Laser graphitization for polarization of diamond sensors

Parrini, G.

doi:10.22323/1.143.0017

Cited by 6 publications

(8 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While both the laser sources were employed in the fabrication of the 3D electrodes, all the superficial contacts were made engraving the diamond surface with the nanosecond Nd:YAG beam. We found [12] that superficial contacts made in this way yield a resistivity comparable to natural graphite and optimal geometric characteristics. In order to use both the sources in the fabrication of hybrid devices, they were employed in the same optical set-up.…”

Section: Pos(rd13)010mentioning

confidence: 73%

Pulsed laser fabrication of 3D diamond sensors

Lagomarsino¹

2015

Proceedings of 11th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors — Po

View full text Add to dashboard Cite

3D detectors, whose electrodes extend perpendicularly to the sensor surface, represent one of the solution proposed for the challenges of radiation-harsh environments in high energy physics [1][2][3][4]. We report on the fabrication and characterization of prototypes of 3D diamond detector, which add to the 3D architecture the advantages of diamond as a sensor for tracking purposes. Two different laser sources, a Nd:YAG 1064 Q-switched laser with 8 ns pulse-width and a Ti:sapphire laser source with 30 fs pulse duration have been used to fabricate arrays of graphitic columns in the bulk of a polycrystalline and a single crystal diamond sample. The columns are staggered and connected to graphitic combs which have been fabricated as well by laser irradiation and used as electric contacts. On each sample, an identical pattern of graphitic combs without columns (2D structure) has also been fabricated as a reference. The charge collection efficiency of each 3D sensor has been measured at different voltages and compared with the corresponding 2D structures. The much lower saturation voltages of the 3D sensors compared to those of the planar ones confirm that charge collection takes place at the columnar electrodes. Moreover, an efficiency of 100% is assured by the sensors fabricated with the fslaser source, while a loss in efficiency up to 30% is observed with the sensors fabricated with the ns-laser. The expected behaviour of 3D diamond sensors after strong radiation damage is discussed.

show abstract

Section: Pos(rd13)010mentioning

confidence: 73%

Pulsed laser fabrication of 3D diamond sensors

Lagomarsino¹

2015

Proceedings of 11th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors — Po

View full text Add to dashboard Cite

show abstract

“…This graphite layer can be directly connected to the front-end electronics, or protected by an additional metalization. With this technique it is possible to realize both microstrips [9] and pads with large area. In [10], electrodes with an area of 4 • 0.85 mm 2 have been created on a pcCVD diamond.…”

Section: Crystal Productionmentioning

confidence: 99%

Diamond Detectors for Timing Measurements in High Energy Physics

Minafra

2020

Front. Phys.

View full text Add to dashboard Cite

Timing detectors are a well-established part of High Energy Physics experimental instrumentation. The choice of sensors with fast (less than 10 ns) and precise (better than 100 ps) signals, together with radiation resistance considerations, are an essential part of the design of a timing detector. In this paper, the main characteristics that make single diamond crystal sensors ideal for timing applications will be described and an introduction to the design of fast front-end electronics will be given. Finally, two examples of diamond timing detectors used in High Energy Physics, the START detector of HADES and the TOTEM/CMS timing detector, will be discussed.

show abstract

“…This procedure is A good laser source is a Nd:YAG that emits 8 ns pulses at 1064 nm [61]. The laser is focused on the surface of the diamond and, when the energy of the pulse is above a threshold (on the order of 10 J cm 2 pulse ) the diamond is "burned" into graphite.…”

Section: Graphitized Read-out Electrodesmentioning

confidence: 99%

“…The sample is fixed on a three-axis stage that can be controlled numerically with micrometric precision. Also, a low power laser diode, a digital The diamond sample (in blue) is mounted on a three-axial micrometric stage which is exposed to the laser that is focused using an 8 mm lens (OB); the same optics transmit light into a digital camera and a laser diode which is, together with a power meter, used to check the proper alignment and to monitor the procedure [61].…”

Section: Graphitized Read-out Electrodesmentioning

confidence: 99%

See 1 more Smart Citation

Development of a timing detector for the TOTEM experiment at the LHC

Minafra

2017

Eur. Phys. J. Plus

View full text Add to dashboard Cite

he LHC is at present the world's largest and highest-energy particle accelerator, hosted at CERN, the European particle physics laboratory near Geneva. The TOTEM experiment was designed to measure the total pp cross section and to study elastic scattering and diffractive dissociation at LHC. The protons that underwent elastic interaction are lightly deflected and, to detect them, TOTEM has installed silicon strip detectors at more than 200 m from the interaction point that can transversally approach the beam down to few millimetres, thanks to a movable piece of the vacuum chamber called Roman Pot.During the first period of operation of the LHC, the TOTEM run campaigns were accomplished during low luminosity dedicated data taking. However, to allow the investigation of rare phenomena, an upgrade program has been proposed by the TOTEM Collaboration, to make possible the data taking at higher luminosities. In particular, a cornerstone of the upgrade program is the inclusion of a fast timing detector in the experimental apparatus to improve the capability of the apparatus to work in high pileup conditions.The main topic of this thesis is the design and the characterization of a fast timing detector for high energy protons. After a survey of the most promising sensor technologies available for fast timing measurements, it was proved, thanks to an extensive campaign of tests using particle beams, that the needed resolution, below 100 ps, was achievable using diamond sensors. In particular, different approaches for the front-end electronics were investigated: some commercially available amplifiers and the timing detector designed by the HADES Collaboration were characterized.Then, a diamond detector, fully compliant with the TOTEM requirements, was designed, tested and prepared for the installation in the RP system. In parallel, 13Introduction other solutions were investigated, such as 3D graphitized diamond sensors and an amplitude dependent amplifier, designed to increase the signal to noise ratio: the gain of the amplifier is small for low amplitude input (noise) and higher in presence of a signal.In particular, the first chapter describes the TOTEM experiment and the main physics results obtained during the first run of the LHC. Then, the physics motivation and the technological challenges of the consolidation and upgrade programs are discussed. Particular attention is given to the impedance optimization of the Roman Pot, described in the second chapter. In fact, the Roman Pot creates a cavity inside the primary vacuum that can resonate at the passage of the beam.This resonance can introduce instabilities in the beam and can, in the worst cases, damage the detector because of the excessive heat generated. The Roman Pot has been optimized in this sense and two new shapes have been designed and realized and, only thanks to this optimization, the Roman Pot can be safely inserted at few millimetres from the beam even at the highest intensities foreseen for the LHC.In the third chapter, the properties of diamond are dis...

show abstract

Laser graphitization for polarization of diamond sensors

Cited by 6 publications

References 8 publications

Pulsed laser fabrication of 3D diamond sensors

Pulsed laser fabrication of 3D diamond sensors

Diamond Detectors for Timing Measurements in High Energy Physics

Development of a timing detector for the TOTEM experiment at the LHC

Contact Info

Product

Resources

About