The experiment is divided into five working packages:
1. Construction of a hybrid diamond pixel detector ultra resistant to radiation (LE, MI-BI, PV).
2. Construction of a two-dimensional dosimetry for intensity modulated radiotherapy (IMRT) and hadron therapy (FI, LNS).
3. Comparative study of polycrystalline diamond sensors produced by industry and by the Russian Academy of Science and their applications in dosimetry and charged particles tracking (PG, RM3).
4. Realization of ohmic contacts on diamond metal-less and bump-bonding between the diamond sensor and readout chip with the use of laser techniques (LE).
5. Studies of timing properties of diamond detectors (CT,LNS).
We realize a diamond pixel detector ultra resistant to radiation using a front-end electronic of new generation capable of working with thresholds lower than approximately 1000 electrons. This value is much lower than the minimum threshold attainable by the existing front-end chip (about 2500 electrons), such as the one used by ATLAS and CMS detectors, which are optimized for silicon.
This proposal identifies the new technology of vertical scale integration the best response to the challenges presented by the diamond sensor. In particular, we will use the developments carried out by VIPIX collaboration in this area to build a prototype chip that allows to detect the signals coming from diamond after very high doses of radiation (about 10E16 particles/cm2). We will then built prototypes of pixel detectors using 'bump-bonding' between polycrystalline diamond sensors and the new chip optimized for the diamond. These detectors, after irradiations with protons at LNS, will be characterized in a test beam at Fermilab.
We build a two-dimensional large diamond dosimeter for IMRT radiotherapy and hadron therapy with electric contacts optimized for operation in photovoltaic regime in order to reduce the instability and the slow dynamic response in the dosimetric measure so far observed with polycrystalline diamond with standards electrode contacts. The development of electrical contacts on polycrystalline diamond with the characteristics required will be done at INFN Florence. The final product will then be a two-dimensional device, which will be validated with beams and a read-out electronic for on-line reading, using the experience gained in the development of two-dimensional silicon dosimeters. In this regard, it is important to remember that the IBA Dosimetry company has already expressed interest in continuing the collaboration with the group in Florence for a possible upgrade of the silicon system involving the use of diamond PCVD.
We make a comparative study of CVD diamond, poly and monocrystalline, from different reactors and sites, but all high-quality material for tracking and dosimetry.
This study is of considerable interest for all working packages. In fact, the industry leader in the production of high quality PCVD diamond is the company named Element Six Ltd. (UK) and it is still the almost unique supplier. Therefore, we want to evaluate the properties of CVD diamond produced by the Russian Academy of Sciences (Moskow). The comparative study will be done by providing an array of pixel detectors to be characterized on bench, with sources and with electron and proton beams. In this context, we will study also the integration of the first stage of pre-amplification directly on the diamond sensor surface, taking advantage of the experience of Roma3 group in the realization of diamond MESFET devices.
We investigate the possibilities offered by modern laser techniques to achieve the bump-bonding between the diamond sensor and the readout chip. In particular, we want to obtain metal-less (graphite) ohmic contacts by means of laser light opaque to the diamond, and interconnect diamond sensors and readout chips by locally heating the point of contact with back-irradiation of laser light transparent to the diamond. This would simplify the process of bump-bonding with obvious benefits in terms of costs. These developments will be carried out in L3 laboratory of the Physics Department of Lecce.
We examine and characterize the temporal resolution of detectors based on single-crystal and polycrystalline diamond in order to demonstrate the feasibility of its use as a bunch-to-bunch luminometer for experiment in future colliders with a time resolution less than 200 ps in the presence of high background. We implement a prototype system for data acquisition and on-line processing based on front-end electronic (commercial or custom) and FPGA to read and manipulate fast signals coming from multiple detectors.