1. Si Sensors for Additional Tracker
Atsushi Taketani
2013/07/31

2. Am I still in PHENIX?
Taken in July 19th 2013

3. Example of tracker concept
Silicon modules made of a large silicon sensor
9.6 cm x 9.6 cm (maximum from 6inch wafer)
Read-out by 10 SVX4 chips (128ch/chip)
75um strip width
Two layers of single sided silicon
B4: R=36cm 24 ladders x 10 sensor/ladder =240 SMs
B5: R=58cm 40 ladders x 16 sensor/ladder = 640 SMs
Total: 880 SMs = 8,800 SVX4 = 1,126,400ch
Occupancy: 0.9 % at B4 and 0.35% at B5 in the most central Au+Au collisions (if 2strip/track)

4. Yasuyuki’s tracker concept
Detail of the extended tracker need to be decided. This is one example of conceptual design B5
To cover |h|<1.1
R=60 cm zmax = 80cm Area = 6.0m2
R=36 cm zmax = 48cm Area = 2.2m2
Total Area: 8.2m2 of silicon (single layer)
The area and channel counts doubled if each layer has X and U B4
h=1

5. Pixel detector module
Sensor module consists of 4 ALICE Pixel readout chips Bump-bonded to silicon sensor
One readout unit, half stave, made from two sensor modules
Half stave is mounted on the support structure
Pixel BUS to bring data out and send control signal in to the readout chip is mounted on the half stave
Each detector module is built of two half staves, read out on the barrel ends
Full stave
22cm
1.4cm
Half stave
Pixel BUS
Data
Sensor Module
Sensor
Sensor
Thermo plate + cooling
ALICE LHCB1 chip 5

6. Consideration Total area covered ~ 8m2
May be doubled for Z-phi readout.
If we can use 10cm×10cm sensor = 0.01m2, total ~ ~ 2000 sensors.
Total amount of cost for sensor modules
R&D
Parts production
Quality Assurance cost
Production for assembly as ladders

7. R&D Many efforts with clever people
PHENIX has many experienced experts.
This cost may depend on choice of sensor
and choice of readout electronics a lot.
SVX4 is old chip, but it is enough for our purpose.
We had many experience for SVX4.
Currently considering HPK and Korean solution.

8. Parts Production Si sensors Readout ASIC PCB on sensor modules
Ladder supports ( Carbon?)

9. Quality Assurance cost
Assembly cost is not cheap.
All parts must be tested as realistic operation condition and satisfied specific criteria.
Otherwise combined module must not work.
E.g. pixel readout chip had about 50% yield. 16 chips per ladder. Then =

10. Visit Korea and HPK
Y. Akiba, A.T. Y. Goto, and I. Nakagawa visited to ETRI and Nanofab at South Korea in 2013 Feb discussing about possibility of production with Y. Kowan. We are still considering.
Y. Akiba, A.T. H. Torii, and T. Sumita visited to HPK about trial in 2013 June.

11. Discussion with HPK Sensor size Strip We requested 10mm×10mm
Sensor size is 98mm×98mm, live area is 95×95 max.
Strip
Single sided, single strip orientation
1280 strips per sensor for 10 SVX4 chips
75mm pitch -> 96mm total, need to reduced little bit.

12. Sensor thickness Depletion Voltage Breakdown voltage Readout pad
Requested 300mm, HPK standard is 320mm.
Depletion Voltage
Expected 75V, and Max 100V
Breakdown voltage
250V
Readout pad
AC readout
2 readout pad
AC resistance 10KW
Wafer Resistance
Available wafer is higher than 2KW cm

13. Price and Schedule About 1000 US$ per sensor for mass production
We need 1500 ~2000 sensors total, including spare.
HPK can delivery them for 1year to 1.5 years after purchase order.
For prototype, it will take less than 6 month, after all specification is defined.

14. Compare to Korean’s offer
ETRI in Korea has good price for us through Yonsei.
We would like to know how it works for MPCX.
Total amount of sensor cost must include the sensor Quality Assurance cost.
Everybody said HPK quality is good, sampling QA may be OK.

15. Summary
We had new member to dedicated for VTX work in Wako, Takayuki Sumita, and Hisa Torii.
We still are considering both possibility in Korea or HPK for production sensors.