1. Success is when preparation meets opportunity
BCM upgrade issues
W. Lohmann
Success is when preparation meets opportunity

2. BCM upgrade issues
BCM1
BCM2+BSC2

3. Technical stop: Decembre/Jan 2010/11: very likely no access
BCM upgrade issues
Technical stop: Decembre/Jan 2010/11: very likely no access
Installation of one Totem touches BCM2 and BSC
Very likely no access to pixel, no PLT installation
BCM1F: DAQ completion, recording more ‘coincidences’.
Shut down (one year) 2012: -demontage/montage because of pixel
upgrade
- PLT installation
BCM1F:
- may expect radiation damage of the FE-ASIC and laser diode, >
replacement should be prepared.
- backend may be kept
Other systems:
- Preventive maintainance
BSC: complete replacement with radiation hard scintillators, new PM’s

4. BCM upgrade issues
Shut down (one year) 2015/16: replacement BCM2, BCM1F and BSC
Challenges: - larger intensities, more collision products, larger background
- tag incoming background
BCM1F:
- faster ASICs (higher rates), shaping time O(10ns)
Digital optical signal transmission (use available components-to be found)
Supplement of BSC using GaAs sensor inner rings

5. Two rings of sensors on both sides of the IP
BCM upgrade issues
Two rings of sensors on both sides of the IP

6. BCM upgrade issues Metallisation is e.g. V (30 nm) + Au (1 m)
GaAs sensors:
semi-insulating GaAs, doped with Sn and
compensated by Cr
produced by Tomsk University
Thickness 500 m
5x5 mm2 pads
Mounted on a 0.5 mm PCB
Metallisation is e.g. V (30 nm) + Au (1 m)
Results of current-
voltage characteristics
Rpad ~ 500 MΩ
Cpad ~ 12 pF
See talk by Sasha

7. A first prototype was tested in an electron beam in July/August
BCM upgrade issues
A first prototype was tested in an electron beam in July/August
Sensors from JINR
8 channelFE chips
ASICS from UST
Assembly of a module (DESY)
Results given in the talk by Olga
These ASICs are not a priory radiation hard- needs further discussions

8. First application of sapphire sensors at FLASH
4x sapphire sensors, 1x1 cm2
4x diamond sensors, 1x1 cm2
Signal from the beam halo, 9 mA run Septembre 2009
to beam dump
Sapphire sensors are
relatively cheap
Extreme radiation hard (12 MGy, 1017 e-cm-2)
Low signals (so far)

9. BCM upgrade issues
A few remarks having read the upgrade proposal:
Table 9.2 I do not fully believe
The program is very ambitious and we are a relatively small group
The preparation of the 2011/12 shutdown should have priorityPLT installation needs care to avoid damage of other systems
Can we approach standard solutions for the readout of the fast systems
after 2015
More MC simulations may be necessary to better understand what we may expect at higher luminosity in several subdetectors
LHC machine people would like to have one fully functional BCM1F module
in order to test its performance for standard LHC monitoring-
We should come to a conclusion soon