For the upcoming Super LHC (SLHC) experiments on the LHC upgrade, Si detectors will still be considered as the main detectors for inner tracker. However, the radiation level in SLHC will be up to 10 times more than that in LHC due to the increase of luminosity from 1034 cm-2s-1 to 1035 cm-2s-1. In this study a new approach for radiation hard detectors based on the current injection in the detector bulk is considered. It is shown that the symmetric p+-n-p+ structures as well as regular p+-n-n+ silicon detectors after irradiation by neutrons up to 5middot1014 cm-2 can operate at self-stabilized current injection (SSCI) or space charge limited current (SCLC) mode. This provides a stable electric field profile at any higher fluences with the electric field distributed in the entire detector thickness (full depletion mode). In this study operation of heavily irradiated Si detectors in the SSCI mode is confirmed by the measurements of I-V characteristics, which show the region with square I on V dependence and then the sharp current rise at a threshold voltage. It is shown that the threshold voltage rises linearly with the irradiation fluence that allows biasing the detectors by higher voltage with the fluence increase. This is obviously helpful for reduction of the collection time and consequently the related charge loss due to trapping.

Semiconductor pixel detectors were originally developed for particle physics experiments as a logical development from silicon microstrip detectors. offering the potential for high spatial precision, two dimensional location of ionising charged particle trajectories. The development became practical, as with microstrip detectors. only with the availability of suitable VLSI read-out electronics and reliable (and affordable) interconnect technology, ("flip-chip" bonding).Pixel detectors have also been studied more recently as imaging devices, particularly for X-rays in medical and non-destructive testing applications, and in synchrotron radiation beams.In the following, a description is given of the evolution and current state of development of pixel detectors for all of these applications. Reference is made to both monolith ic and hybrid semiconductor pixel detectors, considering not only silicon, (crystalline and amorphous), but also alternative semiconductor materials. The performance and limitations of current read-out electronics and bonding technology for hybrid detectors are discussed, together with the relative merits of charge integrating versus photon counting read-out for X-ray imaging applications. The paper concludes with an outline of potentially valuable future development possibilities.

We have designed two different X-ray pixel array readout Integrated Circuits for silicon pixel detectors operating between 4keV and 25keV. The first allows full readout of the deposited charge for each X-ray photon and is intended for imaging X-ray spectroscopy. The second is a photon counting device capable of very high rates (1MHz per pixel) but without energy resolution. This paper compares the architectures of these two detectors and presents experimental data from complete bump-bonded devices. These detectors have many applications from X-ray diffraction to material inspection and satellite based X-ray imaging.

As part of the LHC magnet development program, CERN in collaboration with Oxford Instruments has designed, built and tested a one metre model of a 70 mm aperture low-beta quadrupole. The magnet features a four layer coil, and is designed for 250 T/m at 1.9 K. We review the results of the magnet training and quench propagation studies performed at 4.3 K and 1.9 K, and report on the magnetic field measurements.

We have utilized biochemical, molecular biological, and functional neurochemical measurements to investigate the integrated and long-term effects of a single dose of nicotine on the noradrenergic system in the central nervous system of the rat, from enzyme induction to transmitter release. We have found that a single systemic injection of nicotine (0.8 mg/kg) increases messenger RNA for the rate-limiting enzyme in the synthesis of catecholamines, tyrosine hydroxylase, two to six days later in the noradrenergic cell body region, the locus coeruleus (and not in the dopaminergic cell body regions, substantia nigra and ventral tegmental area). This was then followed by a time-dependent increase in enzyme activity, measured in vitro, in terminal regions of the ascending dorsal noradrenergic bundle up to four weeks later. Functionally, the increase in tyrosine hydroxylase activity in the terminals four weeks after a single administration was associated with an increase in the capacity to release noradrenaline in the hippocampus, measured using in vivo microdialysis in freely moving animals. This occurred in response to an acute systemic nicotine injection (0.4 mg/kg) but not to a local, intrahippocampal, challenge with 250 muM nicotine.These experiments have revealed a long-term effect of nicotine on noradrenergic activity in the central nervous system, associated with induction of tyrosine hydroxylase. This is accompanied by a time-dependent increase in terminal tyrosine hydroxylase activity and an increase in noradrenaline release.

In recent years there has been a renewal of interest from many disciplines, including high energy physics, particle astrophysics and medicine, in developing GaAs as a detector. This work reports on the assessment of some Schottky barrier devices, made from LEC starting material for particle physics experiments [1], as X-ray detectors. The detectors measured 3.0 mm × 5.0 mm × 135 μm with a small, 1 mm diameter. Schottky contact in the centre. In the best devices a charge separation efficiency above 90% was achieved and measured resolutions at 122 keV and 60 keV were ∼8% and ∼6% HWHM respectively. Carrier trapping and device instabilities are the dominant limitations to better performance.

The detection of gas phase atoms from a caesium source has been demonstrated by two photon resonant ionisation spectroscopy (2RPI). An excimer pumped dye laser system was used in conjunction with a proportional counter, operated at low pressure. Two photon ionisation spectra of caesium have been recorded in the 455-460nm region with the two prominent transitions at 455.5 and 459.3nm being well resolved. The dependence of the widths and relative intensities of the two transitions on incident laser fluence has been investigated.

Electroproduction of hadrons is studied in the kinematic region W < 2.8 GeV and 0.3 < Q2 < 1.4 GeV2 using the DESY streamer chamber. Prong cross sections, charged-particle multiplicities and inclusive π− distributions are presented. The average charged multiplicity is found to be independent of Q2 in the Q2 range studied here; however it is lower than in photoproduction. The fraction of forward π− is found to be significantly less in electroproduction than in photoproduction. The 〈p⊥2〉 for inclusive π− is, for all x values, similar to that found in photoproduction.

We have measured the inclusive electroproduction of positive and negative hadrons in the quark fragmentation region using the streamer chamber at DESY. Data are presented in terms of the variable zp = p/v in the kinematic region 1.8 < W < 2.8 GeV and 0.3 < Q2 < 1.4 GeV2. The positive hadron distributions contain a strong proton component. After subtraction of the proton component and elastic rho events, the distribution (1/σtot) dσ/dzp for positive and negative hadrons agrees well with the corresponding distribution from e+e− annihilation (DORIS data). This behaviour supports the validity of the quark-parton model at surprisingly low Q2 and W.

Qausi-elastic ω production by ep scattering in the kinematic region 0.3. < Q2 < 1.4 GeV2 and 1.7 < W < 2.8 GeV was studied using a streamer chamber at DESY. The production angular distribution for γVp → ωp has a strong non-peripheral component for W < 2 GeV. The ω production cross section falls by a factor of 4 as W changes from 1.7 to 2.8 GeV. In contrast the cross section for ω production with |t| < 0.5 GeV2 is W independent between 1.7 and 2.8 GeV and for W > 2.0 GeV consistent in both W and Q2 dependence with the predictions of a model based on one-pion exchange and diffraction.

The reaction γVp → pπ+π− was studied in the W, Q2 region 1.3–2.8 GeV, 0.3–1.4 GeV2 using the streamer chamber at DESY. A detailed analysis of rho production via γVp→ϱ0p is presented. Near threshold rho production has peripheral and non-peripheral contributions of comparable magnitude. At higher energies (W > 2 GeV) the peripheral component is dominant. The Q2 dependence of σ(γVp→ϱ0p) follows that of the rho propagator as predicted by VDM. The slope of dσ/dt at 〈Q2〉 = 0.4 and 0.8 GeV2 is within errors equal to its value at Q2 = 0. The overall shape of the ϱ0 is t dependent as in photoproduction, but is independent of Q2. The decay angular distribution shows that longitudinal rhos dominate in the threshold region. At higher energies transverse rhos are dominant. Rho production by transverse photons proceeds almost exclusively by natural parity exchange, σTN ⩾ (0.83 ± 0.06) σT for 2.2 < W < 2.8 GeV. The s-channel helicity-flip amplitudes are small compared to non-flip amplitudes. The ratio R = σL/σT was determined assuming s-channel helicity conservation. We find R = ξ2Q2/Mϱ2 with ξ2 ≈ 0.4 for 〈W〉 = 2.45 GeV. Interference between rho production amplitudes from longitudinal and transverse photons is observed. With increasing energy the phase between the two amplitudes decreases. The observed features of rho electroproduction are consistent with a dominantly diffractive production mechanism for W > 2 GeV.

From measurements of the reaction ep→eπ−Δ++ near threshold the nucleon axial-vector form factor is determined, using the PCAC calculations by Adler and Weisberger. The results are consistent with form factor determinations from single pion electroproduction. A dipole fit yields mA = (1.18 ± 0.07) GeV.

An experiment has been carried out to determine the imaginary part of the two-photon exchange amplitude by measuring the polarisation of the recoil proton in elastic electron-proton scattering. The polirisation was found to be −0.006 ± 0.030 at q2 = 1.3 (GeV/c)2, +0.052 ± 0.55 at 1.5 (GeV/c)2 and +0.065 ± 0.087 at 1.9 (GeV/c)2.