Difference between revisions of "Active Collimator Interface Specification"
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The collimator provides 8 outputs that are dependent on current and position. The outputs have the following characteristics, listed below. Lead shielded local amplification is necessary within 1 m of the device in order to limit bandwidth truncation due to the extra input capacitance of the coaxial cable. Digital electronics are to be located elsewhere, in a VME crate mounted in an electronics rack in Hall D proper. The x,y position coordinates are computed from the 8 measured currents through an algorithm to be provided by the UConn group. | The collimator provides 8 outputs that are dependent on current and position. The outputs have the following characteristics, listed below. Lead shielded local amplification is necessary within 1 m of the device in order to limit bandwidth truncation due to the extra input capacitance of the coaxial cable. Digital electronics are to be located elsewhere, in a VME crate mounted in an electronics rack in Hall D proper. The x,y position coordinates are computed from the 8 measured currents through an algorithm to be provided by the UConn group. | ||
| − | + | ====System Requirements==== | |
# Position measurements | # Position measurements | ||
#* 500 pA to 5 μA electron beam | #* 500 pA to 5 μA electron beam | ||
| − | #* 200 μm resolution | + | #* 200 μm RMS resolution on photon beam centroid at collimator entrance |
| − | #* bandwidth is 1 kHz above 50 nA, and | + | #* bandwidth is 1 kHz above 50 nA, and I(electron beam)/50nA in kHz below 50 nA |
# Feedback control | # Feedback control | ||
#* bandwidth 1 kHz | #* bandwidth 1 kHz | ||
#* latency less than 150 μs | #* latency less than 150 μs | ||
| − | |||
# 8 preamplifiers | # 8 preamplifiers | ||
#* dc gain dynamically selectable in 6 discrete ranges: 10<sup>12</sup>, 10<sup>11</sup>, 10<sup>10</sup>, 10<sup>9</sup>, 10<sup>8</sup>, 10<sup>7</sup>, 10<sup>6</sup> V/A | #* dc gain dynamically selectable in 6 discrete ranges: 10<sup>12</sup>, 10<sup>11</sup>, 10<sup>10</sup>, 10<sup>9</sup>, 10<sup>8</sup>, 10<sup>7</sup>, 10<sup>6</sup> V/A | ||
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#* bipolar output signals with range [-10, 10] V | #* bipolar output signals with range [-10, 10] V | ||
#* preamp bandwidth: varies with gain range, compute using gain-bandwidth product | #* preamp bandwidth: varies with gain range, compute using gain-bandwidth product | ||
| − | #* all 6 ranges have the same gain-bandwidth product: | + | #* all 6 ranges have the same gain-bandwidth product: 10<sup>13</sup> Hz * V/A |
#* bandwidth in any gain setting obtained as (gain-bandwidth product) / (dc gain) | #* bandwidth in any gain setting obtained as (gain-bandwidth product) / (dc gain) | ||
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# 8 analog outputs from the active collimator readout board | # 8 analog outputs from the active collimator readout board | ||
#* x+ coarse, x- coarse, x+ fine, x- fine, y+ coarse, y- coarse, y+ fine, y- fine | #* x+ coarse, x- coarse, x+ fine, x- fine, y+ coarse, y- coarse, y+ fine, y- fine | ||
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#* coarse outputs gain: 100 mV difference / cm | #* coarse outputs gain: 100 mV difference / cm | ||
#* fine outputs gain: 10 V difference / cm | #* fine outputs gain: 10 V difference / cm | ||
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# 2 analog magnet control outputs | # 2 analog magnet control outputs | ||
#* single ended (?) | #* single ended (?) | ||
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#* ? kHz bandwidth | #* ? kHz bandwidth | ||
#* ? resolution | #* ? resolution | ||
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# Digital I/O | # Digital I/O | ||
#* Beam Sync input for pulsed mode | #* Beam Sync input for pulsed mode | ||
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#** ? kHz bandwidth | #** ? kHz bandwidth | ||
#* Other and/or spare I/O ? | #* Other and/or spare I/O ? | ||
| − | |||
# EPICS control | # EPICS control | ||
#* remote gain control for preamps, independent 3-bit values for 8 channels | #* remote gain control for preamps, independent 3-bit values for 8 channels | ||
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#** adjustable up to 4k points at 4ksps, triggered by 30Hz or Beam Sync for Ops | #** adjustable up to 4k points at 4ksps, triggered by 30Hz or Beam Sync for Ops | ||
#** circular buffers for FSD captures for Ops | #** circular buffers for FSD captures for Ops | ||
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# Physics analog outputs for Hall D data acquisition system | # Physics analog outputs for Hall D data acquisition system | ||
#* 8 buffered analog outputs providing raw collimator sector currents | #* 8 buffered analog outputs providing raw collimator sector currents | ||
#* 8 analog outputs for processed signals (x+/x- coarse and fine, y+/y- coarse and fine) | #* 8 analog outputs for processed signals (x+/x- coarse and fine, y+/y- coarse and fine) | ||
#* signals will be digitized and recorded using standard GlueX data acquisition | #* signals will be digitized and recorded using standard GlueX data acquisition | ||
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# Physics digital data outputs | # Physics digital data outputs | ||
#* none | #* none | ||
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# 4 diagnostic analog outputs (?) | # 4 diagnostic analog outputs (?) | ||
#* single ended (?) | #* single ended (?) | ||
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#* ? kHz bandwidth | #* ? kHz bandwidth | ||
#* ? resolution | #* ? resolution | ||
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# 2 diagnostic analog inputs (?) | # 2 diagnostic analog inputs (?) | ||
#* single ended (?) | #* single ended (?) | ||
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#* ? kHz bandwidth | #* ? kHz bandwidth | ||
#* ? resolution | #* ? resolution | ||
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# Account code? | # Account code? | ||
Latest revision as of 12:19, 5 February 2013
The collimator provides 8 outputs that are dependent on current and position. The outputs have the following characteristics, listed below. Lead shielded local amplification is necessary within 1 m of the device in order to limit bandwidth truncation due to the extra input capacitance of the coaxial cable. Digital electronics are to be located elsewhere, in a VME crate mounted in an electronics rack in Hall D proper. The x,y position coordinates are computed from the 8 measured currents through an algorithm to be provided by the UConn group.
System Requirements
- Position measurements
- 500 pA to 5 μA electron beam
- 200 μm RMS resolution on photon beam centroid at collimator entrance
- bandwidth is 1 kHz above 50 nA, and I(electron beam)/50nA in kHz below 50 nA
- Feedback control
- bandwidth 1 kHz
- latency less than 150 μs
- 8 preamplifiers
- dc gain dynamically selectable in 6 discrete ranges: 1012, 1011, 1010, 109, 108, 107, 106 V/A
- exact dc gain depends on termination load used on output
- nominal values above are stated by manufacturer for 100 Ohm load
- plans are to use 75 Ohm output cable (RG-59/U or equivalent)
- coordinates computed from diff/sum ratios, independent of gain scale
- bipolar output signals with range [-10, 10] V
- preamp bandwidth: varies with gain range, compute using gain-bandwidth product
- all 6 ranges have the same gain-bandwidth product: 1013 Hz * V/A
- bandwidth in any gain setting obtained as (gain-bandwidth product) / (dc gain)
- 8 analog outputs from the active collimator readout board
- x+ coarse, x- coarse, x+ fine, x- fine, y+ coarse, y- coarse, y+ fine, y- fine
- differential outputs (four signals, each in +/- pairs)
- each output is unipolar from 0 to 2 V
- output circuits have >1 kHz bandwidth
- coarse outputs gain: 100 mV difference / cm
- fine outputs gain: 10 V difference / cm
- 2 analog magnet control outputs
- single ended (?)
- unipolar from 0 to ? V (?)
- ? kHz bandwidth
- ? resolution
- Digital I/O
- Beam Sync input for pulsed mode
- 30 Hz input for line sync of waveforms
- 4(?) BPM inputs (just to be safe?)
- 0.5 nA to 5 μA electron beam
- ? kHz bandwidth
- Other and/or spare I/O ?
- EPICS control
- remote gain control for preamps, independent 3-bit values for 8 channels
- coarse and fine position read backs at 1 Hz for Ops
- waveform buffers
- adjustable up to 4k points at 4ksps, triggered by 30Hz or Beam Sync for Ops
- circular buffers for FSD captures for Ops
- Physics analog outputs for Hall D data acquisition system
- 8 buffered analog outputs providing raw collimator sector currents
- 8 analog outputs for processed signals (x+/x- coarse and fine, y+/y- coarse and fine)
- signals will be digitized and recorded using standard GlueX data acquisition
- Physics digital data outputs
- none
- 4 diagnostic analog outputs (?)
- single ended (?)
- bipolar +/- V (?)
- ? kHz bandwidth
- ? resolution
- 2 diagnostic analog inputs (?)
- single ended (?)
- bipolar +/- V (?)
- ? kHz bandwidth
- ? resolution
- Account code?
