1. RPC HV-LV project Introduction System requirements and description
I.N.F.N. Naples
Introduction
System requirements and description
SASY-2000 project
Prototype tests
Alfonso Boiano1, Flavio Loddo2, Pierluigi Paolucci1, Antonio Ranieri2
1) I.N.F.N. of Naples, 2) I.N.F.N. of Bari
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

2. Riunione Referee Roma - 6 Sttembre 2002
Introduction
I.N.F.N. Naples
The idea of the HV-LV system for the RPC detector of the LHC experiments is to split the system in two:
LOCAL: SY1527 mainframes placed in control room and a 48 Volts High Power Source;
REMOTE: distribution system placed in the UXC zone around the detector. It consists of a 6U custom crate housing 2 independent controllers and up to 8 distribution board equipped with 4 HV + 8 LV floating channels.
The system will work in very hard conditions due to the high magnetic field and high radiation environment.
A common project (SASY 2000) to realize this system is going on between the I.N.F.N. and the CAEN company.
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

3. requirements and system description
I.N.F.N. Naples
requirements:
system working in high magnetic field;
system working in an high radiation environment;
local system in control room + distributed remote systems on the detector;
low voltage (48 Volts) running from the local to the remote system;
floating HV (12KV–1mA) and LV (7V–0.42A (ana.) and 7V–0.9A(dig.)) channels (noise reduction).
wheel 1 2 3 4 5
TOT
gaps
408
2040
HV ch.
204
1020
front-end
936
4680
LV ch.
312
1560
having chosen 2 gaps per HV channel and 6 FEBs per LV channel
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

4. I.N.F.N.-CAEN SASY2000 project
I.N.F.N. Naples
Detector region
Control Room 4 8 … 16
HV #1
HV #2
Branch controller #1
Complex ch. 1
256
Remote
boards
LV #1
LV #4
Branch controller #2
HV #1023
HV #1024
Complex ch. 512 …
256
LV #2047
LV #2048
Branch controller #16
What do we need ??
26 ch * 12 sect * 5 wheels = 1560 LV
17 ch * 12 sect * 5 wheels = 1020 HV
One mainframe is enough for the barrel
48 Volts
High Power Source
The remote board has 2 Complex ch. each equipped with: 2 HV ch and 4 LV ch.
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

5. Riunione Referee Roma - 6 Sttembre 2002
Test performed
I.N.F.N. Naples
SASY 2000 prototype
The HV-LV prototype 0 consists of: HV board (SA2001), 3 LV boards (SA2002) and 1 controller.
It has been split in three pieces, following a “logical separation” of the system, in order to study the functionality of every single piece and component.
The following tests has been performed on both the prototypes and will be repeated for the final boards:
Magnetic field test up to 7 KGauss (at CERN) (see attached results shown by CERN in May 2002)
Radiation test up to 10 LHC eq-years (at Louvain La Neuve) (results shown)
Test on the RPC to study the noise condition (to be performed at the test station in Bari);
High Stress Test to study the system under very hard conditions (to be performed in Napoli).
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

6. Neutron radiation test
I.N.F.N. Naples
The SASY2000 HV-LV prototype has been tested twice (May-Aug 2002) at the Louvain La Neuve radiation facility.
The total neutron fluence requests
for 10 LHC years is about 1x1012 n/cm2 (note: in RE1/1 region) corresponding to 2 hours and 40 min with a beam at 1 mA at 70 cm
SASY2000
In first session the system worked well for 30 min. corresponding to 1.8 • 1011 n/cm2 (a factor 6 higher than that expected on RB4!) We lost the communication with the prototype. CAEN reported a known loss of current gain due to irradiation on CNY17 opto-insulator used to enable the HV/LV channels. The prototype was irradiated for 80 min corresponding to 4.8*1011 n/cm2.
On the second prototype (ATLAS one) the gain current loss was cured using a lower value biasing resistor. Was registered a few SE on the controller with loss of communication but the normal condition was restored after 1 s on power OFF/ON condition (it will be implemented by firmware an HOT RESET to recover the communication without interruption of remote power supply).
After the irradiation the SASY2000 was tested outside, preserving its original functionality. (robustness of hardware)
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

7. Magnetic field test setup
Magnet: MNP24-1 at CERN Bldg. 168
B: up to 10 kGauss
B around CMS: .44T
Test condition: 0-7 kGauss
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

8. Magnetic field tolerance
up to 5 kGauss
Test condition
SA2001: VOUT = 8kV, Rload=12 M
SA2002: VOUT0 = 4.7 V, VOUT1 = 5.0 V, IOUT0,1 = 1.9A
Da 0 a 5 kGauss: loss of efficiency 2% (// B) 0% ( B)
(efficiency defined as =Pload/PDC-DC converter) (75%  73%)
Future improvements:
transformer oriented according  B  it will work reliably up to 8 kGauss
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

9. High Stress Test in Naples
I.N.F.N. Naples
The High Stress Test is based on a large number of cycles of the following tests:
Low current (1 mA) test at “working” voltage (10 KV);
Medium range current scan (from 10 to 300 mA) at “working” voltage:
High current (1 mA) test at “working” voltage (10 KV);
Over-current and Trip test (I > 1 mA);
Maximum voltage test (12 KV) at different absorbed currents;
Discharge and short circuit test made with two pins at different distances;
Imon, Vmon calibration test made with an independent volt-meter.
Different HV resistors
A PC running LabVIEW will be used to control the system and to analyze the data.
Final HV-LV cable/connector will be used.
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

10. HV-LV architecture for a barrel sector
I.N.F.N. Naples
26 LV channels Remote Boards HV channels
RB4
4 LV
2 bi-gaps
2 bi-gaps
4 HV ch
1 RB
2 RB
RB3
2 bi-gaps
2 bi-gaps
4 HV ch
4 LV
3 bi-gaps
6 LV ch
3 HV ch
RB2
1 RB
1 RB
4 LV ch
2 bi-gaps
2 HV ch
4 LV ch
2 bi-gaps
2 HV ch
RB1
1 RB
1 RB
4 LV ch
2 bi-gaps
2 HV ch
2 bigaps = 96 strips = 6 febs
LVD channel
HV channel
LVA channel
RB = remote board
26 ch * 12 sect * 5 wheels = 1560 LV
17 ch * 12 sect * 5 wheels = 1020 HV
4 remote boards * 12 sect * 5 wheels = 240 RB
23-Feb-1923-Feb-19
Riunione Referee Roma - 6 Sttembre 2002

11. Barrel cables routing LV HV 26 LV ch/cable + 17 HV ch/cable per sector
I.N.F.N. Naples
26 LV ch/cable + 17 HV ch/cable per sector
LV-HV 1 2
LV-HV
LV-HV 3 4
LV-HV
Sector -4
Sector -5
LV-HV
Muon racks
2 RPC HV-LV crates
Sector –6 LV HV
26 LV ch/cable
26 LV
17 HV
LV-HV 5 6
LV-HV 7 8
Elect. house
17 HV
26 LV
17 HV ch/cable LV
48 remote boards/wheel  240 Remote Board
1 crates/rack  8 crates/wheel  40 crates
23-Feb-1923-Feb-19
26 ch * 12 sect * 5 wheels = 1560 LV
17 ch * 12 sect * 5 wheels = 1020 HV HV