Thorben Quast

Simulations of particle showers in calorimeters are computationally time-consuming, as they have to reproduce both energy depositions and their considerable fluctuations. A new approach to ultra-fast simulations is generative models where all calorimeter energy depositions are generated simultaneously. We use GEANT4 simulations of an electron beam impinging on a multi-layer electromagnetic calorimeter for adversarial training of a generator network and a critic network guided by the Wasserstein distance. The generator is constrained during the training such that the generated showers show the expected dependency on the initial energy and the impact position. It produces realistic calorimeter energy depositions, fluctuations and correlations which we demonstrate in distributions of typical calorimeter observables. In most aspects, we observe that generated calorimeter showers reach the level of showers as simulated with the GEANT4 program.

High energy photon colliders (γγ,γe) are based on e - e - linear colliders where high energy photons are produced using Compton scattering of laser light on high energy electrons just before the interaction point. This paper is a part of the Technical Design Report of the linear collider TESLA. 1 Physics program, possible parameters and some technical aspects of the photon collider at TESLA are discussed.

A bstract The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 380 GeV, 1 . 5 TeV, and 3 TeV. Its aim is to explore the energy frontier, providing sensitivity to physics beyond the Standard Model (BSM) and precision measurements of Standard Model processes with an emphasis on Higgs boson and top-quark physics. The opportunities for top-quark physics at CLIC are discussed in this paper. The initial stage of operation focuses on top-quark pair production measurements, as well as the search for rare flavour-changing neutral current (FCNC) top-quark decays. It also includes a top-quark pair production threshold scan around 350 GeV which provides a precise measurement of the top-quark mass in a well-defined theoretical framework. At the higher-energy stages, studies are made of top-quark pairs produced in association with other particles. A study of t ̄ tH production including the extraction of the top Yukawa coupling is presented as well as a study of vector boson fusion (VBF) production, which gives direct access to high-energy electroweak interactions. Operation above 1 TeV leads to more highly collimated jet environments where dedicated methods are used to analyse the jet constituents. These techniques enable studies of the top-quark pair production, and hence the sensitivity to BSM physics, to be extended to higher energies. This paper also includes phenomenological interpretations that may be performed using the results from the extensive top-quark physics programme at CLIC.

The High Luminosity phase of the Large Hadron Collider will deliver 10 times more integrated luminosity than the existing collider, posing significant challenges for radiation tolerance and event pileup on detectors, especially for forward calorimetry. As part of its upgrade program, the Compact Muon Solenoid collaboration is designing a high-granularity calorimeter (HGCAL) to replace the existing endcap calorimeters. It will feature unprecedented transverse and longitudinal readout and triggering segmentation for both electromagnetic and hadronic sections. The electromagnetic section and a large fraction of the hadronic section will be based on hexagonal silicon sensors of 0.5–1 cm2 cell size, with the remainder of the hadronic section being based on highly-segmented scintillators with silicon photomultiplier readout. The intrinsic high-precision timing capabilities of the silicon sensors will add an extra dimension to event reconstruction, especially in terms of pileup rejection. First hexagonal silicon modules, using the existing Skiroc2 front-end ASIC developed for CALICE, have been tested in beams at Fermilab and CERN in 2016. We present results from these tests, in terms of system stability, calibration with minimum-ionizing particles and resolution (energy, position and timing) for electrons, and the comparisons of these quantities with GEANT4-based simulation.

EUDAQ is a generic data acquisition software developed for use in conjunction with common beam telescopes at charged particle beam lines. Providing high-precision reference tracks for performance studies of new sensors, beam telescopes are essential for the research and development towards future detectors for high-energy physics. As beam time is a highly limited resource, EUDAQ has been designed with reliability and ease-of-use in mind. It enables flexible integration of different independent devices under test via their specific data acquisition systems into a top-level framework. EUDAQ controls all components globally, handles the data flow centrally and synchronises and records the data streams. Over the past decade, EUDAQ has been deployed as part of a wide range of successful test beam campaigns and detector development applications.

We present a concept of a laser system for a photon collider at the TESLA linac. It is based on an external optical ring cavity which is pumped by a short-pulse laser. A detailed discussion of the geometry of the external cavity is given.

Silicon pad sensors are proposed as active material in highly granular sampling calorimeters of future collider experiments such as the Compact Linear Collider (CLIC) or the International Linear Collider (ILC). The electromagnetic section of these designs often include O(1000 m2) of silicon pad sensors. For the luminosity measurement, a dedicated forward calorimeter called LumiCal is foreseen. More recently, the CMS experiment has decided to use the same concept in its endcap calorimeter upgrade for the HL-LHC. The sensors are typically produced from 6- or 8-inch wafers and consist of a few hundred smaller cells, each with an area of O(0.1 to 1 cm2). For the prototyping phase of these projects, several design choices have to be evaluated while for mass production, thousands of sensors have to be tested for quality control. For the electrical characterisation of these sensors, it is important to bias them under realistic conditions. To fulfil these requirements, ARRAY, a compact, modular and cost efficient system for large area silicon pad sensor characterisation has been developed and successfully commissioned. It consists of two plugin printed circuit boards: an active switching matrix with 512 input channels that holds all controls and a passive probe card that connects to the sensor. The latter can then be adapted to any sensor geometry. All design files are open source. The system has been used to measure currents ranging from 500 pA to 5 μA and capacitances between 5 pF and 100 pF. A precision of better than 0.2 pF on capacitance measurements in that range can be achieved. Examples of calibration and measurement results for leakage current and capacitance are presented.

As part of its HL-LHC upgrade program, CMS is developing a High Granularity Calorimeter (HGCAL) to replace the existing endcap calorimeters. The HGCAL will be realised as a sampling calorimeter, including an electromagnetic compartment comprising 28 layers of silicon pad detectors with pad areas of 0.5–1.0 cm2 interspersed with absorbers. Prototype modules, based on 6-inch hexagonal silicon pad sensors with 128 channels, have been constructed and include many of the features required for this challenging detector. In 2016, beam tests of sampling configurations made from these modules have been conducted both at FNAL and at CERN using the Skiroc2 front-end ASIC (designed by the CALICE collaboration for ILC). In 2017, the setup has been extended with CALICE's AHCAL prototype, a scinitillator based sampling calorimeter, and it was further tested in dedicated beam tests at CERN. There, the new Skiroc2-CMS front-end ASIC was used for the first time. We highlight final results from our studies in 2016, including position resolution as well as precision timing-measurements. Furthermore, the extended setup in 2017 is discussed and first results from beam tests with electrons and pions are shown.

The Compact Linear Collider (CLIC) is a high-energy high-luminosity linear electron-positron collider under development. It is foreseen to be built and operated in three stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. It offers a rich physics program including direct searches as well as the probing of new physics through a broad set of precision measurements of Standard Model processes, particularly in the Higgs-boson and top-quark sectors. The precision required for such measurements and the specific conditions imposed by the beam dimensions and time structure put strict requirements on the detector design and technology. This includes low-mass vertexing and tracking systems with small cells, highly granular imaging calorimeters, as well as a precise hit-time resolution and power-pulsed operation for all subsystems. A conceptual design for the CLIC detector system was published in 2012. Since then, ambitious R&amp;D programmes for silicon vertex and tracking detectors, as well as for calorimeters have been pursued within the CLICdp, CALICE and FCAL collaborations, addressing the challenging detector requirements with innovative technologies. This report introduces the experimental environment and detector requirements at CLIC and reviews the current status and future plans for detector technology R&amp;D.

VISPA provides a graphical front-end to computing infrastructures giving its users all functionality needed for working conditions comparable to a personal computer. It is a framework that can be extended with custom applications to support individual needs, e.g. graphical interfaces for experiment-specific software. By design, VISPA serves as a multipurpose platform for many disciplines and experiments as demonstrated in the following different use-cases. A GUI to the analysis framework OFFLINE of the Pierre Auger collaboration, submission and monitoring of computing jobs, university teaching of hundreds of students, and outreach activity, especially in CERN's open data initiative. Serving heterogeneous user groups and applications gave us lots of experience. This helps us in maturing the system, i.e. improving the robustness and responsiveness, and the interplay of the components. Among the lessons learned are the choice of a file system, the implementation of websockets, efficient load balancing, and the fine-tuning of existing technologies like the RPC over SSH. We present in detail the improved server setup and report on the performance, the user acceptance and the realized applications of the system.

The VISPA internet platform enables users to remotely run Python scripts and view resulting plots or inspect their output data. With a standard web browser as the only user requirement on the client-side, the system becomes suitable for blended learning approaches for university physics students. VISPA was used in two consecutive years each by approx. 100 third year physics students at the RWTH Aachen University for their homework assignments. For example, in one exercise students gained a deeper understanding of Einsteins mass-energy relation by analyzing experimental data of electron-positron pairs revealing J/Ψ and Z particles. Because the students were free to choose their working hours, only few users accessed the platform simultaneously. The positive feedback from students and the stability of the platform lead to further development of the concept. This year, students accessed the platform in parallel while they analyzed the data recorded by demonstrated experiments live in the lecture hall. The platform is based on experience in the development of professional analysis tools. It combines core technologies from previous projects: an object-oriented C++ library, a modular data-driven analysis flow, and visual analysis steering. We present the platform and discuss its benefits in the context of teaching based on surveys that are conducted each semester.

Latest developments in many research fields indicate that deep learning methods have the potential to significantly improve physics analyses. They not only enhance the performance of existing algorithms but also pave the way for new measurement techniques that are not possible with conventional methods. As the computation is highly resource-intensive both dedicated hardware and software are required to obtain results in a reasonable time which poses a substantial entry barrier. We provide direct access to this technology after a revision of the internet platform VISPA to serve the needs of researches as well as students. VISPA equips its users with working conditions on remote computing resources comparable to a local computer through a standard web browser. For providing the required hardware resources for deep learning applications we extend the CPU infrastructure with a GPU cluster consisting of 10 nodes with each 2 GeForce GTX 1080 cards. Direct access through VISPA, preinstalled analysis software and a workload management system allowed us on one hand to support more than 100 participants in a workshop on deep learning and in corresponding university classes, and on the other hand to achieve significant progress in particle and astroparticle research. We present the setup of the system and report on the performance and achievements in the above mentioned usecases.

In order to cope with the increased radiation level and the challenging pile-up conditions at High Luminosity-LHC, the CMS collaboration will replace its current calorimeter endcaps with the High Granularity Calorimeter (HGCAL) in the mid 2020s. This dissertation addresses two important topics related to the preparation of the HGCAL upgrade: experimental validation of its silicon-based design and fast simulation of its data. Beam tests at the DESY (Hamburg) and the CERN SPS beam test facilities in 2018 have been the basis for the design validation. The associated experimental infrastructure, the algorithms deployed in the reconstruction of the recorded data, as well as the respective analyses are reported in this thesis: First, core components of the silicon-based prototype modules are characterised and it is demonstrated that the assembled modules are functional. In particular, their efficiency to detect minimum ionising particles (MIPs) traversing the silicon sensors is found to be more than 98% for most of the modules. No indication of charge sharing between the silicon pads is observed. Subsequently, the energy response is calibrated in situ using the beam test data. Equalisation of the different responses among the readout channels is achieved with MIPs hereby deploying the HGCAL prototype as a MIP-tracking device. The relative variation of the inferred calibration constants amounts to 3% for channels on the same readout chip. The calibration of the time-of-arrival information is performed with an external time reference detector. With it, timing resolutions of single cells including the full prototype readout chain around 60ps in the asymptotic high energy limit are obtained. The calorimetric performance of the HGCAL prototype is validated with particle showers induced by incident positrons and charged pions. For electromagnetic showers, the constant term in the relative energy resolution is measured to be (0.52±0.08) %, whereas the stochastic term amounts to (22.2±0.3)% √GeV. This result is in good agreement with the calorimeter simulation with GEANT4. The prototype’s positioning resolution of the shower axis, after subtracting the contribution from the delay wire chambers in the beam line used as reference, is found to be below 0.4 mm at 300 GeV. At the same energy, the angular resolution in the reconstruction of the electromagnetic shower axis in this prototype is measured to be less than 5 mrad. The analysis of the hadronic showers in this thesis makes use state-of-the-art machine-learning methods that exploit the calorimeter’s granularity. It is indicated that the energy resolution may be improved using software compensation and also that the separation of electromagnetic and charged pion-induced showers in the calorimeter may benefit from such methods. The measurements of the hadronic showers are adequately reproduced by GEANT4 simulation. Altogether, the obtained results from the analysis of the beam test data in this thesis are in agreement with the full functionality of the silicon-based HGCAL design. The final part of this thesis provides a proof of principle that generative modelling based on deep neural networks in conjunction with the Wasserstein distance is a suitable approach for the fast simulation of HGCAL data: Instead of sequential simulation, a deep neural network-based generative model generates all calorimeter energy depositions simultaneously. This generator network is optimised through an adversarial training process using a critic network guided by the Wasserstein distance. The developed framework in this thesis is applied to both GEANT4-simulated electromagnetic showers and to positron data from the beam tests. Ultimately, this fast simulation approach is up to four orders of magnitude faster than sequential simulation with GEANT4. It is able to produce realistic calorimeter energy depositions from electromagnetic showers, incorporating their fluctuations and correlations when converted into typical calorimeter observables.

In order to cope with the increased radiation level and the challenging pile-up conditions at High Luminosity-LHC, the CMS collaboration will replace its current calorimeter endcaps with the High Granularity Calorimeter (HGCAL) in the mid-2020s.This dissertation addresses two important topics related to the preparation of the HGCAL upgrade: experimental validation of its silicon-based design and fast simulation of its data.Beam tests at the DESY (Hamburg) and the CERN SPS beam test facilities in 2018 have been the basis for the design validation.The associated experimental infrastructure, the algorithms deployed in the reconstruction of the recorded data, as well as the respective analyses are reported in this thesis: First, core components of the silicon-based prototype modules are characterised and it is demonstrated that the assembled modules are functional.In particular, their efficiency to detect minimum ionising particles (MIPs) traversing the silicon sensors is found to be more than 98% for most of the modules.No indication of charge sharing between the silicon pads is observed.Subsequently, the energy response is calibrated in situ using the beam test data.Equalisation of the different responses among the readout channels is achieved with MIPs hereby deploying the HGCAL prototype as a MIP-tracking device.The relative variation of the inferred calibration constants amounts to 3% for channels on the same readout chip.The calibration of the time-of-arrival information is performed with an external time reference detector.With it, timing resolutions of single cells including the full prototype readout chain around 60 ps in the asymptotic high energy limit are obtained.The calorimetric performance of the HGCAL prototype is validated with particle showers induced by incident positrons and charged pions.For electromagnetic showers, the constant term in the relative energy resolution is measured to be (0.52 ± 0.08)%, whereas the stochastic term amounts to (22.2 ± 0.3)% √ GeV.This result is in good agreement with the calorimeter simulation with GEANT4 .The prototype's positioning resolution of the shower axis, after subtracting the contribution from the delay wire chambers in the beam line used as reference, is found to be below 0.4 mm at 300 GeV.At the same energy, the angular resolution in the reconstruction of the electromagnetic shower axis in this prototype is measured to be less than 5mrad.The analysis of the hadronic showers ix x

We report on the MBI User Facility at BESSY II, presently under construction, which is dedicated to study the dynamics of photo-induced processes by combining laser and synchrotron pulses. In this paper we focus on the synchronization of a modelocked ultrafast Ti:sapphire laser to the Berlin electron storage ring for synchrotron radiation (BESSY). Two different techniques have been applied -- one based on a digital phase comparator and the other based on analog high-harmonic mixing. Both schemes may be easily adjusted to either single, multi- or hybrid-bunch operation of the synchrotron. Moreover, the temporal accuracy of the synchronization unit suitably matches the widths of the synchrotron pulses (some ten picoseconds) to be expected at BESSY II. Therefore, the currently performed test experiments at BESSY I provide the basis for time- resolved photon-induced experiments which combine laser and SR-undulator pulses in a pump-probe scheme at BESSY II. This facility will be available within the first half of 1999.

The CMS Collaboration is preparing to build replacement endcap calorimeters for the HL-LHC era. The new high-granularity calorimeter (HGCAL) is, as the name implies, a highly-granular sampling calorimeter with approximately six million silicon sensor channels (approx. 1.1cm2 or 0.5cm2 cells) and about 250 thousand channels of scintillator tiles readout with on-tile silicon photomultipliers. The calorimeter is designed to operate in the harsh radiation environment at the HL-LHC, where the average number of interactions per bunch crossing is expected to exceed 140. Besides measuring energy and position of the energy deposits, the electronics is also designed to measure the time of their arrival with a precision in the order of 50ps. This paper summarises the reasoning and ideas behind the HGCAL, describes the current status of the project, and highlights some of the challenges ahead.

The VISPA project provides a graphical frontend to computing infrastructures. Currently, the focus of the project is to give an online environment for the development of data analyses. Access is provided through a web GUI, which has all functionality needed for working conditions comparable to a personal computer. This includes a new preference system as well as user configurable shortkeys. As all relevant software, data and computing resources are supplied on a common remote infrastructure the VISPA web framework offers a new way of collaborative work where analyses of colleagues can be reviewed and executed with just one click. Furthermore, VISPA can be extended to the specific needs of an experiment or other scientific use cases. This is presented in the form of a new GUI to the analysis framework Offline of the Pierre Auger collaboration.

The Visual Physics Analysis (VISPA) software is a toolbox for accessing analysis software via the web. It is based on latest web technologies and provides a powerful extension mechanism that enables to interface a wide range of applications. It especially meets the demands of sophisticated experiment-specific use cases that focus on physics data analyses and typically require a high degree of interactivity. As an example, we developed a data inspector which is capable of browsing interactively through event content of several data formats, e.g., MiniAOD which is utilized by the CMS collaboration. Visual control of a chain of user analysis modules as well as visualization of user specific workflows support users in rather complex analyses at the level of ttH cross section measurements. The VISPA extension mechanism is also used to embed external web-based applications which benefit from dynamic allocation of user-defined computing resources via SSH. For example, by wrapping the JSROOT project, ROOT files located on any remote machine can be inspected directly through a VISPA server instance. We present the techniques of the extension mechanism and corresponding applications.

Beyond the attractive strong potential needed for hadronic bound states, strong interactions are predicted to provide repulsive forces depending on the color charges involved. The repulsive interactions could in principle serve for particle acceleration with highest gradients in the order of GeV/fm. Indirect evidence for repulsive interactions have been reported in the context of heavy meson production at colliders. In this contribution, we sketch a thought experiment to directly investigate repulsive strong interactions. For this we prepare two quarks using two simultaneous deep inelastic scattering processes off an iron target. We discuss the principle setup of the experiment and estimate the number of electrons on target required to observe a repulsive effect between the quarks.

The CMS Collaboration is preparing to build replacement endcap calorimeters for the HL-LHC era. The new high-granularity calorimeter (HGCAL) is, as the name implies, a highly-granular sampling calorimeter with approximately six million silicon sensor channels (≈1.1cm 2 or 0.5 cm 2 cells) and about 250 thousand channels of scintillator tiles readout with on-tile silicon photomultipliers. The calorimeter is designed to operate in the harsh radiation environment at the HL-LHC, where the average number of interactions per bunch crossing is expected to exceed 140. Besides measuring energy and position of the energy deposits, the electronics is also designed to measure the time of their arrival with a precision in the order of 50 ps. This paper summarises the reasoning and ideas behind the HGCAL, describes the current status of the project, and highlights some of the challenges ahead.

A source of 100 fs x‐ray pulses with tunable polarization and excellent signal‐to‐background ratio has been constructed in 2004 at BESSY, based on laser‐induced energy modulation (“femtoslicing”) and subsequent angular separation of the short‐pulse x‐rays from an elliptical undulator. After commissioning at the BESSY II storage ring and characterizing the source, short‐pulse radiation is now routinely delivered for pump‐probe applications. The paper summarizes the results from commissioning and operational experience as well as possible upgrade options.

Raw data collected in the beam tests of the HGCAL prototype calorimeter require reconstruction into physics quantities before their analysis. These quantities are 5-dimensional calorimeter hits, impact positions and kink angles of particle trajectories measured with the DATURA beam telescope, impact positions of trajectories derived from the delay wire chambers and time of arrival information using the recorded MCP waveforms. As part of this thesis, algorithms have been designed, implemented and applied for inferring these quantities. This chapter deals with these algorithms as they are the basis for the characterisation and validation studies in the next chapters.

As stated in Sect. 2.4, the High Luminosity LHC (HL-LHC) will provide more than five times the design instantaneous luminosity of the LHC. Despite this being indispensable to measurements with rare topologies that rely on a large set of collisions to analyse, this increase in luminosity would pose significant challenges to the detection of particles with the current CMS detector.

Remark: Italic passages in this chapter are substantively quoted from Ref. []. The original text has been written by Martin Erdmann, Jonas Glombitza (both RWTH Aachen) and the author of this thesis. Towards the end of the last chapter, deep learning-based methods have been used to enhance the HGCAL prototype’s performance in the energy reconstruction of hadronic showers and in the separation of electrons and charged pions. In the latter study, it has been observed that slight differences between the actual calorimeter data and the simulated data may lead to diverging performances that could affect the interpretation of the results obtained from those methods. Deep learning has already proven to provide suitable tools in order to correct for non-trivial differences between the data and the simulation []. However, the simulation of calorimeter showers sequentially with GEANT4 or other expert-engineered tools is still required in such a solution.

After the calibration of the energy scale in the previous chapter, the reconstructed calorimeter hits correspond to localised measurements of the energy density of the recorded particle showers. Calorimeter hits of the same event can be visualised using event displays like in Fig. 10.1. They are the basis for the performance validation of the silicon-based HGCAL prototype to reconstruct the properties of the incident particles which is studied in this chapter.

The principal result of the qualification studies in the previous chapter is that the HGCAL prototype modules provide reconstructable electronic signals for the measurement of deposited energies in the calorimeter cells. However, the conversion of such signals into a physical energy scale relies on prior calibration of the cells’ energy responses as well as calibration of the gains involved in the readout. Referring to the energy derivation recipes formulated by Eqs. 7.8, 7.9 and 7.10 in Sect. 7.2.4, an equivalent statement is that all calibration constants for as many readout channels as possible remain to be derived. This task is discussed in this chapter. Here, the calibrations are not obtained from dedicated calibration experiments, e.g. from charge injection in the laboratory, but in situ from the beam test data directly using minimum ionising and showering particles.

Proton-proton collisions at unprecedented centre-of-mass energies and rates are provided by the Large Hadron Collider (LHC) at CERN in Switzerland. The collisions are the basis for precise testing of the Standard Model of Particle Physics, currently the best theory to describe matter and the fundamental forces on microscopic scales, and enable searches for physics beyond. During its third long shutdown from 2024–2026, the LHC will be upgraded for running at five times its original design instantaneous luminosity. This so-called High-Luminosity era (HL-LHC) of the LHC will last until the end of the 2030s providing around 3000 f\(^{-1}\)b of integrated luminosity to the experiments. This pushes statistical uncertainties of the measurements to a minimum and enhances the sensitivity to rare, new phenomena.

Science is the investigation of relations in nature and the extension of our understanding of them. While ancient scientists tried to explain natural phenomena as a whole, the typical approach in modern science is to reduce complex questions into smaller and more elementary problems. In this sense, particle physics may be considered the most elementary field of science. It studies the smallest known structures, treated as point-like particles, that constitute all observable matter and give rise to the forces between them.

The identification of the most fundamental rules that govern the evolution of the universe, including all its matter and forces, is a long ongoing quest of mankind. For illustration of this task, one may consider the two-dimensional model universe in Fig. 2.1.

The main contribution of this thesis to the upgrade of the CMS endcap calorimeter is the experimental verification of the silicon-based HGCAL design using the prototypes described in Sect. 4.5. For this purpose, the assembled prototypes were tested with particle beams at the DESY (Hamburg) and CERN SPS beam test facilities.

Particle energy measurements are an integral part in many particle physics experiments nowadays. This task is performed by calorimeters. Besides the completion of the four-vector of isolated, charged particles, the relevance of calorimeters has increased ever since the discovery of the W boson [] because of their central role in the reconstruction of the energy flow in complex event signatures (jets and missing transverse energy).

The calorimetric performance can be impaired in case of poor sensor quality, malfunctioning readout chips (ROCs) or inadequate assembly of the prototype modules. In addition, it can be altered if the modules contribute substantial passive material to the total calorimeter depth. In the following, these aspects are investigated closer with four rather independent studies. Theoretical motivations and explanations of the applied methods as well as practical suggestions for their future application are given when appropriate.

Experimental data is the basis for the qualification and performance validation of the HGCAL prototypes presented in this thesis. This data was recorded with single prototype modules and with various prototype calorimeter configurations being exposed to particle beams. Besides that, measurements on the electrical properties of prototype silicon sensors prior to their assembly to modules were made.

The MBI develops a facility at BESSY II dedicated to pump- probe techniques combining synchrotron and laser radiation. The synchronization of laser and synchrotron pulses will allow time resolved experiments on the picosecond time scale at this. The features of the facility, the optical parameters of the synchrotron beamline, the synchronization technique and pulse stretching considerations will be outlined. Current developments will be reported.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

STATISTICAL SOFTWARE FOR MICROCOMPUTERS is a statistical package with 19 procedures, including descriptive statistics, variance analysis, linear regression, and scatterplots. The manual is clearly written. This text/software package is primarily for teaching statistics, especially where control groups are applicable.