is 5.1 cm-thick, has an active area of 7.6 cm x 7.6 cm, and is attached to a photomultiplier ([[https://www.hamamatsu.com/jp/en/R1307.html|Hamamatsu R1307]]). The photo-cathodes are made of a bi-alkali material with a transmission peak at 420 nm. The 32 crystals are arranged in eight rows of 4 crystals each so as to cover approximately the same solid angle than the [[Detectors#Cathode Readout Drift Chambers (CRDC)|CRDCs]]. The frontal and lateral sides of each crystal are covered with two 150-µm thick layers of a white Teflon reflective material to provide light shielding between the crystals. The photocathodes are connected to a [[https://groups.nscl.msu.edu/nscl_library/manuals/caen/MOD.N568B.pdf|CAEN N568B]] 16-channel shaper/amplifier, followed by a [[https://groups.nscl.msu.edu/nscl_library/manuals/phillips/7164H.pdf|Phillips 7164H]] 12-bit ADC. The signals from the crystals are gain-matched to a middle position in the ADC spectra by varying the biases of each photocathode. | The hodoscope is composed 32 sodium-doped cession iodide CsI(Na) scintillating crystals manufactured by [[http://www.scintitech.com/|ScintiTech]]. Each crystal is 5.1 cm-thick, has an active area of 7.6 cm x 7.6 cm, and is attached to a photomultiplier ([[https://www.hamamatsu.com/jp/en/R1307.html|Hamamatsu R1307]]). The photo-cathodes are made of a bi-alkali material with a transmission peak at 420 nm. The 32 crystals are arranged in eight rows of 4 crystals each so as to cover approximately the same solid angle than the [[Detectors#Cathode Readout Drift Chambers (CRDC)|CRDCs]]. The frontal and lateral sides of each crystal are covered with two 150-µm thick layers of a white Teflon reflective material to provide light shielding between the crystals. The photocathodes are connected to a [[https://groups.nscl.msu.edu/nscl_library/manuals/caen/MOD.N568B.pdf|CAEN N568B]] 16-channel shaper/amplifier, followed by a [[https://groups.nscl.msu.edu/nscl_library/manuals/phillips/7164H.pdf|Phillips 7164H]] 12-bit ADC. The signals from the crystals are gain-matched to a middle position in the ADC spectra by varying the biases of each photocathode. |
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| | {{:wiki:hodoscope-drawing.jpg?500 |Schematic layout of the S800 Hodoscope.}} |
| | {{ :wiki:hodoscope-picture.jpg?500|Schematic layout of the S800 Hodoscope.}} |
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