Bulk ion heating with ICRH in JET DT plasmas

Reactor relevant ICRH scenarios have been assessed during DT experiments on the JET tokamak using H mode divertor discharges with ITER-like shapes and safety factors. Deuterium minority heating in tritium plasmas was demonstrated for the first time. For 9% deuterium, an ICRH power of 6 MW gave 1.66 MW of fusion power from reactions between suprathermal deuterons and thermal tritons. The Q value of the steady state discharge reached 0.22 for the length of the RF flat-top (2.7 s), corresponding to three plasma energy replacement times. The Doppler broadened neutron spectrum showed a deuteron energy of 125 keV, which was optimum for fusion and close to the critical energy. Thus, strong bulk ion heating was obtained at the same time as high fusion efficiency. Deuterium fractions around 20% produced the strongest ion heating together with a strong reduction of the suprathermal deuteron tail. The ELMs had low amplitude and high frequency and each ELM transported less plasma energy content than the 1% required by ITER. The energy confinement time, on the ITERH97-P scale, was 0.90, which is sufficient for ignition in ITER. 3He minority heating, in approximately 50:50 D:T plasmas with up to 10% 3He, also demonstrated strong bulk ion heating. Central ion temperatures up to 13 keV were achieved, together with central electron temperatures up to 12 keV. The normalized H mode confinement time was 0.95. Second harmonic tritium heating produced energetic tritons above the critical energy. This scheme heats the electrons in JET, unlike in ITER where the lower power density will allow mainly ion heating. The inverted scenario of tritium minority ICRH in a deuterium plasma was demonstrated as a successful heating method producing both suprathermal neutrons and bulk ion heating. Theoretical calculations of the DT reactivity mostly give excellent agreement with the measured reaction rates

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Assessment of lower urinary tract function in children before and after Swenson's 'pull through' for Hirschsprung's disease

Aims: Long-term sequelae in children with Hirschsprung's disease (HD) are usually related to abnormalities in defecation. However, some of these patients also suffer from voiding dysfunction. The aim of this study is to assess and define the effects of Swenson's 'pull through' procedure in patients with HD on lower urinary tract function by means of urodynamic studies (UDS) performed before and after surgery. Materials and Methods: Six patients with Hirschsprung's disease underwent UDS before and after the definitive procedure. Parameters observed were maximum cystometric capacity, compliance, unstable detrusor contraction (UDCS), leak point pressure, residual volume, end filling pressure, volume at Pdet < 20 cm H 2 O and volume at Pdet < 30 cm H 2 O. Results: On UDS evaluation, one patient (16.6%) showed a small-capacity bladder and one patient (16.6%) showed a large-capacity bladder with occasional uninhibited detrusor contraction (UDCS) preoperatively. All the children had good compliant bladders. Postoperatively, one child was clinically symptomatic and showed hyporeflexic large-capacity bladder without any UDCS, one patient showed a small-capacity bladder with UDCS. Conclusions: In Hirschsprung's disease, neurovesical dysfunction may exist preoperatively and though the incidence of postoperative changes in neurovesical function may appear high, a larger study is required for statistical validation. Children who present with urinary problems after surgery should be assessed urodynamically

Electron absorption of fast magnetosonic waves by transit time magnetic pumping in the JET tokamak

SIGLEAvailable from British Library Document Supply Centre- DSC:4672.262(JET-P--90-02) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Confinement of MeV ions in JET created by ion cyclotron resonance heating

SIGLEAvailable from British Library Document Supply Centre- DSC:4672.262(JET-P--89-84) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Theory of excitation of asymmetric k//-spectrum by phasing the JET ICRF antennae

Available from British Library Document Supply Centre- DSC:4672.2625(JET-R--86/05) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Non-thermal DT yield with (D)T IRCH heating in JET

(ICRH - Ion Cyclotron Resonance Heating)Available from British Library Document Supply Centre- DSC:4672.262(JET-P--89-35) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Results of RF heating on JET and future prospects

Preprint of paper at 7. APS Topical Conf. on Application of RF Power to Plasmas Kissimmee (US) 4-6 May 1987SIGLEAvailable from British Library Document Supply Centre- DSC:4672.262(JET-P--87/21) / BLDSC - British Library Document Supply CentreGBUnited Kingdo