Alignment Electronics for the New Small Wheel



nSW Review
CERN, 12-MAR-15


Kevan Hashemi
Physics Department
Brandeis University
http://alignment.hep.brandeis.edu

Contents

Alignment System
Alignment Electronics
Requirements of nSW
Obsolete Image Sensor
Existing H-BCAM
Existing Bar Head
Linearity of ICX424AL BCAM
Changes Required by ICX424
Simulated nSW Doses
Expected Doses and Test Facilities
Ionizing Radiation Tolerance
Neutron Radiation Tolerance
Single Event Upset Tests
Conclusion
Appendix: Linearity with Quadruple-Pixel Readout
Appendix: Energy Spectrum of Photons and Neutrons
Appendix: Dose Rate Spectrum of Photons and Neutrons
Appendix: Dose Map from Background Group

Alignment System

Alignment Electronics

Requirements of nSW

In the Alignment Bars, and for N-BCAMs and H-BCAMs, we address these challenges as follows:

Obsolete Image Sensor

Property KAC00401 ICX424AL TC255P
Manufacturer Eastman Kodak Sony Semiconductor Texas Instruments
Technology CMOS CCD CCD
Sensor Area 5.1 mm × 3.3 mm 5.8 mm × 4.8 mm 3.4 mm × 2.4 mm
Pixel Dimensions 6.7 μm × 6.7 μm 7.4 μm × 7.4 μm 10 μm × 10 μm
Fill Factor Estimate <80% Observe ≈100% Observe >90%
Uniformity of Dark Current 10% 1% 1%
Uniformity of Sensitivity 10% 1% 1%
Package Size 12.2 mm × 12.2 mm 12.2 mmm × 9.5 mm 10.0 mm × 10.0 mm
Control Interface Volatile Configuration Bits Clock Voltages Clock Voltages
Output Format Serial Digital Pixel Voltages Pixel Voltages
Price ≈$40 $40 ≈$40
Table: Comparison of Image Sensors.

Existing H-BCAM


Figure: The H-BCAM. Installed and operating in HIE-ISOLDE.

Existing Bar Head


Figure: The Bar Head (A2082A). Provides connection to four ICX424 image sensors, four 100-Ω RTDs, and four Blue Nine-LED Arrays.

Linearity of ICX424AL BCAM


Figure: ICX424 BCAM Non-Linearity Across Entire Field of View. Pixels 7.4 μm square. Residuals in microns on sensor plotted versus stage position. Image sharply-focused. Two red lasers at 3.1 m on 300-mm stage, camera focal range 3 m, lens focal length 48 mm, camera V0359. Repeat with poorly-focused spot residuals remain 0.2 μm rms.

Changes Required by ICX424

Simulated nSW Doses


Figure: Simulated Dose Rate versus Radius in nSW After Ten Years. Assume luminosity 5×1034 1/cm2s, beam energy 14 TeV, run time 107 s/yr. Unit 1 Tn means 1012 1-MeV eq. neutrons/cm2. Unit 1 Gy means 1 J/kg ionization energy in Si. Doses we designed for in oSW were 20 Gy and 0.8 Tn.

Expected Doses and Test Facilities

Expect the following doses after ten years running in nSW.

We have made repeated use of the following test facilities:

Ionizing Radiation Tolerance


Figure: ICX424 Quadruple-Pixel Image after 450 Gy. Circle is tungston sphere absorber.

Neutron Radiation Tolerance

Single Event Upset Tests

Conclusion

Appendix: Linearity with Quadruple-Pixel Readout


Figure: ICX424 BCAM Non-Linearity Across Entire Field of View with Quadruple-Pixel Readout. Pixels 14.8 μm square. Residuals in microns on the image sensor plotted versus stage position. Image sharply-focused. Two red lasers at 3.1 m on 300-mm stage, lens focal length 48 mm, camera V0359. Repeat with poorly-focused spot residuals remain 0.2 μm rms.

Appendix: Energy Spectrum of Photons and Neutrons


Figure: Simulated Spectra of Photons and Neutrons at Inner Edge of nSW. Bin for <=1keV contains 40,000 thermal neutrons.

Appendix: Dose Rate Spectrum of Photons and Neutrons


Figure: Simulated Dose Rate Spectrum for Photons and Neutrons at Inner Edge of nSW.

Appendix: Dose Map from Background Group


Figure: Simulated Total Annual Ionizing Dose, Gy/yr. Luminosity 1034 1/cm2s, energy 14 TeV, 107 s running per year, 2012 detector geometry.