The DRESDEN PLATFORM is a research hub for ultra-high dose rate radiobiology.

The recently observed FLASH effect describes the observation of normal tissue protection by ultra-high dose rates (UHDR), or dose delivery in a fraction of a second, at similar tumor-killing efficacy of conventional dose delivery and promises great benefits for radiotherapy patients. Dedicated studies are now necessary to define a robust set of dose application parameters for FLASH radiotherapy and to identify underlying mechanisms. These studies require particle accelerators with variable temporal dose application characteristics for numerous radiation qualities, equipped for preclinical radiobiological research. Here we present the DRESDEN PLATFORM, a research hub for ultra-high dose rate radiobiology. By uniting clinical and research accelerators with radiobiology infrastructure and know-how, the DRESDEN PLATFORM offers a unique environment for studying the FLASH effect. We introduce its experimental capabilities and demonstrate the platform's suitability for systematic investigation of FLASH by presenting results from a concerted in vivo radiobiology study with zebrafish embryos. The comparative pre-clinical study was conducted across one electron and two proton accelerator facilities, including an advanced laser-driven proton source applied for FLASH-relevant in vivo irradiations for the first time. The data show a protective effect of UHDR irradiation up to [Formula: see text] and suggests consistency of the protective effect even at escalated dose rates of [Formula: see text]. With the first clinical FLASH studies underway, research facilities like the DRESDEN PLATFORM, addressing the open questions surrounding FLASH, are essential to accelerate FLASH's translation into clinical practice.

Spectral-temporal measurement capabilities of third-order correlators.

We present a method extending scanning third-order correlator temporal pulse evolution measurement capabilities of high power short pulse lasers to spectral sensitivity within the spectral range exploited by typical chirped pulse amplification systems. Modelling of the spectral response achieved by angle tuning of the third harmonic generating crystal is applied and experimentally validated. Exemplary measurements of spectrally resolved pulse contrast of a Petawatt laser frontend illustrate the importance of full bandwidth coverage for the interpretation of relativistic laser target interaction in particular for the case of solid targets.

Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities.

Laser-driven ion sources are a rapidly developing technology producing high energy, high peak current beams. Their suitability for applications, such as compact medical accelerators, motivates development of robust acceleration schemes using widely available repetitive ultraintense femtosecond lasers. These applications not only require high beam energy, but also place demanding requirements on the source stability and controllability. This can be seriously affected by the laser temporal contrast, precluding the replication of ion acceleration performance on independent laser systems with otherwise similar parameters. Here, we present the experimental generation of >60 MeV protons and >30 MeV u-1 carbon ions from sub-micrometre thickness Formvar foils irradiated with laser intensities >1021 Wcm2. Ions are accelerated by an extreme localised space charge field ≳30 TVm-1, over a million times higher than used in conventional accelerators. The field is formed by a rapid expulsion of electrons from the target bulk due to relativistically induced transparency, in which relativistic corrections to the refractive index enables laser transmission through normally opaque plasma. We replicate the mechanism on two different laser facilities and show that the optimum target thickness decreases with improved laser contrast due to reduced pre-expansion. Our demonstration that energetic ions can be accelerated by this mechanism at different contrast levels relaxes laser requirements and indicates interaction parameters for realising application-specific beam delivery.

[Current standards and novel developments in the treatment of neuroendocrine tumors of the gastroenteropancreatic system]. / Neues zur Therapie von neuroendokrinen Tumoren des gastroenteropankreatischen Systems.

Current guidelines have been published for the diagnosis and therapy of neuroendocrine neoplasms of the gastroenteropancreatic (GEP) system 1. Systemic therapy of inoperable advanced neuroendocrine tumors includes biotherapy with somatostatin analogas, peptid receptor radionuclide therapy (PRRT) with 177Lutetium-DOTA-TATE, chemotherapy with steptozotocin/5-fluorouracil or capecitabine/temozolomide and molecular targeted therapy with everolimus or sunitinib 1 2. For symptom control in patients with carcinoid syndrome biotherapy with somatostatin analogs, PRRT, loco-regional and local-ablative interventional procedures of liver metastases as well as the peripheral serotonin synthesis inhibitor telotristat Ethyl 1 2 3 4 are highly effective. Novel aspects and developments in the diagnosis and treatment of neuroendocrine tumors will be discussed in this review.

Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets.

We report on recent experimental results deploying a continuous cryogenic hydrogen jet as a debris-free, renewable laser-driven source of pure proton beams generated at the 150 TW ultrashort pulse laser Draco. Efficient proton acceleration reaching cut-off energies of up to 20 MeV with particle numbers exceeding 109 particles per MeV per steradian is demonstrated, showing for the first time that the acceleration performance is comparable to solid foil targets with thicknesses in the micrometer range. Two different target geometries are presented and their proton beam deliverance characterized: cylindrical (∅ 5 µm) and planar (20 µm × 2 µm). In both cases typical Target Normal Sheath Acceleration emission patterns with exponential proton energy spectra are detected. Significantly higher proton numbers in laser-forward direction are observed when deploying the planar jet as compared to the cylindrical jet case. This is confirmed by two-dimensional Particle-in-Cell (2D3V PIC) simulations, which demonstrate that the planar jet proves favorable as its geometry leads to more optimized acceleration conditions.

High dynamic, high resolution and wide range single shot temporal pulse contrast measurement.

A novel apparatus for the single-shot measurement of the temporal pulse contrast of modern ultra-short pulse lasers is presented, based on a simple yet conceptual refinement of the self-referenced spectral interferometry (SRSI) approach. The introduction of the spatial equivalent of a temporal delay by tilted beams analyzed with a high quality imaging spectrometer, enables unprecedented performance in dynamic, temporal range and resolution simultaneously. Demonstrated consistently in simulation and experiment at the front-end of the PW laser Draco, the full range of the ps temporal contrast defining the quality of relativistic laser-solid interaction could be measured with almost 80 dB dynamic range, 18ps temporal window, and 18fs temporal resolution. Additionally, spatio-temporal coupling as in the case of a pulse front tilt can be quantitatively explored.