Fission Chambers for Out-of-Core Use CFUM 11
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Product specification CFUM11 Neutron detector Out-core fission chamber Application Features Detection of thermal neutrons in a flux range of 10 to 1011 n.cm-2.s-1 High safety of use Integral HN connector Nuclear characteristics at 20°C Sensitivity to thermal neutrons 1: Pulse mode Fluctuation mode Current mode 10-1 4x10-27 -14 10 Gamma sensitivity: Exposure limits: Gamma radiation: Thermal neutrons Exposure Dose rate 5 10 - 107 105 - 3x1010 7 11 10 - 10 n.cm-2.s-1 n.cm-2.s-1 -2 -1 n.cm .s 10-9 Pulse mode 2 Fluctuation mode 3 4 Current mode Neutron flux range : c.s-1/n.cm-2.s-1 A2.Hz-1/n.cm-2.s-1 -2 -1 A/n.cm .s A/Gy. h-1 19 -2 max 2x10 max 109 max 104 n.cm Gy Gy.h-1 Notes. Electrical characteristics 6 12 Insulating resistance at 600V : Operating voltage: min 10 7 Charge collection time : Detector: Capacitance 600 800 1300 V V V 50 Nominal up to 250°C Maximum at 20°C Limit with no radiation Ω ns 70 pF Unless otherwise stated, all characteristics are given at 20°C 1 Values depending on the characteristics and the calibration of the measurement equipment. The pulse sensitivity is calculated from the (α−neutron) discrimination curve for a discriminating threshold corresponding to a counting rate of 0.01 c.s-1. 2 Pulse mode operating range for a measurement equipment with a resolution shorter than the collection time of the detector. 3 Fluctuation operating range measured on an equipment with a 1 to 30 kHz band pass. 4 Current mode operating range: the lower limit of the current mode operating range depends on the electronics (especially on the input amplifier) and on the signal / parasitic current ratio (parasitic current = leakage current + gamma current + α-current). The upper limit is depending both on the detector and electronics (loss of linearity). 5 Flux corresponding to a 1 % sensitivity loss of the detector. 6 For sensible fission chambers (s > 0.1 c.s-1/n.cm-2.s-1), the αcurrent is predominant in relation to the leakage current from the insulators. The insulating resistance is then measured by the ratio ∆U/∆I of the I=f(U) curve determined without any ionizing radiation. 7 Charge collection time: the measured value depends on the electronics and on the cable capacitance. 8 The use of a gas mixture (Ar + N2) increases the electron velocity and therefore favours a short collection time. 9 In order to avoid humidity penetration during storage, the connector is closed with a cap to be removed just before use. As a general rule, prevent any humidity penetration at the connection level (refer to "Instructions for use and handling" in the package). Other connector types are possible . To be required when ordering. 10 Including temperature increase due to gamma radiation (effective above 104 Gy.h-1). The maximum operating temperature is indicated for pulse operating mode. The leakage current in the cables increases rapidly with temperature. It is therefore necessary to take into account this characteristic, which limits the maximum temperature so that the ratio of wanted signal/parasitic signal remains acceptable. 11 Vibration test conditions: frequency 60 Hz, amplitude ± 1.5 mm. Mechanical and physical characteristics Detector: Materials: Sensitive layer: Filling gas 8 (pressure) Dimensions: Nominal diameter Detector length Sensitive length Connector: Type 9 Insulator Case, electrodes Insulator Brazing Uranium enriched in 235U Mass Aluminium AI2O3 AgCu >90% 0.7 mg.cm-2 Argon + 4% nitrogen (at 400 kPa) 25.4 mm 227 mm 120 mm Watertight female HN Al2O3 21/01/2008

Product specification Neutron detector CFUM11 Outline (dimensions in mm) Max Limiting values Operating temperature Vibration (any axis) 10 11 Shock (perpendicular axis) 250 °C 200 m.s -2 500 m.s -2 The information furnished is believed to be accurate and reliable, but is not guaranteed and is subject to change without notice. No liability is assumed by PHOTONIS for its use. Performance data represents typical characteristics as individual product performance may vary. Customers should verify that they have the most current PHOTONIS product information before placing orders. No claims or...