ATLAS SCT (Semiconductor Tracker)

SPICE simulation: 1E6 mip/pulse plot
SPICE simulation: 1E7 mip/pulse plot
SPICE simulation: 1E8 mip/pulse plot
Hot spot system manuals: PDF, DOC,
Module Testing with Nd:YAG Laser (PDF), (PPT), SCT week 2003 Dec 03
Laser System for Testing SCT Modules (PDF), JPS Miyazaki 2003
Characteristics of Irradiated Silicon Microstrip Detectors with 100 and 111 Substrates, Hiroshima STD Symposium, 2000 (PDF)
Radiation Damage Studies of Silicon Microstrip Sensors (PDF)
IEEE Trans on NS, 47-6 (2000) 1885-1891 (IEEE99 Symposium, Seattle USA).
レーザーを用いた性能評価
Quality of Production Sensors
Precision Module Assembly
QA Test Plan at Production
Laser Scan for Overall Performance Evaluation
Si Irradiation Studies
Kapton Hybrid Testing

Quality of production sensors for SCT-B2

• Statistics of 2000+ (pre)series and production sensors (Oct 2001)
• Statistics of 1093 (pre)series and production sensors (SCT week, June 2001)
• Statistics of 256 pre-series sensors (Sept 2000)
• Statistics of 148 pre-series sensors (July 2000)
• Implant-open of sample detectors (2 per lot) (Mar 2001)

Precision Module Assembly

• Planarity of Hamamatsu Si sensors, compared between single- and double-sided sensors. Bowing is due to smaller CTE of SiO2 than of Si-bulk (sensors are flat at oxidation), which is more obvious for single-sided sensors.
• Planarity of a module (I): Mechanical module is assembled using 4 single sided sensors and a CFRP baseboard (1999/05/24). The reference plane which defines the coordinate system is determined at detector corners with assuming detector thickness of 300 um.
• Planarity of a module (II): Mechanical module is assembled using 4 Glass plates and a CFRP baseboard (1999/05/20). The reference plane is determined from the facings (facing thicknesses are measured using a micrometer).
• Z profile of K3301 module, which was beamtested in Dec 1999. The reference plane is determined by the facings, and only the profile of the up side (the side with "ears" in the facing) is shown.
• Z profile of K3103 module, which was beamtested in Dec 1999. The reference plane is determined by the facings, and only the profile of the up side (the side with "ears" in the facing) is shown.

Kapton Hybrid Testing

• cover page
• describe the tested electrical module
• describe daq system
• photo of the module (heavy... 1.3M)
• example of S-curve
• linerity fit
• gain/offset histograms for chip-1
• gain/offset histograms for chip-12
• summary of gain (FE bias dependence)
• summary of offset (FE bias dependence)
• noise histograms for chip-1 (w/ w/o bond)
• noise histograms for chip-12 (w/ w/o bond)
• summary of noise (FE bias dependence)
• summary

Irradiation Studies

• Edge resistance of proton irradiated samples.
  (Unirradiated) p-in-n sensors are possible to bias from front side using the N+ edge ring. It is measured that the edge resistance of irradiated (p-in-p) samples is high and therefore biasing this way is not adequate, which otherwise would be easier in construction point of view.
  Measurement plot only

Laser scan

The performance of assembled silicon detectors are planned to be tested using a laser injection system. The laser system uses a Nd:YAG laser with the emission peak at 1064nm. See, Y. Unno et al., "A new laser test stand for simulating charged particle tracks", NIM A383. Two plots are given here to demonstrate the initial performance. The tested detector consists of one n-on-n sensor with 768 strips. Every channel is read out via in total 6 ABCD chips mounted on a kapton hybrid. The laser intensity was adjusted with ND filters and polarizers such that the output corresponds to a mip signal (ca.300 mV). The laser spot size is roughly 1 micron square. The number of events is 100 at each data point.


• Response in the region between two strips
  The two curves in each plot are efficiencies of CH1 (in red) and CH2 (in green) as a function of the threshold voltage. Injected positions are (A) on n+ strip of CH1 (located not to hit the Al electrode); (B) midpoint between n+ and p-stop; (C) center of the p-stop strip close to CH1; (D) midpoint between the two p-stop strips; and (E) center of the p-stop strip close to CH2. The laser position is about 8 mm along the strip from the readout end.
  
  
• More systematic measurement of the transverse response
  Resonse of two neighboring channels with laser focus on the sensor surface/100 micron inside the sensor
  Bias voltage at 200V
  Bias voltage at 100V
  (Laser intensity not identical in these voltage settings)
  
  
• Pulse height and efficiencies
  The top plot shows the threshold in mV at 50% efficiency (median) as a function of strip number. The laser was injetced on sampling strips (at position (B) of the above) of channles 0, 20, 40,.., 100, 140, 180,..., 740, 767 (counting from 0). The bottom plot shows the efficiencies at a threshold voltage of 150 mV of the laser injected strip (red), and its neighbors (green and blue).

  The leakage current of this silicon sensor was high and the following 24 channels have been laser trimmed at the readout traces: 69, 145, 164, 212, 214, 216, 242, 243, 245, 248, 288, 289, 292, 308, 314, 337, 339, 420, 580, 587, 635, 718, 720.
  
  

• Pulse height stability studies
  The median pulse height (threshold voltage at 50% efficiency) was measured with keeping the laser system conditions (laser power, spot size, detector conditons) unchanged. Two series of measurements were done for 2 hours; one with the laser on for 12 hr before measurement and anoher with the laser off for two hours. The rms variations were 1.2% and 1.7%, respectively.
  
  
• Pulse height dependence on the laser focus
  The laser focal point was varied at a step fo 20-40 microns and the output pulse height was measured. The top plot shows the median pulse height (mV) and the bottom shows the slope (resolution) normalized by the pulse height. Positive Z means that the focal point is above the detector surface and negative Z means that the focal point is inside the detector (300 microns thick).
  Typical threshold curves at Z=0, +80, and -240 microns are shown here.

QA Plan at Production

Plots shown at MassProduction Workshop at KEK (Jan 7-8, 1999)
• Overall scheme of QA procedure
• QA for FEE chips
• QA at hybrid assembly
• QA at module assembly
• QA with p-irradiation
• explanation of Data Run, procedure, result
• explanation of laser scan