The L3 Wire-amplifier NH19-6112
The L3 Wire Amplifier, type NH19-6112, designed by P. Rewiersma at Nikhef-H Amsterdam in February 1986, outlines the design considerations and performance of a hybrid linear amplifier for the muon detector in the LEP L3 experiment. The amplifier utilizes thin-film technology on a 0.32 x 1.0 inch alumina substrate and features a ten-pin single in-line pin-out. The circuit has an amplification factor of 25 mV/µA and an output rise time of 4 ns. It can drive a 100-ohm twisted-pair cable with a standing power dissipation of only 30 mW. The document includes sections on the introduction, design considerations, circuit description, amplifier performance, application notes, production, testing and reliability, references, electrical schematic, electrical specifications, part list, mechanical specifications, and layout of the hybrid circuit. The L3 muon detector comprises approximately 7000 Z-layer and 24000 P-layer wires, divided into two sections known as Ferris wheels. The Z-layer wires are read out individually, while signals from opposite P-layer wires are combined into a single amplifier for reduced channel count.
The L3 Wire Amplifier is tailored to meet the specific requirements of the muon detector's drift chambers, which are critical for high-resolution muon track detection. The design emphasizes the need for rapid signal processing, as the avalanche signals from the 6-meter long anode wires are subject to bandwidth limitations. Accurate timing extraction from the rising edge of the avalanche signal is essential for precise detection. Testing indicates that if the rise time of the wire amplifier is less than 5 ns, its impact on accuracy is negligible. Optimal drift time resolution is achieved by setting the discriminator threshold to correspond with the eighth arriving primary electron, which translates to approximately 1 µA peak wire current. The wire amplifier's noise must remain significantly below this threshold, ideally between -20 dB and -30 dB, ensuring that the amplifier gain of 24 mV/µA is adequate for effective discriminator triggering.
Given the high density of amplifiers required for the L3 muon detector—over 21,000 electronic channels, including amplifiers, discriminators, and time-to-digital converters (TDCs)—thermal management and spatial constraints are critical. To minimize heat generation and volume within the L3 magnet, the design separates the wire amplifiers from the discriminators, which are located outside the magnet. This separation significantly reduces the power dissipation inside the magnet, as discriminators can consume up to 250 mW per channel. The wire amplifier is engineered to effectively drive a 100-ohm twisted-pair cable, accommodating lengths of up to 25 meters, thus ensuring reliable signal transmission without significant loss or degradation. The comprehensive design and performance characteristics of the L3 Wire Amplifier exemplify the sophisticated engineering required for advanced particle detection applications in high-energy physics.THE L3 WIRE - AMPLIFIER TYPE NH19-6112 P. REWIERSMA NIKHEF-H AMSTERDAM FEBRUARY 1986 Abstract: This note describes in detail the design considerations and performance of the hybrid linear amplifier for the muon detector in the LEP L3 experiment. The L3 WIRE - AMPLIFIER is hybridized in thin-film technology on a 0. 32 x 1. O inch alumina substrate an d has a ten pins single-in_line pin-out. The circuits amplification factor is 25 mV/uA and has an output rise-time of 4 ns. The L3 WIRE - AMPLIFIER outputs can drive 100 ohm twisted-pair cable. The standing power dissipation of the amplifier is only a mere 30 mW. - Contents 1] Introduction 2] Design Considerations 3] Circuit Description 4] Amplifier Performance 5] Application Notes 6] Production, Testing and Reliability 7] References 8] Picture and Figure Captions 9] Electrical Schematic 10] Electrical Specifications 11] Partlist 12] Mechanical Specifications 13] Layout of Hybrid Circuit 1] Introduction [Back to Contents] The LEP 3 muon detector [1] subdivides into appr. 7000 Z-layer and 24000 P-layer wires, equally divided over two sections, the so called Ferris wheels.
The Z-layer wires are read out individually. For the P-layer wires however, the signals from opposite wires in the two Ferris wheels are combined into one amplifier for channel count reduction. The L3 muon detectors aim for high resolution muon track detection and are essentially multiwire driftchambers with < 150 um wire resolution.
Multiple sampling brings the sagitta resolution down to < 50 um [2] [3]. The amount of channels to be installed for the L3 muon detector justified the custom design and hybridization of fully object taylored channel electronics. The total number of electronic channels -i. e. amplifiers, discriminators and TDCs- for the L3 muon detector is over 21000. This note highlights the design considerations and the electronic performance of single channel hybrid L3 WIRE-AMPLIFIER type NH19-6112.
2] Design Considerations [Back to Contents] The demanded performance of the amplifier is set by the operating parameters of the muon detector driftchambers. The avalanche signals from the 6 meter long anode wires are degraded by the finite bandwidth of the wire/pre-amp system.
For high accuracy detection set-ups like the L3 muon detector, the timing information in the rising-edge of the avalanche signal has to be extracted as accurate as possible. The results obtained from tests with a proto-type muondetector show that the contribution of wire-amplifier on the final accuracy degradation can be neglected if its rise-time is better than 5 ns.
Optimum drift time resolution is reached when the discriminator threshold is set to a level corresponding to the 8th arriving primary electron [3]. The gas amplification of the driftchambers is appr. 50k and an average of 100 primary electrons are collected on the wire for a minimum ionizing muon passing through the detector.
Studies of the time development of the anode wire signal translate the level setting of the discriminator threshold - the 8th electron - to appr. 1 uA peak wire current. The noise of the wire-amplifier must be well below this level ( - 20 dB to - 30 dB ) An amplifier gain of 24 mV/uA is considered sufficient for practical discriminator trigger levels ( MVL407 with threshold > 10 mV ).
The large amount of amplifiers situated in the confined space between the two Ferris wheels puts severe constraints on the overall heat generation and the occupied volume of the installed electronics. It was therefore decided to install only the wire-amplifiers inside and to put the discriminators outside the L3 magnet.
This reduces the power dissipation inside the L3 magnet substantially - discriminators can dissipate as much as 250 mW per channel. Having the wire-amplifier and the discriminator separated means that the wire-amplifier must drive a 100 ohms twisted-pair cable with a length of up to 25 met
🔗 External reference
The L3 Wire Amplifier is tailored to meet the specific requirements of the muon detector's drift chambers, which are critical for high-resolution muon track detection. The design emphasizes the need for rapid signal processing, as the avalanche signals from the 6-meter long anode wires are subject to bandwidth limitations. Accurate timing extraction from the rising edge of the avalanche signal is essential for precise detection. Testing indicates that if the rise time of the wire amplifier is less than 5 ns, its impact on accuracy is negligible. Optimal drift time resolution is achieved by setting the discriminator threshold to correspond with the eighth arriving primary electron, which translates to approximately 1 µA peak wire current. The wire amplifier's noise must remain significantly below this threshold, ideally between -20 dB and -30 dB, ensuring that the amplifier gain of 24 mV/µA is adequate for effective discriminator triggering.
Given the high density of amplifiers required for the L3 muon detector—over 21,000 electronic channels, including amplifiers, discriminators, and time-to-digital converters (TDCs)—thermal management and spatial constraints are critical. To minimize heat generation and volume within the L3 magnet, the design separates the wire amplifiers from the discriminators, which are located outside the magnet. This separation significantly reduces the power dissipation inside the magnet, as discriminators can consume up to 250 mW per channel. The wire amplifier is engineered to effectively drive a 100-ohm twisted-pair cable, accommodating lengths of up to 25 meters, thus ensuring reliable signal transmission without significant loss or degradation. The comprehensive design and performance characteristics of the L3 Wire Amplifier exemplify the sophisticated engineering required for advanced particle detection applications in high-energy physics.THE L3 WIRE - AMPLIFIER TYPE NH19-6112 P. REWIERSMA NIKHEF-H AMSTERDAM FEBRUARY 1986 Abstract: This note describes in detail the design considerations and performance of the hybrid linear amplifier for the muon detector in the LEP L3 experiment. The L3 WIRE - AMPLIFIER is hybridized in thin-film technology on a 0. 32 x 1. O inch alumina substrate an d has a ten pins single-in_line pin-out. The circuits amplification factor is 25 mV/uA and has an output rise-time of 4 ns. The L3 WIRE - AMPLIFIER outputs can drive 100 ohm twisted-pair cable. The standing power dissipation of the amplifier is only a mere 30 mW. - Contents 1] Introduction 2] Design Considerations 3] Circuit Description 4] Amplifier Performance 5] Application Notes 6] Production, Testing and Reliability 7] References 8] Picture and Figure Captions 9] Electrical Schematic 10] Electrical Specifications 11] Partlist 12] Mechanical Specifications 13] Layout of Hybrid Circuit 1] Introduction [Back to Contents] The LEP 3 muon detector [1] subdivides into appr. 7000 Z-layer and 24000 P-layer wires, equally divided over two sections, the so called Ferris wheels.
The Z-layer wires are read out individually. For the P-layer wires however, the signals from opposite wires in the two Ferris wheels are combined into one amplifier for channel count reduction. The L3 muon detectors aim for high resolution muon track detection and are essentially multiwire driftchambers with < 150 um wire resolution.
Multiple sampling brings the sagitta resolution down to < 50 um [2] [3]. The amount of channels to be installed for the L3 muon detector justified the custom design and hybridization of fully object taylored channel electronics. The total number of electronic channels -i. e. amplifiers, discriminators and TDCs- for the L3 muon detector is over 21000. This note highlights the design considerations and the electronic performance of single channel hybrid L3 WIRE-AMPLIFIER type NH19-6112.
2] Design Considerations [Back to Contents] The demanded performance of the amplifier is set by the operating parameters of the muon detector driftchambers. The avalanche signals from the 6 meter long anode wires are degraded by the finite bandwidth of the wire/pre-amp system.
For high accuracy detection set-ups like the L3 muon detector, the timing information in the rising-edge of the avalanche signal has to be extracted as accurate as possible. The results obtained from tests with a proto-type muondetector show that the contribution of wire-amplifier on the final accuracy degradation can be neglected if its rise-time is better than 5 ns.
Optimum drift time resolution is reached when the discriminator threshold is set to a level corresponding to the 8th arriving primary electron [3]. The gas amplification of the driftchambers is appr. 50k and an average of 100 primary electrons are collected on the wire for a minimum ionizing muon passing through the detector.
Studies of the time development of the anode wire signal translate the level setting of the discriminator threshold - the 8th electron - to appr. 1 uA peak wire current. The noise of the wire-amplifier must be well below this level ( - 20 dB to - 30 dB ) An amplifier gain of 24 mV/uA is considered sufficient for practical discriminator trigger levels ( MVL407 with threshold > 10 mV ).
The large amount of amplifiers situated in the confined space between the two Ferris wheels puts severe constraints on the overall heat generation and the occupied volume of the installed electronics. It was therefore decided to install only the wire-amplifiers inside and to put the discriminators outside the L3 magnet.
This reduces the power dissipation inside the L3 magnet substantially - discriminators can dissipate as much as 250 mW per channel. Having the wire-amplifier and the discriminator separated means that the wire-amplifier must drive a 100 ohms twisted-pair cable with a length of up to 25 met
🔗 External reference