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Metu-Defocusing Beamline - A 15-30 Mev Proton Irradiation Facility and Beam Measurement System

MetadataDetails
Publication Date2020-01-01
JournalEPJ Web of Conferences
AuthorsB. Demirköz, Caner Seckin, Akanay Avaroğlu, Besna Bulbul, Pelin Uslu
InstitutionsEuropean Organization for Nuclear Research, Middle East Technical University
Citations8
AnalysisFull AI Review Included

Technical Documentation & Analysis: MPCVD Diamond for High-Flux Proton Irradiation Facilities

Section titled “Technical Documentation & Analysis: MPCVD Diamond for High-Flux Proton Irradiation Facilities”

This document analyzes the requirements of the METU-DBL proton irradiation facility, focusing on the critical role of diamond detectors in high-radiation environments, and aligns these needs with 6CCVD’s advanced MPCVD diamond material solutions.


The METU-DBL project establishes a high-flux proton irradiation facility (15-30 MeV) primarily for testing materials and electronics intended for extreme radiation environments, such as the Hi-Lumi LHC and space applications.

  • Core Application: Testing for Single Event Effects (SEE) in sensitive electronic devices, adhering to the stringent ESA/ESCC No: 25100 standard.
  • Critical Material: Diamond detectors are explicitly used for proton flux measurement and calibration due to their superior radiation endurance compared to silicon-based sensors.
  • Performance Requirement: Detectors must operate reliably under high proton fluxes, demonstrated by pretest measurements reaching up to $1.88 \times 10^{11}$ p/cm2/s.
  • Material Specification: The diamond detector utilizes a single diamond crystal positioned between two gold electrodes, requiring high-purity Single Crystal Diamond (SCD) and precise metalization.
  • 6CCVD Value Proposition: 6CCVD provides the necessary high-purity, custom-dimensioned MPCVD SCD and specialized metalization services required to replicate and advance these high-performance radiation detection systems.

The following hard data points are extracted from the METU-DBL paper, highlighting the extreme operating conditions and material requirements.

ParameterValueUnitContext
Proton Energy Range (Facility)15 - 30MeVTAEA SANAEM PAF Cyclotron
ESA/ESCC Standard Energy Range20 - 200MeVRequired for SEE tests
Achievable Flux Range (METU-DBL)105 - 1011p/cm2/sWide selectable flux menu
Maximum Pretest Flux Measured1.88 x 1011p/cm2/sMeasured by diamond detector
Target Beam Area (ESA/ESCC)15.40 x 21.55cm2Required beam size
Beam Uniformity (ESA/ESCC)± 10%Required homogeneity across target area
Beamline Vacuum Level10-6mbarDesired operating pressure
Cooling Subsystem Power50kWRequired for magnets and beam elements
Custom Quadrupole Gradient Strength7.5T/mCritical for achieving ESA/ESCC standard beam profile
Diamond Detector ConfigurationSingle Crystal, Gold ElectrodesN/AUsed for high-end flux measurement

The METU-DBL facility employs advanced techniques for beam monitoring and material testing in a high-radiation environment.

  1. Standard Compliance: The facility adheres strictly to the ESA/ESCC No: 25100 standard for Single Event Effects (SEE) testing, dictating specific requirements for energy range, flux, and beam uniformity.
  2. Beam Monitoring System: Proton beam flux and uniformity are measured using a combination of detectors: TimePix3 pixel detectors, fiber scintillators, and small area diamond detectors.
  3. Diamond Detector Utilization: Diamond detectors are specifically chosen for spot checks and calibration due to their inherent radiation endurance (mentioned as superior to other detectors whose performance might suffer due to radiation damage).
  4. Target Area Scanning: The test table utilizes movable X-Y stages to scan the target area (up to $\pm 760$ mm in X-axis) with 3 mm accuracy, ensuring the Device Under Test (DUT) is positioned where the required $\pm 10$% beam homogeneity is met.
  5. Beam Enlargement and Flux Control: Quadrupole magnets (up to 7.5 T/m gradient strength) are used to enlarge the beam to meet the ESA/ESCC area requirement, while an adjustable conical collimator (aperture 1 x 1 mm2 to 10 x 10 mm2) is used to precisely control the proton flux.
  6. Thermal Management: A 50 kW cooling subsystem manages the heat generated by high currents and secondary particles, including a specialized helium chamber design to cool the titanium scattering foils.

The successful operation of the METU-DBL facility relies on materials that maintain integrity under extreme proton flux. 6CCVD is uniquely positioned to supply the high-purity MPCVD diamond required for these advanced radiation detection and monitoring systems.

Research Requirement6CCVD Material RecommendationTechnical Rationale
High Radiation Endurance (Required for flux monitoring up to 1011 p/cm2/s)Optical Grade Single Crystal Diamond (SCD)Highest purity (low nitrogen content) ensures minimal defect creation and stable charge collection efficiency, critical for long-term operation in high-dose environments (e.g., Hi-Lumi LHC).
Large Area Beam Monitoring (20 cm x 15 cm target area)High-Quality Polycrystalline Diamond (PCD)Available in large plates/wafers up to 125mm. Offers excellent thermal management and sufficient radiation hardness for large-area beam profile screens or monitoring arrays.
High-Resolution Detection (Timepix3 and small area diamond detectors)SCD Wafers with Ultra-Precise ThicknessSCD available from 0.1 ”m to 500 ”m. Precise thickness control is essential for optimizing energy deposition and maximizing signal-to-noise ratio in particle detection.

The diamond detector described in the paper—a single crystal with gold electrodes—is a perfect match for 6CCVD’s custom fabrication services.

  • Custom Dimensions and Shaping: 6CCVD provides custom laser cutting and shaping services to match the exact dimensions required for integration into the movable X-Y stages and detector housings (e.g., the small area diamond detector used for spot checks).
  • Advanced Metalization: The paper specifies the use of gold (Au) electrodes. 6CCVD offers internal metalization capabilities, including:
    • Electrode Deposition: Custom deposition of Au, Pt, Pd, Ti, W, or Cu stacks directly onto the SCD or PCD substrate.
    • Patterning: Precise photolithographic patterning of electrodes for pixelated or strip detector designs, enhancing performance for high-resolution flux mapping.
  • Surface Finish: For optimal electrical contact and minimal surface scattering, 6CCVD guarantees ultra-smooth polishing:
    • SCD: Surface roughness (Ra) < 1nm.
    • Inch-size PCD: Surface roughness (Ra) < 5nm.

6CCVD’s in-house PhD team specializes in the material science and engineering of diamond for extreme environments. We can assist researchers and engineers with material selection, doping levels (e.g., Boron-Doped Diamond, BDD, for conductive applications), and optimal surface preparation for similar Proton Accelerator Facility, Space Radiation, and Single Event Effect (SEE) projects.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Middle East Technical University - Defocusing Beam Line (METU-DBL) project is an irradiation facility providing 15 MeV to 30 MeV kinetic energy protons for testing various high radiation level applications, ranging from Hi-Lumi LHC upgrade, space electronic components to nuclear material research. The project located inside the premises of the TAEA (Turkish Atomic Energy Agency) SANAEM (Saraykoy Nuclear Education and Research Center) close to Ankara, provides users a wide selectable flux menu (10 5 -10 10 p/cm 2 /s). The facility is now being commissioned and the facility will be providing a large test area (20 cm x 15 cm) for material, detector and electronics tests. The proton beam is monitored along the beamline using aluminum oxide screens and the flux and uniformity is measured using three detectors attached to the robotic system for cross- checks. A fiber scintillator detector scans the large irradiation area while small area diamond detector and Timepix3 detector are used for spot checks for calibration. Several samples can be radiated simultaneously inside the irradiation area and the robotic system provides 5 separate holders for samples which can be moved in or out, providing users flexibility for the desired fluence. This talk will first introduce METU- DBL as a radiation test facility, then discuss the radiation monitoring of the beam area and the radiation room, while highlighting how this facility can be used for future testing of materials for radiation tolerance.