1. Univ. of Colorado, Boulder, AGH Univ., INP & Jagiell. Univ. Cracow,
The Future of
@ DESY
Univ. of Colorado, Boulder,
AGH Univ., INP & Jagiell. Univ. Cracow,
JINR, Dubna,
NCPHEP, Minsk,
FZU, Prague,
IHEP, Protvino,
TAU, Tel Aviv,
DESY, Zeuthen
&Vinca Belgrade
Wolfgang Lohmann
November 2005
DESY
see: PRC R&D 01/02 (2002)
Instrumentation of the forward region

2. Ch.G. U. H H.H W.La.
Submitted in August

3. The very Forward Detectors
Measurement of the Luminosity
with precision O(10-4)
Detection of Electrons and Photons at very low angle – extend hermeticity
(Important for Searches)
Fast Beam Diagnostics
Shielding of the inner Detector
L* = 4m
300 cm
VTX
FTD IP
LumiCal: < q < 82 mrad
BeamCal: < q < 28 mrad
PhotoCal: < q < 400 mrad
LumiCal
BeamCal

4. Shape and Segmentation, Key Requirements on the
Measurement of the Luminosity-LumiCal
Gauge Process:
e+e e+e- (g)
Goal: 10-4 Precision
Physics Case: Giga-Z ,
Two Fermion Cross Sections at High Energy,
e+e W+W-
Technology: Si-W Sandwich Calorimeter
Optimisation of
Shape and Segmentation,
Key Requirements on the
Design
MC Simulations
Close contacts to Theorists (Cracow, Katowice, DESY)

5. and mechanical Precision
Requirements on the Mechanical Design
LumiCal IP
< 4 μm
Requirements on
Alignment
and mechanical Precision
(rough Estimate)
Inner Radius of Cal.: < 1-4 μm
Distance between Cals.: < 60 μm Radial beam position: < 0.7 mm
< 0.7 mm

6. Concept for the Mechanical Frame
Decouple sensor frame
from absorber frame
Sensor carriers
Absorber carriers

7. Mechanical Frame Extend the concept to an engineering design
- demonstration that the carrier structure for sensors makes
the control of the inner radius on the mm level possible
FE analysis (gravitational sag, temperature)
, U. H.

8. BeamCal e+e- Pairs from Beamstrahlung are deflected into the BeamCal
15000 e+e- per BX – 20 TeV
10 MGy per year
Rad. hard sensors
GeV
Technologies:
Diamond-W Sandwich
Scintillator Crystals
Gas Ionisation Chamber

9. W-Diamond (or W-Si) sandwich
Design Concept
W-Diamond (or W-Si) sandwich
sensor
Space for electronics

10. Observables Beam Parameter Determination with BeamCal radial moment
detector: realistic segmentation, ideal resolution
single parameter analysis, bunch by bunch resolution, 20 mrad crossing angle
radial moment
azimuthal moment
total energy
L/R, U/D F/B asymmetries, …
Quantity
Nominal Value
Precision sx
553 nm
1.2 nm sy
5.0 nm
0.1 nm sz
300 mm
4.3 mm Dy
0.4 nm
Part of EUROTEV WP5 program (Task reporter: Ch. Grah)

11. Detection of High Energy Electrons and Photons
√s = 500 GeV
√s = 500,1000 GeV
Single Electrons of 50, 100
and 250 GeV
Single Electrons of 200
and 400 GeV
Comparison
500 GeV - 1TeV
Requirements: fine segmented and dense (RM!) calorimeter
dynamic range ~ 104

12. Diamond sensors-Collaboration with FAP
FAP manufactured several samples from large
area wafers
The CCDs are between 10 and 60 mm
Some sensors show microcracks
Some are stable under irradiation, other not.
FAP did diagnostics for us.
100 mm diameter, 500 mm thick
Signal peak as a function of the dose
for three (good) sensors
Surface of a polished diamond (BTU Cottbus)
Surface with microcracks
(BTU Cottbus)
Other suppliers: E6, GPI Moscow

13. Diagnostics tools Raman spectra CCD ~ 20mm CCD ~ 100mm Diamond peak
Graphite bump

14. Photo Luminescense Spectra
CCD ~ 100mm
CCD ~ 10mm
CCD ~ 50mm

15. Sensor tests with Diamonds May,August/2004 test beams
Pads
ADC
Diamond (+ PA)
Scint.+PMT&
signal
gate
Pm1&2
May,August/2004 test beams
CERN PS Hadron beam – 3,5 GeV
2 operation modes:
Slow extraction ~ / s
fast extraction ~ / ~10ns (Wide range intensities)
Diamond samples (CVD):
- Freiburg
- GPI (Moscow)
- Element6
Katerinas talk

16. Signal transport on a sensor plane
Future sensor studies
production of sensors without micro cracks
tight limits on Raman and PL spectra- validation of our
presumptions
Homogeneity
Study of the signal size and leakage current as a function of
large (>MGy) absorbed dose
study of Si pad sensors as a function of the absorbed dose
(backup option)
, Ch. G, Ph.D. student, guest scientists
Signal transport on a sensor plane
Requirement: ultrathin sensor layer (RM!)
Production of a ‘PCB segment’ with pads
Test of different readout technologies
- classical: flexfoil with wire bonds
- innovative: second metallisation with
polymer insulator
, W. La., H.H. Ch. G. , PD, Ing. student

17. Read out electronics for calorimeter prototype test
Requirement: > 103 channels, dynamic range 104
Contacts to LAL Orsay, delivery of first prototypes end 2005
Test measurements
Prototype readout module design and test
If successful – production of ~ 2000 channels
mid , H.H., PD, W. La.
Data Acquisition
Concept for data taking in a testbeam regime
Hard and software development
, H.H., PD, support from IT

18. Mechanical frame for a prototype calorimeter
Sensor planes
Depending on the results of sensor tests and signal readout-
construction of a few full planes (Diamond or Silicon)
Beam test
Production of O(10) planes
, W. La, H.H., Ph.D. PD., guests
Mechanical frame for a prototype calorimeter
Design
Production of frame and absorber discs
, U.H., mechanics workshop

19. Prototype test Resources Testbeam at DESY, test of the full system
Test in the ‘spray beam’ with single electrons at SLAC
Resources
2006/7: kEuro, 12 MW mechanical workshop,
12 MW electronical workshop
2008/9: kEuro, workshop needs still difficult to estimate